JP2011018102A - Detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly precisely detect an object to be detected across the wide range of environmental temperature.SOLUTION: Each of a plurality of detection circuits U generates a detection signal S corresponding to the presence/absence of a detected object. The plurality of detection circuits U are divided into a plurality of first detection circuits U1 and a plurality of second detection circuits U2 with the different ranges of sensible illuminance. A driving circuit 20 selectively executes a first detecting operation to obtain the detection signal S by driving the plurality of first detection circuits U1 in each unit period UP and a second detecting operation to obtain the detection signal S by driving the plurality of second detection circuits U2 in each unit period PU, according to environmental temperature τ detected by a temperature detection circuit 36.

Description

  The present invention relates to a technique for detecting the presence or absence (approach or contact) of an object to be detected.

  Techniques for detecting an object to be detected such as a user's body and a pen-shaped pointing member (stylus) have been proposed. For example, Patent Document 1 discloses a display device in which a plurality of detection circuits including light receiving elements are arranged in a matrix with display pixels. A detection signal corresponding to the illuminance (intensity) of the irradiation light with respect to the light receiving element is output from each of the plurality of detection circuits to the external device.

JP 2004-318819 A

  However, the characteristics of the light receiving element depend on temperature. For example, the temperature at which the light receiving element can sense a predetermined illuminance with a predetermined sensitivity is limited to a specific range. Therefore, the ability to detect an object to be detected with high accuracy is limited when the environmental temperature is within a specific range. For example, when the ambient temperature is outside the temperature range in which the light receiving element can sense a predetermined illuminance with a predetermined sensitivity, it is difficult to obtain a significant detection signal that can discriminate the detected object with high accuracy. In view of the above circumstances, an object of the present invention is to detect an object to be detected with high accuracy over a wide range of environmental temperatures.

  In order to solve the above-described problems, the detection device according to the first aspect of the present invention is a plurality of detection circuits each generating a detection signal corresponding to the illuminance of the irradiation light. Detection signals including a plurality of detection circuits including a plurality of first detection circuits and a plurality of second detection circuits having different temperature ranges that can be sensed by sensitivity, and driving the plurality of first detection circuits in each unit period. A drive circuit that selectively executes a first detection operation for obtaining a detection signal and a second detection operation for obtaining a detection signal by driving a plurality of second detection circuits in each unit period. It has. In the above aspect, the first detection operation for acquiring the detection signal by driving each first detection circuit and the second detection operation for acquiring the detection signal by operation of each second detection circuit are in accordance with the environmental temperature. Since it is selectively executed, there is an advantage that a detected object can be detected with high accuracy over a wide range of environmental temperature as compared with a configuration in which a temperature range capable of sensing a predetermined illuminance is common to all detection circuits. .

  “Selectively executing the first detection operation and the second detection operation” means that the drive circuit executes the first detection operation and the drive circuit executes the second detection operation. Means. Therefore, configurations in which other detection operations can be executed in addition to the first detection operation and the second detection operation are also included in the scope of the present invention. For example, a configuration in which the drive circuit can execute a third detection operation for acquiring a detection signal by driving a third detection circuit different from the first detection circuit and the second detection circuit in addition to the first detection operation and the second detection operation. Naturally satisfies the requirement of “selectively executing the first detection operation and the second detection operation” as long as there is a case where the first detection operation is executed and a case where the second detection operation is executed. . In addition, the “temperature range in which a predetermined illuminance can be sensed with a predetermined sensitivity” means, in other words, a detection signal having a level (current value or voltage value) that is significant for the method or purpose of use of the detection signal. This is a temperature range (for example, range A1 and range A2 in FIG. 4) that can be generated by the detection circuit during irradiation. It does not matter whether the temperature range in which the predetermined illuminance can be detected with the predetermined sensitivity overlaps between the first detection circuit and the second detection circuit.

  In the specific example of the detection device according to the first aspect, each of the plurality of detection circuits is arranged corresponding to each intersection of the plurality of selection lines and the plurality of detection lines and outputs a detection signal by selecting the selection line. The plurality of detection lines include a plurality of first detection lines connected to two or more first detection circuits, and a plurality of second detection circuits connected to two or more second detection circuits. Each of the plurality of first detection lines is located in each gap of the plurality of second detection lines, and the drive circuit sequentially selects each of the plurality of selection lines in each unit period. A selection circuit; a first detection operation for acquiring a detection signal output to each of the plurality of first detection lines in each unit period; and a detection signal output to each of the plurality of second detection lines in each unit period. And an output circuit that selectively executes the second detection operation acquired in step (b). In the above aspect, a set of two or more first detection circuits (first detection lines) and a set of two or more second detection circuits (second detection lines) are arranged in a distributed manner. Compared to a configuration in which one detection circuit (or a plurality of second detection circuits) is unevenly distributed only in a specific region, there is an advantage that it is easy to secure an area that can be used for detection of an object to be detected. In addition, the specific example of the above aspect is later mentioned as 1st Embodiment, for example.

  In the specific example of the detection device according to the first aspect, each of the plurality of detection circuits is arranged corresponding to each intersection of the plurality of selection lines and the plurality of detection lines and outputs a detection signal by selecting the selection line. The plurality of selection lines include a plurality of first selection lines each having two or more first detection circuits connected thereto, and a plurality of second selection lines each having two or more second detection circuits connected to each other. Each of the plurality of first selection lines is located in each gap of the plurality of second selection lines, and the driving circuit sequentially selects each of the plurality of first selection lines in each unit period. A selection circuit that selectively executes a first detection operation to be selected and a second detection operation to sequentially select each of the plurality of second selection lines in each unit period, and is output to each of the plurality of detection lines. And an output circuit that acquires a detection signal in each unit period. In the above aspect, a set of two or more first detection circuits (first selection line) and a set of two or more second detection circuits (second selection line) are arranged in a distributed manner. Compared to a configuration in which one detection circuit (or a plurality of second detection circuits) is unevenly distributed only in a specific region, there is an advantage that it is easy to secure an area that can be used for detection of an object to be detected. In addition, the specific example of the above aspect is later mentioned as 2nd Embodiment, for example.

