Electro-optical device and electronic apparatus

Abstract

To suppress shielding by an upper portion and a decrease in an opening ratio.SOLUTION: An electro-optical device 10 includes: a substrate 102; a pixel electrode 131; a light-emitting layer 132 in contact with the pixel electrode 131 in plan view at an opening region Ar defined by an opening end Ap; a common electrode 133 that sandwiches the light-emitting layer 132 with the pixel electrode 131; a partition wall 161, which is conductive, is in contact with the common electrode 133, and surrounds the pixel electrode 131, the light-emitting layer 132, and the common electrode 133 in the plan view; and an upper portion 163 provided on an upper surface of the partition wall 161 to protrude from the partition wall 161 in cross-sectional view. When a distance of a Z-direction component of a straight line F1 coupling a tip Bp of the upper portion 161 to the opening end Ap is defined as α and a distance of a component of the straight line F1 along a substrate surface is defined as β, there is a relationship of α>β.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present invention relates to an electro-optical device and an electronic device. [Background technology]

[0002] Electro-optical devices using, for example, OLEDs as display elements are known. OLED stands for Organic Light Emitting Diode. Such light-emitting elements have a configuration in which a light-emitting layer is sandwiched between a pixel electrode and a common electrode. Since the common electrode is common to all pixel sections, it is necessary to suppress voltage unevenness due to resistance components. For this reason, a technology is known in which the pixel electrode, light-emitting layer, and common electrode are surrounded in plan view by a conductive partition wall, and a voltage is applied to the common electrode via this conductive wall. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-100414 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the pitch between the pixel portions is narrowed to about several μm, there are problems such as the light emitted from the light-emitting layer being blocked by the upper portion provided on the upper surface of the partition wall, or the aperture ratio in the pixel portion being reduced. [Means for solving the problem]

[0005] In order to solve the above problem, an electro-optical device according to one embodiment of the present disclosure includes a substrate, a first electrode, a second electrode provided between the substrate and the first electrode, an insulating pixel separation layer that covers the periphery of the second electrode and opens in an opening region that overlaps with the second electrode in a planar view, a light-emitting layer provided between the first electrode and the second electrode and in contact with the second electrode in the opening, a partition that has a light-blocking property for light emitted from the light-emitting layer and surrounds the first electrode, the light-emitting layer, and the second electrode in a planar view, and an upper portion that is provided on an upper surface of the partition and protrudes from the partition in a cross-sectional view and has a light-blocking property for light emitted from the light-emitting layer, wherein, in a cross-sectional view, when the distance of the normal component of the shortest straight line connecting the tip of the upper portion to the opening end of the opening region is defined as α and the distance of the component of the straight line that is along the surface of the substrate is defined as β, the relationship α>β holds. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view illustrating a configuration of an electro-optical device according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating an electrical configuration of an electro-optical device. [Figure 3] FIG. 2 is a diagram illustrating a configuration of a pixel circuit in an electro-optical device. [Figure 4] 5A and 5B are diagrams illustrating the operation of the electro-optical device. [Figure 5] FIG. 2 is a plan view showing a main part of a pixel portion in the electro-optical device. [Figure 6] FIG. 1 is a partial cross-sectional view schematically illustrating an electro-optical device. [Figure 7] FIG. 2 is a partial cross-sectional view illustrating an electro-optical device. [Figure 8] FIG. 2 is a partial cross-sectional view illustrating an electro-optical device. [Figure 9] FIG. 2 is a partially enlarged cross-sectional view illustrating an electro-optical device. [Figure 10] FIG. 10 is a diagram showing the relationship between the observation angle and the relative luminance in an electro-optical device. [Figure 11]FIG. 2 is a partially enlarged cross-sectional view illustrating an electro-optical device. [Figure 12] FIG. 2 is a partially enlarged cross-sectional view illustrating the electro-optical device according to the first embodiment. [Figure 13] FIG. 10 is a partially enlarged cross-sectional view illustrating an electro-optical device according to a second embodiment. [Figure 14] FIG. 10 is a partially enlarged cross-sectional view illustrating an electro-optical device according to a third embodiment. [Figure 15] FIG. 10 is a partially enlarged cross-sectional view illustrating an electro-optical device according to a comparative example. [Figure 16] FIG. 10 is a partial cross-sectional view illustrating an electro-optical device according to a first application example. [Figure 17] FIG. 10 is a partial cross-sectional view illustrating an electro-optical device according to a second application example. [Figure 18] FIG. 1 is a perspective view showing a head-mounted display using an electro-optical device according to an embodiment. [Figure 19] FIG. 2 is a diagram illustrating an optical configuration of a head-mounted display. DETAILED DESCRIPTION OF THE INVENTION

[0007] Electro-optical devices according to embodiments will be described below with reference to the drawings. Note that the dimensions and scale of each part in each drawing are appropriately different from those of the actual device. Furthermore, the embodiments described below are preferred specific examples, and therefore various technically preferable limitations are applied. However, the scope of the present disclosure is not limited to these embodiments unless otherwise specified in the following description to the effect that the present disclosure is limited.

[0008] FIG. 1 is a perspective view showing an electro-optical device 10 according to a first embodiment, and FIG. 2 is a block diagram showing the electrical configuration of the electro-optical device 10. As shown in FIG. The electro-optical device 10 is a microdisplay panel that displays color images in, for example, a head-mounted display. The electro-optical device 10 includes a plurality of pixel units and a drive circuit that drives the pixel units. The pixel units and the drive circuit are integrated on a semiconductor substrate. The semiconductor substrate is typically a silicon substrate, but may be another type of semiconductor substrate.

