Photometric device and method for inspecting display
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- KONICA MINOLTA INC
- Filing Date
- 2026-01-09
- Publication Date
- 2026-07-30
Smart Images
Figure JP2026000448_30072026_PF_FP_ABST
Abstract
Description
Photometric device and inspection method for display
[0001] The present disclosure relates to a photometric device and an inspection method for a display.
[0002] A photometric device that measures light from a light emitter is known. For example, a color luminance meter, which is one type of photometric device, can measure the optical characteristics of a display, and based on the measurement results, the color of the display can be adjusted.
[0003] When the display is small, the measurement area for measuring the optical characteristics also becomes small. Generally, in the object to be measured, the amount of light emitted from the measurement area decreases as the area of the measurement area becomes smaller. Therefore, a photometric device that measures optical characteristics by incorporating a larger amount of light from a small measurement area is known (Patent Documents 1 to 3).
[0004] International Publication No. 2011 / 121896, International Publication No. 2018 / 230177, Japanese Patent Application Laid-Open No. 2003-247891
[0005] In recent years, in the field of displays, a technology called Under Panel Solution (UPS) has been developed. UPS is a technology in which a camera module, a face recognition module, etc. are arranged on the back of a display, and a device adopting UPS has a configuration in which it is difficult to visually recognize modules such as a camera through the display. In such a device, the part of the display that overlaps with the module (UPS part) and the part of the display that does not overlap with the module (non-UPS part) have different structures. For example, in the γ adjustment of a display, γ adjustment is required for each of the UPS part and the non-UPS part.
[0006] In order to shorten the tact time in γ adjustment, it is necessary to simultaneously measure the luminance of each of the UPS part and the non-UPS part. Also, from the viewpoint of reducing the influence of the in-plane light emission distribution in the display, it is preferable that the measurement areas of the UPS part and the non-UPS part are close to each other.
[0007] However, in the technologies described in Patent Documents 1 to 3, when the intervals between such a plurality of measurement areas are made extremely narrow and measured simultaneously, the light emitted from the plurality of measurement areas interferes with each other and cannot be measured correctly.
[0008] The problem addressed by this disclosure is to provide a photometric device that can narrow the spacing between multiple measurement areas and improve measurement accuracy. Furthermore, it is to provide a method for inspecting displays using this photometric device.
[0009] To solve the above problems, the photometric apparatus of this disclosure comprises: an objective optical system that images light from a plurality of predetermined regions on a surface to be measured; a plurality of light guiding members that guide the light from the plurality of predetermined regions imaged by the objective optical system by a light-gathering action; and a light-receiving unit that receives the light guided by the plurality of light guiding members.
[0010] The display inspection method of the present disclosure comprises the steps of using the photometric device to photometer the area on which the under panel solution is mounted and other adjacent areas as predetermined areas, or the steps of photometering the area on which the display is folded and other adjacent areas as predetermined areas.
[0011] According to this disclosure, the spacing between multiple measurement areas can be narrowed, and the accuracy of the measurement can be improved.
[0012] This is a block diagram showing the schematic configuration of a photometric device. This is a schematic diagram showing an example configuration of the objective optical system, light guide member, and light receiving unit. This is an enlarged view of part III-III of the schematic diagram shown in Figure 2. This is a schematic diagram showing an example of a field diaphragm. This is an explanatory diagram explaining that light from the measurement area is guided by the light guide member. This is an explanatory diagram explaining that light from the measurement area is guided by the light guide member. This is a cross-sectional view of a bundle fiber. This is a perspective view showing the appearance of a bundle fiber. This is an explanatory diagram explaining that the measurement result changes depending on the positional relationship between the generated image and the optical fiber. This is a schematic diagram showing an example of a spectroscopic unit. This is a schematic diagram showing an example of an object to be measured. This is a schematic diagram showing an example of an object to be measured. This is a schematic diagram showing the configuration of the objective optical system, light guide member, and light receiving unit in Modification 1. This is a schematic diagram showing the configuration of the objective optical system, light guide member, and light receiving unit in Modification 2. This is a schematic diagram showing the configuration of the objective optical system, first light guide member, and first light receiving unit in Modification 3. This is a schematic diagram showing an example in which the entrance of the light beam branching member also functions as an aperture diaphragm.
[0013] Hereinafter, one or more embodiments of this disclosure will be described with reference to the drawings. However, the scope of this disclosure is not limited to the disclosed embodiments.
[0014] [Photometric Device] Figure 1 is a block diagram showing the schematic configuration of the photometric device 100 in this embodiment. The object to be measured 1 is a light-emitting body, and may be, for example, a display, an electronic device equipped with a display, etc. A coloriluminance meter is an example of the photometric device 100 and can measure the color and brightness of the light-emitting body in the object to be measured 1. If the object to be measured 1 is not a light-emitting body, the photometric device 100 may include, for example, an illumination device that irradiates the object to be measured 1 with illumination light in a predetermined geometry. The geometry is not limited, but one example is 45°:0°.
[0015] The photometric device 100 comprises a probe 10 and a control processing unit 50. In the photometric device 100 shown in Figure 1, photometric measurements are taken on two predetermined areas of the object to be measured 1, but the number of predetermined areas may be three or more. In this specification, the predetermined areas to be photometrically measured are also referred to as "measurement areas." The area and measurement angle of the multiple measurement areas are not particularly limited and may differ for each measurement area. However, from the viewpoint of improving the accuracy of measurement, it is preferable that the measurement angles are all the same.
