JPH0562378B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coordinate reading device that is an input device for a digital device such as a computer. More specifically, the present invention relates to a coordinate reading device having a reading medium holding device for holding reading media such as drawings on a tablet.

[Summary of the invention]

The present invention provides a coordinate reading device that detects the coordinate values of a position indicated by a coordinate indicator through electromagnetic coupling between the coordinate indicator and the tablet, in which a reading medium such as a drawing can be placed at an arbitrary position on the tablet. A new reading media holding device is provided to hold the reading media, and a means for detecting the position of the reading media holding device placed on the tablet, and a means for detecting the position of the reading media holding device placed on the tablet, and a means for detecting the coordinate values of the position indicated by the coordinate indicator. By providing a means for converting the coordinates according to the coordinate values of the position, as long as the reading medium is held by the reading medium holding device, the reading medium can be read even if it is moved to any position on the tablet. This allows the calculation of coordinate values in a predetermined coordinate system on the media.

[Conventional technology]

Conventional coordinate reading devices input absolute coordinates relative to a fixed coordinate system on the tablet. Therefore, when inputting reading media such as drawings using a conventional coordinate reading device, it is necessary to fix the reading medium on the tablet in some way so that it does not move during the input operation. It was hot. That is, it is necessary to fix the coordinate system of the reading medium so that it corresponds to the coordinate system on the tablet. Conventionally, for this purpose, a transparent sheet was placed and fixed on top of the reading medium,
A method such as fixing the reading medium with adhesive tape or the like was adopted. FIG. 7 illustrates a conventional example of fixing with a transparent sheet.

[Problem that the invention seeks to solve]

On the other hand, from the standpoint of the worker who performs the reading work, it is better for the reading medium to be able to move freely without being fixed.

When inputting large drawings using a conventional coordinate reading device, in order to input a corner of the drawing, you have to move your body or change the posture of the coordinate reading device, making it difficult to operate. Katta. In such cases, if the drawings can be easily moved and held, improved operability can be expected.

Furthermore, a large coordinate reading device is sometimes used not only for the purpose of reading coordinates, but also as a work desk. In such an environment, a situation may arise in which coordinate reading is temporarily interrupted, another task is performed, and coordinate reading is continued again later. At this time, it is preferable to be able to temporarily move or remove the reading medium. As a matter of course,
When performing the reading operation again, it is necessary to be able to input the same coordinate system as before, but for this purpose, with conventional coordinate reading devices, the coordinate system is fixed on the tablet, so it is necessary to input the reading media again. They had to be placed in the same location on the tablet, making it virtually impossible to satisfy these requirements.

[Means for solving problems]

This invention was made against the above background.

One of the objects of the invention is to provide a coordinate reading device equipped with a reading medium holding device that allows the reading medium to be easily moved on a tablet and can be held at any position.

Another object of the invention is to be able to always calculate coordinate values in a coordinate system fixed on the reading medium even if the reading medium is held at any position on the tablet by the reading medium holding device. An object of the present invention is to provide a coordinate reading device.

In order to achieve the above object, the present invention provides a coordinate reading device that detects coordinate values of a position indicated by a coordinate indicator through electromagnetic coupling between the coordinate indicator and a tablet, and includes means for fixing a reading medium; a reading medium holding device having means for electromagnetically coupling with the tablet; a coordinate value detection means for detecting the position of the reading medium holding device; and coordinate conversion means for converting the coordinate values of the indicated position.

[Effect]

In the coordinate reading device with a reading medium holding device configured as described above, the reading medium can be freely moved and held on the tablet. Furthermore, at this time, the coordinate values of the position indicated by the coordinate indicator are:
Since the coordinates are transformed using the coordinate values of the reading media holding device placed on the tablet, the coordinate system is always fixed on the reading medium, and even if the reading medium moves on the tablet, it will always be in the fixed coordinate system. You can input.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a coordinate reading device with a reading medium holding device according to the present invention will be described with reference to the drawings. There are several types of coordinate reading devices that calculate coordinate values using electromagnetic coupling between a coordinate indicator and a tablet. An example will be described in which the present invention is implemented in a coordinate reading device that calculates coordinate values by detecting an induction signal induced to a sense line built into a tablet using a magnetic field.

