JP5526898B2 - Position detecting device and display device with position detecting function - Google Patents

Description

  The present invention relates to a position detection technique using a magnetic sensor.

  Conventionally, as a magnetic detection type position detection device used for a display device with an input panel, for example, there is a magnetic detection type input panel in which a plurality of Hall elements are provided on a substrate (see Patent Document 1). The Hall element is a magnetic sensor that uses a magnetic effect on a current called a Hall effect, and generates a Hall voltage by applying a magnetic field.

  In a magnetic detection type input panel using a Hall element, an electromagnetic pen that generates a magnetic field is detected by detecting a Hall voltage that is output by the Hall element according to the strength of the magnetic field from the electromagnetic pen, etc. An input position by a pen or the like can be detected.

JP 2009-86183 A

  However, the magnetic detection type input panel described in Patent Document 1 has the following problems because the position of the Hall element that detects the highest Hall voltage among the plurality of Hall elements is detected as the input position.

  That is, in order to detect the input position with high resolution using a magnetic sensor such as a Hall element, it is necessary to arrange a large number of magnetic sensors on the substrate at high density. However, there is a limit to the miniaturization of the magnetic sensor, and the number of magnetic sensors that can be arranged on the substrate is limited. As a result, there is a problem that there is a limit to position detection at high resolution.

  The present invention has been made in view of such conventional problems, and an object thereof is to perform high-resolution position detection without increasing the number of magnetic sensors to be used.

In order to solve the above-described problem, an aspect of the position detection device of the present invention includes a plurality of magnetic sensors that are arranged apart from each other and that individually detect magnetism at an arbitrary input position, and a pair of adjacent sensors. of the plurality of regions defined respectively by the magnetic sensor, determining determines area sum is the maximum of the detected value of the pair of magnetic sensors for partitioning the person region, as a specific region including the said input position means a specific position of the magnetic sensor which is the detection value is the largest among the set of magnetic sensors partitioning the specific region determined by the previous SL-size constant means, said partitioning the specific region e Bei said detected value of a set of magnetic sensors, and calculating means for calculating said input position based on the said calculating means, the magnetic sensor the detected value of the magnetic sensor from the input position Based on the inversely proportional to the cube of the distance to, and calculates the input position, and wherein the.

In order to solve the above-described problem, an aspect of the display device with a position detection function of the present invention is arranged with a display element that displays two-dimensional information and spaced apart from each other, and an arbitrary input position via the display element. more of the regions, the sum of the detected value of the pair of magnetic sensors for partitioning an equivalent region demarcated respectively and a plurality of magnetic sensors, by the adjacent pair of the magnetic sensor for detecting magnetic individually in region but a maximum, the detected value of said pair of magnetic sensor determination means as a specific area, to define the specific region determined by the previous SL-size constant means includes the input position maximum and specific position of the magnetic sensor is, with the detection value of the set of magnetic sensors partitioning the specific area, and calculating means for calculating said input position on the basis of, on the calculating means A control means depending on the calculated input position to control the display operation of the two-dimensional information on the display device, Bei example, said calculation means, the magnetic from the detected value is the input position of the magnetic sensor The input position is calculated based on being inversely proportional to the cube of the distance to the sensor .

  According to the present invention, high-resolution position detection can be performed without increasing the number of magnetic sensors used.

It is sectional drawing of the display apparatus with an input panel common to each embodiment of this invention. It is explanatory drawing of a Hall element. It is a block diagram which shows the circuit structure of an input panel, and the electrical structure of the principal part in a display apparatus with an input panel. The supply timing of the drive voltage for the Hall element, and the detection timing of the Hall output voltage from the Hall element, is a timing chart showing the. It is a flowchart which shows the processing content of the control part in 1st Embodiment. It is a flowchart which shows the touch area | region determination process by a control part. It is the top view and front view of the display apparatus with an input panel which are common in each embodiment. It is explanatory drawing which shows the detected value according to touch area | region used for the coordinate calculation of an input position in 1st Embodiment. It is the figure which showed the specific example of the detection position in 1st Embodiment. (A) is a diagram for convenience showing the thickness of a trajectory line that can be expressed in the first embodiment, and (b) is a diagram for convenience showing the thickness of a trajectory line that can be expressed in the prior art. . It is explanatory drawing which shows the calculation method of the detection position in 2nd Embodiment. It is a flowchart which shows the processing content of the control part in 2nd Embodiment. It is the figure which showed the specific example of the detection position in 2nd Embodiment. It is a figure corresponding to Drawing 10 (a) showing the thickness of the locus line which can be expressed in a 2nd embodiment for convenience.

Hereinafter, an embodiment of the present invention will be described.
(Embodiment 1)
FIG. 1 is a diagram showing a first embodiment of the present invention, and is a cross-sectional view of a display device 1 with an input panel constituting the display device with a position detection function of the present invention.

Input panel-equipped display device 1, LCM for displaying characters and images, and the like: and (Liquid Crystal panel Module liquid crystal panel module) 11 includes a surface light source 31 arranged in this order on the back surface of LCM11, an input panel 41, the ing.

The LCM 11 is a transmissive type, and includes two transparent glass substrates 13 and 14 on the front surface side and the back surface surface joined via a seal material 12, and liquid crystal sealed between both glass substrates 13 and 14. a liquid crystal layer 15 made of, and a polarizing plate 16, 17 which are attached respectively to the outer surfaces of both glass substrates 13 and 14, the.

