FR2481826A1 - ELECTRONIC WATCH - Google Patents

Abstract

An electronic timepiece has 7- segment digital display sections and a dot matrix display section (25). Circuitry is provided to produce a display of characters and/or pictures on the dot display section to illustrate function modes of the electronic timepiece. Slightly altered pictures may be displayed sequentially to give the impression of movement. Thus for example a running figure may be represented. This indicates that the watch is being used as a chronograph. The drive circuit includes a dot matrix pattern generator (22) and a scanning electrode drive circuit (24) for the dot matrix.

Description

The present invention relates to an electronic watch

  comprising a signal generation circuit of reference

  a frequency division circuit, a time counter circuit, a display decoder circuit, a display element, external control means and

  a battery, and an object of the invention is to increase the diversity

  display and improve the operational possibilities. The invention also relates to a liquid crystal display device in which

  combination of a dot matrix display and an

  segments, and in particular on a system of attack

  than a liquid crystal cell in such a device

  tif. For some time, an electronic watch has been considered using a liquid crystal display element as a display means, thinking that it

  is a device capable of appropriating quickly

  a significant part of the market. The reason is, for example, that unlike the needle watch, the electronic watch can be manufactured without technical difficulties with a low manufacturing cost. However, since the electronic watch can be manufactured without technical difficulties, as indicated above, the

  manufactured electronic watches tend to be identical

  that is to say, it is difficult to manufacture

  electronic watches that are different from other

  very electronic, this leading to fierce competition

  born in the price reduction. An object of the invention is therefore to enable an electronic watch to present

  various displays in order to distinguish the electronic watches

  each other. The classic electronic watch

  The liquid crystal display type does not offer great possibilities of operation, although it has been modified to perform various functions. So, in general, in the classic electronic watch manufactured so far, operations are explained with

  letters on the splitter panel of the display.

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  However, because the characters are written in a narrow part, they are too small to be readable

and I have a beautiful aesthetic.

  In view of the foregoing, a method of displaying operating modes using characters or pictographs according to a dot matrix display system is employed in the invention. The observer can instantly read the operating modes thanks to the characters or pictograms displayed. Even a person

  not knowing French can read the modes of operation

  if they are displayed with the help of picto-

  grams. There is known in the prior art a watch which displays images which are constituted by segments representing a chronograph mode, a wake-up mode, etc. In the classic watch, the chronograph mode, for example, is indicated by an image showing a person

  running. However, the classic watch is disadvantage-

  If you increase the number of operating modes, the number of images increases, so

  that the size of each image is necessarily reduced.

  In addition, the classic watch is disadvantageous in that when the display image of a mode other than

  the present mode disappears, the display shows

  its qualities from the point of view of aesthetics. The invention

  was made in order to remove the difficulties

  mentioned above which accompany a classic watch. According to the invention, pictograms and characters are displayed according to the display system

  dot matrix, thanks to which the size of the pictograms

  mes or characters is larger and the area that is not used for display can be minimized. Another object of the invention is to improve the display quality of a liquid crystal display device, so as to produce a display device for

  liquid crystals that can be observed conveniently.

  A liquid crystal display device is advantageous in that its power consumption is low, it operates from a low voltage and it can be miniaturized. As a result, liquid crystal display devices are widely used

  for some time in devices such as

  very portable calculators. These devices having been modified in various ways, it has appeared necessary to make a display panel that can display information of various kinds. As a result, essentially a multiplex drive system has been employed to drive the liquid crystal display device. In addition, a display panel with a matrix of

  points to display information of various kinds.

  The dot matrix display panel is a device

  display in which the image elements of the display

  are formed at the intersections of several electro-

  parallel scanning and several parallel signal electrodes. This display device allows

  to easily display characters or pictograms.

  Therefore, if the segment display system is combined with the dot matrix display system to form a liquid crystal display device, this display device will be more advantageous and convenient to use, since a mode of operation may be displayed by means of characters or pictograms, whereas this display of the mode of operation was difficult or occupied an excessive place in the case of

  displaying various information.

  However, the method of displaying data on the liquid crystal display device which is

  obtained by the combination of the two systems remains

  with regard to the following points.

