Patent Application
20200027937
The present application is based on, and claims priority from JP Application Serial Number 2018-133889, filed Jul. 17, 2018, the disclosure of which is hereby incorporated by reference herein in its entirety.
The present disclosure relates to a light-emitting device and an electronic apparatus.
An organic electroluminescence (EL) device including an organic light-emitting element (OLED; Organic Light-emitting Diode), for example, is known as a light-emitting device. The organic EL device is superior since it has a simpler structure because a lighting device is unnecessary compared to the liquid crystal device, it is thin and has flexibility when an organic light-emitting element and a driving circuit are formed on a plastic substrate, and it can realize a display device that is capable of responding to various shapes.
For example, JP-A-2016-81031 discloses a display device in which a display unit including an organic light-emitting element in a pixel is circular-shaped. The organic light-emitting element is configured to include an anode electrode, an organic light-emitting layer provided on the anode electrode, and a cathode electrode layer provided on the organic light-emitting layer. The organic light-emitting layer emits light by the data current supplied from the drive transistor with respect to the organic light-emitting element described above, and the video is displayed. A driving power supply line, a cathode power supply line, and a gate built-in circuit are each disposed in an arc shape along the circular-shaped display unit.
However, when the display unit is set to be circular-shaped as in the display device of JP-A-2016-81031, the display unit includes parts where the number of pixels attached to various signal wirings related to the display are different, and the capacitance and the resistance of the signal wirings differ depending on the positions of the pixels. Therefore, there is a possibility that differences occur in the emission luminance of the organic light-emitting element, for example, luminance unevenness may occur at the center part and the end part of the display unit. There is a problem in that luminance unevenness in such a self-emitting display device is easily recognized as display unevenness in comparison to a liquid crystal device.
A light-emitting device of the present application includes a display unit including a light-emitting portion in which a light-emitting pixel is disposed and a non-light-emitting portion disposed around the light-emitting portion, a driving circuit configured to drive the light-emitting pixel, and a driving line that is disposed in the display unit and that is coupled to the driving circuit, wherein an outline of the light-emitting portion is a shape different from a rectangle, and an outline of the display unit is a rectangle.
Another light-emitting device of the present application includes a display unit including a light-emitting portion in which a light-emitting pixel is disposed and a non-light-emitting portion disposed around the light-emitting portion, and a driving line that is disposed in the display unit and that is related to the light-emitting pixel, wherein an outline of the light-emitting portion is a shape different from a rectangle, and the shorter a part of the driving line disposed in the light-emitting portion is, the longer a part of the driving line disposed in the non-light-emitting portion is.
In the light-emitting device described above, the light-emitting pixel includes a first electrode and a second electrode, and a light-emitting function layer disposed between the first electrode and the second electrode, the second electrode is a common electrode disposed over the light-emitting portion and the non-light-emitting portion, and the non-light-emitting portion includes a second electrode contact portion disposed along the outline of the light-emitting portion.
In the light-emitting device described above, the second electrode contact portion may be disposed equidistantly from an outer edge of the light-emitting portion.
In the light-emitting device described above, the second electrode contact portion may include an electrode disposed in the same layer as the first electrode, and the electrode and the second electrode may be in contact with each other via the second electrode contact portion.
In the light-emitting device described above, the light-emitting function layer may be formed over the light-emitting portion and the non-light-emitting portion, and an outer edge of the light-emitting function layer may be located between the second electrode contact portion and an outer edge of the light-emitting portion.
In the light emitting device described above, the non-light-emitting portion may include a non-light-emitting dummy pixel between the second electrode contact portion and an outer edge of the light-emitting portion.
In the light emitting device described above, the dummy pixel may include, similarly to the light-emitting pixel, the first electrode, the second electrode, and the light-emitting function layer, and may include an insulating film between the first electrode and the light-emitting function layer.
In the light emitting device described above, the light emitting device may include a sealing film disposed on the display unit and covering at least the light-emitting portion and the second electrode contact portion, and a color filter disposed, on the sealing film, corresponding to the light-emitting pixel.
An electronic apparatus according to the present disclosure includes the light-emitting device described above.
Exemplary embodiments of the present disclosure will be described below with reference to the accompanying drawings. Note that, in the drawings referred to below, the parts described are illustrated in an enlarged or reduced state as appropriate so that those parts can be easily recognized.
Light-Emitting Device
A basic configuration of a light-emitting device according to the present exemplary embodiment will be described with reference to
As illustrated in
The element substrate 10 is slightly larger than the counter substrate 20, and a plurality of external connection terminals 104 for connecting to an external driving circuit are aligned in a terminal part 10a, which is a side part of the element substrate 10 protruding from the counter substrate 20. The data line driving circuit 101 is disposed between the plurality of external connection terminals 104 and the display unit 105. The scanning line driving circuit 102 is disposed between the display unit 105 and each of the two opposing side parts orthogonal to the terminal part 10a of the element substrate 10. An inspecting circuit 103 is disposed between the side part of the element substrate 10 opposite the terminal section 10a and the display 105. The inspecting circuit 103 is configured to be capable of detecting a data signal supplied to each of the plurality of light-emitting pixels from the data line driving circuit 101, and inspecting whether each of the plurality of light-emitting pixels is operating normally. The data line driving circuit 101 and the scanning line driving circuit 102 as the driving circuit, and an inspecting circuit 103 are referred to as peripheral circuits.
In the present exemplary embodiment, a region in which the light 106 is disposed may be referred to as a light-emitting region E1, and a region in which the non-light-emitting portion 107 is disposed so as to surround the light-emitting portion 106 may be referred to as a non-light-emitting region E2. In the present exemplary embodiment, an outline of the display unit 105 is a rectangle (rectangular shape), and an outline of the light-emitting portion 106 (light-emitting region E1) is a circle having a shape different from a rectangle. The light-emitting portion 106 is disposed substantially at the center of the display unit 105, and the non-light-emitting portion 107 (non-light-emitting region E2) is disposed so as to surround the light-emitting portion 106.
