Abstract:
A digital signal recording apparatus and a method of operating the same, used in conjunction with TV and video cameras, for example for security applications, includes a disk feeder system having a disk recorder and an upper compartment for holding fresh unrecorded disks, a pull slider assembly which pulls a first fresh disk at the bottom of the compartment and places the same and a printing head assembly which imprints coded information onto the placed disk, a disk recorder having a sliding table for supporting the disk and a lower compartment which accommodates the recorded disks. Supported by the sliding table the recorded disk is retracted into the disk recorder which, after the completion of recording, generates a command signal to start a new cycle. An exclusive code is imprinted onto the surface of the disk and coded signals commensurate with the exclusive code are generated by a controller and mixed with the digital video signals recorded by the disk recorder to authenticate the recording of the disk outputted from the disk feeder system. The apparatus may be equipped with a pull lever which engages cutouts provided on a fresh disk tray to transport the tray containing fresh disks from a feeding position to a recording head.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application is a continuation-in-part of application Ser. No. 09/688,901 filed Oct. 16, 2000 and now pending. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This invention relates to digital recording apparatuses used in conjunction with television and video cameras for observation, monitoring and security applications.  
           [0004]    2. Description of the Prior Art  
           [0005]    Signals of television cameras used in an observation system are fed to the monitoring site via closed wired circuits, or via public communication lines such as analog telephone lines or digital telephone lines, or via computer network or via RF links are commonly recorded onto a video cassette, such as the well known VHS, using VHS recorder. The VHS recorder is an analog recorder for recording analog television signals. Such analog recording onto VHS cassettes have been accepted by the courts at large as evidence, primarily on the grounds that the altering of the signals content is extremely difficult and moreover, such tampering with the recorded signals by trying to alter its content can be detected by experts. Moreover, the wide use of such analog recording onto VHS cassettes made the analog recording low in cost and popular. With the recent advances in digital recording of television signals it became simple to record the signal of television cameras used in observation system onto a hard disk of a PC or onto a hard disk of a specially constructed digital recorders. However, the hard disk of the PC or of the digital recorder has a finite capacity, which limits the length of time for archiving and/or storing the accumulated recorded signals. This can be solved by adding multiple hard disks or by using retractable hard disks. However, such retractable hard disk is very costly and requires expertise in handling. Another method to archive and store the recorded digital signals is by transferring the recorded digital signals onto digital tapes, cassettes, diskettes or disks such as the well-known CD or DVD.  
           [0006]    This however causes a serious legal problem, hindering the use of the recorded material in courts; first because the recording is no longer the original recorded media, and secondly, it is literally impossible to identify the original from a copied or transferred data, and thirdly it is simple to alter a digitally recorded picture by changing its color, changing its time and date, removing objects from the picture content or adding objects into the picture. The ability to present a modified picture and to present a copied recording as an original recording, prevents the use of the digitally recorded pictures on tape, disk or diskette as evidence in courts. Furthermore, the tapes, disks and diskettes offer a limited recording time for no more than several hours which requires constant attendance for unloading and loading the tapes, disks and the diskettes, alternatively there are variety of automatic machines known as “juke boxes” for loading, unloading the recorded media that also provide for management of the recorded data. Such juke boxes however have also a finite data storage capacity and are very costly.  
         SUMMARY OF THE INVENTION  
         [0007]    An object of the present invention is to provide a method and apparatus for automatically feeding disks into a digital recorder and for automatically authenticating the recorded disks by imprinting coded information onto the disks and recording a coded data commensurating with the imprinted code into the picture signals, thereby providing the means for authentication of the disk as an original recorded media.  
           [0008]    Another object of the invention is to provide a low cost disk changer that can record continuously a number of disks for an extended period of time by means of a simple loading of fresh unrecorded disks and simple unloading of the imprinted/recorded disks.  
