Patent Application
20120098767
The present invention relates to an information input apparatus configured to allow input of information in response to a user's pressing operation on a panel member and corresponding to the pressing force. The invention relates also to a pressure detection unit for use in the information input apparatus.
As an information input apparatus with a touch panel member having an information input function, there is widely used an apparatus with a touch panel disposed on a liquid crystal display. In the case of a digital camera having a liquid crystal monitor, there is known one including a panel member capable of detecting a contact position and a pressing force disposed on the upper face of the liquid crystal display so that different instructions are given depending on the various strengths of the pressing force at the time of contact (See Patent Document 1, FIG. 22 for instance).
Further, in the case of a display apparatus for a car navigation system, there is known an apparatus wherein a touch panel is provided in a surface portion of a liquid crystal display and a pressing force applied to the touch panel is detected for its pressing duration, the number of times of pressing operations, etc, so as to provide different instruction (See Patent Document 2 for instance). Aside from a touch panel, there is also known an apparatus wherein a pressure sensor is disposed under an operation button for effecting e.g. input of characters in a mobile phone for determining a pressure of a pressing operation on this operation button so as to change the size of a character to be inputted, according to the determined pressure value (See Patent Document 3 for instance).
A pressure-sensitive sensor for detecting a pressing pressure to a panel member, as illustrated in
In view of the above, the object of the present invention relating to this application is to obtain an information input apparatus having good response to an information input operation and to obtain also a pressure detection unit for use in the information detection apparatus and having an improved response to an information input operation.
According to the first characterizing feature of an information input apparatus relating to the present invention, the apparatus comprises:
a panel member having a touch type information input function:
a package having a support portion for supporting the panel member;
a pressure detection portion provided between/across the panel member and the support portion for detecting pressing operation force to the panel member, and
an initial load applying portion provided between/across the panel member and the support portion and configured to draw the panel member and the support portion toward each other, thereby to apply an initial load to the pressure detection portion.
With the above arrangement, the initial load applying portion draws the panel member and the support portion toward each other to decrease the distance therebetween, thus reducing the thickness of the pressure detection portion under no-pressure applied state thereof. As a result, an initial load is applied to the pressure detection portion and detection values under the unstable initial stage in the operation are eliminated automatically. When the panel member is pressed, a value detected by the pressure detection portion is within the range of stable detection values of this pressure detecting portion, so this value can be used as it is as an information input value. Therefore, the response is good, so that there is no need for effecting a control for e.g. canceling detection values of the pressure detection section for initial loads within the error range. Further, as the initial load applying portion is configured to apply the initial load to the pressure detection section by drawing the panel member and the support portion toward each other, this initial load applying portion is not to be disposed in the direction which increases the thickness of the information input apparatus. Therefore, the information input apparatus having this initial load applying section can be formed thin also.
According to the second characterizing feature of the information input apparatus relating to the present invention, said initial load applying portion is formed of an elastic member connected to said panel member and said support portion.
With the above-described arrangement, the initial load applying portion can be readily formed of an elastic member. Therefore, the inventive information input apparatus can be manufactured easily and speedily. Incidentally, the elastic member or material to be used as the initial load applying portion can be any of a variety of members or materials, such as an adhesive agent, a double-sided adhesive member, rubber, a torsion coil spring, a plate spring. etc.
According to the third characterizing feature of the information input apparatus relating to the present invention, either between said pressure detection portion and said panel member or between said pressure detection portion and said support portion, there is provided a load transmission portion configured to receive a load from the panel member or the support portion in a concentrated manner and transmit the load to said pressure detection portion in distribution and configured also to allow a posture change of said panel member or said support portion relative to said pressure detection portion.
With the above-described arrangement, when the panel member is pressed, the load transmission portion reliably transmits the load from the panel member or the support portion to the pressure detection portion. Also, even when the peripheral edge of the panel member becomes warped upward at the time of a pressing operation on the panel member, the load transmission portion allows a posture change of the panel member or the support portion relative to the pressure detection portion, so that the load transmission portion can receive the load from the panel member or the support portion in a concentrated manner and transmits this load to the pressure detection portion in distribution, just like when the panel member assumes a horizontal posture. In this way, the pressing operation force to the panel ember is transmitted in a stable manner to the pressure detection portion for detection of its pressure. Hence, the pressing operation force to the panel member can be detected with precision.
