Abstract:
A filmstrip which has a substantially transparent magnetic layer is loaded into a camera. Successive sections of the filmstrip are moved inside the camera to locate corresponding sections of the magnetic layer adjacent an inside face of a magnetic-film-write-on portion of the camera. A hand held stylus is manually moved on an outside face of the magnetic-film-write-on portion, opposite the inside face, to record hand-generated information magnetically on the magnetic layer.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     Reference is made to and priority claimed from U.S. Provisional Application Ser. No. 60/006,313, filed 07 Nov. 1995, entitled METHOD AND CAMERA FOR WRITING HAND-GENERATED INFORMATION ON A FILMSTRIP IN THE CAMERA. 
     CROSS-REFERENCE TO RELATED APPLICATION 
     Reference is made to commonly assigned copending application Ser. No. 08/346,961 filed Nov. 30, 1994. 
     FIELD OF THE INVENTION 
     The invention relates generally to the field of photography, and in particular to cameras. More specifically, the invention relates to a method and camera for writing hand-generated information on a magnetic layer of a filmstrip loaded in the camera. 
     BACKGROUND OF THE INVENTION 
     U.S. Pat. No. 5,130,745 (the &#39;745 patent) to Cloutier et al. discloses a camera designed to utilize a photographic filmstrip having a virtually transparent magnetic recording layer. A magnetic head in the camera is used to read and/or write information from/to the magnetic layer. 
     Cameras are also known in the prior art which enable a camera user to optically record hand-written information onto the light-sensitive layer(s) of a photographic film loaded in the camera. For example, in the early part of this century, Eastman Kodak Company made a camera called the Autographic. This camera provided a small metal stylus and a door that allowed access to a paper backing covering the film. The Autographic camera allowed the camera user to write a message with the stylus on the back of the paper covering the film. The pressure from the stylus fogged the film such that after printing, the hand written message could be read on the front of a picture generated from the film. This method of film exposure is known as pressure fogging. U.S. Pat. Nos. 1,848,814 and 5,162,830 disclose other cameras which enable hand-written information to be optically recorded on photographic film loaded in a camera. 
     Several problems exist with the cameras described in the previous paragraph. At least a portion of the light-sensitive area of the film must be used for optically recording the hand-written information. This portion of the film is thus unavailable for recording an image or part of an image. Further, once the hand-written information is optically recorded on the film, the hand-written information cannot be erased from the film. If a camera operator makes a mistake in recording the information, the mistake cannot be corrected. An additional problem is that the information will always appear in photographs generated from the film. Pictures cannot be generated without the information showing up in the picture, and printing the information on the back of the picture would be quite difficult. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, a filmstrip which has a substantially transparent magnetic layer is loaded into a camera. Successive sections of the filmstrip are moved inside the camera to locate corresponding sections of the magnetic layer adjacent an inside face of a magnetic-film-write-on portion of the camera. A hand held stylus is manually moved on an outside face of the magnetic-film-write-on portion, opposite the inside face, to record hand-generated information magnetically on the magnetic layer. 
     By recording the hand-generated information on the magnetic layer of the film, none of the light sensitive area of the film is occupied by the hand-generated information. As such, the entire light-sensitive area of the film is available for image recording. Further, because the hand-generated information is magnetically recorded, it can be erased and rewritten if a mistake has been made. Additionally, pictures can be created from the filmstrip with the hand-generated information recorded over the image, adjacent the image in a border, or on the back of the picture. 
    
    
     These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is a schematic perspective view of the back of a photographic camera; 
     FIG. 1B is an alternative embodiment of a portion of the camera of FIG. 1A; 
     FIG. 2 is a perspective view of a photographic filmstrip having a magnetic layer, and a cartridge for containing the filmstrip; 
     FIG. 3 is a partial sectional view of the camera of FIG. 1A taken along the lines 3--3; 
     FIG. 4 is a top view of a photographic filmstrip with hand-generated information recorded on the magnetic layer; 
     FIG. 5 is a schematic representation of hand-generated information recorded on a magnetic layer; 
     FIG. 6 is similar to FIG. 3 and displays magnetic field lines emanating from a magnetic stylus; 
     FIG. 7 is a schematic perspective view of a magnetic head array scanning a magnetic layer of a filmstrip; 
     FIG. 8 is a side view of the magnetic head array of FIG. 7 outputting serial data; 
     FIG. 9 is a block diagram representing how hand-generated information on a filmstrip is printed onto a photograph; 
     FIG. 10 is a schematic view of a helical scanner for reading hand-generated information from the magnetic layer of a photographic filmstrip; 
     FIG. 11 is a schematic view of an arcuate scanner for reading hand-generated information from the magnetic layer of a photographic filmstrip; 
     FIG. 12 is a similar view to FIG. 3 and represents an alternative embodiment of the present invention; 
     FIG. 13 is an alternative embodiment of a magnetic stylus which can erase magnetically recorded information; 
     FIG. 14 is an alternative embodiment of FIG. 12 in which a magnetic eraser has been added to the camera; 
     FIGS. 15 and 16 display alternative embodiments of magnetic styli; and 
     FIG. 17 is a perspective view of a still further embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Beginning with FIG. 1A, a photographic camera 20 includes a camera body 22 having an opaque rear wall 24. A view finder 26 is used by a camera operator for composing a scene to be recorded on a photographic filmstrip loaded in camera 10. A shutter button 28 is pressed by the camera operator to record an image of the scene on a frame of the filmstrip. A thinned out section of the rear wall, designated as a magnetic-film-write on portion 30 of wall 24, preferably is made of plastic and is about 1 millimeter thick. A magnetic stylus 32 is releasably secured in a recess 34 of back wall 24 by compliant bosses 36. The purpose of write-on portion 30 and magnetic stylus 32 will be explained below. 
     FIG. 1B discloses an alternative embodiment to FIG. 1A, in which a write-on portion hinged door 38 has been pivotably secured to back wall 24. An over-center spring (not shown) biases door 38 to either a closed position, covering the write-on portion, or an open position exposing write-on portion 38. Door 38 pro-protects the very thin write-on portion from damage (e.g. puncture) when write-on portion is not being used. Alternatively, a sliding door can be used to protect the write-on portion. 
     With reference to FIG. 2, a cartridge 40 is disclosed which houses a photographic filmstrip 42 having a virtually transparent magnetic recording layer. The magnetic layer preferably has a coercivity of less than about 920 oersteds. Such a photographic filmstrip is well known to those skilled in the art and is disclosed in the above-mentioned &#39;745 patent which is incorporated herein by reference thereto. Cartridge 40 is loaded into camera 20, and then filmstrip 42 is advanced from the cartridge to position a frame of the filmstrip in a position to have an image recorded on the frame by the camera. 
     Turning to FIG. 3, a partial sectional view of camera 10 in FIG. 1, loaded with film, is disclosed. A pair of film rails 43 (one is hidden from view) press filmstrip 42 against a multiplicity of dimples 45 located on back wall 24 to hold filmstrip 42 essentially flat in the film plane. Write-on portion 30 thus also acts as a pressure plate in camera 10 and is in very close proximity to filmstrip 42. Dimples 45 allow filmstrip 42 to slide freely between a film gate (not shown) and write-on portion 30. Filmstrip 42 includes a base layer 48, various well-known photo-chemical layers 50 on one side of base 48, and a virtually transparent magnetic layer 46 on the other side of base 48. An anti-static and lubricating layer 44 covers the magnetic layer 46. 
     Magnetic stylus 32 includes a north pole N and a south pole S. Consequently, stylus 32 emits a magnetic field. When a camera operator desires to write hand-generated information on filmstrip 42, the operator removes the stylus from recess 34 of camera 10, grasps the stylus, positions an end of the stylus on an outer surface 52 of write-on portion 30, and moves the stylus on outer surface 52 in a desired pattern. The magnetic field emitted from stylus 32 is recorded in magnetic layer 46 as the stylus is moved, thereby recording the pattern of hand-generated information on magnetic layer 46. Preferably, stylus 32 emits a magnetic field having a strength exceeding about 920 gauss at magnetic layer 46 when an end of the stylus is in contact with outer surface 52. The stylus may itself be one single magnet or a magnet can be contained within the stylus. Further, the magnet in the stylus may be very long or short as necessary in order to obtain the proper strength and shape of the magnetic field emitted by the stylus. Because the coercivity of magnetic layer 46 is preferably less than 920 oersteds, the path of stylus 32 is recorded in the magnetic layer. 
     FIG. 4 displays filmstrip 42 with hand-generated information 54 magnetically recorded on the magnetic layer of the filmstrip. Of course information 54 would not be visible to the unaided human eye, but it has been made visible in the drawings to aid in the explanation of the invention. A dotted line 56 is provided in the figure merely to show the available writing area of write on portion 30. The dotted line is not actually recorded on the film in any manner. 
     FIG. 5 discloses a portion of information 54, namely the letter &#34;J&#34; from the word &#34;Jim&#39;s&#34;. Only the field from the stylus which is in the plane of the magnetic media actually magnetizes the magnetic layer. Arrows 58 represent magnetic field vectors of the information recorded in the magnetic layer. FIG. 6 discloses how a magnetic field 60 from stylus 32 emanates away from the stylus, passes through write on portion 30, and permeates filmstrip 42 to record the magnetic field in the magnetic layer of the filmstrip. 
