KR830000462B1 - Easily track potential recording / playback device - Google Patents

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Description

Easily track potential recording / playback device

1 is a block diagram of an apparatus for recording a signal including a pilot signal and audio signal information on a video disk and a recording signal including video signal information of a synchronous component while moving the spiral track of the video disk according to the present invention.

FIG. 2 is a block diagram of an apparatus suitable for efficiently using the functions of the recording apparatus of FIG.

3 is a block diagram of a reproducing apparatus incorporating a home potential detection and correction apparatus according to the present invention, and a reproducing apparatus suitable for use as a video disc having a pilot signal from a video disc of the apparatus of FIG.

4 and 5 are block diagrams of apparatus suitable for efficiently using certain functions of the playback apparatus of FIG.

FIG. 6 is a drawing of a carriage designed to install elements of the groove potential detection and calibration device, suitable for use as the regeneration device of FIG. 3. FIG.

7 and 8 illustrate a needle arm cartridge removably housed in a carriage compartment of FIG. 6 suitable for mounting any other elements of the groove potential detection and calibration device of FIG. End view.

9 to 11 are schematic diagrams showing the coordination of the carriage and the carriage elements.

12 is a graph of the frequency spectrum of embedded color subcarrier color video signal information suitable for use with the recording system of FIG.

FIG. 13 is a graph of the frequency spectrum of a composite signal including pilot signals and incidental audio signals of video signal information suitable for use with the recording apparatus of FIG.

14 is a schematic diagram of a video disk on which a pilot signal has been processed.

15 and 16 are diagrams of the joint action of the carriage and the carriage elements of FIGS.

TECHNICAL FIELD The present invention relates to an apparatus used for playing a video disc record, and more particularly, to a new video disc recording and playback apparatus for selectively repositioning a player needle from one line of a signal spiral track to another line on a record surface. .

Although the invention is described in detail hereinafter with respect to spirally slotted discs, the principles of the invention are applicable to any disc with a spiral information track on its surface, including flat discs.

John K. October 15, 1974. US Patent Application No. 3842194, issued to Clemens, describes a video disc player of variable capacity. In this apparatus, the information track is constructed because its surface causes a geometric change in the bottom of the spiral groove of a disk made of a conductive material coated with an insulating thin film coating. The change in capacitance appearing between the conductive electrode of the crack needle and the conductive material of the disk occurs as the disk is rotated by the support turntable. The capacity change is detected to reproduce the recorded information.

When recording and reproducing a disc record of the above type, sometimes a defect on the disc groove is skipped across the grooves rather than moving along the continuous line of the spiral groove so that the player needle moves normally toward one end of the disc. Be sure to For example, the needle is repeatedly biased (bends) across one or more convolutions when encountered with such engagement.

In some cases, this outer piece causes the needle to collide with the engagement several times in succession. This state is referred to herein as a " closed groove " state in which a bad effect on the image display (sound reproduction) is caused to reproduce the same record information repeatedly.

It is desirable to detect and correct irregularities in the normal movement of the player needle moving the spiral grooves during recording and reproduction, so as to reduce the potential with respect to the grooves of the disc line.

June 15, 1976 T. W. U.S. Patent No. 3963860, issued to Burus, describes a closed groove detection and correction device for a video disc player.

April 19, 1977 Lee. Five. US Patent Application No. 4018984 to Kaiser describes a system for reproducing records in which spirally staggered video signal synchronization components are successively staggered.

The advantage of the BRUS system is to take staggered positions of the Kaiser video disc record to automatically detect the presence of a closed groove during playback. The Bruces detector includes devices responsive to phase disturbances of the resynchronizing pulses that cause repetition of one or more pre-crossed lines.

When the needle traverses the record radially to perform various special operations such as freezing, fastening and rewinding, it is desirable to have the video signal synchronization component of the video record arranged radially with respect to the record in order to reduce disturbance. Do.

