JPH063744A - Projecting device - Google Patents

Abstract

PURPOSE:To provide a projecting device for size A4 where the OHP sheet of size A4 can be utilized whether it is long lengthwise or long sideways. CONSTITUTION:A Fresnel lens 10 is fixed on a pedestal 12, and the pedestal 12 is supported by many balls so that it can rotate on a turntable 14. At least the reflection mirror 26 of a projecting optical unit 20 consisting of a projecting lens barrel 24 and the reflection mirror 26 rotates centering around the optical axis of the lens barrel 24 on a top unit 18 so as to project an image on a screen in any direction in the circumference of 360 deg..

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection device such as an overhead projector (OHP device).

[0002]

2. Description of the Related Art An OHP device is a device for projecting a graphic or a character written on a transparent sheet (OHP sheet) placed on an original stage on a screen, and a transmissive type in which an illumination lamp is placed under the original. There is a reflection type placed above the original. The reflection type has an advantage that the entire size can be reduced and the weight can be reduced.

In recent years, the widespread use of computers and their advanced functions have made it possible to create various graphs and figures on a computer. Also, page printers such as laser beam printers have become available at low cost,
It is now possible to easily obtain printouts of graphics created by a computer. Page printers are based on plain paper size, and generally A4 size. Page printers that can print on OHP sheets as well as plain paper have been widely commercialized.

In response to this, a reflection type OHP device specialized for A4 size has also been proposed. That is, while the ordinary OHP device has a square document stage so that the OHP sheet can be used in both portrait and landscape orientations,
This OHP device for A4 size is designed so that the document stage is A4 size.
Limited to size. The Fresnel lens of the original stage is rotatable with respect to the pedestal so that the written contents of the OHP sheet can be projected in landscape orientation. That is,
When only the Fresnel lens is rotated by 90 degrees with respect to the projection optical system and the pedestal, the description content of the OHP sheet placed according to the original stage can be projected horizontally on the screen.

[0005]

However, Fresnel lenses are often made of plastic in order to reduce their weight, and they tend to bend during rotational operation. In the reflective case, the curvature of the Fresnel lens leads to blurring of the image on the screen. In the conventional example, it is difficult to rotate the Fresnel lens by 90 degrees while keeping it properly flat, and it is difficult to keep the Fresnel lens correctly flat even at the 90 degree rotated position, and such a holding mechanism is not included.

The present invention is directed to an OHP having such a predetermined size.
An object of the present invention is to provide a projection device capable of projecting a sheet vertically and horizontally.

In recent years, a video conference system via a digital communication line has been developed and proposed. Such a video conference system requires an image input device for inputting figures and graphs of conference materials, and its basic structure is similar to that of an OHP device.

Therefore, a second object of the present invention is to provide a projection apparatus which can be used as such an image input apparatus and OHP apparatus.

[0009]

A projection apparatus according to the present invention rotatably supports a pedestal having a document stage by a turn table. The projection direction of the projection optical unit is rotatable. Furthermore, the projection optical unit can be changed to a video camera unit.

[0010]

By the above means, the document can be rotated from portrait to landscape and from landscape to portrait without curving or deforming the document stage. The rotation of the projection direction due to the rotation of the pedestal is offset by rotating the projection direction of the projection optical unit in the opposite direction.

Since the projection optical unit can be freely changed to a video camera unit, it can be used as a computer or an image input device for image communication.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an external perspective view of an embodiment of the present invention in which the head unit is foldable, FIG. 2 is a side view, and FIG. 3 is a bottom view.

In this embodiment, an A4 size Fresnel lens 10 serving as a document stage is fixed to a pedestal 12, and the pedestal 12 is rotatably mounted on a turntable 14. The Fresnel lens 10 has an A4 size. Details of the relationship between the pedestal 12 and the turntable 14 will be described later.

From the two corners of the end of the pedestal 12, two rotatably supported stanchions 16 and 16 stand, and both stanchions 16 and 1 are supported.
A head unit 18 is held by 6. The head unit 18 includes a projection optical unit 20 for projecting an image of a document on the Fresnel lens 10 on a screen, and an illumination lamp 22 for illuminating the document on the Fresnel lens 10.
It is equipped with. The projection optical unit 20 includes a projection lens barrel 24 and a reflection mirror 26, the details of which will be described later.
It is rotatable on the head unit 18 and also removable.

The struts 16 and 16 can be folded toward the pedestal 12 as indicated by the arrow 30 in FIG. 2, and the head unit 20 is located between the struts 16 and 16 as indicated by the arrow 32 in FIG. It can be folded and the reflection mirror 26 is shown in FIG.
As shown at 4, it can be folded so as to be parallel to the top surface of the head unit 20. These members 16, 16; 2
The whole can be deformed compactly by folding 0 and 26 respectively.

The relationship between the base 12 and the turntable 14 will be described in detail with reference to FIGS. 4 and 5. Figure 4
FIG. 5 is a bottom view in which a part is peeled off so that the internal structure of the pedestal 12 can be seen, and FIG. 5 is a cross-sectional view taken along the line AA of FIG.

The turntable 14 has a structure in which a rising edge 14b having a constant length is provided on the periphery of a disk 14a. On the other hand, in the pedestal 12, a base plate 42 is placed on a bottom plate 40 having a circular opening capable of accommodating the turntable 14, and a cylinder which is inserted into the rising 14b of the turntable 14 with a slight gap on the lower surface of the base plate 42. The protrusion 44 is provided, and the upper surface of the base plate 42 is provided with a recess 46 for accommodating the Fresnel lens 10.

On the lower surface of the cylindrical projection 44, the projection 4
4 to form a circular groove 44a concentric with the turntable 1
A large number of balls (for example, steel balls) 4 between the four discs 14a
8 are arranged. That is, the ball 48 and the circular groove 44a
Thus, the turntable 14 is rotatable with respect to the base plate 42, that is, the pedestal 12, in other words, the pedestal 12
Becomes rotatable with respect to the turntable 14.

Cylindrical protrusion 44 and turntable 14
A similar ball 49 that determines the center of rotation of the pedestal 12 is arranged between the disks 14a.

As shown in FIG. 4, the turntable 14
The rising portions 14b of the base 12 are provided with recesses or grooves 14c at positions of 90 degrees. On the other hand, adjacent to the rising portions 14b, between the bottom plate 40 of the pedestal 12 and the base plate 42,
A substantially V-shaped operation lever 50 is pivotally supported. The operation lever 50 is rotatable around a shaft 52, one end 50a is close to the rising 14b, and the other end 50b is exposed from the pedestal 12 to the outside. The operation lever 5 is provided on the side surface of the pedestal 12.
A recess 12a for operating the end portion 50b of 0 is provided so that the end portion 50b of the operation lever 50 is placed on the pedestal 1.
It is designed so that it does not project into the area 2-4.

The spring 54 is an end portion 50a of the operating lever 50.
Is always urged toward the rising edge 14b, and the end 50a
Abut against the peripheral surface of the rising 14b, and
Where there is 4c, it penetrates into the recess 14c.

In FIG. 4, when the operating lever 50b is rotated counterclockwise with a finger against the clockwise urging force of the spring 54, the end portion 50a or the peripheral surface of the rising 14b of the turntable 14 or Move away from the recess 14c. In this state, the base 12 can freely rotate with respect to the turntable 14. After the end 50a of the operating lever 50 is separated from the recess 14c, the pedestal 12 can be rotated with respect to the turntable 14 with a light force.

When the operating lever 50 is released, the end portion 50a is lifted by the spring 54 from the turntable 14.
When pressed against b, the pedestal 12 is applied with a light force.
Should not rotate, end 50a and rising 14b
It is preferable to give a considerable frictional resistance to the peripheral surface of the.

When the pedestal 12 is rotated about 90 degrees and the end 50a of the operating lever 50 penetrates into the recess 14c next to the rising 14b of the turntable 14, the pedestal 12 is rotated exactly 90 degrees.

Since the base plate 42 which directly supports the Fresnel lens 10 is supported on the turntable 14 through the cylindrical projection 44 and the large number of balls (for example, steel balls) 44, the pedestal 12 is turned. It rotates extremely stably with respect to the table 14, and this rotation does not cause the Fresnel lens 10 to bend or tilt.

When the pedestal 12 is rotated 90 degrees in this way,
The columns 16 and 16 also rotate at the same time, and the projection optical unit 20
Also rotates 90 degrees and faces in the direction without the screen. Therefore, in this embodiment, the projection optical unit 20 is also rotatable on the head unit 18. That is, in this embodiment, the pedestal 12 is rotated by 90 degrees and the pedestal 12 is rotated.
The projection optical unit 20 (at least the reflection mirror 26 thereof) is rotated 90 degrees in the opposite direction so as to cancel the rotation of the projection optical unit 20 due to this rotation. This allows
Enables horizontal projection of OHP sheets.

The rotating structure of the projection optical unit 20 will be briefly described with reference to FIG. FIG. 6 shows a central sectional view of the projection optical unit 20 in the head unit 18. A groove having a predetermined width is cut on the side surface of the projection lens barrel 24 of the projection optical unit 20, and the rotating plate member 60 and the mounting plate member 62 are inserted in the groove. However, although the rotating plate member 60 may be fixed to or separated from the projection lens barrel 24, the mounting plate member 62 is separated from the projection lens barrel 24. Further, the reflection mirror 26 is rotatably attached to the rotating plate member 60. The rotating plate member 60 has a substantially circular shape, and the mounting plate member 62 is sufficiently larger than the rotating plate member 60.

Reference numeral 64 is a chassis of the head unit 18.
One end 62a of the mounting plate material 62 remains flat,
As shown in FIG. 6, the groove 64 of the chassis 64 is cut into the groove 66 by a predetermined amount. On the other hand, the other end 62b of the mounting plate material 62
Is raised in an L-shape, and the projection optical unit 20 is activated by a spring 68 raised and attached to the chassis 64.
It is designed to be fixed at the position shown in the mounted state.

The projection optical unit 20 can be detached from the head unit 18 by lifting the end 62b side against the spring 68. When mounting, the end portion 62a of the mounting plate member 62 is fitted into the groove 66 of the chassis 64, and the end portion 62b is pushed over the chassis 64 over the spring 68. With the end portion 62 b beyond the spring 68, the mounting plate member 62 comes into close contact with the upper surface of the chassis 64, and the projection optical unit 20 is stably mounted on the head unit 18.

The rotating plate member 60 is rotatable with respect to the mounting plate member 62 about the central axis of the projection lens barrel 24, and can be stopped at a 90-degree rotation position or an arbitrary position. The mechanism is as follows. That is, a circular hole is made in the mounting plate member 62, a ball (for example, a steel ball) 70 is inserted therein, and the rotating plate member 60 is used to form the ball 7.
A circular opening 72, which is small enough to prevent the ball 70 from slipping out, is opened at 90 ° radial positions facing 0. Further, below the mounting plate material 62, not only the balls 70 are not dropped from the mounting plate material 62, but also a pressing spring 74 for pressing the rotating plate material 60 is fixed.

In the state shown in FIG. 6, when the rotating plate member 60 (that is, the projection lens barrel 24 and the reflection mirror 26) is to be rotated about the center line of the projection lens barrel 24,
When a rotational force of a predetermined amount or more is applied, the ball 70 disengages from the small opening 72 against the pressing force of the spring 74, and the rotating plate member 60 actually starts rotating with respect to the mounting plate member 62. When rotated 90 degrees, the ball 70 enters the next small opening 72 of the plate member 60 for rotation, and the rotation is restricted and stopped.

With this mechanism, the rotating plate member 60 is rotatable about the center line of the projection lens barrel 24 with respect to the mounting plate member 62, and the rotation is stopped every 90 ° rotation. Of course, the rotating plate member 60 can be stopped at any rotation position. At least the reflection mirror 2
Since 6 is fixed to the rotating plate member 60, the reflection mirror 26 is also rotatable about the center line of the projection lens barrel 24 as a rotation center, and further, the rotation can be stopped at a 90 degree rotation position and an arbitrary position. become.

In this embodiment, the A4 OHP sheet is projected vertically on the screen at the standard position. When the OHP sheet is projected horizontally, the pedestal 12 is rotated in a desired direction while the operation lever 50 is rotated counterclockwise in FIG. 4 to release the turntable 14. Operating lever 50
End 50a of the turntable 14 rises 14
When it penetrates into the recess 14c next to b, the pedestal 12 is just
It means that it has rotated 0 degrees. When the pedestal 12 is rotated 90 degrees in this way, the projection optical unit 20 also rotates integrally,
Since the image is projected in the direction without the screen, the rotating plate member 60 is rotated 90 degrees in the opposite direction so as to cancel it. As a result, the reflection mirror 26 faces the screen, and the image of the OHP sheet is projected horizontally on the screen.

Further, in this embodiment, the projection optical unit 2
Since 0 is detachable from the head unit 18, if a video camera unit provided with a plate material having the same size as the mounting plate material 62 in a brim shape is prepared, it becomes an image input device for a computer or image communication. be able to.

FIG. 7 is a sectional view showing a state where a video camera unit is attached to the head unit 18 instead of the projection optical unit 20. 80 is a video camera
It is a unit. In the present embodiment, since the video camera unit 80 is also rotatable like the projection optical unit 20, the rotating plate member 60 and the corresponding rotating plate member 82,
Also, a mounting plate member 84 having the same size as the mounting plate member 62 is provided, and the ball 70, the small opening 72, and the pressing spring 7 are provided.
Ball 86, small opening 88 and push spring 90 corresponding to 4
Is provided. Of course, if the rotation of the video camera unit 80 is unnecessary, only the mounting plate material 84 may be used.

Further, the end of the mount of the projection optical unit 20 is pivotally supported on the chassis 64, and the projection optical unit 20 is rotated around the pivot point so that the projection optical unit 20 can be removed from the optical axis of the head unit 18. May be. FIG. 8 shows a side view of such a structure with a video camera unit mounted.

[0038]

As can be easily understood from the above description, according to the present invention, the description content of a predetermined size of paper can be projected in both portrait and landscape orientations, and the switching can be realized by a simple operation. Further, since the original stage can be kept flat even when switching between portrait and landscape orientation, the projected image will not be blurred.

Furthermore, since it can be easily used as a computer or an image input device for image communication, the degree of utilization is increased, and as a result, digitized image information can be used at a low cost.

[Brief description of drawings]

FIG. 1 is an external perspective view of the present embodiment.

FIG. 2 is a side view of the present embodiment.

FIG. 3 is a bottom view of the present embodiment.

FIG. 4 is a bottom view showing a state in which a bottom plate is partially peeled off.

5 is a cross-sectional view taken along the line AA of FIG.

6 is a central cross-sectional view of the head unit 18 showing a mounted state of the projection optical unit 20. FIG.

FIG. 7 is a head unit 1 showing a mounted state of a video camera unit 80 instead of the projection optical unit 20.
8 is a central cross-sectional view of FIG.

8 is a side view of another structure of the head unit 20. FIG.

[Explanation of symbols]

10: Fresnel lens 12: Pedestal 14: Turn
Table 14a: Disc 14b: Stand up 16: Support 18: Head unit 20: Projection optical unit 22: Illumination lamp 24:
Projection lens barrel 26: Reflecting mirror 30: Folding and unfolding direction of support column 32: Folding and unfolding direction of head unit 20 34: Folding and unfolding direction of reflecting mirror 26
40: bottom plate 42: base plate 44: cylindrical protrusion 44
a: circular groove 46: dent 48, 49: ball 14
c: recess 50: operating lever 52: shaft 50a: operating lever 50
50b: the other end of the operating lever 50 12a: a recess 54: a spring 60: a plate member for rotation 62: a plate member for mounting 64: a chassis 62a: an end portion of the plate member 62 for mounting 66: a groove 62b: the other end of the plate member 62 for mounting 6
8: Spring 70: Ball 72: Circular opening 74: Push spring 80: Video camera unit 8
2: Plate material for rotation 84: Plate material for mounting 86: Ball 88: Small opening 90: Push spring

Claims (4)

[Claims] 1. A projection device for projecting the written contents of a document on a document stage of a pedestal onto a screen by a projection optical unit, wherein a turn table for rotatably supporting the pedestal is provided, and projection of the projection optical unit. A projection device characterized in that the direction is freely rotatable. 2. The projection apparatus according to claim 1, wherein the projection optical unit can be replaced with a video camera unit. 3. A pedestal on which a document is placed, a projection optical unit for projecting the description on the document on the pedestal document stage onto a screen, and a video camera unit for inputting the description on the document on the pedestal document stage as an image. And a supporting means for supporting the projection optical unit and the video camera unit at a predetermined position on a document stage. 4. A projection device for projecting the contents of a document on a document stage onto a screen by a projection optical unit, wherein the projection optical unit can be replaced with a video camera unit. .