KR850001019B1 - Spindle assembly for a video recorder-playback machine - Google Patents

Abstract

This apparatus is provided for rotatably supporting and driving a video information disk in a video recorder-playback machine. The apparatus comprises a vertically extending journal, having a generally truncated conical shape and supported for rotation in an inverted position within a complementary-shaped spindle housing. The apparatus accurately and precisely drives the information disk for consistently accurate recording and playback of video information, within the narrowly spaced information tracks on the disk, and without signal cross-talk.

Description

Spindle fixture for video recorder

1 is a partially exploded perspective view of a video recording / playback apparatus.

2 is a partially enlarged exploded perspective view of the spindle cookware of the present invention.

3 is an exploded perspective view showing the assembly of the spindle assembly of FIG.

4 is a partially enlarged side view of the spindle assembly.

5 is an enlarged vertical sectional view taken along line 5-5 of FIG.

6 is an enlarged vertical cross-sectional view taken along line 6-6 of FIG.

The present invention relates to a video recording-reproducing apparatus, and more particularly to an improved rotating material drive spindle assembly for smooth and relatively high speed rotation of a video information disc in a video recording-reproducing apparatus.

Video recording-reproducing apparatus are generally well known and have means for recording and / or reproducing the signals using a selected medium for storage of 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, the video signal is frequency modulated to record an signal on the video information disc, such as a laser beam having a power sufficient to physically alter the surface properties of the photosensitive coating on the video information disc. It is used to During reproduction, the low output light beam is reflected from the disc 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 produce 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 and 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 reproduction element. This prevents the wear and deterioration of the machine elements and the disc, so that a good storage video signal is obtained which can be repeatedly reproduced over a long time with good video clarity.

In a video recording-reproducing apparatus using amplified optical beams for signal recording and reproducing, the recording and reproducing optical beams are video information discs by intensive lenses moving radially along the disc's radius simultaneously with the rotation of the disc. Focused on the phase. Thus, closely spaced tracks in the form of spirals representing the degree of video are formed on the disc. For maximum disc clarity and for maximum storage capacity of each disc, the information tracks are as narrow as about 0.5 microns and the center tube spacing between radially adjacent spiral tracks is about 1.5 microns.

Therefore, in order to prevent cross talk between tracks during the recording and / or reproducing operation, it is important that the video information disc is rotatably driven about a precise and constant axis of rotation to minimize radial bias.

In the prior art, various driving spindles for rotating the video information disc have been proposed. However, most of these conventional proposals include a so-called direct drive arrangement in which a rotating spindle supporting the disk is mechanically connected to a high speed drive motor to rotate. These direct drive arrangements impart undesirable system vibrations from the motor to the spindle, resulting in relatively minor radial movement of the spindle during rotation, and thus crosstalk frequently occurs during operation of the device. Several attempts have been made to isolate the spindle from its system vibration by at least partially supporting the spindle in an air bearing. However, these arrangements have never been proven completely satisfactory in eliminating crosstalk between tracks in operation.

The present invention eliminates the problems and disadvantages of the prior art by providing an improved spindle assembly for a video recording / playback apparatus. The improved spindle assembly includes a rotating spindle axis supported for constant and high speed rotation about the vertical axis for accurate drive of the video information disc.

According to the present invention, a spindle assembly for rotationally supporting and driving a video information disc in a video recording / reproducing apparatus is provided. The spindle assembly supports the video information disc for relatively high speed rotation of about 1,800 rpm without radial bias during rotation. Thus, the spindle assembly drives the disc precisely and accurately to record and reproduce the video information in the narrowly spaced information tracks on the disc without signal crosstalk. Moreover, the spindle assembly has little or no vacuum or wear of the components without actual friction during rotation.

