GB2046958A - Electronic timepiece - Google Patents
Electronic timepiece Download PDFInfo
- Publication number
- GB2046958A GB2046958A GB8001114A GB8001114A GB2046958A GB 2046958 A GB2046958 A GB 2046958A GB 8001114 A GB8001114 A GB 8001114A GB 8001114 A GB8001114 A GB 8001114A GB 2046958 A GB2046958 A GB 2046958A
- Authority
- GB
- United Kingdom
- Prior art keywords
- display
- display device
- electrodes
- analog
- seconds
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G04—HOROLOGY
- G04G—ELECTRONIC TIME-PIECES
- G04G9/00—Visual time or date indication means
- G04G9/0082—Visual time or date indication means by building-up characters using a combination of indicating elements and by selecting desired characters out of a number of characters or by selecting indicating elements the positions of which represents the time, i.e. combinations of G04G9/02 and G04G9/08
- G04G9/0094—Visual time or date indication means by building-up characters using a combination of indicating elements and by selecting desired characters out of a number of characters or by selecting indicating elements the positions of which represents the time, i.e. combinations of G04G9/02 and G04G9/08 using light valves, e.g. liquid crystals
-
- G—PHYSICS
- G04—HOROLOGY
- G04G—ELECTRONIC TIME-PIECES
- G04G9/00—Visual time or date indication means
- G04G9/0023—Visual time or date indication means by light valves in general
- G04G9/0029—Details
-
- G—PHYSICS
- G04—HOROLOGY
- G04G—ELECTRONIC TIME-PIECES
- G04G9/00—Visual time or date indication means
- G04G9/02—Visual time or date indication means by selecting desired characters out of a number of characters or by selecting indicating elements the position of which represent the time, e.g. by using multiplexing techniques
- G04G9/06—Visual time or date indication means by selecting desired characters out of a number of characters or by selecting indicating elements the position of which represent the time, e.g. by using multiplexing techniques using light valves, e.g. liquid crystals
- G04G9/062—Visual time or date indication means by selecting desired characters out of a number of characters or by selecting indicating elements the position of which represent the time, e.g. by using multiplexing techniques using light valves, e.g. liquid crystals using multiplexing techniques
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Electric Clocks (AREA)
- Devices For Indicating Variable Information By Combining Individual Elements (AREA)
Abstract
An electronic timepiece has a liquid crystal analog display device for displaying hours, minutes and seconds, combined with a digital display device (not shown) for displaying hours and minutes and optionally seconds. The analog display device uses five transparent line electrodes (L0-L4) and twentyfour transparent block electrodes (BO1 to BO11 and BI0 to BI11) with liquid crystal material sandwiched therebetween. The line and block electrodes are so shaped and arranged that the analog display device effectively has one hundred and twenty picture elements arranged in inner and outer rings each having sixty elements. One (or more) picture elements on one ring, when energised, produces an hours display, one picture element on the other ring, when energised, produces a seconds display and one picture element on the inner ring and a corresponding picture element on the outer ring, when energised, produce a minutes display. A time division multiplex system for energising the analogue and digital display electrodes is described. The digital and analogue displays are adjacent. <IMAGE>
Description
SPECIFICATION
Electronic timepiece
This invention relates to electronic timepieces for producing an analog time display and a digital time display.
One conventional timepiece produces an analog time display and a digital time display simultaneously. The analog time display is produced by a mechanical display device using indicating hands and the digital time display is produced by a completely electronic display device. Both display devices use, in common, a power source, an oscillator and a frequency divider. Synchronism between the analog time display and the digital time display is possible upon initial setting, but it is difficult to return the displays to synchronism if the indicating hands of the analog time display are changed or corrected by external operation. Thus such a simple timepiece effectively functions as two timepieces whose accuracy is the same. Multi-functional operation is not obtainable by combining both displays.
Aecording to the present invention there is provided an electronic timepiece having an analog display device for displaying hours, minutes and seconds and a digital display device for displaying hours and minutes or hours, minutes, and seconds, the analog display device consisting of five transparent line electrodes, twenty-fourtransparent block electrodes and liquid crystal material sandwiched between the line electrodes and the block electrodes, the line electrodes and block electrodes being so shaped and arranged that the analog display device has one hundred and twenty picture elements arranged in inner and outer rings each of which has the same number of picture elements, the arrangement being such that, in operation, one or more picture elements on one ring, when energised, produces an hours display, and one picture element on the other ring, when energised, produces a seconds display and one picture element on the inner ring and a corresponding picture element on the outer ring, when energised, produces a minutes display.
