JPS5819235B2 - electronic clock lighting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a light-receiving electro-optical display device as an electroluminescent device (hereinafter referred to as an EL board).

) This invention relates to a lighting device for an electronic watch that is illuminated by a light source.

Conventionally, a method has been proposed in which an electronic wristwatch equipped with a liquid crystal display device is illuminated by causing an EL plate to emit light, but when making the EL plate emit light, the AC voltage applied between two opposing electrodes is For example, since a peak value of about 150V is required, a strong electric field is generated around the two electrodes of the EL board, and this electric field causes damage to liquid crystal display devices and clock circuits placed near the EL board. MOS-F that constitutes
Electric field elements such as ETs were affected, resulting in malfunctions.

In order to prevent this, methods such as separating the EL plate from the electric field element or installing an electric field shielding plate made of a separate member are recommended for electronic watches that require high-density arrangement of components in a limited space. It is difficult.

A conventional EL board has two electrode plates facing each other with a luminescent substance in between, and has a structure in which light is obtained by applying an alternating current voltage between the two electrodes, and one electrode plate is connected to a clock circuit. Even if the potential was fixed by connecting a part of the EL plate, the electric field generated around the other electrode plate caused malfunction of the electric field element near the EL plate.

In addition, when connecting the two electrode plates to the drive power source of the EL board, attach a lead wire to each electrode plate and pull it out through the exterior moisture-proof material of the EL board, and connect one end of this lead wire to the EL board. In the conventional method of connecting to a drive power source, it is extremely difficult to process or solder the lead wires in wristwatches with delicate structures, which hinders mechanization of assembly work.

An object of the present invention is to solve the problems of the electroluminescent device, and to provide an electronic timepiece having a structure that has a complete electric field shield, does not have a negative effect on the timepiece device, and facilitates electrical connection and mechanical holding. The purpose of the present invention is to provide lighting devices.

Details and embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the basic structure of the EL plate of the present invention, in which 1 is a transparent substrate, 2 is a transparent first electrode plate, and 3 is an electroluminescent material (hereinafter referred to as EL material).

), 4 is an insulator, 5 is a second electrode plate, 6 is a third electrode plate, and 7 is an elastic contact member that is pressed against the lower surface of the second electrode plate 5, and has a laminated structure in which they are sequentially overlapped. have.

Normally, the above laminated structure is constructed on the surface of a transparent substrate 1 (glass plate or transparent plastic), and the first electrode plate 2 is formed by etching a thin metal film such as aluminum into a mesh shape, or The second electrode plate 5 is made of a transparent conductive material such as indium oxide or tin oxide.
is a metallic material obtained by bonding a thin film formed by vapor deposition or a thin metal plate.

The third electrode plate 6 is made of a drawn metal plate with spring properties, and as shown in FIG. 2, the plate is bent upward from the solid line by drawing on both the left and right sides. There is a cell electrode connection part 6b and a watch board electrode connection part 6c bent downward from the broken line, and the cell electrode connection part 6b is adhesively fixed to the first electrode plate 2 by conductive adhesive or soldering. .

Further, the third electrode plate 6 has a hole 6a passing through it, through which the lower surface of the second electrode plate 5 is visible, and one end of the elastic contact member 7 is inserted into this hole 6a to connect the second electrode. It is pressed against the lower surface of the plate 5, and the other end is pressed against an electrode of an EL plate drive circuit provided on a watch board, which will be described later.

The contact member 7 is a conductive elastic member such as a metallic coil spring or plate spring, or conductive rubber.

EL substance 3 contains zinc sulfide and a small amount of metal elements (e.g. Cv,
The insulator 4 is made by coating barium titanate or silicon dioxide. It is a thin film obtained by vapor deposition.

Due to the structure of these electrode plates, the EL material 3 and the insulator 4, E
An L plate 10 is configured.

The EL board 10 in the above configuration has a structure in which the first electrode plate 2 and the third electrode plate 6, which are electrically at the same potential, are entirely wrapped, so that there is no space inside the EL board 10. It must have a sufficient shielding effect against the generated high-voltage electric field.

Next, FIG. 3 shows an application example in which the EL plate 10 having the above-described structure is used as a night illumination light source in a wristwatch, and shows the cross-sectional structure of the wristwatch.

In the drawing, reference numeral 9 denotes a liquid crystal display device (hereinafter referred to as an LC panel) using twisted nematic liquid crystal.

), and is driven via a conductive rubber connector 12 by a clock circuit 17 powered by a battery 18.

10 is the EL board explained in FIG. 1, and the EL board 10
There is a translucent diffuser plate 11 between the LC plate 90 and the LC plate 90, which acts as a reflective surface for the light rays passing through the LC plate 9 in daylight and allows the light rays emitted by the EL plate 10 to pass through in a dark place. Light up 9.