[0016] The probe 10 has an objective optical system 11, a first light guide member 12A, a first light receiving unit 13A, a first signal processing unit 14A, and a first calculation unit 15A for measuring a first measurement area RA. The probe 10 has an objective optical system 11, a second light guide member 12B, a second light receiving unit 13B, a second signal processing unit 14B, and a second calculation unit 15B for measuring a second measurement area RB.
[0017] The objective optical system 11 focuses and images light from the first measurement area RA and light from the second measurement area RB, respectively. The first light guide member 12A has an entrance opening at the position where the light from the first measurement area RA is imaged by the objective optical system 11. The first light guide member 12A guides the imaged light from the first measurement area RA by focusing. The first light receiving unit 13A receives the light emitted from the exit opening of the first light guide member 12A, converts the received light into an electrical signal (analog signal) with an intensity corresponding to the intensity of the light.
[0018] In this embodiment, the "imaging position" includes the position where light from the measurement area is imaged by the objective optical system and its vicinity. Here, "nearby" refers to a position that is slightly shifted from the imaging position but has the same optical function as the imaging position. The width of the neighborhood is 10% of the distance from the surface of the object to be measured 1 to the imaging position. For example, if the distance from the surface to be measured to the imaging position is 50 mm, the neighborhood refers to 5 mm before and after the imaging position. In this embodiment, the "non-imaging position" refers to a position where light from the measurement area is not imaged by the objective optical system and the light guide member, and refers to positions excluding the imaging position.
[0019] The first signal processing unit 14A includes an amplifier (not shown) that amplifies the electrical signal from the first light receiving unit 13A, and an A / D converter (not shown) that converts the analog signal from the amplifier into a digital signal (measurement data). The first calculation unit 15A performs predetermined calculation processing using the digital signal (measurement data) output from the A / D converter. This calculates 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), etc.
[0020] The second light guide member 12B, the second light receiving unit 13B, the second signal processing unit 14B, and the second calculation unit 15B in the second measurement area RB also have the same functional configuration as the parts in the first measurement area RA. Hereafter, when the measurement area R is not distinguished, the notation of A and B in each reference numeral will be omitted.
[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 probe 10. The control unit 51 receives data from the probe 10 and performs processing such as displaying and managing the data. The display unit 52 displays the measurement data in the form of a graph, list, etc., under the control of the control unit 51. The user inputs various information related to the measurement (measurement instructions, display mode settings, measurement range, etc.) from the operation unit 53. The storage unit 54 stores various data, including the measurement data.
[0022] Figure 2 is a schematic diagram showing an example configuration of the objective optical system 11, light guide member 12, and light receiving unit 13 according to this embodiment. The X-axis represents the optical axis direction of light from the measurement area R, and the Y-axis represents the direction perpendicular to this optical axis direction. Figure 3 is an enlarged view of the III-III portion of the schematic diagram shown in Figure 2.
[0023] The objective optical system 11 is common to all measurement regions R, and multiple light guide members 12 and light receiving units 13 are provided for each measurement region R. In the example shown in Figure 2, the objective optical system 11 has a first lens group 111 and a second lens group 112, but the objective optical system 11 only needs to have at least the first lens group 111. The first lens group 111 has positive optical power and collects light from the measurement region and guides it to the light guide member 12. The number of elements in each lens group is not particularly limited and may be one or two or more.
[0024] The photometer 100 may have an aperture diaphragm 113. Having an aperture diaphragm 113 allows adjustment of the numerical aperture (brightness) of light from the measurement area, but in this embodiment, it is not necessary to have an aperture diaphragm 113. If the objective optical system 11 has only a first lens group 111, the aperture diaphragm 113 is provided at the rear focal position of the first lens group 111 so that the measurement angle is constant regardless of the measurement position. If the objective optical system 11 further has a second lens group 112, it is preferable to make the rear focal position of the first lens group 111 and the front focal position of the second lens group 112 coincide and provide the aperture diaphragm 113 at this position. This ensures that the measurement angle is constant regardless of the measurement position, and also ensures that the range of incident angles to the light guide member 12 is constant regardless of the position of the light guide member 12.
[0025] Here, "front side" refers to the side of the object being measured 1 that is closer to the surface being measured in the direction of the optical axis (X-axis), and "back side" refers to the side closer to the light-receiving unit 13. Also, "focal position" here includes the focal position and its vicinity. Here, "neighborhood" refers to a position that has the same optical function as the focal position, as described above. The width of the neighborhood is 10% of the distance from the surface of the object being measured 1 to the imaging position. For example, if the distance from the surface being measured to the imaging position is 50 mm, the neighborhood refers to 5 mm in front of and behind the focal position.
[0026] The photometric device 100 may have a field diaphragm 16 between the objective optical system 11 and the light guide member 12. If the shape of the measurement area R is limited by the shape of the entrance in the light guide member 12 without providing a field diaphragm 16, the spacing between the multiple measurement areas R can be narrowed, and the spacing can be brought close to zero, by bringing the entrances of the multiple light guide members 12 close together in the YZ plane.
