KR20010041123A - Device for the projection of a video image - Google Patents

Abstract

Apparatus for projecting a video image, the projection head 60 comprising, in particular, a horizontal refraction mirror 12 having at least one mirror surface 14 for the refraction of the bundle of rays in the horizontal direction of the video image; A vertical refractive mirror 16 for refraction in the vertical direction, wherein the surface reference line 23 of the at least one mirror surface 14 is with respect to the angle ε at the axis of rotation 33 of the horizontal refractive mirror 12. Configured to be tilted at an angle, in the position of the horizontal refraction mirror 12 the beam bundle is in principle directed towards the center of the video image in the projection direction 28

Projected to the mirror surface 14 at an angle,

From here Relates to the surface reference line 23.

Description

DEVICE FOR THE PROJECTION OF A VIDEO IMAGE}

FIELD OF THE INVENTION The present invention relates to an apparatus for projecting a video image, in particular a horizontal refraction mirror having at least one mirror surface for refraction of a bundle of rays in the horizontal direction of the video image, and a vertical refraction for refraction in the vertical direction. And a surface reference line of at least one mirror surface, wherein the surface reference line is configured to be inclined at an angle with respect to ε at the axis of rotation of the horizontal refraction mirror.

In video projection using ray bundles, ray bundles are rapidly refracted by a mirror in the vertical scan direction to show the horizontal scan and perpendicular to it, or the image point of the video image. These mirrors are used as horizontal refraction mirrors and vertical refraction mirrors to serve this purpose depending on their function.

Polygonal mirrors, which allow high refractive speeds for displaying video images, are often used as horizontal refraction mirrors.

Other mirrors with high conversion speeds are also known, but mirrors capable of displaying video images with low point densities such as small galvanometer mirrors are mirrors that will be available in the future for very high horizontal refraction. The "horizontal refractive mirror" is used when the conditions are as follows. It usually means a polygon mirror. But it is not limited by this. The object is only suitable when the horizontal refraction mirror is high speed for the angular change of the bundle of rays by the rotation or the inclination to the axis of rotation.

Operation of laser projection systems by this technique is well known in the patent literature in recent years. Such a projector is constructed in detail as a video system.

The video image is made into an image by scanning by a horizontal refraction mirror and a vertical refraction mirror. Laser beams are used instead of electron beams, but in contrast to picture tubes, which have been used in the past.

Color information and brightness information for all image points of the video image are known by appropriate modulation of the laser beam, preferably by refraction prior to conventional refraction by horizontal and vertical refraction mirrors.

For example, a laser projection system of the type mentioned above is described in DE 43 24 848 C2. One of the embodiments shown in this material is a device for generating a laser beam, a unified beam of laser modulation and other colored laser beams that is spatially separated from a second device, including only horizontal refraction mirrors, inclined mirrors and transfer optics. Shows separation.

The light transmission between the first device and the second device is scanned solely from the first device being executed by the light-conducting fiber.

The scanning second device will also be mentioned below as the projection head. It is essentially a two-axis refracting device, in particular polygon mirrors, in which the transmission of light is carried out by an inclined mirror. Recently, it is also performed by a magnification lens.

However, such a structure is not essential. A laser projection system, for example a dichroic mirror comprising a device, for example, which is incorporated by reference, is also provided in the projection head for multiple combinations of laser bundles from each bundle of rays. In addition, in the projection apparatus according to JP 363-306417, a vertical refraction mirror is provided in front of the polygon mirror. This is also compared with other devices in the citations of the German literature.

Other projection heads according to JP 61-90122 include light sources for red, green and blue. The change of the intensity and the modulation of the light beam color are first induced in the horizontal refraction mirror formed by the polygon mirror, and likewise may be performed by the vertical refraction mirror configured by the polygon mirror. However, vertical refraction mirrors in this case use a large mirror surface to obtain a large number of beams already refracted within the horizontal scanning direction. It should be avoided here that curved mirrors are generally provided for the optical extension of the mirror surface area of a suitable polygonal mirror.

In the projection apparatus according to JP 3-109591, the light beam is first guided by a polygon mirror and then directed to a mirror that is vertically refracted through the lens. Therefore an additional lens is needed in this case.

