Structure to avoid gaps between switches/touch panel and case of a touch panel device

A touch panel device including: a first substrate having a first surface and a second surface arranged on an opposite side of the first surface; a second substrate having a third surface facing the first surface of the first substrate via a space; a first transparent conductive film formed on the first surface; a second transparent conductive film formed on the third surface; an adhesive layer formed between the first transparent conductive film and the second transparent conductive film; and a decorative film that is fixed on the second surface, and includes a switch unit that projects in a direction from second substrate toward the first substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2016-006623 filed on Jan. 15, 2016, the entire contents of which are incorporated herein by reference.

FIELD

A certain aspect of the embodiments is related to a touch panel device.

BACKGROUND

Conventionally, there has been known a touch panel device in which a decorative layer is formed on a non-operation domain receiving no touch input (Japanese Laid-open Patent Publication Nos. 2015-68909 and 2014-77821).

FIG. 1Ais a plain view of a conventional touch panel device.FIG. 1Bis a cross-section diagram taken along line A-A inFIG. 1A. When a resistive film type touch panel is installed as an operation panel of a copy device, for example, a first opening is formed in a substantially center of a resin case, and the resistive film type touch panel is implemented under the first opening, as illustrated inFIGS. 1A and 1B. Then, mechanical switches are disposed around the resistive film type touch panel, and second openings for depressing the mechanical switches are formed on the resin case.

SUMMARY

According to an aspect of the present invention, there is provided a touch panel device including: a first substrate having a first surface and a second surface arranged on an opposite side of the first surface; a second substrate having a third surface facing the first surface of the first substrate via a space; a first transparent conductive film formed on the first surface; a second transparent conductive film formed on the third surface; an adhesive layer formed between the first transparent conductive film and the second transparent conductive film; and a decorative film that is fixed on the second surface, and includes a switch unit that projects in a direction from second substrate toward the first substrate.

The object and advantages of the invention will be realized and attained by the elements and combinations particularly pointed out in the claims.

DESCRIPTION OF EMBODIMENTS

In the touch panel device ofFIGS. 1A and 1B, gaps exist between the touch panel and the case and between the mechanical switches and the case, and hence an erroneous input and a malfunction by the intrusion of foreign matters may occur in the touch panel device, and the touch panel device has a weak waterproofness.

A description will now be given of embodiments of the present invention with reference to the drawings.

FIG. 2Ais a top view of a touch panel device1according to the present embodiment.FIG. 2Bis a cross-section diagram taken along line A-A inFIG. 2A.FIG. 2Cis a diagram illustrating a variation of a decorative film15.

In the present embodiment, the touch panel device1includes a transparent touch panel10, a transparent adhesive layer14and the decorative film15, as illustrated inFIG. 2B. For example, a display (LCD)5is attached under the touch panel10. The adhesive layer14bonds a film13to the decorative film15, and is a double-stick tape or an optical paste, for example.

The touch panel10is a resistive film type touch panel. The touch panel10includes: a glass substrate11which is an example of a lower substrate (a second substrate); a transparent conductive film11A which is an example of a second transparent conductive film; an adhesive layer12; the film13which is an example of an upper substrate (a first substrate); a transparent conductive film13A which is an example of a first transparent conductive film; and electrodes50. The glass substrate11and the film13are transparent. An air gap12A is formed between the glass substrate11and the film13. The adhesive layer12bonds the film13to the glass substrate11, and is a double-stick tape, for example. The film13is composed of a PET (polyethylene terephthalate) film, for example. The conductive film11A is formed on an upper surface of the glass substrate11. The conductive film13A is formed on a lower surface of the film13. The conductive films11A and13A are ITO (Indium Tin Oxide), for example. The conductive films11A and13A contact each other, so that touch input is carried out.

An upper surface of the touch panel10is covered by the decorative film15illustrated inFIG. 2A. The decorative film15includes: the projection-shaped switch units16that project from the film13toward a side opposite to a side where the glass substrate11is provided; an operation domain17opposite to a domain of the touch panel10receiving the touch input; and a decorative domain17A, as illustrated inFIG. 2B. The switch units16, the operation domain17and the decorative domain17A are integrally formed with each other. Embossing is used as a formation method of the switch units16.

The operation domain17is transparent. Each of the switch units16is formed on the film13via a space16A. The adhesive layer14is not provided under each switch unit16. The switch unit16may be transparent or chromatic. For example, the decorative domain17A is black for hiding wirings. Therefore, an operator cannot see the display5arranged under the decorative domain17A, but can see, via the touch panel10and the operation domain17, an image displayed on the display5arranged under the operation domain17. Moreover, when the switch unit16is transparent, the operator can see an image, such as an icon of the button, displayed on the display5. The operation domain17serves as a display domain that displays an image displayed on the display5. The operation domain17may be a through hole. The electrodes50detect the depression of the switch unit16, the touch input of the operation domain17, and coordinates of the touch input.

In the touch panel device1ofFIG. 2B, the switch units16corresponding to the mechanical switches ofFIG. 1Bare formed integrally with the decorative film15. No gap occurs between the touch panel and the case, and between the mechanical switches and the case. Moreover, since all the surface of the touch panel10is covered by the decorative film15, the touch panel device1can prevent the occurrence of a malfunction and an erroneous input by the intrusion of foreign matters, and have excellent waterproofness. Since the decorative film15is flat except for the switch units16, the design of the touch panel device1can be also improved. In addition, since the embossing is performed on the decorative film15and the embossing is not performed on the film13, a crack can be prevented from occurring due to the embossing of the film13and the conductive film13A.