Hereinafter, a direction in which the plurality of external connection terminals 104 are aligned in the terminal part 10a of the element substrate 10 will be described as an X direction, and a direction orthogonal to the X direction on the element substrate 10 will be described as the Y direction. Further, a direction that is orthogonal to the X direction and the Y direction and oriented from the element substrate 10 toward the counter substrate 20 will be described as a Z direction. Additionally, a view taken along the Z direction from the counter substrate 20 side will be called a plan view.
As illustrated in
An element portion 121 including a plurality of light-emitting elements, a sealing film 122 covering the element portion 121, and a color filter 123 disposed corresponding to the light-emitting pixels on the sealing film 122 are disposed in the element substrate 10. Further, a light shielding portion 124 is disposed on the sealing film 122 in a non-light-emitting portion 107 (non-light-emitting region E2) surrounding the light-emitting portion 106 (light-emitting region E1). The element portion 121 is disposed so as to overlap with the color filter 123, and partly overlaps with the light shielding portion 124, in a plan view. That is, light emitted from the light-emitting element of the element portion 121 is emitted from the counter substrate 20 side through the sealing film 122 and the color filter 123. The display unit 105 includes the element portion 121, the sealing film 122, the color filter 123, and the light shielding portion 124, and details of these configurations will be described later. Note that, in the present exemplary embodiment, a semiconductor substrate such as a silicon substrate is used as a base material of the element substrate 10 in which the element portions 121 are formed.
In this light-emitting panel 110, a driving line for electrically connecting the data line driving circuit 101 and the scanning line driving circuit 102 as the driving circuit for driving the light-emitting element in the light-emitting portion 106 is disposed in the display unit 105. A detailed configuration of the driving line will be described later.
Electrical Configuration of Light-Emitting Device
Next, an electrical configuration of the light-emitting device 100 will be described with reference to
As illustrated in
Light-emitting pixels P are disposed in the light-emitting portion 106 across the X direction and the Y direction. The light 106 is circular, and when the X direction is the row direction and the Y direction is the column direction, up to n light-emitting pixels P are aligned in the row direction and up to m light-emitting pixels P are aligned in the column direction. Accordingly, in the display unit 105, driving lines for supplying various signals are disposed corresponding to the plurality of light-emitting pixels P in n columns×m rows aligned in the light-emitting portion 106. Further, in the present exemplary embodiment, three light-emitting pixels P aligned in the X direction (row direction) are serving as one display unit pixel configured to obtain the light emission of red (R), green (G), and blue (B) from the display unit pixel. This enables color display in the light-emitting portion 106.
The control circuit 111 supplies a control signal Ctr1 to the scanning line driving circuit 102 and a control signal Ctr2 to the data line driving circuit 101. Further, the control circuit 111 supplies image data Vdata corresponding to the light-emitting pixels P in each row of the light-emitting portion 106 to the data line driving circuit 101 for each row. Further, the control circuit 111 controls generation of various power supply voltages by the power supply circuit 112.
The control signal Ctr1 is a pulse signal for controlling the scanning line driving circuit 102 and includes a vertical synchronization signal, a horizontal synchronization signal, a clock signal, and an enable signal. The control signal Ctr2 includes a horizontal synchronization signal, a sampling signal, a dot clock signal, a latch pulse signal, and an enable signal for controlling the data line driving circuit 101. The image data Vdata is a digital signal corresponding to a gradation value (gray level) for each of the light-emitting pixels P in a row selected by a scanning signal GWR transmitted from the scanning line driving circuit 102 to the light-emitting portion 106.
The scanning line driving circuit 102 generates, based on the control signal Ctr1, the scanning signal GWR for sequentially selecting and operating pixel circuits 140 (see
The data line driving circuit 101 generates, based on the image data Vdata and the control signal Ctr2, an n-column of the data signal Vid corresponding to a gradation value of each of the light-emitting pixels P in the row selected by the scanning line driving circuit 102 for each horizontal scanning period. The data signal Vid is supplied to the pixel circuit 140 of the light-emitting portion 106 via a first data line 131a disposed in the display unit 105 and extending in the Y direction. Although the detailed configuration of the data line driving circuit 101 is not illustrated in
The power supply circuit 112 generates and supplies the various power supply voltages required for driving the light-emitting portion 106 (pixel circuit 140 of the light-emitting pixel P), the data line driving circuit 101, the scanning line driving circuit 102, and the control circuit 111. Further, the power supply circuit 112 not only supplies the power supply potential related to driving to the data line driving circuit 101, but also supplies a plurality of levels of gradation reference voltage corresponding to the gradation value of the light-emitting pixel P.
The power supply potential generated by the power supply circuit 112 is VDD, VHH, and VEL. VDD is a low voltage (for example, 1.8V) for logic. VHH is a high voltage (for example, 5.5V) for logic and amplifier. VEL is a supply voltage (for example, 5.5V as VHH) to the pixel circuit 140 (see
As illustrated in
The first transistor 141 functions as a drive transistor, and one of the source or the drain is coupled to the power supply line 133, and the other is coupled to one of the source or drain of the third transistor 143 and the fourth transistor 144. Further, the gate of the first transistor 141 is coupled to one of the source or drain of the second transistor 142. A storage capacitor 147 is connected between the gate of the first transistor 141 and the power supply line 133. A power supply potential VEL is supplied from the power supply circuit 112 as described above to the power supply line 133. That is, the storage capacitor 147 functions as a retention capacitor of the gate potential of the first transistor 141 with respect to the power supply potential VEL.
