JPH0616254B2 - Coordinate input device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate input device, and more particularly to a coordinate input device that uses elastic waves to determine the coordinates of a designated point.

[Prior Art] Conventionally, in the coordinate input device of this type, when the vibration input pen and the elastic wave propagating body are in contact with each other, the elastic wave is propagated
The coordinate of the contact point is determined by the propagation delay time. That is, the elastic wave is detected only when the pen is down (when in contact), and is not detected when the pen is up (when not in contact). Therefore, at the time of pen-up, the control unit of the coordinate input device waits without detecting the elastic wave. Therefore, in order to improve the processing capacity by executing another process by the control unit of the coordinate input device at the time of pen-up, it is necessary to detect the state of pen-up or pen-down by some method.

In various conventional coordinate input devices, a switch is provided on the side of the vibration input pen to detect the pen up and down. However, this complicates the structure of the vibration input pen, and has drawbacks such as reduced reliability and difficulty in use.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-described prior art, and propagates without adding a special circuit to a vibration input means such as a vibration input pen for indicating a coordinate position. An object of the present invention is to provide a coordinate input device capable of detecting contact / non-contact of the vibration inputting member with the vibration propagating member based on the delay time and performing efficient coordinate input.

[Means for Solving Problems] To solve this problem, the coordinate input device of the present invention has the following configuration. That is, a vibration input means for inputting vibration, a vibration propagating member for propagating the vibration inputted by contacting the vibration input means, and a vibration propagating member provided on the vibration propagating member and inputted by the vibration input means. A plurality of vibration detecting means for detecting vibration, and a timing of driving start of the vibration input means, which is equal to or longer than a longest delay time determined by a longest distance of an effective input range of any one of the plurality of vibration detecting means and the vibration propagating member. During a predetermined time period from, contact / non-contact of the vibration input means with the vibration propagating member depending on whether or not all of the vibration detection means necessary for deriving the coordinates are completed. And an identification means for identifying.

[Operation] In the configuration of the present invention, a predetermined time from the start timing of driving the vibration input means, which is equal to or longer than the longest delay time determined by the longest distance of the effective input range of any one of the plurality of vibration detection means and the vibration propagation member. During the length, contact / non-contact of the vibration input means with respect to the vibration propagating member is discriminated by whether or not the detection of the vibration by the plurality of vibration detecting means necessary for deriving the coordinates is completed.

[Embodiment] FIG. 1 is a block diagram of a coordinate input device of the present embodiment.
Here, 2 is an elastic wave propagating body for propagating elastic waves, 3 is a vibration input pen for vibrating the elastic wave propagating body 2, 1 is a sensor for converting mechanical vibration transmitted through the elastic wave propagating body 2 into an electric signal,
Reference numeral 5 is a reception waveform detection circuit that detects an elastic wave from an electric signal from each sensor 1 and generates a detection signal, 4 is a vibrator drive circuit that drives a vibrator of the vibration input pen 3, and 6 is a block of each block. A ROM that stores a counter 6a and a processing program, which is a calculation / control block that controls and counts a propagation delay time from a detection signal and calculates coordinates from the numerical value.
6b and an auxiliary storage RAM 6c. The CPU is not shown. Reference numeral 7 is an external device such as a display. In the above structure, the start signal is sent from the calculation / control block 6 to the vibrator drive circuit 4. At this time,
The calculation / control block 6 starts a counter 6a that counts time in synchronization with the start signal. Upon receiving the start signal, the vibrator drive circuit 4 drives the vibrator of the vibration input pen 3 to cause the elastic wave propagating body 2 to generate an elastic wave.
When this elastic wave propagates through the elastic wave propagating body 2 and reaches the sensor 1, the sensor 1 converts the vibration into an electric signal and gives the electric signal to the reception waveform detection circuit 5. Received waveform detection circuit 5
The elastic wave is detected from the electric signal from the sensor 1, and the detection signal is sent to the arithmetic control block 6. Calculation / control block 6
By reading the value of the counter 6a by this detection signal, the propagation delay time can be known.

