CN1512441A - Coordinate detection input system - Google Patents

Abstract

The coordinate detecting input system includes long straight wires for inputting X and Y coordinates and insulating and grounding device; control circuit for detecting electromagnetic field; depressing state detector; zeroing device for geomagnetic and other magnetic interference; and long straight wires and insulating and grounding device for zero correction of X and Y coordinates.

Description

Coordinate detects input system

Technical field

The invention relates to a kind of coordinate and detect input system, refer to that especially a kind of electric current that utilizes produces induced field, converts the system of induced voltage in the hope of the coordinate relative position to by induced field again.

Background technology

General coordinate input system is nothing more than two big classes are arranged: a kind of is contact, and a kind of is contactless.

Contact induction input system, as shown in Figure 1, usually utilizing an AC field to be positioned over one is covered with on the circuit face of lead track as Trackpad, respond on circuit face by the magnetic coil of oscillation source, thereby produce a corresponding induction current curve, be directly proportional with suffered magnetic field intensity by the induction current size, again by induction current through scanning the lead location of electric circuit inspection electric current maximum, the electric current that lead is responded to is via amplifying circuit, and A/D changes to learn the relative position of X-axis Y-axis.It is simple and easy that contact induction input system has action, the simple advantage of control circuit, but it is tired easily to have existed physical construction, the modification fracture, the energising electronic switch produces the spark noise, infiltrates aqueous vapor easily, the shortcoming of oil gas typically is represented as the coordinates of input devices of resistance-type.

And for example in contactless type, as condenser type, the coordinates of input devices of inductance type, same have a control circuit complexity, and production cost is difficult for reducing, and noise disturbs to be difficult for getting rid of and causes input jiffer, the unsettled shortcoming of coordinate input state.

Summary of the invention

The object of the present invention is to provide a kind of general traditional contact and contactless coordinate input system of being different from, make that the input of coordinate can quicker more stable use.

The present invention utilizes in the conductor of energising, ELECTRON OF MOTION is affected by magnetic fields can to produce skew, thereby cause the accumulation of conductor both sides electric charges, and then cause one with the electric current electric field vertical with magnetic direction, when arrival balance and stability state, conduction electrons is subjected to the electric power of this electric field just to offset magnetic force, electric current no longer is subjected to the influence in magnetic field, and the electric field of initiation can obtain by the voltage that measures the conductor both sides, relative when electric field big more, the magnetic field of being caused is also big more, and the voltage of the measurement that is obtained is also big more.

A kind of coordinate detects input system, and it comprises:

The long straight conductor and the insulation earthing device that are used for coordinate input system coordinate X-axis Y-axis;

Control circuit is as detecting the electromagnetic field size;

The detection device that has or not pressed state;

The clearing device of earth magnetism and other integrated magnetic field interference source; And

The check and correction of side in addition that corresponds to the X-axis Y-axis improves the long straight conductor and the ground insulation device of accuracy.

Further essence to above-mentioned purpose of the present invention and effect is understood, and please refer to embodiment shown in the drawings and is described as follows.

Description of drawings

Fig. 1 is the block diagram of existing contact sensing input device;

Fig. 2 decides the schematic isometric of side for the existing ampere right hand;

Fig. 3 is the cut-open view of Fig. 2, is inversely proportional in order to the size in expression magnetic field and the distance of long electric conductor:

Fig. 4 is the magnetic field size chart of the calculating gained and distance electric conductor of Fig. 3;

Fig. 5 is the schematic isometric of structure of the present invention;

Fig. 6 pushes detection device master pseudosection for the present invention;

Fig. 7 is a circuit diagram of the present invention;

Fig. 8 is magnetic field voltage conversion device among the present invention, relative voltage VP wherein to be detected and the coordinate figure of conductor spacing r, expression linear relationship therebetween.

