EP1456715A1

EP1456715A1 - Projection system

Info

Publication number: EP1456715A1
Application number: EP02791619A
Authority: EP
Inventors: Thomas Taubenberger
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2001-12-21
Filing date: 2002-12-09
Publication date: 2004-09-15
Also published as: US20050083492A1; JP2005513574A; CN1605044A; WO2003056389A1

Abstract

The invention relates to a projection system comprising a projection device which is used to produce a projection by emitting projection radiation, and a diaphragm device which is arranged in the beam path of the projection radiation in such a way that part of the projection is blocked out, thus causing a continuous reduction of the intensity of the projection radiation in the blocked-out part of the projection.

Description

description

projection system

The invention relates to a projection system with a projection device and a blending device.

When realizing a large image projection, a large image is generated by projecting radiation onto a projection screen, such as a screen. In order to project the largest possible large image, several, usually many individual projection systems are used, the individual projections of which are combined to form an overall projection, the large image projection. The large image is therefore composed of several, usually many individual images, each generated by one of the individual projections.

Various realizations for large-screen projections are known from [3], which differ, for example, in an arrangement or a number of the individual projection systems or in a form of the overall projection.

4 shows a sketch of a structure 400 of a large-screen projection system 400 with a first 401 and a second 402 projector and a large-screen screen 408.

The first 401 and the second 402 projector each send out projection radiation in the form of a corresponding radiation or projection cone 403 or 404. Corresponding projections 405 and 406 become visible to an observer when the respective projection radiation 403 or 404 hits the large screen 408.

In the case of such a large image projection, as shown by way of example in FIG. 4, overlaps occur in transition areas between the individual projections or individual images, in which two individual projections overlap. On such an overlap area is shown, for example, in FIGS. 4, 408.

Such an overlap or overlap is also referred to as cross-fading or cross-fading.

Brightness falsifications occur in the cross-fade areas, which become disturbing for an observer of the projected large image, since the radiation intensities of the overlapping projections or projection radiations add up (cross-fading problem).

This fading problem is outlined in FIG. 5 on the basis of a corresponding, added intensity curve 500 over a screen width 504 of two projections 501 and 502 covering one part 503 of the screen.

In order to obtain a uniform, correct and (for the observer) not disturbing (added) intensity curve (Fig. 3, 300) of two overlapping parts (Fig. 3, 303)

To ensure projections (Fig. 3, 301, 302), the intensity of the individual projections (Fig. 3, 301, 302) has to start from (Fig. 3, 306) the coverage area (Fig. 3, 303) to an edge (Fig. 3, 307) of the coverage area (Fig. 3, 303) or the respective individual projection (Fig. 3, 301, 302) can be continuously reduced (Fig. 3).

The addition of the intensities of the overlapping individual projections then results in the desired brightness distribution, which is not disturbing for the observer when the large image is made visible on a screen (FIG. 3).

Such a uniform (added) intensity curve 300 of two 306-307 projections 301 and 302 overlapping in a part 303 and reduced in intensity towards the edge 307 over a screen width 304 is shown in FIG. Depending on the projector technology used, ie the type of projector used, a further problem can arise which results in uneven brightness distributions on a projection screen.

Due to their design, LCD projectors in LCD projection systems or DLP projectors in DLP projection systems, which consequently use LCD or DLP technology for image generation and are known, for example, from [3], radiate in addition to those required for image generation Projection radiation still clearly visible scattered radiation or stray light.

This scattered radiation or this scattered light emerges in addition to an image-generating element, an LCD or DLP module, in the case of a respective LCD or DLP projector and also causes a falsification of intensity on the projection screen in addition to the projected image.

With previously available large image or multi-image projection systems, i.e. Projection systems with at least two combined individual projections, for example from [1] known LCD or DLP projection systems, generate the uniform, non-distracting and thus desired intensity curve shown in FIG. 3 in the respective individual projections electronically (soft edge blending ).

For this purpose, in these known projection systems based on the soft edge blending technology, additional, complex and thus cost-intensive electronic assemblies with additional software components are required for the corresponding change in the brightness or the intensity curve (according to that shown in FIG. 3) for the projections ,

The described soft edge blending technique is from the

[1] known LCD or DLP projection systems both integrated into the projectors used and realized as also available as an additional solution at corresponding surcharges.

