JPH012122A - digitizer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a patterned electrode layer and a movable stylus.
In a charge ratio digitizer tablet that establishes communication between the two by capacitively coupling the stylus with the electrode of the active coordinate determination area, the stylus is visually coupled with the electrode of the active coordinate determination area when the menu electrode is driven at a predetermined period. The present invention relates to a menu-embedded circuit configuration that includes a plurality of menu electrodes that select functions or modes depending on the menu electrodes.

[Prior art and issues]

A typical simple digitizer is the wedge strip type, which consists of a digitizer tablet and a cursor or stylus that moves over the tablet, using electric field coupling to ascertain the position of the cursor or stylus on the tablet. . However, the coordinate system usually refers to an xy coordinate system.

The cursor or stylus moves over the digitizer tablet and consists of a housing with a coupling electrode. In some embodiments, the input signal is applied to a coupling electrode of a cursor or stylus. The coupling electrode field is connected to wedge (sawtooth) strip pattern electrodes embedded in the digitizer tablet. confirming the Xlillill position of the cursor using one of the wedge strip pattern electrodes;
On the other hand, check the y-axis position.

Conventional wedge strip pattern electrodes are arranged coplanarly on a printed circuit board and covered with a layer of dielectric material to form a smooth tablet surface. In embodiments that drive coupling electrodes of a cursor or stylus, the patterned electrode induced signals are electronically processed to ascertain the relative position of the cursor with respect to the tablet.

According to the wedge strip digitizer disclosed in US Pat. No. 704,329, the coupling electrode outputs an induced signal to drive the pattern electrode. Digitizer tablet has X axis (X) signal Y axis (Y)
It is equipped with three patterned electrodes that output a signal and a balance (B) signal.

Among these, the X electrodes are composed of a plurality of dielectric rectangular strips arranged at equal intervals in the vertical direction so that the width gradually increases from one side of the tablet to the other side, that is, from the left side to the right side. The Ytlt pole also consists of a plurality of uniform dielectric wedges or sawtooths spaced vertically between the X strips. Even if the cursor moves in the X-axis direction, it does not affect the coupling with the X electrode, and moving the cursor in the y-axis direction does not affect the coupling with the X electrode much.

Balance (hereinafter referred to as rBJ)! The poles substantially cover the exposed (X, not covered by the X electrodes) areas of the digitizer tablet except for the interelectrode spaces.

The coupling electrode, located within the cursor housing and moving across the digitizer tablet surface, has a frequency of 1 typically 10 KHz to 1
is coupled to an oscillator with a frequency of Mllz and x
, induces electrical signals in the Y and B electrodes.

The surface area of the X electrode combined with the coupling electrode increases as the cursor or stylus moves toward the tablet side (wider side of the strip), so more electrical signals are induced in the X electrode.

Similarly, the surface area of the X electrode combined with the coupling electrode increases as the cursor or stylus moves into the tablet area (wider wedge width), so more electrical signals are induced in the X electrode.

Since the X, Y, and Bitt poles completely cover the position coordinate determination area of the tablet except for the narrow spaces between the electrodes, the sum of the X-Y and Bat pole signals substantially corresponds to the cursor (stylus) position. It is considered to be unrelated. The total signal mainly depends on the amplitude of the oscillator signal, the proximity of the coupling electrode to the X, Y, B electrodes, and the
It is determined by the dielectric constant of the material sandwiched between the Y and B electrodes.

Based on mathematical and electronics principles, the cursor's X coordinate is proportional to the X electrode signal divided by the sum of the X, Y, and B electrode signals. Similarly, the X coordinate of the cursor is proportional to the X electrode signal divided by the sum of the X, Y, and B electrode signals.

In theory, this ratio measurement technique should allow accurate measurement of the position of the cursor (stylus) regardless of its proximity to the digitizer tablet and the presence or absence of dielectric material between the two. .

Alternatively, the functions of the coupling electrode and pattern electrode can be reversed. That is, input signals are continuously applied to the X, Y, and B electrodes, and in response, an induced signal is output from the coupled electrode.

In a preferred embodiment of the tablet disclosed in U.S. Pat. No. 704,329, coupling electrodes disposed within the cursor housing are driven according to a predetermined pattern to move across the surface of the digital tablet. Coupled to one or more of the X, Y and B electrodes.

Alternatively, the coupling electrode can be incorporated into a stylus (hereinafter the term "cursor" shall also include a stylus used in place of a cursor).

The capacitively induced signal in the coupling electrode is output to a processing circuit that compensates for resolution distortion and determines the coordinate position of the cursor point.

The surface area of the X electrode coupled to the cursor is towards the tablet side where the width of the strip becomes wider.

It gets bigger as the cursor moves, so the
As the electrode is driven, the electrical signal coupled to the cursor also increases as the cursor moves in the direction of increasing strip width of the X electrode.

Similarly, the surface area of the Y electrode connected to the cursor is 1. The cursor becomes larger as it moves towards the increasing wedge width region of the tablet, so when the Y electrode is driven, the electrical signal coupled to the cursor also increases as the cursor moves in the direction of the increasing wedge width of the Y electrode. Become.

X, Y and Bffi from three drive circuits, respectively.
Square wave signals are applied to the poles and the coupling of these signals to the coupling electrodes of the cursor is sampled according to a predetermined sampling period. Each output signal is amplified, rectified, integrated and counted to form a digital signal representative of the amount of capacitive coupling induced in the cursor by the one or more driven electrodes.

Depending on the mathematical relationship of the wedge strip shape, a microprocessor performs numerical operations on the digital signals to obtain data X, in and Y representing the x, y coordinates of the cursor position on the digitizer surface. That is, in X□. =2CX/(CX10, +C3) (1)Y□. =
20Y/(CX 10 CY 1 CB) (2) In the formula, Cx is
CY is a digital value corresponding to the electrode induced signal, and CY is
It is a digital value corresponding to the Y electrode induced signal, and C
8 is a digital value corresponding to the B electrode induced signal.

, the patterned electrodes have O<X, <1, and O<Y, <
1in in
It is formed so that Let C be the cursor (stylus) output signal when the x, y and B electrodes are driven simultaneously, that is, the digital value representing CX 10, 108.
tus for Calibration of a c
As disclosed in US patent application Ser.
Determine the CY and C8□ values and compensate for noise and offset.

CX=AX-BX(3) CY=AY-BY(4) C=A, -B (
5) In the sum sum sum formula, A
X, AY, and AsuIll are the digital values (i.e., original readings) obtained in response to the X electrode being driven alone, the Y electrode being driven alone, and the X, Y, and B electrodes being driven simultaneously during stylus (cursor) activation, respectively. , and BX, BY, and Bsum were obtained respectively when the stylus (cursor) was not activated, when the X electrode was driven alone, when Y'#, the pole was driven alone, and when the X, Y, and B electrodes were driven simultaneously. A digital value (i.e., a background reading).

