DE19753040C2 - Arrangement for creating an impression of 3D images for visual perception - Google Patents

Abstract

The invention relates to an arrangement for generating an impression of 3-D images for visual perception on the basis of virtual or real images for 3-D vision in the 3-D video or 3-D television area or for 3-D multimedia applications, using a screened, computer-controlled and thus addressable, light-emitting structure, which can be of a voluminous or flat nature, for example an array with fiber-coupled, computer-controlled light sources of different wavelengths or spectral distribution, preferably a planar, self-illuminating partial image, in the sense of, for example, a section perpendicular to the axis through a real or calculated 3-D object, and the information about the 3-D image to be displayed is available in the form of a digital data record as a 3-D point cloud and a first objective with a telecentric output is assigned to the light-emitting structure and a second micro-optical to the first objective assigned to the array, which is connected to a computer-controlled linear scanner, which in turn is followed by a second imaging lens for generating virtual or real images.

Description

1. Technical field of application

The technical field of application is to create the impression of 3D images for visual 3D perception based on virtual or real ones Images for 3D playback. It is clear that the 3D effect is only through the extremely complex interaction of technical components and the visual Sense of the contemplating subject arises. In extreme cases, this does not have to be human but it can also be an animal.

This is generally about the 3D vision in 3D video or 3D TV area, or around 3D multimedia applications of the well-known Usage. For example, 3D films can be played back.

Also the rendering of calculated 3D computer graphics based on the It is possible to display virtual or real 3D images. The image data lie preferably in the form of digitally stored data, for example in the form a point cloud. The 3D impression can be colored, and so can moving objects and scenes are displayed.

2. State of the art

The generation of virtual or real 3D images (in the conventional Use of language) for visual perception for 3D rendering is based on State of the art in the generation of two differentially different images for the left and right eye. For this type of consideration is in many cases two-eyed goggles are required, which are either two different Color filter for the two eyes or two different polarizers having.

There are also shutter glasses that alternate images for the right and left eyes release. There are also glasses in which there is a separate image in each eye canal is produced. Although the quality of this 3D image reproduction can be very good However, this technique was rejected for often very subjective reasons and is experienced even in So far, domestic use has not been very popular. The exception is medical surgical technique. Here, for example, the surgeon wears a Special glasses, called cyber glasses, see VDI News from November 14, 1997, No. 46, P. 3.

Another option is to determine the position of the eye axes human viewer using electronic camera technology (Headfinder, Trucking System) and so from a common screen interface a different image for the left and right eye using a special image To generate technology. However, this is only possible for one observer  and is certainly a good technical possibility, but closes that, for example 3D family television with multiple viewers.

Ultimately, based on the technique proposed by Nipkow, there is one Display of 3D images using a shutter. This is done in real time Perspective center of an image is constantly changing and at the same time only one Gap of the image released for viewing. The shutter can be mechanical or be built optoelectronic. In any case, it is only split by column Approval of the picture the picture is quite faint, since only a very small part of the Light energy reaches the observer.

A 3D imaging method is known from GB 23 07 373 A, in which a sharp image is imaged directly on a moving optical element. there become planar to generate a 3D impression using computer-controlled means Self-illuminating drawing files are shown that show sections of the 3D object. The Mapping then takes place via a focusing screen with imaging systems such as Concave mirror or lens, on the element moving in the direction of image formation. Arrangements with focusing screens, however, have poor light efficiency.

The object of the invention is to provide a device and a method that do not Laser radiation and / or special glasses are required and the depth of field and Improve resolution.

According to the invention this is achieved by the arrangement according to claim 1 and that The method of claim 5. Advantageous embodiments are in the Subclaims specified.

3. Problem solved with the invention

The invention solves the task of generating the impression of virtual and real 3D images for the visual perception of the 3D shape more technical and natural Bodies in space as well as complete scenes also on film or theater stages.

In addition, the rendering of calculated 3D computer graphics on the Based on the representation of virtual or real 3D images, the in Form of a 3D point cloud.

Moving and colored 3D scenes can with a very high depth impression and with high lateral resolution in the form of virtual or real 3D images for visual Perception can be represented as 3D objects. The application area is in Home area for television, video film playback, but also for Computer applications, generally seen in the multimedia field.

Also in professional areas such as medicine, u. a. the surgical Surgical technology, aerospace, simulation technology in general, the computer-aided design (CAD) as well as other C-techniques is the Task of 3D representation of data solved. In the scientific Research can use real data or models, such as molecular representations be presented spatially. The same applies to DNA sequences in molecular biology and the modeling of genes in genetic engineering.  

The possibility of spatial representation of mathematical functions in Education and research should also be mentioned, but also general School education. Not to forget the presentation of art objects and Fashion items. The possibilities to support the Orientation of people and computer-controlled objects in the room.

The 3D images can be viewed as virtual images, for example by using the The viewer sits as if in front of an umbrella and looks into an apparatus.

But also the generation of real images for 3D large-format reproduction for a larger audience is feasible. This is comparable to a 3D laser show.

4. Improvements and advantages achieved compared to the prior art

The application of the invention increases the depth display area or Depth impression and the image quality, including the brilliance and the point density, at Playback of 3D images.

The energy used for image generation is also optimally used. It arises a bright picture. The observation of the 3D image is basically by more than one Possible person. It is not necessary to wear special glasses.

On the use of directional laser radiation, as with laser projectors necessary, can be dispensed with.

5. Principles of the solution

The main features of the method and the arrangement for generating virtual and real 3D images together for visual perception described.

The process of creating virtual and real 3D images for the visual Perception is that by means of a grid, computer-controlled and thus addressable, light-giving structure that is basically voluminous or can be flat in nature, for example an array of micro-optical components like a microlaser array or a microfiber array with fiber-coupled, computer-controlled light sources of different wavelengths, or Spectral distribution a preferably planar self-illuminating partial image, in the sense of a for example, a perpendicular cut through a real or calculated one 3D object, i.e. as a boundary curve. However, it is also possible a separate light source with a computer-controlled micro-mirror array (Direct Mirror Device = DMD) to couple. The information about what is to be displayed 3D image is in the form of a digital data set, for example in the form of a Point cloud in front.

This preferably planar and self-illuminating partial image on the array micro-optical components, which is also referred to as the first array, is through a first lens with a telecentric output, i.e. telecentric on the side facing away from the first array, preferably as a real image  pictured. There is a depth range for the sharpness, which is less Aperture of the lens on the telecentric side enlarged, but the Luminous intensity of the lens and thus the brightness also decreases. This Depth range is based on the approval of an acceptable Circle of confusion diameter for the pixels to be observed, the ultimately from the overall optical structure and the visual resolution the viewer. Basically, this first array can also are moved linearly, only this is not considered to be technically so advantageous.

There is another one in the depth range of the focus of the telecentric lens Array with micro-optical components, which continues as a second array is referred to with micro-optical and focusing, preferably passive Components. The real image of the planar and self-illuminating image on the first array.

Furthermore, the second array with a preferably linear, computer-controlled precision scanner with a direction of movement in the direction of Axis of the telecentric lens connected.

The scanner has a precise linear guide system, preferably a Parallel spring system for the precise linear movement of the second array with one Stroke in the order of a few millimeters to a few centimeters, however in Depth range of sharpness in the telecentric beam path.

The parallel springs of the parallel spring system can advantageously be made of consist of highly elastic, single-crystalline silicon.

The scanner is located with the second array, preferably in a vacuum, and is with a high-performance linear motor with a computer-coupled Precision encoder coupled. This ensures that a precise linear pre Backward movement with, for example, 25 Hz stroke frequency corresponding to one predetermined target function can be achieved without an unwanted Damping in the sense of braking by the air can occur.

Cross movements of the array to the optical axis can be computer controlled be useful if, for example, the second array consists of several sub-arays exists, each with its own linear motor and so the mechanical Fractures should be made practically invisible. So one can be special large array area, for example for large-screen projection. The Transverse motion occurs during the pixel addressing on the first array is taken into account, is therefore included.

