Optical elements and electronic devices

Abstract

To provide an optical element and an electronic device, capable of detecting changes in the direction of the line of sight.SOLUTION: In an optical element, a center position of a pinhole is disposed at a center position of a sensor region, in a first individual region disposed in a center region, of a plurality of first individual regions, the pinhole does not overlap the sensor region, in the first individual region disposed in a peripheral region different from the center region of the plurality of first individual region, and a distance in planar view between a center region of the sensor region and the pinhole in the first individual region far from the center region is longer than a distance in planar view between the center region of the sensor region and the pinhole in the first individual region close to the center region, in the first individual regions disposed in the peripheral region.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] FIELD Embodiments of the present invention relate to optical elements and electronic devices. [Background technology]

[0002] Electronic devices having a light receiving element and a light emitting element have been developed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-230177 Summary of the Invention [Problem to be solved by the invention]

[0004] The present embodiment provides an optical element and electronic device capable of detecting a change in the direction of the line of sight. [Means for solving the problem]

[0005] An optical element according to one embodiment includes a first substrate having an active region including a plurality of light-emitting regions that emit near-infrared light and a plurality of sensor regions that detect the near-infrared light; a second substrate having a plurality of light-shielding regions and a plurality of pinholes provided in the plurality of light-shielding regions; a plurality of first individual regions, each having one of the plurality of sensor regions, one of the plurality of light-shielding regions, and one of the plurality of pinholes; and a plurality of second individual regions, each having one of the plurality of light-emitting regions, wherein each of the plurality of first individual regions and each of the plurality of second individual regions are arranged alternately, and the plurality of second individual regions are arranged alternately. In the first individual area that is located in the central area among the individual areas, the center position of the pinhole is located at the center position of the sensor area, and in the first individual area that is located in a peripheral area different from the central area among the plurality of first areas, the pinhole does not overlap with the sensor area, and in the first individual area that is located in the peripheral area, the distance in a planar view between the center area of ​​the sensor area and the pinhole in the first individual area that is far from the central area is greater than the distance in a planar view between the center area of ​​the sensor area and the pinhole in the first individual area that is close to the central area. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram illustrating an optical element according to an embodiment. [Figure 2] FIG. 2 is a plan view of the optical element. [Figure 3] FIG. 3 is a cross-sectional view of the optical element. [Figure 4] FIG. 4 is a diagram showing the positional relationship of the optical elements. [Figure 5] FIG. 5 is a diagram showing an application example of the optical element. [Figure 6] FIG. 6 is a perspective view of the electronic device of FIG. [Figure 7] FIG. 7 is a cross-sectional view showing another example of the configuration of the electronic device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. The disclosure is merely an example, and appropriate modifications that a person skilled in the art can easily conceive while maintaining the gist of the invention are naturally included within the scope of the present invention. Furthermore, in order to clarify the explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual embodiment, but these are merely examples and are not intended to limit the interpretation of the present invention. Furthermore, in this specification and each drawing, elements similar to those described above with reference to the previous drawings may be designated by the same reference numerals, and detailed descriptions may be omitted as appropriate. Hereinafter, an optical element according to an embodiment will be described in detail with reference to the drawings.

[0008] In this embodiment, the first direction X, the second direction Y, and the third direction Z are perpendicular to one another, but may intersect at an angle other than 90 degrees. The direction toward the tip of the arrow of the third direction Z is defined as up or upward, and the direction opposite to the direction toward the tip of the arrow of the third direction Z is defined as down or downward.

[0009] Furthermore, when the terms "second member above the first member" and "second member below the first member" are used, the second member may be in contact with the first member or may be located apart from the first member. In the latter case, a third member may be interposed between the first and second members. On the other hand, when the terms "second member above the first member" and "second member below the first member" are used, the second member is in contact with the first member.

[0010] Furthermore, it is assumed that an observation position for observing the optical element is located at the tip of the arrow in the third direction Z, and planar view refers to viewing from this observation position toward the XY plane defined by the first direction X and the second direction Y. Cross-sectional view refers to viewing a cross section of the optical element in the XZ plane defined by the first direction X and the third direction Z, or in the YZ plane defined by the second direction Y and the third direction Z.

