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11. Scheimpflug
11.1 Scheimpflug introduction
What is Scheimpflug?
The lens holder has to be adjusted so that the "sharp focus plane" of the projected image falls together with the plane of the screen
(Fp1→Fp2). This is achieved by changing the distance between the DMD plane and the lens plane (Lp1→Lp2). The closer the lens
plane comes to the DMD plane the further the sharp focus plane will be. It can occur that you won't be able to get a complete focused
image on the screen due to a tilt (or swing) of the lens plane with respect to the DMD plane. This is also known as Scheimpflug's
law. To solve this the lens plane must be placed parallel with the DMD plane. This can be achieved by turning the lens holder to
remove the tilt (or swing) between lens plane and DMD plane (Lp3→Lp4).
Lp1
Lp2
DMD
Image 11-1
Scheimpflug principle
Scheimpflug principle
The "plane of sharp focus" can be changed so that any plane can be brought into sharp focus. When the DMD plane
and lens plane are parallel, the plane of sharp focus will also be parallel to these two planes. If, however, the lens
plane is tilted with respect to the DMD plane, the plane of sharp focus will also be tilted according to geometrical and
optical properties. The DMD plane, the principal lens plane and the sharp focus plane will intersect in a line below the
projector for downward lens tilt.
Scheimpflug adjustment points
The front plate of the Lens holder is equipped with four bronze (Scheimpflug) nuts and four set screws with lock nut. These screws
and nuts are used for Scheimpflug adjustment.
1
11
21
24
14
4
Image 11-2
1
Scheimpflug adjustment nuts No1: Influences the sharp focus plane in the lower left corner of the projected image.
2
Scheimpflug adjustment nuts No2: Influences the sharp focus plane in the lower right corner of the projected image.
3
Scheimpflug adjustment nuts No3: Influences the sharp focus plane in the upper right corner of the projected image.
4
Scheimpflug nut No 4: without adjustment functionality.
11
Set screw for nut No1.
12
Set screw for nut No2.
13
Set screw for nut No3.
14
Set screw for nut No4.
21
Lock nut.
22
Lock nut.
23
Lock nut.
24
Lock nut.
Reference 1, 2 and 3 are adjustment points. Reference 4 is a locking point and NOT used during Scheimpflug
adjustment.
82
Fp1
Fp2
DMD
Lp3
Lp4
2
12
22
23
13
3
Fp4
Fp3
(Scheimpflug)
R5905961 ZEUS 09/03/2015
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