Optics: image projectors – Lens support – Lens position adjustable
Reexamination Certificate
2001-02-28
2002-12-10
Adams, Russell (Department: 2851)
Optics: image projectors
Lens support
Lens position adjustable
C396S428000
Reexamination Certificate
active
06491401
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a projection type picture display apparatus in which pictures output from a projection unit are projecting to a back face of a screen to thereby display the pictures.
2. Description of the Related Art
The prior art is shown
FIGS. 7-11
. In
FIGS. 7-11
, “X”, “Y” and “Z” show the Z-axis, Y-axis and Z-axis of the three dimension space.
FIG. 7
is a side view showing the inside of a conventional multi-projector. Here, the multi-projector described above means a display apparatus which is designed to display a large display frame (picture) by arranging and stacking plural projection type picture display apparatuses (rear projection type video projectors) vertically and horizontally. In
FIG. 7
, it is illustrated that two conventional projection type picture display apparatuses
160
are stacked in the vertical direction.
As shown in
FIG. 7
, the projection type picture display apparatus comprises a cabinet (the housing of the projection type picture display apparatus)
101
, a projection unit
102
which is disposed at the rear side in the cabinet
101
and projects an output picture to the front side, a screen
103
provided at the front face of the cabinet
101
, and a position adjusting mechanism
150
for correcting a position of a outline of a picture to be projected from the projection unit
102
to the screen
103
. The projection unit
102
projects an output picture to a back face of the screen. A large display frame can be displayed by combining and using a plurality of projection type picture display apparatuses
160
each having the above structure. In this case, the projection unit
102
is secured to the upper portion of the position adjusting mechanism
160
so that the position thereof is adjustable.
FIGS. 8
to
10
are diagrams which conceptually show pictures displayed on the screen
103
while each picture is displaced with respect to the screen
103
. As displacements on the screen
103
exist six kinds of displacements which are a vertical displacement (a displacement in the vertical direction), a horizontal displacement (a displacement in the right-and-left direction), an inclining displacement, a projection magnification displacement, a longitudinal trapezoidal distortion and a lateral trapezoidal distortion, or a combination thereof.
In
FIG. 8
, reference numeral
104
a
represents a picture which is improper in projection magnification to the screen
103
(magnification-improper picture), reference numeral
104
b
represents a picture which is improperly inclined with respect to the screen
103
(improperly-inclined picture), and reference numeral
104
c
represents a picture which is improperly displaced in the vertical and horizontal directions with respect to the screen
103
(vertical/horizontal improper picture).
In
FIG. 9
, reference numeral
104
d
represents a picture in which a longitudinal trapezoidal distortion occurs (longitudinal trapezoidal improper picture), and in
FIG. 10
reference numeral
104
e
represents a picture in which a lateral trapezoidal distortion occurs (lateral trapezoidal improper picture).
In most cases, Braun tube (CRT) has been mainly applied to the projection unit
102
because the displacements on the screen
103
of the Braun tube can be easily corrected by an electrical circuit. However, in place of the Braun tube, a liquid crystal device or a digital mirror device for which the optical path cannot be electrically corrected have been recently mainly applied to the projection unit
102
because of the tendency of digitalization of pictures. In this case, a position adjusting mechanism
150
is indispensable for the projection unit
102
for which the optical path cannot be electrically corrected.
FIG. 11
is a perspective view showing the outlook of a conventional position adjusting mechanism
150
.
In
FIG. 11
, reference numeral
150
a
represents a Y-axis moving plate which can move the projection unit
102
in the Y-axis direction, reference numeral
150
b
represents an Y-axis rotating plate which is rotatable around the Y-axis, reference numeral
150
c
represents a Z-axis rotating plate which is rotatable around the Z-axis, reference numeral
150
d
represents an X-axis rotating plate which is rotatable around the X-axis, reference numeral
150
e
represents a Z-axis moving plate which is movable in the Z-axis direction, and reference numeral
150
f
represents an X-axis moving plate which is movable in the X-axis direction.
Next, the position adjusting operation of the conventional picture outlook adjusting mechanism
150
shown in
FIG. 11
will be described with reference to
FIGS. 7
to
11
.
A picture projected from the projection unit
102
is projected onto the screen
103
. At this time, the projection magnification of the picture can be corrected by the adjusting operation of the Z-axis moving plate
150
e
. Further, the lateral trapezoidal distortion can be corrected by the Y-axis rotating plate
150
b
, and the inclination of the picture can be corrected by the adjustment of the Z-axis rotating plate
150
c
. The longitudinal trapezoidal distortion can be also corrected by the adjustment of the X-axis rotating plate
150
d
. Still further, the vertical and horizontal position can be corrected by the adjustment of the X-axis moving plate
150
f
and the Y-axis moving plate
150
d.
Japanese Laid-open Patent Application No. Hei-8-32907 discloses another prior art, and specifically it discloses a technique of separating one display unit (projection type picture display apparatus) into a front side cabinet and a back side cabinet.
As described above, in the conventional projection type picture display apparatuses, six adjusting functions must be adjusted for the position adjusting mechanism
6
, and also six adjusting functions must be provided every adjusting mechanism performing only one adjustment. Therefore, the number of parts of the apparatus and the weight of the apparatus are increased, and the cost is also increased.
SUMMARY OF THE INVENTION
Therefore, the present invention has been implemented in view of the above circumstances and has an object to provide a projection type picture display apparatus which can reduce the number of parts and the weight.
In order to attain the above object, according to the present invention, a projection type picture display apparatus comprising a projection unit for projecting a picture to a back face of a screen and a position adjusting mechanism for supporting the projection unit and for giving six adjusting functions including X, Y, Z directional adjustments for moving the projection unit along X-axis, Y-axis, Z-axis of three dimension space respectively, and X, Y, Z rotational adjustments for rotating the projection unit around X-axis, Y-axis, Z-axis respectively, characterized in that said position adjusting mechanism has an adjusting plate member for performing three adjusting functions of said six adjusting functions.
The adjusting plate member performs the three adjusting functions including Z rotational adjustment for rotating the projection unit around Z-axis, X rotational adjustment for rotating the projection unit around X-axis, and Y directional adjustment for moving the projection unit along Y-axis.
Further the adjusting plate member has a first support shaft extending in the Y-axis direction, a second support shaft which is disposed so as to be in parallel to said first support shaft and spaced from said first support shaft at a predetermined interval in the Z-axis direction, a third support shaft which is disposed so as to be in parallel to said first support shaft and spaced from said first support shaft at a predetermined interval in the X-axis direction, a first adjusting shaft which is selectively engageable with both of said first and second support shafts or only said second support shaft through a gear switching operation, a second adjusting shaft which is selectively engageable with both said first and third support shafts or only said first sup
Adams Russell
Esplin D. Ben
Mitsubishi Denki & Kabushiki Kaisha
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