CS268840B2 - Device for objects' swung-out projection - Google Patents

Abstract

It is mainly used for the projection of physical and chemical experiments in teaching. It replaces horizontal projection with an overhead projector. The essence is to tilt the optical axis of the projector condenser from the horizontal plane and in the projection of the object, illuminated by the condenser, two mirrors and a lens are placed above the condenser part and further onto the projection surface. Both mirrors are radiant, because together they are the lens system higher than in horizontal projection and do not affect the projector condenser part during projection. The projection is performed by a overhead projector, which is equipped with a bed and mirror part of the adapter. The projector is attached to the bed. The mirror part is attached to the lens, the mirror is foldable.

Description

A device for tilted projection of objects It is suitable to use in teaching chemistry or physics for projecting experiments. The projection used here must meet the requirement that the projected image is not vertically inverted, because the projected object (e.g. chemical apparatus) cannot be turned upside down.

The devices used so far mostly use an overhead projector equipped with an adapter for horizontal projection. This adapter will allow the use of an overhead projector that works on the principle of vertical projection (the optical eye of the condenser is vertical), for horizontal projection, in which the axis of symmetry of the beam of rays illuminating the projected object is horizontal.

This horizontal projection is most often realized by placing the overhead projector on its side in the adapter bed. The optical eye of the condenser is horizontal. The lens directs the rays passed through the projected object upwards. There is a mirror here, which directs the image above the projector body and further onto the screen. If we want the image on the screen to be at an acceptable height, the mirror must be high above the lens. The light cone is wide here, the mirror is therefore large and therefore heavy. It can therefore have a special design. The device is quite massive. If we want to use the overhead projector manually, we have to remove it. The adapter itself then takes up a lot of space on the work table. If we use a small mirror in the adapter, the entire field of view cannot be projected. These adapters require adjustment of the tilt or even the position of the mirror after reinserting the overhead projector.

For horizontal projection, an adapter was also designed, using a system of two opposing mirrors. The projector is used here in the same position as for vertical projection. The adapter is placed on the condenser. The first mirror directs about half of the beam of rays coming from the condenser to an approximately horizontal direction. These pass through the projected object and are reflected by the second mirror into the lens of the overhead projector. Despite the fact that this adapter does not allow the entire field of view to be projected, this adapter is inoperative, since it enhances the effect of the condenser. Thanks to the mirrors, the optical path of the rays is extended, but the lens is not located at the intersection of these rays. The projected image therefore has completely dark peripheral parts* only the center is acceptably projected.

The aforementioned shortcomings are eliminated by a device for tilted projection of objects, comprising an optical projector, wherein the condenser eye is tilted from the horizontal plane.

The bed part is equipped with a platform that defines the angle between the condenser eye and the horizontal plane and is used to mount the overhead projector. After the platform is removed, the overhead projector can be used exclusively for rear projection (vertical). The bed part does not interfere with anything, and the tripod rods are out of sight.

The mirror part of the device for the curved projection of objects is prepared for the lens of the rear projector. The mirror ensures the projection of the entire viewing area with dimensions comparable to the size of the lens. The inclination of this mirror relative to the body and the height of the image on the projection surface are regulated by a screw. When using the rear projector for rear projection (vertically), the mirror part remains attached to the mirror and is only tilted.

The advantage of the device for tilted projection of objects with an overhead projector is the use of a small mirror* which therefore displays the entire field of view.

To enable classic rear projection, simply flip it open. Since the bed part is also attached to the rear projector and the tripod rods do not block the projection, it is necessary to remove only the table from the projector for normal projection.

The attached picture shows a side view of a device for tilted projection of objects by an overhead projector. The picture shows the individual parts: mirror with hinge 1, support profile _2, U-shaped rod 3* bed 4, table 5, and string rods 6, hook 7.

The bed 4 is adapted to be put on the legs of the overhead projector, it is secured against being pulled out by a hook _7. which hooks onto the lens support rod and is locked in place by a wing nut. The bed is securely fastened to the projector. The tripod rods J are inserted into the bed and secured from below by wing nuts. The table £ is pushed onto the tripod rods. Mirror with hinge _1 It is adapted so that it is fastened to the lens by a U-shaped rod 3, which is two

CS 258840 82 wing nuts tightened against the support profile _2. Mirror · hinge · _1 it consists of two parts* connected to each other hinge·· The part equipped with the mirror can be folded away (see figure)· In tilted projection, the inclination of this part towards the lens is adjusted by a screw·· which presses on the lens and thus holds it in a fixed position.

As already mentioned, the device for tilted projection of objects is intended for the projection of experiments in chemistry or physics in all types of schools where these subjects are taught. It has been verified that this device can project all experiments in chemistry that have been projected using the horizontal projection method. Tilting the experiment by ⁹⁰ did not cause any complications. Thanks to the new and higher effects already mentioned, the device is more manageable and does not take up space on the workbench like the adapters for the overhead projector used so far. The overhead projector used does not need to be moved, the only manipulation is simply turning it over. This is also advantageous in terms of the device's service life.

Claims (3)

1» Device for the tilted projection of an object by an optical projector* which projects in the transmitted light* an image of an object* placed in front of a condenser* by an objective* formed by two mirrors and a lens* back under the condenser part of this projector and further on the projection surface as a direct image and an inverted image* characterized by the fact that the optical eye of the condenser is tilted from the horizontal plane. 2* The device according to item 1, characterized in that the bed part (1) with a removable tray (5) is attached to the condenser part (B). 3. The device according to item 1*, characterized in that the mirror part (XX) with the tilting mirror (1) is attached to the lens (9) of the rear projector.