Photometric device, colorimeter, colorimeter, and photometric method

Abstract

This optical device comprises: a photometry unit (12A); a first optical unit (11A); a photometry unit (12B); and a second optical unit (11B). The first optical unit (11A) includes: a first lens (22A) disposed closest to the object side; and a first prism (21A) that deflects light from a first site (AR1) and guides same to the first lens. The second optical unit (11B) includes: a second lens (22B) disposed closest to the object side; and a second prism (21B) that deflects light from a second site (AR2) and guides same to the second lens (22B). A first optical axis (AX1) of the first optical unit (11A) from a measurement object (1) to the first prism (21A) is substantially parallel to a second optical axis (AX2) of the second optical unit (11B) from the measurement object (1) to the second prism (21B); and the interval between the first optical axis (AX1) and the second optical axis (AX2) is smaller than the distance between the center of the first lens (22A) and the center of the second lens (22B).

Description

Technical Field

[0001] The present invention relates to an optical device, and a color luminance meter and a colorimeter using the same.

Background Art

[0002] Color luminance meters for measuring the color and luminance of light emitters, and colorimeters for measuring the color of objects are known. For example, color luminance meters are used to measure and adjust the optical characteristics of displays.

[0003] The size of a display varies depending on the size of the electronic device on which the display is mounted. If the size of the display to be measured is small, the measurement range for luminance and chrominance is also reduced. On the other hand, the amount of light emitted from a measurement region of an object under test decreases as the measurement range becomes smaller. For this reason, for example, optical devices for evaluating OLED (Organic Light Emitting Diode) displays are configured to be able to capture a larger amount of light from a small measurement range.

[0004] For example, International Publication No. 2011 / 121896 (Patent Document 1) discloses a measurement optical system for a color luminance meter or a colorimeter measurement optical system. In this measurement optical system, measurement light is split into a plurality of light beams, and each split light beam is received by a light-receiving sensor via an interference film filter. The measurement optical system has an objective lens for condensing light. This objective lens has a circular (φ=27 mm) measurement range.

[0005] International Publication No. 2018 / 230177 (Patent Document 2) discloses a measuring optical system for guiding a greater amount of light from an object to be measured to a light-receiving unit. This measuring optical system comprises an aperture, an optical waveguide for guiding incident light, a first optical system, and a second optical system. The first optical system is positioned on the object side of the aperture and forms an image of the light from the object to be measured onto the aperture surface of the aperture. The second optical system is positioned between the aperture and the optical waveguide and causes each principal ray of each light beam emitted from the aperture surface of the aperture to be incident into the optical waveguide so that each principal ray is parallel to the optical axis.

[0006] Japanese Patent Publication No. 2003-247891 (Patent Document 3) discloses an optical device for minimizing the unevenness of light emitted from multiple emission surfaces, even when the orientation characteristics of the object being measured are asymmetrical. This optical device includes an optical branching means. The optical branching means has multiple emission surfaces that branch and emit light from the object being measured that is incident on the incident surface. The incident surface of the optical branching means is divided into multiple incident regions. Light incident on multiple non-adjacent and different incident regions is emitted from each emission surface of the optical branching means. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] International Publication No. 2011 / 121896 [Patent Document 2] International Publication No. 2018 / 230177 [Patent Document 3] Japanese Patent Publication No. 2003-247891 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] In recent years, a technology called Under Screen Camera (USC) has been developed in the field of displays. USC is a technology that places a camera module on the back of the display. This technology is sometimes called Under Display Camera, but in this specification, we will refer to the relevant technology as "USC".

[0009] Devices employing USC (Ultrasonic Camera) have a configuration that makes it difficult to see the camera through the display. In such devices, the part of the display that overlaps with the camera (referred to as the USC section) has a different structure from the normal part of the display (hereinafter referred to as the normal section). Therefore, when adjusting the display's gamma, gamma adjustment is required for both the USC section and the normal section.

[0010] Furthermore, in order to shorten the cycle time, there is a demand to simultaneously measure the brightness of both the USC section and the normal section. However, there is a light emission distribution within the display surface. Therefore, it is desirable that the normal section to be measured be as close as possible to the USC section. Due to these circumstances, it is required to simultaneously measure the brightness of two closely located areas, such as the USC section and the normal section, with a distance of 10 mm between them.

[0011] Generally, two luminance meter probes are required to simultaneously measure the luminance of two parts of a light-emitting object. To simultaneously measure the luminance of two adjacent parts, the two luminance meter probes must be placed close together. However, due to physical size limitations, it is difficult to place existing luminance meter probes close together (for example, spaced 10 mm apart). On the other hand, if the size of each luminance meter probe is reduced to shorten the distance between them, the aperture of the lens closest to the object becomes smaller, thus reducing the amount of light captured by the luminance meter probe.

[0012] This invention was made in view of the above circumstances, and its object is to provide an optical device that enables the measurement of luminance in adjacent areas while maintaining brightness, as well as a colorimeter and colorimeter using the same. [Means for solving the problem]

[0013] To solve the above problems, an optical device according to one aspect of the present invention comprises a first photometric unit for receiving light from a first part of an object to be measured, a first optical unit, a second photometric unit for receiving light from a second part of an object to be measured, and a second optical unit. The first optical unit has a first lens, which is the lens closest to the object for focusing the light from the first part to the first photometric unit, and a first optical member for deflecting the light from the first part and guiding it to the first lens. The second optical unit has a second lens, which is the lens closest to the object for focusing the light from the second part to the second photometric unit, and a second optical member for deflecting the light from the second part and guiding it to the second lens. The optical axis of the first optical unit from the object to be measured to the first optical member and the optical axis of the second optical unit from the object to be measured to the second optical member are substantially parallel, and the distance between the optical axis of the first optical unit and the optical axis of the second optical unit is smaller than the distance between the center of the first lens and the center of the second lens.