[0009] The electro-optical device 10 is housed in a frame-shaped case 192 that opens to the display region 100. One end of an FPC board 194 is connected to the electro-optical device 10. FPC is an abbreviation for Flexible Printed Circuits. The other end of the FPC board 194 is provided with a plurality of terminals 196 for connecting to a host device (not shown). When the plurality of terminals 196 are connected to the host device, video data, synchronization signals, and the like are supplied to the electro-optical device 10 from the host device via the FPC board 194.

[0010] As shown in FIG. 2, the electro-optical device 10 is roughly divided into a control circuit 30, a data signal output circuit 50, a display area 100, and a scanning line driving circuit 120. In the display area 100, m rows of scanning lines 12 are arranged along the X direction, and (3n) columns of data lines 14 are arranged along the Y direction so as to be electrically insulated from each other and from each other, where m is an integer of 2 or more, and n is an integer of 2 or more.

[0011] To generalize and explain the scanning lines 12, an integer i between 1 and m is used. To distinguish the rows of the scanning lines 12, they are sometimes referred to as rows 1, 2, 3, ..., i, ..., (m-1), and m, from top to bottom in the figure. Similarly, an integer j between 1 and n is used to generalize and describe the data lines 14. To distinguish the columns of the data lines 14, they may be referred to as columns 1, 2, 3, ..., (3j-2), (3j-1), (3j), ..., (3n-2), (3n-1), and (3n) from left to right in the drawing.

[0012] In the display area 100, pixel units 110R that emit light in the red wavelength range, pixel units 110G that emit light in the green wavelength range, and pixel units 110B that emit light in the blue wavelength range are arranged in the following manner, corresponding to the intersections of m rows of scanning lines 12 and (3n) columns of data lines 14. The pixel unit 110R is provided corresponding to the intersection of the scanning line 12 of each row and the (3j-2)th column data line 14. The pixel unit 110G is provided corresponding to the intersection of the scanning line 12 of each row and the (3j-1)th column data line 14. The pixel unit 110B is provided corresponding to the intersection of the scanning line 12 of each row and the (3j)th column data line 14.

[0013] That is, in the display region 100, pixel units 110R, 110G, and 110B are arranged in this order along the X direction. Note that one color is expressed by additive color mixture of three pixel units 110R, 110G, and 110B that are adjacent in the X direction. Therefore, the electro-optical device 10 displays an image in which color pixels are arranged in m rows and n columns. Strictly speaking, the pixel units 110R, 110G, and 110B should be called sub-pixel units, but for convenience of explanation, they will be referred to as pixel units. Furthermore, when the pixel units 110R, 110G, and 110B are described generally without specifying the color, they will be denoted by the reference numeral 110.

[0014] The control circuit 30 controls each unit based on video data Vid and a synchronization signal Sync supplied from a host device (not shown). Specifically, the control circuit 30 generates various control signals to control each unit. The video data Vid specifies the gradation level of pixels in the image to be displayed, for example, using 8 bits. The synchronization signal Sync includes a vertical synchronization signal that instructs the start of vertical scanning of the video data Vid, a horizontal synchronization signal that instructs the start of horizontal scanning, and a dot clock signal that indicates the timing of one pixel of video data.

[0015] The luminance characteristics at the gradation levels indicated by the video data Vid supplied from the host device do not necessarily match the luminance characteristics of the OLED included in the pixel unit 110. Therefore, in order to cause the OLED to emit light at a luminance corresponding to the gradation levels indicated by the video data Vid, the control circuit 30 up-converts the 8 bits of the video data Vid to, for example, 10 bits and outputs the up-converted data as video data Vdata. Therefore, the 10-bit video data Vdata becomes data corresponding to the R, G, and B gradation levels specified by the video data Vid. For up-conversion, a look-up table is used that stores in advance the correspondence between 8 bits of input video data Vid and 10 bits of output video data Vdata.

[0016] The scanning line driving circuit 120 is a circuit for driving the pixel units 110 arranged in m rows (3n) columns, row by row, under the control of the control circuit 30. For example, the scanning line driving circuit 120 supplies scanning signals / Gwr(1), / Gwr(2), ..., / Gwr(m-1), / Gwr(m) to the 1st, 2nd, 3rd, ..., (m-1), and mth scanning lines 12 in that order. Generally, the scanning signal supplied to the i-th scanning line 12 is represented as / Gwr(i).

[0017] The data signal output circuit 50 is a circuit that outputs a data signal via the data lines 14 to the pixel units 110 located in a row selected by the scanning line drive circuit 120 under the control of the control circuit 30. The data signal is a voltage signal obtained by converting 10-bit video data Vdata into analog. That is, the data signal output circuit 50 converts one row's worth of video data Vdata corresponding to the pixel units 110 in columns 1 to (3n) in the selected row into analog data, and outputs it to the data lines 14 in columns 1 to (3n) in this order.

[0018] Although not specifically shown, a power supply circuit is provided outside the display area 100, and this power supply circuit generates power supply potentials Vel and Vct for the control circuit 30, the scanning line driving circuit 120, the data signal output circuit 50, and the OLED. In addition, in the figure, the data signals output to the data lines 14 in the 1st, 2nd, 3rd, ..., (3n-2), (3n-1), and (3n)th columns are expressed as Vd(1), Vd(2), Vd(3), ..., Vd(3n-2), Vd(3n-1), and Vd(3n), respectively. Generally, for example, the potential of the data line 14 in the (3j-2)th column is expressed as Vd(3j-2).

[0019] FIG. 3 is a diagram showing the electrical configuration of the pixel section in the electro-optical device 10. As shown in FIG. The pixel units 110R, 110G, and 110B have the same electrical configuration. Therefore, the electrical configuration of the pixel units 110R, 110G, and 110B will be described using the pixel unit 110R corresponding to the i-th row and the (3j-2)-th column as an example.

[0020] As shown in the figure, the pixel unit 110R includes, from an electrical perspective, P-channel MOS transistors 121 and 122, an OLED 130, and a capacitance element 140. In the description of the pixel section, the term "electrically" is used to refer to the multiple elements that make up the pixel section and the connection relationships between these multiple elements.

