EP0783144A1

EP0783144A1 - Clock

Info

Publication number: EP0783144A1
Application number: EP97300026A
Authority: EP
Inventors: Raymond c/o Integrated Display Techn. Ltd. Chan
Original assignee: Integrated Display Technology Ltd
Current assignee: Integrated Display Technology Ltd
Priority date: 1996-01-04
Filing date: 1997-01-03
Publication date: 1997-07-09
Also published as: GB2308899A; GB9600074D0; CN2337593Y

Abstract

A clock (10B) which is battery-operated and comprises a body (11B) on which a display (13B) is provided for time indication, an internal electronic operating circuit, and a plurality of switches (14B to 16B) provided on the body (11B) for controlling the operation of the operating circuit. The clock (10B) includes an illuminator (13B') for illuminating the display (13B) to facilitate time reading in a low ambient lighting condition and a light indicator (13B') for indicating the location of the clock (10B) in a low ambient lighting condition. The indicator (13B') operates at a relatively lower power level than the illuminator (13B'), such as by flashing or providing light at a lower intensity, for power saving. The indicator (13B') may be provided by a separate LED or a portion or the whole of the illuminator (13B').

Description

The present invention relates to a clock which can easily be located in a low ambient lighting condition.
According to the invention, there is provided a clock which is battery-operated and comprises a body on which a display is provided for time indication, an internal electronic operating circuit, a plurality of switches provided on the body for controlling the operation of the operating circuit, and an illuminator for illuminating the display to facilitate time reading in a low ambient lighting condition, characterised in that the clock includes a light indicator for indicating the location of the clock in a low ambient lighting condition, said indicator operating at a relatively lower power level than the illuminator for power saving.
Preferably, the indicator is arranged to flash.
More preferably, the indicator is arranged to provide light at a relatively lower intensity than the illuminator.
In a first preferred embodiment, the indicator is arranged to be manually enabled or disabled by a user by means of one of the switches.
In a second preferred embodiment, the indicator is arranged to be automatically enabled or disabled under the control of the operating circuit.
More preferably, the operating circuit is programmed to enable or disable the indicator at a time presettable by a user.
It is preferred that the operating circuit incorporates a light-sensitive element to monitor the ambient lighting condition in order to enable or disable the indicator at an appropriate ambient light level.
In one preferred embodiment, the indicator and the illuminator are provided by separate light sources.
More preferably, the illuminator is arranged to be manually enabled or disabled by a user by means of one of the switches, and the indicator is provided behind the knob of said one switch.
In another preferred embodiment, the indicator and the illuminator are provided by the same light source.
More preferably, the indicator is provided by a part of the illuminator.
It is preferred that the illuminator is provided by an electro-luminescent panel and the indicator is provided by a portion or the whole of the panel.
In a preferred embodiment, the indicator and the illuminator are provided by a single electro-luminescent panel which is arranged to flash when acting as the indicator and/or to be driven at a lower power level when acting as the indicator than acting as the illuminator.
It is preferred that the operating circuit and the illuminator and indicator are to be powered by separate battery power sources.
The aforesaid clock may have an alarm function which is arranged to operate independently of the indicator.
The invention will now be more particulary described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a front view of a first embodiment of a clock in accordance with the invention, showing a cover of the clock folded open flat;
Figure 2 is a front view corresponding to Figure 1, showing the cover folded closed;
Figure 3 is a schematic block diagram of electronic operating circuitry of the clock of Figure 1;
Figure 4 is a front view of a second embodiment of a clock in accordance with the invention, showing a cover of the clock folded open flat;
Figure 5 is a right side view of the clock of Figure 4, showing the cover folded back to form a rear stand;
Figure 6 is a schematic block diagram of electronic operating circuitry of the clock of Figure 4;
Figure 7 is a front view of a third embodiment of a clock in accordance with the invention, showing a cover of the clock folded open flat;
Figure 8 is a right side view of the clock of Figure 7, showing the cover folded back to form a rear stand;
Figure 9 is a schematic block diagram of electronic operating circuitry of the clock of Figure 7; and
Figure 10 is a schematic block diagram of electronic operating circuitry of a fourth embodiment of a clock in accordance with the invention.

