JPH05127822A - Touch panel - Google Patents

Abstract

PURPOSE:To reduce surface reflection to prevent glare and improve contrast and display accuracy for the touch panel arranged on a liquid crystal display or the like. CONSTITUTION:The transparent touch panel is equipped with a fixed substrate 1 arranged in front of a display device, movable substrate 2 separately faced to this fixed substrate, and transparent electrodes 3 and 4 respectively formed on the facing planes of the fixed substrate 1 and movable substrate 2. A 1/4 wavelength phase difference board 6, polarizing board 7 and non-glare processed transparent film 8 are successively laminated on the movable substrate 2. The reflection of external light is prevented by the non-glare processed layer. For the light made incident to the touch panel and reflected on the surface of the display device, the phase is shifted at 90 deg. to the incidental light by the phase difference board 6. Therefore, the reflected light shifting the phase is cut without passing through the polarizing board 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch panel arranged on the front surface of a display device such as a liquid crystal display device or a cathode ray tube (CRT).

[0002]

2. Description of the Related Art In a liquid crystal display device, a transparent touch panel for inputting data by pressing is used on a liquid crystal display. This transparent touch panel is usually composed of a fixed substrate arranged on a display body, a movable substrate facing the fixed substrate with a space therebetween, a transparent electrode formed on an opposing surface of the fixed substrate and the movable substrate, and a transparent substrate. It is composed of dot-shaped spacers formed between the electrodes.

In such a touch panel, since external light is reflected by the electrode surfaces of the movable substrate and the fixed substrate,
Anti-glare property and display quality are degraded. JP-A-63-2788
Japanese Unexamined Patent Publication No. 130501/1989 discloses a method for producing an embossed non-glare sheet while irradiating radiation on the surface of a transparent synthetic resin sheet to form a scratch-resistant layer. , An anti-reflection sheet having a transparent polymer film having a specific refractive index, an anti-reflection layer formed on one surface, and a cured polymer film having a specific refractive index and an adhesive layer formed on the other surface Has been done. Further, JP-A-2-228347 proposes a non-glare plastic film containing a polymer containing polypropylene as a main component and a polymer containing polyethylene as a main component. Furthermore, JP-A-64-1
Japanese Patent No. 5789 discloses that a substrate on which a thin film EL element is formed and a transparent plate on which an antireflection film is formed are bonded via an elastic body formed over the entire circumference of the substrate, An EL display panel has been proposed in which an air layer is formed between a substrate and a transparent plate.

Such films and display panels are useful for preventing light reflection from the movable substrate. But,
When the light from the liquid crystal display device passes through the touch panel, it is diffusely reflected by the fixed substrate, the transparent electrodes, the spacers and the fixed substrate, the amount of light is reduced, and the transparency and display quality are greatly reduced.

In JP-A-62-123402, a laminated film composed of a transparent metal thin film and a transparent oxide thin film is formed on one surface of a transparent plastic film, and a polarizing film is formed on the other surface. Laminated antireflection films have been proposed. Further, Japanese Patent Application Laid-Open No. 62-284419 discloses an input device including a display device and an input means having an optical element for polarizing transmitted light from the display device. Further, Japanese Patent Application Laid-Open No. 61-255321 discloses a method of manufacturing a liquid crystal display device including an optical film such as a polarizing plate and a quarter wave retardation plate.

Films and devices having a polarization function are
Since the light can be polarized in a certain direction, the transparency and the display quality can be improved to some extent. However, the external light incident on the display device is reflected by the fixed substrate or the movable substrate, especially the transparent electrode. Therefore, the antiglare property is not sufficient, and the contrast of the display data by the display device, and thus the display quality, deteriorates.

Therefore, an object of the present invention is to provide a touch panel which has a small surface reflection, a high antiglare property, a high contrast and an excellent display accuracy.

[0008]

Means for Solving the Problems As a result of earnest studies, the present inventors have found that the above object can be achieved by sequentially laminating a retardation plate, a polarizing plate and a non-glare-treated layer on a transparent touch panel. Found and completed the present invention.