According to the fourth characterizing feature of the information input apparatus relating to the present invention, said pressure detection portion and said initial load applying portion are provided at least at a portion of the peripheral edge of said panel member.
With the above-described arrangement, the pressure detection portion and the initial load applying portion are disposed at only a portion of the peripheral edge of the panel member where such pressure detection portion and initial load applying portion need to be provided. Therefore, the structure of the panel member can be made simple.
According to the first characterizing feature of a pressure detection unit relating also to the present invention, a pressure detection unit for use in an information input apparatus comprises:
a first substrate;
a second substrate disposed in opposition to said first substrate;
a pressure detection portion disposed between said first substrate and said second substrate for detecting a mutual pressing force of said first substrate and said second substrate; and
an initial load applying portion provided between/across said first substrate and said second substrate for urging said first substrate and said second substrate toward said pressure detection portion, thereby to apply an initial load.
With the above-described arrangement, the initial load applying portion serves to decrease the distance between the first substrate and the second substrate thereby to reduce the thickness of the pressure detection portion under no-pressure applied state thereof. As a result, an initial load is applied thereto. Hence, even when a force of light load is to be detected, as the initial load is being applied to the pressure detection portion in advance, detection values during the unstable initial stage can be eliminated automatically. This serves also to minimize the error range of the detection values (resistance values) relative to the loads, so that precision in the pressure determination can be improved.
Further, the pressure detection unit integrally incorporates the pressure detection portion and the member which applies the initial load, altogether therein. Hence, in manufacturing an information input apparatus provided with a panel member having a touch-type information input function, there is no need to dispose, in the information input apparatus per se, any arrangement corresponding to an elastic member for applying the initial load. Therefore, the construction of the information input apparatus can be made simple. Moreover, as the member for applying the initial load is configured to apply this initial load by drawing the first substrate and the second substrate toward each other, the thickness of the pressure detection unit can be smaller than an arrangement of applying the initial load to the pressure detection portion by pressing the first substrate or the second substrate from the outside thereof.
According to the second characterizing feature of the pressure detection unit relating to the present invention, said initial load applying portion comprises an elastic member connected to said panel member and said support portion.
With the above-described arrangement, the initial load applying portion can be readily formed of an elastic member. Incidentally, the elastic member or material to be used as the initial load applying portion can be any of a variety of members or materials, such as an adhesive agent, a double-sided adhesive member, rubber, a torsion coil spring, a plate spring. etc.
According to the third characterizing feature of the pressure detection unit relating to the present invention, said pressure detection portion includes a pair of electrodes disposed between said first substrate and said second substrate and a conductive pressure-sensitive ink disposed between said pair of electrodes and has electric characteristics which varies in accordance with a load applied from the outside.
With the above-described arrangement, the pair of electrodes and the conductive pressure-sensitive ink together constituting the pressure detection portion can be applied to the first substrate and the second substrate with using the standard printing technique. Hence, the thickness of the pressure detection portion can be smaller. As a result, the pressure detection unit as a whole can be formed thinner.
According to the fourth characterizing feature of the pressure detection unit relating to the present invention, said pressure detection portion includes a pair of electrodes disposed on one of said first substrate and said second substrate and a conductive pressure-sensitive ink disposed on the other of said first substrate and said second substrate and has electric characteristics which varies in accordance with a load applied from the outside.
With the above-described arrangement, the pair of electrodes and the conductive pressure-sensitive ink together constituting the pressure detection portion can be applied with using the standard printing technique in such a manner as to cover the pair of electrodes disposed on one of the first substrate and the second substrate. Hence, as the electrode layer is formed as a single layer, the thickness of the pressure detection portion can be made even smaller. As a result, the pressure detection unit as a whole can be formed even thinner. If comb electrodes are employed as the pair of electrodes disposed on the one substrate, the contact area between the electrodes and the conductive pressure-sensitive ink can be made greater for facilitating sensitivity adjustment as well.
