What is disclosed herein relates to a detection device.
Japanese Translation of PCT International Application Publication Laid-open No. 2017-527045 (JP-A-2017-527045) describes an image acquisition device that includes a display panel, a light source, a light guide plate, a pinhole imaging plate, and an image sensor. In JP-A-2017-527045, the light source is provided at a side end of the light guide plate. Light emitted from the light source travels in the light guide plate, and light reflected by an object to be detected is incident on the image sensor through the optical pinhole imaging plate.
Japanese Translation of PCT International Application Publication Laid-open No. 2018-506806 (JP-A-2018-206806) describes an electronic device that includes an optical image sensor, a pinhole array mask layer, a display layer, a cover layer, and a light source. In JP-A-206806, the light source can direct light toward a finger of a user and guide the light toward the optical image sensor.
Detection devices including an optical sensor are required to detect not only a shape of a fingerprint of an object to be detected such as a finger or a palm, but also various types of biological information on the object to be detected. In this case, the optical sensor may include a plurality of light sources corresponding to the biological information to be detected, and thus, may be difficult to be smaller in size. The light source of JP-A-2017-527045 has an edge-light structure provided at the side end of the light guide plate, and JP-A-2017-527045 does not describe a configuration of providing the light source directly below the display panel. JP-A-2018-206806 does not describe any specific arrangement of the light source.
According to an aspect, a detection device includes: an optical sensor including a sensor base member and a plurality of photoelectric conversion elements that are provided on the sensor base member and configured to output signals corresponding to light emitted to the photoelectric conversion elements; a light-emitting element configured to emit output light toward a direction of an object to be measured; and an optical element including a plurality of first light-transmitting areas and a non-light-transmitting area, and provided between the optical sensor and the object to be measured. In the optical element, the first light-transmitting areas are provided at positions overlapping the respective photoelectric conversion elements so as to penetrate the optical element in a thickness direction of the optical element and are configured to transmit incident light incident on the photoelectric conversion elements, and the non-light-transmitting area is provided between the first light-transmitting areas and has light transmittance lower than light transmittance of the first light-transmitting areas.
The following describes aspects (embodiments) for carrying out the present disclosure in detail with reference to the drawings. The present disclosure is not limited to the description of the embodiments given below. Components described below include those easily conceivable by those skilled in the art or those substantially the same. Moreover, the components described below can be combined as appropriate. What is disclosed herein is merely an example, and appropriate modifications maintaining the gist of the disclosure and easily conceivable by those skilled in the art naturally fall within the scope of the present disclosure. To further clarify the description, the drawings schematically illustrate, for example, widths, thicknesses, and shapes of various parts as compared with actual aspects thereof, in some cases. However, they are merely examples, and interpretation of the present disclosure is not limited thereto. The same element as that illustrated in a drawing that has already been discussed is denoted by the same reference numeral throughout the description and the drawings, and detailed description thereof will not be repeated in some cases where appropriate.
In this disclosure, when an element is described as being “on/upon” another element, the element can be directly on the other element, or there can be one or more elements between the element and the other element.
A first direction Dx and a second direction Dy are directions parallel to a surface of a sensor base member 51 serving as a base body of the optical sensor 5. The first direction Dx is orthogonal to the second direction Dy. The first direction Dx may, however, intersect the second direction Dy without being orthogonal thereto. The third direction Dz is a direction orthogonal to the first direction Dx and the second direction Dy. The third direction Dz corresponds to, for example, a normal direction to the sensor base member 51. Hereinafter, the term “plan view” refers to a positional relation as viewed from the third direction Dz.
The display panel 2 has a display area DA and a peripheral area BE. The display area DA is an area that is disposed so as to overlap a display part DP and displays an image. The peripheral area BE is an area not overlapping the display part DP and is disposed outside the display area DA.
The display panel 2 is a liquid crystal display panel including a liquid crystal layer LC (refer to
The display part DP includes the pixels PX, and the pixels PX are arranged in the first direction Dx and the second direction Dy in the display area DA. The peripheral circuits GC and the coupling terminals T1 are provided in the peripheral area BE. The peripheral circuits GC are circuits that drive a plurality of scan lines GL based on various control signals from the drive IC. The peripheral circuits GC sequentially or simultaneously select the scan lines GL and supply gate drive signals to the selected scan lines GL. Through this operation, the peripheral circuits GC select the pixels PX coupled to the scan lines GL.
The drive IC is a circuit that controls display of the display panel 2. The drive IC may be mounted as a chip on film (COF) on a flexible printed circuit board or a rigid substrate coupled to the coupling terminals T1. The drive IC is not limited thereto and may be mounted as a chip on glass (COG) in the peripheral area BE of the first substrate 10.
As illustrated in
Each of the photoelectric conversion elements 6 is, for example, a photodiode formed of, for example, amorphous silicon. The photoelectric conversion element 6 outputs, to a detection circuit DET (refer to
For example, an inorganic light-emitting element (light-emitting diode (LED)) or an organic electroluminescent (EL) diode (organic light-emitting diode (OLED)) is used as the light-emitting element 7. The display panel 2 is provided so as to face the sensor base member 51 with the optical element 4 interposed therebetween. The light-emitting element 7 emits light L1 toward the display panel 2 and the finger Fg serving as the object to be measured.
