Patent GB-1379050-A (GB)
Title: Reproduction of three-dimensional images using multiimage hologram
IPC: G03B35/24
Filed: 1971-12-23
Abstract: 1379050 Forming three-dimensional images KONISHIROKU PHOTO INDUSTRY CO Ltd 23 Dec 1971 [26 Dec 1970] 60081/71 Heading G2J A four step process is used to form three dimensional images of three dimensional objects, of which the first two steps form a two dimensional matrix of images of the object of which a hologram is formed in the third step, the final step being the reconstruction of the three-dimensional image from the hologram.  STEP 1 A three dimensional object 2 is illuminated with incoherent light. A row of equally spaced lenses 3 forms a series of images of the object on a black and white film 4. These images are each of slightly different view points of the object. If desired each lens of the row 3 may be used sequentially. STEP 2 The developed film 6 is illuminated through a diffusion plate 7 with incoherent light and row of lenses 5, equivalent to lenses 3, forms an image of the original object on a diffusion screen 9. A matrix of lenses 11, of which each row perpendicular to row 5 is associated with an equivalent single lens of row 5, forms a matrix of images on a film 12. To get correct orientation a plane mirror 10 is located between screen 9 and lens matrix 11. STEP 3 The developed image matrix 19 is illuminated through a diffusion plate 21 by coherent light, an equivalent lens matrix 20 forming in the plane of a hologram recasting medium 23 a three-dimensional image of object 2. A coherent reference beam 24 is simultaneously incident on medium 23. STEP 4 The hologram 26 is illuminated with incoherent light from the opposite direction to the reference beam to form a real image 29, a colour filter 28 reducing colour alteration of the image. To give the correct orientation of the final image instead of the plane mirror being located as in STEP 2 it may be located; (a) between the object and lens row 3 in STEP 1. Fig.6 (not shown); (b) between the lens row 5 and the diffusion screen 9 in STEP 2 Figs.7, 8 (not shown); (c) between the lens matrix 20 are the hologram medium 23 in STEP 3 Fig.9 (not shown);(d) between the hologram are the reconstructed image in STEP 4, Fig.10 (not shown). In alternative embodiments the diffusion screen used may be reflective rather than transmissive, Figs.11 and 13 (not shown). The images may be of either still or moving objects. Information is given which it is stated corrects for distortion of the lens system when the object is moving. In a further embodiment the object and its final image may be coloured. In STEPS 1 and 2 a black and white film is exposed to record images of the object using respectively light passed through a red, a green and a blue filter Fig.19 (not shown). The three records formed in STEP 2 are separately illuminated in STEP 3 Fig.20 (not shown) and superimposedly recorded on the hologram record medium, using for example, a different angle of incidence for each separate reference beam, which is then illuminated simultaneously by incoherent red, green and blue light, Fig.21 (not shown). Further modifications of the second step of the process are described with reference to Figs.23 and 24 (not shown).