[0027] When a field diaphragm 16 is provided, it is positioned conjugate to the surface of the object to be measured 1 with respect to the objective optical system 11, that is, at the imaging position of the measurement area R with respect to the objective optical system 11. As a result, light from multiple measurement areas R is guided to the corresponding apertures of the field diaphragm 16. Even if the light from each measurement area R intersects before entering the photometric device 100, it is separated again by the field diaphragm 16. Therefore, multiple close measurement areas R can be measured while maintaining the distance (working distance) between the measurement areas R and the photometric device 100.
[0028] By providing the field diaphragm 16, the shape (shape and size) of the measurement area R can be adjusted. Furthermore, by providing the field diaphragm 16, even if the shapes of multiple measurement areas R are different, each can be adjusted, so a light guide member 12 with the same entrance shape can be used for multiple measurement areas R.
[0029] Figure 4 is a schematic diagram showing an example of a field diaphragm 16. In Figure 4, the direction perpendicular to the plane of the paper is the direction of light propagation from the measurement area R. The field diaphragm 16 has an opening 161 for each measurement area R. In the example shown in Figure 4, the first opening 161A corresponds to the first measurement area RA, and the second opening 161B corresponds to the second measurement area RB. The shape of the opening 161 is not limited and can be set to any shape such as a circle, ellipse, or square depending on the shape of the measurement area R.
[0030] The field diaphragm 16 preferably has a variable mechanism that can change at least one of the position and shape of the aperture 161. This allows the shape of the measurement area R to be changed as needed. By changing at least one of the position and shape of the aperture 161, the shape of the measurement area R that can be measured by the photometric device 100 or the spacing between multiple measurement areas R can be changed. The position and shape of the aperture 161 may be changed manually or automatically using a motor or the like.
[0031] The light guide member 12 and the light receiving unit 13 will be described in detail below.
[0032] (Light guide member) The light guide member 12 is not limited as long as it guides the light of the entire image formed in each measurement area by focusing the light. Examples of the light guide member 12 include lenses. The number of lenses is not limited and may be one or two or more.
[0033] Preferably, the light incident on the light guide member 12 is focused by a lens having positive optical power. This allows the light guide member 12 to narrow the width of the guided light beam, enabling it to guide light from different measurement areas R to the light receiving unit 13 while keeping them separated. As a result, the spacing between multiple measurement areas can be narrowed, and the accuracy of the measurement can be improved.
[0034] Figure 5 is an explanatory diagram illustrating how light from the measurement area R is guided by the light guide member 12. In Figure 5, the light guide member 12 has a single lens. Light from the measurement area R passes through the opening 161 of the field diaphragm 16 and enters the light guide member 12. In the light guide member 12, the incident surface located closest to the objective optical system (not shown) is designated as the first incident surface 121, and the exit surface is designated as the first exit surface 122.
[0035] The first incident surface 121 preferably has positive optical power. As a result, light from the measurement area R, after being incident on the first incident surface, has its beam width narrowed and exits from the first exit surface 122, and is incident on the light receiving unit (not shown) through the incident opening 135 of the light receiving unit. By narrowing the beam width, light from multiple measurement areas R can be sufficiently separated. As a result, the spacing between the multiple apertures 161 in the field diaphragm 16 can be narrowed, and thus the spacing between the multiple measurement areas R can be narrowed. The first incident surface 121 having positive optical power may be spherical or aspherical. Alternatively, the first incident surface having positive optical power may be a diffracting surface.
[0036] Figure 6 is an explanatory diagram illustrating how light from the measurement area R is guided by the light guide member 12. In Figure 6, the light guide member 12 has two lenses. Light from the measurement area R passes through the opening 161 of the field diaphragm 16, enters the first lens 123 of the light guide member 12, and then enters the second lens 124. In the light guide member 12, the incident surface located closest to the objective optical system (not shown), i.e., the incident surface of the first lens 123, is designated as the first incident surface 121, and the exit surface is designated as the first exit surface 122. The incident surface of the second lens 124 is designated as the second incident surface 125, and the exit surface is designated as the second exit surface 126.
[0037] The first incident surface 121 preferably has positive optical power, and the second incident surface 125 more preferably has positive optical power. As a result, light from the measurement area R is incident on the first incident surface, then its beam width is narrowed and it exits from the first exit surface 122. Next, the light exited from the first exit surface 122 is incident on the second incident surface, then its beam width is narrowed and it exits from the second exit surface 126 and is incident on the light receiving unit (not shown) through the incident port 135 of the light receiving unit. By narrowing the beam, light from multiple measurement areas R can be sufficiently separated. As a result, the spacing between the multiple apertures 161 in the field diaphragm 16 can be narrowed, and therefore the spacing between the multiple measurement areas R can be narrowed.
[0038] Preferably, the position of the field diaphragm 16 and the position of the first incident surface 121 coincide in the optical axis direction of the light focused by the objective optical system 11. This allows the width of the light beam passing through the opening 161 of the field diaphragm 16 to be effectively narrowed without widening it. Also, as shown in Figure 6, the first incident surface 121 may extend into the opening 161 of the field diaphragm 16.