Preferably the electronic timepiece includes means for producing four or five voltage levels and producing therefrom signals for driving the analog display device.
Means may be provided for driving both the analog display device and the digital display device with AC waveforms by a v-3v generalised AC amplitude selective multiplexing method.
The electronic timepiece preferably includes time counting means connected in common with the analog display device and digital display device, so that the time indicated by the two display devices is synchronised.
The invention is illustrated, merely by way of example, in the accompanying drawings, in which:
Figure 1(a) shows the arrangement of line electrodes of an analog display device of an electronic timepiece according to the present invention;
Figure 1 {by shows the arrangement of block electrodes of the analog display device of Figure 1(a); Figure 1(c) shows the arrangement of picture elements of the analog display device of Figure 1(a); Figure 2(a) shows the arrangement of common electrodes of a digital display device of an electronic timepiece according to the present invention;
Figure 2(b) shows the arrangement of segment electrodes of the digital display device of Figure 2(a);;
Figure 2(c) shows the arrangement of picture elements of the digital display device of Figure 2(a);
Figure 3 is a plan view of an electronic timepiece according to the present invention;
Figure 4 illustrates driving signals using five voltage levels for driving the electronic timepiece of
Figure 3;
Figure 5 illustrates driving signals using four voltage levels for driving the electronic timepiece of
Figure 3;
Figure 6 is a block diagram of a minute counter of the electronic timepiece of Figure 3; and
Figure 7 is a block diagram of a code converting circuit for the electronic timepiece of Figure 3.
An analog display device of an electronic timepiece according to the present invention will now be described in connection with Figures 1 (a) to 1(c).
Figure 1 (a) shows the arrangement of five transparent line electrodes LO-L4. These electrodes are arranged to meander in parallel on the circumference of the electronic timepiece and are in the form of long curved lines and so are referred to as "line electrodes".
Figure 1 (b) shows the arrangement of twenty-four transparent block electrodes BOo - BOr1 and Blo Bl11. The block electrodes BOo-BO11 form an outer ring and the block electrodes Blo-BI11 form an inner ring. Each block electrode is substantially trapezoidal.
The analog display device consists of the line electrodes and the block electrodes with a layer of liquid crystal material sandwiched therebetween.
Where both electrodes overlap picture elements are formed. Figure 1 (c) shows these picture elements.
As will be seen there is an inner ring of sixty picture elements and an outer ring of sixty picture elements.
It will be appreciated that the picture elements need not be arranged in a circular pattern but may be arranged in an elliptical pattern, square pattern etc.
A digital display device of an electronic timepiece according to the present invention will now be described in connection with Figures 2(a) to 2(c).
Figure 2(a) shows the arrangement of three transparent common electrodes COM1, COM2, COM3.
Figure 2(c) shows the arrangement of thirteen transparent segment electrodes SEG1- SEG13.
The digital display device comprises the common electrodes and the segment electrodes with a layer of liquid crystal material sandwiched therebetween.
Where the electrodes overlap picture elements are formed. These picture elements are shown in Figure 2(c). Hours, minutes and seconds are displayed reading from the left.
Figure 3 is a plan view of an electronic timepiece according to the present invention. The time of AM 1 OH 24M 35S is displayed by both the analog and digital display devices. Considering the analog dis play device one picture element on the inner ring is used for the hours display, one picture element on the inner ring and one on the outer ring are used for the minutes display and one picture element on the outer ring is used for the seconds display. Furthermore, time scales for analog display and displays of AM and PM are provided to facilitate reading of the time indication. Although one picture element is used for the hours display, it is also possible to use two picture elements. Switches (not shown) are provided for change of function and for correction.
The electronic timepiece can thus perform additional functions such as chronograph, another time, remaining time, alarm setting and the like. If the time display is changed into another function by operation of a switch, the time display can be returned to the original time display by operating the swich once more, and both the analog and digital displays will again be synchronised. The analog display device and digital display device can be formed in a single liquid crystal display cell or they can be constructed separately.
