DISPLAY UNIT

Abstract: A large-size display unit in which dark lines between in­ dividual display elements of which the overall unit is composed are eliminated and connections to the display elements are sim­ plified. The inventive display unit includes a plurality of display element board arranged in a matrix, each board having a plural­ ity of the display elements mounted thereon. Each display el­ ement boards has end portions bent backwardly in the vertical and horizontal directions of the board. Signal connectors are mounted on the backwardly bent end portions.

Description: BACKGROUND OF THE INVENTION The present invention relates to a display unit for displaying an image or information outputted by a computer. Fig. 1 shows a front view of a part of a display device in which a large number of display units 3 are disposed. As shown in Fig. 1, display elements 1 are disposed in a matrix on a display element board 2. Each display unit 3 includes the display elements 1 and the display element board 2 on which the display, elements 1 are disposed. Signal connectors 4, 5, 14, 15, 24, 25, 50, 60, 70 and 80 are mounted on the display element board 2 outside the area of the display elements 1. Matrix signals for driving the display elements 1 are applied in the vertical and the horizontal directions of the display unit 3 through these connectors. Connections are made as needed between the signal connectors. In the example shown in Fig. 1, the signal connectors 14 and 24 are connected to each other and the signal connectors 15 and 25 are connected to each other in the vertical direction, and the signal connectors 60 and 70 are connected to each other in the horizontal direction. Other portions are also likewise connected to each other sequentially. Fig. 2 shows a front view of a conventional display device in which a plurality of display units 3 are disposed on a screen 100. When the screen 100 having the display units 3 is to be driven, matrix signals in the vertical and the horizontal directions of the screen 100 are applied to display elements 1 through signal connectors 4, 5, 14, 15, 24, 25, 50, 60, 70 and 80 so as to display information on the screen 100. Since the signal connectors of the conventional display device are disposed as bars outside the display element board 2, signal plug connecting portions 3a must be provided on the peripheral part of the display unit 3. Since the display elements 1 cannot be mounted at the locations of the signal plug connecting portions 3a, the signal connectors and the signal plug connecting portions 3a unavoidably appear as black lines when the screen 100 is seen from a distance. Moreover, since the connection of the display unit 3 is complicated, the assembly and maintenance of the unit are difficult, and the reliability of the display unit is less than desired. A solution to the problem is incorporated in the document US-A-4 471 263, however, it is rather elaborate and complicated to manufacture, as it involves bending backwards individual connecting leads. SUMMARY OF THE INVENTION The present invention was made in order to provide a more advantageous solution to the above-mentioned problems. It is an object of the present invention to provide a display unit in which the joints of an entire screen are made inconspicuous, whose assembly and maintenance are facilitated, and whose reliability is enhanced. In the display unit provided according to the present invention, the end portions of a display element board on which display elements are mounted are bent backwards and signal connectors are disposed on the backwardly bent and portions of the display element board. Since the end portions of the display element board on which the display elements are mounted in the display unit provided according to the present invention are bent in this manner, the distances between the display elements can be made equal to each other. As a result, a large-size screen without conspicuous joints can be constructed. The accompanying drawings show: Fig. 1 shows a front view of a part of a conventional display device; Fig. 2 shows a front view of a conventional display device; Fig. 3 shows a front view of a part of a display device composed of a plurality of display units constructed according to the present invention; Fig. 4 shows a sectional view taken view along a line A-A in Fig. 1; Fig. 5 shows a front view of a display unit of a second embodiment of the present invention; Fig. 6 shows a sectional view taken along a line A-A' in Fig. 5; Fig. 7 shows a sectional view taken along a line B-B' in Fig. 6; and Fig. 8 shows a perspective view of the display unit 3. DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will hereinafter be described referring to the drawings. Fig. 3, in which identical or equivalent portions are shown by the same symbols in Figs. 1 and 2, shows a display element board 2 which holds display elements 1 and on which circuits (not shown) for driving the display elements 1 are provided. The horizontal end portions (right and left end portions) and vertical end portions (upper and lower end portions) of the display element board 2 are bent backwards from the vicinities of the outermost display elements 1. Fig. 4 shows the backwardly bent state of the horizontal end portions of the display element board 2, which are bent backwards at substantially a right angle from the vicinities of the outermost display elements 1. As shown in Fig. 4, a display unit 3 is bent backwards as a whole corresponding to the bending of the end portions of the display