JPH064825U - Cordless digitizer - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the thickness and cost of a cordless digitizer. [Structure] By using conductor patterns 3 and 4 which are formed on a first grid plate and are driving coils and conductor patterns 1 and 2 which are reception coils which are formed on a second grid plate and which are receiving coils 5, 6, Since the position of the position indicator 2 can be detected, the receiving coil group on the third grid plate, which is conventionally required, is not required, and the device can be made thin. Further, since each conductor pattern is formed in a comb shape, the material cost of the conductor pattern and the manufacturing cost are reduced, and the cost of the device can be reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a codeless digitizer which is composed of a tablet and a position indicator wirelessly connected to the tablet, and detects the position of the position indicator mounted on the tablet.

[0002]

[Prior art]

 FIG. 3 is a block diagram of this type of cordless digitizer. The tablet 1 for detecting the position of the position indicator 2 includes a first receiving coil arranged on the first grid plate in parallel with the X axis. Groups y1 to yn, drive coils x1 and x2 arranged on the second grid plate in parallel with the Y axis in a zigzag shape, and second coils arranged on the third grid plate in parallel with the Y axis. The receiving coil groups z1 to z3, the driving circuits 11 and 12, the phase shifter 13, the sine wave oscillator 14, the Y-axis scanner unit 15, the amplifier 16 and the control circuit 17.

Here, the sine wave current signal from the oscillator 14 is constantly applied to the drive coil x1 via the phase shifter 13 and the drive circuit 11, and also in the drive coil x2, the sine wave current signal is always 90% from the sine wave current signal. A cosine wave current signal whose phase is delayed is applied by the drive circuit 12. When the position indicator 2 is placed on the drive coil to which the current signals of the sine wave and the cosine wave are applied, current flows through the coil provided in the position indicator 2 to generate a magnetic field. The control circuit 17 detects the induced voltage generated in the first receiving coil groups y1 to yn by the magnetic field generated by the position indicator 2 by scanning the Y-axis scanner unit 15. Then, the position of the position indicator 2 in the Y-axis direction and the detailed position in the X-axis direction within a certain coil interval are calculated from the detected induced voltage value.

The overall position of the position indicator 2 in the X-axis direction is determined by detecting the direction of the induced voltage generated in the second receiving coil groups z1 to z3. That is, the second receiving coils z1 to z3 are arranged, for example, as shown in FIG. 4, and the region of the tablet 1 in the X-axis direction is divided into eight regions, and the positions are located in any of these regions. When the indicator 2 is mounted, the direction of the induced conductive pressure generated in the second receiving coils Z1 to Z3, that is, in which area from the ON (ON) and OFF (OFF) state of the second receiving coil is mounted. It is detected whether it is placed.

[0005]

[Problems to be solved by the device]

 The conventional cordless digitizer requires the second receiving coil group formed on the third grid plate when detecting the entire position of the position indicator. This second receiving coil group is a three-layer coil pattern in which each coil is formed by a coil pattern of a separate layer, which makes it difficult to thin the digitizer, and when applied to a large digitizer, the coil There is a problem that a large amount of conductors for forming the are required. In addition, it is desirable that three coils are formed in a straight line at the boundary portion of each area as shown in FIG. 4, especially at the boundary portion between areas, but in the case of a large digitizer, Y Since the distance in the axial direction becomes extremely long, a high degree of machining accuracy is required to form a straight line without any misalignment, resulting in a problem of increased cost. In addition, the conductor pattern of the driving coil and the receiving coil is formed in a loop shape, and the conductor pattern is double-folded in order to increase the strength of the transmitted and received radio waves. There was also the problem of rising.