US 4,979,030 is also used as an imaging optics system between two refracting mirrors. This optical mechanical system is arranged as a relay lens between the vertical refractive mirror and the horizontal refractive mirror and is provided to provide a common imaging point for both refractive directions.

This technique is often used. For example, EP 0 488 903 B1 and US Pat. No. 5,051,834 used relay lenses between horizontal and vertical mirrors.

However, according to what has been described before, such optical elements are lost within the range of the beam path and the beam refracting apparatus. Because in their case, the importance of beam elements has increased to show images such as those requiring light loss and small divergence of the light beam. The space requirements also increased due to the added optical elements and the optical paths made by them. In addition, all optical elements located in the beam path always cause some high light loss and resolution loss. Therefore, the components must be carefully selected and used to optimize the projection system.

There are also differences between the well known polygon mirrors. For example, polygon mirrors are known to be within right angles to the axis of rotation of the standard mirror surface. The other known polygonal mirror, ie the reference surface of the mirror surface, is inclined at an angle ε on the axis of rotation.

For example, other costs are also required within this reference. From the result of the curve the mirror surface is tilted and depends on the projection angle of the bundle of rays. Since there is no insurmountable obstacle, this effect can be regarded as laser beam bundle control in that the beam bundle is acted upon by adjusting the contrast of the beam assigned to each image point written on the curve to reproduce the image point accurately. It is. However, additional expenditure calculations and control are further needed.

The object of this invention and the mechanism for the projection of light bundles and video images that make full use of this invention are known. Expenditures for control or optical components have been relatively low.

This object refers to consumption by control, which is a process addressed from the previously mentioned literature. In the position of the horizontal refraction mirror in the center of the video image in the light beam principle projection manipulation it has been manipulated.

Projected onto the mirror surface at an angle.

here Relates to a standard surface.

In this way, first of all several geometric relationships were established between optics in the device. Based on the indicated angle, the bends in the line are less than 3%. Experiments have shown that small line bends of this kind are not perceived as disruptive. Thus, it is possible to eliminate the need for additional costs for image correction.

Unexpectedly, a very simple relationship is given by the choice of the projection angle [theta] to any choice of horizontally refracting mirrors with respect to the tilt of the mirror surface at the angle [epsilon] to the axis of rotation. However, it is also clear from this relationship that it is possible to adjust the tilt angle for the bundle of rays. In principle, none of the normal surfaces of the mirror surfaces with the axis of rotation are previously known or unexpected results.

At all angles it proved to be particularly geometrically advantageous, in accordance with the more preferential development of the present invention. The angle ε has a value of 90 ° and the angle θ is chosen to be equal to 0 °. The other angles ε and the angle ε generated by them will end up in an elliptical shape on the side of the beam on the mirror surface of the mirror that deflects horizontally. Thus, increased accuracy with respect to the mirror surface of the horizontally refracting mirror will require an angle greater than 45 °, among other things. Because the optimal imaging characteristics will be worse. This will increase the manufacturing cost of mirrors that are deflected horizontally. Especially if precision manufactured, it is less than 2 °.

In a further better development of the invention, however, the part of the appliance is provided by a floor plane by this part, on which the appliance itself can be placed on the floor or ceiling. And the axis of rotation of the horizontally refracting mirror with respect to the inclined projection is arranged at an angle to this floor plane. In addition, a device was provided for changing the contrast and color of each described image point. Also, the apparatus referred to there corrects trapezoidal distortion for a given projection angle for tilted projection.

The instrument is user friendly, especially by simply hanging it by the ceiling or floor plane. Because the projection, the projection head or the instrument itself is not located in the viewer's visible passage at the typical ceiling height despite the viewer's position. Each position for the inclined projection is provided for this purpose and the possibility of correcting the crushed trapezoid requires little cost. The distortion that occurs at a given projection angle is a known fact and the information about the series of lines about the distortion can be interpreted more quickly as an image stored and each scanned line can be written within a narrow area.

Even more economical design solutions can be found for the projection head, especially for hanging on the floor or ceiling by the floor plane itself. For this purpose it is provided by a better development of the invention that the angle of the axis of rotation in the bottom plane, such as the angle of inclination projection between the principle projection direction and the normal projection surface, is ± 10 °.

In this aspect, a further advantageous development of the present invention provides a device for the spatial and color adjustments to be spatially separated from at least one part of the instrument. And a beam-guided fiber was provided between the device and the instrument that connected to move the bundle of rays to be continuously refracted by the horizontally refracting mirror.