The second transistor 142 functions as a write transistor, and the other one of the source or drain is coupled to the second data line 131b. The second transistor 142 is controlled in selection/non-selection by the scanning signal GWR supplied to the gate via the scanning line 132. Note that, the scan line 132 is coupled to the scanning line driving circuit 102.
The third transistor 143 functions as a threshold compensation transistor, and is controlled in ON/OFF by a control signal GCMP supplied to the gate.
The fourth transistor 144 functions as a current supply control transistor, and one of the source or the drain is coupled to the other one of the source or drain of the first transistor 141 and one of the source or drain of the third transistor 143. The other one of the source or drain of the fourth transistor 144 is coupled to an anode electrode (anode) 151 as the first electrode of the light-emitting element 150. A control signal GEL is supplied to the gate to control ON/OFF of the fourth transistor 144. For example, by the fourth transistor 144, it is possible to prevent current from flowing to the light-emitting element 150 and causing unintentional emission after power up of the light-emitting device 100.
The fifth transistor 145 functions as a reset transistor, and one of the source or the drain is coupled to the other one of the source or drain of the fourth transistor 144. The other one of the source or drain of the fifth transistor 145 is coupled to the potential line 134. A control signal GORST is supplied to the gate to control ON/OFF of the fifth transistor 145. As described above, the reset voltage VORST is supplied from the power supply circuit 112 to the potential line 134.
One of the source or the drain of the sixth transistor 146 is coupled to the first data line 131a, and the other one is coupled to the second data line 131b. A control signal GFIX is supplied to the gate to control ON/OFF of the sixth transistor 146. The data signal Vid is supplied to the first data line 131a from the data line driving circuit 101. A storage capacitor 148 is connected between the first data line 131a and the second data line 131b. That is, the storage capacitor 148 functions as a transfer capacitor of the data signal Vid transferred from the first data line 131a to the second data line 131b by the sixth transistor 146.
Note that, although not illustrated in detail in
As described above, the anode electrode 151 of the light 150 is coupled to the other one of the source or drain of the fourth transistor 144 and one of the source or drain of the fifth transistor 145. A cathode electrode 153 as a second electrode provided across the plurality of light-emitting elements 150 and serving as a common electrode is coupled to a cathode electrode wiring 139. The cathode electrode potential VCT is supplied to the cathode wiring 139 from the power supply circuit 112. The cathode electrode potential VCT may be a reference potential VSS (for example, 0 V as ground potential).
The light-emitting element 150 is an organic light-emitting diode having a light-emitting function layer between the anode electrode 151 as a first electrode and the cathode electrode 153 as the second electrode. When a current flows between the anode 151 and the cathode 153, excitons (a state where a hole and an electron bind to each other under Coulomb force) are formed by the holes injected from the anode 151 and the electrons injected from the cathode 153, and when the excitons decay (that is, when the holes and electrons recombine), a part of the resulting energy is emitted as fluorescence or phosphorescence. In the present exemplary embodiment, the configuration is such that white light is emitted from the light-emission function layer.
The first transistor 141 and the light-emitting element 150 are connected in series between the power supply line 133 and the cathode wiring 139. The first transistor 141 is a drive transistor, and controls the current flowing in the light-emitting element 150 in accordance with the gate potential. In other words, the first transistor 141 functions as a current source. The ON/OFF of the light-emitting element 150 is controlled by the fourth transistor 144, and the amperage of current flowing in the light-emitting 150 is controlled by the first transistor 141. The second transistor 142, the third transistor 143, the fourth transistor 144, and the sixth transistor 146 are used to control the potential of the node in the pixel circuit 140. As a result, the configuration is such that the light emission corresponding to the predetermined gradation value (gray level) is obtained from the light-emitting 150 at a predetermined timing based on the data signal Vid supplied from the data line driving circuit 101 via the first data line 131a to the pixel circuit 140. Note that the pixel circuit 140 for the driving of the light-emitting element 150 is not limited to a configuration including the first transistor 141 to the sixth transistor 146. For example, a configuration may be adopted in which the second transistor 142 and the third transistor 143 are coupled to the first data line 131a by deleting the second data line 131b, the sixth transistor 146, and the storage capacitor 148. The light-emitting element 150 emits light at a luminance corresponding to the current flowing to the light-emitting element 150, thus, the configuration may include a drive transistor serving as a current source, in order to perform high accuracy gradation control.
Next, the configuration of the driving lines in the display unit 105 will be described with reference to
That is, since the display unit 105 is a rectangle, the length of the scanning line 132 extending in the X direction is constant at L1, and the light-emitting portion 106 has a circle shape different from the rectangle, thus, the shorter the length of the part of the scanning line 132 in the light-emitting portion 106 is, the longer the length of the part of the scanning line 132 in the non-light-emitting portion 107 becomes. Although not illustrated in
Note that a relative position of the light-emitting portion 106 with respect to the display unit 105 is not limited to being located at the center of the display unit 105. In this case as well, technical features related to the length of the driving line described above in the light-emitting portion 106 and the non-light-emitting portion 107 are also included.
Configuration of Display Unit
Next, a configuration of the display unit 105 will be described with reference to
As illustrated in
The dummy pixels DP are disposed so as to surround a light-emitting portion 106 which apparently has a circular outline. In addition, the cathode contact portion 108 is disposed outside the dummy pixels DP. That is, outlines of the dummy pixels DP and the cathode contact portions 108 are also apparently circular. The outside of the cathode contact portion 108 is serving as a wiring portion 109 in which wiring is disposed related to the light-emitting pixels P, the dummy pixels DP, and the cathode contact portion 108.
In the present exemplary embodiment, of course the dummy pixels DP, and additionally the cathode contact portion 108 adjacent to the dummy pixels DP, are configured to imitate the structure of the light-emitting pixels P. The specific structure of the dummy pixels DP and the cathode contact portion 108 will be described later.
