CA1142644A - Video disc player - Google Patents
Video disc playerInfo
- Publication number
- CA1142644A CA1142644A CA000336259A CA336259A CA1142644A CA 1142644 A CA1142644 A CA 1142644A CA 000336259 A CA000336259 A CA 000336259A CA 336259 A CA336259 A CA 336259A CA 1142644 A CA1142644 A CA 1142644A
- Authority
- CA
- Canada
- Prior art keywords
- spindle
- disc
- carriage
- plane
- video disc
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Abstract
ABSTRACT
A video disc player assembly is described employ-ing a fixed base member with a pair of fixed rails, and a movable carriage member employing a pair of linear bearing assemblies in engagement with said rails. A capstan and pulley assembly provides a means for moving the carriage member over the rails in the base member. A motor and spindle are mounted on the carriage for rotary driving of the video disc. A centering means is provided to accur-ately center the disc about the spindle, and a stabilization plate is provided adjacent and parallel to the rotating disc.
A video disc player assembly is described employ-ing a fixed base member with a pair of fixed rails, and a movable carriage member employing a pair of linear bearing assemblies in engagement with said rails. A capstan and pulley assembly provides a means for moving the carriage member over the rails in the base member. A motor and spindle are mounted on the carriage for rotary driving of the video disc. A centering means is provided to accur-ately center the disc about the spindle, and a stabilization plate is provided adjacent and parallel to the rotating disc.
Description
VIDEO DISC PLAYER
-- TECHNICAL FIEL~
Thi~ invention relat~s to an improved video disc player3 and in particular to a vi~eo disc player havlng an lmproved mechanical ~tructure ~or moving the carrla~e member and centering the disc about the spindle.
BRIEF SUMMARY OF THE_INVENTION
Th~ is a brief summary of the video disc player unit. A function of the video dlsc player unit is to pro-vide a support means ~or the video disc or informationcarrier. m e information carrier is adapted to be rotated about its central axi~ at a relatlvely high speed. Di~-posed upon the in~ormation carrier are a serle~ of bump~
and lands succes~ively arranged ~orming an in~ormation track. The arrangements of bumps and lands are indicative o~ a video encoded FM carrier. An alternative embodiment might have an arrangement of bumps and lands lndicatlve o~
another ~orm o~ encoding, such as digital encoding. The support means providing restraint for the informatlon carrier i5 accurately defined with respect to the plane Or an ob~ective lens and imparts a critical de~ree o~
parallellsm to the plane o~ t~he objective lens. The ob~ective lens cooperates with a collimated llght source and optlcal elemen~3, ~uch as mlrrors and lens, in forming a read beamJ and the read beam is utilizable in recovery of ~nformation stored on the lnformation carrier by the arrangement of bumps and land3, which arrangement i3 in-dlcative o~ a vldeo encoded ~requency modulated carrler.
The video disc ij mounted for rotation on a ,. ",~.
'"~''~
' , .
.
.
carriage, and the carriage is mounted for reciprocal motion with respect to the support means on a locator rail and a support follower rail. The carriage includes a locator bearing assembly and a support follower bearing assembly which engage the locator and follower rails, respectively, and a resiliently mounted rolllng retainer is associated with each bearing assembly to maintain engage-ment between the bearing and rail. The locator rail co-operates with the locator bearing assembly to provJ.de alignment means such that only one rail need be aligned ln a plane parallel to a plane deflned by the center line of the spindle and extended radially to the center line of the ob~ective lens. The support ~ollower rail provldes a working surface for the support follower bearing assem-bly such that the support follower bearing assembly pro-vides only a means of support without imparting any angular direction which would be in confllct with the alignment prescribed by the locator bearing assembly.
Although the video disc player unit is provided with both a locator bearing assembly and a support follower bearing assembl~ alternative embodiments need not be so equipped; ~or instance a lathe requiring accurate align-ment of a particular item of kooling would only require the utllization of the locator bearing assembly and lts associated form of support means.
