JP2011164728A - Touch panel device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a touch panel device for reducing the load of a micro-controller with simple circuit configurations. <P>SOLUTION: A touch panel device configured to detect the selective depressed state of each of a plurality of switch elements arrayed like a matrix by a micro-controller is provided with a depressed state detection means for detecting the selective depressed state of any of the plurality of switch elements. In the touch panel, processing for detecting the position of the depressed switch element is selectively executed by the micro-controller by using the depressed state detection signal of the depressed state detection means as an interrupt signal. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a touch panel device, and in particular, relates to an improvement in detecting whether or not a switch element is touched in a touch panel device in which a plurality of switch elements are arranged in a matrix.

  One type of operation panel of an electronic device such as a measuring instrument in which a plurality of switch elements are incorporated is a touch panel device in which a plurality of upper electrodes and lower electrodes are arranged in a matrix form orthogonal to each other.

  FIG. 4 is a configuration explanatory view showing an example of such a conventional touch panel device. In FIG. 4, a plurality of upper electrodes 1 and lower electrodes 2 are formed of, for example, a transparent ITO film, and are arranged in a matrix shape orthogonal to each other. FIG. 4 shows an example in which four upper electrodes 1 and four lower electrodes 2 are provided to form 16 intersections for easy understanding.

  The upper electrodes 11 to 14 are connected to the output port OP (ports P0 to P3) of the microcontroller 3, and the lower electrodes 21 to 24 are connected to the input ports IP (ports P4 to P7) of the microcontroller 3, respectively. ing.

  Each of the 16 intersections formed by the upper electrode 1 and the lower electrode 2 is in an electrically non-contact non-contact state in an initial state where it is not selectively depressed, and the operator selectively depresses a desired intersection position. In this way, a contact state that is electrically conductive is established.

  Resistors R1 to R4 are connected between each input port IP and the common potential point in order to stabilize the potential of the input port in an electrically non-conductive state as an L potential.

  As shown in the timing chart of FIG. 5, the push-down state of each intersection is determined by changing the output port OP (ports P0 to P3) of the microcontroller 3 from the L potential to the H potential sequentially, while changing the input port IP (ports P4 to P4). By detecting the level of P7), it can be recognized as a position coordinate corresponding to the output port OP.

  In Patent Literature 1, in a touch operation input device configured to detect a touch position with an optical sensor, the sleep state is canceled by a position detection signal of one of the optical sensors in the sleep state to reduce power consumption. The structure to be described is described.

JP 2002-82133 A

By the way, in the conventional apparatus shown in FIG. 4, in order to simplify the circuit configuration, the depression at each intersection is always detected by the microcontroller.
As a result, there is a problem that the load on the microcontroller increases.

  On the other hand, in order to reduce the load on the microcontroller, it is conceivable to increase the detection time interval of the depression at each intersection, but the responsiveness is deteriorated.

  Further, as shown by hatched hatching, when the intersection of the upper electrodes 11 and 12 is simultaneously pushed down on the common lower electrode (for example, 21), the output port OP0 at the output level H as shown by tp in FIG. A matching state at a different level to which the output port OP1 of the output L level is connected may result in an increase in current consumption, which may adversely affect device operation.

  The present invention solves these problems, and an object thereof is to realize a touch panel device that can reduce the load on a microcontroller with a simple circuit configuration.

In order to achieve the above object, the invention described in claim 1 of the present invention is:
In a touch panel device configured to detect with a microcontroller a selective depression state of a plurality of switch elements arranged in a matrix,
A depressed state detecting means for commonly detecting a selectively depressed state of any one of the plurality of switch elements;
The microcontroller selectively executes a process of detecting the position of the depressed switch element by using the depressed state detection signal of the depressed state detection means as an interrupt signal.

The invention according to claim 2 is the touch panel device according to claim 1,
The microcontroller has a port that can change input / output and an input hardware interrupt port,
The depressing state detecting means is configured to change the state of selective depressing of any of the plurality of switch elements based on a plurality of diodes that prevent a match between output ports of the microcontroller and a current flowing through any of these diodes. And a common detection circuit.

