JP2006172795A - Electro-optical device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for allowing an appropriate sealing state to be secured. <P>SOLUTION: The electro-optical device includes a first substrate 100, a plurality of light emitting devices (102, 104, 105) formed on the first substrate, a second substrate 120 provided in a manner of covering all the light emitting devices and facing the first substrate and sealing materials 141 provided between the first substrate and the second substrate in a manner of entirely enclosing a predetermined number of the respective light emitting devices, which is smaller than the total number, for restricting a gaseous foreign material from passing through. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electro-optical device including a plurality of pixels each made of a light emitting element such as an organic EL element.

  As an electro-optical device capable of displaying a thin, lightweight and high-quality image, an organic EL (electroluminescence) display device has attracted attention. A general organic EL device has a structure in which an organic EL element responsible for light emission and a drive circuit for driving the organic EL element are formed on a glass substrate. Recently, an organic EL device employing a structure in which a substrate that supports an organic EL element and a substrate that supports a drive circuit and the like are bonded to each other is known.

  Organic EL elements have a property of low resistance to foreign matters such as moisture. Specifically, due to the influence of gaseous foreign substances such as moisture (water vapor) and oxygen, problems such as peeling of the interface between the electrode and the light emitting layer, high resistance due to oxidation of the electrode, or alteration of the light emitting layer itself occur. Cheap. For this reason, techniques for avoiding deterioration of organic EL elements due to moisture or the like have been proposed. For example, in Japanese Patent No. 2800143 (Patent Document 1) and Japanese Patent No. 281499 (Patent Document 2), the entire organic EL element is surrounded by a box-shaped member and the periphery is sealed with a sealing material ( A technique that employs a so-called can sealing structure and suppresses deterioration of an organic EL element is disclosed. JP-A-5-182759 (Patent Document 3) and JP-A-9-274990 (Patent Document 4) disclose a structure in which the entire organic EL element is covered with a sealing material made of moisture-resistant resin or the like ( A technology that employs a so-called surface sealing structure) and suppresses deterioration of an organic EL element is disclosed.

  However, in the can sealing structure described above, if foreign matter has entered from the outside due to molding failure or deterioration of the sealing material, or if foreign matter has originally remained in the sealed space, the foreign matter is sealed. There is an inconvenience that it spreads in the space and causes deterioration over a plurality of organic EL elements.

  On the other hand, the surface sealing structure described above has higher resistance to foreign matter intrusion from the outside than the can sealing structure, but resistance to foreign matter that has remained originally is not so high. In the surface sealing structure, since the sealing material is provided over a wide range, internal stress is generated due to the difference in thermal expansion coefficient between the sealing material and the substrate supporting the organic EL element, the drive circuit, and the like. In some cases, the organic EL element or the like may be damaged.

  Such inconveniences are not limited to the organic EL device, but are common to electro-optical devices using other light emitting elements. For this reason, the technique which avoids each inconvenience of the conventional can sealing structure and surface sealing structure, and obtains a favorable sealing state is desired.

Japanese Patent No. 2800813 Japanese Patent No. 2813499 JP-A-5-182759 JP-A-9-274990

  Therefore, an object of the present invention is to provide a technique that can avoid the disadvantages of the above-described conventional techniques and ensure a good sealing state.

  The first aspect of the present invention includes a first substrate, a plurality of light emitting elements formed on the first substrate, a second substrate disposed to face the first substrate, and the total number A sealing material that is provided between the first substrate and the second substrate so as to surround the whole of each of the smaller number of the light-emitting elements, and suppresses the passage of gaseous foreign substances. An electro-optical device is provided. Here, the “electro-optical device” in this specification refers to a general device including a light-emitting element that emits light by an electrical action, for example, an organic EL or inorganic EL element as a light-emitting element, or generated by application of an electric field. A device including an electron-emitting device that emits light by applying electrons to a light-emitting plate.

  According to such a configuration, a structure in which a predetermined number of light emitting elements are enclosed and sealed by the first substrate, the second substrate, and the sealing material is realized. Thereby, in any case where foreign matter enters from the outside or foreign matter remains inside, the passage of the foreign matter is suppressed for each predetermined unit surrounded by the sealing material, and the organic EL element is spread over a wide range. Can be prevented from deteriorating. Moreover, since the formation area of the sealing material is much smaller than in the case of the surface sealing structure, there is almost no influence of internal stress. Therefore, it becomes possible to ensure a better sealed state than in the past.

  Preferably, the light emitting element is an organic electroluminescence (EL) element.

