JP2010049811A - Electro-optical device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electro-optical device having an optical wiring portion with attenuation of optical signals suppressed. <P>SOLUTION: The electro-optical device is equipped with an element substrate 10 and a counter substrate 20 which are arranged mutually opposed to each other, and on the surface of the element substrate 10 opposed to the counter substrate 20, there are pixel electrodes, driving circuits 14 connected with the pixel electrodes, a light-emission part 32 which converts electric signals to optical signals, and light receiving sections 36 which receive light emitted from the light-emission part 32 and convert it to electric signals to supply to the driving circuits 14. Further, an optical waveguide 34 is provided on the surface of the counter substrate 20 opposed to the element substrate 10 for transmitting the optical signals emitted from the light-emission part 32 to the light receiving sections 36. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electro-optical device and an electronic apparatus.

  In recent years, electro-optical devices such as liquid crystal display devices, plasma displays, and electroluminescence panels have been used as devices for displaying images. These devices are required to have higher functions such as larger display screens and higher definition with diversification of information devices and expansion of information amount.

  However, when the display screen is enlarged, the wiring length becomes longer, so the influence of the electrical resistance and parasitic capacitance of the wiring becomes larger, and the signal supply timing differs at locations near and far from the signal supply side of the entire device. End up. This difference in timing causes, for example, flickering of the image and causes a reduction in display quality.

  Further, as the definition becomes higher, the interval between adjacent wirings becomes narrower, so that capacitive coupling is likely to occur between the wirings. Then, one voltage change (signal change) propagates as noise to the other through the capacitance between the wirings, causing so-called crosstalk that hinders good signal transmission, leading to deterioration in image quality.

  Furthermore, when there is a large amount of information per unit time, such as a moving image display that displays an image while switching screens quickly, it is necessary to transmit a signal at a speed corresponding to the screen switching speed. In order to display a smooth moving image, more image information is required, but due to the influence of wiring resistance, it is difficult to transmit a signal at a speed corresponding to the screen switching speed. Increasing the size and definition of the screen becomes more difficult for the above reasons.

  In order to solve such a problem, a configuration has been proposed in which an optical signal is used as part of a data bus for transmitting an image signal to increase the signal transmission speed (see, for example, Patent Documents 1 to 4). ). With such a configuration, a large-capacity signal can be transmitted at higher speed than an electric signal using metal wiring or the like, in which optical signal transmission causes signal delay due to electric resistance or crosstalk due to capacitive coupling. Can be transmitted.

In addition to optical signal exchange between adjacent light emitting units and light receiving units, an optical waveguide in which the light emitting unit and the light receiving unit are optically connected is provided, and the optical signal emitted from the light emitting unit is placed in a predetermined place. A configuration in which transmission is performed up to the arranged light receiving unit is also known (see, for example, Patent Document 5). In such a configuration, since the path for transmitting the optical signal can be extended, the degree of freedom in arrangement of the light emitting unit and the light receiving unit is increased. In addition, unlike electric signals, problems such as flicker and crosstalk caused by extending the signal path do not occur, and good large-capacity high-speed communication is possible.
JP 08-314413 A JP-A-11-125802 JP 2000-148038 A JP 2004-177873 A JP 2004-126154 A

  However, when an optical signal is transmitted using an optical waveguide, attenuation of light due to the extension of the path becomes a problem. That is, if the light is attenuated and the intensity is reduced during the transmission of the optical signal, it cannot be converted into an electric signal by the light receiving unit, and the signal transmission cannot be performed satisfactorily. As one of the causes of attenuation of the optical signal in this way, the influence of the shape of the wall surface in the optical waveguide can be considered.

  If the inner wall surface of the optical waveguide (cladding-core interface) has an uneven shape, the optical signal transmitted through the optical waveguide is scattered by the wall surface, and the signal intensity tends to be attenuated. Therefore, it is better that the inner wall of the optical waveguide does not have an uneven shape.

  However, in a normal electro-optical device, a pixel electrode, a driving element such as a TFT (Thin Film Transistor) connected to the pixel electrode, a wiring connected to the driving element, and the like are three-dimensionally stacked. . Therefore, the surface on the element substrate side on which the pixel electrode is formed has an uneven shape. In Patent Document 5, an optical waveguide is formed on a substrate on which a light emitting unit and a light receiving unit are formed. When a driving element and wiring for driving the light emitting unit and the light receiving unit are formed on the substrate, It is conceivable that an optical waveguide is formed using a portion having an uneven shape as a base. When an optical waveguide is formed using a surface having an uneven shape as a base, the shape of the inner wall of the optical waveguide has the unevenness reflecting the shape of the base surface, and the optical signal is easily attenuated.