The optical element 4 is provided between the optical sensor 5 and the display panel 2 in the third direction Dz. The optical element 4 has a flat plate shape and is provided in an area overlapping at least the photoelectric conversion elements 6 and the light-emitting elements 7. The optical element 4 includes first light-transmitting areas 41, second light-transmitting areas 42, and a non-light-transmitting area 43. The first light-transmitting areas 41 are provided at positions overlapping the respective photoelectric conversion elements 6 so as to penetrate the optical element 4 in a thickness direction of the optical element 4. Each of the first light-transmitting areas 41 has translucency and transmits the light L2 (incident light) incident on the photoelectric conversion element 6.
The second light-transmitting areas 42 are provided at positions overlapping the respective light-emitting elements 7 so as to penetrate the optical element 4 in the thickness direction of the optical element 4. The second light-transmitting areas 42 transmit the light L1 (output light) emitted from the light-emitting elements 7. The non-light-transmitting area 43 is provided between the first light-transmitting areas 41 and the second light-transmitting areas 42 and have lower light transmittance than that of the first light-transmitting areas 41 and the second light-transmitting areas 42. That is, the light L1 and the light L2 do not pass through the non-light-transmitting area 43.
With the above-described configuration, the light L1 emitted from the light-emitting elements 7 passes through the second light-transmitting areas 42 to be incident on the display panel 2. The light L1 passes through the display panel 2 and is reflected on a surface of or in the finger Fg. The light L2 reflected by the finger Fg passes through the display panel 2 and the first light-transmitting areas 41 to be incident on the photoelectric conversion elements 6. As a result, the optical sensor 5 can detect information on a living body such as a fingerprint and/or a blood vessel image (vein pattern) of the finger Fg based on the light L2. At the time of display, the display panel 2 can display a display image using the light L1 that has passed through the display panel 2. In this manner, the light-emitting elements 7 serve as both a light source for detection and a light source for display.
The following describes detailed configurations of the display panel 2, the optical element 4, and the optical sensor 5.
The array substrate SUB1 includes a first insulating film 11, a second insulating film 12, a third insulating film 13, a fourth insulating film 14, a fifth insulating film 15, pixel signal lines SL, pixel electrodes PE, a common electrode DE, and a first orientation film AL1, on a side of the first substrate 10 facing the counter substrate SUB2.
Herein, in the specification, in a direction orthogonal to the first substrate 10, a direction from the first substrate 10 toward the second substrate 20 will be referred to as “upper side” or simply as “upon”, and a direction from the second substrate 20 toward the first substrate 10 will be referred to as “lower side” or simply as “below”.
The first insulating film 11 is provided upon the first substrate 10. The second insulating film 12 is provided upon the first insulating film 11. The third insulating film 13 is provided upon the second insulating film 12. The signal lines SL are provided upon the third insulating film 13. The fourth insulating film 14 is provided upon the third insulating film 13 and covers the pixel signal lines SL. Although not illustrated in
The common electrode DE is provided upon the fourth insulating film 14. The common electrode DE is continuously provided over the display area DA. The common electrode DE is, however, not limited to this configuration, and may be provided with slits and divided into a plurality of pieces. The common electrode DE is covered with the fifth insulating film 15.
The pixel electrodes PE are provided upon the fifth insulating film 15 and face the common electrode DE with the fifth insulating film 15 interposed therebetween. The pixel electrodes PE and the common electrode DE are formed of, for example, a light-transmitting conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The pixel electrodes PE and the fifth insulating film 15 are covered with the first orientation film AL1.
The first insulating film 11, the second insulating film 12, the third insulating film 13, and the fifth insulating film 15 are formed of, for example, a light-transmitting inorganic material such as a silicon oxide or a silicon nitride. The fourth insulating film 14 is formed of a light-transmitting resin material and has a film thickness greater than those of the other insulating films formed of the inorganic material.
The counter substrate SUB2 includes, for example, a light-blocking layer BM, color filters CFR, CFG, and CFB, an overcoat layer OC, and a second orientation film AL2, on a side of the second substrate 20 facing the array substrate SUB1. The counter substrate SUB2 includes a conductive layer 21 on a side of the second substrate 20 opposite to the array substrate SUB1.
In the display area DA, the light-blocking layer BM is located on the side of the second substrate 20 facing the array substrate SUB1. The light-blocking layer BM defines openings facing the respective pixel electrodes PE. Each of the pixel electrodes PE is partitioned off for each of the openings of the pixels PX. The light-blocking layer BM is formed of a black resin material or a light-blocking metal material.
Each of the color filters CFR, CFG, and CFB is located on the side of the second substrate 20 facing the array substrate SUB1 and overlaps, at ends thereof, the light-blocking layer BM. In an example, the color filters CFR, CFG, and CFB are respectively formed of resin materials colored in red, green, and blue.
The overcoat layer OC covers the color filters CFR, CFG, and CFB. The overcoat layer OC is formed of a light-transmitting resin material. The second orientation film AL2 covers the overcoat layer OC. Each of the first orientation film AL1 and the second orientation film AL2 is formed of, for example, a material that exhibits a horizontal orientation property.
The conductive layer 21 is provided upon the second substrate 20. The conductive layer 21 is, for example, of a light-transmitting conductive material such as ITO. Externally applied static electricity and static electricity charging a second polarizing plate PL2 flow through the conductive layer 21. The detection device 1 can remove the static electricity in a short time, and thus, can reduce the static electricity applied to the liquid crystal layer LC that serves as a display layer. As a result, the display panel 2 can be improved in electrostatic discharge (ESD) resistance.