[0014] A colorimeter and colorimeter according to another aspect of the present invention comprises the optical device described above. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide an optical device that enables measurement in close proximity while maintaining brightness, as well as a colorimeter and colorimeter using the same. [Brief explanation of the drawing]

[0016] [Figure 1] This is a block diagram showing a schematic configuration of a color luminance meter equipped with an optical device according to an embodiment of the present invention. [Figure 2]It is a block diagram showing a schematic configuration of a colorimeter equipped with an optical device according to an embodiment of the present invention. [Figure 3] It is a block diagram showing a configuration example of an optical device according to an embodiment of the present invention. [Figure 4] It is a schematic diagram showing an example of an object to be measured. [Figure 5] It is a diagram showing a configuration of an optical device according to Example 1 of the present invention. [Figure 6A] It is a perspective view of a parallelogram prism according to Example 1 of the present invention. [Figure 6B] It is a front view of the parallelogram prism according to Example 1 of the present invention. [Figure 6C] It is a top view of the parallelogram prism according to Example 1 of the present invention. [Figure 7] It is a diagram showing a state where two parallelogram prisms are arranged close to each other. [Figure 8] It is a diagram showing a configuration of an optical device according to Example 2 of the present invention. [Figure 9A] It is a perspective view of a parallelogram prism according to Example 2 of the present invention. [Figure 9B] It is a front view of the parallelogram prism according to Example 2 of the present invention. [Figure 9C] It is a top view of the parallelogram prism according to Example 2 of the present invention. [Figure 10] It is a diagram showing a configuration of an optical device according to Example 3 of the present invention. [Figure 11A] It is a perspective view of a triangular prism according to Example 3 of the present invention. [Figure 11B] It is a front view of the triangular prism according to Example 3 of the present invention. [Figure 11C] It is a side view of the triangular prism according to Example 3 of the present invention. Description of Embodiments

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference symbols, and description thereof will not be repeated.

[0018] Figure 1 is a block diagram showing a schematic configuration of a coloriluminance meter equipped with an optical device according to an embodiment of the present invention. In the embodiment shown in Figure 1, the object to be measured 1 is a light-emitting body, and may be, for example, a display or an electronic device equipped with a display. The coloriluminance meter 101 according to one embodiment of the present invention can measure the color and brightness of the light-emitting body of the object to be measured 1.

[0019] The coloriluminance meter 101 comprises probes 10A and 10B and a control processing unit 50. Probe 10A includes an optical unit 11A, a photometric unit 12A, a signal processing unit 13A, and a calculation unit 14A. The optical unit 11A receives light from a first part of the object to be measured 1 and directs that light to the photometric unit 12A. The photometric unit 12A converts the light from the first part of the object to be measured 1 into an electrical signal (analog signal) with an intensity corresponding to the intensity of the light. The signal processing unit 13A includes an amplifier (not shown in Figure 1) that amplifies the light from the photometric unit 12A and an A / D converter (not shown in Figure 1) that converts the analog signal from the amplifier into a digital signal (measurement data). The calculation unit 14A uses the digital signal (measurement data) output from the A / D converter to perform predetermined calculations, thereby calculating tristimulus values ​​(X, Y, Z), xyY (chromaticity coordinates, luminance) as defined by the CIE (International Commission on Illumination), TΔuvY (correlated color temperature, color difference from blackbody locus, luminance), and so on.

[0020] Probe 10B has the same configuration as probe 10A. In detail, probe 10B includes an optical unit 11B, a photometric unit 12B, a signal processing unit 13B, and a calculation unit 14B. The optical unit 11B receives light from a second part of the object to be measured 1 and guides that light to the photometric unit 12B. As a result, the photometric unit 12B receives light from the second part of the object to be measured 1. The functions of each block in probe 10B are the same as the functions of the corresponding blocks in probe 10A, so the following explanation will not be repeated.

[0021] The control processing unit 50 includes a control unit 51, a display unit 52, an operation unit 53, and a storage unit 54. The control processing unit 50 is implemented, for example, by a personal computer. The control unit 51 controls the probes 10A and 10B. Furthermore, the control unit 51 can receive data from each of the probes 10A and 10B and perform processing such as displaying and managing the data. The display unit 52 displays the measurement data in the form of graphs, lists, etc., under the control of the control unit 51. Various information related to the measurement (measurement instructions, display mode settings, measurement range, etc.) is input to the operation unit 53. The storage unit 54 stores various data, including the measurement data.

[0022] The optical device according to the embodiment of the present invention can also be applied to a colorimeter. Figure 2 is a block diagram showing a schematic configuration of a colorimeter equipped with the optical device according to the embodiment of the present invention. The configuration of the colorimeter 102 is basically the same as that of the coloriluminance meter 101, but differs from the configuration of the coloriluminance meter 101 in that an illumination unit 40 is added. The illumination unit 40 is a device that irradiates the object to be measured 1 with illumination light at a predetermined geometry (not limited to, but as an example 45°:0°).