In the case of the LCD or DLP projection systems known from [1], corresponding cross-fade control electronics for eliminating the cross-fading problem and the projector used in each case are dependent on one another.

Since these LCD or DLP projection systems known from [1] can only influence image elements (pixels) contained in a projection image for technical reasons, the stray light problem described is not eliminated in these known projection systems either.

The invention is therefore based on the object of specifying a projection system which is easier and cheaper to implement than the known ones and which enables better and more efficient cross-fading in projections.

This object is achieved by the projection system with the features of the independent claim.

The projection system has a projection device set up to generate a projection by emitting a projection radiation, and a glare device which is introduced into a beam path of the projection radiation in such a way that part of the projection is masked out in such a way that a continuous part is hidden in the masked part of the projection Reducing the intensity of the projection radiation.

In the invention, a projection is understood to mean a multidimensional radiation field generated by the projection radiation emitted by the projection device, generally a projection cone, with a predetermined intensity distribution of the projection radiation. In the case of the invention, the beam path is to be understood as a path covered by the emitted projection radiation.

Accordingly, if a projection screen on which the projection radiation is incident is introduced into the beam path of the projection radiation, the projection can be made visible on the projection screen.

The physical principles of radiation, in particular the refraction of radiation at a glare edge, are known from [2]. Fundamentals of optical imaging are known from [4].

The physical effect used in the invention is a so-called vignetting. Vignetting is a physically determined decrease in the brightness of an image towards the edge of the image. This is caused by shadowing edge rays through an aperture. Not all rays emanating from a point of light reach a projection surface. Some of these rays are shadowed. This leads to a decreasing brightness curve towards the edge of the picture.

A particular advantage of the invention is that it provides a mechanical (hardware) solution to the fading problem described.

This solution in the invention is thus simpler and less expensive to implement than, for example, the electronic (software) solution known from the prior art.

Compared to this electronic solution known from the prior art, the invention also has the advantage that the projection system according to the invention is independent of a projector type used in each case. The invention can be implemented with any type of projector, for example an LCD or DLP projector.

Furthermore, the invention has the advantage that an adjustment, i.e. an adaptation of the hidden part to projection conditions is considerably simplified, for example by appropriate shaping or incorporation of the glare device into the beam path.

For example, by simply changing an insertion depth and / or changing the insertion location within the beam path, the hidden part can be changed and thus adapted.

In addition, the invention has the advantage that projection scattered light escaping through the inventive projection system, such as that in LCD and DLP projectors, can be eliminated.

The dependent claims provide preferred, advantageous and non-trivial developments of the subject matter of those claims to which they are jerk-related.

To solve the fade problem described, it is expedient that in a further development the hidden part of the projection lies in an edge region of the projection. The intensity of the projection radiation can thus be reduced in a direction towards the edge of the projection.

Furthermore, it is also expedient for the solution of the cross-fading problem that the intensity in the masked-out part of the projection is reduced to zero. This means that the radiation intensity can be continuously reduced to zero right up to the edge of the projection. By means of a corresponding design of the blending device, for example by means of a corresponding shape, depth and / or a corresponding material, the continuous reduction of the intensity can take place in a targeted manner according to a predefinable functional regulation.

A linear functional specification is expedient because of the simple implementation, i.e. a linear reduction in radiation intensity. Other functional regulations, such as a logarithmic regulation for the course of the reduction in the radiation intensity or a regulation that can be described by a polynomial, are possible.

A light-tight material such as aluminum or a metal can be used as the material for the glare device.

Alternatively, a non-light-tight material, such as tinted plexiglass or tinted filter glass, can also be used. The reduction in the radiation intensity and its functional course is achieved by filter coating the material and / or by changing the optical transparency of the material itself. The intensity profiles adjust accordingly.

The flexibility of the projection system according to the invention can be increased in that the glare device is slidably inserted into the beam path in such a way that the hidden part can be changed. This flexibility can be achieved, for example, by simply changing an insertion depth and / or changing the insertion location, in each case by shifting the blind device in a corresponding direction within the beam path.

For this purpose, in a further development, a corresponding mechanical holder with vertical and horizontal guides is provided for one or more of the inventive glare devices. Since the projection system according to the invention is independent of the type of projector used, any type of projector, such as an LCD or DLP projector [1], can be used in further developments.