A first polarizing plate PL1 is disposed on an external surface of the first substrate 10, or a surface thereof facing the optical element 4 (refer to
The array substrate SUB1 and the counter substrate SUB2 are disposed such that the first orientation film AL1 and the second orientation film AL2 face each other. The liquid crystal layer LC is sealed between the first orientation film AL1 and the second orientation film AL2. The liquid crystal layer LC is formed of a negative liquid crystal material having a negative dielectric anisotropy or a positive liquid crystal material having a positive dielectric anisotropy.
For example, in the case where the liquid crystal layer LC is a negative liquid crystal material, when no voltage is applied to the liquid crystal layer LC, a long axis of a liquid crystal molecule LM is initially oriented in a direction along the first direction Dx in an XY-plane. In contrast, in a state where a voltage is applied to the liquid crystal layer LC, that is, in an on-state where an electric field is formed between the pixel electrodes PE and the common electrode DE, the orientation state of the liquid crystal molecule LM changes under the influence of the electric field. In the on-state, the polarization state of linearly polarized incident light changes in accordance with the orientation state of the liquid crystal molecule LM when the light passes through the liquid crystal layer LC.
Each of the pixels PX includes the sub-pixels SPX. Each of the sub-pixels SPX includes a corresponding one of the switching elements Tr and a capacitance of the liquid crystal layer LC. The switching element Tr includes a thin-film transistor, and in this example, an n-channel metal-oxide-semiconductor (MOS) thin-film transistor (TFT). The fifth insulating film 15 is provided between the pixel electrodes PE and the common electrode DE illustrated in
Color regions colored in three colors of, for example, red (R), green (G), and blue (B) are periodically arranged as the color filters CFR, CFG, and CFB illustrated in
The sensor base member 51 is provided with various types of wiring including, for example, sensor signal lines SLA, sensor scan lines GLA, light source signal lines SLB, and light source scan lines GLB. The sensor scan lines GLA are wiring for supplying drive signals (scan signals) for driving sensor switching elements TrA (refer to
The light source scan lines GLB are wiring for supplying drive signals (scan signals) for driving switching elements included in drive circuits for the light-emitting elements 7. The light source signal lines SLB are wiring for supplying drive voltages to the light-emitting elements 7.
Each of the sensor scan lines GLA and the light source scan lines GLB extends in the first direction Dx. Each of the sensor signal lines SLA and the light source signal lines SLB extends in the second direction Dy. The photoelectric conversion elements 6 are provided in areas surrounded by the sensor scan lines GLA and the sensor signal lines SLA. The light-emitting elements 7 are provided in areas surrounded by the light source scan lines GLB and the light source signal lines SLB. Drive circuits for driving the photoelectric conversion elements 6 and the light-emitting elements 7 are provided in respective areas surrounded by the sensor scan lines GLA, the light source scan lines GLB, the sensor signal lines SLA, and the light source signal lines SLB.
An anode electrode 78 is coupled to the light-emitting element 7. The anode electrode 78 has a larger area than that of the light-emitting element 7 in the plan view. The anode electrode 78 is formed of a metal material such as silver (Ag) and reflects light emitted from a lateral side of the light-emitting element 7 to emit the light L1 toward the display panel 2. That is, an area including the light-emitting element 7 and the anode electrode 78 serves as a light-emitting surface for emitting the light L1.
A width WB1 in the first direction Dx of the anode electrode 78 is greater than a width WA1 in the first direction Dx of the photoelectric conversion element 6. A width WB2 in the second direction Dy of the anode electrode 78 is greater than a width WA2 in the second direction Dy of the photoelectric conversion element 6. With this configuration, the light-emitting elements 7 can well emit the light L1 to the entire display area DA.
The light-emitting elements 7 include first light-emitting elements 7-W and second light-emitting elements 7-NIR, and the first light-emitting element 7-W and the second light-emitting element 7-NIR emit the light L1 having different wavelengths. The first light-emitting elements 7-W emit visible light (for example, white light). The first light-emitting elements 7-W may be composed of a plurality of light-emitting elements or may be composed of combinations each of which includes one or more light-emitting elements and one or more fluorescent bodies. The second light-emitting elements 7-NIR emit, for example, near-infrared light. One second light-emitting element 7-NIR is provided for the multiple first light-emitting elements 7-W (three of the first light-emitting elements 7-W in the example illustrated in
With this configuration, when the display panel 2 performs display, the first light-emitting elements 7-W among the light-emitting elements 7 emit the light L1, and when the optical sensor 5 performs detection, the first light-emitting elements 7-W and the second light-emitting elements 7-NIR among the light-emitting elements 7 emit the light L1. The light-emitting elements 7 are not limited to light-emitting elements emitting the white and near-infrared light L1 and may include light-emitting elements that emit the light L1 having another wavelength. The light L1 having different wavelengths may be emitted depending on the information on the living body to be detected by the optical sensor 5, such as asperities (fingerprint), the blood vessel image, a pulse wave, pulsation, or a blood oxygen concentration of the finger Fg or a palm. For example, in the case of the fingerprint detection, the optical sensor 5 may perform the detection based on the visible light emitted from the first light-emitting elements 7-W, and in the case of the detection of the blood vessel image (vein pattern), the optical sensor 5 may perform the detection based on the near-infrared light emitted from the second light-emitting elements 7-NIR.
