Display device

Abstract

A display device according to the present invention comprises a plurality of light emitting elements, a light receiving unit, and a compensation unit. The compensation unit executes compensation of the light emission intensity of at least one the plurality of light emitting elements on the basis of the received-light intensity of light including light from the light emitting elements in the light receiving unit and the received light intensity of light including light from light emitting sections of the light emitting elements, said intensities being measured in a state in which a substrate of the display device is bent.

Description

Display device

[0001] The present disclosure relates to a display device including a plurality of light-emitting elements.

[0002] In Patent Document 1, in a display device capable of folding a display unit, by measuring the light reception intensity on a second display surface of light from a first display surface, a technique for compensating the light emission intensity of each light-emitting element on the first display surface is disclosed. Patent Document 1 discloses that, between the first display surface and the second display surface, by reversing the relationship between light emission and light reception, it is also possible to perform compensation for the light emission intensity of each light-emitting element on the second display surface.

[0003] Korean Patent Publication No. 10-2022-0147962

[0004] In the display device described in Patent Document 1, both the light-emitting elements located on the first display surface and the light-emitting elements located on the second display surface are used for display on each display surface. Therefore, when the display in the display device is continuously executed, variations occur in the deterioration of each light-emitting element on each display surface. As a result, variations occur in the light emission efficiency and light reception sensitivity of each light-emitting element, and thus, in the technique described in Patent Document 1, it may be difficult to accurately compensate for the light emission intensity of each light-emitting element.

[0005] A display device according to one aspect of the present disclosure is a display device having a display area and a non-display area located outside the display area in a plan view, the display device having a substrate having a first part, a second part, and a folding part located between the first part and the second part and causing the first part and the second part to face each other when folded, a plurality of light-emitting elements including a first light-emitting element on the first part located in a portion of the substrate that overlaps with the display area in a plan view of the substrate and emits light when driven and generates an electromotive force when receiving light, and a portion of the second part located in a portion of the substrate that overlaps with the non-display area in a plan view of the substrate and causes the substrate to fold The device includes: a light-receiving unit that receives a portion of the light from the first light-emitting element and measures the light-receiving intensity in a bent state in which the first and second parts are bent at the bending portion and face each other; a light-emitting unit that is located in the portion of the second part that overlaps with the non-display area in a plan view of the substrate and emits light toward the first light-emitting element in the bent state; and a compensation unit that performs compensation for the light-emitting intensity of at least one of the plurality of light-emitting elements based on the light-receiving intensity of the light including the light from the first light-emitting element measured in the bent state at the light-receiving unit and the light-receiving intensity of the light including the light from the light-emitting unit at the first light-emitting element.

[0006] According to one aspect of this disclosure, the accuracy of compensation for the light emission intensity of each light-emitting element in a display device is improved.

[0007] This document provides a schematic plan view of the display device according to Embodiment 1, a schematic side cross-sectional view of the display device in a folded state, and an enlarged view of the schematic side cross-section. This document also provides another enlarged view of the schematic side cross-section of the display device according to Embodiment 1 in a folded state. This document also provides another enlarged view of the schematic side cross-section of the display device according to Embodiment 1 in a folded state. This document also provides another schematic plan view of the display device according to Embodiment 1. This document also provides a schematic plan view of the display device according to Embodiment 2, and an enlarged view of the schematic side cross-section of the display device in a folded state.

[0008] [Embodiment 1] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, unless otherwise specified, components having the same function are denoted by the same reference numeral and their descriptions are omitted. Also, in this disclosure, for the sake of simplicity of illustration, the scale may differ between drawings even for components denoted by the same reference numeral. However, the components shown in each drawing of this disclosure are merely examples, and their scales are not limited to those shown in the drawings.

[0009] <Overview of the Display Device> Figure 1 shows a schematic plan view F11 of the display device 1 according to this embodiment, a schematic side cross-sectional view F12 of the display device 1 in a folded state described later, and an enlarged view F13 of a part of the schematic side cross-sectional view F12. The x, y, and z axes shown in each drawing of this disclosure correspond to each other in the multiple drawings.

[0010] In this disclosure, all schematic plan views of the display device 1, including schematic plan view F11, are views of the display device 1 as seen from the display surface side of the display area DA, along the normal direction of the upper surface of the substrate 10, which will be described later. In the schematic plan views of the display device 1 according to this disclosure, the row direction DR, which is the longitudinal direction of the display device 1, is the left-right direction toward the plane of the paper, and the column direction DL, which is the short direction of the display device 1, is the up-down direction toward the plane of the paper.

[0011] In this disclosure, all schematic plan views of the display device 1, including schematic side cross-sectional view F12, show a side cross-section of the display device 1 in the folded state described later, for example, in the longitudinal direction of the display device 1, in other words, in a plane along the left-right direction toward the plane of the schematic plan view of the display device 1. In addition, all schematic plan views of the display device 1 according to this disclosure show a side cross-section passing through the plurality of light-emitting elements 2 and non-light-emitting elements 3 described later, for example, a side cross-section parallel to the row direction DR.

[0012] In this disclosure, all enlarged views of the display device 1, including enlarged view F13, show an enlarged view of region A shown in the schematic side cross-sectional view F12. In other words, all enlarged views of the display device 1 according to this disclosure show the vicinity of the end on the side opposite to the folded portion 13 of the first part 11 and the second part 12 of the display device 1, as described later, when it is folded. In addition, all enlarged views of the display device 1 according to this disclosure show an enlarged view of the region including the non-visible light-emitting element 3, as described later, and the light-emitting element 2 located in the vicinity of the non-visible light-emitting element 3 of the display device 1, when it is folded.

[0013] The display device 1 comprises a plurality of light-emitting elements 2, at least one non-light-emitting element 3, and at least one compensation unit 4. The display device 1 also comprises a substrate 10, and in a plan view of the substrate 10, it has a display area DA and a non-light-emitting area NA located outside the display area DA.

[0014] The display device 1 is provided with a plurality of light-emitting elements 2 arranged on the substrate 10 at a position that overlaps with the display area DA in a plan view of the substrate 10. The display device 1 is also located on the substrate 10 in a portion that overlaps with the non-display area NA in a plan view of the substrate 10.

[0015] In particular, the display area DA may be rectangular in a plan view of the substrate 10, and the multiple light-emitting elements 2 may be arranged two-dimensionally in a plan view of the substrate 10. For example, the multiple light-emitting elements 2 may be arranged in a direction along one side of the rectangular substrate 10 in a plan view, for example, along the row direction DR, and also in a direction along the other side substantially perpendicular to that side, for example, along the column direction DL. In this case, the display device 1 may be provided with multiple non-display light-emitting elements 3 arranged along any edge of the substrate 10 at a position that overlaps with the non-display area NA in a plan view of the substrate 10. For example, as shown in Figure 1, the display device 1 may be provided with each of the multiple non-display light-emitting elements 3 arranged along the column direction DL for each of the multiple light-emitting elements 2 arranged along the row direction DR.

[0016] <Light-emitting elements> Each of the light-emitting elements 2 is electrically connected to each of the multiple drive circuits (not shown) which are arranged in a plurality at positions overlapping with the display area DA in a plan view of the substrate 10. Each of the light-emitting elements 2 emits light when driven via the drive circuit. For example, the display device 1 drives each of the light-emitting elements 2 by controlling the core drive circuit via a driver (not shown) which is located on the substrate 10 at a position overlapping with the non-display area NA in a plan view. As a result, the display device 1 extracts light individually from the plurality of light-emitting elements 2 to realize a display in the display area DA.

