Patent Application
20080036859
With reference to
The video capture component 10 can be a CCD or CMOS sensor with high resolution to capture a video signal. An output video signal of the video capture component 10 can be in the formats of RGB, YUV or YCbCr.
The data converter 20, using a high-frequency process performed in digital domain, converts the video signal output from the video capture component 10 to a specific format and then serially transmits the processed video signal in a differential form. Therefore, the data converter 20 outputs a digital serial differential signal. The data converter 20 will be discussed in detail hereinafter.
The signal transmission unit 30 is connected to an output terminal of the data converter 20 to transmit the video signal via one or multiple kinds of transmission media. In this preferred embodiment, the signal transmission unit 30 comprises a photoelectric module 31 and a cable driving module 32. The photoelectric module 31 and the cable driving module 32 are coupled to an output terminal of the data converter 20. The photoelectric module 31 converts the received digital serial differential signal into an optical signal, transmitted via an optical fiber. The cable driving module 32 is used to ensure that the received serial differential signal meets with the SMPTE (Society of Motion Picture and the Television Engineers) standard. Therefore, the processed serial differential signal can be transmitted via a cable of 75 ohms with the desired distance. With this embodiment, the digital surveillance camera in accordance with the present invention can transmit the video signal either by the optical fiber or by the cable.
With reference to
The video processor 21 is used to ensure that an input progressed video meets with the SMPTE standard or the RGB format. The video processor 21 is coupled to the storage media 25 through a bus, so that data of the video processor 21 can be stored in the storage media 25. In this preferred embodiment, the storage media 25 is a DDR/DDR2 memory.
The scrambler 22 scrambles a signal output from the video processor 21 to reduce possible errors during the data transmission and to encrypt the data.
The serializer 23 is coupled to an output terminal of the scrambler 22 to convert a parallel signal output from the scrambler 22 into a serial signal. The serializer 23 then outputs the serialized signal.
The microprocessor 24 is coupled to the video processor 21, the scrambler 22 and the serializer 23 to control the operations of the video processor 21, the scrambler 22 and the serializer 23. The microprocessor 24 can further determine whether or not to enable the scrambler 22 when the optical fiber is selected to transmit the video signal.
With reference to
The signal format converter 211 has an input terminal coupled to the output terminal of the video capture component 10 and converts the received RGB formatted video into the YCbCr/YUV representation. The multiplexer 212 has one input directly from the signal format converter 211 and the other input from the video capture component 10. Depending upon the requirement on the output format, either RGB or YCbCr, of the format converter 211, the signal format converter 211 behaves differently. When the video capture component 10 generates the RGB (YCbCr) formatted video signal and the signal format converter 211 work in the YCbCr (RGB) domain, the converter 211 transforms the RGB (YCbCr) formatted video signal into the YCbCr (RGB) signal and then outputs the YCbCr (RGB) signal to the multiplexer 212. When the output signal of the video capture component 10 is already in YCbCr (RGB) representation, the YCbCr (RGB) video signal is sent directly from the video capture component 10 to the multiplexer 212. Therefore, whether the YCbCr or RGB video signal to be further processed after the multiplexer stage is guaranteed in YCbCr (RGB) domain.
The video scaler 213 is connected to an output terminal of the multiplexer 212 to adjust the resolution of the video output from the multiplexer 212 and then outputs the resized video to a down scan converter 214.
The down scan converter 214 converts the resized progressed video signal output from the video scaler 213 into an interlaced signal, while an interlaced video output is preferred. Therefore, in this invention, a down scan converter 214 can be omitted, if no interlaced signals are under concerns.
To sum up, the present invention provides a digital surveillance camera that can convert a captured video signal to either an optical signal or an electric signal for a long-distance transmission via the optical fiber or the cable. With these signal transmission media, the present invention is capable of transmitting the very high resolution video with comparatively low cost. In addition, the digital surveillance camera uses a CCD or CMOS sensor as the video capture component so that the high quality of the captured videos can be ensured.
Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
