Video player with power
Contents
1. 13 A video disk player for reproducing still pictures on a video display from a composite color video signal recorded as one field per circular track on a flexible magnetic disk having many such tracks said player comprising a playback head for sensing the composite signal recorded on the disk means for urging said playback head into physical contact with a selected track on the disk means for supporting the magnetic disk for rotation relative to said head said supporting means includ ing a drive motor for rotating the disk means for separating luminance and chrominance signals from the composite signal means for separating a synchronizing component from said luminance signal means for generating a substitute synchronizing com ponent signal processing means responsive to said separated synchronizing component for generating a video display signal from input signals derived from said luminance and chrominance separating means a system controller for operating the player accord ing to externally generated instructions said con troller generating a power down signal after a pre determined time interval has elapsed without re ceipt of said external instructions means responsive to said power down signal for inac tivating said drive motor and for routing said sub stitute synchronizing signal to said signal process ing means in lieu of said separated synchronizing signal means responsive to said substitute synchro2. no selection or instruction is received during the play interval and the power down signal PDN is generated the system processor 36 inacti vates the drive motor 14 and sends the blanking signal BLANK to the signal processing circuit 32 The signal BLANK instructs the signal processing circuit to enter its second mode and produce the second video signal a picture blanking signal for the display 34 Meanwhile the drive motor 14 comes to a stop the disk 10 there with and the head 26 no longer generates a playback signal Importantly the head 26 though still adjacent the surface of the disk 10 is no longer traversing the track A and stressing or even wearing away the mag netic material In addition instead of showing an unap pealing noisy raster the display 34 shows a blank black screen or any other image desired for example from a text generator Once the system processor 36 puts the player into the quiescent state due to receipt of the power down signal PDN the system processor 36 immediately sends the signal RST to restart the timer 52 The timer 52 pro ceeds to count until a second predetermined interval of time the quiescent interval has elapsed Should a selec tion from the control unit 40 or an instruction from the auto playback section 38 be received before the second interval has elapsed the system processor 36 energizes the drive motor 14 and deactivates the blanking signal BLANK The circuit 32 then rever
3. one passage of the camera s recording head over a circular track on the disk the head will repetitively pass over the same circular area prior to taking the picture According to the invention a quies cent timer is set when the camera is turned on Then if the camera s shutter is not released in say 5 minutes the camera enters a quiescent state to minimize disk wear and to conserve energy since the camera runs off bat tery power The power consuming part of the camera s electronics as well as a disk motor are inactivated The recording head remains in the recording position and certain parts of the electronics e g a microprocessor remain powered in order to receive and process a reac tivate signal A partial depression of the shutter button restores the camera to full operation and the quiescent timer is reset e g to 5 minutes Alternatively if the shutter button was not depressed for say 30 minutes the quiescent state is terminated and the camera is com 4 717 968 9 pletely inactivated The recording head is retracted to a home position relative the edge of the disk and all of the electronics is shut off The user must reactivate a main power switch to use the camera again The camera therefore utilizes elements of the invention that is the 5 automatic entry of a quiescent state after a first time interval and the automatic termination of the quiescent state and inactivation of the apparatus after a second ti
4. sys tem controller in the meantime starts timing out the predetermined quiescent interval If the quiescent inter val passes without any user input from the remote unit 40 then the signal P EN to the power supply 54 changes state and causes the power supply 54 to deener gize the section 545 producing the supply voltage V This deenergizes the portion of the player devoted to signal processing and to the drive system The system controller 30 remains powered from the supply section 54a which provides the supply voltage V The system controller 30 is shown in greater detail in FIG 3 A microprocessor 100 such as an Intel 8031 microprocessor provides the central processing capa bility Operating programs for the player are stored in a program memory ROM 102 Input data is received from the player directly by the microprocessor 100 and by an input buffer 104 Output data is provided to the player by a latch 106 and could also be provided di rectly by the microprocessor 100 The four phase sig nals 1 64 to the stepper motor 16 are generated by a driver 108 pursuant to instructions relayed from the microprocessor 100 through the latch 106 Addresses and data are moved back and forth through a bus struc ture 110 Memory instructions are accessed by ad dresses latched off the bus 110 by an address latch 112 The system controller components are each enabled by respective lines tied to the microprocessor 100 More particularly
