JP2001143560A - Touch panel and liquid crystal display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch panel and a liquid crystal display device that can easily manage the resistance and has a high reliability by removing input error and impossibility of input. SOLUTION: In a touch panel in which an upper substrate 4A of softer film having an upper resistance film 51 and a lower substrate of a rigid panel having a lower resistance film are folded to oppose with each other so that two dimension coordination value is obtained by a contact position of the upper resistance film 51 and the lower resistance film, at least one of the upper resistance film 51 and the lower resistance film is a laminated structure of ITO film 51A and conductive film 51B and comprises a fine comb shape of resistance films having common connecting portions or one end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a touch panel for detecting input coordinates based on a resistance change due to a pressing force, and a liquid crystal display device formed by laminating the touch panels.

[0002]

2. Description of the Related Art A liquid crystal display device used as a display means of a personal computer or another monitor irradiates an image generated on a liquid crystal panel with illumination light and emits the transmitted light or reflected light to the display surface side. To visualize.

That is, this type of liquid crystal display device generally uses a liquid crystal panel in which a liquid crystal layer is interposed between a pair of substrates having pixel selection electrodes and the like, and the alignment state of liquid crystal molecules in a selected pixel portion. The image is generated by changing. Since the generated image is not in a visible state by itself, the liquid crystal panel is irradiated with light from the outside to illuminate the liquid crystal panel, and the transmitted light or the reflected light is observed.

In recent years, an information terminal in which a liquid crystal display device of this type is used as a display means, and a touch panel for inputting various information from the display screen and stacked on the display screen, is widely used.

There are various types of touch panels based on the principle of operation. Among them, the most popular type is a type of detecting input coordinates based on a resistance change amount, that is, a so-called analog resistive film type.

In general, this analog resistive touch panel has a structure in which one substrate on the information input side is formed of a transparent soft film and the other substrate is formed of a transparent hard substrate made of glass. A resistive film is provided on the opposing surface of the transparent substrates, and a two-dimensional coordinate value is detected from a resistance value between each resistive film contacted by an externally applied pressing force and an output terminal.

FIG. 15 is a schematic diagram illustrating a schematic configuration of a liquid crystal display device with a touch panel. This liquid crystal display device is configured by laminating a touch panel 4 on a liquid crystal panel 1. In the illustrated liquid crystal display device, the light guide plate 2 constituting the auxiliary light source device 3 is interposed between the liquid crystal display device 1 and the touch panel 4, but a device without the auxiliary light source device 3 is also commercially available. 3A is a lamp and 3B is a lamp reflection sheet.

FIG. 16 is an exploded perspective view for explaining a configuration example of a conventional analog resistive touch panel. This touch panel is composed of two transparent substrates. The upper substrate (upper substrate) 4A is made of polyethylene terephthalate (P
A resistance film 11 made of a transparent vapor-deposited film preferably made of indium tin oxide (ITO) is entirely formed on the inner surface of a soft film preferably made of ET) film. Similarly, on the lower substrate (lower substrate) 4B, a resistive film 22 made of a transparent vapor-deposited film preferably made of ITO is entirely formed on the inner surface of a hard substrate made of glass.

Further, a wiring portion 55 electrically connected to the resistive film 11 is formed on one parallel side pair of the resistive film 11 of the upper substrate 4A, and is provided on an interface portion 55 which is a connection portion with an external circuit. Terminals are formed. On the other parallel side pair, lower connection portions 53 and 54 which are electrically insulated from the resistive film 11 are formed, and each of them is routed to the interface portion 55 to form a terminal.

Upper connection portions 43 and 44 are formed in the resistive film 22 of the lower substrate 4B at positions corresponding to the lower connection portions 53 and 54, respectively. Then, when bonded to the upper substrate 4A, the connection points T ₁ of the lower connection portions 53 and 54 of the upper substrate 4A,
Connection points T ₂ and T between T ₃ and the upper connection portions 43 and 44 of the lower substrate
₄ and electrically connected by a conductive material preferably made of silver paste.

The lower connecting portions 53 and 54 and the upper connecting portions 43 and 44 are preferably made of the same material as the resistive film in view of the easiness of the manufacturing process. However, these are formed of a material different from the resistive film. Needless to say, this may be done.

