KR850001022B1 - Spindle clamp assembly for a video recorder - Google Patents

Abstract

A spindle clamp assembly is provided to securely clamp a video information disk in a precisely centered position onto a rotatable drive spindle located on a video machine. The assembly has a radially expandable sleeve and an annular wedge collar mounted over the spindle shaft to radially center the disk. The expandable sleeve cooperates with the wedge collar, which is biased downwards by a spring within the clamp housing, to ensure uniform radial expansion of the sleeve and to center the disk on the spindle. the clamp housing further incldues a device to lock the disk onto the spindle, by positioning a clamping ring in a spring-biased engagement with the disk, thus securing the disk on the spindle for rotation.

Description

Spindle fixture for video recorder

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

2 is an enlarged perspective view of a portion of a video recording and reproducing apparatus, showing a partial exploded view of the use of the spindle holding apparatus of the present invention.

3 is an enlarged cross-sectional view of the spindle fixing device of the present invention in fixed engagement with a rotating spindle drive spindle.

4 is a plan view of the spindle holder.

5 is an enlarged cross sectional view of a portion of the spindle retainer taken along line 5-5 of FIG.

The present invention relates to an improvement of a video recording / reproducing apparatus, and more particularly, to an improved spindle for firmly positioning and precisely centering a video information disc on a rotating drive spindle of the video recording / reproducing apparatus. It relates to a fixing device.

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, a video signal is frequency modulated to amplify an optical beam, such as a laser beam, having a power sufficient to physically alter the surface properties of the photosensitive coating on the video information disk to produce a signal on the video information disk. Used to record. In 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 generate television transmissions and such commonly used complex audio-video signals. However, for convenience the signal is hereinafter referred to as a video information signal.

Video recording and reproducing apparatus using the amplified optical 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 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 video information are formed on the disc. For maximum disk clarity, 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.

Thus, in order to prevent cross talk between tracks during recording and / or playback operations, the video information disc is preferably driven rotationally around a precisely positioned and repeatedly obtained axis of rotation to minimize radial deflection. It is important. In the state of the art, such precise positioning and centering has been obtained by precisely forming a central hole in the disk for receiving the video information disk on a precisely formed rotating spindle. In such a structure, however, the tolerances of the disc holes and the spindle have a decisive influence on the precise centering of the disc within the allowable range of radial errors. This centering problem is more pronounced with prolonged use because the central hole of the disc tends to be widened by wear.

Another problem in the prior art is that the disk must be fixed on the spindle so that it rotates constantly and precisely with the spindle without slimming. This slip problem is relatively fast normal, such as about 1,800 rpm, with the fact that there may be thickness differences in the number of information discs so that the fixing means for securing the disc in place must be adapted to the discs of different thicknesses. Further weighted by disk rotation. In addition, in a mastering device for recording information on a master disk for use in making a disk copy, the master disk is usually made of a brittle material such as polished glass. Thus, the fastening means should be adapted to fasten the disk to the spindle without significant stress so that there is no risk of breakage at the time of fastening or at high speed of rotation.

The present invention provides an improved spindle fixing apparatus for video recording and reproducing apparatus which precisely and repeatedly centers a video information disk on a rotating material drive spindle and firmly fixes the disk in place on the spindle without excessive stress. Eliminate problems and drawbacks

According to the present invention, there is provided a spindle fixing device for a video recording-reproducing apparatus for quickly and easily disposing a video information disc on a spindle at an accurate center position so as to accurately rotate about an axis of the spindle. This disc can be repeatedly placed on and removed from the spindle at a precise center position for high quality recording and reproduction of video information signals. In addition, the fastening device firmly holds the disk to the spindle with a controlled clamping force without imparting an unreasonable stress on the disk. The adjusted holding force is approximately the same size, regardless of the specific thickness of the disc, and thus can be applied to various video information discs of different thicknesses.

The fastening device has a radially expandable sleeve having a conical surface that is supported at an upper end of the rotating drive spindle and is inclined radially inward from above. The face of the sleeve cooperates with a wedge cleat having a conical face disposed on the spindle and inclined radially outward from below. The fastening device also has a housing with fastening means for engaging the top of the spindle to secure the disk to the spindle while the sleeve is received in the central hole of the information disc. The spring in the housing presses the wedge collet downward to cause the sleeve to extend radially, thereby uniformly engaging the disk in the center hole of the disk and thus precisely and repeatedly centering the disk on the spindle. .

The housing also has an annular retaining ring that slightly protrudes into the bottom of the housing for process engagement with the video information disc. The retaining ring is vertically movable relative to the clamp housing and biased by a spring, which fantastically exerts a uniform downward clamping force on the information disc when the retainer is mounted on the spindle.

The vertical movement range of the fixing ring is selected so that the fixing ring engages with and securely fixes the video information disc having a thickness within the crystal thickness range.

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 which 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 throttles the disc relatively fast in recording and reproducing operations. At the same time as the disc rotation, the recording and / or reproducing optical beams are precisely concentrated on the disc 14 by the optical recording-reproducing head 34. The head 34 is mounted on the movable optics carriage 30 which is driven to move radially with respect to the disc. The fixing device 20 cooperates with the spindle assembly 18 to fix the disk 14 exactly in the center position for precise and high speed rotation without significant radial bias or rotational slip.

Apparatus 10, including fixture 20 of the present invention, provides an improvement over the prior art in which fixture 20 is designed to accurately and repeatedly center disk 14 relative to the axis of rotation of spindle assembly 18. The disc 14 is quickly and easily centered by placing the fixture 20 in a fixed engagement with the spindle assembly 18 without requiring close tolerances between the disc center hole 15 and the spindle assembly 18. The present invention provides another improvement that the fastening device 20 is adapted to fasten disks of different thicknesses to the spindle assembly 18 with a uniform fastening force so that it can be applied to various disks of different thicknesses without slip during rotation.

As shown in FIG. 1, the video recording-reproducing apparatus 10 is a device base providing support for a relatively high power laser generator unit 16 such as an argon ion laser for use in recording a predetermined video information signal. Has 12 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. Modulator 24 operates in response to the electronic signal to properly block the amplified light beam and pass the modulated optical signal beam. Thus, it represents the predetermined video information of this generated optical signal beam. 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 the composite audio-video information when supplied to 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 with an angle for reflecting the optical signal beam upwards through the focusing assembly 34. The focus assembly 34 has an objective lens assembly 36 for focusing the optical signal beam at a precise point on the lower side of the video information disc 14.

The optics carriage 30 is movably mounted by the carriage drive assembly 38 along a straight path radially with respect to the disc 14. In this way, the objective lens assembly 36 is movably disposed relative to the disk 14 along the radius of the disk to adjust the focusing point of the recording optical beam on the disk. The carriage drive assembly 38 has a precision lead screw 48 rotatably supported by a bracket 50 that can be mounted to the frame 40 and base 12 by a number of bolts 42. The lead screw 48 is screwed into the lead screw nut 52 which is connected to the push block 46 of the sleeve time by the non-rotating connector 54. The pushblock 46 is freely disposed around the lead screw 48 and is mounted to the upstanding wall 44 of the optics carriage 30 as shown.

The lead screw 48 is arranged in a direction in which the desired radial direction of the optical device carriage 30 is usually parallel to the moving direction. A relatively slow reversible motor 56 and a relatively fast reversible motor 58 are connected to the lead screw 48 via the optional clutch unit 60. The clutch unit rotates its shaft at a relatively slow or relatively fast rotational speed. It is operated to adjust the driving of the lead screw to the center.

As shown in FIG. 1, the optics carriage 30 is driven by the lead screw 48 radially outward 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. In order to ensure that the optical device carriage 30 moves in the opposite direction, ie radially inward, the carriage 30 is mounted to the track member 64 in a straight line by the pin 62.

The track member 64 is coalesced in relation to the disk 14 radially inward by a constant band spring 66 wound over a 68 circumference of the cylindrical portion attached to the frame 40. The track member 64 is slidably mounted on the track guide 70 so as to be suitable for linear movement of the optical device carriage 30 radially inward and outward.

The video information disc 14 is rotated 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 a rotating material drive spindle 72, the drive spindle 72 having an upwardly extending annular shoulder 74 for supporting the disk and the disk. It has an upper shaft portion 76 which is housed in the central hole 15 of.

The drive spindle 72 is installed in an upright spindle housing 78 mounted on the long base 12, and the spindle housing supports the spindle 72 to rotate about its vertical axis at a relatively high speed of about 1,800 rpm. A drive motor (not shown) is connected to the spindle to rotate the spindle 72 at a relatively high speed.

In operation, the optical signal beam is concentrated on the lower side of the video information disc 14 by the radially moving objective lens assembly 36 on the optics 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 disk along the spiral tracks. Disc 14 is attached to a photosensitive coating layer, such as a thin metal layer or a layer of photoresist material that can be physically altered by a high power recording optical beam so that the optical signal beam is physically placed on the disc in the form of discontinuities where the video information 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.

As shown in FIG. 1, a relatively low power laser generator unit 80, such as a helium-neon laser, is mounted on the optics carriage 30 for use in reproducing recorded video information for the disc 14. The low power laser generator unit 80 emits an amplified and collimated steel beam to be reflected from the disc 14, so that the reflected optical beam constitutes a modulated reproduction beam that is alternately reflected and non-reflected in accordance with the recorded video information. do. This modulated reproduction beam has a low power enough to prevent physical deformation of the photosensitive coating layer on the disk 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 the mirror 84 disposed at an angle. The mirror 84 then reflects the beam upwards through the dichroic mirror 32 and the reflected beam is concentrated on the disk 14 by the objective lens assembly 36. The reflected-modulated reproduction beam is reflected through the lens assembly 36 and by the mirror 84 and sent to the appropriate optical and electronic components 86 for demodulating the reproduction ratio in the form of an electronic signal representing the desired video information. .

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 serving to check recording clarity.

The fixing device 20 of the present invention securely holds the information disc 14 on the spindle assembly 18 at a precisely and repeatedly obtained central position to precisely position the optical beam for precise recording and reproduction without crosstalk between closely arranged tracks. It is provided for mounting. In addition, the fixing device 20 is provided for firmly fixing the disk 14 at the equator on the spindle assembly 18 such that the disk rotates constantly and accurately at the desired relatively high rotational speed. The fixing action is obtained in the mastering operation without causing undue stress on the disk so that relatively brittle disks formed of polished glass or the like can be used and can also be applied to disks of various thicknesses.

The fastening device 20 of the present invention is shown in detail in FIGS. 2 to 5, the device being clamshell with fastening means for fastening engagement with the upper axle portion 76 of the rotatable drive spindle 72, as described below. It has a housing 88 which is open in the form of a shell. In addition, the fastener 20 has a radially expandable sleeve 90 and an annular wedge collet 92 which is mounted on the spindle assembly shaft 76 and cooperates with each other and with the securing means to the spindle 72. Center the disk radially.

As shown in detail in FIGS. 2 and 3, the rotating drive spindle 72 has a base 75 which extends radially in a relatively large cross-sectional area, from which the annular shoulder 74 extends upwards. have. The base 75 is connected to the upper shaft portion 76 of a relatively small cross section which is inserted into the central hole 15 of the video information disk 14. The upper shaft portion 76 is arranged in alignment with the vertical axis of the spindle assembly 18, so that the spindle housing 78 The upper shaft portion 76 is rotated about the vertical axis by the rotational drive of the spindle 72.

The spindle upper shaft portion 76 is relatively loosely sized to accommodate the radially expandable sleeve 90, which sleeve is relatively loosely received in the central hole 15 of the disc 14. The sleeve 90 is formed of Delrin or a suitable plastile material such that it is relatively largely retained around the shaft portion 76 by a resilient retaining ring 93 such as a 0-ring contained within the sleeve outer groove 94. It consists of an annular split sleeve. If necessary, the sleeve 90 and the rib shaft portion 76 may have shoulders of a corresponding shape, as indicated at 96, to prevent the sleeve 90 from escaping upward from the shaft portion 76. As shown, it is important that the sleeve 90 has a conical face 98 that is inclined radially inward from above to engage the wedge collet 92.

The wedge collet 92 is received around the upper shaft portion 76 above the expandable sleeve 90 and is formed of stainless steel or such a relatively rigid and non-expandable material. The wedge collet 92 is slidable perpendicularly to the upper axle portion 76 and has a conical face 100 inclined downward radially outward to engage the conical face 98 of the sleeve 90.

The housing 88 of the fixing device 20 has a compression spring 102 for pressing down the wedge collet 92 to engage the sleeve 90 when the device 20 is installed on the spindle 72. In particular, the spring 102 is retained in the annular chamber 140 of the housing 88 and supported by an annular washer 106 below. The washer 106 is retained in the housing 88 by an annular plug 108, the plug 108 being screwed to the housing and protruding radially inwardly protruding radially limiting to limit the downward vertical movement of the washer 106. Has 110 However, when the fixing device 20 is installed on the spindle 72, the washer 106 is supported from below on the wedge collet 92 as shown in FIG. 3 to make the radial expansion of the split sleeve 90 uniform. Thus, the sleeve 90 is expanded to engage the disk 14 in the central hole 15 with a uniform radial force, so that the disk 14 is correctly centered on the spindle 72.

A fixed stud 112 has a spindle screwed into the upper shaft portion 76 and extends upwardly along the axis of the spindle 72 from that portion. The fixing stud 112 has a radially outer groove 114 for receiving the fixing ball 16 for securing engagement with the fixing device 20.

The fixed ball 116 is received in a correspondingly sized radial passage 118 formed near the bottom of the fixed cylinder 120. The fixed cylinder 120 is accommodated in a vertically extending passage 119 in the housing 88.

The fixed cylinder 120 has a cylindrical chamber 122 having an open lower side, and therein is housed a cylindrical cap bushing 124 pressed down by a small compression spring 120 in the chamber. In addition, the fixed cylinder is provided with a push pin 126 projecting downward through the bushing 124 so as to be supported by the upper portion of the study 112. When the fixing device 20 is installed on the upper shaft portion 76 of the spindle 72, the bushing 124 is supported on the top of the stud 112 and the head 127 of the 126 pushed apart is spaced slightly above the top of the stud as shown in FIG. .

The upper end of the fixed cylinder 120 is mounted on a horizontal rod 128 rotatably supported in both ends of the lever arm 130 which is generally U-shaped. On both ends of the lever arm 130, a pair of cam rollers 132 are mounted so as to rotationally engage the upper surface 131 of the housing 88. As shown in FIG. 5, the axis of rotation of the rod 128 is located above the axis of rotation of the rollers 132, so that the position of the fixed cylinder 120 in the passage 119 during the rotation of the lever arm 130 is rotated by the roller 132 rotationally integrated with the housing 88. Is moved perpendicular to 88.

In use, rotating the lever arm 130 in the horizontal position shown in FIGS. 3 to 5 in the direction of the arrow 134 in FIG. 3 moves the fixing cylinder 120 in the housing 88 so that the fixing ball 116 moves with the fixing recess 114 of the stud. To match.

In particular, the cylinder passage 119 in the housing 88 holds the ball 116 in the passage 118 radially inward into the stud recess 114 to secure the fixing device 20 to the stud 112 and to prevent upward movement of the fixing cylinder 120 in the housing 88. It is sized to be. In this position, it is important that the annular washer 106 is supported on the wedge collet 92 for proper radial expansion of the sleeve 90 and accurate centering of the disc 14.

When the lever arm 130 is rotated to the vertical position shown in FIG. 2 in the direction opposite to the arrow 134 in FIG. 3, the head 127 of the pushpin 126 is pushed downward by the rod 128 in the housing 88 of the fixed cylinder 120. Make sure that it is supported by the top of the stud 112. At this point, the fixed cylinder 120 is fixed against the downward movement by the stud effect groove 114 new ball 116, so that the housing 88 is raised relative to the fixed cylinder 120. This upward movement of the housing 88 causes the annular chamber 138 in the housing 88 to be aligned vertically with the radial path 118, thereby moving the ball 116 radially outward from the fixing recess 114 of the stud 112. Thus, the housing 88 and the fixed cylinder 120 are simultaneously raised from the stud 112 and the spring 125 pushes the bushing 124 downward to close the inner diameter of the ball passage 118 and allow the ball 116 to be retained in the housing chamber 138. The head 127 of the push pin 126 restricts the bushing 124 from moving downward out of the fixed cylinder chamber 122. The fastening device 20 is quickly and easily relocated to securely engage the stud 112 by pressing the housing 88 over the stud 112 and moving the lever pressure 130 to the horizontal position shown in FIGS. Thus, the stud 112 causes the bushing 124 to be retracted upwards in the chamber 122 against the force and causes the ball 116 to move radially inward into the stud recess 114 when proper vertical alignment is obtained. On downward rotation of the lever arm 130 the fixed cylinder 120 is moved upwards in the housing 88 causing the ball 116 to be out of alignment with the housing chamber 138 and upwards to enter the stud recess 114. At the same time, the washer 106 is moved to bear on the wedge collet 92.

The housing 88 of the fixing device 20 also has a downwardly open annular chamber 142 formed to enclose the outer circumference of the housing 88 to accommodate the annular fixing ring 144 protruding downward. Its retaining ring 144. It is sized and shaped to engage the top surface of the information disc 14 on a ring aligned perpendicular to the spindle shoulder 74. The retaining ring 144 is disposed in the slot 148 so as to be movable vertically in the chamber 142 by a plurality of cap screws 146 that are spaced around the ring and screwed into the housing 88. In particular, as shown in FIG. 3, each cap screw 146 consists of a cap 150 accommodated in the ring slot 148 and a narrow body portion 152 projecting through the opening 154 and screwed into the housing. It is important that a relatively narrow chamber 156 is formed in the housing 88 surrounding a portion of the body portion 152 of each cap screw 146 and that a relatively low pressure spring 158 is housed in each chamber 156 to act between the housing 88 and the retaining ring 144. Do. Thus, the spring 158 presses the fixing ring 144 downward under pressure to a normal position that engages the head 150 of the cap screw 146.

When the fastening device 20 is mounted to the spindle assembly 18, the fastening ring 144 engages the upper surface of the information disc 14 on the annular shoulder 74 of the spindle 72. The retaining ring 144 retracts upward against the pressure of the spring 158 to annularly apply a uniform holding force around the disk in accordance with the characteristics of the spring 158. It is important that such a withdrawal of the spring 152 form a vertical gap between the cap screw head 150 and the retaining ring 144. Within the allowable limits of the vertical spacing, the retaining ring 144 also applies to disks of varying thickness without adversely affecting the ability of the fastening device 20 to secure the disk in a central position on the spindle assembly 18.

The allowable limit of this vertical spacing is chosen to be relatively narrow with respect to the properties of the spring 158 so that the clamping force applied to a given disk 14 is uniform to a number of disks having a thickness within a predetermined range.

Accordingly, the spindle holding device 20 of the present invention firmly and precisely centers the information disk 14 on the spindle assembly 18 in a precise and repeatable manner. In addition, the fixing device 20 provides a fixing force to the disk for fixedly arranging the disk having a thickness within a predetermined range at high speed without rotation slip. The applied clamping force is applied uniformly and evenly around the disk, just above the lower support in the form of a spindle shoulder 74 so that a relatively low stress is applied to the disk and the fragile like a glass disk is used in the mastering process. Can be used safely on disk

Claims (1)

A device having a rotatable drive spindle having an axial portion for receiving through a central hole in an information disc, and an enlarged base for vertically supporting the disc, the device having an interior of a hole formed in the disc and around the spindle 76. A radially expandable slide 90 that can be accommodated, and fastening means 114, 116 received on and engaged with the spindle 76, and the fastening means 114, 116 above the spindle 76. Received to displace the sleeve 90 radially outward so that the sleeve 90 can expand substantially uniformly radially when the sleeve engages the disk and centers the disk about the spindle 76. The bias means 102, 106 and the fastening means 114, 116 acting between the sleeve and the fastening means 114, 116 are received on the pins 76 so that the disc is displaced. The disk with respect to the spindle, consisting of the fastening means (114, 116) and the fastening means (20) acting between the disk so that the clamping force is generally perpendicular to the disk when holding it firmly on the spindle. Spindle fixture for fast and firm positioning.

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