JPS5814635B2 - Electronic clock with electrochromic display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solid-state electronic timepiece equipped with an electro-optical display device that indicates time information by means of hour and minute hands substantially similar to conventional This invention relates to an electrochromic timepiece display device in which an hour hand and a minute hand are formed on a display plate, whereby one hand moves over the other.

BACKGROUND ART Modern electronic watches are known to use a display device that mimics the movement of the hands of a conventional clock.

In these watches, the clock hands for reproduction are formed on one of the substrates constituting the liquid crystal display device.

Typically, the minute hand is formed on the outer circumferential circle and the hour hand is formed on the inner circumferential circle, as shown in US Pat. No. 3,823,549 and US Pat. No. 3,540,209.

Conventionally, when selectively energizing fixedly disposed conductive parts to perform an action similar to a continuously moving clock hand, the minute and hour hands extend to the center of the dial plate; It was not possible to form a condensed path for one needle to cross over the other needle.

In the present invention, a fully electronic timepiece has been provided with an electro-optical display that exhibits movements substantially similar to those of conventional hour and minute hands.

Each of the hour and minute hands extends into the center of the dial and is formed on the opposite substrate of the electrochromic display, creating a condensed travel path in which one hand traverses the other.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an electronic timepiece that eliminates the movable hands of conventional mechanical timepieces and uses a time display method similar to that of the conventional mechanical timepieces.

These and other objects and features of the present invention will become apparent from the following description of preferred embodiments of the invention.

To facilitate understanding of the present invention, an example of an electronic timepiece shown in FIG. 1 with a conventional so-called "analog" display will be briefly described.

In a typical conventional example, the time display hands 1', 2' are formed from a single layer or electrode attached to one side of a liquid crystal layer.

The minute hand 1' is formed on the outer circumferential circle, and the hour hand 2' is formed on the inner circumferential circle.Therefore, the time display hands 1' and 2' appear on one plane, and are formed on the outer circumferential circle. If the hour hand 2' cannot extend to the center of the dial plate, i.e.
The display path of the minute hand 1' cannot be arranged so as to overlap the display path of the hour hand 2'.

In contrast, FIG. 2 shows a display device of the present invention, which display device is preferably disclosed in US Pat. No. 43,704.
057, Tsuta 3708220, and 3807832.

Ideally, if an electrochromic material is disposed between or on one of the electrodes, and/or part of the electrode is formed of the electrochromic material, a voltage is applied between the electrodes. Then, the light reflectivity and light transmittance of the substance change.

Therefore, when an electrode and an electrochromic film are disposed on the surface of a transparent glass plate, the optical transparency of these combinations can be changed by applying an electric field between the electrochromic materials. It is also possible to darken the area by reducing its light transmission.

The display device shown in FIG. 2 is, for example, a NESA (trademark)
It consists of two substrates made of glass or the like as described above, on which transparent electrodes that are selectively excited are provided to form a minute hand 1 and an hour hand 2.

The minute hand 1 is formed on the inner surface of the upper substrate, that is, the transparent glass,
The hour hand 2 is formed on the inner surface of the lower substrate.

The outer surface of the lower substrate is coated with, for example, a mirror-like or reflective material or a light-colored opaque material.

In this way, the second hand and hour hands 1 and 2 are respectively provided on the inner surfaces of two opposing electrochromic plates or substrates, so when the hands 1 and 2 are continuously excited, these hands move as if they were It moves like the hands on a mechanical clock.

That is, the hands can have the appearance of being in two planes and extending to the center of the dial plate, with one hand, for example the minute hand 1, moving over the other hand.

Next, FIG. 3, which shows an exploded view of the display device of the present invention, will be described.

The lower substrate 3 is made of, for example, opaque ceramic or N
It is made of a transparent material such as ESA glass, and its outer surface is coated with a reflective or bright opaque material.

A transparent conductive layer made of tin oxide or the like is coated or laminated on its inner surface to form the electrodes of the 12 hour hands 2.

