JP5029132B2 - Electro-optical device and electronic apparatus - Google Patents

Description

  The present invention relates to an electro-optical device such as a liquid crystal display device and an organic EL display device, and more particularly to an electro-optical device having a structure that increases the manufacturing accuracy of the device in the manufacturing process of the electro-optical device.

An active matrix driving method is one of driving methods for an electro-optical device including a liquid crystal element, an organic EL element, an electrophoretic element, an electron emitting element, and the like. In an active matrix drive type electro-optical device, a plurality of pixels are arranged in a matrix on the display panel.
Each of the plurality of pixels includes a pixel circuit including an electro-optical element and a driving transistor that supplies driving power to the electro-optical element. In addition, each of the plurality of pixel circuits is disposed corresponding to the intersection of the data line and the scanning line (see, for example, Patent Document 1).

WO98 / 36407

However, when an electro-optical device is mounted on a base and used as various electronic devices such as a mobile phone and a personal computer, the display on the display portion may be unclear depending on the color of the base around the display portion of the electro-optical device. May be.
In addition, when forming a functional film that exhibits an electro-optic function in an effective display area of an electro-optic device, a liquid phase process such as an ink jet method (droplet discharge method) or a gas phase process such as an evaporation method is used When forming a functional film, the uniformity of the film may decrease due to the influence of the local environment or atmosphere. As a result, problems such as display unevenness may occur.

  Accordingly, one object of the present invention is to provide an electro-optical device for solving the above-described problems.

  In order to achieve the above object, a first electro-optical device according to the present invention is an electro-optical device that displays information by individually driving a plurality of pixels arrayed two-dimensionally, and is arranged in the two-dimensional array. Among the plurality of pixels, a pixel group in the effective display area that displays the information, a pseudo pixel group that is adjacent to the effective display area and does not contribute to the display of the information, and a pixel group in the effective display area And a bank film that separates each pixel of the pseudo pixel group and prevents light leakage between adjacent pixels in the effective display area.

  A second electro-optical device of the present invention is an electro-optical device including a plurality of pixels, and the plurality of pixels includes a pixel group in an effective display area in which luminance is set according to a data signal, and The data signal includes a pseudo-pixel group that does not depend on luminance.

  With the configuration of the electro-optical device described above, when film formation is performed using the inkjet method, the ejection amount of the ink is stabilized in the pseudo pixel region, and then the ejection of the film material in the display region is started. As a result, the pixel group in the effective display area can be formed with a constant film thickness.

Even in the case of forming a film using the vapor deposition method, the atmosphere or existence density of the vaporized material may be locally different, which may cause the film thickness of the layers constituting the pixels in the effective display area to be constant. is there. On the other hand, by providing a pseudo pixel group or a dummy pixel area, a functional layer constituting a pixel is formed in an effective display area using a portion where the atmosphere and existence density of the vaporized material are uniform. be able to.
Further, the pseudo pixel group or the dummy pixel region can be used for various purposes. For example, various driving circuits such as a scanning line driving circuit and a data line driving circuit may be provided in the dummy pixel region. With such a configuration, a limited space can be used.

  Preferably, the pseudo pixel group is disposed on at least one side of the pixel group in the effective display area.

  Preferably, the pseudo pixel group is arranged across the pixel group in the effective display area.

More preferably, the pseudo pixel group is arranged around the pixel group in the effective display area.
By setting it as the above structures, the uniformity of the film thickness of the functional layer which comprises the pixel in an effective display area can be improved using a vapor deposition method or the inkjet method.
In addition, when an electronic apparatus is manufactured by mounting the above-described electro-optical device on a base, a dummy pixel area or a pseudo pixel group that does not depend on an image displayed in the effective display area of the electro-optical device in the electronic apparatus may be provided. Therefore, the boundary between the base and the display image becomes clear by providing a region exhibiting an appropriately selected color in the dummy pixel area.

  In the electro-optical device, it is preferable that the bank film has substantially the same shape of each pixel of the pixel group in the effective display area and the pseudo pixel group. With this configuration, the pixels in the effective display area and the pixels included in the dummy pixel area or the pseudo pixel group can be set to substantially the same conditions (for example, film thickness). Instead of directly inspecting the pixels in the region, the pixels in the dummy pixel area or the pseudo pixel group can be inspected.