The invention according to claim 3 is the touch panel device according to claim 1 or 2,
The plurality of switch elements arranged in a matrix form is composed of a plurality of upper electrodes and lower electrodes arranged in a matrix form so as to be orthogonal to each other.

According to a fourth aspect of the present invention, in the touch panel device according to the third aspect,
The plurality of switch elements arranged in a matrix form are constituted by mechanical contact switches.

  As a result, the microcontroller selectively executes the process of detecting the position of the depressed switch element only when any of the plurality of switch elements is depressed, thereby reducing the load on the microcontroller.

It is a configuration explanatory view showing an embodiment of the present invention. It is a flowchart explaining the operation | movement of FIG. It is composition explanatory drawing which shows the other Example of this invention. It is structure explanatory drawing which shows an example of the conventional touch panel apparatus. 5 is a timing chart for explaining the operation of FIG. 4.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing a configuration of an embodiment of the present invention, and the same reference numerals are given to portions common to FIG. The difference between FIG. 1 and FIG. 4 is that the ports P0 to P7 of the microcontroller 3 can be changed in input / output, the ports P0 to P3 are set to the output port OP, and the ports P0 to P7 are set to the input port IP. It is set, port P8 is an input hardware interrupt port, and blocks A and B surrounded by a two-dot chain line are added.

  In FIG. 1, resistances R1 to R4 are potential stabilization resistors when the ports P4 to P7 are used as the input port IP when the depressed position is detected. One end of each of the resistors R1 to R4 is connected to a connection point between the corresponding input port IP and the lower electrodes 21 to 24, and the other end is connected to a common potential point.

  In block A, resistors R5 to R8 are resistors for stabilizing the potential of the detection port when the digital touch panel is not pressed. One end of each of the resistors R5 to R8 is connected to a connection point between the corresponding output port OP and the upper electrodes 11 to 14, and the other end is connected to a common potential point.

  In the block B, the anodes of the diodes D1 to D4 are respectively connected to the connection points of the corresponding output ports OP and the lower electrodes 21 to 24, and the cathodes are connected to the base of the transistor Q1 via the resistor R9. These diodes D1 to D4 function to prevent different levels of matching between the output ports OP.

  The base of the transistor Q1 is connected to the common potential point together with the emitter via the resistor R10. The collector is connected to the power supply VCC via a resistor R11. The transistor Q1 functions as a level converting transistor that prevents the input potential to the hardware input interrupt corresponding port 8 of the microcontroller 3 from becoming an intermediate potential due to the voltage effect of the diodes D1 to D4.

  In such a configuration, the output port OP outputs an H level and waits for a depression of any intersection on the digital touch panel.

  When one of the intersections of the digital touch panel is pushed down and the upper electrode 1 and the lower electrode 2 of the digital touch panel are brought into contact, current flows from the output port OP to one of the diodes D1 to D4 and the resistor R9 to the base of the transistor Q1. Flows.

  As a result, the base potential of the transistor Q1 rises, and the transistor Q1 transitions from the off state to the on state. When the potential of the resistor R10 transitions from H to L, an interrupt of state transition can be detected at the hardware input interrupt corresponding port P8 of the microcontroller 3.

  A flag for starting the pressed position detection program of the digital touch panel from the standby state is set by the interrupt process of the microcontroller 3 that captures the state transition, and the pressed position detection processing operation by the pressed position detection program is executed.

  Further, by checking the level state of the interrupt corresponding input port P8, it is possible to determine whether or not the depression is continued, and the depression position detection processing operation can be continued during the depression.

  FIGS. 2A and 2B are flowcharts for explaining the flow of the operation of FIG. 1. FIG. 2A shows the flow of normal processing, and FIG. 2B shows the flow of interrupt processing.

  In (A), ports P0 to P3 are first set as output ports, and all outputs are initialized to H level (step S1).

  Next, it is determined whether or not there is a detection request (step S2). If there is a detection request, the port number n = 0 is set as an output port (step S3), and if there is no detection request, the process proceeds to a standby process for idling until a detection request is received (step S4).

  The port number n is set as an output port, and its output is set to H level (step S5). The level states of the input ports P4 to P7 in this state are read and stored in a predetermined data storage area (not shown) as an array of data (0) to (3) (step S6).

  Such a series of processing operations are repeatedly executed while updating the port number n by +1 (step S8) until the port number n = 3 (step S7).

