Spectroscopic measurement device

Abstract

To enable evaluation of the spectral characteristics in the entire virtual image by receiving the entire virtual image by using a spectroscopic measurement device.SOLUTION: A spectroscopic measurement device 1 is capable of performing spectral measurement of a virtual image visually perceived by a user through image light emitted from a virtual image display device 100. The spectroscopic measurement device 1 includes: an imaging optical system 10 that forms an image of the image light; an aperture 40 that serves as the entrance pupil which is arranged at the position of the exit pupil where the entire image light is converged by a virtual image forming optical system 110 of the virtual image display device 100, and located on a front surface of the lens of the imaging optical system 10; a spectroscopic element 20 that disperses light passing through the aperture 40; and an image sensor 30 that captures the spectrally dispersed light from the spectroscopic element 20. The device performs spectral measurement of all virtual images formed by the image light.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a photometric device, and more particularly to a spectroscopic measurement device.

Background Art

[0002] In recent years, devices capable of expressing AR (augmented reality) / VR (virtual reality) have become widespread. These devices are devices that allow the user to view a virtual image. As an optical property measurement device for such a virtual image display device, the following document is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the optical property device disclosed in Patent Document 1, only a part of the spots of the virtual image could be measured, and the entire virtual image could not be measured. Further, in addition to the first aperture portion, this optical property device has a second aperture portion inside the device, and thus a part of the virtual image is blocked by the second aperture portion, and the entire virtual image cannot be measured.

[0005] Therefore, at least one of the problems of the present disclosure is to receive the entire virtual image using a spectroscopic measurement device and enable evaluation of the spectroscopic characteristics of the entire virtual image.

[0006] Note that, for those skilled in the art who can read from the embodiments and the descriptions thereof that are characteristic of the present disclosure described in the specification, drawings, etc. of the present disclosure, problems that are obvious may also become problems to be solved by the divided inventions when a divisional application is filed based on the present disclosure.

Means for Solving the Problems

[0007] In order to achieve at least one of the above-described objects, a spectroscopic measurement apparatus according to an embodiment of the present disclosure is a spectroscopic measurement apparatus that performs spectroscopic measurement of a virtual image visually recognized by a user with image light emitted from a virtual image display device, and includes an imaging optical system that forms an image of the image light, a diaphragm that is disposed at a position of an exit pupil where the entire image light is condensed by a virtual image imaging optical system of the virtual image display device and serves as an entrance pupil located in front of a lens of the imaging optical system, a spectroscopic element that spectrally disperses the light that has passed through the diaphragm, and an image sensor that receives the spectroscopically dispersed light, and performs spectroscopic measurement of all virtual images formed by the image light.

Advantages of the Invention

[0008] According to the present disclosure, it is possible to receive the entire virtual image using a spectroscopic measurement apparatus and evaluate the spectroscopic characteristics of the entire virtual image.

Brief Description of the Drawings

[0009]

Figure 1

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Modes for Carrying Out the Invention

[0010] <Introduction> In recent years, devices (virtual image display devices) that can represent AR (augmented reality) / VR (virtual reality) in which users can visually perceive virtual images have become widespread. Such virtual image display devices have an input device, a processing device, an image forming device, an imaging optical system, and a user wearing part such as a head mount. Then, image light emitted by an image forming device such as an organic EL display or a micro LED display allows a user to visually perceive a virtual image through the imaging optical system.

[0011] However, in the optical characteristic device disclosed in Patent Document 1, only some spots of the virtual image were measured, and in addition to the first aperture part, by having a second aperture part inside the device, the virtual image was blocked and the entire virtual image could not be measured. That is, at the time of the invention described in Patent Document 1, there was no technical idea that a two-dimensional entire image similar to the virtual image obtained by a human should be obtained and evaluated, nor was there a technical idea that the spectral characteristics of the entire image should be evaluated.

[0012] In a virtual image display device, complex and diverse optical systems may be used, and if there are wavelength-dependent optical elements in the optical path, an offset in the wavelength of the image light may also occur. Therefore, evaluation by spectral measurement is required. In particular, it is required to form an image and quantitatively evaluate it in the same way as the image that a human is visually perceiving. For such requirements, with only the measurement of spot light, it is not known where in the entire virtual image is being measured, and there is a deficiency as an evaluation method.

[0013] Therefore, in the present disclosure, it was considered to obtain an entire two-dimensional image of the image light that forms a virtual image and enable the evaluation of the spectral characteristics of the entire image. Hereinafter, the configuration for this purpose will be described.

[0014] Hereinafter, description will be made with reference to the drawings. However, the drawings do not necessarily reflect actual dimensions and are schematically represented.

