JP2008084638A - Light emitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that, since in a light emitter with a light-emitting part formed on the surface of a light-transmitting base material, the light emitter is formed on a base material formed in plane, an area of a light-emitting layer pinched by an anode and a cathode contributing to light emission is limited to the above plane area where the light emitter exists, and therefore, it has been impossible to structure a light emitter with excellent brightness. <P>SOLUTION: An area where the light emitter is formed out of an outer periphery face of the base material is formed into an arc-shaped groove, along which, a plurality of light emitting parts are formed. With this, an area of the light-emitting layer contributing to light emission is increased, and a light emitter with a higher brightness can be provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light emitter that emits light, and an object thereof is to provide a light emitter excellent in luminance.

  The current mainstream active matrix flat panel display is a flat panel display consisting of a pixel drive switch consisting of a TFT (Thin Film Transistor) and a pixel display medium on the display surface. The starting substrate is a transparent glass plate such as soda lime. is there. Attempts have been made to use plastic film as the base material, but it has not yet been put into practical use. Currently, liquid crystal is the display medium, and a-Si TFT (Amorphous-Silicon-TFT) is the mainstream as the active matrix. 10 "to 20" diagonal displays are mass-produced for PCs, monitors and the like.

  LCD (Liquid Crystal Display) as a display medium has problems in display performance of television moving images, particularly white, white peak, and responsiveness, compared with CRT (Cathode Ray Tube). In contrast, organic LEDs (Organic Light-Emitting-Diodes) (OLEDs) that have recently been developed and commercialized are self-luminous and can achieve better image quality than LCDs, such as white and white peak responsiveness. .

  On the other hand, the development and commercialization of polycrystalline Si (p-Si), which is a low-temperature process, has been rapidly advanced recently. This is because p-Si TFT performance is high and peripheral circuits can be built in, which has the advantage of cost reduction. In addition to this, it is difficult to drive an OLED with an a-Si TFT in terms of drive current density, and the TFT tends to shift to low-temperature p-Si as a whole, including application to LCD.

  The market requirements for all display devices including active matrix flat display devices are always three points: increase in display size, higher definition, and lower cost. In response to these demands, the current mainstream a-Si TFT-LCD has little room for performance improvement, with a 40 "diagonal television for large size and a display of 20" or less for high definition. In terms of cost, the only way to deal with costs is to increase the size of the glass substrate. In addition, the glass substrate is required to have high precision flatness, and it is difficult to use a substrate having a curved surface.

  On the other hand, linear light emitters in which a plurality of OLED elements are formed in the longitudinal direction are rich in flexibility, and it is known to form a display device by arranging them on a curved substrate (for example, , See Patent Document 1).

  This linear light emitter is formed along one side of a fiber having a square cross section, and is formed of a transparent electrode formed in the longitudinal direction of the fiber, an OLED light emitting layer formed thereon, and further on the OLED light emitting layer in the longitudinal direction. And a plurality of cathode electrodes formed at intervals along the line.

  However, according to the linear light emitter having such a structure, the fiber protrudes on the fiber during winding, cutting, arrangement on the substrate, etc. performed after the OLED element is formed on the fiber. Since the transparent electrode, the OLED light-emitting layer, and the cathode electrode are easily damaged by coming into contact with a jig or the like, this causes a decrease in yield.

  In order to solve this, a linear light emitter in which an insulating film is formed on a side surface of a fiber formed in a rectangular shape and a plurality of light emitting portions are formed along the longitudinal direction of the other surface is known ( For example, see Patent Document 2).

  4 and 5 show an example of a method for manufacturing such a linear light emitter.

That is, first, a light-transmitting fiber 1 made of quartz or the like having a substantially rectangular shape as shown in FIG. 4A wound around a reel (not shown) is prepared, and a base for forming a linear light emitter is prepared. Use as material. The cross section has a size of about 0.3 mm × 0.3 mm, for example.

  In addition, as a light transmissive fiber, in addition to quartz, glass fiber such as borosilicate or soda lime glass, sapphire, and other suitable glass materials, or methyl methacrylate (PMMA), polycarbonate, acrylic, mylar Plastic fibers made of polyester, polyimide, other suitable plastic materials, or the like may be used.

