TWI763860B - Infrared and visible region light control apparatus - Google Patents

Abstract

The present invention provides a light control apparatus which makes it possible to emit light in the infrared region and light in the visible region at the time of incidence as different polarized lights on the detected side, and to control the light amount by these polarized lights.

Specifically, the present invention provides a light control apparatus comprising: at least one polarizing plate having polarization performance with respect to light of the infrared region, at least one polarizing plate having polarization performance with respect to light of the visible region, and a medium having phase or a phase controllable medium; wherein, the light control apparatus controls the transmitted light of the infrared region and the transmitted light of the visible region by making the incident light of the infrared region and the light of the visible region into different polarized lights, respectively.

Description

Light control device for infrared light region and visible light region

The present invention relates to a light control device for controlling light in an infrared light region and a visible light region.

A polarizing plate having a light penetration/shielding function is used in a display device such as a liquid crystal display (LCD) together with a liquid crystal having a light switching function. Application fields of the LCD include small devices such as early computers and clocks, notebook personal computers, word processors, LCD projectors, LCD TVs, car navigation devices, indoor and outdoor information display devices, and measurement devices. Furthermore, it is also applicable to lenses having a polarizing function, and there are applications to sunglasses for improving visibility, polarized glasses for 3D TVs and the like in recent years, and the like.

A general polarizing plate is a film of polyvinyl alcohol or its derivatives that has been stretched and aligned, or a polyolefin-based film in which polyolefin is formed and aligned by removing hydrochloric acid of a polyvinyl chloride film or dehydrating a polyvinyl alcohol-based film. Equal polarizing film base material, dyed or containing iodine, dichroic dye as polarizing element and manufactured. Among these, iodine-based polarizing films using iodine as a polarizing element have excellent polarizing performance, but are weak against water and heat, and have problems in their durability when used for a long time under high temperature and high humidity. On the other hand, a dye-based polarizing film using a dichroic dye as a polarizing element has better moisture resistance and heat resistance than an iodine-based polarizing film, but generally has insufficient polarizing performance. In other words, it is a polarizing plate having a polarizing function for wavelengths targeting the visible light wavelength region, not a polarizing plate targeting the infrared wavelength region.

In recent years, in applications such as identification light sources for touch panels, crime prevention surveillance cameras, sensors, anti-counterfeiting, and communication equipment, polarizers that can be used not only for wavelengths in the visible light region, but also for infrared Polarizers for light areas. In response to such expectations, there have been reports such as an infrared polarizing plate obtained by polyalkylating an iodine-based polarizing plate such as Patent Document 1, an infrared polarizing plate using a wire grid such as Patent Document 2 or 3, and Patent Document 4. The infrared light polarizer obtained by extending glass containing fine particles, such as the type using cholesteric liquid crystals in Patent Documents 5 and 6. In Patent Document 1, the durability is weak, and the heat resistance, wet heat durability, and light resistance are weak, so that it is not practical. Like the wire grid type of Patent Document 2 or 3, it can be processed into a thin film type, and at the same time, it is stable as a product, so it is gradually popularized. However, since the optical properties cannot be maintained without nano-level concavities and convexities on the surface, it cannot be in contact with the surface, so its use is limited, and even anti-reflection and antiglare processing are difficult. The stretched glass type containing fine particles as in Patent Document 4 has high durability and high dichroism, so it is practical. However, since it is an extended glass containing fine particles, the element itself is easily broken and fragile, and it does not have the flexibility of a conventional polarizer, so there are problems in surface processing and bonding with other substrates. The technologies of Patent Document 5 and Patent Document 6 use the conventionally disclosed circularly polarized light, but the color changes depending on the viewing angle, and basically uses a reflective polarizer, so stray light and absolutely polarized light are not easily formed. In other words, there is no polarizing plate corresponding to the infrared wavelength region, which is an absorption-type polarizing element like a general iodine-based polarizing plate, is a thin film type, has flexibility, and has high durability. In addition, even only the function of a polarizer in the infrared light region, rather than a polarizer that can control the visible light region.

Therefore, even if the polarization of the infrared light region and the polarization of the visible light region can be controlled separately, there is no polarizing plate that simultaneously controls the polarized light of each region.

Furthermore, there is no element that can switch between visible light and infrared light and switch each independently.

[Patent Document 1] US 2,494,686 specification

[Patent Document 2] Japanese Patent Laid-Open No. 2016-148871

[Patent Document 3] Japanese Patent Publication No. 2006-507517

[Patent Document 4] Japanese Patent Laid-Open No. 2004-86100

[Patent Document 5] International Publication No. 2015/087709

[Patent Document 6] Japanese Patent Laid-Open No. 2013-064798

[Non-Patent Document 1] Polarized light and its applications, Kyoritsu Press, Chapter 2 (p14-30)

The object of the present invention is to provide a light control device which can be controlled so that incident light with wavelengths in the infrared light region and light with wavelengths in the visible light region become light with different polarizations at the same time.

The present invention also aims to provide optical control of light that can control the polarized light in the incident infrared light region and the polarized light in the visible light region to become polarized light in each region at the same time. In addition, in order to provide light in the infrared light region and light in the visible light region from the same light source, on the detected side, an optical system that can switch between the infrared light region and the visible light region and control the amount of light, that is, it can be dynamically switched and switched. For visible light and infrared light components.

The inventors of the present invention, as a result of continuous intensive research in order to solve the above-mentioned problems, found that by using a medium having a phase or a medium that can control the phase and controlling the light in the infrared light region and the light in the visible light region to be light of different polarizations, respectively, On the detection side, the polarization of light in the infrared light region and the polarization of light in the visible light region can be respectively emitted in the infrared light region and the visible light region.

In addition, the inventors of the present invention have found a light control device that uses both light in the visible light region and light in the infrared light region, and includes at least one polarizing plate having polarization properties for the light in the infrared light region and light in the visible light region. At least one polarizing plate with polarizing properties, wherein the amount of transmitted light in the infrared light region and the amount of transmitted light in the visible light region can be controlled by the medium that can dynamically control the phase, and can be used as the light in the infrared light region. It functions as a switching element for light in the visible light region. In addition, an optical system has been found that can control the amount of light by switching between the infrared light region and the visible light region on the detected side, even if the same light source is used.

That is, the main structure of this invention is as follows.

1)

A light control device, comprising at least one polarizer (IR polarizer) with polarizing properties for light in the infrared region, at least one polarizer (VIS polarizer) with polarizing properties for light in the visible region, and a medium having a phase Or a phase-controllable medium, in which the transmitted light in the infrared region and the transmitted light in the visible region are controlled by making incident light in the infrared region and light in the visible region respectively polarized light differently.

2)

The light control device according to 1), wherein the angle θi between the angle at which the phase-having medium or the phase-controllable medium shows the phase difference value Rλ and the angle at which linearly polarized light appears in the infrared light region is 0≦ The range of θi<180°.