  In addition to the structure formed on the substrate as in Patent Document 5, a structure in which a groove is formed by digging the substrate and the optical waveguide is formed in the formed groove is also known. However, in this case as well, if the formation surface of the optical waveguide has an uneven shape, it is expected that the bottom surface of the groove portion dug down will have a bottom shape reflecting the unevenness of the surface. Therefore, even in this case, it is difficult to form a good optical waveguide.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an electro-optical device provided with an optical wiring portion with little attenuation of an optical signal. Another object is to provide an electronic apparatus including such an electro-optical device.

In order to solve the above-described problem, an electro-optical device according to an embodiment of the present invention includes a first substrate and a second substrate that are arranged to face each other, and a surface of the first substrate that faces the second substrate has pixels. An electrode; a drive circuit connected to the pixel electrode; a light emitting unit that converts an electrical signal into an optical signal and emits the light; and an optical signal emitted from the light emitting unit that receives the light signal and converts the signal into an electrical signal. A light receiving portion for supplying light to the light receiving portion, and an optical waveguide for transmitting an optical signal emitted from the light emitting portion to the light receiving portion is provided on a surface of the second substrate facing the first substrate. It is characterized by that.
According to this configuration, since a part of the wiring is an optical wiring, a signal transmission failure that causes image disturbance such as crosstalk and flicker hardly occurs. Further, since the optical waveguide is formed on the flat surface of the counter substrate, the optical signal is hardly attenuated during transmission through the optical waveguide, and good signal transmission is possible. Therefore, a high-quality electro-optical device having excellent display quality can be obtained.

In the present invention, the light emitting unit includes a first organic electroluminescence element that emits the optical signal, and the pixel electrode sandwiches an organic light emitting layer together with an electrode facing the pixel electrode, and emits light. It is desirable to constitute a part of the second organic electroluminescence element.
According to this configuration, since the light emitting element and the light emitting portion which are formed by the pixel electrode are the same organic EL element, the structure and the forming material can be shared. Therefore, the manufacturing process can be made common, and an electro-optical device having good display characteristics can be easily manufactured.

In the present invention, it is desirable that the first organic electroluminescence element and the second organic electroluminescence element emit light having different wavelengths.
According to this configuration, when the second organic EL element can emit light having a wavelength different from the wavelength according to the light reception sensitivity of the light receiving unit, the light receiving unit is driven only by the light from the first organic EL element. And malfunction can be prevented. For example, even if the light emitted from the second organic EL element is reflected inside the apparatus and reaches the light receiving portion, it is different from the wavelength according to the light receiving sensitivity, which is preferable because it can prevent malfunction.

In the present invention, it is desirable that two or more light receiving portions are commonly connected to one optical waveguide.
According to this configuration, it is possible to reduce the number and area of optical waveguides to be formed, and to reduce the size and the screen size of the device.

In the present invention, it is preferable that the optical waveguide is formed by forming a groove on a surface of the second substrate facing the first substrate and filling the groove with a material for forming the optical waveguide.
According to this configuration, since the groove portion is formed in the flat second substrate, the bottom surface of the groove portion dug down also has a bottom shape reflecting the flatness of the surface, and a good optical waveguide with little optical loss can be formed.

In the present invention, the optical waveguide has an entrance through which the optical signal emitted from the light emitting unit is incident, and an exit through which the optical signal propagating through the optical waveguide is emitted, It is desirable to have a light scattering mechanism that scatters the optical signal in a region overlapping the entrance and exit in the optical waveguide.
According to this configuration, by changing the traveling direction of the optical signal entering or exiting the optical waveguide by scattering, propagation and emission of the optical signal in the optical waveguide are ensured, and good signal transmission is achieved. It becomes possible.

In the present invention, it is preferable that the light scattering mechanism is formed by changing a depth of the groove portion that overlaps the entrance port or the exit port in a plane.
According to this configuration, an optical waveguide capable of easily transmitting good signals can be obtained by changing the processing of the groove.

In the present invention, the light scattering mechanism preferably has a plurality of uneven shapes.
With this configuration, the optical signal is scattered on each surface of the plurality of concave and convex shapes, and the optical signal can be reliably propagated and emitted in the optical waveguide, so that good signal transmission is possible.

An electronic apparatus according to an aspect of the invention includes the above-described electro-optical device.
According to this configuration, it is possible to obtain a good electronic device free from display problems such as crosstalk and flicker.

[First Embodiment]
The electro-optical device according to the first embodiment of the invention will be described below with reference to FIGS. Here, the present invention will be described by taking as an example an organic EL device including a plurality of organic electroluminescence elements (organic EL elements) as light emitting elements. In all the drawings below, the film thicknesses and dimensional ratios of the constituent elements are appropriately changed in order to make the drawings easy to see.

  FIG. 1 is a schematic view showing an electro-optical device (organic EL device) 1A of the present embodiment, FIG. 1 (a) is a schematic perspective view, and FIG. 1 (b) is an element substrate 10 provided in the organic EL device 1A. A schematic plan view is shown.

  As shown in FIG. 1A, an organic EL device 1A of the present embodiment is opposed to an element substrate (first substrate) 10 provided with an organic EL element unit 12 including an organic EL element, and the element substrate 10. The counter substrate (second substrate) 20 and the optical wiring unit 30 disposed across the element substrate 10 and the counter substrate 20 are provided. The optical wiring unit 30 includes a light emitting unit 32 that converts an electrical signal into an optical signal, a light receiving unit 36 that receives an optical signal and converts it into an electrical signal, and a light that is optically connected to the light emitting unit 32 and the light receiving unit 36. And a waveguide 34. Of the members constituting the optical wiring unit 30, the light emitting unit 32 and the light receiving unit 36 are provided on the element substrate 10, and the optical waveguide 34 is provided on the counter substrate 20.

  The element substrate 10 has a substrate body 10A made of glass, quartz, plastic, or the like as a base. On the upper surface (opposite substrate 20 side) of the substrate body 10A, there is provided an element forming layer 11 having a switching element such as a thin film transistor (TFT) for driving the organic EL element part 12, the light emitting part 32, etc., various wirings and the like. . An insulating film is provided to cover these switching elements and various wirings. The upper surface of the element formation layer 11 has a concavo-convex shape due to each component included in the element formation layer 11.

  On the element formation layer 11, a light emitting unit 32 that converts an electrical signal into an optical signal and emits it, a plurality (four in the figure) of light receiving units 36 that receive the optical signal and convert it into an electrical signal, A wiring 16 connected to each of the light receiving parts 36, a drive circuit 14 to which a plurality of wirings 16 are connected, and an organic EL element part 12 having the same number of organic EL elements 122 as the light receiving parts 36 are provided. Yes.

  The light emitting unit 32 includes an organic EL element surrounded by a partition wall 324 as a light conversion element 322 that converts an electrical signal into an optical signal. The light conversion element 322 is a so-called top emission type organic EL element that emits light to the counter substrate 20 side. The light conversion element 322 of the present embodiment is configured to emit red light.

  As the light receiving unit 36, a generally known light receiving element such as a photodiode or a phototransistor in which a transistor (amplifier circuit) is combined with the photodiode can be used. As the photodiode, a PIN photodiode, APD (avalanche photodiode), MSM photodiode or the like can be selected. APD has high characteristics in both light receiving sensitivity and response frequency. The MSM type photodiode has a feature that it is simple in structure and easily integrated with an amplifying transistor. In the light receiving unit 36, the optical signal emitted from the light emitting unit 32 is received, converted into an electrical signal corresponding to the amount of received light, and supplied to the drive circuit 14 via the wiring 16. In the present embodiment, a photodiode having a high light receiving sensitivity for the wavelength of light emitted from the light conversion element 322 is used as the light receiving unit 36.

  The drive circuit 14 latches an electrical signal (image signal) supplied via the light receiving unit 36 and emits it according to the timing of a clock signal supplied via, for example, a wiring (not shown). The image signal is converted into a digital signal for causing the organic EL element 122 to emit light in accordance with the signal in the drive circuit 14 and supplied to the organic EL element unit 12.

  The organic EL element section 12 has the same number of organic EL elements 122 as the light receiving sections 36. The pixel electrode included in each organic EL element 122 is connected to the drive circuit 14, and the organic EL element 122 emits light based on a digital signal supplied from the drive circuit 14. Each organic EL element 122 is surrounded by a partition wall 124 and is isolated one by one. Similar to the light conversion element 322, the organic EL element 122 adopts a top emission method. The organic EL element 122 of the present embodiment is configured to emit white light.

  The organic EL element 122 and the light conversion element 322 both adopt the top emission method and have similar structures. Therefore, all can be formed in the same process except that the material of the light emitting layer included in each is changed. When the material for forming the light emitting layer is a low molecular light emitting material, it is necessary to create the light emitting layer by using mask vapor deposition or the like. When a polymer light emitting material is used as the material for forming the light emitting layer, for example, droplet ejection It is preferable because a light emitting layer can be easily formed separately using a method.

  Further, in the organic EL device 1A of the present embodiment, the organic EL element 122 and the light conversion element 322 emit light of different colors (wavelengths). Normally, the sensitivity of the photodiode used for the light receiving unit 36 with respect to the wavelength of light received varies depending on the type. Therefore, when the light receiving unit 36 having high light receiving sensitivity with respect to light having a wavelength different from that of the light emitted from the organic EL element 122 is used, for example, light emitted from the organic EL element 122 is reflected inside the apparatus and reaches the light receiving unit 36. Even if it does, malfunction can be prevented.

