Video camera apparatus of digital recording type

• US 6,097,879 A
• Filed: 04/02/1997
• Issued: 08/01/2000
• Est. Priority Date: 04/04/1996
• Status: Expired due to Term

• Current Assignee: Hitachi Maxell Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Hoshi, Tomoya, Komatsu, Hiroyuki, Nishizawa, Akihito, Kinugasa, Toshiro
• Primary Examiner(s): Garber, Wendy
• Assistant Examiner(s): ONUAKU, CHRISTOPHER O
• Application Number:
  US08/832,162
• Time in Patent Office: 1,217 Days
• Field of Search: 386/38, 386/39, 386/95, 386/96, 386/97, 386/117, 386/98, 386/99, 386/20, 386/91, 358/909.1, 358/906, 348/705, 348/706, 348/222, 348/231, 348/232, 348/239, 348/512, 348/722, 348/548, 352/8, 352/25, 352/31, 352/37, 352/95
• US Class Current: 386/202
• CPC Class Codes: H04N 9/8045 using predictive coding
• CPC Class Codes: H04N 9/896 using a digital memory with independent write-in and read-out clock generators

Abstract

A digital recording/reproducing video camera apparatus which externally receives analog video and audio signals as a standard video signal for data compression and recording. Selection switches for switching between a camera pick-up mode and a line input mode are switched to their terminals a in the camera pick-up mode and switched to their terminals b in the line input mode. An output signal of a CCD is sent via an amplifier, the switch and an A/D converter to a digital signal processing circuit to generate color and luminance signals. The generated color and luminance signals are fed to a data compression/expansion circuit to remove redundant parts therefrom and then sent to a HDD for recording. In a line input record mode, a line input signal is supplied through the switch and A/D converter to the digital signal processing circuit to generate the color and luminance signals. The generated color and luminance signals are fed to the data compression/expansion circuit to remove redundant parts therefrom and sent to the HDD for recording. The video camera apparatus may include a video signal processing circuit for detecting a time base error in 1 sampling period or less of the synchronization signal caused by performing Y/C separating/demodulating operations on a digital signal and moves a center of a video part in response to its detection result.

Claims

1. A video camera apparatus comprising:

a selection switch for switching between internal and external video signals; and

a signal processing circuit for generating at least color and luminance signals from the video signal selected by the selection switch;

wherein said signal processing circuit includes;

a reference clock generator;

a synchronization signal generator which generates a reference synchronization signal based on a reference clock signal generated from said reference clock signal generator;

an A/D converter which converts said internal and external video signals to a digital video signal;

a synchronization signal separating circuit which separates a synchronization signal from said digital video signal converted by said A/D converter;

a memory which stores the digital video signal converted by said A/D converter;

a memory write pulse generator which generates a write pulse for writing said digital video signal in said memory according to said reference clock signal of said reference clock signal generator;

a memory read pulse generator which generates a read pulse for reading said digital video signal from said memory according to said reference clock signal of said reference clock signal generator;

a difference detecting circuit which detects a difference between the synchronization signal generated by said synchronization signal generator and the synchronization signal separated by said synchronization signal separating circuit; and

a horizontal time-base correcting circuit which corrects a horizontal time-base of the digital video signal read out from said memory.

2. A video camera apparatus as set forth in claim 1, wherein said synchronization signal separating circuit includes an analog synchronization signal separating circuit which separates a synchronization signal from an analog video composite signal received from said A/D converter.

8. A video camera apparatus as set forth in claim 1, wherein an amount of time-base correction carried out by said horizontal time-base correcting circuit is a reciprocal of said difference.

9. A video camera apparatus as set forth in claim 1, further comprising a compressor which converts data output from said signal processing circuit to compressed data.

10. A video camera apparatus as set forth in claim 1, wherein said memory is a RAM.

3. A video camera apparatus comprising:

an A/D converter which converts an analog composite color signal to a digital signal;

a synchronization signal separating circuit which separates a synchronization signal from the converted digital composite color signal;

a phase error detecting circuit which detects a phase difference between the synchronization signal separated by said digital synchronization signal separating circuit and a synchronization signal component contained in the analog composite color signal; and

a center moving circuit which moves a center of the video component of the converted digital composite color signal in response to a result of said phase error detecting circuit.

4. A video camera apparatus as set forth in claim 3, wherein said phase error detecting circuit includes:

level holding circuits which holds a signal level as a reference when said digital synchronization signal separating circuit separates the synchronization signal and a plurality of levels of the composite color signal immediately before and after said reference signal level; and

a phase difference calculating circuit which calculates, on the basis of the signal levels held by said level holding circuits, a phase difference between a timing when the composite color signal reaches said reference level and the synchronization signal actually generated by said synchronization signal separating circuit.

5. A video camera apparatus as set forth in claim 3, wherein said center moving circuit includes an interpolation circuit which replaces the signal of the video component by the output of said interpolation circuit.

6. A video camera apparatus comprising:

an A/D converter which converts an analog composite color signal to a digital signal;

a digital signal processing circuit which processes the converted digital composite color signal;

a synchronization signal generating circuit which generates a synchronization signal for determining a timing of processing operation of the digital signal processing circuit;

a synchronization signal separating circuit which separates a synchronization signal from the analog composite color signal;

a phase error detecting circuit which detects a phase difference between the synchronization signal separated by said analog synchronization signal separating circuit and the synchronization signal generated by said synchronization signal generating circuit; and

a center moving circuit which moves a center of a video component of the converted digital composite color signal in response to a result of said phase error detecting circuit.

7. A video camera apparatus as set forth in claim 6, wherein said center moving circuit includes an interpolation circuit which replaces signals of a video component by the output of said interpolation circuit.