In certain specific applications of the Clemens type video disk system, it may be desirable to provide still operation of the display image. That is, it repeatedly provides output signals of essentially the same display image to the combined television monitor. It is desirable that such an image stop operation provides a viewer with a specific image for a relatively long time. In addition, it is desirable to store the screens of the important data so that a particular display image, which is particularly important in the data storage device, remains.

It is also desirable to provide the ability to quickly feed and rewind the display image in order to be combined with a video disc player. The fast feeding function is particularly useful for scanning the information recorded on the video disc. The rewind function can also be used as an aid in data recovery, which is particularly useful for learning aids for reviewing learning images recorded on a disc continuously.

Moreover, in recording and reproducing a disc record of this type, frequently a coupling on the disc groove causes the player needle to be displaced across the grooves rather than moving along a continuous line of spiral grooves that normally proceed toward one end of the disc. For example, it is convenient (bent) as the needle repeatedly crosses one or more convolutions when it reaches the engagement portion. In some cases, the outer flank causes continuous impingement of the defective portion of the needle. This state is referred to herein as a " closed groove " state in which the player key repeatedly reproduces the same record information by causing an adverse effect on the image display (sound reproduction).

Provide an optional device for repositioning the pickup needle from one line of the record spiral track to another to provide these specific operating features (eg, stop, feed, rewind) and correct closed groove conditions. It is desirable to.

H. June 15, 1976 yen. U.S. Patent No. 393961, issued to Crooks, and U.S. Patent No. 393863, issued to Mr. Lydham, et al. On November 23, 1976, describe a home skip device. For these two home skip devices, the selectively actuated piezoelectric himarph elements cause lateral displacement of the needle supporting end of the needle arm. While other forms of operation, such as the former, can be replaced by piezoelectric bimorph, the lateral displacement of the needle support end of the needle arm depends on compensating the embodiment of Mr. Crooks and Lee.

According to the principles of the present invention, a new system is described for simplifying the detection of the home or track potential state during the playback of a video disc in which video signal synchronization information is arranged radially.

According to the embodiment of the present invention, the recording signal having the video signal information including the pilot signal and the synchronization components is applied on the video disk along the spiral track. The frequency of the synchronization components and the pilot signal is to be recorded on each line of the spiral track as integer synchronization components and non-integer pilot signals.

According to another embodiment of the present invention, a reproducing apparatus is a device which is coupled to a signal pickup to recover a signal excluding other components of a recording signal, and the normality of the signal pickup moving a spiral track by a sudden radial deviation at the position of the signal pickup. A device that generates an error signal indicating the magnitude and direction of a signal pickup during normal movement in response to shifting a pilot signal generated by irregular movement, and further radially deflects the signal pickup in response to an error signal. It is composed of a device that corrects irregularities caused by the movement and substantially returns its normal movement.

The number of pilot signal periods recorded on each line of the spiral track is distinguished from the integer number of pilot signal periods by a very small period of several hours smaller than at least half periods so as to facilitate the detection of the home potential more than one groove line. As an example, the selection of a 0.08 cycle difference reliably detects a groove potential of 6 groove lines or more in any room.

According to the present invention, selective radial repositioning of the player needle is achieved by rotating the needle arm around its longitudinal axis, from which the deviation of the needle tip causes movement of the needle tip across the disc, record track line.

It can be seen that rotating the needle arm in this way is a finite way of combining the action point of the force and the needle tip to cause the needle displacement to be expected by a given force.

According to another feature of the invention, the lateral movement of the needle support end of the needle arm is substantially while ensuring that the needle rotation occurs about the longitudinal axis of the needle arm rather than making the needle arm rotate about its tip. It is stopped.

According to an embodiment in accordance with the principles of the present invention, a magnet device is installed in the player device to cause the needle arm to rotate. The feature of the magnet device can be achieved by controlling movement of the needle arm without making a wire connection to the needle arm.

When explaining the present invention based on the accompanying drawings.

