# US 9,039,198 B2 · Projection apparatus having improved projection properties, and method and procedure, respectively, for projecting an image

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- Number: US 9,039,198 B2
- Document ID: US9039198B2
- Status: Granted
- Kind: B2
- Application number: 12/514,917
- Filed: 2007-11-08
- Published: 2010-06-17
- Granted: 2015-05-26
- Earliest claimed: 2006-11-14
- Assignees: Osram Gesellschaft Mit Beschraenkter Haftung
- Applicants: Jan Oliver Drumm; Henning Rehn; Bakuri Lanchava; Wolfgang Pabst; Robert Kraus
- Inventors: Jan Oliver Drumm; Henning Rehn; Bakuri Lanchava; Wolfgang Pabst; Robert Kraus
- Web page: https://patentgrep.com/patent/US9039198B2

## CPC

- G03B 21/00: Projectors or projection-type viewers; Accessories therefor (devices for changing pictures G03B23/00)
- G03B 21/008: {using micromirror devices}
- H04N 9/3129: {scanning a light beam on the display screen (scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161)}
- H04N 9/317: {Convergence or focusing systems (electronic adjustment of convergence H04N9/3185; convergence or focusing arrangements for cathode ray tubes H04N9/28; means for automatic focusing of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/53)}
- H04N 13/337: using polarisation multiplexing
- H04N 13/365: using digital micromirror devices [DMD]
- G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D)
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

In a method for projecting an image onto a projection area (10) by at least one first (110) and second (210) beam, in order to create an improved image on the projection area, the deviation of the projection of the first and second beam on the projection area is determined, and the intensity of the first and/or second beam is varied over time according to the previously determined deviations.

## Claims

### Claim 1

A method for projecting an image onto a projection screen by means of at least one first and one second beam, wherein by means of the superimposition of the projection of the first and of the second beam onto the projection screen a reference impression of the image is to be generated, wherein the at least first and second beams for projecting the pixels are directed onto the projection screen by means of a first mirror, wherein by means of an actual deviation of the projection of the first and of the second beam onto the projection screen an actual impression of the image is generated which deviates from the reference impression, wherein the method comprises the method steps A) determination of the actual deviation of the projection of the first from the second beam on the projection screen, B) temporal variation of the intensity of the first and/or second beam according to the deviations determined in method step A) to generate the reference impression,
wherein for the accomplishment of method step A) a second mirror is arranged between the first mirror and the projection screen and at any one time only a single beam is operating,
wherein the second mirror is oriented such that it directs the respective beam, which is operating, at least partially onto a detector having a fixed position,
wherein the first mirror for the first beam is brought into a first orientation in which a maximum intensity of the first beam is measured at the detector and wherein the first mirror for the second beam is brought into a second orientation in which a maximum intensity of the second beam is measured at the detector and wherein the first and second orientations of the first mirror are respectively determined thus that the first mirror is irradiated with an additional beam and the deflection thereof is determined by means of a second detector, wherein the orientation of the first mirror is determined by means of the deflection of the additional beam.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the additional beam is arranged having an inclined angle with respect to the at least first and second beams, wherein from the first and the second and/or the third and the fourth orientations of the first mirror an angular deviation between the first and the second beam is determined which is used for the determination of the actual deviation of the first and the second beam on the projection screen.

### Claim 3 (depends on 1)

The method according to claim 1, wherein during the method step A) the first mirror is held in at least one fixed orientation for each beam.

### Claim 4 (depends on 3)

The method according to claim 3, wherein a detector is brought into a first position for the first beam and is brought into a second position for the second beam at which a maximum intensity of the respective beam is measured at the detector.

### Claim 5 (depends on 3)

The method of claim 3, wherein for the determination of the position of the projection of the beams on the detector a plurality of detectors is provided wherein from the positions of the projection of the beams on the plurality of detectors an angular deviation between the first and second beams is determined which is used for the determination of the actual deviation of the first and second beams on the projection screen.

### Claim 6 (depends on 5)

The method according to claim 5, wherein the plurality of detectors is positioned such that all positions of the projections of the beams on the plurality of detectors may be measured.