[0015] <First Embodiment> FIG. 1 is an overall configuration diagram showing a measurement system combining a spectroscopic measurement device 1 according to an embodiment of the present disclosure and a virtual image display device 100 as a measurement object. The spectroscopic measurement device 1 includes at least an imaging optical system 10, a spectroscopic element 20, an image sensor 30, a diaphragm 40, and a housing 50 that houses them. Further, if necessary, a first relay optical system 60 and a second relay optical system 70, which will be described later, may be provided.

[0016] The spectroscopic measurement device 1 has various spectroscopic measurement functions such as a spectroscopic radiometer and a spectroscopic camera. The light incident from the imaging optical system 10 is split into a plurality of wavelengths by the spectroscopic element 20 and forms an image on the light receiving surface of the image sensor 30, so that images for each of the plurality of wavelengths can be acquired.

[0017] The virtual image display device 100 includes an image forming unit 120, a virtual image forming optical system 110, a housing 130, etc., and the illustration of other configurations is omitted. The image forming unit 120 is an image forming device such as a light emitting device such as an organic EL display, a micro LED display, or a liquid crystal display.

[0018] Further, when the virtual image display device 100 is in a pass-through format such as AR and superimposes a virtual image on a real image for display, the image forming unit 120 does not have to be arranged on the optical axis, and a half mirror, a light guiding member, an optical diffraction element, etc. may be used to guide image light to the user from a position different from the optical axis.

[0019] Further, the virtual image forming optical system 110 is usually provided individually corresponding to each of a human left eye and right eye, but in the spectroscopic measurement device 1, they may be measured one eye at a time.

[0020] The image light emitted from the image forming unit 120 is emitted to the outside of the housing 130 through the virtual image forming optical system 110 of the virtual image display device 100.

[0021] Here, the virtual image display device 100 and the spectroscopic measurement device 1 have their separation distance appropriately maintained by a holding device or an alignment tool (not shown). The appropriate distance mentioned here is, for example, a positional relationship in which the exit pupil of the image light emitted from the virtual image display device 100 coincides with the entrance pupil, which is the aperture 40 of the imaging optical system 10 of the spectroscopic measurement device 1.

[0022] Since the position of the exit pupil of the virtual image display device 100 is generally around 15 mm, the position of the entrance pupil of the imaging optical system 10 of the spectroscopic measurement device 1 is in front of the lens or within 20 mm from the lens tip. Therefore, the position of the aperture 40 is also set to a corresponding position.

[0023] The aperture 40 may be, for example, an aperture provided with an opening in a member that blocks light, or a mechanical aperture such as a pinhole. This aperture 40 is arranged so as to correspond to the position of the entrance pupil of the imaging optical system 10 of the spectroscopic measurement device 1. Considering that the pupil diameter of this entrance pupil is equivalent to that of a human pupil, it is equal to or slightly larger than the pupil diameter of the exit pupil of the virtual image display device 100. Specifically, the pupil diameter by the aperture 40 is preferably, for example, 2 to 8 mm in diameter, and more preferably 3 to 5 mm. Thereby, the entire image light forming the virtual image can be captured.

[0024] The imaging optical system 10 has an angle of view greater than or equal to that of the virtual image display device 100 and has a function of imaging the image light emitted from the virtual image display device 100. Although not shown, the imaging optical system 10 may have a lens group in which a plurality of lenses are arranged along the optical axis X. Thereby, all the virtual images formed by the light passing through the position of the exit pupil of the virtual image display device 100 are captured and imaged at a predetermined position. The light that has passed through the imaging optical system 10 is guided to the first relay optical system 60.

[0025] The first relay optical system 60 is an optical system for shaping the light that has passed through the imaging optical system 10 into a light beam within an appropriate range for the spectroscopic element 20. For example, the light beam from the imaging optical system 10 is made into a parallel light beam heading towards the spectroscopic element 20. Although not shown, the first relay optical system 60 may have a lens group in which a plurality of lenses are arranged along the optical axis X.

[0026] The spectroscopic element 20 has a function of splitting the light guided from the imaging optical system 10 into a plurality of wavelengths. The spectroscopic element 20 is, for example, a transmission wavelength change type filter such as a linear variable filter (LVF), a grating element, a prism, or the like. With this spectroscopic element 20, it is possible to acquire an image by selecting the wavelength every 1 nm.

[0027] Specifically, the LVF can extract spectroscopically split light of a plurality of wavelengths with a single filter, has different thicknesses in the direction of rotation or slide movement, and the transmission wavelength changes due to this change in thickness. Therefore, it is possible to change the central wavelength of the output light of the entire two-dimensional image by moving the LVF using a driving mechanism such as a motor. Also, since the transmittance of the transmission wavelength is high and the blocking rate for wavelengths other than the transmission wavelength is high, noise can be reduced by arranging it in front of the image sensor 30.

