Lenses and optical system devices

Abstract

The object of the present invention is to provide a lens and an optical system device capable of measuring the optical properties of a light source or optical element with a simple structure. The lens (1) has an optical axis and includes an incident surface (F) and an exit surface (B). The incident surface (F) and the exit surface (B) are configured such that light incident from a first position (O) at an illumination angle (θ) relative to the optical axis onto the incident surface (F) is refracted by the incident surface (F) and the exit surface (B) and exits from the exit surface (B) at an exit angle θ / m (m>1) relative to the optical axis. The apparent position of the light exiting from the exit surface (B) all starts from a second position (P). In addition, the optical system device includes the lens (1) and a diffuser plate for diffusing the light emitted from the lens (1).

Description

TECHNICAL FIELD

[0001] The present application relates to a lens and an optical system device using the same. BACKGROUND

[0002] In recent years, light sources use light emitting elements such as LEDs. In addition, in order to control the light of various light sources, optical elements such as a microlens array (MLA), a diffractive optical element (DOE), and the like have been developed. Such light emitting elements or optical elements need to evaluate their optical characteristics such as orientation.

[0003] As this evaluation method, for example, there is a method of rotating a light source or a photographing portion using a goniometer and measuring the luminosity at the angle using a sensor. In this case, the measurement itself is relatively easy, but there is a problem that since the measurement itself is performed in points, a long time is required to acquire one distribution of light. In addition, there is a problem that the price of the goniometer is high (for example, Patent Literature 1).

[0004] PRIOR ART DOCUMENT

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 2016-151438 SUMMARY

[0007] Therefore, a method of causing light emitted from a light emitting element or an optical element to be radiated to a visualization plate to observe the orientation thereof is considered. In this case, one orientation data can be measured in a short time, but there is a problem that the light whose distribution of light angle is large cannot be measured because the distribution of light angle that can be radiated to the visualization plate is limited.

[0008] Therefore, an object of the present application is to provide a lens and an optical system device capable of measuring the optical characteristics of a light source or an optical element with a simple structure.

[0009] The lens of the present application has an optical axis, includes an incident surface and an exit surface, and is characterized in that the incident surface and the exit surface are formed so that light incident to the incident surface from a first position at an irradiation angle θ with respect to the optical axis is refracted by the incident surface and the exit surface to be emitted from the exit surface at an exit angle θ / m (m > 1) with respect to the optical axis, and the visual position of the light emitted from the exit surface all starts from a second position.

[0010] In this case, the incident surface is shaped so that the light incident from the first position at the irradiation angle θ is refracted so as to be radiated to the intersection of the exit surface in the direction of the angle θ / m from the second position, and the exit surface is shaped so that the light radiated from the first position via the incident surface is refracted in the direction of the exit angle θ / m.

[0011] In addition, m can be set to an arbitrary value greater than 1, preferably m > 2 is more preferable. Specifically, if set to m = 2, the exit angle can be made half of the incident angle.

[0012] In addition, the optical system device of the present application, characterized by comprising: a lens formed so that light incident at an incident angle θ with respect to an optical axis from a first position is emitted at an exit angle θ / m (m > 1) with respect to the optical axis, and the visual position of the emitted light is all from a second position; and a diffusion plate that diffuses light emitted from the lens.

[0013] In this case, it can also be that there is a wavelength selection filter that transmits only light of a specific wavelength.

[0014] In addition, it can also be that there is a shooting element that detects light from the diffusion plate.

[0015] In addition, it can also be that there is an electronic shutter that adjusts the time of light incident to the shooting element.

[0016] In addition, it can also be that there is a calculation unit that calculates the orientation characteristic based on information of light detected by the shooting element.

[0017] In addition, it can also be that there is a display device that displays the orientation characteristic of light detected by the shooting element.

[0018] In addition, it can also be that there is an anti-reflection member that is disposed in parallel with the optical axis of the lens around the diffusion plate, and absorbs light incident from the diffusion plate.

[0019] In addition, it can also be that there is a light source that irradiates light to the first position.

