JP2005337773A - Electrostatic capacitance type detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic capacitance type detecting device having coordinate detection precision heightened by preventing effects from outside a sensing region as much as possible. <P>SOLUTION: By providing, for example, a shielding member as an electrostatic protection means for extension lines Xa and Ya extended from the sensing region A to switching means 21X and 21Y via derived regions Bx and By, it is possible to suppress the amount of change in electrostatic capacitance for the movement of a body to be detected even if the body to be detected such as a finger is in contact with the derived regions Bx and By. It is therefore possible to reduce effects to detected data D and provide the electrostatic capacitance type detecting device having heightened coordinate detection precision. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a capacitance-type detection device used for a touch panel or a glide point, and more particularly to a capacitance-type detection device that is less susceptible to influences from outside the sensing region and increases detection accuracy.

  As a prior art related to the capacitance type detection device according to the present invention, for example, there is a pad type pointing device as shown in Patent Document 1 below.

  In Patent Document 1, an X electrode layer 20X comprising a plurality of X electrodes x1, x2,..., X15, x16 extending in the X direction and arranged at predetermined intervals in the Y direction is provided on the lower surface of the film substrate 10, An insulating film 12 is formed on the surface (lower surface) of the X electrode layer 20X, and a plurality of Y electrodes y1, extending in the Y direction on the surface (lower surface) of the insulating film 12 and arranged at predetermined intervals in the X direction. A Y electrode layer 20Y made of y2,..., y15, y16 is formed. That is, the X electrode layer 20X and the Y electrode layer 20Y are provided on the lower surface of the film substrate 10 so as to face each other in a matrix form orthogonal to each other with the insulating film 12 interposed therebetween.

The Y electrodes y1, y2,..., Y15, y16 and the X electrodes x1, x2,..., X15, x16 are drawn out through through holes, contacts, electrodes and the like provided at the edge of the insulating film 12. Finally, they are collected at the end portion Ds of the extension portion 11 of the film substrate 10 and connected to the conductive portion 5 of the control substrate circuit 4 therefrom.
JP 2003-99185 A

  The capacitance type detection device is configured such that when a detected object such as a finger is brought close to the X electrode layer and the Y electrode layer, the detected object and each X electrode, and the detected object and each By detecting a change in capacitance formed between the Y electrode and the Y electrode, the position of the detected object in the X and Y directions is detected.

  Therefore, in order to increase the detection accuracy in the X and Y directions, when the detected object approaches the electrodes other than the X and Y electrodes, no capacitance is formed between the electrodes and the detected object. Or, even if the capacitance is formed, it is necessary that the amount of change is small.

  However, in the above-described conventional capacitance type detection device, the drawer is extended from the ends of the Y electrodes y1, y2,..., Y15, y16 and the X electrodes x1, x2,. Since the wire is arranged adjacent to the Y electrode or the X electrode, a capacitance is easily formed between the lead wire and the detection object, and the amount of change cannot be reduced. Therefore, there is a problem that it is difficult to increase the accuracy of detecting the position of the detection target in the X and Y directions.

  The present invention is for solving the above-described conventional problems, and even when a lead-out extension line or the like is provided in the vicinity of the sensing region, by making it less susceptible to influences other than the sensing region, Provided is a capacitance type detection device with improved accuracy of coordinate detection of an object to be detected.

The present invention relates to a sensing region for detecting that a detected object is in contact with or approaching, a plurality of sensor electrodes wired to the sensing region, individual sensor electrodes, and an external circuit provided outside the sensing region. In an electrostatic capacitance type detection device comprising: an extension line for routing between the extension line; and a routing area provided in the vicinity of the sensing area and the extension lines are densely arranged;
Provided in the routing area is an electrostatic protection means for suppressing a change in capacitance formed between the detection object and an extension line when the detection object contacts or approaches the routing area. It is characterized by being.

In the present invention,
In the above, the electrostatic protection means is preferably formed by a shield member that covers the routing area provided with the extension line, and more preferably, the shield member is grounded.

  Further, the sensing area and the routing area are integrally covered with a cover sheet, and the electrostatic protection means determines the thickness of the cover sheet in the sensing area by the plate of the cover sheet in the routing area. It can be attributed to being formed thicker than the thickness dimension.