  The counter substrate 20 has a substrate body 20A made of glass, quartz, plastic or the like as a base. The counter substrate 20 has a function as a protective substrate for physically protecting the element substrate 10, and the surface of the substrate body 20 </ b> A facing the element substrate 10 is a flat surface. An optical waveguide 34 is formed by digging down a part of the flat surface.

  The optical waveguide 34 has a function of transmitting light (optical signal) emitted from the light emitting unit 32 and guiding it to each of the plurality of light receiving units 36. Since the optical waveguide 34 of the present embodiment is formed by digging down the flat surface of the substrate body 20A, the bottom of the optical waveguide 34 on the substrate body 20A side has a good shape with few irregularities. Further, as shown in FIG. 1B, the optical waveguide 34 is provided so as to overlap the light conversion element 322 and the light receiving unit 36 provided in the light emitting unit 32 in a plane.

  The organic EL device 1A may adopt a so-called can sealing structure to bond the element substrate 10 and the counter substrate 20, and fills the space between the element substrate 10 and the counter substrate 20 with an epoxy resin or the like. It is good also as a solid sealing structure. When adopting the can sealing structure, normally, a trapping material that traps moisture is sealed inside, but the trapping material may be provided at a position that does not overlap the optical wiring portion 30 in a plan view.

  FIG. 2 is a schematic cross-sectional view of the organic EL element 122 and corresponds to the line segment AA in FIG. The organic EL element 122 includes a pixel electrode 51, an organic functional layer 52, and a common electrode 53 provided on the element substrate (substrate) 10.

  The pixel electrode 51 is made of a conductive material having a high work function (for example, 5 eV or more), here, indium tin oxide (ITO).

  The common electrode 53 is made of a material having a low work function (for example, 5 eV or less). Examples of the material having a low work function include calcium, magnesium, sodium, and lithium. In addition, these materials alone have high electrical resistance and do not function as electrodes, so patterning a metal layer such as aluminum, gold, silver, or copper to avoid the light emitting part, or transparent metals such as ITO or tin oxide You may use it in combination with the laminated body with an oxide conductive layer. In the present embodiment, a magnesium-silver alloy (MgAg) is used by adjusting the film thickness to 20 nm or less so that transparency can be obtained.

  The organic functional layer 52 has an organic light emitting layer 523 between the pixel electrode 51 and the common electrode 53. The organic functional layer 52 of this example includes a hole injection layer 521, a hole transport layer 522, an organic light emitting layer 523, and an electron transport layer 524 provided in this order from the pixel electrode 51 side.

  FIG. 3 is a block diagram illustrating the flow of an electrical signal (image signal) in the organic EL device 1A. In the organic EL device 1 </ b> A of the present embodiment, a plurality of image signals input from the outside are input to a shift register 42 (not shown in FIG. 1) and re-divided into an appropriate number of data, via an optical wiring unit 30. By being input to the drive circuit 14, the organic EL element 122 is driven according to the drive signal. Each configuration will be described below.

  The electric signal input from the outside includes four data corresponding to the four organic EL elements 122. Therefore, it is first divided by the shift register 42. The divided electric signal is input to the light emitting unit 32, and an optical signal corresponding to the electric signal is emitted. That is, the electrical signal is converted into an optical signal in the light emitting unit 32.

  The emitted optical signal is transmitted through the optical waveguide 34 and received by the light receiving unit 36. The light receiving unit 36 outputs an electrical signal according to the amount of light received. That is, the light signal is converted into an electric signal in the light receiving unit 36.

  Here, the organic EL device 1 </ b> A of the present embodiment compares the electric signal output from the light receiving unit 36 with the electric signal input to the light emitting unit 32, and controls the intensity of light emitted from the light emitting unit 32. A synchronization circuit 44 for feedback is provided. Even if the light intensity decreases in the optical waveguide 34, the signal intensity before and after the optical wiring section 30 is compared and fed back, so that stable signal supply is possible.

  The electrical signal output from the light receiving unit 36 is supplied to the drive circuit 14. The drive circuit 14 of this embodiment includes a sampling latch 141, a load latch 142, a light emission control circuit 143, a level shifter 144, and a DAC circuit 145.

  The electric signal input from the light receiving unit 36 is first latched once by the sampling latch 141, then transmitted to the load latch 142, and loaded from the load latch 142 to the light emission control circuit 143 at a predetermined timing. These latch circuits perform latching and loading in accordance with the timing of a basic clock signal (not shown) input to each circuit.