  Thereby, an organic EL device having high resistance to gaseous foreign matters is obtained.

  When the electro-optical device includes a plurality of basic pixels including a plurality of sub-pixels, the sealing material is preferably provided for each of the light emitting elements corresponding to each of the basic pixels.

  Thereby, since it seals for every basic pixel, the tolerance with respect to a foreign material can be raised more. Further, even if the light emitting element in a certain basic pixel is deteriorated, the influence is not easily spread to the light emitting elements in other adjacent pixels, and there is an advantage that the deterioration can be minimized.

  The sealing material is preferably provided for each of the light emitting elements.

  Thereby, since it seals for every light emitting element, the tolerance with respect to a foreign material can be improved more. In addition, even when a certain light emitting element is deteriorated, there is an advantage that the influence is difficult to spread to other adjacent light emitting elements.

  It is also preferable to further include an adsorbent provided in each space surrounded by the first substrate, the sealing material, and the second substrate and adsorbing the gaseous foreign matter.

  As a result, foreign matter that has entered through the sealing material from the outside or foreign matter that has remained in the space sealed by the sealing material is taken into the adsorbent material, thus ensuring a better sealing state. Is possible.

  Preferably, the adsorbent is provided on the second substrate without being in contact with the light emitting element.

  By preventing the adsorbent from coming into contact with the light emitting element, it is possible to prevent the components contained in the adsorbent from having any adverse effect on the light emitting element.

  Preferably, it further includes a spacer having a predetermined diameter and arranged in the sealing material.

  As a result, the sealing material can be provided with a space corresponding to the spacer diameter at a minimum, so that the sealing material is prevented from becoming extremely thin depending on the location, and the necessary and sufficient barrier properties are ensured. It becomes possible to do.

  The second aspect of the present invention is an electronic apparatus including the above-described electro-optical device. Here, the “electronic device” means a general device including an electric circuit, a display unit, and the like, and the configuration thereof is not particularly limited. Such electronic devices include, for example, an IC card, a mobile phone, a video camera, a personal computer, a head mounted display, a rear or front projector, a television (TV), a roll-up TV, a facsimile, a digital camera, a PDA, Electronic notebooks are included.

  Hereinafter, embodiments of an electro-optical device to which the present invention is applied will be described in detail. In the following description, an organic EL device having a so-called top emission structure is taken as an example of an electro-optical device.

  FIG. 1 is a plan view schematically showing the configuration of each pixel of the organic EL device of the present embodiment. As shown in FIG. 1, the organic EL device 1 according to this embodiment is configured by arranging a plurality of basic pixels 2 including three color pixels (sub-pixels) of R, G, and B in a matrix. ing. Each color pixel includes one light emitting element. In FIG. 1, for convenience of explanation, the structure is simplified and only 12 basic pixels 2 are shown. In the organic EL device 1 of the present embodiment, every predetermined number of organic EL elements (light emitting elements) smaller than the total number, more specifically, every three organic EL elements corresponding to each basic pixel 2 are surrounded by the whole. A sealing material 141 is provided. Here, the sealing material 141 has a property of suppressing the passage of gaseous foreign matters such as water vapor and oxygen.

  FIG. 2 is a schematic cross-sectional view of the organic EL device 1 in the II-II line direction shown in FIG. As shown in FIG. 2, the organic EL device 1 according to the present embodiment includes a light emitting element substrate (first substrate) 100 including an organic EL element, a circuit substrate (second substrate) including a drive circuit for driving the organic EL element, and the like. Substrate) 120 is disposed opposite to each other, and the two are electrically connected by a conductive paste material 140. The organic EL device 1 of this example employs a top emission structure in which light emitted from the light emitting layer is emitted to the outside through the light emitting element substrate 100.

  The light emitting element substrate 100 includes a base material 101, a transparent electrode (anode) 102, a bank (partition wall) 103, a light emitting layer 104, an electrode (cathode) 105, and a separator 106.

  The base material 101 is made of a material such as glass or plastic and has translucency.

  The anode 102 is made of a material such as ITO (Indium-Tin-Oxide) and is formed on the substrate 101.

  The bank 103 is formed on the transparent electrode 102 using an insulator such as acrylic resin, and has an opening at a predetermined position.