As illustrated in
The photoelectric conversion element 6 is a positive-intrinsic-negative (PIN) photodiode. The semiconductor 61 is of amorphous silicon (a-Si). The semiconductor 61 includes an i-type semiconductor 61a, an n-type semiconductor 61b, and a p-type semiconductor 61c. The i-type semiconductor 61a, the n-type semiconductor 61b, and the p-type semiconductor 61c constitute a specific example of the photoelectric conversion element. In
The lower electrode 64 is the anode of the photoelectric conversion element 6 and is an electrode for reading each of the detection signals. The upper electrode 65 is the cathode of the photoelectric conversion element 6 and is an electrode for supplying a power supply signal SVS to the photoelectric conversion element 6.
An insulating layer 56 and an insulating layer 57 are provided upon the first organic insulating layer 55. The insulating layer 56 covers a peripheral portion of the upper electrode 65 and is provided with an opening at a position overlapping the upper electrode 65. Coupling wiring 67 is coupled to the upper electrode 65 at a portion of the upper electrode 65 not provided with the insulating layer 56. The coupling wiring 67 is wiring for coupling the upper electrode 65 to a power supply signal line Lvs. The insulating layer 57 is provided upon the insulating layer 56 so as to cover the upper electrode 65 and the coupling wiring 67. A second organic insulating layer 58 serving as a planarizing layer and an overcoat layer 59 are provided upon the insulating layer 57.
As illustrated in
The light-blocking layer LSA is formed of a material having lower light transmittance than that of the sensor base member 51 and is provided below the semiconductor layer PSA. The insulating layer 52 is provided upon the sensor base member 51 so as to cover the light-blocking layer LSA. The semiconductor layer PSA is provided upon the insulating layer 52. For example, polysilicon or an oxide semiconductor is used as the semiconductor layer PSA.
The insulating layer 53 is provided upon the insulating layer 52 so as to cover the semiconductor layer PSA. The sensor scan line GLA is provided upon the insulating layer 53. A portion of the sensor scan line GLA overlapping the semiconductor layer PSA serves as a gate electrode. The sensor switching element TrA has a top-gate structure in which the sensor scan line GLA is provided on the upper side of the semiconductor layer PSA. However, the sensor switching element TrA is not limited thereto and may have a bottom-gate structure or a dual-gate structure.
The insulating layer 54 is provided upon the insulating layer 53 so as to cover the sensor scan line GLA. The source electrode SEA (signal line SLA) and the drain electrode DEA (anode coupling line 68) are provided upon the insulating layer 54. The source electrode SEA and the drain electrode DEA are each coupled to the semiconductor layer PSA through a contact hole provided in the insulating layers 53 and 54. The lower electrode 64 of the photoelectric conversion element 6 is coupled to the anode coupling line 68 through a contact hole provided in the first organic insulating layer 55.
Although an amorphous silicon material is used as the photoelectric conversion element 6, an organic material, for example, may be used instead. Polysilicon may be used to form a PIN photodiode as the photoelectric conversion element 6.
The cathode of the photoelectric conversion element 6 is supplied with the power supply signal SVS from a power supply circuit. The capacitive element Ca is also supplied with a reference signal VR1 serving as an initial potential of the capacitive element Ca from the power supply circuit.
When the partial detection area PAA is irradiated with the light L2, a current corresponding to an amount of the light flows through the photoelectric conversion element 6. As a result, an electrical charge is stored in the capacitive element Ca. After the sensor switching element TrA is turned on, a current corresponding to the electrical charge stored in the capacitive element Ca flows through the sensor signal line SLA. The sensor signal line SLA is coupled to the detection circuit DET. As a result, the optical sensor 5 can detect a signal corresponding to the amount of the light emitted to the photoelectric conversion element 6 for each of the partial detection areas PAA. The optical sensor 5 may include a switching circuit for switching between coupling and decoupling of the sensor signal line SLA to and from the detection circuit DET for each of the sensor signal lines SLA.
The drive transistor DRT includes a semiconductor layer PSB, the light source scan line GLB, a drain electrode DEB, and a source electrode SEB. An anode power supply line IPL and a base BS are provided upon the insulating layer 54. A portion of the anode power supply line IPL overlapping the semiconductor layer PSB serves as the drain electrode DEB of the drive transistor DRT. A portion of the base BS overlapping the semiconductor layer PSB serves as the source electrode SEB of the drive transistor DRT. A light-blocking layer LSB is provided below the semiconductor layer PSB. The configuration of the drive transistor DRT is similar to the configuration of the sensor switching element TrA illustrated in
The first organic insulating layer 55 is provided upon the insulating layer 54 so as to cover the anode power supply line IPL and the base BS. A light source common electrode CEB, an overlapping electrode PEB, and a cathode electrode CD are of indium tin oxide (ITO). The insulating layer 56 is provided between the light source common electrode CEB and the overlapping electrode PEB in the normal direction to the sensor base member 51.
The anode electrode 78 is a layered body of, for example, ITO, silver (Ag), and ITO. The anode electrode 78 is provided upon the overlapping electrode PEB and is coupled to the base BS through a contact hole CH provided in the first organic insulating layer 55. A coupling layer CL is formed of silver paste and is provided upon the anode electrode 78 between the sensor base member 51 and the light-emitting element 7. The light-emitting element 7 is provided upon the coupling layer CL and is electrically coupled to the coupling layer CL. That is, the light-emitting element 7 is electrically coupled to the anode electrode 78 through the coupling layer CL.