3)

The light control device according to 1) or 2), wherein the angle θv between the angle at which the phase-having medium or the phase-controllable medium exhibits the phase difference value Rλ and the angle at which linearly polarized light appears in the visible light region is − The range of 90°<θv<180°.

4)

The light control device according to any one of 1) to 3), wherein the wavelength of light in the infrared light region is Iλ, the wavelength of light in the visible light region is Vλ, and the error of the retardation value is RD . When the phase difference value of a medium with a phase or a medium with a controllable phase is set as Rλ, the relationship between the following mathematical formula (1) or mathematical formula (2) is respectively satisfied; Vλ-RD≦Rλ≦Vλ+RD The mathematical formula (1) (However, RD means 0 to 40 nm)

Iλ/2-RD≦Rλ≦Iλ/2+RD Mathematical formula (2) (however, RD represents 0 to 40 nm).

5)

The light control device according to any one of 1) to 3), wherein the wavelength of light in the infrared light region is Iλ, the wavelength of light in the visible light region is Vλ, and the error of the retardation value is RD . When the phase difference value of a medium with a phase or a medium with a controllable phase is set to Rλ, the relationship between the following mathematical formula (3) or mathematical formula (4) is respectively satisfied; Vλ/2-RD≦Rλ≦Vλ/2 +RD Mathematical formula (3) (however, RD means 0 to 40nm)

Iλ/4-RD≦Rλ≦Iλ/4+RD Mathematical formula (4) (however, RD represents 0 to 40 nm).

6)

The light control device according to any one of 1) to 3), wherein the wavelength of light in the infrared light region is Iλ, the wavelength of light in the visible light region is Vλ, and the error of the retardation value is RD . When the phase difference value of a medium with a phase or a medium with a controllable phase is set to Rλ, the relationship between the following mathematical formula (5) or mathematical formula (6) is respectively satisfied; Vλ×3/2-RD≦Rλ≦Vλ ×3/2+RD Mathematical formula (5) (however, RD means 0 to 40nm)

Iλ×1/2-RD≦Rλ≦Iλ×1/2+RD Mathematical formula (6) (However, RD represents 0 to 40 nm).

7)

A light control device, which is the light control device described in any one of 1) to 6) for simultaneously controlling the light in the visible light region and the light in the infrared light region, wherein the aforementioned phase-controllable medium is a dynamic The medium that controls the phase.

8)

The light control device according to 7), wherein the medium whose phase can be dynamically controlled is a liquid crystal panel (liquid crystal cell).

9)

The light control device according to 8), wherein the liquid crystal used in the liquid crystal panel (liquid crystal cell) is a twisted nematic liquid crystal (TN liquid crystal; Twisted Nematic liquid crystal) or a super twisted nematic liquid crystal (STN liquid crystal; Super Twisted liquid crystal). Nematic LCD).

10)

The light control device according to any one of 7) to 9), wherein the contrast ratio of transmission to non-transmission of light in the visible light region and light in the infrared light region is 10 or more.

11)

The light control device according to any one of 7) to 9), comprising one polarizing plate (VIS-IR polarizing plate) having polarization properties for light in the visible light region and light in the infrared light region.

12)

The light control device according to 11), wherein, in the VIS-IR polarizing plate, the difference between the orthogonal transmittance of light in the infrared light region and the orthogonal transmittance of light in the visible light region is 1% or less.

13)

The light control device according to any one of 1) to 12), wherein in the IR polarizing plate, the difference between the orthogonal transmittance of light in the infrared light region and the orthogonal transmittance of light in the visible light region is 10 %above.

14)

The light control device according to any one of 1) to 13), comprising: the orthogonal transmittance of light in the infrared light region in the IR polarizing plate is 1% or less and the transmittance of light in the visible light region Polarizing plates with a difference of more than 10%; and the aforementioned VIS polarizing plate shows high transmittance in the infrared light region, shows that the penetration of light in the infrared light region is not easily affected, and the orthogonal transmittance of light in the visible light region is 1%. At least one of the following polarizers.

15)

The light control device according to any one of 1) to 14), wherein the IR polarizing plate or the VIS-IR polarizing plate is an absorption-type polarizing plate.

16)

The light control device according to any one of 1) to 15), wherein the IR polarizing plate or the VIS-IR polarizing plate is a film.

17)

The light control device according to any one of 1) to 16), wherein a medium having a phase difference or a phase controllable medium and at least one polarizing plate are laminated.

18)

A liquid crystal display device, an anti-counterfeiting device or a sensor, comprising the light control device according to any one of 1) to 17).

According to the present invention, the incident light in the infrared region and the light in the visible region can be emitted with different polarizations on the detected side, and the amount of light can be controlled by these polarizations.

In one aspect, according to the present invention, the light intensity of the infrared light region and the light intensity of the visible light region at the time of incidence from the same light source are switched to transmit light in each region on the detected side. Or not penetrate, but can control the amount of light of each.

The light control device of the present invention includes at least one polarizing plate (IR polarizing plate) having polarization properties for light in the infrared region, at least one polarizing plate (VIS polarizing plate) having polarization properties for light in the visible region, and a phase polarizing plate. A medium or a phase-controllable medium, in which the transmitted light in the infrared region and the transmitted light in the visible region are controlled by making incident light in the infrared region and light in the visible region different polarized lights, respectively.

In one aspect, the light control device of the present invention includes a medium that can dynamically control the phase when light in the visible light region and light in the infrared light region are simultaneously incident, wherein the light in the infrared light region and the light in the visible light region are controlled separately. The transmitted light in the infrared region and the transmitted light in the visible light region are controlled as light of different polarizations.

The above-mentioned IR polarizing plate is not particularly limited as long as it is a polarizing plate capable of controlling polarization in the wavelength of the infrared light region. The polarizing plate includes, for example, a polyene type polarizer using an iodine-based polarizing plate such as Patent Document 1, a wire grid polarizing plate such as Patent Document 2 and Patent Document 3, and a glass that is mixed with metal particles and stretched as described in Patent Document 4. A glass polarizing plate, a dye-based polarizing plate containing a dye, etc., in this case, a dye-based polarizing plate is preferably used. The dye-based polarizing plate can be in the form of a film, and can be easily laminated with other polarizing plates, retardation plates, etc., and has the characteristics of flexibility and easy optical control.

The above-mentioned IR polarizing plate has polarization performance with respect to light in a part or all of the wavelength region of 700 to 1400 nm.

The above-mentioned VIS polarizing plate is not particularly limited as long as it is a polarizing plate that can control polarization in the wavelength of the visible light region. Although the polarizing plate can be, for example, an iodine-based polarizing plate, a dye-based polarizing plate, a dye-based polarizing plate that can only control polarized light at a specific wavelength, a type of polarizing plate that uses polyene, etc., but preferably only a specific wavelength can be controlled. A polarized dye-based polarizing plate or a combination of plural types of dye-based polarizing plates capable of polarizing only a specific wavelength is used as a polarizing element capable of controlling polarization only for a specific wavelength. It is preferable that polarized light at a specific wavelength can be detected or controlled by having the polarization property only for light of a specific wavelength.