In
Light-Emitting Pixels and Color Filters
Next, a relationship between the light-emitting pixel P and the color filter will be described with reference to
As illustrated in
The light-emitting pixels P of the same color adjacent in the Y direction and the light-emitting pixels P of different colors adjacent in the X direction are electrically insulated by an insulating film 154. A pixel emission region, that is, a pixel emission area of each of the light-emitting pixels PR, PG, and PB is defined by openings 154r, 154g, and 154b disposed in the insulating film 154. The openings 154r, 154g, and 154b in the present exemplary embodiment are rectangles that are long in the Y direction. In the present exemplary embodiment, the openings 154r, 154g, and 154b are formed so that the pixel emission area of each of the light-emitting pixels PR, PG, and PB is the same, but are not limited to this, the openings 154r, 154g, and 154b may have a different size or shape for each color in consideration of hue balance in the display.
The boundary between the colored layer 123R and the colored layer 123G is located between the opening 154r and the opening 154g adjacent in the X direction. The boundary between the colored layer 123G and the colored layer 123B is located between the opening 154g and the opening 154b adjacent in the X direction. Similarly, the boundary between the colored layer 123B and the colored layer 123R is located between the opening 154b and the opening 154r adjacent in the X direction.
The color filter 123 is configured to include a light-transmissive CF partition wall 123a disposed at a position overlapping with an end part in the X direction of each of the colored layers 123R, 123G, and 123B extending in a stripe shape in the Y direction. Next, a detailed structure of the light-emitting pixel P including the color filter 123 in the light emission panel 110 will be described.
Structure of Light-Emitting Panel
Next, a structure of the light-emitting panel 110 of the light-emitting device 100 will be described with reference to
As illustrated in
The light-emitting element 150 includes the anode 151 as the first electrode, the cathode 153 as the second electrode, and the light-emitting function layer 152 sandwiched between these electrodes. The anode 151 is a transparent electrode, such as Indium Tin Oxide (ITO), and is formed electrically independent of each light-emitting pixels PR, PG, and PB, and the dummy pixels DP.
The light-emitting function layer 152 includes an organic light-emitting layer from which white light is obtained, and is formed over different color light-emitting pixels PR, PG, and PB, and dummy pixels DP. Note that, the configuration of the light-emitting function layer 152 is not particularly limited, but white light can be obtained by combining organic light-emitting layers capable of emitting light of red (R), green (G), and blue (B). Further, a pseudo-white light can be also obtained by combining organic light-emitting layers capable of emitting light of blue (B) and yellow (Y). Further, in addition to the organic light-emitting layer, the light-emitting function layer 152 is configured to include a hole injecting transportation layer disposed on the anode 151 side for efficiently injecting and transporting holes into the organic light-emitting layer, an electron injecting transportation layer disposed on the cathode 153 side for efficiently injecting and transporting electrons to the organic light-emitting layer, and the like.
The cathode 153 is formed from, for example, an alloy of Ag (silver) and Mg (magnesium), which is formed so as to have both light-transmissive and light reflectivity, and is formed over the light-emitting pixels PR, PG, and PB of different colors, the dummy pixels DP, and the cathode contact portion 108.
In the red (R) light-emitting pixel PR, an insulating film 154 is formed so that the opening 154r opens on the anode electrode 151. In the green (G) light-emitting pixel PG, an insulating film 154 is formed so that the opening 154g opens on the anode electrode 151. In the blue (B) light-emitting pixel PB, an insulating film 154 is formed so that the opening 154b opens on the anode electrode 151. On the other hand, in the dummy pixel DP, an insulating film 154 is formed to cover the anode electrode 151. Accordingly, the light-emitting element 150 included in the dummy pixel DP is configured so that no current flows, thus the dummy pixels DP are always in a non-emitting state. Note that, as illustrated in
An electrode 151b formed by using a transparent conductive film is also disposed in the cathode contact portion 108 formed to imitate the structure of the light-emitting pixel P in the same layer as the anode 151 of the light-emitting element 150. Further, an insulating film 154 is formed so that an opening 154c opens on the electrode 151b. In addition, the cathode 153, which is a common electrode, is formed so as to straddle the cathode contact portion 108. An outer edge of the light-emitting function layer 152 is located between the dummy pixel DP and the cathode contact portion 108. That is, the light-emitting function layer 152 is not formed in the cathode contact portion 108, thus, it is in a state where the electrode 151b and the cathode 153 are shorted at the opening 154c of the cathode contact portion 108. Note that, as illustrated in
A reflective layer 135, a first insulating film 136, an optical adjusting layer 138, and the like are formed between the anode 151 of each of the light-emitting pixels PR, PG, and PB, and the dummy pixels DP, the electrode 151b of the cathode contact portion 108, and the circuit unit 140a on which the transistor or the like of the pixel circuit 140 is formed. The reflective layer 135, the first insulating film 136, the optical adjusting layer 138, and the like constitute a light resonance structure. A detailed configuration of the light resonance structure will be described later, but the reflective layer 135 is formed electrically independent for each of the light-emitting pixels PR, PG, and PB, and the dummy pixels DP. The anode electrode 151 included in the light-emitting pixels PR, PG, and PB, and the dummy pixels DP is coupled to the fourth transistor 144 of the circuit unit 140a via an anode contact portion 151a that penetrates the optical adjusting layer 138 and the first insulating film 136 to the reflective layer 135. That is, the reflective layer 135 of the light-emitting pixels PR, PG, and PB, and the dummy pixels DP is formed to function as a relay layer for electrical connection between the anode electrode 151 and the fourth transistor 144.
