JP2006150882A - Electro-optical device, image forming apparatus, and image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electro-optical device which can be manufactured at a low cost. <P>SOLUTION: The electro-optical device 10 comprises a transparent substrate 12, a plurality of OLED elements 14 formed in the substrate 12, a sealing member 24 larger than the substrate 12 and attached to the substrate 12 so as to seal the OLED elements 14 in cooperation with the substrate 12, a circuit element 28 to drive or to control the OLED elements 14, and power lines 20A, 20B, 20C for supplying power to the circuit element 28 and the OLED elements 14. The circuit element 28 and power cable lines 20A, 20B, 20C are provided to the sealing member 24 so as not to be overlapped on the substrate 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electro-optical device including a self-luminous element, and an image forming apparatus and an image reading device including the electro-optical device.

  2. Description of the Related Art In recent years, organic light emitting diodes (hereinafter referred to as “OLEDs” where appropriate) called organic electroluminescent elements and light emitting polymer elements have attracted attention as next-generation light emitting devices that replace liquid crystal elements. The OLED element is used as a display device as disclosed in Patent Document 1 and Patent Document 2, for example.

  In addition, an electrophotographic image forming apparatus has been developed that uses a line head in which a large number of OLED elements are arranged as exposure means, that is, a latent image writer. In such a line head, a plurality of pixel circuits including an OLED element and a transistor for driving the OLED element are arranged. For example, Patent Document 3 and Patent Document 4 disclose such a line head.

JP 2000-58255 A JP 2001-343933 A JP 11-27469 A JP 2001-130048 A

  An electro-optical device typified by the above-described line head includes a substrate on which an OLED element is formed as a constituent element. In the conventional technique, the area of the substrate needs to be larger than a certain size. For example, in the techniques of Patent Document 1 and Patent Document 4, since circuit elements for driving or controlling OLED elements are arranged on this substrate, the area of the substrate must be made a certain size or larger. Since this substrate is obtained by cutting out from an original substrate on which a large number of OLED elements are formed, the larger the substrate constituting one electro-optical device, the smaller the number of sheets obtained from the original substrate.

  Currently, many materials and many processes are required to form an OLED element. There are also costly and time consuming processes unique to OLED elements. Under such circumstances, the cost of forming the OLED element on the original substrate, that is, the manufacturing cost of the original substrate is higher than the manufacturing cost of other substrates. Accordingly, the larger the substrate (the substrate on which the OLED element is formed) constituting one electro-optical device, the higher the manufacturing cost of the electro-optical device. As described above, according to the conventional technique, the area of the substrate (substrate on which the OLED element is formed) constituting one electro-optical device needs to be set to a certain size or more, so that the manufacturing cost of the electro-optical device is sufficiently reduced. I can't.

  Accordingly, the present invention provides an electro-optical device that can be manufactured at a lower cost, and an image forming apparatus and an image reading apparatus including the electro-optical device.

The electro-optical device according to the present invention is attached to the substrate so as to seal the self-light-emitting element in cooperation with the substrate, the plurality of self-light-emitting elements formed on the substrate, and the substrate larger than the substrate. And a circuit for driving or controlling the light-emitting element provided on the sealing body so as not to overlap the substrate, and at least provided on the sealing body so as not to overlap the substrate. A power line for supplying power to one of the circuit and the self-luminous element.
According to this arrangement, since the circuit and the power supply line are provided in the sealing body, it is possible to make the substrate smaller than when at least one of them is provided on the substrate. Therefore, the number of substrates that can be cut out from one original substrate can be increased. On the other hand, the number of sealing bodies that can be cut out from one original substrate is reduced by this increase. Therefore, whether or not the manufacturing cost of the electro-optical device can be reduced depends on whether or not the decrease in cost according to the increase exceeds the increase in cost according to the decrease. . In general, the unit price of the original substrate from which the substrate is cut out is higher than the unit price of the original substrate from which the sealing body is cut out. Therefore, the decrease in cost corresponding to the above increase exceeds the increase in cost corresponding to the above decrease. As described above, according to this arrangement, the manufacturing cost of the electro-optical device can be reduced.
Further, according to this arrangement, the circuit and the power supply line do not overlap with the substrate. Therefore, even if the electro-optical device type is a type in which light from the self-luminous element travels through the substrate (bottom emission type), it is a type in which the light travels through the sealing body (top emission type). Even if it exists, the light from the self-luminous element is not blocked by the circuit or the power line. That is, it is applicable to both types.

  In a preferred embodiment, the circuit is a laminate formed on the substrate or the sealing body. In this embodiment, since the electrical connection by some of the connection terminals is unnecessary, the manufacturing process of the electro-optical device is simplified. In addition, since the electrical connection by some of the connection terminals is not necessary, the probability of occurrence of a conduction failure is reduced, and the reliability of the electro-optical device is improved. In addition, the electro-optical device can be made smaller than when the circuit element is attached to the sealing body.

  The electro-optical device may further include a heat dissipation mechanism that releases heat that has been attached to and transmitted from the sealing body into the outside air. Accordingly, heat generated from the power line and the circuit is easily released into the outside air, so that heat transmitted from the power line and the circuit to the self-light emitting element can be reduced. Therefore, it is possible to reduce the adverse effect of the power line and circuit heat on the self-luminous element.

  An image forming apparatus according to the present invention includes an image carrier, a charger for charging the image carrier, and a plurality of the self-light emitting elements, and a plurality of the self-light-emitting elements on a charged surface of the image carrier. The electro-optical device that forms a latent image by irradiating light from an element, the developing device that forms a visible image on the image carrier by attaching toner to the latent image, and the developer from the image carrier. A transfer unit that transfers the image to another object. As described above, in the electro-optical device according to the present invention, it is possible to reduce the manufacturing cost by saving the substrate on which the self-luminous element is formed. Therefore, the manufacturing cost of the image forming apparatus including the electro-optical device can be reduced. Is possible.

  An image reading apparatus according to the present invention includes the electro-optical device in which a plurality of the self-light-emitting elements are arranged, and a light-receiving device that converts light emitted from the self-light-emitting elements and reflected by a reading target into an electric signal. . As described above, the electro-optical device according to the present invention can reduce the manufacturing cost by saving the substrate on which the self-light-emitting element is formed. Therefore, the manufacturing cost of the image reading apparatus including the electro-optical device can be reduced. Is possible.