In this way, two-dimensional coordinates are formed by the resistive films 11 and 22 formed on the upper and lower substrates, and the coordinate values (x, y) of the pressed point (input point) → (x: X coordinate value, y : Y coordinate value) by an external circuit, a host (microcomputer, personal computer, etc.) not shown recognizes input of characters and symbols.

[0013]

In a conventional touch panel having such a structure, a resistive film (upper resistive film) on an upper substrate is used.
11. Both the lower substrate resistance film (lower resistance film) 22 is ITO
(Indium Tin Oxide) Since the entire surface of the deposited film is formed of a resistive film, the resistance value for detecting the position of the input point for inputting information is set to the lower connecting portions 53 and 54 and the upper connecting portion 43. , 44, and becomes a two-dimensional parameter of the solid resistive film, which differs at the corresponding input point on the resistive film, thereby deteriorating the linearity (linearity).

As a result, the detection of the input point is deteriorated, and an input detection error or a deviation (calibration) from the display position of the liquid crystal panel installed on the rear surface occurs. The external circuit (CPU) has a function of correcting this position, but this function has also caused a decrease in reliability, such as detection failure (input failure), which makes correction impossible.

Further, in the conventional touch panel, since the connection portion with the opposing substrate is provided on the peripheral portion of one substrate (the upper substrate in FIG. 11), the area of the effective input area is limited, and the so-called narrow area is provided. Since it is difficult to form a frame, and since the upper and lower resistive films are formed of a vapor-deposited film such as ITO, it is difficult to control the resistance value. Since the electrical characteristics of the film and the connection part deteriorate and the resistance value fluctuates, it is difficult to manage the resistance.

It is an object of the present invention to provide a touch panel which solves the above-mentioned problems of the prior art, eliminates an input error or an input failure, improves reliability, and can stably manage the resistance value of a resistive film. It is to provide a liquid crystal display device using this touch panel.

[0017]

In order to achieve the above object, a touch panel according to the present invention comprises a resistive film on one or both of an upper substrate and a lower substrate, wherein conductive particles such as carbon or silver are coated with a highly conductive material such as epoxy resin. The coating film mixed with the molecular material is used as a main constituent material, and the resistance film of at least one substrate is formed in a number of thin resistive films having a common connection portion,
The configuration is such that the coordinate value of the input point is detected by a one-dimensional resistance value.

Further, in the liquid crystal display device according to the present invention, the use of the above-mentioned touch panel makes it easy to manage the resistance value of the thin resistive film, and enables highly reliable screen input.

A typical configuration of the present invention is described as follows. That is, the touch panel according to the present invention includes: (1): an upper substrate having an upper resistive film and a lower substrate having a lower resistive film are opposed to each other, and a contact position between the upper resistive film and the lower resistive film is two-dimensionally coordinated. A touch panel for obtaining a detection output as a value, wherein at least one of the upper resistive film and the lower resistive film has a coating film formed by applying a polymer material mixed with conductive material particles, and the upper resistive film and the lower resistive film Each of the resistive films
It is a comb-shaped resistive film thin resistive film formed in a comb shape having a common connection portion at one end, and each comb-shaped resistive film thin resistive film is arranged crosswise.

(2): A lower resistance film connection portion or an upper resistance film connection portion electrically connected to the lower substrate or the common connection portion of the upper substrate is provided on the upper substrate or the lower substrate side in (1). Was.

According to the above configurations (1) and (2), coordinate values in one direction (X direction) and coordinate values in the other direction (Y direction) of the touch panel can be uniquely detected with high accuracy.
Further, since the resistance value of the resistive film of each substrate can be managed by each common connection portion, the change in linearity can be easily corrected, and an input error and undetection can be prevented.

(3): An upper substrate having an upper resistive film and a lower substrate having a lower resistive film are opposed to each other, and the contact output between the upper resistive film and the lower resistive film is defined as a two-dimensional coordinate output. Wherein at least one of the upper resistance film and the lower resistance film has a coating film formed by applying a polymer material mixed with conductive material particles, and one of the upper resistance film and the lower resistance film is A comb-shaped resistive film formed in a comb shape having a common connection portion at one end is a thin resistive film, and the other is a uniform resistive film.

(4): On the side of the substrate having the thin resist film of the comb-shaped resistive film in (3), a resistive film connecting portion electrically connected to a common connecting portion of the other substrate is provided.