In this connection the projection head, i.e. the projection part mentioned above, only needs a mirror that bends vertically and a mirror that bends horizontally. And, if necessary, the magnifying lens is spatially separated from the heavier component, for example a laser. Therefore, it is only necessary to arrange them on the ceiling or floor where applicable without problems. On the other hand, this type of support with heavy components, above all lasers and transducers, will result in more complexity if the whole appliance is suspended from the ceiling or floor.

Joining with light-guided fibers is likewise possible in a simple way. It can also be installed in a simple way with an adjustable plug-in connection at the rest of the instrument for connection with the projection head and the light-guided fiber. However, for example, a mirror device has been provided for transmitting light rays from the projection head to the rest of the instrument. The combination will eventually become more complex. First of all, because the adjustment of the mirror can no longer be carried out by a person without expertise.

As already mentioned above in connection with the prior art, there are several possibilities for the arrangement of mirrors that refract horizontally and mirrors that refract vertically. In this connection, a better development has been provided that the horizontally refracting mirror comes in less than 4 cm in the direction of propagation of the bundle of rays by the vertically refracting mirror followed by the magnifying lens. In this connection, it is particularly advantageous that the mirrors refracting vertically are arranged after the mirrors refracting horizontally. In the opposite arrangement, the spacing in the horizontally refracting mirror and in the projection head mentioned by way of example will result in greater size. The same method is realized when an additional optimal system has been used for optimal magnification of the mirror surface of the mirror which deflects horizontally in accordance with JP 61-90122.

In addition, the relay lens at the point of impact of the bundle of beams on the horizontal refraction mirror is successively inclined with a tilting mirror which must normally be provided in the extension optics in order to ensure that the tilt angle is projected in two dimensions, which actually proceeds from the same point for successive extension optics. Is moved. Image errors due to different extensions are reduced in a completely different way. This approach greatly reduces the cost of the optical element for the expansion optics and keeps the distance between the horizontal and vertical mirrors very short. From this point of view, it is especially advantageous when the distance between the two mirrors is less than 4 cm, since the expansion optics can be economically devised and corrected for the difference of the reflection points at the vertical and horizontal refractions at the expanding pupil inlet. This proved to be.

The indicated distance up to 4 cm also leaves enough space for the movement of the mirror, which is refracted vertically. Due to the elimination of the relay lens system made by this better development, light loss and imaging errors, in particular due to lens dust or heterogeneity of the lens material, have been reduced as a result. Therefore, in accordance with better development, the beam characteristics of the beam bundle have resulted in an improvement over other well known projection systems.

Magnification optics are well known, for example, from DE 43 24 849 C2. In particular, the lens system to be calibrated according to the state of the tangential is indicated in this reference. However, it can also be obtained from this reference that this kind of lens can be realized with two or more steps.

For the purposes of optimization, it has been provided by the better development of the present invention that the magnification optics constitute a lens system with exactly two steps. And corrected according to the tangential state. As a result, the two-stage system provides a benefit to another solution that the cost can be kept small because fewer lenses are selected from a range of technical possibilities. Furthermore, the light loss due to dispersion and reflection has also been conveniently reduced in a manner similar to that already described more fully above in connection with relay systems.

According to a better development of the invention, it has been demonstrated with respect to the arrangement of magnification optics which is advantageous when the first lens of the magnification optics is at a distance of 10 mm to 100 mm from the vertical refraction mirror. By this range of distances, the selection and position of the input pupil, the size of the projection head and the choice of other refraction points between the vertical and horizontal refraction mirrors can be optimized without costly. First of all, the relay system mentioned above can be made unnecessary.

The same purposed gain is also brought about by the better development of the present invention in which the input pupil of the magnification optics is located at a distance of less than 80 mm. Especially less than 30mm from the front of the vertex of the first lens.

The biggest problem in imaging parallel refracting mirrors and vertical refraction mirrors that can only be solved by high spending is the generation of ghost images. For example, polygon mirrors are usually installed in a case with a light entry hole and an exit hole. This hole is closed and hidden by a plane-parallel transparent parallel to the horizon. The bundle of rays reflected by the ray-plane parallel to the horizon-parallel plate strikes the polygon mirror surface again, resulting in the desired derivative of the image when the image is complete. Such ghost images can be reduced by anti-reflection coatings. In other words, it creates an appropriate layer of nonconductivity for these windows.

