JP2011090358A - Inspection device of capacitive touch panel, and inspection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection device applicable suitably to a capacitive touch panel. <P>SOLUTION: The inspection device of the capacitive touch panel 50 includes an inspection part 3 provided with a touch probe 2 on an insulation part 1 as a base, where the surface of the insulation part 1 and a contact part of the touch probe 2 are formed on the same level. The inspection part 3 has an inspection surface on which the capacitive touch panel 50 is placed for inspection. The touch probe 2 is embedded in the insulation part 1, or printed on the surface of the insulation part 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an inspection apparatus and an inspection method for inspecting defects in a touch panel, and more particularly, to an inspection apparatus and an inspection method applicable to a capacitive touch panel.

  In recent years, many touch panels have been used as input devices for electronic devices such as bank ATMs, portable information terminals, car navigation systems, and multifunction devices. These touch panel types include a resistive touch panel that detects changes in the voltage of a transparent electrode with resistance, an optical touch panel that measures changes in the current flowing through the photosensor, and the capacitance between the human body and the detection electrode. Conventionally, a capacitive touch panel or the like for detecting a change is known. The principle of these touch panels is to detect a change in electrical characteristics that occurs upon contact. Therefore, when inspecting the touch panel, it is usually necessary to check whether there is an abnormality in the change in the electrical characteristics.

  For example, in the inspection of a resistance film type touch panel, a voltage is applied to a pair of resistance films constituting the resistance film type touch panel, and an output voltage value (resistance value) corresponding to a predetermined input position is measured. When the output voltage value is less than or equal to a predetermined threshold, the polarity of the voltage applied to the resistance film is switched. By this series of operations, the electrical characteristics (resistance value) of the resistive touch panel are measured, and it can be determined whether the product is a non-defective product or a defective product (see, for example, Patent Document 1).

  In the inspection of the optical touch panel, light irradiation / non-irradiation is performed on a predetermined region of the photosensor formed on the array substrate. By this operation, the electrical characteristics (current value) of the photosensor are measured, and it can be determined whether the product is a non-defective product or a defective product (see, for example, Patent Document 2).

  Although the above Patent Document 1 and Patent Document 2 are different in “voltage value (resistance value)” and “current value” as electrical characteristics to be measured, both are common in that the conductive state of the touch panel is viewed. . Then, even in a capacitive touch panel, which has been in increasing demand in recent years, it is conceivable to measure a conduction state such as a resistance value when inspecting whether the product is a good product or a defective product.

JP 2005-274225 A JP 2008-310374 A

  However, since the capacitive touch panel captures the state and location touched with a finger or the like as a slight change in capacitance (about several pF), it has the same resistance value and current value as in Patent Document 1 and Patent Document 2. It is practically impossible to confirm the abnormality electrically.

  On the other hand, in the inspection of the capacitive touch panel, it is conceivable to measure the conduction state in a state where the capacitive touch panel is mounted on a controller (control IC). In this case, a minute change in capacitance of the capacitive touch panel is indirectly measured on the controller side. However, in this case, even if there is some problem on the controller side, it is determined as a whole that the capacitive touch panel and the controller are defective. For this reason, it is desired for the touch panel manufacturer to perform the inspection with the touch panel alone before mounting the capacitive touch panel on the controller.

  In the inspection of a capacitive touch panel, in order to perform stable capacitance measurement with good reproducibility, it is necessary to increase the contact area between the inspection device and the touch panel. As one technique for that purpose, for example, it is conceivable to form the tip portions of a plurality of touch probes in the inspection apparatus on a flat end surface, and to make the entire end surfaces contact the touch panel evenly. At this time, the touch probe is pressed against the touch panel using the force of an urging means such as a spring. In this case, the strength of the spring for urging each touch probe, the base for housing the touch probe, It is necessary to adjust the play with the touch probe evenly for all the touch probes of the inspection apparatus. Actually, it is very difficult to make these adjustments, and stable measurement cannot be performed if the end surfaces of some touch probes are tilted even slightly with respect to the touch panel.

  Thus, at present, an inspection apparatus and an inspection method that can reliably inspect a capacitive touch panel have not yet been developed. The present invention has been made in view of the above problems, and an object thereof is to provide an inspection apparatus and an inspection method that can be suitably applied to a capacitive touch panel.