           [0009]    The above objects are achieved by an apparatus for digital recording, which comprises an imprinting head assembly, an upper compartment for holding fresh unrecorded disks, a pull slider assembly for pulling a first fresh unrecorded disk at the bottom of the upper compartment and for placing the pulled fresh unrecorded disk under said imprinting head assembly, said imprinting head assembly imprinting coded information onto the freshly placed disk, a disk recorder having a sliding table for supporting said disk, and a lower compartment for accommodating accumulated imprinted/recorded disks. The pull slider and the sliding table operate in concert such that when the pull slider and the sliding table are fully extended the freshly pulled disk and the imprinted/recorded disk are aligned against each other under the imprinting head. The imprinting head is mounted under a sliding piston to slide down and engage the freshly pulled disk for imprinting the coded information onto the disk surface and for pushing downward the freshly imprinted disk away from the pull slider and into the sliding table, which in turn ejects the imprinted/recorded disk from the sliding table into the lower compartment. Supported by the sliding table, the freshly imprinted disk is retracted into the disk recorder for recording. Simultaneously, the sliding piston starts its upward movement raising the imprinting head while the pull slider retracts into the pull slider assembly readying itself for the next disk pull cycle. As the disk recorder completes its recording it will generate a command signal to start a new cycle of pulling, imprinting and loading a fresh disk into the sliding table to finally eject the newly recorded disk in an endless rotation for as long as fresh disks are loaded into the upper compartment and the imprinted/recorded disks are removed from the lower compartment.  
           [0010]    The objects of the invention are also attained by a method for authenticating the recording of digital video signals onto a fresh unrecorded disk by a disk recorder of a disk feeder system including coding generating and mixing means, and a code imprinter, the method comprising the steps of: feeding said fresh disk from a fresh disk compartment of said disk feeder system to said disk recorder through said code imprinter; generating an exclusive code for each said fresh disk fed to said disk recorder and imprinting said exclusive code onto a surface of said fresh disk such that an imprinted disk is fed to said disk recorder; and generating coded signals commensurating with said exclusive code and mixing said coded signals with said digital video signals recorded by said disk recorder, thereby authenticating said recording of the recorded disk outputted from said disk feeder system.  
           [0011]    The objects of the present invention are further attained by a method for authenticating the recording of digital video signals onto a coded disk by a disk recorder of a disk feeder system including a code reader and a code generating and mixing means wherein said coded disk includes an exclusive code imprinted onto its surface, the method comprising the steps of: feeding said coded disk from a fresh disk compartment of said disk feeder system to said disk recorder through said code reader; reading said exclusive code of said coded disk fed to said disk recorder; and generating coded signals commensurating with said exclusive code and mixing said coded signals with said digital video signals recorded by said disk recorder, thereby authenticating said recording of the recorded disk outputted from said disk feeder system.  
           [0012]    The method of the present invention may be adapted for authenticating the reading back of the digital video signals recorded, from the recorded disk, wherein the disk recorder further includes readback means and said disk feeder system further includes a code reader and a code signal extractor and a comparator, and method further comprising the steps of: loaded said recorded disk into said fresh disk compartment for feeding said recorded disk to said disk recorder through said code reader for reading said exclusive code from the surface of said recorded disk and reading back said video digital signals through said readback means; and extracting said coded signals through said code extractor and comparing said reading of said exclusive code with said extracted coded signals and outputting authentication signals when said exclusive code and said coded signals commensurate. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    The foregoing and other objects and features of the invention will become apparent from the following description, given as a non restrictive example and made with reference to the accompanied drawings, in which:  
         [0014]    [0014]FIG. 1 is a perspective view of an exemplary embodiment of a digital recording apparatus according to the invention;  
         [0015]    [0015]FIG. 2 is a perspective view of a well-known disk recorder with a modified sliding table to enable the ejection of a disk downward;  
         [0016]    [0016]FIG. 3A is a perspective view of a pull slider assembly for pulling a fresh disk from a fresh disk stack of the apparatus of the present invention;  
         [0017]    [0017]FIG. 3B is a top view of a pull slider of the pulling slider assembly of FIG. 3A;  
         [0018]    FIGS.  4 A- 4 F are cross-sectional views showing the process of pulling and loading a fresh disk into the pull slider of FIGS. 3A and 3B;  
         [0019]    [0019]FIG. 5 is a sectional view of a combined pull slider and the sliding table of FIG. 2 and FIG. 3;  
         [0020]    FIGS.  6 A- 6 D are side and front views, respectively, of an imprinting head assembly in its engage-rest states;  
         [0021]    [0021]FIG. 7 is a perspective view of the imprinting head incorporating an imprint readout device;  
         [0022]    [0022]FIG. 8 shows a recording disk with an imprint coat; and  
         [0023]    [0023]FIG. 9 is a block diagram of the system control of the apparatus of the present invention.  
