Control Switches To Watch Having A Digital Display

Abstract

A watch wherein the high frequency signal produced by a quartz crystal oscillator is applied to a counter and decoder which produces driving signals for application to a digital display such as light emitting diodes, a liquid crystal display, or a plasma display. Functional push-button switches are provided for adjusting time, and for resetting the counter. The switches are preferably positioned on the upper or front side of the case and electronic or mechanical means are provided for locking said switches.

Description

BACKGROUND OF THE INVENTION

This invention relates to watches incorporating digital displays having low power dissipation such as light emitting diodes (LED), liquid crystal displays, and plasma displays, and wherein a quartz crystal oscillator serves as a time standard, and the counter and driving circuitry for said liquid crystal displays are formed from COS/MOS (metal oxide semiconductor transistors disposed in the complementary symmetry configuration) integrated circuits.

Adjusting devices for conventional mechanical or electronic watches are generally provided on the side of the case. When so positioned, there is a lack of correspondence between the position of the control devices and the particular digits of the display so that adjustment of time is difficult. Further, the adjusting devices of the above-described types of watches are generally push-button type switches which are subject to accidental operation during normal wear.

SUMMARY OF THE INVENTION

Generally speaking, in accordance with the invention, a watch having a digital display, a quartz crystal oscillator for producing a high frequency signal, and a counter and decoder circuit for producing low frequency timing signals from said high frequency signal for driving said digital display is provided. Push-button switch means are connected to said counter and decoder circuits for adjusting time, and for resetting, the counter means. Said switchs may be positioned on the upper or front side of the case.

Mechanical or electronic means are provided for locking said switch means to prevent the accidental operation thereof. Said switch means may include separate switch means for adjusting the hour, the tens digit of the minute, and the units digit of the minute, which switches would be arranged on said upper or front side of the watch case in the same order as said digits of the digital display. Said switch means may be make switches which are off during normal operation and are on when adjusting time or resetting the circuit.

Said switch means may interconnect a source of voltage and the drain electrode of a saturated P or N channel MOS transistor, the source electrode of said transistor being connected to ground, the gate electrode of said transistor being biased to turn said transistor on. Inverter circuit means may be connected to said transistor drain electrode to detect the signal at said transistor drain electrode dependent on the state of said switch means.

Accordingly, it is an object of the arrangement according to the invention to provide an easy and accurate method for adjusting time in electronic watches having digital displays.

Still another object of the invention is to provide an arrangement whereby the careless actuation of adjusting switches will not result in unintentional adjustment.

A further object of the invention is to provide a watch incorporating counter and driving circuitry integrated to the maximum extent.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification and drawings.

The invention accordingly comprises the features of construction, combinations of elements, and arrangements of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of a wrist watch having a digital display in accordance with the invention;

FIGS. 2a and 2b are fragmentary sectional views depicting the mechanical locking arrangement according to the invention for the adjusting switches of an electronic watch incorporating a digital display;

FIG. 3 is a circuit diagram of an electronic device for locking adjusting switches in accordance with the invention;

FIG. 4 is a block diagram of a watch according to the invention;

FIG. 5a is a circuit diagram of a resettable flip-flop having time adjusting circuits in accordance with the invention;

FIG. 5b is a block and circuit diagram of an inverter circuit in accordance with the invention; and

FIG. 6 is a circuit diagram depicting an alternate embodiment of a portion of the circuit of FIG. 5a.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, the wrist watch in accordance with the invention depicted consists of a band 1 secured to a watch case 2 having a digital display panel 3 mounted on a front, upper face thereof. Also mounted on said front upper face are three push-button switches 4 for adjusting time, a push-button switch 5 for system resetting and a push-button switch 6 for starting and stopping the watch. Also provided is a locking device 7 mounted on the side of the watch case.

The three time adjusting switches 4 are adapted so that the left-most switch as viewed in FIG. 1 adjusts the hour indication on the digital display 3, the middle switch adjusts the tens digit of the minute display while the right-most of the push-buttons 4 adjust the units digit of the minute display. Since the alignment of the switches corresponds to the alignment of the digits on display 3, time adjustment can be readily achieved.

