Method and apparatus for an optical laser keypad

• US 6,525,677 B1
• Filed: 08/28/2000
• Issued: 02/25/2003
• Est. Priority Date: 08/28/2000
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Printzis, George A.
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): DANG, HUNG Q
• Application Number:
  US09/649,699
• Time in Patent Office: 911 Days
• Field of Search: 341/22, 341/26, 341/31, 178/18.09, 345/170, 379/368
• US Class Current: 341/31
• CPC Class Codes: H03K 17/943 using a plurality of optical emitters or detectors, e.g. keyboard

Abstract

An optical laser numeric keypad (100) provides a digital signal indicative of which of a plurality of key locations is selected. The optical laser numeric keypad (100) comprises a plurality of optical sensors (132 and 134) each configured to respond to a change in a received light quantity and to provide an electrical signal in response to a selection of a key at a key location. The received light quantity of at least one of the plurality of optical sensors (132 and 134) is changeable by selection of a key location.

Claims

1. An optical laser numeric keypad configured to provide an electrical signal indicative of which of a plurality of key locations is selected, the optical laser numeric keypad comprising:

a plurality of optical sensors each configured to respond to a change in a received light quantity and to provide an electrical signal in response to selecting of a key at a key location, the received light quantity of at least one of the plurality of optical sensors being changeable by selection of a key location; and

a key location indentifier configured to provide a binary number having a bit for each of the row optical sensors and further having a bit for each of the column optical sensors.

2. The optical laser numeric keypad of claim 1, wherein each of the key locations is associated with a distinct set of the plurality of optical sensors, such that selecting of a key location causes a response at the corresponding set of the plurality of optical sensors.

3. The optical laser numeric keypad of claim 1, wherein each of the plurality of key locations is associated with a distinct pair of the plurality of optical sensors, such that selecting of a key location causes a response at the corresponding pair of optical sensors including one of a row optical sensor and one of a column optical sensor.

4. The optical laser numeric keypad of claim 1, wherein a key location is configured to admit a received light quantity toward each of the plurality of optical sensors associated therewith, each of the plurality of optical sensors configured to receive the received light quantity.

5. The optical laser numeric keypad of claim 1, wherein each of the plurality of key locations is defined by a row of key locations and a column of key locations.

6. The optical laser numeric keypad of claim 1, wherein the optical laser numeric keypad resides within and controls a wireless telephone.

7. The optical laser numeric keypad of claim 1, further comprising an optical diverter configured to route a light beam among the plurality of key locations, wherein the optical diverter is a hologram.

8. The optical laser numeric keypad of claim 1, wherein the optical source includes a laser diode and the optical sensors include photo diodes configured to provide an electrical signal when light is received from the optical source and to suppress the electrical signal when light is not received from the optical source.

9. An apparatus for interfacing with a telephone system, the apparatus comprising:

an optical laser numeric keypad configured to provide an electrical signal indicative of which of a plurality of key locations is selected, the optical laser numeric keypad comprising an optical source and a plurality of optical sensors each configured to respond to a change in a received light quantity and to provide an electrical signal in response to selecting of a key at a key location, the received light quantity of at least one of the plurality of optical sensors being changeable by selection of a key location, wherein a light beam from the optical source passes through an optical liquid crystal element within a cavity at each of the plurality of key locations, the light beam being selectably interruptible at each of the plurality of key locations by the application of an electrical potential across the optical liquid crystal element within the cavity sufficient to polarize the optical liquid crystal element orthogonally to the light beam.

10. The apparatus of claim 9, wherein each of the plurality of key locations is associated with a distinct set of the plurality of optical sensors, such that selecting of a key location causes a response at the corresponding set of the plurality of optical sensors.

11. The apparatus of claim 9, wherein each of the plurality of key locations is associated with two of a distinct pair of the plurality of optical sensors, such that selecting of a key location causes a response at the corresponding pair of optical sensors including one of a row optical sensor and one of a column optical sensor.

12. The apparatus of claim 9, wherein a key location is configured to admit a received light quantity toward each of the plurality of optical sensors associated therewith, the optical sensor configured to receive the received light quantity.

13. The apparatus of claim 9, herein the key location resides within a row of key locations and also resides within a column of key locations.

14. The apparatus of claim 9, wherein the apparatus resides within and controls a wireless telephone.

15. The apparatus of claim 9, wherein the light beam passes through a cavity at each of the plurality of key locations, the light beam being selectably interruptible at each of the plurality of key locations by inserting of an opaque object within the cavity.

16. An apparatus for interfacing with a telephone system, the apparatus comprising:

an optical laser numeric keypad configured to provide an electrical signal indicative of which of a plurality of key locations is selected, the optical laser numeric keypad comprising an optical source and a plurality of optical sensors each configured to respond to a change in a received light quantity and to provide an electrical signal in response to selecting of a key at a key location, the received light quantity of at least one of the plurality of optical sensors being changeable by selection of a key location, wherein the optical source is configured to provide a light beam having a plurality of frequencies, at least one frequency for each of the rows and at least one frequency for each of the columns; and

an optical diverter including a hologram having spectral dispersion elements to divert a portion of the light to each of the plurality of columns and a portion of the light to each of a plurality of rows, such that each of the plurality of rows and each of the plurality of columns receives a different frequency.