As illustrated inFIG. 2C, a part of the decorative domain17A other than an outer peripheral domain17B for hiding wirings, not shown, may be transparent in addition to the operation domain17and the switch units16. The operator can see, via the transparent touch panel10, the image displayed on the display5arranged under the part of the decorative domain17A other than the peripheral domain17B. In this case, the adhesive layer14also can be transparent.

Moreover, all the surface of the decorative domain17A may be transparent. In this case, all the surface of the decorative film15is transparent, and therefore a black image for hiding the wirings is displayed on a display domain of the display5corresponding to a domain on which the wirings are arranged.

FIG. 3Ais a cross-section diagram of a first variation of the touch panel device1.FIG. 3Bis a top view of a photoresist.

In the touch panel device1ofFIG. 2A, the resistive film type touch panel10is arranged even under the decorative domain17A, and therefore there may be the erroneous input by the depression of the decorative domain17A. For this reason, an insulating photoresist19is formed on a part of the conductive film11A opposite to the decorative domain17A (i.e., a domain other than the switch units16and the operation domain17), as illustrated inFIG. 3A. The photoresist19serves as a first insulating layer. The photoresist19covers the part of the conductive film11A opposite to the decorative domain17A, so that the erroneous input by the depression of the decorative domain17A can be avoided. As a result, the decorative domain17A ofFIG. 3Aserves as a non-operation domain18that does not receive the touch input. Other components of the touch panel device1are the same as the corresponding components ofFIG. 2B.

The photoresist19includes a hole19A formed at a position opposite to the operation domain17, and holes19B formed at positions opposite to the switch units16, as illustrated inFIG. 3B. The shape of each hole19B is a circle, but may be an N-sided polygon (N is an integer of 3 or more).

A diameter Y1of the hole19B formed at the position opposite to the switch unit16is smaller than a diameter X1of the switch unit16. Preferably, the diameter Y1is smaller than the diameter X1by 1 mm or more. This is because when the diameter Y1is larger than the diameter X1, the conductive film11A contacts the conductive film13A before the switch unit16is pushed down and completely dented, and hence the erroneous input of the switch unit16may occur.

FIG. 4Ais a top view of a first variation of the photoresist19.FIG. 4Bis an enlarged cross-section diagram of peripheral structure of the switch unit16when the switch unit16is depressed. As illustrated inFIG. 4A, the photoresist19includes a ventilation passage2Q which enables an air to flow in and out and connects the holes19B to each other, in addition to the hole19A and the holes19B.

In the photoresist19ofFIG. 3B, each hole19B is formed in an independent circle. Therefore, when the switch unit16is depressed, a portion Z surrounded in the conductive films11A and13A and the photoresist19becomes a vacuum, and hence the film13and the conductive film13A may be hard to come back to original positions, as illustrated inFIG. 4B. For this reason, the ventilation passage20enabling the air to flow to/from the respective holes19B is formed on the photoresist19as illustrated inFIG. 4A, which makes it easy to return the film13and the conductive film13A to the original positions.

FIG. 5Ais a cross-section diagram of a second variation of the touch panel device1.FIG. 5Bis a top view of the first variation of the photoresist19and an UV (Ultraviolet) curing resin21printed on the photoresist19.

In the touch panel device1ofFIG. 5A, an insulating UV curing resin21is formed on the photoresist19by screen printing. The UV curing resin21serves as a second insulating layer. As illustrated inFIG. 5B, an opening21A is formed at a position of the UV curing resin21opposite to the operation domain17and the hole19A, and openings21B are formed at positions of the UV curing resin21opposite to the switch units16and the holes19B. The UV curing resin21is also provided on the ventilation passage20. Due to the insulating UV curing resin21arranged on the ventilation passage20, the erroneous input by the depression of the ventilation passage20can be prevented. Since the insulating UV curing resin21is formed on the photoresist19, an insulation performance between the conductive films11A and13A can be kept even when there is a pinhole in the photoresist19. The shape of each opening21B is a circle, but may be an N-sided polygon (N is an integer of 3 or more).

FIG. 6Ais a top view of the UV curing resin21when the UV curing resin21is formed on the photoresist19.FIG. 6Bis a cross-section diagram taken along line B-B inFIG. 6A.

The diameter of each opening21B of the UV curing resin21is larger than that of each hole19B of the photoresist19, as illustrated inFIG. 6B. Preferably, the diameter of each opening21B is larger than that of each hole19B by 0.5 mm or more.

The photoresist19and the UV curing resin21are arranged on a domain between the opening21A and the openings21B. On the other hand, only the UV curing resin21is arranged on a domain on the ventilation passage20, but the photoresist19is not arranged thereon. For this reason, the position of the UV curing resin21in the domain on the ventilation passage20is lower than that of the UV curing resin21on the domain between the opening21A and the openings21B by the thickness of the photoresist19. In the domain on the ventilation passage20, a space between the conductive film13A and the UV curing resin21serves as the ventilation passage20, so that the air can flow in and out via the ventilation passage20even when the switch unit16is depressed.

FIG. 7Ais a top view of a variation of the UV curing resin21when the UV curing resin21is formed on the photoresist19.FIG. 7Bis a cross-section diagram taken along line C-C inFIG. 7A.

As illustrated inFIG. 7A, the UV curing resin21also may include the ventilation passage20which enables the air to flow in and out and connects the openings21B to each other. In this case, the photoresist19and the UV curing resin21are not formed on the ventilation passage20.

As illustrated inFIG. 7B, the diameter of each opening21B of the UV curing resin21may be smaller than that of each hole19B of the photoresist19. Edge portions21C of the UV curing resin21formed by screen-printing are rounded in comparison with edge portions19C of the photoresist19formed by photolithography. Even when the switch unit16is depressed, the conductive film13A does not touch the edge portions19C of the photoresist19due to this roundness, which can reduce a damage against the conductive film13A of the film13and reduce the occurrence of a crack of the conductive film13A.