[0039] Here, "coincidence" means that the distance between the field diaphragm 16 and the point on the first incident surface 121 furthest from the surface to be measured, in the optical axis direction (X-axis direction), is zero. At this time, the field diaphragm 16 and the first incident surface 121 are in contact. The closer the distance is to zero, the more the light passing through the opening 161 of the field diaphragm 16 can be incident on the first incident surface 121 with almost no widening of the light beam.
[0040] Within the photometric device 100, the multiple light guide members 12 do not all have to be made of the same material and shape. If necessary, light guide members 12 made of different materials or shapes may be combined.
[0041] (Light Receiving Unit) The light receiving unit 13 is not particularly limited as long as it receives light emitted from the exit ports of the multiple light guide members 12. In the example shown in Figure 2, the light receiving unit 13 has a light beam branching member 131 and a light receiving section 132. For example, if only luminance in the measurement area R is measured and chromaticity is not measured, there is no need to branch the light emitted from the exit ports of the light guide members 12, and the light receiving unit 13 does not necessarily have to have a light beam branching member 131.
[0042] Examples of optical beam branching members include bundled fibers, lenses, and mirrors. Alternatively, the same number of single-wire optical fibers as the number of optical beam branches may be bundled together at the entrance and used as an optical beam branching member. In this case, it is preferable that the single-wire optical fibers have a larger cross-sectional diameter than the optical fibers used in the bundled fibers.
[0043] The bundled fiber will be described. FIG. 7 is a cross-sectional view of the bundled fiber, and FIG. 8 is a perspective view showing the appearance of the bundled fiber. The bundled fiber is a member in which a plurality of optical fibers having a diameter of about 0.03 to 0.07 mm are bundled together at one side (the entrance) and separated into a plurality, for example, three corresponding to the three stimulus values (X, Y, Z) at the other side (the exit). In the bundled plurality of optical fibers, if the relationship between the position of the entrance and the exit is biased, the light emitted will also be biased. Therefore, the plurality of optical fibers are randomly woven.
[0044] As shown in FIG. 7, in the bundled fiber, there are gaps between the optical fibers, and the light of the image generated in this gap portion cannot be light-guided. Therefore, if light having specific optical characteristics is incident on this gap portion in a biased manner, the measurement result will vary significantly depending on the positional relationship between the generated image and the optical fiber.
[0045] FIG. 9 is an explanatory diagram for explaining that when the bundled fiber is positioned at the imaging position of the objective optical system 11, that is, in the case of a conventional configuration without the light guide member 12, the measurement result varies depending on the positional relationship between the generated image and the optical fiber. The light-emitting dots of the object to be measured 1 emit light in RED (red), GREEN (green), and BLUE (blue), respectively, and one pixel is formed by these three dots. Images D11 to D16 and D21 to D26 are images corresponding to the light-emitting dots of the object to be measured 1, respectively, and images P11 to P12 and P21 to P22 are images corresponding to the light-emitting pixels of the object to be measured 1, respectively. Here, for the sake of explanation, images D11 to D16 and D21 to D26 are rectangular, and the radii of the optical fibers F11 to F13 and F21 to F23 are the same as the short sides of images D11 to D16 and D21 to D26. Also, it is assumed that the thickness of the cladding layer in the optical fibers F11 to F13 and F21 to F23 is not considered.
[0046] In the case of image P11, the areas of images D11 to D13 (RGB) are all the same, and among these, the areas of images D11 to D13 that overlap with the entrance ports of optical fibers F11 to F12 are also all the same. The same applies to image P12. On the other hand, the positional relationship between image P21 and the optical fiber is different compared to image P11. In image P21, the areas of images D21 to D23 (RGB) are all the same, but among these, the areas of images D21 to D23 that overlap with the entrance ports of optical fibers F21 to F22 are different for each image, and the area of the image that overlaps with the entrance ports of optical fibers F21 to F22 in image D22 is smaller compared to images D21 and D23. That is, due to the bias in the incident light to the optical fiber, a difference occurs in the measured value depending on the positional relationship between the generated image and the optical fiber.
[0047] When the image corresponding to the generated light-emitting pixel is much larger than the entrance port of the optical fiber or much smaller than the entrance port, the difference caused by the positional relationship between the generated image and the optical fiber is relatively small. However, in a relatively small measurement region R (for example, about 2 to 8 mm in diameter) as assumed in this embodiment, it is difficult for a difference to occur in the size between the generated image and the entrance port of the optical fiber, and the difference caused by the positional relationship between the generated image and the optical fiber is relatively large.
[0048] In this embodiment, it is not necessary to measure each light-emitting pixel within the measurement region, but it is sufficient to measure the entire measurement region. In this embodiment, the light emitted from the light guide member 12 enters the light beam branching member 131 such as a bundle fiber. The light beam branching member 131 has an entrance port at a non-imaging position with respect to the object point when each point in the measurement region on the measurement surface in the objective optical system 11 and the light guide member 12 is regarded as the object point, that is, at a position where the light beam emitted from each point in the measurement region spreads as a whole. As a result, the light incident on the light beam branching member 131 is homogenized, and thereafter, the light beam is branched in the light beam branching member 131, and sufficient accuracy can be obtained even if each branched light beam is measured.