The support means as described herein and coupled with the locator bearing assemb]y and the support follower bearing assembly cooperate to provide a critical degree of translational accuracy and a frictionless means of accom-pllshlng thls translational accuracy.
A stabilization plate is mounted on the carriageand provides stabilization means to the video disc such that the video disc is isolated ~rom vibrations and com-pensated for inherent unflatness developed in the disc durlng manufacture. The stabilization means as employed ` in the preferred embodiment determines the vertical dls-tance between the rotating video dlsc member and the " stabilization plate. The vertical distance ls accomplished by the restriction o~ the air exit point located ad~acent to the spindle and motor assembly and the stabilization plate.
~ he increased vertical di~tance between the video disc member and the stabilization plate provides a higher degree of latitude in video disc speci~ications. Prior art video discs would contact or scrape the stabilization plate or other components of the video disc player unlt.
The increasèd vertical distance thus allow~ a disc of greater unflatness to be utilized on the preferred embodi-ment of the video disc player unit.
- The carrlage assembly employs a clamp a~embly providing clamping means to the video disc adapted about its central aperture to be rotated at a high rotational ~peed. This clamping means cooperates with the spindle assembly and a centering device dispo~ed thereon to firmly retain the video disc member about its central aperture upon the spindle assembly and allowing a clamping means which provide~ for a high degree of user convenience. This clamping means or a version thereof would be utilizable in any device wherein a means of firm restraint but allowing a high degree of user convenience would be required.
The carriage assembly also employs a centering device which cooperates with the clamp assembly and pro-vides centering means to compensate for variations ln the radial size o~ the central aperture o~ the video disc member.
~RIEF DESCRIPTIO~ OF ~HE ~RAl~NGS
FIGURE 1 is an elevational view wlth a portion o~
the external housing removed to illustrate the video disc player unit;
FIG. 2 is a bottom plan view of the carriage and the carriage support plate;
FIG. 3 is an elevational view of the basic mechan-ical portion of the video disc player unit taken generally along the line 1-1 of FIG. l;
FIG. 4 is an enlarged elevational view partly in section of the spindle and motor assembly taken gener-ally along the line 3-3 of FIG. 3~
FIG. 5 is an enlarged fragmentary, elevational : -4-view of the locator bearing assembly lndicated in FIG. l;
FIG. 6 is an enlarged, fragmentary, elevatlonal view of the support follower bearing assembly indicated ln FIG. l;
FIG. 7 ls a further enlarged~ partly ~ectlonal view of the support follower bearing as it appears in .-; FIG. 6;
FIG. 8 is a partly ~ectional view taken gener-ally along the line 8-8 o~ FIG. 7;
10 FIG. 9 is an elevational view with the linear bearing partly broken away taken on the line 9-9 of FIG.
7;
FIG. 10 i~ a fragmentary bottom plan view of the spring loaded rolling retainer; and FIG. 11 is a fragmentary elevational view of the loaded rolling retainer.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, which is a diagram of a video disc player unit 1~ utilizable in the playback of an 20 information carrier 2, adapted to be rotated about its center at a relatively high speed. ~he information carrier is a substantially planar subs~rate having a first - surface 3 and a second surface 4 and provided with a central aperture (not shown). Dlsposed between the first 25 surface 3 and the second urface 4 are a series of bumps and lands, the bumps being primarily light de~racting and the land areas being primarily light reflective. The alternately defracting and reflecting bumps and lands are indicative of a modulated FM carrier, the bumps and lands being arranged in such a manner as to form a ~plral having a predetermined pitch. The information carrier 2 will henceforth be referred to as a video disc for ease of description.