Now, consider a case where the input unit of the coordinate input device of the present embodiment detects coordinates in the configuration as shown in FIG. here,
The coordinates of the sensor 1 of S ₀ , S ₁ , and S ₂ are respectively S ₀ (O,
O), S ₁ (X, O), S ₂ (O, Y), and point P
(It is assumed that an elastic wave is emitted at x and y. If the velocity of the elastic wave in the propagating body is Vk, and the delay times to S ₀ , S ₁ , and S ₂ are t ₀ , t ₁ , and t ₂ , , P point coordinates are calculated by the following equations.

For P (x, y), x = X / 2 + V _k ² (t ₀ + t ₁ ) (t ₀ -t ₁ ) / 2X y = Y / 2 + V _k ² (t ₀ + t ₂ ) (t ₀ -t ₂ ) / 2Y (X, Y is the distance between S ₀ -S ₁ and S ₀ -S ₂ ) As described above, by measuring the delay time of the elastic wave generated from the designated point The coordinate position can be determined.

FIG. 3 shows a delay time measuring circuit unit in the calculation / control block 6 of the conventional coordinate input device. Here, when a reset signal is sent from a CPU (not shown), the flip-flops 31 to 33 and the counter 34 which receive the detection signal from the reception waveform detection circuit 5 are reset. Then, the start signal causes the counter 34 to start counting. This start signal is synchronized with the drive signal of the vibrator of the vibration input pen 3, and at this moment, the vibration input pen 3 causes an elastic wave to be generated in the elastic wave propagating body 2. When this elastic wave reaches the sensor 1, a detection signal is sent from the reception waveform detection circuit 5 to the flip-flops 31 to 33 according to the position numbers S _{0 to} S ₂ of the sensor 1. When this detection signal is set to stop 0 to 2, for example, when a signal of stop 0 is sent, the latch 36 latches the counter value at that time in response to this. In the following order, the counter value according to the arrival time at each sensor 1 is set in each latch 36-3.
Latched to 8. The AND circuit 35 is for determining whether or not all the detection is completed, and when all the flip-flops 31 to 33 send out a signal, a flag is set in a predetermined bit in the condition determination latch 39. The CPU detects that the data is complete by reading the contents of the condition determination latch 39. If the data is complete, the CPU sequentially selects the latches 36 to 38, reads the data through the port 40, and Based on the data, the coordinate position is determined by calculation as described above.

In this coordinate input device, the vibration input pen 3 and the elastic wave propagating body 2 come into contact with each other as described above, and the elastic wave reaches the sensor 1 with a certain delay time, whereby coordinate information is obtained. Of these, the longest delay time is defined by the longest distance of the effective input area, the delay of the circuit system, and the like. That is, when the detection signal is not obtained even after the maximum delay time,
It should be recognized as a pen-up state.

FIG. 4 shows a delay time measuring circuit unit in the arithmetic / control block 6 of the coordinate input device of this embodiment. The configuration is the same as that of FIG. 3 except for the time-out flip-flop 41.
In this configuration, the maximum value that can be counted by the counter 34 is matched with the longest delay time, and when the longest delay time is exceeded, the carry-out of the counter 34 is received by the timeout flip-flop 41 and the condition determination latch 39. Flag a given bit. CP
If the flag is set depending on the presence / absence of this flag, U determines that the pen is up, and does not take in data, and moves to the next control. In this way, up / down determination can be performed using the longest delay time.

