JPH0123162Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a display device in which a drive circuit for driving a display element, such as a fluorescent display tube or a plasma display (PDP) that performs matrix display, is formed integrally with the display element.

In general, display devices for electronic devices, electric machines, computer terminals, etc. are composed of display elements such as fluorescent display tubes, liquid crystals, PDPs, and electroluminescence (EL), and drive circuits that drive each display element to display display. There is. The display element and the driving circuit may be configured separately or may be integrally combined, and the present invention belongs to the latter category, and relates to a display device that is compact and has an improved space factor.

Incidentally, in recent years, there has been a demand for display devices to display not only numbers and characters but also arbitrary figures, images, and the like.

Therefore, in order to meet these demands, a so-called dot matrix type display device has been put into practical use, in which a large number of minute anodes consisting of square or circular dots are arranged in a plane and these minute anode groups are driven by a matrix method. It is becoming more and more popular.

This dot matrix type display device is formed with minute anode dots in order to improve the display quality by displaying more precisely, and to increase the density of the display by displaying more information on one display surface. One pixel tends to become smaller. For example, in PDPs, pixels are formed at a pitch of 0.2mm, and in fluorescent display tubes, pixels are formed at a pitch of 0.3mm, which has recently been realized.

As each pixel becomes microscopic in this way, the pitch of electrodes such as anodes and control electrodes that drive these pixels also becomes narrower. Therefore, the number of electrodes disposed in the display element also increases. These electrodes are directly or indirectly extended outside the container of the display element and connected to the drive circuit. In order to have a compact configuration, this drive circuit generally uses an IC, which is placed on the back side of a printed circuit board (hereinafter referred to as PCB) that fixes the display element, and is connected to the lead terminals of the display element using printed wiring. was. As the number of lead terminals increases, the number of ICs also increases, and
The drive circuit also becomes complicated. Therefore, one
It becomes impossible to arrange all ICs on the PCB, and multiple ICs are required.
There is a trend toward configuring PCBs by arranging them in multiple layers.

The present invention will be described below regarding a dot matrix type display device using a fluorescent display tube as a display element.

The conventional dot matrix type fluorescent display tube is
As previously filed by the present applicant and disclosed in Japanese Utility Model Application Publication No. 162692/1987, a strip anode is provided in parallel in the horizontal direction on a substrate, and a large number of linear control electrodes are provided in parallel in the vertical direction. Fluorescent display tubes in which a matrix is assembled with and are known. Lead terminals extend outside the fluorescent display tube from each strip anode and each linear control electrode. Since the pitch interval between each lead terminal is 0.3 mm for both the anode and the control electrode, if all the lead terminals were provided on one side, lead terminals would have to be provided every 0.3 mm, which would be technically difficult.
Therefore, every other electrode is divided and the lead terminals are extended and arranged on both sides facing each other. That is, the odd numbered electrodes extend to the right end of the display section and provide lead terminals, and the even numbered electrodes extend to the left end of the display section and provide lead terminals. As a result, the pitch width of the lead terminals becomes 0.6 mm, making it easier to arrange the lead terminals. As an example of the electrodes, an anode electrode is arranged in the horizontal direction and a control electrode is arranged in the vertical direction. This is an example in which a matrix is assembled with these anodes and control electrodes. The lead terminals of this display device are fixed with solder or the like to through holes or terminals provided in a PCB to which the display element is fixed. By printed wiring from this through hole
It is connected to the drive circuit provided on the back side of the PCB. This drive circuit is composed of ICs to make it small and compact. ICs are placed on the back side of the PCB, and as the number of lead terminals increases, the number of ICs that drive them also increases. Conventionally, as shown in Figures 1 and 2, the display element 1 was placed on the PCB 2, which has a larger area than the display element 1. However, as the display area increases, the number of lead terminals also increases, and accordingly, the number of lead terminals increases. The number has increased to one PCB.
2, there is also a display device with a structure in which the IC3 cannot be arranged completely and is arranged on multiple PCBs 2 and stacked, and jumper wires and connectors are connected between them. However, in this case, at least about half of the drive ICs are multilayer
Since it must be placed between PCBs, if the IC is defective, all jumper wires and connectors must be removed and repaired, which is very troublesome.