The insulating layer 57 is provided on the insulating layer 56 so as to cover the anode electrode 78 and side surfaces of the coupling layer CL. The second organic insulating layer 58 is provided on the insulating layer 57 so as to cover side surfaces of the light-emitting element 7. The cathode electrode CD is provided on the second organic insulating layer 58 and the light-emitting element 7 and is electrically coupled to a cathode terminal ELED2 of the light-emitting element 7 (refer to
The light-emitting layer EM is of, for example, indium gallium nitride (InGaN). The p-type cladding layer PC and the n-type cladding layer NC are of, for example, gallium nitride (GaN). The light-emitting element substrate SULED is of silicon carbide (SiC). Both the anode terminal ELED1 and the cathode terminal ELED2 are of aluminum.
In a manufacturing process of the light-emitting element 7, manufacturing equipment forms films of the n-type cladding layer NC, the light-emitting layer EM, the p-type cladding layer PC, and the cathode terminal ELED2 upon the light-emitting element substrate SULED. Then, the manufacturing equipment forms the light-emitting element substrate SULED into a thin film and forms the anode terminal ELED1 on the bottom surface of the light-emitting element substrate SULED. The manufacturing equipment then cuts the light-emitting element 7 into a square and disposes it upon the coupling layer CL.
With such a configuration, the anode (anode terminal ELED1) of the light-emitting element 7 is coupled to the anode power supply line IPL through the drive transistor DRT. The anode power supply line IPL is supplied with an anode power supply potential PVDD. The cathode (cathode terminal ELED2) of the light-emitting element 7 is supplied with a cathode reference potential. The anode power supply potential PVDD is a higher potential than the cathode reference potential. As a result, the light-emitting element 7 is supplied with a forward current (drive current) by a potential difference between the anode power supply potential PVDD and the cathode reference potential, and thereby, emits light. The configuration of the light-emitting element 7 illustrated in
The first light-transmitting area 41 is circular in the plan view. The second light-transmitting area 42 is rectangular in the plan view. The area of the second light-transmitting area 42 is larger than the area of the first light-transmitting area 41. This configuration can restrain the extraction efficiency of the light L1 from the light-emitting elements 7 from decreasing. However, the shapes in the plan view of the first light-transmitting area 41 and the second light-transmitting area 42 may be modified as appropriate in accordance with the shape of a light-receiving surface of the photoelectric conversion element 6 and the shape of the light-emitting surface of the light-emitting element 7. The shapes of first light-transmitting area 41 and the second light-transmitting area 42 are not limited to being circular and quadrilateral, respectively, and may be, for example, polygonal, elliptical, or irregular-shaped.
As illustrated in
In other words, the first light-transmitting areas 41 and the second light-transmitting areas 42 are areas not overlapping the non-light-transmitting resins 45 and are formed of only the first light-transmitting resins 44 from one surface to the other surface of the optical element 4. The non-light-transmitting area 43 is an area including at least one non-light-transmitting resin 45 between the one surface and the other surface of the optical element 4. Such a configuration allows the optical element 4 to transmit the light L1 through the first light-transmitting areas 41, transmit the light L2 through the second light-transmitting areas 42, and prevent the light L1 and L2 from transmitting through the non-light-transmitting area 43.
As illustrated in
However, one photoelectric conversion element 6 and one light-emitting element 7 may be arranged for each set including more than one pixel PX. The arrangement pitch in the first direction Dx of the photoelectric conversion elements 6 may be an integer multiple of the arrangement pitch in the first direction Dx of the pixels PX. The arrangement pitch in the second direction Dy of the photoelectric conversion elements 6 may be an integer multiple of the arrangement pitch in the second direction Dy of the pixels PX. In the same manner, the arrangement pitch in the first direction Dx of the light-emitting elements 7 may be an integer multiple of the arrangement pitch in the first direction Dx of the pixels PX, and the arrangement pitch in the second direction Dy of the light-emitting elements 7 may be an integer multiple of the arrangement pitch in the second direction Dy of the pixels PX. In
The photoelectric conversion element 6 is provided in an area overlapping at least one of the sub-pixel SPX-R for displaying the red color and the sub-pixel SPX-G for displaying the green color. In
The first light-transmitting areas 41 of the optical element 4 are arranged so as to overlap the photoelectric conversion elements 6. In the plan view, the area of each of the first light-transmitting areas 41 is smaller than the area of each of the photoelectric conversion elements 6. That is, the diameter of the first light-transmitting area 41 is less than the widths WA1 and WA2 of the photoelectric conversion element 6 (refer to
The second light-transmitting areas 42 are arranged so as to overlap the light-emitting elements 7 and the anode electrodes 78. The width in the first direction Dx and the width in the second direction Dy of the second light-transmitting area 42 are respectively less than the widths WB1 and WB2 of the anode electrode 78 (refer to
The light L1 emitted from the light-emitting element 7 passes through the second light-transmitting area 42, the first substrate 10, the liquid crystal layer LC, the color filter CFB, and the second substrate 20, and is incident on the finger Fg. The second light-transmitting area 42 of the optical element 4 desirably has a scattering structure. In this case, the light L1 is scattered in the second light-transmitting area 42 and is emitted over the sub-pixels SPX-R and SPX-G, which are adjacent to the sub-pixel SPX-B, and more than one pixel PX. This configuration can reduce differences in luminance of the light L1 emitted from the display surface of the display panel 2, and thus, can improve the display characteristics.