  In the electro-optical device, each pixel of the effective display pixel group may include a functional layer in which at least one of its constituent elements is formed by an inkjet method.

  The component formed by the inkjet method is, for example, an organic EL film. In addition, for example, a carrier injection layer or a carrier transport layer such as a hole injection layer, a hole transport layer, an electron injection layer, or an electron transport layer may be formed by an inkjet method.

  The organic EL film can be formed using, for example, a polymer containing a fluorene derivative or a phenylene vinylene-based polymer material.

In the electro-optical device, it is preferable that a lyophilic control film having an affinity for the liquid material used in the inkjet method is formed in contact with the functional layer.
When the electro-optical device includes a bank film that separates the pixels, the lyophilic film is preferably formed below the bank film. By making the affinity of the bank film to the liquid material lower than that of the lyophilic film, electrical contamination between pixels is suppressed, and electrical separation between pixels is achieved.
As the material for the bank film and the affinity film, for example, a polyimide whose surface is fluorine-coated and a silicon oxide film whose surface is hydrophilically treated by plasma treatment or the like are used.

  In the electro-optical device, the film thickness of the functional layer constituting the pixel in the pseudo pixel group or the dummy pixel area is inspected, and the quality of the pixels arranged in the effective display area is determined using the inspection result as an index. May be.

  In the electro-optical device, the inspection method may be performed by photoluminescence detection that detects light emitted by irradiating the pseudo pixel with inspection light. Since such an inspection is simple, many electro-optical devices can be inspected in a short time.

  In the electro-optical device, it is preferable that a circuit arrangement region in which a circuit is arranged is provided below the region in which the pseudo pixel group is provided. With such a configuration, a limited space can be used effectively.

  Examples of the circuit provided in the circuit arrangement area include a scanning line driving circuit, a data line driving circuit, a data processing circuit, and an arithmetic circuit.

  The above-described electro-optical device can be used as a display panel of an electronic device such as a computer device, a portable telephone device, a digital camera, an electronic book device, or a portable information processing device.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an explanatory view schematically showing a first embodiment of the present invention. In the present invention, a pseudo pixel region 3 in which pseudo pixels 30 that do not contribute to image display are arranged around the effective display pixel region 2 in which pixels actually used for image display of the display device 1 are arranged. The effective display pixel region 2 is a two-dimensional array of pixels 20 that change optical parameters such as light intensity and transmittance in accordance with electrical signals that carry image information. Each pixel 20 is configured by, for example, an organic EL light emitting element. Each layer of the organic EL light emitting element can be formed by applying a material by an ink jet method.

  In the first embodiment, the pseudo pixels 30 are two-dimensionally arranged on the left and right sides and the upper and lower sides of the effective display screen area 2 with the same pixel shape and arrangement interval as the effective display pixels 20. An inkjet head (not shown) scans the display device 1 in the left-right direction 4 or in the up-down direction 5 to discharge the film forming material. At this time, the inkjet head starts ejection from the pseudo pixel area 3 and forms the effective display pixel area 2 in a state where ejection is stable. In other words, idle ejection that does not contribute to the formation of effective pixels is performed in the pseudo pixel region 3 at the beginning of ink (film formation material) ejection to stabilize the ink ejection amount. In order to prevent evenness, the blanking is further performed in the pseudo pixel region 3. Since the pseudo pixel region 3 of this embodiment is not used for pixel display, it is not necessary to supply a drive signal to the electrode of the pixel. Further, in the embodiments described later, the wiring connection between the driving circuit and the pixel is not performed. However, the shape of the pseudo pixel is formed in the same shape as that of the effective pixel in order to be stabilized at the same discharge amount as the pixel in the effective display pixel area, to synchronize with the discharge timing, etc. The same arrangement is the same arrangement interval.

  FIG. 2 is a partial enlarged view showing an example in which the portion A at the boundary between the effective display pixel region 2 and the pseudo pixel region 3 of the display device 1 is enlarged.

  The effective pixels 20 in the effective display pixel region 2 and the pseudo pixels 30 in the pseudo pixel region 3 are oval or rectangular with four corners rounded. As described above, the effective pixel 20 is connected to a transistor (TFT) and wiring for driving the effective pixel 20, but is not connected to the pseudo pixel 30.

FIG. 3 schematically shows a cross section of the effective pixel 20 and the pseudo pixel 30 in the XY direction shown in FIG. As shown in the figure, a base protective film made of silicon oxide (SiO ₂ ), silicon nitride (SiN x) or the like for preventing alkali ions from entering from a substrate 51 on a transparent substrate 51 such as glass or resin. 52 is formed. Silicon (Si) is deposited on the protective film 52 by a CVD method to form a semiconductor film 53. The semiconductor film 53 is subjected to laser annealing and crystallized to form a polysilicon film. The semiconductor film 53 is patterned to form a TFT region.

Next, silicon oxide is deposited on the semiconductor film 53 and the base protective film 52 by a CVD method using TEOS and oxygen as film materials to form a gate insulating film 54. Next, a metal such as aluminum is deposited as a gate metal, and the gate metal is patterned to form a gate electrode and a wiring 55. On top of this, silicon oxide is deposited by CVD to form an interlayer insulating film 56. Contact holes are opened in the interlayer insulating film 56 in the source / drain regions of the TFT region, a metal such as aluminum is deposited, and this is patterned to form source / drain electrodes and a wiring film 57.
Next, silicon oxide is deposited by CVD to form an interlayer insulating film 58. A contact hole is opened in the interlayer insulating film 58, and a transparent ITO film (Indium Tin Oxide) 59 is deposited. The wiring film 57 and the ITO film 59 are connected. The ITO film 59 is patterned to obtain a pixel electrode film (anode) 59. On top of this, in order to improve the adhesion of the ink (film material) discharged by the ink jet method to the substrate, silicon oxide is deposited by the CVD method to form the lyophilic control film 60. The lyophilic control film 60 is patterned to open each effective pixel portion, and the transparent electrode ITO film 59 is exposed.

  Next, silicon oxide is deposited by a CVD method, and this is patterned to open each region of the effective pixel 20 and each region of the pseudo pixel 30, thereby forming a bank film 61 that prevents light leakage and color mixing between the pixels. Form.

  An organic EL light emitting element is formed in the groove portion opened in the bank film 61 by an ink jet method. That is, an ink jet head (not shown) is relatively moved to scan each opening of the bank film 61, and a film forming material is discharged from the nozzle at a position facing each opening. By starting ejection from the area of the pseudo pixel 30, a certain amount of film forming material is ejected into each opening of the bank film 61 in the area 2 of the effective pixel 20. Further, by discharging the film forming material outside the area of the effective pixel 20, it is possible to supply a certain amount of film forming material to the last effective pixel 20.

  First, the hole transport layer 62 is formed on the ITO film 59 exposed at the bottom of the opening groove of the bank film 61 by an inkjet method. Since the opening end portion 60a of the lyophilic control film 60 is exposed from the opening end portion 61a of the bank film 61 to the bottom of the groove, the liquid film material discharged from the ink jet head is connected to the lyophilic control film opening edge 60a. Familiarity, it becomes easy to spread uniformly at the bottom of the oval opening groove. An organic EL film 63 is formed on the hole transport layer 62 formed on the ITO film 59 by an inkjet method. Although not shown, an electron transport layer may be further formed on the organic EL film 63. Further, the cathode film 64 is formed as a common electrode on the organic EL film 63, and the display device 1 using the organic EL light emitting element as a unit pixel is obtained. Note that a driver circuit having a normal configuration can be used.

  In the first embodiment, the conductive ITO film 59 is not formed on the pseudo pixel 30 side. In this case, there is an advantage that the withstand voltage of the device (pixel) is increased and the yield is improved.

  Since the region of the pseudo pixel 30 is not used as an actual pixel, at least a part of the pixel circuit that drives the effective pixel 20 between the dummy pixel area and the substrate 51 and at least one of the scanning line driving circuit. , A part of the data line driving circuit, and the like can be arranged.

  FIG. 4 shows a second embodiment. In the figure, parts corresponding to those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

  In this example, the ITO film 59 and the lyophilic control film 60 are also formed in the region 3 of the pseudo pixel 30. As a result, similar to the film formation of each layer of the organic EL element in the effective pixel 20, the film formation similar to that of each layer of the organic EL element is performed also in the pseudo pixel 30. However, the wiring to the pseudo pixel is cut off and is not used for displaying image information. It is possible to inspect the uniformity of film formation by irradiating the light emitting film of the pseudo pixel 30 with test light and detecting reaction light emission.

