DE4106137A1 - Image projector - has layers to give alternating positive and negative shapes with replaceable images - Google Patents

Abstract

The appts to give picture and text images, alternately in positive and negative form which are exchangeable and variable for displays and projection, has two intersecting linear polarising layers (1,2) which can be polarised. Two layers (3,4) are between them to pass through the oscillating plane of the linear polarised light to turn it by 90 deg. The layer (4) towards the viewer is mounted to move on its plane in relation to the other layers (1,2,3). Pref the polarising layer (3) away from the viewer has two different zones (31,3b) where only one zone (3a) has the required optical character and the other zone (3b) prevents rotation of the linear polarised light. The moving layer (4) rotates. The layer (3) away from the viewer can be replaced. The second zone (3b) of the layer (3) is formed by cutting or stamping chemical or mechanical action to remove the ability to rotate the penetrating linear polarised light by 90 deg c. The layer (3) is an optically neutral carrier. such as a glass, with the first section (3a) formed by adhesive plastic film segments which can rotate the linear polarised light by 90 deg, such as Tesafilmm (RTM) adhesive film strips. The moving layer (4) is operated by a drive (7), and a light source (8) passes light through the layers (1,2,3,4) with a reflective layer to illuminate the layers (1,2,3,4). ADVANTAGE - The system gives a rapid and trouble-free change and replacement of images to increase the awareness of the positive and negative presentations through alternating change.

Description

The invention belongs to the technical field of display, Imaging and projection devices for images and characters.

The known display and imaging devices for image and Characters are usually based on electrical control of liquid crystal layers or light emitting diodes or fluoroscopy of transparent picture and writing media.

A problem-free change of the picture and characters over the The intended size is usually not possible. Furthermore, for Often only the flashing light method possible to increase attention.

A device similar in construction is disclosed in the published patent application with the number DE 38 38 372 A1 / G 02 B 27/28. These However, the device has two major shortcomings. First is that Exchanging and changing the image and characters complicated, because a polarization layer must always be changed for this, secondly only color changes are possible to increase attention.

The goal is therefore to create a device for imaging and image To construct characters that are both short term and problem-free changing and changing of the picture and characters allows as well to increase attention between the positive and negative image form changes back and forth.

The invention is explained in more detail with reference to the drawing. It shows

Fig. 1 in perspective the principle design of the device according to the invention, in an extended half out of the light beam (6) layer (4)

Fig. 2 is a sectional drawing of the principle construction shown in Fig. 1, at a halfway upwardly out of the light beam (6) drawn out layer (4)

Fig. 3 shows an embodiment of the device with drive device ( 7 ) for the rotatable layer ( 4 ) and its own light source ( 8 ).

According to Fig. 1 and 2, the apparatus has two crossed linear polarizing polarizer (1, 2) between which, both of which have two layers (3, 4) are arranged the property of the plane of vibration of it penetrating the linearly polarized light (6) to 90 ° C., the layer ( 4 ) facing the viewer being mounted so that it can move in relation to the other layers ( 1 , 2 , 3 ).

The layer ( 3 ) facing away from the viewer consists of two different areas ( 3 a, 3 b). Only one area ( 3 a) has said optical property, the other ( 3 b), however, does not rotate the plane of oscillation of the linearly polarized light ( 6 b, 6 c). By these two regions (3 a, 3 b) is defined to be imaged image and character of the form E.

This layer ( 3 ) can, for. B. consist of a plastic film, such as is used for transparent adhesive strips. By cutting out or punching, by chemical action or by mechanical action, a partial area ( 3 b) of this layer or plastic film ( 3 ) can lose the property of rotating the plane of oscillation of the linearly polarized light.

This layer ( 3 ) can also be made of an optically neutral carrier, such as. B. a glass pane exist on which the area ( 3 a) is formed by gluing plastic film parts that have said property (z. B. adhesive tape of the "Tesafilm" brand).

This layer ( 3 ) is interchangeable.

