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Liquid Crystal Display Three Panel Projector Using Three Primary Colors Light Emitting Diode Light Sources

IP.com Disclosure Number: IPCOM000118648D
Original Publication Date: 1997-Apr-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 6 page(s) / 100K

Publishing Venue

IBM

Related People

Hirasaka, Y: AUTHOR [+2]

Abstract

Disclosed is a Liquid Crystal Display (LCD) three panel projector using three primary colors Light Emitting Diode (LED) light sources. It has three primary colors LED panels, three LCD panels assigned to each color data, and one optical system which combines three color beams into a single beam projected onto a screen. Total brightness of each LED panel and partial brightness of them can be controlled.

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Liquid Crystal Display Three Panel Projector Using Three Primary
Colors Light Emitting Diode Light Sources

      Disclosed is a Liquid Crystal Display (LCD) three panel
projector using three primary colors Light Emitting Diode (LED) light
sources.  It has three primary colors LED panels, three LCD panels
assigned to each color data, and one optical system which combines
three color beams into a single beam projected onto a screen.  Total
brightness of each LED panel and partial brightness of them can be
controlled.

      Figs. 1 and 2 show conceptual examples of this projector.  Beam
from a LED light source (1) which emits blue light is transmitted to
a LCD panel (4) assigned to that color data.  Beam from a LED light
source (2) which emits red light is transmitted to a LCD panel (5).
Beam from  a LED light source (3) which emits green light is
transmitted to a LCD  panel (6).  The beams transmitted through a LCD
panel (4), (5) and (6)  are combined into a single beam by a set of
dichroic mirrors (7) in the  case of Fig. 1 or by a dichroic prism
(7) in the case of Fig. 2.  The integrated beam (8) is projected onto
a screen (10) through a projection  lens (9).  The projector using
this light source needs no optical device  which conventional LCD
three panel projectors have in order to separate  white light into
three primary colors.  Each of three primary colors LED  light
sources is controlled independently so color temperature of this
projector lig...