In order to solve the above-mentioned problems, the characteristic configuration of the inspection device for the capacitive touch panel according to the present invention is as follows:
A capacitance touch panel inspection device,
It has an inspection part with a touch probe on the base insulation part,
The surface of the insulating part and the contact part of the touch probe are formed at the same level.

As explained in the background art section, in a capacitive touch panel, the state and location touched with a finger or the like are captured as a slight change in capacitance (about several pF), and thus conduction It was difficult to confirm the state as an abnormal resistance value or current value. Even when measuring the capacitance of the touch panel, it is necessary to bring all the touch probes of the inspection apparatus into contact with the touch panel in an even state, and such an operation is very difficult.
In this regard, the capacitive touch panel inspection apparatus of this configuration has an inspection part in which a touch probe is provided on an insulating part serving as a base. Here, the surface of the insulating part and the contact part of the touch probe are connected to each other. They are formed at the same level. For this reason, at the time of inspection, all the touch probes can be brought into contact with the touch panel in an even state simply by superimposing the capacitive touch panel on the inspection unit of the inspection apparatus. It is possible to measure the capacitance with good and stable.

In the inspection apparatus for the capacitive touch panel according to the present invention,
The inspection unit preferably has an inspection surface on which the capacitive touch panel is placed for inspection.

  With a capacitive touch panel inspection device of this configuration, a good touch condition between the touch panel and touch probe can be achieved simply by placing the capacitive touch panel to be inspected on the inspection surface of the inspection unit. it can. Accordingly, it is possible to more easily perform stable capacitance measurement with good reproducibility.

In the inspection apparatus for the capacitive touch panel according to the present invention,
The touch probe is preferably embedded in the insulating portion.

  If it is the inspection apparatus of the electrostatic capacitance type touch panel of this structure, since the touch probe is embed | buried in the insulation part, durability of an inspection apparatus is high. Moreover, since there is no worry that the touch probe is peeled off, poor contact is unlikely to occur.

In the inspection apparatus for the capacitive touch panel according to the present invention,
The touch probe is preferably printed on the surface of the insulating portion.

  In the inspection apparatus for the capacitive touch panel having this configuration, the touch probe is formed on the surface of the insulating portion by printing. If it is a print, it is easy to freely design the shape of the touch probe. Note that printing of the touch probe can be easily performed at low cost by using an existing printing technique such as screen printing or gravure offset printing.

In the inspection apparatus for the capacitive touch panel according to the present invention,
The size of the touch probe is preferably configured to be 1 / n (n is a natural number larger than 1) times or less the size of the sensor electrode included in the capacitive touch panel.

  With the capacitive touch panel inspection device of this configuration, it is possible to inspect a plurality of types of touch panels with a single inspection device. In the case where the touch probe and the sensor electrode are configured to have the same size, the inspection can only be performed by bringing one touch probe and one sensor electrode into contact with each other. If doubled, the same inspection can be performed by bringing four touch probes into contact with one sensor electrode. Further, with this ¼ size touch probe, it is possible to inspect a ½ size sensor electrode or a ¼ size sensor electrode. That is, by making the size of the touch probe 1 / n (n is a natural number greater than 1) times or less, it is possible to inspect at least as many types of touch panels as the divisor of n.

In the inspection apparatus for the capacitive touch panel according to the present invention,
It is preferable to provide a control unit that controls a connection state between the capacitive touch panel and the touch probe in an inspection state in which the capacitive touch panel is brought into contact with the inspection unit.

  With the capacitive touch panel inspection device having this configuration, the control unit can instantaneously realize the electrical connection / disconnection state by controlling the connection state between the capacitive touch panel and the touch probe. . Thereby, the same effect as making it a contact / non-contact state with respect to a touch panel is acquired, and a finer inspection according to a request can be performed.

The characteristic configuration of the inspection method of the capacitive touch panel according to the present invention for solving the above problems is as follows.
An inspection method for a capacitive touch panel,
A placement step of placing the capacitive touch panel on an inspection portion provided with a touch probe at the same level in an insulating portion serving as a base;
A control step of controlling a connection state between the capacitive touch panel and the touch probe;
It is to include.