With the above configurations (3) and (4), the coordinate value of one of the touch panels (X direction or Y direction) can be uniquely detected with high accuracy from the information of the input point. In addition, since the resistance value of the resistive film of one substrate can be managed by the common connection portion, the change in linearity can be easily corrected according to the above (1) and (2), and an input error and undetection can be prevented. .

Further, since the material of the resistance film is a coating film formed by coating a polymer material mixed with conductive material particles such as carbon and silver, the resistance film is formed more than a conventional film formed by a deposition film such as ITO. The resistance value can be controlled uniformly, and the resistance value of each comb-shaped resistance film can be managed at the common connection part in the above (1) to (4). It can be performed reliably.

Further, by covering the common connection portion with a protective film made of an insulating material, it is possible to suppress the deterioration of the resistance characteristics due to the infiltration of moisture.

It is to be noted that ITO similar to the conventional one may be formed under the resistive film of the polymer material in which the above-described conductive material particles are mixed. In this case, a polymer in which the above-described conductive material particles are mixed on the ITO film is used. Apply material. Further, by covering the upper layer with a protective film, the effect of preventing the deterioration of the resistance characteristics due to the infiltration of moisture can be obtained.

The particles of the conductive material are not limited to the above-described carbon and silver, but may be other similar conductive materials such as nonmetallic conductive materials, gold and other metal materials.
The resin material into which this is mixed may be an appropriate polymer resin material other than epoxy.

A typical configuration of the liquid crystal display device according to the present invention is described as follows. (5): A liquid crystal display device comprising: a liquid crystal panel having a liquid crystal layer sandwiched between a pair of substrates; and a touch panel laminated on a display surface side of the liquid crystal panel, wherein the touch panel has an upper resistive film. And a lower substrate having a lower resistive film and a lower substrate having a lower resistive film, wherein the upper resistive film is a touch panel that obtains a detection output in which a contact position between the upper resistive film and the lower resistive film is a two-dimensional coordinate value. At least one of the lower resistance film and the lower resistance film has a coating film formed by applying a polymer material mixed with conductive material particles, and each of the upper resistance film and the lower resistance film has a common connection portion at one end. The thin resistive films were arranged in a cross shape, and each of the comb-shaped resistive films was crossed.

(6): A resistive film connection portion electrically connected to the common connection portion of the other substrate is provided on one of the upper substrate and the lower substrate in (5).

(7) A liquid crystal display device comprising: a liquid crystal panel having a liquid crystal layer sandwiched between a pair of substrates; and a touch panel laminated on a display surface side of the liquid crystal panel, wherein the touch panel has an upper resistance. An upper substrate having a film and a lower substrate having a lower resistance film are opposed to each other and bonded to each other to obtain a detection output in which a contact position between the upper resistance film and the lower resistance film is a two-dimensional coordinate value. At least one of the upper resistance film and the lower resistance film has a coating film formed by applying a polymer material mixed with conductive material particles, and one of the upper resistance film and the lower resistance film is commonly connected to one end. A plurality of thin resistive films having a portion were formed in a comb shape, and the other was formed of a uniform resistive film.

(8): The upper substrate or the lower substrate in (7), on one side of the comb-shaped substrate, a resistive film connection portion electrically connected to a resistive film of the other substrate is provided. .

With this configuration, the coordinate value in one direction (X direction) and the coordinate value in the other direction (Y direction) of the input point information can be uniquely detected with high accuracy. In addition, the resistance value of the resistive film can be easily controlled, and the resistance value of the resistive film on each substrate can be managed at each common connection, so that changes in linearity can be easily corrected, and input errors and undetection can be prevented. Thus, a liquid crystal display device having improved reliability of screen input can be obtained.

(9): An auxiliary lighting device was inserted between the liquid crystal panel and the touch panel in (5), (6), (7) and (8).

(10): An auxiliary lighting device was installed on the back surface of the liquid crystal panel in (5), (6), (7) and (8).

(11): A protective film was covered so as to cover the common connection portion of the touch panel of (1) to (4) and the touch panel of the liquid crystal display device of (5) to (10).

For this protective film, an epoxy resin, a silicon resin, or another known insulating material or adhesive can be used. By protecting the common connection portion with this protective film, the resistance change of the common connection portion is suppressed, and the resistance value management of the resistance film of each comb-type resistance film is performed by controlling the resistance value of the resistance film of the input portion in this portion. And a reliable touch panel, and a liquid crystal display device using the touch panel can be provided.

