Transmitter for surveillance camera, and surveillance system
First Claim
1. A transmitter for a surveillance camera system, which transmits images taken by a surveillance camera to a television receiver, comprising:
- a power deriving circuit that derives driving power for the surveillance camera from an antenna lead-in wire; and
a radio-frequency converter circuit that converts video signals generated from the images by the surveillance camera into radio-frequency signals, wherein the radio-frequency signals corresponding to the images taken by the surveillance camera are transmitted through the antenna lead-in wire to the television receiver.
1 Assignment
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Accused Products
Abstract
An RF converter circuit 11 that constitutes a video signal superposing/power deriving unit 100 converts video signals generated from images taken by a surveillance camera 10, which derives a direct current voltage as a driving power from an antenna lead-in wire 6 through a filter circuit (LPF circuit 12), to radio-frequency signals. The radio-frequency signals are transmitted through the antenna lead-in wire 6 to a television receiver 2. Images taken by the surveillance camera 1 can be viewed on the television receiver 2 only by selecting the channel assigned to the surveillance camera 1. Accordingly, the driving power for the surveillance camera 1 is not relied upon a solar battery or secondary batteries, and wiring work therefor may be simplified.
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Citations
15 Claims
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1. A transmitter for a surveillance camera system, which transmits images taken by a surveillance camera to a television receiver, comprising:
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a power deriving circuit that derives driving power for the surveillance camera from an antenna lead-in wire; and
a radio-frequency converter circuit that converts video signals generated from the images by the surveillance camera into radio-frequency signals, wherein the radio-frequency signals corresponding to the images taken by the surveillance camera are transmitted through the antenna lead-in wire to the television receiver. - View Dependent Claims (2, 3, 7, 10)
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4. A transmitter for a surveillance camera system, which transmits images taken by a plurality of surveillance cameras to one or more of television receivers, comprising:
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a plurality of power deriving circuits that each derive driving power for corresponding one of the surveillance cameras from an antenna lead-in wire; and
a plurality of radio-frequency converter circuits that each convert video signals generated from the images by corresponding one of the surveillance cameras into radio-frequency signals, wherein the radio-frequency signals corresponding to the images taken by each of the surveillance cameras are transmitted through the antenna lead-in wire to the television receivers;
wherein radio-frequency signals from each surveillance camera are different in frequency band from those from every other surveillance camera, so that a different channel of the television receivers is assigned to the radio-frequency signals from each surveillance camera. - View Dependent Claims (5, 6, 8)
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9. A video signal superposing/power deriving unit comprising:
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a power deriving circuit that derives driving power for a surveillance camera from an antenna lead-in wire; and
a radio-frequency converter circuit that converts video signals generated by the surveillance camera into radio-frequency signals, wherein the radio-frequency signals corresponding to the images taken by the surveillance camera are transmitted through the antenna lead-in wire to the television receiver.
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11. A surveillance system comprising:
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a surveillance camera that uses as driving power a direct current voltage derived by a filter circuit from an antenna lead-in wire to take images to be transmitted to a television receiver;
a radio-frequency converter circuit that converts video signals generated from the images by the surveillance camera into radio-frequency signals, wherein the radio-frequency signals corresponding to the images taken by the surveillance camera are transmitted through the antenna lead-in wire to the television receiver; and
a power supply control circuit that permits power supply to the surveillance camera and transmission of radio-frequency signals to the television receiver when a significant change in a location under surveillance is detected. - View Dependent Claims (12)
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13. A surveillance system comprising:
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a plurality of surveillance cameras that each use as driving power a direct current voltage derived by a filter circuit from an antenna lead-in wire to take images to be transmitted to a television receiver;
a radio-frequency converter circuit that converts video signals generated from the images by the surveillance cameras into radio-frequency signals, wherein the radio-frequency signals corresponding to the images taken by the surveillance cameras are transmitted through the antenna lead-in wire to the television receiver;
a power supply control circuit that permits power supply to each of the surveillance cameras and transmission of radio-frequency signals to the television receiver when a significant change in each location under surveillance is detected; and
a warning generation device that receives the radio-frequency signals, evaluates a level of radio-frequency signals for each channel corresponding to each of the surveillance camera, and generates a warning. - View Dependent Claims (14, 15)
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Specification