The video disc player unit 1 compri~es a spindle and motor assembly 5 for lmparting rotation tothe vldeo disc 2 about its central axis and provided with a clamp assembly 6 for retaining said video disc 2 about the central axis of the spindle and motor assembly 5 and par-allel to a stationary platform hence forth referred to as `;
a stabilizatlon plate 7, The video disc player unit l includes a means of ~ accurately translating ~he spindle and motor a~sembly 5 and - the attached v~deo disc 2 radially beneath an optical bridge 8 provided with a light source and optical path (not shown). The position of the optlcal bridge 8 is maintalned vertlcally above the rotating video disc 2 by means of a number of optical bridge support posts 9 and firmly restrained at point of contact 10 by means of a - lO threaded device 11, such as a screw, which screw is main-tained in a threaded aperture located in the optical bridge support post 9 which aperture is not shown in FIG.
1, to the carriage support plate 12. The optlcal bridge support post 9 passing vertically through an upper plate 13 henceforth known as a pro~ective dust shield, and pro-vided with an aperture (not shown) allowing the transla-tion of the spindle and motor assembly 5 and attached disc
-- TECHNICAL FIEL~
Thi~ invention relat~s to an improved video disc player3 and in particular to a vi~eo disc player havlng an lmproved mechanical ~tructure ~or moving the carrla~e member and centering the disc about the spindle.
BRIEF SUMMARY OF THE_INVENTION
Th~ is a brief summary of the video disc player unit. A function of the video dlsc player unit is to pro-vide a support means ~or the video disc or informationcarrier. m e information carrier is adapted to be rotated about its central axi~ at a relatlvely high speed. Di~-posed upon the in~ormation carrier are a serle~ of bump~
and lands succes~ively arranged ~orming an in~ormation track. The arrangements of bumps and lands are indicative o~ a video encoded FM carrier. An alternative embodiment might have an arrangement of bumps and lands lndicatlve o~
another ~orm o~ encoding, such as digital encoding. The support means providing restraint for the informatlon carrier i5 accurately defined with respect to the plane Or an ob~ective lens and imparts a critical de~ree o~
parallellsm to the plane o~ t~he objective lens. The ob~ective lens cooperates with a collimated llght source and optlcal elemen~3, ~uch as mlrrors and lens, in forming a read beamJ and the read beam is utilizable in recovery of ~nformation stored on the lnformation carrier by the arrangement of bumps and land3, which arrangement i3 in-dlcative o~ a vldeo encoded ~requency modulated carrler.
The video disc ij mounted for rotation on a ,. ",~.
'"~''~
' , .
.
.
carriage, and the carriage is mounted for reciprocal motion with respect to the support means on a locator rail and a support follower rail. The carriage includes a locator bearing assembly and a support follower bearing assembly which engage the locator and follower rails, respectively, and a resiliently mounted rolllng retainer is associated with each bearing assembly to maintain engage-ment between the bearing and rail. The locator rail co-operates with the locator bearing assembly to provJ.de alignment means such that only one rail need be aligned ln a plane parallel to a plane deflned by the center line of the spindle and extended radially to the center line of the ob~ective lens. The support ~ollower rail provldes a working surface for the support follower bearing assem-bly such that the support follower bearing assembly pro-vides only a means of support without imparting any angular direction which would be in confllct with the alignment prescribed by the locator bearing assembly.
Although the video disc player unit is provided with both a locator bearing assembly and a support follower bearing assembl~ alternative embodiments need not be so equipped; ~or instance a lathe requiring accurate align-ment of a particular item of kooling would only require the utllization of the locator bearing assembly and lts associated form of support means.
The support means as described herein and coupled with the locator bearing assemb]y and the support follower bearing assembly cooperate to provide a critical degree of translational accuracy and a frictionless means of accom-pllshlng thls translational accuracy.
A stabilization plate is mounted on the carriageand provides stabilization means to the video disc such that the video disc is isolated ~rom vibrations and com-pensated for inherent unflatness developed in the disc durlng manufacture. The stabilization means as employed ` in the preferred embodiment determines the vertical dls-tance between the rotating video dlsc member and the " stabilization plate. The vertical distance ls accomplished by the restriction o~ the air exit point located ad~acent to the spindle and motor assembly and the stabilization plate.