[0021] In the OLED 130 of the pixel unit 110R, a light-emitting layer 132R is sandwiched between a pixel electrode 131 and a common electrode 133. The light-emitting layer 132R emits light including the R wavelength range. The pixel electrode 131 functions as an anode, and the common electrode 133 functions as a cathode. In the OLED 130, when a current flows from the anode to the cathode, holes injected from the anode and electrons injected from the cathode recombine in the light-emitting layer 132R to generate excitons, which then emit light including the R wavelength range.

[0022] In the OLED 130 of the pixel unit 110G, a light-emitting layer 132G is sandwiched between the pixel electrode 131 and the common electrode 133. The light-emitting layer 132G emits light including a G wavelength range. In the OLED 130 of the pixel unit 110B, a light-emitting layer 132B is sandwiched between the pixel electrode 131 and the common electrode 133. The light-emitting layer 132B emits light including a B wavelength range. Each of the light-emitting layers 132R, 123G, and 132B includes at least a light-emitting functional layer that emits light of the corresponding color. The light-emitting layers 132R, 123G, and 132B may have one or more organic layers sandwiched therebetween that are separate from the light-emitting functional layer.

[0023] In the transistor 121 of the pixel unit 110R in the i-th row and (3j-2) column, the gate node g is connected to the drain node of the transistor 122, the source node is connected to the power supply line 116 of the potential Vel, and the drain node is connected to the pixel electrode 131 which is the anode of the OLED 130. In the transistor 122 of the pixel unit 110R in the i-th row and (3j-2)th column, the gate node is connected to the i-th row scanning line 12 and the source node is connected to the (3j-2)-th column data line 14. The common electrode 133 functioning as the cathode of the OLED 130 is connected to the power supply line 118 at a potential Vct. In addition, since the electro-optical device 10 is formed on a silicon substrate, the substrate potential of the transistors 121 and 122 is set to a potential equivalent to, for example, the potential Vel.

[0024] 3 is electrically common to the pixel units 110G and 110B, except that the light-emitting layer 132R is replaced by the light-emitting layer 132G in the pixel unit 110G and by the light-emitting layer 132B in the pixel unit 110B.

[0025] 1, 2, and 3, the X direction is the extension direction of the scanning lines 12 in the electro-optical device 10, which corresponds to the horizontal direction on the display screen. The Y direction is the extension direction of the data lines 14, which corresponds to the vertical direction on the display screen. The two-dimensional plane defined by the X and Y directions is the substrate surface of the semiconductor substrate. The Z direction in FIG. 1 is perpendicular to the X and Y directions and corresponds to the emission direction of light emitted from the OLED 130. In this description, a planar view refers to viewing the semiconductor substrate from the opposite direction to the Z direction, and a cross-sectional view refers to viewing the semiconductor substrate by cutting it in the direction perpendicular to the substrate surface.

[0026] FIG. 4 is a timing chart for explaining the operation of the electro-optical device 10. As shown in FIG. In the electro-optical device 10, m scanning lines 12 are scanned one by one during a frame (V) period in the order of 1st, 2nd, 3rd, ..., mth rows. In detail, as shown in the figure, the scanning signals / Gwr(1), / Gwr(2), ..., / Gwr(m-1), / Gwr(m) are sequentially and exclusively set to L level by the scanning line driving circuit 120 for each horizontal scanning period (H). In this embodiment, the periods during which adjacent scanning signals / Gwr(1) to / Gwr(m) are at L level are separated in time. Specifically, after scanning signal / Gwr(i-1) changes from L level to H level, the next scanning signal / Gwr(i) goes to L level after a period. This period corresponds to the horizontal blanking interval.

[0027] In this description, the period of one frame (V) refers to the period required to display one frame of the image specified by the video data Vid. If the length of the period of one frame (V) is the same as the vertical synchronization period, for example, if the frequency of the vertical synchronization signal included in the synchronization signal Sync is 60 Hz, it is 16.7 milliseconds, which corresponds to one cycle of the vertical synchronization signal. Furthermore, the horizontal scanning period (H) is the time interval during which the scanning signals / Gwr(1) to / Gwr(m) sequentially go to the L level, but for convenience in the figure, the start timing of the horizontal scanning period (H) is shown approximately in the center of the horizontal blanking period.

[0028] When one of the scanning signals / Gwr(1) to / Gwr(m), for example the scanning signal / Gwr(i) supplied to the scanning line 12 in the i-th row, goes low, the transistor 122 in the pixel unit 110R in the i-th row (3j-2) column, for example, goes on. As a result, the gate node g of the transistor 121 in the pixel unit 110R is electrically connected to the data line 14 in the (3j-2)-th column.

[0029] In this description, the "on state" of a transistor means that the source node and drain node of the transistor are electrically closed, resulting in a low impedance state, and the "off state" of a transistor means that the source node and drain node are electrically open, resulting in a high impedance state. In this description, "electrically connected" or simply "connected" means a state in which two or more elements are directly or indirectly connected or coupled. "Electrically not connected" or simply "not connected" means a state in which two or more elements are not directly or indirectly connected or coupled.

[0030] During the horizontal scanning period (H) when the scanning signal / Gwr(i) is at L level, the data signal output circuit 50 converts the video data Vdata decomposed into R, G, and B into analog potentials Vd(1) to Vd(3n) and outputs them as data signals to the 1st to (3n)th column data lines 14. The video data Vdata decomposed into R, G, and B are the three primary color components of the gradation levels of the pixels in the 1st column to the i-th row and the nth column indicated by the video data Vid. For example, in the case of the (3j-2)th column, the data signal output circuit 50 converts the R gradation level R(i,j) of the pixel in row i and column j indicated by the video data Vid into an analog signal potential Vd(3j-2) and outputs it as a data signal to the data line 14 in the (3j-2)th column. In addition, during the horizontal scanning period (H) when the scanning signal / Gwr(i-1) one row before the scanning signal / Gwr(i) is at L level, the data signal output circuit 50 converts the R gradation level R(i-1,j) of the pixel in the (i-1)th row and jth column into an analog signal potential Vd(3j-2), and outputs it as a data signal to the data line 14 in the (3j-2)th column.

