JPH0540935U - Cordless digitizer - Google Patents

Abstract

(57) [Summary] [Purpose] In an electromagnetic induction type cordless digitizer,
The position indicator is provided with a plurality of switches, and the operating states of the switches are identified efficiently and accurately. [Structure] The position indicator generates a signal of a different pattern corresponding to the operating state of the switch, adds this signal to the magnetic field emitted by the position indicator, and the tablet side determines the pattern of the above signal to switch. It was decided to identify the state.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electromagnetic induction type cordless digitizer, in which a so-called position indicator is provided with a plurality of switches so that a plurality of input states can be detected.

[0002]

[Prior Art]

 In this type of cordless digitizer, a plurality of switches are generally provided on the position indicator, and the position indicator is provided with means for identifying the switch state. As the identification means, by changing the frequency of the magnetic field generated from the position indicator depending on the operating state of the switches and detecting the frequency of the voltage induced on the tablet side, the switch state of the position indicator can be detected. Was to identify.

[0003]

[Problems to be solved by the device]

 In such a conventional device, it is desirable to make the difference in frequency depending on the operating state of each switch as large as possible in order to make an accurate determination. This is because the larger the difference, the easier the identification. However, in this case, there is a problem that the number of identifiable switch operation states cannot be too large. The present invention was made to improve this point, and it is possible to identify many states and to provide a device that can be accurately discriminated.

[0004]

[Means for Solving the Problems]

 Therefore, in the present invention, a plurality of coil groups arranged in the X direction, a sense line group consisting of a plurality of coil groups arranged in the Y direction orthogonal to the coil group, and each of these sense line groups are provided. A tablet consisting of an X-side and Y-side sense circuit for detecting the voltage induced in the coil and a processing device for controlling each of these sense circuits, and at least an oscillator and a magnetic field generated according to the signal generated by this oscillator. When the position indicator is positioned at any position of the tablet, it is guided to each coil group of the tablet based on the magnetic field generated by the coil of the position indicator. A cordless digitizer configured to detect a voltage by each of the sensing circuits and to determine the pointing position coordinates of the position pointing device by the processing device. The position indicator has a plurality of switches and is configured to generate a different magnetic field from the coil depending on the operation state of each switch, and the processing device of the tablet is guided by the coils of the sense line group. Operation of the switch of the position indicator is provided with identification means for detecting the operating state of the switch of the position indicator by identifying which of the different magnetic fields is generated based on the magnetic field. A start signal is added prior to the data signal indicating the switch state to the different magnetic fields indicating the states, and when the processing device detects the start signal, the identifying means is set to the standby state.

[0005]

[Action]

 A data signal indicating the switch operation state and a start signal preceding this data signal are added to the magnetic field generated by the coil of the position indicator by each switch. The data signal indicating the switch operating state has a pattern peculiar to the switch operating state, for example. The voltage signal induced in each coil on the tablet side is obtained by adding these start signal and data signal. The processing device on the tablet side sets the device to the standby state for switch identification when the start signal is detected.

[0006]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. The device shown in FIG. 1 is a cordless digitizer according to the first embodiment of the present invention. The sense line group 1 includes a plurality of coil groups arranged in the X direction and a plurality of coil groups arranged in the Y direction orthogonal to the coil groups. The X-side sense circuit 2 and the Y-side sense circuit 3 are connected to the X-side sense line group and the Y-side sense line group, respectively. These X-side and Y-side sense circuits 2 and 3 have X-side and Y-side selection circuits 21 and 31, and X-side and Y-side reception circuits 22 and 32, respectively. Further, these X-side and Y-side sense circuits 2 and 3 are connected to the processing device 4. On the other hand, the position indicator of this device includes a coil 51 that generates a magnetic field, a capacitor 52 that is connected in parallel to the coil 51, a transmission circuit 53, a power supply unit 54, a frequency dividing circuit 54, signal generation circuits 561 to 564, and switches. It has 571-574. In the normal case, that is, when none of the switches 571 to 574 is operated, the position indicator generates a so-called alternating magnetic field on the basis of the transmission signal from the transmission circuit 53. The alternating magnetic field causes a predetermined induced voltage in the sense line group 1 when the position indicator is positioned on the sense line group 1 of the tablet. The X-side and Y-side sense line groups are sequentially switched and connected to the receiving circuits 22 and 32 by the X-side and Y-side selecting circuits 21 and 31, respectively, and the magnitude of each induced voltage is measured, for example. .. Then, the measured value of each induced voltage is sent to the processing device 4, and a predetermined calculation is performed to determine the indicated position coordinates of the position indicator. The determined designated position coordinates are sent to a host computer or the like and used for various purposes.