Figure 4 shows fundamental driving signals for the electronic timepiece of Figure 3. The driving signals have a 1/3 duty using five voltage values according to a V-3V generalised amplitude selective multiplexing method. The voltage values are, 0, the battery voltage VO, a voltage of 2Vo which is twice VO, a voltage of 3Vo which is three times VO and a voltage of 4Vo which is four times Vo. In order to produce these voltage values so that they are each a function of the battery voltage, voltage boosting should preferably be done by means of a capacitor. The loss of leak current by using a capacitor for voltage boosting is smaller than if the voltage values are set by resistance dividers.Thus voltage boosting using a capacitor is particularly suitable for an electronic timepiece having a power source of limited capacity.
Signals d'1, d'2 and d'3 are fed to the common electrodes of the digital display device and signals P'o, p'1, p'2, P'3, P'12, p'23, p'31, p1123 are selectively applied to the segment electrodes depending upon the display to be produced. For instance, in the case of applying the signals d'1, d'2, d'3 to the common electrodes COM1, COM2, COM3 respectively, the signal p'12 may be applied to the segment electrodes where only COM1 and COM2 are driven.
The subscript of each of the "p" signals (referred to as p-signals hereafter) represent a COM electrode to be flickered when the signal is applied. The effective voltage to be applied to the driven picture elements, namely, the picture elements in the ON state, is thus v1 1/3 VO and the effective voltage to be applied to the non-driven picture elements, namely, the picture elements in the OFF state is V0. This method enables a constant contrast to be obtained in accordance with the effective voltage in the display device. This method of driving a liquid crystal display device
using five voltage values is well-known but it is also
generally known that the method using four voltage values in a V-3V method can be utilized.
Figure 5 shows fundamental driving signals for the
electronic timepiece of Figure 3. The driving signals
have a 1/3 duty using four voltage values in a V-3V generalized AC amplitude selective multiplexing method. The voltage values are, 0, the battery voltage VO, a voltage 2Vo which is twice V0, a voltage 3Vo which is three times VO and a voltage 4Vo which is four times V0. Thus one less voltage level is used compared to the driving method illustrated in Figure 4. Since the reduction in the number of voltage levels and a reduction in current value can be expected, using four voltage values compared to five voltage values is, therefore, more advantageous.
Signals d1, d2, d3 are distributed to the common electrodes and signals po, P1, P2, P3, P12, p23, p31 and P123 are selected and applied to the segment electrodes depending upon the display to be produced.
The relation between the ON state and the OFF state of a given picture element is as before, the effective voltage in the ON state being V1 1/3 V0 and in the
OFF state being V0.
For the analog display device, a signal d'o and a signal do need to be provided in the drive method using five voltage levels and in the drive method using four voltage values respectively. The voltage between the signal for segments and the signal d'o or do is always the effective voltage of the OFF state.
Signal selection in the digital display device is by the conventional method, but signal selection in the analog display device is by a quite novel method which will be described. However, the following description shows only one example and the same result can be obtained if subscripts (1, 2, 3) of the signals are replaced. One picture element on the inner ring is used for the hours display for the purpose of simplification, but it is also possible to use two adjacent picture elements. In the following description no account will be taken of the case where the minutes display positionally overlap the hours display and/orthe seconds display. In actual fact, in such a case, the displayed picture element may be caused to flicker or, one of the overlapping displays, may be moved to the adjacent picture element.Here, a method of driving the analog display device using four voltage values is described, but the same considerations apply for methods using five voltage values. The signal pO is applied to non-selected block electrodes, namely, block electrodes which are not used to produce hours, minutes or seconds displays in order to obtain the OFF state with any d-signal (do to d3). The signal do is applied to non-selected line electrodes in order to obtain the OFF state with any p-signal (p0 to P123)- The signal d2 is applied to one line electrode which is selected to produce the minutes display.
The signal d1 is applied to the line electrodes selected to produce the hours display as long as the line electrode for the hours display is not the same line electrode as thatforthe minutes display. In the case where the same line electrode is selected to produce both hours and minutes displays, the signal d2 is applied to the line electrode. The signal d3 is applied to the line electrode selected to produce the seconds display as long as the line electrode for the seconds display is not the same line electrode as that for the minutes display orthe hours display. In the case where the same line electrodes are selected to produce seconds and minutes displays, the signal d2 is applied. In the case where the same line electrode is selected to produce seconds and hours displays, the signal d1 is applied.