[0023] Figure 3 is a block diagram showing an example of the configuration of an optical device according to an embodiment of the present invention. Figure 3 mainly shows the configuration of the optical unit and photometric unit included in the probe.

[0024] The optical unit 11A (first optical unit) includes an optical element 21A (first optical element), a lens 22A (first lens), and a light beam splitting member 23A. The lens 22A is the lens closest to the object and is for focusing light from a first part of the object to be measured 1 to the photometering unit 12A (first photometering unit). The optical element 21A deflects the light from the first part of the object to be measured 1 and guides it to the lens 22A. The light beam splitting member 23A is an optical waveguide that splits the light beam transmitted through the lens 22A into three light beams and guides those light beams to the photometering unit 12A. For example, a bundle fiber can be used as the light beam splitting member 23A.

[0025] The photometric unit 12A includes filters 24A-1, 24A-2, and 24A-3, and sensors 25A-1, 25A-2, and 25A-3. Filters 24A-1, 24A-2, and 24A-3 are color filters that transmit light emitted from the light beam splitting member 23A with predetermined transmittance characteristics. Specifically, filters 24A-1, 24A-2, and 24A-3 are filters having spectral transmission characteristics corresponding to the color matching functions X, Y, and Z defined by the CIE, and are, for example, interference film filters. Sensors 25A-1, 25A-2, and 25A-3 receive light transmitted through filters 24A-1, 24A-2, and 24A-3, respectively, and output an electrical signal corresponding to the received light intensity. The signals from sensors 25A-1, 25A-2, and 25A-3 are input to the signal processing unit 13A.

[0026] The optical unit 11B (second optical unit) has the same configuration as the optical unit 11A. The optical unit 11B includes an optical member 21B (second optical member), a lens 22B (second lens), and a light beam splitting member 23B.

[0027] Lens 22B is the lens closest to the object and is used to focus light from the second part of the object 1 to the photometer 12B (second photometer). Optical member 21B deflects the light from the second part of the object 1 and guides it to lens 22B. Light beam splitting member 23B is an optical waveguide that splits the light beam that has passed through lens 22B into three light beams and guides those light beams to photometer 12B.

[0028] The photometric unit 12B has the same configuration as the photometric unit 12A. The photometric unit 12B includes filters 24B-1, 24B-2, and 24B-3, and sensors 25B-1, 25B-2, and 25B-3. Filters 24B-1, 24B-2, and 24B-3 are filters having spectral transmission characteristics corresponding to the color matching functions X, Y, and Z as defined by the CIE. Sensors 25B-1, 25B-2, and 25B-3 receive light transmitted through filters 24B-1, 24B-2, and 24B-3, respectively, and output an electrical signal corresponding to the received light intensity. The signals from sensors 25B-1, 25B-2, and 25B-3 are input to the signal processing unit 13B.

[0029] Figure 4 is a schematic diagram showing an example of an object to be measured. The object to be measured 1 is, for example, a smartphone and has a display 2 that employs USC. Therefore, a camera (not shown) is located behind the display 2. The parts of the display 2 to be measured are, for example, a first part 3 (USC part) and a second part 4 (normal part). The first part 3 and the second part 4 are close together, and the distance D (center-to-center distance) between the first part 3 and the second part 4 is, for example, 10 mm.

[0030] In one embodiment, though not limited to this, the minimum measurable width A1 of the first part 3 is a value greater than 0 and less than 3 mm. Similarly, the minimum measurable width A2 of the second part 4 is also set to a value greater than 0 and less than 3 mm.

[0031] (Detailed description of the optical device according to this embodiment) The optical device according to this embodiment may have the configuration described below. The optical device includes a first photometric unit for receiving light from a first part of the object to be measured and , the The system comprises an optical unit, a second photometer for receiving light from a second part of the object to be measured, and a second optical unit. The first optical unit has a first lens, which is the lens closest to the object, for focusing light from the first part to the first photometer, and a first optical member that deflects the light from the first part and guides it to the first lens. The second optical unit has a second lens, which is the lens closest to the object, for focusing light from the second part to the second photometer, and a second optical member that deflects the light from the second part and guides it to the second lens. The optical axis of the first optical unit from the object to be measured to the first optical member and the optical axis of the second optical unit from the object to be measured to the second optical member are substantially parallel, and the distance between the optical axis of the first optical unit and the optical axis of the second optical unit is smaller than the distance between the center of the first lens and the center of the second lens.

[0032] This configuration allows for the measurement of luminance at two points on an object being measured that are spaced closer together than the distance between the first and second optical units. Furthermore, since lenses with a large numerical aperture (NA) or effective aperture can be used for the first and second lenses, each of the first and second optical units can capture more light from corresponding points on the object being measured. Therefore, this embodiment provides an optical device that enables the measurement of color or luminance at adjacent points on an object being measured while maintaining brightness. In this specification, "approximately parallel" is not limited to cases where two lines or two surfaces are strictly parallel, but also includes cases where one line (or surface) is inclined to the other line (or surface) at an angle within a predetermined range.

[0033] According to this embodiment, the first optical member and the second optical member reflect light from the object to be measured and guide it to the first lens and the second lens, respectively. This configuration allows light rays from adjacent parts on the object to be bent, so that light from corresponding parts on the object to be measured can be guided to each of the first optical unit and the second optical unit.