  In the above, a step is formed between the front cover sheet provided in the sensing region and the front cover sheet provided in the routing region, and the step is at least on the front surface and the back surface of the cover sheet. It can be formed on one side.

  The sensor electrodes include a plurality of X electrodes extending in the X direction and arranged at a predetermined interval in the Y direction, and a plurality of Y electrodes extending in the Y direction and arranged at a predetermined interval in the X direction. They are opposed to each other in a matrix while being orthogonal to each other.

  In the capacitance type detection device of the present invention, the routing area is shielded or the thickness of the routing area portion of the cover sheet is formed to be thick. It is possible to block electrostatic coupling between the extension line and the wiring, and it is difficult to form a capacitance therebetween.

  Alternatively, even if the capacitance is formed, the amount of change with respect to the movement of the detection target can be suppressed small, so that the influence on the detection accuracy can be reduced.

  That is, the position detection accuracy as a capacitance type detection device can be increased.

  FIG. 1 is a schematic configuration diagram showing a capacitance type detection device according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG. 1 as a first embodiment of the present invention. 3 is a sectional view similar to FIG. 2 as a second embodiment of the present invention, and FIG. 4 is a sectional view similar to FIG. 2 as a third embodiment of the present invention.

  As shown in FIG. 1, this capacitance type detection device 10 includes a plurality of X electrodes (sensor electrodes) x1, x2,..., Xn extending in the Y direction and arranged at predetermined intervals in the X direction. , And a plurality of Y electrodes (sensor electrodes) y1, y1,..., Yn that extend in the X direction and are arranged at predetermined intervals in the Y direction.

  2, the plurality of X electrodes x1, x2,..., Xn are provided on one surface (surface) of the dielectric sheet 11, and the plurality of Y electrodes y1, y1,. , Yn are provided on the other surface (back surface) of the dielectric sheet 11. That is, the plurality of X electrodes x1, x2, ..., xn and the plurality of Y electrodes y1, y1, ..., yn are opposed to each other in a matrix form orthogonal to each other via the dielectric sheet 11. Yes. Therefore, a capacitance C is formed between the X electrodes x1, x2,..., Xn and the plurality of Y electrodes y1, y1,.

  An insulating film 12 covering the plurality of X electrodes x1, x2,..., Xn is formed on one surface of the dielectric sheet 11, and similarly below the other surface of the dielectric sheet 11. An insulating film 13 is formed to cover the plurality of Y electrodes y1, y1,. A cover sheet 15 is fixed to the upper layer of the insulating film 12, and a substrate 14 is fixed to the lower layer of the insulating film 13. The insulating film 12 and the cover sheet 15 are fixed and the insulating film 13 and the substrate 14 are fixed using an adhesive or the like. The insulating films 12 and 13 themselves are adhesives. Also good.

  The cover sheet 15 is formed of, for example, a polyester resin, and the surface (the surface on the Z1 side) is an operation surface 15a on which a detection object such as a finger contacts and slides. The plurality of X electrodes x1, x2, ..., xn and the plurality of Y electrodes y1, y1, ..., yn are arranged in a matrix at positions on the lower surface side of the operation surface 15a. As shown in FIG. 1, a portion where the cover sheet 15 is provided is a sensing area A of the capacitance type detection device.

  As shown in FIG. 1, the end portions of the plurality of X electrodes x1, x2,..., Xn are led out from the sensing region A as extensions Xa to the outside on the Y2 side in the drawing. The extension line Xa is densely arranged in a routing area Bx provided adjacent to the sensing area A, and is connected to switching means 21X configured by a multiplexer or the like via the routing area Bx. Yes.

  Similarly, end portions of the plurality of Y electrodes y1, y1,..., Yn are drawn out from the sensing area A to the outside on the X2 side in the drawing as extension lines Ya, and are switched through the routing area By. It is connected to the means 21Y.

  The one switching means 21Y is connected to an oscillating means 23 so that a predetermined voltage can be selectively applied from the oscillating means 23 to the Y electrodes y1, y1,. It has become. An amplifier 24 is connected to the other switching means 21X, and its output is connected to the controller 26 via an A / D converter 25.

  The control means 26 is composed mainly of a CPU, and can not only acquire data from the A / D conversion means 25 but also set the switching timing of the switching means 21X, 21Y, for example. ing.