  It is also possible to provide a film formation test wiring separately for some of the pseudo pixels 30 and use it for automation of the quality evaluation of the display device.

  FIG. 5 shows a third embodiment. In the figure, parts corresponding to those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

  In this example, the lyophilic control film 60 is not provided. The pseudo pixel 30 is also provided with an ITO film 59. The ITO film 59 of the pseudo pixel 30 is insulated from the surroundings. Even in such a configuration, the light emitting element of the effective pixel 20 and the light emitting element of the pseudo pixel 30 have the same conditions. Therefore, the uniformity of the film formation can be obtained by inspecting the film of the light emitting element formed in the pseudo pixel 30 portion. Can be discriminated.

  FIG. 6 shows a fourth embodiment. In this example, the region 3 of the pseudo pixel 30 is formed on the left side and the right side of the effective display pixel region 2. In the case where the film forming material is applied to the substrate by moving the inkjet head (not shown) relatively back and forth in the left-right direction, such a pseudo pixel arrangement may be used.

  FIG. 7 shows a fifth embodiment. In this example, the region 3 of the pseudo pixel 30 is formed above and below the effective display pixel region 2. In the case where the film forming material is applied to the substrate by reciprocating the inkjet head in the up and down direction, such a pseudo pixel arrangement may be used.

  An example of an electronic apparatus provided with the display device of the present invention will be described below, but is not limited to the example.

<Mobile computer>
First, an example in which the display device according to the above-described embodiment is applied to a mobile personal computer (information processing device) will be described. FIG. 8 is a perspective view showing the configuration of this personal computer. In the figure, a personal computer 1100 includes a main body 1104 provided with a keyboard 1102 and a display device unit provided with the display device 1106 described above (corresponding to the display device 1 in FIG. Yes.

<mobile phone>
Next, an example in which the display device according to the above-described embodiment is applied to a display unit of a mobile phone will be described. FIG. 9 is a perspective view showing the configuration of this mobile phone. In the figure, a cellular phone 1200 is provided with the display device 1208 described above together with a mouthpiece 1024 and a mouthpiece 1206 in addition to a plurality of operation buttons 1202.

<Digital still camera>
A digital still camera using the display device according to the above-described embodiment as a finder will be described. FIG. 10 is a perspective view showing the configuration of this digital still camera, but it also shows a simple connection with an external device.

  A normal camera sensitizes a film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an image sensor such as a CCD (Charge Coupled Device) to generate an image signal. The display device 1304 described above is provided on the back surface of the case 1302 of the digital still camera 1300, and is configured to perform display based on an imaging signal from the CCD. Therefore, the display device 1304 functions as a finder that displays the subject. A light receiving unit including an optical lens, a CCD, and the like is provided on the observation side (the back side in the drawing) of the case 1302.

  When the photographer confirms an image of the subject displayed on the display device 1304 and presses the shutter button 1308, the CCD image pickup signal at that time is transferred and stored in the memory of the circuit board 1310. The digital still camera 1300 includes a video signal output terminal 1312 and an input / output terminal 1314 for data communication on the side surface of the case 1302. As shown in the figure, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1430 is connected to the input / output terminal 1314 for data communication as necessary. By this operation, the image pickup signal stored in the memory of the circuit board 1308 is output to the television monitor 1330 or the computer 1340.

<E-book>
FIG. 11 is a perspective view showing a configuration of an electronic book as an example of the electronic apparatus of the invention. In the figure, reference numeral 1400 denotes an electronic book. The electronic book 1400 includes a book-type frame 1402 and a cover 1403 that can be opened and closed on the frame 1402. The frame 1402 is provided with a display device 1404 with the display surface exposed on the surface thereof, and further provided with an operation unit 1405. The frame 1402 includes a controller, a counter, a memory, and the like. In this embodiment, the display device 1404 includes a pixel portion formed by filling a thin film element with electronic ink, and a peripheral circuit that is integrated with and integrated with the pixel portion. The peripheral circuit includes a decoder type scan driver and a data driver.