FIG. 1 is a perspective view of a reading medium holding device according to the present invention. In the drawings, reference numeral 1 denotes a reading medium holding device, which has a reading medium holding mechanism 2 and a coil 3a and a coil 3b attached to the lower surface thereof for generating an alternating magnetic field. FIG. 2 is a partial perspective view showing the reading medium holding mechanism 2 of the reading medium holding device, which has a structure in which the reading medium is sandwiched between two plates as shown in the figure. In FIGS. 1 and 2, reference numeral 50 denotes a reading medium held by the reading medium holding mechanism 2. As shown in FIG.

FIG. 3 is a block diagram of a coordinate reading device according to the present invention. In the drawings, reference numeral 1 denotes the reading media holding device described above. Reference numeral 4 denotes a coordinate indicator for indicating the reading position, and like the reading medium holding device 1, a coil for generating an alternating current magnetic field is built inside. Reference numeral 5 (not shown) is an excitation circuit that generates signals for driving these coils. The positions of the coils 3a, 3b, and the coordinate indicator coil must be detected. In order to detect the positions of the three coils, the three coils are sequentially excited by time sharing or are excited at different frequencies, as previously proposed. The figure shows an example in which the magnet is excited by time division, and a time division switch 6 is provided for this purpose. 7 is a tablet that generates an induction signal by electromagnetic coupling using the alternating magnetic field generated by the reading media holding device and the coordinate indicator, and 8 is the coordinate value of the position where the three coils are placed by the signal induced in the tablet. Coordinate value detection circuit for detecting 9
1 is a coordinate conversion circuit that converts the coordinate values of the three coils to the coordinate values of the position indicated by the coordinate indicator, and 10 is a control circuit that controls the entire apparatus.

Next, the effect will be explained.

First, the control circuit 10 selects one circuit of the time division switch 6 and excites the coil 3a. The coil 3a generates an alternating magnetic field, and an induction signal i is induced in the tablet 7 by electromagnetic coupling. Coordinate value detection circuit 8
inputs this guidance signal i and detects the coordinate value c1. Similarly, the control circuit 10 is connected to the time division switch 6.
are sequentially selected, whereby the coordinate value detection circuit 8 detects the coordinate value c2 of the position where the coil 3b is placed and the coordinate value c3 of the position indicated by the coordinate indicator. When the coordinate values of the three coils are detected, the control circuit 10 instructs the coordinate conversion circuit 9, and the coordinate conversion circuit 9 receives this instruction, performs coordinate conversion, and calculates the resulting coordinate value c.

Coordinate transformation is performed as follows. Figure 4 shows
FIG. 3 is an explanatory diagram shown for explaining coordinate transformation processing. In the drawings, X-O-Y is the tablet coordinate system, x-o-y is the reading media coordinate system, and X'-O
−Y′ indicates a coordinate system in which only tilt correction is performed during coordinate transformation. In addition, P1 is the position where the coil 3a built into the reading media holding device 1 is placed, and P2
Similarly, P3 indicates the position where the coil 3b is placed, and P3 indicates the position where the coordinate indicator 4 is placed.

The problem with coordinate conversion is to convert the coordinate value of P3 detected in the tablet coordinate system to the coordinate value in the reading media coordinate system by performing tilt correction and translation correction. To simplify the problem, here the line segments P1 and P2 are o-x in the reading media coordinate system.
The case will be explained assuming that it is parallel to the axis.

First, the coordinate values of the positions of the three coils are
It is detected in the tablet coordinate system as follows.

P1 (X1, Y1) P2 (X2, Y2) (1) P3 (X3, Y3) Next, tilt correction is performed on these coordinate values.
Now, if the angle between the reading media coordinate system and the tablet coordinate system is θ, then the coordinate values in the coordinate system with only tilt correction are calculated using the following equations (2), (3), and (4). Ru.