In practice, this can represent something we haven't expected, which can be an entirely different approach that is generally more profitable. A better development in this problem is characterized by the fact that the body, which is partially transparent to the light beam, is provided in the path of the light beam passed by the light beam bundle after it is reflected by the horizontal refraction mirror. The angle of rotation of the horizontal refraction mirror is greater than 1 ° and is usually between 2 ° and 10 °.

Unexpectedly, experiments have been able to achieve the lens as shown by the effect of the window. For example, the first lens that can be swapped between horizontal and vertical mirrors or extended optics decoded with DE 43 24 849 C2 is suitable to prevent such ghost imaging when the lens angle is properly selected. However, this simple problem was not recognized before.

Polygonal mirrors are usually used in case covers under vacuum conditions or filled with special gases such as helium because of their high speed. Thus, the window must be provided with an entrance or exit to the beam. Ghost imaging of these parallel planes used in this window is almost always a headache. In this problem a better invention must be provided. In other words, a window that is partially transparent to light rays is a plate parallel to the horizontal plane, which is parallel to the horizontal plane provided by covering the case in relation to the atmosphere around the polygon mirror. However, a simple structure of a device such as a projection head that can be obtained for further development in the invention of a device such as a horizontal refractive mirror and a vertical refractive mirror such as a refraction device for beam bundles is a combination of a polygonal mirror or an inclined mirror.

The present invention has been described in more detail by specific experiments.

1 shows a schematic view of a projection system with a tilted projection system.

2 shows a schematic view of a projection head illustrating the principles used by the more advanced invention.

3 shows two illustrations of stacked polygon mirrors in a case illustrating generating and suppressing ghost images.

4 shows two schematic diagrams of a polygonal mirror illustrating different angles and angle relations.

FIG. 5 is a graph showing the dependence of the particularly advantageously selected light beam bundle angle θ on the surface of the polygonal mirror in dependence on the slope of the mirror surface ε in relation to the schematic representation described at the angle shown.

A bundle of rays, in particular a video image by a laser beam, is particularly advantageous in separating the adjusting device and the refraction device for the bundle of rays from the laser in the projection. This allows for a light projection head that is simple to install, regardless of heavy parts such as transformers or laser radiation sources. In particular, the projection head can be fixed to the ceiling of the room so that the projection of the laser image is not severely disturbed by the audience moving around the room. It also increases laser safety because it reduces the likelihood that the viewer can enter the laser deflection zone. This can be dangerous.

For example, if one of the refracting devices fails, all the output from the laser can damage the cornea of the observer's eye.

For the purpose of fixation, for example, there is a tendency for laser projection of video images to the ceiling or to the floor of a room. The projection head is attached to the base with all the components facing in a constant direction. Thus, ideal angular states are always possible despite device position and projection state. Although the present invention has described here an embodiment with particularly best placement of the projection head, the projection head is by no means limited. The insight obtained here can also be translated into a device for laser projection that the projection head is not mechanically or optimally separated from the laser.

The configuration of a projection device 50 of the above-mentioned type is shown briefly in FIG. 1. Three bundles of rays of red, green and blue are produced by the laser 34 and are continuously controlled in terms of the light intensity by the regulator 35. Thereafter, the three laser bundles were integrated into each parallel beam by the device 36 and connected to a fiber conducting light beam that transmits the light bundle to the projection head 60. As a result it was connected behind. The combined bundle of rays 5 was scanned in two orthogonal directions at the projection head 60. Thus, the image is formed of a screen 71 similar to the well known projection method with an electron beam on the screen of a television CRT.

In accordance with the example of FIG. 1, tilted projection was used. That is, when the light beam bundle 5 is located at the center of the scanned image in the main projection direction 28, it hits the screen 71. It looks like Φ, Χ with a 90 ° angle. The image was distorted by the raster projection surface 70 in most general cases, as shown in FIG. The scan lines clearly seen in this raster projection surface 70 can then be bent as discussed long.

The distorted image generated in this way can be generally corrected by the electronic device 33 which ensures that the laser beam 5 is adjusted by means of adjusting each projected projection point on the rectangular screen. The laser beam 5 is whitened out of the image area given by the screen 71.

