Structure for mounting a microphone on a portable radio telephone

• US 5,682,418 A
• Filed: 01/16/1996
• Issued: 10/28/1997
• Est. Priority Date: 05/18/1993
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Ide, Yoshiyuki
• Primary Examiner(s): CUMMING, WILLIAM D
• Application Number:
  US08/585,756
• Time in Patent Office: 651 Days
• Field of Search: 379/58, 379/433, 381/158, 455/89
• US Class Current: 455/575.1
• CPC Class Codes: H04M 1/03 Constructional features of telephone transmitters or receivers, e.g. telephone hand-sets
• CPC Class Codes: H04M 1/19 Arrangements of transmitters, receivers, or complete sets to prevent eavesdropping, to attenuate local noise or to prevent undesired transmission; Mouthpieces or receivers specially adapted therefor circuit arrangements for preventing eavesdropping H04M1/68; telephone cabinets E04H1/14
• CPC Class Codes: H04R 1/38 in which sound waves act upon both sides of a diaphragm and incorporating acoustic phase-shifting means, e.g. pressure-gradient microphone

Abstract

In a portable radio telephone powered by a removable rechargeable battery, a differential microphone having a first and a second microphone element is mounted. A front sound collecting hole is formed in the front of the casing of the telephone and includes the first microphone element. The front sound collecting hole constitutes a transmitter portion. A rear sound collecting hole is formed in a portion of the battery directly opposite in position to the front sound collecting hole. The rear hole is communicated by a passageway to a rear sound collecting portion included in the differential microphone. Speech and noise around the telephone are input to the front hole while only noise, which is opposite in phase to the noise input to the front hole, is input to the rear hole. As a result, the noise input to the front and rear holes cancel each other. The rear hole is formed in a portion of the battery where a space is present. When the rear hole is directly formed in a generating member included in the battery, the inner periphery of the generating member defining the hole is covered with a member made of resin. If desired, the rear hole may be implemented by a through hole, in which case the differential microphone will be inserted in the through hole.

Claims

1. A structure for mounting a microphone on a portable radio telephone having a casing, comprising:

an operating section comprising numeral keys and function keys;

a rechargeable battery removably mounted on a rear of said casing of the telephone and said battery having a hole formed therethrough, said battery including an outer covering, a generating member within said outer covering and a space within said outer covering, a first section of said generating member being positioned on a first side of said hole and a second section of said generating member being positioned on a second side of said hole opposite said first side and said space being positioned between said first section and said second section of said generating member and adjacent said hole;

a differential microphone including a first microphone element and a second microphone element;

a front sound collecting hole comprising a transmitter portion for transmitting sound to said first microphone element of said differential microphone;

a rear sound collecting hole formed in said hole in said battery and directly opposite in position to said front sound collecting hole;

a passageway for connecting said rear sound collecting hole and a rear sound collecting portion which is formed by said second microphone element of said differential microphone;

a rubber packing interposed between said battery and said casing; and

a circuit connected to said differential microphone, for suppressing surrounding noise, comprising a subtractor for receiving output signals of said first and second microphone elements and an equalizer for receiving an output of said subtractor.

2. A structure as claimed in claim 1, wherein said differential microphone is positioned between said rear sound collecting hole formed in said battery and said front sound collecting hole.

13. A structure as in claim 1, wherein said passageway has an L-shape.

14. A structure as in claim 1, wherein said differential microphone is positioned between said rear sound collecting hole formed in said battery and said front sound collecting hole.

3. A structure for mounting a microphone on a portable radio telephone having a casing, comprising:

an operating section comprising numeral keys and function keys;

a rechargeable battery removably mounted on a rear of said casing of the telephone and said battery having a hole formed therethrough, said battery including an outer covering, a generating member within said outer covering and a space within said outer covering, a first section of said generating member being positioned on a first side of said hole and a second section of said generating member being positioned on a second side of said hole opposite said first side and said space being positioned between said first section and said second section of said generating member and adjacent said hole;

a differential microphone including a first microphone element;

a front sound collecting hole comprising a transmitter portion for transmitting sound to said first microphone element of said differential microphone;

a rear sound collecting hole formed in said hole through said battery;

a non-linear passageway for connecting said front and rear sound collecting holes;

a rubber packing interposed between said battery and said casing; and

a circuit connected to said differential microphone, for suppressing surrounding noise, comprising a subtractor for receiving output signals of said first and second microphone elements and an equalizer for receiving an output of said subtractor.