  Hereinafter, various embodiments according to the present invention will be described with reference to the accompanying drawings. In the drawings, the ratio of dimensions of each part is appropriately changed from the actual one.

<First Embodiment>
FIG. 1 is a cross-sectional view showing an electro-optical device according to a first embodiment of the invention, and FIG. 2 is a partial plan view of the electro-optical device. This electro-optical device is used as a line-type optical head for writing a latent image on an image carrier in an image forming apparatus using an electrophotographic system. As shown in these drawings, the electro-optical device 10 includes a transparent substrate 12 and a plurality of OLED elements (self-emitting elements) 14 formed on the substrate 12. The substrate 12 is preferably a flat plate made of glass, quartz, or plastic, and a large number of OLED elements (self-emitting elements) 14 are arranged on the substrate 12 in a row or other appropriate pattern. In the illustrated form, light emitted from each OLED element 14 passes through the transparent substrate 12 and travels downward in FIG. That is, this electro-optical device is a bottom emission type.

On the substrate 12, connection terminals 18AL and 18BL for supplying power to the OLED element 14 and wiring 16 for connecting the OLED element 14 and the connection terminals 18AL and 18BL are formed.
Further, a sealing body 24 is attached to the substrate 12 so as to seal these OLED elements 14 in cooperation with the substrate 12. This sealing isolates the OLED element 14 from the outside air, particularly moisture and oxygen, and suppresses its deterioration. The sealing body 24 is larger than the substrate 12, and may be formed of, for example, glass, metal, ceramic, or plastic. Of course, when the electro-optical device is a top emission type in which light emitted from the OLED element passes through the sealing body 14 and travels upward in FIG. 1, the sealing body 12 must be transparent, Metal cannot be adopted as the material. In the sealing body 24, connection terminals 18 AU and 18 BU for supplying power to the OLED element 14 are formed on the surface facing the substrate 12. An adhesive 22 is preferably used for attaching the sealing body 24 to the substrate 12. At that time, an anisotropic conductive material 133 is preferably used for electrical connection between the connection terminals. As the adhesive, for example, a thermosetting adhesive or an ultraviolet curable adhesive is used.

  The types of sealing used in the field of OLED include film sealing in which the entire surface of the substrate 12 is bonded to the sealing body 24 by the adhesive 22, and the peripheral portion of the substrate 12 is sealed by the adhesive 22. There is a cap sealing that provides a space defined by the sealing body 24 and the substrate 12 around the OLED element 14. In the cap sealing, a desiccant is disposed in this space. This embodiment may use either film sealing or cap sealing. However, regardless of which seal is used, the anisotropic conductive material 133 is used instead of the adhesive 22 for electrical connection between the connection terminal 18AL and the connection terminal 18AU and electrical connection between the connection terminal 18BL and the connection terminal 18BU. Use. One or more passivation layers may be provided in the upper layer of the OLED element 14 in order to further isolate and protect the OLED element 14 from the outside air.

  In the sealing body 24, the power supply lines 20 </ b> A, 20 </ b> B, 20 </ b> C and the connection terminals 30 </ b> AU, 30 </ b> BU, 32 </ b> AU, 32 </ b> BU, 32 </ b> CU are not positioned on the surface facing the substrate 12 in order to drive the OLED element 14. Is formed. Further, although detailed illustration is omitted, wirings for connecting the power supply lines 20A, 20B, and 20C and the connection terminals 32AU, 32BU, and 32CU and a protective film (insulating film) are provided on this surface and should be connected to each other. This protective film is interposed between the non-power supply line and the wiring. Of the connection terminals 32AU, 32BU, and 32CU, the connection terminal 32AU is electrically connected to the power line 20A, and the connection terminal 32BU is electrically connected to the power line 20B, and is electrically connected to the power line 20C. Is the connection terminal 32CU. Further, although not shown in detail, wirings for connecting the connection terminals 30AU and 30BU and the connection terminals 18AU and 18BU are provided on this surface. Of the connection terminals 30AU and 30BU, the connection terminal 30AU is electrically connected to the connection terminal 18AU, and the connection terminal 30BU is electrically connected to the connection terminal 18BU.

  A driver IC for driving the plurality of OLED elements 14, that is, a circuit element 28 is attached to the sealing body 24 on the surface facing the substrate 12. For the attachment of the circuit element 28 to the sealing body 24, the adhesive 26 and the anisotropic conductive materials 131 and 132 are preferably used. As the adhesive, for example, a thermosetting adhesive or an ultraviolet curable adhesive is used.

  As will be described later, the circuit element 28 includes a wiring for supplying power to the plurality of OLED elements 14 and an element for switching on / off the energization of these OLED elements 14. The circuit element 28 has connection terminals 30AL, 30BL, 32AL, 32BL, and 32CL on the surface facing the sealing body 24. The connection terminals 30AL and 30BL are connected to the connection terminals 30AU and 30BU on the sealing body 24 via the anisotropic conductive material 132, respectively, and finally connected to the cathode and the anode of the OLED element 14, respectively.

The power line 20A is a common low potential power line for the OLED element 14 and the circuit element 28. The power supply line 20 </ b> B is a high potential power supply line for the OLED element 14. The power supply line 20C is a high potential power supply line for the circuit element 28. These power supply lines 20A, 20B, and 20C are connected to a power supply device via a flexible substrate (not shown).
The wiring 16, the connection terminals 18AL, 18AU, 18BL, 18BU, 30AL, 30AU, 30BL, 30BU, 32AL, 32AU, 32BL, 32BU, 32CL, 32CU and the power supply lines 20A, 20B, 20C are made of a conductive material such as aluminum. Formed from.

FIG. 3 is a cross-sectional view showing details of each OLED element 14. The OLED element 14 includes a hole injection layer 46 formed on a transparent anode 42 made of ITO (Indium Tin Oxide), a light emitting layer 48 formed thereon, and a cathode formed thereon. 49. The hole injection layer 46 and the light emitting layer 48 are formed in a recess defined by the insulating layer 40 and the partition wall 44. The material of the insulating layer 40 is, for example, SiO ₂ , and the material of the partition wall 44 is, for example, polyimide.