  The light emitting layer 104 is formed in the opening of the bank 103, and emits light by supplying a current through the anode 102 and the cathode 105. The light emitting layer 104 is formed using, for example, a polydialkylfluorene derivative. Further, a hole transport layer or an electron transport layer may be interposed between the light emitting layer 104 and each electrode (anode, cathode). The hole transport layer is formed using, for example, a mixture of polyethylene dioxythiophene and polystyrene sulfonic acid (PEDOT / PSS). The electron transport layer is formed using, for example, a film of calcium, lithium, oxides thereof, fluorides, and the like.

  The cathode 105 is made of a conductive member such as aluminum and is formed on the upper surface of the light emitting layer 104.

  The separator 106 is for defining the cathode 105 for each range corresponding to each light emitting layer 104, and is formed using an insulator such as polyimide.

  The organic EL element is configured to include the anode 102, the light emitting layer 104, and the cathode 105 described above, and when the current is supplied to the light emitting layer 104 through the anode 102 and the cathode 105, the light emitting layer 104 emits light. Is released to the outside through the anode 102 and the substrate 101.

  The circuit board 120 includes a base 121, an insulating layer 122, a circuit chip 123, and wiring 124.

  The base 121 is made of a material such as glass or plastic. Since the organic EL device 1 of the present embodiment employs a top emission type structure, the base material 121 may not have translucency.

  The insulating layer 122 is made of an insulating material such as silicon oxide and is formed on the base material 121. The insulating layer 122 has a function of insulating the wirings 124 from each other.

  The circuit chip 123 is formed at a predetermined position on the insulating layer 122 and drives each organic EL element on the light emitting element substrate 100 side. The circuit chip 123 includes a thin film transistor and other circuit elements used for driving the organic EL element.

  The wiring 124 is formed inside the insulating layer 122 and a part thereof is exposed on the surface. The wiring 124 has a function of electrically connecting the circuit chip 123 and the organic EL element to each other, and various types of externally supplied power. It has a function of transmitting signals to the circuit chip 123.

  The conductive paste material 140 is provided so as to be in contact with both the cathode 105 on the light emitting element substrate 100 side and the wiring 124 on the circuit board 120 side, and has a function of electrically connecting the organic EL element and the circuit chip 123. Bear. As the conductive paste material 140, for example, a silver paste material or the like is preferably used.

  The sealing material 141 is provided between the light emitting element substrate 100 and the circuit board 120 so as to surround the entire three organic EL elements corresponding to one pixel. As described above, the sealing material 141 has a function of suppressing the passage of gaseous foreign matters such as water vapor and oxygen. For example, an acrylic or epoxy resin seal material is preferably used. Such a sealing material 141 can be formed by a technique such as a screen printing method or a dispensing method.

  Note that it is also preferable to mix a spacer having a predetermined diameter in the sealing material 141. As a result, the sealing material 141 can be provided with at least an interval corresponding to the spacer diameter, so that the sealing material 141 can be prevented from becoming extremely thin depending on the location, and a necessary and sufficient barrier property can be ensured. Can be secured.

  The adsorbent 142 is provided in a space surrounded by the light emitting element substrate 100, the sealing material 141, and the circuit substrate 120 (in the pixel region in this example). The position where the adsorbent 142 is provided may be anywhere in the above space in principle. In this example, as shown in the figure, the adsorbent 142 is provided by using an excess space that is located above the circuit board 120 and near the circuit chip 123. The adsorbent 142 has a property of adsorbing gaseous foreign matters such as oxygen and water vapor. As the adsorbent 142, for example, ascorbic acid, Fe, Ti, or an oxygen absorbent composed of a salt or oxide containing these low-valent metal ions, or a hygroscopic agent such as silica gel, diatomaceous earth, or activated alumina is used as a resin. What was mixed can be used. Such an adsorbent 142 can be formed by a method such as a screen printing method or a dispensing method.

  The sealing material 143 is provided on the outer edge of the light emitting element substrate 100 and the circuit substrate 120 and seals the entire organic EL device 1. As the sealing material 143, for example, an acrylic or epoxy resin sealing material is preferably used. Such a sealing material 143 can be formed by a method such as a screen printing method or a dispensing method.

  FIG. 3 is a schematic cross-sectional view illustrating another configuration example of the organic EL device. The structure of each pixel of the organic EL device of this example is the same as that shown in FIG. 1 described above, and FIG. 3 shows a cross section taken along the line II-II in FIG.

