JP2689519B2 - Touch panel device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in the following order.

A Industrial Field B Outline of the Invention C Conventional Technology D Problems to be Solved by the Invention E Means for Solving the Problems (Fig. 1) F Action G Example G ₁ Outline G ₂ Circuit Configuration (1st (Fig. 2) G ₃ circuit operation (normal operation) (Figs. 3 and 4) G ₄ circuit operation (fault diagnosis operation) (Figs. 5 and 6) H Effect of the invention A Industrial application Field The present invention relates to HA systems such as bank online systems, education systems, medical management systems, OA systems, FA systems such as production process management systems, and security systems.
The present invention relates to a touch panel device suitable for use in a system or a communication system.

B Outline of the Invention In a touch panel device that forms a light beam grating with a light receiving element and a light emitting element, a detection means having a first determination level and a second determination level higher than the first determination level is provided on the output side of the light receiving element, and a second detection level is provided. The warning information is generated when a detection output lower than the discrimination level and higher than the first discrimination level is obtained for a finite time or more, so that the need for maintenance can be notified before the touch panel becomes completely inoperative. It is a thing.

C Conventional Technology As a touch panel device that can be input by simply touching the screen with a finger instead of a keyboard, various systems have been proposed in the related art, and an optical system is one example.

That is, the optical method (infrared sensing method) is such that a plurality of light emitting diodes, which are arranged on the lower printed circuit board so as to be positioned around the display screen, emit an infrared beam and the upper side of the opposite side is printed. A plurality of phototransistors arranged on the circuit board receives light, and a plurality of light emitting diodes arranged on the printed circuit board on the right side emits an infrared beam, and the left side on the opposite side. A plurality of phototransistors arrayed on the printed circuit board receive light to form a grid of infrared beams.
A separate address is assigned to each photoelectric element along the optical axis. Which light emitting diode emits light and which photo transistor on the opposite side detects the light by sequentially switching each light emitting diode and its corresponding photo transistor by specifying an address I understand. When a finger or pen touches the display screen, it blocks the infrared beam. X of the blocked light beam
The Y coordinate is sent to the host computer for position determination.

However, in the case of the above-mentioned conventional optical touch panel device, the sense surface (at least the vertical position sense surface)
Since it is a flat surface, it is a CRT when combined with a CRT with a curved surface.
There is a drawback that parallax occurs at the peripheral edge of the.

Therefore, in a latch panel device used in a cathode ray tube having a rectangular image display surface that is curved in a cylindrical shape, a plurality of optical coupling means including a light emitting element and a light receiving element are arranged so that light rays obliquely cross the image display surface. The present applicant has previously proposed a latch panel device which is provided so that the envelope surface formed by light rays forms a plane parallel to the display surface of the cathode ray tube, thereby reducing parallax at the edge of the screen. (JP-A-63-19383).

In addition, a light receiving element is arranged on the upper side with respect to the rectangular image plane, and a light emitting element corresponding to the light receiving element is arranged on the lower side, and the beam is formed by the light receiving element and the light emitting element from the lower left to the upper right. In a touch panel device including a group (Y beam) and a second beam group (X beam) in which beams formed from the lower right to the upper left by the light receiving element and the light emitting element are arranged, in the first beam group, from the left to the right. Direction (or left to right) scan to obtain the coordinate value determined based on the position where the beam is blocked first (finally). In the second beam group, it moves from right to left (from left to right). A touch panel device for obtaining a fixed coordinate value by scanning and first (or last) based on the position where the beam is interrupted, and obtaining a fixed plane coordinate value from these two determined coordinate values was previously developed by the present applicant. Proposed (Japanese Patent Application) No. 63-53186).

D Problem to be Solved by the Invention By the way, since such a touch panel device uses a large number of light emitting elements and light receiving elements, the probability of occurrence of failure is high.

The main causes of failure are element deterioration and deterioration due to external factors. For example, the deterioration of the element may be a decrease in the amount of light emitted from the light emitting element due to aging, a deterioration in the light receiving sensitivity of the light receiving element, or the like. Further, as the deterioration due to external elements, it is considered that the light emission of the light emitting element / light receiving element and the sensitivity decrease due to the adhesion of dust on the light receiving surface.