  The detection device according to the second aspect of the present invention is a plurality of detection circuits each generating a detection signal corresponding to the illuminance of the irradiated light, and has a temperature range in which the predetermined illuminance can be sensed with a predetermined sensitivity. A plurality of detection circuits including a plurality of different first detection circuits and a plurality of second detection circuits, a drive circuit for obtaining a detection signal from the plurality of detection circuits, and a first signal corresponding to the detection signal of each first detection circuit The processing means (for example, the processing unit 62 in FIG. 10) that generates one detection data and second detection data corresponding to the detection signal of each second detection circuit, and the first detection data or the second detection data according to the environmental temperature Selection means (for example, the selection unit 64 in FIG. 10). In the above aspect, the first detection data corresponding to the detection signal generated by the first detection circuit and the second detection data corresponding to the detection signal generated by the second detection circuit are selected according to the environmental temperature. Compared with a configuration in which a temperature range in which a predetermined illuminance can be sensed is common to all the detection circuits, there is an advantage that an object to be detected can be detected with high accuracy over a wide range of environmental temperatures. In addition, the specific example of the detection apparatus which concerns on a 2nd aspect is later mentioned as 4th Embodiment, for example.

  In the second mode, “selecting the first detection data or the second detection data” means that the first detection data may be selected or the second detection data may be selected. Therefore, a configuration in which other detection data different from the first detection data and the second detection data is a selection candidate is also included in the scope of the present invention. For example, the third detection data generated by driving the third detection circuit different from the first detection circuit and the second detection circuit is generated by the processing means in addition to the first detection data and the second detection data, and the first detection data The configuration in which the selection unit selects any one of the data, the second detection data, and the third detection data has a case where the first detection data is selected and a case where the second detection data is selected. Naturally, the requirement of “selecting detection data or second detection data” is satisfied.

  The detection device according to the specific example of the first aspect includes a temperature detection unit that detects an environmental temperature, and the drive circuit includes a first detection operation and a second detection operation according to the environmental temperature detected by the temperature detection unit. Is selectively executed. Similarly, the detection device according to the specific example of the second aspect includes a temperature detection unit that detects the environmental temperature, and the selection unit selects the first detection data or the second data according to the environmental temperature detected by the temperature detection unit. Select the detection data. As described above, according to the aspect including the temperature detection unit, there is an advantage that the environmental temperature can be acquired easily and reliably.

  In addition, the detection device according to the specific example of the first aspect or the second aspect includes a temperature determination that determines whether the environmental temperature is high or low from the detection signal generated by the first detection circuit and the detection signal generated by the second detection circuit. Means (for example, control circuit 30 for executing step SB2 of FIG. 9). According to the above aspect, since it is not necessary to install the temperature detection part which detects environmental temperature independently from a detection circuit, there exists an advantage that the structure of a detection apparatus is simplified. The “environment temperature” in the present invention means the temperature (ideally, the temperature of each detection circuit) of the environment (the surface and surroundings of the detection device) in which the detection device is installed.

  The detection device according to the third aspect of the present invention is a plurality of detection circuits each generating a detection signal corresponding to the illuminance of the irradiated light, and has a temperature range in which the predetermined illuminance can be sensed with a predetermined sensitivity. A plurality of detection circuits including a plurality of different first detection circuits and a plurality of second detection circuits, a drive circuit for obtaining a detection signal from the plurality of detection circuits, and a first signal corresponding to the detection signal of each first detection circuit A processing means (for example, the processing unit 62 in FIG. 12) that generates one detection data and second detection data corresponding to the detection signal of each second detection circuit, and calculates the average of the first detection data and the second detection data Average means (for example, the average part 66 in FIG. 12). In the above aspect, since the first detection data corresponding to the detection signal generated by the first detection circuit and the second detection data corresponding to the detection signal generated by the second detection circuit are averaged, a predetermined illuminance is obtained. Compared with a configuration in which the detection temperature range is common to all detection circuits, there is an advantage that a detection object can be detected with high accuracy over a wide range of environmental temperature. In addition, the specific example of the detection apparatus which concerns on a 3rd aspect is later mentioned as 5th Embodiment, for example.

It is a block diagram of the detecting device concerning a 1st embodiment. It is a circuit diagram of the detection circuit of the detection apparatus which concerns on 1st Embodiment. It is a conceptual diagram which shows the relationship between the 1st detection circuit and 2nd detection circuit in 1st Embodiment. It is a conceptual diagram which shows the difference in the characteristic of the 1st detection circuit and 2nd detection circuit of 1st Embodiment. It is a timing chart which shows operation | movement of the detection apparatus which concerns on 1st Embodiment. It is a flowchart of operation | movement of the control circuit of the detection apparatus which concerns on 1st Embodiment. It is a conceptual diagram which shows the relationship between the 1st detection circuit and 2nd detection circuit in 2nd Embodiment. It is a timing chart which shows operation of a detecting device concerning a 2nd embodiment. It is a flowchart of operation | movement of the control circuit of the detection apparatus which concerns on 3rd Embodiment. It is a block diagram of the detection apparatus which concerns on 4th Embodiment. It is a flowchart of operation | movement of the control circuit of the detection apparatus which concerns on 4th Embodiment. It is a block diagram of the detection apparatus which concerns on 5th Embodiment. It is a flowchart of operation | movement of the control circuit of the detection apparatus which concerns on 5th Embodiment.

<A: First Embodiment>
FIG. 1 is a block diagram of a detection apparatus 100A according to the first embodiment of the present invention. The detection device 100A is a device (for example, a touch panel that detects contact of a user's body) used for detecting an object (detected object). As shown in FIG. 1, the detection apparatus 100A includes a detection unit 10 in which a plurality of detection circuits U are arranged, a drive circuit 20 that drives each detection circuit U, and a control circuit 30 that controls the drive circuit 20. To do. The drive circuit 20 includes a selection circuit 22A and an output circuit 24A. The drive circuit 20 can be composed of a plurality of integrated circuits (chips). A temperature detection unit 36 is connected to the control circuit 30. The temperature detection unit 36 is a temperature sensor that detects the temperature (ideally, the temperature of the detection unit 10) τ in which the detection device 100A is installed.

