WO2014167839A1

WO2014167839A1 - Inspection apparatus and inspection method

Info

Publication number: WO2014167839A1
Application number: PCT/JP2014/002006
Authority: WO
Inventors: Munehiro Yamashita; Tadashi Takahashi
Original assignee: Nidec-Read Corporation
Priority date: 2013-04-09
Filing date: 2014-04-08
Publication date: 2014-10-16
Also published as: TW201439562A; JP2014202702A; TWI489123B

Abstract

There is provided an inspection apparatus configured to inspect display wires of an object to be inspected in which a plurality of x-axis display wires of x-axis wires and a plurality of y-axis display wires of y-axis wires are arranged perpendicular to each other, said inspection apparatus provided with: a power supply device having a first supply unit configured to supply an alternating current (AC) signal having a predetermined voltage, and a second supply unit configured to supply an AC signal having the predetermined voltage and having a phase 180 degrees different from that of the AC signal; a plurality of current detection units electrically connected to the respective plurality of x-axis wires; and an evaluating device configured to evaluate the wires on the basis of detection values from the current detection units, wherein the control is activated to have the constant number of the y-axis wires connected to the first supply unit and the y-axis wires connected to the second supply unit in the connection between the y-axis wires and the power supply device performed by the connecting device.

Description

INSPECTION APPARATUS AND INSPECTION METHOD

The present invention relates to an inspection apparatus configured to detect electrical characteristics of a touch panel, thereby inspecting the touch panel. The present invention more specifically relates to an inspection apparatus and an inspection method which perform application of alternating current (AC) signals and measurement of electrical signals simultaneously on a plurality of wires, thereby inspecting a position detecting function of the touch panel at high speed.
The present invention can preferably perform the inspection on an inspection object having the wires (or patterns) arranged in a matrix in an x-axis direction and a y-axis direction. The inspection objects as described above are collectively referred to as the "touch panel" in the description.

In the inspection object having the wires arranged in the matrix in the x-axis direction and the y-axis direction formed on an ITO film referred to as the touch panel (or a touch screen or a touch display), conventionally, conduction of each wire and a short-circuit between adjacent wires are inspected by bringing each contactor (or needle-shaped conductive probe) into contact with respective one of the wires arranged in the x-axis direction and the y-axis direction.

However, in the method of performing the inspection by bringing each contactor into contact with respective one of the wires as described above, there is no stability between the wire formed on the ITO film and the contactor, and the instability of contact resistance due to the oxide film causes inaccurate measurement of the electrical characteristic, which is problematic. Moreover, since the contactor is pressure-welded with a display wire which forms a display portion of the touch panel, there is such a problem that a dent or damage is formed due to the contact of the contactor with the display wire.

On the other hand, as disclosed in Patent document 1, there is also proposed an inspection technology of accurately inspecting the electrical characteristics such as a resistance value of the touch panel as a whole, in which a predetermined touch input position on the touch panel assembled can be accurately detected. As described above, there is disclosed a technology of inspecting the electrical characteristics of the functions of the touch panel assembled.

There is also another technology, other than the technology disclosed in the Patent document 1, in which due to the arrangement of the touch panel that the x-axis wires cross y-axis wires, the contactor is brought into contact with an intersection point at which the x-axis wire crosses y-axis wire, an inspection signal is supplied from each of the x-axis wire and y-axis wire, and the quality of the x-axis wire and y-axis wire is determined from a detection signal from the contactor.

In the inspection method as described above, however, the inspection needs to be performed the number of times indicated by the multiplication of the total number of the x-axis wires and the total number of the y-axis wires, and there is such a problem that a long inspection time is required.

Recently, there has been a rising demand for productivity growth, and it is thus necessary to reduce a tact time and to complete the inspection in a short time. Particularly in recent years, the touch panel has been used as an inputting device which allows multi-touch. Therefore, there is a rising demand that an accurate position detecting function is provided on the entire panel surface, or a rising demand for short-time evaluation.
Prior Art Document

Patent Document

Patent document 1: Japanese Patent Application Laid Open No. 2005-274225

Summary of the Invention

Problem to be Solved by the Invention

In view of the situations as described above, it is therefore an object of the present invention to provide an inspection apparatus and an inspection method which perform the application of AC signals and the measurement of electrical signals simultaneously on the plurality of wires, thereby inspecting the position detecting function of the touch panel at high speed.

