DE7340590U - Projection device - Google Patents

Description

Hofbauer Werke GmbH & Co. KG, 8370 Regen Pro jection device

The invention relates to a projection device with background projection onto a matt screen using mirrors.

Such devices are known on a small scale and in compact form as film and slide viewers. Also one has the background projection has already been used on a large scale, for example on exhibition stands. In the latter case as in the normal projection onto a screen, the projector is always relatively far away from the screen or the screen, which is why the operator is not easily in the Is able to explain their demonstrations by means of a pointer, for example. It also appears disadvantageous that it is normally withdrawn from the viewer's field of vision, which is perceived as annoying, especially in the case of lesson presentations will.

7340590 07/10/75

The object of the invention is to remedy this by using relatively simple means a large-format Projection is made possible, in which the presenter can be right next to the screen.

This object is achieved according to the invention in that the Device is designed as a cabinet, the upper part of which is essentially occupied by the screen at the front, while at least one projector is arranged in the lower part, accessible from the front.

This projector can be a commercially available film or slide projector be. Two or more such projectors can also be arranged next to one another and are then expedient can be moved alternately into a central projection position.

Since the cabinet will generally be closed, the beam path remains essentially unaffected by dust and Smoke, which benefits the image quality. Especially if, for example through a door, for a certain shielding of the picture screen Care is taken, allows the device according to the invention can also be used in daylight.

All doors can be lockable and also as boards or additional projection surfaces, for example for the use of a cachepot writing instrument. After all, the device can still be mobile. With all these properties, it is ideally suited for so-called media lessons.

The following is a preferred embodiment

of the invention with reference to the figures described in detail.

It shows

1 shows the device in question in a front view, with a door closing the screen partially broken away and doors appearing open on the lower part of the cabinet, and

FIG. 2 shows a section through the same device along the line II-II in FIG. 1, but with the doors closed.

The device has a housing in the form of a cabinet 1, through a front panel 2 into a slightly larger upper part 3 and a correspondingly smaller lower part 4 j is divided. The upper part 3 is essentially

i borrowed entirely occupied by a transparent screen 5,

I which is clamped in a frame 6. This frame, the back

I rests on the support strips 7 on the side, is attached to these by

I kept performing 8. If desired, the fascia strips 8

I can be easily removed and for this purpose a

\ Form a hinged frame »In front of it, as shown, a door

i 9 be disordered, one or both sides as a board, possibly

j iuagntittafel, or projection surface can be formed. These

j door can also act as a screen for screen 5 from being too bright

j serve daylight. It can be lockable.

• The lower part 4 of the cabinet, which is also through the

general lockable doors, 10, is completed, takes a slide projector 11 and next to each other in the example shown a film projector 12. Both projectors are standard projectors. They are in the form of boxes 13 by means of holders

7340590 10J7.75

or 14, in which they are loosely inserted, mounted on a kind of compound slide, which essentially consists of a drawer-like Underframe 15 and a slide plate 16 which can be displaced transversely therein. The underframe 15 is in the cabinet by means of commercially available roller guides 17 mounted so that they can be pulled out, while the slide plate 16 is mounted on by means of slides not shown Plastic rails 18 runs. The possible stroke of the slide plate 16 in the subframe is such that the optical axes the two projectors 11 and 12 can be brought alternately in the middle of the cabinet.

In the beam path, a total of three mirrors, 19, 20 and 21, are arranged within the cabinet 1, which increase in size according to the expansion of the light cone. These mirrors are expediently mirrored on the surface to avoid double reflection. While the first and third mirrors, 19 and 21, respectively, are arranged inclined downwards one above the other in front of the rear wall 22 of the cabinet, the second mirror, 20, is below the image field to be expected on the screen 5 upwards mounted inclined behind the cover 2. Correspondingly, the two projectors 11 and 12 are also inclined so that their lenses are directed upwards towards the first mirror, 19, * In this way a relatively accommodate long beam path in the cabinet 1, as is required for a desirable image size.