Now, consider a state in which any one of the plurality of switches of the position indicator is operated. The position indicator is connected to the signal generating circuits 561 to 564 corresponding to the switches 571 to 574, and is configured to generate a signal pattern according to the operating state of the switches 571 to 574. There is. As each of these signal patterns, for example, the one shown in FIG. 2 can be used. FIG. 2 schematically shows each signal of the position indicator. In the respective signals depicted in FIG. 2, the uppermost one represents the output signal of the transmission circuit 53, the output signal of the frequency dividing circuit in the following order, and the coil of the position indicator in the state where neither switch is operated. The level signal of the magnetic field generated from 51, the generated signal pattern of the coil 51 when the switch 571 is actuated, the generated signal pattern of the coil 51 when the switch 572 is actuated, the switch signal 573 when the switch 573 is actuated. The generated signal pattern of the coil 51 and the generated signal pattern of the coil 51 when the switch 574 is operated are shown. Since the output pattern of each signal generation circuit is switched and changed in accordance with the switch operating state, an induced voltage corresponding to these signal patterns is generated in each sense line on the tablet side. It is possible to identify which of the switches 571 to 574 is operated by the processing device by discriminating the signal pattern of.

Further, in this device, the position indicator is also configured to generate a start signal prior to the data signal having the above-mentioned signal pattern, and the processing device detects the start signal to identify the switch operation state. Has the advantage that the data signal acquisition is more efficient and reliable.

3 and 4 are explanatory views showing a second embodiment of the present invention. The position indicator according to this embodiment is configured to change the frequency of a signal added to the magnetic field generated by the coil 51 of the position indicator as data indicating the switch operating state. That is, as shown in FIG. 4, the frequency is made different according to the operating state of each switch 571-574.

As described above, in the apparatus of this embodiment, as means for changing the frequency of the data signal in accordance with the switch operation state, as shown in FIG. 3, the switches corresponding to the switches 571 to 574 are divided. The frequency division ratio of the frequency circuit 55 is changed. In the case of this method, the pattern of the signal representing each operation state is a simple repetition pattern, and its frequency (cycle) is simply made different, so that the repetition time of the pattern is simply measured. The start signal is not necessary.

[0011]

[Effect of the device]

 As described above, according to the present invention, in the electromagnetic induction type cordless digitizer, the plurality of switches of the position pointing device can be efficiently and accurately identified.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an electromagnetic induction type cordless digitizer according to a first embodiment of the present invention.

FIG. 2 is a signal diagram of each part of the position indicator of the device shown in FIG.

FIG. 3 is a configuration explanatory diagram of a position indicator according to a second embodiment of the present invention.

FIG. 4 is a signal diagram of each part of the position indicator of FIG.

[Explanation of symbols]

 1: Sense line group 2: X side sense circuit 3: Y side sense circuit 4: Processing device 5: Position indicator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Mitsunori Sugiyama 50-3-10 Shinanomachi, Totsuka-ku, Yokohama, Kanagawa Prefecture Graftec Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A group of coils arranged in the X direction,
Sense line groups consisting of a plurality of coil groups arranged in the Y direction orthogonal to this coil group, X-side and Y-side sense circuits for respectively detecting the voltages induced in the coils of these sense line groups, and these A tablet comprising a processing device for controlling each of the sense circuits, and a position indicator including at least an oscillator and a coil that generates a magnetic field according to a signal emitted by the oscillator, and the position indicator includes any of the tablets. Position, the processing device detects the voltage induced in each coil group of the tablet based on the magnetic field generated by the coil of the position indicator, and the processing device detects the voltage at the position indicated by the position indicator. In a cordless digitizer configured to determine coordinates, a plurality of switches are provided and different magnetic fields are generated depending on the operating state of each switch. And the processor of the tablet identifies which of the different magnetic fields the voltage induced in the coils of the sense line group is generated from. By this means, there is an identification means for detecting the operation state of the switch of the position indicator, and a different magnetic field indicating the operation state of the switch of the position indicator is added with a start signal prior to the data signal indicating the switch state. A cordless digitizer in which the processing device is configured to put the identification means in a standby state when the start signal is detected.