The light L2 reflected by the finger Fg passes through the second substrate 20, the color filters CFR and CFG, the liquid crystal layer LC, the first substrate 10, and the first light-transmitting areas 41, and is incident on the photoelectric conversion elements 6. As a result, the optical sensor 5 can detect the various types of biological information such as the fingerprint and the vein pattern.
As described above, the detection device 1 of the present embodiment includes the optical sensor 5, the display panel 2 (liquid crystal display panel), the light-emitting elements 7, and the optical element 4. The optical sensor 5 includes the sensor base member 51 and the photoelectric conversion elements 6 that are provided on the sensor base member 51 and output the signals corresponding to the light emitted to the photoelectric conversion elements. The display panel 2 is provided so as to face the sensor base member 51 in the direction orthogonal to the sensor base member 51. The light-emitting elements 7 are located between the display panel 2 and the sensor base member 51 in the direction orthogonal to the sensor base member 51, and emit the light L1 (output light) to the display panel 2. The optical element 4 includes the first light-transmitting areas 41 and the non-light-transmitting area 43 and is provided between the optical sensor 5 and the display panel 2 in the direction orthogonal to the sensor base member 51. In the optical element 4, the first light-transmitting areas 41 are provided at the positions overlapping the respective photoelectric conversion elements 6 so as to penetrate the optical element 4 in the thickness direction thereof, and transmit the incident light incident on the photoelectric conversion elements 6. The non-light-transmitting area 43 is provided between the first light-transmitting areas 41 and have the light transmittance lower than that of the first light-transmitting areas 41. The light-emitting elements 7 are provided on the sensor base member 51.
With this configuration, the photoelectric conversion elements 6 and the light-emitting elements 7 are provided on the same sensor base member 51. As a result, the detection device 1 can be slimmed as compared with a configuration of providing the light source of the optical sensor 5 on a substrate different from the sensor base member 51. The light-emitting elements 7 serve as both the light source of the optical sensor 5 and the light source of the display panel 2. As a result, a backlight of the display panel 2 can be eliminated.
As illustrated in
The lighting device 8 is provided between the optical sensor 5 and the display panel 2 in the third direction Dz. In other words, the lighting device 8 is provided between the optical sensor 5 and the finger Fg in the third direction Dz. More specifically, the detection device 1A is configured such that the optical sensor 5, the optical element 4A, the lighting device 8, and the display panel 2 are stacked in the order of the optical sensor 5, the optical element 4A, the lighting device 8, and the display panel 2 in the third direction Dz.
The light source scan lines GLB and the light source signal lines SLB (refer to
The light source base member 81 of the lighting device 8 is provided upon the optical element 4A. The light-emitting elements 7 are provided in areas upon the light source base member 81 that overlap the non-light-transmitting area 43 of the optical element 4A. In other words, the light-emitting elements 7 are provided in areas not overlapping the first light-transmitting areas 41 and the photoelectric conversion elements 6. The display panel 2 is provided upon an overcoat layer 85 covering the light-emitting elements 7.
With the above-described configuration, the light L1 emitted from the light-emitting element 7 of the lighting device 8 passes through the first substrate 10, the liquid crystal layer LC, the color filter CFB, and the second substrate 20, and is incident on the finger Fg. The light L2 reflected by the finger Fg passes through the second substrate 20, the color filters CFR and CFG, the liquid crystal layer LC, the first substrate 10, the lighting device 8, and the first light-transmitting areas 41, and is incident on the photoelectric conversion elements 6.
In the present embodiment, the light-emitting elements 7 are provided between the optical element 4A and the display panel 2. With this configuration, the light L1 from the light-emitting elements 7 is incident on the display panel 2 without passing through the optical element 4A. Therefore, the use efficiency of the light of the light-emitting elements 7 can be improved. The photoelectric conversion elements 6 are provided in a layer different from that of the light-emitting elements 7 with the optical element 4A interposed therebetween. With this configuration, the optical element 4A can restrain the light L1 emitted to the lateral sides of the light-emitting elements 7 from being incident on the photoelectric conversion elements 6. This can improve the detection accuracy of the optical sensor 5.
As illustrated in
A second light-transmitting resin 46 constituting the near-infrared light transmitting area 41b is provided so as to cover a lower surface and side surfaces of the non-light-transmitting resin 45 constituting the non-light-transmitting area 43. The first light-transmitting resin 44 constituting the visible light transmitting area 41a is provided in a through-hole provided in the second light-transmitting resin 46.
As illustrated in
As described above, in performing the fingerprint detection, the first light-emitting element 7-W illustrated in
The lighting device 8A includes a light guide plate 82 and a light-emitting element 7A. The light guide plate 82 has a flat plate shape and is disposed so as to face the array substrate SUB1 of the display panel 2. The light guide plate 82 is disposed in an area overlapping at least the display area DA. The light-emitting element 7A is disposed at a side end of the light guide plate 82 and emits the light L1 toward the light guide plate 82.
