GB2261105A - Vibroinsulating apparatus for a CD-Rom drive - Google Patents

Abstract

A vibroinsulating apparatus for a CD-ROM drive uses a pair of vibroinsulating dampers (8) for shielding the pick-up module (2) from vibration applied to the player housing (1). The vibroinsulating dampers (8) are connected between both ends of the pick-up module and support walls of the player housing, respectively, and each comprises a damper body for forming the inner space and having a circumferential surface wall having a predetermined appearance and being closed at its one end, a first connection part (82) for connecting the closed end of the damper body to the support wall of the player housing, a second connection part (84) for connecting the other end of the damper body to the pick-up module (2) by insertion thereof into a through hole formed at each end of the pick-up module and a holder for holding the connection of the other end of the damper body to the pick-up module and permitting air to flow into and out of the inner space of the damper body. In the case of horizontal-type mechanism, the plurality of additional support springs, having different tensile forces determined in consideration of the center of gravity of said pick-up module, stably support the pick-up module. <IMAGE>

Description

VIBROINSULATING APPARATUS FOR ACD-ROM DRIVE 3ACKGROUND OF THE INVENTION Field of the Invention The present invention relates in general to vibroinsulation for a CD-ROM drive, and more particularly to vibroinsulating apparatus for the CD-ROM drive which intercepts or absorbs external shock or vibration applied to the CD-ROM drive housing, thus shielding a disc and a p~k-up actuator carried on a pick-up module supported in the housing from the external shock or vibration Description of the Prior Art C#-nventionally, CD-ROM drive is an element for reading, using a laser beam, information recorded on the signal surface of the disc as causing a pick-up actuator lens to follow the rotating disc.The conventional CD-ROM disc has about 20,00 continued spiral tracks and, in this respect, it is possible to record thereon high density information. Therefore, it is required to provide a precise servo device for precisely shifting the laser beam from a track to another track.

Otherwise stated, in order to accurately read the lnformation recorded on the CD-ROM disc, variation of space between the CD-ROM disc and the pick-up actuator of the servo device of CD-ROM drive should be limited within a lens drive range. In result, the pick-up actuator is generally preferably provided with a vibroinsulating apparatus which permits the actuator to maintain its preset position without displacement even when external shock or vibration is applied to the player housing.

In order to accomplish such a vibroinsulation for the pick-up actuator, there has been a representative known embodiment generally comprising vibroinsulating members and support springs which are provided between the player housing and the pick-up module in order for supporting the pick-up module in vibroinsulation type as depicted in Fig. 1.

With reference to the drawing, this known vibroinsulating apparatus for the CD-ROM drive comprises the vibroinsulating members 5 and support springs 6 and 7 which incorporate both the player housing 1 and the pick-up module 2 in such a manner that the formers are interposed between both ends of the pickup module 2 carrying a pick-up actuator 4 and a disc 3 thereon and side support walls of the player housing 1, respectively, while the latters are connected between the ends of the pickup module 2 and the side support walls of the housing 1 above and below the formers, respectively. In result, it is possible to efficiently intercept the external shock or vibration applied to the player housing 1 from being transmitted to the pick-up module thanking for provision of the vibroinsulating members 5 and the support springs 6 and 7.

Here, the vibroinsulating members 5 interposed between the player housing 1 and the pick-up module 2 generally comprise hydraulic dampers or vibroinsulating rubber dampers, respectively.

As noted in the construction of the above knawn embodiment, the known vibroinsulating apparatus somewhat accomplishes the vibroinsulation of the pick-up module 2 by virtue of the vibroinsulating members 5 and the springs 6 and 7 which absorb or intercept the external shock or v# Dration which is applied to the player housing 1 and to be transmitted to the pick-up module 2.Therefore, it is noted that the known vi broi nsu ati ng apparatus having the afcrement cned construction preferably prevents, when the player housing 4 applied with vibration or shock having an intensity below a predetermined permissible level, the pick-up module 2 frcm being vibrated and, in this respect, permits the laser beam to accurately move from a track to another desired track of the disc , thereby causing no error in reading the infcrmatnon recorded on the disc.

However, the known vibroinsulating apparatus has problem of deterioration of vibroinsulation performance particularly when it is provided with the vibroinsulating members comprising the vibroinsulating rubber dampers.

On the other hand, when the vibroinsulating members 5 comprise the hydraulic dampers, the vibroinsulating apparatus has a problem of expensive cost while it has an advantage in that its vibroinsulation performance is improved in comparison with the vibroinsulating rubber dampers. Furthermore, since it is impossible to stably support the pick-up module 2 only by the vibroinsulating members 5 and springs 6 in the case of the horizontal-type CD-ROM drive depicted in Fig. 1, it is required to provide the additional springs 7, connected between the player housing 1 and the pick-up module 2 as shown in Fig. l, in order to additionally supporting the pick-up module 2. Thus, the known horizontal-type apparatus inevitably has a complex construction and this makes its structural compactness not be accomplished.

SUMMARY OF THE INVENTION It is, therefore, a primary object of the present invention to provide a vibroinsulating apparatus for a CD-ROM drive in which the aforementioned problems can be overcome and which uses inexpensive rubber dampers instead of the expensive hydraulic dampers and causes the rubber dampers to show air cushion effect, thereby reducing the manufacturing cost and improving the vibroinsulation performance.

It is another object of the present invention to provide a vibroinsulating apparatus for a CD-ROM drive which, in order to support the pick-up module and to carry out the vibroinsulation performance, uses in the case of horizontaltype mechanism a plurality of springs of different tensile forces determined in consideration of the center of gravity of the pick-up module, but uses in the case of vertical-type mechanism only the rubber dampers with no addition of spring.

In an embodiment of the present invention, the above objects can be accomplished by providing in vibroinsulat,ng apparatus for a CD-ROM drive, said drive having a player housing and a pick-up module being supported in said player housing and carrying thereon a pick-up actuator and a d-sc, the improvement comprising: vibroinsulating dampers for shie,dln3 said pick-up module from vibration applied to sa d player housing, said dampers being connected between both ends of said pick-up module and support walls of said player housing, respectively, and each of said dampers forming inner space therein and having at one end thereof at least one air through hole through which air flows into and out of said inner space.

In an embodiment of the present invention, the vibroinsulating damper comprises: a damper body for forming the inner space, said damper body having a circumferential surface wall having a predetermined appearance and being closed at its one end; a first connection part for connecting said closed end of the damper body to said support wall of the player housing; a second connection part for connecting the other end of said damper body to said pick-up module by insertion thereof into a through hole formed at each end of said pick-up module; and a holder for holding the connection of the other end of the damper body to said pick-up module and permitting air to flow into and out of said inner space of the damper body, said holder incorporating said second connection part by being enclosed therein and having at least one air through hole for permitting the air to flow into and out of said inner space of the damper body therethrough.

Here, the first connection part comprises an inner threaded depression for permitting the closed end of the damper body to be screwed to the support wall of the player housing, while the second connection part includes an annular groove for permitting the other end of the damper body to be connected to the pick-up module. The annular groove is formed at about the boundary between the other end of the damper body and the second connection part and receives circumferential periphery of the through hole of the pick-up module.

On the other hand, a plurality of additional support springs are provided in order to stably support the pick-up module in the case of horizontal-type mechanism wherein the pick-up module is horizontally supported in the player housing. These support springs have different tensile forces determined in consideration of the center of gravity of the pick-up module and each is connected between the pick-up module and the support wall of the player housing However in the case of vertical-type mechanism wherein the pick-up module is vertically supported in the player housing, the vibroinsulating apparatus supports, using the vibroinsulating dampers with no addition of support spring, the pick-up module.