[0017] The light-emitting element 2 may include, for example, a light-emitting layer between two electrodes containing a light-emitting material such as an organic fluorescent material, an organic phosphorescent material, or a light-emitting quantum dot. In this case, the display device 1 may extract light from each light-emitting layer of the light-emitting element 2 by applying a voltage to the other electrode while keeping one electrode of the light-emitting element 2 at a substantially constant potential.

[0018] Each of the light-emitting elements 2 generates an electromotive force by receiving light, such as by receiving ambient light incident from the display surface side of the display area DA. For example, each of the light-emitting elements 2 may be equipped with a transparent electrode on the display surface side of the display area DA, and light from the aforementioned light-emitting layer may be emitted towards the transparent electrode, while light incident from the side of the transparent electrode may be received by the light-emitting material of the light-emitting layer. In this way, each of the light-emitting elements 2 may generate holes and electrons from the light-receiving light-emitting material and transport them to each of the two electrodes, thereby creating a potential difference between the two electrodes and generating an electromotive force. Since this electromotive force is proportional to the intensity of the light received by the light-emitting element 2, the intensity of the light received by the light-emitting element 2 can be measured by measuring the magnitude of the electromotive force generated by the light-emitting element 2.

[0019] <Non-display light-emitting element and compensation unit> The non-display light-emitting element 3 may have the same configuration as the light-emitting element 2, except that it is located in a part that overlaps with the non-display area NA in a plan view of the substrate 10. In other words, the non-display light-emitting element 3 emits light in conjunction with driving via the drive circuit of the substrate 10, for example, and generates an electromotive force upon receiving light. However, the non-display light-emitting element 3 does not contribute to the display by the display device 1, and is not driven even when the display device 1 is performing a display.

[0020] The compensation unit 4 compensates for the light emission intensity of at least one of the multiple light-emitting elements 2, for example, by a method described later. The light emission intensity of the light-emitting elements 2 may change for the same driving voltage due to, for example, deterioration of the light-emitting material, and this change in light emission intensity may also differ depending on the position of the light-emitting element 2. Therefore, by compensating the light emission intensity of the light-emitting elements 2 with the compensation unit 4, the display device 1 can perform a higher quality display regardless of the change in the light emission intensity of the light-emitting elements 2.

[0021] The position of the compensation unit 4 is not particularly limited, but may be in a position that does not interfere with the display by the display device, for example, it may be located inside the substrate 10 near the corner of the substrate 10 in a plan view. Also, the compensation unit 4 may be included in a part of a device such as a driver that is located in a position where the substrate 10 overlaps with the non-display area NA in a plan view.

[0022] <Substrate> The substrate 10 includes a first part 11, a second part 12, and a bent part 13. In particular, as shown in schematic plan view F11, the bent part 13 is located in a plan view of the substrate 10 from one end of the substrate 10 to the end on the opposite side, and is located between the first part 11 and the second part 12. The substrate 10 can be folded at least at the bent part 13 so that the display surface of the display device 1 is facing inward. This makes the display device 1 smaller overall when the substrate 10 is folded, and allows for a wider display area DA when the substrate 10 is unfolded.

[0023] The bent portion 13 brings the first portion 11 and the second portion 12 to face each other as it is bent. In particular, as shown in the schematic side cross-sectional view F12, the substrate 10 can be bent at the bent portion 13 such that, for example, the ends of the first portion 11 and the second portion 12 on the sides opposite to the bent portion 13 face each other. In this disclosure, the display device 1 in the state in which the substrate 10 is bent at the bent portion 13 so that the first portion 11 and the second portion 12 face each other, as shown in the schematic side cross-sectional view F12, is referred to as the display device 1 in the bent state.

[0024] In the folded display device 1, the normal directions of the upper surfaces on the display side of the first part 11 and the second part 12 are approximately parallel. In other words, in the folded display device 1, the planar direction DP of the upper surfaces on the display side of the first part 11 and the second part 12 are approximately parallel. Furthermore, the thickness direction DT of the folded display device 1 is approximately the same direction as the normal direction of the upper surfaces on the display side of the first part 11 and the second part 12, in other words, it is approximately perpendicular to the planar direction DP. In this disclosure, the enlarged view of the display device 1, including enlarged view F13, shows a portion of the approximate side cross-section of the display device 1 enlarged, with the vertical direction and thickness direction DT relative to the plane of the paper, and the left-right direction relative to the plane of the paper as the planar direction DP.

[0025] In the folded display device 1 according to this embodiment, the positional relationships of each of the light-emitting elements 2 located on the first part 11, each of the light-emitting elements 2 located on the second part 12, and each of the non-displaying light-emitting elements 3 are known. For example, even if the folded part 13 of the substrate 10 of the display device 1 is repeatedly folded and unfolded, the distance in the thickness direction DT between the first part 11 and the second part 12 of the substrate 10 in the folded display device 1 may remain constant.

[0026] For example, the substrate 10 may contain a flexible material such as a resin material in at least the bendable portion 13 so that it can be bent at least in the bendable portion 13. Alternatively, the substrate 10 may contain a rigid material such as a glass substrate in the first portion 11 and the second portion 12, or it may contain the same flexible material as the bendable portion 13. In this case, the display device 1 may be a flexible display device that can be bent regardless of its position in a plan view of the substrate 10. The display device 1 may have light-emitting elements 2 at any of the positions of the first portion 11, the second portion 12, and the bendable portion 13 in the portion of the substrate 10 that overlaps with the display area DA in a plan view.

[0027] <Positional relationship of light-emitting elements> In particular as shown in the enlarged view F13, the display device 1 includes a first light-emitting element 21 located on the first part 11 of the substrate 10 as one of a plurality of light-emitting elements 2. Specifically, the first light-emitting element 21 is located near the end of the portion of the substrate 10 in the first part 11 that overlaps with the display area DA in a plan view, on the side opposite to the bent portion 3. Also, in particular as shown in the enlarged view F13, the display device 1 includes a second light-emitting element 22 located on the second part 12 of the substrate 10 as one of a plurality of light-emitting elements 2. Specifically, the second light-emitting element 22 is located near the end of the portion of the substrate 10 in the second part 12 that overlaps with the display area DA in a plan view, on the side opposite to the bent portion 3. In addition, in particular as shown in the enlarged view F13, the display device 1 includes one of the non-display light-emitting elements 3 located near the end of the portion of the substrate 10 in the second part 12 that overlaps with the non-display area NA in a plan view, on the side opposite to the bent portion 3.

[0028] When the display device 1 is in a folded state, the first light-emitting element 21 and the second light-emitting element 22 face each other in the thickness direction DT. In this disclosure, "two light-emitting elements face each other" means that the upper surface of one light-emitting element on the display surface side of the display device 1 overlaps with at least a portion of the upper surface of the other light-emitting element on the display surface side of the display device 1 in the thickness direction DT.

[0029] Furthermore, one of the non-visible light-emitting elements 3 is adjacent to the second light-emitting element 22 in the planar direction DP, particularly in the row direction DR. In this disclosure, "two light-emitting elements are adjacent" means that no other light-emitting elements, including other light-emitting elements 2 or non-visible light-emitting elements 3, are located between the two light-emitting elements. Also, in this disclosure, "light-emitting element" in the expression "two light-emitting elements are adjacent" includes the non-visible light-emitting element 3.