The above-mentioned VIS polarizing plate has a polarization property for light in a part or all of the wavelength region of 400 to 700 nm. Preferably, the transmittance in the infrared light region is high and there is no absorption. If the light transmittance in the infrared light region is higher than that of the visible light, there is no particular limitation. The so-called "non-absorbing" means that it has high transmittance in the infrared light region, and is not easy to affect the light penetration in the infrared light region, but generally the transmittance of a common polarizer is 30 to 45%. In the case where each wavelength in the infrared light region has a single transmittance of the same level or more, a polarizing plate having a function of transmitting infrared light can be used as the visible light (VIS) polarizing plate of this application. Specifically, the transmittance of the infrared light region is 40% or more, preferably 50% or more, more preferably 60% or more, still more preferably 70% or more, and particularly preferably 80% or more. Especially when the two VIS polarizers are perpendicular to each other, the transmittance of the infrared light region is above 30%, preferably above 40%, more preferably above 50%, still more preferably above 60%, particularly preferably above 70% As mentioned above, it can be used as an excellent VIS polarizer.

The above-mentioned medium having a phase is, for example, called a retardation plate, a wave plate, a retardation film, or the like.

Moreover, as a medium which can control a phase, the liquid crystal panel (liquid crystal cell) etc. which can control a phase by electricity etc. which are used for general liquid crystal monitors etc. which enclose a liquid crystal are mentioned, for example.

Here, the "controllable phase" means that the phase of light as a wave can be controlled. In the case of focusing on polarization performance, for example, wavelength plates, phase-controllable media (wave plates, etc.) are optical functional elements that impart a predetermined phase difference to linearly polarized light, and polarized light can be used for light of a specific axis. Set a different phase in other axes (eg 90°). That is, for light of one polarized light, by providing a wavelength plate or the like on the light path, it becomes polarized light of the opposite axis, or circularly polarized light, elliptical polarized light, or the like can be newly provided. Therefore, a wavelength plate or the like refers to an element that can change the polarization state of incident light by imparting a retardation to two orthogonal polarization components using an oriented birefringent material (for example, a stretched film). This wavelength plate or the like can be incident on the wavelength plate or the like by setting the slow axis of the λ/2 retardation plate at 45° with respect to the axis of polarization when, for example, the wavelength of a specific light is set to λ. The linearly polarized light is rotated by 90°, and polarized light having a polarization axis in a direction orthogonal (90°) to the incident polarization axis is emitted. Furthermore, by setting the slow axis of the λ/2 retardation plate at 22.5° with respect to the axis of the polarized light, the linearly polarized light of the incident wavelength plate (retardation plate) can be rotated by 45°, and the incident polarized light can be emitted. Polarized light with an axis tilted by 45°. Furthermore, when the slow axis of the λ/4 retardation plate is set at 45° with respect to the axis of polarization, linearly polarized light incident on the wavelength plate (retardation plate) can be emitted as circularly polarized light.

The above-mentioned retardation plate, wave plate, and retardation film can be used, and there is no particular limitation as long as the slow axis or fast axis of light of the film can be rotated with respect to the absorption axis of the polarizing plate.

The phase-controllable liquid crystal panel (liquid crystal cell) is a medium that electrically controls the phase. Controlled liquid crystal driving methods include TN (Twisted Nematic; twisted nematic), STN (Super Twisted Nematic; super twisted nematic), IPS (In-Plane-Switching; plane switching), VA (Vertical Alignment; vertical) Alignment type) and other methods, but there are no particular limitations on the liquid crystal and the control method that can control the phases of light in the visible light region and light in the infrared light region. Preferable examples include TN (Twisted Nematic; twisted nematic), STN (Super Twisted Nematic; super twisted nematic), and the like. These are preferred because the driving voltage is low, the price is cheap, and the polarization rotation of 0 to 90° can be easily controlled.

In the above-mentioned light control device, the light in the infrared light region and the light in the visible light region are controlled to be light of different polarizations, respectively, by a medium having a phase or a medium capable of controlling the phase. Thereby, the polarization of light in the infrared light region when incident and the polarization of light in the visible light region when incident can be sensed as different polarized lights on the detection side, respectively. Specifically, by controlling the polarization of the light in the visible light region that can be recognized by the human eye and the light in the infrared light region that is difficult to recognize, the amount of light in the visible light region and the light in the infrared light region can be adjusted at the same time. The light in the area is controlled to be penetrating or not penetrating while the light in the infrared light area is continuously penetrated. In addition, the reverse control can also be performed. In other words, the light in the visible light region can be continuously transmitted while the light in the infrared light region is controlled to pass through or not pass through, and the light and A light control device for each polarization and light intensity of light in the infrared light region.

In the past, infrared light sensors and visible light cameras had to use different types of sensors for sensing light in the infrared light region and light sensing in the visible light region, but by using the device of the present invention, infrared light sensing The detector and visible light camera can be controlled by a light control device. For example, cameras such as mobile phones, generally require separate light control devices for authentication cameras in the infrared light region and cameras in the visible light region. However, by using the above light control devices, the light in the visible light region and the infrared light region can be switched. Light penetration or non-penetration, so infrared light area authentication and visible light area photography, etc. can be performed with a single light control device. Furthermore, by applying this light control device, it can be applied to high security and the like. In addition, since it can be a light-transmitting device, circular polarization control and linear polarization control of infrared light to visible light region, etc., by applying these, it can also be applied to, for example, a device applying a light reflection polarization function, a security application, and the like.

In one aspect, it is preferably a light control device, wherein the angle (phase of incident light) at which the medium with phase or the medium (retardation plate) that can control the phase shows the phase difference value Rλ is the same as that in infrared light. The angle (phase difference) θi between the angles (phases of the emitted light) when the region develops (emits) linearly polarized light is in the range of 0≦θi<180°. In the case where the above-mentioned angle θi is 0°, in other words, in the case of coaxial arrangement, the polarized light in the infrared light region is not affected by the retardation plate or becomes light that is not easy to receive, and the polarization of the retardation plate with the retardation value of λ/2 is set. In this case, by setting the above-mentioned angle θi to 45°, polarized light having an opposite axis reversed by 90° to the incident linearly polarized light can be emitted.

Furthermore, the angle (phase difference) θv between the angle at which the retardation value Rλ is exhibited by the retardation plate (the phase of the incident light) and the angle at which the linearly polarized light is exhibited in the visible light region (the phase of the outgoing light) is − The light control device in the range of 90°<θv<180° can also control the phase difference in the visible light region. θv and θi may be the same or different, and the polarization state of light of a specific wavelength may be controlled by a retardation plate. In other words, the number of retardation plates used is not limited to one. For example, a general liquid crystal display uses a combination of a 1/4λ plate, a 1/2λ plate, etc., and a plurality of retardation plates can also be used in the light control device of the present invention. plate.