  A transparent pixel electrode 18 is patterned on the inner side surface of the glass substrate 14 on the back side, and TFTs (Thin Film Transistors) 19 are formed on portions of the pixel electrode 18 corresponding to the pixels. A color filter 20 having a predetermined color arrangement and a transparent common electrode 21 are sequentially formed in a pattern on the inner surface of the glass substrate 13 on the front side.

The two glass substrates 13 and 14, not shown are provided a pair of alignment films covering the pixel electrode 18 and the common electrode 2 1 respectively, the liquid crystal molecules of the liquid crystal layer 15 is defined by a pair of alignment films It is oriented in the orientation state.

  The surface light source 31 includes a light emitting element 32 such as an LED (Light Emitting Diode) and a light guide plate 33 made of a plate-shaped transparent member that reflects light emitted from the light emitting element 32 toward the LCM 11 inside. ing.

The input panel 41 is for detecting an arbitrary input position with respect to the display screen of the LCM 11 designated by the magnet pen 101 having the pen tip 101a made of a permanent magnet. A plurality of Hall elements are provided on the insulating substrate 42. 43 is provided. Incidentally, the magnet pen 101, as long as it causes a magnetic field to the tip, but may be an electromagnetic pen having a coil for generating a DC magnetic field or ac magnetic field, for example.

  For example, as shown in FIG. 2, the Hall element 43 includes a first and second input terminals 45 a and 45 b, a first and a second input terminal 45 in an element body 44 in which a semiconductor thin film such as InSb (Indium Antimonide) is inserted. Output terminals 46a and 46b. The first and second input terminals 45 a and 45 b and the first and second output terminals 46 a and 46 b are electrically connected to the semiconductor thin film at positions that are diagonal to each other in the element body 44.

  When the Hall element 43 applies a voltage (V) between the first and second input terminals 45a and 45b and applies a magnetic field in a direction penetrating from the front surface to the back surface of the semiconductor thin film, the Hall element 43 causes the first and second input due to the Hall effect. This is a magnetic sensor having a characteristic that a potential difference (VHM) corresponding to the magnetic flux density (B) is generated between the output terminals 46a and 46b. A potential difference (VHM) generated between the second output terminals 46a and 46b by the Hall effect is called a Hall output voltage.

  FIG. 3 is a block diagram illustrating an outline of a circuit configuration of the input panel 41 and an electrical configuration of a main part of the display device 1 with the input panel. As shown in FIG. 3, the Hall elements 43 are arranged in a matrix form having a plurality of rows and a plurality of columns on the insulating substrate 42. FIG. 3 is a diagram showing an example in which the number of Hall elements 43 is 16 and 16 Hall elements 43 are arranged in 4 rows × 4 columns for convenience.

  The insulating substrate 42 is provided with first and second voltage supply lines 47a and 47b in each row in which the Hall elements 43 are arranged in the horizontal direction, and the first and second voltage elements are arranged in each column in which the Hall elements 43 are arranged in the vertical direction. Signal output lines 48a and 48b are provided.

  In the plurality of Hall elements 43 arranged in the same row, the first input terminal 45a included in each Hall element is connected to the first voltage supply line 47a provided for each row, and the second input included in each Hall element 43 is provided. The terminal 45b is connected to a second voltage supply line 47b provided for each row. In each Hall element 43, the first and second input terminals 45a and 45b are connected to the voltage supply circuit 51 through the first and second voltage supply lines 47a and 47b for each row.

  In addition, the plurality of Hall elements 43 arranged in the same column are each connected to the first output terminal 46a included in each of the first signal output lines 48a provided for each column. The output terminal 46b is connected to a second signal output line 48b provided for each column. In each Hall element 43, the first and second output terminals 46a and 46b are connected to the voltage detection circuit 52 via the first and second signal output lines 48a and 48b for each column.

  Although not shown, the voltage supply circuit 51 is a constant voltage circuit that generates a drive voltage to be applied to each Hall element 43, and the generated drive voltage is sent to each Hall via the first and second voltage supply lines 47a and 47b. A switching circuit that sequentially supplies the elements 43 at different timings for each row.

  Although not shown, the voltage detection circuit 52 is connected to each Hall element 43 via the first and second signal output lines 48a and 48b at different timings for each column synchronized with the supply of the drive voltage to each Hall element 43. A voltage sensor that detects the Hall output voltage and an A / D converter that converts the detected voltage value into a digital signal and supplies the digital signal to the digital signal are configured.

  FIG. 4 is a timing chart showing the drive voltage supply timing from the voltage supply circuit 51 to the Hall elements 43 in each row and the detection timing at which the voltage detection circuit 52 detects the Hall output voltage from the Hall elements 43 in each column. .

  The voltage supply circuit 51 supplies the Hall element 43 of each row to the drive period t1 to t4 of each row obtained by equally dividing the position detection period T by the number of rows in which the Hall elements 43 are arranged. In contrast, drive voltages (Vx1 to Vx4) are sequentially supplied. The voltage detection circuit 52 sequentially detects the Hall output voltages (Vy1 to Vy4) of the Hall elements 43 in each column for each driving period t1 to t4. For example, in the driving period t1 of each Hall element 43 in the first row from the top in FIG. 3, the holes of the Hall elements 43 in the order of the first, second, third, and fourth columns from the left in FIG. Output voltages (Vy1 to Vy4) are detected.