[0011] 1A and 1B are diagrams illustrating an optical element according to an embodiment. Fig. 1A is an exploded perspective view of the optical element OPT. The optical element OPT has a sensor element portion SE and an optical path adjusting portion HE. The sensor element unit SE has a base material BA1 and a plurality of individual areas PA. The plurality of individual areas PA are provided in an active area AA of the base material BA1. The sensor element unit SE is also referred to as a first substrate SUB1. The optical path adjusting unit HE has a base material BA2 and a light-shielding layer BM having a plurality of pinholes PH formed therein. The optical path adjusting unit HE is also referred to as a second substrate SUB2.

[0012] As shown in FIG. 1(B), the individual area PA has individual areas PA1 and PA2. The individual area PA1 has a sensor area SA. A light-shielding layer BM and a pinhole PH of the optical path adjustment unit HE are provided so as to overlap the individual area PA1 of the sensor element unit SE. The individual area PA2 has a light-emitting area EA. The individual areas PA1 and PA2 are also referred to as a first individual area and a second individual area, respectively.

[0013] Fig. 2 is a plan view of the optical element. In Fig. 2, the multiple individual areas PA1 and PA2 are arranged alternately. Of the multiple individual areas PA1, in the individual area PA1 provided in the central area CA of the active area AA, the center position of the pinhole PH is located at the center position of the sensor area SA. Note that in Fig. 2, 16 and 12 individual areas PA1 and PA2 are arranged, respectively, but the numbers of the individual areas PA1 and PA2 are not limited to this. Furthermore, the individual areas PA1 and PA2 do not have to be arranged alternately. For example, one individual area PA2 may be provided for every two individual areas PA1. The number of individual areas PA1 relative to the individual areas PA2 can be determined appropriately depending on the sensitivity of the sensor area SA.

[0014] In the individual area PA1 provided in the peripheral area FA away from the central area CA, the pinhole PH does not overlap with the sensor area SA. The distance (called the offset) between the center position of the sensor area SA and the center position of the pinhole PH becomes longer as you move closer to the periphery. That is, the offset amount in the central area CA is 0 (zero), but in the peripheral area FA, it becomes larger the closer to the periphery. In other words, as the distance of the individual area PA1 from the center point CP of the active area AA increases, the distance between the center position of the sensor area SA and the center position of the pinhole PH increases. However, in individual areas PA1 that are the same distance from the center point CP of the active area AA, it is preferable that the center position of the pinhole PH be the same distance from the center point CP of the active area AA.

[0015] In other words, in the individual area PA1 arranged in the peripheral area FA, the distance in a planar view between the central area of ​​the sensor area SA in the individual area PA1 far from the central area CA and the pinhole PH is greater than the distance in a planar view between the central area of ​​the sensor area SA in the individual area PA1 close to the central area CA and the pinhole PH.

[0016] Fig. 3 is a cross-sectional view of an optical element. Fig. 3(A) is a cross-sectional view of the optical element OPT taken along line A1-A2 in Fig. 2. Fig. 3(B) is a partially enlarged view of Fig. 3(A). The optical element OPT shown in Fig. 3 includes a first substrate SUB1 and a second substrate SUB2. The first substrate SUB1 includes a base material BA1, an anode AD, an emission layer EML, a sensor layer SRL, a cathode CD, an insulating layer PAS, and an insulating layer FIL. As described above, the second substrate SUB2 includes a base material BA2, a light-shielding layer BM, and a pinhole PH.

[0017] The base materials BA1 and BA2 are transparent base materials, and examples of the material for the base materials BA1 and BA2 include glass, acrylic, and resin materials such as polyimide. An anode AD is provided on the substrate BA1. The anode AD is formed of a laminate of a transparent conductive layer and a metal layer. The transparent conductive layer may be made of a light-transmitting metal oxide such as indium tin oxide (ITO) or indium zinc oxide (IZO). The metal layer may be made of silver or a silver alloy.

[0018] A plurality of banks BK (also called ribs) are provided on the base material BA1, overlapping with portions of the anodes AD. The banks BK are convex portions formed of an organic insulating layer. A resin material such as an acrylic resin or a polyimide resin is used for the organic insulating layer of the banks BK. The areas between adjacent banks BK correspond to individual areas PA. Although not shown, a driving element for the individual area PA, such as a thin film transistor, may be provided between the base material BA1 and the bank BK.