FIG. 8is a top view of the conductive film11A, the photoresist19and the UV curing resin21located under the switch units16.

InFIG. 8, dot-like photoresists19are formed on the conductive film11A. By the photoresists19circularly arranged inside the opening21B, a space for opening is formed. A diameter24of the opening21B of the UV curing resin21is larger than a diameter23of an opening formed with the photoresists19arranged inside the opening21B. The UV curing resin21is formed on the photoresists19arranged outside the opening21B. In the example ofFIG. 8, the photoresists19are thickly arranged on a portion where the conductive film11A is exposed via the opening21B.

The dot-like photoresists19are formed on the portion where the conductive film11A is exposed, as illustrated inFIG. 8, so that an air hole is formed between the conductive film11A and the UV curing resin21. Therefore, the film13and the conductive film13A easily return to the original positions, as with a case where the ventilation passage20is formed.

Even when a crack occurs in the conductive film13A due to the edges of the photoresists19, the conductive film13A and the photoresists19do not contact each other at positions where no photoresists19exist, and hence the damage of the conductive film13A by the edges of the photoresist19is reduced. Accordingly, the film13and the conductive film13A can be prevented from completely exfoliating at a portion just below the switch unit16except for a crack occurrence portion, a current can flow in the conductive film13A just below the switch unit16, and hence the dot-like photoresists19do not affect on-and-off detection of the switch unit16.

A distance between the centers of the dot-like photoresists19adjacent to each other around the opening21B is equal to or less than 0.275 μm, and a single photoresist19is 0.05 mm square. Since the distance between the centers of the photoresists19adjacent to each other is equal to or less than 0.275 μm, the conductive film11A is prevented from contacting the conductive film13A before the switch unit16is depressed and dented. That is, the occurrence of the erroneous input of the switch unit16can be prevented.

FIG. 9is a cross-section diagram of a third variation of the touch panel device1. An air passage25connecting the hole19A to the outside is formed on the adhesive layer12, as illustrated inFIG. 9. Other elements ofFIG. 9are the same as corresponding elements ofFIG. 3A. Air in the touch panel10can be discharged from the air passage25to the outside of the touch panel10. This makes it possible to suppress distortion of the film13by the temperature and the humidity and to make the film13flat.

FIG. 10Ais a cross-section diagram of a fourth variation of the touch panel device1.FIG. 10Bis a top view of the adhesive layer12and the photoresist19. An air passage26connecting the hole19B to the outside is formed on the adhesive layer12, as illustrated inFIGS. 10A and 10B. The adhesive layer12is also formed between the hole19A and the hole19B, and the air gap12A under the operation domain17is sealed by the adhesive layer12. When the film13sinks low, an interference fringe may occur in the image displayed on the display device. However, since the air gap12A under the operation domain17is sealed, can support the film13and prevent the appearance of the interference fringe. Since the hole19B under the switch unit16is connected to the outside, the distortion of a domain of the film13where the switch unit16is formed can be prevented.

FIG. 11Ais a cross-section diagram of a fifth variation of the touch panel device1.FIG. 11Bis a top view of electrodes28A,29A,28B and29B, and the photoresist19.

In the touch panel device1ofFIG. 11A, the conductive films11A and13A under the switch unit16are separated from the conductive films11A and13A under the operation domain17by an etched domain27. Two electrodes28B are formed opposite to each other on the conductive film11A under the switch unit16. Two electrodes29B are formed opposite to each other on the conductive film13A under the switch unit16. Two electrodes28A are formed opposite to each other on the conductive film11A under the operation domain17. Two electrodes29A are formed opposite to each other on the conductive film13A under the operation domain17. Each of the electrodes28A and29A surrounding the operation domain17serves as a first electrode, and each of the electrodes28B and29B surrounding the switch unit16serves as a second electrode.

In the touch panel10, the switch unit16and the operation domain17share the film13and the glass substrate11. However, each of the conductive films11A and13A is separated at a position between the switch unit16and the operation domain17. The electrodes28A and29A surrounding the operation domain17are provided separately from the electrodes28B and29B surrounding the switch unit16. That is, in the touch panel10ofFIGS. 11A and 11B, two independent touch panels sharing the film13and the glass substrate11are arranged under the switch unit16and the operation domain17.

If the conductive films11A and13A are not separated and the electrodes for the switch unit16and the operation domain17are also not separated, when the switch unit16and the operation domain17are operated at the same time, a coordinate of a middle point between operation positions of the switch unit16and the operation domain17is detected, and hence unintended operation may be input. On the contrary, in the touch panel ofFIGS. 11A and 11B, the conductive films11A and13A under the operation domain17and the electrodes28A and29A are separated from the conductive films11A and13A under the switch unit16and the electrodes28B and29B, and therefore touch input of the respective domains can be detected independently when the switch unit16and the operation domain17are operated at the same time.

Moreover, even when any one of the two touch panels under the switch unit16and the operation domain17has a failure, the configuration ofFIGS. 11A and 11Bhas an advantage of having no influence on the operation of the other touch panel. For example, the two touch panels under the switch unit16and the operation domain17are four-wire type touch panels, but may be five-wire type touch panels. Especially, the touch panel under the switch unit16is preferably the five-wire type touch panel. This is because the five-wire type touch panel in which the electrodes serving as probes are formed on the conductive film13A under the switch unit16can perform position detection even when a crack occurs in the conductive film13A, and the five-wire type touch panel has high durability compared with the four-wire type touch panel.