     With reference to FIGS. 7 and 8, after filmstrip 42 is removed from the camera, the filmstrip is developed to render visible the latent images recorded on the photo-chemical layer(s) of the filmstrip. Filmstrip 42 is then passed by a magnetic FAX head 62 which includes a plurality of magnetic heads 63. The magnetic layer of the filmstrip is closer to the magnetic FAX head than the photo-chemical layer(s). The housing has been made transparent to facilitate viewing. The electrical output of each magnetic head in the array is amplified by an amplifier 64 and integrated by a multiplexer 66 which results in a serial data output 68 from the multiplexer. Serial data output 68 is similar to the serial data output from a charged coupled device (CCD) sensor used in a conventional facsimile machine, thus explaining the use of the term &#34;magnetic FAX head&#34; 62. As the film moves past the magnetic FAX head, signal 68 is clocked out of multiplexer 66 at a rate proportional to the relative speed of filmstrip 42 past magnetic FAX head 62. Signal 68 therefore represents a picture of the hand generated information recorded on the magnetic layer of the filmstrip. 
     FIG. 9 is a block diagram disclosing how the hand-generated information recorded on filmstrip 42 is utilized. After magnetic FAX head 62 scans film 42 to read hand-generated information 54 recorded on the magnetic layer of the filmstrip, serial data 68 from the magnetic FAX head is transferred to a microprocessor 70. The microprocessor 70 compresses the serial data and stores the compressed serial data in a memory 72. A photograph 74, which corresponds to hand-generated information 54, is created from a developed image located adjacent hand-generated information 54 on filmstrip 42. Microprocessor 70 retrieves the compressed serial data from memory 72, decompresses the serial data, and uses the serial data for controlling an inkjet printhead 76 to record the hand generated information on the back of photograph 74. The hand-generated information can alternatively be printed on the image side of the photograph in a border or superimposed over the image by using a linear light emitting diode print head to expose the photographic paper from which photograph 74 is made. 
     FIG. 10 disclose an alternative method for reading the hand-generated information from the magnetic layer of filmstrip 42. A helical scanning head 78 includes a magnetic head 80. The helical scanning head is rotated rapidly in the direction of an arrow 82 while filmstrip 42 is transported past helical scanning head 78 in the direction of an arrow 84. Serial data from magnetic head 80 will have a large amount of skew which is removed by microprocessor 70 (FIG. 9). Such a helical scanner is similar to helical scanners used in video tape players. Transverse scanning, which is another form of helical scanning, can also be used to read the hand-generated information from the magnetic layer of the filmstrip. 
     FIG. 11 discloses a still further alternative method for reading the hand-generated information from the magnetic layer of filmstrip 42. An arcuate scanning head 86 includes a magnetic head 88. The arcuate scanning head is rotated rapidly in the direction of an arrow 90 while filmstrip 42 is transported past arcuate scanning head 86 in the direction of an arrow 92. Serial data from magnetic head 88 will be distorted by the curvature of the scan path (represented by curved lines 94). The distorted serial data can be corrected computationally by microprocessor 70 (FIG. 9) or by providing an inkjet print head with a curvature similar to the curvature of the scan path. 
     Turning now to FIG. 12, a further feature of the present invention will be described. FIG. 12 is similar to FIG. 3 except that dimples 45 have been removed and write-on portion 30 has been provided with an additional magnetic viewing layer 96. Layer 96 comprises a pair of thin, transparent plastic sheets in between which is sealed a light colored powder or liquid filled with soft or weakly magnetic particles. The magnetic particles are preferably dark in color. When stylus 32 is moved on layer 96 in a pattern, the magnetic particles, under the influence of the magnetic field emanating from stylus 32, assume the pattern drawn by the stylus. The dark magnetic particles are set off against the light colored powder or liquid, and are thus visible through the transparent plastic sheet. As such, the camera operator can see the hand-generated information that has been recorded on the magnetic layer of the filmstrip. This aspect of the invention is comparable to several children&#39;s toys on the market. A suitable material for magnetic viewing layer 96 is made by Eurand America. 
     FIG. 13 discloses an alternative embodiment of stylus 32. The stylus includes a first permanent magnet 98 which emits a magnetic field for recording hand-generated information on the magnetic layer of the filmstrip. Stylus 32 also has a second permanent magnet 100 for erasing hand generated information from the magnetic layer. Magnet 100 has elongated north and south poles N, S and emits an elongated magnetic field designated by arrows 102. To erase hand-generated information from the magnetic layer of the filmstrip, the stylus is positioned such that magnet 100 is adjacent the write-on portion and the long axis of magnet 100 is parallel to the plane of the write-on portion. The stylus is then swept across the write-on portion, thereby erasing hand-generated information recorded in the magnetic layer of the filmstrip. 