According to the fifth characterizing feature of the pressure detection unit relating to the present invention, the unit further comprises a load transmission portion provided on at least one of the outer face of said first substrate and the outer face of said second substrate and formed with an area smaller than the contact area between said pressure detection portion and said first substrate or said second substrate.
With the above-described arrangement, when an external load is applied to the pressure detection unit, as the load transmission portion supports the pressure detection portion to receive this external load in a concentrated manner, without dispersing thereof and to transmit this load to the pressure detection portion in a reliable manner. In this way, as the pressure detection portion is pressed reliably, the precision in the pressure determination of the pressure detection unit can be improved.
According to the sixth characterizing feature of the pressure detection unit relating to the present invention, said load transmission portion has a cross section area which is progressively decreased away from the outer surface of either the first substrate or the second substrate on which the load transmission portion is disposed.
With the above-described arrangement, the load transmission portion allows a certain amount of posture change of the pressure detection portion and an external member (e.g. a panel member) for pressing the pressure detection portion. Therefore, in the event of small posture change between the pressure detection portion and the external member, the load transmission portion restricts dispersing of the load from the outside to other portions than the pressure detection portion.
Next, an embodiment of an information input apparatus 1 relating to the present invention will be described with reference to the drawings.
As shown in
In the present invention, as shown in
The shape and size of the opening portion 2A can vary depending on the shape and size of the panel member 4. Also, the mounting depth of the opening portion 2A can vary depending on e.g. the thickness of the panel member 4. Further, the shape and size of the display device opening portion 2a of the opening portion 2A can vary depending on e.g. the shape and size of the display portion 3A. In this embodiment, the opening portion 2A, the display device opening portion 2a, the display portion 3A and the panel member 4 have a rectangular or approximately rectangular shape. However, the shape of e.g. the panel member 4 is not particularly limited, and it can be e.g. circular. The mounting depth of the opening portion 2A should be set such that the surface of the package 2 be located at a substantially same level as the surface of the panel member 4.
The information input apparatus 1 includes a pressure detection means for detecting a pressing operation force applied to the panel member 4. This pressure detection means comprises a pressure detection portion 5 provided between/across the panel member 4 and the support portion 2b of the package 2, and an unillustrated signal processing circuit or the like for processing output signals from this pressure detection portion 5. The construction of the pressure detection portion 5 is not particularly limited as long as it is capable of detecting the pressing force. As shown in
As shown in
The tension member 6a is set between the panel member 4 and the support portion 2b, with its thickness being rendered smaller than the thickness the pressure detection portion 5 under its no-pressure applied state. As the tension member 6a set as above will tend to regain its original thickness, thereby to draw the panel member 4 and the support portion 2b toward each other. In this way, the distance between the panel member 4 and the support portion 2b is reduced and the thickness under the no-pressure applied state of the pressure detection portion 5 is reduced, as a result, an initial load is applied to the pressure detection portion 5.
With the above-described construction of the initial load applying portion 6, an initial load is applied to the pressure detection portion 5 prior to a pressing operation on the panel member 4. Thereafter, when the panel member 4 is press-operated, a value detected by the pressure detection portion 5 can be employed for information input control. Further, as the thickness of the tension member 6a is smaller than the thickness of the pressure detection portion 5 under its no-pressure applied state, the elastic member 6a does not increase the thickness of the information input apparatus 1.
The construction of the pressure detection portion 5 is not particularly limited. However, as one example thereof, a pressure detection portion 5 using pressure sensitive ink will be described next. Referring more particularly to the pressure detection portion 5 with reference to
The material forming the upper electrode 21a and the lower electrode 22a can be a conductive paste containing a metal such as gold, silver, copper, nickel, etc. or carbon or of a mixture containing a plurality of kinds of these materials. The method for forming these electrodes can be a printing technique such as screen printing, offset printing, gravure printing, or flexo printing, photoresist technique, etc. Further, the upper electrode 21a and the lower electrode 22a can also be formed by affixing a metal foil of copper, gold, etc. Moreover, the upper electrode 21a and the lower electrode 22a can be formed by forming an electrode pattern with resist on an FPC plated with a metal such as copper and then etching the portion of the metal foil not protected by the resist. The upper electrode 21a and the lower electrode 22a can be formed by any combination of the above-cited forming techniques or by laminating technique.