  The detection unit 10 includes M selection lines 12 extending in the X direction, M initialization lines 14 extending in the X direction in pairs with the selection lines 12, and Y crossing the X direction. 2N detection lines 16 extending in the direction are formed (M and N are natural numbers). The plurality of detection circuits U are arranged in a matrix of vertical M rows × horizontal 2N columns corresponding to the intersections of the M selection lines 12 (initialization lines 14) and the 2N detection lines 16.

  FIG. 2 is a circuit diagram of each detection circuit U. In FIG. 2, one detection circuit U located in the j-th column (j = 1 to 2N) of the i-th row (i = 1 to M) is representatively illustrated. The detection circuit U is a circuit that generates a detection signal S (S [i, j]) according to the presence / absence (approach or contact) of an object to be detected. As shown in FIG. And a selection switch TSEL and an initialization switch TRST. The light receiving element E generates a photocurrent IP having a current value corresponding to the illuminance (intensity) of the irradiation light with respect to the light receiving element E. For example, a photodiode is suitably employed as the light receiving element E. The illuminance of the irradiation light with respect to the light receiving element E changes according to the presence or absence of the object to be detected above the detection unit 10 and the distance.

  The amplification transistor TAMP, the selection switch TSEL, and the initialization switch TRST are configured by, for example, a transistor (for example, a thin film transistor in which a semiconductor layer is formed of low-temperature polysilicon) formed on the surface of the substrate together with the light receiving element E. Note that the conductivity type of each transistor constituting the detection circuit U is arbitrary.

  The amplification transistor TAMP is an element that generates a detection signal (a current signal obtained by amplifying the photocurrent IP) S [i, j] corresponding to its gate potential. Intervene between. The power supply line 18 is supplied with a predetermined potential VRST from a power supply circuit (not shown). The gate of the amplification transistor TAMP is connected to the light receiving element E (cathode).

  The selection switch TSEL is disposed on the path of the detection signal S [i, j], and controls whether the detection signal S [i, j] is output to the detection line 16. Specifically, the selection switch TSEL of the detection circuit U in the j-th column is arranged in series with the amplification transistor TAMP on a path connecting the feeder line 18 and the detection line 16 in the j-th column. The gates of the selection switches TSEL in the detection circuits U in the i-th row are commonly connected to the selection line 12 in the i-th row.

  The initialization switch TRST is interposed between the gate of the amplification transistor TAMP and the power supply line 18 (or other wiring) and controls the electrical connection (conduction / non-conduction) between the two. The gates of the initialization switches TRST in the detection circuits U in the i-th row are commonly connected to the initialization line 14 in the i-th row.

  As shown in FIG. 3, the plurality of detection circuits U in the detection unit 10 are divided into a first detection circuit U1 and a second detection circuit U2 having different temperature characteristics. As described below, the first detection circuit U1 and the second detection circuit U2 have different temperature ranges in which the light receiving element E can sense irradiation light with a predetermined illuminance with significant sensitivity.

  FIG. 4 is a graph showing the relationship between the temperature of the detection device 100A (detection unit 10) and the sensitivity of the light receiving element E (for example, the current value of the photocurrent IP) when the light receiving element E is irradiated with a predetermined illuminance. As shown by the characteristic F1 in FIG. 4, the light receiving element E of the first detection circuit U1 can detect the predetermined irradiation light with sensitivity exceeding the predetermined value α when the temperature is within the range A1. That is, the photocurrent IP (or the current value of the detection signal S [i, j]) exceeds the predetermined value under the temperature within the range A1. On the other hand, the temperature range A2 in which the light receiving element E of the second detection circuit U2 can detect the irradiation light with sensitivity exceeding the predetermined value α is distributed on the high temperature side as compared with the range A1. The temperature range that can be sensed by the light receiving element E is set separately for the first detection circuit U1 and the second detection circuit U2 according to various factors such as the size and material of the light receiving layer of the light receiving element E, for example. .

  As shown in FIG. 3, the first detection circuit U1 is located in the odd-numbered column ((2n-1) th column), and the second detection circuit U2 is located in the even-numbered column (second nth column) (n = 1). ~ N). That is, the set of M first detection circuits U1 arranged in the Y direction (odd number columns) and the set of M second detection circuits U2 arranged in the Y direction (even number columns) are included in the detection unit 10. Are alternately arranged along the X direction. Therefore, N first detection circuits U1 and N second detection circuits U2 exist in one row.

  As shown in FIG. 3, 2N detection lines 16 include N first detection lines 161 connected to M first detection circuits U1 and M second detection circuits U2, respectively. It is divided into N second detection lines 162 connected to each. The first detection lines 161 are located in odd-numbered columns ((2n-1) th column), and the second detection lines 162 are located in even-numbered columns (second nth column).

  The control circuit 30 in FIG. 1 detects the detection signal S [i, 2n-1] by driving each first detection circuit U1, and the detection signal S [i by driving each second detection circuit U2. , 2n] is selectively executed by the drive circuit 20. In the first detection operation, a plurality of detection circuits U are sequentially selected in units of rows in each unit period (vertical scanning period) PU shown in FIG. 5, and the 2N detection circuits U in the selected row (i-th row) are selected. Of these, the detection signals S [i, 2n-1] (S [i, 1], S [i, 3], S [i, 5],..., S generated by each of the N first detection circuits U1. [i, 2N-1]) is obtained from each first detection line 161. On the other hand, in the second detection operation, the plurality of detection circuits U are sequentially selected in units of rows in each unit period PU, and N second detection circuits out of 2N detection circuits U in the selected row (i-th row). Each detection signal S [i, 2n] (S [i, 2], S [i, 4], S [i, 6],..., S [i, 2N]) generated by each circuit U2 This operation is acquired from the two detection lines 162.

  The control circuit 30 selects one of the first detection operation and the second detection operation according to the environmental temperature τ detected by the temperature detection unit 36. FIG. 6 is a flowchart of processing in which the control circuit 30 selects the operation of the drive circuit 20 (first detection operation / second detection operation). The process shown in FIG. 6 is executed every predetermined time.