[0028] The second relay optical system 70 is an optical system for shaping the light split by the spectroscopic element 20 into an appropriate range for the image sensor 30. The light beam from the imaging optical system 10 is condensed to form a parallel light beam heading towards the spectroscopic element 20. Although not shown, the first relay optical system 60 may have a lens group in which a plurality of lenses are arranged along the optical axis X.

[0029] The image sensor 30 is an element in which a plurality of pixels are two-dimensionally arranged, and is an element such as a CMOS or a CCD, for example. The wavelengths to which the image sensor 30 is sensitive may be, for example, the visible light range for humans of 380 to 780 nm, or other wavelengths in the infrared or ultraviolet ranges. The image received by the image sensor 30 is converted into an electrical signal and outputs the electrical signal to the photometric control unit 80 that is electrically connected.

[0030] The photometric control unit 80 of the spectroscopic measurement device 1 can be realized by, for example, a general-purpose computer 3. For example, it is connected to a computer such as a PC (not shown), stores the measured data, and performs image processing using dedicated software installed on the PC or the like, and can generate data such as measurement results and images representing those measurement results. For example, it can generate data indicating the measurement results of the viewing angle characteristics described later.

[0031] By using such a spectroscopic measurement device 1, it is possible to acquire the entire two-dimensional image of the image light forming the virtual image and evaluate the spectroscopic characteristics of the entire image. In particular, in order to perform spectroscopic measurement of the entire virtual image with the image sensor 30, it is necessary to capture the entire virtual image, so it is important not to block the image light of the virtual image with the aperture.

[0032] FIG. 2 shows a schematic diagram showing a state where the image sensor receives the entire virtual image. In this figure, it schematically shows that the entire virtual image VI is included within the range of pixels where the image sensor 30 can form an image and the entire image is shown. Thus, if the entire virtual image can be captured, the spectroscopic image of the entire virtual image can be received. On the other hand, if only the spot light is captured, for example, like the spot region SP shown in this figure, only a part of the entire virtual image VI can be captured, and spectroscopic measurement of the entire virtual image cannot be performed.

[0033] <Second Embodiment> Hereinafter, a second embodiment different from the above-described first embodiment will be described. Since the second embodiment is different from the first embodiment only in the position of the aperture 40 serving as the entrance pupil, the description will be centered on the different points.

[0034] As shown in FIG. 3, in the second embodiment, the aperture 40 is arranged at the position of the exit pupil of the virtual image display device 100, similar to the first embodiment, but the front lens 11 is arranged in the previous stage on the object side thereof, and is arranged at a position where the distance L1 along the optical axis from the lens surface of the lens 11 to the aperture 40 is 20 mm or less.

[0035] As described above, since the exit pupil of the virtual image display device 100 can generally be set to around 15 mm, the position of the aperture 40 is set within a range of 20 mm or less from the lens surface of the front lens 11 and at a position corresponding to the exit pupil of the virtual image forming optical system 110.

[0036] Further, as in the first embodiment, the aperture diameter PD of the entrance pupil by the aperture 40 is preferably, for example, 2 to 8 mm in diameter, and more preferably 3 to 5 mm.

[0037] In this way, the position of the aperture 40 will be arranged closer to the image sensor 30 side, and the required optical performance of the imaging optical system 10 can be relaxed. For example, the number of lenses included in the lens group can be reduced, and the cost of the imaging optical system 10 can be lowered.

[0038] (Modification 1) In addition, a modification of the first embodiment will be described. As shown in FIG. 4, in Modification 1, the first relay optical system 60 is not arranged at the rear stage of the imaging optical system 10, and the second relay optical system 70 is arranged at the rear stage of the spectroscopic element 20. In this way, various relay optical systems may be appropriately arranged or not arranged according to the condensing of the light beam, and it is not an essential configuration. For such a modification, as in the case of the second embodiment described above, the first relay optical system 60 may not be arranged.

[0039] (Modification 2) In Modification 2 shown in FIG. 5, the virtual image display device 100 has an imaging optical system 10 that can be inserted from a direction substantially perpendicular to the optical axis X of the image light emitted by the virtual image display device 100. For example, a virtual image display device 100 such as an AR / VR device is often designed such that the shape of its housing 130 is in a head-mounted shape that annularly covers the human head, and the mounting portion 131 is designed to be abutted against the back of the head for mounting. In that case, on the extension of the optical system of the image light of the virtual image display device 100, a head mount indicated to the head of the user to be worn may be arranged, and this may interfere with the spectroscopic measurement device 1.