[0019] In the individual area PA1, a sensor layer SRL is provided in a region between adjacent banks BK so as to overlap the anode AD. The sensor layer SRL senses, for example, near-infrared light, more specifically, light with a wavelength of about 800 nm. In this embodiment, an organic photodiode material is used as the material for the sensor layer SRL. The sensor layer SRL is also referred to as an OPD layer. Specifically, the sensor layer SRL is a photoelectric conversion layer capable of photoelectrically converting near-infrared light.

[0020] In the individual region PA2, an emitting layer EML is provided in the region between adjacent banks BK, overlapping with the anode AD. The emitting layer EML emits, for example, near-infrared light, more specifically, light with a wavelength of about 800 nm. In this embodiment, an organic electroluminescence (OLED) light-emitting material is used as the material for the emitting layer EML. The emitting layer EML is also sometimes called an organic EL layer or an OLED layer.

[0021] A cathode CD is provided on the sensor layer SRL and the emission layer EML. The material of the cathode CD is, for example, a conductive layer containing an alkali metal or an alkaline earth metal. Examples of the alkali metal or alkaline earth metal that can be used include magnesium (Mg) and lithium (Li). In this embodiment, an MgAg film, which is an alloy of magnesium and silver, is used as the cathode CD. The cathode CD is provided across a plurality of individual regions PA.

[0022] An insulating layer PAS is provided on the cathode CD. The insulating layer PAS can be made of inorganic materials such as silicon oxide, silicon nitride, or silicon oxynitride. The insulating layer PAS prevents moisture and other external elements from entering the cathode CD, thereby preventing deterioration of the emission layer EML and the sensor layer SRL. An insulating layer FIL is provided to cover the insulating layer PAS. The insulating layer FIL is made of a resin material such as acrylic resin or polyimide resin. The insulating layer FIL can flatten the undulations of the first substrate SUB1 caused by the banks BK.

[0023] Although the electrode provided in the lower layer is the anode AD and the electrode provided in the upper layer is the cathode CD here, this may be reversed depending on the stacked structure of the sensor layer SRL and the light-emitting layer EML. Specifically, the electrode provided in the lower layer may be formed as the cathode CD and the electrode provided in the upper layer as the anode AD.

[0024] The light-shielding layer BM of the second substrate SUB2 is formed using, for example, a material in which a black pigment is mixed into a resin material. In this embodiment, the area of ​​the individual area PA1 where the light-shielding layer BM is provided is also referred to as a light-shielding area. The pinholes PH are through holes provided in the light-shielding layer BM, and one pinhole PH is provided in each individual area PA1.

[0025] In the individual region PA2, the light ELT emitted from the light emitting layer EML is emitted to the upper surface of the optical element OPT. Meanwhile, in the individual area PA1, light ILT enters the sensor layer SRL through a pinhole PH provided in the light-shielding layer BM. The sensor layer SRL converts the incident near-infrared light ILT into an electrical signal by photoelectric conversion. By outputting the electrical signal, the incident near-infrared light ILT can be sensed. The sensor layer SRL is also sometimes called a light-receiving layer or a photoelectric conversion layer.

[0026] As described above, light ILT is incident on the pinhole PH arranged in the central area CA in the direction opposite to the third direction Z, that is, vertically from above. The center of the pinhole PH arranged in the peripheral area FA is shifted from the center of the sensor area SA. Therefore, the light ILT is incident on the pinhole PH arranged in the peripheral area FA at an angle inclined with respect to the third direction, that is, from an oblique direction.

[0027] Figure 4 shows the positional relationship of optical elements. Figure 4(A) shows the positional relationship of the optical element OPT, the eyeball EYE, the light ILT, and the light ELT. Figure 4(B) shows the principle of a pinhole camera. 4(A), near-infrared light ELT is emitted from the light emitting layer EML of the optical element OPT toward the eyeball EYE. The light ELT is reflected by the surface of the eyeball EYE, and light ILT containing, for example, position information of the iris EBL travels toward the sensor layer SRL.

[0028] Here, the principle of a pinhole camera will be explained using Figure 4(B). The pinhole camera CAM shown in Figure 4(B) has a light-shielding part BMC, a pinhole PHC provided in the light-shielding part BMC, and a screen SCN. When external light OLT enters the pinhole camera CAM, only the light that reaches the pinhole PHC can pass through the pinhole PH. This allows an image IMG of the object OBJ to be obtained on the screen SCN.