5. system controller and signal processing blocks shown by FIG 1 FIG 3 is a diagram showing more detail of the sys tem controller and FIG 4 is a functional flow diagram for a computer program that may be used with the system controller of FIGS 1 2 and 3 to place the player in a quiescent state DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG 1 shows a general diagram of a video disk player incorporating a quiescent state and auxiliary features according to the invention A magnetic disk 10 is attached by its hub 12 to a disk drive motor 14 A stepper motor 16 is connected by a reduction gear 18 to a lead screw 20 which mates with a threaded hole 22 in a non rotatable head block 24 A playback head 26 is mounted on the head block 24 The head block 24 is supported for movement radially of the disk 10 so that the playback head 26 may be positioned in contact with a selected track on the disk 10 such as a magnetic track A The player includes a system controller 30 enclosed by broken lines and a signal processing circuit 32 The primary function of the player is to reproduce a play back signal from the selected magnetic track A and to generate from that a video signal suitable for displaying a selected still picture corresponding to the playback signal on a video display 34 For purposes of this inven tion the signal processing circuit 32 operates in two modes in the first mode the circuit 32 responds to the playbac
6. the read and write enable lines RD and WR connect to the buffer 104 and the latch 106 respec tively for read and write operations The address en able ALE and the program store enable line PSEN 40 45 50 55 60 65 8 enable the address latch 112 and the memory 102 re spectively for external data memory access and exter nal program memory fetch operations Each compo nent of the system controller 30 is continuously pow ered by the section 54a of the power supply 54 though the remainder of the player may be deenergized A program of the type shown as a flow diagram in FIG 4 is stored in the program memory 102 for powering parts of the player down the drive motor 14 when in the quiescent state and all of the player but the system con troller 30 and the receiver 44 when in shutdown The player as thus far described assumes that the drive motor 14 stops and the head 26 simply stays put in the quiescent state e g by providing only two of the phase signals 1 64 This makes it quite straightfor ward for the signal processing circuit 32 to resume in the first mode FIG 1 when the motor 14 is restarted again showing the picture last seen on the display 34 However it may be desirable to move the head to some parking position at the edge of the disk or to separate the head from the disk when the drive motor 14 and the player sit in the quiescent state In such a case the mi croprocesser 100 which is normally monit
7. United States Patent ro 11 Patent Number 4 717 968 Painton et al 45 Date of Patent Jan 5 1988 54 O WH POWERBONN FOREIGN PATENT DOCUMENTS 127266 7 1984 Japan 75 Inventors Richard C Painton Webster Jay D Marchetti Rochester John J Acello OTHER PUBLICATIONS East Rochester John J Bradley IEEE Transactions on Consumer Electronics Kihara et Rochester Richard H Bolton East al vol CE 28 No 3 pp 325 330 8 82 Rochester all of N Y User s Manual Iomega Cartridge Disk Subsystem 7 84 73 Assignee Eastman Kodak Company Primary Examiner Robert L Richardson Rochester N Y Attorney Agent or Firm David M Woods 21 Appl No 776 239 57 ABSTRACT A video player includes a playback head that repeatedly 22 Filed Sep 16 1985 passes in contact with a circular track on a flexible magnetic disk in order to reproduce a still picture on a 51 Tnt CIA aene iere conet H04N 5 781 video display By cycling the player into a special quies 52 US D PEE 358 310 358 342 cent state after a certain interval elapses without user 360 10 1 360 35 1 360 69 360 74 1 369 33 instructions excessive disk wear is avoided While in 58 Field of Search 358 335 342 906 310 the quiescent state the disk drive motor is stopped im 360 10 1 35 1 55 69 74 1 74 4 75 105 mobilizing the disk to head interface and the video 369 19 33 display is blanked If user instructions are receive
8. ayer if the on off button is actuated from the control unit 40 The functional routine for putting the player into the quiescent state and then into shutdown is shown by the flow diagram of FIG 4 For the example shown the first predetermined interval play interval is 5 minutes and the second predetermined interval quiescent inter val is 55 minutes The timer 52 is shown in its preferred form as software timing routines 55 and 56 These tim ing routines are interrupted by a selection or an instruc tion and the flow reverts back to the beginning of the diagram If 5 minutes run out before a new selection is entered the display is blanked and the drive motor stops Then if 55 more minutes run out without any selection the player is turned off Thereafter the player only responds to the on off selection from the control unit However any selection forward reverse etc other than on off during the 55 minutes of the quies cent interval turns the drive motor on and returns the last picture to the display Depressing the on off button puts the player into the semi powered shutdown mode The user in effect always picks up where view ing left off regardless of the button pushed except the on off button thereafter the buttons resume their normal functions and other pictures may be displayed FIGS 2a and b taken together are a generally more detailed diagram of the player and in particular of the signal processing c