Means for Solving the Problem

The invention according to claim 1 provides an inspection apparatus configured to inspect display wires of an object to be inspected in which a plurality of x-axis display wires of x-axis wires and a plurality of y-axis display wires of y-axis wires are arranged perpendicular to each other, the inspection apparatus provided with: a power supply device having a first supply unit configured to supply an alternating current (AC) signal having a predetermined voltage, and a second supply unit configured to supply an AC signal having the predetermined voltage and having a phase 180 degrees different from that of the AC signal; a connecting device configured to electrically connect a desired y-axis wire from the plurality of y-axis wires to the fist supply unit and/or the second supply unit of the power supply device; a current detecting device comprising a plurality of current detection units electrically connected to the respective plurality of x-axis wires; an evaluating device configured to evaluate the wires on the basis of detection values from the current detection units of the current detecting device; and a controlling device configured to control the power supply device, the connecting device, the current detecting device, and the evaluating device to inspect the display wires, wherein the controlling device activates the control to have the constant number of the y-axis wires connected to the first supply unit and the y-axis wires connected to the second supply unit in the connection between the y-axis wires and the power supply device performed by the connecting device.
The invention according to claim 2 provides the inspection apparatus according to claim 1, wherein the controlling device controls the connecting device for all the y-axis wires in order.
The invention according to claim 3 provides the inspection apparatus according to claim 1, wherein arrangement of the y-axis wires connected to the first supply unit and the y-axis wires connected to the second supply unit is set in predetermined order.
The invention according to claim 4 provides the inspection apparatus according to claim 3, wherein as the arrangement, there is provided such an arrangement that three and/or two continuous y-axis wires connected to the first supply unit or the second supply unit are arranged side by side.
The invention according to claim 5 provides the inspection apparatus according to

claim

3 or 4, wherein as the arrangement, there is provided such an arrangement that one y-axis wire connected to the second supply unit or the first supply unit is sandwiched between the y-axis wires connected to the first supply unit or the second supply unit.
The invention according to claim 6 provides the inspection apparatus according to claim 1 or 2, wherein the number of the y-axis wires connected to the first supply unit is equal to the number of the y-axis wires connected to the second supply unit.
The invention according to claim 7 provides the inspection apparatus according to claim 6, wherein the power supply device has a third supply unit with a voltage value of zero, and the connecting device connects the third supply unit to a desired y-axis wire of the y-axis wires.
The invention according to claim 8 provides the inspection apparatus according to claim 1, wherein the evaluating device calculates flatness of the object to be inspected, on the basis of the detection values from the current detection units, thereby evaluating the object to be inspected.
The invention according to claim 9 provides an inspection method of inspecting display wires of an object to be inspected in which a plurality of x-axis display wires of x-axis wires and a plurality of y-axis display wires of y-axis wires are arranged perpendicular to each other, said inspection method provided with: a step of supplying a first alternating current (AC) signal to a predetermined y-axis wire and supplying, to another predetermined y-axis wire, a second AC signal having the same magnitude as that of the first AC signal and having a phase 180 degrees different from that of the first AC signal; a step of detecting an electrical signal from each of the x-axis wires; and a step of repeating the steps, collecting a plurality of electrical signals, and evaluating the display wires on the basis of the electrical signals, wherein in the step of supplying the AC signals, it is controlled such that the number of the y-axis wires supplied with the first AC signal is equal to the number of the y-axis wires supplied with the second AC signal.