To illustrate the schematic, the projection head 60 is composed of a polygon mirror 12, an inclined mirror 16 and a magnification optics 37. The polygon mirror 12 is used to project in the horizontal dimension, and the inclined mirror 16 is used to project in the vertical vertical projection direction from the horizontal projected direction.

This polygon mirror 12 has a plurality of mirror surfaces 14. When the polygon mirror is rapidly rotated about the axis of rotation 24, the rays collide with other angles in the time dependent means passing through all the mirror surfaces 14 and are scanned in this way. Such refraction can be done very quickly, where the lines of the video image can be imaged according to known video criteria.

Polygon mirror 12 is usually used to project in the horizontal dimension to obtain a large image point density, and high speed is necessary for this purpose. However, if there is a lack of upright conditions for this mirror, it can also use an inclined mirror. For example, when the inertia decreases, by decreasing the size of this inclined mirror, the increased speed is as expected, basically a polygonal mirror, as shown in the example in the future, but the horizontal deflection of rotation about the axis of rotation. It is intended as a horizontal refraction mirror to allow scanning at.

Magnification optics require an afocal lens system that is adapted to the tangential state. Such a lens system is particularly suitable for the expansion of each area projected by the polygon mirror 12 and the inclined mirror 16. Because they allow the expansion of each area without inclination and independence from the collar. The ratio between the tangent of the output angle and the tangent of the projection angle is constant.

2 known in the example shows the projection head in which the entire refracting device is located on the lid 2. In this case, the intensity adjusted light beams were connected via the light guide 4 according to the video information. As depicted, it is paralleled by lens 6 and directed to polygonal mirror 12 via two mirrors 8 and 10 for refraction in a horizontal dimension.

The inclined mirror 16 provides a vertical axis of rotation at the axis of rotation 240 of the polygonal mirror 12 to refract the video image in a vertical dimension. However, in this embodiment, each position of the inclined mirror 16 and the polygon mirror 12 is directed in such a way that the video image is projected vertically in the plane of FIG. 2. Magnification optics 37 for further enlarging the video image that can be obtained by mirrors 12 and 16 were positioned in this direction.

According to FIG. 2 the projection head has another feature in that it is arranged to be able to rotate about the axis 18 by means of a bearing 21. An unshown motor was provided for adjustment. Rotation opens up entirely new possibilities for entertainment and advertising applications where video images are projected in different directions at different times.

In order to enable this rotation, the light bundles are connected on the shaft 18 and in the same direction as the latter part. However, the refraction of the bundle of rays has been provided by the mirrors 8 and 10 in order to obtain a tilted projection onto the polygon mirror which has been proved particularly advantageous as already mentioned above. These mirrors It is ascertained that in Fig. 2 it can collide on the mirror surface 14 of the polygon mirror. This angle in other angles Will be discussed in more detail according to the reference of FIG. Reference for elucidating the practical realization of the optimal arrangement for rotation has been explicitly made in FIG. 2.

However, a better feature has been made particularly clearly from Figure 3 which shows the two views of the polygon mirror discussed earlier. The polygon mirror 12 is usually enclosed in a cover 13 which allows it to operate in vacuum or helium to require a rotational speed in the initial space. For this reason the glass body 20 provides a cover 13 which is normally closed.

On the other hand, the phenomenon described next and its remedies have been discussed in detail with reference to this glass body 20. This also applies to all other glass bodies 20 'in the ray path, which descriptions relating to the glass body 20 will only be understood by the examples given.

For example, the lens of the rear magnifying prism can also produce the same effect. In detail, for example, the polygon mirror 12 can act in a normal cover in a vacuum in which the window case together with the inclined mirror 15 can be arranged below the inclined mirror 16.

All objects made of transparent objects are 100% conductive. This means that one part of the ray is always reflected back. The position of the mirror 14 or 16 allows this partial ray to be reflected back by the mirror again and produce ghost imaging shifted within the imaging area of the generated video image. This problem can be reduced to the glass body 20 in the ray path with antireflective coating used for the purpose of reducing back deflection. However, in the projection head in Fig. 2, another method is selected. As can be seen at the bottom of FIG. 3, the glass body 20 was arranged at an angle ε for the incidental light bundle. This selected angle [epsilon] is very large and the light rays that can be reflected by the glass body can be reflected in areas not included in the refraction in the mirrors 14 and 16.