9. cluded in the player operates in two modes In its first mode a playback signal recovered from the disk is converted into a first video signal for displaying a still picture on the display In its second mode a second video signal is generated for displaying some predetermined image e g a blank screen on the display in lieu of the still picture A sys tem controller in the player includes timing means for generating a power down signal after a predetermined interval elapses without any selections from the control unit Means responsive to the power down signal inacti vates the drive motor that rotates the disk and instructs the signal processing circuit to enter the second mode and route the second video signal to the display There upon the disk comes to a stop and the display is blanked The player then assumes a quiescent state in which it is still responsive to selections from the user A selection made by the user during the quiescent state will reacti vate the drive motor thereby regenerating a playback 4 717 968 3 signal and instruct the signal processing circuit to re turn to the first mode and route the first video sig nal the picture to the display BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described with reference to the drawings in which FIG 1 is a block diagram showing a video disk player arranged according to the invention FIGS 2a and 2b are diagrams elaborating in particu lar upon the
10. d while in this state the disk drive motor is reenergized 56 References Cited and the video display is resumed showing the still pic U S PATENT DOCUMENTS ture displayed prior to interruption If no user instruc 4 120 010 10 1978 Mitsuya et al 360 75 tions are received during a further interval the player is 4 470 076 9 1984 Arai et al 360 35 Shut off 4 556 919 12 1985 Fujibayashi 360 74 1 4 635 145 1 1987 Horie et al 360 75 X 15 Claims 5 Drawing Figures US Patent Jan 5 1988 Sheet 1 of 5 4 717 968 D eU US Patent Jan 5 1988 Sheet 2 of 5 4 717 968 74 SYNC TIP CLAMP SPEED CONTROL di 0203 04 lit M STOP M LOCK M EN P EN SYSTEM CONTROLLER POWER SUPPLY 30 SIGNAL PROCESSING FIG 2a amp DRIVE SYSTEM US Patent Jan 5 1988 Sheet 3 of 5 4 717 968 Jan 5 1988 Sheet 4 of 5 4 717 968 US Patent Zol WOU YOSSIIOHd E cd cd v NI d ANV 18 OYW NI WAY N3 W 390 UW dOLS W US Patent Jan 5 1988 Sheet 5 of 5 4 717 968 DO SELECTION PRODUCE BLANKING SIGNAL POWER DOWN QUIESCENT STATE SHOW LAST PICTURE TURN ON MOTOR TURN OFF MOTOR FIG 4 INACTIVATE POWER POWER OFF SUPPLY V SHUT DOWN 4 717 968 1 VIDEO PLAYER WITH POWER DOWN CAPABILITY BACKGROUND OF THE INVENTION 1 Field of the Invention T
11. d positioning means to move from track to track according to 5 Said prearranged instructions and said means for generating a power down signal addi tionally generates said power down signal after a predetermined interval has elapsed without receiv ing any prearranged instructions 10 8 In a video disk player capable of cycling between a powered state and a semi powered shutdown the powered state one in which 2 a magnetic disk is sup ported for rotation in contact with a playback head for reproducing a playback signal from a track on the disk 5 according to instructions from a control unit and b a video picture signal is generated from the playback signal for operating a display the semi powered shut down being a condition in which the player is capable of processing at least some instructions from the control unit particularly instructions to return the player to the powered state the improvement of a quiescent state in which the player further comprises means for generating a power down signal after a predetermined time interval has elapsed in the powered state without any instructions from said control unit means responsive to said power down signal for initi ating the quiescent state by arresting movement of 3 the disk relative to the head and by replacing the video picture signal with a blanking signal for blanking the display and means responsive to an instruction from the control unit during the quiescent s
12. djacent a desired track such as the track A Meanwhile a signal M EN provided to a speed control circuit 94 starts the disk drive motor 14 A tachometer circuit not shown monitors the motor speed and when operating speed is attained a signal M LOCK signifies that the disk 10 is locked up at cor rect playback speed If the predetermined play interval passes without any input from the remote unit 40 then the disk drive motor 14 is deenergized by a signal M STOP sent to the speed control circuit 94 from the system controller 30 No playback signal consequently is sensed by the head 26 At the same time the signal BLANK is emitted by the controller 30 to the switch 84 toggling the switch so that the generated sync signal CS forms the signal CSP sent to the encoder 86 in lieu of the playback sync signal CS The clamps 72a 72b and 78 operate during the horizontal drive interval from the generator 90 derived from the signal CSP that is the generated sync signal CS Thus the generated sync signal CSP occurs substantially at horizontal intervals causing a stable picture to appear on the display 34 With the horizontal drive interval of each signal clamped to black by virtue of the clamps 72a 72b and 78 and with no video signal 5 10 15 20 25 30 coming from the field interlacer 68 the video portion of 35 the clamped signals remains at a black level and pro vides a dark blank picture on the display 34 The
