Title:
TELEVISION CALLING UNIT
Document Type and Number:
Japanese Patent JPS63313985
Kind Code:
A
Abstract:
PURPOSE:To eliminate conventional lighting power supply line between a master unit in the room and a slave unit at the door by supplying power to the slave unit from the master unit, providing a first power supply means to receive power for video, and providing a second power supply means to supply power to light-emitting elements for lighting. CONSTITUTION:The in-room master unit 1 is constituted of an in-room master monitoring part 1a and in-room master calling part 1b. The monitoring part 1a consists of a control circuit 8, a constant current circuit 11 as power supply means, and a television monitor 15. The at-door slave unit is constituted of a light-emitting circuit 2a for lighting as the second power supply unit, camera unit 2b, calling/outgoing means 2e, and a fixed current/fixed voltage conversion circuit 12 as the first power supply means. When a visitor depresses the calling button 3 of the slave unit 2, a fixed current for video from the circuit 11 is superposed on the central conductor of a coaxial cable CXC connected to the master unit 1 with the slave unit 2 and the current is supplied to the camera unit 2b, and a part of the current is also supplied to the circuit 2a, so that infrared light-emitting diodes OED1-LEDn as the light-emitting elements for lighting emit light.
Inventors:
SUZUKI TOYOJI
Application Number:
JP14981087A
Publication Date:
December 22, 1988
Filing Date:
June 16, 1987
Export Citation:
Assignee:
AIPHONE CO LTD
International Classes:
H04N5/225; H04N7/14; H04N7/18; (IPC1-7): H04N5/225; H04N7/14; H04N7/18
Domestic Patent References:
| JPS61296872A | 1986-12-27 | |||
| JPS58141086A | 1983-08-22 |
Attorney, Agent or Firm:
Moriya Kazuo
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