JPH0630041B2 - Coordinate reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention senses by an alternating magnetic field generated by a coordinate indicator. These sense the inductive signal induced in the line. Detect and compare by scanning lines sequentially. The present invention relates to an electromagnetic induction type coordinate reading device for calculating the position of the coordinate indicator, and particularly, sense. The present invention relates to a line scanning device.

(Prior Art) A sense of the conventional coordinate reading device. An explanatory view of the line scanning device is shown in FIG. In the figure, the Y-axis direction,
That is, only an explanatory view for detecting the position in the vertical direction is shown, but the same applies to the X-axis direction, and therefore the description is omitted in the illustration and the following description.

Conventionally, when configuring the tablet of this kind of coordinate reading device, sense. One end of line 1 is connected to common ground line 4. It was grounded, and the other end was connected to the switches forming the scanning circuit 2. Although not shown, a scanning signal 5 is applied to the scanning circuit 2 from the control circuit, and one of the switches forming the scanning circuit 2 is closed by this signal to sense. One of the lines is selected.

(Problems to be Solved by the Invention) As described above, in the related art, the sense is used. Each one of the lines
For the book, the switch 1 circuit that constitutes the scanning circuit is necessary, so the sense is used to increase the tablet. When the number of lines is increased, the number of scanning circuits is also increased, and the number of control circuits for controlling the scanning circuits is also increased, the circuits are complicated, and the reliability of the device is low. Especially when constructing a large-sized graphic digitizer, this drawback was a big problem.

The present invention solves the above drawbacks by making sense. The line is divided into multiple sets, and the scanning circuit senses these multiple sets.
The line group can be used in common and has a sense. The purpose is to save labor in the line scanning device.

(Means for Solving the Problem) In order to solve the above-mentioned problems, sense is used in the present invention. Divide the line into multiple groups and sense each group. A sense in which one end of each line is connected to a common scanning circuit and the other end is connected to a common ground line in each set, and then a common ground line of each of these sets is newly provided. It was grounded through the line group selection circuit.

(Operation) According to the present invention, a plurality of sets of scanning circuits are sensed as described above. The number of scanning circuits is reduced because they are shared by the line groups, but at the same time as providing scanning signals to the scanning circuits, sensing is performed. Sense to the line group selection circuit. Sense by giving a line group select signal. You can select one of the lines and sense as before. Scan lines sequentially. You can choose.

According to the present invention, the sense in which the scanning circuit is shared. Although a plurality of line sets can be considered, they can be generally evaluated by the formula 1.

S = M / N + N. . . Formula 1 Here, M: sense. Number of lines N: Sense. Number of line groups S: Required scanning circuit and sense. Number of Switches Constituting Line Group Selection Circuit The sense line group N in Equation 1 is limited by hardware due to the coordinate detection method of the coordinate reading device, but mathematically the solution of N that minimizes S in Equation 1 is used. Can be found, which is N = ▲ √ ▼ M.

(Example) Hereinafter, one example of the present invention will be described.

The embodiment shown in FIG. 1 has eight senses. This is a case where the line is divided into two sets. 1a and 1b are sense. The shape of the line is the same as the conventional one, but one end has two pairs of senses. Both lines are connected to the common scanning circuit 2. A sense newly provided by the present invention after the other end is connected to the common ground lines 4a and 4b in each set. It is connected to the line group selection circuit 10. sense. The other end of the line group selection circuit is commonly grounded. sense. The line group selection circuit 10 is, for example, analog as in the conventional scanning circuit 2. It consists of a switch.

Coordinate reading device sense. Conventionally, the scanning method in the line scanning device will be described below with concrete examples of each method of the present system. Calculation is performed in the conventional method of FIG. The scanning signal 5 from the control circuit 12 enables scanning by sequentially closing the analog switches A to C of the scanning circuit. On the other hand, in the method of FIG. 1, first, senses A to D are detected. Operation when scanning a group of lines. Sense from the control circuit.
Sense by line selection signal 11. Close the analog switch α of the line group selection circuit, open the analog switch β,
Close the analog switches from A to D, then E
To the sense of H. Sense when scanning lines.
Open the analog switch α of the line group selection circuit, close the analog switch β, and sequentially close the analog switches A to D, all sense. Can scan lines.

In the above example, 8 senses. When the line is divided into two sets, it is traditionally a sense. Eight analog switches were required to construct the line scanning device. However,
According to the present invention, the number is reduced to 6. This effect is a large graphic. This becomes even more noticeable when configuring a digitizer. For example, in the case of an AO plate tablet, the width is 1300.48 mm and the length is 1003.52 mm. When the line interval is laid with a resolution of 25 μm at 10,24 mm, the conventional technique requires 225 analog switches, but in the present invention, the formula is used. 1 reduces to a minimum of 15.

(Effects of the Invention) As is apparent from the above description, in the present invention, the sense of the coordinate reading device. Sense to configure line scanning device. Divide the line into multiple sets, connect them to a common scanning circuit, and sense each set. A sense that selects the common ground line for the line. Since the line group selection circuit is provided, sense with the same function as the conventional one. The line scanning device can have a very small-scale circuit configuration, the number of parts is greatly reduced, and the reliability of the coordinate reading device is significantly improved. In addition, great effects can be achieved in cost reduction and labor saving in manufacturing.

[Brief description of drawings]

FIG. 1 is a sense of a coordinate reader according to the present invention. FIG. 2 is an explanatory view of the line scanning device, and FIG. 2 is a sense of the conventional coordinate reading device. It is an explanatory view of a line scanning device. 1 (a, b) ... sense. Line 2 ... Scan circuit 3 ... Common signal line 4 (a, b) ... Common ground line 5 ... Scan signal 10 ... Sense. Line group selection circuit 11 ... Sense. Line group selection signal 12… Calculation. Control circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 59-43489 (JP, A) JP 53-2045 (JP, A) JP 59-108178 (JP, A) JP 52- 10628 (JP, A) "Information Processing Handbook" edited by Information Processing Society of Japan, Ohmsha Co., Ltd., issued January 30, 1975, pp. 13-154, Fig. 13.3.3 96 single-row electrode double-sided control type

Claims (1)

[Claims] 1. A plurality of sense lines arranged in a loop at a constant interval, a coordinate indicator having a coil facing the sense lines, and a scanning circuit for sequentially scanning and selecting the sense lines. In a coordinate reading device that applies an alternating magnetic field to the coil of the coordinate indicator and compares the induced electromotive force generated in the sense line to detect the position of the coordinate indicator, the plurality of sense lines are divided into a plurality of groups. Then, one end of the corresponding sense line of each set is connected to a common scanning circuit, and the other end of the sense line is connected to each set to form a common ground line. Each group is provided with a sense line group selection circuit for selectively grounding, and the sense line group selection circuit is selectively switched by the arithmetic control circuit to perform common scanning for each group. Coordinate reading apparatus characterized by being configured to scan selected sense lines with the road.