The stacking order of the optical sensor 5, the optical element 4A, the lighting device 8A, and the display panel 2 is the same as that in the second embodiment. Specifically, the light guide plate 82 is disposed between the optical element 4A and display panel 2 in the third direction Dz.
As illustrated in
The light L1 emitted from the upper surface 82a of the light guide plate 82 passes through the first substrate 10, the liquid crystal layer LC, the color filters CF, and the second substrate 20, and is incident on the finger Fg. The light L2 reflected by the finger Fg passes through the second substrate 20, the color filters CFR and CFG, the liquid crystal layer LC, the first substrate 10, the light guide plate 82 of the lighting device 8, and the first light-transmitting areas 41, and is incident on the photoelectric conversion elements 6.
In this manner, the detection device 1C is not limited to employing what is called a direct-type of the lighting device 8 and can employ the edge-light-type in which the light-emitting element 7A is provided at a side end of the light guide plate 82. In the present embodiment, as compared with the second embodiment, the light source base member 81 (refer to
The number of the recesses 83 per unit area (arrangement density) increases with increasing distance from the light-emitting element 7A. This configuration can efficiently scatter the light L1 at positions away from the light-emitting element 7A, and thus, can restrain the light L1 from being uneven in a plane. A reflecting layer may be provided between a lower surface 82b of the light guide plate 82 and the non-light-transmitting area 43. This configuration can restrain the light L1 from being emitted outward from the lower surface 82b, and thus, can improve the use efficiency of the light L1. The light-emitting elements 7A may include the first light-emitting element 7-W and the second light-emitting element 7-NIR, and the first light-emitting element 7-W and the second light-emitting element 7-NIR may be provided at the side end of the light guide plate 82.
The lighting device 8B is configured such that the light source base member 81, the first light-emitting elements 7A-W, and the light guide plate 82 are stacked in the third direction Dz in the order as listed. That is, the light source base member 81 is provided upon the optical element 4B, and the light guide plate 82 is provided between the light source base member 81 and the display panel 2.
In performing the fingerprint detection, the first light-emitting elements 7A-W emit the light L1 of visible light, and the light L1 passes through the light guide plate 82 and the display panel 2 to be incident on the finger Fg. The light L2 reflected by the finger Fg passes through the display panel 2, the light guide plate 82, the light source base member 81, and the visible light transmitting areas 41a, and is incident on the photoelectric conversion elements 6. In performing the detection of the blood vessel image (vein pattern), the second light-emitting element 7A-NIR emits the near-infrared light, and the light L1 scattered by the recesses 83 of the light guide plate 82 passes through the display panel 2 to be incident on the finger Fg. The light L2 reflected by the finger Fg passes through the display panel 2, the light guide plate 82, the light source base member 81, the visible light transmitting areas 41a, and the near-infrared light transmitting areas 41b, and is incident on the photoelectric conversion elements 6.
As described above, the first light-emitting element 7A-W and the second light-emitting element 7A-NIR that emit the light L1 having different wavelengths may be provided on different members. In the third modification, the emission surface (upper surface 82a of the light guide plate 82) for emitting the light L1 of the second light-emitting element 7A-NIR is disposed at a position closer to the display panel 2 than the first light-emitting elements 7A-W are. With this configuration, the light L1 from the second light-emitting element 7A-NIR is emitted toward the display panel 2 without passing through the light source base member 81 and the first light-emitting elements 7A-W. Consequently, the detection device 1D can efficiently capture the blood vessel image (vein pattern).
While the optical element 4B includes the visible light transmitting areas 41a and the near-infrared light transmitting areas 41b in the same manner as in the second modification illustrated in
As illustrated in
The sectional configuration of the array substrate SUB1A and the light-emitting elements 7B can employ the same configuration as that of
The display panel 2A includes an overcoat layer 29 covering the light-emitting elements 7B. The finger Fg comes in contact with or proximity to a surface of the overcoat layer 29. However, the present disclosure is not limited thereto. A cover substrate may be provided upon the overcoat layer 29.
As illustrated in
In the following description, the light-emitting elements 7B-R, 7B-G, and 7B-B will each be simply referred to as the light-emitting element 7B when they need not be distinguished from one another. The light-emitting elements 7B may emit light in four or more different colors. The arrangement of the pixels PX and the light-emitting element 7B is not limited to the configuration illustrated in
The cathode (cathode terminal ELED2 (refer to
The anode power supply line IPL supplies the anode power supply potential PVDD serving as a drive potential to the light-emitting element 7B. Specifically, the light-emitting element 7B is supplied with a forward current (drive current) by a potential difference between the anode power supply potential PVDD and the cathode power supply potential PVSS (PVDD-PVSS), and thereby emits light. That is, the anode power supply potential PVDD has the potential difference with respect to the cathode power supply potential PVSS for causing the light-emitting element 7B to emit light. The anode terminal ELED1 of the light-emitting element 7B is coupled to the anode electrode 78, and the second capacitor Cs2 is coupled as an equivalent circuit between the anode electrode 78 and the anode power supply line IPL.
The source electrode of the drive transistor DRT is coupled to the anode terminal ELED1 of the light-emitting element 7B through the anode electrode 78, and the drain electrode of the drive transistor DRT is coupled to the source electrode of the output transistor BCT. The gate electrode of the drive transistor DRT is coupled to the first capacitor Cs1, the drain electrode of the pixel selection transistor SST, and the drain electrode of the initialization transistor IST.