  That is, in the position detection period T, a plurality of Hall elements 43 are scanned from top to bottom and from left to right in FIG. 3, and the Hall output voltage of each Hall element 43 is sequentially detected by the voltage detection circuit 52. The detection result is supplied to the control unit 53.

  As a result, while driving the plurality of Hall elements 43 arranged on the input panel 41, the magnetism at an arbitrary input position instructed by the magnet pen 101 is transferred to the plurality of Hall elements via the LCM 11 and the surface light source 31. 43 can be detected individually.

  Although not shown, the control unit 53 mainly includes a CPU (Central Processing Unit), peripheral circuits such as an input / output interface, a ROM (Read Only Memory) in which a predetermined program is stored, and a working RAM (Random Access Memory). ). The control unit 53 is connected to a display driving circuit 54 that drives the LCM 11.

  The control unit 53 functions as a determination unit, a calculation unit, and a control unit in the present embodiment by executing processing to be described later according to a program stored in the ROM, and the voltage supply circuit 51, the voltage detection circuit 52, and the display drive circuit. 54 to control the operation. Specifically, the control unit 53 controls the drive voltage supply operation to each hall element 43 in the voltage supply circuit 51 and the hall output voltage detection operation of each hall element 43 in the voltage detection circuit 52. Further, by supplying various display data to the display drive circuit 54 and causing the display drive circuit 54 to generate a drive signal corresponding to the display data, the LCM 11 displays two-dimensional information such as characters and images.

  Next, in the present embodiment, the contents of processing executed by the control unit 53 upon detection of an input position (hereinafter referred to as a touch position) that is instructed by the magnet pen 101 will be described.

  Here, the following is assumed. FIG. 7A is a plan view schematically showing the display device 1 with an input panel, and FIG. 7B is a front view schematically showing the display device 1 with an input panel. As shown in FIG. 7, the input panel 41 has i hall elements 43 (hereinafter referred to as sensors) arranged in each column and j arranged in each row. In addition, the distance between the sensors in each row (the distance between the centers of adjacent sensors) is the same, and the distance between the sensors in each column (the distance between the centers of the adjacent sensors) is also the same.

  Moreover, the control part 53 distinguishes each sensor by the column number (0-i) and row number (0-j) of the matrix in which each is located in the case of a process. The input position acquired by the control unit 53 is in the XY coordinates with the origin of the center of the sensor P (0, 0) located in the upper left in FIG. 7A, where the row direction is the x axis and the column direction is the y axis. The position at. That is, the control unit 53 acquires the coordinates (x, y) in the fourth quadrant of the XY coordinates as the position information indicating the arbitrary input position B shown in FIG.

  The distance indicated by Px in FIG. 7A is the distance between the sensors in the XY coordinates in the x-axis direction (row direction) (hereinafter referred to as the pitch in the x-axis direction), and the distance indicated by Py is , A distance in the y-axis direction (column direction) between the sensors in the XY coordinates (hereinafter referred to as a pitch in the y-axis direction).

  Hereinafter, specific processing contents of the control unit 53 will be described with reference to the flowcharts shown in FIGS. 5 and 6. As shown in FIG. 5, when detecting the input position, the control unit 53 first operates all of the sensors P (0, 0) to P (i, j) by operating the voltage supply circuit 51 and the voltage detection circuit 52. ) Data A (0, 0) to A (i, j) of the Hall output voltage (hereinafter referred to as detection values) is acquired (step SA1).

  Next, if the absolute value of the difference between the maximum value and the minimum value of the detection values of all the sensors is not greater than or equal to the threshold value (step SA2: NO), the control unit 53 returns to the process of step SA1 and returns to all the sensors. The detection value data A (0, 0) to A (i, j) are newly acquired. The threshold value is a value determined in advance in consideration of variations in characteristics of the plurality of Hall elements 43, noise included in the detection value, and the like, and an instruction to the input panel 41 (display screen of the LCM 11) by the magnet pen 101. It is a value that can be determined to exist.

  On the other hand, if the absolute value of the difference between the maximum value and the minimum value of the detection values of all the sensors is equal to or greater than the threshold value (step SA2: YES), the control unit 53 detects the sensor P (m , N) (step SA3), the touch area determination process shown in FIG. 6 is performed (step SA4).

  The touch area determination process is a process of determining a specific area including the touch position instructed by the magnet pen 101, and a plurality of unit areas each partitioned by four sensors (a set of sensors) are candidates. This is processing for determining any unit area as a specific area. In the following description, the specific area including the touch position is referred to as a touch area.

  In the touch area determination process, the control unit 53 determines the touch area based on the detection values of the four sensors positioned vertically and horizontally with respect to the specific sensor P (m, n) from which the maximum detection value is obtained. . The area determined as the touch area by the control unit 53 is a lower right area located at the lower right of the specific sensor, an upper right area located at the upper right of the specific sensor, and a lower left area located at the lower left of the specific sensor. , One of the upper left regions located at the upper left of the specific sensor.

  That is, in the touch area determination process, the control unit 53 first determines that the detection value A (m−1, n) of the sensor P (m−1, n) positioned to the left of the specific sensor P (m, n) is It is confirmed whether or not the detected value A (m + 1, n) of the sensor P (m + 1, n) located to the right of the specific sensor P (m, n) is smaller (step SA101).