As the liquid crystal panel used in the liquid crystal display device of the present invention, a so-called simple matrix type, active matrix type, or other known types of liquid crystal panels can be used. It can also be applied to liquid crystal display devices.

Further, the present invention is not limited to the above configuration, and does not depart from the technical idea of the present invention.
Various modifications are possible.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to examples.

FIG. 1 is a schematic diagram of an upper substrate for schematically explaining a first embodiment of a touch panel according to the present invention.
2 is a plan view of the inner surface side, and FIG. 2B is an enlarged cross-sectional view of the upper resistance film 51 of FIG.

FIG. 2 is a configuration diagram of a lower substrate schematically illustrating a first embodiment of the touch panel according to the present invention.
(A) is a plan view of the inner surface side, and (b) is an enlarged sectional view of the lower resistance film 52.

1 (a) and 1 (b), the upper substrate 4A is made of a polyethylene terephthalate (PET) film, and one edge side of its inner surface is made of a coating film of epoxy resin mixed with carbon in the upper layer of the ITO film 51A. A thin comb-shaped resistive film 51 is formed by laminating the conductive films 51B thus formed. One end of a comb-shaped strip resistance film (hereinafter, also simply referred to as a comb-shaped resistance film) 51 is commonly connected to form an upper common connection portion 41. That is, the upper common connection section 4
A large number of thin resistive films (comb-type thin resistive films) 51 extend from one to the other edge.

Terminals Y1 and Y2, which are one terminal, are drawn out from both ends of the upper common connection portion 41. Also,
The first counter electrode wiring portion 55 formed in the vicinity of the upper common connection portion 41 and the outer side (the lowermost side in the figure) of the comb-shaped resistive film 51.
And a second counter electrode wiring portion 56 formed in parallel with the comb-shaped resistive film 51, and terminals X1 and X2 are drawn out, respectively. The first counter electrode wiring portion 55 and the second counter electrode wiring portion 56 are simultaneously formed of the same ITO as the comb-shaped resistance film 51 and the common connection portion 41. These terminals Y
1, Y2 and terminals X1 and X2 form an interface unit for connection to an external circuit.

FIG. 3 is an enlarged sectional view of the upper resistive film 51 of FIG. 1A corresponding to FIG. 1B for explaining a second embodiment of the touch panel according to the present invention. In this embodiment, the upper substrate 4A
Conductive film 5 formed of an epoxy resin coating film in which carbon is mixed and which covers the ITO film 51A.
1B is formed.

In this embodiment, since the upper conductive film 51B is applied so as to cover the entire lower ITO film 51A, the deterioration of the ITO film is reduced, and a highly reliable and long-lasting film without erroneous input is obtained. A long-lasting touch panel is obtained.

The same configuration is applied to the portion B of FIG. 2A relating to the lower substrate. In this case, the upper substrate 4A of FIG. 3 is replaced with the lower substrate 5A, and the comb-shaped resistive films 51 (51A, 51A) are formed.
B) is referred to as the comb-shaped resistance film 52 (52A, 52B).

FIG. 4 is an enlarged sectional view of the upper resistive film 51 of FIG. 1A corresponding to FIG. 1B for explaining a third embodiment of the touch panel according to the present invention. In this embodiment, the upper substrate 4A
Is formed of a single layer of an epoxy resin coating film 51B mixed with carbon.

In this embodiment, in addition to the effects of the first embodiment, the resistance film 51 is formed as a single layer of the conductive film 51B.
Since a vapor deposition process such as a TO film is not required, the production is simplified and the cost can be reduced.

FIG. 5 is an enlarged sectional view of the common wiring portion in FIG. 1A for further explaining the first embodiment according to the present invention. It should be noted that the same configuration is applied to the portion B in FIG. 2A in the first embodiment, and in this case, the reference numeral 4 in FIG.
A is provided on the lower substrate 5A, and the comb-shaped resistive film 51 (51A, 51B)
Is referred to as a comb-shaped resistance film 52 (52A, 52B).

As shown in FIG. 5, the comb-shaped resistive film 51 (5
1A, 51B) are connected to the upper common connecting portion 41 shown in the portion A in FIG. 1A, and the comb-shaped resistive film 5 described in FIG.
1 (51A, 51B), a protective film 71 made of epoxy resin is applied. The protection film 71 prevents the upper common connection portion 41 from invading moisture from the outside and prevents the resistance characteristics from deteriorating.