To compensate for noise and offset, the stylus (
cursor) when inactive, Bx, By and Bsum
A digitizer is provided that is configured to read.

Each background reading is the sum of a digital value corresponding to environmental/inherent noise and a digital value corresponding to an offset, and this total background digital value is stored and used when counting, i.e. when the stylus (cursor) is actuated. Subtract from the resulting reading.

A microprocessor calculates the data obtained using correction factors to compensate for resolution distortion.

Due to the above-mentioned inherent distortion, the xy coordinates cannot be determined only from the values 2CX/Cf3u and 2C9/C5u0. To determine this, a calibration is performed to compensate for resolution distortion, but this calibration is performed using a small conductive plate built into the digitizer tablet, i.e.
Process the output signal of the phantom cursor J.

The patterned electrodes of conventional charge ratio tablets form an active surface area that is used to determine the position coordinates of a stylus (cursor) coupled to the tablet; Another problem is that the tablet does not have a menu means for selecting the mode.

[Means to solve the problem]

A first object of the present invention is to provide a charge ratio tablet that overcomes the above-mentioned drawbacks of conventional charge ratio tablets by incorporating a menu for selecting functions or modes.

A second object of the present invention is to provide a charge ratio tablet comprising a plurality of pattern electrodes for determining the position coordinates of a cursor (stylus) and at least one menu electrode for selecting a function or mode when the cursor (stylus) approaches. Our goal is to provide the following.

The third object of the present invention is to use a handheld cursor (stylus)
An object of the present invention is to provide a charge ratio tablet that performs counting and mode selection using the present invention.

The above object is achieved by providing the charge ratio digitizer with at least one menu electrode driven with the same drive signal that drives one or more of the X, Y, B electrodes.

These menu electrodes are configured such that approaching a driven menu electrode induces a signal on the cursor (stylus) (outside of the signal induced when approaching simultaneously driven X, Y and B electrodes). has been done. The processing circuit is programmed to first detect that the cursor is not close to the shudder determining area formed by the X, Y, and B pattern electrodes, and then detect whether the cursor (stylus) Detect whether the vehicle is approaching This is done by sequentially testing the amplitude of the signal induced during the drive cycle. Next is the processing circuit.

Responsive to detection of predetermined signals in accordance with its program instructions.

According to a preferred embodiment of the present invention, the first and second sets of menu electrodes are formed outside the coordinate determining area formed by the X, Y and B electrodes on the tablet surface. Each of the plurality of electrodes is comprised of three menu electrodes having substantially the same configuration, but the first and second sets of menu electrodes have different configurations.

The first, second and third menu electrodes of each set are driven with the same drive signals that drive the X, Y and B electrodes, respectively. Each menu electrode of the first and second sets (
(referred to as a "first configuration" and a "second configuration," respectively) are signals that are different from those induced by driving the menu electrode having the first configuration and in response to driving the menu electrode having the second configuration. , and a difference in this induced signal can be detected by a processing circuit.

Because it has the ability to detect differences in induced signals resulting from differences in the configuration of each set of menu electrodes, the processing circuitry
It can be determined which set of electrodes the cursor is close to, ie, which set of menu electrodes are capacitively coupled to the cursor electrode.

Also, X, Y and B electrodes (and corresponding menu electrodes)
are sequentially driven, the processing circuit determines which of the sequential drive signals has preferentially detected the induced signal from the cursor electrode, and determines which of the three menu electrodes is the one that detects the cursor electrode. It can be determined whether the electrode is capacitively coupled.

Accordingly, in a preferred embodiment, the processing circuitry detects which of the six menu electrodes (i.e., menu spots) the cursor electrode is close to and then performs the function corresponding to the selected menu spot. Run or enter mode. That is, the processing circuitry can be programmed according to a menu of desired functions or modes.

〔Example〕

Next, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, the strip wedge digitizer (10) has a cursor (20) or stylus (
(not shown), a tablet (40), and an electronic device (100) that provides input signals to the cursor and processes output signals from the tablet; It is made.

In a preferred embodiment of the invention, the digitizer-electronics (1
00) is incorporated in the casing below each layer of the tablet (40) shown in FIG. 2. The circuit diagram of the printed circuit board of this embodiment is shown in FIGS. 6(A) and 6(B). As shown in the figure.

As shown in Figure 1, a digitizer (10) typically comprises a computer (2) having an associated display monitor (3).
) is used as an input device. The monitor (3) is connected to the tablet (4) indicated by numbers (4) (5) on the screen.
Coordinate values representing the relative position of the cursor (20) with respect to the cursor dot (6
) (the position on the screen is adjusted by the position of the cursor (20) on the tablet (40)).

FIG. 2 shows a cross-sectional view of the cursor (20) and a portion of the tablet (40). However, you can also use a stylus instead of a cursor. Cursor (20
) comprises a housing (21) having a depending circumferential side wall (22) that fits flush against the surface of the tablet (40).

On the lower side of the housing (21) (by means not shown)
An annular ground or shield electrode (32) is attached. An annular dielectric spacer (31) is fixed to the lower side of the shield electrode (32) so as to be in contact with the shield electrode (32), and a side wall (22
) such that the edges of the annular coupling electrode (30) are substantially parallel to the tablet surface when seated on the tablet surface.
is fixed.

The diameter of the shield electrode (32) is slightly larger than that of the coupling electrode (30), and overhangs the circumference of the coupling electrode (30).

The coupling electrode (30), dielectric spacer (31) and ground electrode (32), together with the housing (21), are arranged in a circular central opening (34) in which the cross mark (35) is positioned.
). The cross mark (35) is located at the center of the coupling electrode (30). The inner and outer circumferences of the coupling electrode (30) are preferably circular. However, as long as the direction of the cursor does not affect the electrical connection with the tablet electrode, other layers may be used.

The electrical cord (25) connects the cursor (20) to the digitizer-electronic device (100) and connects the terminal (
27), the signal conductor (2) connected to the coupling electrode (30)
6).

A coaxial peripheral conductor (28), ie a coaxial shield, is connected at a terminal (29) to a shield electrode (32) in the cursor. In an embodiment for driving a cursor, from the signal line (26) to the coupling electrode (30), as described below.
sends a drive signal to. In the embodiment driving the tablet electrode, the induced signal is output from line (26).

The cursor housing (21) is shaped to fit comfortably in the hand and includes a series of button switches (37) (see FIG. 1) that communicate with the computer (2).

