FujiFilm FM-DP L Service Manual page 140

INSTALLATION APPENDIX 1 SETTING, CONNECTING, ADJUSTING THE IMAGE I/F BOARD
For example, if a rising edge of the horizontal sync signal is located in the middle of the
rising edge of the sampling clock as shown in [C], a normal image is outputted.
However, if the horizontal sync signal rises with virtually the same timing as the rising
edge of the sampling clock as shown in [D], the timing of the horizontal sync signal
becomes unstable with respect to the sampling clock, so that the count start position is
offset for each line, resulting in pixel offset.
If pixel offset occurs for the reason mentioned above, it can be remedied by varying the
phase of the sampling clock. To do so, adjust the sync signal phase.
Horizontal sync signal
[C]
[D]
Adjustment procedure
In order to prevent occurrence of two types of image artifacts mentioned above, make
sync signal phase adjustments.
Print out while tweaking the phase adjustment rotary switch S1, and determine
optimum conditions based on the resulting images.
Note that the phase can be adjusted in 8 steps (2 ns for one step, from 0 to 14 ns) with
S1.
Digital Video Signals That Permit Proper Image Acquisition According to Version of
DVI90A Board
When connected to a diagnosis unit that outputs digital video signals of the following
specifications, the DVI90A board of version G or later should be used. If an image is
acquired using the DVI90A board of any earlier version, the resulting image will
become improper.
Signal where the total number of pixels per line is odd
• Example of relevant host equipment (there may be more host equipments in addition
to the one shown below)
Hitachi DFA-100 Series (video spec ID No. 518 used)
Total number of pixels per line
• Phenomenon of improper image
• Because image data is acquired with offsets in increments of one pixel per line,
vertical stripes in the image look jaggy.
• Adjustment procedure
If the DVI90A board of version G or later is used, images are acquired properly, so
there is no need for adjustment.
006-252-01
06.15.99 FM2514
= Pixel clock frequency ÷ horizontal sync frequency
= Pixel clock frequency x horizontal sync interval
= H-back + H-active + H-front (displayed on VIDEO ADJUST screen)
1 line
FM-DP L Service Manual
BA1-7
Correct sampling
clock timing
Incorrect sapling
clock timing
FP3B0906.EPS
BA1-7