JPH04130515A - Coordinate position measuring instrument - Google Patents

Abstract

PURPOSE:To notify a signal processor of numerous types of attributes with a simple circuit by providing a modulation circuit modulating a current flowing through a cursor coil with a sign on the side of a cursor and providing a means detecting the modulation sign and determining the type of the attribute on the side of the signal processor. CONSTITUTION:Pushbutton switches 11 for inputting attributes, an encoding circuit 12 converting the state of the switches 11 into a sign code and a modulation circuit 13 modulating the current to be made to flow through a cursor coil 101 corresponding to the sign of the encoding circuit 12 are provided in the cursor. In this case, it is possible to provide the different attributes for the respective attribute input switches and the signal processor determines the attribute of a coordinate position by detecting the input modulation signal. Thus, the attributes of the input coordinate position can be detected with simple construction while dividing them into numerous types.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention measures the planar coordinate position of a cursor on a tablet based on electromagnetic induction between a tablet and a cursor placed on the tablet. The present invention relates to a coordinate position measuring device, and particularly to a so-called cordless digitizer (coordinate position measuring device) that does not require a cord to transmit signals between a cursor and a tablet.

[Prior Art] As prior art to this invention, U.S. Patent No. 4,795,858 rDEVICE owned by the applicant of the present application
FORDETERMINING PO3ITION
C00RDINATES 0FPOINTS O
There is NA5URFACEJ (hereinafter referred to as the above-mentioned US patent).

FIG. 5 is a diagram showing the configuration of a conventional coordinate position measuring device corresponding to FIG. 3 of the above-mentioned US patent.
) is a cursor, (2) is a tablet made by stacking multiple types of grid plates, (3) is a 90 degree phase shift circuit, (
4) is a selector, (5) is a signal processing device, (21), <
22), <23), (24), and (25) are amplifiers, (101) is a cursor coil, (102> is an oscillation circuit, (10B) is an amplifier, and (104) is a battery for cursor power supply, which may be a dry battery or A storage battery is used.

A conductive pattern is formed on each grid plate, and an AC voltage is induced by the magnetic field formed by the AC current flowing through the cursor coil (101).The induced AC voltage is inputted to the input 1.7'z The voltage is processed to calculate the coordinate position of the cursor coil (101) on the tablet (2>).

The feature of the above US patent is that when the phase of the current flowing through the cursor coil (1o1) is required during signal processing in the signal processing device (5), means for extracting this phase from the phase of the voltage input from the tablet (2) is provided. However, since this is not directly related to the present invention, its explanation will be omitted.

By the way, when using coordinate position data measured by a coordinate position measuring device, attributes of the coordinate position are often required. For example, when displaying coordinate position data on a cathode ray tube display, the coordinate positions belonging to a certain group are displayed as red dots, and the coordinate positions belonging to other groups are displayed as black dots. Drawings become easier to understand. Information regarding what color to display is one attribute of the coordinate position 1. Such attributes need to be notified from the cursor (1) side to the signal processing device (5).

[Problems to be Solved by the Invention] The conventional coordinate position measuring device as described above is configured as described above, but has a problem in that it is not provided with a notification means for notifying attributes from the cursor side to the signal processing device side. There is.

For example, a method can be considered in which attributes are notified by the frequency of alternating current flowing through the cursor coil (101), but in such a method, various tuned circuits that generate various frequencies by switching are used on the cursor (1) side. It is necessary to use wideband amplifiers (21) to (25) to amplify various frequencies, and the circuit for frequency discrimination on the signal processing device (5) side is There was a problem that as the number of types increased, the complexity became more complex.

The present invention has been made to solve this problem, and an object of the present invention is to provide a coordinate position measuring device that can notify a signal processing device of many types of attributes using a simple circuit.

[Means for Solving the Problems] A coordinate position measuring device according to the present invention is provided with a modulation circuit on the cursor side that modulates the current flowing through the cursor coil with a code, and detects this modulation code to determine the type of attribute. It was decided to provide the means on the signal processing device side.

That is, as shown in FIG. 4, an attribute input switch group (11), an encoding circuit (12) that converts the state of this switch group (11) into a code, and this encoding circuit (12). A modulation circuit (
13) is added to the cursor (1).

[Operation] For example, by transmitting a 4-bit binary code, up to 16 types of attributes can be distinguished and notified to the signal processing device.

[Examples] Examples of the present invention will be described below with reference to the drawings. 1st
The figure is a block diagram showing the circuit configuration on the cursor side in one embodiment of the present invention, and the same symbols as in FIGS. 4 and 5 are the same.
or equivalent parts, (105) is an amplifier, (106)
are frequency dividing circuits, (107), (108), (109> are binary counters, respectively, Gl, G2.G3.G4.G)
6. G8 is an AND gate, G5. G7 is ORGATE, SWI, SW2. SW3. SW4 is an on/off switch.

FIG. 2 is a waveform diagram showing the waveforms of each part of the circuit in FIG. 1, and FIG.
The waveform at point d is shown, and e 1 , e 2 *e3. e4 indicates the waveform at point e, and fl and f2 indicate the waveform at point f.

In the embodiment shown in FIG. 1, the output of the oscillation circuit (102) is frequency-divided to obtain the rectangular wave shown in FIG. A rectangular wave shown in FIG. a may also be generated.