[0029] In the optical element OPT of this embodiment, it is assumed that the light ILT travels along the same optical path as the external light OLT incident on the pinhole PHC of the pinhole camera CAM. Only the light ILT that follows this optical path passes through the pinhole PH of the optical element OPT. The light ILT that has passed through the pinhole PH is incident on the sensor layer SRL, which converts the light ILT into electricity and outputs information such as the position of the iris EBL as electrical information.

[0030] The distance between the optical element OPT and the eyeball EYE is fixed at a predetermined distance. The pinhole PH provided in each individual area PA is positioned on the optical path based on the predetermined distance and the position of the sensor layer ERL. For example, when the position of the iris EBL changes, the change in the position of the boundary EBD between the iris EBL and the white of the eye EWT is detected by the sensor layer SRL via the light ILT, making it possible to detect changes such as whether the gaze is directed upward or downward.

[0031] 5A and 5B are diagrams showing application examples of the optical element OPT, Fig. 5A is a diagram showing an electronic device for VR (Virtual Reality), and Fig. 5B is a diagram showing an eyeglass-type electronic device. The electronic device ERP shown in FIG. 5(A) has an optical element OPT and a display device DSP. Although not shown to make the drawing easier to understand, optical elements OPT are provided corresponding to the right and left eyes of the observer OBS. The display device DSP may be a single display device that displays two different images corresponding to the right and left eyes of the observer OBS. Alternatively, it may be two display devices that display images corresponding to the right and left eyes of the observer OBS. The display device DSP and the optical element OPT are connected by wiring (not shown) and transmit and receive input signals and output signals to and from each other.

[0032] The electronic device ERP includes a head mounted display (HMD) worn on the head of the observer OBS, a glasses-type device, etc. The electronic device ERP is used to provide the observer OBS with, for example, virtual reality (VR) or augmented reality (AR).

[0033] As described above, the optical element OPT included in the electronic device ERP can detect changes in the position of the eyeball EYE, i.e., changes in the line of sight of the observer OBS. By changing the image displayed on the display device DSP in accordance with the movement of the line of sight of the observer OBS, a sense of virtual reality can be created for the observer OBS.

[0034] The area AA1 of the optical element OPT emits near-infrared light but transmits visible light. The observer OBS can see the image displayed on the display device DSP through the area AA1. This allows the electronic device ERP to provide, for example, virtual reality (VR) to the observer OBS. Furthermore, if the display device DSP is a transparent display, that is, if the outside scenery can be seen through the display device DSP, augmented reality (AR) can also be realized. Such a transparent display can be a transparent display using liquid crystal or a transparent display using organic electroluminescence. Although not shown in Fig. 5A, the display device DSP includes a plurality of pixels. Each pixel includes a switching element that controls the liquid crystal layer or the organic EL light-emitting layer. The resolution of the pixels may be approximately 10 to 100 times the density of the individual regions PA1 of the optical element OPT.

[0035] The eyeglass-type electronic device GLS shown in Fig. 5(B) has an optical element OPT and a lens LNS. Although not shown for ease of viewing the drawing, an optical element OPT and a lens LNS may be provided for each of the right and left eyes of the observer OBS, as in Fig. 5(A). As described above, visible light is transmitted through the area AA1 of the optical element OPT. The observer OBS can see the outside scenery through the area AA1. This allows the eyeglass-type electronic device GLS to provide the observer OBS with, for example, augmented reality (AR).

[0036] Fig. 6 is a perspective view of the electronic device of Fig. 5(A). The electronic device ERP has a housing CAS and a fastener FST. The housing CAS houses an optical element OPT and a display device DSP. Although not shown for ease of viewing the drawing, the housing CAS may also be provided with wiring connected to the optical element OPT and the display device DSP, and a control unit for transmitting and receiving signals to the optical element OPT and the display device DSP.

[0037] In this embodiment, near-infrared light ELT emitted from the light-emitting layer EML is reflected by the eyeball EYE of the observer OBS. The reflected light ILT is incident on the sensor layer SRL through the pinhole PH. Position information of the eyeball EYE and other information contained in the incident light are photoelectrically converted in the sensor layer SRL and output as an electrical signal. The pinhole PH overlaps with the sensor area SA in the central area CA, but does not overlap with the sensor area SA in the peripheral area FA. The offset amount of the center position of the pinhole PH from the center position of the sensor area SA increases as it moves closer to the periphery. From the above, it is possible to detect changes in the direction of the observer's line of sight, and the displayed image can be changed in response to the change in line of sight.