Therefore, the conventional dot matrix type display device cannot have a high packaging density and has a problem of poor space factor.

Furthermore, the input terminals of IC3 are generally arranged in counterclockwise order. Then, in order to increase the packaging density, if PCB 2 is made to be approximately the same size as display element 1, the wiring from the terminal of display element 1 will be
Arranged around the outer circumference of PCB2. Therefore, PCB2
The wiring in one direction and the input terminals of IC3 are arranged in the same direction, so the circuits do not overlap and the matching is good.However, on the other side, when the input terminals of IC3 are turned outward, the arrangement of the input terminals of IC3 is The order and the arrangement order of the electrodes of the display element 1 are reversed, the circuits overlap, and the matching is poor due to wiring on the back surface using through holes. This led to the problem that it could not be installed without complicating the wiring or preparing ICs with a different arrangement order.

Therefore, this invention was developed in view of the above-mentioned circumstances, and it makes it possible to make the PCB approximately the same size as the display element, increase the packaging density, and mount the same IC. The object of the present invention is to provide a display device with a drive circuit that is easy to maintain.

In order to achieve the above object, the present invention provides a display element in which vertical and horizontal electrodes are arranged facing each other in a matrix structure, and the lead terminals of each electrode are divided into two and led out from the four sides of the envelope. The display element is fixed to the front surface, and through holes are provided on all sides to lead out the wiring from the lead terminals to the back surface, and the lead terminals on one vertical side and one horizontal side of the display element are connected through the through holes. A printed circuit board has a plurality of rows of display element driving ICs fixed on the back surface thereof, and a printed circuit board is connected to lead terminals on the other side of each direction of the display element via through holes, and the printed circuit The display element driving IC is fixed to the back side of the board in the same mounting position as the display element driving IC on the back side of the board.
It is characterized in that it is comprised of a pair of flexible circuits fixed to the printed circuit board.

Embodiments of the present invention shown in the drawings will be described in detail below.

FIG. 3 is a plan view of a display device with a drive circuit according to the present invention, but the circuit is omitted and not shown. Fourth
The figure is a longitudinal sectional view taken along line A-A in FIG. 3. A matrix type fluorescent display tube 10 as a display element is fixed to a PCB 11. The fixing method is to connect the external terminal 12 of the fluorescent display tube 10 to the PCB 11.
Fix it to the through hole 13 or the terminal by soldering or the like. The through hole 1 is on the back side of PCB11.
Printed wiring for electrical connection to 3 is provided, and an IC 15 for driving a fluorescent display tube is also provided. A fluorescent display tube driving IC directly disposed on the back surface of the PCB 11 is connected to an external terminal 12 led out to one side of each electrode such as an anode and a control electrode of the fluorescent display tube 10. For example, if the control electrodes are arranged in the vertical direction in Figure 3, the control electrodes are numbered sequentially from the end, and the even-numbered control electrode terminals are led out to the top, and the odd-numbered control electrode terminals are led out to the bottom. derived. Among these electrodes, the electrode led out on the upper side is connected to an external terminal provided on the edge of the PCB 11, and is further connected to the IC 15 arranged on the back surface of the PCB 11 through a through hole 13 on the back surface of the PCB 11. There is. similarly
Anodes are arranged in the lateral direction of the PCB 11, and these anodes are also numbered sequentially from the end, and half of the anodes whose numbers are odd or even are led out to the right side and arranged on the back side of the PCB 11 through the through hole 13. It is connected to the provided drive IC 15. The number of driving ICs 15 is shown in six pieces in FIG. 3, but the number may increase depending on the number of dots and the driving method. Therefore, the area on the back surface of the PCB 11 is occupied by the IC 15 that connects to half of the anode and control electrodes led out to one side and drives these electrodes. Therefore, the other side of the electrodes such as the anode and the control electrode, that is, the electrodes led out to the left side and bottom of the PCB 11 in Figure 3, were connected to the external terminal 12, and further arranged on one side of the PCB 11.
It is connected to the through hole 13a of the FPC 14.
IC1 that drives the electrode on the back side of this FPC14
5 is arranged. The mounting position and circuit of the IC 15 on this FPC 14 may be the same as the mounting position and circuit of the IC on the PCB 11. Because PCB11
This is because the left and right or upper and lower ICs are arranged in the same direction with respect to the through hole 13 formed in the hole.
For example, in FIG. 3, half of the anodes disposed laterally are electrically connected to the back surface through a through hole 13 on the right side of the PCB 11, and an IC 15 electrically connected by printed wiring is disposed on the left side of the through hole 13. The remaining half of the anode is connected to the back side through the through hole 13 on the left side, and this through hole 13
and the through hole 13a of the FPC 14 are connected,
Through this through hole 13a, conduction is established to the back side of the FPC 14, and the FPC 14 arranged on the left side of the PCB 11
IC15 is arranged on the back side of the . In this way, since the IC 15 is disposed in the same positional relationship with respect to the through holes 13 and 13a both left and right and above and below, the order of the input terminals of the IC 15 and the arrangement order of the electrodes can be made the same, improving matching.
Furthermore, the numbers of through holes 13, 13a and ICs 15, as well as the mounting positions of the ICs, can be made the same. Therefore, the circuit between the through hole and the IC 15 can be made the same on the left and right sides. Therefore PCB
Since the same circuit as that on 11 can be placed on FPC 14, wiring work becomes easier. Furthermore, since the ICs are arranged in the same position on the left and right or top and bottom, the circuit can be completed with one type of IC 15.