  Figure 10 shows a characteristic curve

  representing the contrast as a function of the voltage

  In FIG. 1, the reference A designates the effective voltage when the contrast is 10% of the difference in value between the contrast when the effective voltage is equal to zero and the contrast when the actual voltage is saturated, and the reference B denotes the effective voltage when the contrast is 90% of the difference value. The actual voltages A and B "threshold voltage Vth" and "effective saturated voltage Vs" will be referred to respectively when these denominations are applicable. The threshold voltage Vth is such that the contrast with an effective voltage lower than the threshold voltage Vth can be practically considered equal to the contrast with a zero effective voltage. It is essential that we have Eet <Vth, in order to avoid the appearance of halftones. If and e is fixed E and between the effective voltages A and B,

  halftones appear. In the case of the attack system

  in multiplex, the effective voltage Eecl which is applied

  during a lighting operation, and the voltage

  effective Eet for an extinguishing operation have

the following values + 2

E V 1+ N

  OV - 1 a - 2) 2 and O N (designating by N the number of scanning electrodes, by a polarization ratio and by V0 the driving voltage). As these expressions show, the range of the ratio between Eecl and Eet (Eecl / Eet) is reduced when

  the parameter N is increased, i.e. the difference

  The contrast ratio decreases when the parameter N is increased. The parameter N must therefore correspond to as small a number as possible. However, in the case of

  matrix of points, a number of

  It is therefore difficult to obtain a satisfactory display because of the number of electrode terminals, without increasing the parameter up to a duty cycle of 1/7 or 1/8. In the case of a regular configuration display panel, as for a dot matrix structure, even if half-tones

  are produced to a certain extent, the lack of uniformity

  The half-tint produced is not as important as can be expected. However, if parameter N is set to a duty cycle of 1/7 or 1/8 for example, in the case of a 7-segment system, then it is very difficult to read a display with half-tones. . Thereby,

  the parameter N is limited in this case to a cyclic ratio

  than 1/4 to produce a satisfactory display on the liquid crystal surface. In the case where we realize a

  display on a liquid crystal panel in these

  With a duty cycle of 1/8 for the dot-matrix side and a duty cycle of 1/4 for the 7-segment cost, the actual voltages for the lighting operation are Vf V0 / 3 respectively. of V V0 / 3, (with a = 3). Therefore, the display has portions having different contrasts when operating the liquid crystal panel, i.e. the lack of uniformity due to contrast difference

is important.

  An object of the invention is to make disappear

the difficulty described above.

  The invention will be better understood when reading

  the following description of embodiments and in

  Referring to the accompanying drawings in which: Figure 1 is an explanatory representation

  showing an external view of an example of an electronic watch

than corresponding to the invention.

  Figures 2-a through 2-c are explanatory representations showing the fashion indication images which

  are used in the example corresponding to the invention.

  Figures 3-a and 3-b are explanatory representations showing examples of a timing control mode display image in the example corresponding to the invention. Figures 4-a through 4-e are explanatory representations showing mode indication images of

  chronograph in the example corresponding to the invention.

  Figures 5-a through 5-e are representations

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  explanatory notes showing images indicating the mode of

  minute-counter in the example corresponding to the invention.

  Figure 6 is a block diagram that shows

  all the circuits of the electronic watch correspond to

  to the invention. Fig. 7 is an explanatory diagram showing the dot matrix part which is divided into blocks

of picture elements.

  Fig. 8 is a block diagram showing the dot matrix image generator and its circuitry

  peripherals, in the example corresponding to the invention.

  FIGS. 9-a and 9-b are sequential diagrams showing the temporal characteristics of the switching of the images which respectively indicate a

  chronograph mode (Figure 9a) and a counting mode.

minutes (Figure 9b).

  Fig. 10 is a graphical representation showing the contrast as a function of the actual voltage in a liquid crystal display device of

nematic type helical.

  Figure 11-a is an explanatory representation

  tive showing scanning electrodes in a part

  point matrix display, in one embodiment of

of the invention.

  Fig. 11-b is also an explanatory representation showing signal electrodes in the dot matrix display part in this mode of

embodiment of the invention.

  Figure 12-a is an explanatory representation

  tive showing common electrodes in a part

  7-segment display in the embodiment

of the invention.