When the wavelength of light in the infrared light region is Iλ, the wavelength of light in the visible light region is Vλ, the error of the retardation value is RD (Retarder Dispersion), and the retardation value of the retardation plate is Rλ, it satisfies The light control device according to the following mathematical formula (1) or mathematical formula (2) functions as a retardation plate that can provide Vλ in the visible light region, and functions as a retardation plate that can provide Iλ/2 in the infrared light region .

Vλ-RD≦Rλ≦Vλ+RD Equation (1) (However, RD means 0 to 40nm)

Iλ/2-RD≦Rλ≦Iλ/2+RD Mathematical formula (2) (however, RD represents 0 to 40 nm).

In the above-mentioned light control device, in the case where the slow axis of the retardation plate having Rλ is set to be 45° with respect to the incident linearly polarized light, in the visible light region, it continues to be the one that can maintain the incident polarized light. The retardation plate of light functions as a λ/2 polarizer in the infrared light region, so that the reverse polarization axis of the incident polarization axis can be emitted. When the slow axis of the retardation plate having Rλ is set to be 45° with respect to the incident linearly polarized light, and a polarizing plate having an absorption axis orthogonal to the incident axis is provided on the output side, it is possible to Provides a light control device that can transmit light in the visible light region but absorb light in the infrared light region. When it is desired that neither light in the visible light region nor light in the infrared light region is transmitted (absorbed), the slow axis of the retardation plate having Rλ may be set to 0° instead of 45°. In this way, by controlling the slow axis of the retardation plate having Rλ that satisfies the relationship of the above equation (1) or equation (2), the axis of linear polarization, elliptical polarization, and the like can also be controlled. The above-mentioned RD is preferably in the range of 0 to 40 nm, more preferably in the range of 0 to 25 nm, still more preferably in the range of 0 to 15 nm, particularly preferably in the range of 0 to 5 nm. The control of the polarization axis using the above-mentioned phase can be performed with reference to Non-Patent Document 1 and the like.

Furthermore, the light control device satisfying the relationship of the following formula (3) or formula (4) functions as a retardation plate capable of providing λ/2 in the visible light region, and as a retardation plate capable of providing λ/2 in the infrared light region 4 of the retardation plates come into play. Furthermore, Iλ, Vλ, RD and Rλ are as defined above.

Vλ/2-RD≦Rλ≦Vλ/2+RD Mathematical formula (3) (However, RD means 0 to 40nm)

Iλ/4-RD≦Rλ≦Iλ/4+RD Mathematical formula (4) (however, RD represents 0 to 40 nm).

In the above-mentioned light control device, when the slow axis of the retardation plate having Rλ is set at 45° to which linearly polarized light is incident, in the visible light region, it functions as a λ/2 polarizing plate and can emit incident light. The reverse polarized light of polarized light functions as a retardation plate that can function as a λ/4 polarizing plate in the infrared region, and can emit incident polarized light as circularly polarized light. Thereby, when a polarizing plate having an absorption axis perpendicular to the incident axis is provided on the emission side, the visible light region can be controlled to maintain linear polarization, whereas the infrared light region can be controlled to circularly polarized light. When it is desired that neither light in the visible light region nor light in the infrared light region is transmitted (absorbed), the slow axis of the retardation plate having Rλ may be set to 0° instead of 45°. In this way, by controlling the slow axis of the retardation plate having Rλ that satisfies the above equations (3) and (4), the axis of linear polarization, elliptical polarization, and the like can also be controlled. In the case of the above configuration, the reflection in the visible light region can be controlled and the penetration in the infrared light region can be controlled. The preferred structure can be, for example, a polarizing plate that can control the visible light region and the infrared light region, a medium with a phase or a medium that can control the phase, and a polarizing plate that can control the visible light region and the infrared light region. Examples such as visible light can be controlled. The order of the polarizers in the region and the infrared region, the medium having a phase or the phase controllable medium, the polarizer capable of controlling the visible region, and the order of the polarizers capable of controlling the infrared region, etc., are not limited to the configuration. Furthermore, when this method is used, polarization control in which the reflected light in the infrared region has polarization can also be applied. For example, in the case of performing reflection control on one polarizing plate, in the infrared light region, a polarizing plate, a λ/4 retardation plate, and a reflecting plate are laminated in this order. Regarding the absorption axis of the polarizing plate, the retardation plate is When the slow axis is set at 45° at which the linearly polarized light is incident, the linearly polarized light system of the incident light from the polarizing plate is changed to circularly polarized light by the retardation plate, and the light system reflected by the reflecting plate is changed to the reversed light system. Circularly polarized light, the result can show the function of anti-reflection. However, in this case, since the light in the visible light region is continuously maintained in the linearly polarized state, the light is reflected and the reflected light can be detected. Furthermore, even in the case of reflection use, by setting the slow axis of the retardation plate to 0° with respect to the absorption axis of the infrared light polarizing plate, the polarization of the infrared light region is maintained in the state of linear polarization, so as A light control device capable of reflecting both light in the visible light region and light in the infrared light region functions. In the case of the light control device, RD is preferably in the range of 0 to 40 nm, preferably 0 to 25 nm, more preferably 0 to 15 nm, and particularly preferably 0 to 5 nm.

Furthermore, a light control device satisfying the relationship of the following formula (5) or formula (6) functions as a retardation plate capable of providing 3/2λ in the visible light region, and as a retardation plate capable of providing 1 in the infrared light region A retardation plate of /2 λ functions. Furthermore, Iλ, Vλ, RD and Rλ are as defined above.

Vλ×3/2-RD≦Rλ≦Vλ×3/2+RD Equation (5) (However, RD means 0 to 40nm)

Iλ×1/2-RD≦Rλ≦Iλ×1/2+RD Mathematical formula (6) (however, RD represents 0 to 40 nm).