A mechanical locking arrangement for push-button switches 4, 5 and 6 is depicted in FIGS. 2a and 2b. As shown in FIG. 2a, each of the push-buttons of switches 4, 5 and 6 is normally biased in the upper or open position. At such position, the spring contact 10 is out of engagement with the fixed contact 11. When a push-button is depressed, said spring contact engages said fixed contact to close that switch. The mechanical locking device 7 includes a plurality of disc-shaped stoppers 8 mounted in spaced relation on the locking shaft 7, said locking shaft being axially displaceable in the direction of the arrows in FIG. 2b. When the locking shaft is positioned as depicted in FIG. 2b, each of the stoppers 8 is aligned with one of the push-buttons of switches 4, 5 and 6, so as to prevent the displacement of said push-button. In this position, accidental operation of the push-buttons is impossible. When the locking shaft is displaced so that the stoppers 8 are out of registration with the push-buttons, said push-buttons may operate in the normal manner. Individual locking devices may be provided for each push-button, as by providing a push-button which is rotatably mounted, with one rotatable orientation being a locked position, and another rotatable orientation being an operable position.

An electronic locking arrangement according to the invention is depicted in FIG. 3, wherein a locking switch 7 is interposed between the battery and each of the adjusting switches 4, 5 and 6. If the locking switch 7 is in the off position, the remaining switches are inoperative. In such a state, the operation of switches 4, 5 and 6 will not affect the state of the circuits to which said switches are connected. On the other hand, when switch 7 is closed, the remaining switches may then be operated to control their respective circuits. The diodes in series with each of the adjusting switches 4, 5 and 6 are provided to prevent mis-operation when more than two switches are pushed.

Referring now to FIG. 4, a block diagram of the watch in accordance with the invention is depicted. In said watch, a quartz crystal oscillator a generates a time standard signal of high frequency which is applied to a divider circuit b adapted to produce a 1-minute signal. The 1-minute signal from divider b is applied to 1/10 divider c which consists of a 1/10 counter for producing a 10-minute signal. The 1/10 divider applies the 1-minute signal to a decoder c' which produces driving signals for the minute digit of the digital display.

The 10-minute signal from 1/10 divider c is applied to a 1/6 divider d which produces a 1-hour signal. Said 1-hour signal is applied to a 1/24 divider e. The 10-minute signal is applied by 1/6 divider d to decoder d' to produce the driving signals for the tens digit of the minute display while the 1-hour signal is applied by the 1/24 divider e to a decoder e' for driving the hour display. Each of decoders c', d' and e' may include buffer amplifiers. Switches 4a, 4b and 4c are time adjusting switches for the respective adjustment of the hour, the tens digit of the minute display and the units digit of the minute display. Switch 5 is a system resetting switch which resets all of the circuits. Start-stop switch 6 is provided for resetting only divider b. All of the switches are off in the normal operation of the watch, the gate voltage of the controlling inverters in each divider circuit being supplied by resistors R.sub.1, R.sub.2, R.sub.3, R.sub.4, and R.sub.5. If time is to be adjusted, or if the circuits are to be reset, locking switch 7 is first closed, and then the particular one of switches 4, 5 and 6 is pushed.

FIG. 5a depicts the details of the circuitry of one divider stage formed from a resettable flip-flop and the input circuitry thereof. FIG. 5b depicts the circuit diagram of an inverter such as the inverters incorporated in the circuitry of FIG. 5a. The circuits of FIGS. 5a and 5b are formed from COS/MOS transistors. During normal use, both time adjusting switch 4 and resetting switch 5 are off. At this state, transmission gate T.sub.1 is on and transmission gate T.sub.2 is off. The input signals are therefore supplied to the flip-flop through transmission gate T.sub.1. The input gate of inverter I.sub.1 is connected to ground by resistor R.sub.5, and the common resetting line R is at a high state, so that all of the flip-flops are operated in the divider chain. When time is adjusted, additional input signals are applied to the flip-flop by the repetitive turning of switch 4 on and off. When switch 4 is on, transmission gate T.sub.1 is off and T.sub.2 is on. In that case, the input signal is inversed by an inverter I.sub.2 and is applied through gate T.sub.2 to the flip-flop. Therefore, an additional input signal is produced each time switch 4 is turned on.

If switch 5 is turned on, the flip-flop is reset to the 0 state since the gate voltage of inverter I.sub.1 becomes high, and the common resetting line R is set at the ground voltage.

An alternate arrangement to the circuit of FIG. 5A, which dispenses with the resistors such as resistor R.sub.5 is depicted in FIG. 6. In place of resistor R.sub.5, a MOS transistor T.sub.3 replaces resistor R.sub.5 when switch 5 is turned off, the gate voltage of the inverter is set at ground since transistor T.sub.3 is on. The output of the inverter R.sub.1 is therefore high. When switch 5 is closed, the output of inverter I.sub.1 is at the ground voltage, since the gate voltage of the inverter is increased to a high voltage. By controlling the input to the inverter by the drain voltage of a saturated P or N channel MOS transistor, substantial reductions in size and reliability can be produced, since substantially all of the circuits can be produced by monolithic integrated circuits without the need for external resistors. Transistor T.sub.3 is designed to have high impedance for reducing power consumption.