FIG. 12is a cross-section diagram of a sixth variation of the touch panel device1. In the touch panel device1ofFIG. 12, a contact31is formed on the conductive film11A under each switch unit16, and a contact30is formed on the conductive film13A under each switch unit16. Then, a domain of the conductive film11A on which the contact31is formed is separated from the other parts of the conductive film11A by etching. Similarly, a domain of the conductive film13A on which the contact30is formed is separated from the other parts of the conductive film13A by etching. In this case, the switch unit16is decoratively printed so as to hide the contacts30and31. Other elements ofFIG. 12are the same as corresponding elements ofFIG. 3A.

Since each switch unit16has independent contact point structure as illustrated inFIG. 12, simultaneous input of the plurality of switch units16can be performed and the touch input of the operation domain17can be performed while depressing the switch unit16. Here, the contacts30and31are made of the transparent electrodes, and the switch unit16may be transparent. In this case, since the touch panel10and the switch unit16are transparent, an image displayed on the switch unit16by the display5can be changed freely.

FIG. 13is a cross-section diagram of a seventh variation of the touch panel device1. In the touch panel device1ofFIG. 13, a conductive film32as a third transparent conductive film is formed on the film13. That is, the conductive film32is located opposite to the conductive film13A with respect to the film13, and is formed between the adhesive layer14and the film13. Moreover, a contact33is formed on the top of a back side of each switch unit16. Moreover, the insulating photoresist19is formed on the conductive film11A under the switch unit16. Other elements ofFIG. 13are the same as corresponding elements ofFIG. 3A.

InFIG. 13, a switch is composed of the contact33and the conductive film32, and a switch composed of the conductive films11A and13A under the switch unit16is canceled by the photoresist19. Thus, the switch is composed of the contact33and the conductive film32, so that the switch unit16can be arranged on a frame portion (e.g. an outer periphery of the touch panel device1where the adhesive layer12is arranged) of the touch panel device1. The conductive films11A and13A corresponding to the frame portion are prevented from contacting with each other, the switch unit16is arranged on the frame portion of the touch panel device1, and hence the operation domain17can be enlarged.

FIG. 14is a cross-section diagram of an eighth variation of the touch panel device1. In the touch panel device1ofFIG. 14, the film13and the conductive film13A are folded and doubly overlapped under the switch unit16. The folded conductive film13A is opposite to the contact33formed on the top of a back side of each switch unit16. In the configuration ofFIG. 14, the conductive films13A and32do not have to be formed on both surfaces of the film13as illustrate inFIG. 13, and the conductive film13A opposite to the contact33can be formed by folding a part of the film13, which can reduce a manufacturing cost.

An adhesive layer35(e.g. an optical paste and a double-stick tape) is stuck between the folded films13. The lift of the folded film13is prevented by the adhesive layer35.

The adhesive layer14on the folded film13and the folded conductive film13A is made thinner than an adhesive layer14A between the operation domain17and the film13. The thickness of the adhesive layer14A is preferably the same as a total of the thicknesses of the adhesive layer35, the folded film13, the conductive film13A and the adhesive layer14. For example, the thickness of the adhesive layer14A is 175 μm, the thickness of the adhesive layer14is 50 μm, and the total of the thicknesses of the adhesive layer35, the film13and the conductive film13A is 125 μm. Thus, the thickness of the adhesive layer14A is made identical with the total of the thicknesses of the adhesive layer35, the film13, the conductive film13A and the adhesive layer14, and hence the flatness of the decorative film15can be secured

FIG. 15Ais an enlarged cross-section diagram of the switch unit16when the touch panel device1includes dot-like photoresists19.FIG. 15Bis a diagram illustrating state transition of the switch unit16when the touch panel device1includes no dot-like photoresists19.FIG. 15Cis a diagram illustrating a reference example of the switch unit16when the touch panel device1includes no dot-like photoresists19.

As illustrated inFIG. 15A, the plurality of dot-like photoresists19may be formed in a hole19B formed on the conductive film11A just below the switch unit16. It is preferable that a distance between the centers of the dot-like photoresists19is 1 mm or less, and a single dot-like photoresist19is 0.05 to 0.1 mm square.

When the switch unit16is depressed by an operator as illustrated inFIG. 15B, the film13and the conductive film13A just below the switch unit16sink and contact the conductive film11A. Then, when the switch unit16returns to an original shape, a restoring force P1is applied upward to the center of the switch unit16and a downward stress P2is applied to an outer periphery of the switch unit16. Therefore, the film13and the conductive film13A just below the switch unit16are slightly pushed downward by the stress P2. Since the dot-like photoresists19are not formed on the conductive film11A just below the switch unit16inFIG. 15B, the conductive film13A which is pushed downward by the stress P2contacts the conductive film11A, and hence an erroneous input of the switch unit16occurs.

On the contrary, in the configuration ofFIG. 15B, when the switch unit16is depressed by the operator, the conductive film13A contacts a portion of the conductive film11A on which the photoresists19are not formed. Thereby, the conductive films11A and13A conduct each other, and the ON/OFF of the switch unit16is detected. Then, when the switch unit16returns to the original shape, the conductive film13A is slightly pushed down by the downward stress as withFIG. 15A, but the dot-like photoresists19prevent the conductive films11A and13from contacting. Therefore, the erroneous input of the switch unit16can be prevented.

Moreover, to change a click feeling of the switch unit16, there is a method of inserting a click sheet36just below the switch unit16as illustrated inFIG. 15C. In this case, the adhesive layer14bends downward by the thickness of the click sheet36, and the film13is pushed down to some extent even when the switch unit16is not pushed down. In this state, when the periphery of the switch unit16is pushed down or another switch unit16adjacent to the switch unit16is pushed down, the switch unit16may become an ON state. Therefore, even when the click sheet36is used, the dot-like photoresists19are preferably formed on the conductive film11A just below the switch unit16.