All of these failures and deteriorations appear as a phenomenon called a decrease in the infrared beam detection output obtained by a common detection circuit provided for the light receiving element. This phenomenon is equivalent to the state where the beam is half blocked in the case of normal operation, that is, when the infrared beam is blocked by a finger.

However, in the case of the conventional device, no particular measures have been taken against such a decrease in sensitivity, so that there is a drawback that the device is frequently maintained and the man-hour required for this is increased.

In addition, if the maintenance is not performed regularly, it remains faulty and left as it is until the next maintenance period, during which the correct display cannot be performed.

The present invention has been made in view of the above circumstances, and provides a highly reliable touch panel device that warns the necessity of maintenance before the touch panel is completely inoperable and can be used with confidence. is there.

E Means for Solving the Problem A touch panel device according to the present invention is a touch panel device in which a light beam grating is formed by a light receiving element and a light emitting element, the light receiving output from the light receiving element is supplied, and the level of the light receiving output is The first discrimination level and the first discrimination level higher than the light reception level when the element does not receive the light beam.
Of the first detection means for detecting whether or not the second detection level is higher than the second detection level and lower than the normal light reception level, and the first detection means detects the first light reception output level.
And a second detection output indicating that it is between the second determination level and a second detection level, second detection means for detecting whether or not the first detection output is continuously obtained for a predetermined time or more. And a warning information is generated when a second detection output indicating that the first detection output is continuously obtained for a predetermined time or longer is obtained from the second detection means. Is.

According to the present invention, when the first detection means obtains the first detection output indicating that the level of the received light output is between the first and second determination levels, the second detection is performed. When the detection unit obtains the second detection output indicating that the first detection output is continuously obtained for the predetermined time or longer, the warning information is generated.

G. Examples Hereinafter, various examples of the present invention will be described in detail with reference to FIGS.

C ₁ Outline First, the decrease in the infrared beam detection output due to the deterioration of the light emitting element and the light receiving element and the interruption of the infrared beam detection output by the finger are shown as follows.

During the operation of blocking the infrared beam by touching the touch panel with a finger, about half of the infrared beam having a finite thickness (usually about 1 to 3 mm) is blocked and the infrared detection output obtained by the detection circuit decreases. Of course it can happen.

Therefore, it is naturally possible that this will cause deterioration of the element, for example, the amount of emitted light due to dust adhering to the surface of at least one element will be a phenomenon equivalent to a decrease in the amount of received light and will appear as a decrease in detection output. However, the sensitivity decrease due to dust occurs continuously, while blocking about half of the infrared beam (without any other blocked infrared beam, that is, without detecting coordinates) does not occur during normal position designation operation. It only happens transiently.

Therefore, at least one infrared beam is half blocked (while other infrared beams are not blocked) for a finite (for example, 10 seconds) time, or continuously for a finite number of scans (coordinate sample counts) Whether or not
It is possible to determine whether or not the dust really adheres.

If the infrared beam is cut off by a semi-transparent object, if the cutoff continues for the finite time above, first issue a warning message (or sound) such as "Please stop pranks." However, if the interruption continues, the next state (for example, "Maintenance time" is displayed) may be entered.

Of these phenomena, the second phenomenon, that is, the decrease in sensitivity due to dust, is that the touch panel may be used in some cases, that is, it may be used in the street, and when it is used systematically with FA equipment, the work environment is dusty. In addition, the infrared filter on the beam path is directly exposed to the external environment,
It is necessary to pay sufficient attention because dust or dirt is likely to adhere to this portion as well.

Therefore, in the present embodiment, the deterioration of sensitivity due to element deterioration or the deterioration due to dust is detected before the touch panel becomes inoperable and a warning is issued to guarantee the function of the touch panel.

G ₂ Circuit Configuration FIG. 1 shows the circuit configuration of this embodiment, in which the light emitting diode (11) and the phototransistor (12) are arranged on the curved surface of the CRT in an oblique optical coupling relation as described above. There is.

