JP2018087929A - Optical axis adjusting instrument of light source device, light source device, and optical axis adjusting method of the light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device which includes a plurality of LED elements, and can suppress lowering in illuminance caused by positional deviation.SOLUTION: A light source device includes: a light source section in which a plurality of ultraviolet LED elements are arranged; a first optical system collimating each light emitted from the light source section; a second optical system condensing a plurality of light emitted from the first optical system; and an adjustment mechanism which is provided on at least one of the light source section and the first optical system and adjusts a relative positional relationship between the light source section and the first optical system. An optical axis adjusting instrument has a base section, and a fluorescent layer which is arranged on an upper surface of the base portion and generates fluorescent light in a visible range when irradiated with ultraviolet light, and a reference line for positional adjustment is provided in a visible state on a predetermined surface of the base portion.SELECTED DRAWING: Figure 5B

Description

  The present invention relates to an optical axis adjustment instrument for a light source device, a light source device, and an optical axis adjustment method for the light source device.

  Conventionally, light processing technology using light has been used in various fields. For example, an exposure apparatus is used for fine processing using light. In recent years, exposure techniques have been developed in various fields, and are used for producing relatively large patterns and for three-dimensional fine processing among fine processing. More specifically, for example, an exposure technique is used for manufacturing an electrode pattern of an LED, a manufacturing process of MEMS (Micro Electro Mechanical Systems) represented by an acceleration sensor, and the like.

  In these light processing technologies, a discharge lamp having a high luminance has been used as a light source. However, with recent progress in solid-state light source technology, it has been studied to use a light source having a plurality of LED elements arranged therein. As such a technique, for example, Patent Document 1 discloses an exposure apparatus in which a unit composed of a plurality of LED elements is used as a light source, and a fly-eye lens is disposed between the light source and a mask.

JP 2004-335953 A

  Compared with a light source device in which the light source is configured by a lamp, when the light source is configured by an LED element, there is less radiated light flux. For this reason, in order to construct a light source device that achieves high light output, it is necessary to collect as much light as possible from a plurality of LED elements. At this time, if a positional deviation occurs between the plurality of LED elements and the subsequent optical system, a sufficient amount of light cannot be guided to the target optical system using the light. Such misregistration is unavoidable to some extent.

  In view of the above-described problems, an object of the present invention is to provide a light source device that includes a plurality of LED elements, and that can suppress a decrease in illuminance caused by a positional shift. It is another object of the present invention to provide an optical axis adjusting instrument and an optical axis adjusting method applicable to such a light source device.

The present invention is an optical axis adjustment instrument of a light source device,
The light source device
A light source unit in which a plurality of ultraviolet LED elements are disposed;
A first optical system for collimating each of the light emitted from the light source unit;
A second optical system for condensing a plurality of lights emitted from the first optical system;
It is a configuration provided with an adjustment mechanism for adjusting a relative positional relationship between the light source unit and the first optical system, which is provided in at least one of the light source unit and the first optical system,
The optical axis adjusting instrument is:
A base part;
A fluorescent layer that is fixedly disposed on the base portion and generates fluorescence in the visible region when irradiated with the ultraviolet light;
A reference line for position adjustment is provided on a predetermined surface of the base portion so as to be visible.

  As described above, the light emitted from one LED element has a lower luminance than the lamp. For this reason, when it is assumed that the light source is used for a light source that requires a lot of light, such as an exposure apparatus, it is important to collect the light from many LED elements without reducing the luminance as much as possible. .

  Under such a point of view, the present inventors have developed a light source device that condenses light emitted from a plurality of LED elements after collimating in a first optical system. According to such a light source device, the emitted light from each LED element can be imaged at the condensing position. Further, the light emitted from each LED element can narrow the interval between the emitted light beams by adjusting the arrangement of the collimating lens (first optical system), and a light source with a small non-light emitting area is configured. Thereby, a light source device with high luminance is realized.

  In such a configuration, if a positional deviation occurs between the light source unit and the first optical system, it is assumed that the amount of light guided to the subsequent stage of the second optical system decreases. Specifically, for example, if there is a shift in the positional relationship between each LED element and the collimating lens (first optical system) corresponding thereto, the light collection position of the second optical system is shifted, It becomes difficult to efficiently guide light to the subsequent stage of the second optical system. As a result, the amount of light guided to the subsequent stage of the second optical system is reduced, and for example, when used as an exposure apparatus, the illuminance on the exposure surface is reduced.

  From this point of view, the present inventors are considering providing an adjustment mechanism for adjusting the relative positional relationship between the light source unit and the first optical system in the light source device. According to this configuration, even if the light source device is installed in a state where a positional deviation occurs between each LED element included in the light source unit and the corresponding collimating lens (first optical system). By adjusting through the adjustment mechanism, the shift of the light collection position by the second optical system is corrected, and light is efficiently guided to the subsequent stage of the second optical system.