Effect of the Invention

According to the inventions described in claims 1 and 9, the display wires are inspected while the two AC signals having the same magnitude but having 180-degree different phases are supplied to the y-axis wires by the first supply unit and the second supply unit, and the number of the y-axis wires connected to the first supply unit and the second supply unit is constant. By inspecting the operation of the display wires with the constant output, the inspection is performed on the basis of characteristics of the display wires of the object to be inspected. It is thus possible to inspect the position detecting function of the touch panel at high speed.
According to the invention described in claim 2, the connecting device is controlled for all the y-axis wires in order. Thus, the inspection can be performed efficiently on all the display wires of the touch panel.
According to the invention described in claim 3, the arrangement of the y-axis wires connected to the first supply unit and the y-axis wires connected to the second supply unit is set in the predetermined order. Thus, an inspection state can be set by the supplied AC signals to perform the inspection.
According to the invention described in claim 4, regarding the arrangement of the first supply unit and the second supply unit, at least three and/or two continuous y-axis wires connected to the first supply unit or the second supply unit are arranged side by side. If the three continuous y-axis wires are arranged side by side, the inspection can be performed while the y-axis wire in the center is equipotential to the adjacent y-axis wires on the both sides. If the two continuous y-axis wires are arranged side by side, it is possible to set such an inspection condition that one of the two continuous y-axis wires has the same potential as (or is equipotential to) that of one adjacent y-axis wire, but has a different potential from that of the other adjacent y-axis wire.
According to the invention described in claim 5, the arrangement is performed such that one y-axis wire connected to the second supply unit or the first supply unit is sandwiched between the y-axis wires connected to the first supply unit or the second supply unit. Thus, an influence of the AC signals from the other supply unit can be confirmed.
According to the invention described in claim 6, the number of the y-axis wires connected to the first supply unit is equal to the number of the y-axis wires connected to the second supply unit. Thus, the inspection can be performed with zero output of the AC signals supplied to the touch panel.
According to the invention described in claim 7, the power supply device uses the third supply unit with a voltage value of zero to supply signals to the y-axis wires. Thus, the inspection can be performed with setting of the y-axis wires with no signal applied.
According to the invention described in claim 8, the evaluating device can calculate the flatness of the object to be inspected, on the basis of the detection values from the current detection units. Thus, it is possible to comprehend position information indicating that the flatness stands out, and to specify a defective region of the touch panel from the position information.

FIG. 1 is a schematic plan view illustrating one embodiment of a touch panel as an inspection object of the present invention. FIG. 2 is a diagram illustrating a schematic configuration of an inspection apparatus of one embodiment of the present invention. FIG. 2 illustrates a touch panel TP having five x-axis wires formed and four y-axis wires formed. FIGs. 3 are diagrams illustrating a first embodiment regarding an inspection procedure of the present invention. FIGs. 4 are diagrams illustrating a second embodiment regarding an inspection procedure of the present invention.

Modes for Carrying Out the Invention

The best mode for carrying out the invention will be explained.
The inspection apparatus of one embodiment of the present invention can improve inspection efficiency for a circuit board and a glass substrate having a plurality of wires arranged in a matrix in an x-axis direction and a y-axis direction, such as a touch panel.
Thus, firstly, the touch panel as an inspection object of the inspection apparatus of the embodiment will be briefly explained.
FIG. 1 is a schematic plan view illustrating one embodiment of the touch panel as the inspection object of the present invention. In the touch panel TP in FIG. 1, a plurality of x-axis wires arranged in the x-axis direction and a plurality of y-axis wires arranged in the y-axis direction are arranged on a glass substrate. In FIG. 1, 14 x-axis wires (represented by reference numerals Line: X1 to Line: Xe) are formed, and 8 y-axis wires (represented by reference numerals Line: Y1 to Line: Y8) are formed.
The x-axis wires and the y-axis wires on the touch panel TP are arranged to cover a touch area on a screen with the wires (or a portion covered with P1 and P2). As illustrated in FIG. 1, one x-axis wire (and one y-axis wire) is formed by repeating a wide portion and a narrow portion, and the wires are thus formed to cover the entire touch area. Due to the formation as described above, when the touch panel TP is used, it is possible to detect on which x-axis wire and on which y-axis wire a touched position (a contact position) is located. The touch area is formed of x-axis display wires xP of the respective x-axis wires and y-axis display wires yP of the respective y-axis wires.

In the touch panel TP in FIG. 1, the 14 x-axis wires and the 8 y-axis wires are formed; however, the number of the wires is not particularly limited to this example and is adjusted by a touch panel manufacturer, as occasion demands. The touch area of the touch panel TP and tab wires described later are also adjusted and formed by the manufacturer, as occasion demands. The length and size of the wide portion and the narrow portion are also adjusted by the touch panel manufacturer, as occasion demands.