The arrangement according to the invention permits the simple and efficient control of time adjustment and resetting through the positioning and order of the switches. The provision of the locking device increases the reliability of the watch, while the forming of the switches as make switches, avoids the necessity of maintaining the switches in the on position. As used herein, the term "digital display" refers to light emitting diodes, liquid crystal displays, plasma displays, and other low power consumption displays.

It will thus be seen that the objects set forth above, and those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above constructions without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Claims

What is claimed is:

1. A watch comprising quartz crystal oscillator means for producing a high frequency time standard signal; counter and decoder means for producing timing signals from said high frequency time standard signal; display means for providing a digital display of time in response to said timing signals; a watch case containing said quartz crystal oscillator means and counter and decoder means, and having said display means on a side thereof; push-button switch means for the separate adjustment of time and for resetting said counter means, said switch means being positioned on said watch case on the side thereof having said display means thereon, mechanical locking means for selectively retaining said respective switch means in their inoperative states.

2. A watch as recited in claim 1, wherein each of said switch means includes a push-button and means for biasing said push-button in said inoperative position, said switch means push-buttons being substantially aligned along an axis; said mechanical locking means including a shaft member longitudinally displaceable along said axis and a stopper member associated with each of said switch means push-buttons and mounted on said shaft member for registration with the associated push-button member at a first position of said shaft member and non-interference with said push-button at a second position of said shaft member, said shaft member projecting outside of said case for the manual manipulation thereof, said push-buttons being inoperative when said stopper members are in registration therewith.

3. A watch as recited in claim 2, wherein all of said switch means are make switches which are off when inoperative during normal operation of said watch and are on when operative for time adjustment, resetting and setting.

4. A watch as recited in claim 3, including a source of voltage, a ground, inverter circuit means for control by one of said switch means and having an input, and a MOS transistor connected with its source-drain path intermediate said inverter means input and ground, said one switch means being connected intermediate said source of voltage and said inverter input so that the state of said inverter is determined by the drain voltage of said MOS transistor.

5. A watch comprising quartz crystal oscillator means for producing a high frequency time standard signal; counter and decoder means for producing low frequency timing signals in response to said time standard signal; digital display means for the digital display of time in response to said timing signals; switch means including separate push buttons for adjusting time and resetting said counter means; and mechanical locking means operatively coupled to said switch means for selectively rendering said push buttons inoperative.

6. A watch as recited in claim 5, wherein at least some of said push-buttons are aligned along an axis, said locking means including a longitudinally displaceable shaft member, a stopping member associated with each of said aligned push-buttons mounted on said shaft member, said stopping members being selectively positionable at a first position at which said stopping members are in registration with their respective push-buttons to render said push-buttons inoperative, and a second non-interfering position with said push-buttons in response to the manual manipulation of said shaft member.

7. A watch as recited in claim 5, wherein each of said switch means are operative when on, said electronic locking means including further switch means connected in series with each of said first-mentioned switch means for rendering said first - mentioned switch means inoperative when said further switch means is open.

8. A watch as recited in claim 5, wherein all of said switch means are make switches which are off when inoperative during normal operation of said watch and are on when operative for time adjustment and resetting said counter means.

9. A watch as recited in claim 8, including a source of voltage, a ground, inverter means for control by one of said switch means and including an input, and a MOS transistor, said MOS transistor being connected with its source-drain path intermediate said inverter means input and said ground, said one of said switch means being connected intermediate said source of voltage and said input whereby the state of said inverter means is dependent on the stage of said one switch means.

10. A watch comprising a quartz crystal oscillator means for producing a high frequency time standard signal; counter and decoder means for producing timing signals in response to said time standard signal; digital display means for the digital display of time in response to said timing signals; push-button switch means operatively coupled to said counter and decoder means for adjusting time and for resetting said counter means; a source of voltage; a ground; inverter means for operatively coupled said switch means to said counter and decoder means and having an input; and a MOS transistor connected intermediate said ground and said inverter means input, one of said switch means being connected intermediate said inverter means input and said source of voltage, whereby the state of said inverter is responsive to the drain voltage of said MOS transistor.

11. A watch comprising quartz crystal oscillator means for producing a high frequency time standard signal; counter and decoder means for producing low frequency timing signals in response to said time standard signal; digital display means for the digital display of time in response to said timing signals; push-button switch means for adjusting time and resetting said counter means; and electrical locking means operatively coupled to said switch means for selectively rendering said switch means inoperative by the selective disabling of the circuits including said switch means.