That is, according to the present invention, the first substrate provided on the front surface of the display device, the second substrate facing the substrate apart from the first substrate, and the transparent electrode formed on the facing surface of each substrate. A touch panel comprising: a display device;
There is provided a touch panel in which at least a retardation plate and a polarizing plate are sequentially laminated between the substrate and the second substrate.

Further, according to the present invention, a substrate disposed on the front surface of the display device for transmitting surface waves, a first wave transmitting means for transmitting surface waves in the X-axis direction on the surface of the substrate, Of the surface of the substrate, a reflecting means formed in the transmitting direction by the transmitting means and reflecting the surface wave in the Y-axis direction, a first receiving means for receiving the surface wave reflected by the reflecting means, and a surface of the substrate. The second transmitting means for transmitting the surface wave in the Y-axis direction, the reflecting means for forming the surface wave in the transmitting direction by the transmitting means, and the reflecting means for reflecting the surface wave in the X-axis direction, and the reflecting means for reflecting the surface wave A touch panel provided with a second wave receiving means for receiving surface waves, in which a retardation plate and a polarizing plate are sequentially laminated between a display device and a substrate.

[0011]

In this touch panel, incident external light is polarized by the polarizing plate, passes through the phase difference plate, and is reflected on the surface of the display device. And the light reflected on the surface of the display device is
The phase difference plate shifts the phase by 90 ° with respect to the incident light.
Therefore, the reflected light whose phase is shifted by 90 ° is cut without passing through the polarizing plate. On the other hand, the light from the display device is not reflected light with a phase shift, and therefore passes through the polarizing plate. Therefore,
It is possible to prevent deterioration of display quality due to reflection of incident light on the touch panel, and to polarize light from the display device by the polarizing plate, so that contrast and antiglare property are improved.

Further, when the front surface of the touch panel is subjected to non-glare processing, reflection of external light is prevented.

[0013]

Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings.

FIG. 1 is a schematic sectional view showing an example of the transparent touch panel of the present invention, showing a resistive film type touch panel. The transparent touch panel includes a fixed substrate 1 and a movable substrate 2 which are spaced apart and face each other, and are arranged in front of a liquid crystal cell 9 as a liquid crystal display. In this example, the fixed substrate 1 is attached to the liquid crystal cell 9 with an adhesive 10 or an adhesive. The fixed substrate 1 and the movable substrate 2 are preferably formed of a transparent optically isotropic material in order to improve display quality. Examples of such a material include polymer films such as glass, amorphous film, polyether sulfone, polycarbonate, polyarylate, and uniaxially stretched polyethylene terephthalate. The term “film” is used to include a substantially flat sheet. The fixed substrate 1 and the movable substrate 2 may be composed of any combination of glass / glass, glass / film, film / glass, and film / film.

Transparent electrodes 3 and 4 are formed on the facing surfaces of the fixed substrate 1 and the movable substrate 2, respectively. The transparent electrode 3 of the fixed substrate 1 is composed of an electrode group extending parallel to the X-axis direction, and the transparent electrode 4 of the movable substrate 2 is an electrode group extending parallel to the Y-axis direction orthogonal to the direction of the transparent electrode 3. It is composed of. The end portions of the electrode group forming the transparent electrodes 3 and 4 are
Each is connected to a resistor (not shown). Current is supplied to these resistors. Therefore, the contact between the transparent electrodes 3 and 4 due to the pressing and the data input position can be digitally detected corresponding to the contact position.

As the conductive material forming the transparent electrodes 3 and 4, for example, noble metal such as gold palladium, tin oxide,
Metal oxides such as indium oxide and indium tin oxide,
Copper iodide or the like can be used. Preferred transparent electrodes 3,4
Can be formed using tin oxide, indium oxide, indium tin oxide, or the like. The transparent electrodes 3 and 4 can be formed using a conventional thin film forming means such as a vacuum vapor deposition method, a sputtering method, an ion plating method and a plasma CVD method.

A dot spacer 5 for separating the fixed substrate 1 and the movable substrate 2 is interposed between the transparent electrodes 3 and 4.