4. A structure for mounting a microphone on a portable radio telephone having a casing, comprising:

an operating section comprising numeral keys and function keys;

a rechargeable battery removably mounted on a rear of said casing of the telephone comprising a generating member having a hole formed therethrough, said battery including an outer covering, a generating member within said outer covering and a space within said outer covering, a first section of said generating member being positioned on a first side of said hole and a second section of said generating member being positioned on a second side of said hole opposite said first side and said space being positioned between said first section and said second section of said generating member and adjacent said hole;

a differential microphone including a first microphone element and a second microphone element;

a front sound collecting hole comprising a transmitter portion for transmitting sound to said first microphone element of said differential microphone;

a rear sound collecting hole formed in said hole through said generating member of said battery and directly opposite in position to said front sound collecting hole;

a member comprising resin for covering an inner periphery of said hole through said generating member;

a passageway for connecting said front and rear sound collecting holes;

a rubber packing interposed between said battery and said casing; and

a circuit connected to said differential microphone, for suppressing surrounding noise, comprising a subtractor for receiving output signals of said first and second microphone elements and an equalizer for receiving an output of said subtractor.

5. A structure as claimed in claim 4, wherein said differential microphone is positioned between said rear sound collecting hole formed in said battery and said front sound collecting hole.

6. A structure for mounting a microphone on portable electronic equipment having a body, comprising:

a rechargeable battery removably mounted on a rear of said body and said battery having a hole therethrough, said battery including an outer covering, a generating member within said outer covering and a space within said outer covering, a first section of said generating member being positioned on a first side of said hole and a second section of said generating member being positioned on a second side of said hole opposite said first side and said space being positioned between said first section and said second section of said generating member and adjacent said hole;

a differential microphone including a first microphone element and a second microphone element;

a front sound collecting hole for inputting sound from the front of said body into said differential microphone;

a rear sound collecting hole formed in said hole through said battery for inputting sound from the rear of said body into said differential microphone; and

a circuit connected to said differential microphone, for suppressing surrounding noise, comprising a subtracter for receiving output signals of said first and second microphone elements and an equalizer for receiving an output of said subtractor.

7. A structure as claimed in claim 6, wherein said differential microphone is positioned between said rear sound collecting hole which is formed in said battery and said front sound collecting hole.

8. A structure as claimed in claim 7, wherein said rear sound collecting hole is formed in a portion of said battery where a space is present and directly opposite in position to said front sound collecting hole.

9. A structure as claimed in claim 6, wherein said front and rear sound collecting holes are connected by a linear passageway.

10. A structure as claimed in claim 6, wherein said front and rear sound collecting holes are connected by a non-linear passageway.

15. A structure as in claim 8, wherein said front and rear sound collecting holes are connected by a linear passageway.

16. A structure as in claim 8, wherein said front and rear sound collecting holes are connected by a non-linear passageway.

11. A structure for mounting a microphone on portable electronic equipment having a body, comprising:

a rechargeable battery removably mounted on a rear of said body comprising a generating member having a hole formed therethrough, said battery including an outer covering, a generating member within said outer covering and a space within said outer covering, a first section of said generating member being positioned on a first side of said hole and a second section of said generating member being positioned on a second side of said hole opposite said first side and said space being positioned between said first section and said second section of said generating member and adjacent said hole;

a differential microphone including a first microphone element and a second microphone element;

a front sound collecting hole for inputting sound from a front of said body into said differential microphone;

a rear sound collecting hole formed in said hole through said generating member of said battery for inputting sound from a rear of said body into said differential microphone;

a member comprising resin for covering an inner periphery of said hole through said generating member; and

a circuit connected to said differential microphone, for suppressing surrounding noise, comprising a subtractor for receiving output signals of said first and second microphone elements and an equalizer for receiving an output of said subtractor.

12. A structure as claimed in claim 11, wherein said differential microphone is located between said rear sound collecting hole which is formed in said battery and said front sound collecting hole.