[0034] According to this embodiment, the first optical member guides the light from the object to be measured to the first lens by performing a total internal reflection twice, and the second optical member guides the light from the object to be measured to the second lens by performing a total internal reflection twice. Preferably, each of the first and second optical members has an incident surface facing the object, an exit surface facing the corresponding lens of the first and second lenses, a first reflective surface that reflects the light incident on the incident surface, and a second reflective surface that reflects the light reflected by the first reflective surface and guides it to the exit surface, wherein the incident surface and the exit surface are substantially parallel, and the first reflective surface and the second reflective surface are substantially parallel. With this configuration, each of the first and second optical members can bend the light rays from the object to be measured and guide them to the corresponding lens. Therefore, light from two parts on the object to be measured that are spaced closer together than the distance between the first and second optical units can be guided to the first and second optical units, respectively.

[0035] According to this embodiment, each of the first optical element and the second optical element is a parallelogram prism, and the end of the parallelogram prism connecting the incident surface and the first reflective surface may be a chamfered end. With this configuration, each of the first optical element and the second optical element can bend the light ray from the object to be measured twice and guide it to the corresponding lens. Furthermore, the first optical element and the second optical element can be brought close to each other. Therefore, it becomes possible to measure the brightness of two close locations on the object to be measured.

[0036] Mirrors can also deflect light by reflecting it. Therefore, it is possible to realize the first and second optical components using mirrors. However, when using mirrors, it is necessary to consider the possibility that their reflection characteristics may be polarization-dependent. Prisms are more advantageous than mirrors in that they can bend the light beam without polarization dependence.

[0037] In this embodiment, the prism is located in front of (towards the object) the lens closest to the object in the photometering unit. The optical image of the area to be measured rotates due to total internal reflection by the prism. However, in this embodiment, the optical device is designed to receive a greater amount of light from the area to be measured, so the orientation of the optical image formed by the lens closest to the object does not directly affect the measurement of chromaticity or luminance.

[0038] In this embodiment, the first optical member may guide the light from the object to be measured to the first lens by performing a total internal reflection once, and the second optical member may guide the light from the object to be measured to the second lens by performing a total internal reflection once. Preferably, each of the first optical member and the second optical member is a triangular prism and has an incident surface directed toward the object, an exit surface directed toward the corresponding lens of the first lens and the second lens, and a second reflective surface that guides the light incident on the incident surface to the exit surface by performing a total internal reflection.

[0039] According to the above configuration, each of the first optical element and the second optical element can bend light rays from the object being measured and guide them to the corresponding lens.

[0040] In this embodiment, the first optical unit and the second optical unit have the same optical system. By using an optical system with the same configuration, when measuring the color difference between two parts, the color difference can be measured without the model dependence of the measurement between the first optical unit and the second optical unit. This enables highly accurate measurement.

[0041] The minimum measurement width of the measurement range of at least one of the first and second optical units on the object being measured is less than 3 mm. Typically, the size of the USC portion is determined according to the size of the camera mounted on the device. For example, in many smartphones, the camera size (diameter) is about 3 mm. Therefore, by setting the minimum measurement width of the measurement range to less than 3 mm, the color and brightness of the USC portion on the smartphone display can be measured.

[0042] In this embodiment, the measurement angle of at least one of the first optical unit and the second optical unit is less than ±15°. Preferably, the measurement angle of at least one of the first optical unit and the second optical unit is less than ±10°. The term "measurement angle" may be read as "aperture angle". This configuration enables accurate measurement of color and brightness.

[0043] According to this embodiment, the first optical element and the second optical element are each prisms, and the Abbe number νd of the prism material with respect to the d line satisfies νd > 40. If the Abbe number νd is less than 40, the chromatic aberration generated in the prism section increases, which tends to increase the deviation of the measurement range due to wavelength. As a result, the accuracy of the measurement decreases. By satisfying νd > 40, highly accurate measurements become possible. Commercially available materials can be used as materials that satisfy νd > 40. One example is S-LAH65VS (νd = 46.5) provided by Ohara Corporation.

[0044] Preferably, νd > 50. While not particularly limited, an example of an Abbe number νd in one embodiment is νd = 55.4.

[0045] According to this embodiment, the prism has a thickness greater than 10 mm, and the internal transmittance of the prism at a wavelength of 400 nm is greater than 0.9.

[0046] The material of a prism tends to have lower transmittance at shorter wavelengths. By using a prism that satisfies the above conditions, sufficient light can be ensured during measurement, thereby improving the signal-to-noise ratio. Preferably, the prism has a thickness greater than 10 mm, and the internal transmittance of the prism at a wavelength of 400 nm is greater than 0.95. Note that "thickness" refers to the dimension corresponding to the height of the prism from the bottom surface of the prism (the surface closest to the object being measured).

[0047] According to this embodiment, if the refractive index of the prism is n, the optical path length of the principal ray passing through the inside of the prism is A, and the measurement distance of the first and second photometric units is WD0, then A / (WD0×n)<0.9 is satisfied. A / (WD0×n) represents the proportion of the optical path within the prism to the optical path from the object being measured to the first photometric unit (or second photometric unit). The larger this proportion, the smaller the distance between the object being measured and the prism. In other words, the optical device needs to be brought closer to the object being measured. If A / (WD0×n) exceeds 0.9, the optical distance becomes shorter, which reduces the ease of use of the optical device. Although not particularly limited, the value of A / (WD0×n) in one embodiment is 0.69.