In addition to the personal computer shown in FIG. 8, the digital still camera shown in FIG. 10, and the electronic book shown in FIG. 11, the electronic equipment includes electronic paper, a liquid crystal television, a viewfinder type, a monitor direct view type video tape recorder, a car Examples include navigation devices, pagers, electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, and devices equipped with touch panels. And the display apparatus mentioned above is applicable to the display part of these various electronic devices.
By the way, when the electro-optical device of the present invention is mounted on the electronic apparatus as described above, the visibility of the image displayed on the display unit may be reduced due to the balance with the color of the substrate. For example, if the base color is white, silver, or reflective or glossy, and if a similar color such as white or silver is displayed at the boundary of the base of the display unit, the boundary between the display unit and the base is unclear. May be. If there is such a concern, the dummy pixel area is displayed on the display unit regardless of the display color of the display unit by providing a colored region that is different from the base color or has a sufficient contrast. The visibility of the image can be improved.
In the case of a so-called back emission type in which light emitted from the organic EL film 63 is extracted from the substrate 51 side, a coloring material may be attached to the back surface of the substrate 51.
In the case of a so-called top emission type in which light emitted from the organic EL film 63 is extracted from a common electrode (the cathode 64 corresponds to the common electrode in the above embodiment), a colored region may be provided on the common electrode. However, a colored region may be provided instead of the cathode 64.
Further, a configuration may be adopted in which power is supplied to the pixels in the dummy pixel area via the pixel electrode, and a light emitting region that emits a color different from the color of the substrate is provided.

  As described above, in the display device of the present invention, a pseudo pixel is arranged in an area adjacent to the effective display pixel area, and discharge of a film forming material can be started and stopped by an inkjet method in the area including the pseudo pixel. Therefore, it is easy to make the film formation uniform in the effective display area.

FIG. 1 is an explanatory diagram for explaining the outline of the present invention. FIG. 2 is a partially enlarged view showing an A portion shown in FIG. FIG. 3 is a cross-sectional view illustrating a configuration example of the pixel 20 and the pseudo pixel 30 in the effective display area. FIG. 4 is an explanatory diagram for explaining another configuration example of the pseudo pixel 30. FIG. 5 is a cross-sectional view illustrating another configuration example of the pseudo pixel 30. FIG. 6 is an explanatory diagram for explaining another embodiment of the present invention. FIG. 7 is an explanatory diagram for explaining another embodiment of the present invention. FIG. 8 is an explanatory diagram illustrating an example of a portable personal computer using the electro-optical device (display device) according to the present invention. FIG. 9 is an explanatory view illustrating an example of a mobile phone using the electro-optical device according to the invention. FIG. 10 is an explanatory diagram for explaining an example of a digital camera using the electro-optical device according to the invention. FIG. 11 is an explanatory diagram for explaining an example of an electronic book using the electro-optical device according to the invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Display apparatus (electro-optical apparatus), 2 ... Effective pixel area | region, 3 ... Pseudo pixel area | region, 20 ... Effective pixel, 30 ... Pseudo pixel, 60 ... Lipophilic control film | membrane

Claims (6)

An electro-optical device to be mounted on a base of an electronic device,
A plurality of pixels arranged on a substrate,
Among the plurality of pixels, a pixel group in an effective display area for displaying information;
A group of pseudo pixels that are arranged around the effective display area and do not contribute to the display of the information;
With
Each of the plurality of pixels arranged in the effective display area includes a pixel electrode, a common electrode facing the pixel electrode, and a functional layer provided between the pixel electrode and the common electrode. ,
Between the area where the pseudo pixel group is provided and the substrate , at least one circuit of a scanning line driving circuit or a data line driving circuit for driving the pixel group in the effective display area is disposed,
An electro-optical device , wherein a region where the pseudo pixel group is provided is provided with a colored region colored in a color different from a base of the electronic device, and the common electrode is not provided. A part of the circuit for driving the pixel group in the effective display area is disposed below the area where the pseudo pixel group is provided and overlaps the area where the pseudo pixel group is provided. The electro-optical device according to claim 1. The electro-optical device according to claim 1, wherein a pixel circuit is provided corresponding to each pixel of the pixel group in the effective display area. The electro-optical device according to claim 1, wherein the pseudo pixel group is disposed on at least one side of the effective display area. 5. The electro-optical device according to claim 1, wherein a pixel electrode having conductivity is not formed on each pixel of the pseudo pixel group. An electronic apparatus comprising the electro-optical device according to any one of claims 1 to 5 and the base .

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