  Fig. 12-b is also an explanatory representation showing segment electrodes in the

  7-segment display part in the mode of realization

tion of the invention.

  Figure 13-a represents a display of the arrangement

  LCD display corresponding to

  the invention, applied to a watch.

  Figure 13-b shows a display in a mode

chronograph.

  Figures 14-a through 14-e are block diagrams

  showing conventional multiplex drive signals.

  Figures 15-a through 15-e are block diagrams

  showing multiplex attack signals in the

  considered embodiment of the invention.

  Figure 16 is a diagram of a circuit for

  to common electrode signals in the embodiment of

tion of the invention.

  We will now consider Figure 1 which is an external view of an example of an electronic watch corresponding to the invention. The electronic watch includes display elements of the 7-segment type, the at; a

  dot matrix display device 2 and

  push-button type, 3 to 6. The electronic watch is

  tronic corresponding to the invention can operate according to

  a time indication mode (H mode), a chrono-

  graph (CH mode), a ringer setting mode (RS mode), a timer mode (CM mode) and a time adjustment mode (REG). These modes can be switched by pressing the push-button switch 5. Specifically, the modes are selected cyclically (one at a time) each time the push-button switch 5 is actuated. Pusher 3 acts as a start switch in CH mode or CM mode, and as a selection switch in RS mode or REG mode. Pushbutton switch 4 acts as an intermediate time switch and reset switch in the CH mode, as a setting switch in the RS mode and REG mode, and as a setting and reset switch. minutes in the CM mode. The pushbutton switch 6 acts

  lighting switch in all modes.

  The display elements of the 7-segment type la-

  display numeric values and d characters A and P as follows:

  In the H mode, the elements 1a, 1b and 1c show

  hours, minutes and seconds, respectively.

  of. In the CH mode, the elements 1a and 1b respectively display the hours and seconds and the element 1c displays the hundredths of a second. In the RS mode, elements 1a and 1b respectively display the hours and minutes of the time the ringer is set, and the element displays the character "A" for the morning or "P" for the afternoon. . In CM mode, item la displays nothing, item lb displays the number of minutes the minute counter was set, and item lb displays the number of minutes since the minutes start . In the REG mode, elements la and lb display the hours and minutes, respectively, and the element displays the seconds during periods

  other than that during which the correction is

  time, and "A" or "P" during the period during

  from which the time correction is performed.

  The dot matrix display device 2 displays characters or pictograms representing various modes of operation. Figure 2 shows

  examples of pictograms representing the various modes.

  In the example of the electronic watch, a matrix of 16 x 17 points is formed by arranging image elements in 16 columns and 17 lines. The signal electrodes are divided centrally into two groups and the multiplexed attack is carried out with a duty cycle of 1/8. In the CH mode, the dot matrix display device 2 displays a running person (Figure 2-a). In the RS mode, the device 2 displays a pictogram representing the sound emitted by a buzzer (Figure 2-b). In the CM mode, the device 2 displays a pictogram representing an hourglass (FIG.

  2-c). In this way, modes can be intuitively

  tive. In the H mode, the device 2 displays the day of the month and the day of the week by a matrix of 5 x 7 points (Figure 3-a). In the REG mode, the device 2

E48 1826

  displays "REG" at the top line to indicate the REG mode, and nothing at the bottom line in the case of the correction of the seconds, minutes and hours, but it displays the day of the month, the month or the day of the week that must be corrected in the case where the correction relates to the day of the month, the month or the day of the

week (Figure 3-b).

  In addition, in this embodiment of the invention,

  vention, the states in each mode are indicated by pictograms. For example, in the CH mode, before the start of the chronograph, the person running that represents the pictogram takes the position of a runner

  on the starting line, as shown in Fig. 4-a.

