JPH05233126A - Coordinate input device - Google Patents

Abstract

PURPOSE:To provide a coordinate input device which can input plural pieces of tool force information and which can easily correct tool force information with respect to a phase angle without reducing a range where tool force can be detected. CONSTITUTION:A position indicator 2 having a tuning circuit where the center of a tuning frequency changes to one of the plural frequencies which are previously set in accordance with a switch operation, and the tuning frequency continuously changes with at least two of the plural frequencies as a center in accordance with tool force is used. The electric waves of the plural frequencies are transmitted to the position indicator 2. The electric wave reflected from the tuning circuit at that time is received, and the coordinate value of an indicating position and the phase angle are detected from the electric wave. Then, which is the tuning frequency of the tuning circuit is judged among the plural frequencies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a coordinate input device using radio waves.

[0002]

2. Description of the Prior Art Prior to this application,
-213970 (refer to Japanese Patent Publication No. 2-53805)
(Hereinafter, referred to as prior application 1.) A position detecting device (coordinate input device) that obtains coordinate values of a position pointed by the position indicator by exchanging radio waves between the sensing unit and the position indicator. Proposed.

The contents of the prior application 1 will be briefly described. A loop coil of a sensing section is used to transmit a radio wave of a predetermined frequency.
The radio wave is received by the tuning circuit provided in the position indicator. At this time, the loop coil receives the radio wave transmitted from the tuning circuit that has received the radio wave, and the induced voltage is generated.
This is sequentially switched and repeated for a plurality of loop coils of the sense section, and the coordinate value of the indicated position is obtained based on the level of the induced voltage generated in each loop coil.

By the way, in this type of coordinate input device, in addition to the coordinate value of the pointed position, information for specifying the pointed position to be actually input, and parameters other than the coordinate value, such as line thickness, depending on the software. There is a demand for inputting information (hereinafter, referred to as operation information) for changing the hue, density (brightness), etc. of the designated position or the designated area together with the coordinate value of the designated position.

In the prior application 1, the tuning frequency is slightly changed according to the operation of the switch by connecting another capacitor to the coil and the capacitor forming the tuning circuit through the switch. A slight change in the tuning frequency is detected as a change in the phase angle, and is used as the operation information described above.

[0006] Further, in the application of Japanese Patent Application No. 63-308712 (see Japanese Patent Application Laid-Open No. 2-155019) (hereinafter referred to as Japanese Patent Application No. 2), the applicant tunes according to the writing pressure. Position indication with a tuning circuit capable of continuously changing a frequency within a predetermined frequency range and changing the frequency range to any of a plurality of different frequency ranges according to ON / OFF of a side switch We proposed a device that can input multiple writing pressure information for different purposes by using a pen.

[0007]

However, in the device of the prior application 2 described above, the range of the phase angle with respect to the predetermined frequency is divided into a plurality of different frequency regions according to the ON / OFF of the side switch. As the range in which the writing pressure can be detected becomes smaller, the phase angle for one writing pressure when the side switch is turned on and the phase angle for the one writing pressure when turned off are completely different. There is a problem in that different correction values are required to correct the writing pressure information.

In view of the above-mentioned conventional problems, the present invention is capable of inputting a plurality of writing pressure information and easily correcting the writing pressure information with respect to the phase angle without reducing the range in which the writing pressure can be detected. It is an object of the present invention to provide a coordinate input device that can be used.

[0009]

According to the present invention, in order to achieve the above object, according to claim 1, the center of the tuning frequency is changed to any one of a plurality of preset frequencies and the writing pressure is changed. A position indicator having a tuning circuit whose tuning frequency continuously changes around at least two of the plurality of frequencies, and a radio wave generating means for generating radio waves of the plurality of frequencies; Radio wave detection means for receiving radio waves of a plurality of frequencies, coordinate detection means for obtaining coordinate values of the position pointed by the position indicator based on the radio waves received by the radio wave detection means, and received by the radio wave detection means A change in the tuning frequency in the tuning circuit is detected as a change in the phase angle with respect to any one of at least two of the plurality of frequencies based on the radio wave. A coordinate input device comprising phase angle detecting means and tuning frequency determining means for determining which of the plurality of frequencies the center frequency of the radio wave received by the radio wave detecting means is, and also in claim 2. The coordinate input device according to claim 1, further comprising mode setting means for switching and setting the input mode according to the determination result of the tuning frequency.