[0030] <Light-receiving and light-emitting section> In the display device 1 in the folded state, when the first light-emitting element 21 is driven and emits light 21L, light including light 21L is incident on one of the invisible light-emitting elements 3. As a result, the invisible light-emitting element 3 receives light including a portion of light 21L and generates an electromotive force. As described above, the intensity of the light received by the invisible light-emitting element 3 can be measured from this electromotive force. Therefore, the invisible light-emitting element 3 functions as a light-receiving section that receives light including a portion of light 21L from the first light-emitting element 21 and measures the received light intensity. The invisible light-emitting element 3 may also measure the light emission intensity of the first light-emitting element 21 by measuring the light intensity after removing the influence of other ambient light, etc., from the received light intensity.

[0031] In the folded display device 1, when the non-visible light-emitting element 3 located near the first light-emitting element 21 is driven and emits light 3L, light including light 3L is incident on the first light-emitting element 21. As a result, the non-visible light-emitting element 3 functions as a light-emitting part that emits light toward the first light-emitting element 21. Furthermore, the first light-emitting element 21 measures the light intensity received by the first light-emitting element 21, which includes light 3L from the non-visible light-emitting element 3, from the electromotive force described above. The first light-emitting element 21 may also measure the light emission intensity of the non-visible light-emitting element 3 by measuring the light intensity after removing the influence of other ambient light, etc., on the light intensity of the light 3L.

[0032] <Compensation for the light emission intensity of the first light-emitting element> The compensation unit 4 emits light 21L to one of the invisible light-emitting elements 3 and performs compensation for the light emission intensity of the first light-emitting element 21 that receives light including light 3L from the invisible light-emitting element 3. In particular, the compensation unit 4 performs compensation for the light emission intensity of the first light-emitting element 21 based on the light reception intensity of the light including light 21L at the invisible light-emitting element 3 and the light reception intensity of the light including light 3L at the first light-emitting element 21.

[0033] Since the light-emitting elements 2, including the first light-emitting element 21, are used for displaying information in the display device 1, if the display device 1 is used continuously for a long period of time, each of the light-emitting elements 2 may deteriorate, as described above. Deterioration of the light-emitting elements 2 may cause a decrease in the light emission intensity of the light-emitting elements 2 for the same driving voltage. Furthermore, deterioration of the light-emitting elements 2 may cause a decrease in the electromotive force generated in response to received light, in other words, it may cause a decrease in the light-receiving sensitivity of the light-emitting elements 2. However, the rate of decrease in the light emission intensity of the light-emitting elements 2 due to deterioration of the light-emitting elements 2 does not necessarily coincide with the rate of deterioration in the light-receiving sensitivity of the light-emitting elements 2.

[0034] For example, the degradation rate of the light emission intensity of the first light-emitting element 21 can be calculated based on the difference between the actual light emission intensity of the first light-emitting element 21 driven at a certain drive voltage and the initial or ideal value of the light emission intensity of the first light-emitting element 21 driven at the same drive voltage as the first light-emitting element 21. Furthermore, the degradation rate of the light-receiving sensitivity of the first light-emitting element 21 can be calculated based on the difference between the electromotive force actually generated in the first light-emitting element 21 when it receives a certain light and the initial or ideal value of the electromotive force generated in the first light-emitting element 21 when it receives light of the same intensity as the first light.

[0035] As described above, the non-display light-emitting element 3 does not contribute to the display of the display device 1 and is hardly driven regardless of whether the display device 1 is displaying or not. For this reason, even if the display device 1 is used continuously for a long period of time, there is almost no deterioration of the non-display light-emitting element 3. Therefore, the light emission intensity and light receiving sensitivity of the non-display light-emitting element 3 can be considered to be approximately the same as the initial or ideal values ​​of the light emission intensity and light receiving sensitivity of the non-display light-emitting element 3, regardless of the usage time of the display device 1, etc.

[0036] As described above, in the folded display device 1, the positional relationship between each of the light-emitting elements 2 located on the first part 11 and each of the light-emitting elements 2 located on the second part 12 is known. More specifically, in the folded display device 1, the relative positions of the first light-emitting element 21 and the non-emitting element 3 are known. Therefore, in the folded display device 1, the light-receiving intensity of the non-emitting element 3 when light of a predetermined intensity is emitted from the first light-emitting element 21 can be known. Accordingly, it is possible to accurately measure the light emission intensity of the first light-emitting element 21 from the light-receiving intensity of the non-emitting element 3 when the first light-emitting element 21 is emitted in the folded display device 1.

[0037] Therefore, the display device 1 can measure the actual light emission intensity of the first light-emitting element 21 and the rate of degradation of the light emission intensity of the first light-emitting element 21 due to the degradation of the first light-emitting element 21, based on the light-receiving intensity of light including light 21L at the non-display light-emitting element 3. The display device 1 can also measure the actual light-receiving sensitivity of the first light-emitting element 21 and the rate of degradation of the light-receiving sensitivity of the first light-emitting element 21 due to the degradation of the first light-emitting element 21, based on the light-receiving intensity of light including light 3L at the first light-emitting element 21.

[0038] In this embodiment, the compensation unit 4 may perform the measurement of the degradation rate of the light emission intensity and light receiving sensitivity of each of the light-emitting elements 2, including the first light-emitting element 21. Alternatively, the display device 1 may be provided with a calculation unit or the like capable of performing calculations to measure the degradation rate of the light emission intensity and light receiving sensitivity of each of the light-emitting elements 2, for example, at a position that overlaps with the non-display area NA in a plan view of the substrate 10.

[0039] The compensation unit 4 adjusts the applied voltage applied to the first light-emitting element 21 when the display device 1 performs display, based on the degradation rate of the light-emitting intensity of the first light-emitting element 21, thereby compensating the light-emitting intensity of the first light-emitting element 21. The display device 1, which performs display using the first light-emitting element 21 whose light-emitting intensity has been compensated, enables a display with improved display quality.

[0040] The compensation of the light emission intensity of any light-emitting element 2, including the first light-emitting element 21, by the compensation unit 4 may include storing data in a memory (not shown) that links information about the light-emitting element 2 to which the light emission intensity compensation is to be performed with information about the correction value of the applied voltage to the light-emitting element 2. In this case, for example, a driver provided by the display device 1 may read the above data from the memory and drive the light-emitting element 2 to which the light emission intensity compensation is to be performed based on the above data.

[0041] The display device 1 according to this embodiment includes a light-receiving unit and a light-emitting unit, which have substantially constant light-receiving sensitivity and substantially constant light-emitting intensity, as a non-display light-emitting element 3, regardless of the usage time of the display device 1. Furthermore, the display device 1 compensates the light-emitting intensity of the first light-emitting element 21 based on the light-receiving intensity of the non-display light-emitting element 3 and the light-receiving intensity of the first light-emitting element 21 using a compensation unit 4. As a result, the display device 1 can compensate the light-emitting intensity of the first light-emitting element 21 with greater accuracy, regardless of the differences in degradation among the plurality of light-emitting elements 2 used for display.

[0042] The display device 1 according to this embodiment includes a light-receiving unit and a light-emitting unit used for compensating the light emission intensity of the first light-emitting element 21 by the compensation unit 4, as a non-display light-emitting element 3. This eliminates the need for the display device 1 to separately provide a light-receiving unit such as a camera or a light-emitting unit such as an LED light source in the non-display area NA, etc. Furthermore, the non-display light-emitting element 3 may have the same configuration as the light-emitting element 2 except for its position on the substrate 10, in which case the formation of the non-display light-emitting element 3 in the manufacturing method of the display device 1 can be carried out together with the formation of the light-emitting element 2.Therefore, with the above configuration, the display device 1 enables compensation of the light emission intensity of the first light-emitting element 21 with a simpler configuration and simplifies or reduces the cost of the manufacturing method.