[0040]

[0041]

[0040]

[0042]

[0043]

[0044]

[0041] [1] It is arranged at the position of the exit pupil where the entire image light is condensed by the virtual image forming optical system of the virtual image display device, and is a diaphragm serving as an entrance pupil located in front of the lens of the imaging optical system, and a spectroscopic element that splits the light that has passed through the diaphragm, and an image sensor that receives the spectroscopic light split by the spectroscopic element, and is provided with a spectroscopic measurement device that performs spectroscopic measurement of all virtual images formed by the image light. [2] A spectroscopic measurement device that performs spectroscopic measurement of a virtual image visually observed by a user with image light emitted from a virtual image display device, an imaging optical system that forms the image light, and it is arranged at the position of the exit pupil where the entire image light is condensed by the virtual image forming optical system of the virtual image display device, and is a diaphragm serving as an entrance pupil located at a position 20 mm or less from the front surface of the lens of the imaging optical system, and a spectroscopic element that splits the light that has passed through the diaphragm, and an image sensor that receives the spectroscopic light split by the spectroscopic element, and is provided with a spectroscopic measurement device that performs spectroscopic measurement of all virtual images formed by the image light. [3] The spectroscopic measurement device according to [1] or [2], having the imaging optical system that can be inserted from a direction substantially perpendicular to the optical axis of the image light. [4] It includes a reflecting mirror that reflects light rays in a direction perpendicular to the optical axis of the imaging optical system, and The spectroscopic measurement device according to [3], wherein the image sensor is arranged at a position that receives the light reflected in the perpendicular direction. [5] The spectroscopic measurement device according to [1] or [2], including a relay optical system between the imaging optical system and the spectroscopic element, and between the spectroscopic element and the image sensor. [6] The spectroscopic measurement device according to [1] or [2], wherein the pupil diameter of the entrance pupil is equal to the pupil diameter of the exit pupil of the virtual image display device. [7] The spectroscopic measurement device according to [6], wherein the pupil diameters of the entrance pupil and the exit pupil are 2 to 8 mm.

Explanation of Symbols

[0045] 1 Spectrophotometer 3 PC 10 Imaging optical system 20 Spectral element 30 Image sensor 40 Diaphragm 50 Housing 60 First relay optical system 70 Second relay optical system 80 Photometry control unit 90 Reflecting mirror 100 Virtual image display device 110 Virtual image forming optical system 120 Image forming device 130 Housing 131 Mounting part X Optical axis X´ Optical axis

Claims

1. A spectroscopic measurement device that performs spectroscopic measurement of a virtual image visually perceived by a user with image light emitted from a virtual image display device, comprising: an imaging optical system that forms an image of the image light; a diaphragm that is disposed at the position of an exit pupil where the entire image light is condensed by the virtual image imaging optical system of the virtual image display device and serves as an entrance pupil located in front of the lens of the imaging optical system; a spectroscopic element that spectroscopically analyzes the light that has passed through the diaphragm; an image sensor that receives the spectroscopically analyzed light spectroscopically analyzed by the spectroscopic element, and performs spectroscopic measurement of all virtual images formed by the image light.

2. A spectroscopic measurement device that performs spectroscopic measurement of a virtual image visually perceived by a user with image light emitted from a virtual image display device, comprising: an imaging optical system that forms an image of the image light; a diaphragm that is disposed at the position of an exit pupil where the entire image light is condensed by the virtual image imaging optical system of the virtual image display device and serves as an entrance pupil located at a position 20 mm or less from the front surface of the lens of the imaging optical system; a spectroscopic element that spectroscopically analyzes the light that has passed through the diaphragm; an image sensor that receives the spectroscopically analyzed light spectroscopically analyzed by the spectroscopic element, and performs spectroscopic measurement of all virtual images formed by the image light.

3. The spectroscopic measurement device according to claim 1 or 2, having the imaging optical system that can be inserted from a direction substantially perpendicular to the optical axis of the image light.

4. Comprising a reflecting mirror that reflects light rays in a direction perpendicular to the optical axis of the imaging optical system, and the spectroscopic measurement device according to claim 3, wherein the image sensor is disposed at a position that receives the light reflected in the perpendicular direction.

5. The spectroscopic measurement device according to claim 1 or 2, comprising a relay optical system between the imaging optical system and the spectroscopic element, and between the spectroscopic element and the image sensor.

6. The spectroscopic measurement device according to claim 1 or 2, wherein the pupil diameter of the entrance pupil is equal to the pupil diameter of the exit pupil of the virtual image display device.

7. The spectroscopic measurement device according to claim 6, wherein the pupil diameters of the entrance pupil and the exit pupil are 2 to 8 mm.

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