[0010]

According to the first aspect of the present invention, when radio waves of a plurality of frequencies are generated by the radio wave generation means, the radio waves match the tuning frequency of the tuning circuit of the position indicator determined according to the switch operation. Only the radio wave of the specified frequency is tuned, that is, received by the tuning circuit, but the tuning circuit which receives the radio wave emits, that is, reflects the same radio wave. The reflected radio wave is received by the radio wave detecting means, and the received radio wave is sent to the coordinate detecting means to detect the coordinate value of the position pointed by the position indicator, and is also sent to the phase angle detecting means. The phase angle corresponding to the writing pressure applied to the position indicator is detected, and the tuning frequency determining means determines the tuning frequency determined according to the switch operation of the position indicator. According to the second aspect, the mode setting means switches and sets the input mode according to the determination result of the tuning frequency.

[0011]

1 shows an embodiment of a coordinate input device of the present invention, in which 1 is a position detecting device, 2 is a position indicator,
Reference numeral 3 is a host computer, and 4 is a display device.

The position detecting device 1 has a predetermined position detecting surface 1a.
Radio waves of a plurality of preset frequencies, which will be described later, of three frequencies are transmitted / received to / from the tuning circuit of the position indicator 2 operated above, and the x and y coordinate values of the indicated position, the phase angle, and the actual radio wave are transmitted. Detect the received frequency, i.e. the tuning frequency,
These are transferred to the host computer 3. As the position detecting device 1, Japanese Patent Application No. 1-282852 (Japanese Patent Application Laid-Open No. 3-1470) filed by the applicant.
The position detection device described in Japanese Patent No. 12) is used.

FIG. 2 shows a specific structure of the position indicator 2. In the figure, 21 is a housing, 22 is a core, 23 is a coil, 24 is a variable capacitor, 25 is a substrate, and 26, 2 are shown.
7 is a switch unit, and 28, 29 and 30 are capacitors.

The housing 21 is made of a non-metallic material such as synthetic resin and is substantially pen-shaped, and has a through hole through which the core 22 can be inserted at the tip end side thereof. The core body 22 is made of a non-metal material such as synthetic resin or ceramics, and is housed so that one end 22 a thereof protrudes from the through hole of the housing 21 to the outside.

The coil 23 is formed by winding a litz wire having a low high-frequency resistance on a ferrite core having a through hole through which the core 22 can be slidably inserted. It is held between 24 and.

The variable capacitor 24 is formed integrally with the housing, and its capacitance value changes substantially continuously according to pressure or displacement applied from the outside, and increases in this case. The one described in Japanese Patent Laid-Open No. 2-206774 is suitable, but not limited thereto. When one end 22a of the core 22 is pressed against the position detection surface 1a or the like, a pressing force is applied to the variable capacitor 24 via the other end.

The board 25 is for mounting the switch unit 26 and the capacitors 28 to 30 and fixing the positions of the variable capacitor 24 and the coil 23.
One side thereof is fixed to the variable capacitor 24, and the other side is in contact with the bottom of the housing 21 via the switch unit 27.

The switch unit 26 is adapted to be turned on by pressing the operating portion 26a protruding outside the housing 21. Further, the switch unit 27 is configured to be turned on by pressing the operation portion 27a protruding to the outside of the housing 21 via the cap 31 attached to the tip thereof.

The capacitors 28 to 30 are well-known chip capacitors. As shown in FIG. 3, the capacitor 28 is connected to the coil 23 together with the variable capacitor 24, and the capacitor 29 is connected in parallel with the capacitor 28 via the switch unit 26. Further, the capacitor 30 is connected to the capacitor 28 via the switch unit 27.
It is connected in parallel with and forms a known tuning circuit.

