JPS6215834B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a time display device such as a timer or a clock.

Conventional timer or clock display devices have been used to display the elapsed time by lighting up sequentially, or by shifting the display position of the unit display section to display the elapsed time by lighting, but these drive circuits Generally, this has the disadvantage that it is complicated and the number of lead wires between the display section and the drive circuit increases.

Therefore, in the present invention, at least two common electrodes and a plurality of segment electrodes are arranged opposite each other via a liquid crystal, and the ratio of the opposing areas of each segment electrode and the common electrode is set to a predetermined value, and the ratio of the opposing areas of each segment electrode and the common electrode is set to a predetermined value. The present invention provides a display device that applies a varying drive signal between common electrodes to light up a display portion corresponding to the opposing area, and eliminates the above-mentioned drawbacks of the conventional art.

An embodiment of the present invention will be described below based on the drawings.

In FIG. 1, reference numerals 1 and 2 denote common electrodes, and the common electrode 2 is formed into a step shape so as to have a predetermined opposing area with segment electrodes to be described later. 3 to 8 are segment electrodes,
It faces common electrodes 1 and 2 with a liquid crystal interposed therebetween. Here, when the area of each of the opposing surfaces 3a to 8a of the segment electrode facing the common electrode 1 is "24", the area of each of the opposing surfaces 4b to 8b of the segment electrode facing the common electrode 2 is "56", "26'',``14'',``8.4'', and ``5.5''. 9 is a time signal generation circuit, which has a constant period,
For example, a pulse is generated every 10 minutes. 10 is a heptadium step-down counter, which sequentially counts down one step at a time from the time set in the time setting circuit 11 each time a pulse is input, and sequentially changes the output state to a high potential according to each value. do. In the above, the step-down counter 10 and the time setting circuit 11 constitute a timekeeping circuit. 12~
18 is an output transistor, 19 to 26 are resistors, 2
7 is a DC power supply.

Next, the display operation of the 60 minute timer will be explained.

In this example, the response voltage of the liquid crystal is 1.4 volts, and the values of resistors 20 to 26 are 757KΩ, 500KΩ,
344KΩ, 216KΩ, 122KΩ, 60KΩ and 100K
Ω, and the voltage value of the DC power supply 27 is 12 volts. Note that the value of the resistor 19 is set to a high resistance value so that a non-responsive voltage of 1.4 volts or less is generated between terminals p and q.

Therefore, it is assumed that the step-down counter 10 is set to "6" from the time setting circuit 11, which means 60 minutes. As a result, the output of terminal _a6 of the step-down counter 10 becomes high potential,
Transistor 18 turns on and produces a voltage of 7.5 volts across resistor 26 and thus terminals p and q, which is applied between common electrodes 1 and 2. As a result, the display portions corresponding to the opposing surfaces 3a to 8a of the segment electrodes 3 to 8 are lit.