The inspection method for the capacitive touch panel of this configuration has substantially the same effect as the above-described inspection apparatus for the capacitive touch panel. That is, the capacitive touch panel inspection method according to the present configuration executes a mounting step of mounting the capacitive touch panel on the inspection unit in which the touch probe is provided at the same level on the base insulating unit. Thus, all the touch probes can be brought into contact with the touch panel in an even state, and as a result, stable capacitance measurement with good reproducibility becomes possible.
Moreover, an electrical connection / disconnection state can be realized instantaneously by executing a control process for controlling the connection state between the capacitive touch panel and the touch probe. Thereby, the same effect as making it a contact / non-contact state with respect to a touch panel is acquired, and a finer inspection according to a request can be performed.

It is a perspective view which shows the inspection apparatus of the capacitive touch panel which concerns on 1st Embodiment of this invention. It is a perspective view which shows the inspection apparatus of the electrostatic capacitance type touch panel which concerns on 2nd Embodiment of this invention. It is a schematic diagram which shows the size relationship between the touch probe formed on the test | inspection part by the printing method, and the sensor electrode by the side of a touch panel.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment relating to an inspection apparatus and an inspection method for a capacitive touch panel according to the present invention will be described with reference to FIGS. However, the present invention is not intended to be limited to the configurations described in the embodiments and drawings described below, and includes configurations equivalent thereto.

[First Embodiment]
FIG. 1 is a perspective view showing a capacitive touch panel inspection apparatus (hereinafter simply referred to as “inspection apparatus”) 100 according to a first embodiment of the present invention. FIG. 1 shows a state in which each part is separated for easy understanding. The inspection apparatus 100 is used to determine whether or not a capacitive touch panel (hereinafter simply referred to as “touch panel”) 50 manufactured in a separate process is normal.

  The inspection apparatus 100 is roughly composed of an inspection stage 10, a measurement unit 20, and a control circuit 30. The inspection stage 10 has a structure unique to the present invention. The inspection stage 10 includes an inspection unit 3 in which a plurality of touch probes 2 are provided on an insulating unit 1 serving as a base. Each touch probe is denoted by reference numerals 2a to 2j. In the inspection unit 3, the touch probes 2a to 2j are cylindrical metal terminals so that the surface (upper surface) of the insulating unit 1 and the contact portions (upper surface of the column) of the touch probes 2a to 2j are at the same level. The touch probes 2a to 2j are embedded in the insulating portion 1 (so that the two surfaces have substantially the same height). Thereby, a flat surface (inspection surface) is formed in which the upper surface of the insulating portion 1 and the upper surfaces of the touch probes 2a to 2j are substantially flush with each other. By burying such touch probes 2a to 2j, the durability of the inspection apparatus 100 is increased. Further, there is no worry that the touch probes 2a to 2j are peeled off from the insulating portion 1, and poor contact is less likely to occur.

  In the present embodiment, the upper surface of the inspection unit 3 serves as the inspection surface for inspecting the touch panel. On the inspection surface, the touch probes 2a to 2f are arranged in the horizontal direction (corresponding to the X direction of the touch panel), and the touch probes 2g to 2j are arranged in the vertical direction (corresponding to the Y direction of the touch panel). Materials that can be used as the insulating part 1 of the inspection part 3 include polyamide, ultra high molecular weight polyethylene, thermoplastic polyester resin, polyacetal (POM), fluororesin, polyetheretherketone (PEEK), polyamideimide (PAI), etc. Is mentioned.

  The touch panel 50 to be inspected includes a lead wire a and a sensor electrode b. In this embodiment, six lead wires a1 to a6 are provided in the X direction, and four lead wires a7 to a10 are provided in the Y direction. Ten sensor electrodes b1 to b10 are formed near the distal ends of the lead wires a1 to a10. By making the sensor electrodes b1 to b10 and the touch probes 2a to 2j of the inspection unit 3 contact each other, the line potentials of the lead wires a1 to a10 (that is, the lead wires a1 to a10) are measured using the measurement unit 20 described later. Measure the voltage across the capacitance between each and ground).

  When performing the inspection, the touch panel 50 is placed on the inspection surface of the inspection unit 3 of the inspection stage 10. The inspection stage 10 is provided with a stopper 4 for positioning the touch panel 50. Thereby, each sensor electrode b1-b10 by the side of the touch panel 50 can be arrange | positioned directly on each touch probe 2a-2j by the side of the test | inspection stage 10. FIG.