(21) is a microcomputer (= 1-chip microcomputer etc., hereinafter referred to as microcomputer), (22) is a light emitting diode (X) associated with forming an X beam in response to a control signal designating an address from the microcomputer (21) ( 11) a selector for switching, the fixed terminal (22 ₁₎ to (22 ₅₎ are each a switching transistor (23 ₁₎ to (23 ₅₎ via a light emitting diode (11 _10), (11 ₂₀ ), (11 ₃₅ ),
It is connected to the cathodes of ( ₁₁₄₄ ) and ( ₁₁₅₃ ), and its movable terminal ( _22C ) is connected to the positive power supply terminal + B via the resistor (24). In addition, the selector (22) has a release fixed terminal (2
2 _Y ). Light emitting diodes (11 ₁₀ ), (11 ₂₀ ),
The anodes of (11 ₃₅ ), (11 ₄₄ ), and (11 ₅₃ ) are commonly connected and connected to the positive power supply terminal + B via the resistor (25).

Further, (26) is a control signal for designating an address from the microcomputer (21) (same as the address data of the selector (22)).
Associated with forming an X-beam. photo·
A selector for switching the transistor (12),
Its fixed terminal (26 ₁₎ to (26 ₅₎ are each phototransistor (12 _13), (12 _22), (12 _31), (12 _40), (1
2 ₅₀ ) and its movable terminal (26 _C ) is grounded. The selector (26) has an open fixed terminal (26 _Y ).
Having. Phototransistors (12 ₁₃ ), (12 ₂₂ ),
The collectors of (12 ₃₁ ), (1 2 ₄₀ ), and (1 2 ₅₀ ) are connected in common, are connected to the positive power supply element + B via the common load resistor (27), and are connected via the detection circuit (28) to the microcomputer. (2
Connected to port 1 of 1).

Reference numeral (29) is a selector for switching the light emitting diode (11) associated with forming a Y beam in accordance with a control signal designating an address from the microcomputer (21), and its fixed terminal (29 ₁ ) ~ (29 ₅₎ are each a switching transistor (30 ¹⁾ to (30 ₅₎ via a light emitting diode (11
₀₁ ), (11 ₀₂ ), (11 ₅₃ ), (11 ₄₄ ), (11 ₃₅ ), the movable terminal (29 _C ) of which is connected to the resistor (31).
Is connected to the positive power supply terminal + B via. The selector (29) also has a release fixing terminal (29 _X ). The anodes of the light emitting diodes (11 ₀₁ ) and (11 ₀₂ ) are commonly connected and connected to the positive power supply terminal + B via the resistor (25).

Further, (32) is a photo-related element for forming a Y beam in response to a control signal (the same as the address data to the selector (29)) designating an address from the microcomputer (21).
A selector for switching the transistor (12),
The fixed terminals (32 ₁ ) to (32 ₅ ) are respectively photo transistors (12 ₃₁ ), (12 ₂₂ ), (12 ₁₃ ), (12 ₀₄ ), (1
₂₀₅ ) and its movable terminal (32 _C ) is grounded. Also, the selector (32) is an open fixed terminal (32 _Y )
Having. The collectors of the phototransistors (12 ₀₄ ) and (12 ₀₅ ) are commonly connected, connected to the positive power supply terminal + B via the resistor (27), and connected to the microcomputer (21) via the buffer circuit (28). Connected to port 1.

Now, the movable terminal (29 _C ) of the selector (29) and the movable terminal (32 _C ) of the selector (32) are opened by the control signal from the data bus of the port (2) of the microcomputer (21).
While connected to 9 _X ) and (32 _X ), the selector (22) allows the light emitting diodes (11 ₁₀ ), (11 ₂₀ ), (11 ₃₅ ), (1
1 ₄₄ ), (11 ₅₃ ) are driven in sequence, and in response to this, the photo transistor (12 ₁₃ ), (12 ₂₂ ),
(12 ₃₁ ), ( ₁₂₄₀ ) and ( ₁₂₅₀ ) are sequentially driven to sequentially form an X beam, and when the X beam is blocked by a finger, the Y coordinate is detected.