Next, the fiber 1 is pulled out from the reel and guided into a film forming apparatus (not shown). As shown in FIG. 4B, the first, second and third surfaces 1a, 1b adjacent to each other on the outer periphery thereof. A transparent electrode 2 formed by sequentially depositing indium tin oxide (ITO), zinc oxide (ZnO), and tin oxide (SnO ₂ ) on 1c by sputtering is formed to a thickness of about 100 nm. The transparent conductive material is deposited in a substantially vertical direction on each of the first to third surfaces of the fiber 1.

  Next, as shown in FIG. 4C, conductive reflection films 3 and 4 are formed on the transparent electrodes 2 on the first and third surfaces 1a and 1c on both sides of the second surface 1b of the fiber 1 by sputtering. A predetermined thickness is formed. The conductive reflective films 3 and 4 are composed of a two-layer structure conductive film in which chromium (Cr) and aluminum (Al) are sequentially formed, and a two-layer structure conductive film in which titanium (Ti) and aluminum are sequentially formed.

Further, as shown in FIG. 4D, a light transmissive insulating film 5 made of silicon dioxide (SiO ₂ ) is formed on the fiber 1, the transparent electrode 2, and the conductive reflective films 3 and 4 by a chemical vapor deposition (CVD) method. A predetermined thickness is formed on the substrate. Thereafter, a resist 6 is applied on the insulating film 5.

  Next, as shown in FIG. 4E, the resist 6 is exposed, developed and patterned to form an opening 6a in the pixel region on the second surface 1b of the fiber 1. A plurality of the openings 6a are formed at intervals along the longitudinal direction of the fiber 1, and the size of these planes is, for example, 50 μm × 50 μm or less. In addition, since the exposure light irradiated to the resist 6 is also irradiated to the resist 6 on the fourth surface 1d on the opposite side through the fiber 1, the resist on the fourth surface where the transparent electrode 2 is not formed. 6 also has an opening 6b.

  Next, as shown in FIG. 4F, the insulating film 5 is etched through the openings 6a and 6b of the resist 6 by dry etching using a chlorine-based gas to form the openings 5a and 5b. Thereby, a part of the transparent electrode 2 is exposed through the opening 5a on the second surface 1b of the fiber 1, and a part of the fiber 1 is exposed through the opening 5b on the fourth surface 1d.

  Further, as shown in FIG. 5A, an OLED light emitting layer 7 is formed on the transparent electrode 2 by vapor deposition through the opening 5a of the insulating film 5 and the opening 6a of the resist 6, and then magnesium (Mg), A cathode electrode 8 having a two-layer structure formed by sequentially forming silver (Ag) or a two-layer structure formed by sequentially forming calcium (Ca) and aluminum is formed by vapor deposition.

  After that, as shown in FIG. 5B, when the resist 6 is removed by wet or dry, the OLED light emitting layer 7 and the cathode electrode 8 deposited on the resist 6 are removed, so that the OLED light emitting layer 7 and the cathode electrode are removed. 8 is selectively left in the opening 5 a of the insulating film 5. A light emitting element is constituted by the cathode electrode 8, the OLED light emitting layer 7 and the transparent electrode 2.

  Further, after the fiber 1 is cut to a predetermined length, as shown in FIG. 5C, the cathode bumps are formed on the solder bumps 13 on the conductive data line segment wiring 12 formed on the insulating substrate 11. 8 is connected. Thereby, the pixels for one row or one column of the display device are arranged on the insulating base material 11.

  In such a light emitter, the OLED light emitting layer 7 and the cathode electrode 8 constituting each pixel on the fiber 1 are formed in the opening 5a of the insulating film 5 and do not protrude from the upper surface of the insulating film 5, or the insulating film 5 Since the cathode electrode 8 can be protruded by a necessary amount by adjusting the thickness of the fiber, it is possible to prevent the cathode electrode 8 and the OLED light emitting layer 7 from coming into contact with a jig or the like when the fiber 1 is wound or cut. Yield is improved because it is less susceptible to damage.

  Moreover, what was shown by patent document 3 is well-known as another example of the past.