The composition constituting the upper pressure sensitive ink 23a and the lower pressure sensitive ink 23b is comprised of a material whose electric characteristics such as an electric resistance value varies according to an external force. As such composition, it is possible to employ e.g. quantum tunneling effect composite material (commercial name “QTC”) manufactured by Peratech Ltd. in U.K. The upper pressure sensitive ink 23a and the lower pressure sensitive ink 23b can be disposed on the upper electrode 21a and the lower electrode 22a by means of application technique. As such application technique for the upper pressure sensitive ink 23a and the lower pressure sensitive ink 23b, a printing technique such as screen printing, offset printing, gravure printing, flexo printing, etc. may be employed. The pressure sensitive ink may be applied only one face of the upper electrode 21a or the lower electrode 22a.
The upper electrode 21a and the lower electrode 22a are connected to a connector (not shown) and this connector is connected to a pressing detection portion (not shown) incorporated within the information input apparatus 1. With the pressure detection portion 5 having the above-described construction in operation, under the normal (no pressure applied) state, no pressure is applied to the upper pressure sensitive ink 23a or the lower pressure sensitive ink 23b. Under this condition, if a pressing operation force is applied to the touch input face of the panel member 4 disposed on the pressure detection portion 5, this pressing operation force brings the upper pressure sensitive ink 23 and the lower pressure sensitive ink 23b into pressurized contact with each other. With this pressurized contact, there occur reductions in the electric resistance values and contact resistance values of the upper pressure sensitive ink 23a and the lower pressure sensitive ink 23b. Then, by detecting these change in the resistance, the pressing operation force to the touch input face of the panel member 4 can be detected.
Further, in correspondence with increase in the pressing operation force applied to the touch input face of the panel member 4, the external force applied to the upper pressure sensitive ink 23a and the lower pressure sensitive ink 23b increases. As a result, there occur further reductions in the electric resistance value and the contact resistance values. Then, by detecting such resistance changes, the external force applied to the upper pressure sensitive ink 23a or the lower pressure sensitive ink 23b can be detected and the pressing operation force applied to the touch input face of the panel member 4 can be detected.
[Further Embodiments of Information Input Apparatus]
(1) In the foregoing embodiment, the initial load is applied to the pressure detection portion 5 by setting the thickness of the tension member 6a smaller than the thickness of the pressure detection portion under its no-pressure applied condition. However, if it is not possible to reduce the thickness of the tension member smaller than that of the pressure detection portion 5 under the normal condition due to e.g. the material forming this tension member 6a, the application of the initial load to the pressure detection portion 5 can be realized by reverse arrangement of increasing the thickness of the pressure detection portion 5 greater than the thickness of the tension portion 6a. Incidentally, for such increase of the thickness of the pressure detection portion 5, the upper electrode 21a and the lower electrode 22a or the pressure sensitive ink 23a, 23b may be applied or printed in greater thickness than usual or applied or printed in superposition, etc.
(2) The pressure detection portion 5 may be fixedly attached to the panel member 4 to form a portion of an integrated panel unit. Further, as shown in
(3) As shown in
Even if the peripheral edge 4A of the panel member 4 becomes warped upwards during a pressing operation of the panel member 4, the area of contact between the convex load transmission portion 8 and the support portion 2b changes little, and a posture change of the support portion 2b relative to the pressure detection portion 5 is allowed. Therefore, the convex load transmission portion 8, just like the time when the panel member 4 assumes a horizontal posture, receives the load from the support portion 2b in a concentrated manner and transmits this load to the pressure detection portion 5 in distribution. In this way, as the load from the support portion 2b is transmitted to the pressure detection portion 5 in a reliable manner and the pressure is detected thereby, the pressing operation force applied to the panel member 4 can be detected with precision.