Further, the movable terminal (22c) of the selector (22) and the movable terminal (26c) of the selector (26) are respectively opened and fixed terminals (2) by the control signal from the data bus of the port 2 of the microcomputer (21).
2 _Y ) and (26 _Y ) while connected to the selector (29) with the light emitting diodes (11 ₀₁ ), (11 ₀₂ ), (11 ₅₃ ), (1
1 ₄₄ ), (11 ₃₅ ) are sequentially driven, and the phototransistors (12 ₃₁ ), (12 ₂₂ ), (12 ₂₂ ), are correspondingly driven by the selector (32).
(12 ₁₃ ), (12 ₀₄ ), and (12 ₀₅ ) are sequentially driven to sequentially form the Y beam, and when the Y beam is blocked by the finger, the Y coordinate is detected.

As described above, the light emitting diode (11) used for emitting infrared rays in two directions on the lower side of the display area and the phototransistor (12) used for receiving infrared rays in two directions on the upper side are the X beam and the Y beam. Are driven in a time-division manner, and in common they are driven in parallel. Therefore, the number of elements is reduced and the cost can be reduced as compared with the case where each element is independently arranged corresponding to the beam arrangement direction.

Further, as is clear from FIG. 1 drawn in the schematic diagram, since the phototransistors (12) are all directed to the lower side, the sensitivity to external light (sunlight, various types of illumination light: usually comes from above). Is low, and the optical S / N ratio is good even if the direction of the maximum value (angle 0) of the light receiving directivity does not face the direction of the corresponding light emitting diode (11), and there is no problem.

Now, in the present embodiment, a filter circuit (28a), a coupling capacitor (28b), a transistor (28c), and a detection circuit (28) having a first level discriminator (28d) for discriminating the original beam interruption are arranged in a detection circuit (28). 1 level discriminator (28d)
The second level discriminator (28e) having a discrimination level (threshold level) V _th2 higher than the discrimination level (threshold level) V _{th1 of} FIG. Then, when only the output of the second level discriminator (28e) is obtained, a warning that the sensitivity of the light emitting element and the light receiving element is lowered is issued, and maintenance is prompted before the operation becomes impossible. Therefore, the discrimination signals D ₁ and D ₂ output from the level discriminators (28d) and (28e) are supplied to the port 1 of the microcomputer (21) having at least two input terminals.

Fig. 2 shows the detection output waveform obtained on the output (collector) side of the transistor (28c). Waveform W1 is due to aging of the element when the light emitting element and the light receiving element are operating normally. This indicates a case where the sensitivity is lowered due to deterioration or dust adhering to the element surface, or the beam is half blocked. The level W3 indicates the light receiving level when the beam emitted from the light emitting element and entering the light receiving element is blocked. V _th1 is a first discrimination level higher than the level W3 and close _thereto , and V _th2 is a second discrimination level higher than the first discrimination level V _{th1 and} lower than the normal light reception level.

In a normal state, the level discriminator (28d) determines whether or not there is a waveform W1 of the infrared beam detection output, and the output waveform W
If there is 1, there is no interruption of the beam by the finger and the output waveform W
If there is no 1, it is determined that the beam is blocked by the finger.

In addition, the discrimination signal (not shown) by the pseudo output waveform W4 at the time of address switching by the accumulated carriers accumulated when the light receiving element is not operating is the infrared beam connected to the output side of the level discrimination (28d) and (28e). The detection output selection circuit (not shown) or the time selection processing performed when the signal input to the microcomputer (21) is determined is processed so as not to affect the determination of the presence or absence of beam interruption.

G ₃ Circuit Operation (Normal Operation) Next, the normal circuit operation of FIG. 1 will be described with reference to FIGS. 3 and 4. FIG. 3 shows the case where the scanning is stopped after one beam is blocked, and FIG. 4 shows the case where the scanning is continued and the scanning is performed for all the beams even if the one beam is blocked.

First, a description will be given with reference to FIG. In step (41), the contents of the memory of the microcomputer (21), which had previously stored that the X beam had been blocked when the selectors (22) and (26) were selected, are cleared. In step (42), the microcomputer (21) supplies address data to the selectors (22) and (26) to activate the corresponding light emitting diode (11) and phototransistor (12) to generate an X beam. Form.