  3 includes a base material (first substrate) 201, a transparent electrode (anode) 202, a bank (partition wall) 203, a light emitting layer 204, an electrode (cathode) 205, a hole transport layer 207, a base A material (second substrate) 221, an insulating layer 222, a drive circuit portion 223, a sealing material 241, an adsorbing material 242, and a sealing material 243 are included. Among these elements, elements having the same names as those in the organic EL device 1 shown in FIG. 2 described above perform the same functions, and detailed description thereof is omitted here. The organic EL device 1 a of this example employs a top emission structure in which light emitted from the light emitting layer 204 is emitted to the outside through the base material 221. The drive circuit unit 223 performs the same function as the circuit chip 123 described above. Although not shown, wiring for transmitting various signals to the drive circuit portion 223 is also formed in the insulating layer 222.

  As shown in FIG. 3, in the organic EL device 1a of this example, components such as a light emitting element and a drive circuit are stacked on one substrate (base material 201), and then the upper surface side is placed on another substrate (base material 221). ). Also in the organic EL device 1a of this example, a sealing material 241 is provided around each light emitting element corresponding to each basic pixel, as in the organic EL device 1 shown in FIG. Further, the adsorbent 242 is provided on the surface of the base material 221 so as to be separated for each space defined by the sealing material 241. Such an adsorbent 242 can be formed by, for example, a screen printing method.

  As described above, according to the present embodiment, a structure in which each of the three organic EL elements corresponding to one pixel is enclosed and sealed by the light emitting element substrate 100, the circuit board 120, and the sealing material 141 is realized. Thereby, in any case where foreign matter enters from the outside or foreign matter remains inside, the passage of the foreign matter is suppressed for each predetermined unit surrounded by the sealing material, and the organic EL element is spread over a wide range. Can be prevented from deteriorating. Moreover, since the formation area of the sealing material is much smaller than in the case of the surface sealing structure, there is almost no influence of internal stress. Therefore, it becomes possible to ensure a better sealed state than in the past.

  In addition, according to the present embodiment, the end portions of the organic EL device 1 (or 1a) are provided by providing the sealing material 141 in a lattice shape over the entirety of the light emitting element substrate 100 and the circuit substrate 120. In addition, the effect of reducing the gap difference and strength difference between the two substrates in the central portion can also be obtained.

  Moreover, according to this embodiment, since it is not necessary to use an expensive digging glass substrate (glass substrate digging the center) unlike the conventional can sealing structure, it is possible to reduce the cost.

  Moreover, according to this embodiment, since it is not necessary to use a lot of sealing materials like the conventional surface sealing structure, cost reduction is attained.

  Next, electronic devices to which the above-described organic EL device can be applied will be exemplified.

  FIG. 4 is a diagram illustrating an example of an electronic apparatus to which the above-described organic EL device (electro-optical device) can be applied. FIG. 4A shows an application example to a mobile phone. The mobile phone 530 includes an antenna portion 531, an audio output portion 532, an audio input portion 533, an operation portion 534, and a display portion 535, and the display portion 553. Is configured using the organic EL device 1 (or 1a) described above. FIG. 4B shows an application example to a video camera. The video camera 540 includes an image receiving unit 541, an operation unit 542, an audio input unit 543, and a display unit 544. The display unit 544 includes the organic EL described above. It is comprised using the apparatus 1 (or 1a). FIG. 4C shows an application example to a television, and the television 550 is configured such that the display portion 551 uses the organic EL device 1 (or 1a) described above. FIG. 4D shows an application example to a roll-up television, and the roll-up television 560 includes the display portion 561 using the organic EL device 1 (or 1a) described above. The organic EL device according to the present embodiment is not limited to the above-described example, and can be applied to various electronic devices having a display function. For example, in addition to these, it can also be used for a fax machine with a display function, a finder for a digital camera, a portable TV, an electronic notebook, an electric bulletin board, a display for advertisements, and the like.

  In the above-described embodiment, the case where the present invention is applied to the organic EL device as a device for performing image display has been described. However, the present invention has various application ranges other than this. For example, the present invention can be applied to configure an exposure head used in an image forming apparatus (electrophotographic apparatus) such as a printer. That is, an exposure head as an electro-optical device according to the present invention includes a light emitting element that irradiates light to a photoconductor and a drive circuit that individually drives each light emitting element. In a more desirable mode, a configuration is adopted in which line exposure is possible in accordance with the width of various recording materials such as A4 size and A3 size. Hereinafter, a configuration example in this case will be described.