  The anode 42 is connected to the connection terminal 18BL via a conductor not shown in FIG. 3, and the cathode 49 is connected to the connection terminal 18AL behind the connection terminal 18BL, although not shown in detail in FIG. Connected through. These leads are shown schematically as wiring 16 in FIG. The configuration of each OLED element 14 of this embodiment is as described above, but variations of the OLED element according to the present invention include a type in which an electron injection layer is provided between a cathode and a light emitting layer, and an anode and a transparent substrate. It may be a type having another layer such as a type in which an insulating layer is provided between them.

  FIG. 4 is a block diagram illustrating a drive system of the electro-optical device 10. As shown in FIG. 4, the circuit element 28 described above includes a plurality of, for example, 128 data lines L0 to L127 and a selection circuit 280. In addition to the data signals D0 to D127, the circuit element 28 is supplied with various control signals CTL, a first power supply potential VIC, and a ground potential GND. Data signals D0 to D127 are applied to data lines L0 to L127 from a data control circuit (not shown). The first power supply potential VIC is supplied from the high potential power supply line 20C for the circuit element 28, and the ground potential GND is supplied from the common low potential power supply line 20A for the OLED element 14 and the circuit element 28.

  Each of the pixel blocks B1 to B40 shown in FIG. 4 is a set of a plurality of, for example, 128 pixel circuits P that are driven in one unit time. The selection circuit 280 is supplied with a clock signal as the control signal CTL, and the selection circuit 280 sequentially outputs selection signals SEL1 to SEL40 in accordance with the clock signal. The selection signals SEL1 to SEL40 are input to the pixel blocks B1 to B40, respectively, and are supplied to 128 pixel circuits P in the corresponding pixel block. Each of the selection signals SEL1 to SEL40 becomes active for a period (selection period) of 1/40 of the main scanning period for latent image writing.

  The first to forty pixel blocks B1 to B40 are exclusively and sequentially selected by the selection signals SEL1 to SEL40. In this way, the main scanning period is divided into a plurality of selection periods (writing periods), and the pixel blocks B1 to B40 are driven in a time-sharing manner. Therefore, a dedicated data line is provided for each of the 5120 (128 × 40) pixel circuits P. The number of data lines can be reduced. That is, 5120 pixel circuits P can be controlled by 128 data lines L0 to L127. Each of the first to fourth pixel blocks B1 to B40 includes 128 pixel circuits P corresponding to the data lines L0 to L127, respectively. These pixel circuits P are supplied with the second power supply potential VEL and the ground potential GND. The second power supply potential VEL is supplied from the high potential power supply line 20B for the OLED element 14, and the ground potential GND is supplied from the common low potential power supply line 20A for the OLED element 14 and the circuit element 28. Then, the data signals D0 to D127 supplied via the data lines L0 to L127 in each selection period are taken into the pixel circuit P. The data signals D0 to D127 in this example are binary signals for instructing to turn on / off the OLED element.

  FIG. 5 is a circuit diagram of each pixel circuit P. Each pixel circuit P includes a holding transistor 281, a driving transistor 282, and the OLED element 14. In the figure, the part built in the circuit element 28 is denoted by reference numeral 28. As is clear from this, the holding transistor 281 and the driving transistor 282 are built in the circuit element 28. One of the selection signals SEL1 to SEL40 is supplied from the selection circuit 280 to the gate of the holding transistor 281 and the source thereof is connected to one of the data lines L0 to L127, so that one of the data signals D0 to D127 becomes the source. Supplied. The drain of the holding transistor 281 and the gate of the driving transistor 282 are connected by a connection line. A stray capacitance is attached to the connection line, and this capacitance acts as a holding capacitance. In the storage capacitor, a binary voltage is written in the selection period, and the written voltage is held until the next selection period. Therefore, the OLED element 14 emits light only during a period in which the data signals D0 to D127 are signals for instructing the lighting of the OLED element 14 in the period in which the holding transistors are selected by the selection signals SEL1 to SEL40.

  The second power supply potential VEL is supplied to the drain of the drive transistor 282 from the high potential power supply line 20B through the connection terminals 32BU and 32BL. The source of the drive transistor 282 is connected to the anode of the OLED element 14 through the connection terminals 30BL, 30BU, 18BU, 18BL. The drive transistor 282 supplies a drive current corresponding to the voltage (binary value) written in the storage capacitor to the OLED element 14. The ground potential GND is supplied to the cathode of the OLED element 14 from the low potential power line 20A through the connection terminals 32AU, 32AL, 30AL, 30AU, 18AU, and 18AL. The OLED element 14 emits an amount of light corresponding to the magnitude of the drive current.

  As described above, the circuit element 28 is instructed to select which pixel block can be energized and whether to energize the OLED element 14 in the selected pixel block (OLED element). The pixel circuit P (more precisely, the holding transistor 281 and the driving transistor 282) for turning on / off the power supply to 14 is incorporated. However, a circuit equivalent to the selection circuit 280 may be provided outside the circuit element 28, or a control circuit that generates the data signals D0 to D127 or various control signals CTL may be provided inside the circuit element 28. Further, it is possible to provide the pixel circuit P on the same substrate as the OLED element 14, and these variations are within the scope of the present invention. The components of these circuit elements 28 may be provided in one element, that is, an IC chip, or may be distributed to a plurality of elements.

Next, a procedure for manufacturing the electro-optical device 10 according to the first embodiment will be described.
As shown in FIG. 6, first, the OLED element 14, the wiring 16 and the connection terminals 18 AL and 18 BL are formed on the substrate 12. Actually, the OLED element 14, the wiring 16 and the connection terminals 18AL and 18BL are formed on the original substrate from which the plurality of substrates 12 are cut out. By cutting the substrate 12 from the original substrate, the OLED elements 14, the wirings 16 and The substrate 12 on which the connection terminals 18AL and 18BL are formed is obtained.

