KR850001386B1 - Video recorder playback machine - Google Patents

Abstract

A video record/playback machine includes a write laser and a read laser respectively for generating record and playback optical beams which are focused upon the disk by an optical record/playback head. An optics carriage movably positions the head with respect to the disk in moving optical alignment with the write laser and carries the read laser in fixed optical alignment with the head. The machine includes apparatus for monitoring the record optical beam during operation in a record mode, and for substantially simultaneous operation in a playback mode to monitor the playback optical beam during the recording process.

Description

Video recording and playback device

1 is a partially exploded perspective view of a video recording and reproducing apparatus.

2 is a schematic diagram showing an arrangement of optical components of the device.

3 is an exploded enlarged perspective view of a portion of the device showing the optical device carriage and assembly thereof.

The present invention relates to an improvement of a video recording and reproducing apparatus, and more particularly to an improvement of optical components in a video recording and reproducing apparatus of a type including an optical laser beam for recording and reproducing video information from a video information disc. It is about the batch that was done.

Video recording-reproducing apparatus are generally well known and have means for recording and / or reproducing the signals using a selected medium for storing the video information signals. For example, in one type of device, video signals are magnetically recorded for storage and / or playback on so-called video tapes. In another type of device, the video signal is recorded on the information disc for reproduction by the needle in a manner similar to that of sound reproduction from the gramophone record. In another type of system, a video signal is used to frequency modulate an amplified light beam, such as a laser beam, with an output sufficient to physically alter the surface properties of the photosensitive cladding on the video information disk to record the signal on the video government disk. . In reproduction, the low output light beam is reflected from the disk and the generated signal is demodulated to reproduce the recording signal. In all these types of systems, the video information signal is combined with an appropriate audio signal for either recording or playback purposes to generate a composite audio-video signal of the type commonly used for television transmission and the like. However, for convenience the signal is hereinafter referred to as a video information signal.

Video recording-reproducing apparatus using the amplified light beam for recording and reproduction provides an important advantage without any physical contact between the storage medium, i.e., the information disc and the recording and reproducing element. This prevents wear and deterioration of the mechanical elements and discs, resulting in a high quality storage video signal that can be repeatedly reproduced over a long period with good video clarity.

In a video-recording-reproducing apparatus using amplified optical beams for signal recording and reproduction, separate laser generator units are provided for generating high-output recording optical beams and low-output reproduction optical beams, respectively. It consists of a "write" laser and a "read" laser and is optically aligned with an optical record-reproducing head including a lens for focusing the frames on a video information disc and installed in the apparatus.

Typically, the recording-reproducing head is driven radially with respect to the disc simultaneously with the rotation of the disc so that the video information is recorded on and reproduced from the spiral-shaped information track on the disc. It is desirable to form an information track having a narrow width of about 0.5 microns and a narrow center-to-center radial distance of about 1.5 microns in order to obtain maximum information storage with maximum recording and playback time on each disc. Thus, precise optical alignment between the laser generator units and the recording-reproducing head records in the spot image of the information tracks to maximize signal clarity and minimize cross talk between tracks. And proper concentration of regenerative beams.

In the prior art, a "record" laser and a "read" laser are installed on the fixed base of the video recording-reproducing apparatus. A number of reflective mirrors and optical adjustment lenses are provided to align the movable record-playback head with the generated record and playback optical beams. However, these systems require a relatively large number of mirrors that must be manually adjusted to the proper position to achieve the required precise alignment of the record-playback head and the beams. Thus, the system becomes relatively complicated, bulky and expensive, and it is difficult to maintain proper adjustment. Thus, such a system cannot be a commercially acceptable mass production.

Several conventional playback devices have been proposed in which a relatively small "read" laser is installed optically aligned with the playback head to move with the optics carriage. While these types of arrangements simplify the alignment of the reproducing head and the reproducing optical beam, such arrangements are limited to those used only for the reproducing apparatus. In other words, these arrangements have not been applied for use in a recording-reproducing apparatus where additional alignment of the recording beam and the recording beam and the recording-reproducing head generated by the "recording" laser is also required.

The present invention provides an improvement over the prior art by providing a simple and relatively compact mounting and alignment arrangement between a "record" laser and a "read" laser with an optical record-reproducing head in a video recording-reproducing apparatus.

The video recording-reproducing apparatus includes a relatively high power laser generator unit, i.e., a "recording" laser and a relatively low power laser generator unit, i.e., a "reading" laser, for generating recording and reproduction optical signal beams, respectively. Each of the " recording " and " reading " lasers is installed in optical alignment with an optical record-playback head having lenses for focusing the generated optical beams onto a fine spot image on the video information disc. The head is radially linear to the disc at the same time as the disc rotates to record and reproduce the video information from the spiral tracks on the disc.

According to the invention, the optical recording-reproducing head is installed on the optical device carriage which is linearly movable along the radius of the disk in a plane parallel to the disk, so as to be adjusted linearly with respect to the disk.

A "record" laser is installed on the base of the device in a fixed position relative to the optics carriage. At least two reflecting mirrors provided at the base of the apparatus are provided to reflect the optical beam to reflect the recording optical beam along a path parallel to the moving direction of the optical device carriage. A dichroie mirror for reflecting the recording optical beam through the recording-reproducing head which concentrates the beams on the disc is arranged at an angle on the carriage.

A "read" laser is mounted on the optics carriage to move with the recording-reproducing head. Appropriate reflection mirrors reflect the reproducing optical beam and enter the reflective mirror disposed at an angle on the carriage, which reflects the incident reproducing beam, passes through the dichroic mirror, and the disk Sends the record-playhead to focus on.

The optics carriage is a relatively compact subassembly with means for accurately positioning and maintaining the components installed therein so as to be precisely and optically aligned with the recording-reproducing head. With this structure, the optical device carriage is accurately and optically aligned with each other and assembled with each other quickly and easily. The recording optical beam generated by the "recording" laser after installation in the device is quickly and easily aligned with the optical carriage, providing a simple mounting and alignment arrangement to operate the device with the recording mode and / or the playback mode. to provide. If necessary, means can be provided for accurately positioning and holding the " recording " laser and its accessory reflection mirrors on the device base such that they are precisely pre-aligned with the optics carriage, so that the orientation of the various optical beams can be omitted. Can be.

In one embodiment of the invention, a "read" laser is mounted optically aligned with the recording-reproducing head to focus the reproduction optical beam on the disc slightly downstream of the point of focus of the recording optical beam on the disc. Thus, the device can be operated simultaneously with both recording and playback modes, and thus the sharpness of the recorded video information can be continuously monitored during the recording process.

A "recording" laser generates a collimated and amplified continuous beam of light, which is passed through a modulator, such as an acoustic-ray modulator for frequency modulation, with a modulated optical signal beam including a recording optical beam. It is diffracted into a complementary optical beam implied beyond optical alignment with the recording-reproducing head on the optics carriage. This complementary optical signal can form an input to a photosensitive sensing device for driving an electronic demodulator that reverts its complementary optical beam to an electrical signal representing video information. Since this electrical signal is generated from the supplementary beam of the recording optical beam, monitoring the electrical signal can reveal the quality of the recording optical beam during the recording process.

If necessary, this complementary signal can be compared with the information reproduced from the disc to accurately indicate the quality of recording during the recording process.

Other features and advantages of the invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate by way of example the principles of the invention.

As shown in the figure, the present invention is a video recording-reproducing apparatus 10 that uses laser-generated recording and reproduction videos for recording and reproducing video information from a video information disc 14.

The information disc 14 is removably supported by the apparatus on the spindle assembly 18 which adjusts and rotates the disc at a relatively high speed during recording and playback operations. At the same time as the disc rotation, the recording and / or reproducing beams are precisely concentrated on the disc 14 by the optical recording-reproducing head 34. The head 34 is mounted on a movable optics carriage 30 which is driven to move radially relative to the disc. A fastening device 20 cooperates with the spindle assembly 18 to secure the disk 14 exactly in the center position for precise and high speed rotation without significant radial bias or rotational slip.

