GB2083267A

GB2083267A - Video disc player with program search facility

Info

Publication number: GB2083267A
Application number: GB8123365A
Authority: GB
Original assignee: Victor Company of Japan Ltd
Current assignee: Victor Company of Japan Ltd
Priority date: 1980-07-29
Filing date: 1981-07-30
Publication date: 1982-03-17
Also published as: FR2488026B1; DE3129830A1; GB2083267B; JPS6125108Y2; FR2488026A1; JPS5738394U

Abstract

A video disc player e.g. of the capacitive type with servo-controlled head tracking, wherein two types of address signals, indicative of program ("Chapter") number and of elapsed time, are alternately recorded in the vertical blanking periods, has a search facility with address display 24 for driving the pickup to locate a desired address of either type and resume reproduction there at a selected speed. A first actuation of a switch 52, or 53 displays the current address (number or time, respectively); a second actuation clears the display and allows a desired address to be entered from a keyboard 55 into a memory 51 and onto the display. Operation of a switch 54 actuates a search circuit 56 or 58 to drive the pickup radially; the keyboard 55 is then used to select the speed at which reproduction will be resumed when the desired address is reached (as a multiple of normal speed NM), whereupon the current address will also be displayed again. <IMAGE>

Description

SPECIFICATION Apparatus for reproducing a rotary recording medium The present invention generally relates to apparatuses for reproducing rotary recording mediums, and more particularly to an apparatus capable of setting a desired reproducing position within a rotary recording medium with a program number or an address of time position by a simple operation, in which the desired address can be switched over and displayed with ease, and is further capable of performing reproduction at a desired speed which has been set after automatic search is performed to the above set desired address.

There are cases where it is desirable to reproduce an information signal of a predetermined program from the beginning thereof, from a rotary recording medium (hereinafter simply referred to as a disc) recorded with the information signal of a plurality of programs such as a video signal and an audio signal.

In the above case, conventionally, address numbers were established for every field or every track of the video signal in the disc, in a continuous manner from the outermost peripheral part to the innermost peripheral part of the recorded region within the disc. Hence, by setting an address number corresponding to the beginning of a desired program, the reproducing apparatus performed a search operation until the set address number was obtained. However, in this conventional apparatus, an extremely large number of bits was required for the address signal, and further the operation to set the address number corresponding to the beginning of the desired program was troublesome. In addition, there was a disadvantage in that the construction of the apparatus became complex.

Accordingly, it is a general object of the present invention to provide a novel and useful apparatus for reproducing a rotary recording medium in which the above described disadvantages have been overcome.

The present invention provides an apparatus for reproducing a rotary recording medium recorded with an information signal consisting of a plurality of program contents, a first address signal indicating a program number of said information signal, and a second address signal indicating time position of said information signal, said apparatus comprising, reproducing means for reproducing said information signal and said first and second address signals from said rotary recording medium, detection means for detecting said first and second address signals from a signal reproduced by said reproducing means, setting means for setting a program number and time position of a program which is to be reproduced by performing an automatic search, and setting a reproduction mode after completion of the automatic search, indication means for displaying the program number and time position set by said setting means, transferring means for transferring said reproducing means towards forward and backward directions on said rotary recording medium, and controlling means for comparing contents of the program number and time position set by said setting means with contents of first and second address signals being reproduced by said reproducing means, to operate said transferring means, so as to transfer said reproducing means towards a direction where the above compared contents coincide, and to reproduce the program whose program number and time position has been set with a reproduction mode which has been set when the compared contents coincide.

Another and more specific object of the present invention is to provide an apparatus for reproducing a rotary recording medium, which is capable of setting and displaying a program which is to be reproduced by a chapter address or a time address, by establishing addresses (chapter addresses) of program numbers for respective plurality of programs recorded in the rotary recording medium and addresses (time addresses) as time data indicating reproducing times, and further capable of simply switching display to display another address even when one of the above addresses is being displayed, and performing an automatic search to the above set address to automatically perform reproduction with a desired reproducing speed which has been set during the automatic search after completion of the automatic search.

Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.

Figure 1 is a systematic block diagram substantially showing an embodiment of a rotary recording medium reproducing apparatus according to the present invention; Figure 2 is a systematic block diagram showing an example of an address detection circuit within the block system shown in Fig.

1; and Figure 3 is a systematic block diagram showing a circuit capable of performing a part of the operation performed by a micro-computer within the block system shown in Fig.

1, together with a switch and an indicator which operate together with the circuit.

In Fig. 1, a rotary recording medium (hereinafter simply referred to as a disc) 10 in which an information signal such as a video signal and/or an audio signal is recorded, is rotated at a predetermined speed by a turntable 11. A reproducing stylus 13 of a signal pickup device 12 makes contact with the recording surface of the disc 10, to pickup and reproduce the recorded signal from the disc 10. In the present embodiment of the invention, the information signal is recorded on the disc 10 as a variation in geometrical configuration, and the recorded information signal is reproduced from the disc 10 due to variation in the electrostatic capacitance between the disc 10 and an electrode of the reproducing stylus 13.Further, reference signals for performing tracking control are recorded on the disc 10 besides the information signal, and these reference signals are reproduced together with the information signal.

The signal picked up and reproduced from the disc 10, is supplied to a demodulator 15 and a tracking control circuit 16 through a head amplifier 14. Reference signals for tracking control are separated at the tracking control circuit 16, and a tracking control signal is formed from these reference signals. The tracking control signal thus formed by the tracking control circuit 16 is supplied to a coil used for tracking within the pickup device 12.

Accordingly, tracking control is performed so that the reproducing stylus 13 accurately scans over the video signal tracks on the disc 10.

On the other hand, the pickup information signal is demodulated at the demodulator 15, and then supplied to a video signal processing circuit 17 wherein a predetermined signal processing is performed. Hence, the demodulated video signal thus subjected to the predetermined signal processing, is supplied to an image receiving tube (not shown) of a receiver from a terminal 19, through a muting switch 18 which is closed, and reproduced as a reproduced picture. The signal from the demodulator 15 is also supplied to an address signal detection circuit 20 wherein an address signa within the signal thus supplied is detected. The detected address signal is supplied to a micro-computer 21.

Four fields of video signals, for example, are recorded in a spiral track of the disc 10, for one rotation of the disc 10. Further, vertical synchronizing signals are recorded at four positions per one track turn of the disc 10. In each of the vertical blanking periods, a coded address signal (chapter address signal) indicating addresses of program numbers established in order for every plurality of programs recorded in the disc from the outermost peripheral side to the innermost peripheral side of the disc 10 and indicating local addresses within the above plurality of programs, is recorded at a position at the seventeenth H (H indicates a horizontal scanning period) from the rising edge of the vertical synchronizing signal.Further, a coded address signal (time address signal) indicating absolute address of the position of the information signal as a time data indicating the time required to perform normal reproduction from an outermost peripheral position of the disc 10 to the position indicated by the absolute address, is recorded at a position at the eighteenth H from the rising edge of the vertical synchronizing signal. Moreover, in the present embodiment of the invention, the chapter address signal and the time address signal are not recorded continuously, however, the chapter address signal and the time address signal are alternately recorded for every one field.

The address signal detection circuit 20 comprises a block system shown in Fig. 2, for example. The reproduced signal supplied from the demodulator 15 through a terminal 30, is amplified to a desired level at a video amplifier 31 consisting of a differential amplifier.

The reproduced signal thus amplified at the video amplifier 31 is supplied to a band-pass filter 32 wherein the address signal (chapter address signal or time address signal) is obtained. The address signal obtained at the band-pass filter 32 is subjected to waveformshaping at a comparator 33 wherein the level of the address signal is compared with a reference level. The output of the comparator 33 is supplied to a date demodulator 34 and to a self-reproducing type clock pulse generator 35. The data which is demodulated at the data demodulator 34 is successively shifted at shift registers 36, 37, 38, 39, and 40.