FIG. 5 is a processing flowchart of the coordinate input device of this embodiment stored in the ROM 6b. First, step S1
In step S2, initialization of internal clocks, flip-flops, etc. is performed, and in step S2, the vibrator of the vibration input pen 3 is driven and the counter is started. In step S3, detection signals of elastic waves from all the sensors 1 are received from the reception waveform detection circuit 5. If the detection signal is not received within the predetermined maximum delay time, the process is skipped from step S7 and another process is performed. The detection signal is received in step S4, the calculation is performed in step S5 to determine the coordinates, the coordinates are stored in the RAM 6c in step S69, and the coordinates are output to the external display 7 or the like to end one cycle.
Hereinafter, this is repeated according to the sampling number. For output to the outside, the point indicated by the coordinate may be displayed on the display 7, or the coordinate value may be transmitted. The above operation is
R by a CPU (not shown) in the arithmetic / control block 6
It is controlled and executed by the program stored in the OM 6b.

In the embodiment, a counter for measuring delay time is used,
Although it is determined whether the pen is up or down, a dedicated counter may be used. The contents of the counter may be read to make a determination, or a flag may be set by using carry out as in the above embodiment. Alternatively, a method of interrupting the CPU may be used.

Further, it may be performed by software using the internal clock of the CPU, regardless of the hardware.

As described above, since pen up / down can be determined by defining the maximum delay time, it is not necessary to provide a switch or the like on the pen, thereby improving the reliability and the usability by simplifying the structure. Can be done.

In particular, according to the above-described embodiment, whether or not the vibration input pen 3 is in contact with the elastic wave propagating body 2 is determined by the longest delay time defined by the effective input area, and even if that time elapses, all are determined. If no vibration is transmitted to the sensor, the next process is performed without waiting for detection of further vibration. What this means is that the drive cycle of the vibrator provided in the vibration input pen 3 is the shortest. In other words, it is possible to increase the number of samplings per unit time for coordinate detection. Moreover, a circuit for detecting pen up / down is not provided in the vibration input pen.

[Effects of the Invention] As described above, according to the present invention, the vibration of the vibration input means can be controlled by the propagation delay time without adding a special circuit to the vibration input means such as the vibration input pen for indicating the coordinate position. It is possible to detect contact / non-contact with the propagation member and perform efficient coordinate input.

[Brief description of drawings]

FIG. 1 is a block diagram of the coordinate input device of this embodiment, FIG. 2 is a diagram of an input section of the coordinate input device of this embodiment, and FIG. 3 is a calculation / control block 6 of the coordinate input device of the conventional example.
FIG. 4 is a delay time measuring circuit diagram in FIG. 4, FIG. 4 is a delay time measuring circuit diagram in the operation / control block 6 of the coordinate input device of this embodiment, and FIG. 5 is a processing flowchart of the coordinate input device of this embodiment. In the figure, 1 ... Sensor, 2 ... Elastic wave propagating body, 3 ... Vibration input pen, 4 ... Oscillator drive circuit, 5 ... Received waveform detection drive circuit,
6 ... Operation / control block, 6a ... Counter, 6b ... RO
M, 6c ... RAM, 7 ... _{display, S} 0 to S 2 _... sensor position, 31-33 ... flip-flop, 34 ... counter unit, 35 ... the AND circuit, 36 to 38 ... latch, 39
... Condition determination latch, 40 ... Port, 41 ...
It is a flip-flop for timeout.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-57-19884 (JP, A) JP-A-57-19885 (JP, A) JP-A-60-75930 (JP, A)

Claims (1)

[Claims] 1. A vibration input means for inputting a vibration, a vibration propagating member for propagating the vibration inputted by contacting the vibration input means, and a vibration input means provided on the vibration propagating member. A plurality of vibration detecting means for detecting the input vibration, and a drive of the vibration input means for a maximum delay time or more determined by the longest distance of the effective input range of any one of the plurality of vibration detecting means and the vibration propagating member. The contact of the vibration input means with the vibration propagating member depends on whether or not the detection of the vibrations by the plurality of vibration detecting means necessary for deriving the coordinates is completed within a predetermined time period from the start timing. / A coordinate input device, comprising: identification means for identifying non-contact.