JPH01114926A - Coordinate input device - Google Patents

Abstract

PURPOSE:To prevent the check of processing efficiency by providing a storing means for a coordinate input valid area and a discrimination means of a valid area, and executing no input of a coordinate value in case an input coordinate value is out of the valid area. CONSTITUTION:Piezo-electric elements (sensor) 6 for detecting an elastic wave transmitted through a propagation material 8 are arranged on peripheral parts S0, S1, S2 of the material 8. The coordinates of the position P(x, y) of an indication point obtained through a clock counter 18 or the like can be found out from the position P(x, y) and straight distances d0, d1, d2 between respective sensors 6. Namely, oscillation is detected by oscillation waveform detecting circuits 12-14 and the coordinate value of the indication point can be calculated from the distances d0-d2 obtained as the detecting results. Whether the calculated coordinate value is included in the inside or outside of an effective area previously stored in a ROM 20 is decided through a control device 1 or the like, and when the value is included in the effective area, the coordinate value is outputted, and in case of the outside, the coordinate value is not outputted. Since a host device is not forced to execute useless processing, the interruption of processing efficiency in the host device can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coordinate input device, and particularly to a coordinate input device that uses elastic waves to determine the coordinates of a designated point from the arrival time of the elastic waves.

[Conventional technology]

Conventionally, a vibrating pen is brought into contact with a desired position on a vibration transmission plate, the vibration transmitted from that position is detected by a sensor installed in contact with the vibration transmission plate, and the contact position of the vibrating pen is determined from the detection time. There was a coordinate input device.

[Problem to be solved by the invention] For example, when a display device and a related coordinate input device are superimposed to form an integrated input/output device, the required coordinate input surface is the portion that overlaps with the display surface. There may be cases where it is unnecessary to detect the coordinates outside the area.

However, in the past, as mentioned above, coordinate input devices now detect coordinate values even when you want to know the coordinate values for only a part of the coordinate input surface, rather than all of the coordinate input surface that can be physically input. Therefore, whether or not the coordinate input was made in a valid area was determined each time by the information processing device of the host to which the coordinate input device is connected. This forces the host device to perform unnecessary processing,
There was a problem that the processing efficiency of the host device was hindered.

[Means for solving problems]

In order to solve this problem, the present invention provides a determining means on the coordinate input device side to determine whether or not the designated coordinates are within the valid area, and coordinates outside the valid area are not output.

〔Example〕

FIG. 2 shows a block diagram of a coordinate input device embodying the present invention. The coordinate input device shown in FIG. 2 inputs coordinates to an input tablet made of a vibration propagation material 8 using a vibrating pen 3, and transmits the input coordinate information to an information processing device of a host to which this coordinate input device is connected (e.g.・Computer, etc.)

Reference numeral 1 denotes a control device that controls each circuit and calculates coordinates, which will be described later. 20 is a ROM which stores a control program according to the flowchart of FIG. 1 as well as an effective area storage area that defines an effective area.

The vibrating pen 3 is a pen for generating elastic waves in a propagation material 8 that transmits elastic waves, and is composed of a vibration-generating piezoelectric element (imaging element) 4, a horn 5, and its support. 2 is a drive circuit for the pen. 6 is a piezoelectric element (sensor) for detecting the elastic wave propagating through the propagation material 8. 7 is a vibration isolating material that prevents reflection at the end face of the propagation material 6.

Now, since the elastic wave propagates through the wave propagation material 8 at a certain propagation speed V, the distance d between the pointing point of the pen and the sensor is d=v-t (1) where t is given as the propagation time. Since V is a constant specific to the material used as the propagation material, in order to know d, it is sufficient to measure t. Vibration waveform detection circuits 12 to 14, latch circuits 15 to 17, and 18
The time counter is a circuit for measuring this transmission time t.

The control circuit 1 starts the time counter 18 from O at the same time as driving the pen 3.

The vibration generated by the vibrating pen 3 reaches the sensor 6 after a time corresponding to the distance, that is, a transmission time t. The vibration is converted into an electrical signal by the sensor 6, and the preamplifier circuits 9 to 11
The vibration waveform detection circuits 12 to 14 are then reached. When the vibration waveform detection circuit detects transmission of vibration, it outputs a vibration detection signal to the latch circuits 15 to 17.

The latch circuit receives the output of the time counter 18 using the vibration detection signal as a trigger.

From the transmission time measured in this way, the control device 1 calculates (
1) The distance between each sensor and the point indicated by the pen is calculated based on the formula, and then geometric calculations are performed to obtain coordinate values.