The 12 hour hands 2 are electrically insulated from each other so that each hour hand 2
are each coupled by a transparent conductor 4 to the time drive signal of the timekeeping device.

An electrochromic substance 5 is disposed above the hour hand 2.

The electrochromic material 5 is formed into a film, for example by vacuum deposition of tungsten oxide, to the desired optimum thickness, for example about 1 micron.

A first gasket 6 made of, for example, a washer or ring-shaped electrically insulating material is placed in contact with the inner peripheral surface of the substrate 3 .

In contact with the first gasket 6 is placed a counter electrode 7 made of, for example, tungsten or any other suitable material.

However, in addition to this, the counter electrode can be formed outside the field of view of the display on either substrate, for example as a tungsten ring.

The counter electrode 1 is formed in such a way that it can be electrically coupled to a conductive material, such as a liquid conductive electrolyte sealed within the display device 19 .

An electrical connection 8 is made to the counter electrode 7 in order to apply a voltage to the counter electrode 7 by means of an electric clock.

A second gasket 9 formed in the same manner as the first gasket 6 is placed in contact with the counter electrode 7.

On the inner surface of the upper substrate 10, 60 electrodes made of, for example, tin oxide are arranged so as to constitute 60 minute hands 1.

The 60 minute hands 1 are not electrically coupled to each other,
Each minute hand electrode is coupled by a conductor 11 to a minute drive signal from an electric clock.

An electrochromic material layer 12 made of, for example, tungsten oxide is disposed on the minute hand 1 .

The two substrates 3 and 10 are assembled in a sandwich manner such that the tungsten oxide layer faces between the cavities formed by the insulating materials 6 and 9 and the counter electrode 7.

A conductive electrolyte such as dilute sulfuric acid is disposed in the cavity.

This electrolyte is transparent and provides an electrical connection between the counter electrode 7 and the electrochromic material 5, 12, thus causing the electrochromic material above the excited needles 1 and 2 to change color and darken, for example blue.

Needles 1 and 2 are excited continuously and visibly by a positive voltage difference between the selected needle voltage and the counter electrode 7.

The voltage applied between the needle and the counter electrode is applied for only a short period of time, for example a fraction of a second.

This is because the electrochromic material 5, 12 remains in its discolored state until said opposite voltage is subsequently applied between the energized needle and the counter electrode 7.

As described above, the electrochromic material used in the present invention changes from a substantially transparent first state to an opaque second state by applying an electric field having a first voltage, and the electrochromic material changes from a substantially transparent first state to an opaque second state by applying an electric field having a first voltage. It is defined as a substance that substantially maintains the second state until an opposite voltage is applied to return it to the first state.

FIG. 4 shows a block diagram of an electrical circuit for applying voltage to the display for selectively energizing the time hands.

This display device generally includes a reference frequency generator 13, a frequency divider 14, a minute counter 15, an hour counter 16,
It is operated by an electronic circuit consisting of a decoder 17 and a driver circuit 18. The circuits that perform these functions are known, for example, from U.S. Pat. .

However, to give an overview, the reference frequency generator 1
3 couples a crystal oscillator with an output frequency of f hertz to a series of frequency divider circuits 14.

A preferred frequency divider circuit is a low power consumption flip-flop counting circuit that divides the frequency by one-half.

The flip-flop circuits are coupled in cascade as a counter and provide an electrical output at a predetermined rate, such as the usual rate of one pulse per minute.

This output is coupled to a ring counter 15.16 which accumulates the number of pulses received and provides a binary count, e.g. a 6-bit binary count for minutes.
For hour 20, there is a 4-bit binary count.

The minute and hour output counts are coupled to the logic circuit of the decoder 17 and driver 18 to excite the hands 1, 2 of the display, the selected energized hands being the counter 1.
It will display the binary count accumulated during 5.16.

Basically, the driver circuit generates the desired excitation voltage between the needle and the counter electrode 7.

For example, a DC voltage source is applied between the conductive needle and the counter electrode via the conductive couplings 4, 8, 111 by means of an electronic switch mechanism that performs DC polarity conversion.