  By the way, when the light source device is used as a light source for an exposure apparatus, ultraviolet light is emitted from the light source unit. Since ultraviolet light is in a wavelength band that cannot be visually recognized, there is a problem that the optical axis of the light source device cannot be adjusted while viewing an image. Therefore, the optical axis adjusting instrument includes a base portion having a fluorescent layer on the upper surface. As a result, even when the light source unit is composed of a plurality of ultraviolet LED elements, the image generated by exciting the fluorescent layer becomes visible light, so that it is displayed in a visible state. The

  The optical axis adjusting instrument is provided on a predetermined surface of the base portion so that a reference line for position adjustment is visible. This makes it easy to adjust the optical axis of the light source unit and the optical axis of the first optical system by operating the adjustment mechanism so that the fluorescent image appearing on the base unit follows the reference line with the light source unit turned on. Can be adjusted.

The base portion includes a light transmission portion that transmits the ultraviolet light in at least a part of the region,
The ultraviolet light may be configured to be incident on the fluorescent layer through the light transmission portion.

As another aspect,
The base portion includes a light transmission portion that transmits the fluorescence in at least a part of the region,
The reference line is provided on the surface of the base portion opposite to the surface on which the fluorescent layer is formed,
When the ultraviolet light is incident on the fluorescent layer, the fluorescence generated in the fluorescent layer is incident on the surface of the base portion on the side where the reference line is provided via the light transmitting portion. It can be set as a structure.

  An arbitrary shape can be adopted as the reference line. As an example, at least a part of the shape can be a frame shape. As another example, a cross shape or a plurality of rectangular shapes with the same center may be used.

Moreover, the light source device according to the present invention includes:
A light source unit in which a plurality of ultraviolet LED elements are disposed;
A first optical system for collimating each of the light emitted from the light source unit;
A second optical system for condensing a plurality of lights emitted from the first optical system;
A third optical system for dividing the light emitted from the second optical system;
An optical axis adjusting instrument provided on the optical axis of one optical path divided by the third optical system and at a position where the light is condensed by the second optical system;
An adjustment mechanism for adjusting a relative positional relationship between the light source unit and the first optical system, provided in at least one of the light source unit and the first optical system;
The optical axis adjusting instrument is:
A base part;
A fluorescent layer that is fixedly disposed on the base portion and generates fluorescence in the visible region when irradiated with the ultraviolet light;
A reference line for position adjustment is provided on a predetermined surface of the base portion so as to be visible.

  According to the above configuration, the light source unit and the first optical system are operated by operating the adjustment mechanism so that the fluorescent image appearing on the predetermined surface of the base unit follows the reference line with the light source unit turned on. The optical axis can be easily adjusted.

  As said 3rd optical system, a reflective mirror can be used, for example. Of the light emitted from the second optical system and incident on the reflection mirror, most of the light is reflected by the reflection mirror and guided to the subsequent optical system. On the other hand, a very small amount of light incident on the reflection mirror travels through the reflection mirror. That is, the light emitted from the second optical system is divided by the reflecting mirror. A very small amount of ultraviolet light transmitted from the reflecting mirror is incident on the fluorescent layer provided in the optical axis adjusting device to generate fluorescence, and an image in the visible range due to the fluorescence is displayed on the upper surface of the base portion. The optical axis of the light source unit and the optical axis of the first optical system can be adjusted by operating the adjustment mechanism so that the position of the image follows the reference line while visually recognizing this image.

  An integrator optical system may be provided that is disposed on the optical axis of the other optical path divided by the third optical system and whose incident surface is focused at the position where the light is condensed by the second optical system.

  The light emitted from the LED element has less radiated light flux than the lamp. For this reason, for example, in order to use it as a light source device for exposure, it is necessary to collect as much light as possible from a plurality of LED elements. For this purpose, it is necessary to increase the number of LED elements arranged as light sources.

  By the way, since the LED element requires a wiring pattern for supplying power, the LED element itself cannot be arranged completely closely. That is, when arranging a plurality of LED elements, it is necessary to leave a certain distance between adjacent LED elements. The region forming this interval constitutes a region that does not emit light (non-light emitting region). For this reason, even if a plurality of LED elements are simply arranged and the emitted light from each LED element is condensed, a non-light emitting region is inevitably generated. Therefore, simply condensing the light emitted from the plurality of LED elements causes a decrease in luminance on the irradiated surface.