In the above-mentioned light control device, by setting the slow axis of the retardation plate having Rλ to 45° at which the linearly polarized light is incident, it functions as a 3/2 λ polarizing plate in the visible light region, and can emit incident light. The circularly polarized light of the polarized light functions as a λ/2 polarizing plate in the infrared region and functions as a retardation plate capable of emitting incident polarized light on the opposite axis. Thereby, when a polarizing plate having an absorption axis perpendicular to the incident axis is provided on the emission side, the polarized light in the visible light region can be controlled to be circularly polarized light, while the infrared light region can be controlled to be linearly polarized light. When it is desired that neither light in the visible light region nor light in the infrared light region is transmitted (absorbed), the slow axis of the retardation plate having Rλ may be set to 0° instead of 45°. In this way, by controlling the slow axis of the retardation plate having Rλ that satisfies the above equations (5) and (6), the axis of linear polarization, elliptical polarization, and the like can also be controlled. The preferred structure can be, for example, a polarizing plate that can control the visible light region and the infrared light region, a medium with a phase or a medium that can control the phase, and a polarizing plate that can control the visible light region and the infrared light region. Examples such as visible light can be controlled. The order of the polarizers in the region and the infrared region, the medium having a phase or the phase controllable medium, the polarizer capable of controlling the visible region, and the order of the polarizers capable of controlling the infrared region, etc., are not limited to the configuration. Furthermore, when this method is used, polarization control in which the reflected light in the infrared region has polarization can also be applied. In the case of the above configuration, the reflection in the visible light region can be controlled, and the penetration in the infrared light region can be controlled. For example, in the case of performing reflection control on one polarizing plate, in the visible light region, a polarizing plate, a 3/4 λ polarizing plate, and a reflecting plate are laminated in this order, and the reflecting plate is arranged so as to be relative to the absorption axis of the polarizing plate. The retardation plate is set so that the slow axis is 45°, whereby the linearly polarized light of the incident light from the polarizing plate is changed to circularly polarized light by the retardation plate, and the light reflected by the reflecting plate is changed to inversely polarized light Circularly polarized light, the result can show the function of anti-reflection. However, in this case, since the light in the infrared light region is continuously maintained in the state of linear polarization, the light is reflected, and the reflected light can be detected. Furthermore, even in the case of this reflection use, by setting the slow axis of the retardation plate to 0°, it functions as a light control device capable of reflecting both light in the visible light region and light in the infrared light region. In the case of the light control device, RD is preferably in the range of 0 to 40 nm, preferably 0 to 25 nm, more preferably 0 to 15 nm, and particularly preferably 0 to 5 nm.

In the above-mentioned IR polarizing plate of the light control device of the present invention, the transmittance (infrared light region) of light in the infrared light region (wavelength of 700 to 1400 nm) when the two polarizing plates are superimposed so that the absorption axes are perpendicular The orthogonal transmittance of light) and the transmittance of light in the visible light region (wavelength of 400 to 700 nm) when two polarizing plates are superimposed so that the absorption axes are orthogonal to each other (orthogonal transmittance of light in the visible light region) A difference of 10% or more is preferable because the polarization control of the light in the visible light region and the light in the infrared light region becomes easier. For example, if the polarizing plate has polarization properties for the light in the infrared region and also has polarization properties for the light in the visible region, the polarization of the light in each region can be controlled by the retardation plate, but a polarizing plate has the light of 400 to 1400nm. When the degree of polarization is 100%, it is difficult to impart polarization properties only to light in the infrared region or to impart polarization properties only to light in the visible region. On the other hand, by using a polarizing plate having polarization performance for light in each wavelength region, and selecting an appropriate polarizing plate in accordance with the wavelength, polarization control can be performed at various wavelengths. In other words, a polarizing plate that can control the wavelength of light only in the infrared region is used in the infrared region, and a polarizing plate that can only control the wavelength of light in the visible region is used in the visible region, because polarization control can be performed at various wavelengths. Or penetration rate control, so it is better. However, a polarizing plate having polarization performance in the infrared light region may also have polarization performance in the visible light region, so it does not necessarily have polarization performance only in the infrared light region. However, in terms of the function of the light control device of the present invention, it is important to emit light having a different phase (polarized light) between the light in the infrared light region and the light in the visible light region. (S/N ratio) clear is sufficient. Therefore, in the IR polarizing plate, instead of imparting 100% polarization performance at all wavelengths, the transmittance of light from 700 to 1400 nm when the two polarizing plates are superimposed so that the absorption axes are perpendicular to each other is compared with the absorption axis. The difference in transmittance of light from 400 to 700 nm when two polarizing plates are stacked in an orthogonal manner is 10% or more, and the polarization control of light in the visible light region and light in the infrared light region becomes easier. The difference in transmittance is preferably 20% or more, more preferably 30% or more, and still more preferably 40% or more.

Including an IR polarizing plate with an orthogonal transmittance of 1% or less in the wavelength range of light in the infrared light region and a wavelength range of light in the infrared light region that does not absorb light and the polarizing plate exhibits an orthogonal transmittance of 1% or less. The light control device of at least one VIS polarizing plate is preferable because it can separately control the polarization performance of light in the infrared light region and the polarization performance of light in the visible light region. Furthermore, the above-mentioned light control device is preferable because the contrast between the light in the infrared light region and the light in the visible light region is improved, respectively. In addition, each polarizing plate can be used on different axes, and the wavelength of each polarized light to be axially controlled can be divided into visible light region light and infrared light region light on the wavelength axis to perform light control. The respective orthogonal transmittances of the light in the infrared light region and the light in the visible light region are independently 1% or less, whereby sufficient light control can be performed, but preferably 0.3% or less, more preferably 0.1% or less, and even more Preferably, it is 0.01% or less, and particularly preferably, it is 0.005% or less. For example, in the case of a parallel transmittance of 40%, when the orthogonal transmittance is set to 0.1%, the ratio is 40:0.1, in other words, a contrast ratio of 400:1 can be provided. In other words, the contrast of the polarizing plate has a great influence on the optical control device of the present invention, so it is better to control it within the above range.

Regarding the control of the light in the infrared light region and the light in the visible light region of the light control device of the present invention, in terms of the comparison of the amount of light required for the switching of transmission/non-transmission (light shielding), it is necessary to use a general paper medium. contrast ratio. In other words, if the contrast ratio between penetration and light shielding is 10:1 or more, preferably 100:1 or more, and more preferably 1000:1 or more.

When constructing the above-mentioned light control device, it is preferable that at least one of the IR polarizers is an absorption-type polarizer. The above-mentioned absorption-type polarizing plate is characterized in that no stray light is generated. The above-mentioned IR polarizing plate is generally a wire grid type, but in the case of a polarizing plate that controls the refraction, reflection, etc. of light and exhibits a polarizing function, it is caused by scattered light, condensed light, intense light and dark objects, unspecified shapes, light overlapping, light Reflection, refraction, resonance, phase modulation, etc. of light due to the situation of a person moving in a position, etc., and the like, and light of a wavelength other than the original wavelength and light of intensity are displayed. In this case, light with a wavelength other than the original wavelength or light with an intensity becomes stray light. In order to prevent false detection, it is important that such stray light does not occur. In other words, it is preferable to use a polarizing plate that does not generate stray light. For example, in the case where the IR polarizing plate is an absorption type polarizing plate, it is easy to perform optical control because stray light and the like are less likely to occur, so it can be preferably used.

Each of the above-mentioned polarizing plates is easy to laminate and can be flexible. For flexibility, at least one of the IR polarizing plates is preferably a film. In particular, it is preferable to laminate with a medium having a phase or a phase-controllable medium because it can be laminated. By lamination, it is difficult to cause a decrease in transmittance due to the influence of interface reflection and the like, which is preferable for light control.

In addition, each of the above-mentioned polarizers, phase-having media, or phase-controllable media can be rotated by signals such as light, electricity, and the like, and can be set to a desired angle, or the setting can be changed.

The above-mentioned light control device can simultaneously control the polarizations of light in the infrared light region and light in the visible light region, so that the light in the visible light region that can be recognized by the human eye and the polarization of light in the infrared light region that is difficult to recognize can be simultaneously controlled. Therefore, the above-mentioned light control device can be applied to a liquid crystal display device that can switch detection of light in the infrared region and light in the visible region, a photographing device such as a camera that can control the polarization of light in the infrared region and light in the visible region, and the like, It can be used in various applications such as a high-security anti-counterfeiting device or a sensor that functions separately in the infrared light region and the visible light region. It can also be used as a system combining various applications with a light control device.

<Example>

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

<Production of a polarizing plate (IR polarizing plate) with polarization properties for light in the infrared region>

The 45 degreeC aqueous solution of the azo compound of the following chemical formula (1) whose concentration is 0.3% and the mirabilite concentration of 0.1% was prepared as a dyeing solution. In this dyeing solution, a polyvinyl alcohol film having a thickness of 75 μm was immersed for 5 minutes. Then, the film was stretched to 5 times in a 50° C. solution of a 3% boric acid aqueous solution, kept in a taut state, washed with water, and dried to obtain a polarizing element. A triacetyl cellulose film (TAC film; manufactured by FUJIFILM Corporation; trade name TD-80U) obtained by alkali treatment was laminated on both surfaces of the polarizing element through an adhesive of an aqueous polyvinyl alcohol solution, and a film having a center of 835 nm was obtained. Polarizing plate with high polarizing function. This polarizing plate was used as an IR polarizing plate.

<Production of a polarizing plate (VIS polarizing plate) with polarization properties for light in the visible region>

Prepare Kayarus Supra Orange 2GL (manufactured by Nippon Kayaku Co., Ltd.) at a concentration of 0.02%, C.I. Direct Red 81 at a concentration of 0.01%, Blue KW (manufactured by Nippon Kayaku Co., Ltd.) at a concentration of 0.04%, and thenardite at a concentration of 0.1% % concentration of 45 ℃ aqueous solution, as a dyeing solution. In this dyeing solution, a polyvinyl alcohol film having a thickness of 75 μm was immersed for 3 minutes and 30 seconds. Then, the film was stretched 5 times in a 50°C solution of a 3% boric acid aqueous solution, kept in a taut state, washed with water, and dried to obtain a polarizing element. A triacetin-based cellulose film (TAC film; manufactured by FUJIFILM; trade name TD-80U) obtained by alkali treatment was laminated on both surfaces of the polarizing element via an adhesive of an aqueous polyvinyl alcohol solution to obtain a 400 to 650 nm film. A polarizing plate with a polarizing function in the visible light region. This polarizing plate was used as a VIS polarizing plate.

<Production of a polarizing plate (VIS-IR polarizing plate) that can control light in the infrared region and light in the visible region>

The azo compound of the above chemical formula (1) was prepared at a concentration of 0.6%, Kayarus Supra Orange 2GL (manufactured by Nippon Kayaku Co., Ltd.) at a concentration of 0.02%, C.I. Direct Red 81 at a concentration of 0.01%, Blue KW (Nihon Kayaku Co., Ltd.) A 45°C aqueous solution with a concentration of 0.04% and Glauber's salt at a concentration of 0.1% (manufactured by Pharma Co., Ltd.) was used as a dyeing solution. In this dyeing solution, a polyvinyl alcohol film having a thickness of 75 μm was immersed for 5 minutes. Then, the film was stretched to 5 times in a 50° C. solution of a 3% boric acid aqueous solution, kept in a taut state, washed with water, and dried to obtain a polarizing element. A triacetin-based cellulose film (TAC film; manufactured by FUJIFILM; trade name TD-80U) obtained by alkali treatment was laminated on both surfaces of the polarizing element via an adhesive of an aqueous polyvinyl alcohol solution to obtain a film having a thickness of 400 to 900 nm. Polarizing plate with polarizing function. This polarizing plate was used as a VIS-IR polarizing plate.

<Measurement of transmittance of polarizing element>

(Transmittance measurement of polarizing plate)

For each of the obtained polarizing plates, a spectrophotometer (U-4100 manufactured by Hitachi, Ltd.) was used to measure the single transmittance (Ts), parallel transmittance (Tp), and orthogonal transmittance of each wavelength at 380 to 1100 nm. (Tc), degree of polarization (ρ). The so-called single transmittance (Ts) refers to the transmittance obtained by measuring one polarizing plate, and the so-called parallel transmittance (Tp) refers to the penetration obtained by measuring the light absorption axes of two polarizing plates in parallel. The so-called orthogonal transmittance (Tc) refers to the transmittance obtained by measuring the absorption axes of the two polarizing plates at right angles to each other, and the degree of polarization is the value calculated by the mathematical formula (7).

Degree of polarization (%)=100×[(Tp-Tc)/(Tp+Tc)] ^1/2 Mathematical formula (7)

The single transmittance (Ts), parallel transmittance (Tp), and orthogonal transmittance (Tc) at wavelengths of 420 nm, 555 nm, 830 nm, and 840 nm of each of the obtained polarizing plates are shown below. Table 1 shows the values when using the IR polarizing plate, Table 2 shows the values when using the VIS polarizing plate, and Table 3 shows the values when using the VIS-IR polarizing plate.

<Examples A1 to A4>

Fabrication and evaluation of light control devices

The light emitted from the light source part of the U-4100 is irradiated to the light control device, and the transmitted light is incident on the detection part of the U-4100. The light control device is VIS-IR polarizing plate, phase The structure of the difference plate, the VIS polarizer, and the IR polarizer. As the retardation plate, a polycarbonate-based retardation plate showing a retardation value of 420 nm at each wavelength of 420 nm and 840 nm was used. The transmittance when the slow axis of the retardation plate was inclined at 0° and 45° with respect to the VIS-IR polarizing plate was measured. At this time, the polarization axis of each of the VIS polarizing plate and the IR polarizing plate was variously changed and measured. The results are shown in Table 4. 0° in Table 4 refers to the absorption axis of the VIS-IR polarizer. If it is a retardation plate, the slow axis is set to 0°, and if it is a VIS polarizer or an IR polarizer, the absorption axis is set to 0 ° (coaxial). The same applies to 45° and 90°. The so-called St means the penetration rate detected by U-4100 is strong (30 to 50%), the so-called Mi means the penetration rate detected by U-4100 is medium (10 to 25%), the so-called We means the penetration rate detected by U-4100 -4100 detects weak penetration (0 to 2%).

<Examples A5 to A8>

The light control device was evaluated in the same manner as in Examples 1 to 4, except that a polycarbonate-based retardation plate having a retardation value of 210 nm was used at each wavelength of 420 nm and 840 nm. The results are shown in Table 5.

<Examples A9 to A12>

The light control device was evaluated in the same manner as in Examples 1 to 4, except that a polycarbonate-based retardation plate showing a retardation value of 415 nm at each wavelength of 555 nm and 830 nm was used. The results are shown in Table 6.