  The amplification means 24 has a function of amplifying the voltage appearing at the switching means 21X with a predetermined gain, and the A / D conversion means 25 converts the amplified voltage (analog value) into a digital value at a predetermined sampling period. It has a function. In addition, a configuration in which filter means for removing unnecessary noise is provided between the amplifying means 24 and the A / D converting means 25 may be adopted.

The operation of the capacitance type detection device will be described.
The control unit 26 operates the switching unit 21Y and the switching unit 21X, turns on the switch SW1 of the switching unit 21Y, and then sequentially turns on the switches SW1 to SWn on the switching unit 21X side.

  When a predetermined voltage is input from the oscillating means 23 to the Y electrodes y1, y1,..., Yn, the Y electrodes y1, y1,. A dielectric flux is generated between each X electrode x1, x2,..., Xn to form a capacitance C, so that the X electrodes x1, x2,. .., A voltage is applied to xn.

  Here, when a detected object such as a finger is brought into contact with or close to an arbitrary position on the operation surface 15a of the cover sheet 15, a part of the dielectric bundle is pulled out by the detected object, and in the vicinity of the detected object. The located capacitance is reduced. For this reason, since a part of the capacitance C changes, a voltage corresponding to the amount of change is detected from the X electrodes x1, x2,. As the voltage value detected at this time, a higher voltage value is detected as the distance from the detection object is shorter, and a lower voltage value is detected as the electrode is farther away.

  The voltages outputted from the X electrodes x1, x2,..., Xn are inputted to the A / D conversion means 25 through the amplification means 24 and converted into digital data D by the A / D conversion means 25. , The data is sent to the control means 26. Then, the control means 26 determines the position in the X direction on the Y electrode y1 of the detected object from the data D.

  Then, the control means 26 sequentially turns on the switches SW2 to SWn of the switching means 21Y, and sequentially turns on the switches SW1 to SWn on the switching means 21X side for each switch SW of the switching means 21Y. Data D at each intersection of the Y electrodes y1, y1,..., Yn and the X electrodes x1, x2,. The control means 26 determines the coordinate position (coordinate data) of the detected object from these data D.

  Here, in the detection apparatus shown in the first embodiment of FIG. 2, a shield member 31 as an electrostatic protection means is provided in the routing area By adjacent to the sensing area A. The shield member 31 is formed of a metal plate made of a magnetic material, and is fixed to the surface of the routing area By so as to cover the extension line Ya.

  The shield member 31 is preferably configured to cover at least the vicinity of the sensing region A where the detection target is easily accessible, and more preferably an extension line that is an end of the Y electrodes y1, y1,. Ya covers the entire length from the position deviating from the sensing area A until it is connected to the switching means 21Y. In addition, it is preferable to ground the shield member 31 in that a further excellent effect can be expected.

  In this way, by covering the extension portion Ya with the shield member 31, when the detected object approaches the routing area, the area between the detected object and the extension line Ya wired in the routing area By. Thus, no dielectric flux is generated, and it is possible to prevent a capacitance from being formed between the two. Further, even if a capacitance may be formed between the detected object and each extension line Ya, at least the amount of change in the capacitance with respect to the movement of the detected object can be suppressed low.

  Accordingly, the coordinate data detected in the sensing area A, that is, the coordinate data detected by the X electrodes x1, x2,..., Xn and the Y electrodes y1, y1,. Since the voltages generated in the above are not mixed, and even if they are mixed, the value can be made minute, so that the detection accuracy of the coordinate data can be improved.

Next, a second embodiment will be described with reference to FIG.
The configuration of the capacitance type detection means 10 shown in FIG. 3 is substantially the same as the configuration of the first embodiment. However, the electrostatic protection means provided in the routing area By is different from the shield member 31.

  In the second embodiment, by forming the cover sheet 15 with a plate thickness dimension H2 corresponding to the routing area By thicker than the plate thickness dimension H1 of the operation surface 15a, The difference is that a step 15b is provided between them.

  In this way, by forming the plate thickness dimension H2 of the routing area By thicker than the other part (operation surface 15a), the detected object approaches or contacts the routing area By. In the same manner as described above, it is possible to prevent a capacitance from being formed between the object to be detected and the extension line Ya positioned below the routing area By. Alternatively, even if a capacitance may be formed between the detected object and each extension line Ya, at least the amount of change in the capacitance with respect to the movement of the detected object can be kept low. .

