Optics: image projectors – Composite projected image – Multicolor picture
Reexamination Certificate
1999-06-18
2001-11-27
Adams, Russell (Department: 2851)
Optics: image projectors
Composite projected image
Multicolor picture
C353S034000, C353S119000
Reexamination Certificate
active
06322217
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a projection display device which separates light beams from a light source into red, blue and green light beams, modulates these light beams through modulation elements such as liquid crystal panels in response to image information, synthesizes the modulated light beams by a light synthesizing element, and enlarges and projects the light beams on a projection screen by a projection system.
In particular, the present invention relates to a mounting mechanism of a liquid crystal panel to a prism composite constituting a light synthesizing element in this type of projection display device.
2. Description of Related Art
Japanese Patent Application Laid-Open No. 10-10994 discloses a projection display device in which a fixed frame is fixed to the light incident face of a light synthesizing element (a prism composite), and a modulation element frame is detachably mounted to the fixed frame, positioned by a position adjusting member, and then fixed by a fixing member.
In this projection display device, a modulation element is securely positioned and fixed to the light synthesizing element. Hence, displacement in pixel combination can be reduced and the focus can be exactly adjusted. As a result, higher definition can be readily achieved. In addition, the projection display device has a configuration capable of exchanging the modulation element and a miniaturized light synthesizing element, so that the resulting commercial product is compact, lightweight, and highly reliable in spite of external disturbances.
More compact and lightweight projection display devices having higher definition have been required, and thus modulation elements having a pitch which is two-third of the current pixel pitch are being developed.
In a conventional projection display device, however, if the pixel pitch is further decreased, pixel displacement may occur when being allowed to stand at a high or low temperature for a long time after being used at high temperature.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a projection display device provided with an attachment mechanism of a modulation element which will not result in pixel displacement at variable temperatures even when the pixel pitch is decreased.
One embodiment of the invention for achieving the above object is a projection display device that modulates a plurality of color light beams through a plurality of modulation elements in response to image information, synthesizes the modulated color light beams by a light synthesizing element, and enlarges and projects the synthesized color light beams on a projection screen by a projection system, the processing display device consisting of: a frame system fixed to a light incident face of the light synthesizing element; a modulation element frame detachably mounted to the fixed frame system that holds the modulation elements; a position adjusting member that positions the modulation frame and the fixed frame system; and a fixing member that fixes the modulation element frame to the fixed frame system with the position adjusting member therebetween, the fixed frame system having a fixing section that fixes the position adjusting member, and having a deformable section in a portion other than the fixing section, that elastically deforms compared to the fixing section.
In the projection display device discussed above, the fixed frame system includes: a first frame fixed to the light incident face of the light synthesizing element; and a second frame detachably mounted to the first fixed frame and fixed to the modulation element frame, the second fixed frame being fixed to the first fixed frame by a second fixing member, the second fixed frame having a fixing section that fixes the position adjusting member, and at the least one of the first fixed frame and the second fixed frame having a deformable section in one of a portion which does not overlap the fixing section and a portion other than the fixing section, the deformable section being elastically deformable compared to the one portion.
In the projection display device discussed above, the position adjusting member may be provided near a center between two opposing sides of the modulation element frame.
In the projection display device discussed above, the deformable section may be provided between the fixing section and the second fixing member.
In the projection display device discussed above, a spring constant ratio of the deformable section to the modulation element frame may be in a range of 1 to less than 5.
In the projection display device discussed above, the fixing member may consist of an adhesive, and an elongation of the adhesive may be in a range of 50%≦&agr;≦125%.
In the projection display device discussed above, the fixing member may consist of an adhesive, and a tensile strength of the adhesive may be in a range of 40≦&bgr;≦100 (kg/cm
2
).
In the projection display device discussed above, the deformable section may consist of at least one slit.
In the projection display device discussed above, the light synthesizing element may consist of a prism, one of the fixed frame system and the first fixed frame may be provided with a section having a slit as the deformable section, and a frame width W at a section provided with the slit may satisfy a relationship: W<=(a
0
/a
1
)×L, a
0
being a linear expansion coefficient of the prism, a, being a linear expansion coefficient of one of the fixed frame system and the first fixed frame, and L being a length of a bonded section of one side provided with the slit of one of the fixed frame system and the first fixed frame.
In the projection display device discussed above, in the one of fixed frame system and the first fixed frame, a width of a non-slit section among a frame width at the section provided with the slit may be in a range of 0.1 mm to 5 mm.
In the projection display device discussed above, in the one of first fixed frame and the second fixed frame, positions for providing the slit may be non-overlapping with each other.
In the projection display device discussed above, a length of the position adjusting member may be {fraction (1/10)} to ½ a length of the side of the modulation element frame that fixes the position adjusting member.
In the projection display device discussed above, a bonding area between the position adjusting member and the modulation element frame may be larger than a bonding area between the position adjusting member and one of the fixed frame system and the first fixed frame.
Another embodiment of the invention is a projection display device that modulates a plurality of color light beams through a plurality of modulation elements in response to image information, synthesizes the modulated color light beams by a light synthesizing element, and enlarges and projects the synthesized color light beams on a projection screen by a projection system, the projection display device consisting of: a frame system fixed to a light incident face of the light synthesizing element; a modulation element frame detachably mounted to the fixed frame system that holds the modulation elements; a position adjusting member that positions the modulation element frame and the fixed frame system; and a fixing member that fixes the modulation element frame to the fixed frame system with the position adjusting member therebetween, at least one of the modulation element frame and the position adjusting member consisting of a synthetic resin and being annealed at a predetermined temperature for a predetermined time prior to assembly.
REFERENCES:
patent: 5868485 (1999-02-01), Fujimori et al.
patent: 6056407 (2000-05-01), Iinuma
patent: 10-10994 (1998-01-01), None
Fujimori Motoyuki
Iinuma Kazuyuki
Adams Russell
Cruz Magda
Oliff & Berridg,e PLC
Seiko Epson Corporation
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