[0031] The data signal of the potential Vd(3j-2) is applied to the gate node g of the transistor 121 in the pixel unit 110R at the i-th row and the (3j-2)th column via the (3j-2)-th data line 14, and the potential Vd(3j-2) is held by the capacitance element 140. Therefore, the transistor 121 passes a current to the OLED 130 according to the voltage between the gate node and the source node. Even when the scanning signal Gwr(i) goes to H level and the transistor 122 is turned off, the potential Vd(3j-2) is held by the capacitive element 140, and therefore a current continues to flow through the OLED 130. Therefore, in the pixel unit 110R in the i-th row and column (3j-2), the OLED 130 continues to emit light at a brightness corresponding to the voltage held by the capacitive element 140, i.e., the gradation level, until the period of one frame (V) has elapsed and the transistor 122 is turned on again and the voltage of the data signal is applied again.

[0032] Although the pixel unit 110R in the i-th row and (3j-2) column has been described here, the OLEDs 130 of the pixel units 110R, 110G, and 110B in the i-th row other than the pixel unit 110R in the (3j-2) column also emit light at the luminance indicated by the video data Vdata. Also, the OLEDs 130 of the pixel units 110R, 110G, and 110B in rows other than the i-th row emit light at the luminance indicated by the video data Vdata as the scanning signals / Gwr(1) to / Gwr(m) sequentially go to L level. Therefore, in the electro-optical device 10, during a period of one frame (V), the OLEDs 130 in all pixel sections 110, 110G, and 110B from row 1, column 1 to row m (3n) column emit light at the brightness indicated by the video data Vdata, thereby displaying one frame of an image.

[0033] FIG. 5 is a plan view showing an example of the arrangement of pixel sections 110R, 110G, and 110B in the electro-optical device 10, and FIG. 6 is a cross-sectional view of the main part taken along line AA' in FIG.

[0034] As shown in FIG. 5 and as described above, pixel units 110R, 110G, and 110B are arranged side by side in the X direction in a plan view, with this order being repeated.

[0035] 6, the substrate 102 is a semiconductor substrate made of silicon or the like. A circuit layer 143 is provided on the substrate 102. The circuit layer 143 is provided corresponding to each of the pixel sections 110R, 110G, and 110G, and is provided with elements such as transistors 121 and 122 and various wirings. An insulating layer 103 is provided on the upper layer of the substrate 102. A contact hole H2 is provided in the insulating layer 103. The contact hole H2 is filled with a connection member 147 such as tungsten.

[0036] A laminate of the reflective electrode 171 and the pixel electrode 131 is provided for each of the pixel portions 110R, 110G, and 110B. Specifically, a metal wiring layer having light reflectivity, such as Al, its alloy, or Ag, is formed on the insulating layer 103 filled with the connecting member 147. After the film formation, the metal wiring layer is in contact with the connecting member 147, and the reflective electrode 171 is provided by patterning the metal wiring layer into a rectangular shape in a plan view. A transparent conductive layer having optical transparency and conductivity, such as ITO (Indium Tin Oxide), is formed to cover the insulating layer 103 and the reflective electrode 171. After the film formation, the pixel electrode 131 is provided by patterning the transparent conductive layer so that it overlaps the reflective electrode 171 and is located inside the periphery of the reflective electrode 171 in a plan view. The pixel electrode 131 is light-transmitting. When Al is used for the reflective electrode 171, it is preferable to provide a barrier layer of a conductive material such as TiN with a thickness of about several nm between the reflective electrode 171 and the pixel electrode 131 made of ITO.

[0037] The reflective electrode 171 is in contact with the connection member 147 , so that the pixel electrode 131 is electrically connected to the drain node of the transistor 121 included in the circuit layer 143 via the reflective electrode 171 and the connection member 147 .

[0038] A light-transmitting and insulating pixel separation layer 104 is provided to cover the insulating layer 103, the reflective electrode 171, and the pixel electrode 131. After this, an opening region Ar that exposes the pixel electrode 131 is provided in the pixel separation layer 134 by patterning. In detail, in a plan view, the opening region Ar has a rectangular shape defined by an opening edge Ap, and in a cross-sectional view, as shown in FIG. 6, the opening region Ar is provided to overlap the periphery of the pixel electrode 131. After patterning the pixel separation layer 104, the partition wall 161 and the upper portion 163 are provided.

[0039] FIG. 7 is a cross-sectional view showing a stage in the manufacturing process of the electro-optical device 10 where the partition walls 161 and the upper portion 163 have been provided. The partition wall 161 and the upper portion 163 are provided by, for example, collective patterning. In detail, the partition wall 161 and the upper portion 163 are provided at the boundary between the adjacent pixel portions 110R, 110G, and 110B as shown by hatching in FIG.

[0040] The partition walls 161 and the upper portions 163 are arranged in a grid pattern with portions extending along the X direction and portions extending along the Y direction in a plan view. Therefore, the pixel units 110R, 110G, and 110B are surrounded by the partition walls 161 and the upper portions 163 in a plan view.

[0041] The partition wall 161 is made of a conductive metal wiring layer such as aluminum. The upper portion 163 is made of a conductive metal wiring layer such as titanium, and is made of a material that has a lower etching rate than the partition wall, i.e., is less susceptible to etching. The partition wall 161 has a light-blocking property against light emitted by the light-emitting layer 132. In the collective etching, etching of the partition wall 161 progresses faster than etching of the upper portion 163, so that the upper portion 163 becomes wider than the partition wall 161 in plan view, and both ends of the upper portion 163 protrude beyond the side surfaces of the partition wall 161 in cross-sectional view, forming a so-called overhang structure.