  When the port number n becomes 3 (step S7), it is determined whether or not the hardware input interrupt corresponding port P8 is at the L level (step S9).

  If the hardware input interrupt corresponding port P8 is at the L level, the detection request is cleared (step S10), the process returns to step S1 to be initialized, and a series of processing for the next detection request is executed. If it is not L level, it returns to step S2 and repeats a series of processing for the current detection request until the hardware input interrupt corresponding port P8 becomes L level.

  When an interrupt is detected, the process (B) is performed. That is, in (B), ports P0 to P3 are set as input ports (step S11), the next detection request is set (step S12), and the interrupt process is terminated. Then, the process returns to step S1.

  With such a configuration, the microcontroller 3 performs the depressed position detection operation only while one of the intersections of the digital touch panel is depressed. Compared to the conventional configuration in which the depressed position detection operation is always performed, The load on the microcontroller 3 can be reduced.

  Further, it is possible to prevent the occurrence of matching due to the difference in the output level of the output port OP of the microcontroller 3.

  FIG. 3 is an explanatory diagram showing the configuration of another embodiment of the present invention. Components common to those in FIG. In the embodiment of FIG. 3, mechanical contact switches (hereinafter referred to as switches) SW1 to SW16 are orthogonally arranged in a matrix instead of the switch elements in which the plurality of upper electrodes 1 and lower electrodes 2 in FIG. It is an arrangement.

  Specifically, the fixed contacts of the switches SW1 to SW4 are commonly connected to the port P0, the fixed contacts of the switches SW5 to SW8 are commonly connected to the port P1, and the fixed contacts of the switches SW9 to SW12 are connected to the port P2. Are commonly connected, and the fixed contacts of the switches SW13 to SW16 are commonly connected to the port P3.

  On the other hand, the movable contacts of the switches SW4, SW8, SW12, and SW16 are connected in common to the port P4, the movable contacts of the switches SW3, SW7, SW11, and SW15 are connected in common to the port P5, and the switch SW2 is connected to the port P6. , SW6, SW10, SW14 are connected in common, and the switch P1, SW5, SW9, SW13 are connected in common to the port P7.

  In the configuration of FIG. 3 as well, the microcontroller 3 performs the depressed position detection operation only while any of the switches SW1 to SW16 is depressed as in FIG. Compared to the configuration, the load on the microcontroller 3 can be reduced.

  In each of the above embodiments, for convenience of explanation, an example in which the switch elements are arranged in a 4 × 4 orthogonal matrix is shown. However, the present invention is not limited to this, and the switch elements are in an m × n orthogonal matrix. It may be arranged.

  The touch panel device of the present invention is not limited to an operation panel of an electronic device such as a measuring instrument in which a plurality of switch elements are incorporated, but is also effective for an operation panel of an automobile or an operation panel of various industrial devices.

  As described above, according to the present invention, the microcontroller can selectively execute the process of detecting the position of the depressed switch element only when any one of the plurality of switch elements is depressed, A touch panel device that can reduce the load on the microcontroller can be realized.

1 Upper electrode 2 Lower electrode 3 Microcontroller P0-P8 port

Claims (4)

In a touch panel device configured to detect with a microcontroller a selective depression state of a plurality of switch elements arranged in a matrix,
A depressed state detecting means for commonly detecting a selectively depressed state of any one of the plurality of switch elements;
The touch panel device according to claim 1, wherein the microcontroller selectively executes a process of detecting the position of the depressed switch element by using the depressed state detection signal of the depressed state detection means as an interrupt signal. The microcontroller has a port that can change input / output and an input hardware interrupt port,
The depressing state detecting means is configured to change the state of selective depressing of any of the plurality of switch elements based on a plurality of diodes that prevent a match between output ports of the microcontroller and a current flowing through any of these diodes. The touch panel device according to claim 1, wherein the touch panel device is configured with a common detection circuit.   The plurality of switch elements arranged in a matrix form includes a plurality of upper electrodes and lower electrodes arranged in a matrix form so as to be orthogonal to each other. The touch panel device described.   The touch panel device according to claim 3, wherein the plurality of switch elements arranged in a matrix form include mechanical contact switches.

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