  In addition, connection terminals 18AU, 30AU, 30BU, 32AU, 32BU, 32CU and power supply lines 20A, 20B, 20C are formed on the sealing body 24. Actually, the connection terminals 18AU, 30AU, 30BU, 32AU, 32BU, 32CU and the power supply lines 20A, 20B, 20C are formed on the original substrate from which the plurality of sealing bodies 24 are cut out, and the sealing bodies are formed from the original substrates. By cutting 24, the sealing body 24 in which the connection terminals 18AU, 30AU, 30BU, 32AU, 32BU, 32CU and the power supply lines 20A, 20B, 20C are formed is obtained.

The position where the connection terminal and the power supply line are formed in the sealing body 24 is on one of the two widest surfaces. Excluding the connection terminals 18AU and 18BU, the sealing body 24 and the substrate 12 are bonded. In the region protruding from the substrate 12 (region not overlapping the substrate 12). Although not shown, thereafter, the power supply lines 20A, 20B, and 20C may be protected with a protective film. Examples of the protective film include a SiO ₂ film, a SiN film, and a combination thereof. These forming methods may be any known method, and the description thereof is omitted.

  In the formation of the OLED element, the wiring and the connection terminal on the original substrate from which the substrate 12 is cut, a metal layer, an anode, a light emitting layer (a hole transport layer, a light emitting polymer layer and an electron injection layer), a cathode, an insulating layer, a bank, and A layer such as a protective film is required. That is, compared to the case where the connection terminal and the power supply line are formed on the original substrate from which the sealing body 24 is cut out, there are far more types of necessary materials and necessary processes. In particular, it takes time or cost to form the light emitting layer. For example, in the method of forming these layers by applying droplets, the process of applying, drying and baking is complicated and time consuming. Further, for example, even in the sputtering method, the material for the light emitting polymer layer is very expensive, and thus costs are high.

  Next, as shown in FIG. 7, the substrate 12 and the circuit element 28 are arranged with respect to the sealing body 24. In this arrangement, the connection terminals 18AL and 18BL of the substrate 12 are opposed to the connection terminals 18AU and 18BU of the sealing body 24, respectively, and the connection terminals 30AL and 30BL of the circuit element 28 are respectively connected to the connection terminals 30AU and 30BU of the sealing body 24. The connection terminals 32AL, 32BL, and 32CL of the circuit element 28 face each other and face the connection terminals 32AU, 32BU, and 32CU of the sealing body 24, respectively.

  As shown in FIG. 8, next, a sealing thermosetting or ultraviolet curing adhesive 22, 26 is coated on the sealing body 24, while the anisotropic conductive materials 131, 132, 133 are sealed. Coat the connection terminals of the body 24. In the coating of the anisotropic conductive material, the anisotropic conductive material 131 is coated on the connection terminals 32AU, 32BU, and 32CU, the anisotropic conductive material 132 is coated on the connection terminals 30AU, 30BU, and the anisotropic conductive material 132 is formed. The connection terminals 18AU and 18BU are coated.

  As shown in FIG. 9, the substrate 12 is then placed on the adhesive 22 and the anisotropic conductive material 133 and attached to the sealing body 24, and then the adhesive 22 is cured. On the other hand, the circuit element 28 is placed on the adhesive 26 and the anisotropic conductive materials 131 and 132 and attached to the sealing body 24, and then the adhesive 22 is cured. Thus, the connection terminals 18AL and 18BL of the substrate 12 are electrically connected to the connection terminals 18AU and 18BU of the sealing body 24 through the anisotropic conductive material 133, respectively, and the connection terminals 30AL and 30BL of the circuit element 28 are anisotropically conductive materials. The connection terminals 30AU and 30BU of the sealing body 24 are electrically connected to each other through 132, and the connection terminals 32AL, 32BL and 32CL of the circuit element 28 are connected to the connection terminals 32AU and 32BU of the sealing body 24 through the anisotropic conductive material 131. , 32CU, respectively.

As shown in FIG. 9, the sealing adhesive 22 protrudes from the space between the substrate 12 and the sealing body 24 and includes a protruding portion 22 a that partially covers the side ends of the substrate 12 and the sealing body 24. You may have. By providing such a protrusion 22a, the sealing effect can be further enhanced. In order to provide the protruding portion 22a, an amount of adhesive larger than the amount disposed in the space between the substrate 12 and the sealing body 24 is coated on the substrate 12, and the adhesive protrudes from the space. Alternatively, the adhesive may be further coated on the outside after the adhesive 22 is cured.
Thus, the electro-optical device 10 is completed.

  According to the arrangement of this embodiment, the circuit element 28 for driving the OLED element 14 and the power supply lines 20A, 20B, and 20C are provided in the sealing body 24. Therefore, as compared with the case where at least one of them is provided on the substrate 12. Thus, the substrate 12 can be made small. Accordingly, the number of substrates 12 that can be cut out from one original substrate can be increased. On the other hand, the number of sealing bodies 24 that can be cut out from one original substrate is reduced by this increase. Therefore, whether or not the manufacturing cost of the electro-optical device 10 can be reduced depends on whether or not the cost reduction corresponding to the increase exceeds the cost increase corresponding to the decrease. To do.

  The original substrate from which the sealing body 24 is cut out may be formed with a small number of layers (for example, a metal layer and a protective film for connection terminals and power supply lines), whereas the original substrate from which the substrate 12 is cut out. As described above, it is necessary to form a large number of layers, which requires more materials and more processes. Further, as described above, the process of forming the OLED element 14 takes time or cost as compared with the process of forming other elements. Under such circumstances, the unit price of the original substrate from which the substrate 12 is cut out is usually higher than the unit price of the original substrate from which the sealing body 24 is cut out. Therefore, the decrease in cost corresponding to the above increase exceeds the increase in cost corresponding to the above decrease.

  As described above, according to this arrangement, the manufacturing cost of the electro-optical device 10 can be reduced. This leads to a reduction in manufacturing cost of the entire apparatus including the electro-optical device 10.

  Further, since the circuit element 28 and the power supply lines 20A, 20B, and 20C do not overlap the substrate 12, the light from the OLED element 14 travels through the sealing body even in the bottom emission type as in the present embodiment. Even in the top emission type, the light from the OLED element 14 is not blocked by the circuit element 28 or the power supply lines 20A, 20B, 20C. That is, it is applicable to both types.