14 is a clock board; on the clock board 14, a clock circuit 17 and an EL board drive circuit 20 are mounted.

To explain the assembly of the LC board 9, EL board 10, watch board 14, etc., first, the E'L board drive drive circuit 2002 arranged on the watch board 14 is connected to the third pole of the EL board 10. The EL plate 10 is aligned with the contact member 7 and the watch board electrode connection portion 6c, which is a part of the electrode plate 6.
are arranged, and the diffusion plate 11 is placed on top of these.

Next, the conductive rubber connector 12 and the LC board 9 are placed, and the existing mounting is done with metal fittings (not shown in the figure).

) by fixing the LC plate 9 to the watch board 14, the third electrode plate 6 and the contact member 7 on the EL plate 10 are fixed.
By utilizing the springiness of the EL board 10, the entire EL board 10 can be mechanically fixed and held between the LC board 9 and the clock board 14, and the electrical connection of each electrode can be determined.

These components include the case body 13, the back cover 19,
It is housed in an exterior case made of windshield glass 8 degrees Celsius.

FIG. 4 is a block diagram showing an embodiment of the EL plate drive circuit 20 when the EL plate 10 having the electrode structure of the present invention is built into a watch. a common electrode of two electrode plates 2 and 6 arranged in;
There is an electrode of an electrode plate 5 arranged in the middle.

The EL plate driving circuit 20 has a transformer having three windings 22, 23, 24, a transistor 16, a DC bias resistor 21 of the transistor, and an AC feedback capacitor 15, and the EL plate 10 is configured as a tuning capacitor. An anti-coupled oscillator circuit is configured, and the clock circuit 1 is connected to the clock circuit 1 via the switch 25.
It is connected to a power supply battery 18 that is shared with 7.

In such a circuit, by making the number of turns of the transformer's winding 240 sufficiently larger than the number of turns of the other two windings, the direct current voltage of the battery 18 supplied via the switch 25 is changed to a highly distorted alternating current. The voltage can be converted into a voltage and applied to the EL plate 10 via the contact member 7 and the third electrode plate 6.

A common electrode of the two electrode plates arranged on the outer surface of the EL plate 10 is connected to the clock circuit 1 via one winding 22 of the transformer.
Since the EL board 10 is connected to one end of the power supply 7, the potential of the outer circumferential portion of the EL board 10 is kept approximately equal to the potential of the clock circuit 17, and a disturbance electric field is applied to the electric field element constituting the clock circuit 17. It will not be done.

The present invention has been described above in detail regarding the electrode structure of the EL plate 10. By incorporating the EL plate of the present invention as a light source for nighttime illumination into an electronic watch having a light-receiving type electro-optical display device, Even if a high AC voltage is applied to the electrodes of the EL board, accurate and clear display is possible, and the EL
Since the display device or the clock circuit can be placed close to the board, it has become possible to downsize the clock device.

Furthermore, since the EL board is a surface light emitter, uniform illumination can be applied to the entire surface of the display device, and the beautiful luminous color of the EL board can increase the commercial value of the watch.

In addition, the present invention simplifies the mechanical fixing method and electrical connection, eliminates lead wire processing work, facilitates automatic mechanical assembly, improves parts yield due to lead wire breakage accidents, and reduces watch costs. At the same time, it is possible to provide prompt service to consumers without the need for skilled technicians when replacing parts due to damage to the EL board or deterioration of light emitting performance.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an EL plate having an electrode structure according to the present invention;
Fig. 2 is a plan view of the third electrode plate, Fig. 3 is a sectional view of a watch when the EL plate of the present invention is built into a liquid crystal display wristwatch, and Fig. 4 is a watch in which the EL plate of the present invention is built into a watch. FIG. 2 is a block diagram showing an example of a circuit when 2.5, 6... Electrode plate, 3... Electroluminescent substance, 7... Contact member, 9
...Liquid crystal display device, 10°...°...Electroluminescence device, 11...Diffusion plate, 14
...Clock board, 17...Clock circuit, 1
8...Battery, 20...EL board drive circuit.

Claims (1)

[Scope of Claims] 1. An electronic timepiece in which a light-receiving electro-optical display device is illuminated by an electroluminescent device, comprising: a transparent first electrode plate disposed on an upper surface of an electroluminescent material; A third electrode plate made of a metal plate formed to cover the bottom surface of the cell is provided in an electroluminescent device configured with a second electrode plate placed on the bottom surface of the substance, and the third electrode plate is 1. An illumination device for an electronic watch, wherein the plate is electrically connected to a first electrode plate and holds an electroluminescent device fixed to a watch board. 2. An illumination device for an electronic timepiece, characterized in that the third electrode plate according to claim 1 is an electrical connection body to an electroluminescent device drive circuit disposed on a timepiece substrate.