JPH012123A - Digitizer and its calibration method - 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 [Field of Industrial Application] The present invention relates to a method and apparatus for calibrating a digitizer performed by an electrostatic connection between a patterned electrode layer and a movable cursor. The position of the cursor on the digitizer surface is determined by the signal between the cursor and the patterned 'rii' ridge.

[Conventional technology and issues]

Charge ratio digitizing devices of simple construction are of the wedge/strip type; this type of digitizer consists of a digitizing tablet and a cursor or stylus that moves over it; the electric field connection is Used to locate the cursor or stylus relative to the tablet.

The coordinate system is a typical X-Y coordinate system.

The cursor or stylus consists of a housing that moves over the surface of the digitizer tablet and contains connecting electrodes.

In an embodiment, an input signal is applied to a connecting electrode of a cursor or stylus. The connection electrode field is a wedge embedded in the digitizer tablet.
/ Electrically connected to strip-shaped patterned electrodes.

One of the wedge or strip patterned electrodes is used to determine the X-axis position of the cursor, and the other one is used to determine the Y-axis position of the cursor.

The wedge/strip patterned electrodes are conveniently coplanar on the printed circuit board and covered with a layer of dielectric material to provide a smooth tablet surface.

When attempting to actuate the connecting electrode of a cursor or stylus, the signal developed at the patterned ffi pole is
Processed electrically to locate the cursor or styles relative to the tablet.

According to the layer-specific features of the wedge/strip type digitizer, the digitizer tablet has three patterned electrodes, which generate an X-axis signal, a Y-axis signal and a balance signal (n).

The X electrodes are arranged vertically and equidistantly and have multiple guiding angles processed to increase the width from one side of the tablet to the other (e.g. increasing width from left to right of the tablet). The Y electrode is also composed of a plurality of identical guiding wedges or sawtooths that are equally spaced longitudinally with a riwedge sandwiched between the X strips.

Movement of the cursor or stylus in the X-axis direction has a slight effect on the cursor (stylus) connected to the Y electrode, and movement of the cursor (stylus) in the Y-axis direction has a slight effect on the cursor (stylus) connected to the Xff1 pole. ) has a slight effect on

The balance (hereinafter "B") electrode covers approximately the area of the digitizer not covered by the X and Y electrodes, excluding the interelectrode space.

A coupling electrode located within the cursor (stylus) housing and moving over the surface of the tablet face of the digitizer is connected to an oscillator whose frequency is typically in the range of 10 KHz to IMI+z.

Connecting electrodes induce electrical signals to the X, Y and B electrodes. The surface area of the x74 poles connected with the linking electrodes increases with the position or movement of the cursor or stylus towards one side of the tablet where the strip is wider, so more electrical signals are applied to the x electrodes. is induced.

Similarly, the surface area of the Y electrode connected to the connection electrode is
As the cursor or stylus moves towards the part of the tablet where the wedge width increases, more electrical signals are induced into the Y electrode.

It is expected that the sum of the signals on the X, Y and B electrodes is independent of the cursor (stylus) position.

This total signal mainly consists of the amplitude of the oscillator signal,
It depends on the proximity of the linking electrode to the Y and B electrodes and the inductive constant of the material between the linking electrode and the X, Y and B electrodes.

Based on mathematical and electrical concepts, the X coordinate of a cursor or stylus is proportional to the X electrode signal divided by the sum of the X, Y, and B electrode signals. Similarly, the Y coordinate of the cursor or stylus is X.

It is expected to be proportional to the Y electrode signal divided by the sum of the Y and B electrode signals.

In theory, this ratio measurement technique should allow for accurate cursor (stylus) measurements and should be independent of the proximity of the cursor or stylus to the digitizer tablet or any dielectric material in between. be.

In the case of a wedge/strip type digitizer, the functions of the interlocking electrode and the patterned electrode are reversed.

That is, input signals are applied successively to the X, Y and B electrodes, and the induced signals are output from the connected electrodes accordingly.

Prior art wedge/strip systems are disadvantageous due to tablet size irregularities resulting from spacing relationships between the X, Y, and B electrodes within the digitizer.

This phenomenon is hereinafter referred to as "resolution distortion." The spacing between electrodes in the pattern cannot be eliminated because it is necessary to electrically isolate one electrode from another.

The mathematical relationships underlying the design of the wedge/strip digitizer require that accurate data be obtained.
This means that no space can be left between the electrodes.

However, as mentioned above, this is not possible in actual manufacture. If the spacing between the electrodes is known accurately and the overall pattern is consistent, mathematical adjustments can be made to correct for distortions in the output pattern due to the spacing between the electrodes.

Another disadvantage of prior art wedge/strip digitizers is that the readings include values corresponding to environmental and inherent noise, as well as values caused by electrostatic induction.

Ambient noise is due to the tablet acting as an antenna, and inherent noise is caused by unnecessary inductive connections between parts. Furthermore, the leading contains a value corresponding to an offset indicating the difference between the reference potentials of the integrator and the comparator.

Therefore, the necessary structure as a digitizer is the unavoidable space between the tablets' tflt4 and the background effect.

That is, correction for noise and offset can be provided reliably and economically.

SUMMARY OF THE INVENTION According to the invention, a wedge strip digitizer is provided with a fixed condensable cursor to allow correction for resolution distortions, i.e. for calibration of the digitizer. .

A figurative cursor is placed on the tablet on the top surface of the tablet, on the side opposite the X, Y and B electrodes.

The fissile cursor is electrostatically (capacitively) coupled to the x, y and B electrodes.

In a preferred embodiment, a connecting electrode located within the cursor housing and moving over the surface of the digitizer tablet includes a plurality of X, Y and Bm electrodes that are driven according to a predetermined pattern.
connected to the pole. Alternatively, it is also possible to incorporate the connecting electrode into the stylus (hereinafter referred to as the ``cursor'').
is used in the present invention with the understanding that a stylus can be used instead of a cursor (-).

The capacitively induced signals in the coupling electrodes are output to processing circuitry which determines the coordinate position of a point on the cursor, with correction for resolution distortions.

The surface area of the X electrode connected to the cursor increases as the strip is wider and therefore, when the X electrode is actuated, the cursor moves or is positioned towards one side of the tablet.

Similarly, the surface area of the Y electrode connected to the cursor increases as the wedge is wider and therefore, when the Y electrode is driven, as the cursor moves towards the area of the tablet, the surface area of the electrical signal coupled to the cursor increases. increases as the cursor moves towards the increasing wedge width of the Y electrode.

Three separate drive circuits are provided for X, Y and Bf, respectively.
Applying square wave signals to the fi poles, the connections of these signals to the cursor's connection electrodes are sampled according to the scheduled sampling cycle.

Each output signal is simplified, modified, integrated, and digitized to provide a digital signal representing the amount of capacitive coupling induced in the cursor by the plurality of driven electrodes.

The microprocessor follows a mathematical relationship for the wedge strip array to create data Xin and Yin representing the X, Y coordinates of the cursor position on the digitizer surface.
Perform mathematical operations on digital signals. In particular, X1n=2Cx/(cx+Cy+Co) (1
)Yir+-2Cy/(cx+Cy+Ca)
(2) where Cy is a digital value corresponding to the signal induced at the driven X electrode, Cy is a digital value equivalent to the signal induced at the driven Y electrode, and C3 is the digital value corresponding to the signal induced at the driven Y electrode. It is a digital value corresponding to the signal induced at the balance electrode. The geometry of the patterned electrode is either O<Xin<1 or O<Yin<1.

When the X, Y and B electrodes are driven simultaneously, i.e. C
The digital value representing the signal output from x + Cy + CB, the cursor, or the stylus is hereinafter referred to as Csum.

The Cx, Cy and Csum values are obtained by adjusting the original readings to correct for noise and offset according to the following equations:

Cx=Ax-Bx (3)C
y= Ay −B y (4
) Csum = A sum - B sum
(5) Ax, Ay, and Asum are each only the X electrode.

yffi pole only, and if a stylus or cursor is used, the digital value obtained in response to the actuation (i.e. the original reading) of the X, Y and B electrodes together;
Bx, By, and Bsum are the digital values obtained in response to actuation of the X, Y, and B electrodes together, respectively) , background reading).

To compensate for noise and offset, the digitizer structure allows for Bx, By, and Bsu+i readings when a stylus or cursor is unavailable.

The background reading is the sum of the digital values corresponding to the environmental sound and inherent noise, and the digital value corresponding to the offset, which is the sum of this background reading.
Digital values are stored in memory and later subtracted from the readings obtained at the time of digitization, ie when the stylus or cursor is available.

The microprocessor also operates on the acquired data using correction factors to correct for resolution distortions.

Due to the inherent distortion mentioned above, the X and Y coordinates are 'l
(:, cannot be easily determined from the values of x/Csum and zcy/Csum.

The X and Y coordinates can only be determined after calibration has been performed to correct for resolution distortions.

This calibration is done by processing signals from a small conductive plate built into the digitizer tablet. This plate is hereinafter referred to as a "fake cursor."

The fictitious cursor is placed at a defined location near the edge or corner of the active coordinate determination area and has a fictitious cursor center point with predetermined X and Y coordinates. The fidget cursor is switchably connected to the same circuitry that processes the movable cursor output signal.

The data signal directed to the fiducial cursor is digitized by processing circuitry, and the microprocessor then generates stored data corresponding to the defined position of the fiducial cursor electrode and the defined position of the center point of the tablet. Calculate correction factors fx and fy from the data processed using . The correction factors fx and fy are X, Y and B of the tablet.
The obtained data Cx, Cy and Csum are given to correct the distortion of the pattern resulting from the spacing between the fit poles.

In a second embodiment, the link electrodes of the movable cursor and the electrodes of the phantom cursor are selectively driven in place of the X, Y and B electrodes. In response to actuation of the linkage electrodes or the electrodes of the figurative cursor, data signals induced in the X, Y and B electrodes are output to processing circuitry. These C data signals are then processed to correct for resolution distortions and to determine the X and Y coordinates of a point on the movable cursor.

It is an object of the present invention to provide an improved digitizer that eliminates data distortions caused by spacing between electrodes on the tablet surface of a wedge/strip charge ratio digitizer.

Take a background reading, memorize the obtained background value, and subtract the background value to correct for environmental sounds and inherent noise that correspond to the difference between the integral gain and the reference potential of the comparison board. It is also an object of the present invention to coordinate digitized reading.

Another object of the present invention is to provide an improved digitizer that is inexpensive to manufacture and does not require precision in spacing between tablet face electrodes.

The invention also aims to provide an improved method for the calibration of wedge/strip charge ratio digitizers.

Other objects and advantages of the invention will be apparent from the description.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 1, a strip wedge digitizer (10) includes a cursor (20) or stylus (not shown in FIG. 1), a doublet (40),
An electronic device (100) for providing an input signal to a cursor and processing an output signal from a doublet, or for providing an input signal to a doublet and processing an output signal from a cursor.
).

In a preferred embodiment of the invention, the digitizer electronics (
100) is incorporated into the tablet (40) inside the casing, below the layer shown in FIG. Circuit diagrams of the printed circuit board of this embodiment are shown in FIGS. 6A and 68.

As shown in FIG. 1, a digitizer (10) can be used as an input device for a computer (2) having an associated display monitor (3).
used.

Monitor (3) displays double ref +- as shown in (4) and (5) on the monitor display screen.
The coordinate values representing the position of the cursor (20) related to (40) are displayed. The monitor is also used to display a cursor dot (6) whose position on the screen is controlled by the position of the cursor (20) on the tablet (40).

A cross-section of the cursor (20) and a fragmentary portion of the tablet (40) are shown in FIG. It is obvious that a tablet can be used in conjunction with a stylus instead of a cursor.

The cursor (20) is on the digitizer tablet (4).
0) includes a housing (21) with a dependent peripheral side wall (22) sliding on the surface of the housing (21). Housing (21)
Attached to the underside (with equipment not shown) is a tubular ground or shield electrode (32).

A tubular dielectric spacer (31) is fixedly arranged below the connecting ground shield electrode (32).

The tubular continuation t4 (30) is connected to its connecting electrode (
30) is fixedly arranged below a dielectric spacer (31) which connects it exactly parallel to the tablet surface.

The shield electrode (32) is somewhat larger in diameter than the link electrode (30) and overhangs the link electrode (30) at its peripheral edge. A connecting electrode (30), a dielectric spacer (31) and a ground electrode (32) together with a cover (21).

The central circular opening (
34).

The crosshairs (35) are concentrated in the connecting electrodes (30). The inner and outer peripheries of the connecting electrodes are preferably circular, but other shapes may be used as long as the orientation of the cursor does not affect the electrical connection between the fins and the tablet electrodes.

An electrical cord (25) connects the cursor (20) to the digitizer-electronic device (100);
It includes a signal conducting wire (26) connected to a contact electrode (30) at a terminal (27).

The coaxial surrounding conductor (28), ie the coaxial shield.

At the terminal (29) it is connected to the ground or shield electrode in the cursor (20).

When the cursor is driven, a drive signal is provided to the communication electrode (30) by a signal line (26), described below. When the tablet electrode is activated, a guiding signal is issued via the signal line (26).

The cursor housing (21) is shaped to fit snugly into the user's hand and is equipped with a series of pushbutton stitches (37) for communicating with the computer (2).
(see FIG. 1).

It is preferable instead that the cursor is a digitizer with a transformer, the contents of which are taken for reference.
• Replacement by a pressure sensitive stylus similar to that disclosed in commonly assigned U.S. patent application Ser.

The stylus output signal can be sampled during separate sampling cycles to determine the amplitude of the signal, which is a function of the pressure exerted on the stylus tip.
(See pressure cycle in Figure 8).

During this sampling cycle, the stylus is disabled in the sense that no current is capacitively induced in the stylus anode.

Instead, voltage is applied across the end of the stylus,
It produces a current in a circuit containing a force sensing resistive transducer which acts as a variable resistor.

The transducer is made of force sensitive resistive (FSR) material whose resistance varies with the amount of compressive force applied in a direction approximately perpendicular to the plane of the transducer layer. . The resistance of the FSRI-transducer is
decreases as the magnitude of the compressive force increases.

This change in resistance of the FSR material causes a corresponding change in the dC level of the analog signal output during the pressure sampling cycle.

The DC level of the analog signal output from the pressure sensitive stylus can be detected using a comparator built into the digitizer electronics.

The DC level of the analog signal is based on the base I given to the comparator.
It is compared with the PUrtt pressure.

FSR due to increased pressure on the stylus tip.
The resistance of the transducer decreases, so the DC level of the analog signal increases.

When the DC level of the analog signal exceeds the reference voltage, the output of the comparator also goes high. In response to the comparator output going high, a switch closes, which causes the data being digitized from the stylus to flow into the processing circuitry of the digitizer electronics during the X, Y and SUN drive cycles.

During the drive cycle, in response to signals induced to the anode by the driven patterned electrodes of the charge ratio tablet, digitized data is also output via the stylus terminal, but at different times of the sampling cycle. It is.

Thus, the FSR transducer of the pressure sensitive stylus acts as a variable resistor, and the digitizer electronics are closed in response to the variable resistance to achieve a predetermined value.

This predetermined resistance value must be achieved with less pressure than the pressure typically exerted on the tip of a pen refill when the stylus is used by a user to write.

The position of the stylus relative to the digitizer tablet is determined only for these positions of the stylus tip, such that the pressure of the tip against the tablet is equal to the predetermined pressure value, i.e. when the stylus is used to write. , exceeds the pressure values for these locations.

The predetermined pressure value is the pressure at which the analog signal output from the stylus exceeds the stored predetermined analog value.

In response to a stylus output signal exceeding a predetermined stored value, determination of the stylus tip position begins. Similarly, position determination stops when the pressure exerted by the stylus tip falls below the predetermined memorized value.

The tablet (40) of the digitizing device is usually rectangular and has a flat top edge (41) on which the cursor (
20) moves (see Figure 1). The top side (41) is X.

a first region overlying the Y and B electrodes and a second region overlying the plurality of menu electrodes, the second region comprising:
What is outside the first area is as disclosed in U.S. Patent Application No. 1, entitled "Menu for a Charge Ratio Digitizer," the contents of which are incorporated herein by reference. .

The position of the cursor scheduled in the first region of the top edge (41) can be expressed as a value in a limited binary coordinate system. However, it must be kept in mind that only the rectangular portion of the first region is the active coordinate determining region having the same name as the limited binary coordinates.

Thus, the X, Y and B electrodes extend beyond the active coordinate determination area and are below the tablet periphery, but these periphery areas are such that when the cursor is above the periphery, the coordinates of the cursor are determined. It is inactive in the sense that it cannot be done.

In the preferred embodiment, this includes the top edge (42) and the electrode layer (44).
) (see Figure 2) with a periphery of copper shielding (46) (of course, the shielding is not provided over the menu electrodes, as detailed below)
.

Alternatively, the same result can be achieved by programming the microprocessor not to process Xin and Yin values that are greater or less than predetermined limits corresponding to the vicinity of the active coordinate determination region. Therefore, a cursor position that is on an inactive perimeter will not have a corresponding X, Y coordinate.

The coordinate system used in the example is a Cartesian X-Y coordinate system.

The digitizer tablet (40) includes a plastic cover (42). As shown,
Force A (42) is the digitizer tablet (40
) provides a smooth top edge (41).

Under the cover (42), outside the active area of the tablet:
This is a layer (43) of conductive material. X, Y and B electrodes, menu electrodes, bonding electrodes, connecting conductors (U.S. patent application)
7A to 7C of the specification), the electrode layer (44) comprised is an insulating layer (45) poured directly onto the conductive layer. (44) below.

In one embodiment of the digitizer, the digitizer tablet is connected to electronic circuitry by a multiconductor cable (48) as shown in FIG.

Figures 3 and 4 show the basic structure of the x, y and B electrodes. The electrode layer (46) of the digitizer tablet (40) includes a patterned electrode (50) varying in the X direction, a patterned electrode (6) varying in the Y direction, and a patterned electrode (50) varying in the Y direction.
0), and X, Y? to output a balanced (B) signal. ! !
It includes a patterned electrode (70) located between the poles.

The electrodes 14 (50) (60) (70) are arranged in a substantially coplanar, rectangular overall array, and the shield electrodes (80)
This allows them to be surrounded by the same plane.

FIG. 3 does not show the menu electrodes that are incorporated into the tablet in accordance with US Pat.

The X-electrode (50) comprises a 'f5i number of strips, for example strips (51) (53) (54), which are connected to the electrode layer (46) by the X-axis bus (58).
connected along one edge of the.

The strip extends in the Y direction from one side of the bus (58). The strips are approximately parallel to each other;
It has centerlines that are approximately equally spaced. However, the individual strips progressively increase in width in the X direction from one side of the flaplet (40) to the other.

In this way, the strip (52) is connected to the next strip (52).
51) Wider, the strip (53) is wider than the strip (52) and so over the entire surface.

On any strip, the accumulated electrical signal is guided by a bus (58) to the X-axis signal lead (59), which leads to the tablet of the multiconductor digitizer.
It becomes part of the cable (48).

The X electrodes (60) are similar individual wedged serrations sandwiched by a strip pattern of X electrodes (50);
Or have a wedge pattern.

The Yffi pole (60) includes a plurality of wedges extending in the Y direction, and the wedge (61) is connected to the Y-axis bus (68).
connected to. Each wedge (61) has a rim (62)
and (63), which means that the wedge extends from the bus (68) to
It converges as it extends to a narrow end (64) adjacent to the axial bus (58).

The wedges (61) are equally spaced between adjacent strips so that the wedges and strips are sandwiched between each other. The X electrode (60) is connected to the multi-conductor cable (48
) has a bus (68) connected to the digitizer electronics (100) by means of signal leads (69) forming part of the digitizer electronics (100).

The electrode layer (46) of the digitizer is also balanced (B);
It incorporates an electrode layer (70) that approximately covers the area of the electrode layer (46) between the areas covered by the X, X electrodes (50) (60), excluding any gaps left between adjacent electrodes. .

The B electrode (70) is arranged in a meandering manner between the wedge and the strip which are sandwiched between each other, and between each bus facing the tips of the wedge and the strip. for example,(
Takes a long and narrow leg shape like 71), (72), and (73).

For example, the legs (71) and (72) are the strips (
The legs (72) and (73) sandwich the wedge (61). The B electrode leg is the X-axis bus (58)
and are connected by a connection section adjacent to the Y-axis bus (68). For example, legs (71) and (72) are connected by a section (74) between the end of strip (51) and Y-axis bus (68).

The B electrode (70) is connected to the digitizer-electronics (100) by a signal lead (75) which becomes part of the multi-conductor cable (48).

The electrode layer (48) further includes a shield electrode (80) deployed around the X, Y and B electrodes. This shield electrode i-pole (80) is, as shown in FIG.
It can be connected to the shield of the cable (48).

The electrodes (50), (60), and (70) are electrically isolated from each other by a gap separating the electrodes.

The gap between the electrodes is determined by the electrode layer (4) shown in FIG.
6), which is an enlarged cross-sectional view of FIG.

The small space, or gap, provided between the edges of all adjacent electrodes is indicated by the letter S. The spacing is generally constant for a given electrode layer (46), but varies from production source to production run.

Please understand that the scale of FIG. 4 has been enlarged for the purpose of explanation, and the explanation has been made in the form of 8 diagrams.

The actual strip wedge and space (S) are much smaller than shown in this drawing. One successful implementation included five X-axis pattern strips and five Y-axis pattern strips per 25.4 mJ inch).
A wedge was used.

Increase in width from one X-axis strip to an adjacent X-axis strip, such as strips (52) and (53) in FIG.
) was approximately 0.025 mm (0,001 inch).

The digitizer tablet (40) has an effective coordinate-determining surface limited to the area of the respective wedges and strips of the X and Y electrodes (50) (60); , normally does not include the X-axis bus (58) and Y-axis bus (68).

The connecting electrode (30) of the cursor (20) (see Figure 3) and the connecting electrode (30) of the pressure-sensitive stylus (not shown)
The anode) is sized and distanced from the tablet (40) such that it is capacitively connected to a plurality of strips and wedges (minimum of five) during operation of the X and Y electrodes.

Thus, whenever given, X, Y and Bfi
Several elements of each pole are connected to a linking electrode.

X electrode (50), Y electrode (60) and B electrode (70)
may be made of copper, silver, conductive ink, or other conductive material in which the printed circuit board is placed on top of the printed circuit board material that is the dielectric layer (43) of the digitizer tablet (40). I can do it.

Another fabrication technique is to print the electrodes with conductive ink on a thin film of Mylar or similar material.

A film printed with W1 poles can be applied to the top surface of the dielectric layer (43) of the digitizer tablet (40) or to the bottom surface of the plastic cover (42).

The wedge strip digitizer is operated with a capacitive connection between the connecting electrode (30) of the cursor (20) of the digitizer tablet (40) and the patterned X, Y, B electrodes.

In one embodiment, the drive signal input to the cursor (20) is from the electrodes (50) (60) (
70) and the signal output arising from the tablet electrodes is connected to
and are processed to determine the Y coordinate.

The electronic circuitry utilized in this embodiment of the wedge strip digitizer is illustrated in block form in FIG.

The X coordinate is calculated from the signal connected from the cursor (20) to the X electrode (50) and the total signal connected from the cursor 20 to the X, Y, B electrodes. The Y coordinate is the cursor (20
) to the Y electrode (60) and the signal connected to the total signal.

The B electrode (70) provides a balance signal. Asum
- Digital value Csu representing B sum (see equation (5))
n+ gives the strength or magnitude of the total signal connected from the cursor (20).

This Csu+i value varies depending on the orientation of the connecting electrode of the cursor or stylus in relation to the electrode layer (46) and the distance of the connecting electrode from the electrode layer (46).

As mentioned above, the absolute X and Y coordinates are the formulas (1) and (2)%Cx + Cy + Ca, where Cx, Cy and C3 are:
During operation of the cursor or stylus connection electrode, X, Y
,B? I! It is a function of the capacitive connection signal output coming from the pole.

This ratio measurement technique is based on the connection f! of the tablet (4o).
! Eliminates errors caused by variations in the distance between the pole (30) and the electrode layer (44).

Referring once again to FIG.
It consists of a square wave oscillator (tOS) that provides a square wave output signal at a constant frequency in the range up to z.

The square wave oscillator (105) is connected to the oscillator (10
inductor (10) with the output signal of the square wave oscillator passing through a resistor (108) to limit the load on
6) and a regulated LC consisting of a capacitor (107)
Activate the circuit.

The adjusted circuit elements (106) and (107) are
Multiple voltage gains are provided to drive the connecting electrodes of the cursor (20) through the four bodies (26) of the cord or cable (25). The driving signal on the contact type tl (30) is the intensity of the signal induced in the X and Y electrodes according to the coordinate position of the cursor (20) on the tablet (40).
, Y, B electrodes (50) (60) (70).

More specifically, according to the electrode arrangement illustrated in Figure 4, when the cursor (20) approaches the lower edge of the tablet where the wedge of the Y electrode (60) is wide, the larger the Y electrode signal will be. It will be prepared.

Similarly, the fourth
Since the cursor is located on the right side of the tablet shown in the figure, the X? The a-pole signal becomes larger.

Signals from the X, Y, B electrodes (50) (60) (70) are applied to conductors (59) (69) (75), respectively, and these signals are will be processed.

The X electrode signal processing (120) is shown in some detail, and the Y electrode signal processing circuitry (140) and 1
It turns out that the B electrode signals processing circuitry (145) are similar.

The signal from the X electrode (50) provided on the conductor (59) is amplified by the charge amplifier (122), and this amplified signal is sent to the capacitor (123) and resistor (60) to reject 1z frequency noise. 126) (127). This filter is centered at the drive frequency.

This filtered AC signal is sent to a switch (130)
The filtered AC signal is switched synchronously at the frequency of the square wave oscillator (105) by the switch (
130).

switch (13) at the same frequency as the square wave oscillator (105) that generates the input signal for the cursor (20).
0) all other frequencies or pickups are rejected. Therefore, a very high signal-to-noise ratio and digitization equipment! A high degree of accuracy results in determining the coordinate position of the cursor (20) in (40).

The capacitor (132) and the resistor (133) act as a filter to reduce the AC ripple on the output of the operable amplifier (131). Therefore, a stable DC ? indicating the X coordinate of the cursor (20)? ! ! A pressure signal is generated.

The voltage gain is originally determined by the ratio of the value of the register (133) to the value of the register (126).

The Y and B electrode signals are processed similarly. The output of each signal processing circuit is further processed by a microprocessor (1
50).

More specifically, the signal is transmitted to a switch (151) (controlled by a microprocessor (150)).
152) (153) converts the analog value into a digital value (i.e., Cx,
Cy.

Csum). The sampling rate corresponds to the microprocessor (150) to computer (2) reporting ratio, typically 10-12 Hz.

The microprocessor (150) generates background values Bx-By, B to compensate for noise and offsets.
5uI11, and the correction factors fx and fy to compensate for the previously mentioned resolution distortions, calculate the coordinate position of the cursor according to the ratio fenestration technique.

The microprocessor (150) calculates the correction factors fx, fy obtained from the figurative cursor.

Calculation of the correction factor is based on the algorithm described below. Resolution R is 1 inch (2,54
(Note: If the parallel line arrangement is on a tablet, R is the number of lines per inch.) The digitizer can be programmed to have any value of R desired by the user.

Assume that the tablet has a width W and a height h, where W and h are given in inches. In that case, ideally the following
The value ut representing the processed X coordinate is the active region (see Figure 9), from 0 at X=O to Rw at x=W.
changes up to.

Similarly, the value representing the processed Y coordinate - hereinafter referred to as Y out - is the active region, from 0 at Y=O to y=)1
Rh changes up to .

Date Tablet (X ctr = w/2, Y
ctr=h/2), Xin =0.5, Yi
n=0.5. That is, X1n==0.5. Yin=0
．． 5, and also a condensed cursor (Xp, c-+ Yp-c
Assuming that Xin and Yin at the position of the tablet on j are equal to Xin and Yin, respectively, the numbers Xout and You out at point P on the table can be calculated according to the following equation.

X out = X range X in -b,
(6) You out = Y range
Y in −b2 (7) In the above formula, Xin and Yin are
Calculated according to equations (1)-(5): Xd=Xctr-Xp,c,=w/2-Xp
, c, , Yd = Yctr - Yp, c, = h /
2- Yp,c,.

k is a constant, bl and b2 are values representing the signals induced in or by the X and Y electrodes, respectively, when the stylus or cursor is above the margins x = O and y = Q, respectively. Xout and Yout are
These values correspond to the X and Y coordinates of the cursor or stylus, respectively.

During the calibration cycle (i.e., stylus disabled and cursor cursor enabled), the microprocessor
Cx, Cy and c used to calculate n and Yin
get B. Then, the correction factors fx and fy.

x p, C and yp, c and Xctr, Yct
r, Xp, ct Yp, c.

In is calculated using the data stored for IJI 1n X9tr and Y9tl.

When calculating the correction factors fx and fy and selecting the resolution R,
A microprocessor can calculate Xranga and Yrange as shown in Figure 11B.

During the portion of the digitization cycle where the stylus and fidget cursor are disabled, Bx, By, 5sun
(i.e., background reading). During the left part of the digitization cycle, when the stylus is enabled, the X, Y and B electrodes are driven according to a predetermined pattern, so that the microprocessor determines the position of the stylus over the active area of the tablet. ,
Obtain Ax, Ay, and Asum.

The microprocessor then calculates Xin and Yin. At this point, the microprocessor determines whether each P
We have all the information necessary to calculate Xout and You out according to equations (6) and (7) for the points.

Another example of a wedge/strip type digitizer is a type of stylus consisting of a connecting electrode in the shape of a ring or suitable for wrapping around a shape similar to a pen tip.
It can also be used in place of the cursor (20), but the stylus electrode must be sufficiently spaced from the electrode layer (46). This allows an averaging of the effects of special strips or wedges.

As a preferred embodiment of the present invention, electrodes (50) (60
) (70) and associated menu electrodes (not shown) of the digitizing device tablet (40) are driven in sequence by a square wave oscillator such that the signal connected to the cursor determines the position of the cursor on the tablet (40). X,
The electronic circuitry shown in FIGS. 6A and 6B is provided for determining the Y coordinate or for determining and sequentially processing functions or modalities selected by the user from a menu (not shown).

Fake cursor? ! ! The poles (240) are shown in Figures 6A and 6B.
The processing electronics shown in the figure are placed on a printed circuit board. The remaining processing circuitry is isolated from the electrode (44) by a shielding layer (not shown). A figurative cursor electrode is placed near the corner of the tablet so that it can be capacitively connected to a portion of the electrode layer (44).

The center of the coagulant cursor electrode is the predetermined X.

It has a Y coordinate. The condensed cursor electrode consists of an electrode layer (4
4) consisting of opposing circular conductive plates with air spaces between them, dimensioned such that the conductive plates underlie at least one wedge and one strip;

The fictitious cursor (240) is also on the tablet in Figure 3.
Indicated by a circle with a dash (). It should be appreciated that while the size of the figurative cursor has been expanded for the tablet dimensions in FIG. 3, it is shown approximately to scale for the widths of the wedges and strips.

This is due to the fact that the wedges and strips are also not shown in their true dimensional relationship to the tablet.

The tablet, for example, is 30.48 cm (12 inches) wide, but the bottom of each wedge is, for example, only 0.53 cm (0.21 inches), and the approximate cursor diameter is smaller than that of a working professional 1. - Type (prototype): 1, 07
cm (042 inches).

Thus, each digitizer tablet according to the invention has many more wedges and strips than depicted in FIG.

The fiducial cursor electrode (240) is connected directly to the digitizer electronics by line C1, as shown in 6A. The area and contour of the condensed cursor electrode are
Since the quantities in question are the ratios of Cx and cy to Csum, they do not need to correspond to the area and contour of the connecting electrode (30) of the cursor (20).

In preferred embodiments, the figurative cursor electrode may be of other shapes, for example square, but may also be in the form of a circular plate.

The digitizer tablet is placed outside the coordinate determination area.
It has been extended to include menus, as more fully disclosed in U.S. Patent Application No.

This menu is composed of a plurality of menu electrodes each driven by the same drive signal that drives the X, Y, and B electrodes. Menu electrodes are placed in the extended tablet and conductors (50) (69) (75)
In the preferred embodiment, the menu electrodes and the X, Y, B electrodes are connected in a zebra strip arrangement, as described below.

FIG. 7 shows a digitizer electronics device (100
) and the desired connection of the digitizer tablet (40).

In contrast to the embodiments shown in FIGS. 1 and 3, the digitizer electronics and the tablet are not connected by a multiwire cable, but by a number of alternating dielectric insulation layers (281) and (282) stacked in a sandwich fashion. connected by constructed zebra strips (280).

Each layer is made of flexible materials, such as metal foil and plastic. The first plurality of dielectric layers (281) of the zebra strip (280) includes dielectric bonding electrodes (220).
) and (270), the second plurality connects dielectric bonding electrodes (222) and (272), and the third plurality connects dielectric bonding electrodes (224) and (274). , a fourth plurality connects dielectric bonding electrodes (226) and (276).

Bonding electrode (220) (222) (224) (22
6) are drive circuits (214), (216), and (2), respectively.
18) (see Figure 6A). The drive circuit (214) (216) (218) connects the bonding electrode (2
20) (222) (224), by the zebra strip (280) and by the bonding electrode (2
70) (272) and (274), respectively.

In a preferred embodiment, bonding electrodes (270) (27
2) (274) are electrically X, Y, Bffi, respectively.
connected to the pole. Bonding electrode (270) (272)
(274) are also each electrically connected to a menu electrode (not shown).

Bonding electrode (220) (222) (224) (226
) is attached to the printed circuit board (236) of the digitizer electronics (100). Printed circuit board (2
36) is made of dielectric material. Printed circuit board (2
Dielectric plate (228) (230) (
232) (234) are the bonding electrodes (220) (222
) (224) and (226), respectively.

Each pair of opposing plates, separated by a dielectric printed circuit board (236), forms a -aligned capacitor. Therefore, the drive circuits (214) (216) (
The drive signal of the bonding electrode (220) (222)
(224), the corresponding signal is
capacitively plate (228) (230) (23
2).

The hardware structure according to a preferred embodiment of the present invention will be described in detail with reference to FIGS. 6A and 68.

The digitizer electronic device is 803 manufactured by Intel Corporation in the United States.
Microprocessor composed of one chip (200)
Contains. However, for those of ordinary skill in this type of technology, an 8-bit microprocessor
It is obvious that it can be used in place of the 031 chip.

The microprocessor (200) drives the X, Y, and B electrodes, selects the format, and integrates the cursor output signal.

transmission of position coordinates and resetting of counting, transformation, latching and storage chips as detailed below;
Control enabling (preparation).

Microprocessor - (200) pins P0.1 to P
Up to O07, pin Di-D8 of buffer (204)
It is connected to the. The address logic enable (ALE) pin of the microprocessor (200) is
Connected to the latch enable (LE) pin of the buffer (204). Output terminal Ql-08 (ie, pin Ql-08) of buffer (204) is connected to pin AO-A7 of outer memory chip 206. Microprocessor - (200) pin P2.0-P
2.4 are pins A3-A of the outer memory chip, respectively.
connected to l2.

The output terminal (i.e. pin Q) of the memory chip (206)
O-07) are each connected to a line of a data bus (202). The data bus (202) line is
Each is connected to a line connecting a microprocessor (200) and a buffer (204). Pin PSEN of the microprocessor (200) is connected to the output enable (OE) of the outer memory chip (206). The outer memory chip (206) has stored program instructions.

Tables of some of these program directives are provided in Exhibits A and B.
It is attached here as. These program commands, which will be described in detail below, correspond to the flowcharts shown in FIGS. 9 and 10, respectively.

The lines of the data bus (202) are also connected to the respective output terminals of the buffer chip (208) (i.e. pin 0
l-08). Buffer chip (2
The output enable (OC) pin of 08) is connected to the lead (RD) pin of the microprocessor (200). The input terminal (ie, pin Di-D8) of the buffer chip (208) is connected to the output terminal (ie, pin Ql-08) of the counter (210).

The reset terminal (R) of the counter (210) is connected to pin P1.6 of the microprocessor (200).

The pin CLK of the counter (210) is connected to the AND gate (
250) receives a clocking signal from the oscillator (201).

The oscillator (201) is also connected to the CLK pin of the counter (212). The clock (212) is
11.0592-MHz from oscillator (201)
Split the signal and the output 86-KHz signal at pin Q7.

This 86-KHz signal is transmitted to the driver (214) (2
16) takes the form of a square wave oscillation applied directly to (218). Driver (214) (216)
(218) are dielectric plates (i.e. bonding electrodes) placed on one side of the printed circuit board (220) (222)
(224). The fourth guide plate (226) is connected to ground.

As shown in FIG.
2) (224) and (226) are the guide plates (2), respectively.
28) (230) (232) (234) are opposed. These opposing plates form the anode and cathode of each capacitor and are separated by a layer of electrical material (236). Guidance plate (22g) (230) (23
2) (234) is continuously connected to pin (15) of the conversion circuit (238).

The figurative cursor (240) is connected to pin (4) of the conversion chip (238). The stylus or cursor is connected to the terminal (3) of the connector (J2) which is itself linked directly to the pin (14) of the conversion chip (238). The conversion circuit (23g) uses pins (23g) for signals other than those selected under the control of the microprocessor (200).
4) and the pin (14) has been converted so that it is output to the negative terminal of the preamplifier (242).

The conversion gates of the conversion chip (238) depend on control bit data received at pins (9) (10) (11) which are directly connected to output pins Q5, Q6 and Q7 of the latching chip (244).

Latching chip (244) receives an 8-bit signal (at pin DI-08) from microprocessor (200) over data bus 202. As mentioned above, these 8
Three bits of the bit signal control the conversion state of the conversion chip (23g). Drive circuits (214), (216), and (218) operate under the control of the other three bits.

Latch enable (LH) of latching circuit (244)
) pin is directly connected to the light (lIR) pin of the microprocessor (200). The output of the preamplifier (242) is
6) is connected to the reference terminal. App fire (
The output terminal of 246) is connected to the negative terminal of the affifier (248) by a switch SWI of the conversion circuit (250). The output terminal of the amblifier (248) is connected to the positive terminal of the comparator (252). The output terminal of the amblifier (248) is fed back to the negative input terminal by a capacitor (c33).

Amblifier (248) and capacitor (c33)
form an integrator. The output terminal of the comparator (252) is connected to the clocking terminal CLK of the counter (210).

In response to the signal of the amblifier (248) achieving the predetermined value, the comparator issues a signal that stops clocking the counter (210). The output terminal of the comparator (252) is also connected to pin P1.4 of the microprocessor (200).
It is connected to the.

The conversion circuit (250) is a microprocessor (200
) effectively controlled by four switches 5WI-
Consists of 5W4. For example, pin (12) of the conversion circuit (250) controlling switch SW4 is directly connected to pin P1.7 of the microprocessor (200).

Pin (5) of the conversion circuit (250) that controls switch 51i13 is connected to pin 3 of the microprocessor (200).
．． 5 is directly connected. The pin (6) of the conversion circuit (250) that controls the switch S2 is connected to the driver (25
4) is connected to Pl,6. Finally, pin (13) of the conversion circuit (250) that controls switch S1
) is connected to an AND gate, and its input terminal is connected to the counter (2) by a latching circuit (244).
12) and pins po and o of the microprocessor (200).

The conversion circuit (250) is an amblifier (24g)
The charge on the capacitor (c33) connected in parallel with .

Control discharge and reset.

EEFROM258 is a microprocessor (200
) is connected to pins P1.0-P1.3 of This programmable memory has the ability to store special routines performed by the microprocessor.

Finally, the microprocessor-(200) transmission (TX
D) pin is connected to pin C of the level shifter (262). Pin 2 of the level shifter (262) is connected to the terminal (7) of jack J1. Terminal (7)
is utilized to transmit signals to external devices according to the R5232 protocol.

The pin TXD of the microprocessor (200) is also connected by the inverter (264) to the terminal (4) of the jack Jl.
It is connected to the. The terminal (4) of jack J1 is TT
It is used to transmit data to the L device. The receiving (RXD) terminal of the microprocessor (200) is connected to port 5 of jack Jl by resistor R18 and inverter 266.

Calibration of wedge/strip digitizers according to the invention is described in Section 8.9.10. This will be explained in detail with reference to Figure IIA, 118.

The digitizer electronic bag [(100) can be operated in the following two different ways. (1) Processing of signals received from the cursor or stylus (digitization mode) and (2) Processing of signals received from the Ii-like cursor (calibration mode).

In these modes, nine respective signals from the stylus and fidget cursor are induced in response to drive signals.

A typical sampling cycle in digitization mode is one that includes the following: (1) 11 movements of the X electrode alone and cycling of the cursor or stylus output signal; (2) the X, Y, B electrodes; Simultaneous driving of the cursor or stylus output signal, (a)
Driving only the yffl pole and sampling the cursor or stylus output signal.

When a pressure sensitive stylus is used with a tablet, the stylus output signal can be sampled during a fourth sampling cycle to determine the amplitude of the signal that acts as pressure is applied to the stylus tip. The output signal of the stylus is transmitted to the input pin (14) of the conversion chip (238) (see Figure 6A).

Within the conversion chip (238), the stylus signal is transferred from the latching chip (244) to the conversion chip (238).
) is output pin (12) and (
13). When the stylus output control signal is high, the input pin (14) is connected to the output pin (12), whereby the stylus output signal is communicated to the preamplifier (242).

If the stylus output control signal is low, the input pin (14)
is connected to the output pin (13), whereby the stylus output signal is communicated directly to the amplifier (248).

As shown in FIG. 8, the stylus output in response to the X, SUN, Y drive cycles is converted to a preamplifier (242), and the stylus output in response to pressure pulses sent to the stylus is converted to an amplifier (242).
248).

In the fifth sampling cycle, one or more
, Y, and B electrodes are driven, and the amplifier (24g
) is measured to determine the background noise level. During this fifth sampling cycle, the stylus output conversion control signal is low.

The sampling cycle for the preferred implementation of FIGS. 6A and 6B is shown in FIG.

The time for each cycle is 13.9 minutes. The output of the integrator (amblifier 248 and capacitor C33) is shown in the upper part of FIG. First, the X electrode is driven for one hour, and then the capacitor (c33) is discharged. The counter (210) starts counting when the capacitor (c33) starts discharging, and the counter (210) stops when the output of the integrator reaches the predetermined level.

Next, the X, Y, and B electrodes are driven simultaneously for T/2 hours, followed by the capacitor (c33) being discharged again. Again the counter (210) measures the discharge time. Third, the Y electrode is driven for one hour and the discharge time of the capacitor (c33) is measured by the counter (210).

During these first three stages, the stylus is enabled. That is, a capacitively induced current is output from the stylus.

In the fourth and fifth stages, the stylus is disabled and no capacitively induced current is output from the stylus.

In the fourth step, the pressure applied by the user to the stylus tip is measured. This step is only necessary if stylus coordinates are used.

The coordinates are determined relative to the stylus position where the stylus exerts the lowest predetermined pressure on the tablet. In particular, information regarding pressure is required when styli and tablets are used in conjunction with signature verification systems.

In a fifth step, a background reading is performed while the stylus is disabled and one or more electrodes are activated. Even if the capacitively induced current is
Even when there is no output from the stylus, the capacitor (C33)
has a charge stored within it, and that charge creates a limited discharge time.

Since the discharge time is used as a measure of the signal output of the stylus, the limited discharge due to noise and offset must be subtracted from the actual discharge time measured when the stylus is enabled. This limited discharge time is the count (Bx) (By) (
B sum).

In the cycle shown in FIG. 8, the Pack Brown signal is measured only while the X electrode is driven.

In the next cycle (not shown), the background signal is measured while the X, Y, B electrodes are being driven. In the next cycle (not shown), the background signal is measured only while the Y electrode is driven. These background readings were obtained in the first three stages of each cycle (Ax) (A s
um) (Ay).

The output of the integrator during background reading is
It is shown graphically in FIG.

At time (to), the capacitor (c33) is discharged in response to the discharge enable signal output of the microprocessor (200) and the counter (210) is started.

The output of the integrator is at the threshold level VR2
When reached, the comparator (252) gives a signal that
Stop the counter at t.

top counting is stopped (i.e., t5..,)
The digital value at the time is the X electrode, Y electrode or X.

It corresponds to Bx, By, or Bsum depending on whether the Y and B electrodes were driven before background reading.

The values Cx, Csum and cy are obtained in response to continuous driving of only the X electrode, of the X, Y and B electrodes simultaneously, and of the Y electrode only.

Theoretically, the ratios 2Cx/Csum and 2Cy/Csu
m is used to determine the X, Y coordinates of the cursor position.

However, in reality, the X and Y coordinates obtained from these ratios are
Due to the gap between the electrodes, the true coordinates of the cursor or stylus differ.

Any point data to be digitized,
Alternatively, the data relationship between points is modified by the required spacing between the electrodes to prevent dielectric between the electrodes.

The difference between the actual digitized result and the calculated result is the gap size, e.g. 2.54 x 10-”Cm
(10 mils), 3.81 x 10-"Cm (15 mils) space, etc.

For example, by placing the fictitious cursor (240) at a precise location near the corner of the tablet.

Actual measured data can be mathematically combined with predicted data to determine the amount of space-based resolution distortion. The correction factor can be calculated according to equations (6)-(9).

These factors applied to the incoming signal correct the output data for spaces or gaps between the tablet electrodes (50) (60) (70) of the digitizer. These correction factors tend to uniformize the gapped tablet electrode layers and therefore allow for manufacturing variability. Such gap differences are immediately corrected by the approximation cursor.

In summary, what is the actual interelectrode spacing and what can be mathematically predicted?
ll'l spacing differences are resolved using a permanently fixed cursor cursor on the digitizer tablet (40). The fissile cursor (240) has a fixed position and a geometric relationship between the X, Y, Bffi poles at that position and the electrodes (50) (60) (70) to maintain separation between the electrical signals. A correction factor is provided to compensate for the necessary physical gap in between.

The flowchart of the calibration routine according to the present invention is as follows.
This is shown in Figures A and 11B.

The calibration routine itself is attached here as Exhibit B. In calibration mode, the figurative cursor (240) moves from the latching chip (244) to the conversion chip (23).
8) (see box (301) in Fig. 11A) prepared by a signal sent to (see Fig. 6A).

In response to this signal, switch (238) switches the input pin (
4) is switched on to connect it to the output pin (3) which is connected to the preamplifier (242).

Initially, the signal output from the condensed cursor has the lowest amount of integration time - T/2 = 277.8 microseconds (Figure 8
(see T/2) - units of integration time. A count representing discharge time is compared to a threshold level. This threshold level represents the lowest acceptable signal magnitude to achieve a desired signal-to-noise ratio.

The signal from the fictitious cursor is lψ shown in FIG.
Obtained in response to drive cycle. A program table for controlling the charge and discharge of the capacitor (c33) (Figure 6B) during the operating time is attached as Exhibit A (8
(lines 77-1208).

The drive cycle is the same, regardless of which capacitively coupled electrodes (ie, stylus or figurative cursor) are prepared.

Background Reading Bx, By and B s
um is as previously explained (1218-12 in Exhibit A)
(see line 40), original reading Ax, Ay and Asuo
Subtracted from +.

As shown in box (302) of Figure 11A, the microprocessor waits 0.5 seconds before reading to allow the transient to terminate.

After 0.5 seconds have elapsed, the data collection vector in Appendix A is performed 72 times per second. Background - compensated X,
Y, SUN readings are asymmetrically corrected (see box (303)).

Asymmetric correction, background-compensated X, Y, and S
72 in LIM Reading (cx, Cy and Csum)
The samples of are used to create the ratios Xin and Yin, which are processed with a 1-ball IIR digital low-pass filter.

The digital filter filters out high frequency variations in the digital value of the calculated ratio, as high frequencies are based on noise. When processing by the digital filter is complete, the final ratio is stored.

As a next step (block 304), the stored C
The sum value is tested to determine if it is not greater than a predetermined value (eg, 3840) needed to achieve a predetermined signal-to-noise ratio.

If Csum is greater than 3840, the program performs step 307, thereby checking whether the number of integration time units is greater than 4.

As already mentioned, the initial number of units of integration time is .

It is 1. In this first step, the number of units of integration time is not greater than four, so the number of units is increased by one (block 308). Then, box (302) (3
03) The steps written in (304) are normally repeated, but in this case two units of integration time result in a larger value for Csum.

If Csum still does not become 3840 or higher.

Increase the accumulation time to 3 units and, if necessary, increase it from 4 to 5 units. If the minimum level (ie, 3840) cannot be achieved even after five units of integration time, the calibration is considered a failure (block 309). The integration time is set equal to two units, and the slope and intermediate hold are set equal to zero (0).

In this case, the digitizer can still interact with the host computer, but the determined position coordinates will be invalid.

When the Csum value satisfies the threshold condition.

The calibration is deemed to have been carried out satisfactorily and Csum
It is stored for use during the "Out of Proximity" calculation (block (305)).

After that, the Xin value and Yin value (Figure 11A and 1.1
In Figure 8, the X rate and Y rate) are respectively,
x0tr and Y0tr Karahiki Karel (flock 306).

Calibration continues as shown in FIG. 118.

The Xrange and Yrange values are calculated according to blocks (310) and (311), respectively, while the Xd
and yd are the tablet and the cursor (156 in Appendix B).
(see lines 3-1579) are the respective differences between the X and Y coordinates of the mechanical center.

Xrange and Yrange are factors used according to equations (6) and (7) to compensate for resolution distortions. Besides, Xoffset value and Y of
The fset value is calculated according to the equations in blocks (312) and (313).

Xoffset and Yoffset are used to tell the microprocessor where to find the margin for active coordinate determination.

Next, an "out of proximity" threshold level is calculated according to the equation in block (314).

R6 is the first number that can be adjusted up or down, as disclosed in U.S. Patent Application No. 1, Menu for Charge Ratio Tableno 1-.

Finally, the remaining balls are read when no pressure is applied to the stylus. This residual pressure reading is stored and later withdrawn when the stylus is pressed against the tablet 1- and a leap-in representing the true pressure occurs.

The above description of the preferred embodiments has been made for illustrative purposes only and is not intended to limit the scope of the invention as defined in the claims. Numerous modifications and variations can be readily made by those skilled in the art without departing from the spirit and scope of the inventive concept disclosed herein.

[Brief explanation of drawings]

FIG. 1 is a perspective view, partially schematic, of a digitizer used in conjunction with a computer system. FIG. 2 is an enlarged cross-sectional view of a portion of the digitizer tablet and the active portion of the cursor placed upon it in accordance with the present invention. FIG. 3 is a schematic top view showing the pattern according to the invention of the tableno 1 electrode of a wedge strip digitizer according to the prior art. FIG. 4 is a fragmentary view in which a part of the surface of FIG. 6 is greatly enlarged. FIG. 5 is a semi-schematic diagram of the processing circuitry used in the tablet/cursor shown in FIGS. 1-4 according to a preferred embodiment in which the cursor or stylus is driven. 6A and 6B are two parts of a detailed circuit diagram of a tablet-embedded printed circuit board according to the present invention in which the x, Y and B electrodes are driven. FIG. 7 is an enlarged side view of a zebra strip arrangement for connecting an electronic printed circuit board and a tablet. FIG. 8 is a timing diagram for a digitizer according to the present invention. FIG. 9 is a graph of equation (6). FIG. 1O is a graph of the integrator during background reading. ], LA diagram and 1st. Figure I8 is a flowchart of the calibration operation incorporated into the charge ratio tablet according to the invention. (2) Computer (3) Monitor (
4) (5) Screen (6) Cursor dot (10) Digitizer (20) Cursor (21
) Housing (22) Side wall (25) Electrical cord (26) Signal conducting wire (27)
(29) Terminal (28) Conductive wire (3
0) Electrode (31) Spacer (
32) Electrode (34) Opening (3
5) To the cross (37) Push button
Switch (40) Tablet (41)
Top side (42) Cover (44) Electrode layer (46) Shielding (50) Electrode (
51) (53) (54) Strip (58
) bus (59) lead (60)
Y electrode (61) Wedge (62)
(63) Edge (64) Terminal (68
) bus (69) lead (70
) B electrode (71) (72) leg (
74) Section (75) Lead (80
) Shield electrode (100) Digitizer-electronic device (1
05) Oscillator (106) (107) Circuit element (108) Register (122) Amplifier
(126) (127) Register (1
30) Switch (131) Amplifier (1
32) Capacitor (133) Register (150) Microprocessor - (240) IL-like cursor (270) Electrode (280
) Printing of strip drawing (no change in content) FI6.4 FIo, 68 FIG9 FIG, 10 FIG, //13

Claims (24)

[Claims] (1) having a substantially flat top edge and first and second electrodes in a plane parallel to the top edge, the first electrode having a first geometric pattern, and the first pattern having two the second electrode has a second geometric pattern, the second pattern varies in a second coordinate of the two-coordinate system, and both the first and second electrodes have a dielectric material. a digitizer tablet, a coupling device including a coupling electrode that moves over the top of the digitizer tablet and makes an electrostatic connection with the first and second electrodes; It is fixedly arranged on the digitizer tablet to make an electrostatic connection with the electrode, and is arranged on the side of the plane opposite to the top side of the digitizer tablet, and has a single point at predetermined first and second coordinates. A signal generating device for outputting a drive electrical signal to one of the condensed cursor electrode and the concatenated electrode having a dot, the drive signal being applied to the driven electrode and When the device to be electrostatically connected to the first and second electrodes and the coupling device are near the tablet, the first and second coordinates of a point on the coupling device are determined according to the driving signal. An electronic device that receives and processes the signals generated at the two electrodes, and a signal generator that connects the first condensed cursor electrode and the connecting electrode to the first and second electrodes for electrostatic connection to the first and second electrodes. A digitizer characterized by comprising a conversion device that is continuously connected to the device. (2) When the coupling device is located on the tablet surface, the first dielectric layer separates the first and second electrodes from the coupling electrode, and the second dielectric layer separates the first and second electrodes into a coagulated cursor electrode. The digitizer according to claim 1, wherein the digitizer is separated from the digitizer. (3) The first electrode is wedge-shaped, the second electrode is strip-shaped, and the third electrode arranged in a serpentine shape is separated from the first and second electrodes by a spacing device made of an insulating material. 2. The digitizer according to claim 1, wherein the digitizer substantially covers the space between the first and second electrodes. (4) The digitizer according to claim (1), wherein the coupling device includes a cursor. (5) The digitizer according to claim 1, wherein the connecting device includes a stylus. (6) an electronic device for receiving and processing signals, connected to the first, second and third electrodes, for storing a predetermined value based on the geometry of the first, second and third electrodes, for driving the predetermined value; The apparatus compares the processed values determined from the actual signals produced at the first, second and third electrodes by means of the condensed cursor electrodes and calculates a correction factor proportional to the difference between the processed values and the expected values. 4. A digitizer according to claim 3, wherein the correction factor comprises a device for correcting resolution distortions caused by the spacing device. (7) Claim (7) characterized in that the generator for correction factors comprises a memory having a stored calibration routine.
6) Digitizer as described. 8. The digitizer of claim 6, wherein the electronic device includes a device for calculating first and second coordinates of the point of the coupling device using a correction factor. (9) The digitizer according to claim (1), wherein the figurative cursor electrode includes a dielectric plate. (10) a first layer formed of a dielectric material and having a generally planar top edge; first and second electrodes in a plane parallel to the top edge; the first electrode having a first geometric pattern; and the first pattern varies at a first coordinate of a two-coordinate system;
a second electrode having a second geometric pattern, the second electrode pattern varying at a second coordinate of a two-coordinate system, and the first and second electrodes being formed of a dielectric material; Two -layer and one point of the mimicty cursor electrode fixed on a tablet for the digital digitizer have the first and second coordinates, and are located on the side of the plane facing the first layer. From this, it is confirmed that the coagulant cursor electrode and the second layer are separated by a dielectric material, and the thickness and dielectric properties of the dielectric material enable electrostatic connection between the coagulant cursor electrode and the first and second electrodes. Features a digitizer tablet system. (11) A signal generator that outputs a driving electric signal to a figurative cursor electrode, where the driving signal causes an electrostatic connection between the figurative cursor electrode and the first and second electrodes, and one point on the figurative cursor electrode. characterized by comprising an electronic device that receives and processes signals generated at the first and second electrodes in response to a drive signal to determine digital values corresponding to the first and second coordinates measured at the A digitizer tablet system according to claim 10. (12) A signal generating device that generates a driving electric signal to electrostatically connect the first and second electrodes to the first and second electrodes; Claim 10 characterized in that it comprises an electronic device for receiving and processing signals generated at the figurative cursor electrode in response to a drive signal to determine a digital value corresponding to the second coordinate.
) digitizer tablet system. (13) The first electrode is wedge-shaped, the second electrode is strip-shaped, and the third electrode arranged in a serpentine shape is separated from the first and second electrodes by a spacing device made of an insulating material. 11. The digitizer tablet system according to claim 10, wherein the digitizer tablet system substantially covers the space between the first and second electrodes. (14) An electronic device for receiving and processing signals is connected to the first, second, and third electrodes, and a device for storing a predetermined value based on the geometry of the first, second, and third electrodes, and for reproducing the predetermined value. A device that compares the processed value determined from the first, second and third actual signals generated by the cursor electrode, and calculates a correction factor proportional to the difference between the processed value and the expected value, and the correction factor is ,
14. A digitizer tablet system as claimed in claim 13, characterized in that the spacing device includes a device for correcting underlying resolution distortions. (15) The digitizer tablet system according to claim 10, wherein the figurative cursor electrode includes a dielectric plate. (16) having a generally planar top side, having first and second electrodes on a plane parallel to the top side, the first electrode having a first geometric pattern, and the first pattern having a first geometric pattern; a first coordinate of a two-coordinate system; the second electrode has a second geometric pattern; the second pattern varies in a second coordinate of a two-coordinate system; a digitizer tablet formed of a dielectric material; a connecting device that moves on top of the tablet of the digitizing device and includes a connecting electrode that is electrostatically connected to the first and second electrodes; and the first and second electrodes. a figurative cursor electrode fixedly placed at a defined location on the digitizer for making an electrostatic connection with the digitizer and placed on the side of the plane facing the digitizer; A signal generating device that outputs a signal and electrostatically connects the electrode driven by the drive signal, the connecting electrode, and the pseudo cursor electrode, and a point on the connecting device when the connecting device is near the tablet. In order to determine the first and second coordinates of A digitizer that is characterized by being connected to a converter. (17) A wedge/strip digitizer tablet comprising a plurality of patterned electrodes formed of dielectric material to determine the coordinates of a movable connection device placed on an active surface. the movable connecting device has a layer configured such that at least one of the patterned electrodes is actuated, the connecting device is configured such that one of the patterned electrodes is actuated, and the connecting device is proximate to the active surface. At some point, a fixed coagulated cursor electrode, which has a connecting electrode for electrostatic connection with the patterned electrode and further comprises a dielectric plate, is provided between the patterned electrode and the coagulated cursor electrode. a first layer of dielectric material disposed between the patterned electrodes and a proximate connection device; a second layer of dielectric material disposed between the patterned electrodes and a proximate connection device; and a signal generating device that outputs a signal to the pseudo cursor electrode and the connecting electrode according to the drive signal to determine the first and second coordinates of a point on the connecting device when the connecting device is near the tablet. A digitizer system comprising: an electronic processing device for receiving and processing the generated signals; and a conversion device serially connecting a figurative cursor electrode and a connecting electrode to the electronic device; (a) two coordinate dimensions of the active surface; (b) providing a drive signal to the patterned electrode in a predetermined sequence; (c) making an electrostatic connection with the driven patterned electrode; result,
(d) determining the measured coordinates of a point on the fictitious cursor electrode in relation to a two-coordinate dimensional system; (e) based on the actual and measured coordinates; A method for calibrating a digitizer system, comprising the steps of creating first and second correction factors. (18) (f) applying a drive signal to the patterned electrode in a predetermined sequence; (g) resulting in an electrostatic connection with the driven patterned electrode;
(h) determine the measured coordinates of a point on the connecting device relative to the two-coordinate dimensional system; (i) use the first and second correction factors to determine the two-coordinate calculate the actual coordinates of a point on the connecting device relative to the dimensional system;
18. The method of claim 17, further comprising the step of correcting resolution distortions due to spacing between patterned electrodes. (19) A wedge/strip type digitizer tablet having multiple layers of patterned electrodes, each patterned to determine the coordinates of a movable connection device placed on the active surface. The patterned electrode is formed of a dielectric material, and the movable connecting device is connected to the patterned electrode to make an electrostatic connection with the patterned electrode when at least one of the connecting electrodes is actuated and proximate the active surface of the tablet. The device includes a tablet further comprising a dielectric plate, a fixed figurative cursor electrode, a patterned electrode and a first layer of dielectric material disposed between the figurative cursor electrode, a patterned electrode; and a second layer of dielectric material disposed between the connecting device and the adjacent connecting device, a signal generating device for providing a driving electrical signal to at least one of the linking electrode and the figurative cursor electrode, when the connecting device is adjacent to the tablet. , the first of one point on its connecting device,
an electronic processing device that receives and processes signals generated in the patterned electrodes in response to the drive signal to determine second coordinates; and the pseudo cursor electrode and the connecting electrode are connected in series to the signal generating device. A digitizer system, including a transducer, (a) predetermines the actual coordinates of a point on the active surface of the tabled on a figurative cursor electrode relative to a two-coordinate dimensional system; and (b) predetermines a drive signal. (c) measuring the signal generated in the patterned electrode as a result of the capacitive connection with the driven fiducial electrode; (d) determining the fictitious cursor electrode with respect to a two-coordinate dimensional system; A method for calibrating a digitizer system, comprising the steps of: determining measurement coordinates of a point on an electrode; and (e) creating first and second correction factors based on the actually measured coordinates. (20) (f) Applying a drive signal to the connection electrode according to a predetermined sequence; (g) measuring the signal generated in the patterned electrode as a result of electrostatic connection to the driven connection electrode; (h ) determine the measured coordinates of a point on the connecting device associated with the two-coordinate dimensional system; (i) using the first and second correction factors, determine the actual coordinates of that point on the connecting device associated with the two-coordinate dimensional system; 20. Calibration method according to claim 19, characterized in that it comprises the step of calculating coordinates, thereby correcting distortions in resolution due to spacing between patterned electrodes. (21) the first and second electrodes are in a plane, the first electrode has a first geometric pattern, the first pattern varies in a first coordinate of a two-coordinate system, and the second electrode is in a plane; , having a second geometric pattern, the second pattern varying in a second coordinate of a two-coordinate system, the first and second electrodes being formed of a dielectric material, and the first enabling (
a signal generator that outputs a drive signal to at least one of the first and second electrodes in response to a function activation) signal, a port device that receives an analog signal from outside the tablet, and an amplifier that amplifies the analog signal; a conversion device connecting the port device and the amplifier device for freely activating or stopping transmission of the analog signal from the port device to the amplifier device in response to the second activation signal and the stop signal; It consists of an analog/digital converter connected to convert the amplified analog signal into a digital signal, a signal generator, and a control device connected to output a control signal to the converter and analog/digital converter. At an interval of , the first trigger signal is sent to the signal generator, and at a second interval following the first interval, a third trigger signal is sent to the analog/digital converter; A digitizer tablet system characterized in that the control device is programmed to issue a stop signal to the converter during the second interval. (22) The device according to claim (21), further comprising a memory device connected to store the digital signal output by the analog/digital converter in response to a third activation signal from the control device. digitizer tablet. (23) A method for calibrating a digitizer system comprising a wedge/strip type digitizer tablet;
The tablet has a layer composed of a plurality of patterned electrodes, each patterned electrode comprising:
The movable connecting device is formed of a dielectric material, and when at least one of the patterned electrodes is activated and the connecting device is in the vicinity of the active surface, the movable connecting device forms an electrostatic connection with the patterned electrodes. a signal generator for inputting a drive signal to at least one of the patterned electrodes; and a signal generator for inputting a drive signal to at least one of the patterned electrodes; 2.According to the drive signal to determine the coordinates, the connecting device receives an analog signal generated;
A digitizer system comprising a processing device having an electronic processing device for processing, a conversion device for selectively starting and stopping transmission of an output signal from a connecting electrode to the electronic processing device, and an analog/digital conversion device, (a) providing a drive signal to at least one of the patterned electrodes during a first interval; (b) providing a signal to a transducer to stop transmitting an output signal from the connecting device during a first interval; (c) generating and storing a digital signal corresponding to the analog signal received by the analog-to-digital converter during a first interval; and (d) driving the at least one of the patterned electrodes during a second interval. (e) providing a drive signal to a converting device that initiates transmission of an output signal from the connecting device during a second interval; and (f) an analog signal accepted by the analog-to-digital converting device during a second interval. A method for calibrating a digitizer system, comprising the step of generating a second digital signal corresponding to the digitizer system. (24) (g) subtracting the first digital value from the second digital value to obtain a third digital value; and (h) using the third digital value to connect the connecting device associated with the two-coordinate dimensional system. 24. The calibration method according to claim 23, further comprising the step of determining measurement coordinates of the upper point.