Such a light-emitting body includes a pair of moisture-proof films A4 on both sides of a laminated structure in which the organic light-emitting layer A1 is held by a pair of electrode plates including a transparent electrode plate A2 and a back electrode A3 on the display surface side. A4 is laminated. The transparent electrode plate A2 on the display surface side is formed by forming a metal oxide transparent electrode layer A2b on the thermoplastic resin substrate A2a, and further, on the opposite side of the transparent electrode plate A2, a metal oxide or A back electrode A3 made of metal is provided. The laminated structure including the transparent electrode layer A2 and the back electrode A3 is further sealed with a moisture proof film layer A4 or another moisture proof layer A5 made of a metal oxide or the like. Here, the transparent electrode plate A2 and the back electrode A3 are provided with a lead wire connected to a power source A6 (direct current or alternating current) so that a voltage can be applied to the organic light emitting layer A1.
Japanese translation of PCT publication No. 2002-538502 JP 2006-154589 A JP 2006-154589 A

  However, the light emitters described in Patent Documents 1 to 3 have a light emitting surface formed in a planar shape. For this reason, the area of the light emitting layer that contributes to the light emission sandwiched between the anode and the cathode is limited to the above planar area where the light emitting part exists, and a light emitting part with even higher luminance can be configured. There wasn't.

  Further, in Patent Document 2, as shown in FIG. 6, a plurality of rectangular depressions 20 are provided along the longitudinal direction of one surface of the rectangular fiber, and light is emitted in each depression 20 as shown in FIG. 7. The formation of part 9 is also described. In this example, the anode layer (transparent electrode 2) is formed over the entire surface including the side surface of the recess 20 formed in a rectangular shape, and the OLED light emitting layer 7 is formed on the transparent electrode 2, and further on this The cathode layer (cathode electrode 8) is shown in FIG. 2, but in reality, these layers 2, 7, and 8 are extremely thin and formed by sputtering, and the side surfaces emit light. The respective layers constituting the portion 9 are hardly formed. Therefore, these side surfaces hardly contribute to light emission.

  The problem to be solved by the present invention is to increase the area of the light-emitting part by forming the surface on which the light-emitting part is formed in an arcuate depression (including a groove), and the linear shape with excellent luminance of the light-emitting part The object is to provide a light emitter.

  The light-emitting body of the present invention is a light-emitting body in which a light-emitting portion is formed on the surface of a light-transmitting substrate. A region where the light-emitting portion is formed is formed in a recess having an arc cross section, and the light-emitting portion is formed along the recess. Is formed.

  In the present invention, an arc recess is formed on the surface where the light emitting portion is formed, and the light emitting portion is formed in this recess, so that the area of the light emitting layer contributing to light emission is increased, and linear light emission with higher luminance is achieved. The body can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a linear light emitter according to a first embodiment of the present invention. In the figure, 1, 2, 3, 4, 5, 6, 7, and 8 are fibers, transparent electrodes, conductive reflective films, conductive reflective films, insulating films, and transparent protective films, respectively, as in FIGS. , OLED light emitting layer, and cathode electrode, which function in the same manner as in FIGS. 5 to 7 is different in that the surface of the fiber 1 on which the OLED light emitting layer 7 is formed is formed in an arc-shaped groove 21, and the transparent electrode 2, the OLED light emitting layer 7, the cathode are formed on the groove 21. The point is that a plurality of light emitting portions 9 formed by sequentially laminating electrodes 8 are formed along the longitudinal direction.

  In the present embodiment, the cross-sectional shape of the groove 21 is formed in an arc shape, and each layer is laminated along the shape of the groove 21. Therefore, the area of the OLED light emitting layer 7 (light emitting portion) that contributes to light emission corresponds to the surface area of the groove 21, and the area increases compared to the conventional planar area, and the light emitting area can be increased. As a result, the luminance of the light emitting unit can be increased.

  The shape of the groove 21 is preferably a semi-elliptical or semi-circular shape or an arc shape smaller than this. If the shape of the groove 21 is larger than a semi-ellipse or a semi-circle, the light emission area is increased, but the light amount utilization efficiency in the part exceeding the semi-circle is deteriorated. Further, if the shape of the groove 21 is configured with an extremely small arc surface, the groove 21 formed thereby is shallow and close to a flat surface, and the light emitting area cannot be increased. Therefore, the shape of the small arc-shaped groove 21 is preferably 32% to 50% of the circumference. If the shape of the groove 21 is a semicircle (50% of the circumference), it can be increased to about twice the area of the plane, and the light emission luminance can be increased twice.