[0038] <Configuration example 1> Fig. 7 is a cross-sectional view showing another example of the configuration of an electronic device according to an embodiment. The example shown in Fig. 7 differs from the example shown in Fig. 3 in that pinholes are formed in multiple stacked light-shielding layers. In FIG. 7, the optical path adjusting unit HE (second substrate SUB2) of the optical element OPT has light-shielding layers BM1, BM2, and BM3 stacked in this order on a base material BA2. The light-shielding layers BM1, BM2, and BM3 are collectively referred to as the light-shielding layer BM. The light-shielding layers BM1, BM2, and BM3 may be formed using the materials described above. Note that in this configuration example, an example in which three light-shielding layers are stacked will be described, but the number of light-shielding layers is not limited to this, and two or four or more layers may be stacked.

[0039] The light-shielding layers BM1, BM2, and BM3 are provided with pinholes PH1, PH2, and PH3, respectively. The pinholes PH1, PH2, and PH3 are collectively referred to as pinhole PH. The pinhole PH1 partially overlaps with the pinhole PH2, but not the other parts. The pinhole PH2 partially overlaps with the pinhole PH3, but not the other parts. The pinholes PH1, PH2, and PH3 overlap with a shift on the XY plane, and as a whole, form a pinhole PH that extends obliquely with respect to the direction (thickness direction) parallel to the third direction Z. The obliquely extending pinhole PH allows the light ILT to be incident obliquely with respect to a direction parallel to the third direction Z. When the light ILT is incident obliquely, the amount of light that reaches the sensor layer SRL increases, further increasing the sensitivity. This configuration example also provides the same effects as the above embodiment.

[0040] Although the embodiments of the present invention have been described, they are presented as examples and are not intended to limit the scope of the invention. The novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as defined in the claims. [Explanation of symbols]

[0041] AA...active area, AA1...area, BM...light-shielding layer, BM1...light-shielding layer, BMC...light-shielding portion, CA...central area, CP...center point, DSP...display device, EA...light-emitting area, EBD...boundary, EBL...iris of the eye, ELT...light, EML...light-emitting layer, ERL...sensor layer, ERP...electronic device, EWT...white of the eye, EYE...eyeball, FA...peripheral area, FST...fastener, GLS...glasses-type electronic device, HE...light path adjustment portion, ILT...light, LNS...lens, OBS...observer, OPT...optical element, PA...individual area, PH...pinhole, SA...sensor area, SE...sensor element portion, SRL...sensor layer.

Claims

1. a first substrate having an active area including a plurality of light-emitting areas that emit near-infrared light and a plurality of sensor areas that detect the near-infrared light; a second substrate having a plurality of light-shielding regions and a plurality of pinholes provided in the plurality of light-shielding regions; a plurality of first individual areas each including one of the plurality of sensor areas, one of the plurality of light-shielding areas, and one of the plurality of pinholes; a plurality of second individual regions, each having one of the plurality of light emitting regions; Equipped with the plurality of first individual regions include a first individual region A, a first individual region B, and a first individual region C; the plurality of first individual regions and the plurality of second individual regions are arranged alternately, In the first individual region arranged in a central region among the plurality of first individual regions, a center position of the pinhole is arranged at a center position of the sensor region, Among the plurality of first individual regions, in the first individual region arranged in a peripheral region different from the central region, the pinhole does not overlap with the sensor region; In the first individual region disposed in the peripheral region, a distance in a plan view between a central region of the sensor region and the pinhole in the first individual region far from the central region is larger than a distance in a plan view between a central region of the sensor region and the pinhole in the first individual region close to the central region, the plurality of pinholes are arranged so as not to overlap with the plurality of light-emitting regions; An optical element arranged so as to have a focal point where a line connecting the central region of the sensor region and the pinhole in the first individual region A, a line connecting the central region of the sensor region and the pinhole in the first individual region B, and a line connecting the central region of the sensor region and the pinhole in the first individual region C all intersect.

2. the light-shielding region includes a plurality of light-shielding layers and a plurality of the pinholes provided in the plurality of light-shielding layers, The optical element according to claim 1 , wherein the plurality of pinholes are arranged to be offset from one another on a plane, and form a single pinhole that extends obliquely relative to the thickness direction as a whole.

3. The optical element according to claim 1 or 2; An electronic device comprising: a display device.

4. The optical element according to claim 1 or 2; An electronic device comprising: a lens.

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