JPH0133847B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention applies an alternating magnetic field generated from a coordinate indicator to a conducting wire laid on a tablet, and detects the magnitude of the induced voltage induced in this conducting wire to determine the position of the coordinate indicator. The present invention relates to a coordinate reading device for determining coordinates.

Conventionally, an electromagnetic coupling type coordinate reading device uses scanning lines x ₁ ... xn, y ₁ ... ym that are orthogonal to each other, as shown in Fig. 1.
It consists of mutually laminated flat plates 1 and 2 made of an insulating material laid with , scanning circuits 3 and 4, an alternating magnetic field generator 5 as a coordinate indicator, an excitation winding 5a, and an alternating current signal source 6. but the scan line x ₁
...xn, y ₁ ...ym were each formed by laying one loop of conductor wire from one end of the board to the other,
Due to the weak induced voltage caused by electromagnetic induction, noise generated from peripheral electronic circuits,
It was susceptible to external noise such as noise induced by the human body, which adversely affected the accuracy of coordinate values. Furthermore, if extremely strong external noise is present, it is necessary to provide shielding with a non-magnetic metal. Also, since the X-axis scanning lines x _{1 ... 1} ...ym's guidance signal was small and had a negative impact on the accuracy of coordinate values.

The present invention has been made to quickly eliminate the above-mentioned drawbacks, and the conventional scanning line is
By laying conductors in a multi-loop circuit instead of the loop circuit, the number of closed circuits through which the magnetic flux generated from the coordinate indicator increases, increasing the induced power and improving the S/N ratio. The purpose is to

Embodiments of the present invention will be described with reference to the drawings. Second
The figure shows an electromagnetically coupled coordinate reading device with a double loop circuit scanning line, x ₁₁ ... x ₁ n, y ₁₁ ...
y ₁ m are scanning lines perpendicular to each other, 11 and 12 are mutually laminated flat plates made of insulating material on which the scanning lines x _{11 .} . . x _{1 n} , y 11 .
15 is a scanning circuit; 15 is an alternating magnetic field generator as a coordinate indicator; 15a is an excitation winding of the alternating magnetic field generator;
16 is an AC signal source. Figure 3 is an exploded view of mutually laminated flat plates made of insulating material with scanning lines laid down, x ₂₁ ... x ₂ n, x ₃₁ ... x ₃ n are the scanning lines of the X axis, y ₂₁ ... ...y ₂ m, y ₃₁ ... y ₃ m is the scanning line of the Y axis, and 21 and 22 are the scanning lines of the X axis x ₂₁ ...
...x ₂ n, x ₃₁ ...x ₃ n, and 23,
24 is the scanning line of the Y axis y ₂₁ ... y ₂ m, y ₃₁ ... y ₃ m
These flat plates are made of insulating material, and the scanning lines of the Y axis y ₂₁ ...y ₂ m, y ₃₁ ... y ₃ m are connected to the scanning lines of the X axis x ₂₁ ... x ₂ n, x ₃₁ ...They are stacked on top of each other with x ₃ n in between. This is the X-axis scan line
x ₂₁ ... x ₂ n, x ₃₁ ... x ₃ n as the scanning line of the Y axis y ₂₁ ...
y ₂ m, y ₃₁ ... There is no problem even if it is sandwiched between y ₃ m.
h ₂₁ ... h ₂ n, h ₃₁ ... h ₃ n are the laminated flat plates 21, 2
2, 23, 24 to electrically connect the upper and lower corresponding X-axis scanning lines _x21 ... _x2n , _x31 ... _x3n , and _l21 ... _l2 m, l ₃₁ ... l ₃ m
penetrates the laminated flat plates 23 and 24 and electrically connects the upper and lower corresponding Y-axis scanning lines y ₂₁ ... y ₂ m, y ₃₁ ... y ₃ m. With these configurations, the scanning line The loop will be doubled. 25 is the scanning line of the X axis x ₂₁ ...
x ₂ n, x ₃₁ ...x ₃ n signal extraction terminal, 26 is Y
Axis scanning line y ₂₁ ... y ₂ m, y ₃₁ ... y ₃ m signal lead line, scanning line y ₂₁ laid on the flat plate of 23
...y ₂ m and is electrically connected with a through hole. 27 is the scanning line of the X axis x ₂₁ ... x ₂ n, x ₃₁ ... x ₃ n
29 is the common terminal of the common line 28 of the Y-axis scanning line y ₂₁ ... y ₂ m, y ₃₁ ... y ₃ m, and the common terminal of the scanning line 3 laid on the flat plate 24
It is electrically connected to 0 through a through hole. FIG. 4 is an X-axis block circuit. The magnetic flux generated from the coordinate indicator 15 is the same as the conventional one, but the scanning lines x ₂₁ ... x ₂ n, x ₃₁ ... x ₃ n, y ₂₁ ...
Since y ₂ m...y ₃₁ ...y ₃ m are doubled, the loop is doubled, and accordingly, the number of magnetic flux linkages is doubled, and the induced electromotive force increases proportionally.