In the arrangement shown in
(4) The load transmission portion 8, as shown in
(5) The pressure detection portion 5 and the initial load applying portion 6 may be provided at least in some limited portions of the peripheral edge 4A of the panel member 4. And, the initial load applying portion 6, as shown in
(6) The initial load applying portion 6, as shown in
Next, Embodiment Mode 1 of a pressure detection unit relating to the present invention will be described with reference to the accompanying drawings.
[Embodiment Mode 1 of Pressure Detection Unit]
First, the construction of an information input apparatus 1 mounting a pressure detection unit 20 will be explained with reference to
The pressure detection means, as shown in
Next, the construction of the pressure detection unit 20 will be explained. As shown in
As shown in
The pressure detection portion 23 includes the upper electrode 21a formed on the first substrate 1, the lower electrode 22a formed on the second substrate 22 in opposition to the upper electrode 21a, the upper pressure sensitive ink 23a formed on the upper electrode 21a, and the lower pressure sensitive ink 23b formed on the lower electrode 22a in opposition to the upper pressure sensitive ink 23a.
The initial load applying portion 30 includes a tension member 30a and is disposed in the area where the first substrate 21 and the second substrate 22 are opposed to each other and in the peripheral edge of the pressure detection portion 23. The tension member 30a is disposed as being clamped between the first substrate 21 and the second substrate 22 and is configured to urge the first substrate 21 and the second substrate 23 toward the pressure detection portion 23. The tension member 30a is provided as e.g. a non-elastic spacer whose thickness is set smaller than the pressure detection portion 23 (can be adhesive agent per se including the adhesive layer to the substrates 21, 22). And, when the deformation of the first substrate 21 or the second substrate 22 is allowed, the pressure detection portion 23 applied with the initial load is further compressed by the first substrate 21 or the second substrate 22 for detecting the pressing force. Further, the tension member 30a can also be an adhesive agent or double-face adhesive material having elasticity or can be any of various kinds of elastic member such as a rubber, a tension coil spring set under a condition for applying a tensile force. Incidentally, in
In the above, the tension member 30a is configured such that under its free state, its thickness is smaller than the thickness of the pressure detection portion 23. The tension member 30a set as above is subject to a force that tends to retain its original thickness. And, this force serves to bring the first substrate 21 and the second substrate 22 toward each other. In this way, as the distance between the first substrate 21 and the second substrate 22 is reduced and the thickness of the pressure detection portion 23 under the no-pressure applied state is made smaller, an initial load is applied to the pressure detection portion 23.
Next, operations of the pressure detection unit 20 mounted in the information input apparatus 1 will be explained. Inside the information input apparatus 1, the upper electrode 21a and the lower electrode 22a are connected to a connector (not shown), and this connector is connected to a load detection portion (not shown) incorporated in the information input apparatus.
A change in the resistance applied to the upper pressure sensitive ink 23a and the lower pressure sensitive ink 23b of the pressure detection portion 23 when the panel member 4 is pressed is detected. With this detection of change in the resistance, the external force applied to the two pressure sensitive inks 23a, 23b can be detected and the load to the panel member 4 can be detected.
In the above, as the pressure detection unit 20 is provided with the tension member 30a, an initial load is applied to the pressure detection portion 23 prior to the pressing operation of the panel member 4. Thus, the load range from the zero load to the stable detection load which range suffers much detection irregularity can be omitted, so that the detected load can be used as it is for control of information input.
The first substrate 21 and the second substrate 22 of the pressure detection unit 20 can be formed of e.g. a film made of a material such as a material usable for a flexible substrate. As some non-limiting examples thereof, general-purpose resins, such as polyethylene terephthalate, polystyrene resin, polyolefin resin, ABS resin, AS resin, acrylic resin, AN resin can be cited. Further, general-purpose engineering resin such as polystyrene resin, polycarbonate resin, polyacetal resin, polycarbonate modified polyphenylene ether resin, polybutylene terephthalate resin, ultrahigh molecular weight polyethylene resin, or a super engineering resin such as polysulfone resin, polyphenylene sulfide resin, polyphenylene oxide resin, polyarylate resin, polyetherimide resin, polyimide resin, liquid crystal polyester resin, polyacrylic resin, can also be employed.