In step (43), it is judged whether or not the X beam is blocked by a finger or the like, and if not blocked, X in step (44).
Selectors (22) and (2) for switching the light emitting diode (11) and the phototransistor (12) forming the beam;
It is determined whether or not the address data to 6) is the last. If not, only one address data for the selectors (22) and (26) is incremented in step (45) and step (4).
Return to 2), repeat the above operation, and go to step (44)
If it is the last, that is, if there is no interruption over the entire X beam, the process returns to step (41) and the above operation is repeated.

If the X beam is blocked in step (43), the light emitting diode (11) and the phototransistor (12) forming the X beam in step (46) are selected by selectors (22) and ( The corresponding address data given to 26) is stored in the memory of the microcomputer (21) as X coordinate information. The address data detected at this time indicates the position where the beam is first blocked.

Next, in step (47), the contents of the memory of the microcomputer (21), which has memorized that the Y beam was blocked when the selectors (29) and (32) were selected so far, are cleared. . In step (48), address data is supplied from the microcomputer (21) to the selectors (29) and (32) to activate the corresponding light emitting diode (11) and phototransistor (12) to generate a Y beam. Form.

In step (49), it is judged whether or not the Y beam is blocked by a finger or the like. If not blocked, the Y beam is checked in step (50).
Selectors (29) and (3) for switching the light emitting diode (11) and the phototransistor (12) forming the beam
It is judged whether the address data to 2) is the last one, and if it is not the last one, the address data for the selectors (29) and (32) is increased by one in step (51) and the step (4)
Return to 8), repeat the above operation, and go to step (50).
If it is the last, that is, if there is no interruption for all of the Y beams, the process returns to step (41) again and the above operation is repeated.

If the Y-beam is blocked in step (49), the light-emitting diode (11) and the phototransistor (12) forming the Y-beam in step (52) are selected by selectors (29) and ( The corresponding address data given to 32) is stored in the memory of the microcomputer (21) as Y coordinate information. The address data detected at this time indicates the position where the beam was first cut off.

Then, in step (53), each address data stored in the memory of the microcomputer (21) is read out to obtain the X coordinate and the Y coordinate.
Calculate the coordinates.

Further, the coordinates detected by the microcomputer (21) are converted into Cartesian coordinates. That is, for example, assuming that the coordinate values detected as described above are prime coordinate values (oblique coordinate values) (MY, NX),
The objective (orthogonal coordinates) coordinate values (Hy, Vx) corresponding to this are prepared in the ROM built into the microcomputer (21), and conversion from (MY, NX) to (Hy, Vx) is done. The true coordinate value (Hy, Vx) can be calculated.

 Next, a description will be given with reference to FIG.

In step (41), the contents of the memory of the microcomputer (21), which had previously stored that the X beam had been blocked when the selectors (22) and (26) were selected, are cleared. In step (42), the selectors (22) and (26) from the microcomputer (21)
Address data is supplied to the corresponding light emitting diodes (11) and phototransistors (12) to form an X beam.

In step (43), it is judged whether or not the X beam is blocked by a finger or the like, and if not blocked, X in step (44).
Selectors (22) and (2) for switching the light emitting diode (11) and the phototransistor (12) forming the beam;
It is determined whether or not the address data to 6) is the last. If not, only one address data for the selectors (22) and (26) is incremented in step (45) and step (4).
Return to 2) and repeat the above operation.

If the X beam is blocked in step (43), the selector (22) selecting the light emitting diode (11) and the phototransistor (12) forming the X beam in step (46). And corresponding address data given to (26) are stored in the memory of the microcomputer (21) as X coordinate information. Then, the process proceeds to a step (44), and the above operation is repeated.

If it is the last in step (44), that is, if all the scanning of the X beam is completed regardless of whether or not the X beam is completely blocked, the process proceeds to step (47), where it is detected that the beam is blocked. It is judged whether the address data is one piece, continuous or other, and if not, the process returns to step (41) to repeat the above operation, and if so, the process proceeds to step (48).

In step (48), the contents of the memory of the microcomputer (21), which has memorized that the Y beam had been blocked when the selectors (29) and (32) were selected so far, are cleared. In step (49), the selectors (29) and (32) from the microcomputer (21)
Address data to activate the corresponding light emitting diode (11) and photo transistor (12) to form a Y beam.