Since the insertion of the slide magazine into the inclined projector 11 can cause difficulties, it is the one receiving it Box 13 is mounted so that it can be swiveled upwardly with respect to the Schlitteunplatte 16 by means of a hinge 23, and a handle 24 is used to

- 5 -to lift the end of this box facing away from the rear wall 22.

It goes without saying that the cabinet 1 in suitable places Can have ventilation openings for the ventilation air of the projectors, which are not specifically shown in the figures are. It is also equipped with electrical connection options for the projectors. The cover 2 carries to the outside Remote control armatures 25 for the projectors or for the room dimming, appearing at a comfortable grip height and the like, such as switches, push buttons, control lamps, light controls and / or corresponding connection sockets. In addition, the Cover 2 the electrical sub-distribution of the entire installation room including fuses and the like.

In the upper part 3 of the cabinet, outside the beam path, behind the screen 9, but expediently in front of the mirror 21, for the setting of the performances at least one loudspeaker, in the example a spherical loudspeaker 26, can be installed. The device according to the invention can also have A similarly designed cabinet accessory can be combined side by side, which includes a television set, a record player Tape recorder and a cassette recorder and / or the like. Contains. Finally, as shown, the device according to the invention can be moved by means of commercially available roller feet 27.

- Expectations -

Claims (1)

- 6 - claims 1. A projection apparatus rear projection on a matte screen through the intermediary of mirrors, characterized in that it is designed as a cupboard (1), whose upper part is occupied (3) on the front side is substantially of the screen (5), while the bottom 'part (4) at least one projector (11, 12) is arranged. 2. Projection device according to claim 1, characterized in that the projector is a commercially available one Film or slide projector (12 or 11). 3. Projection device according to claim 2, characterized in that the projector (11, 12), preferably loose, inserted into a suitable holder (13, 14) is. 4. Projection device according to one of the preceding claims, characterized in that the projector (11, 12) is arranged with the lens tilted backwards and upwards. 5. Projection device according to claim 3 and 4, characterized in that the holder (13) in.eine horizontal Position can be swiveled up. 6. Projection device according to one of the preceding claims, characterized in that the projector 7340590 1487.75 - 7 (11, 12) can be extended to the front 1st. 7. Projection device according to one of the preceding claims, characterized in that it is in the beam path consecutively three mirrors (19, 20, 21), of which the first (19) and the third mirror (21) in different Height in front of the rear wall (22) and the second mirror (20) below the image field behind the front wall (e.g. 2) is arranged. 8. Projection device according to claim 7 and 4, characterized in that the first (19) and the third mirror (21) downwards and the second mirror (20) inclined upwards is arranged. 9. Projection device according to one of the preceding claims, characterized in that two or more different projectors (11, 12) are arranged side by side. 10. Projection device according to claim 9, characterized in that g e k e η η - shows that the different projectors (11 ,. 12) can be moved alternately into a central projection position. 11. Projection device according to claim 10, characterized in that the projectors on a common Carriages (15, 16) are arranged. 12. Projection device according to one of the preceding claims, Γ- I denote that there are remote control fittings on the outside, preferably immediately below the screen (5) (25), such as switches, push buttons, control lamps, light controls and / or corresponding connection sockets, having. 13. Projection device according to one of the preceding claims, characterized marked that it is the electrical sub-distribution of the installation room, possibly including fuses and the like., contains. 14. Projection device according to one of the preceding claims, characterized characterized that behind the screen (5) outside the beam path at least one loudspeaker (26) is installed. 15. Projection device according to one of the preceding claims, characterized in that the screen (5) and / or the lower part (4) of the cabinet can be closed by at least one door (9, 10). 16. Projection device according to claim 15, characterized in that the door (9) as a board, possibly a magnetic board, and / or additional projection surface is formed. 17. Projection device according to one of the preceding claims, characterized characterized in that it is combined with a - preferably similarly designed - cabinet accessory, which contains a television set, a record player, a tape recorder, a cassette recorder and / or the like. 18. Projection device according to one of the preceding claims, characterized marked that it is movable.