  In the second embodiment, it is only necessary to change the thickness of the cover sheet 15 between the portion of the operation surface 15a corresponding to the sensing region A and the portion corresponding to the routing region By. Can be integrally formed with the same member, so that the number of parts is not increased and the manufacturing cost can be reduced.

  Furthermore, since the operator can clearly distinguish the sensing area and the routing area, the operability of the capacitive detection device 10 can be improved.

The third embodiment shown in FIG. 4 is a modification of the second embodiment.
In the second embodiment, the level difference H2 is increased from the bottom surface of the cover sheet 15 in the outward direction (Z1 direction in the drawing) by increasing the thickness H2 of the portion of the cover sheet 15 that faces the routing area By. Although formed, the third embodiment is different in that the step 15b is formed by increasing the thickness H3 from the surface of the cover sheet 15 toward the inward direction (Z2 direction in the drawing). .

  In the electrostatic capacitance type detection device 10 shown in FIG. 4, since the surface of the cover sheet 15 can be flattened while having the effects of the second embodiment, the electronic device such as a computer can be applied to the electronic device. When the capacitance type detection device 10 is attached, unnecessary irregularities do not appear, and the overall design of the electronic device can be refreshed.

  Although the sensing area and the routing area cannot be clearly distinguished, in this case, the color of the sensing area and the routing area is changed, or grooves (concave portions) or ribs are formed on the surface of the cover sheet 15 serving as a boundary between them. It is possible to cope by forming (convex parts).

  In the second and third embodiments, the step 15b is described as being formed on either the front surface side or the back surface side of the cover sheet 15. However, the present invention is not a Kagura rel, and the cover sheet 15 In this case, since the plate thickness dimension of the routing area By can be further increased, the amount of change in capacitance with respect to the detection target can be further suppressed. Can do.

  In each of the above embodiments, one routing area By has been described, but the same applies to the other routing area Bx.

The schematic block diagram which shows the electrostatic capacitance type detection apparatus which shows embodiment of this invention, As a first embodiment of the present invention, a sectional view taken along line II-II in FIG. Sectional view similar to FIG. 2 as a second embodiment of the present invention, Sectional view similar to FIG. 2 as a third embodiment of the present invention,

Explanation of symbols

10 Capacitance type detection device 11 Dielectric sheet 12, 13 Insulating film 14 Substrate 15 Cover sheet 15a Operation surface 15b Step 21X, 21Y Switching means 23 Oscillating means 24 Amplifying means 25 A / D conversion means 26 Control means 31 Shield member A Sensing area Bx, By Route area Xa, Ya Extension line x1, x2, ..., xn X electrode (sensor electrode)
y1, y2, ..., yn Y electrode (sensor electrode)

Claims (6)

Between a sensing region for detecting that the detected object is in contact with or approaching, a plurality of sensor electrodes wired to the sensing region, and between each sensor electrode and an external circuit provided outside the sensing region In an electrostatic capacitance type detection device comprising: an extension line for connection to be connected; and a routing area provided in the vicinity of the sensing area and the extension lines are densely arranged.
Provided in the routing area is an electrostatic protection means for suppressing a change in capacitance formed between the detection object and an extension line when the detection object contacts or approaches the routing area. Capacitance type detection device.   The electrostatic capacitance type detection device according to claim 1, wherein the electrostatic protection means is formed of a shield member that covers a routing area provided with the extension line.   The capacitance type detection device according to claim 2, wherein the shield member is grounded.   The sensing area and the routing area are integrally covered with a cover sheet, and the electrostatic protection means determines the thickness of the cover sheet in the sensing area by the thickness of the cover sheet in the routing area. The capacitance type detection device according to claim 1, wherein the capacitance type detection device is formed thicker than the dimension.   A step is formed between the front cover sheet provided in the sensing region and the front cover sheet provided in the routing region, and the step is formed on at least one of the front surface and the back surface of the cover sheet. The electrostatic capacitance type detection device according to claim 4.   A plurality of X electrodes extending in the X direction and arranged at a predetermined interval in the Y direction and a plurality of Y electrodes extending in the Y direction and arranged at a predetermined interval in the X direction are orthogonal to each other. 6. The capacitance type detection device according to claim 1, wherein the capacitance type detection device is opposed to each other in a matrix.

Images