Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/10—Beam splitting or combining systems
  • G02B27/1006—Beam splitting or combining systems for splitting or combining different wavelengths
  • G02B27/102—Beam splitting or combining systems for splitting or combining different wavelengths for generating a colour image from monochromatic image signal sources
  • G02B27/104—Beam splitting or combining systems for splitting or combining different wavelengths for generating a colour image from monochromatic image signal sources for use with scanning systems
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
  • G02B26/02—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the intensity of light
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/10—Beam splitting or combining systems
  • G02B27/14—Beam splitting or combining systems operating by reflection only
  • G02B27/145—Beam splitting or combining systems operating by reflection only having sequential partially reflecting surfaces

Definitions

• the invention relates to a device for the defined color and directional influencing of a white light laser beam, in which the white light laser beam is broken down into at least three partial beams of different colors by means of optical means and the intensity of each of the partial beams can be variably controlled, the partial beams by means of optical means are combined into a beam and the combined beam is directed onto a deflection device, which comprises two mirrors which can be pivoted about orthogonal axes, and is deflected in a defined manner.
• Such devices also referred to as laser beam projectors
• laser beam projectors are known.
• the known projectors do not allow any choice of color mixing.
• optical means by means of which the white light laser beam is broken down into partial beams of different colors, prisms or selective filters, that is filters with frequency-dependent reflection and transmission properties, are usually used.
• the intensity of the partial beams is controlled by means of variable diaphragms, each of which has a flap which can be pivoted into the corresponding beam path; depending on the position of the flap, a corresponding proportion of each partial beam is covered.
• variable diaphragms have a limited adjustment speed because of the inertia of the moving parts. As a result, a sharp color separation cannot be achieved in the projection images.
• the present invention has for its object to provide a generic device by means of which the projection of colored representations is possible, in which areas of different colors are sharply distinguished from each other.
• each of the variably controllable diaphragms comprising a cylinder which can be rotated about a rotation axis perpendicular to the respective partial beam and which has a Has opening arranged transversely to the axis of rotation.
• the diaphragms used in the device according to the invention have an extremely low inertia, which results in a high response speed of the diaphragms.
• the mode of operation of the diaphragms enables them to be adjusted without shifting the center of gravity of the moving parts. This also results in very low vibrations from reaction forces.
• the opening in the cylinder preferably consists of a slot in a plane containing the axis of rotation.
• This form of opening is particularly easy to manufacture.
• this embodiment is insensitive to changes in the axial position of the cylinders and thus permits higher manufacturing tolerances.
• the selectivity of various areas of different coloring in the representation produced can also be improved in that the cylinder is designed as a hollow cylinder, which reduces the moment of inertia of the diaphragms and thus increases their response speed.
• Galvanometer scanners are particularly well suited for actuating the cylinders, since these drives have a very high response speed with great accuracy.
• other electro-optical elements come into question within the scope of the invention, namely an opto-acoustic modulator, a liquid crystal switch or a device for polarization rotation of the partial beams.
• a preferred embodiment of the device according to the invention has a focusing device consisting of zv / ei lenses for each partial beam, in the focal plane of which the cylinder of the respective variable diaphragm is arranged.
• a focussing device By focusing the partial beams, the dimensions of the components of the diaphragm, that is to say in particular the cylinder dimensions, can be further reduced, thus reducing the moment of inertia of the diaphragm and increasing its response speed.
• the use of a focussing device also allows the parallelism of the white light laser beam to be less demanding than in the case of devices without focussing devices. This makes it possible to feed the white light laser beam into the device according to the invention via a light guide connection.
• the optical means for splitting the white light laser beam preferably consist of selective filters, edge filters being particularly preferred.
• the color quality of the image generated with the device according to the invention can be further improved by the division of the white light laser beam into partial beams which have relatively precisely defined limits with regard to their frequency, using edge filters.
• the white light laser beam is preferably broken down into exactly three partial beams, the device required for this comprising a total of four edge filters and at least zv / ei deflecting mirrors.
• the edge filters are designed as transmission filters or as reflection filters.
• a red transmission filter is understood to mean such a filter which is permeable to light of the wavelength above, for example, 610 nm, while light with shorter wavelengths is reflected. With a red reflection filter, on the other hand, the situation would be reversed.
• a red reflection filter is preferably used as the first edge filter in the beam path, while in devices in which the white light laser beam and the partial beams are parallel to one another, the first edge filter in the beam path is used as a red filter.
• Transmission filter is formed.
• the three partial beams are preferably parallel to one another, which can be achieved in particular by the fact that the edge filters causing the decomposition of the white light laser beam and a deflecting mirror lie in mutually parallel planes.