  When the base material of the touch panel 50 is made of a hard material having a certain weight such as a glass substrate, the sensor electrodes b1 to b10 and the touch probes 2a to 2j are in good contact with each other due to the weight of the touch panel 50. To do. Here, in order to forcibly press the touch panel 50 toward the inspection unit 3, a weight (not shown) may be placed on the touch panel 50 or an urging means for applying an urging force may be provided. As an urging means, for example, a vacuum suction mechanism (not shown) is provided in the inspection unit 3, and the touch panel 50 is sucked to the inspection unit 3 side. By installing these weights and biasing means, the contact state between the touch panel 50 and the inspection unit 3 is made more uniform over the entire surface, so that stable capacitance measurement with good reproducibility can be performed.

  On the other hand, for example, when the base material of the touch panel 50 is made of a lightweight and flexible material such as a resin film, the touch panel 50 may warp and the sensor electrode may float. Therefore, in such a case, the above-described weight and urging means are used. For example, a glass substrate (not shown) serving as a weight is placed on the touch panel 50, and the entire glass substrate is biased downward as necessary. Alternatively, a vacuum suction mechanism (not shown) is provided in the inspection unit 3 so that the touch panel 50 is adsorbed to the inspection unit 3 side. By these measures, it is possible to ensure uniform contact between the sensor electrodes b1 to b10 and the touch probes 2a to 2j.

  When the touch panel 50 is placed on the inspection stage 10, the probe block 21 of the measurement unit 20 is connected to the lead wires a1 to a10. Actually, as shown in FIG. 1, ten auxiliary lines 51 extending from the lead wires a <b> 1 to a <b> 10 are formed in the end region of the touch panel 50, and the probe block 21 is applied to the auxiliary lines 51. In this state, the capacitance detection circuit 22 of the measurement unit 20 measures the line potential of the lead wires a1 to a10.

  When measuring the line potential, the control circuit (control unit) 30 controls the contact state (connection state) between the sensor electrodes b1 to b10 and the touch probes 2a to 2j. The control circuit 30 is configured by a programmable logic device (FPGA), and is designed to have a function of a switch that individually connects / disconnects each of the touch probes 2a to 2j to the ground. For example, when the control circuit 30 applies a ground potential to the touch probe 2a, the same effect as when a human touches the sensor electrode b1 with a finger can be obtained. On the other hand, the control circuit 30 disconnects the touch probe 2a from the ground potential, thereby obtaining the same effect as when the human is not touching the sensor electrode b1 with a finger. In this way, by making full use of the control circuit 30 to control the contact state between the sensor electrodes b1 to b10 and the touch probes 2a to 2j, an electrical connection / disconnection state can be realized instantaneously. As a result, a finer inspection can be performed according to the request.

[Second Embodiment]
FIG. 2 is a perspective view showing a capacitive touch panel inspection apparatus (hereinafter simply referred to as “inspection apparatus”) 200 according to the second embodiment of the present invention. FIG. 2 shows a state in which each part is separated for easy understanding. The inspection apparatus 200 is used to determine whether or not a capacitive touch panel (hereinafter simply referred to as “touch panel”) 50 manufactured in a separate process is normal.

  The configuration of the inspection apparatus 200 is substantially the same as the configuration of the inspection apparatus 100 described in the first embodiment except for the inspection stage 10. Therefore, in this embodiment, only the inspection stage 10 will be described, and the description of the measurement unit 20 and the control circuit 30 will be omitted.

  The inspection stage 10 has a structure unique to the present invention. The inspection stage 10 includes an inspection unit 3 in which a plurality of touch probes 5 are provided on the insulating unit 1 serving as a base. Each touch probe is denoted by reference numerals 5a to 5j. In the inspection unit 3, the touch probes 5a to 5j are part of the printed circuit board, and the surface (upper surface) of the insulating unit 1 and the contact portions (conductive print units) of the touch probes 5a to 5j are at the same level. It is configured as follows. That is, a flat surface (inspection surface) is formed in which the upper surface of the insulating portion 1 and the upper surfaces of the touch probes 5a to 5j are substantially flush with each other. The printing of the touch probes 5a to 5j can be easily performed at low cost by an existing printing technique such as screen printing or gravure offset printing.