On the movable substrate 2, a quarter-wave retardation plate 6, a polarizing plate 7 and a non-glare transparent film 8 are sequentially laminated. By combining the quarter-wave retardation plate 6, the polarizing plate 7 and the non-glare-treated transparent film 8 in this order, the surface reflection is small and the antiglare property and the contrast can be remarkably enhanced. That is, the non-glare-processed transparent film 8 can prevent reflection of light incident from the outside, and light incident on the transparent touch panel is polarized by the polarizing plate 7 and transmitted through the quarter-wave retardation plate 6. To do. Phase plate 6
The light transmitted through is reflected on the surface of the liquid crystal cell 9,
Since the phase is shifted by 90 ° by the / 4 wavelength retardation plate 6, it does not pass through the polarizing plate 7. Therefore, it is possible to prevent deterioration of display quality due to reflected light. On the other hand, the light from the liquid crystal display device
The quarter-wave retarder 6, the polarizing plate 7 and the non-glare transparent film 8 are sequentially transmitted. At this time, light from the liquid crystal display device is polarized by the polarizing plate 7 and travels in a fixed direction. Therefore, it is possible to prevent reflection of external light,
Light from the liquid crystal display device can be prevented from diffusing and reaching the outside, and antiglare property and contrast can be enhanced.

The data input position on the transparent touch panel may be detected in an analog manner. In this case, the transparent electrodes 3 and 4 are formed on the entire surfaces of the fixed substrate 1 and the movable substrate 2, and resistors are formed on both sides of the fixed substrate 1 in the X-axis direction. Resistors may be formed on both sides.

Further, the spacer is not limited to the dot-shaped spacer formed on the fixed substrate or the movable substrate, but may be a spacer which joins the fixed substrate and the movable substrate by separating the peripheral portions of the fixed substrate and the movable substrate. It may be composed of a transparent electrically insulating liquid filled between the substrate and particles dispersed in the electrically insulating liquid.

In the touch panel shown in FIG. 1, the movable substrate and the retardation plate may not be formed separately, but the movable substrate may be constituted by the retardation plate. 1 / as a phase plate
It is preferable to use a four-wavelength phase difference plate.

Further, the retardation plate and the polarizing plate are not limited to those on the movable substrate, but may be provided between the display device such as a liquid crystal cell and the fixed substrate.
The layers may be sequentially laminated outward. In this case, the fixed substrate may be composed of a retardation plate.

Further, the substrate or the like located on the front surface of the touch panel is non-glare processed, or
A layer such as a non-glare-treated film is preferably formed. When the front surface of the touch panel is non-glare processed, reflection of external light can be prevented.

The input means for inputting the data may be any sheet-like input means capable of detecting the data input position, and is not limited to the transparent touch panel, but is disclosed in JP-A-61-23.
Surface acoustic waves (S
A touch panel using (AW) may be used.

FIG. 2 is a schematic sectional view of a touch panel according to another embodiment of the present invention, and FIG. 3 is a plan view of the touch panel as the sheet-like input means in FIG. The same elements as those shown in FIG. 1 will be described with the same reference numerals.

This touch panel has a substrate 11 for transmitting surface acoustic waves, and an ultrasonic oscillator 12 as a first transmitting means for transmitting surface waves in the X-axis direction on the surface of the substrate 11.
It has and. The substrate 11 is made of non-glare processed glass.

The surface acoustic wave from the ultrasonic oscillator 12 travels in the X-axis direction, and the surface acoustic wave is reflected in the Y-axis direction by the first reflecting means 13 composed of a plurality of first reflection gratings 13a. It That is, the plurality of first reflection gratings 1
3a is formed at an angle of 45 ° with respect to the transmitting direction of the surface acoustic wave and is separated by a half wavelength. Therefore, the surface acoustic wave traveling in the X-axis direction has a plurality of first reflection gratings 13.
It is reflected in parallel to the Y-axis direction corresponding to the interval of a.

The surface acoustic wave reflected by the first reflecting means 13 is reflected by the second reflecting means 14 composed of a plurality of second reflecting gratings 14a at an angle of 45 °, and the first receiving means. Is received by the transducer 15 as. That is, the plurality of second reflection gratings 14a are formed at 45 ° with respect to the incident angle of the surface acoustic wave, separated by a half wavelength, like the first reflection grating 13a. The pressing position corresponds to the traveling time of the disturbance component of the surface acoustic wave in the X-axis direction in the output signal detected by the first wave receiving transducer 15. Utilizing this fact, the output signal detected by the first receiving transducer 15 is
Differentiated by the differentiating means of the signal processing circuit to detect the pressed position in the X-axis direction.