In accordance with the present invention, he vibroinsulating apparatus shows desirable air cushion effect caused by the vibroinsulating dampers and, in this respect, shields the pick-up module from external shock and vibration applied to the player housing. Also, in the case of the horizontal-type mechanism wherein the pick-up module ls horizontally arranged, the pick-up module is supported by not only the aforementioned vibroinsulating dampers but also leftside and right-side support springs having different tensile forces determined in consideration of the center of gravity of the pick-up module, thereby improving the vibroinsulation esficiency. In this respect, the pick-up module a efficiently shielded from the external shock and vibration and this permits the pick-up actuator carried by the pick-up module to accurately read the information recorded on the disc without error.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description talxen in conjunction with the accompanying drawings, in which: Fig. 1 is a front view showing vibroinsulating apparatus for a CD-ROM drive in accordance with the prior art; Fig. 2 is a schematic view showing a relation between the center of gravity of a mechanism and different tensile forces of support springs; Fig. 3 is a front view showing horizontal-type vibroinsulating apparatus for a CD-ROM drive in accordance with the present invention; Fig. 4 is an enlarged sectioned view of a vibroinsulating damper shown at the circle A of Fig. 3;; Fig. 5 is a perspective view showing a plastic holder of the vibroinsulating damper of Fig. 4; and Fig. 6 is a front view showing vertical-type vibroinsulating apparatus for a CD-ROM drive in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, with reference to Fig. 2 showing a general relation between the center of gravity of a rectangular mechanism and different tensile forces of support springs, the springs have different tensile forces when the central point, or the geometrical center, of the mechanism is different from the center of gravity of the mechanism.

If the mechanism M, having the central point Go and the center of gravity G1 as depicted in Fig. 2, is resiliently 'supported by four support springs "a" and "b", preferably tension coil springs, which are connected between four corners of the rectangular mechanism M and opposite side supports S atid S , respective 1)', aid each of the left-side springs "a" has the same tensile force as that of each of the right-side springs "b" , the mechanism ri ill have a tilt to one side, for example, to the left, and this causes the mechanism not to stably resist against the external brati on.

In result, when the center of gravity G. of the mechanism M is positioned at the left of the central point Go as depicted in Fig. 2, it is preferred to make the tensile force of each left-side spring "a" be larger than that of each right-side spring "b" such that the external vibration to be transmitted to the mechanism M is reliably intercepted by the springs "a" and "b" and, in this respect, the mechanism M is permitted to stably supported with no influence of the external vibration. Here, the ratio of the tensile force @ of the left-side spritig "a" to the tensile force ss of the right- side spring "b is expressed as follows: a/B = [ l 9 (1 -l#) ] / [ l - (l - lj)3 2a + 2B = W wherei n a : tensile force of the left-side spring; ss : tensile force of the right-side spring; 1 : distance between the central point Go and a side edge of the mechanism M; li: distance between the center of gravity G1 and a near side edge to the center Gi of the mechanism M; and W : weight of the mechanism M.

It is required to consider the above relations in embodying the vibroinsulating apparatus according to the present invention. In result, the tensile force of each-side springs used for supporting the horizontal--type mechanism of this invention is determined in accordance with the above relations. Widen the central point Go of tie mechanism does not coincide with the center of gravity G1, the left-side and right-side springs a and b connected between the courtiers of the pick-up module and the player housing are constructed in such a manner that the left-side springs have a different tensile force from the right-side springs.In addition, it is more preferred to cause all of the four springs to have different tensile forces from each other in consideration of the center of gravity G1 of the mechanism M, however, because there is a problem in determination all of the different tensile forces of the four springs and in preparation thereof, the vibroinsulating apparatus of this invention is preferably designed in order to make the left-side springs have a different tensile force from that of the right-side springs.

Hereinafter, the preferred embodiments of the present invention are described in detail in conjunction with Figs. 3 to 5.

In the preferred embodiments of this invention, a part of the elelnents of the present embodiments is common with those of the prior embodiment shown in Fig. 1, and therefore, those elements common to both the present preferred embodiments and the prior embodiment will carry the same reference numerals.

Also, the prefix "vi bro" , for example, shown at the words "v Ibroinsulation" and "vibroabsorption" in this specification represents "vibration", arid therefore, the words "vibroinsulation" and "vibroabsorption" denote insulation of vibration and absorption of vibration , respectively.

Referring now to Fig. 3 showing a primary embodiment or a horizontal-type embodiment of vibroinsulating apparatus for a CD-ROM drive in accordance with the present invention, this horizontal-type embodiment -is to horizontally support a pickup module 2 carrying thereon a disc 3 and a pick-up actuator 4. This embodiment includes a pair of vibroinaulating dampers 8 interposed between the opposite ends of the pick-up module 2 and opposite side walls of the player housing 1 respectively, in such a manner that both ends of each damper 8 are mounted to the end of the pick-up module 2 and the side wall of the housing 1, respectively.In addition, first and second pairs of springs 9 and 9', preferably tension coil springs, of different tensile forces from each other pair are connected between opposite upper ends of the pick-up module 2 and opposite upper portions of the side walls of the player housing 1, respectively.