<Examples A13 to A14>

The light emitted from the light source part of the U-4100 is irradiated on the light control device, and the reflected light is incident on the detection part of the U-4100. The light control device is VIS polarizing plate, IR polarizing plate, The structure of retardation plate and reflector. As the retardation plate, a polycarbonate-based retardation plate showing a retardation value of 210 nm at each wavelength of 420 nm and 840 nm was used. The transmittance when the slow axis of the retardation plate was inclined at 0° and 45° with respect to the VIS polarizing plate was measured. At this time, each polarization axis of the IR polarizing plate was variously changed and measured. The results are shown in Table 7. 0° in Table 7 means relative to the absorption axis of the VIS polarizer. In the case of a retardation plate, the slow axis is set to 0°, and in the case of an IR polarizer, the absorption axis is set to 0° (coaxial). The same applies to 45° and 90°. St, (Mi) and We have the same meanings as in Table 4.

<Examples A15 to A16>

The light emitted from the light source part of the U-4100 is irradiated on the light control device, and the reflected light is incident on the detection part of the U-4100. The light control device is VIS polarizing plate, IR polarizing plate, The structure of retardation plate and reflector. A polycarbonate-based retardation plate having a retardation value of 415 nm at each wavelength of 555 nm and 830 nm was used as the retardation plate. The transmittance when the slow axis of the retardation plate was inclined at 0° and 45° with respect to the VIS polarizing plate was measured. At this time, each polarization axis of the IR polarizing plate was variously changed and measured. The results are shown in Table 8. 0°, 45°, 90°, St, (Mi), and We in Table 8 have the same meanings as in Table 7.

<Comparative Examples A1 to A4>

Table 9 shows the results of measuring the transmittance using the optical control device (Comparative Examples 1 to 4) in which the retardation plate was removed from Examples A1 to A4. Similar to the conventional polarizing plate, the transmittance decreases when the absorption axes of the polarizing plate are orthogonal at each wavelength, and the transmittance increases when the absorption axes are parallel. Only the function of the traditional polarizer can control the transmittance of the parallel position and the orthogonal position, and it cannot be an optical device that can individually control the transmittance at each wavelength.

<Comparative Examples A5 to A6>

Table 10 shows the results of measuring the transmittance using the optical control device (Comparative Examples 5 to 6) in which the retardation plate was removed from Examples A13 to A14. Similar to placing a conventional polarizing plate on a mirror, no change in transmittance was seen at all, and no change was seen between incident light in the visible light region and light in the infrared light region.

From the results of Examples A1 to A12, it is known that in each light control device, for the same light source, the amounts of light in the infrared light region and light in the visible light region can be controlled separately. Furthermore, in Examples A5 to A8 and Examples A13 to A14 and Examples A9 to A12 and Examples A15 to A16, it is known that the results by light control when light penetrates and the light by reflection Controls yielded different results. From the above results, it is shown that the light control device obtained by the present invention can change the light of the visible light region and the light of the infrared light region respectively even when the same light source having the light of the visible light region and the light of the infrared light region is used. It is effective for devices with different light intensity and polarization.

<Example B1>

The light emitted from the light source part of the U-4100 is irradiated to the light control device, and the transmitted light enters the detection part of the U-4100. The light control device is VIS-IR polarizing plate, STN in this order from the light source side. Type of liquid crystal cell, VIS polarizer, IR polarizer. At this time, the layers are stacked so that the absorption axis of the VIS polarizer is parallel to the absorption axis of the VIS-IR polarizer so that the absorption axis of the IR polarizer is 90° with respect to the absorption axis of the VIS-IR polarizer. ° way to layer and use. Regarding the bonding to the liquid crystal cell, what was obtained by bonding each polarizing plate so that the visible light region would have the lowest transmittance when a voltage was applied to the STN cell was used as a measurement sample of the present case. The STN-type liquid crystal cell is arranged so as to have a slow axis in the 45° direction when the initial axis is set to 0° when a voltage is applied, and the retardation becomes 1/2 λ at each wavelength of 420 nm and 840 nm. the phaser. At this time, Table 11 shows the measurement results of light with a wavelength of 420 nm and a wavelength of 840 nm when the voltage was turned ON and OFF. The amount of light (%) that enters the detection portion of the U-4100 after passing through the above-mentioned light control device is expressed in terms of the amount of light that passes through only the VIS-IR polarizing plate.

<Example B2>

The light emitted from the light source part of the U-4100 is irradiated to the light control device, and the transmitted light enters the detection part of the U-4100. The light control device is VIS-IR polarizing plate, STN in this order from the light source side. Type of liquid crystal cell, VIS polarizer, IR polarizer. At this time, the layers are stacked so that the absorption axis of the VIS polarizer is perpendicular to the absorption axis of the VIS-IR polarizer so that the absorption axis of the IR polarizer becomes 0 with respect to the absorption axis of the VIS-IR polarizer. ° way to layer and use. Regarding the bonding to the liquid crystal cell, when no voltage is applied to the STN cell, the polarizing plate bonded together so that the visible light region has the lowest transmittance is used as the measurement sample of the present case. When an STN-type liquid crystal cell is used with an applied voltage, it is arranged so as to have a slow axis in the 45° direction when the initial axis is set to 0°, and the retardation becomes 1/2 at each wavelength of 420 nm and 840 nm. Phaser of λ. At this time, Table 11 shows the measurement results of light with a wavelength of 420 nm and a wavelength of 840 nm when the voltage was turned ON and OFF. The amount of light (%) that enters the detection portion of the U-4100 after passing through the above-mentioned light control device is expressed in terms of the amount of light that passes through only the VIS-IR polarizing plate.

<Example B3>

The light emitted from the light source unit of the U-4100 is incident on the VIS polarizer, IR polarizer, STN type liquid crystal cell, and reflector in this order from the light source side, and the reflected light is incident on the detection unit of the U-4100. The IR polarizing plate is bonded at 45° with respect to the absorption axis of the VIS polarizing plate, and the bonding to the liquid crystal cell is used so that the infrared light region has the lowest reflectance when no voltage is applied to the STN cell. The one obtained by bonding each polarizing plate was used as the measurement sample of this case. STN-type liquid crystal cells are arranged so as to have a slow axis in the direction of 45° when the initial axis is set to 0° when a voltage is applied, and the retardation becomes 1/4 λ at each wavelength of 420 nm and 840 nm. the phaser. At this time, Table 11 shows the measurement results of light with a wavelength of 420 nm and a wavelength of 840 nm when the voltage was turned ON and OFF. The amount of light (%) when reflected from the above-mentioned light control device and incident on the detection portion of the U-4100 is represented by the amount of light reflected from only the VIS-IR polarizing plate and the reflecting plate.