  When the processing of FIG. 6 is started, the control circuit 30 sets a threshold value τTH (SA1). The threshold value τTH is variably set according to, for example, an operation from the user on the operation unit (not shown). Then, the control circuit 30 determines whether or not the environmental temperature τ detected by the temperature detector 36 is lower than the threshold value τTH (SA2). When the environmental temperature τ is lower than the threshold value τTH (SA2: YES), the control circuit 30 selects the first detection operation for acquiring the detection signal S [i, 2n-1] from the first detection circuit U1 (SA3). On the other hand, when the environmental temperature τ exceeds the threshold value τTH (SA2: NO), the control circuit 30 selects the second detection operation for acquiring the detection signal S [i, 2n] from the second detection circuit U2 (SA4).

  The selection circuit 22A in FIG. 1 generates a selection signal GSEL [i] (GSEL [1] to GSEL [M]) that specifies selection / non-selection of each selection line 12 and outputs it to the selection line 12 in the i-th row. Then, the initialization signal GRST [i] (GRST [1] to GRST [M]) is generated and output to the i-th row initialization line 14 (see FIG. 2). A configuration in which a circuit for generating selection signals GSEL [1] to GSEL [M] and a circuit for generating initialization signals GRST [1] to GRST [M] are separately mounted is also employed.

  As shown in FIG. 5, each unit period PU includes M selection periods PSEL [1] to PSEL [M]. The selection signal GSEL [i] is set to a high level (active level meaning selection of the i-th row) in the selection period PSEL [i] within each unit period PU, and is set to a low level except for the selection period PSEL [i]. Maintained. The initialization signal GRST [i] is set to a high level (active) within a predetermined period before the start of the selection period PSEL [i], and is maintained at a low level during other periods (not shown).

  When the initialization signal GRST [i] is set to a high level, the initialization switches TRST of the 2N detection circuits U (U1, U2) in the i-th row are turned on. Therefore, the potential of the gate of each amplification transistor TAMP in the i-th row is initialized to the potential VRST of the feeder line 18. Then, when the initialization signal GRST [i] changes to the low level and each initialization switch TRST in the i-th row transitions to the OFF state, the gate of the amplification transistor TAMP enters an electrically floating state. Therefore, the potential of the gate of the amplification transistor TAMP is set to a potential corresponding to the photocurrent IP of the light receiving element E.

  As shown in FIG. 5, in the selection period PSEL [i], the selection signal GSEL [i] is set to a high level, so that each of the 2N detection circuits U (U1, U2) in the i-th row is selected. The switch TSEL transitions to the on state. Therefore, in each of the 2N detection circuits U in the i-th row, the current flowing through the amplification transistor TAMP can be output to the detection line 16 in the j-th column as the detection signal S [i, j]. . Since the potential of the gate of the amplification transistor TAMP is set according to the photocurrent IP, the detection signal S [i, j] is a current signal having a current value corresponding to the illuminance of the irradiation light with respect to the light receiving element E.

  The output circuit 24A of FIG. 1 includes N switches 42 [1] to 42 [N] and a signal processing circuit 44 as shown in FIG. The switch 42 [n] selectively selects the first detection line 161 (a end) in the (2n-1) th column and the second detection line 162 (b end) in the second n column adjacent to each other. To conduct. The control circuit 30 controls the switches 42 [1] to 42 [N] with the output of the control signal GX.

  When the first detection operation is selected in the process of FIG. 6, the control circuit 30 supplies a high-level control signal GX, which indicates selection of the first detection line 161 (a end), to the switch 42 [ 1] to 42 [N]. The switches 42 [1] to 42 [N] conduct the N first detection lines 161 (first detection circuit U1) to the signal processing circuit 44 in response to the control signal GX. Accordingly, in each of the selection periods PSEL [1] to PSEL [M] in each unit period PU, as shown in FIG. 5, N first detection circuits U1 out of 2N detection circuits U in the i-th row. Detection signal S [i, 2n-1] (S [i, 1], S [i, 3], S [i, 5],..., S [i, 2N-1] ]) Is supplied in parallel to the signal processing circuit 44 via each first detection line 161. That is, the drive circuit 20 (output circuit 24A) performs the first detection operation. On the other hand, since the signal processing circuit 44 and the N second detection lines 162 are electrically insulated, no current (detection signal S [i, 2n]) flows through the amplification transistor TAMP of each second detection circuit U2. .

  When the second detection operation is selected in the process of FIG. 6, the control circuit 30 sets the control signal GX to a low level (a level meaning selection of the second detection line 162) as shown in FIG. 5. The N second detection lines 162 (second detection circuit U2) are conducted to the signal processing circuit 44. Therefore, in the selection period PSEL [i] in each unit period PU, as shown in FIG. 5, N systems generated by the N second detection circuits U2 among the 2N detection circuits U in the i-th row. Detection signals S [i, 2n] (S [i, 2], S [i, 4], S [i, 6],..., S [i, 2N]) are transmitted via the second detection lines 162. To the signal processing circuit 44 in parallel. That is, the drive circuit 20 performs the second detection operation. On the other hand, since the signal processing circuit 44 and the N first detection lines 161 are electrically insulated, a current (detection signal S [i, 2n-1]) is supplied to the amplification transistor TAMP of each first detection circuit U1. Not flowing.

  The signal processing circuit 44 in FIG. 3 sequentially selects the N detection signals S supplied in parallel from the detection unit 10 within the selection period PSEL [i], and outputs one detection signal SOUT. S (parallel to serial) converter. The detection signal SOUT is supplied to an external device via the control circuit 30 and then used to determine the presence or absence of the detection object and to specify the shape of the detection object. A configuration is also employed in which the control circuit 30 determines the presence or absence and shape of an object to be detected using the detection signal SOUT.

  As described above, the drive circuit 20 detects the detection signal S [i, 2n-1] by driving the first detection circuit U1, and the detection signal S [i by driving the second detection circuit U2. , 2n] is selectively executed according to the environmental temperature τ detected by the temperature detection unit 36. Therefore, compared with a configuration in which the temperature range in which the light receiving element E can sense the irradiated light with a predetermined sensitivity is common to all the detection circuits U, it is possible to detect the detection object with high accuracy over a wide range of the environmental temperature τ. (In other words, there is an advantage that a sufficient dynamic range of the current value of the detection signal S [i, j] can be secured). For example, in the configuration in which the light receiving element E having the characteristic F1 in FIG. 4 is mounted on all the detection circuits U in the detection unit 10, the object to be detected when the environmental temperature τ is high (for example, on the upper limit side within the range A2). In the configuration in which the light receiving element E having the characteristic F2 shown in FIG. 4 is mounted on all the detection circuits U, detection of an object to be detected is performed when the environmental temperature τ is low (for example, on the lower limit side of the range A1). It becomes difficult. In the first embodiment, the first detection operation is executed when the environmental temperature τ is low (when the temperature is lower than the threshold value τTH), and the second detection operation is performed when the environmental temperature τ is high (when the temperature is higher than the threshold value τTH). As a result, the detection signal S [i, j] that can clearly distinguish the detected object can be generated regardless of whether the environmental temperature τ is in the range A1 or the range A2. Since the portable electronic device such as a mobile phone easily changes the environmental temperature τ as the user moves, the above effect is particularly effective when the detection apparatus 100A is mounted on the portable electronic device. .

  Further, since the first detection circuit U1 and the second detection circuit U2 are selectively used, the detection signals S [i, j] are always obtained from all the detection circuits U in each unit period PU (that is, Compared with a configuration in which current flows in the amplification transistors TAMP of all the detection circuits U, it is possible to suppress deterioration of elements (for example, the amplification transistors TAMP) constituting each detection circuit U. In each unit period PU, since the current (detection signal S [i, j]) flows only in one amplification transistor TAMP of the first detection circuit U1 and the second detection circuit U2, the detection signal is always output from all the detection circuits U. Compared with the configuration for acquiring S [i, j], there is also an advantage that the power consumed in the detection unit 10 is reduced.

  Further, since the first detection circuit U1 and the second detection circuit U2 are distributed in the X direction in the detection unit 10, the first detection circuit U1 and the second detection circuit U2 are arranged in a specific manner in the detection unit 10. Compared with a configuration that is unevenly distributed in the region, the entire detection unit 10 can be used for detection of an object to be detected (a sufficiently large area can be detected).

<B: Second Embodiment>
Next, a second embodiment of the present invention will be described. In addition, about the element which an effect | action and function are the same as that of 1st Embodiment in each following form, the same code | symbol as above is attached | subjected and each detailed description is abbreviate | omitted suitably.

  As shown in FIG. 7, the detection unit 10 includes 2M selection lines 12 and initialization lines 14 (not shown) extending in the X direction, and N detection lines 16 extending in the Y direction. It is formed. Therefore, the plurality of detection circuits U are arranged in a matrix of 2M vertical rows × N horizontal columns. The plurality of detection circuits U are divided into a first detection circuit U1 located in an odd-numbered row and a second detection circuit U2 located in an even-numbered row. That is, a set of N first detection circuits U1 arranged in the X direction (odd rows) and a set of N second detection circuits U2 arranged in the X direction (even rows) are included in the detection unit 10. Are alternately arranged along the Y direction. The 2M selection lines 12 include M first selection lines 121 each having N first detection circuits U1 connected thereto, and M lines each having N second detection circuits U2 connected thereto. And the second selection line 122.

  As shown in FIG. 7, the drive circuit 20 according to the second embodiment includes a selection circuit 22B and an output circuit 24B. Similarly to the signal processing circuit 44 of the first embodiment, the output circuit 24B sequentially selects the N detection signals S supplied in parallel from the detection unit 10 and outputs one detection signal SOUT.

  As shown in FIG. 7, the selection circuit 22 </ b> B includes M switches 52 [1] to 52 [M] and a signal generation circuit 54. As shown in FIG. 8, the signal generation circuit 54 (for example, a shift register) sequentially controls the control signals G0 [1] to G0 [1] to be set to high level (active) in each selection period PSEL [i] in the unit period PU. G0 [M] is generated. That is, the waveform of the control signal G0 [m] (m = 1 to M) is the same as that of the selection signal GSEL [m] of the first embodiment.

  The switch 52 [m] in FIG. 7 selectively signals the first selection line 121 (a end) in the (2m-1) th row and the second selection line 122 (b end) in the second m row adjacent to each other. Connected to the generation circuit 54. The switches 52 [1] to 52 [M] are controlled by a control signal GX supplied from the control circuit 30. The control circuit 30 sets the level of the control signal GX according to the operation (first detection operation / second detection operation) selected in the processing of FIG.

  When the first detection operation for obtaining the detection signal S [i, j] from the first detection circuit U1 is selected, the control circuit 30 selects the first selection line 121 (a end) as shown in FIG. Meaning high level control signal GX is output to switches 52 [1] to 52 [M]. The switches 52 [1] to 52 [M] connect the M first selection lines 121 to the signal generation circuit 54 in accordance with the control signal GX. Therefore, the control signal G0 [m] generated by the signal generation circuit 54 is selected from the selection signals GSEL [2m-1] (GSEL [1], GSEL [3], GSEL [5],..., As shown in FIG. , GSEL [2M-1]) is output to the first selection line 121 in the (2m-1) th row. That is, the selection circuit 22B sequentially selects each of the M first selection lines 121 in each selection period PSEL [m] within the unit period PU.

  Therefore, in each selection period PSEL [m] in the unit period PU, as shown in FIG. 8, N detection signals S generated by the N first detection circuits U1 in the (2m-1) th row. [2m-1, j] (S [2m-1,1], S [2m-1,2], S [2m-1, N]) are supplied in parallel to the output circuit 24B via each detection line 16 Is done. That is, the drive circuit 20 (selection circuit 22B) performs the first detection operation. On the other hand, since the signal generation circuit 54 and the M second selection lines 122 are electrically insulated, no current flows through the amplification transistor TAMP of each second detection circuit U2.