The gate electrode of the output transistor BCT is coupled to an output control signal line MSL. The output control signal line MSL is supplied with an output control signal BG. The drain electrode of the output transistor BCT is coupled to the anode power supply line IPL.
The source electrode of the initialization transistor IST is coupled to an initialization power supply line INL. The initialization power supply line INL is supplied with an initialization potential Vini. The gate electrode of the initialization transistor IST is coupled to an initialization control signal line ISL. The initialization control signal line ISL is supplied with an initialization control signal IG. That is, the initialization power supply line INL is coupled to the gate electrode of the drive transistor DRT through the initialization transistor IST.
The source electrode of the pixel selection transistor SST is coupled to a video signal line SL. The video signal line SL is supplied with a video signal Vsig. A pixel control signal line SSL is coupled to the gate electrode of the pixel selection transistor SST. The pixel control signal line SSL is supplied with a pixel control signal SG.
The source electrode of the reset transistor RST is coupled to a reset power supply line RL. The reset power supply line RL is supplied with a reset power supply potential Vrst. A reset control signal line RSL is coupled to the gate electrode of the reset transistor RST. The reset control signal line RSL is supplied with a reset control signal RG. The drain electrode of the reset transistor RST is coupled to the anode terminal ELED1 of the light-emitting element 7B and the source electrode of the drive transistor DRT.
The first capacitor Cs1 is provided as an equivalent circuit between the drain electrode of the reset transistor RST and the gate electrode of the drive transistor DRT. The drive circuit PICA can reduce a variation in gate voltage of a parasitic capacitance and a leakage current of the drive transistor DRT by the first capacitor Cs1 and the second capacitor Cs2.
The gate electrode of the drive transistor DRT is supplied with a potential corresponding to the video signal Vsig (or a gradation signal). That is, the drive transistor DRT supplies a current corresponding to the video signal Vsig to the light-emitting element 7B based on the anode power supply potential PVDD supplied through the output transistor BCT. In this manner, the anode power supply potential PVDD supplied to the anode power supply line IPL is lowered by the drive transistor DRT and the output transistor BCT. As a result, the anode terminal ELED1 of the light-emitting element 7B is supplied with a potential lower than the anode power supply potential PVDD.
One electrode of the second capacitor Cs2 is supplied with the anode power supply potential PVDD through the anode power supply line IPL, and the other electrode of the second capacitor Cs2 is supplied with the potential lower than the anode power supply potential PVDD. That is, the one electrode of the second capacitor Cs2 is supplied with the potential higher than that of the other electrode of the second capacitor Cs2. For example, the one electrode of the second capacitor Cs2 is the anode power supply line IPL, and the other electrode of the second capacitor Cs2 is the anode electrode 78 and an anode coupling electrode coupled thereto.
In the display panel 2A, peripheral circuits GCA (refer to
With the above-described configuration, the light L1 emitted from each of the light-emitting elements 7B of the display panel 2A travels toward the finger Fg, as illustrated in
In the detection device 1E of the fourth embodiment, the light-emitting elements 7B serving as display elements of the display panel 2A also serve as the light source of the optical sensor 5. Therefore, the detection device 1E can be made smaller (slimmer) than the case of the first to the third embodiments.
In the first direction Dx, the light-emitting element 7B-NIR is arranged adjacent to the light-emitting element 7B-G. In the second direction Dy, the light-emitting element 7B-NIR is arranged adjacent to the light-emitting element 7B-R. In the second direction Dy, the light-emitting element 7B-G is arranged adjacent to the light-emitting element 7B-B. In the first direction Dx, the light-emitting element 7B-R is arranged adjacent to the light-emitting element 7B-B.
The arrangement of the light-emitting elements 7B-NIR, 7B-R, 7B-G, and 7B-B is not limited to the example illustrated in
The display of the display panel 2A and the detection of the optical sensor 5 may be performed in a time division manner or in a simultaneous manner. Since the light-emitting element 7B-NIR emits the invisible light, the display characteristics are not much affected even when the light-emitting element 7B-NIR emits the light L1 during a display period in which the display is performed by the light-emitting elements 7B-R, 7B-G, and 7B-B. Therefore, the optical sensor 5 can detect the biological information based on the light emitted from the light-emitting element 7B-NIR during the display period.
That is, as illustrated in
Also in the fifth modification, the light L1 emitted from the light-emitting element 7B travels toward the finger Fg. The light L2 reflected by the finger Fg passes through the openings of the array substrate SUB1A and is incident on the photoelectric conversion elements 6. As a result, the detection device 1F can detect the information on the living body. In the fifth modification, the optical element 4A is not provided. Therefore, the detection device 1F can be slimmed as compared with the fifth embodiment.
While the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above. The content disclosed in the embodiments is merely exemplary, and can be variously modified within the scope not departing from the gist of the present disclosure. Any modification appropriately made within the scope not departing from the gist of the present disclosure also naturally belongs to the technical scope of the present disclosure.
Number | Date | Country | Kind |
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2019-088581 | May 2019 | JP | national |
This application claims the benefit of priority from Japanese Patent Application No. 2019-088581 filed on May 8, 2019 and International Patent Application No. PCT/JP2020/015786 filed on Apr. 8, 2020, the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/JP2020/015786 | Apr 2020 | US |
Child | 17452407 | US |