Referring firstly to Figures 1 to 3 of the drawings, there is shown a first clock 10 embodying the invention, which clock 10 is portable and operated on standard dry battery cells. The clock 10 has a pocket-size slim rectangular body 11 having a front side 12 on which a digital LCD (liquid crystal display) display 13 is provided. The clock 10 includes a cover 11' which is hinged to the clock body 11 for folding forwards onto the front side 12 to cover the front side 12 except the LCD display 13 and backwards to extend from the back side of the clock body 11 at an acute angle to act as a rear stand. The LCD display 13 is designed to display, in digital form, the current time and a presettable alarm time, with an alarm set indicator in the form of a bell. An electro-luminescent (EL) back-light panel 13' is provided on the back of the LCD display 13 to facilitate or permit time reading in a dark or low ambient lighting environment.
A plurality of switches are provided on the body front side 12 below the LCD display 13 for controlling the operation of the clock 10, which consist of a slide-switch 14 for selecting TIME SET, LOCK and ALARM SET operation modes, a pair of triangular press-switches 15 for advancing the numerical setting up and down, another slide-switch 16 for switching the ALARM function ON and OFF, and another press-switch 17 for performing a SNOOZE function and switching on and off the back-LIGHT function, all as generally known in the art.
As shown in Figure 3, the clock 10 incorporates internal electronic operating circuitry for controlling the operation of the clock 10. The operating circuitry is designed based on a micro-processor as a clock driving circuit 20 to perform the various clock functions, as generally known in the art. The clock driving circuit 20 is connected directly to the LCD display 13 and indirectly to the EL back-light panel 13' via a back-light driving circuit 21, for controlling their respective functions. A first battery power supply 23 is employed to supply power to the clock driving circuit 20. A second battery power supply 24 is used to supply power to the back-light driving circuit 21 via the press-switch 17, for switching on and off the EL back-light panel 13'. The press-switch 17 is connected directly to the clock driving circuit 20 for controlling the snooze function. User controls 18 provided by the switches 14 to 16 are connected directly to the clock driving circuit 20.
The knob of the press-switch 17 is semi-transparent or translucent and, internally thereof, an LED (light-emitting diode) 17' is provided to render, when necessary, the knob illuminating. The LED 17' is to be driven by an LED driving circuit 22 which is connected indirectly to the second battery power supply 24 via a further slide-switch 19. The slide-switch 19 is provided on the back of the clock body 11 for enabling and disabling the operation of the LED driving circuit 22. The LED driving circuit 22 is designed to drive the LED 17' in an intermittent or flashing manner.
It is to be appreciated that the driving circuits 20 to 22 may be partially or fully integrated together. Also, the two battery power supplies 23 and 24 may be replaced by a single battery power source. The battery power supplies/source employed may be rechargeable and used in combination with solar power panels.
In a dark or low ambient lighting environment, such as in the middle of the night, a user of the clock 10 may wish to read the time. The clock 10 must first be found or located before the user can read the time therefrom. A Night Finder function provided by means of said flashing of the LED 17' and hence the press-switch 17 will enable the user to find the clock 10 easily. Once getting to the clock 10, the user may press the press-switch 17 to turn on the back-light panel 13' to read the time on the LCD display 13.
Continuous turning on of the back-light panel 13' will not only cause too much power drain of the battery power supply 24 but will also unnecessarily disturb the user's sleeping. The flashing of the LED 17' (the press-switch 17 visually), when enabled by means of the back slide-switch 19, is controlled at a reasonably low frequency so as not to drain too much power and yet sufficiently prominent to indicate the location of the clock 10.
The physical association of the Night Finder LED 17' with the press-switch 17, the latter being for turning on the back-light panel 13', has the particular advantage, in this example, that the press-switch 17 is readily locatable in terms of position for the user to turn on the back-light panel 13' as a necessary step before time can be read. It is, however, envisaged that the Night Finder LED 17' may be provided at a separate position, such as centrally above the LCD display 13, to provide independent prominence.
Although the alarm function of the clock 10 operates independently of the Night Finder LED 17', by reason of the illumination by the Night Finder LED 17', the press-switch 17 (acting also as a snooze button) is readily locatable by the user to activate the snooze function in response to an alarm setting off.
Referring next to Figures 4 to 6 of the drawings, there is shown a second clock 10A embodying the invention, which has a construction similar to that of the first clock 10 described above, with like parts designated by the same reference numerals suffixed by a letter "A" compared with the first clock 10. In this clock 10A, the cover 11A' is designed to close the entire front side 12A of the clock body 11A including the LCD display 13A. Also, the switch 17A (for the snooze and back-light functions) is provided on the back of the clock body 11A, in the form of a micro-switch, for triggering by the cover 11A' in the condition acting as a rear stand. In order to activate the snooze function and/or to switch on the back-light panel 13A', the user is required to press the clock body 11A slightly backwards against the cover stand 11A' for operating the micro-switch 17A. The internal operating circuitry of the clock 10A is also similar to and operates in substantially the same manner as that of the previous clock 10.