[0049] Light is emitted from each point of multiple measurement areas and guided by the objective optical system 11 and the light guide member 12. Preferably, the light emitted from the exit port of the light guide member 12 is parallel light, and the light beam emitted from the centroid point of the measurement area preferably enters the entrance of the light beam branching member 131 perpendicularly. This allows the light that enters the entrance of the light beam branching member 131 to propagate efficiently. The light beam branching member 131 can partially propagate incident light even if it has an angle, depending on the value of the angle. Therefore, it is preferable that the light emitted from the exit port of the light guide member 12 is generally parallel light, and should enter the entrance of the light beam branching member 131 approximately perpendicularly, so that the light beam branching member 131 can propagate all of the light that enters the entrance. For example, parallel light only needs to be parallel within a range of ±5°, and the angle of incidence to the entrance should be perpendicular within a range of ±5°.
[0050] The light-receiving unit 132 has a light-receiving sensor. In one example shown in Figure 2, the light-receiving unit 132 has three filters 133 and three sensors 134. The three sensors 134 are, for example, silicon photocells (SPCs) and have substantially the same light-receiving sensitivity. The light-receiving unit 132 may also have a focusing lens. The focusing lens is located between the light beam branching member 131 and each filter 133.
[0051] Filters 133-1, 133-2, and 133-3 are color filters that transmit light emitted from the light beam branching member 131 with predetermined transmittance characteristics. Specifically, filters 133-1, 133-2, and 133-3 are filters having spectral transmission characteristics corresponding to the color matching functions X, Y, and Z as defined by the International Commission on Illumination (CIE), and are, for example, interference film filters.
[0052] Sensors 134-1, 134-2, and 134-3 each receive light that has passed through filters 133-1, 133-2, and 133-3, respectively. Sensors 134-1, 134-2, and 134-3 each output received signals corresponding to tristimulus values (X, Y, Z). The signals from sensors 134-1, 134-2, and 134-3 are input to the signal processing unit 14.
[0053] In other embodiments, the light receiving unit 132 may include, for example, a filter corresponding to a standard luminous efficiency defined by the International Commission on Illumination (CIE) and a sensor. The sensor receives light transmitted through the filter and outputs an electrical signal corresponding to the received light intensity. The signal from the sensor is input to the signal processing unit 14.
[0054] In other embodiments, the light receiving unit 13 may have, for example, a spectral unit. Figure 10 is a schematic diagram showing an example of a spectral unit 70. The spectral unit 70 has a diffraction grating 72 and a line sensor 73. The diffraction grating 72 is a light beam branching member that branches the light beam at predetermined wavelengths. The line sensor 73 consists of multiple sensors connected in a straight line, that is, multiple light receiving parts combined into one. The line sensor 73 receives light whose wavelengths have been dispersed by diffraction, and the number of sensors corresponds to the number of light beam branches.
[0055] The spectral unit 70 may have a lens 71. Light emitted from the light guide member 12 passes through the incident slit 74 and enters the spectral unit 70. The diffraction grating 72 is of the reflective type, and the incident light is diffracted and reflected by the diffraction grating 72. The light reflected by the diffraction grating 72 enters the lens 71 and is imaged as a wavelength-dispersive image on the light-receiving surface of the line sensor 73 by the lens 71. The line sensor 73 outputs an electrical signal corresponding to the imaged wavelength-dispersive image. The signal from the line sensor 73 is input to the signal processing unit 14.
[0056] Within the photometric device 100, the multiple light-receiving units 13 do not all have to have the same configuration, material, and shape. If necessary, light-receiving units with different configurations, materials, or shapes may be combined. For example, of the two light-receiving units 13, one light-receiving unit 13 may receive light branched by the light beam branching member 131 to acquire tristimulus values, while the other light-receiving unit 13 may receive light by the spectral unit 70 to acquire spectral data.
[0057] [Object under measurement] Figure 11 is a schematic diagram showing an example of an object under measurement 1. The object under measurement 1 is, for example, a smartphone and has a display 2 equipped with a UPS (Under Panel Solution). Behind the display 2, for example, a camera (not shown) is mounted. The size of the camera is not particularly limited, but for example, it is about 4 mm in height and 14 mm in width. The area behind where the camera is mounted is called the UPS section 3, and the area where the camera is not mounted is called the non-UPS section 4. As mentioned above, for example, when adjusting the gamma of the display 2, it is preferable that the measurement area 31 of the UPS section and the measurement area 41 of the non-UPS section be set as close together as possible. Brightness and the like are measured in these measurement areas. In Figure 11, the measurement area 31 of the UPS section is selected as a part of the UPS section 3, but the entire UPS section 3 may be used as the measurement area.
[0058] The area of the UPS section 3 in the display is very narrow, and the measurement area 31 of the UPS section is also very narrow. On the other hand, the area of the non-UPS section 4 in the display is wide, so the measurement area 41 of the non-UPS section does not necessarily need to be as narrow as the measurement area 31 of the UPS section. Furthermore, from the viewpoint of obtaining sufficient light for measurement and improving accuracy, it is preferable that the measurement area 41 of the non-UPS section be somewhat wide.