<Second Embodiment>
FIG. 10 is a cross-sectional view showing an electro-optical device according to the second embodiment of the invention, and FIG. 11 is a partial plan view of the electro-optical device. The electro-optical device 50 is different from the electro-optical device 10 described above in that the circuit element 28 is not attached to the sealing body 24, but a circuit laminate 58 having the same function as the circuit element 28 is provided in the sealing body 24. It is only the point that was made to form.

  Since the circuit laminate 58 is formed in the sealing body 24, the connection terminals 30AL, 30AU, 30BL, 30BU, 32AL, 32AU, 32BL, 32BU, 32CL, 32CU, the anisotropic conductive materials 131, 132, and the adhesive 26 is not necessary. That is, the electro-optical device 50 forms the equivalent circuit of FIG. 5 without using these connection terminals, anisotropic conductive material, and adhesive.

Next, a procedure for manufacturing the electro-optical device 50 according to the second embodiment will be described.
As shown in FIG. 12, first, the OLED element 14, the wiring 16, and the connection terminals 18AL and 18BL are formed on the substrate 12. Details of this formation are as described in the first embodiment. In addition, connection terminals 18AU, 30AU, 30BU, 32AU, 32BU, 32CU, power supply lines 20A, 20B, 20C and a circuit laminate 58 are formed on the sealing body 24. Actually, the connection terminals 18AU, 30AU, 30BU, 32AU, 32BU, 32CU, the power supply lines 20A, 20B, 20C and the circuit laminate 58 are formed on the original substrate from which the plurality of sealing bodies 24 are cut out. By cutting out the sealing body 24 from the substrate, the sealing body 24 in which the connection terminals 18AU, 30AU, 30BU, 32AU, 32BU, 32CU, the power supply lines 20A, 20B, 20C and the circuit laminate 58 are formed is obtained.

  The positions where the connection terminals, the power supply lines, and the circuit laminate are formed in the sealing body 24 are on one of the two widest surfaces. Excluding the connection terminals 18AU and 18BU, the sealing body 24 and the substrate This is a region that protrudes from the substrate 12 when the 12 is bonded (region that does not overlap the substrate 12). Although not shown, thereafter, as described in the first embodiment, the power supply lines 20A, 20B, and 20C may be protected by a protective film.

  Next, as shown in FIG. 13, the substrate 12 is disposed with respect to the sealing body 24. This arrangement is performed so that the connection terminals 18AL and 18BL of the substrate 12 face the connection terminals 18AU and 18BU of the sealing body 24, respectively.

  As shown in FIG. 14, a sealing thermosetting or ultraviolet curable adhesive 22 is then coated on the sealing body 24, while the anisotropic conductive material 133 is applied to the connection terminal 18 AU of the sealing body 24. Coat on 18BU.

As shown in FIG. 15, next, the substrate 12 is placed on the adhesive 22 and the anisotropic conductive material 133 and attached to the sealing body 24, and then the adhesive 22 is cured. Thus, the connection terminals 18AL and 18BL of the substrate 12 are electrically connected to the connection terminals 18AU and 18BU of the sealing body 24 via the anisotropic conductive material 133, respectively.
Thus, the electro-optical device 50 is completed.

  According to the arrangement of this embodiment, since the circuit laminate 58 and the power supply lines 20A, 20B, and 20C that drive the OLED element 14 are formed on the sealing body 24, when at least one of them is provided on the substrate 12. In comparison, the substrate 12 can be made smaller. Accordingly, the number of substrates 12 that can be cut out from one original substrate can be increased. On the other hand, the number of sealing bodies 24 that can be cut out from one original substrate is reduced by this increase. Therefore, whether or not the manufacturing cost of the electro-optical device 10 can be reduced depends on whether or not the cost reduction corresponding to the increase exceeds the cost increase corresponding to the decrease. To do. As described above, the process of forming the OLED element 14 takes time or cost compared to the process of forming other elements. Therefore, the unit price of the original substrate from which the substrate 12 is cut out is usually higher than the unit price of the original substrate from which the sealing body 24 is cut out. Therefore, the decrease in cost corresponding to the above increase exceeds the increase in cost corresponding to the above decrease. As described above, according to this arrangement, the manufacturing cost of the electro-optical device 50 can be reduced. This leads to a reduction in manufacturing cost of the entire apparatus including the electro-optical device 50. Further, since the circuit laminate 58 and the power supply lines 20A, 20B, and 20C do not overlap with the substrate 12, as described in the first embodiment, the circuit laminate 58 and the power supply lines 20A, 20B, and 20C can be applied to both the bottom emission type and the top emission type.

  Further, since the circuit for driving the OLED element 14 is the circuit laminate 58 formed on the sealing body 24, electrical connection by some connection terminals is not necessary. Thereby, the manufacturing process of the electro-optical device is simplified. In addition, since the electrical connection by some of the connection terminals is not necessary, the probability of occurrence of a conduction failure is reduced, and the reliability of the electro-optical device is improved. Further, since the circuit laminate 58 is smaller than the circuit element 28, it contributes to miniaturization of the electro-optical device.

<Third Embodiment>
The electro-optical device according to the third embodiment is obtained by modifying the electro-optical device 10 or the electro-optical device 50 described above. The electro-optical device according to this embodiment is different from the electro-optical device 10 or the electro-optical device 50 described above in that the heat generated by the power supply lines 20A, 20B, 20C and the circuit (the circuit element 28 or the circuit laminate 58). However, it is only a point that is difficult to be transmitted to the OLED element 14.

  The power supply lines 20A, 20B, 20C and the circuit generate considerable heat. On the other hand, the OLED element 14 is easily affected by heat. Therefore, it is desirable that the heat of the power supply lines 20A, 20B, 20C and the circuit is not easily transmitted to the OLED element 14. In order to realize this, in this embodiment, instead of the sealing body 24, a sealing body formed of a material having a lower thermal conductivity than the substrate 12 is adopted, while heat is transferred to the outside air by heat conduction. The structure which attached the radiation fin to discharge | release to the sealing body is taken.

  For example, when the substrate 12 is formed of glass, the sealing body is formed of steatite or forsterite having a lower thermal conductivity than glass. Of course, the sealing body may be formed of a material other than these materials, but it is necessary to select a material having characteristics essential to the sealing body that does not allow moisture or oxygen to pass therethrough. Note that whether steatite or forsterite is used may be determined according to which of low thermal conductivity and high light transmittance is important. For example, it is appropriate to adopt steatite if importance is placed on low thermal conductivity, and forsterite is appropriate if importance is attached to high light transmittance.