The x-axis wire and the y-axis wire have an x-axis tab wire xT and a y-axis tab wire yT (or tab wire parts T) formed, respectively, such that one end of the x-axis wire or y-axis wire can be connected to an electronic component, such as a driver. The tab wire part T is formed by extending each electric connection part connected to another electronic component. The tab wire part T is formed in a place away from the touch area, as viewed planarly, thereby allowing electrical connection. In the touch panel TP in FIG. 1, the tab wire part T of each wire (or the x-axis wire and the y-axis wire) is formed on the right side of the sheet. The tab wire parts T can be formed in parallel in one place other than the touch area. The x-axis wire is formed of the x-axis display wire xP and the x-axis tab wire xT. The y-axis wire is formed of the y-axis display wire yP and the y-axis tab wire yT.
In the description, for convenience of explanation, a display wire w1 is used to indicate the x-axis display wire xP and/or y-axis display wire yP, and a tag wire w2 is used to indicate the x-axis tag wire xT and/or y-axis tag wire yT.

An inspection apparatus 1 of one embodiment of the present invention has a power supply device 2, a connecting device 3, a current detecting device 4, an evaluating device 5, and a controlling device 6. FIG. 2 is a view illustrating a schematic configuration of the inspection apparatus 1. FIG. 2 illustrates the touch panel TP having five x-axis wires formed and four y-axis wires formed.

The power supply device 2 has a first supply unit 21 configured to supply an AC signal having a predetermined voltage, and a second supply unit 22 configured to supply an AC signal having the predetermined voltage and having a phase 180 degrees different from that of the AC signal. The first supply unit 21 and the second supply unit 22 can use an AC power supply for generating an AC signal. The first supply unit 21 and the second supply unit 22 generate the AC signals having the phases 180 degrees different from each other, and the total output is thus zero.

The first supply unit 21 and the second supply unit 22 can be set, for example, by grounding two AC power supplies between them, connecting the two AC power supplies in series, and adjusting the phases (refer to FIG. 2). The AC signals supplied by the first supply unit 21 and the second supply unit 22 can be set, for example, to have a voltage value with an effective value ranging from 1 to 10 V in a frequency range of 10 kHz to 100 kHz.

The power supply device 2 can be also provided with a not-illustrated third supply unit (not illustrated). The third supply unit is set to supply a signal with an output of zero. The third supply unit can set, as a supply signal, an electric potential of a ground point between the first supply unit 21 and the second supply unit 22.

The connecting device 3 selects a desired y-axis wire yw from the plurality of y-axis wires yw, and electrically connects the selected y-axis wire yw to the first supply unit 21 and/or the second supply unit 22 of the power supply device 2. The connecting device 3 is connected to a y-axis tab wire ytw of the y-axis wire yw, and an inspection signal is supplied to a y-axis display wire ytw via the y-axis tab wire ytw. For example, the connecting device 3 can use a contactor 31 to be connected to the y-axis tab wire ytw, and a change unit 32 electrically connected to the first supply unit 21 and/or the second supply unit 22 of the power supply device 2. There are prepared the same number of contactors 31 as the number of the y-axis tab wires ytw. The change unit 32 can adopt, for example, a switching element configured to perform an ON/OFF operation. If the power supply device 2 is provided with the first supply unit 21 and the second supply unit 22, two change units 32 are provided to be connected to the respective supply units. If there are set the three supply units which are the first to third supply units, three change units 32 are provided. The operation of the change unit 32 allows conductive connection between the y-axis tag wire ytw and any of the supply units of the power supply device 2.

The connecting device 3 is controlled to have the constant number of the y-axis wires yw connected to the first supply unit 21 and the y-axis wires yw connected to the second supply unit 22. By setting the constant number of the y-axis wires connected to the first supply unit 21 and the y-axis wires connected to the second supply unit 22, the output of inspection signals supplied to an x-axis wire xw is always constant.

The third connecting device 3 has the constant number of the y-axis wires yw connected to the first supply unit 21 and the y-axis wires yw connected to the second supply unit 22. Preferably, the number of the y-axis wires yw connected to the first supply unit 21 is equal to the number of the y-axis wires yw connected to the second supply unit 22. In this case, an influence on the x-axis wire wx of the signals from the y-axis wires yw is eventually zero, and a current detected by a current detection unit 41 from the x-axis wire xw is also zero. Moreover, even if the third supply unit is set, the output of the inspection signals supplied to the x-axis wire xw from the connecting device 3 is constant or zero, because inspection signals supplied by the third supply unit are zero.
The connecting device 3 is controlled by the controlling device 6 to operate in the above conditions.