In order to generate a predetermined projection pattern or a projection form, it is expedient to use a plurality of blind devices, by means of which a part of the projection can be masked out.

The plurality of glare devices can be introduced into the beam path in such a way that a part of the projection that is not masked out has the specifiable shape or pattern. Such a shape or such a pattern can, for example, be a projection cone with a rectangular base area.

In a further development, the projection system according to the invention has a projection screen for displaying the projection.

In a further development of the invention, a large projection unit is realized in such a way that at least two of the inventive projection systems are aligned with one another in such a way that the respectively hidden parts of the respective projection overlap at least partially.

A so-called cross-fading takes place in the covered part, with the intensities of the covered projections adding up to a composite overall intensity.

In this case, in order to achieve a cross-fade that is as uniform and non-distracting as possible for an observer, the overlapping takes place in such a way that a constant course of an intensity composed of the intensities of the two projection radiations is established for the covered part. In order to realize a large projection unit as large as possible, such as is desired for demonstration purposes at trade fairs or similar demonstration events, it is expedient to use or combine several or many of the projection units according to the invention, which are aligned with one another in such a way that a large projection is also possible a predefinable shape, in particular a large projection cone with a rectangular base.

Such a large projection cone then generates a regular large projection image with transitions or cross-fades between the individual projections that are barely visible to an observer when hitting a large projection screen.

In the figures, an embodiment of the invention is shown, which is explained in more detail below.

Show it

Figure 1 Optical Hardware Edge Blending System (H-EBS) according to an embodiment;

FIG. 2 shows a sketch of a multi-image projection with a multi-image projection system with an optical hardware edge blending system according to an exemplary embodiment;

Figure 3 Sketch with a composite, uniform intensity curve with two combined

Projection systems or projections without fading problem;

FIG. 4 sketch of a structure of a multi-image project system with two projection systems combined with one another; Figure 5 Sketch with a composite, uneven intensity curve in two combined projection systems with cross-fading problem.

FIG. 6 sketch of a structure of a hardware edge blending (H-EBS) multi-image project system with two combined H-EBS projection systems;

Design example: Optical Hardware Edge Blending System (H-EBS)

FIG. 6 shows a structure 600 of a large-image projection system, in this case a two-image projection system, a so-called hardware edge blending (large-image projection) system 601 (H-EBS).

The H-EBS 600 shown comprises a first 601 and a second 602 H-EBS projector, in this case an LCD projector, and a large screen 608.

It is also noted that any projector, for example a DLP projector, can be used with the H-EBS.

The first 601 and the second 602 H-EBS projector each send out projection radiation in the form of a corresponding radiation or projection cone 603 or 604. Corresponding (individual) projections 605 and 606 are visible to an observer when the respective projection radiation 603 or 604 strikes the large screen 608.

So-called H-EBS diaphragm devices 609, 610 are introduced into the projection cones or beam paths 603, 604 of the H-EBS projectors 601, 602 (FIG. 1), The two H-EBS projectors 601 and 602 are aligned with one another in such a way that both projections 605 and 606 are visible side by side on the large screen 608.

In an overlap area 607, which is changed by the H-EBS aperture devices 609, 610, i.e. can be enlarged or reduced (see also Fig.l), the two projections 605 and 606 overlap (crossfade or crossfade).

2 shows a structure 200 or an H-EBS single projection 200 through one of the two H-EBS projectors 601 or 602, 201.

2 shows in particular the projection cone or

Beam path 202 of the H-EBS projector 201 introduced H-EBS glare device 609 or 610, 206 (see also FIG. 1).

The H-EBS diaphragm device 206 is attached in the direction of the beam path 202 after a projector optics 207 in front of the H-EBS projector 201.

A (radiation) diffraction effect 205 on a glare edge 208 of the H-EBS blending device 206, which (radiation) diffraction effect 205 is known from [2], ensures that a projection 203, in this case a projected image 203, 204 is faded out almost uniformly towards an image edge 209.

As a result, the intensity curve 210 in the case of a single projection, in this case the projection 203, is corresponding to the uniform (added) intensity curve 300 shown in FIG. 3 with two 306-307 projections that overlap in one part 303 and are reduced in intensity towards the edge 307. NEN 301 AND 302 REDUCES 204. This intensity reduction takes place in a mirror-image manner by means of a corresponding structure in the second H-EBS projector 601 or 602, so that the uniform (added) intensity curve 300 according to FIG. 3 is obtained during the cross-fading.