FIG. 16Ais a cross-section diagram illustrating a reference example of the touch panel device1.FIG. 16Bis a diagram illustrating a process flow for processing the decorative film15and producing the touch panel device1. Other elements of the touch panel10ofFIGS. 16A and 16Bare the same as corresponding elements of the touch panel10ofFIG. 3A.

In the touch panel device1ofFIG. 16A, the decorative film15corresponding to the operation domain17is cut off, and the adhesive layer14under the operation domain17is also cut off. In this case, the increase of the input load to the touch panel10can be suppressed and the transmissivity of the touch panel10can be maintained, compared with a case where the decorative film15is arranged on the operation domain17. On the other hand, an edge37of the adhesive layer14is exposed from a portion where the decorative film15is cut off, and hence foreign substances may attach to the adhesive layer14.

Therefore, when convex-shaped embossing is performed on the decorative film15in order to form the switch unit16as illustrated inFIG. 16B, recess processing is performed on a portion of the decorative film15which corresponds to the operation domain17and on which the adhesive layer14is formed, and the operation domain17is transformed to a concave. Then, the portion of the decorative film15corresponding to the operation domain17is cut off. A reference numeral39indicates a recess formed by the recess processing. The decorative film15in which the portion corresponding to the operation domain17is cut off is fixed on the touch panel10with the adhesive layer14, so that the touch panel device1is produced.

The recess processing is performed on the operation domain17, so that an edge38of the recess39of the decorative film15extends downward. That is, the edge38, i.e., a wall portion extending downward is formed on a boundary between the operation domain17and the non-operation domain18. Thereby, after the operation domain17is cut off, the adhesion layer14is not exposed by the edge38, and hence the adhesion of the foreign substances is prevented. Since the edge38extends downward, an edge face of the decorative film15is also decorated and the design can be improved.

FIG. 17Ais a top view of a ninth variation of the touch panel device1.FIG. 17Bis a cross-section diagram taken along line D-D inFIG. 17A.

The touch panel device1according to the ninth variation does not include the decorative film15. The touch panel10according to the ninth variation is the resistive film type touch panel, and includes the glass substrate11, the conductive film11A, the adhesive layer12, the film13, the conductive film13A, and a decorative printing layer40. The glass substrate11and the film13are transparent. The air gap12A is formed between the glass substrate11and the film13. The adhesive layer12is the double-stick tape, for example. The decorative printing layer40is formed between the conductive film13A and the adhesive layer12arranged on an outer periphery of the touch panel10, and for example is made of a black ink or a black film to hide a wiring, or the like. The film13is composed of the PET (polyethylene terephthalate) film, for example. The conductive film11A is formed on the upper surface of the glass substrate11. The conductive film13A is formed on the lower surface of the film13. The conductive films11A and13A contact each other, so that touch input is carried out. A transparent insulating photoresist44is formed on the conductive film11A. The photoresist44prevents the conductive films11A and13A from contacting each other.

The film13includes: projection-shaped switch units41that project by embossing; an operation domain42opposite to a domain of the touch panel10receiving the touch input; and a non-operation domain43opposite to a domain of the touch panel10not receiving the touch input. A domain of the film13just above the photoresist44becomes the non-operation domain43.

Since the photoresist44is transparent, the operator can see an image displayed on the display5just below the photoresist44. As a result, in a part other than the outer periphery of the touch panel10on which the decorative printing layer40is arranged, the operator can see the image displayed on the display5.

In the touch panel device1according to the ninth variation, the embossing is directly performed on the film13, the decorative film15is not stuck on the film13, and therefore the increase of the input load to the touch panel10can be suppressed.

The ventilation passage20illustrated inFIG. 5Bmay be formed so as to connect openings of the photoresist44to each other. Moreover, the UV curing resin21illustrated inFIG. 5Amay be formed on the photoresist44. The UV curing resin21formed on the photoresist44also may include the ventilation passage20which enables the air to flow in and out and connects the openings21B to each other (seeFIG. 7A). The hole diameter of each opening21B of the UV curing resin21formed on the photoresist44may be smaller than that of each hole of the photoresist44(seeFIG. 7B). Moreover, the air passage25connecting the air gap12A to the outside may be formed on the adhesive layer12ofFIG. 17B(seeFIG. 9). In addition, the conductive films11A and13A just below the non-operation domain43between the switch unit41and the operation domain42ofFIG. 17Bare separated by etching, and the electrodes28A,29A,28B and29B may be formed such that the independent touch panels are arranged under the switch unit41and the operation domain42, respectively (seeFIG. 11B). A plurality of dot-like photoresists44may be formed on the conductive film11A just below the switch unit41ofFIG. 17B(seeFIG. 15A).

FIG. 18Ais a top view of the switch unit41, andFIG. 18Bis a cross-section diagram taken along line E-E inFIG. 18A. A reference numeral41B ofFIGS. 18A and 18Bindicates an inner diameter of the switch unit41.

The conductive film11A is formed on the glass substrate11. A pair of etching domains45is formed on the conductive film11A just below the switch unit41by laser etching, and the conductive film11A inside the pair of etching domains45is removed. Wiring patterns46are formed inside the etching domains45, respectively. The pair of wiring patterns46is electrically insulated from the conductive film11A. Moreover, one of the wiring patterns46is electrically insulated from the other of the wiring patterns46. The pair of wiring patterns46is connected to a processor100detecting ON/OFF of the switch unit41.