The electrode 151b included in the cathode contact portion 108 is also coupled to the reflective layer 135 via the contact portion 151c that penetrates the optical adjusting layer 138 and the first insulating film 136. The reflective layer 135 in this case is formed so as to function as part of the cathode wiring 139 (see
A sealing film 122 is formed so as to cover the element portion 121 including the circuit unit 140a and the light-emitting element 150 of the pixel circuit 140, the dummy pixels DP, and the cathode contact portion 108. The sealing film 122 is configured to include a first sealing film 122a made of an inorganic film formed at least over the display unit 105, an intermediate sealing film 122b made of an organic film formed to alleviate irregularities in the surface of the first sealing film 122a, and a second sealing film 122c made of an inorganic film formed to cover the intermediate sealing film 122b. The intermediate sealing film 122b is formed so as to overlap with the light-emitting pixels PR, PG, and PB, the dummy pixels DP, and the cathode contact portion 108 in a plan view. That is, an outer edge of the intermediate sealing film 122b is located outward the cathode contact portion 108. The first sealing film 122a and the second sealing film 122c made of the inorganic film are stacked outside the outer edge of the intermediate sealing film 122b. In order to prevent moisture, oxygen, or the like from entering into the light-emitting element 150 and deactivating the light-emitting function layer 152, the inorganic is formed by a vapor deposition method or the like, for example, using an oxy nitride film (SiON film) of silicon and the like. The film thickness of the first sealing film 122a constituted by the inorganic film is 400 nm, for example, and the film thickness of the second sealing film 122c is 800 nm, for example. The organic film is formed by a printing method or the like, for example, using an epoxy resin which is excellent in translucency. The film thickness of the intermediate sealing film 122b is 2.6 μm, for example.
In forming the colored layers 123R, 123G, and 123B of the striped color filter 123 on the sealing film 122 in which the surface is in a flat state, a transparent CF partition wall 123a is first formed. The CF partition wall 123a is formed in a stripe shape between light-emitting pixels P of different colors that are adjacent to each other in a plan view by coating a photosensitive resin that does not include a color material for the color filter 123 to form a photosensitive resin layer having a predetermined film thickness, and exposing, developing, and post-baking the photosensitive resin layer. The height (film thickness) of the CF partition wall 123a on the sealing film 122 is less than the thickness of the colored layers 123R, 123G, and 123B formed later. In other words, the colored layers 123R, 123G, and 123B are formed so as to cover the CF partition wall 123a.
The colored layers 123R, 123G, and 123B are formed in a striped shape by coating a photosensitive resin that includes the color material of a corresponding color to form a photosensitive resin layer having a predetermined film thickness, and exposing, developing, and post-baking the photosensitive resin layer. As a method for coating the photosensitive resin including a color material, a spin coating method is used, for example, by forming the CF partition wall 123a in advance, and a structure is formed in which the predetermined film thickness is easily secured in the colored layers 123R, 123G, 123B. In the present exemplary embodiment, the colored layer 123G of green (G), the colored layer 123B of blue (B), and the colored layer 123R of red (R) are formed in this order. The film thicknesses of the colored layers 123R, 123G, 123B are not necessarily the same, and are set in consideration of the transmittance of color light and color purity in display. In the present exemplary embodiment, the average film thickness of the colored layer 123G of green (G) is approximately 1.0 μm, the average film thickness of the colored layer 123B of blue (B) is approximately 1.3 μm, and the average film thickness of the colored layer 123R of red (R) is set to approximately 1.6 μm. That is, the colored layers are formed in ascending order of the film thickness.
In the present exemplary embodiment, the colored layer 123G of green (G), the colored layer 123B of blue (B), and the colored layer 123R of red (R) are layered in this order so as to overlap with the dummy pixels DP and the cathode contact portions 108 in a plan view to form a light shielding portion 124. In the non-light-emitting portion 107 surrounding the light-emitting portion 106, the light shielding portion 124 is formed by overlaying with the colored layers 123R, 123G, and 123R of different color, and light that leaks obliquely from the light-emitting portion 106 is shielded by the non-light-emitting portion 107.
The filler 40 is coated so as to cover the color filter 123, and the light-transmissive counter substrate 20 is adhered to cure the filler 40. The filler 40 is, for example, a thermosetting epoxy resin with a film thickness of approximately 2.0 μm.
Light Resonance Structure
Next, the light resonance structure of the light-emitting panel 110 will be described with reference to
As described above, the light-emitting panel 110 of the light-emitting device 100 of the present exemplary embodiment is configured to transmit the white light from the light-emitting element 150 through the colored layers 123R, 123G, and 123B of the color filter 123, and extracts the color light of any of red (R), green (G), and blue (B) from the light-emitting pixel P. In addition, from the viewpoint of improving the color purity of the color light, a light resonance structure corresponding to the wavelength of the color light is incorporated in the light-emitting pixel P.
As illustrated in
In the light-emitting pixels PR, PG, and PB, by varying an optical distance between the reflective layer 135 and the cathode 153, a light resonance is generated between the reflective layer 135 and the cathode 153, and the intensity of light having a specific wavelength is improved in accordance with the color light. The resonant wavelength A as the specific wavelength obtained by light resonance is guided by the following Expression 1:
mλ=2nd+Φ (1)
In Expression 1, m refers to as a dimension of the light resonance with a positive integer (0, 1, 2, . . . ), n is a refractive index of an optical layer between the reflective layer 135 and the cathode 153, d is the film thickness of the optical layer, and Φ is a reflection phase shift. In practice, since there are a plurality of layers between the reflective layer 135 and the cathode 153, the sum of the product of the refractive index and the film thickness of each layer is applied to determine the value of mλ.
Further, in the light-emitting pixels PR, PG, and PB, the film thickness of the anode electrode 151 is equivalent, and the film thickness of the light-emitting function layer 152 between the anode 151 and the cathode 153 is also equivalent. In the present exemplary embodiment, by varying the optical distance between the anode electrode 151 and the reflective layer 135 in the light-emitting pixels PR, PG, and PB, a light resonance corresponding to m=1 in Expression 1 described above is caused. Note that, even in the sealing film 122 and the color filter 123 on the cathode 153, while slight, a reflection is generated at mutual interfaces. The dimensions of the light resonance due to these reflections correspond to m=5 to 10, but considering the refractive index and the film thickness of the optical layer configuring the sealing film 122 and the color filter 123, the light resonance due to these reflections can be substantially neglected.
