Ricoh Sargas-PJ1 Field Service Manual page 147

Fan 1, 2 Exhaust fan mounted on the left cover.
Fan 3 Intake fan mounted on the optical engine to cool the phosphor wheel.
Fan 4 Intake fan to cool the laser bank.
Fan 5 Intake fan mounted on the right cover to cool the laser bank.
Intake fan mounted on the bottom shielding, under the optical engine to cool the
Fan 6*
DMD module.
Fan 7* Blower Inside of the Optical Engine to cool the phosphor wheel.
* Fan 6 and Fan7 are located at the inside the Optical Engine + Base Unit where the service engineer
cannot access. Replace the Optical Engine + Base Unit if Fan 6 and/or Fan 7 are required to replace.
Projection Light
Blue laser light turns into a diffused light in its optical path and then its coherence is lowered as it passes
through the filter wheel and other parts, so the projection light is not dangerous.
* What's coherence?
Coherence refers to the characteristic of waves, indicating the degree of interference (clarity of the
interference fringes). Natural light and lamp light have diverse light wavelength and direction of
radiation. Thus, they have low coherence.
On the other hand, laser has the same light wave length and direction of radiation. Thus, it has high
coherence.
Light
This picture shows the relationship between the visible light and wave length in units of nanometer.
Wavelength
• The light energy (E) can be calculated by the formula E=a (constant)/wavelength, and the shorter
the wavelength, the higher the energy.
• The red laser light is used for the CD/DVD laser light source and optical receivers.
Laser
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