When the pair of wiring patterns46is not formed under the switch unit41, if a crack occurs in the conductive film13A under an outer periphery41A of the switch unit41, a voltage value detected at the time of pushing of the switch unit41becomes abnormal and the processor100may not accurately detect ON/OFF of the switch unit41.

On the contrary, when the pair of wiring patterns46is formed just below the switch unit41, even if the crack occurs in the conductive film13A under the outer periphery41A, the conductive film13A just below the switch unit41is electrically connected between the wiring patterns46, and hence the processor100can accurately detect ON/OFF of the switch unit41. For example, when a voltage of 5V is applied to one of the wiring patterns46and a voltage of 0V is applied to the other of the wiring patterns46, if the switch unit41is depressed, the conductive film13A just below the switch unit41contacts the wiring patterns46, the wiring patterns46are electrically connected to each other, and hence the processor100can accurately detect ON of the switch unit41. Therefore, regardless of the occurrence of the crack of the conductive film13A, the processor100can accurately detect ON/OFF of the switch unit41by detecting a voltage from the switch unit41.

The wiring patterns46are made of silver, for example. Since other wirings of the touch panel10are made of silver, the wiring patterns46can be formed together with the other wirings of the touch panel10and hence the manufacturing cost of the touch panel10can be suppressed.

Moreover, the wiring patterns46may be made of a transparent conductive film (Indium Tin Oxide), for example. In this case, the wiring patterns46can be formed by only performing etching of the conductive film11A by laser etching, and hence the manufacturing cost of the touch panel10can be suppressed.

In the case of the touch panel device1including the decorative film15, the etching domains45and the wiring patterns46may be formed on the conductive film11A just below the switch unit16.

FIG. 19Ais a top view of a first variation of the switch unit41, andFIG. 19Bis a cross-section diagram taken along line F-F inFIG. 19A.

InFIGS. 19A and 19B, an insulating layer47such as the photoresist is formed on the wiring patterns46and the conductive film11A. The insulating layer47includes an opening47A having a diameter smaller than the inner diameter41B of the switch unit41. The wiring patterns46and the conductive film11A arranged under the opening47A are exposed from the opening47A. InFIGS. 19A and 19B, when the switch unit41is depressed, the conductive film13A just below the switch unit41is electrically connected between the wiring patterns46inside the opening47A.

Since the insulating layer47is formed around the opening47A, an erroneous input of the switch unit41is reduced, compared with the structure of the switch unit41ofFIGS. 18A and 18B. Moreover, since an exposure part of the wiring patterns46becomes narrower than that of the wiring patterns46ofFIGS. 18A and 18Bby the formation of the insulating layer47and is arranged under the insulating layer47, the processor100can detect ON of the switch unit41when the operator steadily depresses the switch unit41.

Here, in the case of the touch panel device1including the decorative film15, the etching domains45and the wiring patterns46may be formed on the conductive film11A just below the switch unit16, and the insulating layer47such as the photoresist may be formed on the wiring patterns46and the conductive film11A.

FIG. 20is a diagram illustrating an arrangement relationship between the switch units41and the wiring patterns46. Here, marks “A” to “G” are added to the wiring patterns46in order to distinguish the wiring patterns46.

A wiring pattern46A as a common terminal and any one of wiring patterns46B to46G are included in the inner diameter41B of each of the switch units41. The wiring pattern46A is insulated from the wiring patterns46B to46G. The wiring patterns46A provided in the inner diameters41B of the switch units41are coupled with each other as a common terminal. Thus, the wiring patterns46A included in the respective switch units41are made common, so that the number of wirings can be reduced.

It is assumed that a voltage is applied to the wiring pattern46A and the wiring pattern46B is grounded, or the voltage is applied to the wiring pattern46B and the wiring pattern46A is grounded. In this case, a current flowing into the wiring patterns46A and46B changes in accordance with a force applied to the conductive films11A and13A when the switch unit41turns on. Therefore, the processor100can detect a depression pressure of the switch unit41based on a current value when the switch unit41turns on.

Here, in the case of the touch panel device1including the decorative film15, the pair of wiring patterns46may be formed on the conductive film11A just below each of the switch units41, and the wiring pattern46A as the common terminal and any one of the wiring patterns46B to46G may be included in the inner diameter41B of each of the switch units41.

FIG. 21is a diagram illustrating an arrangement relationship between the switch units41and the wiring patterns46. Here, marks “A” to “G” are added to the wiring patterns46in order to distinguish the wiring patterns46. Moreover, marks “−1” to “−6” are added to the inner diameters41B in order to distinguish the inner diameters41B of the switch units41.

The wiring pattern46A as the common terminal and any one of the wiring patterns46B to46G are provided in the inner diameter41B of each of the switch units41. Then, a voltage of 5V is applied to an end T1of the wiring pattern46A, and another end T2of the wiring pattern46A is grounded, for example.

The same are a resistance value R1of the wiring pattern46A between the inner diameters41B-1and41B-2, a resistance value R2of the wiring pattern46A between the inner diameters41B-2and41B-3, a resistance value R3of the wiring pattern46A between the inner diameters41B-3and41B-4, a resistance value R4of the wiring pattern46A between the inner diameters41B-4and41B-5, and a resistance value R5of the wiring pattern46A between the inner diameters41B-5and41B-6.

When the voltage of 5V is applied between the end T1and the another end T2of the wiring pattern46A, voltages of 3.75V, 3.25V, 2.75V, 2.25V, 1.75V and 1.25V are applied to the wiring patterns46A in the inner diameters41B-1to41B-6, respectively. Therefore, the processor100can detect a position of a depressed switch unit41based on a voltage value when each switch unit41turns on.

Thus, the wiring patterns46A between two adjacent switch units41have the same resistance value, and therefore the processor100can detect the position of the depressed switch unit41based on a voltage value when each switch unit41turns on.

