GB2530549A

GB2530549A - Wristwatch battery changing method

Info

Publication number: GB2530549A
Application number: GB1416973.4A
Authority: GB
Inventors: Richard George Hoptroff
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-09-25
Filing date: 2014-09-25
Publication date: 2016-03-30
Also published as: GB201416973D0

Abstract

A wristwatch has a primary replaceable power source, such as a battery, and a secondary rechargeable power source, such as a capacitor. When the primary power source is being replaced the secondary power source supplies power to the watch. Preferably the secondary power source is charged by the primary power source.

Description

WRISTWATCH BATTERY CHANGING METHOD

This invention is about maintaining time information and volatile data in battery-powered wristwatches while a battery is being changed.

Battery-powered wristwatches require a battery change from time to time.

Even ii the battery is changed while the watch is still keeping time, the process will generally take at least a minute, so the correct time must he re-set after battery changing.

An additional problem in analog watch movements with hands driven by stepper motors is that the timepiece microcontroller may need to know the state of the display. i.e. the direction in which the hands are pointing. This information, normally stored in volatile memory, would be lost when the battery is changed and so this information must be re-set after battery changing.

The state of the art is to accept that a data recovery step is inevitable after battery changing in order to re-set the time, and if necessary. the information about the state of the display. With a simple wristwatch, this might be resetting the time using the crown. In a sophisticated microcontroller-based watch, the non-volatile memory must be recovered by external means, such as pressing the pushers, or using an interface such as a physical serial connection or wireless radio connection.

A limitation of the state of the art is that this data recovery step is a burden. If it could be eliminated, battery changing would be simplified and require less skill.

This invention provides method of preserving and maintaining the data during a battery change. provided the change is relatively fast. Accordingly, and with reference to figure 1. the invention is the following method: 1. Timepiece controller 101 maintains the current time in time memory 102. The time is updated with reference to crystal oscillator 103 and displayed on a display 104. The system is powered by removahle battery 105. A large capacitor 106 is in parallel with the battery. A sensor 107 is connected to timepiece controller 101. Additional memory 108 is provided that can store the state of the display. This might be volatile or non-volatile.

2. When the battery 105 is low and needs replacing, sensor 107 is activated. The timepiece controller 101 then enters a low power mode, where it continues to maintain the current time in time memory 102 with reference to oscillator 103 but does not update display 104. The display state is stored in memory 108.

3. Battery 105 is removed and timepiece controller 101 in low power state is powered by capacitor 106.

4. If the capacitor has been able to maintain the current time in time memory until the new battery 105 is inserted, timepiece controller 101 in low power state is now powered by new battery 105. Sensor 107 is activated again and, with reference to the state of the display stored in memory 108, display 104 is adjusted to correctly display the time represented in time memory 102.

5. If the capacitor has not been able to maintain the current time in time memory until the new battery 105 is inserted, then the time must be re- set manually. However, if memory 108 is non-volatile, then at power-up from a completdy powered down state (i.e. when capacitor 106 had discharged), the state of the display can determined from the non-volatile memory 108 and does not need to here-set.

A typical embodiment would be an analog wristwatch whose mechanical part is driven by regular one-second pulses, and whose sensor 107 is a pushbutton.

When the pushbutton 107 is pressed, position of the hands is stored in volatile memory 108. The pulses are suspended, but time memory 102 continues to be updated. The battery 105 is changed and then the pushbutton 107 is pressed again. On this occasion, the timepiece controller 101 compares the position of the hands stored in volatile memory 108 with the time represented in time memory 102 to deternune the number of pulses required to restore the display.

Timepiece controller 101 then issues a series of rapid pulses so that the display once again displays the correct time.

In a second embodiment, memory 108 is non-volatile. This would at power-up read the display state (i.e. the position of the hands) from the non-volatile memory.

In a third embodiment, sensor 107 is a switch or photodiode that can detect the removal and replacement of the watch back. In this embodiment, the act of removing the back initiates the low power mode and the act of replacing the back restores normal operation.