Here, the tuning frequency of the tuning circuit is such that neither switch unit 26, 27 operates.
In the three states, in which only the switch unit 26 is operated and only the switch unit 27 is operated, a predetermined phase angle range (here, −60 ° to 60 °) is set.
Degrees) which can be detected on the side of the position detecting device 1 and are close to each other at frequencies f1, f2 and f3, for example, 562.5 kHz, 531.25 kHz and 500 kHz.
It is set to z.

The above-mentioned frequency is the center value of the tuning frequency, and actually, in a state in which neither of the switch units 26 and 27 is operated and no writing pressure is applied, 562.5 kHz on the position detecting device 1 side. Is set to a frequency detected as a phase angle of 60 °, and the phase angle can be continuously changed to −60 ° by gradually applying a writing pressure of maximum 500 g. Similarly, when only the switch unit 26 is operated and no writing pressure is applied, 531.
The frequency is set to be detected as a phase angle of 60 ° of 25 kHz, and the phase angle can be continuously changed to −60 ° by gradually applying a writing pressure of maximum 500 g. Furthermore, similarly, when only the switch unit 27 is operated and no writing pressure is applied, a phase angle 6 of 500 kHz is applied to the position detecting device 1 side.
It is set to the frequency detected as 0 °, and the maximum is 5
The phase angle is set to -60 by gradually applying the writing pressure of 00g.
It is set so that it can be changed continuously up to °.

FIG. 4 shows a first figure having a different size at the indicated position according to the writing pressure, based on the information on the x and y coordinate values of the indicated position detected by the position detecting device 1, the phase angle and the tuning frequency. , For example, a mode for writing a black circle “●”, a second figure having a different size depending on the writing pressure, for example, a mode for writing a white circle “○” and a predetermined area having a different size depending on the writing pressure are erased. 6 shows the flow of a program in the host computer 3 when realizing the mode.

Next, the operation of the device will be described.

First, when the position indicator 2 is made to approach on the position detecting surface 1a of the position detecting device 1 with its core 22 facing downward, the position detecting device 1 makes the x and y coordinate values and phase of the indicated position. The corner and tuning frequency are detected and transferred to the host computer 3. In the host computer 3, the writing pressure and position detection device 1 in the position indicator 2 stored in advance
The phase angle of the transferred data is converted into writing pressure information according to the table showing the relationship with the phase angle in.

At this time, since the writing pressure is 0 when the core 22 is not in contact with the position detecting surface 1a, regardless of which tuning frequency the host computer 3 has,
A cursor, for example, “+” is displayed at the designated position on the display device 4.

Next, when the core body 22 of the position indicator 2 is brought into contact with the position detecting surface 1a and the writing pressure becomes 50 g or more, the host computer 3 checks the tuning frequency at that time. At this time, the switch units 26, 2 of the position indicator 2
If none of 7 is operated, the tuning frequency is f1 (= 562.5 kHz) as described above. Therefore, the writing pressure at that time is the spread information of the first figure, here the black circle proportional to the writing pressure. The image is converted into a diameter of “●”, an image of a black circle “●” having the diameter is drawn at a designated position in a frame memory (not shown), and this is displayed on the display device 4.

Since the above-described processing is repeated while the data is being transferred from the position detecting device 1, when the position indicator 2 is moved while changing the writing pressure within the range of 50 to 500 g, the position indicator 2 moves along the trajectory of the indicated position. Images of black circles "●" having different diameters are continuously arranged, and an image similar to the case of using a brush is obtained.

At this time, if only the switch unit 26 of the position indicator 2 is operated, the tuning frequency is f2 (= 531.25 kHz) as described above, and the writing pressure at that time is the second The spread information of the figure, here converted into the diameter of the white circle “○” proportional to the writing pressure, draws the image of the white circle “○” having the diameter at the indicated position in the frame memory (not shown), and displays it. Display on top.

Since the above-mentioned processing is repeated while the data is being transferred from the position detecting device 1, when the position indicator 2 is moved while changing the writing pressure within the range of 50 to 500 g, the position indicator 2 moves along the trajectory of the indicated position. Images of white circles with different diameters are lined up continuously.