The third connecting device 3 is also controlled by the controlling device 6 described later to set the arrangement of the y-axis wires yw connected to the first supply unit 21 and the y-axis wires yw connected to the second supply unit 22 in predetermined order.
For example, as the arrangement by the connecting device 3, it is possible to adopt such an arrangement that three and/or two continuous y-axis wires yw connected to the first supply unit 21 are arranged side by side. The connecting device 3 is controlled to have a combination of the three continuous y-axis wires yw connected to the first supply unit 21. In the three continuous y-axis wires yw connected to the first or second supply unit, the y-axis wire yw located in the center is connected equipotentially to the adjacent y-axis wires yw on the both sides. The current detection unit 41 detects the influence on the x-axis wire in the above condition.

Moreover, the connecting device 3 can be also controlled to have a combination of the two continuous y-axis wires yw connected to the first supply unit 21. In the same manner, the connecting device 3 can be also controlled to have a combination of the three or two continuous y-axis wires yw connected to the second supply unit 22. In this case, the y-axis wire yw on one side connected to the first or second supply unit has the same potential as (or is equipotential to) that of one adjacent y-axis wire yw (or the y-axis wire yw on the other side connected to the first or second supply unit), but has a different potential from that of the other adjacent y-axis wire yw. The current detection unit 41 detects the influence on the x-axis wire xw in the above condition.

Furthermore, the connecting device 3 is controlled to set such an arrangement that one y-axis wire yw connected to the second supply unit 22 or the first supply unit 21 is sandwiched between the y-axis wires yw connected to the first supply unit 21 or the second supply unit 22. In this case, the sandwiched y-axis wire yw is sandwiched between the y-axis wires yw supplied with the different AC signals. The current detection unit 41 detects the influence on the x-axis wire xw in the above condition.

The arrangement of the connecting device 3 as described above is controlled by the controlling device 6. By processing the arrangement combinations in order, the evaluation of the touch panel TP described later can be performed.

The current detecting device 4 is provided with a plurality of current detection units 41 electrically connected to the respective plurality of x-axis wires xw. The current detecting device 4 is provided with the same number of the current detection units 41 as the number of the x-axis wires xw of the touch panel TP as the inspection object. The current detection unit 41 can adopt, for example, an ammeter. Each of the current detection units 41 transmits a detection result to the evaluating device 5 described later. The current detection unit 41 detects, as the current of the x-axis wire xw, the influence on the x-axis wire xw by the AC signals supplied to the y-axis wires yw via the connecting device 3 from the power supply device 2 described above.

The evaluating device 5 evaluates the wires on the basis of detection values from the current detection units 41 of the current detecting device 4. The evaluating device 5 has a storage unit (not illustrated) configured to store information about the detection values of the current detection units 41 in association with information about the y-axis wires yw, and stores therein the detection results of the current detection units 41. The evaluating device 5 also stores therein state information about the inspection signals supplied from the power supply device 2. The state information about the inspection signals is, for example, information about the y-axis wires connected to the first supply unit 21, information about the y-axis wires yw connected to the second supply unit 22, and information about the y-axis wires yw connected to the third supply unit, or the like. It is possible to comprehend which y-axis wires yw are supplied with the respective inspection signals supplied by the first to third supply units.

In the inspection apparatus 1, the output of the inspection signals supplied from the power supply device 2 to the x-axis wire xw is constant, and the inspection signals with the constant output are repeatedly supplied. Thus, if the wires are well formed, the detection values are also constant. Therefore, the evaluating device 5 measures an inconstant detection value and specifies its region on the basis of the plurality of detection values collected, and thus can detect a defect in the position detecting function of the touch panel TP.

