US005771109A Ulllted States Patent [19] [11] Patent Number: 5,771,109 DiFrancesco [45] Date 0f Patent: Jun. 23, 1998 [54] METHOD AND APPARATUS FOR 5,537,203 7/1996 Carr ...................................... .. 356/236 [)IGITIZING FILMS USING A 5,548,120 8/1996 Parker et al. ...................... .. 250/341.7 STROBOSCOPIC SCANNING SYSTEM FOREIGN PATENT DOCUMENTS [75] Inventor: David DiFrancesco, EngleWood, Calif. 498945 1/1939 United Kingdom . 2011756 7/1979 United Kingdom H04N 3/36 [73] Assignee: PiXar, Richmond, Calif. 2025731 1/1980 United Kingdom ........... .. H04N 3/36 OTHER PUBLICATIONS [21] Appl. No.: 651,164 [22] Filed: May 17’ 1996 gilciggriA High Resolution Digital Film Scann IDS4000 [51] Int. Cl.6 ..................................................... .. H04N 1/46 Laser Based Color Film Recorder System With GaAs [52] US. Cl. ......................... .. 358/507; 358/506; 205/228 Microlaser, D- Difrancesco, 17—20, Jan- 1989 [58] Field of Search ........................... .. 382/132; 358/474, High Resolution CCD Film Scanner For Special Effects 358/475, 480, 481, 486, 487, 491, 500, Applications, Mike Davis et al., unpublished. 506, 509, 510, 512, 501, 527; 355/32, 33, _ _ 37, Primary Examzner—ThoInas Lee Assistant Exammer—Jerome Grant, II [56] References Cited- Attorney , A 8 em, or Firm—Hecker & Harriman US. PATENT DOCUMENTS [57] ABSTRACT 3,584,147 6/1971 The present invention is a method and apparatus for digi 3,584,148 6/1971 Flory et al. .. tiZing ?lm frames. The invention utilizes different colored 3,637,937 1/1972 DCVCSOII et al. ...................... .. 340/680 Strobe housed in an integrating Sphere, instead of the 3,679,827 7/1972 BoltZ ....................................... .. 348/97 prior art ?lter and Shutter mechanism_ The invention’s 2/ {$305 egal' ' control system ?ashes each strobe light in sequence for a 4’255’764 32981 Héw‘zar 3443/98 predetermined time to expose a ?lm frame to various color 4’309’746 1/1982 362/259 components. The various color components of the ?lm 4’310’847 1/1982 Frohbach et a1_ 348/104 frame are projected onto a CCD array With the aid of a lens. 4319:2530 3/1982 R005 et at _____ __ 348/97 Each strobe light is ?ashed at a desired frequency and for the 4,330,793 5/1982 Stemme er a1, _ 348/104 predetermined time in order to saturate the CCD array With 4,495,516 1/1985 Moore et al. 348/104 the component of light corresponding to that strobe light. 4,623,929 11/1986 Johnson et a1- - 315/241 5 The color data corresponding to each color component are 4,681,427 7/1987 Hummer 355/32 passed to digital signal processors for processing and stor 4’688’O9g 8/1987 Funston 348/96 age. In one embodiment of the invention, the strobe lights j’gig’gés girglirllsfnner ' are red, green, and blue strobe lights. 5:155:586 10/1992 Levy etal. .. 348/104 5,249,056 9/1993 Foung et al. ............................ .. 348/97 57 Claims, 5 Drawing Sheets U.S. Patent Jun. 23, 1998 Sheet 1 0f 5 5,771,109 Q2 Q5 \AENGw Q3 N 6E NE we“ NE $63 mumbsm U.S. Patent Jun. 23, 1998 Sheet 2 0f 5 5,771,109 U.S. Patent Jun. 23, 1998 Sheet 3 0f 5 5,771,109 204 FIG. 4 406 TRANSPORTFILM 47< 4,\ , INTEGRA TING CONTROL SPHERE “0 CAMERA SYSTEM / 404 U.S. Patent Jun. 23, 1998 Sheet 4 0f 5 5,771,109 E/ KmRm Smg gn?\A \\Qk EuE:“g En AIIIINRE§§§$95EEQE mm..rb. §m8Q5§ 5mm“WQ\||\ \§Sm_ _ NW“\ 3% Q U.S. Patent Jun. 23, 1998 Sheet 5 0f 5 5,771,109 FIG. 6 602 START FLASH RED STROBE LIGHT 604 AT 75HZ FOR ONE / 608 SECOND TO SATURATE THE CCD ARRAY U PROCESS TRANSFER THE RED RED COLOR COLOR DATA T0 DIGITAL f 606 DA TA SIGNAL PROCESSORS FLASH GREEN STROBE LIGHT A7 8H2 FOR ONE SECOND r0 SATURA r5 / 5'0 674 THE CCD ARRAY PROCESS TRANSFER THE GREEN GREEN COLOR COLOR DATA TO DIGITAL DA TA SIGNAL PROCESSORS \CIZ FLASH BLUE STROBE LIGHT AT JOHZ FOR ONE SECOND TO SATURATE 620 THE CCD ARRAY PROCESS BLUE TRANSFER THE BLUE COLOR COLOR DATA T0 DIGITAL /- 678 DA TA SIGNAL PROCESSORS 1 DIGITIZE NEXT FRAME \ 622 5,771,109 1 2 METHOD AND APPARATUS FOR chroniZation devices. The ?lter sWitching mechanism and DIGITIZING FILMS USING A the shutter system also require regular and costly mainte STROBOSCOPIC SCANNING SYSTEM nance. In addition to all of these disadvantages, the prior art ?lter sWitching mechanism is sloW. Three different ?lters BACKGROUND OF THE INVENTION must be sWitched to digitiZe each ?lm frame. A typical full 1. Field of the Invention length ?lm has thousands of ?lm frames. Thus, digitiZing the The present invention relates to the ?eld of ?lm digitizing entire ?lm can take hours longer just for the time consumed apparatus. in sWitching the three red, green, and blue ?lters. 2. Background Art Another dif?culty With the prior art ?lm digitiZing appa ratus is that the light produced by light source 104 is a Film digitiZing apparatus are used to transform images from ?lm frames to digital data for storage and display by “parallel light.” In other Words, the light generated by light source 104 is not uniformly distributed over ?lm plane 102. computer systems. FIG. 1 shoWs the functional blocks of a prior art ?lm digitiZing apparatus 100. A light source 104 Typically, the intensity of the light is larger in the center of ?lm plane 102. This results in a non-uniform exposure of emits White light toWard ?lm plane 102 Which holds a ?lm 15 frame (not shoWn). A colored ?lter 105 is placed betWeen CCD array 110 and in a delay in saturating the edges of the light source 104 and ?lm plane 102. Filter 105 is typically CCD array. Sometimes additional optics or ?ber optic face plates are used to correct this non-uniform exposure of the a red, green, or blue ?lter and permits only one of these basic CCD array. HoWever, this increases cost and also results in colors to pass through. Alens 109 focuses onto a CCD array 110 the light component ?ltered by ?lter 105 (for example, loss of light in the system. the blue light component). The folloWing patents disclose ?lm digitiZing apparatus. During operation of the prior art ?lm digitiZing apparatus Flory (US. Pat. No. 3,584,147) discloses an apparatus for 100, the White light emanating from light source 104 is generating triggering pulses for actuation of a blue strobe ?ltered by colored ?lter 105. The component of light passing light at desired times. According to Flory ‘i147, light from the blue strobe light is transmitted forWard to a camera through ?lter 105 exposes the ?lm frame held by ?lm plane 25 102. After passage of a short time CCD array 110 becomes through a ?lm frame, tWo dichroic mirrors, and a lens saturated With the color component of the ?lm correspond system. A continuous yelloW light is transmitted backWard ing to colored ?lter 105. For example, if ?lter 105 is a blue through the tWo dichromatic mirrors to a photo detector ?lter, the CCD array becomes saturated With the blue color Which develops the triggering pulses for actuating the blue component of the ?lm frame. The digitiZed color data are strobe light. Flory (US. Pat. No. 3,584,148) discloses an then fed from the CCD array to computer storage. apparatus for illuminating a ?lm frame several times by a As stated above, according to the prior art, light source strobe light operating at a predetermined rate. The apparatus images the ?lm onto a photosensitive surface. The apparatus 104 is a White light source. The prior art White light source includes rotating mirrors in the optical path to compensate 104 typically consists of continuous Wave xenon or halogen for the motion of the ?lm betWeen successive strobe light lamps. In order to expose CCD array 110 to the basic colors, 35 namely, red, green, and blue, three different colored ?lters ?ashes so that each ?lm frame is imaged onto the same are utiliZed. A red ?lter is used to pass through only the red photosensitive area. component of the White light. Likewise, a green ?lter is used Deveson et al (“Deveson”, US. Pat. No. 3,637,937) is to pass through the green light component, and a blue ?lter directed to an apparatus for producing video signals from a photographic ?lm. The Deveson apparatus attempts to over is used to pass through blue light component, of the White 40 light emanating from light source 104. Each ?lter 105 is come overexposure or underexposure of the photographic inserted betWeen ?lm plane 102 and light source 104 (or ?lm such that the video signals accurately represent the alternatively, betWeen ?lm plane 102 and lens 109) for a image on the photographic ?lm. Deveson uses a “variable predetermined period of time. The ?lter is then removed and density light ?lter” to vary the illumination of the ?lm as a replaced With one of the other tWo ?lters for a predetermined 45 part of its apparatus. period of time. Thus, each one of the red, green, and blue BoltZ (US. Pat. No. 3,679,827) is directed to an apparatus ?lters is sequentially inserted, removed, and replaced With a used in continuous ?lm projection systems. BoltZ attempts different colored ?lter. This ensures that only one of the three to maintain a light replica of a ?lm frame stationary on a colors red, green, or blue is passed through to CCD array photosensitive camera tube While the ?lm frame is in 110.