Instead of this cursor, select [Digitizer stylus with pressure transducer (Digitizer 5tylus w
A pressure sensitive stylus similar to that disclosed in US patent application Ser.

During each sampling period, the stylus output signal is sampled to determine the amplitude of the signal as a function of the pressure applied to the stylus tip (see pressure cycle in FIG. 8).

If no current is capacitively induced in the stylus anode during this sampling period, the stylus is unusable. Instead, a voltage is applied across the stylus terminals to cause current to flow through a circuit that includes a sensitive resistive transducer that acts as a variable resistor. The transducer is formed of a force sensitive resistance (FSR) material whose resistance varies as a function of compressive force applied in a direction approximately perpendicular to the plane of the transducer layer.

The resistance of the FSR transducer decreases as the compression force increases,5 and this resistance variation changes the dc level of the analog signal output during the pressure sample link.

A comparator built into the digitizer electronics is used to detect the dc level of the output signal from the pressure sensitive stylus.

The dc level is compared to the substrate voltage supplied to a comparator.

As the pressure on the stylus tip increases, the resistance of the FSR transducer decreases, thus increasing the da level of the analog signal. When the DC level of the analog signal exceeds the reference voltage,
The output of the comparator goes high and the switch closes in response, sending digitized data from the stylus to the processing circuitry of the digitizer electronics during the X, Y and SUM drive periods.

“Method and Apparatus for Calibrating Charge Ratio Tablets”
d and Apparatus for Calib
ratio of aCharge Ratio T
The quantified data is also responsive to signals induced at the anode by one or more drive pattern electrodes of the charge ratio tablet during the drive period, as disclosed in U.S. Pat. and output via the stylus terminal, which is staggered during the sampling period.

Therefore, the FSR converter of the pressure-sensitive stylus acts as a variable resistor, and the switch of the digitizer electronics
Closes in response to variable resistance reaching a predetermined value. This predetermined resistance value must be obtained at a pressure slightly lower than the pressure applied to the tip of the refill pen tip when writing with the stylus.

The position of the stylus tip relative to the digitizer tablet is determined only with respect to the position of the stylus tip where the pressure of the stylus tip relative to the tablet exceeds a predetermined pressure value, that is, the position of the stylus during writing. This predetermined pressure value is the pressure at which the analog signal output from the stylus exceeds the stored predetermined analog value, and in response to this stylus output signal, determination of the stylus tip position is started; When the pressure exerted by the stylus tip drops below a predetermined value, positioning is aborted.

The digitizer tablet (40) is generally rectangular and has a planar top surface (41) on which the cursor (20) is moved.
)have.

According to the invention, the top surface (41) includes X, Y and BT [
! The menu electrode is divided into a first area that covers the menu electrode, and a second area that is located outside the first area and covers the menu electrode (see FIG. 7(A)).

The predetermined position of the cursor in the first area can be represented by a finite two-dimensional coordinate system, but only the right angle part of the first area constitutes an active coordinate determination area that is the same as the finite two-dimensional coordinates. Therefore, the X, Y and B electrodes extend beyond the active coordinate determination area and lie below the tablet periphery, but these peripheries cannot determine their coordinates once the 14°-cursor is over the edge. In that sense, it is inert.

In a preferred embodiment, a copper border serving as a shield (46) is provided between the upper layer (42) and the electrode layer (44).
This is done by providing (46) (see Figure 2). (However, no shield is provided over the menu electrode.) Instead, it is possible to avoid processing X and Y values outside the predetermined limited values corresponding to the edge of the active coordinate determination area.
The microprocessor may be programmed in the same way.

Therefore, the cursor position on the inert periphery is x, y
It cannot be expressed in coordinates. The coordinate system used in the preferred embodiment is a Cartesian x-y coordinate system.

The digitizer tablet (40) is provided with a plastic cover (42), which allows a smooth top surface (41) to be formed. Outside the tablet active area below the cover (42) there is a copper shielding border (46), below which is a layer of dielectric material (43).

Further, directly above the dielectric material layer, an electrode layer (see FIGS. 7(A) to 7(C)) consisting of 44) is provided.

In one embodiment of a conventional digitizer, the digitizer
The tablet is connected to the electronic circuit by a multi-core cable (48) (see Figure 3). Figures 3 and 4
The figure shows the conventional basic structure of the X, Y, and B electrodes. The electrode layer (46) has a pattern of electrodes (50) varying in the X direction.
, a pattern electrode (60) that changes in the Y direction, and
A pattern electrode (70) is provided between the electrodes and outputs a balance (B) signal. Electrode (50) (60) (7
0) are arranged in substantially coangular rectangular shapes and are surrounded by a shield electrode (80).

Since FIG. 3 shows a conventional tablet, the menu electrode (which is incorporated into the tablet) according to the present invention is not shown.

The X electrode (50) is connected to the electrode layer (
46) - multiple strips connected along the edge (
51) (52) (53) (54).

The strips extend substantially parallel to each other in the Y direction from the - side of the bus (58) and have centerlines that are substantially equally spaced apart, the width of each strip being approximately equal to the width of the tablet ( It gradually becomes wider in the X direction from the - side of 40) to the other side, and the strip (52) is wider than the strip (51), and the strip (52) is wider than the strip (52).
53) is provided over the entire surface.

Electrical signals stored on either strip are connected to the bus (
58) to an X-axis signal lead wire (59) that forms part of the multi-core cable (48).

The Y electrode (60) has a sawtooth or wedge pattern consisting of identical wedges sandwiched between the strip patterns of the X electrode (50). Namely.

The Y electrode (60) includes a plurality of wedges (61) extending in the Y direction and interconnected by a Y-axis bus (69).

Each wedge (61) has a bus (61) as a wedge extension.
68) to the narrow road end (64) adjacent to the X-axis path (58).
) consisting of an elongated substantially triangular area with wedges (62) (63) converging towards (63), the wedges and the strips being equidistantly spaced midway between adjacent strips such that they are between each other. has been done. Also,
The Y-electrode (60) comprises a bus (68) connected to the digitizer electronics (100) by a signal lead (69) forming the negative part of the multi-core cable (48).

The electrode layer (46) of the digitizer tablet (40) further includes an electrode N (46) area between the areas occupied by the X and Y electrodes (50) (61), excluding the residual gap between adjacent electrodes. A balance (B) electrode (70) is incorporated. The B electrodes (70) are in the form of elongated legs (71) (72) (73) arranged in a serpentine arrangement between the intervening wedge and the strip and between the wedge strip tip and the opposing bus. .

