Cordless digitizer transducer/cursor status transmission apparatus and method

• US 5,525,981 A
• Filed: 07/29/1994
• Issued: 06/11/1996
• Est. Priority Date: 01/30/1992
• Status: Expired due to Fees

• Current Assignee: Einstruction Gtco Holdings, LLC
• Original Assignee: CalComp, Inc. (Martin Marietta Corporation)
• Inventors: Abernethy, Brian L.
• Primary Examiner(s): Peng, John K.
• Assistant Examiner(s): HILL, ANDREW M
• Application Number:
  US08/282,822
• Time in Patent Office: 683 Days
• Field of Search: 341/34, 341/22, 341/20, 178/18, 178/19, 178/20, 364/174, 364/175, 340/825.68, 340/825.69
• US Class Current: 341/34
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/04162 for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware

Abstract

A cordless transducer/cursor having a transmitter for use in conjunction with the receiver of a digitizer tablet. The transmitter receives parallel binary signals representing the status of non-positional functions such as command button status and the pressure applied to a stylus of the transducer/cursor and converts these into a serial stream of binary data for electrostatic or electromagnetic transmission to the receiver which, in turn, converts the serial stream into a plurality of parallel binary signals consistent with those received and converted by the transmitter.

Claims

1. In a cordless digitizer system having a cordless transducer/cursor and a digitizer tablet in which the position of a cordless transducer/cursor on the digitizer tablet is determined electromagnetically by means of a positional signal transmitted from the transducer/cursor to the digitizer tablet at a first frequency, a transmitting apparatus disposed in said cordless transducer/cursor for wirelessly transmitting the status of a non-positional function of the cordless transducer/cursor to a receiving apparatus of the digitizer tablet, the transmitting apparatus comprising:

a) status means for representing the status of the non-positional function of the transducer/cursor as a binary number comprising at least one parallel binary bit;

b) a parallel-to-serial shift register connected to receive said binary number in parallel and output a serial stream of binary pulses representing said binary number, wherein the absence of a pulse represents one binary state and the presence of a pulse represents the other binary state; and

,

c) wireless transmission means for separately transmitting said serial stream of binary pulses other than in conjunction with the positional signal.

2. The transmitting apparatus of claim 1 wherein:

said wireless transmission means transmits said serial stream of binary pulses electrostatically.

3. The transmitting apparatus of claim 1 wherein:

said wireless transmission means transmits said serial stream of binary pulses employing a second frequency.

4. A cordless digitizer system having a cordless transducer/cursor and a digitizer tablet, comprising:

a transmitting apparatus disposed in said cordless transducer/cursor for wirelessly transmitting the status of a non-positional function of the cordless transducer/cursor to a receiving apparatus of the digitizer tablet, the transmitting apparatus comprising,

status means for representing the status of the non-positional function of the transducer/cursor as a binary number comprising at least one parallel binary bit,

a clock producing a regular series of clock pulses,

a parallel-to-serial shift register connected to receive said binary number in parallel and output a serial stream of binary pulses representing said binary number and synchronized to said clock pulses, wherein the absence of a pulse represents one binary state and the presence of a pulse represents the other binary state, and,

output means for wirelessly transmitting said serial stream of binary pulses separately, other than in conjunction with a positional signal.

5. A cordless digitizer system according to claim 4, wherein the receiving apparatus of the digitizer tablet comprises:

a) receiver means for receiving said serial stream of binary pulses wirelessly transmitted from the transducer/cursor;

b) clock recreation means for providing pulses which are synchronous with said clock pulses to which said serial stream of binary pulses were synchronized; and

,

c) a serial-to-parallel shift register receiving said serial stream of binary pulses from said receiver mean and producing in combination with said pulses from said clock recreation means a parallel binary output corresponding said binary number from said status means.

6. A cordless digitizer system according to claim 4 wherein:

said status means comprises at least one button actuated switch.

7. A cordless digitizer system according to claim 4 wherein:

said status means comprises a pressure-to-digital converter outputting a parallel binary signal indicating levels of pressure being exerted on the cordless transducer/cursor.

8. In a cordless digitizer system having a cordless transducer/cursor and a digitizer tablet over which the transducer/cursor is moved, a method for wirelessly transmitting from a transmitting apparatus disposed in said cordless transducer/cursor the status of a non-positional function of the cordless transducer/cursor to a receiving apparatus of the digitizer tablet comprising the steps of:

a) in the transmitting apparatus of the transducer/cursor,

a1) generating a parallel binary signal representing the status of the non-positional function,

a2) converting the parallel binary signal into a serial stream of binary pulses synchronous with a series of first clock pulses and representing the parallel binary signal, wherein the absence of a pulse represents one binary state and the presence of a pulse represents the other binary state, and

a3) wirelessly transmitting the serial stream to the receiving apparatus of the digitizer tablet separately, other than in conjunction with a positional signal; and

,

b) in the receiving apparatus of the digitizer tablet,

b1) receiving the serial stream,

b2) synchronizing the received stream with a series of second clock pulses duplicating the first clock pulses, and

b3) converting the serial stream to a parallel binary signal representing the status of the non-positional function.

9. In a cordless digitizer system having a cordless transducer/cursor including a plurality of non-positional functions and a digitizer tablet over which the transducer/cursor is moved, a method for wirelessly transmitting from a transmitting apparatus disposed in said cordless transducer/cursor the status of a non-positional function of the cordless transducer/cursor to a receiving apparatus of the digitizer tablet comprising the steps of:

a) in the transmitting apparatus of the transducer/cursor,

a1) generating a plurality of parallel binary signals representing the status of respective ones of the non-positional functions,

a2) converting the plurality of parallel binary signals into a common serial stream of binary pulses synchronous with a series of first clock pulses and representing the parallel binary signal, wherein the absence of a pulse represents one binary state and the presence of a pulse represents the other binary state, and

a3) wirelessly transmitting the serial stream to the receiving apparatus of the digitizer tablet separately, other than in conjunction with a positional signal; and

,

b) in the receiving apparatus of the digitizer tablet,

b1) receiving the serial stream,

b2) synchronizing the received stream with a series of second clock pulses duplicating the first clock pulses, and

b3) converting the serial stream to a plurality of parallel binary signals representing the status of respective ones of the non-positional functions.