Then, the control unit 53 detects that the detection value A (m−1, n) of the sensor P (m−1, n) located on the left is the detection value A (m + 1) of the sensor P (m + 1, n) located on the right. , N) (step SA101: YES), the detected value A (m, n-1) of the sensor P (m, n-1) positioned above the specific sensor P (m, n). but it confirms whether the detected value or a (m, n + 1) is smaller than a particular sensor P (m, n) sensor P (m, n + 1) located below the (step SA 102).

  If the detection value A (m, n−1) of the sensor located above is smaller (step SA102: YES), the control unit 53 determines that the touch area is the lower right area (step SA103). ). FIG. 7A is a diagram illustrating an example of the touch position B by the magnet pen 101 when the touch area is the lower right area.

  On the contrary, if the detection value A (m, n-1) of the upper sensor is equal to or higher than the detection value A (m, n + 1) of the lower sensor (step SA102: NO), the control unit 53 The touch area is determined to be the upper right area (step SA103).

  Further, the control unit 53 also when the detection value A (m-1, n) of the sensor located on the left is equal to or larger than the detection value A (m + 1, n) of the sensor located on the right (step SA101: NO Further, it is confirmed whether or not the detection value A (m, n-1) of the upper sensor is smaller than the detection value A (m, n + 1) of the lower sensor (step SA105).

  If the detection value A (m, n-1) of the sensor located above is smaller (step SA105: YES), the control unit 53 determines that the touch area is the lower left area (step SA106). . Conversely, if the detection value A (m, n-1) of the upper sensor is equal to or higher than the detection value A (m, n + 1) of the lower sensor (step SA105: NO), the control unit 53 The touch area is determined to be the upper left area (step SA107).

  That is, in the touch area determination process, the control unit 53 specifies a unit area having the maximum sum of detection values of the four magnetic sensors that divide the unit area as a touch area among the plurality of unit areas. In the above touch area determination process, if the touch position is directly above any sensor, the touch area is determined as the upper left area.

  After the end of the touch area determination process, the control unit 53 returns to the process of FIG. 5 and continues the following process. That is, when the touch area is the lower right area (step SA5: lower right area), the control unit 53 detects the detection values A (m, n) of the four sensors that divide the lower right area shown in FIG. ), A (m + 1, n), A (m, n + 1), A (m + 1, n + 1), the column number m and row number n of the specific sensor P (m, n) described above, and the x-axis direction, And the following equation (1-1) using the pitches Px and Py in the y-axis direction:

によって、タッチ位置を示す座標値（Ｘ，Ｙ）を算出する（ステップＳＡ６）。

To calculate the coordinate value (X, Y) indicating the touch position (step SA6).

  In addition, when the touch area is the upper right area (step SA5: upper right area), the control unit 53 detects the detection values A (m, n) of the four sensors that divide the upper right area shown in FIG. A (m + 1, n), A (m, n-1), A (m + 1, n-1), column number m and row number n of a specific sensor P (m, n), x-axis direction, and The following formula (1-2) using pitches Px and Py in the y-axis direction

によって、タッチ位置を示す座標値（Ｘ，Ｙ）を算出する（ステップＳＡ７）。

To calculate the coordinate value (X, Y) indicating the touch position (step SA7).

  When the touch area is the lower left area (step SA5: lower left area), the control unit 53 detects the detection values A (m, n) of the four sensors that divide the lower left area shown in FIG. A (m−1, n), A (m, n + 1), A (m−1, n + 1), the column number m and row number n of the specific sensor P (m, n), the x-axis direction, and The following formula (1-3) using pitches Px and Py in the y-axis direction

によって、タッチ位置を示す座標値（Ｘ，Ｙ）を算出する（ステップＳＡ８）。

To calculate the coordinate value (X, Y) indicating the touch position (step SA8).

  In addition, when the touch area is the upper left area (step SA5: upper left area), the control unit 53 detects the detection values A (m, n) of the four sensors that divide the upper left area shown in FIG. A (m-1, n), A (m, n-1), A (m-1, n-1), column number m and row number n of a specific sensor P (m, n), x The following formula (1-4) using the pitches Px and Py in the axial direction and the y-axis direction

によって、タッチ位置を示す座標値（Ｘ，Ｙ）を算出する（ステップＳＡ９）。

To calculate the coordinate value (X, Y) indicating the touch position (step SA9).

  The calculation by the above formulas (1-1) to (1-4) is performed by using the detection values (the hall output voltages of the hall elements 43) of the four sensors that define the touch area as the x-axis of the touch position in the touch area. This is a calculation used as a value representing the direction and the degree of deviation in the y-axis direction. More specifically, on the premise that the detection value of each sensor changes in proportion to the distance between each sensor and the touch position, the weighting using the detection values of the four sensors as weights (weight values) as they are. The average is calculated as a deviation amount of the touch position in the touch area in the x-axis direction or the y-axis direction.

  Thereafter, the control unit 53 performs a process according to the touch position using the coordinates (X, Y) calculated in any of the processes of steps SA6 to SA9 as the detection position (step SA10). The processing corresponding to the touch position is, for example, display of characters and images on the LCM 11 that is determined in advance corresponding to the touch position. Thereafter, the control unit 53 repeats the processing from Step SA1 to Step SA10.