For example, the legs (71) and (72) are the strips (5
1), and the legs (72) and (73)
are in lateral contact with the wedge (61) and are interconnected by a coupling section adjacent to the X-axis bus (58) and the Y-axis bus (68), such as legs (71) and (72).
are connected by a section (74) between the ends of the strip (51) and the Y-axis bus (68).

The BtR pole (70) is connected to the digitizer by a signal lead (75) forming part of the multi-core cable (48).
Connected to an electronic device (100).

The electrode layer (46) further includes a shield electrode (80) provided around the X, Y, and B electrodes;
80), as shown in Figure 3, the cable (4
8) Can be connected to the shield.

Electrodes (so) (60) and (70) are electrically isolated from each other by a spacing gap. Details of the gap are shown in FIG. 4, which is a partially enlarged view of the electrode layer (46) in FIG. 3. The small spacing or gap provided between adjacent electrode edges is designated by the symbol (S).

The spacing is generally constant for a given electrode layer (46), but varies between production source and production run.

FIG. 4 is schematic; the actual strip wedges and spacing (S) are more precise.

In some embodiments, the unit length (1 inch)
) are provided with five X-pattern strips and a Y-axis pattern wedge, respectively.

For example, the width increases from one X-axis strip to an adjacent strip, such as strips (52) and (53) in FIG. 3, by approximately 0.001 inches.

The digitizer tablet (40) each has a valid coordinate determining surface limited to the wedge strip area of the X electrode (50) and Y electrode (60), but the valid digitizing surface generally includes: The X-axis bus (50) and Y-axis bus (68) are not included.

Coupling electrode (30) of cursor (20) (see Figure 2)
and the coupling electrode of the pressure sensitive stylus (not shown) is X,
Tablet I-(40) is dimensioned to allow capacitive coupling of the coupling electrode to a plurality (preferably at least 5) of strips and wedges when driving the Y electrode.
is separated from. Therefore, at any time, each X, Y,
Several elements of the B electrode can be coupled to a coupling electrode.

X electrode (50), Y electrode (60) and B electrode (7o)
is formed of copper, silver, conductive ink, or other conductive material and is deposited on the printed circuit board forming material that constitutes the dielectric layer (43).

During the manufacturing process, electrodes are printed with conductive ink on a thin film made of Mylar or a similar material, and the resulting thin film is attached to the top surface of the dielectric layer (43) or the bottom surface of the plastic cover (42). do.

The Wedge° Strip Digitizer has a cursor (2
0) bonding electrode (30) and the tablet (40) X,
It operates by capacitive coupling with Y and B pattern electrodes. In one embodiment, the drive signal input to the cursor (20) is sent to the electrodes (50) (60) (70), and the output signals from the electrodes are processed to , find the Y coordinate.

In a preferred embodiment of the invention, the electrode (50) is connected to a square wave oscillator.
(60), (70), and associated menu electrodes, and send the cursor binding signal to the electronic circuitry (see Figures 6(A) and 6(B)) for sequential processing and the tablet (40). ) or find the function or mode selected from the menu (300).

A pseudo cursor electrode (
240) is provided. The remaining processing circuitry is shielded from the electrode (44) by a shield layer (not shown). The pseudo cursor electrode is disposed on the electrode layer (44) near the tablet corner so as to be capable of capacitive coupling, and has predefined x and y coordinates at its center.

The pseudo-cursor electrode consists of a circular conductive plate facing the electrode layer (44) across a space and is dimensioned to underlie at least one wedge and strip. The position of the pseudo cursor electrode on the tabletop 1- in FIG. 3 is indicated by a dotted circle, but its dimensions are not to scale.

As an example of actual size, one side of the tablet is 30.48cm.
(12 inches), the base of each wedge is 0.5
3 mm (0,021 inch), and the diameter of the cursor is also only 1.07 mm (0,042 inch).

The cursor electrode (240) is connected to the line (C) shown in FIG. 6(A).
At I), the digitizer is connected directly to the electronics.

In accordance with the present invention, the digitizer tablet is expanded to include a menu in addition to the coordinate determination area shown in FIG. The menus are X, Y,
It consists of a plurality of menu electrodes driven by the same drive signal that drives the B electrode. Connect the menu electrode to the conductor (
59) (69) can be connected to the junction along (75), but in a preferred embodiment of the invention, the menu electrode and
The Y-B electrodes are connected in a striped pattern (details will be shown below).

FIG. 5 is an example of a preferred connection between a digitizer-electronic device (100) and a tablet (40). Figures 1 and 3
Unlike the conventional example shown in the figure, both cables are not multi-core cables, but are made of flexible materials such as metal foil and plastic, and conductive layers (281 ), and an insulating layer (282
) connected by stripes (280).

The first set of multiple conductive layers (281) includes a conductive junction electrode (22
0) and (270), the second set connects conductive bonding electrodes (222) and (272), and the third set connects electrodes (222) and (272).
The fourth set connects electrodes (226) and (276).

Each bonding electrode consists of a conductive plate, and each bonding electrode (22
0) (222) and (224) are connected to drive circuits (214), (216), and (218), respectively, and the bonding electrode (226) is grounded (see FIG. 8(A)). The drive signals output from the drive circuits (214), (216), and (218) are transmitted to the bonding electrode (220), respectively.
(222) (224), striped strip (280),
and conveyed by bonding electrodes (270) (272) (274).

As best shown in FIGS. 7(A) to 7(C), the bonding electrodes (270), (272), and (274) are connected to the X, B, and Y electrodes, respectively, and the menu electrode ( 284) (286) (288), and (
285) (287) (289) are connected.

In a preferred embodiment, menu electrodes (284) (286)
(288) are each plate-shaped, and menu electrodes (285), (287), and (289) are each composed of a plurality of bar electrodes.

As shown in FIG. 7(A) to FIG. 7(C), the menu electrode (2g4) (28s), the bonding electrode (270) (via the conducting wire (293)), and the bus (55) are connected to each other. , by connecting it to the bus conductor (290) and forming a first circuit? X received at ttt4 (270)
The drive signal is sent to the menu electrodes (284) (285) and X1i! Simultaneously transmit to the pole (50).

The menu electrodes (286) (287) are connected to the bus conductors (2
91) to the bonding electrode (272), and the bonding electrode (272) is connected to the B electric tfi by a bus conductor (294).
(70) to form a second circuit, thereby simultaneously transmitting the B drive signal received at the junction electrode (272) to the menu electrode (286) (287) and the B electrode (70).

Further, the menu electrodes (288) (289) are connected to the bonding electrode (274) by a bus conductor (292), and the bonding electrode (274) is connected to the Y electrode (60) by a bus conductor (295). , by forming a third circuit, the Y drive signal received at the junction electrode (276) is simultaneously transmitted to the menu electrode (288) (289) and the Y electrode (60).

