JPS589394B2 - electronic clock lighting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an electroluminescence device (hereinafter referred to as EL board) built into a timepiece as a night illumination light source for an electronic timepiece having a light-receiving electro-optical display device. It is something.

An object of the present invention is to shield the electric field generated around the electrode of an EL plate that requires a high driving voltage so as not to have an adverse effect on a timepiece device, and to prevent the electric field generated around the electrode of the EL plate and the electric field
The purpose is to facilitate connection with the L plate drive circuit.

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, the lead wires attached to each electrode plate are pulled out through the exterior moisture-proof material of the EL board, and one end of this lead wire is connected to the drive power source of the EL board. With the conventional method of connecting to a power source, it is extremely difficult to process or solder the lead wires for watches with delicate structures, which not only prevents mechanization of assembly work but also makes it difficult to replace defective EL plates. It is also inconvenient when doing so.

However, the EL board of the present invention has an electrode plate with a three-layer structure, and the top layer electrode plate and the bottom layer electrode plate are connected to form one electrode, and this electrode is connected to a part of the clock circuit. At the same time, an alternating current voltage is applied between this electrode and the electrode plate of the intermediate layer to cause the EL plate to emit light.Both the upper and lower surfaces of the EL plate are approximately equal to the potential of the clock circuit, and the EL plate There is no strong electric field that could cause malfunctions in clock circuits or liquid crystal display devices that are close to the board.

In addition, by making all the external connection electrode parts of the EL board flat, it has become possible to connect by crimping, and at the same time,
By making the crimp surfaces parallel, the EL plate and the drive power circuit for the EL plate can be arranged in a stacked manner via the elastic contact member, and electrical continuity between the two can be obtained.

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

FIG. 1 is a cross-sectional view showing the basic structure of the EL plate of the present invention. In the figure, from the top, a transparent first electrode plate 1, an electroluminescent material (hereinafter referred to as EL material) 4, It has a laminated structure in which an insulator 5, a second electrode plate 2, an insulator 6, and a third electrode plate 3 are sequentially stacked.

Usually, the seed layer structure is constructed on the surface of a transparent plate (glass plate or transparent plastic) 7.

The first electrode plate 1 is made of a thin metal film such as aluminum etched into a mesh shape, or a transparent conductive material such as indium oxide or tin oxide.

The second electrode 2 and the third electrode 3 are made of metal, and are obtained by bonding thin films formed by vapor deposition or thin metal plates.

The EL material 4 contains zinc sulfide and a small amount of metal elements (e.g. Cu,
There are two types: one is a powder mixed with Mn, etc.), and the other is a powder coated with a suitable binder, and the other is a thin film formed by vapor deposition.

The insulator 5 is a thin film obtained by coating barium titanate or vapor depositing silicon dioxide.

If a transparent material such as silicon dioxide is used, the insulator 5 may be formed on both sides of the EL material 4.

Insulator 6 between second electrode plate 2 and third electrode plate 3
is a dielectric material such as a plastic film or a plastic film, but in order to minimize the capacitance formed between the two electrode plates, it is preferable to use a material with a low dielectric constant and to be sufficiently thick.

In addition, the insulator 6 is in close contact with the first electrode plate 1 or the transparent substrate 7 at the outer periphery of the EL plate, and in order to obtain the effect of moisture-proofing the EL material, it is necessary to select a material with low air permeability. .

The first electrode plate 1 and the third electrode plate 3 are electrically connected at the outer periphery of the EL plate, wrap the second electrode plate 2 from above and below, and make the upper and lower surfaces of the EL plate equipotential. When built into a watch, it is connected to a part of the watch circuit, and the potential on the top and bottom surfaces of the EL board is approximately equal to the potential of the watch circuit, so even when the EL board is turned on, it will A disturbance electric field is not applied to the electric field element located in the area.

The third electrode plate 3 and the insulator 6 have a through hole 8 through which the lower surface of the second electrode plate 2 is exposed.

One end of an elastic contact member 9 is inserted into this hole 8 and pressed against the lower surface of the second electrode plate 2, and the other end is connected to the EL board and the drive power circuit of the EL board which is actively arranged. At the same time, one end of the elastic contact member 10 is also pressed against the lower surface of the third electrode plate 3 of the EL board, and the other end is pressed against the other electrode of the drive power circuit of the EL board. .

The contact member 9 or 10 is a conductive elastic member such as a metal coil spring or plate spring, or conductive rubber.