The only major difference resides in the provision of the Night Finder function, which, in the case of the clock 10A, is provided by means of a small portion 17A', at the bottom right corner, of the EL back-light panel 13A' for the LCD display 13A. In operation, the Night Finder driving circuit 22A, which is switchable on and off by means of the switch 19A provided on the back of the clock body 11A, drives the EL portion 17A' to flash in order to indicate the location of the clock 10A.
As the EL portion 17A' is only a very small part of the overall EL back-light panel 13A', it is comparatively much less power-consuming and may, therefore, be energised continuously instead of intermittently. It is appreciated that the EL portion 17A', whether flashing or being driven continuously, will provide light at an (average) intensity which is relatively lower than that provided by the overall back-light panel 13A'.
The Night Finder portion 17A' of the EL back-light panel 13A' may be chosen to be provided right behind a segment of the time digits or the time colons (flashing every second) or any other preferred location to have the desired visual prominence.
Reference is now made to Figures 7 to 9 of the drawings, which show a third clock 10B embodying the invention. This clock 10B has a construction similar to that of the second clock 10A described above, with like parts designated by the same reference numerals suffixed by a letter "B" instead of "A" compared with the second clock 10A. The internal operating circuitry of the clock 10B is also similar to and operates in substantially the same manner as that of the previous clock 10A.
The only major difference resides in the provision of the Night Finder function, which, in the case of the clock 10B, is provided by means of the whole of the EL back-light panel 13B' driven by the back-light driving circuit 21B without a separate Night Finder driving circuit. A Night Finder timing circuit 22B is connected to the back-light driving circuit 21B, which timing circuit 22B is switchable on and off by means of the switch 19B provided on the back of the clock body 11B and is designed to provide a timing signal for the back-light panel 13B' to flash in order to indicate the location of the clock 10A. In such a flashing mode, the driving circuit 21B drives the back-light panel 13B' at a lower intensity than in the continuous mode for normal back-lighting. The combination of flashing and lower intensity driving minimises power consumption.
Reference is finally made to Figure 10 of the drawings, which shows the internal operating circuitry of a fourth clock embodying the invention. This operating circuitry is similar to and operates in substantially the same manner as that of the previous clock 10B, with like parts designated by the same reference numerals suffixed by a letter "C" instead of "B". The only major difference resides in the configuration of the clock driving circuit 20C which now incorporates the Night Finder timing circuit to also provide a timing signal for the back-light panel 13C' to flash, at a reduced intensity, for indicating the clock location.
It is envisaged that the LCD display may be back-lighted by means of, for example, one or more LEDs, with one or more of them being driven to flash at a suitable frequency or to light up continuously, preferably at a reduced intensity, to indicate the clock location.
It is clear that the use of a separate less power-consuming light source (as in the clock 10) or only a part of the LCD display back-light light source (as in the clock 10A) to provide the Night Finder function, particularly but not necessarily together with its flashing or intermittent illumination, minimises power consumption. The demand of power is also minimised by using the whole of the LCD display back-light light source (as in the clock 10B or the fourth clock) in a flashing mode, particularly but not necessarily at a reduced intensity, to provide the Night Finder function. Power consumption is known to be critical for battery-operated clocks. As the light provided by the Night Finder function is of a reduced intensity or average intensity, compared with that of the normal back-lighting for time reading, the battery life can be maximised and the disturbance to a sleeping user can be minimised.
In the described embodiments, the Night Finder function is capable of being enabled (used) or disabled (not used) manually a user operating the switch 19 or 19A. It is envisaged that, alternatively, the Night Finder function may be automatically enabled/disabled under the control of the internal operating circuitry of the clock. In one design, the micro-processor of the operating circuitry is programmed to enable and disable the Night Finder function at different times respectively, such as at dusk and at dawn, which are presettable by the user to automatically cover only the hours of darkness. In an alternative design, the operating circuitry incorporates a light-sensitive element, such as a photo-diode/sensor, to monitor the ambient light level and, accordingly, to automatically enable or disable the Night Finder function at a suitable time when the indoor lighting condition becomes too dark or sufficiently bright, respectively, for sight.
It is to be appreciated that the clock of this invention may have, alternatively, an analogue time display in the form of hour, minute and second hands.
The invention has been given by way of example only, and various other modifications of and/or alterations to the described embodiments may be made by persons skilled in the art without departing from the scope of the invention as specified in the appended claims.