Menu electrodes (284) (286) (288) are
respectively, connecting the coupling electrode of the stylus to said electrode (284).
(286) When the stylus is capacitively coupled to one driven electrode in (288), the stylus induced signal is the signal induced when the stylus is capacitively coupled to the three electrodes while the X, Y, and B electrodes are being driven simultaneously. is configured so that it is outside the range of

Also, menu electrodes (285) (287) (289
) respectively connect the coupling electrode of the stylus to the electrode (2).
85) (287) When capacitively coupled to one driven electrode of (289), the stylus-induced signal becomes x, y,
The structure is such that during simultaneous driving of the B electrodes, the signals are outside the range of signals induced when the stylus is capacitively coupled to the three electrodes.

Furthermore, during the X, Y drive period, the stylus-induced signal pair obtained when the stylus is capacitively coupled to one of the six menu electrodes falls into a different range pair of each menu electrode.

Based on the difference in these induced signals, the processing circuit first determines whether there is capacitive coupling between the stylus and the coordinate determining electrodes (X, Y, B electrodes), and if the answer is No, the stylus is connected to any menu electrode. It can be determined whether there is capacitive coupling.

Menu electrodes (284) to (289), conductor wires (290
) to (295), and bonding electrodes (270) (27
2) (274) (276) are all electrode layers (4)
This is part of 3).

Bonding electrode (220) (222) (224) (22
6) is attached to a printed circuit board (236) made of dielectric material.

On the other side of the circuit board (236) are electrodes (220), respectively.
) (222) (224) (226), conductive plates (228) (230) (232) (23
4), each pair of opposing plates separated by a circuit board (236) forming a capacitor array.

Therefore, the drive circuit (214) (216) (21
The driving signals output from the bonding electrodes (2)
20) (222) (224), the plate (22
8) Corresponding signals are capacitively induced at (230) and (232), respectively.

Next, a hardware configuration according to a preferred embodiment of the present invention will be described with reference to FIGS. 6(A) and 6(B).

The digitizer electronics consists of a microprocessor (2) consisting of an Intel (Intθ1) type 8031 chip.
00), but other 8-bit microprocessors can be used instead. The microprocessor (200) controls the driving of the X, Y, B electrodes, mode selection, integration of cursor output signals, transmission of position coordinates, and resetting and actuation of counters, switches, latches, and storage chips.

Pins (po, o) to (Po, 7) of the microprocessor (200) are connected to pins (Di) to (D8) of the buffer (204). Its address logic enable (ALE) pin is also connected to the latch enable (LE) pin of the buffer (204). Output terminals (pins) (Ql) to (Q8) of the buffer (204)
are the pins (AO) of the external storage chip (206), respectively.
) to (A7).

Output terminals (pins) (QO) to (Ql) of the memory chip (206) are each connected to a line of the data bus (202). 'The lines of the data bus (202) connect to the microprocessor (200) and buffer (204), respectively.
) is connected to the connection line.

The pin (PSEN) of the microprocessor (200) is
Connected to the output enable (OE) pin of the external storage chip (206). The external storage chip (206) includes
Program instructions are stored, some of which are shown in appendix 8A and B. These program instructions are
These correspond to the flowcharts shown in FIGS. 9 and 10, respectively.

The data bus (202) line further includes a buffer chip (
208) are connected to output terminals (pins) (Ql) to (Q8). Additionally, the output enable (OC) pin of the buffer chip (208) is connected to the microprocessor (20
0) is connected to the readout (RD) (pin) of the input terminal (
Pins) (Dl) to (D8) are respectively counters (
210) output terminals (pins) (Ql) to (Q8). The reset terminal (R) of the counter (210)
) is the pin (PL, 6) of the microprocessor (200).
), and the pin (CLK) connects to the oscillator (20
1) through an AND gate (256).

The oscillator (201) is connected to the CLK pin of the counter (212). The counter (212) has one oscillator (2
86KH which frequency divides the 1 1, 0592MHz signal input from 01) and oscillates a square wave from the pin (Ql).
Drivers (214) (216) (218) that output z signals and are connected to bonding electrodes (220) (222) (224) arranged on the negative side of the printed circuit board, respectively.
Ship directly to. Incidentally, the fourth bonding electrode (226) is grounded.

As clearly shown in FIG.
2) (224) and (226) are conductive plates (
228) (230), (232), and (234) are arranged to face each other, forming the anode and cathode of each capacitor, and are separated by a dielectric material layer (236). Also, conductive plates (228) (230) (232)
(234) is the pin (15) of the switch circuit (238)
connected in series.

A pseudo cursor (240) embedded in the control panel is connected to a pin (H) of a switch circuit (238). The stylus or cursor is connected to the connector (J2) terminal (3).
The connector is connected to the switch circuit (23
8) is directly connected to the pin (14).

The switch circuit (238) is connected to the microprocessor (20
0) and pins (4) and (14).
) received at either selected signal (or
(none of them) is output to the negative terminal of the preamplifier (242). The switch circuit (238) outputs the output bins (Q5) (Q6) (Ql) of the latch circuit (244).
The switching operation is performed according to the control bit data received at pins (9), (10), and (11) connected to the terminal.

The latch circuit (244) is connected to the microprocessor (200
) via the data bus (202) (on pins (Dl) to (D8)). As mentioned above, 3 bits of the 8-bit signal are sent to the switch circuit (
The other three bits control which driver (214) (216) (218) is activated. The latch enable (LE) pin of the latch circuit (244) is connected to the microprocessor (20
It is directly connected to the write (WR) pin of 0).

The output of the preamplifier (242) is connected to the positive terminal of the amplifier (246). Also, the amplifier (246)
The output terminal of the switch circuit (250) is connected to the switch (S
The output terminal of the amplifier (248) is connected to the positive terminal of the comparator (252), and the capacitor (C
33), it is fed back to the negative input terminal.

The amplifier (248) and capacitor (C33) form an integrator. The output terminal of the comparator (252) is connected to the clock terminal (CLK) of the counter (210), and in response to the input signal from the amplifier (248) reaching a predetermined level, the counter (210) is clocked. Issues an operation stop signal. The output terminal of the comparator (252) is further connected to a pin (Pl, 4) of the microprocessor (200).

The switch circuit (250) includes a microprocessor (20
0) are controlled by four switches (SWI) to (SW
4). For example, the switch circuit (250)
Pin (12) (controls switch (SW4)) is:
It is directly connected to the pin (Pl, 7) of the microprocessor (200), and the pin (5) (which controls the switch (5113)) is connected to the pin (3, 5) by the pin (Pl, 7). /(6) (which controls switch (SV2)) is connected to pin (r'1.6) via driver (254), and pin (13) (which controls switch (SWI)) is connected to AND gate (256 )
are connected to each other.

In addition, the input terminal of the AND gate (256) is connected to the pin (Q) of the counter (212) via the latch circuit (244).
7) and microprocessor (200) pin (po
, o) to operate.

The switch circuit (250) controls charging, discharging, and resetting operations of a capacitor (C33) connected in parallel with the amplifier (248).

EFROM (258) is a microprocessor (20
0) to pins (Pl, O) to (Pl, 3), and stores special routines executed by the microprocessor.

Finally, the transmit (TXD) pin of the microprocessor is
Connected to pin (C) of level shifter (262),
The pin (Z) of the shifter (262) is connected to the terminal (7) of the jack (Jl) transmitting to an external device according to the R5232 protocol. Microprocessor (2
The pin (TXD) of 00) is further connected to the inverter (264
) to transmit data to the TTL device.
1) is connected to terminal (4).

The receive (RXD) terminal of the microprocessor (200) is connected to pin (5) of the jack (Jl) via a resistor (R18) and an inverter (266).

8-10, details of the operation of a wedge strip digitizer according to the present invention incorporating a function or mode selection menu will now be described.

A typical sampling period in counting mode (see Figure 8) includes at least the following: (1
) Drive only the x electrode to sample the cursor (stylus) output signal. (2) Simultaneously drive the X, Y, and B electrodes to sample the cursor (stylus) output signal. (3) Drive only the Y electrode and sample the cursor (stylus) output signal.

Using a pressure sensitive stylus with a tablet, the stylus output signal can be sampled during the fourth sampling period to determine the amplitude of the signal as a function of the pressure on the stylus tip.

The output signal of the stylus is sent to the input pin (14) of the switch circuit (238) (see Figure 6(A)). The switch circuit (238) receives the stylus output signal from the latch circuit (244) via the pin (11) and receives the control signal (stylus output switch control (STY
LUS 0UTPUT 5liilITCHC0NTR0
output pin (12) or (13) depending on the
Switch to

When the stylus output switch control signal is H, the input pin (14) is connected to the output pin (12), so
The signal is sent to a preamplifier (242).

If it is L, the input pin (14) is the output pin (13)
Since the signal is connected to the amplifier (248), it is directly sent to the amplifier (248).

As shown in FIG. 8, the stylus output in response to the X5UN and Y drive cycles is sent to the preamplifier (242), and the stylus output in response to the pressure pulse is sent to the amplifier (242).
48).

During the fifth sampling period, the background noise level is determined by driving one or more of the X, Y, and B electrodes and measuring the input signal of the amplifier (248); during this period, the stylus output switch The control signal is L.

The sampling period for the preferred embodiment of FIGS. 6(A) and 6(B) is shown in FIG. 8. The duration of each cycle is 1
It is 3.9 milliseconds. The output of the integrator (amplifier (248) and capacitor (C33)) is shown in the upper part of FIG.

First, the X electrode is driven for a time (T), and the capacitor (C
33). The counter (210) starts counting when the capacitor (C33) starts discharging and stops when the integrator output reaches a predetermined level. Second, time T
After driving the X, Y, and B electrodes simultaneously, the capacitor (C33) is discharged again, and the discharge time is counted again by the counter (210). Third, the X electrode is driven for a time T, and the discharge time of the capacitor (C33) is counted by the counter (210).

During the first to third stages described above, the stylus is in an enabled state and a capacitively induced current is output from the stylus. In the next 4th and 5th stage.

The stylus is in a disabled state and produces no capacitively induced current.

In the fourth stage, the pressure applied to the tip of the stylus is measured, but this fourth stage is provided only when a stylus is used. The stylus position coordinates are determined when the stylus is pressed against the tablet with at least a predetermined pressure. Especially when using styluses and tablets with signature verification methods.

Pressure information is required.

In the fifth stage, the stylus is disabled and a background reading is taken while driving one or more electrodes. with inherent environmental noise and integrator (UR1).

Due to the offset due to the difference in reference potential with the comparator (LIR2), the capacitor (C33) stores a charge that produces a finite discharge time even when no capacitively induced current is drawn from the stylus.

Since the discharge time is used as a measure of the stylus output signal, the finite discharge time due to noise and offset must be subtracted from the actual discharge time measured when the stylus is enabled. This compensation method is disclosed in co-pending US patent application Ser.

In response to continuous driving of only the X electrode, the X, Y and B electrodes, and only the
, /C to find the x and y coordinates of the cursor position50
However, in reality, the coordinates obtained in this way deviate from the actual coordinates because there is a gap between the electrodes. Correct the relationship between data at arbitrary points and data between digitized points by the space required between electrodes.

Prevents conduction between electrodes.

The actual quantification result and calibration result are, for example, 0.254
It varies depending on the size of the gap, such as mm (10 mil) or 0.381 mm (15 mil). As disclosed in the above-mentioned US patent specification, for example, if a pseudo cursor (240) is placed with high precision at a well-known spot near the tablet corner and the actual measurement data and mathematical preliminary data are combined, the vIi pole The amount of resolution distortion caused by the gap can be determined.

FIG. 9 shows a flowchart for executing a menu routine in response to capacitive coupling between a stylus coupling electrode and a selected menu electrode. The corresponding routines are listed in Appendix A.

As shown in lines 1912-1918 of Appendix A, the microprocessor compares the St1M signal to a predetermined threshold to determine if the stylus is "out of proximity" to the coordinate determining electrode. X.

This indicates that the degree of capacitive coupling with the y, s and ta voltages has become below a predetermined threshold. ).

If not in close proximity, the microprocessor is shown schematically in Figure 9 and marked with #! A (lines 1930 to 205
8) Out of proxy
mity) Execute the J menu spot identification routine.

According to the routine in Figure 9, if the stylus is in anti-proximity, reset the good data counter (
Block 302) L, set low amplitude flag.

When the stylus approaches the coordinate-determining electrode, a useful data counter is used, and resetting the counter is a preliminary step to return the stylus to the proximity state (however, this is not the main idea of the present invention, so the details will be omitted). ).

The next step is to calculate the x,y coordinates (block 30
4). That is, in response to the X and Y drive signals, each count value corresponding to the discharge time of the induced signal is stored. Next, the microprocessor tests to determine whether the menu function is enabled (block 306).

When enabled, each range of X and Y values corresponds to one of the six menu electrodes by testing the X and Y values to identify the menu electrode to which the stylus is capacitively coupled. Determine whether it is within the range. In an operative embodiment of the present invention, the X, Y limits of each menu electrode are linear.

Y1=7000-8500. X1=500-18
00; Y2=4000-6500. X2=500
-1800; Y3=1000-2500. X3=
500-1800;'/4=1500-3000.
X4=2000-4300; Y5=1000-250
0. X5=6000-8500:Y6=1800
-3500. X6=4500-6000: However, the limited value changes depending on the shape of the menu electrode, the arrangement state of the menu electrode on the tablet, and changes in ambient conditions.

Furthermore, even if the X ranges overlap, the corresponding Y ranges do not overlap. For example, XI, X2 and x3 are in the same range, but Yl, Y2 and Y3 are in different ranges. Similarly, even if the Y ranges overlap, the corresponding X ranges do not. For example, Y4. Y5 and Y6 overlap, and X4. X5 and x6 do not overlap.

Thus, by testing the X and Y count values to identify capacitively coupled menu electrodes, one can determine which range the X and Y count values fall into.

These series of steps are performed by the decision block (30) in FIG.
7) to (318). Y count value.

range Y1 and the X count value is in range XI, the microprocessor executes the next step (block 3).
20) in the menu routine MENUSI (Appendix B).

Lines 2618 to 2625) are executed.

If No, the Y count is tested to determine whether it falls within range Y2, and if it does, the X count is tested to determine whether it falls within range X2.

Once the X count and Y count are in range x2 and range Y2, respectively, the microprocessor in the next step (block 322) enters the menu routine MEN
Execute US2 (Appendix B, lines 2630-2637).

Conversely, if NO, the test procedure continues as shown in FIG.

When the X, Y count pair falls into a lunge of the six pairs of x, Y ranges, the corresponding menu subroutine is executed. In the preferred embodiment, these menu subroutines include:
At least a subroutine for lowering the r anti-proximity threshold level, a subroutine for increasing the r anti-proximity threshold level,
A subroutine to increase the stylus pressure threshold level and a subroutine to decrease the stylus pressure threshold level are included.

Subroutines MENUS5 and MENUS6 can be written to perform other functions selected by the user.

FIG. 10 shows a flowchart of each menu subroutine according to a preferred embodiment. Modify the desired parameter threshold level only if the stylus pressure is below a predetermined value, ie, a "switch" release.

The value corresponding to each parameter threshold level is stored in a register, and the pressure applied to the menu spot with the stylus is released to release the "switch" (block 33).
2) Then, set the corresponding memory threshold level value to “1”.
” (block 334).

To modify the parameter threshold level value by n units, press and release the stylus against the corresponding menu spot n times, each time pressing
Change by 1. Play tone (block 336)
), "1" Inform the user that the modification is complete.

As can be seen from the above description, according to the present invention, since the function or mode selection menu means is built into the tablet, position coordinates can be determined more easily and quickly than with conventional devices.

[Brief explanation of drawings]

FIG. 1 is a partially schematic perspective view of a digitizer for use with a computer system. FIG. 2 is an enlarged cross-sectional view of a digitizer tablet and a portion of the active area of a cursor positioned h1 thereon. FIG. 3 is a schematic top view of a conventional wedge strip digitizer tablet electrode pattern. FIG. 4 is a fragmentary enlarged view showing a portion of the surface of FIG. FIG. 5 is an enlarged side view of the stripe arrangement connecting the electronic printed circuit board and the tablet. Figures 6(A) and 6(B) are detailed circuit diagrams of the printed circuit board incorporated into the tablet showing the x, y and B electrodes activated. 7(A)-7(C) are diagrams illustrating printed wiring circuits of a charge ratio digitizer tablet according to the present invention. FIG. 8 is a timing diagram of a digitizer according to the present invention. FIG. 9 is a flowchart of a charge ratio tablet menu program according to the present invention. FIG. 10 is a flowchart of a menu routine incorporated into the program of FIG. (2) Computer (3) Display monitor (4) (5) Coordinates (6) Cursor dot (10) Digitizer (20) Cursor (
21) Housing (22) Side wall (25)
Code (26) Signal line (27) (
29) Terminal (28) Coaxial conductor (30)
Coupling electrode (31) Dielectric spacer (32
) Earth electrode (34) Opening (35) Cross (37) Button switch (40) Tablet (41) Top surface (4
2) Cover (upper layer) (43) Dielectric material layer (
44) Electrode layer (45) Insulating layer (46
) Shield voter (electrode layer) (48) Multi-core cable (50) X pattern electrode (51) to (5
4) Strip (58) X-axis bus (59) X-axis signal lead wire (60) Y-pattern electrode (61)
(62) (63) Wedge (64) Narrow end
(68) Y-axis bus (69) Signal lead wire
(70) B pattern electrode (71) (72)
(73) Leg (74) Section (75) Signal lead wire (80) Shield electrode (100) Digital electronic device 1i (200) Microprocessor (201) Oscillator, (202)
Data bus (204) Buffer (206
) External storage chip (208) buffer (
210) (212) Counter (214) (216)
(218) Driver (220) (222) (
224) (226) Bonding electrode (228) (230)
(232) (234) Conductive plate (236) Printed circuit board (238) Switch circuit (240) Pseudo cursor (242) Preamplifier (244)
) Latch circuit (246) (248) Amplifier
(250) Switch circuit (252) Comparator
(254) Driver (256) AND gate
(258) EFROM (262) Level shifter (264) (266) Inverter (
270) (272) (274) Junction type pi (280
) Striped strip (281) (282) Insulating layer (284) (285) (286) (287) (
288) (289) Menu electrode-1 (290) (291) (292) (293) (
294) ('295) Bus line (300) Menu
(S) switch (Jl) jack
(Jl) Connector (C33) Capacitor
(VRI) Integrator (VR2) Comparator
(ci) Line (S) Gap engraving of drawing (no change in content) FIG, 4 FIG, 6El FIG, 9

Claims (25)