In step (50), it is judged whether or not the X beam is blocked by a finger or the like, and if not blocked, Y is determined in step (51).
Selectors (29) and (3) for switching the light emitting diode (11) and the phototransistor (12) forming the beam
It is determined whether or not the address data to 2) is the last. If not, only one address data for the selectors (29) and (32) is incremented by one in step (52) and step (4).
Return to 9) and repeat the above operation.

If the X beam is blocked in step (50), the selector (22) selecting the light emitting diode (11) and the phototransistor (12) forming the Y beam in step (53). And corresponding address data given to (26) are stored in the memory of the microcomputer (21) as X coordinate information. Then, the process proceeds to step (51) to repeat the above operation.

If it is the last in step (51), that is, if the scanning of all the Y beams is completed regardless of whether or not all the Y beams have been blocked, the process proceeds to step (54), where the address detected in response to the beam blocking is detected. It is judged whether the data is one piece, continuous, or not, and if not, return to step (41) and repeat the above operation,
If so, proceed to step (55).

In step (55), each address data stored in the memory of the microcomputer (21) is read out to calculate the X coordinate and the Y coordinate. If the number of the address data detected at this time is one, it is determined as it is (value obtained by doubling the data), and if the number of detected data is plural, it is determined from the value obtained by adding the first and second data. (That is, it corresponds to Japanese Patent Application No. 63-53186, and it is a method of detecting the fingertip when the beam is scanned in the direction in which it is covered by the finger, and when two beams (of the fingertip) are intercepted Then, the coordinates detected by the microcomputer (21) are converted into Cartesian coordinates in the same manner as described above. That is, for example, the coordinate value detected as described above is converted into a prime coordinate value (oblique coordinate value) (MY, NX)
Then, if the coordinate value (Hy, Vx) of the corresponding purpose (orthogonal coordinate) is prepared in the ROM built into the microcomputer (21) and the conversion of (MY, NX) → (Hy, Vx) is performed, The target true coordinate value (Hy, Vx) can be obtained.

G ₄ Circuit Operation (Fault Diagnosis Operation) Next, the operation of diagnosing a failure of the light emitting element, the light receiving element, etc. in the circuit of FIG. 1 will be described with reference to FIG.

Turn on the power and in step (41) the level discriminator (28e)
Of the determination signal (M) in the microcomputer (21) that stores the result of determining whether or not the determination signal D2 of is low level (L).
2) (not shown), that is, clear the memory that stores the state of sensitivity reduction of the infrared beam. Counter (M2C) in the microcomputer (21) that is set when the discrimination signal D2 of the level discriminator (28e) is low level in step (42)
(Not shown), that is, the counter for determining the finite time duration of the sensitivity lowering element is cleared. This counter is once for the entire scan including X beam scan and Y beam scan D2 = L
If there is a state of, the D2 = L judgment memory is set once, and the number of times of occurrence is counted.

At the step (43), the discrimination signal D1 of the level discriminator (28d)
Clears the determination memory (M1) (not shown) in the microcomputer (21) that stores the result of determining whether or not the beam was at the low level, that is, the memory that stores the state in which the beam was interrupted. In step (44), D1 = L and X address memory (XAM) (not shown) in the microcomputer (21) used for coordinate value detection are cleared. In step (45), D1 = L, Y address memory (YAM) (not shown) in the microcomputer (21) used for coordinate value detection is cleared.

Thus, in steps (41) to (45)
Initial settings are made to determine the phenomenon of W2.

In step (46), the X address is set to 0, X beam scanning is started, in step (47) the X address is incremented by 1, and in step (48) the level discriminator (28
The determination signal D2 of e) is determined whether or not it is at a low level to prepare for sensitivity determination. Then, if the discrimination signal D2 is at the low level, the discrimination memory (M2) for storing that the discrimination signal D2 is at the low level is set in step (49).