On the other hand, the output of the shift register 40 is also supplied to a decoder 42 wherein a synchronizing bit existing at the beginning of the address signal of twenty-nine bits is detected. The detected synchronizing bit is supplied to a switching pulse generating circuit 43 comprising a flip-flop, for example, to set the switching pulse generating circuit 43. The switching pulse generating circuit 43 is reset by a vertical synchronizing signal of the video signal which is supplied from the video signal processing circuit 17 through a terminal 44. Hence, the above switching pulse generating circuit 43 generates a switching pulse in response to the above setting and resetting operations.

A switching circuit 46 is switched over by a switching pulse supplied from the switching pulse generating circuit 43, and passes the clock pulse from the clock pulse generating circuit 35 in order to read in data during a period in which the data of the address signal exists. Further, the switching circuit 46 performs a switching operation to pass the clock pulse supplied from the micro-computer through a switching terminal 45, to shift the data through the shift resisters 36 through 40 by the clock pulse.

A signal specifying the kind of address signal (chapter address signal or time address signal) which is to be detected, is supplied from the micro-computer 21 to the decoder 42, through a terminal 47. Accordingly, the decoder 42 is set to detect teh synchronizing bit of the chapter address signal or the synchronizing bit of the time address signal, according to the above specifying signal. In a case where the decoder 42 is set to detect the synchronizing bit of the chapter address signal (or the time address signal), the address signal detection circuit 20 detects the chapter address signal (or the time address signal).

The detected address signal obtained from an output terminal 41 is supplied to the micro-computer 21. A block system describing a part of the operation performed by the micro-computer 21, is shown in Fig. 3. In Fig.

3, the detected address signal of the address signal detection circuit 20 from the output terminal 41, is supplied to a random access memory (RAM) 51 through a terminal 50.

When the operator wants to know the program number of the picture being reproduced while observing the reproduced picture in the image receiving tube of the above receiver, a chapter switch 52 of a switch group 23 is pushed. Hence, a signal corresponding to a program number ("1 2", for example) of the chapter address stored into the RAM 51 at the point in time when the switch 52 was pushed, is supplied to an indicator 24 as an indication signal. Therefore, the indicator 24 displays "CP1 2".

On the other hand, when it is desirable to know the position of the picture being reproduced in time elapsed from the beginning part of the recorded signal (signal part recorded at the outermost peripheral part of the disc) when normal reproduction is performed, a time switch 53 of the switch group 23 is pushed. Hence, a signal corresponding to a data (twenty-five minutes and thirty-two seconds, for example) of the time address stored into the RAM 51 at the point in time when the switch 52 was pushed, is supplied to the indicator 24 as an indication signal. Therefore, the display "CP1 2" indicating the program number disappears, and the indicator 24 then displays "2532".

Next, description will be given with respect to the operation in a case where a desired program address position or a time position is set, and an automatic searching operation is performed to search that desired position, to perform reproduction with a mode which has been preset from that desired position.

In a state where "2532" is displayed in the indicator 24, and reproduction is to be performed from a position where the time address is thirty-one minutes and two seconds ("3102"), for example, the time switch 53 is first pushed. When the time switch 53 is pushed in a state where the indicator 24 is displaying time, the indicator is constructed to clear the display. Accordingly, when the above time switch 53 is pushed, the display "2532" at that point in time disappears from the indicator 24. Next, keys corresponding to numbers "3", , "0", and "2" of ten keys 55 in the switch group 23 are pushed, according to the above desired time address which is to be set. Hence, the time address "3102" is specified and stored into the RAM 51, and the display "3102" is displayed in the indicator 24.

Ten keys are provided in the keys 55, and numbers "1", "1", ---, "8", and "9" are provided below each of the respective keys, while markings "1/16" "1/8", "NM(normal)", "2", ---, and "5" are provided above each of the corresponding keys.

The numbers indicated below the keys are used upon specifying of the address, and the markings above the keys are used upon setting the reproduction mode (reproducing speed) after the automatic searching operation.

After the display ' "31 02" is displayed in the indicator 24 by setting the above time address, a start switch 54 is pushed. Therefore, a signal is supplied to a time serach circuit 58 from the RAM 51. The above time search circuit 58 rotates a motor 22 with a rotational direction and a rotational speed respective of the difference between the time address of the signal being reproduced and the above set time address, Hence, the motor 22 transfers the signal pickup device 12 along the radial direction of the disc 10.

Accordingly, a time search operation is performed, and the signal pickup device 12 is transferred at a high speed until the detected time address signal from the address signal detection circuit 20 coincides with the above set time address. Moreoever, during the period in which the above time search operation is performed, the muting switch 18 is opened, and the signal from the video signal processing circuit 17 is prevented from being supplied to the image receiving tube. Thus, unpleasant pictures are not reproduced in the image receiving tube during the above time search operation.

After the above start switch 54 is pushed, the desired reproduction mode (reproducing speed) after completion of the search is set by manipulating the keys 55. A key corresponding to the desired reproducing speed of the plurality of speeds marked above the keys ("NM" for normal reproduction, "2" for double-speed quick-motion reproduction, and "1 /2" for 1/2-speed slow-motion reproduction, for example) is pushed. In the present embodiment of the invention, a key corresponding to the mark "NM" for normal reproduction is pushed, for example.

When the detected time address signal from the address signal detection circuit 20 and the set time address coincide, a signal for normal reproduction is obtained from the RAM 51, A normal reproduction circuit 57 thus operates, and the whole reproducing apparatus is put into a normal reproduction mode in which reproduction is performed at a normal speed.

Accordingly, search is automatically performed with respect to the above set time address, and normal reproduction is performed from that set position. Moreover, when a key corresponding to the mark "2" for double-speed quick-motion reproudction is pushed after pushing the start switch 54, for example, double-speed quick-motion reproduction is performed after the above search operation is completed.

During the period in which the above search operation is performed, the time "3102" as a time address is displayed in the indicator 24. However, when the search operation is completed and normal reproduction is started, the time display of the time address at each position upon normal reproduction is continuously performed from the time "3102". In addition, upon normal reproduction, when the operator wants to know the program number of the program being reproduced, a program number "CP25", for exam ple, of the program being reproduced is displayed in the indicator 24 when the chapter switch 52 is pushed.

Furthermore, in a case where reproduction is to be performed from a program whose program number is "54", for example, in a state where "CP25" is displayed in the indicator 24, the chapter switch 52 is first pushed. By this operation, the part "25" of the display "CP25" in the indicator 24 disappears. Then, keys of the keys 55 corresponding to the numbers "5" and "4" are pushed in that order, which corresponds to the desired program number "54". Therefore, a display "54" appears beside the display "CP", and the display in the indicator 24 becomes ' "CP54".

When the start switch 54 is pushed, and a key in the keys 55 corresponding to the marking "NM" for normal reproduction is then pushed, a signal is supplied from the RAM 51 to operate the chapter search circuit 56. The chapter search circuit 56 rotates the motor 22 at a rotational speed and a rotational direction corresponding to the difference between the program number of the chapter address signal within the signal being reproduced and the above set program number, so that the signal pickup device 12 is transferred along the radial direction of the disc 10. Hence, the signal pickup device 12 is transferred at a high speed until the program number of the detected chapter address signal obtained from the address signal detection circuit 20 coincides with the set program number, to perform a chapter search operation.During this chapter search operation, the muting switch 18 is opened.

When the above program numbers of the two chapter addresses coincide, a signal for normal reproduction is obtained from the RAM 51. Accordingly, the normal reproduction circuit 57 is operated, and the whole reproducing apparatus is put into a normal reproduction mode in which reproduction is performed at a normal speed. Therefore, search is performed automatically with respect to the above set chapter address, to perform normal reproduction from the set position.

Moreover, during the period in which the above search is performed, a program number "CP54" as a set chapter address, is displayed in the indicator 24. Accordingly, when the search operation is completed and normal reproduction is started, the program number at each position upon normal reproduction is continuously displayed from the program number "CP54", in the indicator 24.

Next, description will be given with respect to the relationship between the operation of the switch group 23 and the display in the indicator 24. In a case where the chapter switch 52 or the time switch 53 is successively pushed twice, the numerical display in the indicator 24 disappears, and the display mode of the keys 55 corresponds to the switch which was pushed twice in succession.

On the other hand, when the chapter switch 52 or the time switch 53 is pushed only once, the indicator 24 displays a data corresponding to the switch which was pushed.

That is, when the time switch 53 is pushed when the time as the time address is displayed in the indicator 24, the time display in the indicator 24 disappears, and the keys 55 are put into a time address selection mode.

On the other hand, when the chapter switch 52 is pushed when the program number as the chapter address is displayed in the indicator 24, the program number display in the indicator 24 disappears, and the keys 55 are put into a chapter address selection mode.

Moreover, when the chapter switch 52 is pushed when the time as the time address is displayed in the indicator 24, the program number of the program being reproduced is displayed in the indicator 24. On the other hand, when the time switch 53 is pushed when the program number is displayed in the indicator 24, the time as the address of the signal being reproduced is displayed in the indicator 24.

In addition, when the start switch 54 is pushed when the program number of the time is displayed in the indicator 24, the keys 55 are put into a speed selection mode for select- - ing the reproducing speed after completion of the search operation.

In the present embodiment of the invention, the so-called electrostatic capacitance reproduction system which performs reproduction according to the variation in the electrostatic capacitance is used as the reproduction system, however, the present invention is not limited to this application, and can be applied to a so-called optical reproduction system which performs reproduction by use of a lazer beam.

Further, this invention is not limited to the above described embodiments, but various variations and modifications may be made without departing from the scope of the pre sent invention.

Claims

1. An apparatus for reproducing a rotary recording medium recorded with an information signal consisting of a plurality of program contents, a first address signal indicating a program number of said information signal, and a second address signal indicating time position of said information signal, said apparatus comprising:: reproducing means for reproducing said information signal and said first and second address signals from said rotary recording medium; detection means for detecting said first and second address signals from a signal reproduced by said reproducing means; setting means for setting a program number and time position of a program which is to be reproduced by performing an automatic search, and setting a reproduction mode after completion of the automatic search; indication means for displaying the program number and time position set by said setting means; transferring means for transferring said reproducing means towards forward and backward directions on said rotary recording medium; and controlling means for comparing contents of the program number and time position set by said setting means with contents of first and second address signals being reproduced by said reproducing means, to operate said transferring means so as to transfer said reproducing means towards a direction where the above compared contents coincide, and to reproduce the program whose program number and time position has been set with a reproduction mode which has been set when the compared contents coincide.

2. An apparatus for reproducing a rotary recording medium as claimed in claim 1 in which said setting means has a first switch for program number setting mode, a second switch for time position setting mode, and a plurality of keys for setting program number and time position.

3. An apparatus for reproducing a rotary recording medium as claimed in claim 2 in which said controlling means clears a numerical display in said indication means when said first switch is pushed in a state where teh program number is displayed in said indication means, and puts the apparatus in a state possible for setting a program number by said keys.

4. An apparatus for reproducing a rotary recording medium as claimed in claim 2 in which said controlling means clears a time display in said indication means when said second switch is pushed in a state where teh time is being displayed by said indication means. and nuts the apparatus in a state possible for setting a time position by said keys.

5. An apparatus for reproducing a rotary recording medium as claimed in claim 2 in which said controlling means displays a time position of a signal being reproduced in said indication means when said second switch is pushed in a state where the program number is displayed in said indication means.

6. An apparatus for reproducing a rotary recording medium as claimed in claim 2 in which said controlling means displays a program number of a signal being reproduced in said indication means when said first switch is pushed in a state where the time is displayed in said indication means.

7. An apparatus for reproducing a rotary recording medium as claimed in claim 2 in which said controlling means enables setting of a reproduction mode which is to be started upon completion of the automatic search, when said keys are operated after starting of the automatic search.