[0048] In this embodiment, the refractive index Nd of each of the first optical member and the second optical member is 1.4 or higher. With this configuration, light rays can be bent by 90° by total internal reflection inside each of the first optical member and the second optical member. Preferably, the refractive index Nd is 1.6 or higher.

[0049] In optical systems with large apertures and large measurement angles, the upper ray (a ray tilted at a positive angle relative to the principal ray) and the principal ray are incident on the reflective surface at different angles. To cause total internal reflection of light incident at a larger angle of incidence, a higher refractive index of the optical element is desirable. Furthermore, by allowing light to pass through an optical element made of a medium with a high refractive index, a larger working distance can be secured. Therefore, it is preferable that the refractive index Nd satisfies the above conditions.

[0050] In this embodiment, the aperture of each of the first and second lenses is greater than twice the distance between the center of the measurement range of the first photometer and the center of the measurement range of the second photometer. This configuration makes it possible to measure close-up areas on the object being measured while maintaining brightness.

[0051] Furthermore, as shown in Figures 1 and 2, according to this embodiment, the colorimeter and colorimeter are equipped with the optical device described above. This makes it possible to realize a colorimeter and colorimeter that can measure close-proximity areas while maintaining brightness. [Examples]

[0052] The following describes various embodiments of the present invention. [Example 1] Figure 5 shows the configuration of an optical device according to Embodiment 1 of the present invention. As shown in Figure 5, probe 10A has a photometric unit 12A (first photometric unit) and an optical unit 11A (first optical unit). Probe 10B has a photometric unit 12B (second photometric unit) and an optical unit 11B (second optical unit).

[0053] The photometric unit 12A receives light from the first part AR1 of the object to be measured 1. The photometric unit 12B receives light from the second part AR2 of the object to be measured 1. As shown in Figure 3, each photometric unit has three sensors. In each embodiment, these three sensors are combined and represented as a single sensor.

[0054] The optical unit 11A includes a lens 22A (first lens) and a prism 21A (first optical element). The lens 22A is the lens closest to the object and focuses the light from the first part AR1 of the object to be measured 1 onto the photometer 12A. The prism 21A deflects the light from the first part AR1 of the object to be measured 1 and guides it to the lens 22A.

[0055] The optical unit 11B includes a lens 22B (second lens) and a prism 21B (second optical element). The lens 22B is the lens closest to the object and focuses the light from the second part AR2 of the object 1 to the photometer 12B. The prism 21B deflects the light from the second part AR2 of the object 1 and guides it to the lens 22B. Note that in Figure 5, only the lens closest to the object of each optical unit is shown.

[0056] Optical axis AX1 is the optical axis of optical unit 11A, extending from the first part AR1 of the object under test 1 to the lens 22A. Optical axis AX2 is the optical axis of optical unit 11B, extending from the second part AR2 of the object under test 1 to the lens 22B. The portion of optical axis AX1 from the first part AR1 of the object under test 1 to the prism 21A and the portion of optical axis AX2 from the second part AR2 of the object under test 1 to the prism 21B are parallel. Also, the portion of optical axis AX1 from the center of lens 22A to the prism 21A and the portion of optical axis AX2 from the center of lens 22B to the prism 21B are parallel.

[0057] The interval D represents the distance between the center of the first part AR1 and the center of the second part AR2. The interval D1 represents the interval between optical axes AX1 and AX2. The interval D2 represents the distance between the center of lens 22A and the center of lens 22B. The relationship D2 > D > D1 holds between D, D1, and D2. Therefore, the interval D1 is smaller than the interval D2. Furthermore, D2 > 2 × D. According to Example 1, it is possible to measure the color luminance of adjacent locations on the object to be measured while maintaining high optical performance.

[0058] In Example 1, each of the prisms 21A and 21B is a parallelogram prism, which causes light from the object to be measured 1 to undergo total internal reflection twice and guide it to the corresponding lens. Figures 6A, 6B, and 6C show the shape of the parallelogram prism according to Example 1 of the present invention. Figure 6A is a perspective view of the parallelogram prism according to Example 1 of the present invention, Figure 6B is a front view of the parallelogram prism according to Example 1 of the present invention, and Figure 6C is a top view of the parallelogram prism according to Example 1 of the present invention.

[0059] A parallelogram prism has surfaces 31 to 36. Surface 31 is the incident surface, facing the object. Surface 32 is the exit surface, parallel to surface 31 and facing the corresponding lens. Surfaces 33 and 34 are parallel to each other and each is a parallelogram with a pair of vertical angles of 45°. Surfaces 35 and 36 are reflective surfaces arranged parallel to each other. Surface 35 is the first reflective surface that reflects light incident on surface 31 (incident surface). Surface 36 is, This is a second reflective surface that reflects the light reflected by surface 35 and guides it to surface 32 (the output surface). The distance between surface 31 and surface 32 corresponds to the "thickness" of the parallelogram prism. "t" shown in Figure 6(B) represents the "thickness" of the parallelogram prism.

[0060] The ends of the parallelogram prism connecting the incident surface (surface 31) and the first reflection surface (surface 35) may be chamfered. Figure 7 shows two parallelogram prisms placed close together. The smaller the distance between the two parts of the object to be measured 1, the closer the prisms 21A and 21B need to be to each other. However, if the opposing ends 37 of prisms 21A and 21B are not chamfered, the ends 37 may come into contact with each other, as shown in Figure 7(A). As shown in Figure 7(B), chamfering the opposing ends 37 can prevent contact between the ends 37. Therefore, The prisms 21A and 21B can be brought closer together. Therefore, it becomes possible to measure two adjacent parts on the object being measured 1.