In addition, even if the time determined from the maximum transmission time (i.e., the transmission time when the distance between the sensor and the pointing point is maximum on the coordinate input surface) and the circuit delay time after the pen is driven, the vibration waveform remains unchanged. If not detected, it is time for pen-up, so the measurement of the transmission time is stopped and the control from the drive of the vibrating pen 3 described above is repeated.

The above operations are repeated to detect the indicated point coordinates.

Although the number of sensors for calculating coordinate values is arbitrary, two or more, in this example, three sensors, So, S+, and S2, are arranged at the periphery of the propagation material 8, as shown in FIG. , the straight-line distance do, d1 between the position P of the pointing point and each sensor
．． The coordinates of P(x, y) can be obtained from d2 using the 3-square process as shown in the following equation.

(However, rx and ry are the distances between the sensors SO and Sl, and SO and S2, respectively. Also, the origin O is the position of the circumcenter (center of the circumcircle) of a right triangle whose vertices are the positions of the three sensors. ) In this embodiment, a transparent member such as glass is used as the propagation material 8, and by overlapping it with a display device such as an LCD, an integrated input/output device can be constructed. At this time, an example of how the two devices overlap is shown in FIG. In such a case, what is required as the coordinate input surface is a portion that overlaps with the display surface, that is, a portion of the display area in FIG. 4, and it is unnecessary to detect the coordinates of the designated point in an area other than this. Therefore, when coordinates are input to this unnecessary portion, the control device 1 performs processing as shown in FIG. 1 in order to prevent the coordinate values from being output to the host device.

First, in step 1, the vibrating pen 3 is driven and vibration is detected. Next, in step 2, the coordinate values of the indicated point are calculated from dO-d2 obtained as a result of vibration detection. In steps 3 to 6, it is determined whether the calculated coordinate value is inside or outside of the valid area stored in advance. If it is, the coordinate value is output in step 7, and the process returns to step 1. Start detecting the coordinates of the next indicated point. On the other hand, if it is outside the effective area, step 7 is not executed and no coordinate values are output.

As described above, according to this embodiment, it is possible to provide a coordinate input device that does not output coordinate values set outside the effective area and does not force the host device to perform unnecessary processing.

[Other Examples]

In the case of a device with integrated input/output for the purpose of inputting figures, instead of ignoring the instruction point made outside the effective area, coordinate the point to the edge of the effective area closest to the instruction point. There may also be cases where it is desired to consider that an input has been made. In this case, processing as shown in FIG. 5 may be performed. That is, in step 11.12, as in the case of FIG. 1, the vibrating pen 3 is driven, vibration is detected, dO to d2 are obtained, and the coordinate values of the indicated point are calculated. Next steps 13-16
In step 1, it is determined whether the calculated coordinate value is inside or outside of the valid area stored in advance, and if it is within, step 17 is reached and the coordinate value is output, and the process returns to step 11 to calculate the next indicated point coordinate. Start detection. On the other hand, if it is outside the effective area, steps 13' to 16' are carried out to set the coordinate values to a point on the periphery of the effective area closest to the indicated point, and step 17 is reached where the coordinates of the point on the periphery are determined. Output.

That is, for example, when coordinates are input for point a in FIG. 4, the coordinate value of point b is output.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to realize a coordinate input device that does not output detected coordinate values when coordinates are input outside the effective area, or assumes that the coordinates are input at the periphery of the effective area. In other words, there is no need for the host device to judge each time whether or not the coordinate input was made in a valid area. This means that
This has the effect of not forcing the host device to perform unnecessary processing, that is, not impairing the processing efficiency of the host device.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing the control procedure of an embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of the present invention. FIG. 3 is a diagram for explaining how to obtain coordinates, FIG. 4 is a diagram showing an effective area, and FIG. 5 is a diagram showing another embodiment of the present invention.

Claims (2)

[Claims] (1) In a coordinate input device that includes a vibrating pen having a vibration generating means, a transmission plate that transmits vibration, and a vibration sensor provided on the transmission plate, and detects coordinate values from the vibration transmission time, a storage means for storing a valid input area; a determining means for determining whether the coordinates of a pointing point indicated by the vibrating pen are within the valid area stored in the storage means; and the determining means. and determining means configured to not output the input coordinate values when it is determined that the coordinate input by the vibrating pen is outside the effective area. . (2) The control means outputs the coordinate value of the peripheral edge of the effective area closest to the input coordinate value instead of the input coordinate value.
) The coordinate input device described in item 2.