very useful tool before LCD projector.

1. Presented By- SANJOG ZIMBAR

2.  INTRODUCTION
 HISTORY
 MAJOR PARTS
 CONSTRUCTION
 WORKING
 ADVANTAGES
 DISADVANTAGES
 APPLICATION
 FUTURE DEVELOPMENT

3.  Created by FRENCH inventor “JULES DUBOSCH” in 1870
 First used as cellphane roll over for police work
 Widely used I schools & bussiness in late 1950s and early
1960s
 A major manufacture in early period was the ‘3M” company
 But in 1953 “BUHL INDUSTRIES” became the leading
contributor
 Very popular in 1990s as they were in almost every school in
U.K.
 During world war 2 as a tool to train groups of survicemen.

4.  Also called as “VIEWGRAPH”
 Basic but very reliable tool used to display images or
written material onto a wall or screen.
 F0r audience and presenter can see properly.
 Consist of a large box containing a cooling fan &
lamp, with a long arm extended above it.

5.  Lamp and Reflector- (with condensor)
 Blower-(cooling Fan)
 Base Mirror- change the angle of the light
 Projection Stage- consist fresnel lens for magnifying
& focusing image upword.
 Upper Section- 1. Focusing knob 2. mirror

9.  With the help of focusing lens project light from an
illuminated slide onto a projection screen where real
image is formed.
 Depend upon size of transparencies used.
 Includes a mirror just after and before the focusing
lens to fold optical system towards the horizontal.
 At the base the high intensity bulb with reflector is
present which must be fan cooled.
 Condenser is most important part ,which is coollect
all the light and concentrate on the fresnel lens.

10.  On the fresnel lens the
transparencies is placed.
 also includes manual
focusing mechanism which
raise or lower the position
of the focusing lens.

11.  Simple technology
 Equipment Cost
 Transparencies
 Annotations

12.  Heat and Noise- fan create noise to dissipating heat
created by the incandescend lamp
 Bulky and Heavy Equipment- difficult to carry for
more than short distance .
 Projection Surface- required enough room
 Subject Matter- Display only which is write on the
platform

13.  Classrooms and Business conference rooms.

14.  Now a days replacement for OHP , document
cameras , computer projection system, and
interactive whiteboard.
 Such system allow the presenter to project video
directly from computer file using software such as
microsoft ppt &libreoffice.

15. THANK Y0U….!