[0043] As described above, the compensation of the light emission intensity of the first light-emitting element 21 by the compensation unit 4 is performed when the display device 1 is in a bent state. For example, the display device 1 may perform the above-mentioned compensation when it detects that the substrate 10 has been bent by the user using an unillustrated detection unit. Alternatively, the display device 1 may perform the above-mentioned compensation each time it detects that the substrate 10 has been bent a predetermined number of times.

[0044] The bending of the display device 1 often occurs when the user has finished using the display device 1, such as when the user has finished viewing the display of the display device 1. Therefore, the display device 1 can execute the compensation of the emission intensity of the first light-emitting element 21 by the compensation unit 4 for each use of the display device 1 by the user. Further, the compensation of the emission intensity of the first light-emitting element 21 by the compensation unit 4 is executed when the display device 1 is in the bent state. Therefore, the display device 1 reduces the emission of the first light-emitting element 21 and the non-display light-emitting element 3, etc. during the compensation of the emission intensity of the first light-emitting element 21 by the compensation unit 4 from being visually recognized by the user.

[0045] <Compensation of Emission Intensity of Second Light-Emitting Element> The display device 1 according to the present embodiment can execute the compensation of the emission intensity of a light-emitting element 2 different from the first light-emitting element 21 by the compensation unit 4. For example, the display device 1 can execute the compensation of the emission intensity of the second light-emitting element 22 by the compensation unit 4. The compensation of the emission intensity of the second light-emitting element 22 by the compensation unit 4 will be described in detail with reference to FIG. 2. FIG. 2 is another enlarged view of the display device 1 in the bent state.

[0046] In the bent state of the display device 1, the light 21L emitted from the first light-emitting element 21 may be received not only by the non-display light-emitting element 3 but also by the second light-emitting element 22 facing the first light-emitting element 21, as shown in FIG. 2. In this case, an electromotive force is generated in the second light-emitting element 22 by receiving light including the light 21L from the first light-emitting element 21.

[0047] Here, by the method described above, the deterioration rate of the emission intensity of the first light-emitting element 21 can be made known. Also, in the display device 1 in the bent state, the relative positions of the first light-emitting element 21 and the second light-emitting element 22 are substantially constant. Therefore, it is possible to make the initial value or the ideal value of the received light intensity of the second light-emitting element 22 when light of a predetermined intensity is emitted from the first light-emitting element 21 in the display device 1 in the bent state known. Therefore, by measuring the actual received light intensity of the second light-emitting element 22 when the first light-emitting element 21 emits light, it is possible to measure the deterioration rate of the light-receiving sensitivity of the second light-emitting element 22.

[0048] Further, as shown in FIG. 2, when not only the non-display light-emitting element 3 but also the second light-emitting element 22 emits light in the folded state of the display device 1, the first light-emitting element 21 receives light including not only the light 3L from the non-display light-emitting element 3 but also the light 22L from the second light-emitting element 22. In this case, an electromotive force is generated in the first light-emitting element 21 by receiving light including the light 3L from the non-display light-emitting element 3 and the light 22L from the second light-emitting element 22.

[0049] Here, since the degradation rate of the light reception sensitivity of the first light-emitting element 21 can be made known by the method described above, the actual electromotive force generated in the first light-emitting element 21 when receiving light of a predetermined intensity can be made known. Also, as described above, since it can be considered that almost no degradation of the light emission intensity of the non-display light-emitting element 3 has occurred, the intensity of the light 3L from the non-display light-emitting element 3 can be made substantially constant.

[0050] Further, in the display device 1 in the folded state, the relative positions of the first light-emitting element 21 with respect to the second light-emitting element 22 and the non-display light-emitting element 3 are substantially constant. Therefore, it is possible to make known the light reception intensity of the first light-emitting element 21 when light of a predetermined intensity is emitted from each of the second light-emitting element 22 and the non-display light-emitting element 3.

[0051] Therefore, by measuring the electromotive force generated in the first light-emitting element 21 when the second light-emitting element 22 and the non-display light-emitting element 3 emit light, the light reception intensity in the first light-emitting element 21 can be measured. Then, by subtracting the component of the light 3L from the light reception intensity, the component of the light 22L in the light reception intensity in the first light-emitting element 21 can be measured. As described above, the actual intensity of the light 22L from the second light-emitting element 22 can be measured, and thus the degradation rate of the light emission intensity of the second light-emitting element 22 can be measured.

[0052] Thereby, based on the degradation rate of the light emission intensity of the second light-emitting element 22, the compensation unit 4 adjusts the applied voltage applied to the second light-emitting element 22 when the display device 1 executes display, and executes compensation for the light emission intensity of the second light-emitting element 22. The display device 1 that performs display using the second light-emitting element 22 whose light emission intensity is compensated enables display with improved display quality.

[0053] In this embodiment, the display device 1 compensates for the light emission intensity of the second light-emitting element 22 based on the light reception intensity of the non-display light-emitting element 3 and the second light-emitting element 22, respectively, and the light reception intensity of the first light-emitting element 21, using a compensation unit 4. As a result, the display device 1 can compensate for the light emission intensity of the second light-emitting element 22 with greater accuracy, regardless of differences in degradation among the multiple light-emitting elements 2 used for display.

[0054] In particular, the compensation unit 4 according to this embodiment does not perform compensation for the emission intensity of the second light-emitting element 22 based solely on the light-receiving intensity of the second light-emitting element 22 including light 21L and the light-receiving intensity of the first light-emitting element 21 including light 22L. More specifically, the compensation unit 4 performs compensation for the emission intensity of the second light-emitting element 22 based on the light-receiving intensity of the first light-emitting element 21 including light 3L and light 22L. In other words, the compensation unit 4 performs compensation for the emission intensity of the second light-emitting element 22 using the non-visible light-emitting element 3 as well.

[0055] With the above configuration, the compensation unit 4 can use the non-luminescent element 3, which can be considered to have no degradation in luminous efficiency and light-receiving sensitivity as described above, to compensate for the luminous intensity of the second element 22. Therefore, with the above configuration, the compensation unit 4 can perform compensation for the luminous intensity of the second element 22 with greater accuracy.

[0056] However, as described above, the degradation rate of light emission intensity and light reception sensitivity of the first light-emitting element 21 has already been determined by the method described above. For this reason, in this embodiment, the compensation unit 4 may perform compensation for the light emission intensity of the second light-emitting element 22 based only on the light reception intensity of the second light-emitting element 22 with respect to light including light 21L and the light reception intensity of the first light-emitting element 21 with respect to light including light 22L.

[0057] In this case as well, the degradation rate of the light emission intensity and light receiving sensitivity of the first light-emitting element 21 is measured based on the light receiving intensity of the first light-emitting element 21 with light including light 3L and the light receiving intensity of the non-receiving light-emitting element 3 with light including light 21L, as described above. Therefore, in the above case as well, the compensation unit 4 also performs compensation for the light emission intensity of the second light-emitting element 22 based on the light receiving intensity of the first light-emitting element 21 with light including light 3L and the light receiving intensity of the non-receiving light-emitting element 3 with light including light 21L.