In the recording apparatus of FIG. 1, the video signal source 30 supplies the video carrier frequency modulator 32 with a video signal including luminance information, chromaticity information indicating continuous scanning of color images to be recorded, and synchronization information. The video signal was released on March 18, 1975. H. Embedded subcarrier type as described in US Patent Application No. 3872498 to Pritchard. 12 shows the frequency spectrum of a video signal in the form of a buried color subcarrier. According to the principle of the prechard invention, the modulated color subcarrier as shown by the dotted line in FIG. 12 is embedded in the intermediate frequency band of the luminance signal.

The image carrier frequency modulator 32 modulates the modulated image carrier signal of the instantaneous frequency wave of the instantaneous frequency that has been changed for its high frequency shift region (e.g., 4.3 MHz to 6.3 MHz) selected by the amplitude of the video signal input at its output terminal. Generate.

The recording apparatus of FIG. 1 also includes an audio signal source 34 for supplying a preferred audio signal for the color image to be recorded to the low pass filter 36 having a cutoff frequency of 20 kilohertz.

The recorder 38 includes a turntable for rotatably supporting a disc on which a signal is recorded along a spiral track. The recorder 38 is also comprised of a drive system for rotating the turntable at a speed correlated with the video signal synchronization component so that the synchronization components are arranged radially on the disc. In other words, an integer number of synchronous components are generated by the turntable rotation. The correlation between the turntable speed and the image signal synchronization components is shown schematically in the figure by the connection between the recorder 38 and the reference oscillator 40.

A reference oscillator 40 operating at an NTSC color subcarrier frequency (i.e., 3.58 MHz) is used in the television signal generation system to supply the synchronous component of the video signal. The output of the reference oscillator 40 is also supplied to the pilot signal generator 42. The pilot signal generator 42 generates a pilot signal having a constant frequency (21.18 kHz on playback of a disc record) at its output so that when a fixed non-integer pilot signal period (field of video signal information is generated compared to the disc rotation) 2926.92) is generated by the turntable rotation. The other thing that comes with this particular choice of pilot signal frequency is

(1) The selected pilot signal frequency does not impair audio performance and is not high enough to cause a substantial increase in the bandwidth of the modulated audio carrier spectrum but must be higher than the audio signal information useful band.

(2) The selected pilot signal frequency can be easily counted from an NTSC color subcarrier (eg divided by 169).

(3) The number of pilot signal cycles and the number of pilot signal cycles formed in each of the spiral tracks at small time periods at least smaller than half periods so that the selected pilot signal frequency facilitates the reliable detection of more home potentials than one home circuit. The number of pilot signal periods is different. In an example, the selection of a 0.08 period difference reliably detects a home potential of six groove lines or more in any direction. 14 schematically illustrates a video disk 64 having a pilot signal stored there along the spiral information track. Arrows in FIG. 14 indicate the direction of rotation of the video disc relative to the player needle.

The adder 44 combines the speech signal and the pilot signal at the output of the low pass filter 36 so that the pilot signal amplitude is one tenth of the maximum amplitude of the speech signal. FIG. 13 shows the frequency spectrum of the signal present at the output of adder 44. FIG.

The voice carrier frequency modulator 46 modulates the instantaneous frequency that is varied over a low frequency deviation region (e.g. 716 kHz ± 55 kHz) selected by the signal amplitude at the output of the adder 44 at its output terminal. Generates a sound carrier signal.

The combiner 48 combines these signals at the output terminals of the image carrier modulator 32 and the acoustic carrier modulator 46 to supply a composite recording signal to the recorder 38. The recorder 38 is used to make a disc that is used to make a video disc copy 64 by the method described in Clemenz's patent. Block 50 in FIG. 1 indicates this recording process.

카운터(54)의 입력신호로서 적합한 구형파에 대한 정현기준신호(즉, NTSC방식의 칼라부반송파)를 발생시킨다. 기준신호 1/169 주파수의 카운터 출력신호는 단안정 멀티바이브레터(56)에 의하여 구형파로 되고, 기본성분은 기준발진기(40)의 1/169 주파수로 바람직한 파이롯트 신호 정현파를 제공하도록 필터(58)에 의해 선택된다.2 shows a signal generator 42 for generating a pilot signal of counting in the reference oscillator 40 used to synchronize the turntable to the recorder 38. Clipper (52) is digital

A sinusoidal reference signal (i.e., NTSC type color subcarrier) for a square wave suitable as an input signal of the counter 54 is generated. The counter output signal of the reference signal 1/169 frequency is square wave by the monostable multivibrator 56, and the basic component is the filter 58 to provide the desired pilot signal sine wave at 1/169 frequency of the reference oscillator 40. Is selected by.

As shown in FIG. 3, video disc player 60 (e.g., of the type shown in the Clemens patent referred to above) is a spiral track with video signal information including pilot signals and sync components. And a turntable 62 for rotatably supporting the video disk 64 having formed thereon. The frequencies of the sync components and the pilot signal are such that an integer sync component and a non-integer pilot signal period are formed on each line of the spiral track. The player 66 also has a carriage 66 (FIG. 6) which is displaced simultaneously with the radial movement of the player needle during playback. The carriage 66 is provided with a compartment for removably storing the cartridge 68 (FIGS. 7 and 8) of the signal pickup device.

The pickup circuit 70, which responds to the output of the pickup signal, generates a pulse train representing the information recorded at its output terminal. The pickup circuit 70 is a type disclosed in U.S. Patent Application No. 4080625 issued to Kawamodo et al. On March 21, 1978. The output of the pickup circuit 70 is supplied to a pair of wide-pass filters 72 and 74. The video broadcast bandpass filter 72 is a video carrier component of the recorded signal to exclude its voice carrier components not only near the side regions but also against the deviation frequency of high frequency video carriers (e.g. 4.3 to 6.3 megahertz). It has a relatively wide passband that selectively passes.

The voice carrier bandpass filter 74 also filters the voice carrier components of the recorded signal to exclude its video carrier components near the sideband region and for shifts of low frequency voice carriers (e.g. 716 kHz ± 55 kHz). It has a relatively narrow passband to pass selectively.

The outputs of each bandpass filter 72 and 74 are fed to respective demodulators 76 and 78. Image demodulator 76 generates recorded video signal information including synchronization components (e.g., FIG. 12) at its output terminal, and audio demodulator 78 records audio signal information and pilot at its output. Generate a signal (e.g., FIG. 13).

The image signal processor 80 coupled to the image demodulator separates the chromaticity information at the luminance level. The composite video signal generator 82 recombines chromaticity and luminance information by NTSC. The transmitter 84 processes voice, luminance and chromaticity information to form a signal suitable for the color television receiver 86 and allows a color image display to be generated by the recorded information. In an embodiment, signal transmission to the antenna terminal of a color television receiver is preferred, and the circuit includes devices for combining the separated components to form a new composite signal that modulates a suitable radio frequency carrier. Jay filed December 6, 1976. blood. A transmission apparatus is described in Yiwu United States Patent Application No. 747866.

The pilot signal bandpass filter 88 having a relatively narrow passband (e.g. 21.18 kHz ± 1.5 kHz) passes the reproduced pilot signal to exclude other recorded information. The phase-locked loop 90, which responds to deviations in the phase of the reproducing pilot signal that occurs irregularly during the normal progression of a player needle moving a spiral track due to a sudden radial deviation of the needle position, is caused by irregularities occurring during the normal progression of the needle arm. Generate an error signal of magnitude and polarity. At this time, the home potential driving circuit 92 responding to the generation of an error signal having a magnitude exceeding a given threshold generates a standard calibration pulse. Appropriate groove dislocation devices (e.g., FIGS. 9-11) that respond to the calibration pulses cause radial dislocations of the player needle position to eliminate irregularities in the normal progression of the player needles.

4 shows a block diagram of the elements of a phase locked loop (PLL) 90 used to detect a sudden phase discontinuity in a pilot signal generated when a needle is displaced into an adjacent groove. The phase of the input signal is compared with the phase of the reference oscillator 94 by a phase detector 96 that generates an error signal of an average component proportional to the phase difference between the input and reference signals. The error signal is filtered by the loop filter 98, and the voltage controller 100 controls the frequency of the reference oscillator 94 to supply the relative phase between the two signals to the reference oscillator 94 with a nominal average. Is authorized to.

범위에 대할 위상 불연속의 크기이며 입력위상 변화의 방향에 일치하는 방향에 있다.Thus, the reference oscillator 94 tracks the frequency and phase of the input of the pilot signal with the time constant determined by the loop filter 98. When the needle is displaced to other grooves, the phase of the input signal changes abruptly as it produces the error signal output of the phase detector. The magnitude of the error signal change is approximately 180

The magnitude of the phase discontinuity over the range, which is in a direction consistent with the direction of the input phase change.

제한치 전위의 숫자를 나타내는데 사용될 수 있다. 한 회전의 2826.92 파이롯트 주기의 경우에, 각 홈전위를 위한 위상은 대략 28

의 위상변위에 해당한다. 이러한 위상은 후진을 위해 전진되고 전진을 위하여 지체된다. 전위후 오차신호는 필터와 루우프 이득에 의하여 결정된 속도로 그것의 평균치로 여파되고, 루우프필터(98)에 의하여 결정된 시간간격의 평균화된 파이롯트 신호 입력의 신규설정 위상을 연속적으로 발생시키는 기준발진기(94)의 또 다른 전위는 일어나지 않는다. 위상검파기(96), 전압제어기(100) 및 기준발진기(94)의 기능들은 CD 4046AE 계수집적회로 (COS/MOS) 마이크로파워 위상 고정루우프)로 편리하게 결합된다.Therefore, the error signal indicates the direction of the needle potential and the predetermined groove for the pilot signal generated by adding or losing a complete period measured along the recording radius by the needle groove potential.

Can be used to represent the number of limit potentials. In the case of 2826.92 pilot periods in one revolution, the phase for each groove potential is approximately 28

Corresponds to the phase shift of. This phase is advanced for backwards and delayed for forwards. The post-potential error signal is filtered to its average at a rate determined by the filter and the loop gain, and the reference oscillator 94 continuously generates a new set phase of the averaged pilot signal input at a time interval determined by the loop filter 98. Another potential of) does not occur. The functions of phase detector 96, voltage controller 100 and reference oscillator 94 are conveniently combined into a CD 4046AE coefficient integrated circuit (COS / MOS) micropower phase locked loop).

5 shows a block diagram of a component used to perform limited calibration of displaced grooves by actuating a groove potential that receives an error signal from the phase locked loop 90. The fixation system shown allows the needle to displace a nominally fixed number of grooves for reverse potential detection of at least one groove. This limited correction is sufficient to eliminate record defects in which the needle displaces one groove backward and also causes the same groove to be driven repeatedly when the needle encounters the defect again after one rotation of the record.

The magnitude and direction of the potential can be determined by the phase locked loop error signal and the needle can be repositioned in the continuous groove of the same groove where it is relocated, so it will be apparent to those skilled in the art.

The error signal filter 102 of FIG. 5 provides the most effective discrimination against noise and pseudo signals of the error signal and maximizes the peak voltage generated with a phase compared to the maximum of the noise and pseudo signals. 98). The phase corresponding to the reverse potential of at least one groove is detected by the output of the threshold detector 104 used to trigger the monostable multivibrator 100. The monostable multivibrator 106 acts in two ways: firstly, the device does not respond to a phase locked error signal and reactivates the phase locked loop by resuming tracking in a new groove (about 10 milliseconds). Second) to provide a standardized signal to the pulse generator 108. When triggered by the multivibrator 106, the pulse generator 108 provides a standard calibration pulse (0.3 volts amplitude) to the groove potential electromagnets 110 to 116 that advance the needle by approximately three grooves as described above. And duration 1.0 milliseconds). Electromagnets 110-116 are located near the needle arm, as described in more detail below.

It has been known and used to correct the reverse potential due to very small interruption of the program played on the video disc when the three grooves are advanced. The current in the pulse generator 108 compensates for the difference in intensity between the front and back electromagnets 126 to 132 to ensure robust home potential application and to compensate for the difference in strength of the magnets 120 to 122 installed in the needle device. do.

The track potential device is shown with reference to FIGS. 6 to 11. 6 shows a carriage 88 having a compartment 118 for the player needle device for releasably receiving the cartridge 68 shown in FIGS. 7 and 8 and also shown in dashed lines in FIG. . 9 to 11 illustrate the operation of the track potential device.

The track potential device is a carriage for the pair of permanent magnets 120 and 122 rigidly fixed to the needle arm 124 (7, 8 and 9 to 11 degrees) and the permanent magnet fixed to the needle arm to interact with each other. And electromagnets 126, 128, 130, and 132 provided at 66 (FIGS. 6 and 9 to 11). Electromagnets 126 and 128 are acted upon by windings 110 and 112 respectively on magnetic pole surfaces 134 and 136. Electromagnets 130 and 132 are actuated by respective windings 114 and 116 on magnetic pole surfaces 134 and 136.

The carriage 66 is equipped with a needle arm traction device 142 that translates the needle arm in a manner that corrects periodic deviations in the relative speed of the needle / record during regeneration. Periodic deviations in the needle / record relative speed are caused by turntable eccentricity, inaccuracy in mounting, and distortion of the record plate. An example needle arm traction device is described in US Patent Application No. 3983318, issued on September 28, 1976 to M. E. Miller and below.

The needle arm elevating device 144 is installed in the carriage 166 to gently place the player needle on the video disc to perform recording and reproducing operation. U.S. Patent No. 40,501,1 to J. C. Blazy et al., October 11, 1877, describes a needle arm device.

The pair of walls 146 and 148 established in the carriage 66 to operate simultaneously with the chimney-shaped portion 150 fixed to the front end of the needle arm 124 (FIGS. 7-9) It is repositioned laterally to drive the needle while seated on the disk and is also installed as an essential closed groove removal device. US Patent Application No. 3961131, issued to B. K. Taylor on June 1, 1976, describes a manual closed groove removal device using a mount device. Manual devices using a combination of wall and chimney-shaped components are not used for the removal of closed grooves that occur during player operation, but as a backup.

The carriage 66 shown in FIG. 6 is opened when the needle arm 124 is lowered by the needle arm elevating device 144 so that the needle protrudes from the pallet during recording and reproducing so that the needle and record are engaged. 152 is spoken.

The device 154 is coupled with the cartridge needle arm retractor when the cartridge lid 156 is closed while receiving the cartridge 68 in the pallet compartment 118.

The replaceable cartridge 68 shown in FIGS. 2 and 8 is of the type described in U.S. Patent Application No. 4030124 issued to J. A. Allen on June 14, 1977. FIG. The cartridge 68 basically includes a fuselage 160 for fixing the body 158, a coupler 160 for fixing the needle arm 124 to the back plate 162, and a suspension device 164 for flexibly installing the back plate in the cartridge body. ), A spring 166 for selectively supporting the needle arm in the cartridge body, a needle supporter 168 for fixing the player needle 170 to the needle arm, and a terminal formed in the cartridge body, It consists of the leaf | plate spring 172 which electrically connects an electrode.

The terminal 174 formed in the cartridge fuselage when the cartridge 68 is accommodated in the pallet compartment 118 and then the lid 156 is closed is used to electrically connect the needle electrode to the rest of the player circuit. In contact with the terminal 176 provided therein, the needle arm traction device 142 is coupled to the back plate 162 of the cartridge to deliver a periodic needle arm traction operation to the needle 170. In FIG. 6, when cartridge 68 is housed in pallet compartment 118, electrodes 134 and 136 are positioned near magnet 120, and electrodes 138 and 140 are magnet 122. Will be located in the vicinity. The electromagnets 130 and 132 are sized to fit the needs within the cartridge body 158.

9 to 11 show the operation of the track potential device. The polarities of the magnetic pole surfaces 134 to 140 are as shown in FIGS. 10 and 11 which show that each electromagnet acts in response to the generation of a control error signal.

The direction of the magnet 122 causes the electromagnets 130 and 132 to rotate the needle arm around the clockwise longitudinal axis observed at the needle end, as shown in FIG. 11 and the bias of the needle tip from the axis of rotation. Allows continuous radial movement of the needle tip across the grooves on the record.

While the track potential device using one magnet device can be fully operated, the addition of another magnet device allows the performance of the track potential device when several groove potentials (for example, crossing 3 to 20 groove lines) are desired. It can be seen that to improve.

Moreover, it has been known that needle movement between grooves can be achieved by placing the female rotating magnet device with the needle mounted end in another location.

The orientation of the magnet 120 is also such that the actuation of the electromagnets 126 and 128 generates a force that prevents the lateral movement of the needle arm 124 without disturbing its rotational motion. For example, the external lateral motion of the needle arm is hindered when moving radially inward toward the needle tip. The reduction of the lateral movement of the needle arm and its continuous vibration decreases the more reliable operation of the track potential device. Moreover, the lateral movement arrest causes the rotation of the needle arm to be caused by the rotation of the needle about the needle arm axis rather than the rotation of the needle arm about the needle tip.

It will be seen in FIGS. 15 and 15 that the total lateral drive force of the magnet 120 is independent of the magnet position in its operating area. In FIG. 16, curves 180 and 182 represent the lateral drive forces generated by the magnetic pole surfaces 134 and 136, respectively. Curve 184 in FIG. 16 represents the total lateral drive force of the magnet 120.

The relative excitation of the electromagnets is adjusted to reduce movement to the side of the needle arm to minimize as the needle arm is rotated about its longitudinal axis to move the needle tip from one concave groove to the other. This adjustment is made by proportionally distributing the excitation current via the front and back windings by the resistor 178 shown in FIG.

It is also desirable to use a relatively strong electromagnet device to reduce the mass added to the needle arm device by making the magnet fixed to the needle arm relatively small. The position of the magnet 120 at the top of the chimney 150 causes the lateral driving force to be generated by electromagnets contained in the carriage when the needle arm 124 is lowered to come into contact with the needle during record reproduction. It can be seen.

The following is known about the magnetic device.

(1) The magnet device rotates the needle arm about the longitudinal axis of the needle arm in an efficient way of combining the needle tip and the point of application of the driving force so that a predetermined needle displacement can be generated by a given driving force.

(2) The positions of the magnets are such as to minimize the operation due to the record eccentricity, the record distortion and the influence on the dynamic characteristics of the needle arm.

(3) When the needle arm is lowered to contact the needle and record during regeneration, the needle arm electromagnets can be placed in the carriage.

It will be appreciated that the above description relates to home disks but also applies to suitable flat disks. The player needle may again move the same track for multiple defects on the flat discs. The described apparatus can be advantageously used to clarify the playing state of the flat disk by the principles of the present invention.

Claims (1)

When the relative speed between the needle and the record is set, the previously recorded information is reproduced by the needle moving the track, and the above recorded information formed along the continuous line toward the needle tip is detected. The recording and reproducing apparatus in which the arm 124 supports the needle 170 moving the track at one end thereof in the longitudinal axis direction, and the combiner 160 flexibly supports the end of the needle arm away from one end. In which the magnets 120, the electromagnets 126, and 128 displace the radial positions of the needles moving the tracks to selectively rotate the needle arms around the longitudinal axis for easy track potential reproduction. Device.

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