[0006]

[Means for Solving the Problems]

 In order to solve such a problem, the present invention provides first and second drive coils formed in a comb shape on the first grid plate and arranged in parallel and at equal intervals in the X direction. First and second receiving coils which are formed in a comb shape on the grid plate and which are orthogonal to the first and second drive coils and are arranged parallel to each other and at equal intervals; The drive coil is divided into a plurality of blocks, and switch means for selectively supplying a sine wave current and a cosine wave current to the first and second drive coils of the divided blocks, and the first and second drive coils. Scanning means for scanning the induced voltage generated in the first and second receiving coils via the position indicator by energizing the switch, and from the selection address of the block by the switch means when the maximum value of the induced voltage is detected. Determines the overall position of the position indicator in the Y direction, and Y-direction position of the determined from the phase difference between the induced voltage and the sine or cosine wave current, X-direction position of the position indicator is intended been Unishi by determining the selection address of the scanning means.

[0007]

[Action]

 Therefore, when detecting the position of the position indicator, the receiving coil group formed on the third grid plate, which has been conventionally required, is not required, and the device can be made thinner and the drive coil can be used. The cost of the device can be reduced by forming the receiver coil and the receiving coil in a comb shape.

[0008]

【Example】

 Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a cordless digitizer according to the present invention. In the figure, the tablet 1 for detecting the pointing position of the position pointing device 2 is composed of comb-shaped conductor patterns 3 and 4 which are driving coils arranged parallel to the X axis and arranged at equal intervals, and parallel to the Y axis. A sine wave (sin ωt, −sin ωt) and a cosine for each block unit of the comb-shaped conductor patterns 5 and 6 which are receiving coils arranged at equal intervals and the comb-shaped conductor patterns 3 and 4 which are Y-axis patterns. X-axis scanner for scanning the induced voltage generated in the comb-shaped conductor patterns 5 and 6 which are X-axis patterns and are composed of a switch group 7 for passing a current signal of a wave (cosωt, -cosωt) and switches s1 to sn The control circuit 17 includes a unit 8 and a CPU. The comb-shaped conductor patterns 3 and 4 are formed in a first grid plate shape (not shown), and the comb-shaped conductor patterns 5 and 6 are formed in a second grid plate shape (not shown).

Here, the switch group 7 is controlled by the control circuit 17, and a sinusoidal current signal and a cosine delayed by 90 ° in phase with respect to the comb-shaped conductor patterns 3 and 4 in the Y-axis pattern or the block are respectively controlled. When the wave current signals are simultaneously supplied, a magnetic field is generated in the region where the selected comb-shaped conductor patterns 3 and 4 are arranged. When the position indicator 2 is placed in this region, the generated magnetic field causes the coil provided in the position indicator 2 to resonate, and the position indicator 2 generates a magnetic field. As a result, the magnetic field generated by the position indicator 2 induces a voltage on the comb-shaped conductor patterns 5 and 6 intersecting with the magnetic field. The control circuit 17 detects the induced voltage generated in the comb-shaped conductor patterns 5 and 6 by sequentially switching each switch in the X-axis scanner unit 8 to determine the position of the position indicator 2 in the X and Y directions. To do.

Next, FIG. 2 is a configuration diagram of the position indicator 2 which is placed on the tablet 1 and whose position is detected, and includes a coil L, capacitors C1 and C2, and a switch SW. When the position indicator 2 is applied to, for example, a stylus pen, the capacity of the variable capacitor C2 is changed by the writing pressure, and this information is transmitted to the tablet 1 so that the drawing or the like according to the writing pressure can be performed. . When the diameter of the coil L is D, the coil diameter D is set to be smaller than the distance W between the comb-shaped conductor patterns 3 to 6.

Next, the detailed operation of the cordless digitizer will be described. As shown in FIG. 1, the switch group 7 is composed of four switches adjacent to each other, and is composed of switch blocks 7 _{0 to} 7 ₆ arranged at intervals of two switches. 7 _0-7 per ₆ are sequentially selected and turned earthenware pots by being closed, so that the conductor pattern corresponding to the block φ0 of Y-axis pattern initially is driven, closing switch block 7 ₀ is selected and Is made. As a result, the sine wave current and the cosine wave current respectively flow in the comb-shaped conductor patterns 3 and 4 in the block φ0. At the same time, the control circuit 17 sequentially switches and connects the switches s1 to sn in the X-axis scanner unit 8 at predetermined time intervals, and outputs the output at each time interval in the selected address of the Y-axis side block and the switch s1 on the X-axis side. Stored together with the selected address of ~ sn. After that, the control circuit 17 selects the next switch block 7 ₁ and performs the same processing.

