JPS6316322A - Display device with touch detecting function - Google Patents

Abstract

PURPOSE:To eliminate the wrong displays caused by the parallax by laminating alternately the transparent electrode films and the transparent insulated films directly onto a display screen to form an electrostatic touch panel. CONSTITUTION:The transparent conductive films (ITO conductive films) 4 and 6 and alumina (alpha-Al2O3) insulated films 5 and 7 are laminated alternately on the screen of a CRT display 1 by an electronic beam vapor deposition process. Thus a four-layer touch panel 2 is obtained. When a finger touch is given to the panel 2, a capacitor is formed where the film 7 is defined as a dielectric matter together with the film 6 as an electrode of the other side and a finger as an earth electrode respectively. Thus the presence or absence of a finger touch is decided by the change of the electrostatic capacity of a CR oscillator. Then the coordinates are detected from a ratio between a vertical resistance and a horizontal resistance set on the basis of the finger touch point. Thus the desired information is displayed without producing any parallax since the panel 2 is adhered closely to the display 1.

Description

[Detailed Description of the Invention] [Summary] As a method of eliminating parallax and downsizing the device, a capacitive touch panel is directly attached to the display surface that displays information by using a transparent conductive film and a transparent insulating film. A display device formed in

[Industrial application field]

The present invention relates to a display device having a touch detection function on a display surface.

2. Description of the Related Art In order to process large amounts of information at high speed, information processing devices have made remarkable progress, and devices are being made larger in capacity and smaller in size.Display devices are one of these peripheral terminal devices.

That is, cathode ray tubes (CRT), liquid crystal display panels, plasma display panels, and the like are used, and each is being made larger in area and in color.

CRTs are the most widely used display devices, and are used to display information in various institutions including financial institutions.

For example, when used as a bank terminal, you can contact the information processing device through the keyboard and touch the required key to inquire about your deposit balance.

Information such as transfers and payments can be displayed on the screen.

The present invention relates to a display device that integrates such a display and a keyboard.

[Conventional technology]

Display devices are used to communicate information to multiple people,
In some cases, an individual interacts with a machine, and in the latter case, the person displays the required information on a display by selectively touching keys on a keyboard.

Although the present invention relates to the latter application, the display Wf
In some cases, the keyboard may take up too much space.

For example, plasma display panels (hereinafter referred to as PDP) and electroluminescent panels (hereinafter referred to as EL panels) are made into a single film with a thickness of about 1□+m.

On the other hand, a keyboard has a disproportionately large volume compared to this.

Therefore, it is necessary to make the keyboard for selecting information, including the CRT display, as small as possible, but there is a limit to the size of the keys from an ergonomic standpoint.

Therefore, as a method to solve this problem, a transparent touch panel is installed in front of the display, and by touching an item displayed on the display with a finger, only the specified item diagram is enlarged and displayed.

That is, indium oxide (Inz
Solid solution of o3) and tin oxide (Snow) (commonly known as ITO)
A transparent conductive film is formed using photolithography to form a wiring pattern in the X direction and a
A matrix-like transparent electrode is formed by forming a wiring pattern in the same direction and facing each other with a small interval between them, and by touching the transparent electrode on a designated item with a finger, the wiring pattern in this part becomes conductive. By this, the finger position and notch position are detected.

A method is used to display the contents of this item on a display.

In contrast, the inventors constructed a transparent conductive film on the front surface of the display, and are currently applying for a patent (Japanese Patent Application No. 107621/1989).
A touch panel equipped with a coordinate detection function is provided to detect the finger touch position and display the contents of the designated item.

This principle is based on the CRT display 1 as shown in Figure 3.
A touch panel 2 similar to this is installed on top of the
As shown in the partially enlarged view of FIG. 2, this touch panel 2 has a transparent conductive film 4, an insulating film 5. Transparent conductive film6. The capacitance C is configured by laminating an insulating film 7, with the insulating film 5 as a dielectric and the transparent conductive films 4 and 6 as electrodes.
It forms a capacitor.

When the touch panel 2 is touched with a finger in such a state, the insulating film 7
A capacitor is formed in which the transparent conductive film 6 is used as a dielectric, the transparent conductive film 6 is used as one electrode, and the finger is used as a ground electrode.This changes the capacitance of the CR oscillator, thereby detecting the presence or absence of a finger touch, and detecting the finger touch point. The coordinates are detected from the resistance ratio in the vertical direction and the resistance ratio in the horizontal direction of the panel.

In this way, necessary information is selected and displayed by touching the display with a finger.

However, it is difficult to form the display surface and the 7-inch panel in complete contact with each other, and therefore, if the display pattern is minute, the display may display incorrectly due to the parallax between the finger touch position and the display. This improvement was necessary.

[Problem that the invention seeks to solve]

As mentioned above, by touching the transparent touch panel provided on the display with your finger, you can specify the display content and display the necessary information on the display, but there is a gap between the touch panel and the display. There is a gap, and the challenge is to eliminate display errors due to this parallax.

[Means for solving problems]

The above problem can be solved by installing a capacitive touch panel by alternately laminating a transparent electrode film and a transparent colored border film directly on the display surface, automatically detecting the finger touch position on the touch panel and displaying specified information. This can be solved by taking the following method.

[Effect]

The present invention eliminates parallax and simplifies the display by providing a touch panel directly on a display such as a CRT, PDP, or EL.

FIG. 1 is a sectional view showing a state in which a touch panel 8 is provided directly on a CRT display 1, and the touch panel 8 is constructed by alternately laminating transparent conductive films and insulating films as shown in FIG. It is extremely easy to form.

This eliminates the need for a holding mechanism for the touch panel on the display, which was conventionally necessary, and it is possible to reduce costs accordingly.

〔Example〕

An ITO conductive film and an alumina (α-Aβ203) insulating film were repeatedly deposited on the display surface of a 12-inch CRT by electron beam evaporation to form a touch panel with a four-layer structure as shown in FIG.

Here, the ITO film thickness is about 1 μm, and the alumina film thickness is about 2 μm.

The CRT formed in this way with a capacitive touch function was attached to the device and displayed using the coordinate detection method described above. Since it is in close contact with the CRT, there is no parallax, which solves the problems of the prior art.

Note that the results are similar for FDP, 'EL, and liquid crystal display panels.

〔Effect of the invention〕

As described above, by implementing the present invention, detection accuracy can be improved and costs can also be reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the relationship between a touch panel and a CRT display according to the present invention, FIG. 2 is a partial sectional view of the touch panel, and FIG. 3 is a sectional view showing the relationship between a conventional touch panel and a CRT display. . In the figure, (2) is a CRT display, 2.8 is a touch panel, 4.6 is a transparent conductive film, and 5.7 is an insulating film.

Claims (1)

[Claims] A touch panel characterized in that a capacitive touch panel is provided by alternately laminating transparent conductive films and transparent insulating films on a display surface, and specified information is displayed by automatically detecting a finger touch position on the touch panel. Display device with detection function.