  On the other hand, when the second detection operation for obtaining the detection signal S [i, j] from the second detection circuit U2 is selected, the control circuit 30 sets the control signal GX to the low level, so that the M second The selection line 122 is conducted to the signal generation circuit 54. Therefore, the control signal G0 [m] generated by the signal generation circuit 54 is selected from the selection signals GSEL [2m] (GSEL [2], GSEL [4], GSEL [6],..., GSEL as shown in FIG. [2M]) is output to the second selection line 122 in the 2m-th row. That is, the selection circuit 22B sequentially selects each of the M second selection lines 122 in each selection period PSEL [m] within the unit period PU.

  Therefore, in each selection period PSEL [m], N detection signals S [2m, j] (S [2m, 1], S [2m] generated by the N second detection circuits U2 in the 2mth row. , 2], S [2m, N]) are supplied in parallel to the output circuit 24B via the detection lines 16. That is, the drive circuit 20 performs the second detection operation. On the other hand, since the signal generation circuit 54 and the M first selection lines 121 are electrically insulated, no current flows through the amplification transistor TAMP of each first detection circuit U1.

  As described above, the detection signal S [2m-1, j] is acquired by driving the first detection circuit U1, and the detection signal S [2m, j] is acquired by driving the second detection circuit U2. Since the second detection operation to be performed is selectively executed according to the environmental temperature τ, the same operation and effect as in the first embodiment are realized in the second embodiment.

<C: Third Embodiment>
In the first embodiment, the temperature detector 36 measures the environmental temperature τ, but in the third embodiment, the level of the environmental temperature τ is determined from the detection signal S [i, j] generated by each detection circuit U. FIG. 9 is a flowchart of processing in which the control circuit 30 according to the third embodiment of the present invention selects the operation (first detection operation / second detection operation) of the drive circuit 20. The processing of FIG. 9 is executed at every predetermined time.

  Prior to the processing of FIG. 9, a situation is generated in which the illuminance of the irradiation light with respect to each detection circuit U of the detection unit 10 is substantially equal. For example, the illuminance of each detection circuit U is set to be approximately equal when the user arranges paper (for example, a gray card) whose entire surface is set to a predetermined gradation close to the detection unit 10. Under the above situation, the control circuit 30 detects the detection signal S [i, j] (detection signal SOUT) from all the detection circuits U (both the first detection circuit U1 and the second detection circuit U2) of the detection unit 10. ) Is acquired (SB1). For example, the control circuit 30 sets the control signal GX to a high level and causes the drive circuit 20 to execute the first detection operation, thereby detecting the detection signal S [i, 2n-1] of each first detection circuit U1. The detection signal S [i, 2n] of each second detection circuit U2 is acquired as the detection signal SOUT by setting the control signal GX to the low level and causing the drive circuit 20 to execute the second detection operation. .

  Since the characteristic F1 of the first detection circuit U1 and the characteristic F2 of the second detection circuit U2 are in the relationship shown in FIG. 4, each first detection circuit U1 when the environmental temperature τ is low (for example, within the range A1). When the current value of the detection signal S [i, 2n-1] exceeds the current value of the detection signal S [i, 2n] of each second detection circuit U2 and the environmental temperature τ is high (for example, within the range A2) ) Has a tendency that the current value of the detection signal S [i, 2n] of each second detection circuit U2 exceeds the current value of the detection signal S [i, 2n-1] of each first detection circuit U1. Therefore, the control circuit 30 determines whether the environmental temperature τ is high or low (whether it is low) from the detection signal S [i, j] acquired in step SB1 of FIG. 9 (SB2).

  Specifically, the control circuit 30 detects the average value Iave1 of the current values of the detection signals S [i, 2n-1] generated by the plurality of first detection circuits U1 and the detection signals generated by the second detection circuits U2. After calculating the average value Iave2 of the current value of S [i, 2n], if the average value Iave1 exceeds the average value Iave2, it is determined that the environmental temperature τ is low (SB2: YES), and the average value Iave2 is When the average value Iave1 is exceeded, it is determined that the environmental temperature τ is high (SB2: NO). When it is determined that the environmental temperature τ is low, the first detection operation is selected (SB3), and when it is determined that the environmental temperature τ is high, the second detection operation is selected (SB4).

  In the above embodiment, since the level of the environmental temperature τ is determined according to the detection signal S [i, j] from the detection circuit U, the temperature detection unit 36 in FIG. 1 is unnecessary. Therefore, there exists an advantage that the structure of a detection apparatus is simplified. A method for determining the level of the environmental temperature τ from the detection signal S [i, j] is arbitrary. For example, a predetermined value for the average value Iave1 of the detection signal S [i, 2n-1] of the first detection circuit U1 and the average value Iave2 of the detection signal S [i, 2n] of the second detection circuit U2 is predetermined. The environmental temperature τ is estimated by the calculation of (for example, a value obtained by multiplying the average value Iave1 or the average value Iave2 by a predetermined coefficient as the environmental temperature τ), and the environmental temperature τ is compared with the threshold temperature τTH. A method of determining the height of the is also adopted. The configuration of the third embodiment is similarly applied to the second embodiment.

<D: Fourth Embodiment>
FIG. 10 is a block diagram of a detection apparatus 100B according to the fourth embodiment of the present invention. In the detection unit 10 of the detection apparatus 100B, a plurality of detection circuits U are arranged in a matrix of vertical M rows × horizontal N columns. The plurality of detection circuits U are divided into a first detection circuit U1 and a second detection circuit U2 as in the above embodiments.

  The drive circuit 20 includes a selection circuit 22A (FIG. 3) and an output circuit 24B (FIG. 7). The selection circuit 22A sequentially selects each of the M selection lines 12 within the unit period PU with the outputs of the selection signals GSEL [1] to GSEL [M], and the output circuit 24B supplies the detection circuit 10 in parallel. The N detection signals S [i, j] are sequentially selected to output one detection signal SOUT. That is, in the first to third embodiments, the detection signal S [i, j] is selectively acquired from the first detection circuit U1 or the second detection circuit U2, whereas in the fourth embodiment, The detection signals S [i, j] are acquired from each of the first detection circuits U1 and each of the second detection circuits U2 within each unit period PU. As described above, the first detection circuit U1 and the second detection circuit U2 (the first detection operation and the second detection operation) are not distinguished at the stage of obtaining the detection signal S [i, j]. The control circuit 30 does not output the control signal GX to the drive circuit 20.