[0042] As will be described later, the side surfaces of the partition walls 161 are tapered in cross section, i.e., the width in the X direction or Y direction narrows toward the top in the drawings, but are not shown tapered in Figures 6 and 7 for the sake of simplicity. The partition walls 161 extend to the outside of the display region 100 and are electrically connected to the output terminal of the power supply circuit. This allows the partition walls 161 to be maintained at the potential Vct generated by the power supply circuit. Moreover, the upper portion 163 is made of a conductive metal wiring layer, but may be made of an insulating material.

[0043] FIG. 8 is a cross-sectional view showing the manufacturing process of the electro-optical device 10 immediately after the light-emitting layer 132R is formed. The light-emitting layer 132R is deposited from above in the drawing. Therefore, the light-emitting layer 132R is formed so as to cover the opening region Ar of the pixel separation layer 104 in the pixel section 110R, and is also formed on the upper surface of the upper portion 163. In other words, the light-emitting layer 132R is formed in the pixel section 110R so as to overlap the pixel electrode 131, using the already-provided upper portion 163 as a mask. Therefore, the light-emitting layer 132R is formed by self-alignment rather than photolithography, which eliminates the need for an exposure process using an expensive fine metal mask. At this stage, the light-emitting layer 132R is also provided on the pixel portions 110G and 110B of different colors, but will be removed by etching later.

[0044] After the light-emitting layer 132R is formed, a transparent, reflective, and conductive layer is formed to provide the common electrode 133. The common electrode 133 is in contact with the sidewall of the partition wall 161. Therefore, the common electrode 133 is maintained at the potential Vct via the partition wall 161.

[0045] At this stage, the light-emitting layer 132R, the common electrode 133, and the sealing layer 155 are provided in layers above the pixel electrode 131 in the pixel sections 110G and 110B. To ensure that the pixel unit 110G has the light-emitting layer 132G of the correct color, the pixel unit 110R is first protected by covering it with photoresist. After this, the light-emitting layer 132R, common electrode 133, and sealing layer 155 in the pixel units 110G and 110B are removed by etching to expose the pixel electrode 131. In the pixel section 110G, similarly to the pixel section 110R, the G light-emitting layer 132G is formed by self-alignment using the upper portion 163 as a mask, and the common electrode 133 and the sealing layer 155 are provided on top of it.

[0046] At this stage, the light-emitting layer 132G, the common electrode 133, and the sealing layer 155 are provided in layers above the pixel electrode 131 in the pixel section 110B. In order to form the light-emitting layer 132B of the correct color in the pixel unit 110B, the pixel unit 110G is first protected by covering it with photoresist. After this, the light-emitting layer 132G, common electrode 133, and sealing layer 155 in the pixel unit 110B are removed by etching to expose the pixel electrode 131. In the same manner as in the pixel sections 110R and 110G, in the pixel section 110B, the B light-emitting layer 132B is formed by self-alignment using the upper portion 163 as a mask, and the common electrode 133 and the sealing layer 155 are provided on top of it. This results in the configuration shown in FIG.

[0047] 6, the same conductive layer as the light-emitting layers 132R, 132G, and 132B and the common electrode 133 is superimposed on the upper surface of the upper portion 163, but is spaced apart near the boundaries of the pixel portions 110R, 110G, and 100B. This space is caused by etching for the protection of the photoresist. After this, one or more insulating sealing and planarizing layers are applied. In the electro-optical device 10, even if the light generated in the light-emitting layers 132R, 132G, and 132B travels in the direction opposite to the Z direction, it is reflected by the reflective electrode 171 and emitted in the Z direction.

[0048] In this embodiment, the upper portion 163 has a so-called overhang structure that protrudes from the partition wall 161. Such an overhang structure makes it possible to deposit the light-emitting layers 132R, 132G, and 132B in a self-aligned manner. However, on the other hand, when an overhang structure is provided, there are problems such as blocking of emitted light and a decrease in aperture ratio. In the following description, since it will be explained to distinguish between colors, the pixel portion will be denoted by the reference numeral 110 and the light-emitting layer will be denoted by the reference numeral 132.

[0049] 9 is an enlarged cross-sectional view showing the pixel unit 110 in the electro-optical device 10, illustrating the stage up to the formation of the common electrode 133. The angle formed by a line F1 connecting the opening edge Ap to the tip Bp of the portion on the upper surface of the upper portion 163 protruding from the partition wall 161 and a line F2 passing through the opening edge Ap and pointing in the substrate normal direction (Z direction) is defined as θ. The region of the light-emitting layer 132 that emits light when a voltage is applied is the region where the light-emitting layer 132R is sandwiched between the pixel electrode 131 and the common electrode 133, that is, the opening region Ar where the light-emitting layer 132 contacts the pixel electrode 131.

[0050] The arrangement interval of the partition walls 161 in the X direction is equal to the pitch of the pixel units 110R, 110G, and 110B. In a microdisplay with a pixel pitch of approximately 2 to 3 μm, if the height of the partition walls 161 and the upper portion 163 is approximately 0.5 to 0.7 μm, a large angle θ significantly narrows the width W of the aperture area Ar, resulting in a decrease in the aperture ratio. When the aperture ratio decreases, the luminance of the light-emitting layer 132 must be increased to ensure brightness. This can be achieved by increasing the current density when driving the light-emitting layer 132. However, driving the light-emitting layer 132 at a high current density exponentially deteriorates the light-emitting layer 132. Specifically, if the current density is increased four times, the luminance life will be reduced to one-tenth or less. A shorter luminance life will not only darken the screen but also cause problems such as image burn-in, which can adversely affect product quality. The luminance life is the period of time until the luminance is reduced to half when the light-emitting layer 132 is driven under the same conditions.