The scanning circuit of the double loop circuit according to the invention comprises:
It is possible to significantly improve the induced electromotive force compared to the scanning line of a single loop circuit without increasing the magnetic flux density generated from the coordinate indicator, and it is possible to significantly improve the induced electromotive force compared to the scanning line of a single loop circuit. It becomes less susceptible to external noise such as noise, and S/
The N ratio was improved, and the accuracy of coordinate values could be improved. In addition, when there is little external noise, the coordinate indicator 1 can be used to obtain the same induced electromotive force as the conventional one.
The magnetic flux generated from the AC signal source 16 could be reduced by half, and the energy consumption of the AC signal source 16 could be reduced. In this example, a four-layer board was used.
We have described the scanning line of a double-loop circuit, but even in a conventional two-layer board, it is possible to form a double loop by laying a slightly smaller loop on the same surface of each layer, and this method and multi-layer board It is clear that a multiple loop scanning line with two or more layers can be formed by combining the methods described above, and in this case, there is an effect of improving the S/N ratio and saving power consumption compared to a double loop scanning circuit.

By stacking the Y-axis scanning lines _y21 ... _y2m , _y31 ... _y3m between the X-axis scanning lines _x21 ... _x2n , _x31 ... _x3n , X-axis scanning line x ₂₁ ... x ₂ n,
x ₃₁ ... Number of magnetic flux penetrating x ₃ n and Y-axis scanning line y ₂₁ ...
...y ₂ n, y ₃₁ ... y ₃ m The difference in the number of magnetic fluxes passing through y 3 m is significantly reduced, and the influence of the thickness of the board disappears, making it as if the X-axis and Y-axis scanning lines were laid out on the same plane. A similar effect was obtained and the accuracy of coordinate values was improved. The same effect as if the X-axis and Y-axis scanning lines were laid out on the same plane was obtained, and the accuracy of coordinate values was improved.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a conventional electromagnetically coupled coordinate reading device, Figure 2 is a configuration diagram of an electromagnetically coupled coordinate reading device with a double loop circuit scanning line, and Figure 3 is a configuration diagram of an electromagnetically coupled coordinate reading device with a scanning line installed. An exploded view of flat plates laminated together made of insulating material, Figure 4 is an X-axis block circuit diagram,
15... Coordinate indicator, x ₂₁ ... x ₂ n, x ₃₁ ... x ₃ n is the scanning line of the X axis, y ₂₁ ... y ₂ n, y ₃₁ ... y ₃ m is the scanning line of the Y axis shows.

Claims (1)

[Claims] 1. Sequentially applying scanning signals to the scanning lines of the tablet, which are formed by orthogonally intersecting a plurality of scanning lines laid parallel to each other in the X-axis direction and a plurality of scanning lines laid parallel to each other in the Y-axis direction. A coordinate reading device that determines the position of the coordinate indicator by detecting an electromagnetic induction signal superimposed on a scanning signal by bringing a coordinate indicator having an excitation winding that generates an alternating magnetic field on the plurality of scanning lines close to each other. In , the scanning line loop circuit is a multiple loop circuit formed by a scanning line in the Y-axis direction sandwiching a scanning line in the X-axis direction,
A coordinate reading device characterized in that the multiple loops are connected by through holes provided in a substrate.