  As shown in FIG. 10, the control circuit 30 includes a processing unit 62 and a selection unit 64. The processing unit 62 generates detection data D1 corresponding to the first detection circuit U1 and detection data D2 corresponding to the second detection circuit U2. The detection data D1 is a set of a plurality of detection values d1 (the same number as the first detection circuit U1) corresponding to the current value of the detection signal S [i, j] of each first detection circuit U1. On the other hand, the detection data D2 is a set of a plurality of detection values d2 (the same number as the second detection circuits U2) corresponding to the current value of the detection signal S [i, j] of each second detection circuit U2. That is, the detection value d1 corresponds to a numerical value corresponding to the illuminance of the light receiving element E of the first detection circuit U1, and the detection value d2 corresponds to a numerical value corresponding to the illuminance of the light receiving element E of the second detection circuit U2.

  As illustrated in FIG. 10, the processing unit 62 includes an A / D (analog to digital) converter 622 and a separation circuit 624. The A / D converter 622 performs detection value d (d1) of each detection circuit U by A / D conversion of each detection signal S [i, j] supplied from the output circuit 24B as the detection signal SOUT (analog current signal). , D2). The separation circuit 624 generates the detection data D1 and the detection data D2 by separating the detection value d processed by the A / D converter 622 into the detection value d1 and the detection value d2. The selection unit 64 selects and outputs either the detection data D1 or the detection data D2 according to the environmental temperature τ.

  FIG. 11 is a flowchart of the operation of the control circuit 30 in the fourth embodiment. The process shown in FIG. 11 is executed every predetermined time. When the process is started, the control circuit 30 sets the threshold value τTH (SC1) and then detects the detection signals S [of all the detection circuits U (both the first detection circuit U1 and the second detection circuit U2) of the detection unit 10. i, j] is acquired as the detection signal SOUT (SC2). Then, the processing unit 62 of the control circuit 30 generates detection data D1 and detection data D2 from the detection signal SOUT acquired in step SC2 (SC3).

  Next, the control circuit 30 specifies the environmental temperature τ (SC4). For example, the method of the first embodiment using the temperature detection unit 36 is adopted to specify the environmental temperature τ. Then, the selection unit 64 of the control circuit 30 determines whether or not the environmental temperature τ is lower than the threshold value τTH of step SC1 (SC5). When the environmental temperature τ is lower than the threshold τTH (SC5: YES), the selection unit 64 selects the detection data D1 generated in step SC3 and outputs it to the external device (SC6). The detection data D2 is discarded. On the other hand, when the environmental temperature τ exceeds the threshold value τTH (SC5: NO), the selection unit 64 selects the detection data D2 generated in step SC3 and outputs it to the external device (SC7). The detection data D1 is discarded. The external device uses the detection data D1 or the detection data D2 selectively output from the control circuit 30 to determine the presence or absence of the detection object and specify the shape of the detection object. A configuration is also employed in which the control circuit 30 determines the presence / absence or shape of the detection object using the detection data D1 selected in step SC6 or the detection data D2 selected in step SC7.

  As described above, in the fourth embodiment, the detection data D1 (detection value d1) corresponding to the detection signal S [i, j] of each first detection circuit U1 and the detection signal S [ The detection data D2 (detection value d2) corresponding to i, j] is selected according to the environmental temperature τ. Therefore, as in the first embodiment, the effect that the detection object can be detected with high accuracy over a wide range of the environmental temperature τ is realized. Further, in the fourth embodiment, the configuration for selectively driving the first detection circuit U1 and the second detection circuit U2 is unnecessary, and therefore the configuration of the drive circuit 20 is different from that in the first embodiment. There is also an advantage of being simplified.

  In addition, instead of the configuration in which the temperature detection unit 36 is used to specify the environmental temperature τ, a third method for determining the level of the environmental temperature τ according to the detection signal S [i, j] from each detection circuit U is used. The configuration of the embodiment may also be adopted. That is, step SC1 in FIG. 11 is omitted, and step SC4 and step SC5 in FIG. 11 are processes for determining the level of the environmental temperature τ from the detection signal S [i, j] acquired in step SC2 (step in FIG. 9). It is replaced with the same processing as SB2. The control circuit 30 selects the detection data D1 when the environmental temperature τ is low (SC6), and selects the detection data D2 when the environmental temperature τ is high (SC7).

<E: Fifth Embodiment>
FIG. 12 is a block diagram of a detection apparatus 100C according to the fifth embodiment. The detection device 100C has a configuration in which the selection unit 64 of the control circuit 30 in the fourth embodiment (FIG. 10) is replaced with an average unit 66. The averaging unit 66 generates detection data DOUT by averaging the detection data D1 and the detection data D2 generated by the processing unit 62. The detection data DOUT is a set of a plurality (M · N / 2) of detection values d0 corresponding to each set of the first detection circuit U1 and the second detection circuit U2 adjacent to each other. The detection value d0 includes the detection value d1 of the first detection circuit U1 (for example, i-th row and j-th column) in the detection data D1, and the second detection circuit U2 (for example, i-th row (j + 1) -th column) in the detection data D2. Is equivalent to the average value of the detected value d2).

  FIG. 13 is a flowchart of the operation of the control circuit 30 in the fifth embodiment. The process shown in FIG. 13 is executed every predetermined time. When the processing is started, the control circuit 30 detects the detection signals S [i, of all the detection circuits U (both the first detection circuit U1 and the second detection circuit U2) of the detection unit 10 as in Step SC2 of FIG. j] is acquired as the detection signal SOUT (SD1). Then, the processing unit 62 of the control circuit 30 generates the detection data D1 and the detection data D2 from the detection signal SOUT as in step SC3 of FIG. 11 (SD2). The averaging unit 66 of the control circuit 30 generates the detection data DOUT by averaging each detection value d1 of the detection data D1 and each detection value d2 of the detection data D2, and outputs the detection data DOUT to the external device (SD3). The external device uses the detection data DOUT output from the control circuit 30 to determine the presence / absence of the detection object and specify the shape of the detection object. A configuration is also employed in which the control circuit 30 determines the presence / absence or shape of an object to be detected using the detection data DOUT generated in step SD3.