As the material for forming the upper electrode 21a and the lower electrode 22a of the pressure detection portion 23, a conductive paste containing a metal such as gold, silver, copper, or nickel, or carbon, or a mixture of a plurality of these can be employed. The method for forming the upper electrode 21a and the lower electrode 22a on the first substrate 21 and the second substrate 22 can be a printing technique such as screen printing, offset printing, gravure printing, or flexo printing, photoresist technique, etc. Further, the upper electrode 21a and the lower electrode 22a can also be formed by affixing a metal foil of copper, gold, etc. Moreover, the upper electrode 21a and the lower electrode 22a can be formed by forming an electrode pattern with resist on an FPC plated with a metal such as copper and then etching the portion of the metal foil not protected by the resist. The upper electrode 21a and the lower electrode 22a can be formed by any combination of the above-cited forming techniques or by laminating technique.
The composition constituting the upper pressure sensitive ink 23a and the lower pressure sensitive ink 23b is comprised of a material whose electric characteristics such as an electric resistance value varies according to an external force. As such composition, it is possible to employ e.g. quantum tunneling effect composite material (commercial name “QTC”) manufactured by Peratech Ltd. in U.K. The upper pressure sensitive ink 23a and the lower pressure sensitive ink 23b can be disposed on the upper electrode 21a and the lower electrode 22a by means of application technique. As such application technique for the upper pressure sensitive ink 23a and the lower pressure sensitive ink 23b, a printing technique such as screen printing, offset printing, gravure printing, flexo printing, etc. may be employed. The pressure sensitive ink may be applied only on one face of the upper electrode 21a or the lower electrode 22a.
The pressure detection unit 20 is affixed to the lower face of the panel member 4 of the information input apparatus 1 by means of an adhesive agent such as glue or an adhesive layer such as a double-sided tape and at least one such unit is disposed to be concealed within an ornamental portion of the peripheral edge 4A of the panel member 4. Therefore, the respective materials for forming the pressure detection unit 20 are not limited to transparent materials but can be colored materials.
[Embodiment Mode 2 of Pressure Detection Unit]
In Embodiment Mode 1, explanation was made with using the pressure detection portion 23 including the pair of electrodes 21a, 22a disposed between the first substrate 21 and the second substrate 22 and the pressure sensitive inks disposed between the pair of electrodes. Instead, the pressure detection portion 23 can be configured such that a pair of electrodes disposed on either one of the first substrate 21 and the second substrate 22 and the pressure sensitive inks disposed on the other one first or second substrate to cover the pair of electrodes. With this configuration,
the thickness of the pressure detection portion can be made even smaller. As a result, the pressure detection unit 20 as a whole can be formed even thinner. If the pair of electrodes are provided in the form of combs or helix to control the contact area with the pressure sensitive inks, signals in the desirable detection range can be obtained.
[Embodiment Mode 3 of Pressure Detection Unit]
As shown in
[Embodiment Mode 4 of Pressure Detection Unit]
Preferably, as shown in
[Further Embodiments of Pressure Detection Unit]
(1) In the foregoing embodiment, an initial load is applied to the pressure detection portion 23 by rendering the thickness of the tension member 30a smaller than the thickness of the pressure detection portion 23 under its no-load applied state. However, when it is not possible to render its thickness smaller than the thickness of the pressure detection portion 23 under its normal state, the initial load can be applied to the pressure detection portion 5 by the reverse arrangement of rendering the thickness of the pressure detection portion 23 greater than the thickness of the tension member 30a. Incidentally, in order to increase the thickness of the pressure detection portion 23, the upper electrode 21a, the lower electrode 22a or the pressure sensitive inks 23a, 23b will be applied in a greater thickness than usual or in superposition, etc.