<Example B4>

As an evaluation of the light control device, the light emitted from the light source unit of the U-4100 described above was incident on U-IR polarizer, TN-type liquid crystal cell, VIS polarizer, and IR polarizer as viewed from the light source side. -4100 detection section. At this time, the layers are stacked so that the absorption axis of the VIS polarizer is parallel to the absorption axis of the VIS-IR polarizer so that the absorption axis of the IR polarizer is 90° with respect to the absorption axis of the VIS-IR polarizer. ° way to layer and use. Regarding bonding to a liquid crystal cell, when a voltage is applied to a TN cell, a polarizing plate is used as a measurement sample of the present case so that the infrared light region transmittance is minimized by the polarizing plate for infrared light. At this time, Table 11 shows the results of light with a wavelength of 420 nm and a wavelength of 840 nm when the voltage was turned ON and OFF. The results represent the amount of light (%) that enters the detection portion of the U-4100 after passing through the above-mentioned light control device, based on the amount of light that passes through only the VIS-IR polarizing plate.

It can be seen from the results of Examples B1 to B4 that in each light control device, the amount of light in the infrared light region and light in the visible light region can be independently and dynamically controlled while using the same light source. Especially from Examples B1 and B2, it is known that the light in the visible light region and the infrared light region can be switched by the light control of the light in the visible light region and the light in the infrared light region when penetrating, that is, through a medium that dynamically displays the phase. The transmittance of light in the light area. Furthermore, from Example B3, it was found that the light control of the above-mentioned light control device is effective even when a reflector is used. From the above results, it is shown that the light control device obtained by the present invention can easily switch and control the transmittances of light in the visible light region and light in the infrared light region even when the same light source is used. Words are valid.

[Industrial Availability]

It can control the polarization of incident light with wavelengths in the infrared light region and the wavelengths in the visible light region into different polarizations at the same time, and can be applied to a liquid crystal display device that can switch detection of light in the infrared light region and light in the visible light region. Controllable Various applications such as imaging devices such as cameras that polarize light in the infrared region and light in the visible region, anti-counterfeiting devices that provide high security, and sensors that function separately for light in the infrared region and visible region.

Claims (17)

A light control device, comprising at least one polarizer (IR polarizer) with polarizing properties for light in the infrared region, at least one polarizer (VIS polarizer) with polarizing properties for light in the visible region, and a polarizer for the visible region. A polarizing plate (VIS-IR polarizing plate) having polarizing properties between light and light in the infrared region, and a medium having a phase or a phase-controllable medium, wherein the incident light in the infrared region and the visible light region are The light of different polarized light respectively controls the penetrating light in the infrared light region and the penetrating light in the visible light region. The light control device according to claim 1, wherein the angle between the angle at which the phase-having medium or the phase-controllable medium exhibits the phase difference value Rλ and the angle at which linearly polarized light appears in the infrared region θi is in the range of 0≦θi<180°. The light control device according to claim 1, wherein the angle θv between the angle at which the phase-having medium or the phase-controllable medium exhibits the phase difference value Rλ and the angle at which linearly polarized light appears in the visible light region is: -90°<θv<180° range. The light control device according to any one of Claims 1 to 3, wherein the wavelength of light in the infrared region is Iλ, the wavelength of light in the visible region is Vλ, and the retardation value is When the error of RD is set as RD, and the phase difference value of the medium with phase or the medium with controllable phase is set as Rλ, the relationship of the following mathematical formula (1) or mathematical formula (2) is satisfied respectively; Vλ-RD≦Rλ≦ Vλ+RD Mathematical formula (1) (however, RD means 0 to 40nm) Iλ/2-RD≦Rλ≦Iλ/2+RD Mathematical formula (2) (however, RD represents 0 to 40 nm). The light control device according to any one of Claims 1 to 3, wherein the wavelength of light in the infrared region is Iλ, the wavelength of light in the visible region is Vλ, and the retardation value is When the error of RD is set as RD, and the phase difference value of the medium with phase or the medium with controllable phase is set as Rλ, the relationship of the following mathematical formula (3) or mathematical formula (4) is satisfied respectively; Vλ/2-RD≦ Rλ≦Vλ/2+RD Equation (3) (however, RD represents 0 to 40 nm) Iλ/4-RD≦Rλ≦Iλ/4+RD Equation (4) (however, RD represents 0 to 40 nm). The light control device according to any one of Claims 1 to 3, wherein the wavelength of light in the infrared region is Iλ, the wavelength of light in the visible region is Vλ, and the retardation value is When the error of RD is set as RD, and the phase difference value of the medium with phase or the medium with controllable phase is set as Rλ, the relationship of the following mathematical formula (5) or mathematical formula (6) is satisfied respectively; Vλ×3/2- RD≦Rλ≦Vλ×3/2+RD Mathematical formula (5) (however, RD means 0 to 40nm) Iλ×1/2-RD≦Rλ≦Iλ×1/2+RD Mathematical formula (6) (however, RD means 0 to 40 nm). The light control device according to any one of items 1 to 3 of the scope of the application, which is used for simultaneously controlling the light in the visible light region and the light in the infrared light region, wherein the phase-controllable medium is dynamic The medium that controls the phase. The light control device according to claim 7, wherein the medium whose phase can be dynamically controlled is a liquid crystal panel (liquid crystal cell). The light control device according to claim 8, wherein the liquid crystal used in the liquid crystal panel (liquid crystal cell) is a twisted nematic liquid crystal (TN liquid crystal; Twisted Nematic liquid crystal) or a super twisted nematic liquid crystal (STN liquid crystal). Liquid Crystal; Super Twisted Nematic Liquid Crystal). The light control device according to claim 7, wherein the contrast ratio between transmission and non-transmission of light in the visible light region and light in the infrared light region is 10 or more. The light control device according to claim 1, wherein, in the VIS-IR polarizing plate, the difference between the orthogonal transmittance of light in the infrared light region and the orthogonal transmittance of light in the visible light region is 1% the following. The light control device according to any one of claims 1 to 3, wherein, in the IR polarizing plate, the orthogonal transmittance of light in the infrared light region and the orthogonal transmittance of light in the visible light region are equal to each other. The difference is more than 10%. The light control device according to any one of claims 1 to 3 of the scope of the patent application, comprising: the orthogonal transmittance of light in the infrared light region in the IR polarizing plate is 1% or less and a distance between the light in the visible light region and the A polarizing plate with a transmittance difference of 10% or more; and the aforementioned VIS polarizing plate shows high transmittance in the infrared light region, shows that the penetration of light in the infrared light region is not easily affected, and the orthogonal transmittance of light in the visible light region is At least one polarizing plate with 1% or less. The light control device as described in any one of items 1 to 3 of the scope of the application set, wherein, the aforementioned IR polarizing plate or the aforementioned VIS-IR polarizing plate is an absorbing polarizing plate. The light control device according to any one of claims 1 to 3, wherein the IR polarizing plate or the VIS-IR polarizing plate is a film. The light control device according to any one of claims 1 to 3 of the claimed scope, wherein a medium having a phase or a medium with controllable phase and at least one polarizing plate are laminated. A liquid crystal display device, an anti-counterfeiting device or a sensor, which is provided with the light control device described in any one of items 1 to 16 of the scope of the patent application.