DE2655643A1 - DEVICE FOR CLEANING THE PLAYING NEEDLE OF A RECORD PLAYER - Google Patents

Description

70235 / Kö

RCA 70,235 * 3-

British / US Serial Nos. 50279-75 / 667386 '. Filed: December 8, 1975 / March 16, 1976

RGA Corporation

New York, N.Y. (V.St.A.)

Device for cleaning the playback needle of a record player

The invention relates to a device for cleaning the playback needle a turntable with a rotatable turntable and with a playback needle attached to one end of a pick-up arm is supported, which is pivotably mounted at its other end in a housing that is separated from the turntable between a Rest position and a playing position is displaceable over the turntable. The device works automatically and is for example an optical disc player such as that disclosed in U.S. Patent Er. 3 842 194 type described is suitable.

In this known video disk player, the playback needle is in the form of an insulating support with a conductive one serving as an electrode Covering held at one end of the pick-up arm. The end of the arm removed from the needle is pivotably mounted in the arm housing, as a sheath or capsule made of conductor material with a bottom opening through which the needle while playing a Plate protrudes, is formed. The arm housing is rotating in the radial direction during the playback process Plate moved forward so that the needle point in the

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following turns or circumferences of the plate groove one essentially can maintain constant posture or positional orientation. When passing the recorded information embodying changes in geometry in the bottom of the groove under the tip of the needle changes accordingly between the needle electrode and a conductor coating (under a dielectric coating) on the plate surface formed capacity. These changes in capacitance are converted into electrical signals by means of a suitable pick-up circuit converted to a television receiver after appropriate processing can be forwarded to reproduce the recorded information.

During playback, rubbish or dirt of various kinds (e.g. from the needle or The plate's splintered fragments accumulate, which interferes with the correct detection of the tiny changes in the groove bottom can affect.

The invention has for its object to provide a device for automatically cleaning the playback needle, whereby the adverse effects of such accumulation of rubbish can be reduced.

A device of the type mentioned is characterized according to the invention by a brush with a holder in which a Number of bristles attached; by a bracket that holds the bracket at a point near the turntable under the walkway of the housing between rest and play position; and by an arrangement which the rotation of the pickup arm by one to the plate support surface of the turntable essentially parallel axis controls so that the playback needle while the housing is in the rest position and while it is between the rest position and an intermediate position between the rest and play position moves so far from the housing that it protrudes from the Bristles is detected, the height of the holder at its mounting point on the level of the support surface of the turntable is related in such a way that the playback needle is raised from the bristles when the housing is in the rest position.

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is based, which corresponds essentially to their height when detecting the plate surface.

The automatic needle cleaning takes place during the passage of the arm housing from the rest position (separated from the turntable carrying the record) to the play position above the Turntable when playing a record and during the return to the rest position after the playback process has ended .

The brush of the cleaning device (e.g. made of nylon bristles) is in one place (on one side of the turntable) attached, which crosses the housing during its passage to the rest position and back. One serves with the gate part automatic arm lowering at rest (as described in US patent application Ser. No. 667309) in order to achieve that the playback needle is brushed by the bristles of the brush during the movement of the housing in the vicinity of the rest position will.

In the arrangement according to the above-mentioned US patent application causes an electrically operated device to lower the pickup arm, so that the playback needle during playback can be picked up by the record groove and run in it. In contrast, during the movement of the housing in a selected lowered play position and switched off from this position the electrical actuation to a raised position for the To create the doffer arm by withdrawing the needle in the housing (so that, for example, the outer edge of the plate is exposed). In the arrangement according to the said US patent application, however, it is sought to maintain the raised Avoid arm position at rest (so that the arm does not "sit down" or kink due to a resilient mounting element caused, which then leads to the fact that the arm can no longer move properly). To this end, will In addition, a mechanical arm lowering process triggered when the housing approaches the rest position, so that the Arm can take its normal "playback" position in the idle state.

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According to the invention, the brush is arranged so that in the case of the mentioned mechanically triggered arm lowering the protruding playback needle when it approaches the rest position, from the bristles the brush is detected, the brush the needle end of the released or relieved needle arm in the final Supports rest position. The height of the brush is chosen so that the bristles support the needle at a height that is substantially corresponds to the level of the plate surface, so that it is ensured that the rest position of the arm is essentially his corresponds to the normal playback position.

A brush cleaning mechanism is a further development of the invention provided, which shakes the brush when the housing is moved into and out of the rest position to remove dirt particles and remove dust or debris.

The invention is explained in detail below with reference to the drawing. Show it:

Pig. 1 in plan view of an ifadelsäuberungsvorrichtung according to an embodiment of the invention;

.Pig. 2 shows a side view of the device according to FIG. 1 with associated Sharing a video disc player;

Pig. 3 shows a perspective illustration of a needle lowering mechanism suitable for the device according to FIG. 1; and

Pig. Figure 4 is a cross-sectional view of the Pig mechanism. 3.

Pig. 1 'shows a flap cleaning device in plan view for an optical disc player according to an embodiment of the invention, the device comprises a base plate 11 of a bolt 13 stands up. On the bolt 13 is a component 14 with three protruding under a spring ring or a lock nut 15 Arms 14a, 14b and 14c are rotatably mounted. The end of the arm 14b remote from the bolt 13 ends in an upstanding one Projection 14e with a hole quite far down, into which one end of a helical spring 18 is hooked, which with its other end rests on a cylindrical projection 16 of the base plate 11 and a second bolt 17 under one Retaining ring 19 includes.

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The spring 18 pushes the component 14 in a .Drehlage, in which the arm 14c detects the side of a third bolt 20 projecting upwards from the base plate 11 (in FIG. 1 in solid lines rotation position shown). At its end remote from the bolt, the arm 14a has an upwardly bent projection 14d. If the Arm 14c engages the bolt 20, the projection 14d of the arm 14a is in the vicinity, but on one side, the free one Ends of a number of substantially straight bristles, the other ends of which are fixed in a holder 22 and one Brush 21 form. The holder 22 is fastened in a capsule 23 which protrudes above the level of the base plate 11. In the Base plate 11 is a bore or recess 24 under the brush 21. Further ones provided in the base plate 11 Holes 25, 26 are used to receive bolts (not shown) for fastening the cleaning device in the appropriate position on one side of the turntable.

As shown in the side view of Fig. 2, is in a desired position and arrangement of the cleaning device in the turntable, the upper end of the projection 14e in the path of the arm housing 30 of the turntable from the vicinity of the turntable 40 in the rest position. Pig. 2 shows in section part of the housing envelope with the housing base 32 and part of the outer wall 31 at a point (of the housing path to the rest position) immediately before the projection 14e is grasped by the housing wall 31. When the projection 14e is grasped by the housing wall 31 , their movement (in the direction indicated by the arrow in Pig. 2) causes the component 14 to rotate counterclockwise from the direction indicated in Pig. 1 position shown in solid lines. In the course of this counterclockwise rotation (with tensioning of the each 18), the projection 14d runs through the brush 21, the bristles being shaken through the recess 24 while throwing off dust and debris. The rotation continues until the housing 30 reaches its rest position, indicated in Pig. 2 by the dashed position representation of the outer wall (31 ¹ ) · The counterclockwise rotation of the component 14 is limited by the stop of the arm 14 on the side of the bolt 17. This border location is in Pig. 1 by the dashed arm position representation (14a ',

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14d ') indicated.

In the case of the housing position shown in solid lines in FIG. 2 the playback needle 35 is retracted into the housing 30 due to a raised position of its support arm 36 (above the Bottom opening 33). At a later point at the lay of the case 30 in its rest position after the Yorsprung Hd by the brush 21 is passed through, the mechanically operated lowering of the arm 36 takes place (for example in the US patent application mentioned described manner), so that the needle 35 settles through the opening 33 on the bristles of the brush 21 can. The needle position when sitting on the bristles is indicated by the dashed line "d". When moving the Housing, the needle 35 runs along the bristles of the brush until it reaches its rest position (e.g. according to the dashed line Line "r") · When the housing is at rest, the needle end of the Arm 36 supported by brush 21. The altitude of the The brush is chosen so that the needle 35 is supported at a level substantially that of the grooved surface 42 is adapted to a recording disk 41 resting on the turntable (in FIG. 2 by the dashed line "h" indicated level).

At the beginning of a playback process, the one described above is repeated Reverse cleaning process. The needle 35 runs along the bristles of the brush from position "r" into the Position "d" while the housing 30 is moving from the rest position. When passing through position "d", it is raised again. When the wall 31 moves away from the rest position (31 '), the rotates Spring 18 the component 14 in a clockwise direction. After the arm 36 has been raised again, the projection 14d passes through When moving back into the position shown in FIG. 1, the brush 21 again.

3 and 4 show, in perspective and cross-sectional views, a needle lifting and lowering device of the one in FIG mentioned US patent application described type, by means of which in the manner explained above, the playback needle 35 during their Runs lowered between positions "d" and "r", during theirs

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Between the position "d" and a play position raised and can be lowered in the playing position on the disc to be played.

Like in Pig. 3 and 4, in the arm housing 30, on the bottom 32 thereof, is a support frame 65, e.g. appropriate means (not shown) attached. The support frame 65 serves as a holder for an electromagnet 66 with a core 68 made of magnetic material which is surrounded by a winding 67 and with two forming an air gap 70 between them Pole pieces 69, 69 'is in connection. The winding 67 is with their ends connected to excitation current terminals 71, 71 '.

A leaf spring 72 anchored at one end to the support frame 65 carries a permanent magnet 74 at its free end and an armrest 73. The notched or incised foot portion 81 of a stamp 80 rests on the leaf spring 72 approximately in the middle of its length, the spring 72 sitting with its middle part in the incisions of the foot part 81. Of the The punch 80 is loosely fitted into a shaft which extends upward in the support frame 65 to an opening 64 in its upper part extends. The punch 80 passes through the opening 64 and a corresponding opening 37 in the roof wall 34 of the housing

The arrangement shown in Fig. 3 and 4 of the leaf spring 72 and the magnet 74 with the armrest 73 results when the Electromagnet 66 is not energized and the plunger 80 is not displaced by external forces. In this illustrated condition supports the armrest 73 the needle arm 36 in a raised Position so that the playback needle 35 cannot protrude through the opening 33 in the housing base 32. Such an increase in the Needle is desirable during the movement of the housing between the playback layers and an intermediate layer between these and the rest position,

When the housing 30 is in a desired playback position above the turntable 40, the winding exciter terminals are connected 71, 71 * an excitation voltage of suitable magnitude and polarity is applied, so that the field induced in the gap 70 the permanent magnet 74 is pushed downwards. As a result of this

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The repulsive movement bends the spring 72 downward, as a result of which the armrest 73 with the needle arm 36 supported thereon is lowered so that the playback needle 35 can protrude so far down through the opening 33 that it touches the surface 42 of the Plate captured. Desirably, the excitation voltage becomes larger than that for manufacture of the contact between the needle and the record, so that the arm 36 from contact with the armrest 73 during playback is exempt.

At the end of a playback process, the electromagnet 66 is de-energized and the spring 72 presses the armrest 73 into the position shown in FIG. 3 and 4 shown raised position back. This position becomes the rest position during the initial part of the movement of the housing 30 maintained, including the period of time that the stop of the housing side wall 31 on the arm projection 14e (Fig. 2) follows when the arm projection 14d passes through the bristles of the brush 21. However, when the needle 35 reaches position "d" (FIG. 2), the arm 36 is lowered again by moving the ram 80.

As shown in Fig. 3, when moving against the rest position (i.e. in direction R) the housing 30 is placed under a rigid cover 38 led. From the cover 38 stands in the path of the towering upper part of the punch 80 is a jib link or guide thumb 39 downward, which opposes the approaching upper end of the punch 80 a guide surface "s". When moving of the housing, the upper end of the punch 80 is gripped by this guide surface "s" and thereby the punch 80 downwards pressed. As a result of the movement of the ram 80, the spring 72 bends downward, as a result of which the armrest 73 is pressed down so far is that the needle 35, which now protrudes downward through the opening 31, is gripped by the bristles of the brush 21. The surfaces of the needle tip are brushed by the bristles as the needle passes between layers "d" and "r". During this movement interval, the armrest 73 is lowered so far that it is out of contact with the arm 36, which is now is supported by the contact of the needle with the bristles of the brush 21. The support by the brush 21 takes place so that

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⁹ λα.

"When in the rest position" is the housing 30, the altitude of the Needle 35 is essentially the same as "when detecting the Surface of the disc to be played. At such an altitude is the Eederkoppler C at the rear end of the arm 36 in an essentially tension-free state (in contrast to the tensioned state during arm lifting, as shown in Fig. 3)

When a new playback process begins, the lowered one runs Needle 35 along the bristles of the brush 21 until the needle position "d" is reached, and the punch 80 is detached from the guide surface "s" of the thumb 39 when the housing 30 is moved released in the direction P (Pig. 3) from the depressed position. The spring 72 then pushes the armrest 73 in the raised position shown in Fig. 3 and 4 curück, so that the Play needle 35 during its movement from the position "d" in a Play position remains withdrawn.

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Claims (7)

Claims Device for cleaning the playback needle of a turntable with a rotatable turntable and with a playback needle, which is held at one end of a pick-up arm, the other end of which is pivotably mounted in a G-e housing, which can be moved between a rest position offset from the turntable and playback positions above the turntable by a brush with a holder (22) in which a number of bristles (21) are fixed; by a carrier part (11), that holds the holder at a location near the turntable under the path of the housing (30) between the rest and playback position; and by an arrangement (39, 80, 72, 73) t which the rotation of the pick-up arm (36) by one to the plate support surface of the Turntable controls the essentially parallel axis in such a way that the playback needle, while the G-housing (30) assumes the rest position and while it moves between the rest position and an intermediate position between the rest and play position, so far out of the housing protrudes that it is gripped by the bristles (21) of the brush, the height of the holder at its mounting point is related to the level of the support surface of the turntable so that the playback needle (35) is in the rest position G-ehäuse (30) is supported by the bristles (21) at an altitude which is essentially its altitude when the Plate surface corresponds. 2. Device according to claim 1, characterized by a brush cleaning device (14) which in the course of the displacement movement of the housing (30) during each housing passage the brush cleans between resting and playing positions. 3. Device according to claim 2, characterized in that that the brush cleaning device (14) is a rotatable component with a first projection (14e) and a second projection (14d), wherein a portion of the first projection is arranged in the path of the housing (30) that when moving the Housing from a playback to the rest position of this Teilstüek detected by the housing and thereby the component in a first direction 709826/0706 original inspected is rotated, the bristles (2.1) of the brush from a part of the second gate, which extends from a first position on one side to a second position on the other side of the holder (22) can be moved, grasped and shaken off. 4 «gate direction according to claim 3, characterized in that the brush cleaning device (14) also has a spring arrangement (18) which the rotatable component in the to the first rotates in the opposite direction, the bristles (21) from said part of the second projection (I4d) as it moves from the second to the first position in the course of the movement of the housing (30) from the rest position to a playback position and be shaken off. 5. Apparatus according to claim 4, characterized in that the second projection (I4d) relative to the first projection (I4e) is oriented so that the shaking of the bristles during movement of the housing between the intermediate layer and the playback layers he follows. 6. Apparatus according to claim 5, characterized in that the arm rotation controlling arrangement (80) a retraction of the Playback needle (35) in the housing (30) during its movement between the intermediate layer and the playback layers. 7. Device according to one of the preceding claims, characterized in that the bristles (21) from the holder (22) protrude in a direction essentially parallel to the running direction of the housing (30). 709826/0706