This solves the fading problem in the H-EBS system described.

1 shows the H-EBS blending device 609, 610, 206 and 100 (introduced into the beam path 202 of the H-EBS projector 201).

The H-EBS diaphragm device 100 has a rectangular front plate 103, on which vertical 104 and horizontal 105 guides for mounting vertically 102 and horizontally 101 diaphragms are attached.

The screens 101, 102 each have a straight, non-curved screen edge 111.

The panels 101, 102 can be moved within their respective guides 104 and 105 and can be fixed in a desired position by means of locking options 106.

The front plate 103 is attached or aligned in front of the projector optics 207 of the H-EBS projector 201 in such a way that a horizontal axis of symmetry 109 and a vertical axis of symmetry 110 of the front plate 103 each coincide with an optical axis 108 of the projected radiation cone 202.

The horizontal and vertical arrangement of the diaphragms 101, 102, as well as the free displacement of the diaphragms 101, 102 within their guides 104, 105 make it possible for any, in this case any rectangular, openings 107 to pass through the projection radiation to be adjustable. A different shape for the diaphragms 101, 102 or a different line arrangement for the diaphragm edges 111 also enable differently shaped passage openings 107, for example curved passage openings 107.

This flexibility in the adjustment of the passage opening 107 allows all edges of a projected image to be variably blended and the cross-fading to be flexibly adapted (adjustment).

Important advantages of the described H-EBS 600 are:

The adjustment of the crossfade or the adjustment is flexible and easy. - The cost is significantly reduced compared to soft edge blending solutions.

- Stray light that occurs is eliminated.

The H-EBS 600 is independent of the type of projector used and its input signal source.

The following publications are cited in this document:

[1] Product information, LCD or DLP projection systems, available on December 17, 2001 at http: //www.barco. com / projection systems /;

[2] Jost J. Marchesi, Handbook of Photography - Volume 1 / The basics, Verlag Photographie, ISBN 3723100244

[3] TAN projection technology, TANORAMA ™ POWERWALL, FA. TAN Projektionstechnologie GmbH & Co. KG,, available on December 17, 2001 at http: // www. tan. de.

[4] Christian Hofmann, Die Optik Figure, 1st edition, page 175, Akademische Verlagsgesellschaft Geest & Porting K.-G., Leipzig, 1988.

Claims

claims

1.Projection system with a projection device set up to generate a projection by emitting a projection radiation, and a glare device which is introduced into a beam path of the projection radiation in such a way that part of the projection is masked out in such a way that a continuous part is hidden in the masked part of the projection Reducing the intensity of the projection radiation.

2. Projection system according to claim 1, wherein the hidden part of the projection is in an edge region of the projection.

3. Projection system according to one of the preceding claims, in which the intensity is reduced to zero in the hidden part of the projection.

4. Projection system according to one of the preceding claims, in which the continuous reduction of the intensity takes place according to a predefinable functional regulation, in particular a linear functional regulation.

5. Projection system according to one of the preceding claims, in which the glare device is slidably introduced into the beam path in such a way that the hidden part can be changed.

6. Projection system according to one of the preceding claims, wherein the projection device is an LCD or DLP projector.

7. Projection system according to one of the preceding claims, with several blind devices, through which a part of the projection can be hidden.

8. The projection system as claimed in claim 7, in which the plurality of blind devices are introduced into the beam path in such a way that a part of the projection which is not masked out has a predeterminable shape, in particular a projection cone with a rectangular base area.

9. Projection system according to one of the preceding claims, with a projection screen for displaying the projection.

10. Large projection unit with at least two projection systems each according to one of the preceding claims, in which large projection unit the at least two projection systems are aligned with one another such that the hidden parts of the respective projection overlap at least partially.

11. Large projection unit according to the preceding claim, in which the overlap takes place in such a way that a constant course of an intensity composed of the intensities of the two projection radiations is established for the covered part.

12. Large projection unit according to one of the two preceding claims, with a plurality of projection systems which are aligned with one another in such a way that a large projection with a predeterminable shape, in particular a large projection cone with a rectangular base, is established.

13. Large projection unit according to the preceding claim, with a large projection screen for displaying the large projection.