  According to the above configuration, the light emitted from the plurality of LED elements is condensed after being collimated in the first optical system. Thereby, the emitted light from each LED element can be imaged in a condensing position. In addition, the light emitted from each LED element can narrow the interval between the emitted light beams by adjusting the arrangement of the collimating lens (first optical system), and a light source with a small non-light emitting area is configured. . Thereby, a light source device with high luminance is realized.

  The integrator optical system may be configured by a light guide member that guides light incident from the incident surface to the exit surface while repeatedly reflecting on the inner surface.

  According to this configuration, since light with high radiation intensity is condensed on the incident surface of the light guide member, light with high luminance and uniform illuminance distribution is emitted from the light emission surface of the light guide member. be able to. In addition, as a light guide member, it can comprise with a rod integrator or a light tunnel, for example.

  The integrator optical system may be configured by a fly-eye lens in which a plurality of lenses are arranged in a matrix.

  The illuminance distribution on the irradiated surface can be made uniform by the fly-eye lens. Thereby, the light source device with high luminance and uniform illuminance distribution can be realized.

The plurality of LED elements are arranged on a predetermined plane,
The adjustment mechanism may be configured to be capable of adjusting a relative positional relationship between the light source unit and the first optical system with respect to a direction parallel to the predetermined plane.

  Further, the adjustment mechanism may be configured so that at least one of the light source unit and the first optical system can rotate on a plane parallel to the predetermined plane.

  Further, as a specific aspect, the light source unit may include an LED board, the adjustment mechanism may be attached to the LED board, and the first optical system is stored in the lens holder. The adjustment mechanism may be attached to the lens holder.

Further, the present invention is an optical axis adjustment method for a light source device,
The light source device
A light source unit in which a plurality of ultraviolet LED elements are disposed;
A first optical system for collimating each of the light emitted from the light source unit;
A second optical system for condensing a plurality of lights emitted from the first optical system;
It is a configuration provided with an adjustment mechanism for adjusting a relative positional relationship between the light source unit and the first optical system, which is provided in at least one of the light source unit and the first optical system,
A base portion and a fluorescent layer that is fixedly disposed on the base portion and generates fluorescence in the visible region when irradiated with the ultraviolet light, and is positioned on a predetermined surface of the base portion for position adjustment. A step (a) of arranging an optical axis adjustment instrument provided in a state in which the reference line of the second optical system is visible at the condensing position of the second optical system;
With the light source unit turned on, the adjustment mechanism is operated so that the image projected on the surface of the optical axis adjustment instrument matches the reference line, and the light source unit and the first optical system And (b) adjusting the relative positional relationship between the two.

  According to the above method, the light source unit and the first optical system are operated by operating the adjustment mechanism so that the fluorescent image appearing on the base unit follows the reference line in a state where the light source unit is turned on and ultraviolet light is emitted. And the optical axis can be adjusted. The “condensing position” here is not necessarily limited to the focal position of the second optical system, and may be a position where light is collected within a range where an image can be visually recognized.

  According to the present invention, in a light source device including a plurality of ultraviolet LED elements, even if a positional deviation occurs between the optical system and the ultraviolet LED element, a decrease in luminance and illuminance associated with the positional deviation is suppressed. can do.

It is drawing which shows typically an example of the optical system of a light source device. It is drawing which shows typically an example of arrangement | positioning relationship between a light source part and a 1st optical system. It is drawing which shows typically an example of arrangement | positioning relationship between a light source part and a 1st optical system. It is drawing which shows typically an example of arrangement | positioning relationship between a light source part and a 1st optical system. It is typical drawing which shows the state which mounted the optical axis adjustment instrument in the light source device. It is typical drawing which shows the state which mounted the optical axis adjustment instrument in the light source device. It is drawing which shows the instrument for optical axis adjustment typically. It is drawing which shows typically the image in the surface of the fluorescent layer of the instrument for optical axis adjustment before position adjustment. It is drawing which shows typically the image in the surface of the fluorescent layer of the tool for optical axis adjustments after performing the adjustment of a 1st step. It is drawing which shows typically the image in the surface of the fluorescent layer of the instrument for optical axis adjustments after performing a 2nd step adjustment. It is drawing which shows typically the image in the surface of the fluorescent layer of the instrument for optical axis adjustments after performing the adjustment of a 3rd step. It is drawing which shows typically an example of arrangement | positioning relationship between a light source part and a 1st optical system. It is drawing which shows typically an example of arrangement | positioning relationship between a light source part and a 1st optical system. It is drawing which shows typically the structure of 2nd embodiment of a light source device. It is drawing which shows the instrument for optical axis adjustment typically. It is drawing which shows typically an example of the optical system of a light source device. It is drawing which shows typically an example of a structure of exposure apparatus.

  Hereinafter, a light source device and an optical axis adjusting instrument of the present invention will be described with reference to the drawings. In addition, the dimension ratio in each figure does not necessarily correspond with an actual dimension ratio.

[First embodiment]
FIG. 1 is a drawing schematically showing an example of the optical system of the first embodiment of the light source device. The light source device 1 includes a light source unit 2, a first optical system 5, a second optical system 7, and an integrator optical system 8. In the light source device 1 according to the present embodiment, the light source unit 2 is accommodated in the LED board 22, and the first optical system 5 is accommodated in the lens holder 23. Although not shown in FIG. 1, the LED board 22 and the lens holder 23 are configured so that the relative positional relationship between them can be adjusted. An example of a specific configuration will be described later.

  The light source unit 2 includes a plurality of LED elements 3. In this embodiment, the some LED element 3 is arrange | positioned on the predetermined plane as an example. However, in the present invention, any arrangement mode of the plurality of LED elements 3 may be used. In the present embodiment, the plurality of LED elements 3 are elements that emit light in the ultraviolet region. As an example, the emission wavelength is 400 nm or less.

  The first optical system 5 is an optical system that collimates the light emitted from the plurality of LED elements 3, and is configured by arranging a plurality of collimating lenses 6 corresponding to the LED elements 3.

  The second optical system 7 is an optical system that condenses the light emitted from the first optical system 5 at the focal point 7 f of the second optical system 7.

  In the present embodiment, the integrator optical system 8 is constituted by a rod integrator 9. The rod integrator 9 is arranged such that the incident surface 9a is positioned at the focal point 7f of the second optical system 7. However, in this specification, “arranged at the focal position” means that the lens is moved by a distance of ± 10% in a direction parallel to the optical axis 11 with respect to the focal distance, in addition to the case where it completely coincides with the focal position It is assumed that the concept includes a position. Note that the optical axis 11 in FIG. 1 is an axis orthogonal to the incident surface of the integrator optical system 8, that is, the incident surface 9a of the rod integrator 9.

  The rod integrator 9 has a function of uniformizing the illuminance distribution of light on the exit surface 9b by guiding the light incident on the entrance surface 9a to the exit surface 9b while repeating total reflection on the side surface. It is an example of (light guide). Such a light guide member includes, for example, a columnar member made of a light-transmitting material such as glass or resin, a hollow member whose inner surface is formed of a reflecting mirror, and the like. The latter configuration is sometimes called a light tunnel. In addition, the light guide member may be configured by dividing a plurality of optical paths in a direction parallel to the optical axis.

  2, 3, and 4 are diagrams illustrating an example of an arrangement relationship between the light source unit 2 and the first optical system 5, respectively. In the example illustrated in FIG. 2, the LED board 22 in which the light source unit 2 is accommodated and the lens holder 23 in which the first optical system 5 is accommodated are integrally held with screws or the like. In FIG. 2, a clamping screw 41 provided separately from the screw is shown. This clamping screw 41 is an example of an adjusting mechanism.

  FIG. 3 is an example of a schematic plan view when the inside of FIG. 2 is viewed from the LED board 22 side. FIG. 4 is a perspective view schematically showing the inside of FIG. In this example, the LED board 22 and the lens holder 23 are configured such that the positional relationship can be adjusted by three clamping screws 41 and two ball plungers 42. In FIG. 4, for convenience of illustration, a part of the clamping screw 41 and the ball plunger 42 are not shown.

  The ball plunger 42 has a built-in spring. When the three clamping screws 41 are pushed and pulled while the screwing between the LED board 22 and the lens holder 23 is slightly loosened, the hard sphere at the tip of the ball plunger 42 moves. By this movement, the relative positional relationship between the LED board 22 and the lens holder 23 can be adjusted. Specifically, as shown in FIG. 3, movement in the X direction, movement in the Y direction, and rotational movement in the θ direction are possible. In addition, the some LED element 3 is arrange | positioned on the plane (XY plane) comprised by the X direction and Y direction here.

  An example of a specific method of position adjustment will be described with reference to the drawings. 5A and 5B are schematic drawings showing a state in which an optical axis adjusting instrument is mounted on the light source device 1. FIG. 5C is a perspective view schematically showing only the optical axis adjusting instrument. 5A and 5B, a part of the light source device 1 is shown in a transparent manner, and some elements such as the rod integrator 9 and the power supply unit are not shown. Below, it demonstrates using the coordinate axis shown in FIG. 5A, FIG. 5B, and FIG. 5C as needed.

  The optical axis adjusting instrument 50 includes a base portion 52 and a fluorescent layer 53. FIG. 5C corresponds to the drawing when the optical axis adjusting instrument 50 is viewed from an angle different from that of FIG. 5B. As shown in FIG. 5C, the base portion 52 is provided with a light transmission portion 54. In FIG. 5C, the fluorescent layer 53 arranged in a fixed manner on the back side surface via the light transmission part 54 is displayed. In FIG. 5C, the fluorescent layer 53 is hatched for the sake of display. This light transmission part 54 may be comprised by the cavity, and may be comprised by the material which permeate | transmits ultraviolet light.

  The fluorescent layer 53 is disposed on a predetermined surface of the base portion 52, and generates fluorescence in the visible range when irradiated with ultraviolet light. The optical axis adjusting instrument 50 is provided on a surface on the side where the fluorescent layer 53 is arranged in a state where a reference line 55 for position adjustment is visible. The reference line 55 may be printed in advance on a predetermined surface of the base portion 52 of the optical axis adjusting instrument 50. In the embodiment shown in FIGS. 5A and 5B, an example in which the reference line 55 is drawn in a frame shape is shown.

  The optical axis adjusting instrument 50 is installed on a base 51 and is configured to be position adjustable in the Y-axis direction. FIG. 5A shows a state in which the optical axis adjustment instrument 50 is closest to the light source device 1 side, and FIG. 5B shows that the light axis adjustment instrument 50 is moved in the Y-axis direction from the state of FIG. 5A. The state separated from 1 is shown. Further, the optical axis adjusting instrument 50 of the present embodiment is configured to be removable from the base 51.

  When the LED element 3 mounted on the LED board 22 is turned on, the ultraviolet light emitted from the LED element 3 enters the second optical system 7 via each collimator lens 6 in the lens holder 23. Thereafter, the ultraviolet light emitted from the second optical system 7 is directed to the installation location of the optical axis adjusting instrument 50 after the optical axis 11 is bent in the Y-axis direction via the reflection mirror 49. 5A and 5B, the reflection mirror 49 is shown, but this is provided for adjusting the direction of the optical axis, and is not an essential element in the present embodiment.

  In this embodiment, the fluorescent layer 53 is disposed on the surface of the base portion 52 that is farther from the LED board 22 that constitutes the light source when viewed along the optical axis 11 (FIG. 5C). reference). That is, the ultraviolet light incident on the optical axis adjusting instrument 50 is incident on the fluorescent layer 53 provided on the surface on the base portion 52 via the light transmitting portion 54. The fluorescent layer 53 is excited by the incident ultraviolet light and generates fluorescence.

  After installing in this way, while adjusting the position of the image in the fluorescent layer 53, the adjustment mechanism (in this example, the clamping screw 41) is operated to adjust the relative positional relationship between the LED board 22 and the lens holder 23. To do. Each of FIGS. 6A to 6D schematically shows a photograph of an image at each time point. In each figure, an area appearing as an image is denoted by reference numeral 60. A position that is the center of the image 60 is indicated by reference numeral 62. Here, it is assumed that the light source unit 2 is configured by arranging 85 LED elements 3 in an 80 mm square region.

  As an example, the clamping screw 41 can move in the forward and backward directions of 0.4 mm by making one turn, and can be moved by 0.1 mm by making 1/4 turn. As shown in FIG. 3, the lens holder 23 can be rotated with respect to the LED board 22 by relatively moving the two clamping screws 41 provided on the same side. As an example, when the interval between the two clamping screws 41 is 60 mm, the relative positional relationship between the two clamping screws 41 is about 1 mm in order to rotate the light source unit 2 of 80 mm □ by 1 °. 2 and a half) can be realized by shifting. At this time, the relative positional relationship may be shifted by moving only one clamping screw 41 out of the two clamping screws 41, or moving one forward and moving the other backward. By doing so, the relative positional relationship may be shifted.

  FIG. 6A corresponds to the initial time, for example. 6A shows that the center 62 of the image is deviated from the center O of the reference line 55. FIG. Moreover, since the image 60 has shown the circular shape and the image 60 is blurred, it turns out that it cannot be said that the light from each LED element 3 is condensed on the substantially same location. Such a situation suggests that a positional shift has occurred between the light source unit 2 and the first optical system 3.

  FIG. 6B shows the measurement results after the lens holder 23 is rotated by 1 ° with respect to the LED board 22 by operating the adjustment mechanism from the state of FIG. 6A. An image 60 shown in FIG. 6B shows a rectangular shape corresponding to the shape of the light source unit 2, and it can be seen that the image is clearly projected as compared with the state of FIG. 6A. Thereby, it can be seen that the center of the LED element 3 and the optical axis of the corresponding collimating lens 6 are closer than in the state of FIG. 6A.

  FIG. 6C shows the measurement result after the lens holder 23 is moved 0.2 mm in the X direction with respect to the LED board 22 by further operating the adjustment mechanism from the state of FIG. 6B. FIG. 6D shows the measurement results after the lens holder 23 is moved 0.2 mm in the Y direction with respect to the LED board 22 by further operating the adjustment mechanism from the state of FIG. 6C. 6C, the position of the center 62 of the image 60 is closer to the center O of the reference line 55 in the state of FIG. 6C. In the state of FIG. 6D, the center 60 of the image 60 is further moved to the reference line. Approaching the center O of 55.

  As described above, the LED element 3 and the corresponding optical axis of the collimating lens 6 are adjusted by operating the adjusting mechanism while confirming the position of the fluorescent image appearing on the surface of the optical axis adjusting instrument 50. Can do. According to the state shown in FIG. 6D, the light emitted from the plurality of LED elements 3 can be collected at almost one point. Therefore, after that, the optical axis adjusting device 50 is removed, and the rod integrator 9 is arranged so that the light incident surface 9a of the rod integrator 9 is positioned at the position, so that the illuminance on the light emitting surface 9b of the rod integrator 9 is increased. High light can be guided.

  In the present embodiment, the case where the clamping screw 41 is used as the adjustment mechanism has been described. However, the adjustment mechanism is not limited to this configuration. For example, as shown in FIG. 7A, the cam 44 may be used, or the pin 45 may be used. 7A, the rotation axis of the cam 44 may be attached to the lens holder 23 or the LED board 22. 7B, the base portion of the pin 45 may be attached to the lens holder 23 or the LED board 22.

[Second Embodiment]
FIG. 8A is a drawing schematically showing the configuration of the second embodiment of the light source device, which is illustrated in accordance with FIGS. 5A and 5B. FIG. 8B is a perspective view schematically showing only the optical axis adjusting instrument, and is illustrated in accordance with FIG. 5C. This embodiment is different from the first embodiment in that an optical axis adjusting instrument 50 is provided in the light source device 1.

  As shown in FIG. 8A, the light source device 1 of the present embodiment includes a reflection mirror 49. As a result, the ultraviolet light emitted from the second optical system 7 has its optical axis bent in the X direction via the reflection mirror 49 (optical axis 11), and then the subsequent optical system (rod integrator 9, FIG. 8A). (Not shown). The reflection mirror 49 corresponds to a “third optical system”.

  By the way, the reflection mirror 49 reflects most of the incident light while transmitting very little light. That is, part of the ultraviolet light emitted from the second optical system 7 passes through the reflection mirror 49 and travels in the Z direction (optical axis 12). The optical axis adjusting instrument 50 is disposed at a position displaced in the Z direction with respect to the reflection mirror 49, and ultraviolet light transmitted through the reflection mirror 49 is incident thereon.

  As shown in FIG. 8B, also in the present embodiment, the base portion 52 is provided with a light transmission portion 54. In FIG. 8B, the fluorescent layer 53 disposed on the back surface via the light transmission part 54 is displayed. In FIG. 8B, the fluorescent layer 53 is hatched for the sake of display. This light transmission part 54 may be comprised by the cavity, and may be comprised by the material which permeate | transmits ultraviolet light.

  Also in this embodiment, the fluorescent layer 53 is disposed on the surface of the base portion 52 on the side farther from the LED board 22 constituting the light source when viewed along the optical axis 12 (FIG. 8B). That is, the ultraviolet light incident on the optical axis adjusting instrument 50 is incident on the fluorescent layer 53 provided on the surface on the base portion 52 via the light transmitting portion 54. The fluorescent layer 53 is excited by the incident ultraviolet light and generates fluorescence. Then, this fluorescent image appears on the surface of the fluorescent layer 53.

  Accordingly, the relative positional relationship between the LED board 22 and the lens holder 23 can be adjusted by operating the adjustment mechanism while confirming the position of the image on the fluorescent layer 53.

  Also in the present embodiment, the optical axis adjusting instrument 50 is ± in the direction of the optical axis 12 (Z-axis direction in this example) with respect to the focal length of the second optical system 7 from the focal position of the second optical system 7. It is preferable to install it at a position separated by a distance of 20% or less. Preferably, the displacement distance from the focal position with respect to the position of the optical axis adjusting instrument 50 is within ± 10% of the focal distance of the second optical system 7.

  In the light source device 1 of the present embodiment, the optical axis adjusting instrument 50 may be disposed on the optical axis 11 side, and the subsequent optical system (rod integrator 9) may be disposed on the optical axis 12 side. Moreover, in the light source device 1 of the present embodiment, the optical axis adjusting instrument 50 may be fixed by a method such as screwing, and may be configured to be removable by loosening the screw.

[Another embodiment]
Hereinafter, another embodiment will be described.

  <1> In each of the above embodiments, the fluorescent layer 53 provided in the optical axis adjusting instrument 50 constitutes a light source when viewed along the optical axis (11, 12) of the surface of the base portion 52. It demonstrated as what is arrange | positioned in the surface of the far side with respect to LED board 22 to do. On the other hand, the fluorescent layer 53 is disposed on the surface of the base portion 52 that is closer to the LED board 22 that constitutes the light source when viewed along the optical axis (11, 12). It doesn't matter.

  In this case, the fluorescence generated in the fluorescent layer 53 is irradiated to the surface of the base portion 52 opposite to the surface on which the fluorescent layer 53 is formed, via the light transmitting portion 54. On this surface, the reference line 55 for position adjustment is drawn as described above. For this reason, the collimating lens corresponding to the LED element 3 is operated by operating the adjusting mechanism while confirming the position of the fluorescent image appearing on the surface of the optical axis adjusting instrument 50 by the same method as in the above embodiments. 6 optical axes can be adjusted.

  Under the above configuration, the light transmission part 54 may be formed of a cavity or a material that transmits fluorescence.

  <2> In each of the above-described embodiments, it has been described that the light transmission portion 54 is provided in a part of the base portion 52. However, the entire base portion 52 may be made of a light transmissive material. At this time, when the fluorescent layer 53 is disposed on the surface of the base portion 52 that is far from the LED board 22 that constitutes the light source when viewed along the optical axis 11, the base portion 52 is The material may be made of a material that transmits ultraviolet light. Conversely, when the fluorescent layer 53 is disposed on the surface of the base portion 52 that is closer to the LED board 22 constituting the light source when viewed along the optical axis 11, the base portion 52 is The material may be made of a material that transmits fluorescence.

  <3> The fluorescent layer 53 may be fixedly disposed at a position where the ultraviolet light emitted from the plurality of LED elements 3 can enter in the base portion 52. Within the range satisfying this condition, the structure of the base portion 52 and the arrangement position of the fluorescent layer 53 are arbitrary.

  <4> As shown in FIG. 9, the integrator optical system 8 may be composed of a fly-eye lens 10. Also in this case, high-intensity light is collected on the incident surface of the fly-eye lens 10, and high-intensity light is emitted from the fly-eye lens 10. Note that in another configuration described above, the integrator optical system 8 may be configured by the fly-eye lens 10.

  <5> The light source device 1 described above can be used as a light source for an exposure device or a projector. FIG. 10 is a drawing schematically showing a configuration of an exposure apparatus including the light source device 1.

  The exposure apparatus 19 includes a projection optical system 15 and a mask 16 at the subsequent stage of the integrator optical system 8, and a projection lens 17 as necessary. A mask 16 is placed at a position projected by the projection optical system 15, and a photosensitive substrate 18 to be a target for printing a pattern image of the mask 16 is placed after the mask 16. In this state, when light is emitted from the light source unit 2, the light is collected by the second optical system 7, and then irradiated to the projection optical system 15 as light whose illuminance distribution is uniformed by the rod integrator 9. Is done. The projection optical system 15 projects the pattern image of the mask 16 onto the photosensitive substrate 18 directly or via the projection lens 17.

  <6> In the above-described embodiment, the lens holder 23 can be moved with respect to the LED board 22 in the X direction, the Y direction, and the rotation direction on the XY plane. However, it may be configured to be movable in at least one of these directions, or may be configured to be movable in another direction (for example, a direction orthogonal to the XY plane). Further, the LED board 22 may be configured to be movable with respect to the lens holder 23.

  <7> In each embodiment described above, the light source device 1 may be provided with an optical system such as a reflection optical system as appropriate for the purpose of changing the optical path.

  <8> The reference line 55 provided on the surface of the optical axis adjusting instrument 50 can have any shape as long as it functions as a reference for position adjustment. For example, in addition to the frame shape described above, a cross shape or a plurality of rectangular shapes with the same center can be employed.

  <9> In FIG. 1, the light source device 1 is configured to include the integrator optical system 8. However, in the present invention, after the light emitted from the plurality of ultraviolet LED elements 3 is collimated by the collimating lens 6, the second optical The present invention is applicable to the light source device 1 configured to be condensed by the system 7.

DESCRIPTION OF SYMBOLS 1: Light source device 2: Light source part 3: LED element 5: 1st optical system 6: Collimating lens 7: 2nd optical system 7f: Focus of 2nd optical system 8: Integrator optical system 9: Rod integrator 9a: Rod integrator Entrance surface 9b: Exit surface of rod integrator 10: Fly eye lens 11: Optical axis 12: Optical axis 15: Projection optical system 16: Mask 17: Projection lens 18: Photosensitive substrate 19: Exposure device 22: LED board 23: Lens Holder 41: Clamping screw 42: Ball plunger 44: Cam 45: Pin 49: Reflection mirror 50: Optical axis adjustment instrument 51: Base 52: Base part 53: Fluorescent layer 54: Light transmission part 55: Reference line 60: Image 61: Reference area 62: Image center

Claims (10)

An instrument for adjusting the optical axis of a light source device,
The light source device
A light source unit in which a plurality of ultraviolet LED elements are disposed;
A first optical system for collimating each of the light emitted from the light source unit;
A second optical system for condensing a plurality of lights emitted from the first optical system;
It is a configuration provided with an adjustment mechanism for adjusting a relative positional relationship between the light source unit and the first optical system, which is provided in at least one of the light source unit and the first optical system,
The optical axis adjusting instrument is:
A base part;
A fluorescent layer that is fixedly disposed on the base portion and generates fluorescence in the visible region when irradiated with the ultraviolet light;
An instrument for adjusting an optical axis of a light source device, wherein a reference line for position adjustment is provided on a predetermined surface of the base portion so as to be visible. The base portion includes a light transmission portion that transmits the ultraviolet light in at least a part of the region,
2. The optical axis adjusting device according to claim 1, wherein the ultraviolet light is configured to be incident on the fluorescent layer through the light transmitting portion. The base portion includes a light transmission portion that transmits the fluorescence in at least a part of the region,
The reference line is provided on the surface of the base portion opposite to the surface on which the fluorescent layer is formed,
When the ultraviolet light is incident on the fluorescent layer, the fluorescence generated in the fluorescent layer is incident on the surface of the base portion on the side where the reference line is provided via the light transmitting portion. The optical axis adjusting instrument according to claim 1.   The optical axis adjusting instrument according to any one of claims 1 to 3, wherein at least a part of the reference line is drawn in a frame shape. A light source unit in which a plurality of ultraviolet LED elements are disposed;
A first optical system for collimating each of the light emitted from the light source unit;
A second optical system for condensing a plurality of lights emitted from the first optical system;
A third optical system for dividing the light emitted from the second optical system;
An optical axis adjusting instrument provided on the optical axis of one optical path divided by the third optical system and at a position where the light is condensed by the second optical system;
An adjustment mechanism for adjusting a relative positional relationship between the light source unit and the first optical system, provided in at least one of the light source unit and the first optical system;
The optical axis adjusting instrument is:
A base part;
A fluorescent layer that is fixedly disposed on the base portion and generates fluorescence in the visible region when irradiated with the ultraviolet light;
A light source device, wherein a reference line for position adjustment is provided on a predetermined surface of the base portion so as to be visible. The base portion includes a light transmission portion that transmits the ultraviolet light in at least a part of the region,
The light source device according to claim 5, wherein the ultraviolet light is configured to be incident on the fluorescent layer through the light transmission portion. The base portion includes a light transmission portion that transmits the fluorescence in at least a part of the region,
The reference line is provided on the surface of the base portion opposite to the surface on which the fluorescent layer is formed,
When the ultraviolet light is incident on the fluorescent layer, the fluorescence generated in the fluorescent layer is incident on the surface of the base portion on the side where the reference line is provided via the light transmitting portion. The optical axis adjusting instrument according to claim 5.   The light source device according to claim 5, wherein at least a part of the reference line is drawn in a frame shape.   An integrator optical system is provided on the optical axis of the other optical path divided by the third optical system, the incident optical surface being disposed at a position where the light is condensed by the second optical system. Item 9. The light source device according to any one of Items 5 to 8. An optical axis adjustment method for a light source device,
The light source device
A light source unit in which a plurality of ultraviolet LED elements are disposed;
A first optical system for collimating each of the light emitted from the light source unit;
A second optical system for condensing a plurality of lights emitted from the first optical system;
It is a configuration provided with an adjustment mechanism for adjusting a relative positional relationship between the light source unit and the first optical system, which is provided in at least one of the light source unit and the first optical system,
A base part and a fluorescent layer that is fixedly disposed on the base and generates fluorescence in the visible region when irradiated with the ultraviolet light, and is provided on a predetermined surface of the base part for position adjustment. A step (a) of disposing an optical axis adjustment instrument provided in a state in which the reference line is visible at the light collecting position of the second optical system;
With the light source unit turned on, the adjustment mechanism is operated so that the image projected on the surface of the optical axis adjustment instrument matches the reference line, and the light source unit and the first optical system And (b) adjusting the relative positional relationship of the optical axis adjustment method for the light source device.

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