[0020] In addition, it can also be that there is an imaging lens for imaging light of the light source to be irradiated to the first position.

[0021] In addition, it can also be that there is a polarization filter that transmits only light polarized in a specific direction.

[0022] The lens can use the lens of the present application described above.

[0023] Effects of the Invention

[0024] The lens of the present application can make the light distribution angle of light from a light source or an optical element 1 / m (m > 1). Therefore, the optical system device of the present application using this lens can measure the optical characteristics of the light source or the optical element with a simple structure. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1is a diagram for explaining the lens of the present application.

[0026] Figure 2 is a diagram for explaining the manufacturing method of the lens of the present application.

[0027] Figure 3 is a diagram for explaining the manufacturing method of the lens of the present application.

[0028] Figure 4 is a diagram showing an outline sectional view of an optical system device of the present application.

[0029] Figure 5 is a diagram showing an outline sectional view of another optical system device of the present application.

[0030] Figure 6 is a diagram showing an outline sectional view of another optical system device of the present application.

[0031] BRIEF DESCRIPTION OF DRAWINGS

[0032] F incident surface

[0033] B exit surface

[0034] O first position

[0035] P second position

[0036] 1 lens

[0037] 2 diffusion plate

[0038] 3 wavelength selection filter

[0039] 4 imaging element

[0040] 5 antireflection member

[0041] 6 light source

[0042] 7 imaging lens

[0043] 100 measurement object DETAILED DESCRIPTION

[0044] Hereinafter, the lens 1 of the present application will be explained. As shown in Figure 1 the lens 1 of the present application has an optical axis and mainly includes an incident surface F and an exit surface B.

[0045] The incident surface F and the exit surface B cause light incident from position 1 O at an angle θ relative to the optical axis to exit from the exit surface B through refraction at an exit angle θ / m (m > 1) relative to the optical axis. Here, m can be 2 or more, and even 3 or more. Specifically, if m = 2, the exit angle can be half the incident angle. Furthermore, the incident surface F and the exit surface B are configured such that the apparent position of all light rays exiting from the exit surface B starts from position 2 P. Here, the apparent position (position 2 P) refers to the position of the point where the light ray exiting from the exit surface B intersects the optical axis when the ray extends along the optical axis direction.

[0046] In more detail, the incident surface F is shaped such that light incident from position 1 O at an angle θ is refracted at the intersection of the exit surface B and the direction from position 2 P at an angle θ / m.

[0047] Furthermore, the exit surface B has the following shape: so that the light incident from position 1 O via the incident surface F is refracted in the direction of the exit angle θ / m.

[0048] The incident surface F and the exit surface B can be formed arbitrarily, for example, in the following manner.

[0049] (1) As Figure 2 As shown, determine any first position O (origin) and the optical axis (x-axis) passing through that first position O.

[0050] (2) In the xy plane containing the optical axis ( Figure 2 In the paper, any position on the optical axis determines the point F0(f, 0) representing the incident surface F and the point B0(b, 0) representing the exit surface B.

[0051] (3) On the optical axis and on the side opposite to the incident plane F, the second position P(-p, 0) is determined.

[0052] (4) Define the small angles δα and δβ that have the relationship δβ=δα / m (m>1).

[0053] (5) The point group representing the incident surface F is sequentially named F0, F1, F2...F from the optical axis side. n (n is a natural number), the point group representing the exit surface B is sequentially named B0, B1, B2...B from the optical axis side. n (n is a natural number).

[0054] (6) is defined as F1=(f,ftan(δα)), B1=((b+l), (b+l)tan(δβ)).

[0055] (7) Since vectors OF1, F1B1, and LB1 are already determined, according to Snell's law, the inclination Φ of the incident plane F relative to the x-axis is such that ray OF1 is refracted and becomes ray F1B1. F1 And the tilt Φ of the exit surface B relative to the x-axis, which causes ray F1B1 to be refracted into ray LB1. B1 Sure.

[0056] Passing through point F1 and having an inclination Φ f The intersection point of the straight line and the straight line passing through point O and having an inclination of 2δα is F2.