[0051] FIG. 10 is a diagram showing an example of a change in luminance with respect to the observation angle in an electro-optical device. In the figure, the observation angle on the horizontal axis is the angle from the substrate normal direction, when the Z direction, which is the substrate normal direction, is set to 0 degrees. Also, in the figure, the relative luminance on the vertical axis is the relative luminance value normalized to 1.0 when the observation angle is 0 degrees.

[0052] As shown in the figure, the relative brightness decreases as the observation angle increases. The angle at which the brightness is 50% of the brightness at an observation angle of 0 degrees is in the range of 30 to 40 degrees, and the observation angle at which the brightness is 25% of the brightness at 0 degrees is approximately 45 degrees. When the observation angle is 45 degrees or more, the relative brightness decreases, making it unsuitable for use, and as mentioned above, the aperture ratio also decreases significantly. For this reason, in a microdisplay, the limit of the angle θ at which brightness can be ensured and the decrease in aperture ratio can be suppressed is 45 degrees.

[0053] On the other hand, a smaller angle θ results in a higher aperture ratio. However, if the angle θ is too small, the light emitted from the light-emitting layer 132, particularly the light emitted from the vicinity of the opening end Ap, is blocked by the portion Shd of the upper portion 163 that protrudes beyond the partition wall 161, as shown in Fig. 11, reducing the utilization efficiency of the emitted light. The light blocked by the portion Shd is reflected by the portion Shd and then undergoes multiple reflections by the side surfaces of the partition wall 161, other reflective members, the interface of the insulating layer, and the like, which can also cause stray light.

[0054] Approximately 60% of the total amount of light emitted from the light-emitting layer 132 is emitted in the range of 0 to 20 degrees. Therefore, if the light emitted at an angle θ of 20 degrees is not blocked by the upper portion 163, it is believed that the light emitted from the light-emitting layer 132 can be efficiently extracted to the outside of the electro-optical device 10. It should be noted that if the angle θ is smaller than 20 degrees, the brightness will be high, but the high-brightness light will be blocked by the portion Shd, causing multiple reflections, which is not preferable.

[0055] Therefore, if the angle θ is less than 45 degrees, it is possible to prevent a decrease in the aperture ratio while ensuring the necessary brightness. Furthermore, if the angle θ is equal to or greater than 20 degrees and equal to or less than 40 degrees, it is possible to increase the aperture ratio while ensuring higher brightness. For convenience, the distance of the component of the straight line F1 connecting the opening end Ap to the tip Bp in the substrate normal direction (Z direction) is defined as α, i.e., the height of the tip Bp relative to the opening end Ap is defined as α. Also, the distance of the component of the straight line F1 in the direction along the substrate surface is defined as β, i.e., the distance from the opening end Ap to the tip Bp when viewed in a plan view is defined as β.

[0056] The angle θ is tan -1 It is expressed as (β / α). Conversely, if the angle θ is less than 45 degrees, α>β Also, if the angle θ is greater than or equal to 20 degrees and less than or equal to 40 degrees, then tan 20°≦(β / α)≦tan 40° It can be expressed as: The common electrode 133 is an example of a "first electrode," and the pixel electrode 131, or the laminate of the reflective electrode 171 and the pixel electrode 131, is an example of a "second electrode."

[0057] 12 is a cross-sectional view showing a main part of the electro-optical device 10 according to the first embodiment. In the first embodiment, the angle θ is set to 30 degrees. In this example, since the angle θ is 30 degrees, if α is 0.6 μm, β is approximately 0.346 μm. Furthermore, when the angle θ is 30 degrees, the width W of the opening region Ar is approximately 1.5 μm.

[0058] Of the total amount of light emitted from the light-emitting layer 132, about 80% is emitted in the range of 0 to 30 degrees, and of this, light between 20 and 30 degrees is emitted without being blocked by the portion Shd. Therefore, in the first embodiment, the light emitted from the light-emitting layer 132 can be used efficiently.

[0059] 13 is a cross-sectional view showing a main part of an electro-optical device 10 according to a second embodiment. In the second embodiment, the angle θ is set to 20 degrees. In the second embodiment, the aperture ratio is higher than in the first embodiment, and therefore bright luminance can be ensured. Therefore, the second embodiment is advantageous over the first embodiment in terms of the luminance life of the light-emitting layer.

[0060] 14 is a cross-sectional view showing a main part of an electro-optical device 10 according to a third embodiment. In the third embodiment, the angle θ is set to 40 degrees. In the third embodiment, the aperture ratio is smaller than in the first embodiment, but the amount of light blocked by the portion Shd is reduced, and as a result, more light can be emitted from the light-emitting layer 132. Specifically, in the third embodiment, approximately 90% of the light emitted from the light-emitting layer 132 can be emitted.

[0061] FIG. 15 is a cross-sectional view showing a main portion of an electro-optical device according to a comparative example for comparison with the first to third embodiments. In this comparative example, the angle θ is set to 50 degrees, which is greater than 45 degrees. When the angle θ is 50 degrees, approximately 95% of the light emitted from the light-emitting layer 132 can be emitted. However, the width W of the aperture region Ar is approximately half that of the first embodiment, and the area is approximately one-quarter of that of the first embodiment. Therefore, in order to ensure the same brightness in the comparative example as in the first embodiment, the current density of the light-emitting layer 132 must be approximately four times that of the first embodiment. As described above, quadrupling the current density reduces the brightness life to one-tenth, shortening the brightness life. This shortened brightness life not only darkens the screen over time but also adversely affects product quality, such as causing image burn-in.

[0062] The above-described first to third embodiments (hereinafter referred to as "embodiments, etc.") can be modified or applied in various ways as follows.