When the switch units41are arranged on a line, the wiring patterns46B to46G can be made into a single wiring pattern as a common terminal. In this case, an independent wiring pattern need not be prepared for each switch unit41, and the pair of wiring patterns can be shared by the switch units41.

Here, in the case of the touch panel device1including the decorative film15, the pair of wiring patterns46may be formed on the conductive film11A just below each of the switch units41, and the wiring patterns46A as the common terminal between the adjacent switch units41may have the same resistance value.

FIG. 22Ais a top view of the decorative film15and electrodes50.FIG. 22Bis a cross-section diagram of a tenth variation of the touch panel device1, and illustrates a cross-section surface taken along line G-G inFIG. 22A.FIG. 22Cis a diagram illustrating a first variation of the non-operation domain18.FIG. 22Dis a diagram illustrating a second variation of the non-operation domain18.FIG. 23Ais a diagram illustrating a third variation of the non-operation domain18.FIG. 23Bis a diagram illustrating a fourth variation of the non-operation domain18.FIG. 23Cis a diagram illustrating wiring structure of the touch panel device1.FIG. 23Dis a diagram illustrating a variation of the film13.

Hereinafter, a description will be given of a method for making good use of a frame portion of the touch panel device1which was a dead space in the past.

InFIG. 22A, the decorative film15includes the projection-shaped switch units16that project by embossing, the operation domain17and the non-operation domain18, as with the decorative film15ofFIG. 2A. InFIG. 22A, the non-operation domain18is a frame portion49of the touch panel device1. The frame portion49of the touch panel device1is an outer periphery domain of the touch panel device1having a width within 10 mm, and is a domain where the adhesive layer12is formed. The switch units16are formed on the frame portion49of the touch panel device1. The switch units16are formed outside electrodes50for detecting the touch input and the coordinate of the touch input, as illustrated inFIG. 22A.

The electrodes50are formed on the conductive film13A, and formed at positions adjacent to the air gap12A, as illustrated inFIG. 22B. A contact52is formed on the top of the back side of each switch unit16, and a contact51is formed on the film13just below each switch unit16so as to be opposed to the contact52via the space16A. The contacts52and51are connected to a processor, not shown. When the contact51contacts the contact52, the processor detects ON of the switch unit16.

FIG. 22Cillustrates a first variation of a right side of the non-operation domain18ofFIG. 22B. InFIG. 22C, a through-hole53is formed in the center of the adhesive layer12. When the switch unit16is depressed, the conductive film13A contacts the conductive film11A via the through-hole53, and hence the depression of the switch unit16is detected. The diameter of the through-hole53is 0.5 mm or more and less than 5 mm, for example. Moreover, the height of the through-hole53or the adhesive layer12is preferably 0.2 mm or less.

FIG. 22Dillustrates a second variation of the right side of the non-operation domain18ofFIG. 22B. InFIG. 22D, the through-hole53is formed in the center of the adhesive layer12. An insulating layer54such as the photoresist is formed on the conductive film11A inside the through-hole53, and further a conductive layer55such as silver or silver carbon is formed on the insulating layer54. The silver carbon is superior to silver in the durability such as against corrosion.

Since a distance between the conductive film13A and the conductive layer55is shorter than a distance between the conductive films11A and13A, the switch unit16can be input by a light load.

Here, it is preferable that a position of an upper surface of the conductive layer55is calculated by multiplying 0.5 to 1.0 (exclusive of 1.0) by the height of the adhesive layer12, i.e., a position which is higher than the center of the height of the adhesive layer12and does not exceed the height of the adhesive layer12. This is because when the position of the upper surface of the conductive layer55is too low, the input sensitivity of the switch unit16decreases, and when the position of the upper surface of the conductive layer55is equal to or more than the height of the adhesive layer12, false detection of the ON state occurs.

FIG. 23Aillustrates a third variation of the right side of the non-operation domain18ofFIG. 22B. InFIG. 23A, the projection-shaped switch unit16is not formed on the frame portion49of the touch panel device1. However, the through-hole53is formed in the center of the adhesive layer12, and hence the touch input can be performed on the frame portion49. When the decorative film15is transparent, for example, an image such as an icon image from the display5can be displayed on the frame portion49. This makes it possible to make good use of the frame portion49of the touch panel device1which was a dead space in past.

FIG. 23Billustrates a fourth variation of the right side of the non-operation domain18ofFIG. 22B. When the width of the switch unit16is larger than the width of the adhesive layer12, the conductive film13A may not contact the conductive film11A due to the thickness of the adhesive layer12even if the switch unit16is depressed. Therefore, when the width of the switch unit16is larger than the width of the adhesive layer12, the insulating layer54is formed on the conductive film11A so as to be adjacent to the adhesive layer12, and further the conductive layer55such as silver or silver carbon is formed on the insulating layer54. Thereby, the distance between the conductive film13A and the conductive layer55is shorter than the distance between the conductive films11A and13A, and hence it becomes easy to perform the touch input of the switch unit16.

Here, it is preferable that the position of the upper surface of the conductive layer55is calculated by multiplying 0.5 to 1.0 (exclusive of 1.0) by the height of the adhesive layer12, i.e., the position which is higher than the center of the height of the adhesive layer12and does not exceed the height of the adhesive layer12. This is because when the position of the upper surface of the conductive layer55is too low, the input sensitivity of the switch unit16decreases, and when the position of the upper surface of the conductive layer55is equal to or more than the height of the adhesive layer12, false detection of the ON state occurs.