  As an advantage when the touch probe 5 is formed by a printing method, it is easy to design the shape of the touch probe 5 freely. Therefore, an inspection stage 10 having a different print pattern of the touch probe 5 is prepared, and a mechanism for exchanging them is added. Alternatively, the inspection unit 3 may be removable from the inspection stage 10 and only the inspection unit 3 may be replaced. Thereby, it is possible to inspect a plurality of types of touch panels 50 with one inspection apparatus 200.

  FIG. 3 is a schematic diagram illustrating a size relationship between the touch probe 5 formed on the inspection unit 3 by a printing method and the sensor electrode b on the touch panel 50 side. FIG. 3A shows an example in which the size (L1) of the touch probe 5 and the size (L2) of the sensor electrode b are substantially equal. Here, the “size” of the touch probe 5 or the “size” of the sensor electrode b means an effective width in the parallel direction for each element. FIG. 3A corresponds to the relationship between the touch probes 5a to 5j and the sensor electrodes b1 to b10 shown in FIG. Thus, if the touch probe 5 and the sensor electrode b are substantially the same size, the inspection can be performed by bringing one touch probe 5 and one sensor electrode b into contact with each other.

  On the other hand, FIG. 3B shows an example in which the size of the touch probe 5 is made smaller than the size of the sensor electrode b. In this example, the size (L3) of the touch probe 5 is set to ¼ or less the size (L2) of the sensor electrode b. Note that the sensor electrode b does not necessarily need to be in full contact with the touch probe 5, and therefore, when recognizing the size in the present invention, the space between two adjacent touch probes 5 is also the size of the touch probe 5. You may consider it part. With such a size relationship, the four touch probes 5 and one sensor electrode b are brought into contact with each other, and the same inspection as in FIG. 3A can be performed. In addition, if the touch probe 5 is ¼ or smaller in size, it is possible to inspect a ½ size sensor electrode (not shown) or a ¼ size sensor electrode (not shown). In the former case, two touch probes are brought into contact with one sensor electrode, and in the latter case, one touch probe is brought into contact with one sensor electrode. That is, by setting the size of the touch probe 5 to 1 / n (n is a natural number greater than 1) times or less, it is possible to inspect the types of touch panels 50 corresponding to at least a divisor of n.

[Inspection method for capacitive touch panel]
By using the capacitive touch panel inspection devices 100 and 200 of the present invention described above, the capacitive touch panel inspection method of the present invention can be implemented. Here, as an example, an inspection method using the inspection apparatus 100 will be described with reference to FIG.

  In the inspection method of the present invention, a placement step of placing the capacitive touch panel 50 on the inspection unit 3 in which the touch probe 2 is provided at the same level on the insulating unit 1 as a base, and the capacitance The control process which controls the connection state of the touch panel 50 and the touch probe 2 is executed.

<Installation process>
In the placement process, the touch panel 50 is placed on the inspection surface of the inspection unit 3 of the inspection stage 10. The inspection stage 10 is provided with a stopper 4 for positioning the touch panel 50. Thereby, each sensor electrode b1-b10 by the side of the touch panel 50 can be arrange | positioned directly on each touch probe 2a-2j by the side of the test | inspection stage 10. FIG.

  When the base material of the touch panel 50 is made of a hard material having a certain weight such as a glass substrate, the sensor electrodes b1 to b10 and the touch probes 2a to 2j are in good contact with each other due to the weight of the touch panel 50. To do. Here, in order to forcibly press the touch panel 50 toward the inspection unit 3, as an additional process, a weight placing process for placing a weight (not shown) on the touch panel 50 or an urging force for applying an urging force. You may perform a process. In the urging process, for example, a vacuum suction mechanism (not shown) is provided in the inspection unit 3 and the touch panel 50 is adsorbed to the inspection unit 3 side. By performing these weight placing steps and biasing steps, the contact state between the touch panel 50 and the inspection unit 3 is made more uniform over the entire surface, so that stable capacitance measurement with good reproducibility is performed. be able to.

