Canon image Prograf iPF780 Series, Service Manual

Page: 231 / 326

Chapter 7
7-18
1. Checking "OUTPUT 0" and "OUTPUT 1" when media (excluding clear film) is fed
[Check 1]
Check whether the multi sensor performance has degraded or whether the media is compatible with the multi sensor.
When "Media edge (diffuse reflection) gain" and "Media edge (diffuse reflection) current value" are maximum values and "Media edge (diffuse reflection) media
output" is 186 or less, an error occurs.
Maximum value of "Media edge (diffuse reflection)" gain: 255
Maximum value of "Media edge (diffuse reflection)" current value: 320
When the multi sensor and media are normal, the following values are displayed:
[Check 2]
Check whether the multi sensor performance has degraded or whether the media is compatible with the multi sensor.
When the difference between "Media edge (diffuse reflection) gain" and "Media edge (diffuse reflection) platen output" is 100 or less, an error occurs.
When the multi sensor and media are normal, the difference is about 300-600.
[Check 3]
Check the effect of external diffuse light.
When the difference between "Media edge (diffuse reflection) external light output" and "Media edge (diffuse reflection) platen output" is 500 or more, the effect
of diffuse light is judged as being great.
When the effect is normal, the difference is about 50-300.
[Check 4]
Check whether the media is compatible.
When the result of "Media edge (regular reflection) gain"x"Media edge (regular reflection) current value" is five times as large as the result of "Media edge (diffuse
reflection) gain"x"Media edge (diffuse reflection) current value", the media is judged as being incompatible with the multi sensor.
If the media is compatible, the result is about 0.5 to 1.5 times for plain/glossy paper; about 1-3 times for tracing paper.
[Check 5]
Check whether the media is compatible.
When the result of "Media edge (diffuse reflection) gain"x"Media edge (diffuse reflection) current value" is in one of the following, the media may be incompatible
with the multi sensor.
- Nine or more times as large as that of plain paper (normally, 2000-7000)
- Ten or more times as large as that of glossy paper (normally, 1600-5000)
- Three or more times as large as that of tracing paper (normally, 6000-20000)
2. Checking "OUTPUT 0" when clear film is fed
[Check 1]
Check whether the multi sensor performance has degraded or whether the media is compatible.
When the "Media edge (regular reflection) gain" and "Media edge (regular reflection) current value" are maximum values and "Media edge (regular reflection)
media output" is 186 or less, an error occurs.
Maximum value of "media edge (regular reflection)" gain: 255
Maximum value of "media edge (regular reflection)" current value: 320
When the multi sensor and media are normal, the following values are displayed:
[Check 2]
Check whether the multi sensor performance has degraded or whether the media is compatible.
When the difference between "Media edge (regular reflection) gain" and "Media edge (regular reflection) platen output" is 100 or less, an error occurs.
When the multi sensor and media are normal, the difference is about 250-500.
[Check 3]
Check the effect of external diffuse light.
When the difference between "Media edge (regular reflection) external light output" and "Media edge (regular reflection) platen output" is 500 or more, the effect
of diffuse light is judged as being great.
When the effect is normal, the difference is about 50-300.
3. Checking "OUTPUT 2/OUTPUT 3" and "OUTPUT 4/OUTPUT 5/OUTPUT 6"
[Check 1]
Check whether the multi sensor performance has degraded or whether the media is compatible.
When "GAP gain" and "GAP current value" are maximum values and "GAP media output" is 93 or less, an error occurs.
Maximum value of "GAP gain": 255
Maximum value of "GAP current value": 320
When the multi sensor and media are normal, "GAP gain" is about 30-250; "GAP current value" is about 200.
Media edge (diffuse reflection)
gain
Media edge (diffuse reflection)
current value
Media edge (diffuse reflection)
media output
Plain paper About 10-35 About 200 About 500-600
Glossy paper About 8-25
Tracing paper About 30-100
Media edge (regular
reflection) gain
Media edge (regular
reflection) current value
Media edge (regular
reflection) media output
Clear film About 10-60 About 200 About 500-600