[0061] The parameters for Example 1 are shown below. (1) Probes 10A, 10B Konica Minolta probe (model number CA-VP402) Working distance (distance from the bottom surface of the prism to the DUT (object under test)): 7.2 mm Lens diameter of lenses 22A and 22B: 24.5mm Housing width (probe body width) W1, W2: 47mm Measurement diameter at the first site AR1 and the second site AR2: 2 mm Measurement angle (aperture angle): ±10° (2) Prisms 21A, 21B Dimensions: 20mm x 16.55mm x 18mm (See Figures 6A-6C) Thickness: 11.703mm Internal transmittance at a wavelength of 400nm: 99% (when transmitted through a 10mm thickness) Glass material: Ohara Corporation S-BSM18 (Nd: 1.638, νd: 55.38) (3) Placement Length of the principal ray passing through the prism A: 51.9417 mm Probe measurement distance WD0: 28mm Distance D (center-to-center distance) between site 1 AR1 and site 2 AR2: 10 mm Distance between optical axes D2: 23.5 mm [Example 2] Figure 8 shows the configuration of the optical device according to Embodiment 2 of the present invention. The configuration shown in Figure 8 is basically the same as the configuration of Embodiment 1 shown in Figure 5, so a detailed explanation will not be repeated. In addition to lenses 22A and 22B, lenses 26A and 26B are also shown in Figure 8. The number of lenses in each of the optical units 11A and 11B is not particularly limited.

[0062] Similar to Example 1, the relationships D2>D>D1 and D2>2×D hold true for intervals D, D1, and D2. Therefore, according to Example 2, it is possible to measure the color luminance of adjacent locations on the object being measured while maintaining high optical performance.

[0063] Similar to Example 1, in Example 2, prisms 21A and 21B are both parallelogram prisms. The size of prism 21A differs between Example 1 and Example 2. The size of prism 21B is the same in both Example 1 and Example 2. As in Example 1, the optical axis AX1 from the first part AR1 of the object under test 1 to prism 21A and the optical axis AX2 from the second part AR2 of the object under test 1 to prism 21B are parallel. Also, the optical axis AX1 from the center of lens 22A to prism 21A and the optical axis AX2 from the center of lens 22B to prism 21B are parallel.

[0064] Figures 9A, 9B, and 9C show the shape of a parallelogram prism according to Embodiment 2 of the present invention. Figure 9A is a perspective view of the parallelogram prism according to Embodiment 2 of the present invention, Figure 9B is a front view of the parallelogram prism according to Embodiment 2 of the present invention, and Figure 9C is a top view of the parallelogram prism according to Embodiment 2 of the present invention. Surface 31 is the incident surface facing the object, surface 32 is the exit surface, and surfaces 35 and 36 are the reflection surfaces. Surfaces 33 and 34 are each parallelograms with a pair of vertex angles of 45°. The ends of the parallelogram prism connecting the incident surface (surface 31) and the first reflection surface (surface 35) may be chamfered. "t" indicates the thickness of the prism.

[0065] The data relating to the optical device in Example 2 is shown below. (1) Probe (1A) Probe 10A Konica Minolta probe (model number CA-VP410) Working distance (from the bottom surface of the prism) and others Distance to the object being measured: 6 mm Lens 22A lens diameter: 23.7mm Housing width (probe body width) W1: 47mm Measurement diameter at part 1, AR1: 10 mm Measurement angle (aperture angle): ±8.5° (1B) Probe 10B Konica Minolta probe (model number CA-VP402) Working distance (distance from the bottom surface of the prism to the object being measured): 7.2 mm Lens diameter of lenses 22A and 22B: 24.5mm Housing width (probe body width) W2: 47mm Measurement diameter at site 2, AR2: 2 mm Measurement angle (aperture angle): ±10° (2) Prisms 21A, 21B (2A) Prism 21A Dimensions: 25mm x 25.5mm x 18mm (See Figure 9) Prism thickness: 18.031 mm Internal transmittance at a wavelength of 400nm: 92.4% (when transmitted through a thickness of 10mm) Glass material: Ohara Corporation S-LAH60 (Nd: 1.834, νd: 37.16) (2B) Prism 21B Dimensions: 20mm x 16.55mm x 18mm (See Figure 6) Thickness: 11.703mm Internal transmittance at a wavelength of 400nm: 99% (when transmitted through a 10mm thickness) Glass material: Ohara Corporation S-BSM18 (Nd: 1.638, νd: 55.38) (3) Placement Length A of the principal ray passing through the prism: 78.862mm (Prism 21A), 51.9417mm (Prism 21B) Probe measurement distance WD0: 30mm (probe 10A), 28mm (probe 10B) Distance D (center-to-center distance) between site 1 AR1 and site 2 AR2: 10 mm Distance between optical axes D2: 23.5 mm

[0066] Figures 11A, 11B, and 11C show the shape of a triangular prism according to Embodiment 3 of the present invention. Figure 11A is a perspective view of the triangular prism according to Embodiment 3 of the present invention, Figure 11B is a front view of the triangular prism according to Embodiment 3 of the present invention, and Figure 11C is a side view of the triangular prism according to Embodiment 3 of the present invention. The triangular prism has surfaces 31A to 35A. Surface 31A is the incident surface facing the object, and surface 32A is the exit surface facing the corresponding lens. Surface 33A is a reflective surface that reflects the light incident on surface 31A (incident surface). Surfaces 33A and 34A are arranged parallel to each other. The shape of each of surfaces 34A and 35A is an equilateral triangle. The height from surface 31A to the vertices of the equilateral triangles (surfaces 34A and 35A) corresponds to the "thickness" of the triangular prism. In Figure 11B, "t" indicates the thickness of the prism. Similar to Examples 1 and 2, the optical axis AX1 from the first part AR1 of the object under test 1 to the prism 21A is parallel to the optical axis AX2 from the second part AR2 of the object under test 1 to the prism 21B.

