Abstract:
A moving-image recording/reproducing apparatus for recording/reproducing a plurality of moving images by using a plurality of moving-image I/O passages includes: a plurality of moving-image recording/reproducing devices and a switch device for selectively establishing a connection between the plurality of moving-image I/O passages and the plurality of moving-image recording/reproducing devices. The apparatus further includes a control device for controlling the switching operation of the switch device, wherein the control device performs the recording/reproducing of the moving images input/output from each of the moving-image I/O passages by allocating the moving images to each of the moving-image recording/reproducing devices in accordance with an instructed sequential order, and controls the switching operation in such a manner that a plurality of the moving-image I/O passages are not allocated concurrently to the same moving-image recording/reproducing device.

Description:
This application is a continuation of application Ser. No. 08/091,410, filed Jul. 14, 1993 now abandoned, which is a continuation of application Ser. No. 07/553,411, filed Jul. 17, 1990 now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a moving-image recording/reproducing apparatus, and, more particularly, to a moving-image recording/reproducing apparatus capable of simultaneously recording/reproducing data to and from a plurality of video cameras, VTRs, video disks, displays, printers which are I/O means for moving images connected thereto. 
     2. Description of the Prior Art 
     A variety of moving-image recording/reproducing apparatuses have been developed. For example, a structure which employs an optical disk has been disclosed in Japanese Patent Laid-Open No. 57-78639. According to that disclosure, video signals, audio signals and data signals are, as shown in FIG. 1, recorded on an optical disk, the above-described video, audio and data signals being recorded as optical information (pits) by utilizing the optical permeability, the reflection characteristics, the phase characteristics and the polarization characteristics thereof in spiral or concentric information tracks after the above-described signals have been encoded. 
     Information recorded on the optical disk is reproduced in such a manner that an optical disk  63  is rotated at, for example, 1800 rpm/minute by a spindle  64  and light emitted from a light source  66  such as a laser is applied to a spiral or concentric information track  65  the optical disk  63  via a lens  67 , a half mirror  68 , a reflection mirror  69  and an objective lens  70 . Then, reflected light from the information track  65  which has been modulated in accordance with optical information is inverted so as to be reflected by the half mirror  68 . This reflected light is detected by a light receiving device  72  via a lens  71  so that information is reproduced. In order to make light such as a laser beam accurately follow the information track  65 , focusing and tracking error signals are detected from a signal detected by the light receiving device  72 . In response to the thus detected focusing and tracking error signals, the objective lens is moved in the focusing or tracking direction by the actuator  62 . According to the disclosure, the structure is arranged in such a manner that the above-described optical devices ( 66  to  72 ) are supported by an optical head  73  so as to be integrally moved in the radial direction of the optical disk  63 . As a result, the information tracks are successively scanned in the radial direction. In the case where information is recorded on the optical disk  63 , a structure is employed in which the half mirror  68 , the lens  71  and the light receiving device  72  are omitted from the optical system shown in FIG. 1 and a modulator is disposed between the light source  66  and the objective lens  70 . Furthermore, light having energy larger than that of the light used at the time of the reproduction operation is emitted from the light source  66 , the light having the larger energy being modulated by the modulator in accordance with information to be recorded. The thus modulated light is applied from the inner portion toward the outer portion or from the outer portion toward the inner portion of the optical disk  63 . During the moving process, a spiral or concentric information track is formed for each rotation. 
     When an access to information is made at the time of novel recording or novel reproducing, the optical head  73  is moved in the radial direction by a slider or a linear motor (omitted from the illustration) to a position close to a desired track (rough access). Then, the optical beams are converged onto the subject track (precise access) by using an optical polarizing means (the actuator  62 ). The time in which the optical head  73  is moved from a certain track to a desired track with performing the rough access and the precise access is called “seeking time”. Furthermore, the time taken to seek one-third of all of the tracks is called “average seeking time”, the average seeking time usually being several tens of milleseconds (ms). 