The evaluating device 5 calculates flatness of the touch panel TP on the basis of the detection values from the current detection units 41 as described above, thereby evaluating the wires (and particularly, the display wires) of the touch panel TP. Specifically, the evaluating device 5 obtains a difference or a deviation from an average value on the basis of the detection values from the current detection units 41, or calculates a difference of the detection value from a reference value set in advance, thereby calculating the output of each wire or the output of each of the intersection points between the x-axis wires and the y-axis wires and plotting the calculation result as the flatness. At this time, if the touch panel TP is non-defective, the flatness is uniform because each wire or each intersection point has uniform output. However, if the wire has a defect, the output influenced by the defect is detected, and the flatness becomes low.
The evaluating device 5 evaluates the display wires of the touch panel TP on the basis of the detection values as described above. Visualization allows simple and easy evaluation of the touch panel TP.

The controlling device 6 controls the power supply device 2, the connecting device 3, the current detecting device 4 (or the current detection units 41), or the evaluating device 5, and performs the inspection on the display wires as described above. The controlling device 6 controls the connecting device 3 for all the y-axis wires yw in order, by which all the display wires formed on the touch panel TP can be inspected.

An explanation will be given to an operation of connecting to the power supply device by the connecting device, performed by the inspection apparatus 1.
In FIGs. 3, the first to third supply units are set as the power supply device 2, and conveniently, the AC signal of the first supply unit 21 is set to be (+), the AC signal of the second supply unit 22 is set to be (-), and the signal from the third supply unit is set to be zero. FIG. 3(a) is a diagram schematically illustrating the touch panel TP, where 8 x-axis wires xw and 12 y-axis wires are illustrated. FIG. 3(b) illustrates an inspection procedure (a step S1 to a step S12) using the first to third supply units. In an inspection method illustrated in FIGs. 3, the number of the y-axis wires yw connected to the power supply device 2 is set to be 6, and the total output of AC signals supplied from the 6 y-axis wires yw is set to be zero.

In the inspection method, the AC signal (+) of the first supply unit 21 is supplied to the two y-axis wires yw, the AC signal (-) of the second supply unit 22 is supplied to the two y-axis wires yw, and the AC signal (0) of the third supply unit is supplied to the two y-axis wires yw. In the step S1, a y-axis wire yw1 and a y-axis wire yw2 are connected to the first supply unit 21, a y-axis wire yw3 and a y-axis wire yw4 are connected to the second supply unit 22, and a y-axis yw5 and a y-axis yw6 are connected. The controlling device 6 is set to transmit a control signal to operate the connecting device 3 as described above, and to transmit, to the evaluating device 5, detection signals from the current detection units 41 connected to the respective x-axis wires xw.

As a next inspection process, the y-axis yw2 and the y-axis yw3 are connected to the first supply unit 21, the y-axis wire yw4 and the y-axis wire yw5 are connected to the second supply unit 22, and the y-axis wire yw6 and a y-axis wire yw7 are connected. If the connection is performed, the current detection units 41 detect respective electrical signals, and transmit the detection values to the evaluating device 5.
In the inspection method, the AC signal is set in the order of (+), (+), (-), (-), (0), and (0); however, the AC signal is not particularly limited to this order as long as the total output of the AC signals is zero as described above.

If the detection values are transmitted to the evaluating device 5 in the inspection process in the step S2, the inspection process is moved to the next step S3. In the step S3, the y-axis wire yw3 and the y-axis wire yw4 are connected to the first supply unit 21, the y-axis wire yw5 and the y-axis wire yw6 are connected to the second supply unit 22, and the y-axis wire yw7 and a y-axis wire yw8 are connected. If the connection is performed, the current detection units 41 detect respective electrical signals, and transmit the detection values to the evaluating device 5.
The same processing is repeated from the step S4 to the step S12 so that the processing is repeated from the y-axis wire yw1 to a y-axis wire yw12.
Then, the changing or switching is performed by the connecting device 3 from the y-axis wire yw1 to the y-axis wire yw12, and the detection values in each inspection process are transmitted to the evaluating device 5. The evaluation is performed on the basis of the detection values. In this case, if there is no problem in the position detecting function of the touch panel TP, the detection values of the current detecting device 4 are constant (e.g. zero) because the total output of the inspection signals supplied is zero. If there is a problem in the position detecting function, a specific detection value is obtained as a measurement result, and its specific region is specified by using position information from the x-axis wire and the y-axis wire.