(2) In Embodiment Mode 1 described above, explanation was made with using the pressure detection portion 23 including the pair of electrodes and the two layers of pressure sensitive ink 23a, 23b disposed between these electrodes. However, the construction of the pressure detection portion 23 is not particularly limited as long as it can detect a pressing force. And, the pressure sensitive ink can be a single layer. Further, the shape of the pressure sensitive ink is not limited to the dot-like shape, but can be circular, rectangular or frame-like in its plan view. Further, the electrodes of the pressure detection portion 23 need not necessarily be disposed like a frame. Instead, they may be disposed individually on a frame-like substrate.
(3) In Embodiment Mode 1 described above, the upper pressure sensitive ink 23a or the lower pressure sensitive ink 23b is disposed at the respective corners of the first substrate 21 or the second substrate 22. However, the present invention is not limited thereto. The upper pressure sensitive ink 23a or the lower pressure sensitive ink 23b can be disposed like spots along the peripheral edge of the first substrate 21 or the second substrate 22. As shown in
(4) In Embodiment Mode 1 described above, the pressure detection unit 20 is affixed to the lower face of the panel member 4. Instead of this, the pressure detection unit 20 can be affixed not to the panel member 4, but to the support portion 2b of the package.
(Evaluation Test of Determination Precision of Pressure)
Next, there will be explained results of effect confirmation tests with using pressure detection units 20 including a tension member 30a having a thickness made smaller than the thickness of the pressure detection portion 23.
In this, as an embodiment of the pressure detection unit relating to the present invention, as shown in
The silver electrodes 21, 22a each had a diameter of 4 mm and a thickness of 10 μm and the pressure sensitive ink 23a had a diameter of 3 mm and a thickness of 20 μm, and the carbon had a diameter of 3 mm and a thickness of 10 μm (the total thickness of the pressure detection portion 23 was 50 μm) and each of these was printed in approximately circular. The tension member 30a (glue printing) in each of Samples S1-S15 had a thickness of 30 μm and the thickness of the double-sided tape in each one of Samples S16-30 was 70 μm. As the pressure sensitive ink 23a, the “QTC” (commercial name) manufactured by Peratech Ltd. in U.K. was employed. Incidentally, the upper film 21 was a PET film having a thickness of 50 μm and the lower film 22 comprised a PET film having a thickness of 50 μm and a PET film having a thickness of 38 μm affixed to each other. To the 50 μm thickness PET film in the upper film 21 and the lower film 22, the silver electrodes 21a, 22a were printed and on the 38 μm thickness film of the lower film 22, a bump (not shown) having a diameter of 1 mm and a height of 100 μm was disposed.
After the respective samples S1-S30 was placed on a testing table, a weight was disposed at a center portion C of each sample S1-S30 where the pressure sensitive ink 23a was located and a resistance value was determined for three times from each sample. This operation was repeated for a plurality of times, with varying the weight of the weight and the resistance value in response to each load applied to the pressure sensitive ink was determined.
In the embodiments of the present invention (samples S1-S15), as shown in
In the embodiment examples of the present invention (samples S1-S15), as shown in
From the above-described test results, it was confirmed that by disposing the tension member 30a having a thickness smaller than the thickness of the pressure detection portion 23 between the first substrate 21 and the second substrate 22, the pressure determination precision can be improved even when the load from the outside is small.
Incidentally, through appropriate combinations of the desired embodiments of the various embodiment modes described above, the advantageous effect of each embodiment mode can be provided.
The information input apparatus and the pressure detection unit both relating to the present invention can be used advantageously in an electronic instrument, such as a mobile telephone, a smart telephone, a PDA, a car navigation apparatus, a digital camera, a digital video camera, a game machine, and a tablet, in order to provide such electronic instrument with a greater number of functions and to improve its operability.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-088329 | Mar 2009 | JP | national |
| 2009-088330 | Mar 2009 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2010/054964 | 3/23/2010 | WO | 00 | 11/30/2011 |
