JPS628194A - Input/display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an input/display device having a key input section on a liquid crystal display device.

[Prior art]

A conventional input device for a liquid crystal display device is constructed by having two substrates each having transparent electrodes formed in a stripe shape, with the electrode surfaces facing each other with a space in between so that the electrodes are perpendicular to each other.

[Problem that the invention seeks to solve]

However, in the conventional and advanced techniques described above, since two substrates are used, the mass increases, and the light transmittance also decreases, making the display of the liquid crystal display device placed below unclear.

Therefore, the present invention aims to solve these problems.

Therefore, the objective is to provide a liquid crystal display device that is equipped with an input device that maintains the clarity of the display without substantially changing the size and mass of the liquid crystal display device.

[Means to solve the problem]

In the input/display device of the present invention, a key electrode is formed using a transparent conductive film on the adhesive surface of an upper (operation side) polarizing plate constituting a liquid crystal display device, and the key electrode is connected to a finger via the upper polarizing plate. The feature is that input is performed by detecting the change in capacitance caused by pressing with the button.

- [Function] According to the above configuration of the present invention, a polarizing plate is used as a dielectric between the key electrode and the human body. Further, the input device is directly formed on the liquid crystal display device to constitute an input/display device in which input and display are integrated.

The input/display device of the present invention will be described below with reference to the drawings.

〔Example〕

FIG. 1 is a block diagram of an embodiment of the input/display device of the present invention.

In a reflective liquid crystal display device, a lower substrate (the electrode substrate is simply referred to as a substrate) 4 and an upper substrate 3 are bonded together with a seal 6 to sandwich a liquid crystal 7. ing. The upper substrate 3 and the lower substrate 4 are generally made of glass, but may also be plastic films.

A transparent conductive film is applied to the adhesive surface, such as
The upper polarizing plate 2, on which the key electrode X having a thickness of several 100× is formed by patterning the upper polarizing plate 2, is attached to the upper substrate 3. By doing this, the upper polarizing plate 2 functions as a dielectric between the key electrode and the human body.

FIG. 2 shows a first embodiment of a key force detection circuit using the embodiment of the input/display device of the present invention shown in FIG. % indicates the key electrode.

Now if we take out only one key electrode and draw an equivalent circuit, the third
It will look like the figure. The key electrode X has a minute capacitance Ok,
Together with the resistor R, it forms an integrating circuit. Therefore, the waveform of the applied pulse is rounded as shown in Fig. 4 (2), although Fig. 4 (1) to (5) shows changes in the applied pulse, and the AM''D gate is connected to the terminal E of the counter 0. ) I) The 4th m (3) whose pulse width is shortened from TIN to TOFF
waveform is added.

Now, when a human body touches the key electrode X through the polarizing plate 2, the volume fiOM of the human body is added as shown within the broken line in FIG. 5, and the value of the time constant OXR of the integrating circuit increases. Therefore, the waveform is shown in Figure 4 (
4), and the waveform shown in FIG. 4(5) in which the pulse width is shortened from Trot to ToN is applied to the terminal X of counter 0 by AND gate D.

What is the pulse width when the human body does not touch it? The pulse width TON when touching o11 has the relationship 'l'OFν>TON. Therefore, counter 0 is operated only for the time period of "Ii" level of the pulse applied to terminal E of counter C,
Using the count value as data, microphone w7'a Nanatsusa B
By importing and comparing the information, you can confirm whether or not there is an input.

When the number of key electrodes is plural, apply pulses sequentially to KO~1c% using the switch circuits 19W1 and sv2, and each count value is taken as data to the microclip Danatsusa B and compared to determine the input key. It is possible to determine the number of

5g is a second embodiment of a key force detection circuit using the embodiment of the input/display device of the present invention shown in FIG. 1; This is the 2nd v! :i key human power detection circuit #! AN of Example 1
D game) D is replaced with an OR gate/0.

The equivalent circuit of the key manual section is shown in Figure 6. The pulse applied to terminal E of counter C becomes longer in width as shown in Figure 7 (1) to (5), which show changes in the applied pulse waveform, and the count value when ON is a larger value than the count value at 01F1. shows.

A in the first embodiment of the key human force detection circuit of the second vl
If ND game) D is used, the thickness of the polarizing plate 2 can be up to several tens of microns.

Also, a second embodiment of the key human power detection circuit shown in FIG.
If the OR game) 0 is used, the thickness of the polarizing plate 2 is
) can be used for up to 100 micron grooves [Effects of the Invention] As described above, the input/display device of the present invention has the advantage of forming transparent electrodes on the components of the liquid crystal display device. Since the device can also be configured, it is possible to configure an input/display device without changing the appearance or mass of the liquid crystal display device. Additionally, manufacturing is limited because no new parts are used in the input device. Further, the key detection circuit can be manufactured using general engineering, so the circuit cost can be kept low.

Furthermore, since only one layer of transparent key electrodes is added to the liquid crystal display device, it is possible to manufacture an input/display device that does not impair the clarity of the display of the liquid crystal display device.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the configuration of an input/display device according to the present invention. FIG. 2 is an explanatory diagram of a first embodiment of the key human force detection circuit. FIG. 3 is an equivalent circuit diagram of the embodiment shown in FIG. 2. FIGS. 4(1) to 4(5) are explanatory diagrams showing changes in pulses applied to the circuit of FIG. 2. FIG. 5 is an explanatory diagram of a second embodiment of the key human force detection circuit. Figure 6 is #! FIG. 5 is an equivalent circuit diagram of the embodiment shown in FIG. 5; #! 7 (1) to (5) are explanatory diagrams showing changes in pulses applied to the circuit of FIG. 5. that's all

Claims (1)

[Claims] A key electrode is formed using a transparent conductive film on the adhesive surface of the operation-side polarizing plate that constitutes the liquid crystal display device, and input is performed by detecting a change in capacitance by pressing the key electrode with a finger through the upper polarizing plate. An input/display device characterized by: