JPS62137621A - Correcting method for hand-written input position coordinate signal - Google Patents

Abstract

PURPOSE:To improve linearity by permitting a control signal group to fetch each coordinate signal so as to store a correction equation and calculating a real coordinate value from said stored signal at the time of an actual input. CONSTITUTION:An input position detector is constructed of the 1st parallel electrode group 4 composed of plural electrodes, an insulating substrate equipped with the 1st resistance 5, an insulating substrate with a constitution similar to the former substrate and a voltage-sensitive sensor 3 installed between both substrates. In order to correct an input position coordinate signal, the 1st read group 8 pulled out of the 1st parallel electrode group 4 at the same interval, the 2nd read group 9 pulled out of the 2nd parallel electrode group 6 in the same manner and a coordinate signal generating switch group 10 connected in correspondence to said groups are provided. The switch group 10 is controlled on and off by a control signal group 11. Thus, prior to entering in a use mode, the switch group 10 is turned on and off to fetch an initial value. Then the correction equation regarding coordinates X and Y is stored, and corrects and calculates the signal at the time of an actual input so as to output.

Description

DETAILED DESCRIPTION OF THE INVENTION <Object of the Invention> The present invention relates to a novel correction method for a parallel electrode group type input position detection device.

<Prior Art and Topics> Recently, a parallel electrode group type input position detection device that can detect input devices for handwritten characters and figures using an ordinary writing instrument has been proposed and put into practical use. (Special Publication No. 57-34543). According to the input position detection method in this device, the linearity of the input position detection device is determined by the accuracy of the resistor in contact with the parallel electrode group.

In order to improve the linearity of this input position detection device, the resistor in contact with the parallel electrode group may be trimmed, or the input position may be actually Methods such as inputting information to reference points are used. However, all of these methods have the disadvantage that it takes time to improve accuracy and increases costs.

<Object of the Invention> The present invention has been made for the purpose of providing a simple correction method capable of improving the linearity of an input position detection device in order to solve the drawbacks of these conventional techniques. In this method, lead groups are pulled out at a certain q interval from the parallel electrode group, connected to the corresponding coordinate signal generation switch group, each coordinate signal is taken into the control system by the control signal group in advance, the correction formula is memorized, and the actual The present invention is characterized in that, upon input, true input coordinate values are calculated using the correction formula.

<Configuration of the Embodiment> Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic explanatory diagram of the input position detection device of the present invention, where l is a flexible insulating substrate, and a first parallel electrode group 4 consisting of a plurality of electrodes provided in parallel on the back surface. and a first resistor/body 5 in contact with it. 2
is an insulating substrate, and is composed of a second parallel electrode group 6 consisting of a plurality of electrodes provided in parallel on the surface and a second resistor 7 in contact with the second parallel electrode group 6. 3 is a pressure-sensitive sensor provided between orthogonal parallel electrode groups.

FIG. 2 is a configuration diagram of an embodiment of the input position coordinate signal correcting method of the present invention, and 8 is a first group of leads drawn out from the first group of parallel electrodes 4 at a certain interval.

Similarly, reference numeral 9 denotes a second lead group drawn out from the second parallel electrode group 6 at a certain interval. Each lead group 8, 9 is connected to a corresponding coordinate signal generation switch group 10, respectively.

The coordinate signal generation switch group 10 is controlled to be turned ON or OFF by a control signal group 11, respectively.

12 is a constant current source, 13.14 is an amplifier, 15°16 is X
This is an input position coordinate signal in the Y orthogonal coordinate and is sent to the control system.

<Operation of the Embodiment> Since the configuration is as described above, when this is used, the operation is as follows. Before the control system enters the tablet use mode, after confirming that there is no input, switch group 1 for generating the seat ring signal.
The initial value 17 is taken in by sequentially turning 0 to 0N10FF using the control signal group 11. In this embodiment, Sw of the coordinate signal generation switch group 10
By turning on o, the signals (Xo, Yo
) is generated and taken in as an initial value, and by turning on SWn, the signal (xn,
yn) is generated and taken as an initial value.

Similarly, by turning on 5Wa (1≦a≦n), the input signal xa is input to the positions Lxa in the horizontal direction and LYa in the vertical direction.
+ya is generated and taken in as the initial value. FIG. 3 is an explanatory diagram of the correction method according to the present invention, taking the X coordinate as an example, and plots the distance on the horizontal axis and the position coordinate signal on the vertical axis. 17 is the initial value imported by the above operation, 18
is an ideal value when there is no linearity error.

Here, the correction formula for the section from LXa- to LXa is as follows.

Here, X: Actual input position coordinate signal Xa: Position coordinate signal at distance LXa from the origin (initial value) X a-J;
Position coordinate signal (initial value) X at a distance of "Xa-1" from the origin
a: Position coordinate signal (ideal value) at distance LXa from the origin
a-,: Position coordinate signal (ideal value) of distance Lxa-1 from the origin Similarly, correction formulas are stored for each of the X and Y orthogonal coordinates. The position coordinate signal actually input by hand is subjected to a correction calculation according to the above-mentioned correction formula, and then subjected to processing such as image display in the control system.

Other Modifications> Although the explanation has been given using a tablet as an example, the method according to the present invention is applicable not only to tablet input devices but also to electronic whiteboards, transparent input devices, and item input devices.

Furthermore, although the present invention has been described with reference to both the X and Y rectangular coordinates as objects of correction, it is also possible to correct only one of them. Furthermore, it can be applied to a case where the number of lead groups coming out at a certain interval is different from the orthogonal parallel electrode groups. In addition, the structure of the tablet input surface is not limited to a structure in which a pressure-sensitive sensor is sandwiched between upper and lower electrodes, but also a structure in which a protruding structure is formed on an insulator on either the upper or lower electrodes, the upper electrode, or the lower electrode without using a pressure-sensitive sensor. Needless to say, it can be applied to input surface structures as well, and has a wide range of applications.

<Effects of the Invention> As described above, according to the present invention, there is no need to trim the resistor in contact with the parallel electrode group, and the linearity of the input position detection device can be improved. In addition, it is no longer necessary to actually enter the reference point on the input surface in order to import the initial value for correction in the control system, allowing highly accurate initial values to be imported and stable correction possible. Become.

Furthermore, since the initial values are loaded each time the tablet is used, the optimum correction for the environment in which it is used is always performed. In addition, it has the excellent effect of eliminating the influence on the handwritten input position coordinate signal due to changes over time of the resistor etc. in contact with the parallel electrode group, so its industrial value is considerable.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of an input position detection device according to the present invention;
FIG. 2 is a block diagram of an embodiment of the input position coordinate signal correcting method of the present invention, and FIG. 3 is an explanatory diagram of the input position coordinate signal correcting method of the present invention. 1: Burnable insulating substrate, 2: Insulating substrate, 3: Pressure-sensitive sensor, 4. first parallel electrode group, 5: first resistor,
6: second parallel electrode group; 7. second resistor, 8: first lead group, 9: second lead group, 10: seated image signal generation switch group, 11 control signal group, 12: constant current groove, 13,
14: Amplifier, 15.16-Human position coordinate signal, 17:
Initial value, 18: Ideal when there is no linearity error (direct, 19
: Ideal straight line when there is no linearity error, 20: Actual coordinate signal output value.

Claims (1)

[Claims] In a parallel electrode group type input position detection device, lead groups (8, 9) are pulled out at a certain interval from the parallel electrode group (4, 6) and connected to the corresponding coordinate signal generation switch group (10). A method for automatically correcting input position coordinates, characterized in that coordinate signals are taken into a control system in advance by a control signal group (11), a correction formula is stored, and true input coordinate values are calculated using the correction formula upon actual input.