     FIG. 14 is an alternative embodiment of FIG. 12 in which a magnetic eraser 104, similar to magnet 100 in FIG. 13, is provided in the camera. A portion of film rail 43 has been removed to facilitate viewing. Magnetic eraser 104 includes a magnet having elongated north and south poles N, S which extend into and out of the plane of the paper on which FIG. 14 is located. Magnetic eraser is moved in the direction of an arrow 106 to erase hand generated information recorded on the magnetic layer of filmstrip 42. Magnetic eraser can be moved manually by a knob which extends outside the camera body and is attached to magnetic eraser 104. A spring can be used to bias the magnetic eraser to its home position shown in FIG. 14. Alternatively, a camera motor can be used for powered movement of the magnetic eraser. A permanent magnetic material suitable for use as the magnetic eraser is disclosed in U.S. Pat. No. 4,893,208 which issued on Jan. 1, 1990 in the name of McClure, and which is incorporated herein by reference. 
     Turning to FIG. 15, further description of magnetic stylus 32 will be provided. In this embodiment a small permanent magnet 108 is secured to one end of a stylus body 110 which is made of a non-magnetic material such as aluminum. The spreading of the magnetic field 112 is determined by the length of the magnet. The shorter the magnet the more confined the magnetic field surrounding the magnet and the sharper the line written by the stylus. However, as the length of the magnet is reduced, so too is the magnetic field strength. A balance must be reached such that the magnetic field is strong enough to magnetize the film but not so large that the width of the track recorded by the stylus is so wide that the hand-generated information is not readable. 
     FIG. 16 discloses a still further embodiment of stylus 32. In this embodiment, a spherical permanent magnet 114 is secured for rotation to one end of stylus 32, much like a ball point pen. The sphere should have two or more magnetic poles N, S, and the magnetic field emanating from spherical magnet 114 must be strong enough to reach through the camera write-on portion to record hand-generated information on the magnetic layer of the filmstrip. 
     Turning to FIG. 17, a further embodiment of the present invention will be described. In this embodiment, the write-on portion of the camera is replaced by a magnetic layer of rubber 116 containing magnetic particles such as barium or strontium-ferrite. A non-magnetic stylus, made of plastic or aluminum, is used in conjunction with the rubber magnetic layer. Filmstrip 42 is spaced a small distance (e.g. 2 mm) from magnetic rubber layer 116. When the camera operator writes with the stylus on rubber layer 116, the portion of the rubber layer under the stylus is pressed closer to filmstrip 42. As such, a magnetic signal is recorded on magnetic layer 46 of filmstrip 42 wherever magnetic rubber layer 116 has been pressed closer to the filmstrip by the stylus. Accordingly, hand-generated information is recorded on the magnetic layer of the filmstrip. 
     It should be noted that the magnetic layer on the filmstrip may include one or more tracks adjacent one or both edges of the filmstrip. These tracks may have information which was recorded on them by a magnetic head in the camera and/or another piece of equipment. It is important that provision be made to prevent the magnetic stylus of the present invention from altering information recorded on these tracks. One method of achieving this goal is to design the magnetic-film-write-on portion such that it does not overlap the magnetic tracks. In this case, the back wall of the camera should be designed to prevent the stylus from getting close enough to the magnetic tracks to alter data on the tracks. Alternatively, small bars made of a soft magnetic material such as iron or permalloy can be positioned at the top and bottom of the write-on portion to shield the magnetic tracks from the magnetic field emitted from the stylus. Of course, the embodiment described above having a magnetic eraser in the camera would also have to shield any magnetic tracks from the eraser&#39;s magnetic field. 
     The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention. 
     PARTS LIST 
     20 camera 
     22 camera body 
     24 rear wall 
     26 view finder 
     28 shutter button 
     30 write-on portion 
     32 magnetic stylus 
     34 recess 
     36 bosses 
     38 hinged door 
     40 cartridge 
     42 photographic filmstrip 
     43 film rails 
     44 anti-static layer 
     45 dimples 
     46 magnetic layer 
     48 base layer 
     50 photochemical layer(s) 
     52 outer surface 
     54 hand-generated information 
     56 dotted line 
     58 arrows 
     60 magnetic field 
     62 magnetic FAX head 
     64 amplifier 
     66 multiplexer 
     68 serial data output 
     70 microprocessor 
     72 memory 
     74 photograph 
     76 inkjet printhead 
     78 helical scanning head 
     80, 88 magnetic heads 
     82, 84, 90, 92 arrows 
     86 arcuate scanning head 
     94 curved lines 
     96 magnetic viewing layer 
     98, 100, 108 permanent magnets 
     102, 106 arrows 
     104 magnetic eraser 
     110 stylus body 
     112 magnetic field 
     114 spherical permanent magnet 
     116 rubber magnetic layer