Low-feedback compact wireless telephone

• US 6,311,071 B1
• Filed: 06/01/2000
• Issued: 10/30/2001
• Est. Priority Date: 06/20/1994
• Status: Expired due to Fees

• Current Assignee: Microtalk Technologies Incorporated
• Original Assignee: Microtalk Technologies Incorporated
• Inventors: Kobylarz, Daniel E., Zochert, Carrie L., Maser, Steven, Anderson, Marlyn J., Voroba, Barry
• Primary Examiner(s): MAUNG, NAY AUNG
• Application Number:
  US09/585,110
• Time in Patent Office: 516 Days
• Field of Search: 455/550, 455/575, 455/40, 455/556, 455/569, 455/570, 379/428, 379/432, 368/10, 368/13, 381/83, 381/92, 381/93, 381/155, 381/76
• US Class Current: 455/550.1
• CPC Class Codes: H04B 1/385 Transceivers carried on the body, e.g. in helmets
• CPC Class Codes: H04M 1/20 Arrangements for preventing acoustic feed-back H04M1/62 takes precedence
• CPC Class Codes: H04M 1/585 implemented without inductive element
• CPC Class Codes: H04M 1/725 Cordless telephones user interfaces specially adapted therefor H04M1/724
• CPC Class Codes: H04M 9/08 Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic

Abstract

The present invention is directed to apparatus and methods for reducing sidetone feedback in a portable wireless telephone system by positioning the speaker and the microphone to reduce acoustic feedback and by controlling the amplifier gain in the transmitter section of the wireless telephone to reduce amplification of sidetone which has been acoustically coupled from the speaker to the microphone. The wireless telephone may be configured as a watch with a wrist strap for retaining it to the user, as a piece of jewelry such as a brooch or pendant, as a voice capable pager/intercom, or as an identification badge for an employee. In one embodiment, the base station includes circuitry for further reducing sidetone feedback. In additional embodiments, the wireless telephone may include a quick-release outboard battery, a retractable earpiece, and an ergonomic keypad.

Claims

1. A method of manufacturing a wireless telephone, comprising the steps of:

providing a directional speaker connected to a speaker interface circuit positioned for containment within a telephone body member and a directional microphone connected to a microphone interface circuit positioned for containment within the telephone body member, the telephone body member having a fixed configuration;

providing a wireless interface circuit positioned for containment within the telephone body member, and further providing a controller connected to the microphone interface circuit, the speaker interface circuit and the wireless interface circuit positioned for containment within the telephone body member;

positioning the directional speaker such that sound generated by the speaker radiates predominately in a first direction;

fixing the directional microphone such that the directional microphone is positioned so as to be most sensitive to sound arriving from a second direction approximately 90 degrees offset from the first direction; and

encompassing the directional speaker, the directional speaker interface circuit, the directional microphone, the directional microphone interface circuit, the wireless interface circuit, and the controller within the telephone body member, wherein the wireless telephone is operable during non-communication and communication operations with the telephone body member in the fixed configuration.

2. The method of claim 1, wherein providing the directional speaker and directional microphone includes providing the directional microphone at a position that is located between approximately 2.5 cm and 6.8 cm from the directional speaker along at least one surface of the telephone body member.

3. The method of claim 1 wherein the telephone body member has at least two connected faces, one face being positioned at an angle of approximately 90 degrees with respect to the other face, the first direction being substantially perpendicular relative to one of the two faces and the second direction being substantially perpendicular to the other of the two faces.

4. The method of claim 3, wherein the telephone body member has a top face and a side face, the side face being positioned at an angle of approximately 90 degrees with respect to the top face, the first direction being substantially perpendicular relative to the top face and the second direction being substantially perpendicular to the side face.

5. The method of claim 4, wherein the directional speaker and directional microphone are positioned such that the first direction and second direction are in a nonintersecting relationship and separated by an offset distance, and further wherein the offset distance is at least an entire length of the top face.

6. The method of claim 1, wherein the telephone body member is configured to be worn on a user'"'"'s wrist in the fixed configuration, and further wherein the wireless telephone is operable to receive communications and transmit communications without manipulation of the telephone body member into another configuration different than the fixed configuration and without removal from the user'"'"'s wrist.

7. The method of claim 6, wherein the method further includes providing a keypad extending through the telephone body member to allow for programing the wireless telephone.

8. The method of claim 6, wherein the method further includes attaching at least one wrist strap to the telephone body member for retaining the wireless telephone on the user'"'"'s wrist.

9. The method of claim 1, wherein the method further includes providing a base station, wherein providing a base station includes providing a telephone unit interface and a telephone line interface, and further wherein the method includes reducing gain of the microphone circuit of the wireless telephone to limit the amount of speaker sound fed back to the base station.

10. The method of claim 9, wherein the method further includes reducing sidetone in the telephone line interface.