[0059] In Figure 11, the measurement area 31 of the UPS section and the measurement area 41 of the non-UPS section are shown as circular, but the shape is not particularly limited and may be rectangular. The width w1 of the measurement area 31 of the UPS section is, for example, 3 mm. The width w2 of the measurement area 41 of the non-UPS section is, for example, 5 mm. The distance D between the center of the measurement area 31 of the UPS section and the center of the measurement area 41 of the non-UPS section, i.e., the interval D of the measurement distance, is, for example, 10 mm. In the photometering device 100 of this embodiment, accurate photometry can be performed even if the area and spacing between multiple measurement areas are relatively small. Furthermore, the performance of the display can be inspected from the photometry results.
[0060] Figure 12 is a schematic diagram showing an example of an object to be measured 1. The object to be measured 1 is, for example, a smartphone and has a foldable display 2. The display 2 can be folded in half with its center line as the folding point. The area of the display 2 that is folded, i.e., the area near the center line of the display 2, is called the folded portion 6. The area of the display 2 that is not folded, i.e., the area of the display 2 excluding the folded portion 6, is called the unfolded portion 8. From the viewpoint of reducing the influence of the in-plane light emission distribution in the display, it is preferable that the measurement area 61 of the folded portion and the measurement area 81 of the unfolded portion be set as close together as possible. Brightness and the like are measured in these measurement areas R. In Figure 12, the measurement area 61 of the folded portion is selected as a part of the folded portion 6, but the entire folded portion 6 may be used as the measurement area R.
[0061] The area of the bent portion 6 in the display is very narrow, and the measurement area 61 of the bent portion is also very narrow. On the other hand, the area of the non-bent portion 8 in the display is wide, so the measurement area 81 of the non-bent portion does not necessarily need to be as narrow as the measurement area 61 of the bent portion. Furthermore, from the viewpoint of obtaining sufficient light for measurement and improving accuracy, it is preferable that the measurement area 81 of the non-bent portion be somewhat wide.
[0062] [Display Inspection Method] The photometer 100 of this embodiment can accurately measure light in multiple measurement areas, even if the area is relatively small and the spacing is narrow. For displays equipped with a UPS, the UPS section 3 and the non-UPS section 4 are measured separately. The performance of the display can be inspected from the photometering results. For foldable displays, the foldable section 6 and the non-foldable section 8 are measured separately. The performance of the display can be inspected from the highly accurate photometering results. In other words, the accuracy of display inspection can be improved.
[0063] The following describes some of the variations of this disclosure.
[0064] [Modification 1] Figure 13 is a schematic diagram showing the configuration of the objective optical system 11, the light guide member 12, and the light receiving unit 13 in Modification 1. The light guide member 12 and the light receiving unit 13 do not have to be common, and may have different configurations for each measurement area. In Modification 1, the objective optical system has only a first lens group 111, and an aperture diaphragm 113 is provided at the focal position on the light receiving unit side of the first lens group 111. In Figure 13, the focal length of the first lens group 111 is f1.
[0065] By providing the aperture diaphragm 113, the light passing through a predetermined point in the opening of the aperture diaphragm 113 becomes light that has been emitted from within the measurement area R at the same angle. In other words, by providing the aperture diaphragm 113, light beams within the same angular range can be directed into the entrance of the light guide member 12 from all points within the measurement area R.
[0066] In this embodiment, the object to be measured 1 is a display, and the color tone of the display changes depending on the viewing angle. Therefore, by providing an aperture diaphragm 113 to capture light beams within the same angular range, the accuracy of the measurement can be improved. The shape of the aperture diaphragm 113 is not particularly limited and can be set to any shape such as a circle, ellipse, or square depending on the angle of light to be captured from the measurement area R.
[0067] [Modification 2] Figure 14 is a schematic diagram showing the configuration of the objective optical system 11, light guide member 12, and light receiving unit 13 in Modification 2. In Modification 2, the objective optical system 11 has a first lens group 111 and a second lens group 112. The focal position of the first lens group 111 on the light receiving unit side coincides with the focal position of the second lens group on the surface to be measured. An aperture diaphragm 113 may also be provided at this position. In Figure 14, the focal length of the first lens group 111 is f1, and the focal length of the second lens group 112 is f2.
[0068] The light guide member 12 and the light beam branching member 131, which propagate light from the opening of the field diaphragm 16 until it is received by the light receiving unit 132, have limitations on the angle at which light can propagate. Therefore, it is preferable that the angle of light passing through the opening of the field diaphragm 16 is small. In the modified example 2, as shown in Figure 14, the objective optical system 11 is provided such that the focal position on the light receiving unit side of the first lens group 111 and the focal position on the surface to be measured side of the second lens group coincide. This allows light incident perpendicularly from the measurement area R to the photometer 100 to be incident perpendicularly to the field diaphragm 16 even if the incident position at the field diaphragm 16 is away from the optical axis, thereby increasing the propagation efficiency in the light guide member 12 and the light beam branching member 131.
[0069] [Modification 3] Figure 15 is a schematic diagram showing the configuration of the objective optical system 11, the first light guide member 12A, and the first light receiving unit 13A in Modification 3. Note that in Figure 15, only the light from the first measurement area RA is shown, and the light from the second measurement area RB is omitted.