[0058] Furthermore, in this embodiment, an example has been described in which the compensation unit 4 performs compensation for the light emission intensity of the first light-emitting element 21, and then performs compensation for the light emission intensity of the second light-emitting element 22, but the embodiment is not limited to this. For example, the display device 1 may emit light from the first light-emitting element 21, the second light-emitting element 22, and the non-emitting element 3 in the folded state prior to the compensation unit 4 performing compensation for the light emission intensity of the first light-emitting element 21. In this way, the display device 1 may measure the degradation rate of light emission intensity and light receiving sensitivity of each of the first light-emitting element 21 and the second light-emitting element 22 at the same time using the method described above. In this method, the compensation unit 4 may perform compensation for the light emission intensity of each of the first light-emitting element 21 and the second light-emitting element 22 at the same time. With the above configuration, the compensation unit 4 can perform compensation for the light emission intensity of multiple light-emitting elements 2 at the same time, so it can perform compensation for the light emission intensity of more light-emitting elements 2 in a shorter time or with simpler operation.

[0059] In the folded state of the display device 1, the first light-emitting element 21 and the second light-emitting element 22 face each other. This allows the display device 1 to bring the light-emitting portion of the first light-emitting element 21 and the light-emitting portion of the second light-emitting element 22 closer together. With this configuration, the display device 1 increases the intensity of the light 21L incident on the second light-emitting element 22 and the intensity of the light 22L incident on the first light-emitting element 21, and consequently, the compensation unit 4 can perform compensation of the light emission intensity of the second light-emitting element 22 with greater accuracy.

[0060] In the display device 1, the second light-emitting element 22 and the non-emitting element 3 are adjacent to each other. Therefore, when the display device 1 is folded, it is easier to ensure that both the second light-emitting element 22 and the non-emitting element 3 receive the light 21L from the first light-emitting element 21. Thus, with the above configuration, the display device 1 can perform compensation of the light emission intensity of the second light-emitting element 22 by the compensation unit 4 with a simpler configuration or with greater accuracy.

[0061] <Compensation for the light emission intensity of the third light-emitting element> Further compensation for the light emission intensity of the light-emitting element 2 by the compensation unit 4 will be explained in detail with reference to Figure 3. Figure 3 shows other enlarged views F31 and F32 of the display device 1 in the folded state. In particular, enlarged views F31 and F32 show the third light-emitting element 23 and the fourth light-emitting element 24 of the light-emitting element 2.

[0062] The third light-emitting element 23 is located on the first part 11 of the substrate 10. In particular, the third light-emitting element 23 is adjacent to the side of the bent portion 13 of the first light-emitting element 21 in the planar direction DP, especially in the row direction DR. The fourth light-emitting element 24 is located on the second part 12 of the substrate 10. In particular, the fourth light-emitting element 24 is adjacent to the side of the second light-emitting element 22 opposite to the non-displaying light-emitting element 3 in the planar direction DP, especially in the row direction DR. Also, in the folded state of the display device 1, the third light-emitting element 23 and the fourth light-emitting element 24 face each other.

[0063] As shown in the enlarged view F31, assume that when the display device 1 is folded, light 21L is emitted from the first light-emitting element 21 and light 23L is emitted from the third light-emitting element 23. In this embodiment, light including a portion of light 21L and a portion of light 23L is incident on both the second light-emitting element 22 and the non-insulating light-emitting element 3.

[0064] Furthermore, as shown in the enlarged view F31, let's assume that when the display device 1 is folded, light 22L is emitted from the second light-emitting element 22 and light 3L is emitted from the non-emitting element 3. In this case, in this embodiment, light including a portion of light 22L and a portion of light 3L is incident on both the first light-emitting element 21 and the third light-emitting element 23.

[0065] As described above, the degradation rates of light emission intensity and light reception sensitivity in the first light-emitting element 21 and the second light-emitting element 22 can be known. Furthermore, in the folded display device 1, the relative positions of the third light-emitting element 23, the second light-emitting element 22, and the non-receiving light-emitting element 3 are substantially constant. For this reason, in the folded display device 1, when light of a predetermined intensity is emitted from the third light-emitting element 23, the initial or ideal values ​​of the light reception intensity of the second light-emitting element 22 and the non-receiving light-emitting element 3 can be known. For the same reason, in the folded display device 1, when light of a predetermined intensity is emitted from the second light-emitting element 22 and the non-receiving light-emitting element 3, the initial or ideal values ​​of the light reception intensity of the third light-emitting element 23 can be known.

[0066] As described above, the actual intensity of light 23L from the third light-emitting element 23 can be measured using the same method as described above, and consequently, the degradation rate of the emission intensity of the third light-emitting element 23 can be measured. Furthermore, the actual light-receiving intensity at the third light-emitting element 23 can be measured using the same method as described above, and consequently, the degradation rate of the light-receiving sensitivity of the third light-emitting element 23 can be measured.

[0067] As a result, the compensation unit 4 adjusts the applied voltage applied to the third light-emitting element 23 when the display device 1 performs display, based on the degradation rate of the light-emitting intensity of the third light-emitting element 23, thereby compensating for the light-emitting intensity of the third light-emitting element 23. The display device 1, which performs display using the third light-emitting element 23 whose light-emitting intensity has been compensated, enables a display with improved display quality.

[0068] In this embodiment, the compensation unit 4 compensates for the light emission intensity of the third light-emitting element 23 based on the light reception intensity, including light 21L and light 23L, measured in the folded state at the second light-emitting element 22 and the non-display light-emitting element 3, respectively. Furthermore, the compensation unit 4 compensates for the light emission intensity of the third light-emitting element 23 based on the light reception intensity, including light 22L and light 3L, measured in the folded state at the first light-emitting element 21 and the third light-emitting element 23, respectively. As a result, the display device 1 can compensate for the light emission intensity of the third light-emitting element 23 with greater accuracy, regardless of the differences in degradation among the multiple light-emitting elements 2 used for display.

[0069] In particular, the compensation unit 4 uses the first light-emitting element 21, the second light-emitting element 22, and the non-receiving light-emitting element 3 to perform compensation for the light emission intensity of the third light-emitting element 23. In other words, the compensation unit 4 uses a plurality of light-emitting elements 2 whose degradation rates of light emission intensity and light-receiving sensitivity are already known, and the non-receiving light-emitting element 3, which is considered not to experience degradation in light emission intensity and light-receiving sensitivity, to perform compensation for the light emission intensity of the third light-emitting element 23. This allows the compensation unit 4 to perform compensation for the light emission intensity of the third light-emitting element 23 with greater accuracy.

[0070] However, in this embodiment, the compensation unit 4 may perform compensation for the emission intensity of the third light-emitting element 23 based only on, for example, the light-receiving intensity of the third light-emitting element 23 containing light 22L and the light-receiving intensity of the second light-emitting element 22 containing light 23L. In this case as well, the compensation unit 4 performs compensation for the emission intensity of the third light-emitting element 23 indirectly using the first light-emitting element 21, the second light-emitting element 22, and the non-emitting element 3.

[0071] Furthermore, in this embodiment, an example has been described in which the compensation unit 4 performs compensation for the light emission intensity of the first light-emitting element 21 and the second light-emitting element 22, and then performs compensation for the light emission intensity of the third light-emitting element 23, but the embodiment is not limited to this. For example, the display device 1 may emit light from the first light-emitting element 21, the second light-emitting element 22, the third light-emitting element 23, and the non-emitting element 3 in a folded state prior to the compensation unit 4 performing compensation for the light emission intensity of the first light-emitting element 21 and the second light-emitting element 22. In this way, the display device 1 may measure the degradation rate of light emission intensity and light receiving sensitivity of each of the first light-emitting element 21, the second light-emitting element 22, and the third light-emitting element 23 at once using the method described above. With the above method, the compensation unit 4 may perform compensation for the light emission intensity of each of the first light-emitting element 21, the second light-emitting element 22, and the third light-emitting element 23 at once. With the above configuration, the compensation unit 4 can perform compensation for the light emission intensity of more light-emitting elements 2 at once, and therefore can perform compensation for the light emission intensity of more light-emitting elements 2 in a shorter time or with simpler control content.