The details of this lighting operation will be explained below. When the display device constituted by the common electrodes 1 and 2 and the segment electrodes 3 to 8 is converted into an equivalent circuit centered on capacitance, it becomes approximately the circuit shown in the second diagram. here,
Capacitors 3A to 8A correspond to the capacitance between common electrode 1 and segment electrodes 3 to 8,
Capacitors 4B-8B correspond to the capacitance of common electrode 2 and segment electrodes 3-8. Note that since the opposing electrodes of the common electrode 2 and the segment electrode 3 are short-circuited, there is no capacitor component corresponding to both electrodes. Now, as is well known, the capacitance of a capacitor is proportional to its area, and since this area is as described above, when a voltage is applied between terminals p and q shown in the second diagram, the voltage applied to capacitors 3A to 8A is becomes the voltage state shown in the diagram shown in the third figure. Therefore, in the set output of "6" mentioned above, 7.5 volts is applied between terminals p and q, so as is clear from the third diagram, the capacitors 3A to 8A shown in the second diagram have a voltage of 1.4 volts or more. It takes. Therefore, the display portions corresponding to the facing surfaces 3a to 8a shown in the first figure are lit, indicating that 60 minutes have been set. After 10 minutes have elapsed after "6" is set in the step-down counter 10, a pulse is generated from the time signal generating circuit 9, which is input to the counter, and its content becomes "5". Therefore, the output of terminal _a6 becomes a low potential, and the output of terminal _a5 becomes a high potential. As a result, the voltage between terminals p and q becomes 5.4 volts. As is clear from the third diagram, the capacitor 8A shown in the second diagram has a voltage of 1.0 volts, and a voltage of 1.4 volts or more is applied to the remaining capacitors 3A to 7A. As a result, only the display portions corresponding to the facing surfaces 3a to 7a shown in the first diagram are lit, indicating that 50 minutes have elapsed. Thereafter, by similar operation, the lights on the opposing surfaces 7a to 4a are turned off one after another every 10 minutes, and when 60 minutes have passed, a high potential output is generated at the terminal _a0 of the step-down counter 10, and the light is turned off on the opposing surfaces 3A. The corresponding display section is turned off.

In the above example, specific numerical values were specified to facilitate understanding of the operation, but the present invention is not limited to these values. In particular, when lighting the display section, the lighting voltage is determined by the area ratio of the opposing surfaces 3a to 8a and the opposing surfaces 4b to 8b, and this ratio is appropriately set as necessary. Further, the shape of the electrode is not limited to this example, but can be any shape as long as the set area ratio can be obtained. An example of this will be explained in the case of the electrode shown in the first figure.The common electrode 2 is not made into a step shape but is made into a rectangular shape, and the opposing surfaces 4b to 6 of the segment electrodes 4 to 6 are
The portion corresponding to b may be appropriately bent to face the common electrode 2. FIG. 4 shows only the shape of the electrode arrangement.

Further, in this embodiment, for the sake of explanation, DC voltage driving is shown, but it goes without saying that the invention is not limited to this and AC driving may be used.

In this example, the display is performed in a subtractive manner, but by using an up counter instead of a step-down counter and sequentially increasing the effective value in the case of voltage or constant voltage, integrated display is possible. . Therefore, by providing a counter for counting each digit of the time and arranging a display section of the present invention for each digit, an analog clock can be constructed.

As described in detail above, the present invention provides two common electrodes with a plurality of segment electrodes, sets the ratio of the opposing areas of each common electrode and the segment electrode to a predetermined value, and adjusts the distance between the common electrodes according to the elapsed time. By changing the drive signal applied to the display area, the elapsed time is shown in an analog manner on the display section corresponding to the facing area.
There are very few lead wires between the drive circuit and the electrodes, and the drive circuit also has a simple configuration because it only applies a drive signal between the common electrodes.

[Brief explanation of the drawing]

Fig. 1 shows an electrode arrangement pattern and its driving circuit as an embodiment of the present invention, Fig. 2 shows an equivalent circuit mainly showing the capacitance of the display section shown in Fig. 1, and Fig. 3 shows the operation of Fig. 1. Voltage state diagram between electrodes for explanation,
FIG. 4 shows an electrode arrangement pattern of another embodiment. DESCRIPTION OF SYMBOLS 1...Common electrode, 2...Common electrode, 3-8...Segment electrode, 9...Time signal generation circuit, 10...Step down counter.

Claims (1)

[Claims] 1 Construct a plurality of display parts consisting of a plurality of segment electrodes facing two parallel common electrodes with a liquid crystal interposed therebetween, and each segment electrode has an equal area facing one of the common electrodes, and the other common electrode A clock circuit is provided which generates an elapsed output at regular intervals, and an output voltage generation circuit is provided which generates a different voltage in response to each elapsed output of this clock circuit. A time display device in which the output of the output voltage generation circuit is supplied between the common electrodes and the display portions are sequentially turned on.