Specifically, in the light-emitting pixel PR, a first insulating film 136 that covers the reflective layer 135 and functions as a planarization layer, a second insulating film 137 that covers the first insulating film 136 and for electrically independently partitioning the reflective layer 135, a first optical adjusting layer 138a, and a second optical adjusting layer 138b are formed between the reflective layer 135 and the anode 151. The reflective layer 135 is made of, for example, aluminum (Al) which is a light reflective metal, or an alloy including Al. The first insulating film 136 is, for example, a silicon oxide film (SiO2 film) having a refractive index of 1.46, and the film thickness is 35 nm, for example. The second insulating film 137 is, for example, a silicon nitride film (SiN film) having a refractive index of 1.8, and the film thickness is 50 nm, for example. The first optical adjusting layer 138a and the second optical adjusting layer 138b are, for example, a silicon oxide film (SiO2 film) having a refractive index of 1.46, and the film thickness is 50 nm, for example. The first optical adjusting layer 138a and the second optical adjusting layer 138b may be collectively and simply referred to as an optical adjusting layer 138. Accordingly, the refractive index of the optical adjusting layer 138 is 1.46, and the film thickness is 100 nm. The anode 151 is formed, for example, using an ITO film with a refractive index of 1.7 to 1.8, such that the film thickness is 20 nm, for example. The light-emitting function layer 152 includes an organic light-emitting layer or the like as described above, but in the present exemplary embodiment, the refractive index is 1.7 to 1.8 and the film thickness is 100 nm, for example. The cathode 153 is, for example, an alloy including silver (Ag) and magnesium (Mg), and is formed so that the film thickness is 20 nm, for example, so as to have light transmittance and light. According to the light resonance structure of the light-emitting pixel PR, resonant light having a resonance wavelength A of approximately 610 nm with improved light intensity due to light resonance is obtained. The color light of red (R) with improved color purity is obtained from the light-emitting pixel PR by transmitting such a resonance light through the colored layer 123R.
In the light-emitting pixel PG, a first insulating film 136, a second insulating film 137, and a second optical adjusting layer 138b are formed between the reflective layer 135 and the anode 151. In other words, compared to the light-emitting pixel PR, the optical distance between the reflective layer 135 and the cathode 153 is reduced by only an amount that the first optical adjusting layer 138a is not formed. According to the light resonance structure of the light-emitting pixel PG, resonant light having a resonance wavelength A of approximately 540 nm with improved light intensity due to light resonance is obtained. The color light of green (G) with improved color purity is obtained from the light-emitting pixels PG by transmitting the colored layer 123G with such a resonant light.
In the light-emitting pixel PB, a first insulating film 136 and a second insulating film 137 are formed between the reflective layer 135 and the anode 151. In other words, compared to the light-emitting pixel PR, the optical distance between the reflective layer 135 and the cathode 153 is reduced by only an amount that the optical adjusting layer 138 is not formed. According to the light resonance structure of the light-emitting pixel PB, resonant light having a resonance wavelength λ of approximately 470 nm with improved light intensity due to light resonance is obtained. The color light of blue (B) with improved color purity is obtained from the light-emitting pixel PB by transmitting the colored layer 123B with the resonant light.
According to the light-emitting device 100 of the first exemplary embodiment, the following effects can be achieved.
(1) The light-emitting panel 110 of the light-emitting device 100 includes a display unit 105 including a circular light-emitting portion 106 in which a plurality of light-emitting pixels P are disposed, and a non-light-emitting portion 107 disposed around the light-emitting portion 106. A data line driving circuit 101 and a scanning line driving circuit 102 for driving the pixel circuit 140 including the light-emitting element 150 in the light-emitting pixel P is disposed in the periphery of the display unit 105. A first data line 131a and a scanning line 132 are disposed in the display unit 105 as driving lines that electrically connect the driving circuit and the pixel circuit 140. The light 106 is circular and the display unit 105 is rectangular, thus, the shorter the length of the part of the driving line disposed in the light-emitting portion 106 is, the longer the length of the part of the driving line disposed in the non-light-emitting portion 107 becomes. In other words, for the driving line across the display unit 105, the length of the driving line disposed in the X direction or the length of the driving line disposed in the Y direction is constant. That is, the circular light-emitting portion 106 includes a portion where the number of light-emitting pixels P attached to the driving line extending in the X direction or the Y direction is different, but the capacitance and the resistance of the driving line are substantially constant, thus, the light-emitting device 100 in which variations in the driving load on the driving line is reduced and the luminance unevenness, that is, the display unevenness between the light-emitting pixels P is unlikely to occur, can be provided.
(2) The cathode contact portion 108 as the second electrode contact portion is disposed with a predetermined number of dummy pixels DP sandwiched between the cathode contact portion 108 and the circular light-emitting portion 106. Therefore, the distance between the light-emitting portion 106 and the cathode contact portion 108 is equidistant, and the wiring resistance from the cathode contact portion 108 to the cathode 153 in the light 106 is made uniform, thus, the luminance unevenness in the light-emitting portion 106 due to variations in the wiring resistance can be further reduced.
(3) The cathode contact portion 108 is formed to imitate the structure of the light-emitting pixels P, and includes an electrode 151b formed in the same layer as the anode 151 of the light-emitting element 150. The electrode 151b is in contact with the cathode 153 at the opening 154c of the insulating film 154 formed on the electrode 151b. Further, the electrode 151b is coupled to the cathode wiring 139 via the contact portion 151c. The cathode electrode potential VCT is applied to cathode wiring 139. Therefore, when forming the anode 151, the electrode 151b that configures the cathode contact portion 108 can be formed, thus the manufacturing process is not complicated, and the light-emitting device 100 having a simple configuration can be provided.