[0072] In the display device 1, the first light-emitting element 21 and the third light-emitting element 23 are adjacent to each other. Therefore, in the folded state, the display device 1 makes it easier to receive light including light 22L and light 3L on both the first light-emitting element 21 and the third light-emitting element 23. Accordingly, with the above configuration, the display device 1 can perform compensation of the light emission intensity of the third light-emitting element 23 by the compensation unit 4 with a simpler configuration or with greater accuracy.

[0073] <Compensation for the light emission intensity of the fourth light-emitting element> Next, as shown in the enlarged view F32, assume that light 21L is emitted from the first light-emitting element 21 and light 23L is emitted from the third light-emitting element 23 when the display device 1 is folded. In this case, in this embodiment, light including a portion of light 21L and a portion of light 23L is incident on both the second light-emitting element 22 and the fourth light-emitting element 24.

[0074] Furthermore, as shown in the enlarged view F32, let's assume that when the display device 1 is folded, light 22L is emitted from the second light-emitting element 22 and light 24L is emitted from the fourth light-emitting element 24. In this case, in this embodiment, light including a portion of light 22L and a portion of light 24L is incident on both the first light-emitting element 21 and the third light-emitting element 23.

[0075] As described above, the degradation rates of light emission intensity and light reception sensitivity in the first light-emitting element 21, the second light-emitting element 22, and the third light-emitting element 23 can be known. Furthermore, in the folded display device 1, the relative positions of the fourth light-emitting element 24 and the first and third light-emitting elements 21 and 23 are substantially constant. For this reason, in the folded display device 1, when light of a predetermined intensity is emitted from the fourth light-emitting element 24, the initial or ideal values ​​of the light reception intensity of the first and third light-emitting elements 21 and 23 can be known. For the same reason, in the folded display device 1, when light of a predetermined intensity is emitted from the second and fourth light-emitting elements 22 and 24, the initial or ideal values ​​of the light reception intensity of the first and third light-emitting elements 21 and 23 can be known.

[0076] As described above, the actual intensity of light 24L from the fourth light-emitting element 24 can be measured using the same method as described above, and consequently, the degradation rate of the emission intensity of the fourth light-emitting element 24 can be measured. Furthermore, the actual light-receiving intensity at the fourth light-emitting element 24 can be measured using the same method as described above, and consequently, the degradation rate of the light-receiving sensitivity of the fourth light-emitting element 24 can be measured.

[0077] As a result, the compensation unit 4 adjusts the applied voltage applied to the fourth light-emitting element 24 when the display device 1 performs display, based on the degradation rate of the light-emitting intensity of the fourth light-emitting element 24, thereby compensating for the light-emitting intensity of the fourth light-emitting element 24. The display device 1, which performs display using the fourth light-emitting element 24 with compensated light-emitting intensity, enables a display with improved display quality.

[0078] In this embodiment, the compensation unit 4 compensates for the light emission intensity of the fourth light-emitting element 24 based on the light reception intensity of the second light-emitting element 22 and the fourth light-emitting element 24, respectively, measured in the bent state, including light 21L and light 23L. Furthermore, the compensation unit 4 compensates for the light emission intensity of the fourth light-emitting element 24 based on the light reception intensity of the first light-emitting element 21 and the third light-emitting element 23, respectively, measured in the bent state. As a result, the display device 1 can compensate for the light emission intensity of the fourth light-emitting element 24 with greater accuracy, regardless of the differences in degradation among the multiple light-emitting elements 2 used for display.

[0079] Furthermore, according to the method described above, the display device 1 can perform the above-mentioned compensation by the compensation unit 4 without measuring the emission of light from the non-visible light-emitting element 3 or the light intensity received by the non-visible light-emitting element 3. Thereafter, the compensation unit 4 can compensate the light emission intensity of one adjacent light-emitting element 2 on the opposite side of the third light-emitting element 23 and the first light-emitting element 21 using the same method as described above. The compensation unit 4 can also compensate the light emission intensity of one adjacent light-emitting element 2 on the opposite side of the fourth light-emitting element 24 and the second light-emitting element 22 using the same method as described above. By repeatedly performing the above, the display device 1 can compensate the light emission intensity of each of the multiple light-emitting elements 2 using only the light-emitting elements 2 located in the display area DA with the compensation unit 4.

[0080] In particular, the compensation unit 4 uses a plurality of light-emitting elements 2, including the first light-emitting element 21, the second light-emitting element 22, and the third light-emitting element 23, whose degradation rates of light emission intensity and light-receiving sensitivity have already been determined, to perform compensation for the light emission intensity of the fourth light-emitting element 24. This allows the compensation unit 4 to perform compensation for the light emission intensity of the fourth light-emitting element 24 with greater accuracy.

[0081] However, in this embodiment, the compensation unit 4 may perform compensation for the emission intensity of the fourth light-emitting element 24 based only on, for example, the light reception intensity of the fourth light-emitting element 24 including light 23L and the light reception intensity of the third light-emitting element 23 including light 24L. In this case as well, the compensation unit 4 performs compensation for the emission intensity of the fourth light-emitting element 24 indirectly using the first light-emitting element 21, the second light-emitting element 22, and the third light-emitting element 23.

[0082] In this embodiment, an example has been described in which the compensation unit 4 performs compensation for the light emission intensity of the first light-emitting element 21, the second light-emitting element 22, and the third light-emitting element 23, and then performs compensation for the light emission intensity of the fourth light-emitting element 24, but the invention is not limited to this. For example, the display device 1 may first measure the degradation rate of the light emission intensity and light receiving sensitivity of the first light-emitting element 21 using the non-emitting element 3 in the manner described above. Then, the display device 1 may make the first light-emitting element 21, the second light-emitting element 22, the third light-emitting element 23, and the fourth light-emitting element 24 emit light in the folded state.

[0083] At this point, as described above, the degradation rate of the light emission intensity and light receiving sensitivity of the first light-emitting element 21 is known. Therefore, the display device 1 may, based on the said degradation rate, measure the degradation rate of the light emission intensity and light receiving sensitivity of the second light-emitting element 22, the third light-emitting element 23, and the fourth light-emitting element 24 at once using the method described above. The compensation unit 4 may, using the method described above, perform compensation for the light emission intensity of the first light-emitting element 21, the second light-emitting element 22, the third light-emitting element 23, and the fourth light-emitting element 24 at once.

[0084] With the above configuration, the compensation unit 4 can perform compensation for the light emission intensity of more light-emitting elements 2 at once, thus enabling the compensation of more light-emitting elements 2 in a shorter time or with simpler control. In particular, by the above method, if the degradation rate of the light emission intensity and light receiving sensitivity of any one of the multiple light-emitting elements 2 is determined, the compensation unit 4 can compensate for the light emission intensity of that light-emitting element 2 and multiple light-emitting elements 2 located in the vicinity of that light-emitting element 2 at once.