Furthermore, the curvature of the first lens of the expanding optics was chosen by the law that the reflected light beam does not hit the mirrors 14 and 16 again. The selected angle is very large and the light rays repeatedly reflected by the polygon mirror are not obtained in the vertical refraction mirror 16. The bent or inclined position does not need to be particularly large. Because the knowledge already presented in the introduction of the 1 ° angle ξ is sufficient for the proper design of polygon mirrors. The same effect can be obtained at the inclined position at each Ψ.

Due to the lenses in the expansion optics, only two steps of apocalyptic systems were provided to assure the smallest possible light loss or to increase the compression of the projection head by FIG. 2. Unexpectedly, the proper angle for maximum utilization can always be obtained for the first lens on which it is based on flexion. Angular rays reflected back from the first lens are reflected in the spatial zone. It can no longer be obtained by the refraction mirrors 12 and 16.

Additional angles are shown in FIG. 3. The angle β shown is the maximum equilibrium bending angle of the bundle of rays produced by each dynamic mirror surface 14. The maximum bending angle Y is given vertically. Flexure in the vertical range is shown in FIG. 3. In addition, the offset V is shown in FIG. 3. This offset V is characterized by the distance of the axis of rotation relative to the projection direction of the polygon mirror 12 and r * sin ( The radius r of the polygon mirror, The reason for applying the offset V is not clear. However, it is advantageous in terms of optimal raster geometry and angle selection. In other words, the projection head has a mirror 16 which is bent perpendicularly to the horizontal refraction mirror 12. The projection refraction of the light beam bundle 5 having a right angle of rotation and a diameter p is made in the direction projected vertically in the direction Y projected horizontally at the angle β. The principle projection axis 28 mentioned above is determined by the angles β / 2 and Y / 2 as for the angles described in more detail in the future, in particular the bundle of rays 5 being a standard surface mirror of the mirror surface 14. With respect to (23) When you wake up in a good scanning state. In that regard, a straight line perpendicular to the standard surface named from the center of the mirror surface 14 intersects the straight line passing through the axis of rotation 24.

As we know from the mathematically well-known concept of oblique lines, straight lines do not have intersections in space. In order to achieve the desired intersection, the above-mentioned offset V must be provided and can be determined under certain assumptions for a wide variety of geometrical states, usually by vector computation. 2 and 3 also help to understand the geometric relationship.

Other angles and quantities are presented in FIG. 3 and refer to the projection head design that describes various suitable states. The glass body is also shown, in particular located between the polygon mirror 12 and the inclined mirror 16. As already presented above, this type of glass body 20 may also be provided between the inclined mirror 16 and the screen 22 as described in the glass body 20 '. However, it is also valid in this case. Incline ξ 'should be chosen in such a way that the reflected beam does not fall back on the inclined mirror 16 and the polygon mirror 12.

However, it has been found to be particularly good when the body 20 or 20 'is inclined perpendicularly to the refractive direction of the polygon mirror. Because empirically smaller slopes are needed in this direction to interfere with ghost imaging. It can also be observed that angles smaller than 10 ° are perfectly suitable. In particular, the surface inclination angle of the body 20 or 20 'with respect to the projection direction should be greater than 1 ° and should be between 2 ° and 10 ° yarns.

The ghost image mentioned above can be effectively suppressed and extinguished at this small angle. However, the angle must be small enough. Other refractions in the glass body 20 or 20 'cannot produce any unwanted color separation due to the dispersion of conventional materials.

This opinion is suitable for the maximum utilization of projection heads in beam bundles with diameter d for sizes from 1 to 10 mm with screens larger than 1 m in HDTV or PAL. Thus, all optical components have a necessary space in which they are not optically active. For example, there are fibers, mounts, housings, measuring devices, controls, drives and the like. The diameter d of the bundle of rays is set by the distance between the geometric solution and the projection surface of the projector. In particular, it was used for reference video. This is also the result of the minimum horizontal refraction angle β and the vertical refraction angle Y maintained. In this respect, it has proved to be suitable as a reference point in FIG. 2 based on practical considerations of quantity.