FIG. 6 is an enlarged sectional view of the common wiring portion in FIG. 1A for further explaining the second embodiment according to the present invention. The same configuration is applied to the portion B in FIG. 2A in the second embodiment, and in this case, the upper substrate 4 in FIG.
A is provided on the lower substrate 5A, and the comb-shaped resistive film 51 (51A, 51B)
Is referred to as a comb-shaped resistance film 52 (52A, 52B).

As shown in FIG. 6, the comb-shaped resistive film 51 (5
1A, 51B) is connected to the upper common connection portion 41 shown by the portion A in FIG. 1A, and the comb-type resistance film 51 (5
1A, 51B) and a protective film 7 made of epoxy resin
1 is applied. The protection film 71 prevents the upper common connection portion 41 from invading moisture from the outside and prevents the resistance characteristics from deteriorating.

FIG. 7 is an enlarged sectional view of the common wiring portion in FIG. 1A for further explaining the third embodiment according to the present invention. The same configuration is applied to the portion B in FIG. 2A in the third embodiment, and in this case, the upper substrate 4 in FIG.
A is replaced with the lower substrate 5A, and the comb-shaped resistor film 51 (51B) is replaced with the comb-shaped resistor film 52 (52B).

As shown in FIG. 7, a comb-shaped resistive film 51 (51B) composed of a single layer of an epoxy resin coating film 51B mixed with carbon is connected, as shown in FIG. In the common connection part 41, the comb-shaped resistance film 51 described with reference to FIG.
A protective film 71 made of epoxy resin is applied to cover (51B). The protection film 71 prevents the upper common connection portion 41 from invading moisture from the outside and prevents the resistance characteristics from deteriorating.

Then, the inner surfaces of the upper substrate 4A and the lower substrate 4B shown in FIG. 1 having the structures of the first to third embodiments are opposed to each other, and the respective comb-shaped resistive films 51 and 52 intersect ( In this case, they are adhered so as to be orthogonal.

At this time, the connection points T ₁ and T _{3 of the} upper substrate 4A
The electrical connection with the known silver paste T ₂ and T ₄ of the lower substrate 4B. As a result, the terminals Y1 and Y2 and the terminals X1 and X2 are connected to the upper common connecting portion 41 of the upper substrate 4A and the lower substrate 4A.
B becomes a detection terminal by bridging with each of the lower common connection portions 42. In an external circuit, a connection point between the contact point of the upper comb-shaped resistive film 51 and the lower comb-shaped resistive film 52 at the input point by pressing and each common connection point. The coordinate value (x, y) is detected based on the resistance value corresponding to the distance.

FIG. 8 is an equivalent circuit diagram for explaining the principle of detecting the coordinates of an input point on the touch panel according to the present invention.
FIG. 8 shows a case where the upper substrate and the lower substrate shown in FIGS. 1 and 2 are used. In the figure, reference numeral 61 denotes a resistance group of the upper common connection portion 41;
Represents the resistance of the upper comb-shaped resistive film 51, 63 represents a contact portion (input point),
64 indicates the resistance of the lower comb-shaped resistive film 52, and 65 indicates the resistance of the lower common connection part.

The terminals Y1 and Y2 are drawn out from both ends of the resistor group 61 of the upper common connection part 41, and the terminal X1 or the terminal X2 is drawn out of the resistance 65 of the lower common connection part.
The voltage Vcc (V) is applied to the terminal Y1, and the terminal Y2 is set to the ground potential. The voltage Vcc (V) is resistance-divided by the series-connected resistors of the term group 61. Voltage Vcc (V)
The voltage divided by the resistor can be detected on the resistor 62 of the upper comb-shaped resistive film 51.

The input area of the touch panel (the area where the intersection of the upper comb resistance film 51 and the lower comb resistance film 52 is formed:
When the contact portion 63 is generated by pressing somewhere on the input surface), the voltage Vy (V) is detected from the contact portion 63 to the terminal X1 or X2 via the resistor 65 of the lower common connection portion.

The change of the detection voltage Vy (V) depends only on the resistance group 61 of the upper common connection portion 41. Therefore,
Linearity is assured by managing the resistance values of only the upper common connection 41 and the lower common connection 42. These resistance films 51,
52 is constituted by any of the above-described embodiments, and the upper common connecting portion 41 and the lower common connecting portion 42 are protected by the protective film as described above, thereby eliminating problems such as variations in the resistance value of the resistive film. In addition, the deterioration of the resistance characteristics due to the infiltration of moisture can be avoided, and the reliability is improved.