### Claim 7

A projection apparatus comprising at least one first and second source of radiation for generating a first and second beam, a projection device for projecting the first and second beams onto a projection screen, wherein an image is projected onto the projection screen, an electronic control for the first and second source of radiation, a detection device for detecting a deviation between the projections of the first and second beams on the projection screen, wherein the projection apparatus is arranged such that depending on the deviation between the projections of the first and second beams on the projection screen detected by means of the detection device the electronic control for at least one of the first and second source of radiation are configured to be delayed such that the deviation is reduced and corrected, respectively, wherein the at least first and second sources of radiation comprise lasers, wherein the projection device comprises a first mirror for directing the at least first and second beams onto the projection screen,
wherein a second mirror is arranged between the first mirror and the projection screen and at any one time only a single beam is operating,
wherein the second mirror is oriented such that it directs the respective beam, which is operating, at least partially onto a detector having a fixed position,
wherein the first mirror for the first beam is brought into a first orientation in which a maximum intensity of the first beam is measured at the detector and wherein the first mirror for the second beam is brought into a second orientation in which a maximum intensity of the second beam is measured at the detector and wherein the first and second orientations of the first mirror are respectively determined thus that the first mirror is irradiated with an additional beam and the deflection thereof is determined by means of a second detector, wherein the orientation of the first mirror is determined by means of the deflection of the additional beam.

### Claim 8

A method for projecting an image onto a projection screen by means of at least one first and one second beam, wherein by means of the superimposition of the projection of the first and of the second beam onto the projection screen a reference impression of the image is to be generated, wherein the at least first and second beams for projecting the pixels are directed onto the projection screen by means of a first mirror, wherein by means of an actual deviation of the projection of the first and of the second beam onto the projection screen an actual impression of the image is generated which deviates from the reference impression, wherein the method comprises the method steps A) determination of the actual deviation of the projection of the first from the second beam on the projection screen, B) temporal variation of the intensity of the first and/or second beam according to the deviations determined in method step A) to generate the reference impression,
wherein for the accomplishment of method step A) a second mirror is arranged between the first mirror and the projection screen and at any one time only a single beam is operating,
wherein the second mirror is oriented such that it directs the respective beam, which is operating, at least partially onto a detector having a fixed position,
wherein for the first beam a third orientation of the first mirror is measured in which the first beam has a maximum intensity on a second detector and wherein for the second beam a fourth orientation of the first mirror is measured in which the second beam has a maximum intensity on a second detector and wherein the third and fourth orientations of the first mirror are respectively determined thus that the first mirror is irradiated with an additional beam and the deflection thereof is determined by means of a second detector, wherein the orientation of the first mirror is determined by means of the deflection of the additional beam.

### Claim 9

A method for projecting an image onto a projection screen by means of at least one first and one second beam, wherein by means of the superimposition of the projection of the first and of the second beam onto the projection screen a reference impression of the image is to be generated, wherein the at least first and second beams for projecting the pixels are directed onto the projection screen by means of a first mirror, wherein by means of an actual deviation of the projection of the first and of the second beam onto the projection screen an actual impression of the image is generated which deviates from the reference impression, wherein the method comprises the method steps A) determination of the actual deviation of the projection of the first from the second beam on the projection screen, B) temporal variation of the intensity of the first and/or second beam according to the deviations determined in method step A) to generate the reference impression,
wherein for the accomplishment of method step A) a second mirror is arranged between the first mirror and the projection screen and at any one time only a single beam is operating,
wherein the second mirror is oriented such that it directs the respective beam, which is operating, at least partially onto a detector having a fixed position,
wherein for the accomplishment of the method step A) a second semi-transparent mirror is positioned between the first mirror and the projection screen and all beams are operating simultaneously, wherein they generate the actual impression on the projection screen, wherein the beams are partially directed onto a detector by means of the second mirror,
wherein for the separation of the beams a filter is provided between the second mirror and the detector or a diffractive element is provided behind the second mirror,
wherein the first mirror is brought into a first orientation in which the plurality of detectors measures an intensity maximum of the first beam and wherein the first mirror is brought into a second orientation in which the plurality of detectors measures an intensity maximum of the second beam, and wherein the first mirror is brought into a third orientation in which the plurality of detectors measures an intensity maximum of the first beam and wherein the first mirror is brought into a fourth orientation in which the plurality of detectors measures an intensity maximum of the second beam, wherein the first and second and the third and fourth orientations of the first mirror are respectively determined thus that the first mirror is irradiated with an additional beam and the deflection thereof is determined by means of a second detector, wherein the orientation of the first mirror is determined by means of the deflection of the additional beam and wherein the additional beam is arranged having an inclined angle with respect to the at least first and second beams.

