Projectors or projection-type viewers; Accessories therefor (devices for changing pictures G 03 B 23/00; zoetropes G 03 B 25/00; photographic printing apparatus G 03 B 27/00; arrangements for obtaining special effects on stages or in circuses or in arenas F 21 P 5/02; optical projection comparators G 01 B 9/08; projection microscopes
G 02 B 21/36)
21
/
02
•
Multiple-film apparatus
21
/
04
•
•
Picture "juke-boxes"
21
/
06
•
affording only episcopic projection
21
/
08
•
affording epidiascopic projection
21
/
10
•
Projectors with built-in or built-on screen (projection screens in general G 03 B 21/56)
21
/
11
•
•
for microfilm reading
21
/
12
•
adapted for projection of either still pictures or motion pictures (prolonged exhibition of single frame G 03 B 21/38)
21
/
13
•
Projectors for producing special effects at the edges of picture, e.g. blurring
21
/
132
•
Overhead projectors, i.e. capable of projecting hand-writing or drawing during action (epidiascopic projectors G 03 B 21/08)
21
/
134
•
Projectors combined with typing apparatus or with printing apparatus
Projecting separately subsidiary matter simultaneously with main image (light pointers G 02 B 27/20)
21
/
28
•
•
Reflectors in projection beam
21
/
30
•
•
adapted to collapse or fold, e.g. for portability
21
/
32
•
•
Details specially adapted for motion-picture projection (with film moving continuously through the gate
G 03 B 41/02)
21
/
34
•
•
•
Change-over arrangements
21
/
36
•
•
•
•
Fades, dissolves, or wipes
21
/
38
•
•
•
Prolonged exhibition of single frame
21
/
40
•
•
•
Eliminating or reducing effect of flicker
21
/
42
•
•
•
Preventing damage to film due to abnormal operation of projector
21
/
43
•
•
•
Driving mechanisms
21
/
44
•
•
•
•
Mechanisms transmitting motion to film-strip feed; Mechanical linking of shutter and intermittent feed (film-strip feed per seG 03 B 1/00)
21
/
46
•
•
•
•
•
affording adjustment for framing
21
/
48
•
•
•
•
•
for altering frame speed; for regulating constancy of film speed
21
/
50
•
•
•
Control devices operated by the film strip during the run (controlling or regulating speed G 03 B 21/48)
21
/
52
•
•
•
•
by prepared film
21
/
53
•
•
Means for automatic focusing, e.g. to compensate thermal effects (automatic focusing in general G 02 B 7/09; systems for automatic generation of focusing signals G 02 B 7/28) [5]
21
/
54
•
Accessories
21
/
56
•
•
Projection screens
21
/
58
•
•
•
collapsible, e.g. foldable; of variable area
21
/
60
•
•
•
characterised by the nature of the surface, e.g. lenticular, fluid
21
/
62
•
•
•
•
translucent
21
/
64
•
•
Means for mounting individual pictures to be projected, e.g. frame for transparency