An explanation will be given to another operation of connecting to the power supply device by the connecting device, performed by the inspection apparatus 1.
In FIGs. 4, the first and second supply units are set as the power supply device 2, and conveniently, the AC signal of the first supply unit 21 is set to be (+), and the AC signal of the second supply unit 22 is set to be (-). FIG. 4(a) is a diagram schematically illustrating the touch panel TP, where 8 x-axis wires xw and 12 y-axis wires are illustrated. FIG. 4(b) illustrates an inspection procedure (a step S1 to a step S12) using the first and second supply units.

In an inspection method illustrated in FIGs. 4, the number of the y-axis wires yw connected to the power supply device 2 is set to be 9. Moreover, in the inspection method, the following setting is performed with this order as one group; namely, three continuous y-axis wires yw connected to the first supply unit 21 are set, one y-axis wire yw connected to the second supply unit 22 is set, two continuous y-axis wire yw connected to the first supply unit 21 are set, one y-axis wire yw connected to the second supply unit 22 is set, one y-axis wire yw connected to the first supply unit 21 is set, and one y-axis wire yw connected to the second supply unit 22 is set. In other words, in the inspection method, the AC signal is set in the order of (+), (+), (+), (-), (+), (+), (-), (+), and (-). The controlling device 6 is set to transmit the control signal to operate the connecting device 3 as described above, and to transmit, to the evaluating device 5, the detection signals from the current detection units 41 connected to the respective x-axis wires xw.

As a next inspection process (the step S2), the controlling device 6 controls the operation of the connecting device 3 to set the AC signal in the order of (+), (+), (+), (-), (+), (+), (-), (+), and (-), for the y-axis wires yw which are from the y-axis wire yw2 to a y-axis wire yw10. If the connection is performed, the current detection units 41 detect respective electrical signals, and transmit the detection values to the evaluating device 5.

If the detection values are transmitted to the evaluating device 5 in the inspection process in the step S2, the inspection process is moved to the next step S3. Even in the step S3, the controlling device 6 controls the operation of the connecting device 3 to set the AC signal in the order of (+), (+), (+), (-), (+), (+), (-), (+), and (-), for the y-axis wire yw3 to a y-axis wire yw11. If the connection is performed, the current detection units 41 detect respective electrical signals, and transmit the detection values to the evaluating device 5.
The same processing is repeated from the step S4 to the step S12 so that the processing is repeated from the y-axis wire yw1 to a y-axis wire yw12.
Then, the changing or switching is performed by the connecting device 3 from the y-axis wire yw1 to the y-axis wire yw12, and the detection values in each inspection process are transmitted to the evaluating device 5. The evaluation is performed on the basis of the detection values. Even in this case, if there is no problem in the position detecting function of the touch panel TP, the detection values of the current detecting device 4 are constant because the total output of the inspection signals supplied is zero. If there is a problem in the position detecting function, a specific detection value is obtained as a measurement result, and its specific region is specified by using position information from the x-axis wire and the y-axis wire.
The above is the explanation of the configuration of the inspection apparatus of the present invention.

Next, the operation of the inspection apparatus of the present invention will be explained.
If the touch panel TP is set for the inspection apparatus 1, the contactors 31 of the connecting device 3 are conductively connected to the y-axis wires yw, and the current detection units 41 of the current detecting device 4 are conductively connected to the x-axis wires xw. At this time, the controlling device 6 stores therein information necessary to inspect the touch panel TP. For example, the controlling device 6 stores information about the inspection method, such as information about the position and the number of the x/y-axis wires of the touch panel TP, information about the output of the AC signals supplied by the first supply unit and the second supply unit, and a connection procedure.
Moreover, the x-axis wires xw and the y-axis wires yw of the touch panel TP are connected to the current detection units 41 and the connecting device 3, respectively. In this manner, the inspection preparation of the touch panel TP is performed. After the inspection preparation is performed, the inspection is started.

The controlling device 6 transmits an operation signal for operating the connecting device 3. At this time, the first supply unit 21 and the second supply unit 22 of the power supply device 2 are connected to the y-axis wire yw1 to the y-axis wire yw4 in a desired combination to perform a desired inspection. The combination for connecting to the power supply device 2 is set by an inspector in advance (e.g. refer to FIGs. 3 or FIGs. 4).