  Such a fiber 1 is made by preliminarily making the shape of a quartz preform with a similar shape with the groove 21 and heating and drawing the same as in the case of manufacturing a conventional communication quartz optical fiber. Can be manufactured.

  By the way, since the transparent electrode 2 formed along the longitudinal direction of the fiber 1 is connected to a selection line signal wiring (not shown) at its end, it is preferable to electrically reduce the resistance value. In the above structure, the resistance value of the transparent electrode 2 can be substantially reduced by configuring the conductive reflective films 3 and 4 with a conductive metal. However, in order to further reduce the resistance, a lower layer portion of the transparent electrode 2 made of a transparent conductive material is previously formed on the first surface 1a and the third surface 1c of the fiber 1 by vapor deposition, and then, The transparent electrode 2, the conductive reflective films 3 and 4, the insulating film 5, the OLED light emitting layer 7, and the cathode electrode 8 may be formed through the above-described steps.

  FIG. 2 shows another embodiment of the present invention. Compared with the embodiment of FIG. 1, a convex lens 22 is formed on the fiber 1 on the light emitting side surface of the light emitting section 9 to control the light emission angle. Is configured to do. Thereby, light can be condensed and the effect that the light intensity of a unit area is emphasized can be acquired.

  FIG. 3 shows still another embodiment of the present invention. By appropriately controlling the radius R of the arc of the groove 21, the light intensity surface distribution of the light exit surface can be adjusted.

    In each of the above-described embodiments, the cross section of the fiber is approximately rectangular, elliptical, or circular, but is not limited thereto, and may be polygonal, cylindrical, or other shapes.

  In the above-described embodiment, the light emitting unit 9 having the OLED has been described. However, a light emitting element having another light emitting layer may be used. Further, an active element such as a transistor may be used instead of the light emitting element.

  In addition, although the said Example demonstrated the case where the circular groove | channel was formed along the longitudinal direction of the fiber 1, and the linear light-emitting body in which the several light emission part was formed along this groove | channel was shown, The light-emitting body in which the surface of the base material on which the light-emitting portion is formed is formed in a recess having a hemispherical cross section and one light-emitting portion is formed in the recess may be used in the present invention. Also in such an embodiment, since the surface on which the light emitting portion is formed is formed in an arc shape, the surface area can be increased as compared with the planar shape, and light emission with increased brightness in the same manner as described above. The body can be provided.

It is a principal part cutting | disconnection end elevation of the linear light-emitting body which concerns on 1st Embodiment of this invention. It is a principal part cutting end elevation of the linear light-emitting body which concerns on 2nd Embodiment of this invention. It is a principal part cutting | disconnection end elevation of the linear light-emitting body which concerns on 3rd Embodiment of this invention. (A)-(f) is principal part cut sectional drawing (the 1) which shows the process of forming a light emitting element in the fiber in a conventional example. (A)-(c) is principal part cut sectional drawing (the 2) which shows the process of forming a light emitting element in the fiber which concerns on an example of the past. It is a principal part cutting end view which shows an example of the conventional fiber. It is a principal part cutting end view which shows the other conventional light emitting element formed in the fiber of FIG. It is a principal part cutting end view which shows the other light emitting element different from the above conventional.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fiber 1a Surface 1b Surface 1c Surface 1d Surface 2 Transparent electrode 3 Conductive reflective film 4 Conductive reflective film 5 Insulating film 5a Opening part 5b Opening part 6 Resist 6a Opening part 6a Opening part 6b Opening part 7 OLED light emitting layer 8 Cathode electrode 10 Insulating base material 11 Insulating base material 12 Data line segment wiring 13 Solder bump

Claims (3)

  In the luminous body in which the light emitting portion is formed on the surface of the light-transmitting base material, the surface of the base material on which the light emitting portion is formed is formed in a recess having an arc cross section, and the light emitting portion is formed in the recess. Characteristic light emitter.   The base material is made of a light-transmitting fiber, and a circular arc recess (groove) is formed along the longitudinal direction of the base material in a part of the outer periphery of the base material, and a plurality of light emitting portions are formed along the recess. The light-emitting body according to claim 1, wherein   The light emitter according to claim 2, wherein the shape of the recess is an arc smaller than a semicircle.

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