The radius r of the polygon mirror must be 20 mm and the distance d from the axis of rotation 24 of the polygon mirror must be 40 mm. The offset V mentioned here must be in the range of 0 to 10 mm. In particular, an offset V of 5 mm is used in the specific example.

bracket Must be at the size of β to enable the maximum possible compression. Additionally required Must be greater than β / 2 and the optimal value is Obtained in the polygon mirror 12 showing in the same manner as the specific example for = 30 ° and β = 26 °. Specifically, for a vertical refraction angle based on a standard television given at a ratio of 3: 4, an angle Y of 20 ° is given. However, as shown in FIG. 4, the angle δ missed at right angles was found to be advantageous. 4 also shows a point 26 indicating the axis of rotation of the vertical refractive mirror 10.

The s, t and w amounts shown in FIG. 4 represent the distance of the axis of rotation of the vertical refractive mirror 16 from its refracting surface in the direction shown.

In order to design the projection head in the manner shown by the example of FIG. 2, the following relationship must be taken into account and the following features are provided in terms of reference to dimensions.

1. The axis of rotation of the polygon mirror 12 is offset V = r * sin ( 2) and impinge on the distance d> r, which relates to the intersection of the principle reflection axes in the plane of the light beam, and exit from the vertical refraction mirror.

2. When the plane of the light beam is created on the vertical refraction mirror, it is at an angle δ as the principle projection axis, and the outgoing light beam is a mirror which is perpendicularly refracted by the symmetry of the vertical refraction angle Y and the horizontal refraction angle β on the principle projection axis. Leaves a trail on The axis of rotation of the vertical refraction mirror is in principle w = s * sin (δ / 2) distance from the projection axis and moved equilibrium by the distance t = s * sin (δ / 2) from the plane of the light beam exiting the horizontal refraction mirror. It was done.

Optically, the angle δ should be made 90 °. In this regard, 90 ° +/− 10 ° in detail is particularly advantageous for minimizing the projection head. This applies in particular to an arrangement of devices which are refracted by a combination of polygonal mirrors and inclined mirrors. In all cases, the angle δ should be greater than 90 ° -y / 2 to prevent blurring of the ceramic or image. It should also not be greater than 120 °. Because the reflection ratio for the bundle of rays will be less good in such cases.

Moreover, the distance d between the horizontal refraction mirror and the projection axis should satisfy the condition d-r <4 cm. At such a distance, it is possible without the relay optics made for the inflection point of the polygon mirror 12 to coincide with the image refraction point of the mirror 16.

The different inflection points of the two mirrors do not design the same magnification optics. Therefore, since a small distance is provided, it is possible to save additional optical components such as the relay optics mentioned above. Thus, unnecessary light loss can be prevented. Regarding the design, the first lens of the magnification optics should also have an area of 10mm to 100mm behind the vertical refraction mirror. The refracting surfaces of the polygon mirror 12 and the vertical refraction mirror 16 are located at the entrance pupil of the magnification optics and the optical axis of the magnification optics is in principle identical to the projection axis.

In this regard, it has proved to be particularly advantageous for minimization as well as for optical imaging capability when the entrance pupil of the magnification optics lies at a distance less than 80 mm. And, in detail, less than 30mm before the first lens vertex.

4 shows another angle ε related to the other mirror surface slope of the mirror surface 14 'indicated by the broken line. In the embodiment shown in FIG. 2 an angle ε of 90 ° was used. Because it has been observed that at different angles the lines can only be represented in a curved way.

However, it was shown that an unexpectedly different angle ε is also possible when it is considered that line flexion in the order of magnitude of 3% is hardly recognizable by the human eye. It is sufficient for the display of the video picture as a whole. Although often it is not required for accuracy for CAD applications, if the image was not distorted before screening, it was recalibrated by the mirror surface angle ε deviating from 90 °.

However, control over the necessary rules and costs for this purpose was realized when properly selected as the inclination angle θ of the light beam bundle on the mirror surface.

This has been explained in particular in Fig. 5, and two are shown on the right side to account for a clearer angle θ. As shown in FIG. 4, the same angle ε is used as the angle between the axis of rotation and the standard mirror surface 23. The top part shows the dependence of the angle ε on the θ tilted angle as appropriately selected as the bend 32. Point 30 is determined from the above mentioned assumption of the allowable bend of the bend 32 of 3%. Tolerance ranges appeared roughly similar to point thickness.