Claims

CLAIMS1. A wristwatch comprising: a controller for controfling operation of the wristwatch: a replaceable power source for supplying power to the controller; and a rechargeable power source for supplying power to the controller when the rcplaceable power source is removed from the wristwatch.
2. A wristwatch as claimed in claim 1, including a display For displaying time and a sensor which is operatively coupled to the controller, the sensor being arranged to cause the controller to switch between a normal-power mode in which the controller is arranged to update the display over time and a low-power mode in which the controller is arranged not to update the display over time.
3. A wristwatch as claimed in claim 2, including a time memory. wherein the controller is arranged, in the low-power mode, to update over time a current time stored in the time memory but not to update over time the display.
4. A wristwatch as claimed in claim 2 or 3, including a display memory, wherein the controller is arranged, in the normal-power mode, to store a current state of the display in the display memory and to switch to the low-power mode, in response to activation of the sensor.
5. A wristwatch as claimed in claim 4, wherein the controller is arranged. in the low-power mode, to update a current state of the display based on a time stored in the display memory and to switch to the normal-power mode, in response to activation of the sensor.
6. A wristwatch as claimed in any of claims 2-5, wherein the sensor includes a pushbutton, a switch or a photodiode and is arranged to be activated in response to removal of a hack panel of the wristwatch.
7. A wristwatch as claimed in any of claims 2-6, wherein the sensor includes a photodiode which is arranged to be activated in response to a transition between a light state and a dark state.
8. A wristwatch as claimed in any preceding claim, wherein the replaceable power source includes a battery.
9. A wristwatch as claimed in any preceding claim, wherein the rechargeable power source is non-replaceable.
10. A wristwatch as claimed in any preceding claim, wherein the rechargeable power source includes a capacitor or a spring.
11. A wristwatch as claimed in any preceding claim, wherein the replaceable power source and the rechargeable power source are arranged in parallel.
12. A wristwatch as claimed in any preceding claim, wherein the rechargeable power source is arranged to be charged by the replaceable power source.
13. A method for a wristwatch contmller, comprising the steps of: receiving power from a replaceable power source of the wristwatch; and receiving power from a rechargeable power source of the wristwatch when the replaceable power source is removed from the wristwatch.
14. A method as claimed in claim 13, comprising switching, in response to an input from a sensor of the wristwatch, between a normal-power mode in which the controller updates a display of the wristwatch over time and a low-power mode in which the controller does not update the display over time.
15. A method as claimed in claim 14, comprising, in the low-power mode, updating over time a current lime stored in a lime memory and not updating over time the display.
16. A method as claimed in claim 14 or 15, comprising, in the normal-power mode, storing a current state of the display in a display memory of the wristwatch and switching to the low-power mode, in response to activation of the sensor.
17. A method as claimed in claim 16, comprising, in the low-power mode, updating a current state of the display based on a time stored in the display memory and switching to the normal-power mode, in response to activation of the sensor.
18. A method as claimed in any of claims 14-17, wherein the sensor includes a pushbutton, a switch or a photodiode, and comprising the sensor being activated in response to removal of a back panel of the wristwatch.
19. A method as claimed in any of claims 14-18, wherein the sensor includes a photodiode, and comprising the sensor being activated in response to a transition between a light state and a dark state.
20. A method as claimed in any of claims 13-19, wherein the replaceable power source includes a battery.
21. A method as claimed in any of claims 13-20, wherein the rechargeable power source is non-replaceable.
22. A method as claimed in my of claims 13-21, wherein the rechargeable power source includes a capacitor or a spring.
23. A method as claimed in any of claims 13-22, wherein the replaceable power source and the rechargeable power source are arranged in paralleL
24. A method as claimed in my of claims 13-23, wherein the rechargeable power source is arranged to be charged by the replaceable power source.
25. A computer program product directly loadable into the internal memory of a digital computer, comprising software codc portions for performing the steps of claims 13-24 when said product is run on a computer.