Next, the method of applying driving signals to the selected block electrodes (hereinafter referred to as Bl) on the inner ring will be described. The signal p12 is applied to the block electrode Bl selected for both hours and minutes displays. The signal p2 is applied to the block electrode BI selected to produce only the minutes display. However, in the case where the same line electrode is selected for the hours display and the minutes display, the signal p2 or the signal p12 may be applied.To the block electrode BI which is selected to produce only the hours display, the signal p1 is applied in the case where the line electrode for the hours display is different from that selected for the minutes display, and the signal p2 or p12 is applied in the case where the same line electrode is selected for both the hours display and the minutes display.
The method of applying driving signals to the block electrode (hereinafter referred to as BO) on the outer ring will be described. To the block electrode selected to produce both the minutes and seconds display, the signal p12 or p123 is applied in the case where the same line electrode is selected for the minutes display and the seconds display, the signal P2 or P23 or P123 is applied in the case where the same line electrode is selected for all the hours, minutes and seconds displays, and the signal 123 is applied in other cases, but in this case when the same line electrode is selected for both the minutes and seconds displays, the signal p2 may be applied.
To the block electrode BO selected for only the minutes display, the signal p2 is applied. But in this case when the same electrode is selected for the minutes and seconds displays, the signal P23 may be applied and when the same line electrode is selected for all the hours, minutes and seconds displays, the signal P23 or P123 may be applied. To the block electrode BO selected for only the second display, the signal p3 is applied in the case where the line electrode for the seconds display is different from that for the minutes display or that for the hours display. In the case where the same line electrode is selected for the seconds and hours displays, the signal p1 or P31 is applied.In all other cases, the signal application is the same as in the case of the minutes display.
In the case of producing the display shown in
Figure 3, the line electrode L4 and the block electrode BO7 are selected in the seconds display, the line electrode L4 and the block electrode BO4 and B14 are selected in the minutes display, and the line L2 and the block electrode Bllo are selected in the hours display. So the signal d2 is applied to the line electrode L4, the signal d1 to the line electrode L2, the signal p2to the block electrode BO7, BO4 and B4, and the signal p1 to the block electrode By10.
In another embodiment, not illustrated, of the present invention, the outer ring is for the hours display and the inner ring is used for the seconds display but signal selection is fundamentally the same as already described for the illustrated embodiment.
As mentioned above, the analog display device and the digital display device can be driven by the same signals and the number ofterminals can be
reduced by the multiplexing drive method, and, as a
result, complexity of the circuit of the electronic timepiece is reduced.
Figure 6 shows an embodiment of a minutes counter for the electronic timepiece of Figure 3. The minutes counter comprises a ten-ininutes counter and a one-minute counter both of which are decoded with a binary code. Input 61 is a carry-in signal applied from a seconds counter (not shown), input 62 is a manually applied set signal, input 63 is a reference signal for resetting, and output 64 is a carry-out signal applied to an hours counter (not shown). Bit signals are applied from respective flip-flops and are called a, ss, Y, 6, E, 5, ss for convenience. In both the analog and digital display devices, the minutes displays are performed by this counter. Since the digital display can be performed by means of a well-known conventional decoder, description of it is omitted.Regarding the analog display device, especially in the selection of a given line electrode, the given line electrode is selected in the reciprocating selection method in order of LO, L1,
L2, L3, L4, L4, L3, L2, L1, L0 according to the one-minutes counter. So, in this case, conversion into the code has to be performed. As suitable code converting circuit is shown in Figure 7. In this circuit a bit signal a becomes 0101001010 according to the minutes counter, a bit signal b becomes 0011001100, a bit signal c becomes 0000110000 and a bit signal d becomes 0000011111. These bit signals a, b, c takes symmetrical codes every five minutes and the signals for selecting the line electrode can be easily obtained when such codes are decoded.If bit signals
E, 4, n and dare decoded, th signals for selecting the block electrodes are obtained. Thus, the minutes counter can be used in common in the analog display device and the digital display device.
Moreover, the seconds counter and the hours coun- ter can be also used in common, and so, synchronization of both displays is obtained because all the time counters are used in common. In the case where the electronic timpiece can perform other functions and different types of counter are provided for such functions, the digital display device and the analog display device can still be synchronized with each other. Synchronizm can be maintained when the display of another function is changed back to the original time display.
The electronic timepiece of Figure 3 has, of course, an oscillator, a frequency divider, a voltage source etc., but these are not described because their design and construction is well known.
The electronic timepiece of Figure 3, as will be appreciated has both liquid crystal analog and digital display devices and so the invention may be applied to a wristwatch in which miniaturisation is particularly important.