[0063] FIG. 16 is a partial cross-sectional view showing a main part of an electro-optical device 10 according to a first application example of the embodiment etc. In the first application example, the pixel units 110R, 110G, and 110B are provided with an optical resonance structure corresponding to the color. The optical resonance structure refers to a structure in which, when the optical distance between the reflective surface of the common electrode 133 and the reflective surface of the reflective electrode is Lr in the pixel unit 110R, Lg in the pixel unit 110G, and Lb in the pixel unit 110B, the optical distances Lr, Lg, and Lb are set to distances corresponding to the wavelengths of the respective colors. In addition, specifically, the following measures can be considered for setting the optical distances Lr, Lg, and Lb to distances corresponding to the wavelengths of the respective colors. That is, As a first measure, the film thickness of the light-emitting layers 132R, 132G, and 132B is made different for each color. As a second measure, the film thickness of the light-transmitting pixel electrode 131 is made different for each color. As a third measure, the sum of the film thickness of the pixel electrode 131 and the film thickness of the light-emitting layer 132R, 132G, or 132B is made different for each color. Figure 16 shows the first of these options.

[0064] The optical distances Lr, Lg, and Lb are: Lr>Lg>Lb This is the relationship. In the optical resonance structure, light emitted from the light emitting layer 132R, 132B or 132B resonates due to reflection between the reflective electrode 171 and the common electrode 133, and is emitted at a resonance wavelength set corresponding to the R, G or B color. Therefore, in the first application example having an optical resonant structure, light of a wavelength corresponding to a color is intensified and emitted, which makes it possible to sharpen and increase the intensity of the spectrum and improve the purity and brightness of the color.

[0065] Although not shown in the figure, the light-emitting layer 132R, 132G, or 132B actually has a laminated structure including a hole injection layer, a hole transport layer, a light-emitting functional layer, an electron blocking layer, an electron transport layer, an electron injection layer, etc. Therefore, by adjusting the thickness of these layers for each color, the film thickness of the light-emitting layer 132R, 132G, or 132B can be made different for each color. Strictly speaking, the optical distance is the distance between the reflective electrode 171 and the common electrode 133 multiplied by the refractive index of the pixel electrode 131 and the light-emitting layer, which are the media between the reflective electrode 171 and the common electrode 133, but in the figure it is simply shown as a physical distance.

[0066] In addition, in the first application example, it is possible to omit the transparent pixel electrode 131. When the pixel electrode 131 is omitted, the optical distances Lr, Lg, and Lb can be set to distances corresponding to the wavelengths of the respective colors by the first measure described above.

[0067] FIG. 17 is a partial cross-sectional view showing a main part of an electro-optical device 10 according to a second application example. The second application example is similar to the first application example in that the pixel units 110R, 110G, and 110B have optical resonance structures corresponding to the colors. However, unlike the first application example, the second application example is different from the first application example in that the optical distances Lr, Lg, and Lb are adjusted by the film thickness of the insulating layer provided between the pixel electrode 131 and the reflective electrode 171. Note that Figure 17 shows an example in which the insulating layer provided between the pixel electrode 131 and the reflective electrode 171 is not provided in the pixel section 110B, is a single layer in the pixel section 110G, and is a two-layer structure in the pixel section 110R, in which an additional insulating layer is added to the single insulating layer provided in the pixel section 110G. As the thickness of the light-emitting layer 132 increases, the electric field weakens, and therefore a higher voltage must be applied to obtain the same brightness. However, in the second application example, the optical distances can be set to Lr > Lg > Lb while the thicknesses of the light-emitting layers 132R, 132G, and 132G are the same. Therefore, in the second application example, it is not necessary to drive the R light-emitting layer 132R, which has the longest optical distance, at a high voltage in order to improve color purity and brightness.

[0068] In the embodiments and the like, the aperture shapes of the aperture regions Ar in the pixel units 110R, 110G, and 110B are rectangular, but are not limited to this. For example, they may be polygonal, such as hexagonal, or circular, elliptical, etc. Furthermore, the aperture areas of the aperture regions Ar may not be uniform in the pixel units 110R, 110G, and 110B, but may be different for each color. For example, the aperture areas of the aperture regions Ar may be B>G>R. The pixel units 110R, 110G, and 110B may be aligned in either the X direction or the Y direction. Alternatively, the pixel units 110R and 110B may be aligned in the same column, and the pixel unit 110G may be aligned in a column adjacent to the column of the pixel units 110R and 110B.

[0069] In the description of the embodiment, the light emitting layers 132R, 132G, and 132B are formed in this order, but the order of film formation is not limited to this.

[0070] Next, an electronic device to which the electro-optical device 10 according to the embodiment is applied will be described. The electro-optical device 10 is suitable for applications requiring small-sized pixels and high-definition displays. Therefore, a head-mounted display will be used as an example of the electronic device.

[0071] FIG. 18 is a diagram showing the appearance of a head-mounted display, and FIG. 19 is a diagram showing its optical configuration. First, as shown in Fig. 18, the head mounted display 300 has temples 310, a bridge 320, and lenses 301L and 301R in appearance similar to ordinary eyeglasses. Furthermore, as shown in Fig. 19, the head mounted display 300 is provided with an electro-optical device 10L for the left eye and an electro-optical device 10R for the right eye near the bridge 320 and behind the lenses 301L and 301R (below in the figure). The image display surface of the electro-optical device 10L is disposed on the left side in FIG. 19. As a result, the image displayed by the electro-optical device 10L is emitted in the 9 o'clock direction in the figure via the optical lens 302L. The half mirror 303L reflects the image displayed by the electro-optical device 10L in the 6 o'clock direction while transmitting light incident from the 12 o'clock direction. The image display surface of the electro-optical device 10R is disposed on the right side, opposite the electro-optical device 10L. As a result, the image displayed by the electro-optical device 10R is emitted in the 3 o'clock direction in the figure via the optical lens 302R. The half mirror 303R reflects the image displayed by the electro-optical device 10R in the 6 o'clock direction while transmitting light incident from the 12 o'clock direction.