As illustrated inFIG. 23C, four electrodes50are connected to an FPC (Flexible Printed Circuit)58for touch panel wiring via wirings56ato56d, and the conductive layer55and the conductive film13A are connected to the FPC58for touch panel wiring via wirings57aand57b, respectively. The FPC58is connected to a processor59that detects ON/OFF of the switch unit16, and the touch input and the coordinate on the operation domain17.

In the above-mentioned touch panel device1, a single layer PET film is used as the film13. However, a two-layer film13-4that includes two PET films13-1and13-2sandwiching an adhesive layer13-3may be used as the film13, as illustrated inFIG. 23D. Since the film13-4is higher in flexibility than the single layer PET film, the input sensitivity of the touch panel device1improves. Particularly, since the outer periphery of the touch panel device1has lower flexibility than the center thereof, it is effective that the frame portion49of touch panel device1uses the film13-4.

FIG. 24Ais a top view of the film13and the electrodes50.FIG. 24Bis a cross-section diagram of an eleventh variation of the touch panel device1, and illustrates a cross-section surface taken along line H-H inFIG. 24A.FIG. 24Cis a diagram illustrating a first variation of the non-operation domain43.FIG. 24Dis a diagram illustrating a second variation of the non-operation domain43.FIG. 25Ais a diagram illustrating a third variation of the non-operation domain43.FIG. 25Bis a diagram illustrating a fourth variation of the non-operation domain43.

Hereinafter, a description will be given of a method for making good use of the frame portion of the touch panel device1which was the dead space in past.

InFIG. 24A, the film13includes the projection-shaped switch units41that project by embossing, the operation domain42and the non-operation domain43, as with the film13ofFIG. 17B.

InFIG. 24A, the non-operation domain43is the frame portion49of the touch panel device1. The frame portion49of the touch panel device1is the outer periphery domain of the touch panel device1having a width within 10 mm, and is the domain where the adhesive layer12is formed. The switch units41are formed on the frame portion49of the touch panel device1. The switch units41are formed outside the electrodes50for detecting the touch input and the coordinate of the touch input, as illustrated inFIG. 24A.

The electrodes50are formed on the conductive film13A, and formed at positions adjacent to the air gap12A, as illustrated inFIG. 24B. The conductive film13A is formed on the back side of each switch unit41, and the contact51is formed on the adhesive layer12just below each switch unit41. The conductive film13A and the contact51are connected to a processor, not shown. When the conductive film13A contacts the contact51, the processor detects ON of the switch unit41.

FIG. 24Cillustrates a first variation of a right side of the non-operation domain43ofFIG. 24B. InFIG. 24C, the through-hole53is formed in the center of the adhesive layer12. When the switch unit41is depressed, the conductive film13A contacts the conductive film11A via the through-hole53, and hence the depression of the switch unit41is detected. The diameter of the through-hole53is 0.5 mm or more and less than 5 mm, for example. Moreover, the height of the through-hole53or the adhesive layer12is preferably 0.2 mm or less.

FIG. 24Dillustrates a second variation of the right side of the non-operation domain43ofFIG. 24B. InFIG. 24D, the through-hole53is formed in the center of the adhesive layer12. The insulating layer54such as the photoresist is formed on the conductive film11A inside the through-hole53, and further the conductive layer55such as silver or silver carbon is formed on the insulating layer54. The silver carbon is superior to silver in the durability such as against corrosion.

Since the distance between the conductive film13A and the conductive layer55is shorter than the distance between the conductive films11A and13A, the switch unit41can be input by a light load.

Here, it is preferable that the position of the upper surface of the conductive layer55is calculated by multiplying 0.5 to 1.0 (exclusive of 1.0) by the height of the adhesive layer12, i.e., the position which is higher than the center of the height of the adhesive layer12and does not exceed the height of the adhesive layer12. This is because when the position of the upper surface of the conductive layer55is too low, the input sensitivity of the switch unit41decreases, and when the position of the upper surface of the conductive layer55is equal to or more than the height of the adhesive layer12, false detection of the ON state occurs.

FIG. 25Aillustrates a third variation of the right side of the non-operation domain43ofFIG. 24B. InFIG. 25A, the projection-shaped switch unit41is not formed on the frame portion49of the touch panel device1. However, the through-hole53is formed in the center of the adhesive layer12, and hence the touch input can be performed on the frame portion49. For example, an image such as an icon image from the display5can be displayed on the frame portion49. This makes it possible to make good use of the frame portion49of the touch panel device1which was a dead space in past.

FIG. 25Billustrates a fourth variation of the right side of the non-operation domain43ofFIG. 24B. When the switch unit41is provided in the vicinity of the frame portion49and the adhesive layer12gets under the switch unit41as illustrated inFIG. 25B, the conductive film13A may not contact the conductive film11A due to the thickness of the adhesive layer12even if the switch unit41is depressed. Therefore, the insulating layer54is formed on the conductive film11A so as to be adjacent to the adhesive layer12, and further the conductive layer55such as silver or silver carbon is formed on the insulating layer54. Thereby, the distance between the conductive film13A and the conductive layer55is shorter than the distance between the conductive films11A and13A, and hence it becomes easy to perform the touch input of the switch unit41.

Here, it is preferable that the position of the upper surface of the conductive layer55is the position calculated by multiplying 0.5 to 1.0 (exclusive of 1.0) by the height of the adhesive layer12, i.e., the position which is higher than the center of the height of the adhesive layer12and does not exceed the height of the adhesive layer12. This is because when the position of the upper surface of the conductive layer55is too low, the input sensitivity of the switch unit41decreases, and when the position of the upper surface of the conductive layer55is equal to or more than the height of the adhesive layer12, false detection of the ON state occurs.

In the touch panel device1ofFIGS. 24A to 25B, the two-layer film13-4ofFIG. 23Dmay be used as the film13.