Claims (6)
1. An electronic timepiece having an analog display device for displaying hours, minutes and seconds and a digital display device for displaying hours and minutes or hours, minutes, and seconds, the analog display device consisting of five transparent line electrodes, twenty-four transparent block electrodes and liquid crystal material sandwiched between the line electrodes and the block electrodes, the line electrodes and block electrodes being so shaped and arranged that the analog display device has one hundred and twenty picture elements arranged in inner and outer rings each of which has the same number of picture elements, the arrangement being such that, in operation, one or more picture elements on one ring, when energised, produces an hours display, and one picture element on the other ring, when energised, produces a seconds display and one picture element on the inner ring and a corresponding picture element on the outer ring, when energised, produces a minutes display.
2. An electronic timepiece as claimed in claim 1 including means for producing four or five voltage levels and producing therefrom signals for driving the analog display device.
3. An electronic timepiece as claimed in claim 1 or 2 in which means are provided for driving both the analog display device and the digital display device with AC waveforms by a V-3V generalised AC amplitude selective multiplexing method.
4. An electronic timepiece as claimed in any preceding claim including time counting means connected in common with the analog display device and digital display device, so that the time indicated by the two display devices is synchronized.
5. An electronic timepiece substantially as herein described with reference to and as shown in the accompanying drawings.
6. A liquid crystal timepiece simultaneously displaying analog displays which display hour, minute and seconds on concentric circles or varieties thereof and digital displays which display hour and minute, or hour, minute and seconds by using one or a plurality of liquid crystal display cells, wherein in the display portion for analog display transparent electrodes are provided on the both inner surfaces of the base plates which sandwich the liquid crystal layer, five transparent line electrodes are provided on one inner surface and twenty-four transparent block electrodes are provided on the other inner surface, a hundred and twenty (120) picture elements are obtained by putting said block electrodes and said line electrodes together one upon the other, sixty (60) picture elements are arranged on the inner periphery and sixty (60) picture elements are arranged on the outer periphery, one or a plurality of picture elements on one periphery are used for the hour display in analog mode, one picture element on the other periphery is used for the seconds display, one picture element on the inner periphery and that on the outer periphery are used for the minute display.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1260079A JPS55104784A (en) | 1979-02-06 | 1979-02-06 | Liquid crystal watch |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2046958A true GB2046958A (en) | 1980-11-19 |
| GB2046958B GB2046958B (en) | 1983-03-09 |
Family
ID=11809837
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8001114A Expired GB2046958B (en) | 1979-02-06 | 1980-01-14 | Electronic timepiece |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS55104784A (en) |
| DE (1) | DE3003956A1 (en) |
| FR (1) | FR2448743A1 (en) |
| GB (1) | GB2046958B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2204429A (en) * | 1987-04-24 | 1988-11-09 | Salim Emile Kahil | Clock or watch |
| GB2213965A (en) * | 1987-12-23 | 1989-08-23 | Goro Saito | Analog display on an electronic timepiece |
| GB2350716A (en) * | 1999-06-02 | 2000-12-06 | Promotec Ltd | Digital time display has additional graphics |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2419538A1 (en) * | 1978-03-07 | 1979-10-05 | Suwa Seikosha Kk | ANALOGUE WATCH WITH LIQUID CRYSTALS |
-
1979
- 1979-02-06 JP JP1260079A patent/JPS55104784A/en active Pending
-
1980
- 1980-01-14 GB GB8001114A patent/GB2046958B/en not_active Expired
- 1980-02-04 FR FR8002362A patent/FR2448743A1/en not_active Withdrawn
- 1980-02-04 DE DE19803003956 patent/DE3003956A1/en not_active Withdrawn
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2204429A (en) * | 1987-04-24 | 1988-11-09 | Salim Emile Kahil | Clock or watch |
| GB2204429B (en) * | 1987-04-24 | 1991-09-04 | Salim Emile Kahil | Timepiece. |
| GB2213965A (en) * | 1987-12-23 | 1989-08-23 | Goro Saito | Analog display on an electronic timepiece |
| GB2350716A (en) * | 1999-06-02 | 2000-12-06 | Promotec Ltd | Digital time display has additional graphics |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2046958B (en) | 1983-03-09 |
| JPS55104784A (en) | 1980-08-11 |
| FR2448743A1 (en) | 1980-09-05 |
| DE3003956A1 (en) | 1980-08-07 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PE20 | Patent expired after termination of 20 years |
Effective date: 20000113 |