JPS6161637B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic timepiece having a main battery and an auxiliary battery.

The purpose of the present invention is to prevent the operation of electronic circuits including volatile memory or stop the clock function when replacing the main battery, and to avoid the troublesome task of setting the time or resetting the memory after replacing the battery. The purpose is to provide an easy-to-use electronic clock that eliminates work.

The technology of electronic watches has improved in recent years, and the development of crystal watches has been remarkable. In particular, the direction of development is diverse, including higher precision, multifunctionality, and design-oriented thinning and miniaturization.

For example, high-precision clocks range from 10 seconds per month to ultra-high precision watches with 1 second per month or 3 seconds per year, making it unnecessary to adjust the time even once until the battery is replaced. A considerable number of watches that are not available have also appeared. For such watches, if the clock stops every time the battery is replaced, the once accurate clock must be set again, and to set the time accurately, the clock must rely on a time signal service such as a telephone. Not only was it annoying, but it also caused a lot of psychological resistance.

In this way, as technology related to electronic watches has improved, the inconvenience of the watch stopping when replacing the battery or the memory being erased has increased.

One means for solving such problems is shown in FIG. 1 below.

In FIG. 1, 1 is a time standard source, 2 is an electronic circuit including a volatile memory, 3 is a time and other display means, 4 is a main battery, 5 is a battery voltage drop detection circuit,
Reference numeral 6 denotes an auxiliary battery which is connected in parallel with the main battery 4 via a resistor 7 and a diode 8. Reference numeral 9 denotes a switch, which is normally open when the main battery is installed, and is configured to mechanically detect this and close when the main battery is removed. Then, set the voltage of the auxiliary battery below the battery voltage drop detection voltage,
If you choose an appropriate value that is higher than the clock's operation stop voltage, even when the main battery voltage drops and the battery voltage drop detection circuit starts operating, the main battery voltage will be applied to the auxiliary battery, and the remaining power will be almost 100%. Capacity is secured. Therefore, the auxiliary battery can supply sufficient power to the watch for at most several minutes when the main battery is removed for battery replacement. And when the new main battery is connected again,
The auxiliary battery will be charged again and return to 100% capacity.
Resistor 7 is for suppressing unnecessary current from flowing through the auxiliary battery at this time.
It is also possible to omit the diode 8. However, in the case of such small auxiliary batteries, it is difficult to extract large currents, for example, it is difficult to drive buzzers, lighting lamps, step motors, etc.
If you try to drive it forcibly, a voltage drop may occur, leading to various problems such as the crystal stopping oscillation or the memory being erased.

In the case of a digital display clock such as a liquid crystal display device, the time display is continued by an auxiliary battery when the battery is replaced, and there is no need to set the memory or time after battery replacement. In the case of a watch, as mentioned above, with a small auxiliary battery, it is almost impossible to extract the peak current of several microamperes from the step motor drive pulse. In addition, even if the drive is forced, the rate of erroneous feeds will increase, and the battery voltage may drop, which may adversely affect other oscillation, frequency dividing circuits, memory circuits, etc. . Therefore, in the present invention, after the main battery becomes unable to operate the clock, the step motor stops driving, and until the main battery returns to operating the clock,
During the period when the step motor drive was stopped,
The number of pulses to drive the step motor is counted, and when the main battery returns to its original condition, the counted number of drive pulses are added to the normal pulses to rapidly advance the pointer. The displayed time does not change due to replacement, and just like a digital watch, all you have to do is replace the battery, eliminating the need for the troublesome setting operations associated with it. FIG. 3 is a block diagram of an embodiment of the invention. A main battery 4 normally supplies current to an oscillation circuit 15, a frequency division circuit 16, a frequency division ratio memory 17, a drive circuit 18, and a control circuit 19, and stores the capacity of the auxiliary battery 6. Reference numeral 21 denotes a detection means that detects that the main battery has been removed and the clock can no longer be operated by the main battery, and this output causes the control circuit 19 to stop the pulses that drive the step motor 22 and change the number of pulses. are counted and stored in memory 20. When the main battery is inserted again and the main battery voltage becomes normal, the detection means 21 detects this, the control circuit releases the stoppage of the drive pulses, and adds the number of drive pulses counted in the memory 20 to the normal drive pulses. This structure is such that the step motor is moved rapidly and the pointer 23 is returned to its original position.