[0067] The parameters for Example 3 are shown below. (1) Probes 10A, 10B Konica Minolta probe (model number CA-VP402) Working distance (distance from the bottom surface of the prism to the object being measured): 7.7 mm Lens diameter of lenses 22A and 22B: 24.5mm Housing width (probe body width) W1, W2: 47mm Measurement diameter at the first site AR1 and the second site AR2: 2 mm Measurement angle (aperture angle): ±10° (2) Prisms 21A, 21B Dimensions: 25mm x 25mm x 25mm (See Figures 11A to 11C) Thickness: 21.651 mm Internal transmittance at a wavelength of 400nm: 99.6% (when transmitted through a thickness of 10mm) Glass material: Ohara Corporation S-FPL55 (Nd: 1.438, νd: 94.66) (3) Placement Length of the principal ray passing through the prism A: 31.1496 mm Probe measurement distance WD0: 28mm Distance D (center-to-center distance) between site 1 AR1 and site 2 AR2: 10 mm Distance between optical axes (distance between the centers of lenses 22A and 22B) D2: 50.0 mm While embodiments and examples of the present invention have been described, the embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims, and all modifications within the meaning and scope of equivalents of the claims are intended to be included. [Explanation of Symbols]

[0068] 1 Object to be measured, 2 Display, 3 First part, 4 Second part, 10A, 10B Probe, 11A, 11B Optical unit, 12A, 12B Photometer, 13A, 13B Signal processing unit, 14A, 14B Calculation unit, 21A, 21B Optical component (prism), 22A, 22B, 26A, 26B Lens, 23A, 23B Light beam splitting member, 24A-1~24A-3, 24B-1~24B-3 Filter, 25A-1~25A-3, 25B-1~25B-3 Sensor, 31, 31A, 32, 32A, 33, 33A, 34, 34A, 35, 35A, 36 Surface, 37 End (prism), 40 Illumination unit, 50 Control processing unit, 51 Control unit, 52 Display section, 53 Operation section, 54 Memory section, 101 Color luminance meter, 102 Colorimeter, A1, A2 minimum measurement width, AR1 1st part, AR2 2nd part, AX1, AX2 optical axis, D, D1, D2 interval.

Claims

1. A photometric device for measuring chromaticity and / or luminance, A first photometric unit for receiving light from a first part of the object to be measured, A first optical unit having a first lens which is the lens closest to the object for focusing light from the first part to the first photometer, a first light beam splitting member which splits the light from the first lens and guides it to the first photometer, and a first optical member which deflects the light from the first part and guides it to the first lens, A second photometric unit, different from the first photometric unit, for receiving light from a second part of the object to be measured, The device comprises a second lens, different from the first lens, which is the lens closest to the object for focusing light from the second part to the second photometer; a second light beam splitting member, which splits the light from the second lens and guides it to the second photometer; and a second optical unit having a second optical member, different from the first optical member, which deflects the light from the second part and guides it to the second lens. The first photometric unit comprises a filter having spectral transmission characteristics corresponding to the color matching functions X, Y, and Z defined by the CIE, and a plurality of sensors that receive light transmitted through the filter and output electrical signals. The second photometric unit comprises a filter having spectral transmission characteristics corresponding to the color matching functions X, Y, and Z defined by the CIE, and a plurality of sensors that receive light transmitted through the filter and output electrical signals. Furthermore, a first calculation unit calculates the chromaticity and / or luminance by performing calculation processing using the digital signal obtained by digitally converting the electrical signal output from the first photometric unit, The system comprises a second calculation unit that calculates the chromaticity and / or luminance by performing calculations using the digital signal obtained by digitally converting the electrical signal output from the second photometric unit, The first and second parts are different parts that do not overlap with each other. Light from the first part is guided to the first photometric unit by the first optical unit. Light from the second part is guided to the second photometric unit by the second optical unit, which is different from the first optical unit. A photometer in which the optical axis of the first optical unit extending from the object to be measured to the first optical member and the optical axis of the second optical unit extending from the object to be measured to the second optical member are substantially parallel, and the distance between the optical axis of the first optical unit and the optical axis of the second optical unit is smaller than the distance between the center of the first lens and the center of the second lens.

2. The photometer according to claim 1, wherein the first optical member and the second optical member guide light from the object to be measured to the first lens and the second lens, respectively, by total internal reflection.

3. The first optical member causes the light from the object to be measured to undergo total internal reflection twice, thereby guiding the light from the object to be measured to the first lens. The photometer according to claim 2, wherein the second optical member causes the light from the object to be measured to undergo total internal reflection twice and guides the light from the object to be measured to the second lens.