On the surface of the substrate 11, the ultrasonic oscillator 1 as the second wave transmitting means for transmitting the surface wave in the Y-axis direction.
Equipped with 6. The surface acoustic wave generated by the ultrasonic oscillator 16 is directed in the X-axis direction by the third reflecting means 17 including a plurality of third reflecting gratings 17a formed for each half wavelength at an angle of 45 ° with respect to the transmitting direction. Is reflected in. The reflected surface acoustic wave is reflected in the Y-axis direction by the fourth reflecting means 18 composed of the fourth plurality of reflection gratings 18 a, and received by the second wave receiving transducer 19. The output signal detected by the second wave receiving transducer 19 is differentiated by the differentiating means of the signal processing circuit in the same manner as described above, and the pressing position in the Y-axis direction is detected.

Therefore, the pressing position on the substrate 11 can be detected by the traveling time of the disturbance component of the surface acoustic wave in the X-axis direction and the traveling time of the disturbance component of the surface acoustic wave in the Y-axis direction.

In the touch panel having such a structure,
As shown in FIG. 2, between the substrate 11 and the liquid crystal cell 9, a quarter-wave retardation plate 6 and a polarizing plate 7 are sequentially laminated outward. Note that reference numeral 10 indicates an adhesive or an adhesive.

In the input means utilizing the disturbance of the surface acoustic wave, the surface wave reflected by the reflecting means in the Y-axis direction and the surface wave reflected by the reflecting means in the X-axis direction are reflected by the reflecting means in the X-axis direction. It is not necessary to reflect and receive waves in the X-axis direction and the Y-axis direction respectively. For example, the waves are received by a plurality of elements arranged side by side at the Y-axis direction end of the substrate and the X-axis direction end of the substrate. The pressing position on the −Y axis may be detected.
Further, the pressing position may be detected by an optical type or capacitance type detecting means.

The touch panel of the present invention is applicable not only to liquid crystal display devices but also to display devices such as CRTs.

[0034]

Since the touch panel of the present invention has the retardation plate and the polarizing plate sequentially laminated, the surface reflection is small, the antiglare property and the contrast are high, and the display accuracy is excellent.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a transparent touch panel of the present invention.

FIG. 2 is a schematic cross-sectional view of a touch panel according to another embodiment of the present invention.

FIG. 3 is a plan view of the touch panel in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fixed substrate 2 ... Movable substrate 3, 4 ... Transparent electrode 6 ... Quarter wave retardation plate 7 ... Polarizing plate 8 ... Non-glare processed transparent film 9 ... Liquid crystal cell 11 ... Substrate 12, 16 ... Ultrasonic oscillation Child 13a, 14a, 17a, 18a ... Reflective grating 13, 14, 17, 18 ... Reflecting means 15, 19 ... Receiving transducer

Claims (2)

[Claims] 1. A display device comprising: a first substrate provided on a front surface of a display device; a second substrate spaced apart from and facing the substrate; and a transparent electrode formed on a facing surface of each substrate. A touch panel in which at least a retardation plate and a polarizing plate are sequentially laminated between a display device and a first substrate or on a second substrate. 2. A substrate disposed on the front surface of the display device for transmitting a surface wave, a first wave transmitting means for transmitting a surface wave in the X-axis direction on the surface of the substrate, and the wave transmitting means. Reflecting means formed in the transmitting direction and reflecting the surface wave in the Y-axis direction, first receiving means for receiving the surface wave reflected by the reflecting means, and in the Y-axis direction of the surface of the substrate. Second transmitting means for transmitting the surface wave, reflecting means for reflecting the surface wave in the X-axis direction formed in the transmitting direction by the transmitting means, and receiving the surface wave reflected by the reflecting means. Second
Of the wave receiving means, wherein the retardation plate and the polarizing plate are sequentially laminated between the display device and the substrate.