TWI229235B - Holographic stereogram device - Google Patents

Abstract

The present invention uses a hologram lens in the process of creating a holographic stereogram, and also uses an image that has been processed with Fourier transform as a source image for projection onto a recording medium, instead of projecting original image itself. The present invention comprises a lens arranged between the source image and the recording medium to perform the inverse Fourier transform in order to convert the image back into a normal image. The present invention allows the hologram unit to include more than one image pixel, eliminating the need for the diffuser of the prior art and simplifying illumination requirement of film transparency or liquid crystal display panel.

Description

1229235

Stereogram)

V. Description of the invention (1) The technical field to which the invention belongs The present invention relates to the improvement of three-dimensional holograms (Holographic production technology. The prior art holograms (Homogram) is a three-dimensional image (3d) that can generate objects : 4 The side of the ordinary clothes as the king's picture is to use the optical system to guide the laser to the surface of the object, so that the laser light reflected from the surface of the object and another parameter =, 2: "Learn the surface of a flat plate. These two The interference fringes of the track light are recorded on the optical flat plate and become a full-image. This method of making a full-photograph includes an object entity and precise erection of optical elements to generate the reflected light and reference light of the object. Interference fringes. Because the human brain can combine different two-dimensional images received by the left and right eyes to produce the effect of three-dimensional images, and these two-dimensional images can be pictures of objects or computer-generated images of different perspectives of the object 3. Therefore, a three-dimensional image can be produced by a full-frame image. Stereogram is a pair of images that can show two of the object = view angle. Generally, a three-dimensional image is produced by a stereo image. There is only one parallax (HorizontaiParallax). There are many ways to present the different perspective images of object two to the left eye and the right eye. The commonly used method is to use the stereo viewer to restrict the right eye to see only :: One-view image of the body 'The left eye only sees another image with a different perspective. The ancient i-pictures can also be printed into red and green images, and the corresponding filters for the left and right eyes I, so that the left and right eyes can see See different perspectives of objects 的 Examples of stereo holograms can be found in US Patent No. 6, 0 3 7, 9 71

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Another stereo king image is called a lenticular stereo hologram. This is one of the methods of seeing stereoscopic images without the aid of stereo glasses. This lenticular stereoscopic technique is to stagger narrow sections of two sets of perspective images, and place these image sections behind a group of frames. In this way, two sets of image fragments with different perspectives can be respectively projected to the left eye and the right eye to form a three-dimensional image. No. 5,795,154. Holographic graphic stereogram is another way. Its two different perspective images are encrypted by spatial frequency. When this holographic image is illuminated by a light source, two different perspective images will be Appears at different angles from the hologram. The diffraction angle is related to the distance between the eyes and the observation distance. Take a typical example to illustrate. If the distance between the two eyes is 50 mm (cm) and the observation distance is 400 M, the diffraction angle is about 7.5 degrees. ',, Fan are shown in Figure 1. The left beam is bounded by rays 1023 and 1021), and the right beam is bounded by rays 103a and 103b, both of which are projected to the right eye 104 and the left eye 105 after being diffracted through the stereoscopic IQ. Light rays 102a and 1038 are projected from a stereoscopic element i0 6 of a stereoscopic element 1101. This method uses only horizontal parallax to form interference with two light beams such as 10a and 10a in a slit, and simultaneously combines each narrow segment of a full-image to produce a full-image. For details, please refer to the paper published in September 1986 "Mark Holzbach, 'Three dimensional image processing for synthetic holographic stereograms'1, M. S. thesis.

I ill ill Page 6 1229235 V. Description of the Invention (3)

Massachsetts Institute of Technology, Sep. 1986, pp. 186;) ", 2000 paper" Optical Composition and Color Imaging of Array Holographic Printers with Variable Print Dot Pitch (CK Lee et al ·, 丨, Optical configuration auu representation of a variable-pitch dot matrix holographic printer 丨 1 Appl. 0pt ·, Vol. 39, No. 1,?. 40 (2000)) ", and US Patent No. 5,237,433, No. Nos. 5, 475, 511 and 5, 793, 503. Fig. 2 (a) shows how the hologram of Fig. 1 is made. A convergent laser beam 201 is used to illuminate a slide 202 (this object may be a liquid crystal display panel). The image contained in the projection sheet 202 is projected onto a rotating diffusion sheet 20 5. The diffusion sheet 20 05 can evenly illuminate light on the recording plane 207. In order to record stereoscopic images, the image contained in segment 204 is the image seen by the left eye: and the image contained in segment 203 is the image seen by the right eye. These two images are diffused by the diffusion sheet 205 and projected onto the recording plane 207. Another reference to the laser light 206 is to discriminate the two projected light from the flat image 7 0 a # ~, to the holographic recording area 209 of the recording surface 207 to produce interference fringes I · t to limit the holographic image. § The recorded area 209 is a narrow band-shaped area, and the area 20 9 recording is completed. 'The recording plane m will move a king record and another set of new images will be projected onto the diffuser standing upright: Hologram record. The width of the slit 208 determines the two f-line down degrees of the full image. Repeat this step until, for example, the analysis of photographs. Most of the narrow band-shaped recording areas 209 are full-scale stereo recordings, and the recording surface is filled with m. It is a simple process to transfer stereo images to the same monophoto. As shown in figure two: Π29235 V. Description of the invention (4) — ^ " ~ " ^ Image ^ When the light is irradiated, close your eyes to the position of the diffuser 205, and you will be able to record stereoscopic images of redundant objects. The diffusion sheet 203 can also be replaced by a cylindrical lens 4 to focus the laser beam into a linear beam with a width equal to the width of the slit 208, as shown in Fig. 3 (a). The one shown in Figure 3 (a) is a further development of the city concept disclosed in Figures 2 (a) and 2 (b). Film 3 0 2 contains images of most objects with different viewing angles illuminated by similarly converging laser beams, replacing a pair of stereo images originally recorded. Most images of objects from different angles of view on film 302 are recorded on the same holographic unit 309. For example, pixels 303 and 304 are two images with a specific angle to the object. These two images are projected onto the recording plane 307 after being diffused by the diffuser 3 μ. In addition, a reference laser light 306 ′ and two projection lights from the diffusion sheet 305 are introduced, and both of them are recorded on the hologram unit 309 of the recording plane go ?. Figure 3 (b) shows how to create these perspective images. The layers 3 11 and 3 1 2 respectively represent a two-dimensional image of a specific perspective of the object. The perspective images are stacked together to form a cube 310. In front of this cube 31o, the bands 313, 314 are image units at specific positions of the viewing angle 311 or any other viewing angle. In order to properly record the hologram unit j corresponding to the image position χ =] •, the function recorded on the film is g (z = n 3, y, x =. Where j is the position on the xy plane and η is the angle of view In the image, δ represents the width of the layer 311 or 312. Mathematically, the light distribution of the lenticular lens on the focusing plane can be expressed as ... (1)

jlm & A-IF, Μ / 2 G (u-j ^ y) = Y ^ g (thV ^ e «= 1λ / 2

V. Description of the invention (5) where G (A ~ jA, y) is the degree of recording, and the light g (z = n is the light distribution on the image segment. As seen in the angular image #, where sin = η accounts / λρ. , = X = J), the whole eye is moved to the stereo holographic field at the angle θη incident. After the holographic image recording is completed, it gradually changes with different viewing angles. ": At the same position, the eye will also see the image processing method of the object." The "three-dimensional width △ of the synthesized stereoscopic hologram" in the paper determines the three-dimensional image. Therefore, the degree of the holographic unit. Analysis of the reconstructed stereoscopic image. SUMMARY OF THE INVENTION The main object of the present invention is to # include more than one image pixel. Θ is a technology that enables the holographic unit to package another object of the present invention, an improved technique of the image method. ^ About the above It is known that the production of stereoscopic wholes uses a computer to generate a full-spectrum wheaten. When making a stereoscopic monograph, Komin used the original image itself to find a transformation in the Founer Transforra image of the image. Every day * ,,, and members are not on the panel, not the household. Jiang- 庶 I e: One image is placed between the image and the recording medium. The mirror transforms the shirt into an inverse Fourier transform (Inverse Fourier)

Transform) to produce a normal image. Fourier-transformed holograms are generated using a computer to record more than one pixel at a time. In this way, the angle of the image can be independently controlled without being affected by the slit width of the recording hologram unit. Furthermore, Fourier transform encryption can add random phase to holographic pixels. This random phase change can produce a uniform lighting effect, so = use the diffuser proposed by the previous technology. This can effectively simplify the projection 1229235 V. Description of the invention (6) Illumination requirements of the liquid crystal display panel. Embodiment Please refer to FIG. 4. The principle of the present invention is that a laser beam 401 is used to illuminate a projection sheet or a liquid crystal display panel 402. The laser light may be irradiated from the back of the display panel 40 2, or may be irradiated from the front by a beam splitter (see US Patent 6,043, 9 1 3). Different from the prior art in which the viewing angle image pixels are displayed on a slide or a liquid crystal display panel (as shown in FIG. 3 (a)), the present invention is a Fourier-transformed image displaying a group of image pixels. The function g (n y /) represents the image of the n-th angle of view when the object is located at x = i. Then the Fourier transform of (n 乂 i) segment is defined as: (2) ′ y’1 where k-1.1, n = 1 ... N and i = 0 ... N / m. The images displayed on one panel are (3), multiple pieces or liquid crystal display. Segments 404 and 403 shown in Figure 4 are based on the function 〇Gn (k, y) as a complex function and cannot be displayed on film 11) , Y). Because of this, another equivalent function is used as follows: (4) or on the display panel,

V. Description of the invention (7)} ή = Α + Re {Gw (A :? y)} It is a constant, and Re {} is expressed as the function of the soil function Hn (k, y) in brackets as the function g (n, Fourier transform of y,] ·) = two.卩 section. Lens Mei is used to perform the inverse Fourier = function of image segmentation. ::: Pixels 4. 9, 41. , 411, 412. : Conversion 'is explained by taking four image pixels as an example. However, a real example can also be used. Only using a mask containing a slit 408 can limit the number of pixels. The reconstructed image of the clip is like Xin. Like. , F is the Fourier's record = until the entire stereo full-frame recording is completed, and the full-frame early full-field image of the present invention and Xian Yu Du & > Nine Holographic Units $ If ^ The main difference is that this The invention can be used in the heart of a transformation function, such as the following equation; enter U) In the image J2tsk, the mother pixels are added so that ^ < random phase changes can be made, so that each pixel is different tones, when the full body image is reconstructed Interference fringes are generated. The prior art, 1229235 V. Description of the invention (8) is to use a rotating diffuser placed in front of the film or display panel to achieve the same effect. The present invention can remove this element from the recording system to reduce the complexity of the system. The ones shown in Figs. 5 (a) and 5 (b) are the top and side views of the optical system designed according to the concept shown in Fig. 4, respectively. A parallel laser beam 501 illuminates a liquid crystal (LCD) display panel 502, and the liquid crystal display panel 502 is used as a source image to replace the projection sheet in FIG. 2 (a). In order to avoid confusion when explaining the present invention, the optical elements that generate parallel beams and guide them to illuminate the projection sheet or the liquid crystal display panel 502 are not shown in the figure. Figure 5 (a) is a top view of this optical system. The image segment 503 is a Fourier transformed full image y (k, y). After illuminating the LCd panel 502, the light beam is focused through a spherical lens 04t and a spherical lens is used to perform an inverse Fourier transform to generate a diffraction reconstructed image. Due to the nature of Hn (k, y) itself, the image reconstructed by M (k, y) will deviate from the optical axis due to diffraction. The slit $ 0 5 is used to restrict a certain order of the diffracted light of f Hn (k, y) from passing through. The light beam from the lens 504 passes through the spherical lens 506 and becomes a parallel beam. After passing through the lenticular lens 507, it is focused on the recording plane 508. The lens 506 forms a telecentric optical system (Telecentric Optical, and hstem). Basically, this lens group will image the image reconstructed on the plane 505 in. Have recorded on the plane 5 0 8. Since nn (k, y) is the Fourier transform of the function g (n, y, j) =, the inverse Fourier transform is performed via the lens 504, and then the image is reconstructed by the lens group 506 (, 5 07 'and the reconstruction function § (11, y ,〗) On the recording plane 508. The slit 009 is used to limit the recording width of the hologram unit 5 丨 〇. The hologram of the recording plane μ 8 is recorded with the help of the reference beam 5 11 1229235 5 Explanation of the invention (9) Fig. 5 (b) is a side view of the optical system of this embodiment. The light beam on the surface 505 is converted by a spherical lens 506; ^ = t ηΛΛ Take a beam of ten rays. LCD panel The image of 502 will be imaged on the recording plane 508 along the direction of this beam. The image of recording plane 5 08 is an enlarged image of the 502 image of the LCD panel, and its magnification is determined by the focal length ratio of the lens group 50 6 and the lens group 504. Determined. The light beam from the / LC]) panel M2 is combined with the reference light beam 51! To form a hologram unit 51. The feature of this 5 recorded system is that each hologram unit is relative to a group of image pixels defined by formula (2). The resolution of the image is independent of the full-image width.

