Telephone and telephone system having temporary transfer and hold-release functions

• US 5,095,504 A
• Filed: 09/28/1988
• Issued: 03/10/1992
• Est. Priority Date: 10/01/1987
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Nishikawa, Shigeru, Izumi, Michihiro, Ueno, Shugoro
• Primary Examiner(s): Ng, Jin F.
• Assistant Examiner(s): Chan, Wing F.
• Application Number:
  US07/250,222
• Time in Patent Office: 1,259 Days
• Field of Search: 379/156, 379/157, 379/162-164, 379/201, 379/212, 379/215, 379/393, 379/396
• US Class Current: 379/162
• CPC Class Codes: H04M 3/20 with means for interrupting existing connections; with means for breaking-in on conversations
• CPC Class Codes: H04M 3/487 Arrangements for providing information services, e.g. recorded voice services or time announcements
• CPC Class Codes: H04M 3/58 Arrangements for transferring received calls from one subscriber to another; Arrangements affording interim conversations between either the calling or the called party and a third party substation line holding circuits H04M1/80
• CPC Class Codes: H04Q 11/04 for time-division multiplexing H04Q11/0001 takes precedence

Abstract

In a telephone system for performing channel control among telephones connected to a plurality of telephone lines, a call during a conversation between first and second telephones is placed on hold by a hold request from, say, the second telephone, and the call is capable of being transferred to a third telephone. It is also possible for the holding first telephone to instruct that the holding state be cancelled during the call transfer processing. When such a hold cancellation input from the first telephone is detected, the second telephone that requested the hold is so notified by an alarm. If the first telephone is subsequently hung up, the holding call is released and the connecting line of the first telephone is opened. When the second telephone cancels the holding state, the holding call is released and communication between the first and second telephones is restored. It is also arranged so that the holding first telephone can cause a message to be outputted from the second telephone that initiated the hold, thereby informing the second telephone of a desire to have the holding state cancelled. Thus, whereas a holding telephone is incapable of cancelling the holding state in the prior art, the foregoing arrangement makes it possible for the holding telephone to instruct cancellation of the holding state and to send a prescribed message to the telephone that initiated the hold.

Claims

1. A telephone system for performing channel control among telephones connected to a plurality of telephone lines, comprising:

transfer means for placing a call between first and second telephones on hold and then transferring the call to a third telephone in accordance with a transfer instruction from the second telephone during a conversation between the first and second telephones;

alarm means for issuing an alarm to the second telephone of transfer suspension when there is a transfer suspension input from the first telephone during transfer processing by said transfer means, wherein said alarm means issues the alarm via a speaker of said second telephone; and

reconnecting means for releasing a connecting line of the third telephone in response to a return input from the second telephone which has received a transfer suspension alarm from the first telephone during transfer processing, and forming a channel between the first telephone and the second telephone.

2. The system according to claim 1, wherein the transfer suspension input is reception of a signal above a predetermined level from the first telephone.

3. The system according to claim 1, further comprising releasing means for releasing a connecting line of the holding first telephone when it is detected that the first telephone has been hung up after the second telephone is alarmed of transfer suspension by said alarm means.

4. The system according to claim 1, wherein the transfer suspension input is reception of an input signal of a transfer suspension instructing key from the first telephone.

5. The system according to claim 1, wherein said alarm means issues an alarm by causing a predetermined audio signal to be outputted from the second telephone.

6. The system according to claim 1, wherein said alarm means issues an alarm by causing a predetermine display to be made by the second telephone.

7. A telephone having a function for temporarily placing a conversation on hold, comprising:

comparing means for comparing a received signal level from a connected line in a holding state with a specific threshold level;

hold release means for releasing the hold condition in response to manual operation in order to resume the conversation; and

alarm means for issuing an alarm when said comparing means senses that the received signal level is higher than the specific threshold level, the alarm issued by said alarm means indicating that the held party requests a release of the hold condition;

wherein the hold condition is released in response to manual operation after an alarm had been issued by said alarm means.

8. The telephone according to claim 7, wherein said alarm means outputs a predetermined audio signal.

9. The system according to claim 7, further comprising transfer means for placing a call between the first and second telephones on hold and then transferring the call to a third telephone in accordance with a transfer instruction from the second telephone during a conversation between the first and second telephones.