Here, the tensile forces of the springs 9 and 9' are determined in consideration of the above-mentioned relation between the central point and the center of gravity of the pick-up module 2 carrying thereon the disc 3 and the pick-up actuator 4.

Turning to Fig. 4 showing the vibroinsulating damper 8 in detail, the damper 8 comprises a frusto-conical damper body 81 constructed such that it forms inner space therein and its diameter is gently enlarged toward one connection end thereof to the pick-up module 2 but decreased toward the other connection end thereof to the player housing 1. A first connection part 82 is integrally formed with the damper body 81 in order to permit the one end of the damper 8 to be mounted on the side wall of the player housing 1. The damper body 81 is additionally provided at the other end thereof with a second connection part 84 for mounting the body 81 on the pick-up module 2 by insertion into a through hole formed at each end of the pick-up module 2.This second connection part 84 has an air through hole at its end and encloses a plastic circular holder 11 having at least one air through hole Ila communicating with the inner space of the pick-up module 2 through the air through hole of the second connection part 84.

Here, the first connection part 82 is constructed to have an inner threaded depression for permitting the one end of the damper 8 to be screwed to the side wall of the player housing 1.

On the other hand, the second connection part 84 is provided with an annular groove 83 at the boundary between the other end of the damper body 81 and the second connection part 84. In mounting the damper 8 on the end of the pick-up module 2, the circumferential periphery of the through hole formed at the end of the pick-up module 2 engages with the annular groove 83 of the second connection part 84 by insertion thereinto.

If described in detail, in order to screw the one end of the damper 8 to the side wall of the player housing 1, a screw 10 passes through a connection hole formed at the side wall of the player housing 1 and engages with the inner threaded depression of the first connection part 82. While in order to mount the other end of the damper 8 on the pick-up module 2, the circumferential periphery of the through hole formed at the end of the pick-up module 2 engages with the annular groove 83 of the second connection part 84 by insertion of the periphery into the annular groove 83.

In the second connection part 84 of the damper 8 protruding into the inside of the pick-up module 2, the plastic circular holder 11 having at least one air through hole 11a communicating with the inner space of the pick-up module 2 through the air through hole of the second connection part 84 is enclosed, thereby causing the air to flow into or out of the inner space of the damper body 81 through the air through holes and, in this respect, the damper 8 to have desired air cushion effect.

On the other hand, it is preferred to prepare, using a vibroinsulating material, the vibroinsulating damper 8 interposed between the side wall of the player housing 1 and the end of the pick-up module 2. Here, the vibroinsulating material is selected from a group having desired elasticity and damping characteristics which are appropriate for vibroinsulation, low repellency and excellent vibroabsorption.

In consideration of the above conditions, the vibroinsulating damper 8 is preferred to be made of isobuthylene-isoprene rubber.

Since the shape of the vibroinsulating damper 8 gives much influence to the support strength and vibroinsulation characteristics thereof, it is important to determine the shape of the vibroinsulating damper 8. Here, in consideration of the characteristics of the raw material of the damper body 81, the strength of the body 81 is increased when the body 81 is applied with shearing force than when applied with normal force, as a result, it is preferred to construct the damper 8 such that it has a tapering angle e of about 20 Fg. 6 shows a second alternate embodiment or verticaltype embodiment of the vibroinsulating apparatus for a CD-ROM drive of this invention. In this embodiment, the pick-up module 2 is supported and vibroinsulated only by the vibroinsulating dampers 8 which are disposed between the upper and lower ends of the vertically arranged pick-up module 2 and the player housing l, respectively, with no addition of spring.

Each of the vibroinsulating dampers 8 used in this second alternate embodiment has the same shape as that of the primary alternate embodiment shown in Fig. 3. In addition in this embodiment, the mechanism is sufficiently supported and vibroinsulated by the vibroinsulating dampers 8 with no additional spring by virtue of its vertical support arrangement.

The operational effect of the vibroinsulating apparatus of this invention will be described hereinafter.