[Claims] (1) a substantially flat top surface, and a first shape pattern that is located on a plane substantially parallel to the top surface in a first region and that changes with the first coordinates of the two coordinate systems, and the second coordinates of the two coordinate systems; a digitizer tablet having a first electrode made of a conductive material, a second electrode, and a third electrode disposed between the first and second electrodes, each of which has a second shape pattern and a third shape pattern that change with the time; a first menu electrode made of a conductive material and having a fourth shape pattern and fixed to a second area located outside the first area of the digitizer tablet; 2. coupling means comprising a coupling electrode capacitively coupled to a third electrode and the menu electrode, and applying a predetermined drive electrical signal to at least one of the coupling electrodes during each of a plurality of drive cycles according to a predetermined sequence; The signal generating means is configured to output a signal to induce a signal in the coupling electrode during capacitive coupling between the coupling electrode and the driven electrode, and the coupling electrode covers the first region and the first,
In response to simultaneously supplying a predetermined drive signal to each of the first, second and third electrodes when the coupling electrode is in a position where maximum capacitive coupling occurs with the second and third electrodes, when the received signal has a magnitude in an exclusive first range and the coupling electrode is positioned such that it covers and has maximum capacitive coupling with the first menu electrode; In response to the application of the predetermined drive signal to the first menu electrode, the first, second, third and A digitizer characterized by configuring a four-shaped pattern. (2) receiving and processing a signal induced in the coupling electrode in response to a drive signal, and when the magnitude of the coupling electrode induced signal is within the first range, the coupling means for the tablet is electronic means having first means for determining first and second coordinates of a point; and second means for performing operations other than coordinate determination when the magnitude of said coupled electrode induced signal is within said second range. The digitizer according to claim 1, further comprising: (3) The first electrode is wedge-shaped, the second electrode is strip-shaped, and the third electrode is arranged in a meandering manner and separated from the first and second electrodes by a spacing means made of an insulating material. A digitizer according to claim 1, wherein the digitizer substantially fills the space between the first and second electrodes. (4) The digitizer according to claim (1), wherein the combining means is a cursor. (5) The digitizer according to claim (1), wherein the coupling means is a stylus. (6) The digitizer according to claim 1, wherein the first menu electrode comprises a plate connected to a bus. (7) The digitizer according to claim (1), wherein the first menu electrode comprises a plurality of fingers connected to a bus. (8) The digitizer according to claim (1), wherein the first electrode and the first menu electrode are connected to the signal generating means by a joining means. (9) The digitizer according to claim (8), wherein the joining means is a conductive plate. (10) The digitizer according to claim (1), wherein the second electrode and the first menu electrode are connected to the signal generating means by a joining means. (11) The digitizer according to claim (10), wherein the joining means is a conductive plate. (12) A second electrode made of a conductive material fixed to the second area, connected to the signal generating means, and having a fourth shape pattern.
The digitizer according to claim 1, further comprising: and a third menu electrode. (13) first, second and third electrodes, and the first, second and third menu electrodes are respectively
13. The digitizer according to claim 12, wherein the digitizer is connected to the signal generating means by a third connecting means. (14) A fourth portion made of a conductive material fixed to the second region, connected to the signal generating means, and having a fifth shape pattern.
, a fifth and a sixth menu electrode, and the fifth pattern is such that the coupling electrode covers the fourth, fifth or sixth menu electrode and is positioned to have maximum capacitive coupling with the menu electrode. , the fourth, fifth or sixth
In response to supplying the predetermined drive signal to the menu electrode,
Claim (12) characterized in that the signal induced in the coupling means is configured to have a magnitude within a third range that is mutually exclusive with respect to the first range.
Digitizer listed. (15) first, second and third electrodes, said first, second and third menu electrodes, and said fourth, fifth and sixth electrodes;
Digitizer according to claim 14, characterized in that the menu electrodes are connected to the signal generating means by first, second and third connecting means, respectively. (16) The digitizer according to claim 15, wherein the fourth shape pattern is a rectangular plate, and the fifth shape pattern is composed of a plurality of parallel bars. (17) comprising a substantially flat upper surface, an electrode array in a plane substantially parallel to the upper surface, and an insulating material layer provided between the upper surface and the electrode array, wherein the electrode array is located in the first region; first, second and third pattern electrodes disposed in the second region; first, second and third menu electrodes disposed in the third region; The first, second, and third regions do not overlap, and the first pattern electrode, first menu electrode, and first bonding electrode are connected to form a first circuit. the second pattern electrode, the second menu electrode, and the second bonding electrode are connected to form a second circuit, and the third pattern electrode, the third menu electrode, and the third bonding electrode are connected to form a second circuit; forming a third circuit, the first pattern electrode having a first shape pattern that changes with the first coordinate of the two coordinate system, and the second pattern electrode having a first shape pattern that changes with the first coordinate of the two coordinate system. the third pattern electrode has a second shape pattern that changes with the coordinates;
has a shape pattern, is arranged between the first and second electrodes, and is spaced apart from the first and second pattern electrodes by a spacing means made of an insulating material;
A digitizer tablet characterized in that the second and third menu electrodes each have a fourth shape pattern. (18) It is characterized by comprising fourth, fifth, and sixth menu electrodes disposed in the second region, connected to the first, second, and third circuits, respectively, and having a fifth shape pattern. The tablet according to claim (17). (19) The first, second, and third signal generating means are connected to the first, second, and third bonding electrodes, respectively, and output predetermined drive signals to each circuit. 17) The tablet described above. (20) means for forming a first electrostatic field having a characteristic that varies within a first range along a first coordinate direction; a second electrostatic field having a characteristic that varies within a second range along a second coordinate direction;
means for forming an electrostatic field, and forming a third electrostatic field having characteristics that vary along the first and second coordinate directions, and when the first, second and third electrostatic field characteristics are summed, a third electrostatic field is formed; a digitizer tablet comprising means configured to provide three ranges of values;
, second and third electrostatic field forming means are disposed in a first region of a plane substantially parallel to the top surface of the tablet;
The digitizer further comprises a fourth electrostatic field forming means located in the second area of the plane and having a characteristic having a value outside the third range. (21) (a) first electrode means fixed to a first region of the plane and generating an electrostatic force that varies in first and second coordinate directions in response to reception of a drive signal; (b) said plane; (c) second electrode means fixed to a second region of the drive signal for generating an electrostatic force in response to receiving the drive signal; (c) connected to the first and second electrode means to cause the drive (d) signal generating means for outputting a signal; (d) said drive of said means when moved relative to said first and second electrode means and capacitively coupled to said first and second electrode means; (e) coupling means for providing an induced output signal in response to receiving a signal; first means for processing said output signal in a first routine in response to having a predetermined capacitive coupling threshold level with said coupling means having a value less than or equal to said predetermined capacitive coupling threshold level; processing means comprising second means for responsively processing said output signal in a second routine. (22) The second electrode means is composed of a plurality of electrodes, and the second signal processing means is configured such that the coupling means has a value equal to or lower than the predetermined capacitive coupling threshold level with the first electrode means. 22. The digitizer according to claim 21, further comprising means for responsively determining which of the plurality of electrodes is capacitively coupled to the coupling means. (23) Claim (21) characterized in that the second means includes means for changing the stored value by a predetermined amount.
Digitizer listed. 24. The digitizer of claim 23, wherein the stored value represents a stylus proximity threshold level. (25) A digitizer according to claim 23, wherein the stored value represents a stylus pressure threshold level.