The bend 32 is obtained by a bend matching method. Flexure is described by the following disclosure. here, to be.

When used for this problem, as shown in Fig. 5, the angle of the inclination angle θ ranges for all ε in such a way that the expenditure on the rectifier of the image shown by the storage and calculation units is reduced as shown in Fig. 1 by reference 33. It is too expensive to modify various megahertz video frequencies. So, at other angles, we used a complex system for accurate image representation without making the most of that.

Of course, the above-mentioned maximum utilization for the video projection head has also changed under different conditions. For example, an inclined mirror is used instead of what the polygon mirror 12 represents. In addition, an acousto-optic modulator is also used as one of two refractors, namely a vertical refraction mirror and a horizontal refraction mirror. By reference, the refractive angles Y and β are usually smaller. However, this is corrected for proper extension optics.

However, the dimensions shown are essentially independent of the change, and when each component is rearranged in the form of a different bend, adjusting the values in the same way will be easily adjusted by those skilled in the art.

Claims (13)

In the apparatus for projecting a video image, Projection head 60 includes a horizontal refraction mirror 12 having at least one mirror surface 14 for refraction of a bundle of rays in the horizontal direction of the video image, and a vertical refraction mirror 16 for refraction in the vertical direction. Wherein the surface reference line 23 of the at least one mirror surface 14 is inclined at an angle with respect to ε at the rotation axis 33 of the horizontal refraction mirror 12, At the position of the horizontal refraction mirror 12 the beam bundle is directed towards the center of the video image in the main projection direction 28, Projected to the mirror surface 14 at an angle, From here Is directed to a surface reference line (23). An apparatus according to claim 1, wherein each ε has a value of 90 ° and θ = 0 °. The method according to claim 1 or 2, At least one part of the device is constituted by the floor plane, Can be fixed to the floor or ceiling on this part or the device itself, The axis of rotation 24 of the horizontal refraction mirror 12 for tilted projection is arranged inclined in this bottom plane, The instrument 33 is provided for contrast and color adjustment of each colored image point, Wherein the trapezoidal distortion due to the projection angle due to the oblique projection is calculated and adjusted in the modulation. The method of claim 1, wherein And the angle of the axis of rotation (24) in the base plate equal to the angle of inclined projection between the principle projection direction (28) and the normal projection surface. The method according to claim 3 or 4, Between the device and the device there is a device for contrast and color control spatially separated from at least one part of the device and a light guide fiber which connects to move the light bundle to be continuously refracted by the horizontal refraction mirror 12. Apparatus characterized in that the. The method according to any one of claims 1 to 5, The horizontal refraction mirror (12) is characterized in that it is located at a distance of less than 4 cm in the direction of propagation of the bundle of rays by a vertically refracting mirror (16) followed by a magnification optics (37). 7. Device according to claim 6, characterized in that the expansion optics (37) are configured in the lens system with precise two steps which are modified according to the conditions of the tangent. 8. Device according to claim 6 or 7, characterized in that the distance of 10 mm to 100 mm in the vertical refraction mirror (16) is the first lens of the expansion optics (37). Device according to one of the claims 6 to 8, characterized in that the entrance pupil of the augmentation optics (37) is located at a distance closer than 80 mm, in particular closer than 30 mm from the front of the vertex of the first lens. 11. The body (20), (20 ') according to any of the preceding claims, wherein the bodies (20, 20') are partially transparent to the rays in the beam path passed by the bundle of rays after being refracted by the horizontal refraction mirror (12). The body 20, 20 ′ is in contact with the axis of rotation 24 of the horizontal refraction mirror 12 and / or with the axis of rotation of the vertical refraction mirror 16 which is greater than 1 ° at all points generated by the scanning. Device having a gradient for ξ, ξ ', Ψ, Ψ'. 11. The device of claim 10, wherein the slopes (ξ, Ψ) are between 2 ° and 10 °. 12. The body (20, 20 ') according to claim 10 or 11, wherein the body (20, 20') is a transparent housing (13) for a polygonal mirror that is partially transparent to the light beam, is a plate parallel to the horizontal plane, and is a horizontal refracting mirror (12). A device characterized in that it is made. 13. Apparatus according to any one of the preceding claims, characterized in that the horizontal refraction mirror (12) and the vertical refraction mirror (16) are a combination of a polygon mirror and an inclined mirror.