In the case of application of external shock and vibration to the player housing 1, the vibroinsulating dampers 8, showing the intrinsic vibroinsulation characteristics caused by the characteristics of its raw material and desired air cushion effect caused by the plastic holder 11 having the air through hole Ila and resistance of the air contained in the space inside the dampers 8, damps or intercepts the external shock and vibration to be transmitted from the player housing 1 to the pick-up module 2, thereby accomplishing the desired vibroinsulating object. In accordance, the pick-up actuator 4 is efficiently protected from external disturbance and this permits the pick-up actuator 3 to accurately read the data of the rotating disc.

In addition, when the mechanism is horizontally arranged as shown in Fig. 3, the pick-up module 2 is supported by not only the vibroinsulating dampers 8 but also the left-side and right-side springs 9 and 9' of different tensile forces determined in consideration of the center of gravity of the pick-up module 2 and, in this respect, the vibration applied to the player housing 1 is efficiently prevented from transmission to the pick-up module 2.

As described above, the present invention provides vibroinsulating apparatus for a CD-ROM drive which is provided with vibroinsulating dampers show desirable air cushion effect caused by its shape, as a result, improves the vibroinsulation efficiency. Also, in the case of a horizontal-type mechanism wherein a pick-up module is horizontally arranged, the pick-up module is supported by not only the aforementioned vibroinsulating dampers but also left-side and right-side support springs having different tensile forces determined in consideration of the center of gravity of the pick-up module, thereby improving the vibroinsulation efficiency.

Furthermore, the present vibroinsulating apparatus ~ is provided with the vibroinsulating dampers made of inexpensive rubber material and efficiently supports and vibroisulates, in the case of a vertical-type mechanism, the pick-up module using the vibroinsulating dampers with no addition of support spring, thereby reducing the manufacturing cost and simplifying the construction of the CD-ROM drive, as a result, accomplishing the desired compactness of the mechanism.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims (7)

WHAT IS CLAIMED IS:

1. In vibroinsulating apparatus for a CD-ROM drive, said drive having a player housing and a pick-up module being supported in said player housing and carrying thereon a pickup actuator and a disc, the improvement comprising: vibroinsulating dampers for shielding said pick-up module from vibration applied to said player housing, said dampers being connected between both ends of said pick-up module and support walls of said player housing, respectively, and each of said dampers forming inner space therein and having at one end thereof at least one air through hole through which air flows into and out of said inner space.

2. The vibroinsulating apparatus according to Claim 1, wherein each said vibroinsulating damper comprises: a damper body for forming said inner space, said damper body having a circumferential surface wall having a predetermined appearance and being closed at its one end; a first connection part for connecting said closed end of the damper body to said support wall of the player housing; a second connection part for connecting the other end of said damper body to said pick-up module by insertion thereof into a through hole formed at each end of said pick-up module; and a holder for holding the connection of the other end of the damper body to said pick-up module and permitting air to flow into and out of said inner space of the damper body, said holder incorporating said second connection part by being enclosed therein and having at least one air through hole for permitting the air to flow into and out of said inner space of the damper body therethrough.

3. The vibroinsulating apparatus according to Claim 2, wherein said first connection part includes: an inner threaded depression for permitting said closed end of the damper body to be screwed to said support wall of the player housing.

4. The vibroinsulating apparatus according to Claim 2, wherein said second connection part includes: an annular groove for permitting the other end of said damper body to be connected to said pick-up module, said annular groove being formed at about the boundary between the other end of said damper body and said second connection part and receiving circumferential periphery of said through hole of the pick-up module.

5. The vibroinsulating apparatus according to Claim 1, wherein each said vibroinsulating damper is made of rubber.

6. The vibroinsulating apparatus according to Claim 1, wherein said apparatus further comprises: a plurality of additional support springs for stably supporting said pick-ttp module in the case of horizontal-type mechanism wherein said pick-up module is horizontally supported in said player housing, said support springs having different tensile forces determined in consideration of the center of gravity of said pick-up module and each of said support springs being connected between said pick-up module and said support wall of the player housing.

7. Vibroinsulatina apparatus substantially as hereinbefore described with reference to and as shown in Figures 3 to 5 or Figure 6 of the accompanying drawings.