  The light emission control circuit 143 converts the input image signal (electric signal) into a light emission control signal (electric signal) that causes the organic EL element 122 to emit light. Based on this emission control signal, the emission intensity and emission time of the organic EL element 122 are set.

  The level shifter 144 is provided between both circuits in order to reduce the potential difference between the driving voltage of the light emission control circuit 143 driven at a high voltage (for example, 15V) and the DAC circuit 145 driven at a low voltage (for example, 3.5V). This is a step-down type level shifter.

  The DAC circuit 145 latches the light emission control signal input from the light emission control circuit 143 via the level shifter 144 in synchronization with various control signals, converts the latched electric signal into an analog signal, and generates a drive signal (electric signal). Is output to the organic EL element 122. Then, each organic EL element 122 emits light based on the drive signal. The organic EL device 1A of this embodiment processes and drives the image signal input in this way.

  FIG. 4 is a schematic cross-sectional view illustrating the configuration of the optical waveguide 34. The optical waveguide 34 can be formed by forming a groove by patterning and etching the substrate body 20A and filling the groove with a material for forming the optical waveguide 34. As a material for forming the optical waveguide 34, a transparent resin or glass (sol-gel glass) formed using a sol-gel method can be used.

  The optical waveguide 34A shown in FIG. 4A emits the optical signal L toward the incident port 340A for guiding the optical signal L emitted from the light emitting unit 32 shown in FIG. Injection port 340B. Further, light scattering particles forming the light scattering mechanism 341a are dispersed in the vicinity of the entrance 340A and the exit 340B. As the light scattering particles, for example, silica particles, glass particles or metal particles are used. Such an optical waveguide 34A, for example, discharges a liquid optical waveguide material (resin or the like) from a inkjet nozzle or the like to a predetermined portion, and also supplies a liquid optical waveguide material containing light scattering particles from another inkjet nozzle or the like. It can be formed by discharging to a site.

  The optical waveguide 34B shown in FIG. 4B is provided with a light scattering mechanism 341b on the surface of the substrate body 20A on the surface of the optical waveguide 34B so as to overlap the exit port 340B in a plane. The light scattering mechanism 341b has a configuration in which the depth of the groove forming the optical waveguide 34 is changed. Furthermore, the optical waveguide 34C shown in FIG. 4C has a configuration in which a plurality of concave and convex light scattering mechanisms 341c are provided at positions overlapping the entrance port 340A and the exit port 340B on the surface of the substrate body 20A. Yes.

  In such an optical waveguide, the optical signal L (L1) emitted from the light emitting unit 32 enters the optical waveguide from the entrance 340A. The optical signal L (L2) propagating in the optical waveguide is scattered by the light scattering mechanism. Of the scattered light signal L, the optical signal L (L3) emitted from the emission port 340B is emitted toward the light receiving unit 36, and the optical signal L2 not emitted from the emission port 340B further propagates in the optical waveguide. The exit 340B may be provided with a member such as a condensing element in order to converge an optical signal scattered and emitted to the light receiving unit 36.

  Further, the optical waveguide may be formed on the surface of the substrate body 20A as well as being formed by providing the substrate body 20A with a groove as shown in FIG. FIG. 5 is a schematic cross-sectional view illustrating the configuration of the optical waveguide 34D. Such an optical waveguide 34D can be formed by providing a clad material 50 on the surface of the substrate body 20A, etching the clad material 50 by mask patterning, and filling the optical waveguide forming material. Here, the optical waveguide 34D is illustrated as having the same light scattering mechanism as the optical waveguide 34A shown in FIG.

  FIG. 6 is a schematic diagram showing a signal flow in the organic EL device 1A of the present embodiment having the above-described configuration.

  First, an electrical signal input from the outside is converted into an optical signal L 1 by a light emitting unit 32 provided on the element substrate 10, and enters an optical waveguide 34 provided on the counter substrate 20. The optical signal L2 propagating through the optical waveguide 34 is emitted toward the light receiving unit 36 provided on the element substrate 10 (optical signal L3), and is converted into an electric signal E1 by the light receiving unit 36. The electric signal E1 output from the light receiving unit 36 is converted into a driving signal E2 in the driving circuit 14 and supplied to the organic EL element unit 12. The organic EL element unit 12 emits light based on the drive signal E2.

  As described above, in the organic EL device 1 </ b> A of the present embodiment, a signal for driving the organic EL element unit 12 in the optical wiring unit 30 propagates through the counter substrate 20. Since the optical waveguide 34 is provided on the counter substrate 20 that is relatively flat with respect to the surface of the element substrate 10, the optical waveguide 34 has a better quality that is less attenuated by scattering than when provided on the element substrate 10. Therefore, signal transmission can be performed satisfactorily.