  As described above, in the fifth embodiment, the detection data D1 (detection value d1) corresponding to the detection signal S [i, j] of each first detection circuit U1 and the detection signal S [ Detection data DOUT is generated by averaging with detection data D2 (detection value d2) corresponding to i, j]. That is, each detection value d0 of the detection data DOUT is a numerical value reflecting both the photocurrent IP of the first detection circuit U1 and the photocurrent IP of the second detection circuit U2. Therefore, as in the first embodiment, the effect that the detected object can be detected with high accuracy over a wide range of the environmental temperature is realized. In addition, since the configuration for selectively driving the first detection circuit U1 and the second detection circuit U2 is unnecessary, the configuration of the drive circuit 20 can be simplified as in the fourth embodiment. is there. Furthermore, in the fifth embodiment, since the detection data DOUT is generated by the average of the detection data D1 and the detection data D2, it is not necessary to specify the environmental temperature τ using the temperature detection unit 36 or each detection circuit U. . Therefore, there is an advantage that the configuration and operation of the detection apparatus 100C are simplified.

<F: Modification>
Various modifications are added to the above embodiment. Specific modifications are exemplified below. Two or more aspects arbitrarily selected from the following examples may be merged.

(1) Modification 1
In each of the above embodiments, the plurality of detection circuits U are divided into two types (first detection circuit U1 and second detection circuit U2). However, a configuration in which the plurality of detection circuits U are divided into three or more types may be employed. For example, assuming that a plurality of detection circuits U are divided into K types (K ≧ 3), in the first embodiment, the switch 42 [n] selectively selects any one of the K detection lines 16. A configuration in which the signal processing circuit 44 is conducted is employed, and in the second embodiment, a configuration in which the switch 52 [m] selectively conducts any one of the K selection lines 12 to the signal generation circuit 54 is employed. . Further, in the fourth embodiment, the selection unit 64 selects any of the K detection data generated by the processing unit 62, and in the fifth embodiment, the K detection data generated by the processing unit 62 The average unit 66 calculates the average.

(2) Modification 2
The method of dividing the first detection circuit U1 and the second detection circuit U2 is arbitrary. For example, a configuration in which a plurality of detection circuits U are arranged so that the first detection circuit U1 and the second detection circuit U2 are adjacent to each other in both the X direction and the Y direction is also employed. Further, the configuration in which the first detection circuit U1 and the second detection circuit U2 are arranged in a distributed manner is not essential in the present invention. For example, a configuration in which a plurality of first detection circuits U1 are distributed in one region as viewed from a boundary line defined in the detection unit 10 and a plurality of second detection circuits U2 is distributed in the other region is also employed.

(3) Modification 3
The application of the detection device 100 (100A, 100B, 100C) is not limited to a touch panel. For example, the detection device 100 according to each of the above embodiments includes a fingerprint sensor that detects a user's fingerprint, a vein sensor that detects a vein of the user's hand, and a reading device (scanner) that detects reflected light from a document. Can be used.

100A, 100B, 100C... Detecting device, 10... Detecting section, U... Detecting circuit, U1... First detecting circuit, U2. , 16... Detection line, 18... Feeder line, 20... Drive circuit, 22A, 22B... Selection circuit, 24A and 24B. 1] to 42 [N] …… Switch, 44 …… Signal processing circuit, 52 [1] to 52 [M] …… Switch, 54 …… Signal generation circuit, 62 …… Processing unit, 622 …… A / D Converter, 624... Separation circuit, 64... Selection unit, 66.

Claims (6)

A plurality of detection circuits each generating a detection signal corresponding to the illuminance of the irradiation light, wherein the plurality of first detection circuits and the plurality of second detection circuits are different in temperature ranges in which the predetermined illuminance can be sensed with a predetermined sensitivity. A plurality of detection circuits including a detection circuit;
A first detection operation for obtaining a detection signal by driving the plurality of first detection circuits in each unit period, and a first detection operation for obtaining a detection signal by driving the plurality of second detection circuits in each unit period. A detection device comprising: a drive circuit that selectively executes two detection operations according to an environmental temperature. It has a temperature detector that detects the ambient temperature,
The detection device according to claim 1, wherein the drive circuit selectively executes the first detection operation and the second detection operation according to the environmental temperature detected by the temperature detection unit. A plurality of detection circuits each generating a detection signal corresponding to the illuminance of the irradiation light, wherein the plurality of first detection circuits and the plurality of second detection circuits are different in temperature ranges in which the predetermined illuminance can be sensed with a predetermined sensitivity. A plurality of detection circuits including a detection circuit;
A drive circuit for obtaining the detection signals from the plurality of detection circuits;
Processing means for generating first detection data corresponding to the detection signal of each first detection circuit and second detection data corresponding to the detection signal of each second detection circuit;
And a selection unit that selects the first detection data or the second detection data according to an environmental temperature. It has a temperature detector that detects the ambient temperature,
The detection device according to claim 3, wherein the selection unit selects the first detection data or the second detection data according to the environmental temperature detected by the temperature detection unit. The detection apparatus according to claim 1, further comprising a temperature determination unit that determines whether the environmental temperature is high or low from the detection signal generated by the first detection circuit and the detection signal generated by the second detection circuit. A plurality of detection circuits each generating a detection signal corresponding to the illuminance of the irradiation light, wherein the plurality of first detection circuits and the plurality of second detection circuits are different in temperature ranges in which the predetermined illuminance can be sensed with a predetermined sensitivity. A plurality of detection circuits including a detection circuit;
A drive circuit for obtaining the detection signals from the plurality of detection circuits;
Processing means for generating first detection data corresponding to the detection signals of the first detection circuits and second detection data corresponding to the detection signals of the second detection circuits;
A detection device comprising: averaging means for calculating an average of the first detection data and the second detection data.

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