Depending on the current, computer-controlled position of the second Arrays on the first array each become a sectional image of the 3D structure to be imaged shown as luminous. For example, up to 1000 are self-illuminating and, if necessary, colored sectional images per second are generated on the first array. Depending on the technical possibilities and targets, a higher or lower slice frequency can be realized.  

The array preferably consists of convex microlenses, i.e. with focusing ones Effect. The size of the microlenses is chosen so that each microlens for example corresponds to a pixel. By the computer-controlled Precision movement of the second array at approximately 25 Hz and within the The focus range of the telecentric lens is created for the human Observer the impression of a 3D image in space. By arranging focusing microlenses with a relatively large numerical aperture, For example, 0.3 or more of each luminous pixel becomes a light beam in radiated a relatively large solid angle range.

This resulting picture already has a 3D character for the observer, however, has a relatively shallow depth and is relatively small. Therefore a second imaging lens with the aim of enlarging the image and the depth downstream. The image on the second lens array, which can be seen as an intermediate picture, in the sense of technical optics done virtually or real through the second lens.

It is essential that the virtual image with both eyes at the same time is looked through the second lens. The second array points in relation to the second lens an intrafocal position with the limit case of the focal position. In The focal position of the second array is behind the second by one viewer Objectively seen an image in infinity. With the linear movement of the array in In the direction of the second lens, the image is created as a virtual image, but with the eye can be viewed like a magnifying glass without a screen.

A real image is generated for the large image projection. Here is the second Array each in the extrafocal projection of the second imaging lens, which then represents a specially adapted projection lens. The real pictures arise in the direction of light behind this lens, for example in a fog wall or a cloud chamber. A computer-controlled three-dimensional matrix is also included computer-controlled microreflectors conceivable in different 25 Hz cycles Depths, i.e. in the room, can be switched, for example so that the beam strikes them or can happen. This also creates a 3D impression for the observer. Also Veil walls can be used for more artistic projects.

In the virtual representation of the images, a monolithic lens can be used as the second lens Lenses with a diameter well above the eye relief can be used. It’s better to have a large Fresnel lens like this, also to design micro parts, which with regard to all imaging errors, including the color errors should be corrected. This large lens has exactly one optical axis. Microlenses can also be used here.

For example, several microlenses can even be arranged one behind the other in the light direction be arranged to correct the aberrations, or an optimization of the Achieve Figure.

When designing the large lens, all possibilities of optical know-how can how's the image correction, including microstructuring for the Design of the lens can be used. Even the most modern micro Antireflection techniques can be used for the surface design of the lens  become. Instead of such a high-tech lens can also be used for the second lens a multi-lens lens can also be used.

The second lens can be coupled with an airtight recipient that the second array, the scanner, the inside of the second lens and the recipient walls enclose a vacuum already mentioned. Thereby owns the recipient has a transparent entrance window through which the light from the telecentric lens falls on the second array.

It is also conceivable that only the second array and the scanner are in a vacuum are located. However, this may result in the crooked rays that arise due to the large aperture of the microlenses result in an imaging problem Connection with the exit window then necessary. It can Astigmatism may occur.

When designing the second array, knowledge of the dynamics can be more dynamic elastic body can be applied. The due to the no small Acceleration forces in the second array thanks to the high-performance linear motor occurring dynamic deformations of the second array, soft plastic can exist, can be included in the creation of the images for the 3D effect become. Finally, the surface shape of the second array is basically free selectable. The shape of the array at a given time only needs to be fairly accurate be known. A curved shape is also conceivable, for example in the sense mass and deformation minimization. This is possible because all the points for the Creation of the individual images are addressable in time and place.

The second lens can also be a concave mirror, preferably in an off-axis Arrangement, be. The second array is in an on-axis position. The combination of concave mirrors can also be used to correct aberrations and one or more lenses can be selected. This approach can also be used micro-optical components can be designed as Fresnel mirrors. Is essential only here that this mirror has a single optical axis.

It is completely clear that 3D visualization involves data streams in gigabyte Range can go per second. Data reduction techniques can also be used be used.

The image pickup of the real 3D objects and scenes can with the same by the applicant with a priority of 5.11.1997 filed patent application entitled Method and apparatus for generating a 3D point cloud for the topometry (3 D-Videometrie) or the 3D Vision for multimedia applications, (DE 197 49 974.0-31) can be realized.

6. Embodiments

In FIG. 1, the apparatus for generating 3D images for visual 3D perception on the basis of virtual or real images is represented in the essential components. The computer-controlled photo series, which is created on an addressable light-emitting structure in the form of a laser diode matrix, is imaged by a first lens with a telecentric output.

The current image comes through a window onto a microlens array focusing microlenses. Each microlens represents a pixel, of which a wide open bundle due to the relatively large numerical aperture of the Microlenses, for example starting from 0.3. The microlens array is with one computer-controlled high-precision linear scanner connected. In the Laser diode matrix, the images are generated so that a real or virtual 3D Object is broken down into vertical sections and each on the surface of the 3D object lying object points are represented as image points on the laser diode matrix. The 3D object is available as a 3D point cloud. Taking into account the Image relationships through the 1st lens, the linear scanner with the Microlens array so that the real or virtual 3D object whose 3D Data set as a point cloud and thus as a template for the control of the laser diode matrix served, is built in a geometry-like sense.

There is a linear scanner for unimpeded movement of the microlens array in a vacuum. This hinders the highly dynamic movement the air friction excluded.

That of the microlenses, which actually represent the pixels, of the microlens array outgoing beams are guided through a second lens. This is practically a large lens with a loupe effect, for example with a 400 mm focal length. From today's perspective, this large lens can be an absolute High-tech product incorporating all modern optical technologies represent with the aim of correcting the imaging of the microlens array among the real conditions of viewing the 3D image by a group of people from different depths of the living space.

Due to the intrafocal position of the microlens array, the technical optics a virtual image, which one or more people directly can be perceived. Taking into account the entire figure of the Laser diode matrix up to the eye of the observer or the laser diode matrix and the linear scanner is controlled so that on the one hand a 3D impression is created that comes very close to the natural feeling. On the other hand, they are special, too extremely distorting effects, especially for multimedia applications, feasible.

Fig. 2 shows the formation of the virtual image from the viewer. When point A on the microlens array moves from position 1 to position 2 , the virtual points A11 'and A2' arise in the known manner, namely in different depths and sizes. These mapping ratios must be converted into the control information for the laser diode matrix and the linear scanner in connection with the 3D point cloud. This creates the 3D impression of the viewer in connection with the visual 3D perception.

Claims (5)

1. Arrangement for generating an impression of 3D images for visual perception with a rasterized, computer-controlled and thus addressable light-emitting first array, by means of which a planar, self-illuminating partial image is represented in the sense of a perpendicular cut through a 3D object, and
the information about the 3D image to be displayed is in the form of a digital data record, and a lens with a telecentric output is assigned to the array, but telecentrically on the side facing away from the first array, and
a second array, consisting of a refractive or diffractive microlens array, is assigned to the objective in the depth range of the focus, on which the real image of the planar and self-illuminating partial image is created, and
the microlens array is connected to a computer-controlled scanner with a direction of movement in the direction of the axis of the objective. 2. Arrangement according to claim 1, characterized, that the first array is a single or multi-colored laser diode array. 3. Arrangement according to claim 1, characterized, that the second array is movable by means of a linear motor.   4. Arrangement according to claim 1, characterized, that the second imaging optics is a Fresnel lens. 5. Process for generating images that look like 3D images convey to an observer with an arrangement according to claims 1-4, characterized, that the computer fed the control of the first array with the layers saved data depending on the distance between the illuminating he most array and the movable second microlens array controls such that in Eye of the viewer a 3D image in the sequence of the layers shown is mapped.