  FIG. 9 shows the pitch Px in the x-axis direction, which is the horizontal spacing between the plurality of hall elements 43, and the pitch in the y-axis direction, which is the vertical spacing between the plurality of hall elements 43, as shown in FIG. It is the figure which showed the specific example of the touch position (X, Y) detected (calculated) by the control part 53 when both Py are 5 mm. 9A is an x-X coordinate correspondence diagram showing the relationship between the actual x coordinate and the detected x coordinate value (X), and FIG. 9B is the actual y coordinate detected. It is a y-Y coordinate corresponding | compatible figure which shows the relationship with y coordinate value (Y).

  Note that FIG. 9 shows that the actual touch position is the center of the sensor whose column number and row number indicated by P (0,0) in FIG. 7A are both “0”, and P (m, n The figure which showed the detection result according to the several touch position when it is a several position which equally divides the straight line which ties the center of the sensor whose row number and row number are both "1" into several into a plurality. It is.

  As described above, in this embodiment, when there is an instruction from the magnetic pen 101, the control unit 53 determines the touch area including the touch position, and then detects four sensors that divide the determined touch area. Get the touch position based on the value.

  For this reason, in this embodiment, even if the touch position is a position where the sensor (Hall element 43) is not arranged, that is, an arbitrary position between arbitrary adjacent sensors, as shown in FIG. The position can be detected with a certain accuracy. Therefore, in the present embodiment, position detection with high resolution can be performed without increasing the number of magnetic sensors to be used.

  Therefore, for example, when the process of step SA10 in the control unit 53 is a process of displaying on the LCM 11 a line connecting the detected touch positions, that is, a locus line representing the locus of the magnet pen 101, it is narrower than before. Trajectory lines can be displayed.

  FIG. 10A is a diagram conveniently showing the relationship between the arrangement of the Hall elements 43 and the thickness of the locus line 200 that can be displayed on the LCM 11. The locus line 200 is a horizontal line parallel to the x-axis. It is the figure which illustrated the case where it is, the case where it is a vertical line parallel to a y-axis, and the case where it is a 45 degree diagonal line. FIG. 10B is a diagram corresponding to FIG. 10A showing the thickness of the locus line 200 when the touch position of the magnet pen 101 is detected by the conventional technique.

  Here, in the present embodiment, the column number (m) and the row are used as values indicating the position of the specific sensor from which the maximum detection value A (m, n) is obtained among the sensors that divide the touch area. The case where the touch position (X, Y) is calculated using the number (n) has been described. However, when calculating the touch position (X, Y), the coordinate position (x, y) of the specific sensor in the XY coordinates may be used as a value indicating the position of the specific sensor.

  When the coordinate position (x, y) of a specific sensor is used, for example, the expression (1-1) is expressed by the following expression (1-5)

に変更すればよい。

Change to

(Embodiment 2)
Next, a second embodiment of the present invention will be described. The present embodiment relates to a display device with an input panel having the same configuration as that of the first embodiment shown in FIGS.

  In the display device with an input panel of the present embodiment, the ROM constituting the control unit 53 causes the control unit 53 to calculate the touch position using a calculation formula different from that of the first embodiment when detecting the touch position. A program for storing is stored.

  First, calculation formulas used in this embodiment will be described. In the calculation formula used in the present embodiment, the detection values of the four sensors that partition the touch area (the hall output voltage of the hall element 43) are also biased in the x-axis direction and the y-axis direction of the touch position in the touch area. Some are used as a value indicating the degree.

  However, the calculation formula used in the present embodiment reflects the actual change characteristic of the detection value of each sensor corresponding to the change in the distance from the touch position, and the change in the detection value of each sensor from the touch position. This is a calculation formula derived as follows on the assumption that it is inversely proportional to the cube of the distance.

That is, when the touch position is directly above any of the sensors, the detection value P ₀ of the sensor is as follows, assuming that the distance from the surface of the LCM 11 to the sensor is d as shown in FIG.

P ₀ = α × d ⁻³ (2-1)

Can be represented by α is a constant, and this constant α is

α = P ₀ × d ³ (2-2)

It can be expressed as

On the other hand, when the touch area including an arbitrary touch position is, for example, the lower right area of a specific sensor (the sensor having the maximum detection value), as shown in FIG. 11, the actual touch position B (x, If the distance from y) to the line segment that is the upper side of the touch area is Δy, and the distance from the actual touch position B (x, y) to the line segment that is the left side of the touch area is Δx, a specific sensor P ( m, n) and detected values A (m, n), A (m + 1, n), A of sensors P (m + 1, n) and P (m, n + 1) respectively located on the right and bottom of the specific sensor (M, n + 1) is

A (m, n) = α {(Δx) ² + (Δy) ² + d ² } ^{− (3/2)}
... (2-3)

A (m + 1, n) = α {(Px−Δx) ² + (Δy) ² + d ² } ^{− (3/2)}
Where Px: sensor pitch in the x-axis direction
... (2-4)

A (m, n + 1) = α {(Δx) ² + (Py−Δy) ² + d ² } ^{− (3/2)}
Where Py: sensor pitch in the y-axis direction
... (2-5)
Can be represented by

  Further, the formulas (2-3) to (2-5) can be expressed by the following formulas (2-3 ′) to (2-5 ′).