         [0024]    [0024]FIG. 10 is a perspective view of another exemplary embodiment of a digital recording apparatus according to the invention;  
         [0025]    [0025]FIG. 11 is a perspective view of an expanded exemplary embodiment of a digital recording apparatus of FIG. 10 with two disk recorders;  
         [0026]    [0026]FIG. 12 is a perspective view of a digital recording apparatus of FIG. 11 with the disk recorders, a fresh tray stack and a recorded tray stack in an elevated position;  
         [0027]    [0027]FIG. 13 is a perspective view of an embodiment of a tray for supporting a disk;  
         [0028]    FIGS.  14 A- 14 D are perspective views, also showing enlarged view of some parts of a pull slider assembly for pulling a fresh tray from a fresh tray stack of the apparatus of the present invention;  
         [0029]    [0029]FIG. 15 is a perspective view of an elevating platform for up-down moving of the tray stacks and the disk recorders;  
         [0030]    FIGS.  16 A- 16 D are perspective views showing the process of retracting a pull lever and transporting the trays to and from the disk recorder; and  
         [0031]    FIGS.  17 A- 17 D are perspective views showing the retracting and transporting process of the trays with two pull levers. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0032]    [0032]FIG. 1 shows an exemplary embodiment of a digital recording apparatus  1  which includes a compartment  3  for holding a fresh stack of disks  5  on top of a pull slider assembly  10 . The pull slider assembly includes a pull slider  12  that is shown extended all the way out from the pull slider assembly  10 , containing and supporting a pulled fresh disk  5 B into a position directly under an imprinting head  9 . A disk recorder  15  which is mounted under the pull slider assembly  10 , includes a sliding table  17  shown in its extended state and supporting an imprinted/recorded disk SH in a position directly under the fresh disk  5 B. An imprinting assembly  7  which has the imprinting head  9  is attached to a sliding piston  8  which slides down to engage the imprinting head  9  with the upper surface of the fresh disk  5 B for imprinting a coded information  5 C onto the disk  5 B and for pushing the disk  5 B downward out from the pull slider  12  all the way toward the imprinted/recorded disk SH in order to insert the newly imprinted disk  5 B into the sliding table  17  and eject the imprinted/recorded disk  5 H from the sliding table  17  into a lower compartment  30 . The ejected disk  5 H shown in FIG. 1 falls as a free falling disk  5 J onto an accumulated imprinted/recorded disk stack  5 M. A compartment cover  32  is shown opened but it is normally closed during the operation. The compartment cover  32  has a window  32 A for instant viewing of the lower compartment content.  
         [0033]    As the ejected disk  5 J falls into the lower compartment  30  the sliding piston  8  shown in lowered position along with the imprinting head starts its upwards movement cycle away from the pull slider  12  so as to bring the imprinting head  9  into its rest position. Immediately after the imprinting head  9  is pulled up the pull slider  12  that is now emptied from the disk  5 B starts its retracting cycle back into the pull slider assembly  10 . Simultaneously the sliding table  17  that is now loaded with a fresh disk  5 B with an imprint SC starts its retracting cycle back into the disk recorder  15 . The disk recorder  15  shown in FIG. 2 with its sliding table  10  is modified to provide for ejecting the disk downwards, is a well-known disk recorder used in personal computers, such as CD or DVD recorders. The disk recorder  15  will start its recording of picture signals fed to it through the electronic circuits contained in the system control  40  shown in detail in FIG. 9 and described in detail below. The system control  40  also generates the imprinted coded information SC, and mixes commensurating coded signals into the recording of the pictures signals which ties together the physical imprint of the disk to the contained recorded signals, for authenticating the imprinted disk as an original media. Referring to FIG. 2 the disk recorder  15  comprises a case  15 H, a body  15 A, a recording control circuit  15 B, a recording and playback head  1 SE, a disk drive  15 C, a head drive  15 F and the sliding table  17 . The sliding table  17  includes a geared bar  17 D driven by a driving gear  15 D reciprocally, and a motor controlling the gear  15 D. Such a motor is a well known motor with a gear assembly and is therefore not shown. The sliding table further includes an opening  17 C for providing the supported disk  5 H of FIG. 1 to be ejected downwards, a tapered circumferential rim  17 A for supporting the disk  5 B or  5 H of FIG. 1 while moving the disk in and out from the disk recorder, and circumferentially extending tongs  12 B for gripping the disk SH prior to the final ejection. The disk drive  15 C of the well known disk recorder  15  raises the disk upwards away from the sliding table  17  during the recording or playback process, by the well known disk drive  15 C and lifting mechanism (not shown), and the recording/playback head  15 E travels throughout the width of the disk by the well known head drive mechanism  15  (not shown). Accordingly, the supported freshly imprinted disk  5 B of FIG. 1 is driven into the disk recorder  15  by the sliding table  17 ; it is then lifted by the disk drive  15 C for recording, and when the recording is complete the disk drive  15 C lowers the freshly recorded disk  5 D onto the sliding table which is then extended outwards by the drive gear  15 D and placed into the position under the fresh pulled disk  5 B. The pull slider assembly  10  is constructed essentially with a pull-sliding table  12  similar to the sliding table  17  of the disk recorder  15 .  
