CN108180408B

CN108180408B - Relay lens and lighting system

Info

Publication number: CN108180408B
Application number: CN201711240073.8A
Authority: CN
Inventors: 刘健鹏; 郑昱
Original assignee: Journey Technology Ltd
Current assignee: Journey Technology Ltd
Priority date: 2017-11-30
Filing date: 2017-11-30
Publication date: 2020-11-03
Anticipated expiration: 2037-11-30
Also published as: CN108180408A

Abstract

The invention discloses a relay lens and an illumination system. The relay lens includes a first portion and a second portion. The first incident surface of the first part is a plane perpendicular to the light path, and the first emergent surface of the first part is a convex spherical surface. The second part is located at the center of the first part, a second incident surface of the second part is a plane perpendicular to the optical path, and the curvature of a second exit surface of the second part is smaller than that of the first exit surface. Because there is no strict requirement on whether the illumination light at the central position is collimated into parallel light, when the curvature of the second emergent surface of the second part at the central position of the first part is smaller than that of the first emergent surface of the first part, the rise of the relay lens can be reduced on the premise of not influencing the illumination effect, and therefore the total length of the relay lens is reduced.

Description

Relay lens and lighting system

Technical Field

The invention relates to the field of illumination, in particular to a relay lens and an illumination system.

Background

The miniaturization of the optical path structure is a trend of the development of optical instruments, and especially in the field of illumination of wearable devices, the demand of the miniaturized optical instruments is stronger. However, miniaturization of the optical path generally requires novel optical elements such as aspheric surfaces, fresnel lenses, and binary optical lenses. The difficulty of processing these lens elements is high compared to spherical lens elements, which is represented by the complexity of the required processing and inspection equipment, which increases the cost and processing cycle of such elements.

Fig. 1 is a schematic diagram of a relay lens in a lighting system of a prior art wearable device. The relay lens is a spherical lens, the direction A in the figure is the length direction of the relay lens, and f represents the rise of the relay lens. The light rays emitted by each point on the light source B are refracted by the relay lens and then become parallel light. Generally, in order to make better use of the light emitted from the light source, the acceptance angle of the relay lens needs to be as large as possible, which results in a larger rise of the relay lens. The rise largely determines the total length of the relay lens, so reducing the rise of the lens is an important means to reduce the relay lens.

Disclosure of Invention

The embodiment of the invention provides a relay lens and an illuminating device. The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed embodiments. This summary is not an extensive overview and is intended to neither identify key/critical elements nor delineate the scope of such embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

In a first aspect, an embodiment of the present invention provides a relay lens, where the relay lens includes: a first portion and a second portion;

the first incident surface of the first part is a plane perpendicular to the optical path; the first exit surface of the first part is a convex spherical surface;

the second portion is located at the center of the first portion; a second incident surface of the second portion is a plane perpendicular to the optical path; the curvature of the second exit surface of the second portion is smaller than the curvature of the first exit surface.

Based on the relay lens, as an optional first embodiment, the second portion is a through hole located at a central position of the first portion;

the second emergent surface is a plane and is parallel to the second incident surface.

Based on the relay lens, as a second optional embodiment, the second exit surface is a concave spherical surface.

Based on the relay lens, as a third optional embodiment, the second exit surface is a plane and is parallel to the second incident surface.

Based on the second embodiment and the third embodiment, as an optional fourth embodiment, the refractive index of the material of the second portion is greater than or less than the refractive index of the material of the first portion.

Based on the relay lens and any one of the first to third embodiments, as an optional fifth embodiment, a maximum cross-sectional dimension of the second exit surface is obtained as follows:

calculating the corresponding relation between the different section sizes of the second emergent surfaces and the illumination efficiency and illumination uniformity;

and selecting a dimension corresponding to a case where any one of the illumination efficiency and the illumination uniformity reaches a set minimum value as a maximum cross-sectional dimension of the second emission surface.

In a second aspect, embodiments of the present invention provide a lighting system, including: a light source and a relay lens;

the relay lens comprises a first part and a second part;

Based on the lighting system, as an alternative first embodiment, the second part is a through hole located at the center of the first part;

Based on the illumination system, as an optional second embodiment, the second exit surface is a concave spherical surface.

Based on the illumination system, as a third optional embodiment, the second exit surface is a plane and is parallel to the second incident surface.