  That is, the detection values A (m, n), A (m + 1, n), and A (m, n + 1) of each sensor are Q (m, n), Q (m + 1, n), and Q (m, n + 1), respectively. Can be converted to

here,

Q (m + 1, n) −Q (m, n) = − 2Δx × Px + Px ²
... (2-6)
Therefore, the distance Δx is

Δx = (Px / 2) − {(Q (m + 1, n) −Q (m, n)) / 2Px}
... (2-7)
And the distance Δy is

Δy = (Py / 2) − {(Q (m, n + 1) −Q (m, n)) / 2Px}
... (2-8)
It can be expressed as

  Therefore, the actual touch position (X, Y) includes the converted detection values Q (m, n), Q (m + 1, n), Q (m, n + 1), and the specific sensor P (m, n). The following equation (3-1) using column number m and row number n and pitches Px and Py in the x-axis direction and y-axis direction

により表すことができる。

Can be represented by

  On the other hand, by the same procedure as described above, the sensor P (m, n−) positioned above the specific sensor P (m, n) when the touch area is the upper right area of the specific sensor P (m, n). The detected value A (m, n-1) of 1) is expressed by the following formula (2-9)

に変換することができる。

Can be converted to

  Therefore, the actual touch position (X, Y) when the touch area is the upper right area of the specific sensor P (m, n) is the detected values Q (m, n) and Q (m + 1, n) after conversion. , Q (m, n-1), column number m and row number n of a specific sensor P (m, n), and pitches Px and Py in the x-axis direction and y-axis direction (3-2)

により表すことができる。

Can be represented by

  Further, when the touch area is the lower left area of the specific sensor P (m, n), the detection value A () of the sensor P (m−1, n) located to the left of the specific sensor P (m, n). m-1, n) is represented by the following formula (2-10)

  Therefore, the actual touch position (X, Y) when the touch area is the lower left area of the specific sensor P (m, n) is the detected values Q (m, n), Q (m−1, n), Q (m, n + 1), column number m and row number n of a specific sensor P (m, n), and pitches Px and Py in the x-axis direction and y-axis direction (3-3)

により表すことができる。

Can be represented by

  Furthermore, the actual touch position (X, Y) when the touch area is the upper left area of the specific sensor P (m, n) is the detected values Q (m, n), Q (m−1, n), Q (m, n-1), column number m and row number n of a specific sensor P (m, n), and pitches Px and Py in the x-axis direction and y-axis direction Formula (3-4)

により表すことができる。

Can be represented by

  In the present embodiment, the touch position (X, Y) is calculated using the calculation formulas (3-1) to (3-4) derived as described above. In the present embodiment, the data of the constant α expressed by the equation (2-2) is calculated in advance based on the design value distance d and the actual detection value of an arbitrary sensor, and the control unit 53 Is stored in the ROM constituting the.

  Next, in the present embodiment, the contents of processing executed when the control unit 53 detects the touch position will be described with reference to the flowchart of FIG.

  When detecting the touch position, the control unit 53 first operates the voltage supply circuit 51 and the voltage detection circuit 52 to detect the detection values (hall output voltages) of all the sensors P (0,0) to P (i, j). ) Data A (0,0) to A (i, j) are acquired (step SC1).

  If the absolute value of the difference between the maximum and minimum detection values of all sensors is not greater than or equal to the threshold value (step SC2: NO), the control unit 53 returns to the process of step SA1 to detect all sensors. Value data A (0, 0) to A (i, j) are newly acquired. The threshold value is a value determined in advance in consideration of variations in characteristics of the plurality of Hall elements 43, noise included in the detection value, and the like, and an instruction to the input panel 41 (display screen of the LCM 11) by the magnet pen 101. It is a value that can be determined to exist.

  On the other hand, if the absolute value of the difference between the maximum value and the minimum value of the detection values of all the sensors is equal to or greater than the threshold value (step SC2: YES), the control unit 53 detects the sensor P (m , N) (step SC3), the touch area determination process shown in FIG. 6 is performed (step SC4).

  The processing so far is the same as the processing of Step SA1 to Step SA4 already described in the first embodiment. Thereafter, the control unit 53 calculates coordinate values (X, Y) indicating the touch position by using different calculation formulas corresponding to the touch area determined by the touch area determination process.

  That is, when the touch area is the lower right area (step SC5: lower right area), the control unit 53 determines the specific sensor P (m, n) from which the maximum detection value is obtained and the right of the specific sensor. And the detection values of the three sensors P (m + 1, n) and P (m, n + 1) positioned below, that is, the detection values A (m, n) and A shown in FIG. (M + 1, n), A (m, n + 1) are converted into new detected values Q (m, n), Q (m + 1, Q) using the equations (2-3 ′) to (2-5 ′) described above. n) and Q (m, n + 1) (step SC6).

  Subsequently, the control unit 53 detects the detected values Q (m, n), Q (m + 1, n), Q (m, n + 1) of the three sensors after conversion, and the column number m of the specific sensor P (m, n). Then, the coordinate value (X, Y) indicating the touch position is calculated by the equation (3-1) using the row number n and the pitches Px and Py in the x-axis direction and the y-axis direction (step SC7).