  According to the organic EL device 1A having the above-described configuration, a part of the wiring is an optical wiring, so that a signal transmission failure that causes image disturbance such as crosstalk and flicker hardly occurs. Further, since the optical waveguide 34 of the optical wiring is formed on the flat surface of the counter substrate, the optical signal is hardly attenuated during transmission through the optical waveguide, and good signal transmission is possible. Therefore, a high-quality organic EL device 1A having excellent display quality can be obtained.

  In the present embodiment, the pixel electrode connected to the drive circuit 14 constitutes a part of the organic EL element 122, and the light conversion element 322 of the light emitting unit 32 is also an organic EL element. By providing the organic EL element in common, the structure and the forming material can be shared, and the manufacturing process can be shared. Therefore, the organic EL device 1A having good display characteristics can be easily manufactured.

  In the present embodiment, the organic EL element 122 and the light conversion element 322 emit light having different wavelengths. Therefore, malfunction can be prevented.

  In the present embodiment, the optical wiring unit 30 includes two or more light receiving units 36, and two or more light receiving units 36 are commonly connected to one optical waveguide 34. As a result, the number and area of the optical waveguides 34 can be reduced, and the apparatus can be downsized and the screen can be increased.

  In this embodiment, an organic EL element is used as the light conversion element 322. However, other light sources such as a light emitting diode (LED) and a semiconductor laser (LD) can also be used.

  In this embodiment, the organic EL element 122 and the light conversion element 322 emit light of different colors, but the same color of light may be emitted. In that case, since the same organic EL element 122 and the light conversion element 322 can be formed in the same manufacturing process, manufacture becomes easy.

  In the present embodiment, four light receiving portions 36 are connected to one optical waveguide 34 and signals are supplied to the four organic EL elements 122. However, a pair of the light receiving portion and the optical waveguide is provided. 1, one light receiving unit 36 may be connected to one optical waveguide 34.

  In the present embodiment, the organic EL element unit 12 emits white light. However, the present invention is not limited to this. For example, the counter substrate 20 may include a color filter layer that converts light emitted from the organic EL element 122 into various color lights. In that case, an optical waveguide is provided at a position that does not overlap with a colored portion through which light passes in the color filter layer. Even in such a case, since the color filter layer can be formed with a uniform thickness, the surface shape is much flatter than the unevenness of the surface of the element formation layer 11. Therefore, a better optical waveguide can be obtained as compared with the case where the element substrate 10 is formed.

[Second Embodiment]
FIG. 7 is an explanatory diagram of an organic EL device 1B according to the second embodiment of the present invention. The organic EL device 1B of this embodiment is partly in common with the organic EL device 1A of the first embodiment. The difference is that, in contrast to the organic EL device 1A that includes four organic EL elements (light emitting elements) in a straight line, the organic EL device 1B is arranged in a matrix. Therefore, in this embodiment, the same code | symbol is attached | subjected about the component which is common in 1st Embodiment, and detailed description is abbreviate | omitted.

  FIG. 7 is a plan view schematically showing the configuration of the organic EL device 1B. As shown in FIG. 7, the organic EL device 1B includes a substrate body 10A having light transmissivity and electrical insulation, and a sub-pixel X formed of an organic EL element, which is located at a substantially central portion of the substrate body 10A. And a display area AR (inside the two-dot chain line frame in FIG. 7) arranged in a shape and having a substantially rectangular shape in plan view.

  Each sub-pixel X can extract red (R), green (G), or blue (B) light by emitting light. The light of each color may be emitted directly from each color by the organic EL element included in the sub-pixel X. After the sub-pixel X emits white light, the light passes through the color filters corresponding to R, G, and B. Thus, the light may be modulated to light of each color. In the display area AR, the sub-pixels X of the same color are arranged in the vertical direction in the figure, forming a so-called stripe arrangement. In the display area AR, full-color display can be performed by mixing RGB light emitted from the sub-pixels X arranged in a matrix.

  Each sub-pixel X is configured near the intersection of the data line 85 and the scanning line 95, and the data line 85 is adjacent to the display area AR in the arrangement direction of the sub-pixel X (in the figure, the display area AR). One end is connected to the data line driving circuit 80 arranged on the upper side. In addition, one end of the scanning line 95 is connected to a scanning line driving circuit 90 disposed at a position adjacent to the display area AR (left side of the display area AR in the drawing) in the direction intersecting with the arrangement direction of the sub-pixels X.

  A data signal (electrical signal) input from the outside of the apparatus is input to the data line driving circuit 80 through the electronic circuit 60, the optical wiring unit 30, and the integrated circuit 70 in this order. A plurality of optical wiring portions 30 can be provided as necessary, but are omitted in the drawing.