  The heat radiating fin is made of a metal material such as aluminum or copper, and is attached to the surface on which the power supply lines 20A, 20B, 20C and the circuit are formed. More specifically, the power supply lines 20A, 20B, and 20C are attached to the circuit. However, a protective film exists between the power supply lines 20A, 20B, and 20C and the heat radiation fin. The shape and number of radiating fins are arbitrary. For example, in an electro-optical device obtained by modifying the electro-optical device 10, one radiating fin is pasted so as to cover the power supply lines 20A, 20B, and 20C, and another radiating fin is pasted so as to cover the circuit device 28. You may make it attach, and you may make it stick one radiating fin bent so that power supply line 20A, 20B, 20C and the circuit apparatus 28 may be covered.

  The heat radiation fins are attached to the power supply lines 20A, 20B, 20C and the circuit by adhering the heat radiation fins to the power supply lines 20A, 20B, 20C and the circuit. The timing at which this bonding is performed is arbitrary. For example, it may be between the step shown in FIG. 6 and the step shown in FIG. 7, or between the step shown in FIG. 12 and the step shown in FIG. Alternatively, for example, it may be after the step shown in FIG. 10 or after the step shown in FIG.

  According to the arrangement of this embodiment, since the thermal conductivity of the power supply lines 20A, 20B, 20C and the material of the sealing body in which the circuit is arranged is lower than the thermal conductivity of the material of the substrate 12, the power supply lines 20A, 20A, Compared with the case where 20B and 20C and a circuit are arrange | positioned on the board | substrate 12, the heat transmitted to the OLED element 14 can be reduced. Thereby, the bad influence which the heat of power supply line 20A, 20B, 20C and a circuit has on the OLED element 14 can be made small.

  Since the heat radiation fins are provided, the heat generated by the power lines 20A, 20B, and 20C and the circuit is easily released into the outside air as compared with the case where the heat radiation fins are not provided. 20C and the heat transferred from the circuit to the OLED element 14 can be reduced. Therefore, the adverse effect of the power lines 20A, 20B, 20C and the heat of the circuit on the OLED element 14 can be reduced.

<Image forming apparatus>
As described above, each electro-optical device according to the first to third embodiments is used as a line-type optical head for writing a latent image on an image carrier in an image forming apparatus using an electrophotographic system. Is possible. Examples of the image forming apparatus include a printer, a printing part of a copying machine, and a printing part of a facsimile.

  FIG. 16 is a longitudinal sectional view showing an example of an image forming apparatus using each of the electro-optical devices as a line type optical head. This image forming apparatus is a tandem type full color image forming apparatus using a belt intermediate transfer body system.

  In this image forming apparatus, four organic EL array exposure heads 10K, 10C, 10M, and 10Y having the same configuration have four photosensitive drums (image carriers) 110K, 110C, 110M, and 110Y having the same configuration. The exposure positions are respectively arranged. The organic EL array exposure heads 10K, 10C, 10M, and 10Y are the electro-optical devices described above.

  As shown in FIG. 16, this image forming apparatus is provided with a driving roller 121 and a driven roller 122, and an endless intermediate transfer belt 120 is wound around these rollers 121 and 122, as indicated by arrows. Thus, the periphery of the rollers 121 and 122 is rotated. Although not shown, tension applying means such as a tension roller that applies tension to the intermediate transfer belt 120 may be provided.

  Around the intermediate transfer belt 120, photosensitive drums 110K, 110C, 110M, and 110Y having photosensitive layers on four outer peripheral surfaces are arranged at predetermined intervals. The subscripts K, C, M, and Y mean that they are used to form black, cyan, magenta, and yellow visible images, respectively. The same applies to other members. The photosensitive drums 110K, 110C, 110M, and 110Y are rotationally driven in synchronization with the driving of the intermediate transfer belt 120.

  Around each photosensitive drum 110 (K, C, M, Y), a corona charger 111 (K, C, M, Y), an organic EL array exposure head 10 (K, C, M, Y), and Developers 114 (K, C, M, Y) are disposed. The corona charger 111 (K, C, M, Y) uniformly charges the outer peripheral surface of the corresponding photosensitive drum 110 (K, C, M, Y). The organic EL array exposure head 10 (K, C, M, Y) writes an electrostatic latent image on the charged outer peripheral surface of the photosensitive drum. In each organic EL array exposure head 10 (K, C, M, Y), the arrangement direction of the plurality of OLED elements 14 is aligned with the bus (main scanning direction) of the photosensitive drum 110 (K, C, M, Y). Installed. The electrostatic latent image is written by irradiating the photosensitive drum with light from the plurality of OLED elements 14. The developing device 114 (K, C, M, Y) forms a visible image, that is, a visible image on the photosensitive drum by attaching toner as a developer to the electrostatic latent image.

  The black, cyan, magenta, and yellow developed images formed by the four-color single-color image forming station are sequentially transferred onto the intermediate transfer belt 120 to be superimposed on the intermediate transfer belt 120. As a result, a full-color visible image is obtained. Four primary transfer corotrons (transfer devices) 112 (K, C, M, Y) are arranged inside the intermediate transfer belt 120. The primary transfer corotron 112 (K, C, M, Y) is disposed in the vicinity of the photosensitive drum 110 (K, C, M, Y), and the photosensitive drum 110 (K, C, M, Y). The electrostatic image is electrostatically attracted from the toner image to transfer the visible image to the intermediate transfer belt 120 passing between the photosensitive drum and the primary transfer corotron.

  A sheet 102 as an object on which an image is to be finally formed is fed one by one from the sheet feeding cassette 101 by the pickup roller 103, and between the intermediate transfer belt 120 and the secondary transfer roller 126 in contact with the driving roller 121. Sent to the nip. The full-color visible image on the intermediate transfer belt 120 is secondarily transferred to one side of the sheet 102 by the secondary transfer roller 126 and fixed on the sheet 102 through the fixing roller pair 127 as a fixing unit. . Thereafter, the sheet 102 is discharged onto a paper discharge cassette formed in the upper part of the apparatus by a paper discharge roller pair 128.