Next, in step (50), it is determined whether or not the discrimination signal D1 of the level discriminator (28d) is at low level. If it is low level, it is stored in step (51) that the discrimination signal D1 is at low level. Set the judgment memory (M1). Then, in step (52), the discrimination signal D1 is at the low level, that is, the X-beam interrupted address is stored in the X-address memory (XAM), and the coordinates are detected.
Then, in step (53), it is determined whether or not the X address is the last, and if it is not the last, the process returns to step (47) to repeat the above operation, and if it is the last, the process proceeds to step (54). If the discrimination signal D2 is not low level in step (48) or the discrimination signal D1 is not low level in step (50), the process proceeds to step (53). If the X address is not the last one, the process proceeds to step (47). Returning to the above, the above-mentioned operation is repeated.

In this way, the X beam is scanned in steps (46) to (53).

In step (54), the Y address is set to 0 and Y beam scanning is started, in step (55) the Y address is incremented by 1, and in step (56) the level discriminator (28
The determination signal D2 of e) is determined whether or not it is at a low level to prepare for sensitivity determination. Then, if the determination signal D2 is at the low level, the determination memory (M2) that stores that the determination signal D2 is at the low level is set in step (57). (When it is set again, the previous state does not change.) Next, in step (58), it is judged whether or not the discrimination signal D1 of the level discriminator (28d) is low level, and if it is low level, step (58 In step 59), the determination signal D1 is set in the determination memory (M1) that stores that it is at the low level. When it is set again, the previous state does not change. Then, in step (60), the fact that the discrimination signal D1 is at the low level is stored in the Y address memory (YAM), whereby the coordinates are detected. Then, in step (61), it is determined whether or not the Y address is the last, and if it is not the last, the process returns to step (55) to repeat the above operation, and if it is the last, the process proceeds to step (62). If the discrimination signal D2 is not low level in step (56) or the discrimination signal D1 is not low level in step (58), the process proceeds to step (61). If the Y address is not the last, proceed to step (55). Returning to this, the above-mentioned operation is repeated, and if it is the last, the process proceeds to step (62).

In this way, the Y beam is scanned in steps (54) to (61). As a result, step (46) ~
At (61), the entire surface scanning of the X beam scan and the Y beam scan is completed.

Next, in steps (62) to (69), it is determined whether or not there is a desensitized element, that is, whether or not there is a desensitized element (beam) that lasts for a finite time or longer in the state where no beam is blocked. That is, in step (62), the level discriminator (28
e) It is determined whether or not the determination memory (M2) that stores the determination result of whether the determination signal D2 is at the low level is set, and if it is set, that is, the waveform W2 or
If it is a phenomenon of W3, in step (63) the level discriminator (28
It is determined whether or not the determination memory (M1) that stores the result of determining whether or not the determination signal D1 in d) is at the low level is set. If not set, that is, the waveform W2
If so, go to step (64).

Then, in step (64), when the discrimination signal D2 of the level discriminator (28e) is at the low level, the counter (M2) that is set and counts the set state of the discrimination memory (M2)
Count up C) once. It is set in step (65) when the discrimination signal D2 of the level discriminator (28e) is at a low level, and whether or not the count value of the counter (M2C) for counting the state of the discrimination memory (M2) is N or more, That is, the sensitivity decrease duration is determined. Here, N is set to a certain value in order to determine whether it is a finite time or longer. That is, the determination memory (M2) with D2 = L is set once by one full-scan (step 62). The counter (M2C) for checking how many times D2 = L is set in the determination memory (M2) once is incremented once (step 64).
Therefore, (1 sample rate) × (N) has a finite time. If the count value of the counter is equal to or greater than N in step (65), a warning is issued in step (66) because there is a sensitivity lowering element. However, coordinate measurement can be performed.

Then, in step (67), the determination memory (M2) that stores the result of determining whether the determination signal D2 of the level discriminator (28e) is at the low level is reset and the next measurement (that is, X beam, Y beam In preparation for scanning, step (4
Return to 6) and repeat the above operation. If the count value of the counter (M2C) is not N or more in step (65), the process proceeds to step (67) to perform the above operation.

If the decision memory (M2) of D2 = L is not set in step (62), that is, if the phenomenon of waveform W1 is present, the decision signal D2 of the level discriminator (28e) is high level in step (68). This resets the counter (M2C) and returns to step (46) to repeat the above operation. That is, if the half-blocking state of the beam is not continuous, the counting of the half-blocking state of the beam is stopped and reset.