Next, when mounting a display device equipped with an IC in various devices, as shown by the dashed line in Figure 4,
It is possible to mount the FPC 14 by bending it below the PCB 11.

Furthermore, the present invention is not limited to the above-described embodiments, and can be practiced without changing the gist of the present invention.

For example, the display element may be a PDP other than a fluorescent display tube.
This can also be applied to LCDs.

As described above, the present invention fixes a display element to the surface of a PCB with through holes on all sides, and connects the display element to the back surface of the PCB and the FPC through the through holes.
Since the drive IC is separately arranged on the back side, it has the following effects.

(1) Since the PCB on which the display element is fixed can be made to be approximately the same size as the display element, it can be made smaller than the conventional example, which has the effect of making the display device more compact.

(2) Since the drive IC is arranged separately on the back side of the PCB and the back side of the FPC, even display elements with a matrix structure with a large number of electrodes can be placed on each of the PCB and FPC in a single layer. Since it can be bent under the PCB, it is possible to increase the packaging density.

(3) Since the drive IC is arranged on the PCB and FPC through through holes that distribute the electrodes left and right or up and down, the order of the input terminals of the drive IC and the order of the electrodes can be the same, making it possible to create one type of device. This has the effect of allowing circuits to be assembled using several ICs.

(4) Since the wiring of the drive IC arranged on the PCB and FPC can be routed in the same way, manufacturing is facilitated.

(5) The practical effects are great, such as making it extremely easy to repair the drive IC if it is defective.

[Brief explanation of the drawing]

FIG. 1 is a bottom view of a conventional display device, FIG. 2 is a front view of a conventional display device, and FIG. 3 is a bottom view showing an embodiment of a display device with a drive circuit of the present invention.
FIG. 4 is a longitudinal sectional view taken along line A-A in FIG. 3. 10...Display element (fluorescent display tube), 11...
PCB, 12...External terminal, 13...Through hole, 14...FPC, 15...IC.

Claims (1)

[Scope of utility model registration request] A display element in which vertical and horizontal electrodes are arranged facing each other in a matrix structure, the lead terminals of each electrode are divided into two and led out from the four sides of an envelope, and the display element is fixed to the surface, Through-holes are provided on all sides to lead out the wiring from the lead terminals to the back surface, and a display element driving IC is provided on the back surface to be connected to the lead terminals on one vertical side and one horizontal side of the display element via the through-holes. A printed circuit board is fixed in multiple rows to the display element, and is connected to the lead terminals on the other side of each direction of the display element through through holes, and is mounted in the same way as the display element driving IC on the back side of the printed circuit board. 1. A display device with a drive circuit, comprising a pair of flexible circuits fixed to the printed circuit board, with a display element drive IC fixed to the rear surface in a positional relationship.