Sheet type large display unit

Abstract: A sheet type large display unit (1) has a predetermined number of display dots (3) made of light emitting ele­ ments (3b) disposed in matrix manner relative to a dis­ play structure (2, 5). Each of the display dots (3) has one or more light emitting elements (3b) mounted on a printed circuit board (3a), and the display structure is made of a flexible sheet member (2, 5) which sand­ wiches the display dots (3) by means of adhesive agent or the like.

Description: The present invention relates to a large display unit which is used outdoors for advertisement, announcement or the like, and more particularly, to a large display unit in which a plurality of display units are combined to constitute a single large display, the display units disposed in rows and columns each displaying one character. A display unit of this kind is described in DE-A-3 037 500. Fig.4 shows a display unit 20 of similar kind. A display panel 21 of the unit 20 made of hard metal or resin is formed with display windows 21a in the form of, for example, 24 x 24 matrix. A light emitting element holder 22 made of, for example, a printed circuit board is mounted on the back of the display plate 21. Light emitting elements (not shown) such as light emitting diodes (LED) are mounted on the holder 22 to face the display windows 21a and display illuminated dots. A driver circuit board 23 is mounted on the back of the light emitting element holder 22 to receive a character code from an external circuit and convert it into suitable drive signals which are supplied to the light emitting elements to display a corresponding character. Since the display unit 20 of this type is mainly intended to be used outdoors, it is housed within a water proof casing 24 provided with a water proof connector 24a. Further, the display windows 21a are also covered with glass to seal it from external environment. Thus, the entire structure of the display unit 20 is made water proof. The conventional display unit 20, however, is associated with many problems much as in the following because of the rigid structure thereof: (1) The weight and volume are large so that transportation and maintenance of the display unit become difficult. (2) A large frame is required to mount the display unit because of its large weight, resulting in semipermanent installation and poor portability which are not suitable for temporary use in such as entertainments, parties, meetings or the like. (3) Because of semipermanent installation, a some measure to cope with damage from wind becomes necessary, resulting in an expensinve mounting frame. (4) The larger the size of the display unit becomes, the greater the weight and a need of strong mounting frame become. Thus, it is impossible to make a larger display unit than a maximum presently available one of 90 x 90 cm. Consequently, it becomes difficult to clearly recognize a displayed character from a remote position and to attract viewers when the display unit is used outdoors. From FR-A-2 512 238 it is known to dispose display dots in a matrix and to mount them between flexible members. It is the object of the present invention to provide a large display unit of flexible structure, and with light weight, small volume, and good portability. According to the main claim, the display unit comprises a predetermined number of display dots each made of light emitting elements and disposed in matrix manner relative to a display structure, wherein the light emitting elements of each of said display dots are mounted on a separate printed circuit board, and said display structure is made of flexible sheet members which sandwich said display dots which are attached by means of adhesive agent or the like. A preferred embodiment of the sheet type large display unit according to the present invention will be described with reference to the accompanying drawings. Fig.1 is a front view showing an embodiment of the sheet type large display unit according to the present invention; Fig.2 shows an example of a displayed character on the display unit; Fig.3 is a perspective, broken view showing the main part of the embodiment shown in Fig.1; and Fig.4 is a perspective, broken view showing a conventional display unit. Referring to Fig.1, a sheet type large display unit (hereinunder referred to simply as a display unit) is generally indicated by reference numeral 1. A display surface member 2 of the display unit 1 is adapted to be mounted with display dots 3 disposed in matrix similar to the conventional. For example, 18 x 10, 24 x 24 dot matrix or the like may be selectively used in dependence upon a desired character resolution. By selectively turning on proper display dots 3, a character, for example, Chinese character as shown in Fig.2 can be displayed. One character is generally displayed on one display unit 1. The detail of the display unit 1 is shown in Fig.3, wherein the display surface member 2 generally of square shape is made of a sheet type transparent resin rich in flexibility, the reverse side of which is coated with an adhesive agent. Each of the display dots 3 is constructed of a desired number of light emitting elements 3b such as light emitting diodes (LEDS) mounted on a substrate 3a such as a printed circuit board. For example, 576 display dots 3 are used for a 24 x 24 dot display unit, and each display dot 3 is connected by lead wires 4 to a driver circuit (not shown) to drive it in a specific drive method such as dynamic, static or other drive methods. The display dots 3 on the substrate 3a and the lead wires 4 are fixedly attached to a back sheet 5. The back sheet 5 is covered with the display surface member 2 to fixedly attach them together, to thus assemble the display unit 1 of this invention. Various modifications may be made to the above embodiment. For example, the substrate 3a for mounting the display dots 3 may use a printed circuit board either of hard or soft material. The attachment among the display surface member 2, display dots 3 and back sheet 5 may be effected using an adhesive agent, or other means such as high frequency welding whereby peripheral portions thereof are welded. Further, colors of the light emitting elements 3b disposed within each display dot 3 may use red, yellow and green. To selectively activate the light emitting element, it becomes possible to realize a display unit 1 of three colors. Since the display unit 1 is constructed of the display surface member and back sheet which are both made of flexible material, the entire structure of the display unit 1 is flexible. In addition, the display surface member 2 and back sheet 5 are made of sheet material so that the display unit 1 becomes thin and light weighted. Furthermore, the display dots 3 are covered by the display surface member 2 and back sheet 5 so that a sufficient water proof performance is realized. A water proof connector and water proof driver circuit may be provided on the display unit 1 as conventional. As described so far, the display unit of this invention is applicable to various fields in practical use due to its sheet structure, and has the following advantages: (1) The weight is light, and the display unit can be folded or rolled up so that transportation and maintenance become very easy. (2) The display unit is light weighted and can be properly installed with simple means such as those used for a hanging screen. Therefore, temporary installation for parties, meetings or the like becomes easy, or dismounting the display unit can be made readily in an emergency such as typhoon. The display unit is low in cost and has a good portability. (3) A large type display unit can be readily realized which allows easy recognition of characters from a remote position, thus attracting a viewer.

Claims: A sheet type large display unit (1) comprising a predetermined number of display dots (3) each made of light emitting elements (3b) and disposed in matrix manner relative to a display structure (2, 5) characterised in that the light emitting elements (3b) of each of said display dots (3) are mounted on a separate printed circuit board (3a), and that said display structure is made of flexible sheet members (2, 5) which sandwich said display dots (3) which are attached by means of adhesive agent or the like. A sheet type large display unit according to claim 1, wherein said light emitting elements (3b) comprise light emitting diodes. A sheet type large display unit according to claim 1 or 2, wherein light emitting elements (3b) of two or more colours are provided.

Inventors: IRIE TADASHI, TANAKA ISSEI, UCHIDA AKIO, IRIE, TADASHI, TANAKA, ISSEI, UCHIDA, AKIO
Applicants: STANLEY ELECTRIC CO LTD, STANLEY ELECTRIC CO., LTD.
Application year: 1988
Main classification: G09F13
IPC codes: G09F13, G09F9