Four button cursor and method for digitizing tablet
First Claim
1. A cursor for use in digitizing points along a digitizing surface of a digitizer, the cursor comprising in combination:
- (a) bottom surface means for sliding the cursor smoothly along the digitizing surface;
(b) housing means attached to the bottom surface means and grippable by a hand of an operator for enabling the operator to hold and operate the cursor;
(c) alignment indicia means attached in fixed relationship to the housing means for enabling the operator to visually align the cursor with the points to be digitized;
(d) non-directional antenna means attached in fixed relationship to the alignment indicia means for transmitting an antenna signal to the digitizing surface substantially independently of the rotational orientation of the cursor about an axis perpendicular to the plane of the digitizing surface when the bottom surface means rests on the digitizing surface; and
(e) means for producing the antenna signal on the antenna means in response to pressure applied to the cursor by the hand of the operator, wherein the antenna signal producing means includei. circuit means for producing a plurality of different frequency signals,ii. means responsive to the signals produced by the circuit means for producing the antenna signal,iii. a plurality of switch buttons arranged around a post,iv. a plurality of control switches corresponding to the switch buttons, respectively, connected to the circuit means for causing the circuit means for produce a signal having a frequency determined by the states of the control switches.
4 Assignments
0 Petitions
Accused Products
Abstract
A cordless four button cursor unit for accurately digitizing points along a digitizing tablet surface has an insulative housing including four buttons, each shaped as a quadrant of a circle and arranged about a hub. The hub acts as a stationary support from which an operator'"'"'s fingers can conveniently "roll" to actuate any of the buttons. An antenna loop integral with a printed circuit board extends forward of the housing and subtends a cross hair on the bottom surface of a transparent substrate. A pair of conductive touch plates on opposite sides of the housing are short circuited by the resistance of an operator'"'"'s hand, enabling an oscillator to effectuate operation of the cursor unit, causing the antenna to transmit electrostatic signals of frequencies representing button commands. The capacitance of the operator'"'"'s body adds to the ground plane capacitance, so that transmission of electrostatic signals by the ground plane to the digitizing tablet is avoided. When the opeator'"'"'s hand breaks contact with the touch plates, the oscillator is disabled before data errors can be produced by the resulting decrease in gound plane capacitance.
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Citations
25 Claims
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1. A cursor for use in digitizing points along a digitizing surface of a digitizer, the cursor comprising in combination:
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(a) bottom surface means for sliding the cursor smoothly along the digitizing surface; (b) housing means attached to the bottom surface means and grippable by a hand of an operator for enabling the operator to hold and operate the cursor; (c) alignment indicia means attached in fixed relationship to the housing means for enabling the operator to visually align the cursor with the points to be digitized; (d) non-directional antenna means attached in fixed relationship to the alignment indicia means for transmitting an antenna signal to the digitizing surface substantially independently of the rotational orientation of the cursor about an axis perpendicular to the plane of the digitizing surface when the bottom surface means rests on the digitizing surface; and (e) means for producing the antenna signal on the antenna means in response to pressure applied to the cursor by the hand of the operator, wherein the antenna signal producing means include i. circuit means for producing a plurality of different frequency signals, ii. means responsive to the signals produced by the circuit means for producing the antenna signal, iii. a plurality of switch buttons arranged around a post, iv. a plurality of control switches corresponding to the switch buttons, respectively, connected to the circuit means for causing the circuit means for produce a signal having a frequency determined by the states of the control switches. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A cursor for use in digitizing points along a digitizing surface of a digitizer, the cursor comprising in combination:
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(a) bottom surface means for sliding the cursor smoothly along the digitizing surface; (b) housing means attached to the bottom surface means and grippable by a hand of an operator for enabling the operator to hold and operate the cursor; (c) alignment indicia means attached in fixed relationship to the housing means for enabling the operator to visually align the cursor with the points to be digitized; (d) non-directional antenna means attached in fixed relationship to the alignment indicia means for transmitting an antenna signal to the digitizing surface substantially independently of the rotational orientation of the cursor about an axis perpendicular to the plane of the digitizing surface when the bottom surface means rests on the digitizing surface; (e) means for producing the antenna signal on the antenna means in response to pressure applied to the cursor by the hand of the operator; (f) a ground plane conductor, the antenna signal producing means being electrically grounded to the ground plane conductor; and (g) conductive touch plate means disposed on an external surface of the housing means and electrically connected to the ground plane conductor for adding capacitance of the operator'"'"'s body to the capacitance of the ground plane conductor, to substantially avoid transmission of error producing signals to the digitizing surface by the ground plane conductor. - View Dependent Claims (8, 9, 10, 11)
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12. A voltage multiplier circuit, comprising in combination:
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(a) first means for conducting a first respective signal; (b) second means for conducting a second respective signal which is 180 degrees out of phase with the first respective signal; (c) first and second capacitors each having a first terminal coupled to the first means, and third and fourth capacitors each having a first terminal coupled to the second means; (d) first, second, third and fourth diodes; (e) a P channel field effect transistor and an N channel field effect transistor; (f) third means for coupling the second terminal of the first capacitor, the cathode of the first diode, the anode of the second diode, and the gate electrode of the P channel field effect transistor together; (g) first means for coupling the source electrode of the P channel field effect transistor, the second terminal of the capacitor, and the cathode of the second diode together; (h) fifth means for coupling the second terminal of the second capacitor, the anode of the third diode, the cathode of the fourth diode, and the gate electrode of the N channel field effect transistor together; (i) sixth means for coupling the second terminal of the fourth capacitor, the anode of the fourth diode, and the source electrode of the N channel field effect transistor together; (j) means for coupling the anode of the first diode to a first supply voltage conductor and means for coupling the cathode of the third diode to a second supply voltage conductor; and (k) means for coupling the drain electrode of the P channel field effect transistor and the N channel field effect transistor to an output conductor. - View Dependent Claims (13, 14, 15, 16)
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17. A method of digitizing points along a digitizing surface, comprising the steps of:
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(a) placing a sheet having points to be digitized on the digitizing surface; (b) placing a cursor unit having a housing grippable by a hand of an operator onto the sheet; (c) gripping the housing by means of the operator'"'"'s hand, and (1) automatically connecting the capacitance of the operator'"'"'s body in parallel with the capacitance of an internal ground plane conductor to provide an increased total effective ground plane capacitance, and (2) automatically enabling a first circuit to produce a first repetitive signal in response to pressure applied by the hand to the housing; (d) coupling the first repetitive signal to an antenna attached to the housing and positioned to transmit an antenna signal to grid conductors embedded in the digitizing surface; (e) providing an alignment indicia attached to the housing in fixed relationship to the antenna; (f) sliding the cursor unit along the digitizing surface to align the alignment indicia with a first point to be digitized; and (g) actuating a first switch to cause the first circuit to generate a first cursor command signal on the antenna to indicate that the coordinates of the first point are to be digitized. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
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Specification