X3′=Y3sinθ+X3cosθ Y3′=Y3cosθ−X3sinθ (2) The coordinate values calculated using equation 2) are corrected by parallel movement. The reading media coordinate system is a coordinate system fixed to the reading media holding device.
The location must be initialized before reading. To do this, it is sufficient to set the coordinate values of P1 or P2 in the reading media coordinate system. now
If the coordinate value of P1 in the reading media coordinate system is expressed as P1 (x1, y1) (5), the coordinate value of P3 in the reading media coordinate system is calculated by the following equation (6).

x3=X3'-(X1'-x1) y3=Y3'-(Y1'-y1) (6) The coordinate value detection circuit 8, coordinate value conversion circuit 9 and control circuit 10 explained above are actually micro It is realized by a computer circuit, and the above processing is also programmed. FIG. 5 shows a flowchart of the program.

The essence of the present invention is to perform coordinate transformation so that the reading coordinate system does not change even if the reading medium is held at an arbitrary position on the tablet by the reading medium holding device. Various mechanisms other than the one shown in this embodiment are conceivable for holding the reading medium. FIG. 6 is a sketch showing another embodiment of the reading medium holding device, and in this example, the reading medium 50 is held by being sandwiched between transparent sheets 20. In this embodiment as well, the methods of coordinate detection and coordinate transformation are performed in the same manner as in the previous embodiment.

In addition, the coordinate reading device applied in the embodiments described above is of an electromagnetic coupling type, and moreover, it reads coordinate values from the induction signal induced to the tablet by the alternating magnetic field generated from the excitation coil built into the coordinate indicator. Although the present invention is limited to a coordinate reading device of a detection type, the reading medium holding device and the method of fixing a coordinate system on a reading medium by coordinate transformation according to the present invention can be easily applied to coordinate reading devices of other types. It is. That is, the electrostatic coupling method, the vibration wave propagation method, and the like can be applied as long as the coordinate values of multiple points on the tablet can be detected.

〔Effect of the invention〕

As explained above, in the present invention, the coordinate reading device is provided with a reading medium holding device that holds the reading medium at an arbitrary position on the tablet, and further includes a means for detecting the coordinate value of the position where the reading medium holding device is placed. and means for performing coordinate exchange on the coordinate values of the position indicated by the coordinate indicator using the coordinate values, the coordinate values of the position indicated by the coordinate indicator are fixed to the reading medium. It is possible to realize a coordinate reading device that can convert coordinate values into coordinate values in a coordinate system, and according to this coordinate reading device, the reading medium can be freely moved on the tablet even during reading work. It is possible to reduce the burden on the operator during reading work, which has a significant effect on improving operability.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the reading media holding device, FIG. 2 is a perspective view of the reading media holding mechanism of the reading media holding device, FIG. 3 is a block diagram of the coordinate reading device with the reading media holding device, and FIG. 5 is a flowchart of a coordinate value calculation program, FIG. 6 is a perspective view of another embodiment of the reading medium holding device, and FIG. 7 is a diagram illustrating coordinate transformation. , is an explanatory diagram of a conventional reading medium fixing method. DESCRIPTION OF SYMBOLS 1... Reading media holding device, 2... Reading media holding mechanism, 3a... Coil, 3b... Coil, 4... Coordinate indicator, 5... Excitation circuit, 6... Time division switch,
7...Tablet, 8...Coordinate value detection circuit, 9...Coordinate conversion circuit, 10...Control circuit, 50...Reading medium.

Claims (1)

[Scope of Claims] 1. A movable reading medium holding device comprising a tablet, a coordinate indicator for indicating a position on the tablet, a means for holding a reading medium, and a means for transmitting the position on the tablet. and coordinate detection means for detecting the coordinate values of the position indicated by the coordinate indicator and the coordinate values of the position on the tablet on which the reading medium holding device is placed, and the reading medium holding device is placed on the tablet. a coordinate conversion means for converting the coordinates of the position indicated by the coordinate indicator into the coordinates of a coordinate system fixed on the reading medium according to the coordinates of the position on the tablet; A coordinate reading device with a reading medium holding device, comprising: control means for controlling the coordinate detection means and the coordinate conversion means so as to automatically perform the coordinate conversion.