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Ccd camera circuit, For tlp511) -1, 1. outline -1 – Toshiba TLP511E User Manual

Page 43: Ccd camera circuit (for tlp511)

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8-1

8. CCD CAMERA CIRCUIT

(For TLP511)

8-1. Outline

The camera section of the unit employs the color board

camera with 3 times zoom lens. The camera video circuit

is assembled in one PC board and composed of the CCD

and drive circuit, pre-amp and AD converting circuit

(CDS, AGC and AD), video signal process circuit (DSP,

MICON) and power supply circuit.

Fig. 8-1-1 shows a block diagram of CCD camera circuit.

8-1-1. CCD and Drive Circuit

The CCD (Q101) circuit employs 1/3 inch 480,000 pixels

IT-CCD. The horizontal transmission pulse (H1, H2 and

RG) and vertical transmission pulse (øV1 – øV4 and

SUB) are supplied through the drive signal generation

circuit and vertical drive IC (Q103 and Q202) inside DSP

(Q203) by 28.5 MHz clock signal output from the

oscillator (Z201).

8-1-2. Pre-amp and AD Coversion Circuit

(CDS, AGC, AD)

The video signal developed from CCD (Q101) enters the

pre-amp IC (Q201) through the buffer (Q102).

After the signal is processed the noise reduction process

(CDS) inside the IC and amplified (AGC), the signal is

converted to AD, and then output as 10 bits digital data.

8-1-3. Video Signal Process Circuit

(DSP, MICON)

The video signal, which became 10 bits digital data,

enters the DSP (Q203) for video signal process. After the

signal is separated into the luminance and color signals,

the signal process is carried out on the luminance and

color signals respectively and DA-converted.

The luminance signal adds the sync signal and passes

through 7 MHz low pass filter. The color signal is

developed through the video driver IC (Q206) after

passing 4.43 MHz band pass filter.

All kinds of parameters on DSP (Q203) are set up by the

microprocessor (Q303) and picture quality adjustment,

etc. are carried out.

These parameters are memorized in the E

2

PROM

(Q306). Also, the zoom, focus, etc. controls of lens are

carried out by communicating with the external device

through RS-232C driver IC (Q304).

8-1-4. Power Supply Circuit

The power supply circuit generates DC voltages (+15V,

+5V, +3.3V, –8.2V) necessary to the camera signal

process and power supply voltage (+9V, +5V) for lens.

Lens +9V, develops the power supply voltage (+9V)

entered from outside directly and for lens +5V, input +9V

is developed through the regulator IC (Q801).

The signal process +5V develops the power supply

voltage (+5V) entered from outside directly and the

signal process +3.3V, the input +5V is developed through

the regulator IC (Q802). The DC voltage of +15V, –8.2V

are developed from the constant voltage circuit through

the change pump circuits of Q804 – Q806.

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