In FIG. 1, for example, when the position indicator 2 is mounted on the Y-axis pattern block φ2, when the switch block 7 ₁ in the switch group 7 is selected and closed, the Y-axis pattern block A sine wave current and a cosine wave current respectively flow in the comb-shaped conductor patterns 3 and 4 in φ2 to generate a magnetic field, and the generated magnetic field causes the coil L of the position indicator 2 to resonate and the position indicator 2 to move further. A magnetic field is generated. On the other hand, the comb-shaped conductor patterns 5 and 6 in which an induced voltage is generated by the magnetic field generated by the position indicator 2 are connected to the respective switches in the X-axis scanner unit 8. This switch has three contacts, two of which are connected to the input side and the ground (GND) side of the control circuit 17, respectively, and the other contacts are open (OPEN) terminals. . When the comb-shaped conductor patterns 5 and 6 are sequentially selected, first switch s1 is switched to the input side of the control circuit, switch s3 is switched to the ground side, the other switch is connected to the open terminal, and then switch s2 is controlled. The input side of the circuit, the switch s4 is switched to the ground side for selection.

Now, the position of the position indicator 2 in the X direction is, for example, in the comb-shaped conductor pattern 6 connected to the switches s2 and s4. At this time, the contact of the switch s2 is the input side of the control circuit and the switch. If the contact of s4 is connected to the ground side and the contact of another switch is connected to the open terminal, the comb-shaped conductor pattern 6 in which a loop is formed by these switches s2 and s4 will generate a voltage due to the magnetic field generated by the position indicator 2. Is induced. Then, the X direction position of the position indicator 2 is determined from the switch selection address corresponding to the maximum value of the induced voltage. Further, the position of the position indicator 2 in the Y direction is roughly determined from the selected block address of the switch group 7 when the maximum value of the induced voltage is detected, and the detailed position in the block is comb-shaped. It is determined from the phase difference between the sine wave voltage signal or the cosine wave voltage signal applied to the conductor pattern 3 and the detected induced voltage signal.

[0014]

[Effect of device]

 As described above, according to the present invention, the first and second driving coils formed on the first grid plate and the first and second receiving coils formed on the second grid plate are used. Since the position of the position indicator can be detected, the receiver coil group on the third grid plate, which was required in the past, is not required, and the device can be made thinner, and the drive coil and receiver coil are comb-shaped. Since it is formed on the substrate, the material cost and the manufacturing cost of the conductor pattern of each coil are reduced, and the cost of the device can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a cordless digitizer according to the present invention.

FIG. 2 is a diagram showing a configuration of a position indicator mounted on a tablet in the digitizer.

FIG. 3 is a block diagram of a conventional digitizer.

FIG. 4 is a diagram for explaining a detection situation of the entire position of a position indicator in a conventional digitizer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 tablet 2 position indicator 3 to 6 comb-shaped conductor pattern 7 switch group 8 X-axis scanner section 17 control circuit

Claims (1)

[Scope of utility model registration request] 1. A cordless digitizer comprising a tablet and a position indicator wirelessly connected to the tablet, for detecting the position of the position indicator mounted on the tablet, and a comb on the first grid plate. First and second drive coils that are formed in a parallel shape and are arranged in parallel and at equal intervals, and are formed in a comb shape on the second grid plate and are orthogonal to the first and second drive coils and And second receiving coils arranged in parallel at equal intervals, and first and second drive coils of the divided block, which divides the first and second drive coils into a plurality of blocks Switch means for supplying a sine-wave current and a cosine-wave current, and the first and second via the position indicator by energizing the first and second drive coils.
Scanning means for scanning the induced voltage generated in the receiving coil, and when the maximum value of the induced voltage is detected, the entire position in one direction of the position indicator is selected from the selected address of the block by the switch means. With the decision
The position in the block is obtained from the phase difference between the sine wave current or cosine wave current and the induced voltage, and the position of the position indicator in the other direction is determined from the selection address of the scanning means. Digitizer.