FIG. 9 is a structural diagram of an upper substrate and a lower substrate schematically illustrating another configuration example of the touch panel according to the present invention. In this configuration example, the upper substrate 4A has the same configuration as that of FIG. 1, and the lower substrate 4B has the same configuration as the conventional lower substrate described with reference to FIG.

In this configuration example, the resistance value of the resistive film 22 formed on the lower substrate 4B is more stable than that of the upper substrate because the lower substrate is a hard plate made of glass. The resistance value can be made more uniform by forming a laminated structure of an ITO film and a coating film of an epoxy resin mixed with carbon as in the case of the resistance film of the substrate.

Then, the upper substrate 4A and the lower substrate 4B are bonded together with the inner surfaces thereof facing each other. In this case, the connection point T ₁ and T ₃ of the upper substrate 4A with a silver paste to the connecting point T ₂ and T ₄ of the lower substrate 4B are electrically connected.

As a result, based on the resistance value corresponding to the distance between the contact point between the upper comb-shaped resistive film 51 and the resistive film 22 of the lower substrate and the common connection point of the upper substrate 4A, the input point due to the pressing. A coordinate value (x, y) is detected.

Next, a configuration example of a liquid crystal display device using the above touch panel will be described. In the following liquid crystal display device, a device provided with an auxiliary lighting device is taken as an example, but this auxiliary lighting device can be omitted.

FIG. 10 shows a first embodiment of the liquid crystal display device according to the present invention.
FIG. 2 is an exploded perspective view illustrating the configuration of the embodiment. 1 is a reflective liquid crystal panel, 1A is an upper transparent substrate, 1B is a lower transparent substrate, 1C is a polarizing plate, and 1D is a reflecting plate. In this embodiment, the lower substrate is formed as a transparent plate and the reflection plate is provided on the rear surface. However, the lower substrate may be subjected to reflection processing on the inner surface. In that case, the reflector 1D is unnecessary.

Reference numeral 2 denotes a light guide plate made of an acrylic plate or the like constituting an auxiliary light source device, 3 denotes an auxiliary light source device, and 3A denotes a linear lamp (a linear light source composed of a linear fluorescent lamp or a light emitting diode array; 3B is a lamp reflection sheet, 4 is a touch panel, 4A is a soft film sheet (upper substrate), and 4B is a hard substrate (lower substrate, glass plate in this embodiment) such as glass or acrylic.

Then, a 1.5 mm thick acrylic light guide plate 2, a lamp 3A and a reflection sheet 3B are placed on the liquid crystal panel 1.
, And a touch panel 4 is further laminated thereon. The touch panel 4 has any of the configurations described in FIGS. 1 to 7 or the configuration described in FIG. Note that the liquid crystal panel 1 is not limited to the reflective type as shown, but may be a transflective type.

On the upper surface of the light guide plate 2, that is, on the touch panel 4 side, there are micro-prism-like, slit-like or dot-like irregularities or printing (dot-like printing in this embodiment) 5 for light diffusion. Lamp 3A that constitutes
Used a cold cathode fluorescent tube having a diameter of 2.0 mm.

FIG. 11 is a sectional view taken along the line AA of FIG. 10 for explaining the operation of the auxiliary light source device in the first embodiment of the liquid crystal display device according to the present invention described in FIG. The light guide plate 2 constituting the auxiliary light source device 3 has a dot-shaped print 5 on the touch panel side surface, and as shown by an arrow in the figure,
The light from the lamp 3A is reflected toward the liquid crystal panel 1, and the light reflected from the liquid crystal panel 1 is transmitted through the touch panel 4 and emitted to the display surface side.

It is preferable that the liquid crystal panel, the auxiliary light source device, and the touch panel are integrated by bonding the ends thereof with a double-sided tape, but other fixing means such as a mechanical holding frame or an adhesive may be used. May be used.

The auxiliary light source device may be turned on at all times. However, when the auxiliary light source device is mounted on a portable information device such as a so-called PDA or a notebook personal computer that needs to suppress power consumption, it is turned on as necessary. It can also be configured.

According to this embodiment, it is possible to obtain a liquid crystal display device using a touch panel with high reliability by eliminating input errors and inability to input.