[0057] Additionally, it passes through point B1 and has an inclination Φ. b The intersection point of the straight line and the straight line passing through point L with an inclination of 2δβ is B2.

[0058] (8) Since the vector OF was also determined through calculation, n-1 F n-1 B n-1 LB n-1 Therefore, according to Snell's law, the light ray OF n-1 It is refracted and becomes light ray F n-1 B n-1 The incident surface F is tilted Φ relative to the x-axis F(n-1) and to make light F n- 1B n-1 It is refracted and becomes light LB n-1 The tilt Φ of the exit surface B relative to the x-axis B(n-1) Sure.

[0059] Through point F n-1 And it has a tilt ΦF (n-1) The intersection point of the straight line and the straight line passing through point O and having an inclination of nδα is F. n .

[0060] Additionally, through point B n-1 And it has a tilt Φ B(n-1) The intersection point of the straight line and the straight line passing through point L and having an inclination of nδβ is B. n .

[0061] (9) By calculating the points F0, F1, F2...F... n (n is a natural number), B0, B1, B2...B n (n is a natural number) connecting these points can form an incident surface F and an exit surface B on the xy plane (refer to...) Figure 3 In addition, point F n With point B n Between, as long as it does not obstruct the light F n B n It can also be any shape.

[0062] (10) Rotate the planar shape thus formed about the optical axis to form the incident surface F and the exit surface B of the lens 1 of the present invention.

[0063] Furthermore, the lens 1 of the present invention may also have a portion that does not interfere with the incident surface F and the exit surface B, such as a support portion on the side for supporting the lens 1.

[0064] In addition, such as Figure 4 As shown, the optical system device of the present invention is a device for measuring the optical properties of the object to be measured 100, and mainly includes a lens 1 and a diffuser plate 2.

[0065] Here, the object being measured 100 refers to a self-emitting light-emitting element such as an LED, or an optical element such as a microlens array (MLA) or a diffractive optical element (DOE) that controls the emission of incident light. Of course, any device capable of emitting incident light is acceptable and is not limited to these.

[0066] Lens 1 is configured such that light incident from position 1 O at an illumination angle θ relative to the optical axis exits at an exit angle θ / m (m > 1) relative to the optical axis, and the apparent position of the exited light all begins from position 2 P. That is, the light distribution angle of the light from the light source 6 or the optical element is 1 / m (m > 1). Here, m can be set to 2 or more, and further, it can be set to 3 or more. This reduces the incident angle of the light irradiated onto the diffuser plate 2, and reduces the size of the diffuser plate 2. For example, if m = 2, the exit angle can be half the incident angle. The lens 1 of the present invention described above can be used as this lens.

[0067] The diffuser plate 2 diffuses the light emitted from the lens 1. As a result, the orientation of the three-dimensional light emitted from the lens 1 can be converted into a two-dimensional image.

[0068] Furthermore, the optical system device of the present invention may also include a wavelength selective filter 3. The wavelength selective filter 3 is an optical element that allows only light of a specific wavelength to pass through while blocking light of wavelengths other than that specific wavelength. Knowing the wavelength of the light detected from the object being measured, the measurement can be performed by using the wavelength selective filter 3, which allows only that light to pass through, thus eliminating other light that acts as noise. The wavelength selective filter 3 is disposed between the object being measured 100 and the imaging element 4, preferably between the diffuser plate 2 and the imaging element 4, and more preferably in front of the imaging element 4, in a manner that prevents light of wavelengths other than that specific wavelength from entering the imaging element 4. Examples of wavelength selective filters 3 include bandpass filters, long-pass filters, short-pass filters, and color filters.

[0069] Furthermore, in order to capture optical characteristics as data rather than visually, the optical system device of the present invention can also be as follows: Figure 4 It has other devices such as a camera element 4 or a processing unit, as shown.

