Canon EOS 30D White Paper page 19

camera more comfortable to grasp.
The EOS 30D's basic internal construction and major parts configuration are the same
as those of the EOS 20D. However, parts count data reveal the extent to which the
EOS 30D has been reconsidered. The number of circuit boards, 28, is the same as in
the EOS 20D, but lead wires have been reduced from 19 to 15. Optical parts count is
the same, 20, but mechanical parts have risen from 301 to 338 and electrical parts
have risen from 826 to 898. Screws and washers have declined slightly, from 167 to
164. In this tally, the shutter unit and DC/DC converter each count as one unit and the
E-ring counts as a washer. It is clear from this and from the following discussion that
the EOS 20D got a thorough going-through and that extensive changes have been made
to enhance mechanical and electrical reliability, reduce sources of noise and improve
overall performance.
The EOS 30D's basic circuit board configuration is based on the EOS 20D's. There are
six rigid, printed boards centering on the digital control and camera control circuit
boards, and 22 flexible printed boards on which the sensor and switches are mounted.
It is different from the EOS 20D in that the 2.5-inch TFT monitor is incorporated;
adaptation has been made for a different AE sensor package and soldering by hand has
been eliminated.
The digital control circuit board is a highly integrated 10-layer board. It contains the
following: the ADIC that converts the output from the CMOS sensor into digital signals,
the imaging signal processing circuit that includes the IC that generates the CMOS sensor's
drive pulse, the digital imaging processing circuit that includes the DiG!C II, the memory
circuit that includes the DDR SDRAM for the image buffer memory, and other items such
as the TFT liquid-crystal control circuit. The board's number 2 and 9 layers are GND
layers to prevent signal interference between the external-layer pattern and the
internal-layer pattern and to prevent undesirable phenomena caused by noise.
The camera control circuit board has six layers. It contains the following: the main
microcomputer IC that regulates the camera's operation by controlling the various sensors
and mechanical components, the display panel and viewfinder display drive control, the
display microcomputer IC that controls various switches and the EEPROM that retains
adjustment data (AE, AF, etc).
Flash circuit board
External interface
connection circuit board
V. PERFORMANCE, DESIGN AND CONSTRUCTION
Power source circuit board
Digital control Camera control
circuit board circuit board
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