FIG. 12 shows a second embodiment of the liquid crystal display device according to the present invention.
It is a schematic cross section explaining an Example. In this embodiment, a transmissive liquid crystal panel 1 and an auxiliary light source device, a so-called backlight 3
It has. A backlight 3 is stacked on the rear surface of the transmissive liquid crystal panel 1, and illumination light from the backlight 3 passing through the liquid crystal panel 1 is modulated by an image formed on the liquid crystal panel 1, and is modulated on the front side of the liquid crystal panel 1. To visualize the image. The touch panel 4 according to the present invention is stacked on the display surface side (screen side) of the liquid crystal panel 1, and information is input from the display surface of the liquid crystal panel 1. The touch panel 4 has any one of the configurations described with reference to FIGS.
Alternatively, it has the configuration described in FIG.

That is, this liquid crystal display device has a liquid crystal layer sandwiched between two transparent substrates (glass substrates) 1A and 1B, and a rear surface of a liquid crystal panel 1 provided with a polarizing plate 1C on its front and back sides. A substantially rectangular transparent light guide plate 2, a lamp 3A installed along one edge of the light guide plate 2, and a lamp reflection sheet 3;
An auxiliary light source device 3 having B is provided, and while the light from the illumination light source 3 is being propagated to the light guide plate 2, the liquid crystal panel 1 is illuminated from the back by deflecting the path toward the liquid crystal panel. In addition, dot printing 5 and the like are formed on the back surface of the light guide plate 1 so as to obtain uniform brightness over the entire area of the liquid crystal panel.

Further, on the back side of the light guide plate 2, there is provided a reflection plate 11 for totally reflecting light emitted from the light guide plate 2 to the back surface and returning the light to the liquid crystal panel 1.

Such an auxiliary light source device, that is, the backlight 3 is laminated on the liquid crystal panel 1 via a light diffusion film 12 or a light amount distribution correcting member such as a prism plate (not shown) to form a transmission type liquid crystal display device. Is configured.

FIG. 13 is a five-view drawing for explaining the actual configuration of the liquid crystal display device according to the present invention. That is, FIG.
Is formed by stacking a light guide plate 2 constituting a fund light on a liquid crystal panel 1 (contained in a housing constituted by an upper case 18 and a lower case 19), and further stacking a touch panel 4 thereon. A display device is configured.

The display area of the liquid crystal display device is indicated by reference numeral 15, and the input area of the touch panel 4 is indicated by reference numeral 20.

The liquid crystal panel 1 forms a housing by accommodating the liquid crystal panel and the drive circuit therein and engaging the hooks 22 and hooks 21 formed on the upper case 18 with the lower case 19.
The front light is a lamp 3A along one side of the light guide plate 2.
(Inside the lamp reflection sheet 3B), and the touch panel 4 is stacked on the light guide plate 2.
The signal cable of the touch panel 4 and the power cable of the lamp 3B are not shown. Reference numeral 23 denotes an interface connector for connecting to the host computer.

FIG. 14 is a perspective view illustrating a configuration example of a portable information terminal as an example of an electronic device on which the liquid crystal display device according to the present invention is mounted. This portable information terminal (PDA)
Houses the host computer 50 and battery 52,
It comprises a main unit 47 having a keyboard 49 on its surface, and a display unit 48 on which a liquid crystal display device 46 and a front light inverter 54 are mounted.

A mobile phone 60 can be connected to the main unit 47 via a connection cable 61, and can communicate with a remote place.

An interface cable 53 is provided between the liquid crystal display 46 of the display unit 48 and the host computer 47.
Connected by

Further, the pen holder 5 is provided on a part of the display section 48.
7 is provided, in which the input pen 56 is stored.

In this liquid crystal display device, various information is input by inputting information using the keyboard 49 and pressing the surface of the touch panel with the input pen 56, tracing or writing, or displayed on the liquid crystal panel. The user can select information, select a processing function, and perform various other operations.

Note that this type of portable information terminal (PDA)
Is not limited to those shown in the drawings, but may have various shapes, structures, and functions.

[0088]

As described above, according to the present invention,
The management of the resistance value of the resistive film is facilitated, the input error and the input failure are eliminated, and a highly reliable and long-life touch panel and a liquid crystal display device using the touch panel can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an upper substrate schematically illustrating a first embodiment of a touch panel according to the present invention.

FIG. 2 is a configuration diagram of a lower substrate schematically illustrating a first embodiment of a touch panel according to the present invention.