     The above-described moving-image recording/reproducing apparatuses are widely used in a variety of fields in which moving images are used, such as explanation, education and instruction. In the above-described fields, a moving-image recording/reproducing means  76  is, as shown in FIG. 2, connected to a plurality of terminals  75  for displaying a moving image via a communication cable  74 . However, a problem arises in the above-described structure in that, when one moving-image recording/reproduction is performed from any of the plurality of the terminals, another moving-image recording/reproduction to and from the other terminals cannot be conducted. Since the recording/reproduction of the moving image usually takes several minutes or longer, there arises the necessity of a waiting time from start of the recording/reproducing operation performed by a terminal to its completion. 
     In order to overcome the above-described problem, another control system as shown in FIG. 3 has been disclosed. According to this structure, the same continuous moving-images have been recorded on a plurality of moving image recording/reproducing means  76  and a corresponding moving-image recording/reproducing means is selected from the plurality of terminals. As a result, optional moving-image recording/reproducing operations can be simultaneously performed. 
     However, according to the above-described structure, a copy of each of the moving images must be recorded on the recording medium of each of the moving-image recording/reproducing means. Therefore, the overall capacity of the recording medium is reduced and the quantity of moving images which can be recorded/reproduced is thereby reduced (due to the overlap, i.e. redundant, recording). 
     SUMMARY OF THE INVENTION 
     Accordingly, it is and an object of the present invention to provide a moving-image recording/reproducing apparatus capable of simultaneously recording/reproducing a plurality of moving images, the moving-image recording/reproducing apparatus being arranged in such a manner that the recording medium corresponding to a plurality of moving-image recording/reproducing means does not overlap-record the same moving image so as to utilize the maximum recording capacity thereof. 
     In order to achieve the above-described object, according to the present invention, there is provided a moving-image recording/reproducing apparatus for recording/reproducing a plurality of moving images by using a plurality of moving-image I/O passages, the moving-image recording/reproducing apparatus comprising: a plurality of moving-image recording/reproducing means, switch means for selectively establishing a connection between the plurality of moving-image I/O passages and the plurality of moving-image recording/reproducing means, and control means for controlling the switching operation of the switch means, wherein the control means performs the recording/reproducing of the moving images input/output from each of the moving-image I/O passages by allocating the moving images to each of the moving-image recording/reproducing means in accordance with an instructed sequential order and controls the switching operation in such a manner that a plurality of the moving-image I/O passages are not allocated concurrently to the same moving-image recording/reproducing means. 
     Other and further objects, features and advantages of the invention will be appear more fully from the following description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is structural view which illustrates an optical head portion of a conventional moving-image recording/reproducing apparatus which employs an optical disk; 
     FIGS. 2 and 3 each illustrate a configuration in which the conventional moving-image recording/reproducing apparatus is connected to terminals for displaying the image via communication cables; 
     FIG. 4A is a structural view which illustrates an embodiment of the moving-moving image recording/reproducing apparatus according to the present invention; 
     FIG. 4B is a top illustrative view of recording media in FIG. 4A; 
     FIG. 5 illustrates the state of the recording regions and set recording sequency in each of the recording media shown in FIGS. 4A and 4B; 
     FIG. 6 illustrates the operations of each of the optical heads and I/O passages on a time table for the apparatus shown in FIG. 4A; and 
     FIG. 7 illustrates another embodiment of the moving-image recording/reproducing apparatus according to the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An embodiment of the present invention will now be described with reference to the drawings. 
     Referring to FIG. 4A, reference numeral  1  represents a system controller (control means) which controls a crossbar switch  2  for switching the connection between I/O passages  10 ,  20  and  30  for a moving image and optical heads  14 ,  24  and  34  (structured in the same manner as those shown in FIG. 1) which serve as moving-image recording/reproducing means. Encoders  11 ,  21  and  31  and decoders  17 ,  27  and  37  are in parallel disposed between the crossbar switch  2  and the optical heads  14 ,  24  and  34  for the purpose of converting a moving-image signal and an optical recording signal, respectively. The optical heads  14 ,  24  and  34  are secured to sliders  18 ,  28  and  38  so as to move in the radial directions of the optical disks  15 ,  25  and  35  which serve as recording media (FIG.  4 B), the optical heads  14 ,  24  and  34  being moved by slider motors  13 ,  23  and  33  so that data is recorded/reproduced from a desired track. The slider motors  13 ,  23  and  33  are connected to controllers  12 ,  22  and  32  so as to be operated in response to a control command issued from the system controller  1 . The system controller  1  has a control table  6  comprising memory devices. The control table  6  storing the state of use of all of the tracks of each of the optical disks  15 ,  25  and  35  (empty track information, contents of the moving images recorded on each of the tracks and the like) and the state of use of each of optical heads  14 ,  24  and  34  {the state of the operation performed by each of the optical heads  14 ,  24  and  34 , e.g. recording mode, reproduction mode or non-operation state, and the address of the region and the track which is being operated). Referring to FIG. 4A, reference numerals  16 ,  26  and  36  represent motors for operating the optical disks  15 ,  25  and  35 . According to this embodiment, each of the optical disks  15 ,  25  and  35  is divided into five physical recording regions (from the outer circumference to the inner circumference)  41  to  55  (FIG.  4 B). 
     According to this embodiment, the recording procedure performed by the system controller  1  has been previously set in such a manner that the moving images for a file are successively recorded on the total recording regions (15 regions) on the three optical disks  15 ,  25  and  35 , the moving images being recorded in image units for one image. When the image recording on the first 15 recording regions has been completed, the recording operation returns to the first recording regions and recording on the empty tracks is performed. In this case, the optical heads  14 ,  24  and  34  are so controlled that they complete the accesses in a predetermined seeking time. 
     The operation will be described with reference to FIGS. 5 and 6, the description being made about a case in which the I/O passage  20  is commanded to reproduce moving image A during a reproduction of the same moving image A through the I/O passage  10 , and the I/O passage  30  performs a recording of moving image B. Referring to the drawings, symbols a i  and b i  represent the i-th image unit of the moving image A and that of the moving image B respectively. 
     When the system controller  1  receives a record/reproduce signal  3  to be supplied to the I/O passage  10 , the system controller  1  switches the crossbar switch  2  so as to establish a connection between the I/O passage  10  and the decoder  17 . Furthermore, the system controller  1  makes reference to the control table  6  so as to retrieve the track on which first image unit a 1  of the moving image A has been recorded. As a result, the system controller  1  transmits a signal, which represents a command to move the optical head  14 , to the controller  12 . The controller  12  controls the slide motor  13  so as to move the optical head  14  to a desired track. Then, the optical head  14  reads a desired recording signal, the signal then being converted into a desired image signal by the decoder  17 . As a result, the first image unit of the moving image A is transmitted from the I/O passage  10  via the crossbar switch  2 . The controller  1  then switches the crossbar switch  2  so as to establish a connection between the I/O passage  10  and the decoder  27 . Then, the system controller  1  makes reference to the control table  6  so as to retrieve the track on which second image unit a 2  of the moving image A has been recorded. As a result, the system controller  1  transmits a signal, which represents a command to move the optical head  24 , to the controller  22 . The controller  22  controls the slide motor  23  so as to move the optical head  24  to a desired track. A recording signal thus read out is converted by the decoder  27  into an image signal so as to be transmitted as a reproduction signal from the I/O passage via the crossbar switch  2 . As described above, the system controller  1  switches the I/O passage  10  to the decoders  17 ,  27 ,  37  in accordance with a predetermined sequence and reads out the recording signal from each of the recording regions of the optical disks  15 ,  25  and  35  in accordance with the contents of the control table  6 . As a result, reproduction signals for the moving image A are successively transmitted through the I/O passage  10 . 
     When a command to record image signal B through the I/O passage  30  is, in the form of a record/reproduction signal  5 , supplied to the system controller  1  at a time t 3  during the above-described reproduction of the moving image A, the system controller  1  retrieves the control table  6  and detects that the optical head  14  does not reproduce the image unit (a 5 ) of the moving image A which is reproduced at time t 5 . Furthermore, it detects that reproduction from a third recording region  43  has been performed at previous time t 4 . As a result, the system controller  1  retrieves an empty track in the third recording region  43  from the control table  6  so as to record the first image unit b 1  of the moving image B on the third recording region  43  of the optical disk  15 . As the same time, the information concerning the thus retrieved track in the control table  6  is changed from information representing “an empty track” to information representing the contents to be recorded on the retrieved track. Furthermore, the system controller  1  moves the optical head  14  to the retrieved empty track via the controller  12  and simultaneously it switches the crossbar switch  2  so as to establish a connection between the I/O passage  30  and the encoder  11  at the time t 5 . Then, the image unit b 1  is converted into an optical recording signal by the encoder  11  so that it is recorded on the retrieved track by the optical head  14 . At the time t 5 , the fifth image unit a 5  of the moving image A is reproduced by the optical head  24  and the first image unit b 1  of the moving image B is recorded by the optical head  24 . Then, the system controller  1  switches the crossbar switch  2  so as to establish a connection between the I/O passage  10  and the decoder  37  and between the I/O passage  30  and the encoder  21 . Simultaneously, the system controller  1  retrieves the control table  6  (every time when information is recorded on a track, the information concerning this track is changed to represent the recorded contents) so as to move the optical heads  24  and  34  to a desired track so that the recording signal is reproduced/recorded. Then, the recording/reproducing of the moving images A and B is similarly and in parallel performed. 
     When a command for reproduction of the moving image A, which is already being reproduced through the I/O passage  10 , through the I/O passage  20  is, in the form of the recording/reproducing signal  4 , supplied to the system controller  1  at a time t 12 , the system controller  1  retrieves the control table  6  so that the fact that the moving image A is being reproduced is detected. Furthermore, the additional fact is detected that the optical head  14  will perform, at a time t 17 , recording in the recording region in which the first image unit al of the moving image A is recorded, that is, the recording region  41  of the optical disk  15 . A still further fact is detected that the optical head  14  will not perform recording/reproducing at time t 18 . As a result, the system controller  1  switches the crossbar switch  2  so as to establish a connection between the I/O passage  20  and the decoder  17  at the time t 18 . At this time, the I/O passage  10  has been connected to the decoder  37 , while the I/O passage  30  has been connected to the encoder  21  so as to be used for recording/reproducing image units a 18  and b 14 . Then, parallel recording/reproducing is performed in which the moving image A is reproduced through the I/O passages  10  and  20  and the moving image B is recorded through the I/O passage  30 . 
     As shown in FIG. 4B, according to this embodiment, the structure is arranged in such a manner that each of the optical disks  15 ,  25  and  35  is divided into 5 recording regions and the recording operation is moved to the next recording region after one operation of the recording/reproducing from all of the three I/O passages  10 ,  20  and  30  has been completed. Furthermore, the moving order to the recording regions is, for example, arranged in such a manner that the optical head  14  records/reproduces the optical disk  15  by circulating the five recording regions of the optical disk  15  in a sequential order: the recording region  41 , the recording region  43 , the recording region  45 , the recording region  44 , the recording region  42  and the recording region  41 . 
     The optical head  14  reproduces the track having image unit al on the recording region  41  at the time t 18 , and then it reproduces the track having image unit a 19  on the recording region  43  at time t 19 . When the track having image unit a 1  is positioned at the outermost position of the recording region  41  and the track having image unit a 19  is positioned at the innermost position of the recording region  43 , the distance between these tracks becomes 3T−1 assuming that the number of the tracks in each of the recording regions is T. Therefore, the optical head  14  is able to complete its access for the next recording/producing within the seeking time in the above-described recording manner by setting T to be one half or less, preferably one-third, of the number M of tracks which can be sought by the optical head in the non-image signal period (called “a vertical blanking” in an ordinary moving image) of the moving-image signal, where the number M is thus the number of tracks which can be sought by an actuator  62  for use in precise accessing in the above-described period. 
     FIG. 7 illustrates the arrangement of optical heads  59 ,  60  and  61  according to another embodiment of the present invention. According to this embodiment, an optical head  62  is provided so as to serve as a sole recording means. Furthermore, the recording region is divided into three exclusive regions: an inner portion  56 , a central portion  57  and an outer portion  58  to which the optical heads  59 ,  60  and  61  are arranged to exclusively perform the recording/reproducing to and from the corresponding portions. The above-described regions  56 ,  57  and  58  are each, similarly to the optical disks shown in FIG. 4B, divided into, for example, 5 recording regions. Therefore, similarly to the case in which the recording media correspond to the optical heads (see FIG.  4 A), the recording/reproducing can be conducted in parallel with each of the I/O passages. 
     Although the invention has been described in its preferred forms with a certain degree of particularly, it is understood that the preferred forms may be changed in the details of construction and other combinations and arrangements of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.