Embodiment

According to Fig. 2 and Fig. 3, the electromagnetic principle of institute of the present invention basis is described.Fig. 2 is the expression Ampere's right-handed screw rule, wherein along the length direction inflow current 1 of long conductor 1, forms magnetic field 2 around long conductor 1.As shown in Figure 3, the magnetic field intensity that is set in radius r void is H, then by

φ HdL two I ... .. (1), wherein, dL is the path of integration of sealing,

As can be known:

By dL=rd θ, substitution formula (1)

φH∑rdθ＝i ....(2)

Magnetic flux B=μ H H=B/ μ, substitution formula (2)

B/μ∑rdθ＝I ....(3)

By ∑ rd θ=2 π r, substitution formula (3) B/ μ 2 π r=I

B＝μ/2πrI ....(4)

By formula (4) as can be known magnetic field size with apart from being inversely proportional to of conductor 1, as shown in Figure 4 apart from t.

Below with reference to Fig. 5,6 and 7 explanation the present invention.

Structure of the present invention makes the coordinate input system that an electromagnetic induction is changed, and mainly comprises: long straight conductor L1, the L2 of coordinate input system coordinate X-axis Y-axis and insulation earthing device; Control circuit 3 is as the detection device that detects the electromagnetic field size; What have or not pressed state detects switch 4; The clearing device of earth magnetism and other integrated magnetic field interference source; The in addition side check and correction that corresponds to the X-axis Y-axis improves the long straight conductor L3 of accuracy, 14 and the ground insulation device.

Control circuit 3 as shown in Figure 7, main system is by the long straight conductor L1 around the coordinate input, L2, L3, L4 is connected to the stable pulse power with microprocessor μ P control, obtain corresponding voltage by the magnetic effect element again, because of voltage with apart from long straight conductor the relation of linear inverse ratio is arranged, so draw the corresponding value of corresponding coordinate X-axis Y-axis.This device has linear relationship because of magnitude of voltage and X-axis Y-axis, so can directly represent the corresponding value of X-axis Y-axis and a push switch (as Fig. 6) is arranged on the magnetic field induction electric pressure converter with the magnitude of voltage of A/D conversion, when started by press on represents to push, this device will send the on signal to microprocessor μ P, make a check and correction flyback action at integrated magnetic field earlier by microprocessor μ P again.Then in regular turn four long straight conductors are sent pulse current by microprocessor μ P again.Can get a corresponding magnitude of voltage via the magnetic field induction conversion equipment when the L1 electric current flows through, this magnitude of voltage can get an X-axis coordinate values with respect to coordinate through the conversion of A/D analog/digital again.In like manner the coordinate values of Y-axis also is the induced field that produces via when the L2 electric current flows through, and obtains corresponding Y-axis coordinate values by the magnetic field induction conversion equipment again.

In order to improve the accuracy of system, at the L1 that flows through, L2, L3, the mean value of several pulses switch is adopted in the current impulse of L4, and L3, the corresponding long straight conductor of L4 is that auxiliary sampler, purpose are to improve the stable and accuracy of system.This magnetic field electric pressure converter corresponding voltage Vp to be detected with apart from r one linear relationship is arranged apart from long straight conductor, as Fig. 8.Then the Vp value of the big more conversion of induced field is big more near lead more when pressing operation point distance, then the more little then Vp of induced field value is more little when the pressing operation point leaves electrified wire, because there is one-to-one correspondence A/D conversion value and position, this device is directly represented pressing position with the A/D conversion value.

According on the structure chatted, the present invention mainly comprises length around the input system and directly conducts electricity and connect leading-in device and micro-computer controlling apparatus, magnetic field induction converter, the wired and radio transmission device formation of signal.

One end of the long straight conductor of the present invention around the coordinate input system is connected to the current/voltage source with microcomputerized control, and the other end of long straight conductor then is connected to earth terminal.This conduction connect leading-in device at electric current live end external demand wrap insulate earthing device to prevent other non-essential interference.

In sum, the coordinate that the invention provides a kind of a whole new mind mode detects input system, makes that the input of coordinate can quicker more stable use.

Claims (1)

1. a coordinate detects input system, it is characterized in that, comprising:

The long straight conductor and the insulation earthing device that are used for coordinate input system coordinate X-axis Y-axis;

Control circuit is as detecting the electromagnetic field size;

The detection device that has or not pressed state;

The clearing device of earth magnetism and other integrated magnetic field interference source; And

The check and correction of side in addition that corresponds to the X-axis Y-axis improves the long straight conductor and the ground insulation device of accuracy.

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