(4) The dummy pixels DP is provided between the outer edge of the light-emitting portion 106 and the cathode contact portion 108. The light-emitting function layer 152 is formed over the circular light-emitting portion 106 and the dummy pixels DP. An outer edge of the light-emitting function layer 152 is located between the dummy pixel DP and the cathode contact portion 108. Thus, in the formation of the light-emitting function layer 152, for example, even if the thickness of the film on the outer edge side of the light-emitting function layer 152 fluctuates, such variation in film thickness can be prevented from affecting the light-emitting portion 106. That is, by providing the dummy pixels DP in the non-light-emitting portion 107, it is possible to make the film thickness of the light-emitting function layer 152 in the light-emitting portion 106 to be uniform, thus the luminance unevenness in the light-emitting portion 106 caused by variations in the film thickness of the light-emitting function layer 152 can be further reduced. In addition, the anode electrode 151 of the light-emitting element 150 in the dummy pixel DP is covered by the insulating film 154, thus, the anode 151 and the light-emitting function layer 152 are isolated and are non-emitting. That is, the configuration is such that light emission is not generated unexpectedly in the non-light-emitting portion 107.
(5) The light-emitting pixel P in the light-emitting portion 106 has a light-emitting element 150 and a colored layer selected from among red (R), green (G), and blue (B) disposed on the sealing film 122 covering the light-emitting element 150. A light shielding portion 124 formed by laminating a plurality of colored layers 123G, 123B, and 123R of a plurality of colors on the sealing film 122 is disposed in the non-light-emitting portion 107 that surrounds the light-emitting portion 106. Therefore, the full color can be displayed in the light-emitting portion 106, and the light-shielding portion 124 is configured using the three-color colored layers 123G, 123B, and 123R, and thus a step of newly forming the light shielding portion 124 is unnecessary. In addition, by disposing the light shielding portion 124 on the sealing film 122, the light shielding portion 124 can be disposed adjacent to the light-emitting element 150. Accordingly, light that leaks to the outside of the light 106 in an oblique direction with respect to the normal direction from the light-emitting pixels P located at the outer edge of the light 106 can be reliably shielded by the light shielding portion 124. That is, a light-emitting device 100 capable of displaying a good-looking color can be provided.
Electronic Apparatus
Next, an example of an electronic apparatus to which the light-emitting device 100 of the first embodiment is applied will be described with reference to
As illustrated in
As illustrated in
The HMD 1000 includes a controller (not illustrated) for causing an image to be displayed on each of the left and right light-emitting devices 100L and 100R. The controller includes a built-in storage medium for storing images, audio, and the like to be displayed, and is capable of inputting image signals and the like from outside. Further, the controller is also capable of wired or wireless connection to an external network. That is, various image sources can be used to enjoy audio, music, and the like attached to the image.
The HMD 1000 of the present exemplary embodiment includes a pair of light-emitting devices 100L and 100R corresponding to the left eye and the right eye, and in the light-emitting portion 106, luminance unevenness in the light-emitting pixel P is reduced, and a good-looking display is possible. Further, light leakage from the non-light-emitting portion 107 other than the light-emitting portion 106 is prevented. Thus, by mounting the HMD 1000, the user M can become immersed in and view the image displayed in the light-emitting portion 106.
Note that, the human has an angle of view range of approximately 150 degrees in the horizontal direction and approximately 130 degrees in the vertical direction, thus, in order to ensure immersion, the image may be visible in an angle range of not less than 100 degrees in the horizontal direction and the vertical direction, respectively. Accordingly, in order to make the image in the light-emitting portion 106 visible in an angular range of not less than 100 degrees, the size of the light-emitting portion 106 may be adjusted, or an optical element such as a lens corresponding to each of the left and right light-emitting portions 106 may be disposed.
Note that, the present disclosure is not limited to the exemplary embodiments described above, and various modifications and improvements can be added to the above-described embodiments. Such modified examples are described below.
The outline of the light-emitting portion 106 in the light-emitting device 100 is not limited to being circular.
For example, as illustrated in
Further, the outlines of the light-emitting portion 106 may not be all curved. For example, as illustrated in
Further, as illustrated in
Note that the outline of the light 106 is not limited to a circular shape, an elliptical shape, an elliptical shape in which a part is linear, or a track shape, and may be a polygon having a pentagonal shape or more. Alternatively, it may be cross-shaped or star shaped.
The configuration of the light-emitting pixels PR, PG, and PB from which red (R), green (G), and blue (B) emission are obtained, in other words, the configuration of the color filter 123 corresponding to the light-emitting pixels PR, PG, and PB is not limited to being striped.
Note that the light-emitting pixel PG of green (G) and the light-emitting pixel PR of red (R) may be disposed so as to be adjacent to each other in the Y direction, and the light-emitting pixel PB of blue (B) may be disposed so as to be adjacent to them in the X direction. In either case, only the colored layer 123B of blue (B) is in a striped configuration.
Further, the light-emitting pixels P included in the display unit pixels are not limited to three primary colors: red (R), green (G), and blue (B), and may be configured by four color light-emitting pixels P including a color other than the three primary colors, for example, a yellow color (Y).
In the light-emitting device 100 of the first exemplary embodiment, one light-emitting portion 106 is disposed in the display unit 105, but the present disclosure is not limited to this. For example, when the light-emitting device 100 is applied to the HMD 1000 of the second exemplary embodiment, the display unit 105 may be configured to include two light-emitting portions 106 corresponding to the left eye and the right eye.