Furthermore, at this time, if only the switch unit 27 of the position pointing device 2 is operated, the tuning frequency is f3 (= 500 kHz) as described above, so the writing pressure at that time is the spread information of the erasing area. Here, the diameter of the circle is converted into a diameter proportional to the writing pressure, the inside of the circle having the diameter centered on the designated position in the frame memory (not shown) is erased, and this is displayed on the display device 4.

Since the above-described processing is repeated while the data is being transferred from the position detecting device 1, if the position indicator 2 is moved while changing the writing pressure within the range of 50 to 500 g, the locus of the indicated position is the same as above. A region along the line and having a width corresponding to the writing pressure is erased.

As described above, according to the above-described embodiment, the black dot "●" can be input and the size thereof can be adjusted according to the writing pressure only by using the position indicator 2 in contact with the position detecting device 1. In addition, the white circle "○" can be input only by operating the switch unit 26, and the size thereof can be adjusted according to the writing pressure. Furthermore, only by operating the switch unit 27, the erasing operation and the erasing area can be performed. You can adjust the size of. Further, since a plurality of pieces of writing pressure information having different purposes described above are transmitted to the position detecting device 1 side by changing the center frequency of the tuning circuit of the position indicator 2, the range of the phase angle with respect to one conventional frequency is changed. There is no reduction in the range in which the pen pressure can be detected, unlike the case where the pen pressure is divided, and since the phase angle for one pen pressure is almost the same at each frequency, the conversion between the phase angle and the pen pressure Can be performed using the same table, and correct writing pressure information can be continuously input even if the operation state of the switch unit 26 or 27 is changed while the writing pressure is being applied.

[0033]

As described above, according to claim 1 of the present invention, in the tuning circuit of the position indicator, the center of the tuning frequency is changed to any of a plurality of preset frequencies in response to the switch operation. At the same time, the tuning frequency continuously changes centering on at least two of the plurality of frequencies according to the writing pressure, so that it is possible to input a plurality of writing pressure information for different purposes. Since it does not divide the phase angle range for one frequency,
The range in which the pen pressure can be detected is not reduced, and the phase angle for one pen pressure is almost the same at each frequency. Therefore, there is only one correction value for the pen pressure for the phase angle. be able to.

According to the second aspect of the present invention, the input mode can be set only by operating the switch of the position indicator, and the position indicator can be largely moved to set the mode, or a keyboard or the like can be used for the host computer. There is no need to enter various commands.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a coordinate input device of the present invention.

FIG. 2 is a sectional perspective view showing a specific configuration of the position indicator in FIG.

FIG. 3 is a configuration diagram showing a circuit of a position indicator in FIG.

FIG. 4 is a flowchart of a program in the host computer.

[Explanation of Codes] 1 ... Position detection device, 2 ... Position indicator, 3 ... Host computer, 4 ... Display device, 21 ... Housing, 22 ... Core body, 23
... coil, 24 ... variable capacitor, 25 ... substrate, 2
6, 27 ... Switch unit, 28, 29, 30 ... Capacitor.

Claims (2)

[Claims] 1. The center of the tuning frequency is changed to one of a plurality of preset frequencies in response to a switch operation, and the tuning frequency is set to at least one of the plurality of frequencies in response to a writing pressure. A position indicator having a tuning circuit that continuously changes as a center, a radio wave generation unit that generates radio waves of the plurality of frequencies, a radio wave detection unit that receives radio waves of the plurality of frequencies, and a radio wave detection unit that receives the radio waves. Coordinate detection means for obtaining the coordinate value of the position pointed by the position indicator based on the radio wave, and the change of the tuning frequency in the tuning circuit based on the radio wave received by the radio wave detection means among the plurality of frequencies. And a center of the radio wave received by the radio wave detection means. Coordinate input apparatus characterized by wave number and a determining tuning frequency determining means which of the plurality of frequencies. 2. The coordinate input device according to claim 1, further comprising mode setting means for switching and setting an input mode according to a determination result of a tuning frequency.