  When the push-button switch 3 is pressed, five images corresponding to FIGS. 4-b, 4-c, 4-d, 4-e

  and 4-a-are displayed successively, so that the observer

  voyeur sees the person running. If, under these conditions, the push-button switch 3 is pressed again, the counter stops its counting operation, the elements

  7-segment display shows the time and movement of

  the person running is arrested. If you press

  the push-button switch 4 while the chrono-

  graph is in operation, the person who is represented on the dot matrix display device continues to run, but the time indicated by the 7-segment display elements is frozen, that is, indicates an intermediate time. It is therefore possible to visually determine the operating states of the electronic watch corresponding to the invention. We will also describe the CM mode, as another example. The CM mode may be indicated by five images shown in Figures 5-a through 5-e. In the CM mode, a desired duration is first set by operating the push-button switch 4. The minutes-minute minute can be set to a maximum of one minute.

  duration of 99 minutes. In this case, the display device

  dot-matrix ge presents the image shown in Figure 5-a. When under these conditions we support

248 1,826

  on the push-button switch 3, the images represent

  5-a to 5-e are presented in succession.

  observers see the sand falling into the hourglass. This indicates that the timer is running. When switch 3 is pressed again, the operation of the minute counter is stopped and the displayed image is also stopped. The remaining time display of the minute counter is reset by pressing the push-button switch 4. As shown in

  previous description, it can be determined visually

  at a glance the modes of operation of the

  electronic watch of the invention. This electronic watch

  that is extremely convenient to use.

  We will now explain the circuit of the electronic watch described above. Figure 6 is a block diagram showing the circuit of the electronic watch corresponding to the example of the invention. The circuit comprises: a reference signal generation circuit 7; a frequency division circuit 8; a time counter 9; an anti-rebound circuit 10 a control circuit 11; a clock setting counter 12; a chronograph counter 13 a latch circuit 14; a minute counter; a ring time detection circuit 16; a count arrival detection circuit at zero 17; a multiplexer 18 for the displayed data; a 7-segment type display decoder; a segment electrode driver 20 for an element

  7-segment display; an electronic driver circuit

  common members 21 for a 7-segment display element a dot matrix pattern generator 22 a signal electrode driver 23 for a dot matrix display device; a scanning electrode driving circuit 24 for the dot matrix display device; a liquid crystal display panel 25; a voltage booster circuit 26 a battery 27; a noisy driver circuit 50; and a sounder 51. A reference signal (32768 Hz) emitted by the

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  reference signal generation circuit 7 is frequency-divided by the frequency division circuit 8 to provide a 1 Hz signal which is applied to the input of the time counter 9. The time counter 9 counts the signal in the order "second" "minute" and "hour". The output signals of the counters are applied by the multiplexer 18 to the decoder 19, in which they are converted into 7-segment signals. The 7-segment signals are applied by the segment electrode driver 20 of the 7-segment display elements to the panel

  25, to attack this last

  deny. In the RS mode, the CH mode and the CH mode, the multi-

  plexeur 18 is switched by means of a signal M which is output from control circuit 11 so that data from the appropriate counter is displayed on the 7-segment display elements. The described operation

  above is identical to that of a self-winding chronograph.

  and we will not describe it further. The display of the dot matrix part, which constitutes the essential aspect of the invention, will be described. The table below shows the kinds of data that are displayed

  on the dot matrix part in the various modes.

  As regards this table, it should be noted that 16 x 17

  images are divided into three blocks U 1 U2 and U3

  in the top line and a block D in the lower row

  as shown in Figure 7.

248 1,826

Board

U 1U2 U3D

  Indication Mode Space Space Day of the Hour 1,2,3 0 - 9 Week Time Mode Racer Racer Racer Racer Graph Setup Mode Symbol Symbol Ringer Symbol Ringer Ring Ringer Ringer Ringer Mode Hourglass Hourglass Hourglass Hourglass minutes Second REG Space Minute REG Space Time REG Space -4 4M Space at) EJOUR E-1,2,3 0- 9 REG 0 Esmois 0-9 M REG Day EG Weekday RG week As shown in the table above, the number of modes is ten (10) and it is therefore necessary to use 4-bit mode codes to specify the modes. In

  each mode, a code needed to switch the settings

  rations is determined according to the largest number of configurations displayed in the blocks. For example, in blocks U1 and U3, the chronograph mode and the minute-count mode have the largest number of configurations (five). 3-bit configuration codes are therefore required in this case. In the U2 block, it is necessary

  to display the numbers "0" to "9", and codes of confi-

  4-bit gurations are needed. In block D, 3-bit configuration codes are required to display a day of the week in the indicative mode.

48 182 6

  the time and the time setting mode. To specify the segment data of the dot matrix display, scan codes (3 bits with a duty cycle of 1/8) specifying the scanning electrodes, as well as the mode codes and configuration codes described

above are necessary.

  FIG. 8 is a block diagram showing a segment configuration generator in the part at

  matrix of points, and its peripheral circuits. The cir-

  which is shown in Figure 8 includes: deco-

  addressers 28a to 28d; parts of memory 29a to

  29d belonging to a read-only memory generator

  figurations; output latch and level shift circuits 30a to 30d belonging to the ROM of the configuration generator; multiplexers 31a to 31d; a counter of tens of days 32; a counter of days 33; a daytime counter of the week 34; a decoder tens of months 46; a decoder of the months 47

  and groups of clock gates 35, 36 to 45, 48 and 49.

  Note that, in FIG. 8, the circuit elements whose numbers carry the suffix "A" are relative to the block U1, the circuit elements whose number bears the suffix "B" are relative to the block U29 the circuit elements whose numbers carry the suffix "C" are relative to the block U3, and the circuit elements whose numbers carry the suffix "D" are relative to the block D. When addressing the blocks, a mode code (MD1 - MD4 ) and a scan code (S1 - S3) are respectively applied to the terminals A0 to A3 (4 bits) and to the terminals A4 to A6 (3 bits)

  address decoders 28a to 28d. Configuration codes

  blocks are applied at terminals A7 to A10

  address decoders 28a to 28d. In the mode of indication

  time, the clock gates 42 to 45 are closed, while the gates 38 to 41 are open, so that the output signals <10 d and P 30 d from the tens of days counter are applied at terminals A7 and A8 in block U1, and the space or number 1, 2 or 3 that is specified by output signals C <1d and p10d is displayed on block U%. Similarly, the number 0, 1, 2 ... or 9 that is specified by the data

  the output of the day counter is Nd, Pd, d and Sd.

  in the U2 block. A space is displayed in block U3.

  The day of the week that is specified by the 3-bit output signal iDY, ADY and YDY of the day counter of the

  week is displayed in block D. In the chronograph mode

  graph, the clock doors 38 to 41, 36 and 37 are closed,

  while the clock doors 42 to 45 and 35 are open.

  As a result, the configurations shown in FIGS. 4-a to 4-e are switched by the output signals of the DCB counters of tenths of seconds in the chronograph counter 13. FIG. 9-a is a sequential diagram in which the configurations are switched by the ec OS output signals, & c 1 S and ScL-S. When the

10 10

  the chronograph counter is maintained in the state of restoration

  ration, the configuration shown in Figure 4-a is displayed. However, once the level of a CRUN signal is raised up or "H", to start the chronograph counter, the states of the outputs Ich1S, 1 11

  XOe S and e 1S are changed and the configurations represented

  4-a to 4-e are thus switched every 200 ms in the order indicated. When the signal

  CRUN is placed at the low level or "B" is the chrono counter.

  graph is stopped and, under the effect of the output signal

  1iS, t 1s or Se present at this time, the configuration

  posted rider, ie the rider, is stopped.

  In the operation of indicating an intermediate time

  the counter is operated and the configurations displaying the runner are switched; however,

  segment is stopped and displays the corresponding time.

  laying one turn. The display of the time in the 7-segment part resumes when the operation corresponding to the display of the lap time is stopped. In the timer mode, the clock gates 38 to 41 and 35 are closed, while the clock gates 42 to 45 and 36 are open, so that the counter signals PTRS, TRS and ETRS of the counters seconds in the minute counter (DCB in increasing direction) are applied to the terminals A7 to A9 of the address decoders 28a, 28d, to switch the displayed configurations. The figure