  The image forming apparatus shown in FIG. 16 uses the electro-optical devices having an organic EL array as writing means, so that the manufacturing cost of the device can be reduced as compared with the conventional case.

Next, another embodiment of the image forming apparatus according to the present invention will be described.
FIG. 17 is a longitudinal sectional view of another image forming apparatus using the electro-optical devices as line type optical heads. This image forming apparatus is a rotary developing type full-color image forming apparatus using a belt intermediate transfer body system. In the image forming apparatus shown in FIG. 17, a corona charger 168, a rotary developing unit 161, an organic EL array exposure head 167, and an intermediate transfer belt 169 are provided around a photosensitive drum (image carrier) 165. Yes.

  The corona charger 168 uniformly charges the outer peripheral surface of the photosensitive drum 165. The organic EL array exposure head 167 writes an electrostatic latent image on the charged outer peripheral surface of the photosensitive drum 165. The organic EL array exposure head 167 is each of the electro-optical devices described above, and is installed such that the arrangement direction of the plurality of OLED elements 14 is along the bus line (main scanning direction) of the photosensitive drum 165. The electrostatic latent image is written by irradiating the photosensitive drum with light from the plurality of OLED elements 14.

  The developing unit 161 is a drum in which four developing units 163Y, 163C, 163M, and 163K are arranged at an angular interval of 90 °, and can rotate counterclockwise about the shaft 161a. The developing units 163Y, 163C, 163M, and 163K supply yellow, cyan, magenta, and black toners to the photosensitive drum 165, respectively, and attach the toner as a developer to the electrostatic latent image, thereby the photosensitive drum 165. A visible image, that is, a visible image is formed.

  The endless intermediate transfer belt 169 is wound around a driving roller 170a, a driven roller 170b, a primary transfer roller 166, and a tension roller, and is rotated around these rollers in a direction indicated by an arrow. The primary transfer roller 166 transfers the visible image to the intermediate transfer belt 169 that passes between the photosensitive drum and the primary transfer roller 166 by electrostatically attracting the visible image from the photosensitive drum 165.

  Specifically, in the first rotation of the photosensitive drum 165, an electrostatic latent image for a yellow (Y) image is written by the exposure head 167, and a developed image of the same color is formed by the developing unit 163Y. The image is transferred to the transfer belt 169. Further, in the next rotation, an electrostatic latent image for a cyan (C) image is written by the exposure head 167, and a developed image of the same color is formed by the developing device 163C. The intermediate transfer is performed so as to overlap the yellow developed image. Transferred to the belt 169. Then, during the four rotations of the photosensitive drum 9, the yellow, cyan, magenta, and black visible images are sequentially superimposed on the intermediate transfer belt 169. As a result, a full-color visible image is formed on the transfer belt 169. It is formed. When images are finally formed on both sides of a sheet as an object on which an image is to be formed, the same color images of the front and back surfaces are transferred to the intermediate transfer belt 169, and then the front and back surfaces are transferred to the intermediate transfer belt 169. A full-color visible image is obtained on the intermediate transfer belt 169 by transferring the visible image of the next color.

  The image forming apparatus is provided with a sheet conveyance path 174 through which a sheet passes. The sheets are picked up one by one from the paper feed cassette 178 by the pick-up roller 179, advanced through the sheet transport path 174 by the transport roller, and between the intermediate transfer belt 169 and the secondary transfer roller 171 in contact with the drive roller 170a. Pass through the nip. The secondary transfer roller 171 transfers the developed image to one side of the sheet by electrostatically attracting a full-color developed image from the intermediate transfer belt 169 collectively. The secondary transfer roller 171 can be moved closer to and away from the intermediate transfer belt 169 by a clutch (not shown). The secondary transfer roller 171 is brought into contact with the intermediate transfer belt 169 when a full-color visible image is transferred onto the sheet, and is separated from the secondary transfer roller 171 while the visible image is superimposed on the intermediate transfer belt 169.

  The sheet on which the image has been transferred as described above is conveyed to the fixing device 172 and is passed between the heating roller 172a and the pressure roller 172b of the fixing device 172, whereby the visible image on the sheet is fixed. The sheet after the fixing process is drawn into the discharge roller pair 176 and proceeds in the direction of arrow F. In the case of double-sided printing, after most of the sheet passes through the paper discharge roller pair 176, the paper discharge roller pair 176 is rotated in the reverse direction and introduced into the double-sided printing conveyance path 175 as indicated by an arrow G. The Then, the visible image is transferred to the other surface of the sheet by the secondary transfer roller 171, the fixing process is performed again by the fixing device 172, and then the sheet is discharged by the discharge roller pair 176.

  Since the image forming apparatus of FIG. 17 uses the exposure head 167 (each electro-optical device described above) having an organic EL array as writing means, the manufacturing cost of the device can be reduced as compared with the conventional case.

  The image forming apparatus to which each of the electro-optical devices can be applied has been described above. However, the electro-optical device can be applied to other electrophotographic image forming apparatuses. Are within the scope of the present invention. For example, the above electro-optical devices can be applied to an image forming apparatus that directly transfers a visible image from a photosensitive drum to a sheet without using an intermediate transfer belt, and an image forming apparatus that forms a monochrome image. Is possible.

<Image reading device>
Each of the electro-optical devices can be used as a line-type optical head for irradiating light to a reading target in the image reading device. Examples of the image reading apparatus include a scanner, a reading portion of a copying machine, a reading portion of a facsimile, a barcode reader, and a two-dimensional image code reader that reads a two-dimensional image code such as a QR code (registered trademark).

  FIG. 18 is a longitudinal sectional view showing an example of an image reading apparatus using each of the electro-optical devices as a line-type optical head. A flat platen glass 202 is provided on the upper part of the cabinet 201 of the image reading apparatus, and a document 203 is placed on the platen glass 202 with its image surface facing downward. A platen cover (not shown) presses the document 203 toward the platen glass 202.