In this way, an excitation voltage is applied to the selected needle and that needle becomes visible.

In this case, the excitation voltage is applied to the selected needle and ρ counterelectrode for only a fraction of the display time, since the electrochromic device remains in the discolored state until a suitable voltage opposite to it is applied. applied.

A change in the output count of the minute or hour counters 15, 16 causes the previously excited minute or hour hands 1, 2 to
becomes colorless and the needle representing the current binary count is excited.

Another embodiment of the present invention will be described below with reference to the exploded view of FIG.

This display device is similar to the electrochromic device shown in FIG. 3, except that the opposite electrode 22 is formed on one substrate, for example, the lower substrate on which the hour hand 2 is formed, by sputtering or vacuum evaporation. The third point is that
The device is different from the one shown in the figure.

The counter electrode 22 is formed on the outer peripheral surface of the hour hand formed on the inner surface of the lower substrate, and a gasket 21 is provided between the substrates 3 and 10.
It is designed to make electrical contact with a liquid electrolyte sealed in a cavity formed by assembling it in a sandwich-like manner.

Further, the counter electrode 22 is disposed so as not to form a visible display section, for example, so as to be located outside the visible display section.

The electrodes constituting the hour hand and minute hands 1, 2 are coated with or placed on electrochromic substances 5, 12 in the form of a thin film.

The specific embodiments of the present invention described above are shown to facilitate understanding of the present invention, and are not intended to limit the present invention.

For example, although the display device of this embodiment displays minutes and hours, it can also display seconds.

[Brief explanation of drawings]

Fig. 1 is a plan view showing a conventional wristwatch display device, Fig. 2 is a plan view showing a wristwatch display device of the present invention, Fig. 3 is an exploded perspective view showing the display device of the present invention, and Fig. 4 is a plan view showing a display device of a wristwatch according to the present invention. FIG. 5 is a block diagram of a logic circuit used in the present invention to selectively display the display sections of FIGS. 1 and 2, and FIG. 5 is an exploded perspective view showing a display device according to another embodiment of the present invention. . 1... Minute hand, 2... Hour hand, 3, 10... Board, 5
,12...electrochromic substance, 6,9.21
... Gasket, 7,22... Opposite electrode.

Claims (1)

[Scope of Claims] A first substrate having a plurality of conductive hands for displaying one minute and having an electrochromic material provided on at least the upper surface of the minute display hands; a plurality of conductive hands for displaying hours; has a department;
a second substrate provided with an electrochromic material on at least the upper surface of the display needle; a counter electrode;
an electrolyte sealed between the substrate and the second substrate and in electrical contact with the counter electrode and the electrochromic material on the first and second substrates; for indicating time in at least hours and minutes; , an electronic timepiece comprising an electrochromic display device comprising a minute display hand and a device for applying a voltage between the counter electrode and one hour display hand and the counter electrode. 2. 60 minute hands are formed on the first substrate to extend radially to the center, and at least 12 hour hands are formed on the second substrate to extend radially to the center. An electronic timepiece comprising an electrochromic display device according to claim 1. 3. An electronic timepiece comprising the electrochromic display device according to claim 1, wherein the counter electrode is disposed on the outer peripheral surface of the display section. 4. An electronic timepiece equipped with an electrochromic display device according to claim 1, wherein the opposite electrode is disposed on the periphery of one of the substrates. 5. An electronic timepiece equipped with an electrochromic display device according to claim 1, wherein the opposite electrode is disposed between the first and second substrates and is insulated from both substrates by an insulating member. . 6. The counter electrode is electrically insulated from the needle display portion on the upper and lower substrates by an insulating material between the upper substrate and the counter electrode and an insulating material between the lower substrate and the counter electrode. An electronic timepiece comprising the electrochromic display device according to item 3. 7. An electronic timepiece equipped with an electrochromic display device according to claim 4, wherein the opposite electrode is disposed around a time display hand.