Operation of the device shown in FIGS. 1 and 2: The light beam ( 6 ) is linearly polarized when crossing the polarizer layer ( 2 ). In the layer ( 3 ), the vibration planes of the light beams ( 6 a, 6 b) of the light beam ( 6 ) are rotated by 90 ° C because they have passed through the area ( 3 a). The vibration planes of the light beams ( 6 b, 6 c), however, remain unchanged. The movable layer ( 4 ) is half pulled out of the light beam, so that only one half of the light beams ( 6 a, 6 b) crosses it, the oscillation planes rotating by 90 ° C. The vibration planes of the light beams ( 6 c, 6 d), however, remain unchanged. When the light rays strike the polarizer layer ( 1 ), only the light rays ( 6 b, 6 d) can now pass through, whose plane of vibration runs parallel to that of the polarizer layer ( 1 ). This condition is only met by the light beams whose oscillation plane has only been rotated once by 90 ° C after being polarized by the polarization layer ( 2 ). The result is an image ( 5 ) whose outline corresponds to the two different areas ( 3 a, 3 b) of the layer ( 3 ). The half of the picture from which the layer ( 4 ) is drawn appears in negative (white on black) and the other in positive (black on white).

According to FIG. 3, in addition to the components of FIGS. 1 and 2, the device has a drive device ( 7 ) for rotating the layer ( 4 ) and an integrated light source ( 8 ).

By turning the layer ( 4 ), here in the form of a circular disc, the image ( 5 ) changes constantly between the positive and the negative. This effect occurs in that the layer ( 4 ), such as. B. an adhesive film, the plane of vibration of the penetrating linear polarized light can only rotate by 90 ° C when it is at a certain angle to this plane of vibration. The effect of rotating the layer ( 4 ) is almost the same as constantly pushing the layer ( 4 ) in and out of the light beam path.

The device is suitable for displaying or projecting informative and decorative images and characters.

The device can be manufactured easily and inexpensively, in particular if a separate light source is dispensed with and the layer ( 4 ) is moved or rotated manually.

A particular advantage lies in the layer ( 3 ) as the carrier of the pictorial and written characters to be reproduced. Inexpensive plastic films that are easy to process can be used here. So z. B. the desired picture and characters by cutting or punching out. However, it is also possible to label the plastic films with caustic liquids or mechanical pressure, whereby the areas treated in this way lose their property of rotating linearly polarized light by 90 ° C. ( 3 b).

Claims (9)

1. Apparatus for imaging alternating and changeable pictorial characters and characters, alternating in positive and negative form, characterized in that it has two crossed linearly polarizing polarizer layers ( 1 , 2 ), between which two layers ( 3 , 4 ) are arranged , both of which have the property of rotating the plane of oscillation of the linearly polarized light penetrating them by 90 ° C., the layer ( 4 ) facing the viewer being movably mounted in its plane relative to the other layers ( 1 , 2 , 3 ). 2. Device for imaging alternating and changeable pictograms and characters, which alternate in positive and negative form, characterized in that it has two crossed linearly polarizing polarizer layers ( 1 , 2 ), between which two layers ( 3 , 4 ) are arranged , both of which have the property of rotating the plane of oscillation of the linearly polarized light penetrating them by 90 ° C., the layer ( 3 ) facing away from the viewer consisting of two different areas ( 3 a, 3 b), of which only one area ( 3 a) has said optical property and the other ( 3 b), on the other hand, is unable to rotate the plane of oscillation of the linearly polarized light. 3. Device according to claim 1, characterized in that the movable layer ( 4 ) is rotatably arranged. 4. The device according to claim 2, characterized in that the layer facing away from the viewer ( 3 ) is replaceable. 5. Apparatus according to claim 2 and 4, characterized in that the area ( 3 b) of the layer ( 3 ) by cutting or punching, by chemical action or by mechanical action has lost the property, the vibration level of the layer ( 3 ) Rotate penetrating linear polarized light by 90 ° C. 6. Apparatus according to claim 2 and 4, characterized in that the layer ( 3 ) made of an optically neutral carrier, for. B. a glass pane, on which the area ( 3 a) is formed by gluing plastic film parts which have the property of rotating linear polarized light penetrating them by 90 ° C, such as. B. the transparent adhesive strips of the "Tesafilm" brand. 7. The device according to claim 1 or 3, characterized in that a drive device ( 7 ) for moving the layer ( 4 ) is provided. 8. Device according to one of claims 1 to 7, characterized in that it is provided with a light source ( 8 ) for illuminating the layers ( 1 , 2 , 3 , 4 ) in transmitted light. 9. Device according to one of claims 1 to 7, characterized in that it is provided instead of a light source ( 8 ) with a reflective layer for illuminating the layers ( 1 , 2 , 3 , 4 ) in incident light.