Claims

A clock (10B) which is battery-operated and comprises a body (11B) on which a display (13B) is provided for time indication, an internal electronic operating circuit, a plurality of switches (14B to 16B) provided on the body (11B) for controlling the operation of the operating circuit, and an illuminator (13B') for illuminating the display (13B) to facilitate time reading in a low ambient lighting condition, characterised in that the clock (10B) includes a light indicator (13B') for indicating the location of the clock (10B) in a low ambient lighting condition, said indicator (13B') operating at a relatively lower power level than the illuminator (13B') for power saving.
A clock (10B) as claimed in claim 1, characterised in that the indicator (13B') is arranged to flash.
A clock (10B) as claimed in claim 1, characterised in that the indicator (13B') is arranged to provide light at a relatively lower intensity than the illuminator (13B').
A clock (10B) as claimed in claim 1, characterised in that the indicator (13B') is arranged to be manually enabled or disabled by a user by means of one of the switches (17B).
A clock (10B) as claimed in claim 1, characterised in that the indicator (13B') is arranged to be automatically enabled or disabled under the control of the operating circuit.
A clock (10B) as claimed in claim 5, characterised in that the operating circuit is programmed to enable or disable the indicator (13B') at a time presettable by a user.
A clock (10B) as claimed in claim 1, characterised in that the operating circuit incorporates a light-sensitive element to monitor the ambient lighting condition in order to enable or disable the indicator (13B') at an appropriate ambient light level.
A clock (10) as claimed in claim 1, characterised in that the indicator (17') and the illuminator (13') are provided by separate light sources.
A clock (10) as claimed in claim 8, characterised in that the illuminator (13') is arranged to be manually enabled or disabled by a user by means of one of the switches (17), and the indicator (17') is provided behind the knob of said one switch (17).
A clock (10B) as claimed in claim 1, characterised in that the indicator (13B') and the illuminator (13B') are provided by the same light source.
A clock (10A) as claimed in claim 10, characterised in that the indicator (17A') is provided by a part of the illuminator (13A').
A clock (10B) as claimed in claim 10, characterised in that the illuminator (13B') is provided by an electro-luminescent panel and the indicator (13B') is provided by a portion or the whole of the panel.
A clock (10B) as claimed in claim 10, characterised in that the indicator (13B') and the illuminator (13B') are provided by a single electro-luminescent panel which is arranged to flash when acting as the indicator (13B') and/or to be driven at a lower power level when acting as the indicator (13B') than acting as the illuminator (13B').
A clock (10B) as claimed in claim 1, characterised in that the operating circuit and the illuminator (13B') and indicator (13B') are to be powered by separate battery power sources.
A clock (10B) as claimed in claim 1, having an alarm function which is arranged to operate independently of the indicator (13B').