By applying a driving voltage to the EL board via these two conductive contact members, it has become possible to eliminate the need for processing the lead wires or soldering them.

FIG. 2 is an application example in which the EL plate having the above-described structure is used as a light source for night illumination in a wristwatch, and shows the cross-sectional structure of the wristwatch.

In the drawing, reference numeral 26 denotes a liquid crystal display device using twisted nematic liquid crystal, and is driven by a clock circuit 12 using a battery 11 as a power source.

13 is an EL board having the above-described structure, and the battery 1
It is electrically coupled via two elastic contact members 9 and 10 to two electrodes on the upper surface of an EL board drive circuit 14 whose power source is EL board drive circuit 1 .

Note that the electrode plate on the outer surface of the EL plate is connected to a part of the clock circuit 12 via the contact member 10 pressed against the stamping electrode plate and the EL plate drive circuit.

These components are housed in an exterior case consisting of a case body 15, a back lid 16, and a windshield 17.

In this configuration, the EL plate 13 acts as a reflecting surface for light rays penetrating the liquid crystal display device 26 in daylight, and illuminates the liquid crystal display device 26 with the light rays emitted by the EL plate 13 in a dark place.

FIG. 3 is a block diagram showing an embodiment of the EL plate drive circuit 14 when the EL plate 13 having the electrode structure of the present invention is built into a watch. a common electrode of two electrode plates 1 and 3 arranged in;
There is an electrode of an electrode plate 2 arranged in the middle.

The EL plate driving circuit 14 has a transformer having three windings 19, 20, 21, a transistor 22, a DC bias resistor 23 of the transistor, and an AC feedback capacitor 24, and the EL plate 13 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 the power supply battery 11 which is shared with 2.

In such a circuit, by making the number of turns of the winding 21 of the transformer sufficiently larger than the number of turns of the other two windings, the DC voltage of the battery 11 supplied via the switch 25 is changed to a high voltage AC. The voltage can be converted into a voltage and applied to the EL plate 13 via the two contact members 9 and 10.

A common electrode of the two electrode plates arranged on the outer surface of the EL plate 13 is connected to the clock circuit 1 via one winding 19 of the transformer.
Since the EL board 13 is connected to the general power supply of 2, the potential of the outer circumferential portion of the EL board 13 is kept approximately equal to the potential of the clock circuit 12, and no disturbance electric field is applied to the electric field elements constituting the clock circuit 12. It never happens.

The details of the present invention regarding the electrode structure of the EL plate 13 have been explained above. 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, it is possible to uniformly illuminate 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, when manufacturing such watches, work such as lead wire processing and soldering is performed to facilitate automatic assembly by machines, which improves parts yield due to lead wire breakage accidents and reduces watch costs. At the same time, it becomes possible to provide prompt service to consumers without the need for skilled technicians even 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 sectional view of a watch when the EL board of the present invention is built into a liquid crystal display type wristwatch, and FIG. 3 is a block diagram showing an example of a circuit when the EL board of the present invention is built into a watch. 1, 2, 3... Electrode plate, 4... Electroluminescent substance, 9, 10... Contact member, 12...;... Clock circuit, 13 . . . Electroluminescence device, 14 . . . EL board drive circuit.

Claims (1)

[Claims] 1. In an electroluminescent device arranged in a stacked manner on the back side of a light-receiving electro-optic display device, a transparent first electrode plate arranged on the upper surface of the electroluminescent material. and a second electrode plate disposed on the lower surface of the electroluminescent material, and a third electrode plate facing the second electrode plate with an insulator interposed therebetween; The third electrode plate and the second electrode plate are electrically connected to the first electrode plate, and the third electrode plate and the second electrode plate are connected to an electroluminescence device driving circuit via a conductive elastic member. A lighting device for electronic clocks. 2. In an electroluminescent device arranged in a layered manner on the back side of a light-receiving electro-optic display device, a transparent first electrode plate arranged on the upper surface of the electroluminescent material, and the electroluminescent material a second electrode plate disposed on the lower surface of the board, and a third electrode plate facing the second electrode plate with an insulator interposed therebetween, the third electrode plate and the first electrode plate. a first contact member having elasticity that is electrically connected to the lower surface of the third electrode plate and is pressed to the lower surface of the third electrode plate; An alternating current voltage is applied between the electroluminescent material and a second elastic contact member inserted into a small hole reaching the lower surface of the plate and pressed against the lower surface of the second electrode plate to cause the electroluminescent substance to emit light. , an illumination device for an electronic watch, characterized in that it illuminates the electro-optical display device.