After transmitting transmits the control signal to the connecting device 3, the controlling device 6 activates the current detection units 41 connected to the x-axis wires xw1 to xw5. The current detection units 41 measure the current and transmit the detection values to the evaluating device 5. Then, the controlling device transmits the control signal to the connecting device 3 to perform the next inspection, and in the same manner, the current detection units 41 transmit the detection values to the evaluating device 5.

After the inspection is repeated until the last order, the evaluating device 5 calculates the flatness of the touch panel TP as the inspection object on the basis of the collected detection values. According to the flatness, it is evaluated whether the position detecting function of the touch panel TP is good or there is a defective position. In particular, in the inspection apparatus and the inspection method of the present invention, the inspection can be performed the number of times according to the number of the wires on one side, and the inspection can be thus performed in about two seconds, although an inspection time of about 20 seconds is required in the conventional position inspection method. Therefore, the inspection time can be significantly reduced.

Description of Reference Numerals

1 inspection apparatus
2 power supply device
3 connecting device
4 current detecting device
5 evaluating device
6 controlling device

Claims

An inspection apparatus configured to inspect display wires of an object to be inspected in which a plurality of x-axis display wires of x-axis wires and a plurality of y-axis display wires of y-axis wires are arranged perpendicular to each other, said inspection apparatus comprising:
a power supply device having a first supply unit configured to supply an alternating current (AC) signal having a predetermined voltage, and a second supply unit configured to supply an AC signal having the predetermined voltage and having a phase 180 degrees different from that of the AC signal;
a connecting device configured to electrically connect a desired y-axis wire from the plurality of y-axis wires to the fist supply unit and/or the second supply unit of the power supply device;
a current detecting device comprising a plurality of current detection units electrically connected to the respective plurality of x-axis wires;
an evaluating device configured to evaluate the wires on the basis of detection values from the current detection units of the current detecting device; and
a controlling device configured to control the power supply device, the connecting device, the current detecting device, and the evaluating device to inspect the display wires, wherein
the controlling device activates the control to have the constant number of the y-axis wires connected to the first supply unit and the y-axis wires connected to the second supply unit in the connection between the y-axis wires and the power supply device performed by the connecting device.
The inspection apparatus according to claim 1, wherein the controlling device controls the connecting device for all the y-axis wires in order.
The inspection apparatus according to claim 1, wherein arrangement of the y-axis wires connected to the first supply unit and the y-axis wires connected to the second supply unit is set in predetermined order.
The inspection apparatus according to claim 3, wherein as the arrangement, there is provided such an arrangement that three and/or two continuous y-axis wires connected to the first supply unit or the second supply unit are arranged side by side.
The inspection apparatus according to claim 3 or 4, wherein as the arrangement, there is provided such an arrangement that one y-axis wire connected to the second supply unit or the first supply unit is sandwiched between the y-axis wires connected to the first supply unit or the second supply unit.
The inspection apparatus according to claim 1 or 2, wherein the number of the y-axis wires connected to the first supply unit is equal to the number of the y-axis wires connected to the second supply unit.
The inspection apparatus according to claim 6, wherein
the power supply device has a third supply unit with a voltage value of zero, and
the connecting device connects the third supply unit to a desired y-axis wire of the y-axis wires.
The inspection apparatus according to claim 1, wherein the evaluating device calculates flatness of the object to be inspected, on the basis of the detection values from the current detection units, thereby evaluating the object to be inspected.
An inspection method of inspecting display wires of an object to be inspected in which a plurality of x-axis display wires of x-axis wires and a plurality of y-axis display wires of y-axis wires are arranged perpendicular to each other, said inspection method comprising:
a step of supplying a first alternating current (AC) signal to a predetermined y-axis wire and supplying, to another predetermined y-axis wire, a second AC signal having the same magnitude as that of the first AC signal and having a phase 180 degrees different from that of the first AC signal;
a step of detecting an electrical signal from each of the x-axis wires; and
a step of repeating the steps, collecting a plurality of electrical signals, and evaluating the display wires on the basis of the electrical signals, wherein
in the step of supplying the AC signals, it is controlled such that the number of the y-axis wires supplied with the first AC signal is equal to the number of the y-axis wires supplied with the second AC signal.