Optical: systems and elements – Lens – With variable magnification
Reexamination Certificate
2001-02-28
2002-10-22
Ben, Loha (Department: 2873)
Optical: systems and elements
Lens
With variable magnification
C359S811000, C359S813000, C359S819000, C359S823000
Reexamination Certificate
active
06469839
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a projector apparatus, and more particularly to a projector apparatus for enlarging and projecting an image on a display device such as a liquid crystal panel on a screen through a projector lens by means of light to be projected from a light source such as a lamp.
2. Description of the Prior Art
Conventionally, as a projector apparatus for enlarging and projecting an image on a personal computer screen or a video apparatus, there is a liquid crystal projector apparatus using a liquid crystal panel for the display device. The liquid crystal projector apparatus forms an image by transmitting and shielding light to be projected from a lamp light source by means of liquid crystal devices disposed in a two-dimensional plane shape on the liquid crystal panel, enlarges and projects the light passed through the liquid crystal panel on the screen by means of the projector lens, and the image is formed on the screen thereby.
The liquid crystal projector apparatus has a mechanism for performing focus and zoom adjustment by rotating a lens-barrel portion, namely, by moving entirely or partially a lens group consisting of lenses in a lens axial direction through the use of a cam and screw mechanism or the like.
As the above-described projector apparatus, there are apparatuses disclosed in Japanese Patent Laid-Open Nos. 11-258565, 10-319499, 09-138377, and 05-249409, and Japanese Utility Model Laid-Open No. 05-021246, or the like.
Since a position of the projector lens is generally fixed to the liquid crystal panel, the liquid crystal projector apparatus can only project the image for a fixed screen position depending upon a position to install the projector apparatus. For this reason, it is necessary to adjust the projector apparatus or the screen to an adequate position, and it takes a lot of time and labor for adjustment.
In most of liquid crystal projectors, the projector lens is fixed to the liquid crystal panel in deviated relationship above by a fixed amount in advance, and the image is projected obliquely above, whereby even in the case where the projector apparatus is set up on top of a stand or the like, it is possible to project the image on a screen at an elevated position, and the projected image is made easy to see.
In the case where the position of the image on the screen should be further deviated upward, however, it is necessary to deviate a direction of projection upward through the use of a height adjusting mechanism mounted onto the front-side leg portion of the projector apparatus. Also, in this case, since the liquid crystal panel surface and the screen surface have different angles, there is a problem that the projected image is warped into a trapezoid shape.
In order to prevent the projected image from being warped into a trapezoid shape, it is necessary to separately prepare for a screen having an inclination mechanism for causing the screen angle to coincide with the liquid crystal panel angle. For this reason, some high-performance projector apparatuses are mounted with a mechanism for adjusting the center position of the projector lens to that of the display device by using a projector lens having a large diameter for a size of the display device and moving the projector lens in parallel with the display device surface by electrically-powered driving such as a motor. These necessitate a complicated mechanism for moving up and down, and right and left while accurately holding a heavy projector lens, leading to an increase in cost.
BRIEF SUMMARY OF THE INVENTION
Thus, it is an object of the present invention to solve the above described problems, to provide a high-precision mechanism in a simple structure as a positional adjusting mechanism for the projector lens to the display device surface, and to provide a projector apparatus capable of manually moving the projector lens by means of a user interface unified into the focus and zoom adjusting mechanism.
Also, it is another object of the present invention to provide the projector apparatus capable of performing a high-precision movement of the projector lens on a two-dimensional plane in a simple structure, and manually moving the projector lens by means of a user interface unified into the focus and zoom adjusting mechanism of the projector lens.
According to the present invention, there is provided a projector apparatus for enlarging and projecting an image on a display device on a screen through a projector lens by means of light to be projected from a light source, comprising:
a lens guide member fixed to the projector lens, whose sectional shape is plural uneven shapes stretched in one axis; a lens holding member holding the projector lens and having a section of plural uneven shapes, which are brought into tight contact with the surface having plural uneven shapes of the lens guide member; and a pressure adjusting mechanism for adjusting pressure to be applied to the surface having plural uneven shapes of the lens guide member and the surface having plural uneven shapes of the lens holding member in a direction of the normal thereto.
According to the present invention, there is provided another projector apparatus for enlarging and projecting an image on a display device on a screen through a projector lens by means of light to be projected from a light source, comprising:
a lens guide member fixed to the projector lens, having a surface of plural uneven shapes stretched in one axial direction; an X guide member having a surface, which are brought into tight contact with the surface having plural uneven shapes of the lens guide member; a Y guide member having a surface of plural uneven shapes stretched in an axial direction intersecting at right angles the X guide member; and a base guide member having a surface, which are brought into tight contact with the surface having uneven shapes of the Y guide member, and being fixed to its own apparatus.
More specifically, in order to achieve the above described object, the projector apparatus according to the present invention is configured by: a lens guide portion fixed to the projector lens, whose section is configured by plural uneven shapes so as to enable the projector lens to move in parallel to the surface of the liquid crystal panel, having the surface configured such that uneven shapes stretch in one axis; a lens holding member, in which section, which are brought into tight contact with the surface having plural uneven shapes of the lens guide portion, has a surface of plural uneven shapes; and a lens fixing portion having a pressure adjusting mechanism for adjusting pressure to be applied to the surfaces having plural uneven shapes which have been formed on the lens guide portion and the lens holding portion in a direction of the normal thereto.
As compared with a case where a guide shaft or the like is used, a contact area between the lens guide portion and the lens holding portion is increased by the surfaces of plural uneven shapes of the lens guide portion and the lens holding portion, and it becomes possible to accurately move the projector lens in parallel with a planar direction of the liquid crystal panel. Also, as compared with a case where the surfaces are planar shapes, the contact area is increased by applying pressure to the surfaces of uneven shapes in the direction of the normal thereto. For this reason, it becomes possible to generate a significant static frictional force for fixing the projector lens portion. Thereby, it becomes possible to arrange the structure so as to adjust and fix the projector lens position with a low parts count.
An operating unit of the lens fixing portion mounted to the outer periphery of the projector lens is rotated around the central axis of the projector lens, whereby pressure in the direction of the normal to the surface of an uneven structure formed in the lens guide portion and the lens holding portion is adjusted to thereby adjust the static frictional force, and it becomes possible to adjust and fix the projector le
Ben Loha
NEC ViewTechnology Ltd.
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