[0070] The imaging element 4 detects light from the diffuser plate 2. As this imaging element 4, a solid-state imaging element 4, such as a CCD image sensor or a CMOS image sensor, can be used, which converts an image into an electrical signal. In addition to visible light, the imaging element 4 can also use a device sensitive to infrared, ultraviolet, or X-rays. Furthermore, the imaging element 4 can also be equipped with an electronic shutter or similar device that adjusts the time it takes for light to be incident on it.

[0071] The processing unit calculates orientation characteristics based on information about the light detected by the imaging element 4. For example, the light detected by the imaging element 4 may differ from the orientation characteristics of the actual object being measured due to errors caused by lens 1 deformation, errors caused by the angle of light incident on the diffuser 2 or the in-plane uniformity of the diffuser 2, or differences in light intensity between the diffuser 2 and the far field. The processing unit can also correct for these errors based on the information about the light detected by the imaging element 4 and calculate the actual orientation characteristics.

[0072] When correcting the distortion of lens 1, for example, a chessboard of known size is repositioned within the frame of the imaging element 4 to acquire various images. Then, the coordinates of the grid points are extracted from the images, and correction parameters are calculated based on the correspondence between the actual spatial coordinates and the camera coordinates. The processing unit can correct the distortion of lens 1 based on the light information detected by the imaging element 4 and the correction parameters, and calculate the actual orientation characteristics.

[0073] Furthermore, when correcting for errors caused by the angle of light incident on diffuser 2 or the in-plane uniformity of diffuser 2, for example, light is directly irradiated onto diffuser 2 from position P using a laser pointer, causing various changes in the position (x, y) of the light irradiating diffuser 2, and image data is acquired using imaging element 4. Then, based on the brightness of the laser pointer light, a correction coefficient K(x, y) is calculated, expressed by the following formula.

[0074] K(x, y) = Intensity of light at position (x, y) / Intensity of light from laser pointer

[0075] The processing unit can correct errors caused by the angle of light incident on the diffuser plate 2 or the in-plane uniformity of the diffuser plate 2 based on the light information detected by the imaging element 4 and the aforementioned correction coefficient K(x, y).

[0076] Furthermore, regarding the difference in light intensity between diffuser 2 and the far field, let the distance between the apparent light source and diffuser 2 be D, the distance from the optical axis on diffuser 2 be r, the incident angle of light from the light source toward lens 1 relative to the optical axis be θ, the incident angle of light from lens 1 toward diffuser 2 relative to the optical axis be θ / m, and the light intensity on diffuser 2 be I. r (r) Let the light intensity in the far field through lens 1 be I' θ When (θ / m), the following formula holds true.

[0077]

[0078] Additionally, let the light intensity in the far field when not passing through lens 1 be I. θ When (θ),

[0079]

[0080] Therefore, the following equation holds true.

[0081]

[0082] Therefore, the processing unit can correct the difference in light intensity between the diffuser plate 2 and the far field based on the light information detected by the imaging element 4 and the above formula.

[0083] The display unit displays the orientation characteristics of the light detected by the imaging element 4. This allows for easy confirmation of the orientation characteristics of the object being measured 100. A known display can be used as the display unit.

[0084] Furthermore, light diffused by the diffuser plate 2, other than the light directly incident on the imaging element 4, can become noise when it is reflected or incident on the imaging element 4. Therefore, the optical system device of the present invention preferably includes an anti-reflection member 5, which is arranged parallel to the optical axis of the lens 1 around the diffuser plate 2 and absorbs the light incident from the diffuser plate 2. As long as the anti-reflection member 5 absorbs the light incident from the diffuser plate 2, it is possible to prevent the light from being reflected and incident on the imaging element 4.

[0085] Furthermore, this is unnecessary when the object being measured 100 is self-illuminating, such as a light-emitting element. However, it is necessary when the object being measured 100 is an optical element such as a microlens array (MLA) or a diffractive optical element (DOE). Figure 5 As shown, a light source 6 is required to illuminate the object being measured 100. This light source 6 can be any device, as long as it can illuminate the object being measured 100 positioned at the first position O; for example, a vertical-cavity surface-emitting laser (VCSEL) can be used. Furthermore, the distance between the light source 6 and the first position O can be arbitrary, as long as it allows light to be illuminated within the measurement range of the object being measured 100.