The electronic apparatus to which the light-emitting device 100 of the first embodiment is applied is not limited to the HMD 1000 of the second exemplary embodiment. For example, a light-emitting device 100 may be used as a display device for a personal digital assistant that is mounted on an arm.
Contents derived from the exemplary embodiments will be described below.
The light-emitting device of the present application includes a light-emitting portion in which a light-emitting pixel is disposed, a non-light-emitting portion disposed around the light-emitting portion, a driving circuit configured to drive the light-emitting pixel, and a driving line which is disposed in a display unit including the light-emitting portion and the non-light-emitting portion, and which is coupled to the driving circuit, wherein an outline of the light-emitting portion is a shape different from a rectangle, and an outline of the display unit is a rectangle.
According to the configuration of the present application, the outline of the light-emitting portion is a shape different from a rectangle, thus, the number of the light-emitting pixels attached to the driving line varies depending on the position of the driving line in the light-emitting portion. On the other hand, since the outline of the display unit is rectangular, the length of the driving line disposed along the short side or the long side of the display unit can be made constant, thus, even if the number of the light-emitting pixels attached to the driving line varies, the capacitance and the resistance of the driving line can be made substantially constant. That is, even if the outline of the light-emitting portion is different from the rectangle, for example, a shape such as a circle, it is possible to provide a light-emitting device that reduces variation in the drive load related to the driving line and does not cause luminance unevenness, that is, display unevenness between the light-emitting pixels.
The other light-emitting device of the present application includes a light-emitting portion in which a light-emitting pixel is disposed, a non-light-emitting portion disposed around the light-emitting portion, and a driving line which is disposed in a display unit including the light-emitting portion and the non-light-emitting portion, and which is related to the light-emitting pixel, wherein an outline of the light-emitting portion is a shape different from a rectangle, and the shorter a part of the driving line disposed in the light-emitting portion is, the longer a part of the driving line disposed in the non-light-emitting portion is.
According to the configuration of the present application, the outline of the light-emitting portion is a shape different from a rectangle, thus, the number of the light-emitting pixels attached to the driving line varies depending on the position of the driving line in the light-emitting portion. On the other hand, the shorter the part of the driving line disposed in the light-emitting portion is, the longer the part of the driving line disposed in the non-light-emitting portion is, thus the length of the driving line disposed across the display unit can be constant. That is, even if the number of the light-emitting pixels attached to the driving line varies, the capacitance and resistance of the driving line can be made substantially constant. That is, even if the outline of the light-emitting portion is different from the rectangle, for example, a shape such as a circle, it is possible to provide a light-emitting device that reduces variation in the drive load related to the driving line and does not cause luminance unevenness, that is, display unevenness between the light-emitting pixels.
In the light-emitting device described above, the light-emitting pixel includes a first electrode and a second electrode, and a light-emitting function layer disposed between the first electrode and the second electrode, the second electrode is a common electrode disposed over the light-emitting portion and the non-light-emitting portion, and the non-light-emitting portion includes a second electrode contact portion disposed along the outline of the light-emitting portion.
According to this configuration, the second electrode contact portion is disposed along the outline of the light-emitting portion, and variations in the potential supplied to the second electrode serving as a common electrode in the light-emitting portion via the second electrode contact portion can be reduced. That is, the luminance unevenness in the light-emitting portion caused by the variation in the potential can be reduced.
In the light-emitting device described above, the second electrode contact portion may be disposed equidistantly from an outer edge of the light-emitting portion.
According to this configuration, wiring resistance from the second electrode contact portion to the second electrode is made uniform, thus the luminance unevenness in the light-emitting portion due to variations in the wiring resistance can be further reduced.
In the light-emitting device described above, the second electrode contact portion may include an electrode disposed in the same layer as the first electrode, and the electrode and the second electrode may be in contact with each other by the second electrode contact portion.
According to this configuration, when forming the first electrode, the electrode constituting the second electrode contact portion can be formed, thus, the manufacturing process is not complicated, and a light-emitting device having a simple configuration can be provided.
In the light-emitting device described above, the light-emitting function layer may be formed over the light-emitting portion and the non-light-emitting portion, and an outer edge of the light-emitting function layer may be located between an outer edge of the light-emitting portion and the second electrode contact portion.
According to this configuration, the occurrence of unexpected emission from the light-emitting function layer in the non-light-emitting portion can be reduced.
In the light emitting device described above, the non-light-emitting portion may include a non-light-emitting dummy pixel between an outer edge of the light-emitting portion and the second electrode contact portion.
According to this configuration, even in a case where the thickness of the film on the outer edge side of the light-emitting function layer fluctuates in the formation of the light-emitting function layer, such variation in film thickness can be prevented from affecting the light-emitting portion. That is, by providing the dummy pixels in the non-light-emitting portion, it is possible to make the film thickness of the light-emitting function layer in the light-emitting portion to be uniform, thus the luminance unevenness in the light-emitting portion caused by variations in the film thickness of the light-emitting function layer can be further reduced.
In the light emitting device described above, the dummy pixel may include the first electrode, the second electrode, and the light-emitting function layer, similar to the light-emitting pixel, and the dummy pixel may include an insulating film between the first electrode and the light-emitting function layer.
This configuration may prevent unexpected emission in the dummy pixels.
In the light emitting device described above, the light emitting device may include a sealing film disposed on the display unit and covering at least the light-emitting portion and the second electrode contact portion, and a color filter disposed corresponding to the light-emitting pixel on the sealing film.
According to this configuration, a light-emitting device capable of displaying full color in the light-emitting portion, and in which display unevenness is unlikely to occur can be provided.
An electronic apparatus according to the present disclosure includes the light-emitting device described above.
According to the configuration of the present application, the display unevenness is unlikely to occur, and an electronic apparatus having excellent display quality can be provided.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-133889 | Jul 2018 | JP | national |