[0070] In Modification 3, the objective optical system 11 has a first lens group 111 and a second lens group 112. No aperture diaphragm is provided at the light-receiving unit side focal position 114 of the first lens group 111, but an aperture diaphragm 113 is provided at a position conjugate to the light-receiving unit side focal position 114 with respect to the second lens group 112 and the first light guide member 12A. In this case, the same effect as providing an aperture diaphragm at the light-receiving unit side focal position 114 can be obtained. Note that in Figure 15, the focal length of the first lens group 111 is f1.
[0071] The objective optical system 11 and the light guide member 12 have different optical axes. However, in Figure 15, the light emitted from the light receiving unit side focal position 114 is imaged at the position of the aperture diaphragm 113, and the position of the aperture diaphragm 113 can be said to be conjugate to the light receiving unit side focal position 114 with respect to the second lens group 112 and the first light guide member 12A. By providing the aperture diaphragm 113 at this position, the opening (aperture angle) of the aperture diaphragm 113 can be arbitrarily controlled for each measurement area R. For example, it is preferable to increase the aperture angle from the viewpoint of securing the amount of light, and to decrease the aperture angle from the viewpoint of securing measurement accuracy. Note that when the aperture diaphragm is provided at the light receiving unit side focal position 114, the opening (aperture angle) of the aperture diaphragm is the same in all measurement areas R, and the angle of the light taken in is the same in all measurement areas R.
[0072] Furthermore, even without providing the aperture diaphragm 113, the shape of the entrance of the first light beam branching member 131A can be restricted to provide the function of an aperture diaphragm. Figure 16 shows the same configuration as Figure 15, with the objective optical system 11, the first light guide member 12A, and the first light receiving unit 13A, but without the aperture diaphragm. In this case, the entrance of the first light beam branching member 131A also functions as an aperture diaphragm.
[0073] In this embodiment, the configurations of the light guide member 12 and the light receiving unit 13 described above may be partially combined.
[0074] In this embodiment, the photometric device 100 comprises an objective optical system 11, a plurality of light guide members 12, and a light receiving unit 13. The objective optical system 11 images light from a plurality of predetermined regions (measurement regions R) on the surface to be measured. The plurality of light guide members 12 guide the light from the plurality of measurement regions R imaged by the objective optical system 11 by focusing light. The light receiving unit 13 receives the light guided by the plurality of light guide members 12. This makes it possible to narrow the spacing between the plurality of measurement regions R and improve the accuracy of measurement.
[0075] In this embodiment, it is preferable to provide the field diaphragm 16 at a position conjugate to the surface to be measured with respect to the objective optical system 11. This allows for adjustment of the shape of the measurement area R.
[0076] In this embodiment, each of the multiple light guide members 12 has an incident surface to which light imaged by the objective optical system 11 is incident. Preferably, the first incident surface 121 located closest to the objective optical system 11 has positive optical power. This makes it possible to narrow the spacing between the multiple measurement regions R and improve the accuracy of the measurement.
[0077] In this embodiment, the field diaphragm 16 is provided at a position conjugate to the surface to be measured relative to the objective optical system 11. It is preferable that the position of the field diaphragm 16 and the position of the first incident surface 121 coincide in the optical axis direction of the light imaged by the objective optical system 11. This allows the width of the light beam passing through the aperture 161 of the field diaphragm 16 to be effectively narrowed without widening it.
[0078] In this embodiment, it is preferable that the light receiving unit 13 has a light beam branching member 131 that branches the light beam guided by the light guide member 12 into multiple light beams, and the same number of light receiving units 132 as the number of light beam branches. This makes it possible to measure the chromaticity in the measurement area R. In addition, it is possible to narrow the spacing between the multiple measurement areas R and improve the accuracy of the measurement.
[0079] In this embodiment, it is preferable that the light beam branching member 131 has an entrance at a non-imaging position relative to the object point, when each point in a plurality of predetermined regions (measurement region R) on the surface to be measured is considered an object point, in the objective optical system 11 and the light guide member 12. As a result, the light incident on the light beam branching member 131 is made uniform, and sufficient accuracy can be obtained even when the light beam is subsequently branched using the light beam branching member 131 and measured for each branched light beam.
[0080] In this embodiment, the light beams guided by the objective optical system 11 and the light guide member 12 from each point of a plurality of predetermined regions (measurement region R) on the surface to be measured are parallel light, and it is preferable that the light beam emitted from the centroid point of the predetermined region (measurement region R) is incident perpendicularly to the entrance of the light beam branching member 131. This allows the light incident on the entrance of the light beam branching member 131 to propagate efficiently.
[0081] In this embodiment, it is preferable that the objective optical system 11 includes at least a first lens group 111, and that an aperture diaphragm 113 is provided at the focal position on the light-receiving unit side of the first lens group 111. This allows light beams within the same angular range to be incident on the entrance opening of the light guide member 12 from all points within the measurement region R.
[0082] In this embodiment, the objective optical system 11 preferably comprises a first lens group 111 and a second lens group 112. Both the first lens group 111 and the second lens group 112 have positive optical power, and it is preferable that the focal position of the first lens group 111 on the light-receiving unit side coincides with the focal position of the second lens group 112 on the surface to be measured. As a result, light incident perpendicularly to the photometer 100 is incident perpendicularly to the light guide member 12, so that the light guide member 12 can efficiently guide the light beam to the light-receiving unit 13.