  FIG. 5 is a schematic block diagram showing an optical engine part of an electrophotographic apparatus including an exposure head to which the present invention is applied. An electrophotographic apparatus 600 shown in FIG. 5 includes an image data output device 601, an exposure head (line head) 602, a focusing rod lens 603, a photosensitive drum 604, a charger 605, a developing device 606, and a transfer device 607. Has been. Printing in the electrophotographic apparatus 600 is performed as follows. First, the surface of the photoreceptor formed on the photoreceptor drum 604 (or belt) is uniformly charged by the charger 605. The exposure head 602 is used to irradiate the charged photosensitive drum 604 with light according to the content of the image data output from the image data output device 601. As a result, the light-irradiated portion is neutralized, and a latent image due to electrostatic charges is written on the photosensitive drum 604. Next, electrostatically charged toner (colored fine particles) is sprayed on the photosensitive drum 604 by the developing device 606, so that a latent image due to the electrostatic charge becomes visible as an image due to the toner. Next, the sheet 608 is pressed onto the photosensitive drum 604 and, for example, an electric field is applied to transfer the toner to the sheet 608. Next, the toner is fused to the paper 608 by means such as applying heat by the transfer unit 607. The charge is erased from the surface of the photosensitive drum 604 after the transfer by applying, for example, an alternating electric field or entire surface light irradiation. Thereafter, the toner remaining after the transfer is removed.

  The present invention is not limited to the contents of the above-described embodiments, and various modifications can be made within the scope of the gist of the present invention.

  For example, in the above-described embodiment, the sealing material 141 is provided so as to surround the whole of the three organic EL elements corresponding to one pixel, but is adjacent to the organic EL device 1b shown in FIG. The sealing material 141 may be provided for each of a number of organic EL elements corresponding to a plurality of pixels (two pixels in the illustrated example), and each color pixel 2a as in the organic EL device 1c shown in FIG. The sealing material 141 may be provided for each individual organic EL element corresponding to 2b and 2c.

  In the above-described embodiment, the configuration in the case where the present invention is applied to a so-called top emission type organic EL device has been exemplified. However, the present invention is similarly applied to a so-called bottom emission type organic EL device. The invention can be applied. Further, the organic EL device 1a illustrated in FIG. 3 has a structure in which the organic EL elements are separated from each other by partition walls. However, the organic EL device 1a has a structure having no such partition walls. Similarly, the present invention can be applied.

  In the above description, an organic EL element is taken as an example of the light emitting element, but various other light emitting elements (for example, an inorganic EL element and an electron emitting element) can be employed. is there.

It is a top view which shows roughly about the structure of each pixel of the organic electroluminescent apparatus of one Embodiment. It is a schematic cross section of the organic EL device in the II-II line direction shown in FIG. It is a schematic cross section explaining the other structural example of an organic EL apparatus. It is a figure which shows the example of the electronic device which can apply an organic EL apparatus. It is a schematic block diagram which shows the optical engine part of the electrophotographic apparatus comprised including the exposure head to which this invention is applied. It is a figure explaining the other structural example of a sealing material. It is a figure explaining the other structural example of a sealing material.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Organic EL apparatus, 100 ... Light emitting element substrate, 101 ... Base material, 102 ... Transparent electrode (anode) 102, 103 ... Bank, 104 ... Light emitting layer, 105 ... Electrode (cathode) 105, 106 ... Separator 106, 120 ... Circuit board, 121 ... base material, 122 ... insulating layer, 123 ... circuit chip, 124 ... wiring, 140 ... conductive paste material, 141 ... sealing material, 142 ... adsorbing material

Claims (8)

A first substrate;
A plurality of light emitting elements formed on the first substrate;
A second substrate disposed opposite the first substrate;
A sealing material that is provided between the first substrate and the second substrate so as to surround the entire number of the light emitting elements less than the total number, and suppresses the passage of gaseous foreign substances,
An electro-optical device comprising:   The electro-optical device according to claim 1, wherein the light emitting element is an organic electroluminescence element. The electro-optical device includes a plurality of basic pixels including a plurality of sub-pixels.
The electro-optical device according to claim 1, wherein the sealing material is provided for each of the light emitting elements corresponding to each of the basic pixels.   The electro-optical device according to claim 1, wherein the sealing material is provided for each of the light emitting elements.   2. The electro-optical device according to claim 1, further comprising an adsorbent provided in each of the spaces surrounded by the first substrate, the sealing material, and the second substrate and adsorbing the gaseous foreign matter.   The electro-optical device according to claim 5, wherein the adsorbent is provided on the second substrate without being in contact with the light emitting element.   The electro-optical device according to claim 1, further comprising a spacer having a predetermined diameter and arranged in the sealing material. An electronic apparatus comprising the electro-optical device according to claim 1.

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