FIG. 3 is an enlarged cross-sectional view of an upper resistive film 51 of (a) corresponding to (b) of FIG. 1 and illustrating a second embodiment of the touch panel according to the present invention.

FIG. 4 is an enlarged sectional view of (a) an upper resistance film 51 corresponding to (b) of FIG. 1 and illustrating a third embodiment of the touch panel according to the present invention.

FIG. 5 further illustrates a first embodiment according to the present invention.
It is an expanded sectional view of a common wiring part in (a).

FIG. 6 further illustrates a second embodiment according to the present invention.
It is an expanded sectional view of a common wiring part in (a).

FIG. 7 further illustrates a third embodiment according to the present invention.
It is an expanded sectional view of a common wiring part in (a).

FIG. 8 is an equivalent circuit diagram illustrating the principle of detecting the coordinates of an input point on the touch panel according to the present invention.

FIG. 9 is a configuration diagram of an upper substrate and a lower substrate schematically illustrating another configuration example of the touch panel according to the present invention.

FIG. 10 is an exploded perspective view for explaining the configuration of the first embodiment of the liquid crystal display device according to the present invention.

FIG. 11 is a sectional view taken along the line AA of FIG. 10 for explaining the operation of the auxiliary lighting device in the first embodiment of the liquid crystal display device according to the present invention.

FIG. 12 is a schematic sectional view illustrating a second embodiment of the liquid crystal display device according to the present invention.

FIG. 13 is a five-sided view illustrating the actual configuration of the liquid crystal display device according to the present invention.

FIG. 14 is a perspective view illustrating a configuration example of a portable information terminal as an example of an electronic device on which the liquid crystal display device according to the present invention is mounted.

FIG. 15 is a schematic diagram illustrating a schematic configuration of a liquid crystal display device with a touch panel.

FIG. 16 is an exploded perspective view illustrating a configuration example of a conventional analog resistive touch panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal panel 2 Light guide plate 3 Auxiliary light source device 4 Touch panel 4A Upper substrate 4B Lower substrate 41 Upper common connection part 51 Comb-shaped resistive film 51A ITO film 52B Conductive film 55 First counter electrode wiring part 56 Second counter electrode wiring part 71 Protective film.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaki Chiba 3300 Hayano Mobara-shi, Chiba F-term in Hitachi Display Group 5B087 AA02 CC12 CC14 CC16 CC36 5G006 AA07 AZ01 FB14 FD02 5G023 CA24 5G435 AA14 BB12 HH15

Claims (3)

[Claims] An upper substrate having an upper resistive film and a lower substrate having a lower resistive film are bonded to each other so as to obtain a detection output in which a contact position between the upper resistive film and the lower resistive film is a two-dimensional coordinate value. A touch panel, wherein at least one of the upper resistance film and the lower resistance film has a coating film formed by applying a polymer material mixed with conductive material particles, and each of the upper resistance film and the lower resistance film has one end. A touch panel, comprising: a comb-shaped thin resistive film formed in a comb shape having a common connection portion; 2. An upper substrate having an upper resistive film and a lower substrate having a lower resistive film are bonded to each other so as to obtain a detection output in which a contact position between the upper resistive film and the lower resistive film is a two-dimensional coordinate value. A touch panel, wherein at least one of the upper resistance film and the lower resistance film has a coating film formed by coating a polymer material mixed with conductive material particles, and one of the upper resistance film and the lower resistance film is at one end. A touch panel comprising a comb-shaped thin resistive film formed in a comb shape having a common connection portion, and the other end formed of a uniform resistive film. 3. A liquid crystal display device comprising: a liquid crystal panel having a liquid crystal layer sandwiched between a pair of substrates; and a touch panel laminated on a display surface side of the liquid crystal panel, wherein the touch panel has an upper resistive film. An upper substrate having a lower resistance film and a lower substrate having a lower resistance film facing each other, and a touch panel for obtaining a detection output having a contact position between the upper resistance film and the lower resistance film as a two-dimensional coordinate value; At least one of the lower resistive films has a coating film formed by applying a polymer material mixed with conductive material particles, and each of the upper resistive film and the lower resistive film has a comb-shaped resistive film having a common connection portion at one end. A resistive film formed in the shape of
A liquid crystal display device comprising a plurality of thin comb-shaped resistive films arranged in an intersecting manner.