JAI CV-A33CL Functions and Operations, Basic functions, Cmos Sensor, Pixel principle

To column processing

Buffer amplifier

2 x 10 bit digital shift register

Fig. 7. CMOS principle layout

Video process

Photo diode

Start exposure

1

Light

Fig. 8. Pixel principle.

Charge capacitor

4

Pixel memory

Reset memory

Stop exposure 2

Read row 3

CV-A33CL

6. Functions and Operations

In the following the format shown in “7.3. CV-A33CL command list” are used for function commands and parameters.

6.1. Basic functions

The CV-A33CL camera is a progressive scan camera with 10 or 8 bit video output in single channel Camera Link.

Programmable partial scan, where the start line and the number of lines can be selected with 1 line increment is also available.

There are 4 modes: Normal continuous, and 3 trigger modes: Edge Pre-Select (EPS), Pulse Width Control (PWC) and Auto Trigger.

The accumulation is LVAL a-synchronous.

In the following some of the functions are shown in details.

6.1.1. CMOS Sensor

The CMOS sensor principle layout is shown. The sensor is an array of active photosensitive pixels. The global shutter is working simultaneously on all pixels. The readout can be random row by row. 4 columns are feed through a 4 to 1 multiplexer to an A/D converter. The digitized row signals are placed in a vertical register by a 1 to 4 multiplexing. From here it is read out with the pixel clock pulses, even if the window of interest has fewer columns. The frame speed depends only of the height of the window, not of the width.

Pixel principle and column processing with A/D converting is shown below.

	R
T	O
	W
I
M	D
I	E
N	C
	O
G
	D
Control	E
and
set up

Pixel

Column

Process

and A/D

6.1.2. Pixel principle

Each pixel consists of a sensing part, a pixel memory and an amplifier. The function can in short be

described. The photo diode and charge capacitor is reset when switch 1 is closed. The signal accumulation starts when sw 1 open. The charge is transferred to the

pixel memory capacitor when sw 2 close. The accumulation stop when sw 2 open, and the signal is now temporary stored in the memory capacitor. After

reset of the charge capacitor, a new accumulation can start. The signal on the pixel memory capacitor is read out to the column by the read row signal. The memory can now be reset.

With this construction all pixels will integrate at the same time, (Global shutter). The resulting image is temporary stored in the pixel memory during read out, while a new exposure can be started.

All timing is set up in the timing block by an internal serial link.

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