Incidentally, the voltage drop of the main battery can be detected mechanically or electrically, and one example is shown in FIG. Figure 2 shows a switch (switching means) that mechanically detects that the main battery has been removed and switches the power source to the auxiliary battery.
As an example, Fig. 2-a shows a state in which the main battery is installed, 4 is the main battery, 6 is the auxiliary battery, 7 is the resistor,
8 is a diode, 10 is a battery lead plate, and the pin connected to the negative electrode of the auxiliary battery 11 is in an open state. Therefore, the voltage of the main battery 4 is applied to the auxiliary battery 6, and the clock drive IC 12 is driven by the main battery 4. Fig. 2-b shows a state in which the main battery is removed, the battery lead plate 10 and the pin 11 are in a closed state, the auxiliary battery 6 is connected to the clock driving IC 12, and the auxiliary battery drives the IC. Also, by utilizing the change in potential difference between points 13 and 14, the circuit can prohibit functions that consume large currents or stop driving the step motor when the main battery is not installed. It is possible to say that Various other mechanisms can be considered as means for detecting whether or not the main battery is attached, and many methods of electrical detection can also be considered.

The circuit that detects the voltage drop and outputs the signal is
This method is disclosed in Japanese Patent Application Laid-open No. 139763/1983, and also includes stopping the supply of drive pulses to the drive circuit according to an input signal, storing the stopped drive pulses in a memory, and furthermore, storing the stopped drive pulses in a memory. A control circuit for fast forwarding a step motor by a number of times is presented in Japanese Patent Application Laid-Open No. 51-69668.
Since this is an obvious technique, the details will be omitted.

As described above, the present invention includes a main battery and an auxiliary battery that is charged by the main battery, and when the watch becomes inactive due to a voltage drop in the main battery, the oscillation circuit is activated by the auxiliary battery. , activates the frequency dividing circuit to stop supplying drive pulses to the drive circuit, stores the number of stopped drive pulses in memory, and when the main battery voltage reaches normal voltage, the drive pulses stored in memory are restored. Since the step motor is configured to rapidly advance by several minutes of pulses, the clock will not malfunction even if the main battery voltage drops due to replacement of the main battery, etc., and it can always provide highly accurate time information, making it an exceptional watch. This has the advantage of eliminating the need for correcting the guideline. Furthermore, since the auxiliary battery does not operate the drive circuit, the battery section can be made smaller.

[Brief explanation of the drawing]

Figure 1...Block diagram showing prior art, Figure 2...
Mechanism diagram showing an embodiment of the battery switching means of the present invention,
FIG. 3: A block diagram showing an embodiment of the present invention.

Claims (1)

[Claims] 1 Power supplies 4 and 6, an oscillation circuit 15, a frequency division circuit 16 that divides the output of the oscillation circuit, a drive circuit 18 operated by the output of the frequency division circuit, and a step motor 22 driven by the drive circuit. , in an electronic timepiece having hands driven by the step motor, detecting a voltage drop in the main battery 4, the auxiliary battery 6 charged by the main battery during normal operation of the timepiece, and the main battery when the timepiece becomes inactive; and detecting means 21 for switching the power source from the main battery to the auxiliary battery, connected between the frequency dividing circuit and the driving circuit, and stopping supply of driving pulses to the driving circuit when the detecting means detects the voltage. a control circuit 19 which stores the number of drive pulses stored in the memory 20 and supplies a fast feed signal to the step motor by the number of pulses stored in the memory when the main battery voltage is in a clock operating state;
An electronic clock characterized by comprising the following.