[0085] In the folded state of the display device 1, the third light-emitting element 23 and the fourth light-emitting element 24 face each other. This allows the display device 1 to bring the light-emitting portion of the third light-emitting element 23 and the light-emitting portion of the fourth light-emitting element 24 closer together. With this configuration, the display device 1 increases the intensity of the light 23L incident on the fourth light-emitting element 24 and the intensity of the light 24L incident on the third light-emitting element 23, and consequently, the compensation unit 4 can perform compensation of the light emission intensity of the fourth light-emitting element 24 with greater accuracy.

[0086] In the display device 1, the second light-emitting element 22 and the fourth light-emitting element 24 are adjacent to each other. Therefore, in the folded state, the display device 1 makes it easier to receive light 21L from the first light-emitting element 21 and light 23L from the third light-emitting element 23 on both the second light-emitting element 22 and the fourth light-emitting element 24. Thus, with the above configuration, the display device 1 can perform compensation of the light emission intensity of the fourth light-emitting element 24 by the compensation unit 4 with a simpler configuration or with greater accuracy.

[0087] <Example of a method for compensating the light emission intensity of multiple light-emitting elements> A method for compensating the light emission intensity of each of the multiple light-emitting elements 2 provided in the display device 1 according to this embodiment using the compensation unit 4 will be described in more detail with reference to Figure 4. Figure 4 is another schematic plan view of the display device 1 according to this embodiment. In particular, Figure 4 shows both multiple light-emitting elements 2 located on the first part 11 and multiple light-emitting elements 2 located on the second part 12 as the multiple light-emitting elements 2.

[0088] As shown in Figure 4, in a plan view, one of the multiple invisible light-emitting elements 3 arranged along one of the edges of the rectangular substrate 10, for example, along the column direction DL, is designated as the invisible light-emitting element 3A. In addition, each of the multiple light-emitting elements 2 that overlap with the invisible light-emitting element 3A in a direction substantially perpendicular to the direction in which the multiple invisible light-emitting elements 3 are arranged, in other words, in the row direction DR, is designated as the light-emitting element 2A.

[0089] In this case, the multiple light-emitting elements 2A include, in a plan view, a first light-emitting element 21A and a third light-emitting element 23A, in order from the side opposite to the folded portion 13 on the first portion 11, in the portion that overlaps with the display area DA. The multiple light-emitting elements 2A also include, in a plan view, a second light-emitting element 22A and a fourth light-emitting element 24A, in order from the side of the non-display light-emitting element 3 on the second portion 12, in the portion that overlaps with the display area DA.

[0090] Using the method described above, the folded display device 1 can measure the degradation rate of the light emission intensity and light receiving sensitivity of the first light-emitting element 21A using the non-display light-emitting element 3A. Furthermore, using the method described above, the folded display device 1 can measure the degradation rate of the light emission intensity and light receiving sensitivity of the second light-emitting element 22A, the third light-emitting element 23A, and the fourth light-emitting element 24A using the first light-emitting element 21A whose degradation rate is known.

[0091] Furthermore, by applying the above-described method to other light-emitting elements 2A, the folded display device 1 can measure the degradation rate of the light emission intensity and light-receiving sensitivity of multiple light-emitting elements 2A. In particular, the display device 1 can sequentially measure the degradation rate of the light emission intensity and light-receiving sensitivity of the light-emitting elements 2A on the first part 11 in the direction from the first light-emitting element 21A to the third light-emitting element 23A. The display device 1 can also sequentially measure the degradation rate of the light emission intensity and light-receiving sensitivity of the light-emitting elements 2A on the second part 12 in the direction from the second light-emitting element 22A to the fourth light-emitting element 24A.

[0092] As described above, the display device 1 can measure the degradation rate of the light emission intensity and light receiving sensitivity of multiple light-emitting elements 2A using the non-display light-emitting element 3A. Therefore, the compensation unit 4 can perform compensation for the light emission intensity of multiple light-emitting elements 2A at once using the above method.

[0093] Furthermore, as shown in Figure 4, one of the multiple invisible light-emitting elements 3 that is different from invisible light-emitting element 3A is designated as invisible light-emitting element 3B. Also, each of the multiple light-emitting elements 2 that overlap with invisible light-emitting element 3B in the row direction DR is designated as light-emitting element 2B. In this case, the display device 1 can measure the degradation rate of the light emission intensity and light receiving sensitivity of the multiple light-emitting elements 2B using the invisible light-emitting element 3B in the same manner as described above. Therefore, the compensation unit 4 can perform compensation for the light emission intensity of the multiple light-emitting elements 2B at once using the above method.

[0094] In other words, the compensation unit 4 can use one of the invisible light-emitting elements 3 arranged in the column direction DL to perform compensation for the light emission intensity of multiple light-emitting elements 2 that overlap with the invisible light-emitting element 3 in the row direction DR. The compensation unit 4 may use any of the invisible light-emitting elements 3 arranged in the column direction DL to perform compensation for the light emission intensity of multiple light-emitting elements 2 that overlap with the invisible light-emitting element 3 in the row direction DR, or it may use each of the invisible light-emitting elements 3. This allows the compensation unit 4 to efficiently perform compensation for the light emission intensity of each of the light-emitting elements 2 located on the first part 11 and the second part 12. Therefore, a display device 1 having multiple light-emitting elements 2 arranged two-dimensionally on a rectangular substrate 10 in plan view can perform compensation for the light emission intensity of the multiple light-emitting elements 2 more efficiently by the compensation unit 4.

[0095] The compensation unit 4 may compensate for the light emission intensity of the light-emitting element 2 located on the bent portion 13. For example, the bent display device 1 may emit light from the light-emitting element 2 located at the end of the first portion 11 or the second portion 12 on the bent portion 13 side, and measure the light-receiving intensity of the light-emitting element 2 on the bent portion 13. Alternatively, the bent display device 1 may emit light from the light-emitting element 2 on the bent portion 13 and measure the light-receiving intensity of the light-emitting element 2 located at the end of the first portion 11 or the second portion 12 on the bent portion 13 side. In this way, the bent display device 1 may measure the degradation rate of the light emission intensity and light-receiving sensitivity of the light-emitting element 2 on the bent portion 13. In this way, the compensation unit 4 can perform compensation for the light emission intensity of the light-emitting element 2 on the bent portion 13 in the same manner as described above.

[0096] [Embodiment 2] <Other Examples of Light Receiving and Light Emitting Units> Figure 5 shows a schematic plan view F51 of the display device 1 according to this embodiment and an enlarged schematic side cross-section view F52 of the display device 1. The display device 1 according to this embodiment has the same configuration as the display device 1 according to the previous embodiment, except that it has multiple light receiving units 5 and multiple light-emitting units 6 instead of multiple non-displaying light-emitting units 3.

[0097] The display device 1 includes, for example, a plurality of light-receiving units 5 and a plurality of light-emitting units 6 arranged in positions that overlap with the non-display area NA in a plan view of the substrate 10 on the second part 12. In particular, the display device 1 may include, for example, a plurality of light-receiving units 5 and a plurality of light-emitting units 6 arranged along the column direction DL at the end of the second part 12 opposite to the bent part 13.

[0098] The light-receiving unit 5 has, for example, a light-receiving surface on the side of the display surface of the display device 1, and the display device 1 can measure the intensity of light incident on each light-receiving surface of the light-receiving unit 5. The light-receiving unit 5 may include various devices, including conventionally known light-receiving devices capable of measuring the light-receiving intensity at the light-receiving unit 5, such as a camera or a light-receiving element.