4. Each of the first optical member and the second optical member is The incident plane directed toward the object, An exit surface directed toward the corresponding lens among the first and second lenses, A first reflective surface that causes total internal reflection of light incident on the incident surface, The first reflective surface has a second reflective surface that totally reflects the light totally reflected by the first reflective surface and guides it to the output surface, The incident surface and the exit surface are substantially parallel. The photometric apparatus according to claim 3, wherein the first reflective surface and the second reflective surface are substantially parallel.

5. Each of the first optical member and the second optical member is a parallelogram prism, The photometer according to claim 4, wherein the end of the parallelogram prism connecting the incident surface and the first reflecting surface of the parallelogram prism is a chamfered end.

6. The first optical member causes the light from the object to be measured to undergo a total internal reflection once and guides the light from the object to be measured to the first lens. The photometer according to claim 1 or 2, wherein the second optical member causes light from the object to be measured to undergo total internal reflection once and guides the light from the object to be measured to the second lens.

7. Each of the first optical member and the second optical member is a triangular prism, The incident plane directed toward the object, An exit surface directed toward the corresponding lens among the first and second lenses, The photometric apparatus according to claim 6, further comprising a second reflective surface that totally reflects light incident on the incident surface and guides it to the exit surface.

8. The photometer according to any one of claims 1 to 7, wherein the first optical unit and the second optical unit have an optical system with the same configuration.

9. The photometric apparatus according to any one of claims 1 to 8, wherein the minimum measurement width of the measurement range of at least one of the first optical unit and the second optical unit on the object to be measured is less than 3 mm.

10. The photometric apparatus according to any one of claims 1 to 9, wherein the measurement angle of at least one of the optical units, the first optical unit and the second optical unit, is less than ±15°.

11. Each of the first optical member and the second optical member is a prism, The photometric apparatus according to any one of claims 1 to 7, wherein the Abbe number νd with respect to the d line of the prism material satisfies νd > 40.

12. The prism has a thickness greater than 10 mm. The photometric apparatus according to claim 11, wherein the internal transmittance of the prism at a wavelength of 400 nm is greater than 0.

9.

13. Let n be the refractive index of the prism. Let A be the optical path length of the principal ray passing through the inside of the prism. If the measurement distance of the first photometric unit and the second photometric unit is defined as WD0, A / (WD0×n)<0.9 A photometric apparatus according to claim 11 or claim 12, satisfying the requirements.

14. The photometric apparatus according to any one of claims 1 to 13, wherein the refractive index Nd of each of the first optical member and the second optical member is 1.4 or greater.

15. The photometer according to any one of claims 1 to 14, wherein the aperture of each of the first lens and the second lens is greater than twice the distance between the center of the measurement range of the first photometer and the center of the measurement range of the second photometer.

16. A colorimeter comprising a photometric device according to any one of claims 1 to 15.

17. A colorimeter comprising a photometric device according to any one of claims 1 to 15.

18. The light from the first part of the object to be measured is reflected by the first reflective surface, The light reflected by the first reflective surface is focused by the first lens, The light focused by the first lens is received by the first photometer, Light from a second part of the object to be measured is reflected by a second reflective surface different from the first reflective surface. The light reflected by the second reflective surface is focused by a second lens different from the first lens, A photometric method for measuring the chromaticity and / or luminance of the first and second parts by receiving light focused by the second lens with a second photometric unit, The optical path from the first part to the first photometric unit and the optical path from the second part to the second photometric unit are independent optical paths. The optical axis from the object to be measured to the first reflective surface and the optical axis from the object to be measured to the second reflective surface are substantially parallel, and the distance between the optical axis of the first reflective surface and the optical axis of the second reflective surface is smaller than the distance between the center of the first lens and the center of the second lens. The object to be measured is a display of an electronic device, the electronic device has a camera module located on the back of the display, and the camera module is configured to capture images through the display. A photometric method in which the first part of the object to be measured is the part on the back where the camera module is located, and the second part of the object to be measured is the part on the back where the camera module is not located.

19. The light totally reflected by the first reflecting surface is totally reflected by a third reflecting surface arranged substantially parallel to the first reflecting surface. The photometric method according to claim 18, wherein the light totally reflected by the second reflecting surface is totally reflected by a fourth reflecting surface arranged substantially parallel to the second reflecting surface.

20. The first reflective surface and the third reflective surface are surfaces of a parallelogram prism, The second reflective surface and the fourth reflective surface are surfaces of the parallelogram prism, The photometric method according to claim 19, wherein the end of the parallelogram prism connecting the incident surface of the parallelogram prism to the first reflecting surface and the second reflecting surface is a chamfered end.

21. The first and second parts are different parts that do not overlap with each other. The light focused by the first lens is divided into multiple light beams by the first light beam splitting member, each divided light beam is transmitted through a filter having spectral transmission characteristics corresponding to the color matching functions X, Y, and Z defined by the CIE, each light beam transmitted through the filter is converted into an electrical signal by multiple sensors, and the chromaticity and / or luminance of the first part is calculated by performing predetermined calculation processing on the electrical signal. A photometric method according to any one of claims 18 to 20, comprising: dividing the light focused by the second lens into a plurality of light beams by a second light beam splitting member; transmitting each divided light beam through a filter having spectral transmission characteristics corresponding to the color matching functions X, Y, and Z defined by the CIE; converting each light beam transmitted through the filter into an electrical signal by a plurality of sensors; and performing predetermined calculation processing on the electrical signal to calculate the chromaticity and / or luminance of the second part.

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