The spindle assembly includes a vertically extending spindle axis that is rotationally driven at a lower end by a relatively high speed direct current motor. The spindle axis is upwardly formed to form a shoulder for vertically supporting the video information disc and an upper portion comprising an upwardly protruding stud inserted into the center hole of the disc for positioning the disc on the spindle axis. Extends. If necessary, fixing means may be provided for securing engagement with the studs and for securing engagement to the disks for centering the disks to the studs.

The spindle axis has an inverse truncated cone journal in its middle part. This journal is rotatably supported in a correspondingly shaped spindle housing formed of a number of patches separated by fittings of suitable size to ensure close engagement between the journal and the spindle housing. Thus, the journal provides a relatively large support surface for supporting the spindle axis against radial and downward axial thrust loads. Its radial load can cause radial bias in high speed rotation.

The spindle housing has an inlet passage for air under pressure to the contact area between the journal and the support surface of the spindle housing. In particular, the air passages formed perpendicular to the spindle housing portions allow pressurized air to pass through the annular slots formed vertically adjacent the shims without throttling. The shims have annular slots and radially inwardly open notches through which pressure is applied so that air under pressure can be moved along the height of the spindle assembly for smooth and accurate rotation of the journal on the air cushion. At these positions, the contact area between the journal and the housing support surface is annularly supplied.

The spindle housing is fixed to the base ring which suitably secures the spindle assembly to the video recording / playback apparatus. The thrust plate is preferably mounted at the bottom of the journal to rotate with the journal in rotational engagement with the bottom surface of the base ring to provide a support surface for supporting the axially directed thrust load. A portion of the pressurized air is injected into the contact area between the thrust plate and the base ring to form an air cushion between them.

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 implemented in a video recording-reproducing apparatus 10 which uses laser-generated recording and reproducing videos for recording and reproducing video information from the video information disc 14. The information disc 14 is removably supported by the apparatus on the spindle assembly 18 which adjusts and accurately rotates the disc at a relatively high speed during recording and reproducing operations. The fixture 20 operates to lock the disk 14 in the exact center position on the spindle assembly 18 for accurate and high speed disk rotation without slim.

The device 10 including the spindle assembly 18 of the present invention allows the video information disc 14 to be constantly and precisely rotated relative to the vertical side of the spindle assembly at a relatively high rotational speed without the spindle assembly 18 having significant radial bias. It provides an improvement of the prior art designed to be. The spindle assembly 18 is relatively simple in structure and assembly and operates constantly and smoothly without significant vibration or undue wear of the components. Thus, the spindle assembly 18 is particularly suitable for use in the video recording-reproducing apparatus 10, in which constant and accurate rotation of the disk 14 is required to prevent crosstalk between information tracks on the disk.

As shown in FIG. 1, the video recording and reproducing apparatus 10 uses a relatively high power laser generator unit 16, such as an argon ion laser, for use in recording a predetermined video information signal on the disk 14. As shown in FIG. It has a device base or table 12 that provides support for it. The high power laser generator unit 16 emits a largely amplified and collimated light beam, which is reflected by an appropriate mirror assembly 22 and sent to an electronically driven modulator 24. The modulator 24 is driven by a suitable frequency modulated electronic signal supplied by the input lead 26. The electronic signal represents the desired video information. The modulator 24 is operated in response to the electronic signal to properly block the amplified light beam and pass the modulated optical signal beam. Thus, this generated optical signal beam represents some video information. In many cases, the electronic signal constitutes a composite audio-video signal of the type normally used for television transmission, i.e., the signal generates an optical signal beam representing composite audio-video information when supplied to the modulator 24. However, for the sake of clarity, it is hereinafter referred to as video information.

The modulated optical signal beam is incident on the second mirror assembly 28 and reflected on the movable optics carriage 30. This optical device carriage 30 has a dichroic mirror 32 arranged at an angle for reflecting the optical signal beam upwardly through the optical recording-reproducing head 34. The record-playback head 34 has an objective lens assembly 36 for concentrating the optical signal beam at a precise point on the underside of the video information disc 14.

The optical carriage 30 is movably mounted to the carriage drive assembly 38 along a straight path radially relative to the disk 14. In this way, the recording-reproducing head 34 is movably disposed with respect to the disk 14 along the radius of the disk to adjust the point of focus of the optical signal beam on the disk. The carriage driven cook 38 is a precision lead screw rotatably supported by a bracket 50 that can be mounted to the frame 40 and the base 12 by a number of bolts 42. Has 48). The lead screw 48 is screwed into the lead screw nut 52 which is connected to the push block 46 of the sleeve type by a non-rotating connector 54. The push block 46 is freely disposed about the lead screw 48 and is mounted to the upstanding wall 44 of the optics carriage 30 as shown.

The lead screw 48 is arrange | positioned in the direction parallel to the moving direction of the desired radial direction of the optical device carriage 30. As shown in FIG. 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 is at a relatively slow rotational speed or It operates to regulate the movement of the lead screw about its axis at a relatively high rotational speed.

As shown in FIG. The optics carriage 30 drives the lead screw 48 radially with respect to the disc 14 whenever the lead screw 48 is rotated to press the lead screw nut 52 against the pushblock 46. When the lead screw is rotated in the opposite direction, the lead screw nut 52 also moves in the opposite direction along the screw. The carriage 30 is mounted to the linear slide member 64 by pins 62 in order to ensure that the optics carriage 30 moves in the opposite direction, ie radially inward.

The slide member 64 is pressed against the disk 40 radially inward by a constant band band spring 66 wound around the cylindrical portion 68 mounted on the frame 40. The slide member 64 is slidably mounted to the frame 40 and slidably mounted to the straight track member 70 which is adapted to linearly move the winding device carriage 30 radially inward and outward. .

The video information disc 14 is housed on the spindle assembly 18 of the present invention such that the disc rotates at a relatively high speed about the vertical axis of the spindle assembly 18 as described below. Rotation of such a disk is performed simultaneously with the linear movement of the optical device carriage 30 in response to the operation of the carriage drive assembly 38. Thus, in operation, the optical signal beam is concentrated on the lower side of the video information disc 14 by the radially moving recording-reproducing head 34 on the optical device carriage 30 simultaneously with the high speed rotation of the disc. By properly adjusting the relationship between the radial motion and the rotational speed, the optical signal beam is concentrated on the disc along closely spaced tracks of the spiral orientation. The disk 14 has a thin metal layer or a photosensitive coating layer such as a photoresist material suitable for being physically deformed by a high output optical signal beam so that the optical signal beam is physically placed on the disk in the form of discontinuous portions that will exhibit some video information. Is recorded. In practice, the disk is rotated at a speed of about 1,800 rpm, and closely spaced tracks are formed with a width of about 0.5 microns and a center-to-center spacing of about 1.5 microns.

A fixing device 20 is provided for firmly fixing the video information disk 14 on the spindle assembly 18 to apply to a high speed rotation of the disk without a slim. However, it is important that the fixture also has a means for centering the disk on the spindle assembly so that the disk can be accurately rotated at high speed without radially biasing the spindle assembly.

As shown in FIG. 1, a relatively low power laser generator unit 80, such as a belium-neon laser, is mounted directly on the optical device carriage 30 for use in reproducing video information recorded from the disk 14. have. The low power laser generator unit 80 emits an amplified and collimated light beam to be reflected from the disk 14, the reflected optical beam being a modulated reproduction beam that is alternately reflected and non-reflected in accordance with the recorded video information. Configure. This modulated regeneration beam has exceptionally low power to prevent physical deformation of the photosensitive coating layer on the disc 14.

The amplified light beam from the low power laser generator unit 80 is reflected by a suitable mirror assembly 82 on the optics carriage 30 and is incident on an angled mirror 84. The mirror 84 then reflects the beam upwards through the dichroic mirror 32, and the reflected beam is concentrated on the disc 14 by the recording-reproducing head 34. The reflected-modulated reproduction beam is reflected through the head 34 and by the mirror 84 to the appropriate optical and electronic component 86, which components 86 provide the desired video information. Demodulate in the form of an electronic signal. The electronic signal can be supplied to a suitable video display device such as a television receiver for reproduction of recorded video information. It is important that reproduction can be done simultaneously with or without the recording function to check recording clarity.

The spindle device 18 of the present invention is provided to support the disk 14 for rotation about a precise vertical axis without radial deflection so that the disk rotates accurately with respect to the record-playback head 34. Thus, the spindle assembly 18 maintains the proper position of the disc relative to the optical beams in rotation for precise recording and playback without crosstalk between closely spaced tracks.

The spindle assembly 18 is shown in detail in FIGS. 2-6, which assembly is supported to rotate about the correct vertical axis 71 in the spindle housing 78 of the corresponding shape. Has) The spindle shaft 72 is formed of a single piece of stainless steel or the like and is sized to be accommodated in the electric motor 75 to drive the spindle shaft 72 at a relatively high rotational speed of about 1,800 rpm. And a rod-shaped lower end 73. The drive motor 75 is a high-speed direct current motor for imparting rotational torque to the lower end 73 of the shaft without physical contact with the shaft 72. It is. Thus, the shaft 72 is driven to rotate at high speed with minimal frictional resistance and vibration between the motor 75 and the shaft 72.

The lower end 73 of the shaft 72 is connected to a journal 77 having an inverted truncated cone shape for supporting engagement with the spindle housing 78. This journal 77 has a form having an upper annular dog portion 74 for vertically supporting the information disk 14. An upper stud 76 protrudes partly and upwardly into the journal 77 coaxially with the vertical axis 71 and is inserted into the central hole 15 of the information disk 14 to hold the disk on the spindle assembly. do. As shown in FIGS. 1 and 2, the stud 76 is adapted to cooperate with the fixing device 20 to center and fix the disk in place. The journal 77 of the spindle shaft 72 has a downward shoulder 88 at its lower end. With the shoulder 88, the journal 77 extends upward in radial direction to form a reverse truncated cone. This conical journal 77 is housed in a spindle housing 78 with a support surface 90 that is inclined radially inward of the truncated cone. It is important that the support surface 90 of this housing is shaped to correspond to each other so as to engage the journal, so that the journal 77 is supported in the housing 78 so as to rotate exactly about the vertical axis 71. It is also important that the relative cone shapes of the journal 77 and the support surface 90 allow the journal to adapt to both downward axial thrust loads and radial loads in operation. Moreover, most of the support surface area of the journal 77, ie, the portion of the journal clothing (large diameter) portion of the load to be supported by the journal, i.e. most of the information disc 14 on the studs 76. Adjacent to the top of the journal.

As shown in detail in FIG. 4, the spindle housing 78 is formed of a plurality of housing portions (three parts 92, 94 and 96 are shown in the figure) which vertically overlap. All of them have a radially inwardly inclined support surface formed coaxial with the vertical axis of rotation 71 of the spindle axis, the support surface supporting the journal 77 together with the corresponding support surfaces of the other housing parts. To form a conical support surface 90. The upper and lower portions 92 and 96 of the housing portions are mounted to the intermediate housing portion 74 by a plurality of bolts 91 and 93, respectively.

A thin disc shaped shim 98 is inserted between the upper and middle housing portions 92 and 94, and another thin disc shaped shim 100 is the middle housing portion 94 and the lower housing portion 96. It is inserted between). Their shims 98 and 100 are shaped to adjust the height positions between the housing portions, respectively, so that the housing support surface 90 closely matches the shape of the journal 77. Thus, the journal 77 is rotated accurately and constantly about the vertical axis 71.

Pressurized air is injected into the contact area between the journal 77 and the housing support surface 90 to smoothly support the journal to rotate on the air cushion. In particular, as shown in FIGS. 4-6, the intermediate housing portion 94 has a radially protruding air inlet 102 for connection to a pressure air source (not shown). This inlet 102 supplies air to a flow path 104 extending along the height of the middle housing part 94. The flow passage is through the slotted annular recessed portion that is opened upward of the upper end of the housing portion 94, that is, the slotted annular recessed portion that is through the passage 106 and is opened downward of the lower portion of the housing portion 94. That is, through the flow path 108 and without throttling. As shown in FIGS. 5 and 6, these two slotted recesses 106 and 108 are notched inwardly in the radial direction of the beast formed in adjacent shims 98 and 100, respectively. It is annularly arranged to communicate with the notches 110 and 112. These notches 110 and 112 provide a plurality of flow paths for supplying pressure air radially inward from the grooves 106 and 108 at the contact area between the journal 77 and the housing support surface 90. to provide. Thus, pressurized air is uniformly supplied to the contact area between the journal and the support surface at multiple vertically spaced locations around the journal and along the journal height. It is important that this pressure air flows up and down along its contact area and is discharged from the spindle assembly, so that the follicles are rotatably supported in operation by an annular continuous air membrane.

The lower housing portion 96 of the spindle housing 78 has an annular dog 114 formed with a lower recess for receiving the base ring 116. As shown, this base ring 116 is mounted to the lower housing portion 96 by bolts 93 and also to the device table 12 by a number of bolts 118, thus, Spindle assembly 18 is secured to the small load on the device.

A lower cylindrical thrust plate 120 is provided to support the vertical thrust load during operation of the spindle assembly 18. In particular, the thrust plate 120 is attached to the shoulder 88 of the journal by a plurality of screws 122 in which a fitting 124 of a suitable size is inserted between the shoulder 88 and the thrust plate. . This thrust plate is sized to have an upper support surface engaging with the lower surface of the base ring 116. As shown in FIG. 4, the pressure air is supplied to the support surface by the flow passage 126 of the lower housing portion 96 aligned with the flow passage 104 of the intermediate housing portion 94. The lower passage 126 supplies a portion of the pressure air to the annular slot 128 through the annular leak passage 130 through the contact area between the thrust plate 120 and the base ring 116.

Thus, the spindle assembly 18 of the present invention provides a relatively simple and thus relatively inexpensive assembly for accurately supporting the video information disc to rotate accurately and smoothly about the correct vertical axis. The rotation of the spindle assembly is not frictional, so that the disk is not subjected to device and / or system vibrations that may cause rotation when the device is operated in recording or low power mode.

Conical journal 77 is disposed on the air support surface for application to radial loads and downward axial thrust loads, and thrust plate 120 is disposed on the air support surface for application to upward axial thrust loads. Pressure air forming the air support surfaces is supplied directly to the appropriate support surface via a plurality of internal flow paths and slotted annular recesses formed in the spindle housing without throttling. Since the air supplied to the support surface is not subjected to throttling, air flows uniformly on the support surfaces, so that smooth rotation of the spindle axis without vibration is achieved.

Claims (1)

A reverse frustoconical journal (77) forming an upward shoulder (74) for vertical support with the disc and upward from the shoulder (74) along the axis of the journal (77) for receipt in a central hole of the disc. Radially inward support of the truncated cone for accommodating the spindle 77 with the spindle shaft 72 having protruding studs 76 and the journal 77 rotating about the vertical axis 71. A spindle housing having a face 90 and formed with passage means 104 for substantially uniformly annular communication of the air under pressure into a conical contact region between the journal 77 and its support face 90 ( 78, the spindle housing 78 is formed of a plurality of vertically overlapping portions 6 (92, 94, 96) connected to each other to form a conical support surface 90, Adjusting the conical support surface 90 to closely match the shape Rotating annular shims 98, 100 inserted between each adjacent pair of housing portions 92, 94, 96 to heighten the housing portions 92, 94, 96 relative to one another. Spindle assembly for supporting the disk.

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