  In addition, when the touch area is the upper right area (step SC5: upper right area), the control unit 53 includes the specific sensor P (m, n) from which the maximum detection value is obtained and the specific sensor P (m , N), the detected values of the three sensors P (m + 1, n) and P (m, n−1) respectively located on the right and above, that is, the detected value A shown in FIG. (M, n), A (m + 1, n), and A (m, n-1) are replaced with the previously described equations (2-3 '), (2-4'), and (2-9). And converted into new detection values Q (m, n), Q (m + 1, n), and Q (m, n-1) (step SC8).

  Subsequently, the control unit 53 includes a column of detection values Q (m, n), Q (m + 1, n), Q (m, n−1) of the three sensors after conversion and a specific sensor P (m, n). A coordinate value (X, Y) indicating the touch position is calculated by an equation (3-2) using the number m, the row number n, and the pitches Px, Py in the x-axis direction and the y-axis direction (step SC9). ).

  In addition, when the touch area is the lower left area (step SC5: lower left area), the control unit 53 determines the specific sensor P (m, n) from which the maximum detection value is obtained and the specific sensor P (m , N), the detected values of the three sensors P (m−1, n) and P (m, n + 1) respectively located on the left and the lower side, that is, the detected value A shown in FIG. (M, n), A (m-1, n), A (m, n + 1) are used with the previously described formulas (2-3 ′), (2-10), and (2-5 ′). And converted into new detection values Q (m, n), Q (m-1, n), and Q (m, n + 1) (step SC10).

  Subsequently, the control unit 53 includes a column of detection values Q (m, n), Q (m−1, n), Q (m, n + 1) of the three sensors after conversion and a specific sensor P (m, n). A coordinate value (X, Y) indicating the touch position is calculated by an equation (3-3) using the number m, the row number n, and the pitches Px, Py in the x-axis direction and the y-axis direction (step SC11). ).

  In addition, when the touch area is the upper left area (step SC5: upper left area), the control unit 53 determines the specific sensor P (m, n) from which the maximum detection value is obtained and the specific sensor P (m , N), the detected values of the three sensors P (m−1, n) and P (m, n−1) respectively located on the left and above, that is, the detection shown in FIG. The values A (m, n), A (m-1, n), A (m, n-1) are converted into the previously described formulas (2-3 ′), (2-10), and (2-9). ) To convert to new detection values Q (m, n), Q (m-1, n), Q (m, n-1) (step SC12).

  Subsequently, the control unit 53 detects the detected values Q (m, n), Q (m−1, n), Q (m, n−1) of the three sensors after conversion, and the specific sensor P (m, n). The coordinate value (X, Y) indicating the touch position is calculated by the equation (3-4) using the column number m and row number n of the above and the pitches Px and Py in the x-axis direction and the y-axis direction ( Step SC13).

  Thereafter, the control unit 53 performs a process according to the touch position using the coordinates (X, Y) calculated in any of the processes of steps SC6 to SC12 as the detection position (step SC14). The processing corresponding to the touch position is, for example, display of characters and images on the LCM 11 that is determined in advance corresponding to the touch position. Thereafter, control unit 53 repeats the processes of steps SC1 to SC14.

  FIG. 13 is a diagram corresponding to FIG. 9 and showing a specific example of the touch position (X, Y) detected (calculated) by the control unit 53 in the present embodiment.

  As described above, also in this embodiment, when there is an instruction from the magnet pen 101, the control unit 53 determines the touch area including the touch position, and then detects the detected values of the four sensors that divide the determined touch area. The coordinate value (X, Y) indicating the touch position is acquired based on the above.

  Therefore, as in the first embodiment, even if the touch position is a position where the sensor (Hall element 43) is not arranged, that is, an arbitrary position between arbitrary adjacent sensors, as shown in FIG. The touch position can be detected. Therefore, in the present embodiment, position detection with high resolution can be performed without increasing the number of magnetic sensors to be used.

  Moreover, in this embodiment, the coordinate values (X, Y) indicating the touch position are calculated using a calculation formula based on the actual change characteristics of the detected value corresponding to the distance from the touch position in each sensor. Thus, the touch position can be detected with high accuracy as shown in FIG.

  In other words, in the first embodiment, the coordinate value indicating the touch position using a calculation formula based on the assumption that the detection value of each sensor changes in proportion to the distance between each sensor and the touch position ( X, Y) is calculated. For this reason, as shown in FIG. 9, when the touch position is close to the top (center) of the sensor, the detection accuracy of the touch position is greatly reduced.

  On the other hand, in the present embodiment, the coordinate value (X, Y) indicating the touch position is calculated using a calculation formula based on the change characteristic of the detection value corresponding to the distance from the touch position in each sensor. Even when the touch position is close to the top (center) of the sensor, the detection accuracy of the touch position does not decrease. Therefore, position detection with higher resolution can be performed as compared with the first embodiment.

  Therefore, for example, when the process of step SC14 in the control unit 53 is a process of displaying on the LCM 11 a line connecting the detected touch positions, that is, a locus line representing the locus of the magnet pen 101, the first implementation is performed. A trajectory line narrower than the form can be displayed. FIG. 14 is a diagram corresponding to FIG. 10 showing the relationship between the arrangement of the Hall elements 43 and the thickness of the locus line 200 that can be displayed on the LCM 11 in the present embodiment for convenience.