~ he increased vertical di~tance between the video disc member and the stabilization plate provides a higher degree of latitude in video disc speci~ications. Prior art video discs would contact or scrape the stabilization plate or other components of the video disc player unlt.
The increasèd vertical distance thus allow~ a disc of greater unflatness to be utilized on the preferred embodi-ment of the video disc player unit.
- The carrlage assembly employs a clamp a~embly providing clamping means to the video disc adapted about its central aperture to be rotated at a high rotational ~peed. This clamping means cooperates with the spindle assembly and a centering device dispo~ed thereon to firmly retain the video disc member about its central aperture upon the spindle assembly and allowing a clamping means which provide~ for a high degree of user convenience. This clamping means or a version thereof would be utilizable in any device wherein a means of firm restraint but allowing a high degree of user convenience would be required.
The carriage assembly also employs a centering device which cooperates with the clamp assembly and pro-vides centering means to compensate for variations ln the radial size o~ the central aperture o~ the video disc member.
~RIEF DESCRIPTIO~ OF ~HE ~RAl~NGS
FIGURE 1 is an elevational view wlth a portion o~
the external housing removed to illustrate the video disc player unit;
FIG. 2 is a bottom plan view of the carriage and the carriage support plate;
FIG. 3 is an elevational view of the basic mechan-ical portion of the video disc player unit taken generally along the line 1-1 of FIG. l;
FIG. 4 is an enlarged elevational view partly in section of the spindle and motor assembly taken gener-ally along the line 3-3 of FIG. 3~
FIG. 5 is an enlarged fragmentary, elevational : -4-view of the locator bearing assembly lndicated in FIG. l;
FIG. 6 is an enlarged, fragmentary, elevatlonal view of the support follower bearing assembly indicated ln FIG. l;
FIG. 7 ls a further enlarged~ partly ~ectlonal view of the support follower bearing as it appears in .-; FIG. 6;
FIG. 8 is a partly ~ectional view taken gener-ally along the line 8-8 o~ FIG. 7;
10 FIG. 9 is an elevational view with the linear bearing partly broken away taken on the line 9-9 of FIG.
7;
FIG. 10 i~ a fragmentary bottom plan view of the spring loaded rolling retainer; and FIG. 11 is a fragmentary elevational view of the loaded rolling retainer.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, which is a diagram of a video disc player unit 1~ utilizable in the playback of an 20 information carrier 2, adapted to be rotated about its center at a relatively high speed. ~he information carrier is a substantially planar subs~rate having a first - surface 3 and a second surface 4 and provided with a central aperture (not shown). Dlsposed between the first 25 surface 3 and the second urface 4 are a series of bumps and lands, the bumps being primarily light de~racting and the land areas being primarily light reflective. The alternately defracting and reflecting bumps and lands are indicative of a modulated FM carrier, the bumps and lands being arranged in such a manner as to form a ~plral having a predetermined pitch. The information carrier 2 will henceforth be referred to as a video disc for ease of description.
The video disc player unit 1 compri~es a spindle and motor assembly 5 for lmparting rotation tothe vldeo disc 2 about its central axis and provided with a clamp assembly 6 for retaining said video disc 2 about the central axis of the spindle and motor assembly 5 and par-allel to a stationary platform hence forth referred to as `;
a stabilizatlon plate 7, The video disc player unit l includes a means of ~ accurately translating ~he spindle and motor a~sembly 5 and - the attached v~deo disc 2 radially beneath an optical bridge 8 provided with a light source and optical path (not shown). The position of the optlcal bridge 8 is maintalned vertlcally above the rotating video disc 2 by means of a number of optical bridge support posts 9 and firmly restrained at point of contact 10 by means of a - lO threaded device 11, such as a screw, which screw is main-tained in a threaded aperture located in the optical bridge support post 9 which aperture is not shown in FIG.