         [0034]    Shown in FIGS. 3A and 3B, is the pull slider assembly  10  including a case  10 H, a body  10 A, a control circuit  10 B, an opening for fresh disks  10 C, a support  10 S for the first disk in the stack, a cushion  10 G and a pull slider  12 . The pull slider  12  includes a geared bar  12 D driven by the driving gear  10 D reciprocally, an opening  12 C for allowing a fresh disk to be pushed through downwards, a tapered circumferentially extending rim  12 A for centering the pulled disk and tongs  12 B extending downwards from rim  12 A for gripping the pushed disk during the imprinting process. The pull slider  12  further has a flexible pull lever  12 S shown in FIG. 3A for pulling the first or the bottom disk  5 A from the fresh disk  5  stack shown in FIG. 1.  
         [0035]    FIGS.  4 A-FIG. 4F show the process of pulling and feeding the disk  5 A into the sliding table, wherein FIG. 4A shows the pull slider  12  at its initial retraction and the flexible pull lever  12 S which is about to be compressed under the disk  5 A. FIG. 4B shows the pull slider  12  at its mid-way retraction with the pull lever  12 S/D slides under the disk  5 A. FIG. 4C shows the pull slider  12  fully retracted and the pull lever  12 S stretching fully behind the disk  5 A, ready to engage the disk rim. FIG. 4D shows the pull slider  12  in its early movement outwards pulling the disk  5 A to a point just before the disk  5 A leaves its support  10 S and cushion  10 G. FIG. 4F shows the disk  5 B being pulled by the movement of the pull slider  12  outwards and falling into the tapered rim  12 A while the newly first fresh disk  5 A falls onto the cushion  10 G.  
         [0036]    When the recording of the disk is complete the control system  40  generates a start cycle command to the pull slider  12  to pull and feed a fresh disk  5 B to its imprinting position under the imprinting head and to the sliding table to remove the imprinted/recorded disk  5 D from the disk recorder and position the disk under the disk  5 B. Thereafter, as the disks are positioned under the imprinting head  9  the piston  8  starts its downward movement to engage the printing head  9  with the upper surface of the fresh disk  5 B and thereby also push the imprinted disk  5 B downwards into the sliding table  17  all the way so that the imprinted/recorded disk SH is ejected into the lower compartment  30 .  
         [0037]    [0037]FIG. 5 shows the pull slider and the sliding table being combined into a single sliding table  22  in which the pulling of a disk from the fresh disk compartment and the feeding of the disk to the disk recorder is performed by a single sliding table, wherein the tapered rim  12 A, tongs  12 B and the pull lever  12 S of the pull slider  12  are replaced by a tapered rim  22 A, tongs  22 B and a pull lever  22 S of the combined slider  22 . The tapered tongs  17 B and the geared bar  17 D of the sliding table  17  are replaced by tapered circumferentially extending tongs  27 B and a geared bar  27 D of the combined slider  22 , which otherwise operates in the same manner as the two individual sliders  12  and  17 .  
         [0038]    The shown pull lever  12 S of FIGS. 3A and 3B or the pull lever  22 S of FIG. 5 are simplified illustrations of a pull lever. In practice such lever may be supplied with means for preventing damage to the disk surface, by using rollers, balls or other rotating parts to prevent direct touch by the pull lever onto the surface of the disk. Similarly, the tapered rim  12 A or the tong  12 B of FIG. 3A and the tongs  17 B of FIG. 2 or the tapered rim  22 A and the tongs  22 B and  27 B of FIG. 5 are simplified illustrations of the support means for the processed disks. Many other shapes and forms can be used for placement, support and ejection of the processed disks. Similarly, the geared bars  12 D and/or  27 D of FIG. 3A and FIG. 5, respectively, along with the drive gears  10 D and  15 D can be differently constructed to drive the sliding table  17 , the pull slider  12  or the combined slider  22 .  
         [0039]    Shown in FIG. 6A, FIG. 6B and FIG. 6C is an imprinting head assembly  70  which consists of the imprinting head  9 , piston  8 , a motor assembly  70 M, a cam  70 C, a spring  70 S and a guide  70 G. FIG. 6A shows a side view of the assembly  70  with the piston  8  and the imprinting head  9  in their engaged state denoted at  50 A and their rest state denoted at  50 , FIG. 6B shows a front view of the assembly  70  in its engaged state identical to that of FIG. 6A, with its spring  70 S fully compressed, while FIG. 6C shows the same front view of the assembly but with its piston  8  in a raised position and the imprinting head  9  being in its rest position. The spring  70 S of FIG. 6C shown in its decompressed or expanded state. The guide  70 G shown attached to part of the body of the imprint assembly  7  (not shown in these figures) is a well-known bushing for guiding the piston up-down movement. FIG. 6D shows another well known reciprocal arm  71 A supporting the imprinting head  9  attached to a threaded bushing  71 B driven up-down by a threaded shaft  71  and powered by the motor  70 M. The illustrated movement of the imprinting head assembly is achieved by use of a well known up-down piston or a threaded shaft driven mechanism. However, there are many other well known mechanical devices to drive an imprinting head up-down and for applying pressure onto the imprinted disk while imprinting a coded information  5 C shown in FIG. 1 so as to place/eject the disks into and from their respective sliders. The imprinting head itself can be a well known laser imprinter, a well known heat stamping head, a well known LED illuminator/imprinter, a well known ink jet imprinter, a well known optical/chemical imprinting head, a well known ribboned imprinter, or a well known adjustable rubber pad. Many other well known imprinting methods and heads can be utilized and moreover, as will be explained later, the fresh disks  5  of FIG. 1 can be fed already imprinted to the fresh disk compartment  3  and/or the imprinter head can be replaced by a well known sticker applicator, sticking imprinted bar codes or other imprinted coded, non removable stickers onto the fresh disk surface.  
         [0040]    Shown in FIG. 7 is the imprinting head assembly  9  including a transparent surface  9 A for providing a light passage for lasers  9 B or LEDs  9 C along with a reader/sensor  9 D for reading the imprinted code. The reader/sensor  9 D shown uses a wide angle lens with an CCD device. However, any other well known type of imprint reader/sensor such as CMOS, pin diodes or photo transistors can be used instead. The lasers  9 B and LEDs  9 C can be used for the imprinting process, while the LEDs  9 B can be used for illuminating the imprint to enable the reader/sensor  9 D to read the imprint such as the imprinted code  5 C shown in FIG. 1.  
         [0041]    The conventional disk recorder  15  shown in FIG. 2 further includes playback circuits for reading the signals from the recorded disk and for outputting the playback signals to a processing circuits of the system control  40 .  
         [0042]    Shown in FIG. 9 is a block diagram of the system control  40  which includes a master control circuit  41  for setting, controlling and operating the system, a recording processor circuit  42  for processing video input signals fed through a video input  48  and code signals fed from a code generator  45  and for feeding the processed signals to the disk recorder  15  in accordance to control command of the master control circuit  41 . The code generator  45  also generates an exclusive, individual coded information to the imprinting head  9  for each disk being fed to the imprinting head  9 , wherein the coded signals fed to the recorded processor  45  commensurate with each such exclusive, individual coded information fed to the imprinting head  9 . A playback processor  43  of the system control  40  receives the read out signals from the disk recorder  15  and the read out code from the imprinting head  9  via the code reader circuit  44  and compares the code contained in the playback signals with the code read by the imprinting head, and feeds the comparison data to the master control circuit  41  and/or generates a yes or no signal to the master control circuit and/or into a display signals through a video out terminal  47 . A loading, unloading, sensing and control circuit  46  is fed with sensing signals from well known sensors such as LED interrupters, or micro switches (not shown) for sensing the state of the pull slider  12 , sliding table  17 , imprinting head  9  and/or gauging such item as the level of fresh disks  5  or the level of accumulated recorded disks  5 M shown in FIG. 1. The loading, unloading, sensing and control circuit  46  feeds the received data to the master control circuit  41  and receives control commands from the master control circuit. It is clear that by the read-write arrangement of the system control  40  it is possible to load pre-imprinted fresh disks and to generate a code signal commensurating with the pre-imprinted code that is read by the reader/sensor  9 D of the imprinting head  9  and feed the generated code signal to the record processor circuit  42  for recording the video signals mixed with the generated code. The code signal generated by the code generator  45  may be an encrypted code, and use such data as time and date, station number, camera number, recorder number etc. It can be so designed that the imprinted coded information cannot reveal to the laymen any details of the actual recorded code, and that it will be impossible for a laymen to decipher the recorded code. By this it will only be possible to playback a recorded disk using the digital recording apparatus shown in FIG. 1 and only when the readout code and the extracted code from the playback signal commensurate. Only under such condition it will be possible to verify that the recorded disk is an original recorded media.  
         [0043]    The disk  5  shown in FIG. 8 consists of a disk body  5 U, a recording layer  5 R, a top layer  5 T and an imprinted surface or a labeled surface  5 L. A pre-imprinted label can be attached to the disk surface to form labeled surface  5 L but only if such a pre-imprinted label is a well known label that cannot be removed from the disk without being torn, thereby, preventing the re-use of such label with another disk. The layer or the label  5 L shown covers most of a disk surface  5 T. However, a smaller label  5 L can be used instead, or it is possible to attach such labels by a well known (not shown) label applicator incorporated with the imprint head assembly.  
         [0044]    The imprinted surface or the imprinted layer and/or the label  5 L can be made of a soft materials or combined with soft materials or such layers can be provided with a soft rim for providing scratch protection to the disks when they are stacked up one on top of the other. Furthermore, the layer  5 T can be a layer specifically matching the imprinting process such as optical/chemical process.  
         [0045]    For the purpose of submission of evidence in courts it is preferable to use a well-known disk  5  that cannot be erased, nor re-recorded. Such imprinted disk that can only be recorded once and is recorded with a mix of code signals as explained above, provides a proof that such a digitally recorded disk is an original recorded media. Moreover, even the use of re-writable disk that can be erased and/or re-recorded and which is recorded by using the recording processes described above greatly inhibits the ability of a laymen to manipulate any individual picture and/or part of a picture, particularly when the code signals mixed with the picture signals are dynamic, encrypted and vary for every individual picture being recorded. Moreover, the controller can be programmed to read first the coded signals and the exclusive code and generate record stop command to prevent re-recording of a recorded/imprinted disk or to prevent the recording of a twice imprinted disk.  
         [0046]    The present invention also provides for a continuous feed of disks to a digital recorder apparatus for instances that do not require the disk to be used as evidence. Alternatively the present invention can be used for an automatic search of a disk for a playback purposes only and the like.  
         [0047]    The disks changing mechanism of the digital recording apparatus  1  of FIG. 1 uses gravitation and the free fall of disks for the loading/unloading process. However, such disk changing method prevents the introduction of multiple disk recorders  15 , nor does it provide for individual trays or containers to support or protect the disks  5 .  
         [0048]    A digital recording apparatus  130  of FIG. 10, which shows a further embodiment of the present invention, offers a different disk changer mechanism wherein fresh disks  5  are supported by a tray  60 . The stack of the fresh disks consisting of multiple trays  60 W each containing a disk  5  shown in FIG. 10 is placed between the bottom tray  60 E and the top tray  60  inside a fresh disk compartment  59  shown with its front cover  54  in the open position. The trays in the fresh disk compartment  59  are supported by an elevating platform  80  which raises the entire stack in steps equal to a single tray thickness, readying the tray  60  for a pull cycle by a pulling assembly  100 . The pulling assembly  100  transports the tray  60  to a position  60 A which is the loading position of a disk onto a disk recorder assembly  55 . The disk recorder assembly  55  is identical to the well known disk recorder  15  of FIG. 2 except that it is operated without the outer cover  15 H and without the sliding table  17  which is no longer needed because the disk  5 W is loaded by the tray  60 A directly to the disk driver  15 C shown in FIG. 2. The disk recorder  55  is supported by a holder  55 A having a length equal to the length of the tray  60 .  
         [0049]    As the pulling assembly  100  completes its forward cycle to load the tray  60  into the disk recorder  15  or to its new position  60 A the elevating platform  80  is activated to elevate the stack of the fresh disk trays  60 W by a single step so as to bring the upper disk  60 W into position  60 . Once the tray carrying the fresh disk  5  is in position  60  the imprinter or the code reader  9  will operate in a manner described for the digital apparatus  1  of FIG. 1, with the exception that it no longer applies pressure onto the disk  5  to eject it. Furthermore, when the code reader  9  reads the code from the disk surface it does not need to slide down or to contact he disk, because it can read the code from a distance. When the imprint or the readout is complete the tray  60  with the disk  5  becomes ready for transporting and when the disk recorder  55  completes the recording of the disk  5 W the disk driver  15 C of FIG. 2 releases the disk  5 W, thereby readying the changer mechanism for a new loading/unloading cycle to begin.  
         [0050]    The pulling assembly  100  moves in a reciprocal movement on the guide rail and gear rack assembly  101  in a retraction direction  107  all the way to engage the tray  60  and in a transporting direction  108  to pull the tray  60  toward the disk recorder  55  and into position  60 A. As the tray  60  starts its movement into position  60 A its front side  64  shown in FIG. 13 pushes the tray  60 A with the recorded disk  5 W toward the position  60 B and when the tray  60  reaches into position  60 A the prior tray  60 A is pushed all the way out from the disk recorder  55  onto the elevating platform  80 B. The elevating platform  80 B is identical to the elevating platform  80  for lowering the recorded trays stack as shown in FIG. 12 by a step equal to one tray thickness. By this step the changer mechanism  130  is readying itself to start the next unloading cycle.  
         [0051]    The pulling assembly  100  shown in FIG. 14A includes a body  102  accommodating a motor  104  with a gear  105  for engaging a gear rack  101 A such that the reciprocal rotation of the motor  104  drives the pulling assembly  100  in the retracting direction  107  and the transporting direction  108 . The pulling assembly  100  further includes a pulling lever  103  for engaging a tray cutout  65 L shown in FIG. 13 and for pulling the tray  60  during the transporting cycle.  
         [0052]    Shown in FIGS.  16 A- 16 D is the movement of the pulling assembly  100  during retraction and transporting actions. FIG. 16A shows clockwise rotation  107 A of the gear as it begins the retracting movement from the position  100 A which is its maximum forward state or loading position. As shown in FIGS. 16B and 14A the pulling assembly is in its middle-way retraction with its pull lever  103  depressed inwards by the tray side so as not to obstruct the retracting movement and, as shown in FIG. 14A, the pull lever  103  has a pivoted lever  103 A impelled outwards by a spring  103 B. FIG. 16C shows the pulling assembly  100 C starting its transporting cycle from its maximum retracting position at which time the pull lever  103  is impelled into the tray cutout  65 L to engage the tray  60  and pull it toward the loading position  60 A. FIG. 16D shows the process of the transporting cycle in which the tray  60  is in its middle-way position  60 D pushing the tray  60 A to a middle-way position  60 U.  
         [0053]    Instead of using the motor  104 , the gear  105  and the guide rail with a gear rack  101  (FIG. 14A) for transporting and retracting the pulling assembly  100  it is possible to use many other types of transporting mechanisms such as a chain, belt, threaded shaft or timing belt. Shown in FIG. 14B is such mechanism  120  using a timing belt  121 , driven by a motor  124  and sprockets or timing gears  122  and  123  (FIG. 14B). A body  125  of the pulling assembly  120  is similar to the body  102  of pulling assembly  100  except that it is driven by the timing belt  121  shown in FIG. 14B instead of the motor  104  and gear  105  of FIG. 14A.  
         [0054]    Instead of using a single pull lever  103  it is possible to use multiple pull levers such as the  103  and  113  as shown in FIG. 17A, which depicts the movement of a pulling assembly  110 A at the initial retracting cycle. FIG. 17B shows a pulling assembly  110 B at its middle-way retracting cycle with its pull lever  113  being depressed by the side of the tray  60 A. FIG. 17C shows a pulling assembly  110 C at the start of the transporting cycle and FIG. 17D shows a pulling assembly  110 D at its middleway transporting cycle. The pull lever  103  shown in FIGS. 17C and 17D is shown engaging the fresh tray  60 , while the pull slider  113  is engaging the recorded disk tray  60 A and transporting the tray  60  to a mid position  60 D and the tray  60 A to mid position  60 U.  
         [0055]    The pull levers  103  shown can be made in different shapes, or they can be made to engage a cutout or cutouts such as the cutout  65 L of the tray  60  shown in FIG. 113 from the upper surface of the tray or it can be made to engage the cutouts  65 L of both sides of the tray simultaneously. The pull lever  103  shown in FIG. 14A consist of a hinged pull lever  103 A driven or propelled by a spring  103 B however instead of the pull lever  103 A it is possible to use a pull lever similar to the pull lever  12 S of FIG. 4B without the use of the spring  103 B. Moreover, the pull lever  103 A can be differently shaped or constructed as long as it does not hinder the retraction of the pulling assembly  103  and engages the tray  60  during the transporting cycle.  
         [0056]    Instead of using a spring propelled or self propelled pull lever it is possible to use a motorized or electrically activated pull lever or a pull pin such as  103 M and  103 N as shown in FIGS. 14C and 14D. The pull lever  103 M comprises a motor  103 U with a worm and a mating worm gear with a cam assembly  103 P. A motor  103 U will rotate the worm gear/cam assembly such that the cam protrudes during the transporting and retracts inwards into the pulling assembly body  102  during the retracting cycle. The pull lever  103 N is a plunger pin  103 W of a magnetic activated plunger unit  103 Q that is retracting into the plunger body when electrical power is applied to the plunger coil during the retracting cycle, while during the transporting cycle the electrical power is cut, the plunger  103 W is propelled and engages the cutout  65 L of the tray  60 .  