### Claim 10

A projection apparatus comprising at least one first and second source of radiation for generating a first and second beam, a projection device for projecting the first and second beams onto a projection screen, wherein an image is projected onto the projection screen, an electronic control for the first and second source of radiation, a detection device for detecting a deviation between the projections of the first and second beams on the projection screen, wherein the projection apparatus is arranged such that depending on the deviation between the projections of the first and second beams on the projection screen detected by means of the detection device the electronic control for at least one of the first and second source of radiation are configured to be delayed such that the deviation is reduced and corrected, respectively, wherein the at least first and second sources of radiation comprise lasers, wherein the projection device comprises a first mirror for directing the at least first and second beams onto the projection screen,
wherein a second mirror is arranged between the first mirror and the projection screen and at any one time only a single beam is operating,
wherein the second mirror is oriented such that it directs the respective beam, which is operating, at least partially onto a detector having a fixed position,
wherein for the first beam a third orientation of the first mirror is measured in which the first beam has a maximum intensity on a second detector and wherein for the second beam a fourth orientation of the first mirror is measured in which the second beam has a maximum intensity on a second detector and wherein the third and fourth orientations of the first mirror are respectively determined thus that the first mirror is irradiated with an additional beam and the deflection thereof is determined by means of a second detector, wherein the orientation of the first mirror is determined by means of the deflection of the additional beam.

### Claim 11

A projection apparatus comprising at least one first and second source of radiation for generating a first and second beam, a projection device for projecting the first and second beams onto a projection screen, wherein an image is projected onto the projection screen, an electronic control for the first and second source of radiation, a detection device for detecting a deviation between the projections of the first and second beams on the projection screen, wherein the projection apparatus is arranged such that depending on the deviation between the projections of the first and second beams on the projection screen detected by means of the detection device the electronic control for at least one of the first and second source of radiation are configured to be delayed such that the deviation is reduced and corrected, respectively, wherein the at least first and second sources of radiation comprise lasers, wherein the projection device comprises a first mirror for directing the at least first and second beams onto the projection screen,
wherein a second mirror is arranged between the first mirror and the projection screen and at any one time only a single beam is operating,
wherein the second mirror is oriented such that it directs the respective beam, which is operating, at least partially onto a detector having a fixed position,
wherein a second semi-transparent mirror is positioned between the first mirror and the projection screen and all beams are operating simultaneously, wherein they generate the actual impression on the projection screen, wherein the beams are partially directed onto a detector by means of the second mirror,
wherein for the separation of the beams a filter is provided between the second mirror and the detector or a diffractive element is provided behind the second mirror,
wherein the first mirror is brought into a first orientation in which the plurality of detectors measures an intensity maximum of the first beam and wherein the first mirror is brought into a second orientation in which the plurality of detectors measures an intensity maximum of the second beam, and wherein the first mirror is brought into a third orientation in which the plurality of detectors measures an intensity maximum of the first beam and wherein the first mirror is brought into a fourth orientation in which the plurality of detectors measures an intensity maximum of the second beam, wherein the first and second and the third and fourth orientations of the first mirror are respectively determined thus that the first mirror is irradiated with an additional beam and the deflection thereof is determined by means of a second detector, wherein the orientation of the first mirror is determined by means of the deflection of the additional beam and wherein the additional beam is arranged having an inclined angle with respect to the at least first and second beams.

### Claim 12 (depends on 9)

The method according to claim 9, wherein a plurality of detectors is used as the detector and the respective beam which is directed onto the plurality of detectors generates a projection on the plurality of detectors.

### Claim 13 (depends on 9)

The method according to claim 9, wherein from the first and second and/or the third and fourth orientations of the first mirror an angular deviation between the first and the second beam is determined which is used for the determination of the actual deviation of the first and second beams on the projection screen.

### Claim 14 (depends on 9)

The method according to claim 9, wherein in method step A) the first mirror has at least one defined orientation for each beam.

### Claim 15 (depends on 14)

The method according to claim 14, wherein a detector for the first beam is brought into a first position and for the second beam is brought into a second position in which a maximum intensity of the respective beam is measured at the detector.

### Claim 16 (depends on 14)

The method according to claim 14, wherein for the determination of the position of the projection of the beams on the detector a plurality of detectors is used and wherein from the positions of the projection of the beams on the plurality of detectors an angular deviation between the first and the second beam is determined which is used for the determination of the actual deviation of the first and second beams on the projection screen.