  Here, the calculation formula described in the present embodiment is an example, and the touch position (X, Y) may be calculated using another calculation formula when the present invention is implemented. Even in this case, if a calculation formula based on the actual change characteristic of the detection value corresponding to the distance from the touch position in each sensor is used, the touch position is detected with high accuracy as in the present embodiment. be able to.

  In the first embodiment and the second embodiment, the configuration (FIG. 3) in which the Hall elements 43 are arranged in a matrix form having a plurality of rows and a plurality of columns on the insulating substrate 42 has been described. However, although the calculation formula used for calculating the touch position (X, Y) is complicated, the Hall elements 43 are arranged in a delta shape in which, for example, a plurality of Hall elements 43 in each row are shifted by a half pitch every other row. It doesn't matter.

1 Display device with input panel 11 LCM
31 Surface light source 41 Input panel 42 Insulating substrate 43 Hall element 44 Element body 45a, 45b Input terminal 46a, 46b Output terminal 47a First voltage supply line 47b Second voltage supply line 48a First signal output line 48b Second Signal output line 51 voltage supply circuit 52 voltage detection circuit 53 control unit 54 display drive circuit 101 magnet pen

Claims (14)

A plurality of magnetic sensors arranged separately from each other and individually detecting magnetism at an arbitrary input position;
Of the plurality of regions defined respectively by the adjacent pair of the magnetic sensor, the area sum is the maximum of the detected value of the pair of magnetic sensors for partitioning an equivalent region includes the input position Determining means for determining as a specific area;
The position of certain of the magnetic sensor the detected value is the largest among the set of magnetic sensors partitioning the specific region determined by the previous SL-size constant means, the set of partitioning the specific region and the detected value of the magnetic sensor, and calculating means for calculating said input position based on,
Bei to give a,
The calculation means calculates the input position based on the detection value of the magnetic sensor being inversely proportional to the cube of the distance from the input position to the magnetic sensor.
A position detecting device characterized by that. The calculation unit, the one of the detection values of the set of magnetic sensors defining the specific area, based on at least one detection value other than the maximum of the detected value and the detection value of the maximum, the input position The position detection device according to claim 1 , wherein: The calculation means represents the detected values of the set of magnetic sensors that divide the specific area, the degree of deviation of the input position in the XY coordinates in the specific area in the x-axis direction and the y-axis direction. by calculation using the value, the position detecting device according to claim 2, characterized in that for calculating said input position. The position detecting device according to claim 1, wherein the magnetic sensor is a Hall element. The Hall element is a four-terminal element in which a Hall element body having a semiconductor thin film is provided with a first input terminal, a second input terminal, a first output terminal, and a second output terminal.
The first input terminal and the second input terminal, and the first output terminal and the second output terminal are electrically connected to the semiconductor thin film at positions diagonal to each other in the Hall element. The position detection device according to claim 4, wherein the position detection device is connected. The first input terminal and the second input terminal are electrically connected to the semiconductor thin film so as to form a first diagonal line in the Hall element, and the first output terminal and the second input terminal The second output terminal is electrically connected to the semiconductor thin film so as to form a second diagonal line that intersects the first diagonal line in the Hall element. Position detection device. The position detection device according to claim 5, wherein the semiconductor thin film contains InSb. A display element for displaying two-dimensional information;
A plurality of magnetic sensors arranged separately from each other and individually detecting magnetism at an arbitrary input position via the display element;
Of the plurality of regions defined respectively by the adjacent pair of the magnetic sensor, the area sum is the maximum of the detected value of the pair of magnetic sensors for partitioning an equivalent region includes the input position Determining means for determining as a specific area;
The position of certain of the magnetic sensor the detected value is the largest among the set of magnetic sensors partitioning the specific region determined by the previous SL-size constant means, the set of partitioning the specific region Calculating means for calculating the input position based on the detection value of the magnetic sensor;
And control means for controlling the display operation of the two-dimensional information on the display device in response to the input position calculated by said calculation means,
Bei to give a,
The calculation means calculates the input position based on the detection value of the magnetic sensor being inversely proportional to the cube of the distance from the input position to the magnetic sensor.
A display device with a position detection function. The calculation means is configured to determine the input position based on a maximum detection value and at least one detection value other than the maximum detection value among the detection values of the set of magnetic sensors that define the specific region. The position detecting device according to claim 8, wherein: The calculation means represents the detected values of the set of magnetic sensors that divide the specific area, the degree of deviation of the input position in the XY coordinates in the specific area in the x-axis direction and the y-axis direction. The position detection device according to claim 9, wherein the input position is calculated by calculation used as a value. The position detection device according to claim 8, wherein the magnetic sensor is a Hall element. The Hall element is a four-terminal element in which a Hall element body having a semiconductor thin film is provided with a first input terminal, a second input terminal, a first output terminal, and a second output terminal.
The first input terminal and the second input terminal, and the first output terminal and the second output terminal are electrically connected to the semiconductor thin film at positions diagonal to each other in the Hall element. The position detection device according to claim 11, wherein the position detection device is connected. The first input terminal and the second input terminal are electrically connected to the semiconductor thin film so as to form a first diagonal line in the Hall element, and the first output terminal and the second input terminal 13. The second output terminal is electrically connected to the semiconductor thin film so as to form a second diagonal line that intersects the first diagonal line in the Hall element. Position detector. The position detection device according to claim 12, wherein the semiconductor thin film contains InSb.

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