[0083] In this embodiment, it is preferable that the objective optical system 11 includes at least a first lens group. An aperture diaphragm 113 may be provided in the optical system, which is located on the light-receiving unit 13 side of the focal position of the first lens group 111 on the light-receiving unit side, and which includes a light guide member 12, at a position conjugate to the focal position of the first lens group 111 on the light-receiving unit side. This allows the aperture (aperture angle) of the aperture diaphragm 113 to be controlled arbitrarily for each measurement region R.
[0084] In this embodiment, the objective optical system 11 preferably comprises at least a first lens group. In an optical system including a light guide member 12, located on the light-receiving unit 13 side of the focal position on the light-receiving unit side of the first lens group 111, a light beam branching member 131 may be provided at a position conjugate to the focal position on the light-receiving unit side of the first lens group 111, which branches the light guided by the light guide member 12 into multiple light beams. As a result, the entrance opening of the light beam branching member 131 functions as an aperture diaphragm.
[0085] The display inspection method of this embodiment uses a photometric device 100. The display inspection method includes the step of photometrically measuring a predetermined area (measurement area R) consisting of the area on which the under panel solution is mounted (measurement area 31 of the UPS section) and the surrounding area (measurement area 41 of the non-UPS section). Alternatively, the display inspection method includes the step of photometrically measuring a predetermined area consisting of the area where the display is folded (measurement area 61 of the folded section) and the surrounding area (measurement area 81 of the non-folded section). This improves the accuracy of display inspection.
[0086] Furthermore, the detailed configuration and operation of each device constituting the photometric device may also be modified as appropriate, without departing from the spirit of this disclosure.
[0087] This disclosure enables a photometric device to narrow the spacing between multiple measurement areas and improve measurement accuracy. In a display equipped with a UPS, the photometric device is used to measure the UPS area and the non-UPS area separately. In a foldable display, the photometric device is used to measure the foldable area and the non-foldable area separately. The performance of the display can be inspected from the photometric results. In other words, displays equipped with a UPS and foldable displays can be inspected more accurately.
[0088] 11 Objective optical system 111 First lens group 112 Second lens group 113 Aperture diaphragm 114 Focal position on the light-receiving unit side 12 Light guide member 13 Light-receiving unit 131 Light beam branching member 132 Light-receiving section 16 Field diaphragm 161 Aperture 100 Photometer R Measurement area
Claims
1. A photometric apparatus comprising: an objective optical system that images light from multiple predetermined regions on a surface to be measured; multiple light guiding members that guide the light from the multiple predetermined regions imaged by the objective optical system by a light-gathering action; and a light-receiving unit that receives the light guided by the multiple light guiding members.
2. The photometer according to claim 1, further comprising a field diaphragm at a position conjugate to the surface to be measured with respect to the objective optical system.
3. The photometric apparatus according to claim 1 or 2, wherein each of the plurality of light guide members has an incident surface into which light imaged by the objective optical system is incident, and the first incident surface located closest to the objective optical system has positive optical power.
4. The photometer according to claim 3, wherein the field diaphragm is provided at a position conjugate to the surface to be measured with respect to the objective optical system, and the position of the field diaphragm and the position of the first incident surface coincide in the optical axis direction of the light imaged by the objective optical system.
5. The photometer according to claim 1 or 2, wherein the light receiving unit has a light beam branching member that branches the light beam guided by the light guiding member into a plurality of light beams, and a number of light receiving units equal to the number of light beam branches.
6. The photometer according to claim 5, wherein the light beam branching member has an entrance opening at a non-imaging position relative to a plurality of predetermined regions on the surface to be measured, when each point in the region is defined as an object point.
7. The photometric apparatus according to claim 6, wherein the light beams guided by the objective optical system and the light guide member from each point of a plurality of predetermined regions on the surface to be measured are parallel light, and the light beam emitted from the centroid of the predetermined region is incident perpendicularly to the entrance of the light beam branching member.
8. The photometer according to claim 1 or 2, wherein the objective optical system comprises at least a first lens group, and the first lens group is provided with an aperture diaphragm at the focal position on the light-receiving unit side.
9. The photometer according to claim 1 or 2, wherein the objective optical system comprises a first lens group and a second lens group, both of which have positive optical power, and the focal position of the first lens group on the light-receiving unit side coincides with the focal position of the second lens group on the surface to be measured.
10. The photometer according to claim 1 or 2, wherein the objective optical system comprises at least a first lens group, and the optical system, which includes the light guide member, is provided with an aperture diaphragm at a position conjugate to the light-receiving unit side focal position of the first lens group, located on the light-receiving unit side than the light-receiving unit side focal position of the first lens group.
11. The photometer according to claim 1 or 2, wherein the objective optical system comprises at least a first lens group, and the optical system, which includes the light guide member, is located on the light-receiving unit side of the first lens group's focal position on the light-receiving unit side, and the optical system is further comprising a light beam branching member at a position conjugate to the light-receiving unit side of the first lens group for branching the light guided by the light guide member into a plurality of light beams.
12. A method for inspecting a display, comprising the steps of using the photometric apparatus described in claim 1 or claim 2 to photometer an area on which an under panel solution is mounted and other adjacent areas as predetermined areas, or a step of photometering an area on which the display is folded and other adjacent areas as predetermined areas.