It is well known that the waveforms at points c and d in Figure 1 are as shown in c and d in Figure 2. Gl, G
2. G3. G4 is the corresponding switch SWI,
SW2. SW3. The signal is passed only when SW4 is turned on, and G6 becomes logic "H" only while waveforms a and d are both logic rH, and the output of G5 is logic "H." In the figure, switches SWI, SW2 . SW
3゜When only one switch of SW4 is turned on, the waveform at point e in Figure 1 is shown as el in Figure 2.
, G2. G3. The waveform is shown as G4.

The waveform at point f in Figure 1 will be as shown in Figure 2 if SW2 and SW3 are turned on at the same time, and
4 is turned on at the same time, the result is as shown in Fig. 2 f2. SWI, SW2. When SW3 and SW4 are in the on state, and the numerical values are 1.2 and 4.8, respectively, f
The bit pattern in the latter half of the point signal represents a numerical value from 0 to 15, and 16 types of attributes can be notified. Gate G8 constitutes a modulation circuit.

The first half of the waveform at point f is used for coordinate position measurement, and at the same time is used for hoop synchronization for the second half of the signal. Furthermore, since the operation of measuring the coordinate position is similar to that of the conventional device, the explanation will be omitted.

FIG. 3 is a block diagram showing a decoding circuit provided on the signal processing device side in an embodiment of the present invention.
110) is a detector, (111) is an amplifier, (112) is a phase detection circuit, and (113) is a low-pass filter (hereinafter referred to as L).
PF), (114) are voltage controlled oscillators (hereinafter abbreviated as CO), (115), (116), (11
G9.7) is a binary counter similar to (107), (108), and (109) in FIG. GIO, Gll.

G12 is an AND gate, (118), (119)
), (120), (121> are memory, (12
2> is a decoder.

7)-(112)-(113)-(114) constitute a phase-locked loop, and are phase-locked to the waveforms fl and f2 in FIG. 2 to generate the waveform shown in FIG. 2a. Binary counter (115).

(116) and (117) are respectively (107).

Corresponding to (108) and (109), gate G9゜GIO
, Gll, G12 are Gl, G2, G3., respectively. G
4, and 09 to G12 have a binary counter (
117) as shown in FIG. 2d, these gates receive the signals el, G2 . G3. G4
Output only the part indicated by and store it in memory (118) to (121).
). That is, memories (118) to (121
) is the same pattern as the on/off pattern of SW1 to SW4 in FIG.
~The attribute set by SW4 is signal processing device (5)
will be detected.

If necessary, the 4-bit signal can be decoded by the decoder (122) to generate 16 types of signals.

In the above embodiment, an example of a code generation and code detection circuit suitable for using a binary 4-bit code has been described. can be designed. For example, a plurality of attribute input switches may be connected in a matrix, and a microprocessor may be used to generate one code in response to the on/off of each switch.

With this configuration, it is possible to assign different attributes to each attribute input switch, and the user only needs to recognize the unique attributes of each switch, which has the advantage of improving operability. be.

Further, although the case where the code modulation is amplitude modulation has been described, a modulation method other than amplitude modulation may be used.

In addition, although the above-mentioned US patent uses a battery as a power source for the cursor (1), since a power source such as a dry cell battery has a relatively short lifespan and is undesirable, the applicant has decided to use a battery as a power source for the tablet (2) separately from the claimed invention. Provide a grid plate for power supply to the tablet (2; Needless to say.

Furthermore, the above-mentioned US patent was an invention aimed at detecting the phase of a current flowing through a cursor coil (101) in a signal processing device (5).

However, the cursor coil (101
) There is also a coordinate position measuring device that uses a measurement method that does not require the signal processing device to know the phase of the current flowing through the position. It is clear that the present invention can be applied to such a coordinate position measuring device as long as the device detects the voltage induced by the magnetic field generated by the cursor (1) on the tablet side.

[Effects of the Invention] As described above, the present invention has the advantage that by adding a simple circuit, it is possible to obtain a coordinate position measuring device that detects attributes of input coordinate positions in a large number of types.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the circuit configuration on the cursor side in an embodiment of the present invention, Fig. 2 is a waveform diagram showing waveforms of each part in Fig. 1, and Fig. 3 is a signal processing in an embodiment of the invention. FIG. 4 is a block diagram showing a decoding circuit provided on the device side, FIG. 4 is a schematic configuration diagram of the present invention, and FIG. 5 is an explanatory diagram showing the configuration of a conventional coordinate position measuring device. 1...Cursor, 2...Tablet, 102...
Oscillation circuit, SWI, SW2. SW3. SW4...Switch, G8...Modulation circuit, 5...Signal processing device. In addition, the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] A tablet configured by stacking a plurality of types of grid plates each having a grid-like conductor pattern formed thereon, and a cursor that is placed on the tablet and generates an electromagnetic field that is coupled to the grid-like conductor pattern of the tablet. and a signal processing device that inputs a voltage induced in the grid-like conductor pattern by the electromagnetic field from the cursor, performs signal processing on the input voltage, and calculates the planar coordinate position of the cursor on the tablet. In the coordinate position measuring device, the cursor includes a plurality of switches for setting attributes of the coordinate position, and a circuit that generates a predetermined modulation signal corresponding to the switch setting pattern of the plurality of switches. and a modulation circuit that modulates the electromagnetic field generated by the cursor with the generated modulation signal, and the signal processing device determines the attributes of the coordinate position by detecting the modulation signal in which the input voltage is modulated. A coordinate position measuring device characterized by comprising determining means.