  On the other hand, for example, when the base material of the touch panel 50 is made of a lightweight and flexible material such as a resin film, the touch panel 50 may warp and the sensor electrode may float. Therefore, in such a case, the above-described weight placing step and biasing step are executed. For example, a glass substrate (not shown) serving as a weight is placed on the touch panel 50, and the entire glass substrate is biased downward as necessary. Alternatively, a vacuum suction mechanism (not shown) is provided in the inspection unit 3 so that the touch panel 50 is adsorbed to the inspection unit 3 side. By these measures, it is possible to ensure uniform contact between the sensor electrodes b1 to b10 and the touch probes 2a to 2j.

<Control process>
Next, a control process is performed. Here, as a preparation, the probe block 21 of the measurement unit 20 is connected to the lead wires a1 to a10. Actually, as shown in FIG. 1, ten auxiliary lines 51 extending from the lead wires a <b> 1 to a <b> 10 are formed in the end region of the touch panel 50, and the probe block 21 is applied to the auxiliary lines 51. In this state, the capacitance detection circuit 22 of the measurement unit 20 measures the line potential of the lead wires a1 to a10.

  In the control step, when measuring the line potential, the control circuit (control unit) 30 controls the contact state (connection state) between the sensor electrodes b1 to b10 and the touch probes 2a to 2j. The control circuit 30 is configured by a programmable logic device (FPGA), and is designed to have a function of a switch that individually connects / disconnects the touch probes 2a to 2j to / from the ground, for example. For example, when the control circuit 30 applies a ground potential to the touch probe 2a, the same effect as when a human touches the sensor electrode b1 with a finger can be obtained. On the other hand, the control circuit 30 disconnects the touch probe 2a from the ground potential, thereby obtaining the same effect as when the human is not touching the sensor electrode b1 with a finger. In this way, by controlling the contact state between the sensor electrodes b1 to b10 and the touch probes 2a to 2j by executing the control process, an electrical connection / disconnection state can be realized instantaneously. As a result, a finer inspection can be performed according to the request.

[Another embodiment]
<1> In the above embodiment, the control means 30 is configured by a programmable logic device (FPGA), and the FPGA has a function of a switch that individually connects / disconnects the touch probes 2a to 2j or the touch probes 5a to 5j to the ground. However, it is possible to configure the FPGA as a device that applies an arbitrary voltage to the inspection unit 3. In this case, since a pulse voltage, a DC voltage, or the like can be adopted as the applied voltage, a wider and detailed inspection can be performed.

<2> The inspection apparatus and the inspection method of the capacitive touch panel according to the present invention can be suitably applied to the inspection of the capacitive touch panel, but other electronic devices utilizing changes in the electrostatic capacitance. It can also be used in other inspections.

  The inspection device and the inspection method for the capacitive touch panel according to the present invention can be used, for example, for inspection of input devices of electronic devices such as bank ATMs, portable information terminals, car navigation systems, and multifunction devices.

DESCRIPTION OF SYMBOLS 1 Insulation part 2 Touch probe 3 Inspection part 4 Stopper 5 Touch probe 30 Control part 50 Capacitive touch panel 100 Capacitive touch panel inspection apparatus 200 Capacitive touch panel inspection apparatus

Claims (7)

A capacitance touch panel inspection device,
It has an inspection part with a touch probe on the base insulation part,
The inspection apparatus in which the surface of the insulating part and the contact part of the touch probe are formed at the same level.   The inspection apparatus according to claim 1, wherein the inspection unit has an inspection surface on which the capacitive touch panel is placed for inspection.   The inspection apparatus according to claim 1, wherein the touch probe is embedded in the insulating portion.   The inspection apparatus according to claim 1, wherein the touch probe is printed on a surface of the insulating portion.   The size of the touch probe is configured to be 1 / n (n is a natural number greater than 1) times or less the size of the sensor electrode included in the capacitive touch panel. The inspection device described.   The control part which controls the connection state of the said capacitive touch panel and the said touch probe in the test | inspection state which made the said capacitive touch panel contact | abut to the said test | inspection part is provided. Inspection device according to item. An inspection method for a capacitive touch panel,
A placement step of placing the capacitive touch panel on an inspection portion provided with a touch probe at the same level in an insulating portion serving as a base;
A control step of controlling a connection state between the capacitive touch panel and the touch probe;
Inspection method including

Images