         [0057]    The tray  60  shown in FIG. 13 includes a recessed compartment  63  for supporting a disk, the side cutouts  65 L and  65 N for engaging the tray by the pull lever of FIG. 14B, a single or dual groves  62  (FIG. 13) for supporting a single or dual guides  68  of the tray on top of it in the tray stack. The single or dual guides  68  are provided for aligning the tray  60  into position onto the tray under it in the tray stack. Instead of the cutout  65 L used for engaging the pull lever  103  it is possible to add a projected portion on the side of the tray for engaging the pull lever. A grove  61  on the side of the tray  60  guides the tray movement onto the side rail  58  of the disk changer  130  of FIG. 10.  
         [0058]    The elevating platform  80  shown in FIG. 15 comprises a platform body  71  attached to a motor  72  with dual ended shaft terminated with a clockwise worm  73  at one end and a counterclockwise worm  73 A at the other end. The platform  71  is further attached to two gear assemblies  74  and  74 A, each consisting of a mating worm gear  76  and  76 A and a shaft  74 S terminated with two gears  75  and  75 A. The dual gear assemblies  74  and  74 A are positioned against the dual gear racks  53  and  53 A respectively, such that when the motor is energized and operated reciprocally the elevating platform will elevate or descend along the gear racks  53  and  53 A that are mounted inside the fresh and the recorded tray compartments  59  and  85  of FIG. 10, respectively.  
         [0059]    Well known LEDs, micro-switches or magnetic hall sensors and the like (not shown) can be employed to ensure correct and precise movements. Alternatively the motor  72  can be a stepping motor so that its step movements are precisely controlled, or other well known microprocessor control systems can be utilized to correctly and precisely set the up-down steps of the elevating platform  80  and/or how many steps should be incorporated in each command. Many other well known mechanical arrangements can be employed to raise or lower the elevating platform  80  such as chains and sprockets, timing belt with timing gears similar to the one shown in FIG. 14B or threaded shafts similar to the one shown in FIG. 6D.  
         [0060]    The digital recording apparatus  130  of FIG. 10 comprises a single disk recorder  55  having a finite recording capacity per time unit and it may be necessary to provide multiple disk recorders  55  to increase the recording capacity per time unit. For this the digital recording apparatus  131  of FIG. 11 comprises two disk recorders  55  mounted on top of an elevating platform  80 A, which is identical to the elevating platforms  80  and  80 B for elevating or descending the disk recorders  55  along the gear racks  53  and  53 A mounted in the disk recorder compartment  90 .  
         [0061]    The upper disk recorder  55 - 1  is positioned precisely as the disk recorder  55  of FIG. 10 is positioned and when the loading and unloading trays to and from the disk recorder  55 - 1  takes place the digital recording apparatus  51  will operate in the exact same manner as the digital recorder apparatus  130  of FIG. 10 is operated. However, when the need to unload and load a tray into the lower disk recorder  55 - 2  the elevating platform  80 A is activated to raise the disk recorder  55 - 2  along with the disk recorder  55 - 1  by several steps to align the disk recorder  55 - 2  with the tray  60  and tray  60 Z shown in FIG. 12.  
         [0062]    Same procedure will be applied to three, four, or more disk recorders  55  that may be added to the digital recorder apparatus  51 . Alternatively, the three elevating platforms  80 ,  80 A,  80 B and the pulling assembly  100  along with an elevating platform for the guide rail and gear rack assembly  101  (not shown) may be raised or lowered in concert, such that the loaded and unloaded trays are aligned for transporting the fresh trays  60  into the respective disk recorders  55 - 1 , or  55 - 2  or into additionally added disk recorders  55  and the recorded trays  60 B onto the recorded tray stack.  
         [0063]    The disk-feeding apparatuses  130  and  131  of FIGS. 10 and 11 respectively, can be used for recording of digital signals onto well known digital disks such as CD or DVD for purposes other than video and/or with or without the use of the imprinter and/or the code reader  9 . For such application it is possible to use the described disk feeding apparatus with or without the imprinter and/or the code reader  9 .  
         [0064]    It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purpose of the disclosure, which modifications do not constitute departures from the spirit and scope of the invention: