JPH0331946Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a reflective overhead projector (OHP), particularly one using a Fresnel lens or a Fresnel reflector as a reflector.

As a conventional reflective OHP, a Fresnel lens or Fresnel reflector plate is fitted onto the top of the base, fixed with adhesive, a translucent material is placed on top of the Fresnel lens, etc., and the material is placed above the base. There is one in which the material is irradiated with illumination light from a head section provided through a support, and the reflected light from the material is projected onto a screen via a projection lens and a reflecting mirror in the head section. In such a reflective OHP, the Fresnel lens or Fresnel reflector is easily damaged and must be replaced frequently, and furthermore, it is necessary to slightly shift its position for purposes such as optical axis adjustment.

However, in the past, Fresnel lenses and the like were fixed to the base, which took time and effort to remove, and it was inconvenient that the lens could not be moved once it had been fixed.

The present inventor has devised the present invention in view of the conventional problems as described above, and its purpose is to enable easy attachment and detachment of the Fresnel lens or Fresnel reflector provided on the top surface of the base. It is an object of the present invention to provide a reflective overhead projector in which optical axis adjustment and Fresnel lenses, etc., can be easily replaced.

In order to achieve this purpose, the present invention uses a so-called reflective type
A concave part for attaching the Fresnel reflector is formed on the base of the OHP, and hook-and-loop fasteners are attached to the four corners and the center of this concave part, and the hook-and-loop fasteners are also attached to the four corners and the center of the back of the Fresnel reflector. The gist of this is that a hook-and-loop fastener has been pasted to secure it in place.

A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is an overall perspective view of a reflective OHP according to the present invention, and this OHP 1 has a Fresnel reflector 3 attached to the upper surface of a base 2 having a substantially box shape. The Fresnel reflector 3 may be a Fresnel lens with silver coating on the back surface and further reinforced with a copper plate or the like, or a reflector with a Fresnel portion engraved on the surface. Then, a support column 5 is attached to one end of the base 2 via a joint part 4 so as to be movable up and down,
A head section 8 containing a projection lens 6, a projection reflector 7, etc. in addition to a light source lamp is fixedly supported at the tip of the support column 5.

The irradiated light from the head section 8 irradiates the translucent material placed on the Fresnel reflector 3, and the reflected light is projected onto the screen via the projection lens 6 and the projection reflector 7. .

FIG. 2 shows the top surface of the base 2 before the Fresnel reflector 3 is attached, and an octagonal recess 9, which is approximately the same shape as the Fresnel reflector 3, is formed on the top surface of the base 2. Cutouts 10, 10 for inserting fingers are provided on the left and right sides of this recess.
Then, hook-and-loop fasteners 11 having a large number of hooks formed on the surface are attached to the four corners and the center of the recess 9.

Further, FIG. 3 shows the back side of the Fresnel reflector 3, and when the Fresnel reflector 3 is fitted into the recess 9 on the back side of the Fresnel reflector 3,
Surface fasteners 12, each having a large number of loops on its surface, are adhered to portions corresponding to the surface fasteners 11, that is, the four corners and the center of the back surface of the Fresnel reflector 3, using an adhesive or the like.

In the above, in order to attach the Fresnel reflector 3 to the recess 9 of the base 2, the Fresnel reflector 3 is attached to the recess 9.
The four corners and center of the Fresnel reflector 3 may be pressed from above. In addition, in order to remove the Fresnel reflector 3 from the base 2, the above-mentioned notches 10, 10
The Fresnel reflector 3 can be removed by simply inserting a finger into it and lifting it upward.

Incidentally, the above is merely an example of the implementation of the present invention, and the shape and size of the attached surface fastener are arbitrary, and the shape of the Fresnel reflector is not limited to the above.

As is clear from the above description, according to the present invention, in a so-called reflective OHP, hook-and-loop fasteners are pasted on the four corners and the center of the recess on the top surface of the base where the Fresnel reflector is attached, and at the same time, on the back side of the Fresnel reflector. Since surface fasteners are attached to the four corners and the center, which correspond to the surface fasteners mentioned above, the Fresnel reflector can be attached and removed with simple operations. The gap between the base and the Fresnel reflector can be absorbed by the hook-and-loop fastener, making it easy to fine-tune the optical axis and replace damaged Fresnel lenses. By providing this, the center of the Fresnel reflector does not bulge when it is attached, and by attaching it to the four corners, it has many advantages such as easy positioning.

[Brief explanation of the drawing]

The drawings show a preferred embodiment of the present invention, and FIG. 1 is a perspective view of the entire reflection type overhead projector according to the present invention, and FIG. 2 shows a state in which the Fresnel reflector is removed from the base. Perspective view, 3rd
The figure is a perspective view showing the back side of the Fresnel reflector. In the drawings, 1 is a reflective overhead projector, 2 is a base, 3 is a Fresnel reflector, 8 is a head portion, 9 is a recessed portion, and 11 and 12 are surface fasteners.

Claims (1)

[Scope of utility model registration request] In a reflective overhead projector in which a Fresnel reflector is provided on the top surface of the base to condense and reflect the irradiated light from the head, a recess is formed in the base to accommodate the Fresnel reflector, and the four corners and the center of the recess are formed in the base. In addition to pasting hook-and-loop fasteners on the
A reflective overhead projector characterized in that surface fasteners fixed to the surface fasteners are attached to the back surface of the Fresnel reflector at locations corresponding to the four corners and the center of the recessed portion.