The video recording-reproducing apparatus 10 of the present invention includes an improvement of the prior art provided with a simple facility for precisely aligning recording and reproduction optical beams with respect to the recording-reproducing head 34. The device 10 is designed for quick and easy assembly of recording and reproducing optical beams and optical components in a desired alignment without requiring significant or complicated adjustments. The arrangement is also relatively small in size and is particularly suited for the simultaneous operation of the device into both recording and playback modes so that the recording information can be monitored during the recording process.

The apparatus is also adapted to provide an auxiliary recording optical beam for use in monitoring the quality of the recording beam during the recording process and, if necessary, to compare the quality of the recording beam with the sharpness of the recorded information. .

As shown in Figs. 1 and 2, the video recording and reproducing apparatus 10 uses argon for use in recording the video information of the adjustment on the relatively high power laser generator unit 16, i.e., the disc 14. It has a base 12 that provides support for a "recording" laser, such as an ion laser. The " recording " laser 16 emits large collimated copper light beams, which are arranged on mirrors 21 arranged at a pair of angles on the mirror mounting assembly 22 mounted at the device base 12. The " recording " Incident. The two mirrors 21 reflect the amplified light beams to the modulator subassembly 17, which properly blocks the beams, and from the modulator subassembly, a recording optical beam is emitted which represents the desired video information.

The modulator subassembly 17 includes a plate 13 that is suitably mounted to the device base 12 and provided with an electronically driven modulator 24, such as an acoustic-ray modulator. The modulator 24 is aligned with the concentrating lens 23, mounted on the subassembly plate 13, for the passage of the light beam reflected by the mirror 21. The lens 23 is located between the modulator 24 and the mirror 21 to focus the light beam that will pass through the modulator.

The modulator 24 is perforated by a suitable frequency modulated electronic signal supplied through the input lead 26. The electronic signal represents the desired video information. The modulator 24 operates in response to the electronic signal to diffract a portion of the amplified light beam as shown by arrow 9 in FIG. 2, and a modulated recording optical beam as shown by arrow 11 in FIG. Passes through without diffraction. Thus, the generated recording optical beam 11 represents the predetermined video information, and the diffracted beam 9 becomes the modulated supplemental beam of the recording optical beam to also display the predetermined video information. In many cases, the electronic signal constitutes a composite audio-video signal of the type normally used for television transmission, and generates an optical signal beam representing the composite audio-video information when supplied to the modulator 24. However, for clarity, only the video information is described.

The modulated recording optical beam from the modulator 24 passes through the second focusing lens 19, which is also mounted to the subassembly plate 13, to the second mirror mounting assembly 28, which is mounted to the device base 12. Incident on a pair of mirrors 25 of the image. The mirror 25 acts to reflect the modulated second optical beam 11 to the movable optics carriage 30, which is reflected again and then by the optical record-reproducing head 34. It is concentrated on the surface of the information disk 14. More specifically, another focusing lens 27 is provided in the optical device carriage 30 so that the lens 27 focuses the recording optical beam on the dichroic mirror 23. The mirror 32 is provided at an angle on the carriage 30 to reflect the beam 11 upward through the recording-reproducing head 34.

The recording-reproducing head 34 has a focusing lens 36 for concentrating the recording optical beam 11 to a precise spot image on the lower side of the video information disc 14. In addition, the recording-reproducing head 34 maintains the focusing head 36 at a predetermined distance from the disk to maintain the precise focus of the recording optical beam on the disk. It has the means to operate at the distance of.

The optical device carriage 30 is provided to be movable by the carriage drive assembly 38 along a straight path in the radial direction with respect to the disk 14. In this way, the focusing lens 36 of the recording-reproducing head 34 is movable relative to the disk 14 along the radius of the disk to adjust the focusing point of the recording optical beam on the disk. As shown the carriage drive assembly 38 is a precision lead rotatably supported by a bracket 50 that can be mounted to the frame 40 and the base 12 by a number of bolts 42. It has a lead screw 48. The lead screw 48 is screwed into the lead screw nut 52 which is connected to a push block 46 of a sleeve type by a non-rotating connector 54. The push block 46 is freely disposed around the lead screw 48 and is mounted to the upstanding wall 44 of the optical device carriage 30.

The lead screw 48 is arrange | positioned in the direction where the desired of the optical device carriage 30 is generally parallel with the radial direction of movement. A relatively slow reversible motor 56 and a relatively fast reversible motor 58 are connected to the lead screw 48 via an optional clutch unit 60, which clutch unit or It operates to control the movement of the lead screw about its axis at a relatively high speed.

As shown in FIG. 1, the optics carriage 30 is radially relative to the disc 14 each time the lead screw 48 is rotated to squeeze the lead screw nut 52 to the push block 46. It is driven by the lead screw 48 to the outside. When the lead screw is rotated in the opposite direction, the lead screw nut 52 moves in the opposite direction along the screw. The carriage 30 is mounted to the straight track member 64 by means of a blood 62 so as to ensure the optical carriage 30 moves in the opposite direction, ie radially inward with respect to the disk 14. . The track member 64 is rolled against the disk 14 radially inward by a constant force bend spring 66 wound around a cylindrical portion 68 mounted to the frame 40. The track member 64 is slidably provided on the track guide 70 attached to the frame 40. The track guide 70 is of a type suitable for linear movement of the optical device carriage 30 radially inward and outward.

The video information disc 14 is rotationally driven about the vertical axis by the spindle assembly 18 simultaneously with the linear movement of the optical device carriage 30. More specifically, the disk 14 is vertically supported on the rotating drive spindle 72, and the drive spindle 72 has an annular shoulder extending upwardly for supporting the disk. and an upper shaft portion 76 received in the center hole 15 formed in the disk 74. The drive spindle 72 is installed in an upright spindle housing 78 mounted to the device base 12, which rotates the spindle 72 about its vertical axis at a relatively high speed of about 1,800 rpm. Be supportive. A drive motor (not shown) is connected to the spindle to rotate the spindle 72 at a relatively high speed. In addition, a fixing device 20 is provided on the upper shaft portion 76 of the spindle 72 to fix the disk to the exact center position for high speed rotation.

In operation, the recording optical beam is concentrated on the lower side of the video information disk 14 by the radially moving lens 36 on the optical device carriage 30 simultaneously with the high speed rotation of the disk. By suitably adjusting the relationship between the radial motion and the rotational speed, the recording optical beam is concentrated on the disk along the spiral tracks. The disk 14 is attached to a photosensitive coating layer, such as a thin metal layer or a layer of photoresist material, which can be physically altered by a high power recording optical beam so that the optical beam is physically placed on the disk in the form of discontinuous portions where the video beam exhibits some video information. Is recorded. In fact, the closely spaced tracks are about 0.5 microns wide and about 1.5 microns between centers.

The high power recording optical beam is quickly and easily optically aligned with the recording-reproducing head 34 without adjustment of the optical components. In particular, the rack member 64 causes the optical device carriage 30 to move along a precise straight passageway, which determines the proper size and position of the drive assembly 38 on the frame 40 relative to the base 12. By determining the direction and position relative to base 12 may be predetermined. The mirror mounting assemblies 22 and 28 on the base 12 reflect through the modulator 24 along the precise straight path to the high power recording optical beams so that they are dichroic regardless of the radial position of the optical device carriage 30. It acts to enter the wing mirror 32. The " recording " laser 16, together with the mirror mounting assemblies 22 and 28 and the modulator subassembly 17, can be mounted to the base image 12 at exactly a predetermined position by preformed mounting holes on the base. The recording optical beam causes the components on the base 12 to be properly and automatically optically aligned with the recording reproduction head 34 after installation. When additional direction adjustment of the recording optics beam is required, one or both of the mirror mounting assemblies 22 and 28 are recorded for incidence into the microwing mirror 32 of the copper optics carriage 30. It can be formed with adjustable mirrors to adjust the optical beam accurately and quickly.

Using a relatively low power laser generator unit 80, i.e., a "read" laser, such as a helium-neon laser, as shown in Figures 1 and 2, for reproducing the recorded video information for the disc 14. To generate a reproducing optical beam. The " read " laser 80 emits an amplified and collimated optical beam of light having a different frequency than the recording optical beam to be reflected from the disk 14, so that the reflected beam alternates in accordance with the recorded video information. It constitutes a modulated reproduction beam that is reflected and nonreflected. This modulated reproduction beam has a low power enough to prevent physical alteration of the photosensitive coating layer on the disc 14.

The "read" laser 80 is mounted directly on the optical device carriage 30 to move with the record-playback head 34. Thus, the "read" laser 80 is mounted in a fixed position relative to the head 34 so that no optical alignment or adjustment with the head 34 is required. However, the optics carriage 30 has a small subassembly adapted to support the " read " laser 16 and the " read " laser 80 without interfering with the " recording " laser 16 generated thereby. .

In particular, as shown in detail in FIG. 3, the optical device carriage 30 is a pair of upwardly concave support brackets by a number of pins 35 received in the positioning holes 37 of the platform 31. It has a relatively small horizontal platform 31 on which 33 is mounted.

In addition, a curved retainer strap 39 is disposed over the "read" laser 80 and secured to the bracket 33 by screws 41 to fire the "read" laser 80 onto the bracket 33. do. If necessary, cushioning strips 43 of felt material or the like are disposed between the strap 39 and the laser 80 such that the laser 80 in the bracket 33 due to vibration or the like. To prevent movement). Thus, the "read" laser 80 is firmly and accurately placed on the optical device carriage 30.

A relatively small mirror mounting assembly 82 is mounted closely to the "read" laser 80 by the pins 47 received in the preformed mounting holes 49 of the platform 31. This mirror mounting assembly 82 is precisely positioned for the reflection of the azeotropic beam emitted by the "read" laser along a path parallel to the direction of motion of the optics carriage 30 as shown by beam 81 in FIG. The first mirror 45 and the second mirror 51 determined. Thus, the light beam 81 from the "read" laser 80 is reflected along a path parallel to the recording optical beam 11 generated by the "recording" laser 16, and the recording optical beam 11 Runs away at intervals on the beam 81 from the " read " laser 80 as shown in FIG.

A concentrated subassembly 83 is mounted to the upstanding wall 44 of the optical device carriage 30 and to the subassembly is located along the path of the light beam 81 from the “read” laser 80. The lens 84 is provided. As shown in FIG. 3, the concentrated subassembly 83 is sized to be accommodated in a correspondingly shaped recess 85 of the carriage wall 44, and is screwed 86 by the subassembly. 83 is mounted in the recess 85.

However, this screw 86 is received through the long slot 87 formed in the subassembly 83 so that the upright position of the subassembly in the recess 85 is adjusted within the limits provided by the slot 83. It becomes possible.

The focus lens 84 of the subassembly 83 concentrates the light beam 81 from the " read " laser 80 to polarize the beam splitter cube 88 and the quarter wave plate 89. Will pass through. The divider cube 88 and the plate 89 are mounted at fixed positions on the subassembly 83. The beam 81 is then sent to the reflecting mirror 53 disposed at an angle, reflected upward and sent to the recording-reproducing head 34 via the dichroic mirror 32. The reflecting mirror 53 is supported by a bracket 59 attached to the carriage wall 44 in the recess 57 by a screw 59, and a dichroic mirror is directly above the reflecting mirror 53. It is supported on another bracket 61 at the position of and mounted to the carriage wall 44 in the recess 63 by means of a screw 65. Thus, the dichroic mirror 32 causes the recording optical beam 11 to be reflected upward toward the recording-reproducing head 34 while simultaneously recording the beam 81 from the "read" laser 80 upwards. -Positioned to pass through the reproduction head 34.

Thus, the "read" laser beam 81 is concentrated on the video information disc 14 by the recording-reproducing head 34, which beam 81 is from the disc surface according to the surface shape of the disc 14; Reflected and antireflected. The reflected portion of the light beam 81 constitutes a modulated optical reproduction beam that is reflected downward through the dichroic mirror 32 to the reflecting mirror 53.

The reflecting mirror 53 then constitutes the reproduction optical beam. The reflecting mirror 53 then reflects the reproduction optical beam through the quarter-wave plate 89. The plate 89 acts to prevent the passage of light at other frequencies, such as the frequency of the recording optical beam, and allows the reproduction optical beam to pass freely to the polarizing beam divider cube 88.

The polarizing beam splitter cube 88 is a mirror for reflecting the return reproduction optical beam in the transverse direction to the 50-50 beam splitting machine cube 91 mounted on the subassembly 83 alongside the polarizing cube 88. Has a rear surface 90. This 50-50 beam splitter cube 91 reflects a portion of the reproducing optical beam into the aperture 71 of the plate 73 and directs another portion of the beam to a small reflective mirror 75 on the concentrated subassembly. The reflecting mirror 75 is provided at an angle so that the incident part of the beam is reflected at an angle with respect to the first part of the beam toward the hole 71. A photodetector 77, such as a photosensitive diode, is disposed behind the hole 71 and operates in response to incident light to generate an electrical signal indicative of predetermined video information carried by the reproduction optical beam. This electrical signal is suitable frequency modulation discriminator 79 for reprocessing and demodulation to generate an electrical signal for supply to a suitable video display device 92, such as a television receiver for playback of recorded video information. Can be supplied to. Also, the pore detector 77 may be used to determine and provide an electrical signal for adjusting the position of the focusing lens 36 of the recording-reproducing head 34 relative to the disk 14.

The various optical components on the optical device carriage 30 are precisely arranged to focus the beam 81 from the “read” laser 80 onto the disk 14 without requiring alignment adjustment. That is, the components are fixed in place on each other and on the carriage 30 for proper alignment after assembly. In addition, the components are optically aligned with the recording optical beam 11 and positioned to operate properly without any interference between the recording optical beam and the reproduction optical beams.

Reflective mirror 53 is supported on bracket 55 such that the " read " laser beam 81 reflects at a slight angle to the recording optical beam. This angle is selected such that the beam 81 is concentrated on the disk 14 slightly downstream of the point of focus of the recording optical beam 11, ie about a few microns downstream.

Thus, the two beams are not concentrated at exactly the same point on the disc 14, and the apparatus can operate as a recording mode and a reproduction mode at the same time so as to reproduce recorded information simultaneously. Thus, the sharpness of the recorded information can be detected during the recording process. This is particularly advantageous when the apparatus is operated to produce a "master" disc 14 for use in mass production of disc copies by immediately indicating the quality of recording by simultaneous reproduction of recorded information.

As shown in FIG. 2, the apparatus has means for monitoring the quality of the recording optical beam during the recording process. In particular, the diffracted beam 9 from the modulator 24 constitutes a supplemental beam of the recording optical beam 11, which supplemental beam 9 is mirrored by a mirror 93 to a photodetector such as a photosensitive diode. Reflected at 94. The photodetector 94 generates an electrical signal representing the video information in the same manner as the photodetector 77 of the optical device carriage 30, and the electrical signal is input to an appropriate frequency modulation discriminator 95. The discriminator 95 demodulates the signal and supplies it to a display device 96 such as a television receiver to generate an electrical information signal suitable for monitoring the quality of the recording optical beam during the recording process.

The monitored recording signal and the monitored reproduction signal can be compared during the recording process to precisely indicate the quality of video recording on the disc 14. This comparison is made by delaying the output from the demodulator 95 slightly so that the beam 81 from the " read " laser 80 concentrates slightly below on the disk 14, 99, together with a comparator 98 connected to the outputs of demodulators 79 and 95. This comparison is also particularly useful in applications where the apparatus is used to make master discs for mass production of disc copies. By comparing the quality of the signals, it is possible to immediately monitor the various video signals, so that after completing the recording process, defects can be detected in advance without having to check the recorded signal and rewriting the new disc. can do.

Claims (1)

A " recording " laser operative to generate a first light beam traveling along the first passage for use in recording information on the disc, means for rotatably supporting the disc, and moving relative to the support means. And a read-out laser capable of generating a first light beam which travels along a second passage fixedly optically aligned with the head for use in reproducing information from a disc, the optical recording-reproducing head, wherein A carriage assembly comprising means optically aligned in the first passage to reflect a first light beam to the head, and the carriage assembly moving generally parallel to the first passage portion relative to the support means and to the disc To optically align the reflecting means with the first light beam regardless of the position of the carriage assembly. And means for retaining, said reflecting means including beam coupling means, said carriage assembly further reflecting said second light beam through said beam coupling means to said head for reflecting said mirror adjacent said beam coupling means. And the beam coupling means is configured to be a passage of the second optical beam, for recording and reproducing information on an information storage disk.

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