[0099] The light-emitting unit 6 is, for example, a light source that emits light on the display surface side of the display device 1, and the display device 1 can control whether or not each of the light-emitting units 6 emits light at any given time. The intensity of the light emitted by each of the light-emitting units 6 may be substantially constant. Alternatively, the display device 1 may arbitrarily control the intensity of the light emitted by each of the light-emitting units 6. The light-emitting unit 6 may include various light sources that emit light, including conventionally known light sources such as light-emitting diodes.

[0100] As described above, the light-receiving section 5 and the light-emitting section 6 are located at the end of the second section 12 opposite to the bent section 13. Therefore, as shown in the enlarged view F52, in the bent display device 1, the light-receiving section 5 and the light-emitting section 6 are located in the vicinity of the first light-emitting element 21 and the second light-emitting element 22. In particular, the light-receiving section 5 or the light-emitting section 6 may be adjacent to the second light-emitting element 22 in the planar direction DP.

[0101] Therefore, in the folded state of the display device 1, light including a portion of the light 21L from the first light-emitting element 21 is incident on the light-receiving surface of the light-receiving unit 5. As a result, the folded state of the display device 1 can measure the light-receiving intensity at the light-receiving unit 5 that has received light including the light 21L. Also, in the folded state of the display device 1, light including a portion of the light 6L from the light-emitting unit 6 is incident on the first light-emitting element 21. As a result, the folded state of the display device 1 can measure the light-receiving intensity at the first light-emitting element 21 that has received light including the light 6L. Here, the light-receiving unit 5 and the light-emitting unit 6 do not contribute to the display in the display area DA of the display device 1, and the light-receiving unit 5 and the light-emitting unit 6 do not operate during the display by the display device 1. For the same reasons as described above, it can be assumed that there is no deterioration in the light-receiving sensitivity of the light-receiving unit 5, and that there is no deterioration in the light-emitting intensity of the light-emitting unit 6.

[0102] As a result, the folded display device 1 can measure the degradation rate of the light emission intensity and light receiving sensitivity of the first light-emitting element 21 based on the light-receiving intensity of the light including light 21L at the light-receiving unit 5 and the light-receiving intensity of the light including light 6L at the first light-emitting element 21. Therefore, the compensation unit 4 according to this embodiment can perform compensation for the light emission intensity of the first light-emitting element 21 based on the light-receiving intensity of the light including light 21L at the light-receiving unit 5 and the light-receiving intensity of the light including light 6L at the first light-emitting element 21, measured in the folded state of the display device 1. Thus, for the same reasons as described above, the display device 1 according to this embodiment can compensate for the light emission intensity of the first light-emitting element 21 with greater accuracy, regardless of the degradation differences among the plurality of light-emitting elements 2 used for display. Furthermore, the compensation unit 4 according to this embodiment may perform compensation for the light emission intensity of other light-emitting elements 2 different from the first light-emitting element 21 by the same method as described above.

[0103] In this embodiment, the compensation unit 4 compensates for the light emission intensity of the light-emitting element 2 using a light-receiving unit 5 and a light-emitting unit 6 instead of a non-visible light-emitting element 3. The light-receiving unit 5 does not need to have a light-emitting mechanism, and the light-emitting unit 6 does not need to have a mechanism for measuring the light-receiving intensity. Therefore, the display device 1 in this embodiment simplifies the mechanisms of the light-receiving unit 5 and the light-emitting unit 6, and consequently simplifies the overall configuration of the device.

[0104] Furthermore, the display device 1 according to this embodiment reduces the degradation of light receiving sensitivity in the light receiving unit 5 and the degradation of light emission intensity in the light emission unit 6 by simplifying the mechanisms of the light receiving unit 5 and the light emission unit 6. Therefore, the display device 1 according to this embodiment can perform compensation of the light emission intensity of the light-emitting element 2 with even greater accuracy by the compensation unit 4.

[0105] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

[0106] 1 Display device 2 Light-emitting element 3 Non-removable light-emitting element (light-receiving part, light-emitting part) 4 Compensation part 5 Light-receiving part 6 Light-emitting part 10 Substrate 11 Part 1 12 Part 2 13 Bending part 21 First light-emitting element 22 Second light-emitting element 23 Third light-emitting element 24 Fourth light-emitting element

Claims

1. A display device having a display area and a non-display area located outside the display area in a plan view, comprising: a substrate having a first part, a second part, and a bending part located between the first part and the second part and causing the first part and the second part to face each other when bent; a plurality of light-emitting elements, including a first light-emitting element on the first part, located in a portion of the substrate that overlaps with the display area in a plan view of the substrate, and emitting light when driven and generating an electromotive force upon receiving light; a light-receiving element located in the second part that overlaps with the non-display area in a plan view of the substrate, and measuring the light-receiving intensity by receiving a portion of the light from the first light-emitting element when the substrate is bent at the bending part and the first part and the second part face each other; and a light-emitting element located in the second part that overlaps with the non-display area in a plan view of the substrate, and emitting light toward the first light-emitting element in the bent state, A display device comprising: a compensation unit that performs compensation for the light emission intensity of at least one of the plurality of light-emitting elements based on the light-receiving intensity of light including light from the first light-emitting element in the light-receiving unit and the light-receiving intensity of light including light from the light-emitting unit in the first light-emitting element, measured in the aforementioned folded state.

2. The display device according to claim 1, wherein the light-receiving unit and the light-emitting unit are non-reflective light-emitting elements that emit light in conjunction with driving and generate an electromotive force upon receiving light.

3. The display device according to claim 1 or 2, wherein the light-emitting element includes a second light-emitting element on the second part, and the compensation unit performs compensation for the emission intensity of at least one of the plurality of light-emitting elements based on the light-receiving intensity of light including light from the first light-emitting element at each of the light-receiving element and the second light-emitting element, measured in the folded state, and the light-receiving intensity of light including light from the light-emitting element and light from the second light-emitting element at the first light-emitting element.

4. The display device according to claim 3, wherein the second light-emitting element faces the first light-emitting element in the folded state.

5. The display device according to claim 3 or 4, wherein the second light-emitting element is adjacent to the light-receiving element and the light-emitting element.

6. The display device according to any one of claims 3 to 5, wherein the light-emitting element includes a third light-emitting element on the first part, and the compensation unit performs compensation for the light emission intensity of at least one of the plurality of light-emitting elements based on the light-receiving intensity of the light including light from the first light-emitting element and light from the third light-emitting element in each of the light-receiving element and the second light-emitting element, measured in the folded state, and the light-receiving intensity of the light including light from the light-emitting element and light from the second light-emitting element in each of the first light-emitting element and the third light-emitting element.

7. The display device according to claim 6, wherein the third light-emitting element is adjacent to the first light-emitting element.

8. The display device according to claim 6 or 7, wherein the light-emitting element includes a fourth light-emitting element on the second part, and the compensation unit performs compensation for the emission intensity of at least one of the plurality of light-emitting elements based on the light-receiving intensity of light including light from the first light-emitting element and light from the third light-emitting element at each of the second and fourth light-emitting elements, measured in the folded state, and the light-receiving intensity of light including light from the second light-emitting element and light from the fourth light-emitting element at each of the first and third light-emitting elements.

9. The display device according to claim 8, wherein the fourth light-emitting element faces the third light-emitting element in the folded state.

10. The display device according to claim 8 or 9, wherein the fourth light-emitting element is adjacent to the second light-emitting element.

11. The display device according to any one of claims 1 to 10, wherein the display area is rectangular in plan view, the plurality of light-emitting elements are arranged two-dimensionally in plan view of the substrate, and a plurality of light-receiving units and light-emitting units are provided along any edge of the display area.

Images