With the understanding of the technologies disclosed herein, the present invention can also be demonstrated in different forms without departing from the basic characteristics. For example, the use of a lens to perform inverse Fourier transform, etc., is a patent claim of the present invention and is not limited to those disclosed in the embodiments.

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Brief description of the drawings Brief description of the drawings Figure I is a user watching a hologram. Figures 2 (a) and 2 (b) are generated by known techniques. Two = two. Figures 3 (a) and 3 (b) are known techniques. Schematic photo of making a king.

Method diagram. —Three-dimensional full image J from above the solid angle of view J FIG. 4 is a recording stereogram 5U) and 5 (b) proposed by the present invention are intended for the original image 2 to which the present invention is applied. The top and side views of the optical system of the sheet '. , (See Figure 4) the representative symbols of the main part of the stereoscopic image 101 stereoscopic holograms 102a, 102b, 103a, 103b light 1 0 4 right eye '1 0 5 left eye 2 0 2 slides 205, 305 Diffuser 2 〇7, 3 0 7 recording plane 2 0 9 recording area 3 0 3, 3 0 4 image 310 cube 313, 314 picture strip 4 0 2 display panel 4 0 5 lens 4 0 7 recording plane 2 0 1 laser Beam 20 3, 204 Fragment 20 6, 30 6 Reference laser light 208, 308 Slot 302 Film 3 0 9 Holographic unit 311, 312 Layer 401 Laser beam 403, 404 Segment 406 Reference laser light 408 Masks 409, 410, 411, 412 image pixels 1229235 Schematic description of 501 laser beam 5 0 3 image fragment 505, 509 slit 5 0 8 recording plane 51 1 reference beam 502 LCD panel 5 0 4, 5 0 6 spherical lens 5 0 7 column Lens 5 1 0 Holographic unit

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Claims (1)

1229235 6. Scope of patent application · 1 · A system for recording stereo holograms on a recording medium, including: a source image display film including a plurality of pixels transformed by Fourier transform; a laser light source placed on a display film; On one side, 俾 is used to illuminate the display sheet to generate an image beam; a lens system is placed on the other side of the display sheet, and 俾 is used to focus the image beam on a recording medium; the lens system includes an inverse Fourier transform lens. 2. The system according to item 1 of the scope of patent application, wherein the display sheet is a liquid crystal display panel. 3. The system according to item 1 of the scope of patent application, wherein a first photomask is placed between the lens system and the recording medium; the first photomask includes a slit for restricting transmission to the recording medium. The order of the diffracted light wave. 4. The system according to item 1 of the scope of patent application, wherein a second photomask is placed between the lens system and the recording medium; the second photomask includes a slit for restricting the recording medium on the recording medium. Record width. 5. The system according to item 1 of the scope of patent application, wherein the source image is multiplied by a random phase change before the Fourier transform calculation. 6. The system according to item 1 of the scope of patent application, wherein the lens system comprises a telecentric optical system of a spherical lens and a lenticular lens. 7 · A system for recording stereoscopic full-photographs on a recording medium, including: a liquid crystal display panel displaying source images, which can display Fourier-transformed complex images; pixels not displayed on the liquid crystal display panel are subjected to Fourier transform Before the conversion calculation, the image pixels have been multiplied by a random phase change; Page 16 1229235 VI. Patent application scope Illumination of the display with a laser light source; Diffraction of the source image with a holographic lens; Perform inverse Fourier transform on the source image; and use a lens system including an inverse Fourier transform lens to focus The image is on a recording medium. 11. The method according to item 10 of the scope of patent application, further comprising: using a first photomask with a slit to limit the multi-level diffracted light transmitted from the display sheet. 1 2. The method as described in item 10 of the scope of patent application, further comprising: A slit with a second reticle is used to limit the recording width recorded on the recording medium. 1 3. The method as described in item 10 of the scope of patent application, further comprising: before performing Fourier transform calculations, multiplying the source image pixels by a random phase change. Page 18