The technical scheme provided by the embodiment of the invention has the following beneficial effects:

because there is no strict requirement on whether the illumination light at the central position is collimated into parallel light, when the curvature of the second emergent surface of the second part at the central position of the first part is smaller than that of the first emergent surface of the first part, the rise of the relay lens can be reduced on the premise of not influencing the illumination effect, and therefore the total length of the relay lens is reduced.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a schematic diagram of a relay lens in a lighting system of a prior art wearable device;

FIG. 2 is a cross-sectional view of a relay lens in an exemplary embodiment;

FIG. 3 is a schematic diagram of the optical path of a relay lens in an exemplary embodiment;

FIG. 4 is a cross-sectional view of a relay lens in an exemplary embodiment;

fig. 5 is a cross-sectional view of a relay lens in an exemplary embodiment.

Detailed Description

The following description and the drawings sufficiently illustrate specific embodiments of the invention to enable those skilled in the art to practice them. The examples merely typify possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in or substituted for those of others. The scope of embodiments of the invention encompasses the full ambit of the claims, as well as all available equivalents of the claims. Embodiments may be referred to herein, individually or collectively, by the term "invention" merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept if more than one is in fact disclosed. Herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed. The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the structures, products and the like disclosed by the embodiments, the description is relatively simple because the structures, the products and the like correspond to the parts disclosed by the embodiments, and the relevant parts can be just described by referring to the method part.

In an exemplary embodiment, the relay lens includes a first portion and a second portion.

The first incident surface of the first portion is a plane perpendicular to the optical path; the first exit surface of the first part is a convex spherical surface.

The second portion is located at the center of the first portion; the second incident surface of the second portion is a plane perpendicular to the optical path; the curvature of the second emission surface of the second portion is smaller than the curvature of the first emission surface.

The light path refers to the direction of light from the light source to the object to be irradiated.

Since there is no strict requirement on whether the illumination light at the central position in the illumination system is collimated into parallel light, when the curvature of the second exit surface of the second portion located at the central position of the first portion in the relay lens in the exemplary embodiment is smaller than the curvature of the first exit surface of the first portion, the rise of the relay lens can be reduced on the premise of not affecting the illumination effect, thereby reducing the total length of the relay lens.

Fig. 2 is a cross-sectional view of a relay lens in an exemplary embodiment. The relay lens includes a first portion 21 and a second portion 22.

The first incident surface 211 of the first section 21 is a plane perpendicular to the optical path. The first exit surface 212 of the first section 21 is a convex spherical surface.

The second portion 22 is located at the center of the first portion 21. The second incident surface 221 of the second portion 22 is located on a plane perpendicular to the optical path, and the second exit surface 222 of the second portion 22 is a plane and parallel to the second incident surface 221.

Fig. 3 is a schematic diagram of an optical path of a relay lens in an exemplary embodiment. The dotted line in fig. 3 represents an optical axis, the direction of which coincides with the optical path. 3 representative light source points are selected, where 201 is the center point and 202 and 203 are the upper and lower two edge points.

Rays

2013, 2014, 2015 and 2016 emitted by 201 are collimated by the relay lens into parallel rays, and

rays

2011, 2012, 2017 and 2018 emitted by 201 are directly transmitted from the second portion 22 without turning. 202 are collimated by the relay lens into parallel rays, but at an angle to the optical axis.

Light rays

2031 and 2032 emitted by 203 are collimated by the relay lens to be parallel rays, but at an angle to the optical axis.

As an alternative embodiment, the material of the second portion 22 may be the same as or different from the material of the first portion 21. The dotted line in fig. 2 is only to illustrate the boundary between the first portion 21 and the second portion 22, and when the materials of the second portion 22 and the first portion 21 are the same, the second portion 22 and the first portion 21 may be a unitary structure.

It can be seen that, compared to the relay lens shown in fig. 1, the relay lens in the exemplary embodiment is equivalent to grinding the central portion of the emergent side, so that the light of the light source at the central portion is not turned but directly transmitted to the illuminated area, and on the premise of not affecting the illumination effect, the rise of the relay lens is reduced, thereby reducing the total length of the relay lens.

The choice of the size of the second exit face 222 can be derived statistically.

The light source and the conventional relay lens shown in fig. 1 are used as initial models, and the correspondence between the ground size and the illumination efficiency and uniformity is counted. Assuming that the ground-out dimensions are calculated in proportion to the overall dimensions of the initial model, the illumination efficiency is calculated in relative light intensity, a portion of the statistical data is reported in table one below.

Watch 1

Relative grind off size (%)	Relative light intensity (%)	Uniformity (%)
			0	100	88.3
1.7	100	87.43
			3.3	98.5	86.7
5	95.5	86.2
			8.3	90.0	86.9
10	86.6	86.6

According to the statistical data shown in table one, the relative light intensity drops to 90% of the non-polished level when the relative abraded size is 8.3%, while the uniformity is substantially unchanged. Thus, the relative intensity of 90% can be taken as the set minimum, and the corresponding maximum relative rub-off dimension is 8.3%.

Fig. 4 is a block diagram of a relay lens in an exemplary embodiment. The relay lens includes a first portion 41 and a second portion 42.

The first incident surface 411 of the first portion 41 is a plane perpendicular to the optical path. The first exit surface 412 of the first part 41 is a convex spherical surface.

The second portion 42 is located at the center of the first portion 41. The second incident surface 421 of the second portion 42 is located on a plane perpendicular to the optical path, and the second exit surface 422 of the second portion 42 is a concave spherical surface.

In the present exemplary embodiment, since the second emitting surface 422 is a concave spherical surface, after the light of the light source is emitted from the second emitting surface 422, a light spot distribution with a dark center and a bright edge is formed, and the set lighting requirement is met. Compared with the relay lens shown in fig. 1, the relay lens is equivalent to the central part on the emergent side, and the rise of the relay lens is reduced on the premise of not influencing the illumination effect, so that the total length of the relay lens is reduced.

In an alternative embodiment, the refractive index of the material of the second portion 42 may be higher or lower than the refractive index of the first portion 41, or may be the same as the refractive index of the first portion 41.

As an alternative embodiment, to match the set illumination requirements of different spot distributions, second exit surface 422 may also be a spherical surface, a parabolic surface, a hyperbolic surface, a cylindrical surface, etc. with a curvature smaller than that of first exit surface 412.

The selection of the cross-sectional dimension of the second exit surface 422 can still be obtained in the statistical manner described above, and will not be described herein again. The cross section refers to a plane perpendicular to the optical path.

Fig. 5 is a block diagram of a relay lens in an exemplary embodiment. The relay lens includes a first portion 51 and a second portion 52.

The first incident surface 511 of the first portion 51 is a plane perpendicular to the optical path. The first exit surface 512 of the first part 51 is a convex spherical surface.

The second portion 52 is a through hole located at the center of the first portion 31. At this time, the second incident surface 521 and the second exit surface 522 of the second portion 52 are both planar and parallel to each other.

It can be seen that, compared to the relay lens shown in fig. 1, the relay lens in the present exemplary embodiment, equivalently, the central portion of the first portion 41 is removed, so that the light of the light source in the central portion is not turned, but directly transmitted to the illuminated area, and on the premise of not affecting the illumination effect, the rise of the relay lens is reduced, thereby reducing the total length of the relay lens.

The size of the second exit surface 522 may still be statistically selected, and will not be described here.

In an exemplary embodiment, a lighting system includes: a light source and a relay lens. The structure of the relay lens may be that of any of the exemplary embodiments described above. Because there is no strict requirement on whether the illumination light at the central position is collimated into parallel light, when the curvature of the second emergent surface of the second part at the central position of the first part is smaller than that of the first emergent surface of the first part, the rise of the relay lens can be reduced on the premise of not influencing the illumination effect, and therefore the total length of the relay lens is reduced.

It is to be understood that the present invention is not limited to the procedures and structures described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims

1. A relay lens, characterized in that the relay lens comprises a first part and a second part; the first incident surface of the first part is a plane perpendicular to the optical path; the first exit surface of the first part is a convex spherical surface;

the second portion is located at the center of the first portion; a second incident surface of the second portion is a plane perpendicular to the optical path; the curvature of the second exit surface of the second portion is smaller than the curvature of the first exit surface of the first portion;

the maximum cross-sectional dimension of the second emergent surface is obtained by the following steps:

2. The relay lens according to claim 1, wherein the second portion is a through hole located at a central position of the first portion;

3. The relay lens of claim 1, wherein the second exit surface is a concave spherical surface.

4. The relay lens of claim 1, wherein the second exit surface is planar and parallel to the second entrance surface.

5. The relay lens of claim 3 or 4, wherein the refractive index of the material of the second portion is greater than or less than the refractive index of the material of the first portion.

6. An illumination system, characterized in that the illumination system comprises: a light source and a relay lens;

the relay lens comprises a first part and a second part;

the second portion is located at the center of the first portion; a second incident surface of the second portion is a plane perpendicular to the optical path; the curvature of the second exit surface of the second portion is smaller than the curvature of the first exit surface;

7. The illumination system of claim 6, wherein the second portion is a through hole located at a central position of the first portion;

8. The illumination system of claim 6, wherein the second exit surface is a concave spherical surface.

9. The illumination system of claim 6, wherein the second exit surface is planar and parallel to the second entrance surface.