13. fe of the disk The compromise unfortunately often dictates a rather short life Some published work by Sony Corporation shows that after 24 hours of playback over the same track the signal output has declined about one dB a figure found to be acceptable by the Sony authors see The Electronic Still Camera A New Concept in Photography by N 5 20 25 30 35 40 45 50 55 60 65 2 Kihara et al IEEE Transactions on Consumer Electron ics Vol CE 28 No 3 Aug 1982 pp 325 330 The Sony publication while not drawing an outright con clusion about performance after 24 hours of use shows signal output dropping even further A 0 5 to 1 0 dB additional signal loss is about all that can be tolerated in a commercial system considering that a total loss of 3 db would mean half the signal power is lost Faced with the likelihood of a serious wear problem developing after 24 hours of use on one track it is im perative that disk to head contact be kept to a useful minimum useful in the sense that such apparatus is in fact being used during the period of disk to head contact For example if for some reason the user should leave the player say to answer the telephone the disk to head contact is no longer serving a useful pur pose It is also likely that the player could be left on through forgetfulness or inattention Whatever is done to alleviate wear should place little or no demand on the user The use
14. he automatic play 10 15 20 25 30 35 45 50 55 65 4 back section 38 When automatic playback is selected the prearranged instructions in the instruction memory 46 determine the arrangement of playback according to an operating program 48 More entry buttons or dual functions for the existing buttons may be desirable on the control unit 40 for specifying and entering the ar rangement for automatic playback The player is put into a quiescent state according to the invention upon receipt of a power down signal PDN from a power down program 50 The signal PDN is generated after a timer 52 indicates the elapse of a predetermined interval of time the play interval with out the system processor 36 receiving any selections from the control unit 40 or instructions from the auto matic playback section 38 Should the processor 36 receive a selection or automatic instruction before the signal PDN is generated it sends a reset signal RST to restart the timer 52 which again starts counting from the beginning of the play interval The play interval is set to such a time say five minutes that only in rare situations would no selection or instruction be re ceived while a user is actually viewing a set of pictures Ordinarily then the quiescent state would never be invoked during use of the player and the user would go through the pictures unaware of the continuously reset ting timer 52 On the other hand if
15. his invention pertains to video apparatus of the type that processes signals representative of a still picture recorded on a magnetic medium More particularly the invention relates to a video player that reproduces a still picture by repeatedly transversing a circular track on a magnetic disk 2 Description Relative to the Prior Art Video apparatus according to this invention utilizes a magnetic disk having a flexible recording member on which a picture is recorded as one field of a composite color video signal A disk ordinarily contains many pictures recorded on separate tracks Each picture may be put on the isk by a video still camera employing an electronic imager to capture an image of the still pic ture A recording circuit in the camera transfers for each picture the contents of the imager to the magnetic disk as for example a circular record track containing one video field The recorded disk is removed from the camera and inserted into a video player to reproduce each recorded field as a visible picture A disk drive motor in the player rapidly rotates the magnetic disk at an angular velocity of 3600 r p m which corresponds to the repe tition frequency of a television field Each revolution of the disk thus generates a playback signal having the correct field rate for NTSC reproduction To complete a video frame the player forms a second field from a second pass over the recorded field and interlaces the two fields for repr
16. ircuit 32 FIG 3 shows more detail of the system controller 30 which appears in both FIGS 1 and 2a Components already discussed in con nection with FIG 1 are given like numbered reference characters The playback signal generated by the play back head 26 is in the preferred embodiment a low level line sequential fm signal which is provided to the input terminals of a preamplifier and equalization circuit 60 Rf equalization compensates for distortion present in the output voltage from the playback head The output voltage from the preamplifier and equalization circuit 60 is fed to a separation filter 62 for separating the lumi nance Y and chrominance C signals from the play back signal The separate Y and C signals are applied to respective limiters 64a and 64b in order to eliminate amplitude fluctuations The limited Y and C fm signals are demodulated in respective circuits 66a and 66b which also attenuate the higher frequencies deempha sis according to the amount that they were intention ally boosted at recording It should be recalled that the signal recorded on the disk 10 track A represents one field of a television signal In order to provide a full frame signal the demodulated Y and C signals are ap plied to a field interlacer 68 As is conventional the interlacer 68 internally switches between two signal paths one path directly passes the signals through for one field the other path includes a 0 5 H delay and pr