If the decision memory (M1) with D1 = L is set in step (63), that is, if the phenomenon of waveform W3 is present, the decision signal D1 of the level discriminator (28a) is in the low level in step (69). This resets a counter (M2c) that counts the set state of D ₂ = L determination memory (M2) for each scan. That is, since there is a beam that has been blocked, the counting of the half-blocked state of the beam is stopped and reset, and the process proceeds to step (70) to start coordinate measurement. As in the above case, if the half-blocking state of the beam is not continuous, the counting of the half-blocking state of the beam is stopped and reset.

Prepare the next measurement by resetting the decision memory (M2) for D2 = L in step (70), resetting the decision memory (M1) for D1 = L in step (71), and measuring the coordinates in step (72). And process the coordinates. Then, in step (73), it is determined whether or not the obtained coordinates are within the effective area (display area in FIG. 1). If the coordinates are within the effective area, the coordinates are sent out in step (74), and the step ( Return to 46) and repeat the same operation as above. If it is not within the effective area in step (73), the process returns to step (46) and the same operation as described above is repeated.

FIG. 6 summarizes the phenomena of the above-mentioned waveforms W1, W2, and W3, the events corresponding to them, and the determination conditions thereof.

In the above embodiment, the detection output of the detection circuit (28) is compared with the first and second discrimination levels in the state of the analog signal and is output. However, the detection output is A / D converted. It may be output.

H As described above, according to the present invention, in the touch panel device in which the light beam grating is formed by the light receiving element and the light emitting element, the light receiving output from the light receiving element is supplied, and the level of the light receiving output is First detection means for detecting whether or not there is a first determination level higher than the light receiving level when the light beam is not received and a second determination level higher than the first determination level and lower than the normal light receiving level. And the level of the received light output from the first detecting means is
And a second detection means for detecting whether or not the first detection output indicating that the first detection output is obtained is continuously obtained for a predetermined time or longer. Then
When the second detection means obtains the second detection output indicating that the first detection output is continuously obtained for a predetermined time or more, the warning information is generated, so that the touch panel is completely The need for maintenance can be notified before it becomes inoperable, and thus the number of man-hours required for maintenance can be reduced, and moreover, correct display is always possible and stable use can be achieved, and the reliability of the device can be improved.

Further, according to the present invention, the first detection means supplies the light receiving output from the light receiving element, and the level of the light receiving output is higher than the light receiving level when the light receiving element does not receive the light beam. If only the first detection output indicating that it is between the second determination level higher than the first determination level and lower than the normal light reception level is obtained, the touch panel is touched by the finger and the light emitting element enters the light receiving element. Since it is indistinguishable from the case where a part of the light beam to be blocked is indistinguishable, the first detection means obtains the first detection output indicating that the level of the light reception output is between the first and second determination levels. When
Since the second detection means for detecting whether or not the first detection output is continuously obtained for a predetermined time or more is also provided, it is possible to reliably detect the deterioration of the touch panel performance.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention, FIG. 2 is a diagram for explaining the present invention, and FIGS. 3 to 5 are flowcharts for explaining the operation of FIG. Sixth
The figure is an explanatory view of the failure diagnosis according to the present invention. (11) is a light emitting diode, (12) is a photo diode, (28) is a detection circuit, (28d) is a first level discriminator, (28e) is a second level discriminator, and V _th1 is a first level discriminator. The discrimination level, V _th2, is the second discrimination level.

Claims (1)

(57) [Claims] 1. A touch panel device having a light-receiving element and a light-beam grating to form a light beam grating, when a light-receiving output from the light-receiving element is supplied and the level of the light-receiving output is such that the light-receiving element does not receive a light beam. A first detection level that is higher than the light receiving level of the second light source and a second detection level that is higher than the first light receiving level and lower than the normal light receiving level, and the first detection means. When the detection means obtains the first detection output indicating that the level of the received light output is between the first and second determination levels, the first detection output continues for a predetermined time or more. Second detection output for detecting whether or not the second detection output is obtained, the second detection output indicating that the first detection output is continuously obtained by the second detection means for the predetermined time or more. Warning information when The touch panel device is characterized in that so as to live.