  9-b shows the temporal characteristics of the switching

  configurations. When the minute counter is initially set, the seconds counters are set to zero (0) and so the pattern shown in Figure 5-a is displayed. Once the level of a TRRUN signal is raised to "H" level to start a

  subtraction minutes, the config-

  Rations ranging from that shown in Figure 5-a to that shown in Figure 5-e are switched in synchronism with the output signals "TRS to ETRSo Thus, the configurations are switched every two seconds and the first configuration appears at the end In the ring setting mode, the bell symbol (shown in Figure 2-b) is always displayed, regardless of the data that is applied to the terminals A7 to A9. Displays depend on the setting modes, ranging from the second to the day of the week.In setting modes from the second to the hour, the letters "R", "E" and "G" '(for "setting" ) are respectively displayed in blocks U1, U2 and U3, and a space is displayed

  in Block D, irrespective of the data that is applied

  on terminals A7 to A9. In the correction of the day of the month, a date is displayed in blocks U1 and U2 by the output signals of the counter of tens of days and the counter of the days, as in the indication mode of

  time, and the character "J" representing the correct mode of

  the day is displayed in block U3. Simultaneously, the term "REG" representing the time setting mode is displayed in block D. In the correction mode of the

  months, only clock doors 48, 49 and 40 are open.

  your. As a result, the output data of the month decoder is applied to the terminals A7 to A9, so that a month is displayed in the blocks U1 and U2, while the character "MI" representing the correction mode of the month is displayed

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  in the U3 block and, as in the case of the day correction mode, the word "REG" is displayed in block D. In the case of the day of the week correction mode, the word "REG" is displayed in the blocks U1, U2 and U3, and the day of the week that is specified by the output data OLDy, pDY and DY from the weekday counter of the week

  34 is displayed in the D-block by three letters in French.

  Configuration Generator ROM

  which is so addressed applies the data corresponding to

  to the number of segments in the blocks (six for U1 and U2, five for U3 and seventeen for D) to the respective circuits of parallel data latches 30a to 30d, in which the data are recorded at appropriate times and are stored as control signals for the segment drive multiplexers 31a-31d during the duration of a scan signal. Since the signals for the signal electrodes are processed in a parallel mode, as described above, it is not necessary to perform the series-to-parallel conversion, which is

  which leads to a decrease in energy consumption.

  The memory capacity that is needed for the configuration generator ROM is about 17.8 configurations. Because it is necessary

  to use 272 bits for each configuration, the general

Configurator must have a capacity of approximately 5000 bits. Since the level of integration of the elements has recently been significantly improved, this number

  bits can easily be saved in a single chip.

  On the other hand, the power consumed for the transfer of display data is increased, but this problem can be solved by the use of lithium batteries or solar cells. In the embodiment described above, the dot matrix portion and the 7-segment portion are disposed on the same plane panel, in plan view. However, two panels can be placed on top of each other, so that the 7-segment part is on the first panel and the dot-matrix part is

248 1826

  established on the second panel. In addition, the 7 segment portion and the dot matrix portion may be displayed using two panels. In this case, it is possible to use for the dot matrix part a structure called "active element matrix panel" in which

  an active element is formed on each pixel.

  In the embodiment described above, the configuration generating circuit is controlled by

  the addressing of the configuration generator ROM

  tions. However, the read-only memory generator

  gures may be designed so that the output signals for all modes are provided in a

  parallel and are controlled by a multiplexer.

  As the above description shows, the

  electronic watch of the invention makes it easy to read

  the mode displays. So, the electronic watch

  of the invention has a remarkable novelty.

  We will now consider Figures 11-a and 11-b which represent another embodiment of the invention. More precisely, figure ila represents

  eight transparent electrodes that extend horizontally

  on one side of a dot matrix display part.

  These electrodes are called scanning electrodes and

  respectively bear the references Y1, Y2, ... and Y8.

  Figure 11-b shows thirty-four transparent electrodes on the other side of the display part. These electrodes are called signal electrodes and are respectively designated by the references X1, X2, ... and X34. A liquid crystal layer is interposed between the scanning electrodes and the signal electrodes. Intersections of

  scanning electrodes and signal electrodes constituting

  kill the picture elements. A matrix of dimension points

  16 x 17 is formed in this embodiment.

  Figures 12-a and 12-b show another embodiment of the invention. More specifically, the

  Figure 12-a shows a configuration of transparent electrodes

  segment of a 7-segment display part which comprises four electrodes called "common electrodes", COM1, COM2, 24th 182: 5 COM3 and COM4. Figure 12-b shows the other transparent electrode configuration of the 7-segment display part, which comprises twelve so-called "segment electrode" electrodes, SEG1, SEG2, ... and SEG12. A liquid crystal layer is interposed between the common electrodes and the segment electrodes, so as to form picture elements at the intersections of the common electrodes and the electrodes.

segment electrodes.

  Fig. 13-a shows a display presented by the liquid crystal display device corresponding to the invention, which is applied to a watch. The 7-segment display shows "10 hours, 24 minutes, seconds" (10: 24 35 ").

  seconds are respectively indicated by "H", "M" and "S".

  The dot matrix display part displays "20, Sunday". Figure 13-b shows a display in a chronograph mode. The 7-segment display portion displays "2 minutes, 23.54 seconds, (2 '23.54"), and the dot matrix display portion shows a man running. If there are about five corresponding images

  to movement and if these images are presented

  it can be determined at a glance that the watch

  counts the time in chronograph mode.

  Figures 14-a through 14-e show examples of drive voltage signals in a multiplex drive method. Figure 14-a shows an example of a signal that is applied to the scanning electrodes. A period T of the signal goes from t = 0 to t4. In the period T, the first frame goes from t = 0 to t2 (with t2 = t4 / 2), and the second frame goes from t to t4. In the second frame, the polarity of the

  voltage applied to liquid crystals is inversely

  to prevent deterioration of the liquid crystal.

  The selection time interval in the first frame ranges from t = 0 to t1 and the selection time interval in the second frame ranges from t2 to t3. The "enlightened" states and

  "extinct" liquid crystals, which correspond to the ele-

  images, are determined by signals that are

  applied to the signal electrodes while the electro-

24,182 6

  sweeps are selected, i.e. the "illuminated" and "off" states are not determined by the signals that are applied to the signal electrodes during

  the scanning electrodes are not selected.

  The ratio between a time interval during which a scanning electrode is selected and the duration of a period, that is: (t1 + (t3 - t2)) / t4, in Fig. 14-a, is called "cyclic attack ratio". Thus, in the case where the number of scanning electrodes is N and each scanning electrode is scanned independently, the duty cycle is 1 / N. Figures 14-b and 14-c respectively show a signal that is applied to a selected signal electrode during the complete period and a signal that is applied to an unselected electrode. The voltage signals which in this case are applied between the scanning electrode and the signal electrodes are shown respectively in FIGS. 14-d and 14-e. The actual voltages that are applied to liquid crystals in the "illuminated" states and turns you off "

  are obtained from the expression indicated above.

  In the case where the dot matrix display part is attacked with a duty ratio equal to 1/8,

  we have Eecl Vo / 3 and Eet = V0 / 3 (with a 3).

  The general multiplex attack system has the structure described above. In the case where this system is applied to the duty ratio equal to 1/4 of the 7-segment part, we have: Eecl - \ V0 / 3. We will find

  below the description of a means of doing

  so that this value coincides with the actual tension

  Eclipse of the dot matrix display part.

  Figures 15-a through 15-e show drive voltage signals of the 7-segment portion. Figure -a shows an example of a signal that is applied from the side of the common electrodes. A period T of the signal goes from t = 0 to t 'S. In a period T, the first frame goes from t = 0 to a, and the second frame goes from a to t'5. The time intervals of selection in the first and second frames go respectively from t-O to t'1 and from t = t'3 to t 'In

248 1826

  the time interval t '2 - a of the first frame and in the time interval t'4 - t'5 of the second frame, the effective voltage is equal to zero (0) regardless of the selection or the absence of selection. Figure 15-c shows a signal that is selected in the meantime

  of time 0 - t'2 and which is not selected in the inter-

  time range to - 4. In this case, the voltage signals shown in FIGS. 15-d and 15-e are

  applied to the common electrode and the segment electrode.

  In this embodiment, to ensure that the effective voltage in the "illuminated" state in the case where the 7-segment portion has a duty ratio of 1/4, is equal to that in the case where the matrix of points has a duty cycle of 1/8, the ratio between a time interval in which an electrode is

  is selected and the duration of a period is

  ie: t1 + (t'3 - a) ti5 'and set to 2/6 the ratio relative to a time interval in which the effective voltage is set to zero, that is to say (a1 - 4. The effective voltage in the "illuminated" state is then 0/3, which is equal to that of the dot matrix part. The effective voltage in the "off" state is Vy0, which is less than the actual voltage for the 1/4 duty cycle ratio, so that the halftones hardly appear,

at a low angle of observation.