17. ising a playback head for sensing the signals recorded on the disk and providing a playback signal 65 a disk drive for supporting the magnetic disk for rotation relative to said head said disk drive in cluding a drive motor for rapidly rotating the disk 20 25 12 means for positioning the playback head in contact with a selected track on the disk means for generating a first synchronizing signal referenced to said playback signal and a second synchronizing signal from a free running sync gen erator signal processing means responsive to said playback signal and to said first synchronizing signal for generating a video display signal for reproducing a picture on the display device a remote control unit for communicating user track selections to the player means for receiving said selections from said remote control unit and utilizing them to control said posi tioning means means for generating a power down signal after a predetermined time inierval has elapsed without any selections from said receiving means means responsive to said power down signal for de energizing said disk drive motor and for replacing said first synchronizing signal with said second synchronizing signal said signal processing means then substituting a picture blanking signal in lieu of said display signal and means responsive to a selection from said control unit for actuating said disk drive motor and regenerat ing the display signal
18. k signal sensed by the playback head 26 and produces a first video signal for displaying the selected still picture on the video display 34 in the second mode it responds to a control signal BLANK and produces a second video signal for displaying some predeter mined image normally that of a blank screen in lieu of the still picture The first mode is depicted in FIG 1 by the display 34 being in solid line and its connection to the circuit 32 also in solid line the alternative second mode is shown by broken line both as to the same display 34 and its connection to the circuit 32 The positioning of the head 26 in correspondence with the selected track A and the rotation of the disk 10 are controlled by the system controller 30 A system processor 36 residing in the system controller 30 re sponds to selection instructions from an automatic play back section 38 and from a control unit 40 which is the user interface with the player The user turns the player on or off and controls the order of picture viewing by forward and reverse buttons from the control unit 40 As shown here the control unit 40 emits a coded infra red signal 42 which is received by an IR receiver 44 and transmitted to the system processor 36 An arrange ment for automatically viewing the pictures on the disk 10 for example as to the order or the time allotted for displaying each picture is entered via the control unit 40 to an instruction memory 46 in t
19. me interval in the quiescent state The camera also includes the important option of easily terminating the quiescent state by instructions from a control unit such as a shutter and reactivating the apparatus anytime during the second interval What is claimed is 1 Video apparatus for processing signals represent ing still pictures said apparatus utilizing a magnetic medium on which the signals are recorded on recircu lating tracks said apparatus comprising a magnetic head means for positioning said magnetic head in contact with a selected track a control unit for entering instructions to the appara tus regarding the processing of the signals means for supporting the medium for rotation relative to said magnetic head so that said head repeatedly passes a selected track means for generating a first power down signal after a first predetermined interval has elapsed without any instructions from said control unit 30 means responsive to said first power down signal for arresting said rotation of the medium means for generating a second power down signal after a further predetermined interval has elapsed following said first interval and means responsive to said second power down signal for inactivating the apparatus 2 Video apparatus as claimed in claim 1 further com prising means responsive to an instruction entered through said control unit during said further predetermined interval for resuming rotation of
20. n claim 14 further compris ing means responsive to an instruction entered through said control unit during said further predetermined interval for resuming said rotation of the medium a timer for counting out said first interval and means responsive to resumed rotation of the medium for resetting said timer to again start counting said first interval
21. nergizing said con troller means and said signal processing means means responsive to the elapse of said predetermined interval for initiating a further predetermined inter val means for generating a second power down signal after said further predetermined interval has elapsed and means responsive to said second power down signal for inactivating only the part of said power supply that energizes said signal processing means 5 A video player for producing still pictures on a video display from signals recorded on circular tracks on a magnetic medium said player comprising a playback head for sensing the signals recorded on the medium means for positioning said playback head in contact with a selected circular track a control unit for entering user selections to the player particularly selections directed to said head positioning means and indicating the identity of the selected track drive means for moving the medium relative to said playback head so that said head repeatedly tra verses a selected track and accordingly generates a playback signal representative of a selected still picture signal processing means responsive in a first mode to said playback signal for generating a first video signal suitable for displaying said selected still pic ture on the video display and in a second mode for generating a second video signal suitable for dis playing a predetermined image on the video dis play in lieu of said selec
22. nizing signal for clamping the input signals to said signal processing means to dc levels corresponding to a blank display and means responsive to the receipt of an external instruc tion for reactivating said drive motor and for rer outing said separated synchronizing signal to said signal processing means 4 717 968 13 14 Imaging apparatus for recording signals repre senting pictures on circular tracks on a magnetic me dium said apparatus comprising a recording head for recording the signals on the medium means for positioning said recording head in contact with a selected circular track a control unit for entering user instructions to the apparatus means for supporting the medium for rotation relative to said recording head so that said head repeatedly passes a selected track and when instructed by said control unit records the signals representative of a selected still picture means for generating a first power down signal after a first predetermined interval has elapsed without any instructions from said control unit 5 10 15 20 25 30 35 45 50 55 65 14 means responsive to said first power down signal for arresting said rotation of the medium means for generating a second power down signal after a further predetermined interval has elapsed following said first interval and means responsive to said second power down signal for inactivating the apparatus 15 Apparatus as claimed i
23. oduction on a video display Since the display time for a complete frame is one thirtieth of a second the player must repeatedly cycle the same video frame to the display one minute of viewing for exam ple corresponds to 3600 passes over the recorded track U S Pat No 4 470 076 describes a player of this type that is one that presumes continued passage over a single track for continued viewing of a single picture Such continued passage however is not without its problems The recording member includes a magnetic coating on a flexible substrate A playback head as well as a record head must remain in intimate contact with the surface of this type of disk for effective playback or recording Too much contact pressure between the head and the disk can quickly scrape the track clear of the magnetic coating and ruin the disk Too little contact pressure results in an unstable interface and consequently degrades signal output The disk to head contact therefore is ordinarily stabilized with mini mum contact pressure by using such assists as a grooved guide plate to aerodynamically and gently urge the disk to the head Nonetheless continued passage of the head over the same track will apply enough stress and wear to the magnetic coating to eventually change its magnetic properties and thereby reduce signal output a phenomenon called the Villari effect Clearly a compromise is made between contact pres sure and the useable li
24. oring track locations anyhow memorizes the location of the track A i e track 1 or 2 etc in its internal or external memory Then if play is resumed within the quiescent interval 55 minutes the microprocessor 100 will call for this track location and signal the stepper motor 16 to move the head 26 back to the track it was before play back was interrupted The preceding disclosure of the operation of the sys tem controller 30 constitutes a sufficient specification of the operating software for putting the player in or out of the quiescent state and shutdown and for accomplish ing ancillary activities starting and restarting a timing routine producing the blanking signal providing the stepper motor phase signals controlling the disk drive motor and the like A programmer of ordinary skill can from this specification develop the program code to accomplish the stated operation without engaging in any undue experimentation or effort The invention has been described in detail with par ticular reference to a presently preferred embodiment but it will be understood that variations and modifica tions can be effected within the spirit and scope of the invention For example while video apparatus accord ing to the invention has been described in connection with a player it may also be described in connection with a video still camera that utilizes a similar type of magnetic disk Though the picture recording takes place during
25. ovides the interlaced field The luminance signal Y for adjacent lines of the recorded field may be averaged 5 10 20 25 30 35 40 45 50 55 60 65 6 to generate the luminance of each line of the interlaced field Ordinarily the chrominance for the interlaced field is just a repeat of the recorded field Since the signal from the disk is line sequential that is a pair of color difference signals alternate from line to line it is necessary to store the color difference signal from each line and repeat it for the next line so that both color difference signals are available for subsequent processing Such a store and repeat operation is per formed by a chroma repeater 70 The color difference signals R Y and B Y are then applied to respective clamps 72a and 72b for establishing appropriate dc lev els Meanwhile the tips of the synchronization portion of the luminance signal Y are clamped in a sync tip clamp 74 and then clipped off the signal in a sync clip per 76 an operation that is desirable for subsequent encoding The clipped luminance signal is then clamped to an appropriate dc level in a clamp 78 As will be shown the clamps 72a 72b and 78 operate on their respective signals whether the player is receiving a playback signal from the disk 10 or is in the quiescent state and the disk 10 is stopped A playback synchronization signal CS is provided by a synchronization separator 80 connected into the pa
26. r may feel obliged to answer the telephone but cannot be expected to intervene on behalf of the player anymore than for an ordinary television which is usually left unattended and operating in such situa tions SUMMARY OF THE INVENTION The invention treats the problem of minimizing disk wear without intervention from the user by cycling the apparatus into a special quiescent state in which the disk is stopped after a certain interval without user input Even though disk to head contact may be maintained which is optional disk wear is minimized since the disk is immobilized with respect to the head Any subse quent user input within a further interval that of the quiescent state causes the apparatus to resume opera tion with the same track being accessed as prior to entering the quiescent state After the quiescent interval elapses without user input the apparatus shuts off In the quiescent state and until the user reactivates the apparatus the apparatus remains mostly powered ex cept for the disk drive This not only ensures a quick and simple reactivation but permits a more hospitable user environment For example in the case of a player the display screen is blanked so as to keep the partial shutdown as inconspicious as possible A video player according to an embodiment of the invention produces still pictures on a video display depending on user selections entered from a control unit A signal processing circuit in
27. stantial portion prefer ably all of the horizontal drive interval Since the sync signals exist only for a short time at the beginning of the drive interval a suitably long triggering pulse for the logic 88 is generated from the sync signal CSP by a horizontal drive generator 90 The logic 88 also needs to recognize the presence of the 0 5 H delayed interlace field in order to correctly time the clamps this is done by a signal F from the field interlacer 68 The clamped luminance and color difference signals are formulated into an NTSC signal by the encoder 86 in relation to timing information provided by the playback sync sig nal CSP The encoded video signal is converted into a radio frequency signal by an rf modulator 92 and sent to the video display 34 The player is controlled according to user demands by the system controller 30 User selections are entered 4 717 968 7 through the hand held remote unit 40 which has its own battery power source The remote unit 40 includes an infra red transmitter which generates a coded infra red signal IR that radiates through space to the receiver 44 The receiver 44 decodes the input signal IR and provides the decoded user signal REM IN to the system controller Pursuant to the appropriate user command the four motor phase signals 1 44 applied to the step per motor 16 which accordingly steps through its posi tions as directed The lead screw 20 is turned and the head 26 is positioned a
28. tate for resuming move 35 ment of the disk relative to the head and for return ing the playback signal to the display 9 A player as claimed in claim 8 further comprising means operative in the quiescent state for generating a second power down signal after a further predeter o mined interval has elapsed without receiving any in structions from the control unit and means responsive to said second power down signal for putting the player into shutdown 10 A player as claimed in claim 8 further including 45 an automatic display facility responsive to prearranged instructions which are optionally provided in lieu of instructions from the operator control unit said means for generating a power down signal therefore generat ing said signal after either a predetermined interval has 59 elapsed without receiving any instructions from the control unit or a predetermined interval has elapsed without receiving any prearranged instructions from the automatic display facility 11 A player as claimed in claim 8 in which said 55 means for generating a power down signal comprises timing means for counting through said predetermined interval and for providing a timing signal at the end thereof and means responsive to said timing signal for generating said power down signal 60 12 A video disk player for reproducing pictures on a video display from signals recorded on circular tracks on a flexible magnetic disk said player compr