  The electronic circuit 60 has a shift register that divides a plurality of input data signals. In the shift register, the data signal is divided according to the number of the optical wiring units 30 arranged and transmitted to each optical wiring unit 30.

  Each optical wiring unit 30 has the same configuration as the optical wiring of the first embodiment. The organic EL device 1B includes a counter substrate (not shown) facing the substrate body 10A, and the optical waveguide 34 included in the optical wiring unit 30 is disposed on the counter substrate. The light emitting unit 32 and the light receiving unit 36 are respectively formed on the element substrate side having the substrate body 10A.

  In the integrated circuit 70, the supplied data signal is latched and released in accordance with the timing of the clock signal supplied via, for example, a wiring (not shown). The data signal is converted into a digital signal in the integrated circuit 70 and supplied to the data line driving circuit 80.

  In addition, it is good also as providing the test | inspection circuit which can test | inspect the operating condition of the organic EL apparatus 1B, and can test | inspect the quality of a display apparatus in the middle of manufacture or the time of shipment, and a defect.

  FIG. 8 is a block diagram illustrating the flow of data signals in the organic EL device 1B. In the following description, description of the contents common to the organic EL device 1A of the first embodiment is omitted.

  Data signals input from the outside are divided by the shift register 42 in accordance with the number of optical wiring sections 30 formed. The divided data signal is input to the light emitting unit 32 and an optical signal corresponding to the data signal is emitted. The optical signal is transmitted through the optical waveguide 34 and received by the light receiving unit 36. The light receiving unit 36 outputs an electrical signal according to the amount of light received.

  The electrical signal output from the light receiving unit 36 is supplied to the integrated circuit 70. The integrated circuit 70 of this embodiment includes a sampling latch 71, a load latch 72, and a light emission control circuit 73. The input electrical signal is latched by the sampling latch 71 and loaded by the load latch 72. In the light emission control circuit 73, it converts into the light emission control signal which makes the organic EL element of the sub pixel X light-emit.

  The drive signal output from the integrated circuit 70 is input to the data line drive circuit 80. The data line driving circuit 80 of this embodiment includes a level shifter 81, a DAC circuit 82, and an amplifier 83. The input drive signal has its potential lowered by the step-down type level shifter 81 and is input to the DAC circuit 82. The DAC circuit 82 converts the light emission control signal into an analog signal and generates a drive signal. The drive signal is amplified by the amplifier 83 and is output to the sub-pixel X through the data line 85 in synchronization with various control signals. Then, each sub-pixel X emits light (displays) based on the drive signal. The organic EL device 1B of the present embodiment processes and drives the data signal in this way.

  According to the organic EL device 1B having the above-described configuration, since a part of the wiring is an optical wiring, a signal transmission failure that causes image disturbance such as crosstalk and flicker is less likely to occur. Further, since the optical waveguide 34 of the optical wiring is formed on the flat surface of the counter substrate, the optical signal is hardly attenuated during transmission through the optical waveguide, and good signal transmission is possible. Therefore, it can be set as the high quality organic EL apparatus 1B excellent in display quality.

[Electronics]
Next, an embodiment of the electronic device of the present invention will be described. FIG. 9 shows an example of an electronic apparatus using the organic EL device of the present invention, and FIG. 9A schematically shows an image forming apparatus (optical printer) 1000 provided with the electro-optical device as a line head. FIG. 9B is a perspective view showing a mobile phone.

  The optical printer 1000 shown in FIG. 9A includes a photosensitive drum 160 as an image carrier in the vicinity of the travel path of the transfer medium 220. Around the photosensitive drum 160, an exposure device 100L, a developing device 180, and a transfer roller 210 are sequentially arranged along the rotation direction of the photosensitive drum 160 (the arrow direction in the drawing). The photosensitive drum 160 is rotatably provided around the rotation shaft 170, and a photosensitive surface 160A is formed on the outer peripheral surface of the photosensitive drum 160 at the central portion in the rotation axis direction. The exposure device 100L and the developing device 180 are arranged in a long axis shape along the rotation shaft 170 of the photosensitive drum 160, and the width in the long axis direction substantially coincides with the width of the photosensitive surface 160A.

  The exposure apparatus 100L has a line head (electro-optical device) 100 having a plurality of organic EL elements 100A, and an image forming unit having a plurality of lens elements 120A for imaging the light emitted from the line head 100 at an erecting equal magnification. And an optical element 120. The line head 100 and the imaging optical element 120 are held by a head case (not shown) while being aligned with each other, and are fixed on the photosensitive drum 160. Here, the line head 100 includes an optical wiring having the above-described structure. Therefore, the optical printer 1000 is less prone to exposure failure.

  A cellular phone 1300 shown in FIG. 9B includes the organic EL device of the present invention as a small-sized display portion 1301 and includes a plurality of operation buttons 1302, an earpiece 1303, and a mouthpiece 1304. . Accordingly, it is possible to provide a mobile phone 1300 including a display unit that is configured by the electro-optical device of the present invention and has excellent display quality.

  Since these electronic apparatuses are provided with the electro-optical device of the present invention, crosstalk and flicker do not occur, and high-quality electronic apparatuses can be obtained.

  In addition, the electro-optical device of the present invention is not limited to the electronic device described above, but an electronic book, a projector, a personal computer, a digital still camera, a television receiver, a viewfinder type or a monitor direct-view type video tape recorder, a car navigation device, It can be suitably used as image display means for devices such as pagers, electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, touch panels, etc. With such a configuration, images such as crosstalk and flicker can be used. An electronic device including a display portion with high display quality without any disturbance can be provided.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above embodiment, an organic EL device including an organic EL element including a pixel electrode is used, but a liquid crystal device may be used. In that case, a common electrode may be formed on the counter substrate side depending on the driving method of the liquid crystal device. However, in order to keep the formation region of the optical waveguide flat, it is preferable not to provide the common electrode in the formation region. The same applies to the alignment film provided in the liquid crystal device. Similarly, a plasma display device can be provided.

1 is a schematic diagram illustrating an electro-optical device according to a first embodiment of the invention. 1 is a schematic cross-sectional view of an organic EL element included in an electro-optical device according to a first embodiment. FIG. 3 is a block diagram illustrating a signal flow in the electro-optical device according to the first embodiment. It is a schematic sectional drawing explaining the structure of the optical waveguide with which an electro-optical apparatus is provided. It is a schematic sectional drawing explaining the structure of the optical waveguide with which an electro-optical apparatus is provided. FIG. 6 is a schematic diagram illustrating a flow of each signal in the electro-optical device according to the present embodiment. FIG. 6 is a schematic diagram illustrating an electro-optical device according to a second embodiment of the invention. FIG. 10 is a block diagram illustrating a signal flow in an electro-optical device according to a second embodiment. It is a perspective view which shows the electronic device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1A, 1B ... Organic EL device (electro-optical device), 10 ... Element substrate (first substrate), 20 ... Counter substrate (second substrate), 30 ... Optical wiring part, 32 ... Light emitting part, 34, 34A, 34B, 34C, 34D ... optical waveguide, 36 ... light receiving unit, 51 ... pixel electrode, 340A ... entrance, 340B ... exit, 341a, 341b, 341c ... light scattering mechanism, 1000 ... image forming apparatus (electronic device), 1300 ... mobile Telephone (electronic equipment), X ... subpixel

Claims (9)

A first substrate and a second substrate disposed to face each other;
On the surface of the first substrate facing the second substrate, a pixel electrode;
A drive circuit connected to the pixel electrode;
A light emitting unit for converting an electric signal into an optical signal and emitting the light signal;
A light receiving unit that receives an optical signal emitted from the light emitting unit, converts the light signal into an electrical signal, and supplies the electric signal to the drive circuit; and
An electro-optical device, wherein an optical waveguide that transmits an optical signal emitted from the light emitting unit to the light receiving unit is provided on a surface of the second substrate facing the first substrate. The light emitting unit includes a first organic electroluminescence element that emits the optical signal,
The electro-optical device according to claim 1, wherein the pixel electrode constitutes a second organic electroluminescence element that sandwiches an organic light emitting layer together with an electrode facing the pixel electrode and emits light.   The electro-optical device according to claim 2, wherein the first organic electroluminescence element and the second organic electroluminescence element emit light having different wavelengths.   4. The electro-optical device according to claim 1, wherein two or more light receiving portions are connected in common to one optical waveguide. 5.   The optical waveguide is formed by forming a groove on a surface of the second substrate facing the first substrate and filling the groove with a material for forming the optical waveguide. 5. The electro-optical device according to claim 4. The optical waveguide has an entrance through which the optical signal emitted from the light emitting unit is incident, and an exit through which the optical signal propagating through the optical waveguide is emitted,
6. The light scattering mechanism according to claim 1, further comprising a light scattering mechanism that scatters the optical signal in a region overlapping the entrance and the exit in the optical waveguide. Electro-optic device.   The electro-optical device according to claim 6, wherein the light scattering mechanism is formed by changing a depth of the groove that overlaps the entrance or the exit in plan.   The electro-optical device according to claim 6, wherein the light scattering mechanism has a plurality of uneven shapes.   An electronic apparatus comprising the electro-optical device according to claim 1.

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