  FIG. 16 represents a circuit diagram relating to the signal of the common electrodes in this mode of

  embodiment of the invention. The circuit includes: a circuit

  fired energy source 71; three multiplexers

  voltage level version 72; two AC liquid crystal drive multiplexers, 73; and four analog multiplexers 74. In Fig. 16, the reference W designates a signal whose level is changed at each frame. Thus, the signal W is low in the first frame (O - a in Fig. 15-a) and is high in the second frame (a to 5 in Fig. -A). Further, in Fig. 16, the reference G0 denotes a signal for controlling the time intervals (t'2 - a and t'4 - t 'in Fig. 15-a) in which the effective voltage is set to zero (O), and the signal is at a high level during these time intervals. On the

  Figure 16, references G1, G2, G3 and G4 refer to

  respectively signals that control the common electrodes COM1, COM2, COM3 and COM4. These signals G1 to G4 are

  at high levels while they select the elec-

  respective common trodes. The signals of the segment electrodes will not be described because these signals

  can be obtained in the same way.

  As regards the circuit, it must comprise an oscillator part, a frequency divider part and a counter part. However, these parts will not be described because their designs are well known. We will not describe the watch structure either

necessary.

  As is apparent from the foregoing description,

  in the case where at least two configurations having a value different from the driving duty cycle are created in the same liquid crystal device, the time intervals in which the effective voltage is applied are made in accordance with the invention. is set to zero, such that the actual voltages in the "illuminated" state are

  almost equal. As a result, the display device

  The liquid crystal display corresponding to the invention can be easily observed and has a beautiful appearance. The liquid crystal display device of the invention can therefore be effectively applied to a watch in

  which aesthetics is important.

  Note that the 7-segment display part as the dot matrix display part is not limited to liquid crystal elements and can

  be constituted by electrochromic display elements

  or by elements of the LED display.

  minescentes. It goes without saying that many modifications can be made to the device described and shown,

  without departing from the scope of the invention.

Claims (8)

  An electronic watch comprising a reference signal generating circuit, a frequency dividing circuit, a time counter circuit, a display decoder circuit, display elements, external operating means and a battery , characterized in that it comprises a dot matrix display part, in addition to a 7-segment type digit display part, and a circuit which realizes mode or function display by presenting characters or images in this dot matrix display part. An electronic watch according to claim 1, characterized in that the 7-segment type digit display part and the dot matrix display part are constituted by at least one of the following elements: LCD display, an electrochromic display element and an element electroluminescent diodes.   3. Electronic watch according to claim 2, characterized in that the segment display part of the 7-segment type and the display-matrix part of   dots are formed on the same liquid crystal panel. of, in plan view.   4. Electronic watch according to claim 2, characterized in that the 7-segment type digit display part and the matrix display part of   points are respectively formed in different layers   annuities of a liquid crystal panel structure multilayer.   5. Electronic watch according to claim 2, characterized in that the 7-segment type digit display part and the matrix display part of   points are attacked in multiplex with different reports   attack using a display element liquid crystal.   Electronic watch according to claim 2, characterized in that a display panel is used for the dot matrix display part in which a   active element is formed for each pixel.   7. Electronic watch according to claim 1, characterized in that it comprises a circuit which switches function display configurations with the aid of the counter circuit output signals which function. in respective modes.   A liquid crystal display device in which a plurality of segment electrodes and a plurality of signal electrodes are disposed on a substrate, a plurality of common electrodes and a plurality of scanning electrodes are disposed on the other substrate, to provide a segment display and a plurality of electrodes. dot-matrix display, the segment display and the dot-matrix display being multiplexed with different drive duty cycles, characterized in that   approximately the actual voltages that are   to the illuminated picture elements of the segment display and the dot matrix display, in   giving a low value to the effective tension of the   segment chase, using the segment signal and the common signal that take the same electrical potential   at least once during a frame interval.