JVC 340 SC - Manual (Page 86)

Chapter 2—Functional Descriptions
! 2- 2-74 HJT Model 330, 340SC, and 370SC Service Manual
CRT
Relay
Lens
ILA
Projection
Lens
Screen
CRT Image
Combined Image and High
Intensity Light=Bright Image
Arc
Lamp
Cold
Mirror UV Filter and
Condensing
Lens
Prism
Blue Dichroic
Mirror
Green Dichroic
Mirror
Red Dichroic
Mirror
Blue Down-
Steering Mirror
Red Down-
Steering Mirror
Green Down-
Steering Mirror
Blue Light High Intensity
CRT Image Focuses
Image onto
the ILA
Image and
High intensity
Arc lamp light
are combined
at the ILA and
reflected back
toward prism
Prism horizontally polarizes
the light and directs it to the
ILA. Also passes reflected
vertically polarized light
coming from the ILA to the
projection lens
Generates
high intensity
light beam
Filters
infrared
light
Filters out U.V.
light. Condenses
the light beam
Blue dichroic reflects blue, passes
green & red. Green dichroic reflects
green, passes red.
Down-steering mirrors steer
light to correct prism.
Green light to
green prism
Red light to
red prism
High Intensity Light
Figure 2-19 Optical Block Diagram