  Inside the cabinet 201, a high speed carriage 204 and a low speed carriage 205 are arranged so as to be movable in the horizontal direction. An organic EL array exposure head 206 that irradiates the original 203 and a reflecting mirror 207 are mounted on the high-speed carriage 204, and two reflecting mirrors 208 and 209 are mounted on the low-speed carriage 205. These organic EL array exposure head 206 and reflecting mirrors 207, 208, and 209 extend in the direction perpendicular to the paper surface (main scanning direction) in FIG. The organic EL array exposure head 206 is installed so that the arrangement direction of the plurality of OLED elements 14 is along the main scanning direction.

  A document reader 210 is disposed at a fixed position inside the cabinet 201. The document reader 210 includes an imaging lens 212 and a line sensor (light receiving device) 213 composed of a large number of photosensitive pixels (charge coupled devices). The line sensor 213 extends in the direction perpendicular to the paper surface (main scanning direction) in FIG. 18, and is arranged so that the arrangement direction of the plurality of photosensitive pixels is along the main scanning direction.

  Light emitted from the organic EL array exposure head 206 passes through the platen glass 202 and is reflected by the lower surface of the document 203. Reflected light from the original 203 is transmitted through the platen glass 202, reflected by the reflecting mirrors 207 to 209, and then imaged by the line sensor 213 by the imaging lens 212. The high-speed carriage 204 moves in the horizontal direction so that the entire surface of the original 203 is irradiated by the organic EL array exposure head 206, and the low-speed carriage 205 moves at half the speed of the high-speed carriage 204 to The length of the reflected light path reaching 213 is kept constant.

  As described above, each of the electro-optical devices is used as an organic EL array exposure head 206 that is an illumination device of an image reading device. Therefore, the manufacturing cost of the apparatus can be reduced as compared with the conventional case. However, in this type of lighting device, it is preferable that all of the OLED elements 14 in the range corresponding to the width of the document emit light continuously for a long period of time. Therefore, in the drive systems of FIGS. 4 and 5, the pixel blocks B1 to B40 are not time-division driven, but the pixel blocks in the range corresponding to the width of the document are continued for at least the length of the document. Therefore, the selection signal may be given simultaneously. Further, all the data signals D0 to D127 may be turned on simultaneously during that period. Alternatively, the data lines L0 to L127 and the holding transistor 281 that transmit the data signals D0 to D127 may be eliminated.

  The image reading apparatus to which each of the electro-optical devices can be applied has been described above. However, the above-described electro-optical device can be applied to other image reading devices. Is in range. For example, the light receiving device may move together with the electro-optical devices as illumination devices, or the light receiving device and the electro-optical devices may be fixed together so that the document or the reading target is moved and read. .

<Other applications>
The electro-optical device according to the present invention can be further applied to various exposure devices, illumination devices, and image display devices.

1 is a cross-sectional view illustrating an electro-optical device according to a first embodiment of the invention. FIG. 2 is a partial plan view of the electro-optical device illustrated in FIG. 1. It is sectional drawing which shows the detail of the OLED element in the said electro-optical apparatus. It is a block diagram which shows the drive system of the said electro-optical apparatus. FIG. 5 is a circuit diagram of each pixel circuit in the drive system of FIG. 4. FIG. 3 is a diagram illustrating a first step in a procedure for manufacturing the electro-optical device illustrated in FIG. 1. It is a figure which shows the next process of FIG. It is a figure which shows the next process of FIG. It is a figure which shows the next process of FIG. FIG. 6 is a cross-sectional view illustrating an electro-optical device according to a second embodiment of the invention. FIG. 11 is a partial plan view of the electro-optical device illustrated in FIG. 10. It is a figure which shows the first process of the procedure which manufactures the electro-optical apparatus shown in FIG. FIG. 13 is a diagram showing a step subsequent to FIG. 12. It is a figure which shows the next process of FIG. It is a figure which shows the next process of FIG. 1 is a longitudinal sectional view illustrating an example of an image forming apparatus using each electro-optical device according to an embodiment of the invention. FIG. 6 is a longitudinal sectional view illustrating another example of an image forming apparatus using each electro-optical device according to an embodiment of the invention. 1 is a longitudinal sectional view showing an example of an image reading apparatus using each electro-optical device according to an embodiment of the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,50 ... Electro-optical apparatus, 12 ... Board | substrate, 14 ... OLED element (self-light-emitting element), 20A ... Low-potential power line, 20B ... High-potential power line, 20C ... High-potential power line, 24 ... Sealing body, 28 ... Circuit elements, 58 ... Circuit laminate, L0 to L127 ... Data lines, 280 ... Selection circuit, 10K, 10C, 10M, 10Y, 167, 206 ... Organic EL array exposure head (electro-optical device), 110K, 110C, 110M 110Y, 165 ... photosensitive drum (image carrier), 111,168 ... corona charger, 114 ... developer, 112 ... primary transfer corotron (transfer device), 120,169 ... intermediate transfer belt, 161 ... developing unit, 163Y, 163C, 163M, 163K ... developer, 166 ... primary transfer roller (transfer device), 203 ... original, 210 ... original reader, 213 ... line Capacitors (the light-receiving device).

Claims (5)

A substrate,
A plurality of self-luminous elements formed on the substrate;
A sealing body attached to the substrate so as to seal the self-luminous element in cooperation with the substrate larger than the substrate;
A circuit for driving or controlling the self-luminous element provided in the sealing body so as not to overlap the substrate;
An electro-optical device provided with at least one of the circuit and the self-light-emitting element provided on the sealing body so as not to overlap the substrate.   The electro-optical device according to claim 1, wherein the circuit is a laminate formed on the substrate or the sealing body.   The electro-optical device according to claim 1, further comprising a heat dissipation mechanism that releases the heat attached to the sealing body and conducted to the outside air. An image carrier;
A charger for charging the image carrier;
The plurality of self-light-emitting elements are arranged, and a latent image is formed by irradiating light on the charged surface of the image carrier with the plurality of self-light-emitting elements. An electro-optic device;
A developing unit that forms a visible image on the image carrier by attaching toner to the latent image;
An image forming apparatus comprising: a transfer unit that transfers the visible image from the image carrier to another object. The electro-optical device according to any one of claims 1 to 3, wherein a plurality of the light-emitting elements are arranged;
An image reading apparatus comprising: a light receiving device that converts light emitted from the light-emitting element and reflected by a reading target into an electric signal.

Images