[0086] Furthermore, it is preferable that all objects being measured, such as microlens arrays, are inspected during mass production. In this case, the position of the object being measured 100 relative to the light source 6 is controlled using actuators or the like, but the possibility of contact is high when the distance between the light source 6 and the object being measured 100 is close. Therefore, as... Figure 6 As shown, the optical system device of the present invention may also include an imaging lens 7 for imaging the light from the light source 6 and illuminating the first position O. If the light from the light source 6 is illuminating the first position O via the imaging lens 7, the distance between the light source 6 and the object to be measured 100 can be reduced. Furthermore, the distance between the imaging position and the first position O can be arbitrary, as long as light can be illuminating the measurement range of the object to be measured 100.

[0087] A polarizing filter is an optical element that allows only light polarized in a specific direction to pass through. When the object being measured is a component that polarizes light in a specific direction, such as a polarizer or a phase difference element, a polarizing filter allows only light polarized in the specified direction to be measured. The polarizing filter may also have a rotation unit for rotating it. The polarizing filter can be positioned between the object being measured 100 and the imaging element 4, preferably between the diffuser plate 2 and the imaging element 4, and more preferably in front of the imaging element 4, in a manner that prevents light other than light polarized in the specific direction from incident on the imaging element 4.

Claims

1. An optical system device, characterized by comprising: The optical system device is used for measuring optical characteristics of a measurement object, comprising: a lens formed so that light incident from a first position at an incident angle θ with respect to an optical axis is emitted at an emission angle θ / m (m > 1) with respect to the optical axis, and the apparent position of the emitted light is all from a second position; a diffusion plate diffusing the light emitted from the lens, converting the light distribution of the three-dimensional light emitted from the lens into a two-dimensional image; and a shooting element detecting the light from the diffusion plate.

2. The optical system device according to claim 1, characterized in that: a wavelength selection filter is provided which transmits only light of a specific wavelength.

3. The optical system device according to claim 1, characterized in that: an electronic shutter is provided which adjusts the time of light incident to the shooting element.

4. The optical system device according to claim 2, characterized in that: an electronic shutter is provided which adjusts the time of light incident to the shooting element.

5. The optical system device according to any one of claims 1 to 4, characterized in that: an arithmetic unit is provided which calculates an orientation characteristic based on information of the light detected by the shooting element.

6. The optical system device according to any one of claims 1 to 4, characterized in that: a display device is provided which displays the orientation characteristic of the light detected by the shooting element.

7. The optical system device according to any one of claims 1 to 4, characterized in that: an anti-reflection member is provided which is arranged in parallel with the optical axis of the lens around the diffusion plate, and absorbs the light incident from the diffusion plate.

8. The optical system device according to any one of claims 1 to 4, characterized in that: a light source is provided which irradiates light to the first position.

9. The optical system device according to claim 8, characterized in that: an imaging lens is provided which images the light of the light source to be irradiated to the first position.

10. The optical system device according to any one of claims 1 to 4, characterized in that: a polarization filter is provided which transmits only light polarized in a specific direction.

11. The optical system device according to any one of claims 1 to 4, characterized in that: the lens has an optical axis, and includes an incident surface and an emission surface, the incident surface and the emission surface are formed so that light incident from a first position at an incident angle θ with respect to the optical axis to the incident surface is emitted from the emission surface at an emission angle θ / m (m > 1) with respect to the optical axis by refraction of the incident surface and the emission surface, and the apparent position of the light emitted from the emission surface is all from a second position.

12. The optical system device according to claim 11, characterized in that: the incident surface is shaped so that the light incident from the first position at the incident angle θ is refracted so as to be incident to the intersection of the emission surface in a direction of angle θ / m from the second position, the emission surface is shaped so that the light incident from the first position via the incident surface is refracted in a direction of the emission angle θ / m.

13. The optical system device according to claim 11, characterized in that: m≥2。

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