[0072] In this configuration, a person wearing the head-mounted display 300 can observe the images displayed by the electro-optical devices 10L and 10R in a see-through state in which the images are superimposed on the outside world. Furthermore, in this head-mounted display 300, when the electro-optical device 10L displays the image for the left eye and the electro-optical device 10R displays the image for the right eye among the binocular images with parallax, the wearer can perceive the displayed image as if it had depth and a three-dimensional effect.

[0073] In addition to the head-mounted display 300, electronic devices including the electro-optical device 10 can also be applied to electronic viewfinders in video cameras and interchangeable lens digital cameras, smart watches, display units of wearable devices, light bulbs in projection projectors, and the like.

[0074] From the above-described exemplary embodiments, the following embodiments can be understood: In order to facilitate understanding of each embodiment, reference numerals in the drawings are written in parentheses for convenience, but this is not intended to limit the embodiments to those shown in the drawings.

[0075] An electro-optical device (10) according to one aspect 1 includes a substrate (102), a first electrode (133), a second electrode (131, 171) provided between the substrate (102) and the first electrode (133), an insulating pixel separation layer (104) that covers the periphery of the second electrode (131, 171) and opens in an opening region (Ar) that overlaps with the second electrode (131, 171) in a planar view, a light-emitting layer (132) provided between the first electrode (133) and the second electrode (131, 171) and contacts the second electrode (131, 171) in the opening region (Ar), and a light-shielding layer (104) for blocking light emitted by the light-emitting layer (132). and a partition wall (161) surrounding the first electrode (133), the light-emitting layer (132), and the second electrode (131, 171) in a planar view, and an upper portion (163) provided on an upper surface of the partition wall (161) and protruding from the partition wall in a cross-sectional view, and having a light-blocking property against light emitted from the light-emitting layer (132), wherein, in a cross-sectional view, when the distance of a component of the shortest straight line connecting a tip of the upper portion (163) and an opening end (Ap) of the opening region (Ar) in a normal direction to the substrate (102) is defined as α and the distance of a component of the straight line along the surface of the substrate (102) is defined as β, the relationship α>β holds.

[0076] In the electro-optical device according to the first aspect, if α>β, that is, the angle θ is greater than 45 degrees, it is possible to ensure brightness and prevent a decrease in the aperture ratio due to a narrower aperture region.

[0077] In the electro-optical device (10) according to a specific aspect 2 of aspect 1, the α and β have a relationship of tan 20°≦(β / α)≦tan 40°. According to the second aspect, it is possible to prevent a decrease in the aperture ratio while ensuring high brightness and to increase the efficiency of use of emitted light.

[0078] In an electro-optical device (10) relating to another specific aspect 3 of aspect 1, the second electrode (131, 171) is a laminate of a reflective electrode (171) that is reflective when viewed from the substrate (102) and a pixel electrode (131), and the first electrode (131) is translucent and reflective.

[0079] In an electro-optical device (10) according to a fourth specific aspect of the first aspect, the second electrode (171) is a reflective electrode (171) having reflectivity, and the first electrode (133) is light-transmitting and reflective.

[0080] An electro-optical device (10) according to a fifth specific example of the first example includes a sealing layer (155) that has insulating and light-transmitting properties and covers the first electrode (133).

[0081] In the electro-optical device (10) according to a sixth specific aspect of the first aspect, the partition wall (161) is conductive, and the first electrode (133) is in contact with the partition wall (161).

[0082] The electronic device (300) according to the eighth aspect includes the electro-optical device (10) according to any one of the first to seventh aspects. [Explanation of symbols]

[0083] 10...electro-optical device, 102...substrate, 103...insulating layer, 104...pixel separation layer, 131...pixel electrode, 132, 132R, 132G, 132B...light-emitting layer, 133...common electrode, 143...circuit layer, 161...partition wall, 163...upper portion, 300...head-mounted display.

Claims

1. A substrate; A first electrode; a second electrode provided between the substrate and the first electrode; a pixel separation layer having insulating properties, covering a periphery of the second electrode, and opening in an opening region overlapping with the second electrode in a plan view; a light-emitting layer provided between the first electrode and the second electrode and in contact with the second electrode at the opening; a partition wall that has a light-blocking property against light emitted from the light-emitting layer and surrounds the first electrode, the light-emitting layer, and the second electrode in a plan view; an upper portion provided on an upper surface of the partition wall, protruding from the partition wall in a cross-sectional view, and having a light-blocking property against light emitted from the light-emitting layer; Including, In a cross-sectional view, the shortest straight line connecting the tip of the upper portion and the opening end of the opening region is The distance of the normal direction component to the substrate is defined as α, When the distance of the component of the straight line along the surface of the substrate is β, α＞β An electro-optical device having the following relationship.

2. In the α and the β, tan20°≦(β / α)≦tan40° 2. The electro-optical device according to claim 1, wherein the following relationship exists:

3. the second electrode is a laminate of a reflective electrode and a pixel electrode, the reflective electrode having reflectivity when viewed from the substrate, The first electrode has light-transmitting and reflective properties. The electro-optical device according to claim 1 .

4. the second electrode is a reflective electrode having reflectivity, The first electrode has light-transmitting and reflective properties. The electro-optical device according to claim 1 .

5. a sealing layer having insulating and light-transmitting properties and covering the first electrode; The electro-optical device according to claim 1 .

6. the partition wall is conductive, The first electrode is in contact with the partition wall. The electro-optical device according to claim 1 .

7. 7. An electronic device comprising the electro-optical device according to claim 1.

Images