29. ted still picture means for generating a power down signal after a predetermined interval has elapsed without any selections from said control unit means responsive to said power down signal for inac tivating said drive means thereby arresting said relative movement and for instructing said signal processing means to enter said second mode and route the second video signal to the display and means responsive to a selection entered through said control unit for reactivating said drive means and for instructing said signal processing means to route the first video signal to the display 6 A player as claimed in claim 5 further comprising a receiver for detecting selections entered into the control unit a power supply operative in a playback mode for energizing the player to effect playback and in an off mode for enabling the receiver to detect at least certain selections from said control unit means responsive to said first power down signal for generating a second power down signal after a further predetermined interval has elapsed without any selections from said control unit and means responsive to said second power down signal for inactivating said power supply by placing it in said second mode 7 A player as claimed in claim 5 further comprising 4 717 968 11 a memory for storing prearranged instructions which are optionally provided in lieu of selections from said control unit means for automatically directing sai
30. th of the Y signal Alternatively a synchronization signal CS is locally generated by a free running sync genera tor 82 and used during the quiescent state to stabilize the picture on the display 34 Both sync signals are applied to the input terminals of a switch 84 its output signal is a composite sync signal CSP necessary for proper gen eration of an NTSC encoded signal in an encoder 86 The switch 84 is operated according to the condition of the signal BLANK also described in connection with FIG 1 received from the system controller 30 The signal BLANK changes state and toggles the switch 84 whenever the head 26 is moving between tracks or when the disk 10 is not rotating the quiescent state This invention is especially concerned with the latter occurrence When the signal BLANK is high because the motor 14 is off or the head is between tracks the switch 84 conducts the locally generated sync signal CS through to the encoder 86 as the playback sync signal CSP At other times when the signal BLANK is low the switch 84 conducts the playback synchroniza tion signal CS through to the encoder 86 as the play back sync signal CSP The clamps 72a 72b and 78 operate concurrently with the proper sync signal to clamp the color differ ence signals R Y and B Y and the luminance signal Y at correct dc levels for the encoder 86 The clamps are operated at selected dc levels L1 L2 and L3 by clamp and blank logic 88 during a sub
31. the medium a timer for counting out said first interval and means responsive to resumed rotation of the medium for resetting said timer to again start counting said 45 first interval 3 A video player for producing still pictures on a video display from signals recorded on circular tracks on a magnetic medium said player comprising a playback head for sensing the signals recorded on 59 the medium means for positioning said playback head in contact with a selected circular track a control unit for entering user selections to the player regarding selected tracks means for supporting the medium for rotation relative to said playback head so that said head repeatedly senses a selected track and accordingly generates a playback signal representative of a selected still picture means for generating a power down signal after a predetermined interval has elapsed without any selections from said control unit and means responsive to said power down signal for ar resting said rotation of the medium and discontin 65 uing generation of said playback signal 4 A video player as claimed in claim 3 further com prising 20 35 55 60 10 controller means for receiving and processing in structions from said control unit signal processing means responsive to said playback signal for generating a video signal suitable for displaying said selected still picture on the video display a power supply for selectively e
32. ts to its first mode during which its sends the first video signal to the dis play 34 and shows the selected still picture from the track A At the same time the timer 52 is reset and starts counting again toward the elapse of the play interval The quiescent interval is set to a suitably long time say one hour during which the user has an opportunity to resume viewing at the point of interruption If however the end of the quiescent interval is reached without receipt of a selection or an instruc tion the player is put into a semi powered shutdown in which most but not all of the player is deenergized For this reason a power supply 54 is provided having two powered modes a playback mode and an off mode In the playback mode both power lines V and V are 4 717 968 5 energized providing power to the system controller 30 and to the signal processing circuit 32 thereby effecting playback The power supply 54 is put into the off mode upon receipt of a disable signal P EN from the system processor 36 after the quiescent interval has run out The power supply 54 responds to the signal P EN by deenergizing the line V leaving energized only the power line V The energized line V is connected to the receiver 44 and to the processor 36 to interpret and act upon an on off signal from the control unit 40 via the receiver 44 This means that all parts of the player are deenergized except those parts necessary to restart the pl
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