• the edge filters bringing about the union of the partial beams and a deflecting mirror are preferably arranged in mutually parallel planes. This arrangement additionally offers the advantage of a high degree of compactness of the device, which also has a positive effect with regard to the possible uses.
• a high degree of selectivity between the areas of the generated image with different colors is further favored by the fact that the means for splitting the white light laser beam for the intensity control of the partial beams, for the combination of the partial beams and for the deflection of the combined beam, are mounted on a common base plate.
• the selective filters and the deflecting mirrors are expediently fastened in holders which enable adjustment about three, but at least about two axes running perpendicular to one another and parallel to the mirror or filter plane.
• the holders preferably have a circular-cylindrical extension with which they engage in a circular-cylindrical bore in the base plate so as to pivot about the axis of the bore, and two hinge-like pivot zones.
• FIG. 1 shows a plan view of the entire device in cal atic representation and in FIG. 2 shows the structure of the variable diaphragms used in the device according to FIG. 1 in more detail.
• the device built on a base plate 1 can be divided into four functional areas.
• the white light laser beam W or W ' is split into partial beams
• the dimming area II the intensity of the partial beams TR, TB and TG' is modulated
• the combining area III the partial beams are combined into a colored beam B and in a deflection area IV, the combined beam B is deflected in a defined manner and forms the deflected combined beam BA producing the image.
• the white light laser beam W is broken down by means of two edge filters 2, of which the first in the beam path is designed as a red reflection filter RR and the second in the beam path as a blue reflection filter BR. In this way, the white light laser beam W is converted into a red partial beam TR, a blue partial beam TB and a green one Partial beam TG disassembled.
• the green partial beam TG meets a mirror 3 and, as a reflected green partial beam TG ', is parallel to the red partial beam TR and the blue partial beam TB.
• the two edge filters 2 and the deflection mirror 3 are parallel to each other and form an angle of 45 ° with the axis of the white light laser beam W, so that the partial beams TR, TB, TG 'are perpendicular to the white light laser beam W.
• the first edge filter 2 in the beam path would be designed as a red transmission filter, while the structure of the device otherwise corresponds to that described above.
• the dim area II has for each partial beam a focusing device consisting of two lenses 4a, 4b and a variable diaphragm 5 arranged in the focal plane thereof.
• the variable diaphragm 5 comprises a cylinder 6, which is designed as a hollow cylinder and has one axis ent- holding plane is slotted, whereby two opposite windows 7a, 7b are formed in the cylinder wall.
• the cylinder 6 is rotated about its axis by a rotary drive 8 (arrow 9).
• the aperture and the associated drive are explained in more detail below with reference to FIG. 2. It is pointed out that, for the sake of illustration, the proportions shown in the figures of the drawing do not correspond to those of structural embodiments; for example, the diameter of the cylinder 6 is shown relatively large.
• the aperture can be transferred from its completely open state (upper and lower partial beam) to its completely closed state (middle partial beam) by an extremely small angular rotation of the cylinder 6.
• the partial beams modulated in the dimming area II are combined to form the combined beam B.
• two edge filters 10 and a deflecting mirror are located in the combination area 11 arranged parallel to one another and at 45 ° to the incident modulated partial beams TRm, TBm, TGm.
• a blue reflection filter BR and a red transmission filter RT are used as edge filters.
• the middle aperture ie that for the blue sub-beam TB, assumes its completely resolved position and the intensity of the modulated blue sub-beam TBm is therefore zero
• the combined beam B consists exclusively of the red and the green modulated sub-beam TRm or TGm together and thus has a yellow color.
• a deflection device is constructed on the base plate 1, which comprises two mirrors 14, 15 which can be pivoted about orthogonal axes 12, 13.
• the combined beam B first strikes the lower mirror 14 and is directed by the latter towards the upper mirror 15, from which it is reflected as a deflected beam BA.
• the two mirrors 14, 15 are each driven by a galvanometer scanner 16, 17, which define the position of the mirrors 14, 15 as a function of the voltage applied.
• FIG. 2 shows a perspective view of one of the diaphragms as used in the device according to FIG. 1.
• the cylinder 6 is designed as a hollow cylinder with a small wall thickness; over part of its height it has two rectangular windows 7a, 7b, which are arranged opposite one another on the circumference of the cylinder.
• the two windows together defining an opening in the cylinder 6 are produced by slitting the cylinder 6 in a plane containing the axis of rotation 18.
• the cylinder 6 can be rotated with respect to the axis of rotation 18 by a rotary drive 8, which is designed as a galvanometer scanner.
• the angular position of the cylinder 6 is thereby set, the projection of the effective passage area defined by the two windows 7a and 7b changing in the direction of the partial beam T when the cylinder is rotated.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Mechanical Optical Scanning Systems (AREA)
• Mechanical Light Control Or Optical Switches (AREA)
• Facsimile Scanning Arrangements (AREA)
• Optical Communication System (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6379015

Family Applications (1)

Country Status (6)

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Family Cites Families (6)

• 1989
  • 1989-04-20 DE DE19893912914 patent/DE3912914A1/de not_active Withdrawn
• 1990
  • 1990-03-29 AU AU53410/90A patent/AU625665B2/en not_active Ceased
  • 1990-03-29 EP EP19900905192 patent/EP0422151A1/de not_active Withdrawn
  • 1990-03-29 WO PCT/EP1990/000497 patent/WO1990013208A1/de not_active Ceased
  • 1990-04-16 ES ES9001258U patent/ES1014186Y/es not_active Expired - Lifetime
  • 1990-04-19 IT IT5297590U patent/IT220494Z2/it active IP Right Grant

Non-Patent Citations (1)

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