element board 2. Shown at 50, 60, 70 and 80 in Fig. 4 are signal connectors attached to the backwardly bent end portions 2a of the display element board 2. Penetration type connectors, male and female combination type connectors, or the like can be used in attaching the signal connectors to the backwardly bent end portions of the display element board 2. In this embodiment, not only the horizontal end portions (right and left end portions) of the display element board 2, but also the vertical end portions (upper and lower end portions) of the board 2 are bent backwards. Similar signal connectors are attached to the backwardly bent vertical end portions of the board 2 as well. The operation of the display unit of this embodiment will now be described. Information is displayed on a screen 100 in the same way as a conventional display device. Since the horizontal and the vertical end portions of the display element board 2 are bent backwards according to the present invention, the distances between the display elements 1 can be made equal to each other so that a large-size screen without conspicuous joints can be constructed. As for the coupled state of the display units 3 in the horizontal direction, the distance a between the display elements 1 of each display unit 3 and that b between the display elements of the adjacent display units 3 are made substantially equal to each other, as shown in Fig. 3. As for the coupled state of the display units 3 in the vertical direction, the distance c between the display elements 1 of each display unit 3 and that d between the display elements 1 of the adjacent display units 3 are also made substantially equal to each other. As a result, the large-size screen without conspicuous joints can be constructed. Since the signal connectors 50, 60, 70 and 80, which are attached to the backwardly bent and portions 2a of the display element board 2, are penetration types, male and female combination types, or the like, intermediate connecting cables are not needed. Since the display units 3 can be simultaneously secured to each other, a screen of high dimensional accuracy can be easily constructed. Although the end portions of the display element board are almost squarely bent backwards in the above-described embodiment, the angle of the backward bending is not limited to about 90°, but may be arbitrarily determined as far as the above-described operation is attained. According to the present invention, the end portions of the display element board on which the display elements are mounted are bent backwards and the signal connectors are disposed on the backwardly bent end portions, as described above. As a result, the distances between the display elements can be made equal to each other so that a large-size screen without conspicuous joints can be easily constructed. In addition, a cable for making connections between the display units is not needed, and hence the assembly and maintenance or the display units can be efficiently carried out and the reliability of the display units is enhanced. Figs. 5, 6, 7 and 8 show another embodiment of the present invention, namely, in the form of a fluorescent display tube. Shown at 27 in Fig. 7 is a filament which is heated by a filament drive signal applied thereto from the outside through signal connectors 50 and 60 and filament drive signal plugs 33 and which when heated generates thermions. The thermions are absorbed by a display element 1 to which a positive potential is applied through a control grid 26 so that the display element 1 is caused to emit light. As shown in Figs. 6 and 7, filament braces 28 and control grid braces 29 are bent backwards, similarly to the first embodiment shown in Figs. 3 and 4, so that the dead zone of the peripheral portion of a display unit 3 is reduced and the display elements 1 can be placed as closely to the periphery of the display unit 3 as desired. As a result, a large-size screen without conspicuous joints can be constructed. The present invention can be applied not only to the above-described fluorescent display tube, but also to a display unit such as a cathode-ray display tube and a liquid crystal display unit which employ different principles of light emission from the fluorescent display tube.

Claims: A display unit comprising: a plurality of display element boards; a plurality of display elements being mounted on each of said display element boards, end portions of each of said display element boards in at least one of vertical and horizontal directions of said board being bent backwards; and signal connectors disposed on at least some of said backwardly bent end portions of said boards. The display unit of claim 1, wherein said signal connectors are disposed on both vertically and horizontally bent end portions of said display element boards. The display unit of claim 1, wherein said end portions of said display element boards are bent backwards at an angle of substantially 90°. The display unit of claim 1, wherein said display unit is a fluorescent tube type display unit, and further comprising a plurality of heated filaments for generating thermions and at least one control grid disposed adjacent said filaments, and wherein said end portions of said display element boards comprise filament braced and control grid brace's for supporting said filaments and control grid, respectively.

Inventors: TERAZAKI, NOBUO C/O MITSUBISHI DENKI K.K.
Applicants: MITSUBISHI DENKI KABUSHIKI KAISHA
Application year: 1986
Main classification: G09F9
IPC codes: G09F9, G06F3, H01J31