1, to the carriage support plate 12. The optlcal bridge support post 9 passing vertically through an upper plate 13 henceforth known as a pro~ective dust shield, and pro-vided with an aperture (not shown) allowing the transla-tion of the spindle and motor assembly 5 and attached disc
2 throughout their range of linear translation.
The accurate translation of the spindle and motor assembly 5 and the attached video disc 2, radially with respect to the video disc 2 ~eneath the optical bridge 8, is provided by 2 carriage 14 having a locator bearing assembly 15 and a support follower bearing assembly 16 allowlng an accurate linear translation of the spindle and motor assembly 5 and the attached video disc 2, and a restraining force is supplied by a resiliently attached rolling retainer 17. The means of resilient attachment is accomplished by a number of springs and grommets which will be discussed in detail in FIG. ll. Said resiliently attached rollin~ retainer 17 supplies a downward force to the locator b~ææing assembly 15 and the support follower bearing assembly 15.
The translational motion imparted to the carriage 14 is supplied by a carria~e drive capstan (not shown~ and dlrected to the carriage 14 by means of a carriage drive cable 18. The carriage drive cable 1~ is directed circum-: ferentially about a carriage drlve pulley l9 b~ means of a carriage drive cable guide 20. The carriage drive pulley l9 supplies a carriage posltion potentiometer 21 ;:
.
-6~
~' with a motive force directly relatable to the location of the carriage 14. The carrlage position potentiometer renders a direct current voltage proportional to the posi-tion o~ the carriage 14 at any given moment.
The carriage support plate 12 ls suppli~d with a number of structural support rlbs 22 utilized to strengthen the carrlage support plate 12, the carriage support plate 12 also having stif~ening ribs 23 located in the area of the locator bearing assembly 15, and the support ~ollower bearing assembly 15 where structural integrity has the highest degr~e of significance.
The carriage support plate 12 having an upper plane 24 and a lower plane 25 securel~J conjolned by means of a connecting angle 26 which cooperates wlth the upper plane 27 of the carriage 14, and the lower p~ane ?8 of the carriage 14 which are interconnected by means of a connec~
ing angle 29 to lorm a more compact video disc player unit 1. Also indlcated ,by FIG. 1 at the arrows 29A and 29B are two substantially parallel surfaces, which sur~aces cooperate to mainta1n the points of contact of the linear bearing which will be described in detail in FIG. 5.
The carriage support plate 12 forms a secure attachment to the base 30 by means of a carriage support post 31 through a shock mounting dead rubber grommet 32, and ls restrained by a threaded device, such as a stud ~, (not shown). The carriage support plate 12 cooperates with the carriage support post 31 to ~orm a rigid support ~or the carriage.
In order to conta-ln the rotating disc 2 and the collimated light source (not shown), to the area o~ the video disc player unit 1, the unit 1s aupplled with two side covers 33 and a cover 34 which is flrmly attached through a hinge 35 allowing access to the mechanical `; portion of the video disc player unlt 1. The cover 34 i.s supplied with a mechanical stop 36 which attaches to the ~ront cover 37 o~ the video disc player unit 1.
Now referring to FIG. 2 which indicates a bottom plan view o~ the carrlage support plate 12, and the car-- riage 14) and thelr relationship.
FIG. 2 shows the protective dust cover 13 and its aperture 38 allowing ~or the translatlon of the . carriage 14 throughout its range of tra-~lel.
The translation o~ the carrlage 14 is achieved by means of th0 carriage drive capstan 39 at which point the carr-Lage drive cable 18 is wound circumferentially about the carriage drive capstan shalt 40. The path o~
the carriage drive cable 18 is pre~cribed by a number of carriage drive cable guides 20.
It can be seen by a person skilled in the art~
that as the carriage drive capstan 39 and its associated carriage drive capstan shaft 40 are rotated, t'ne carriage drive cable 18 will be wound or ~nwound circumferentially about the carriage drive capstan shaft 4OJ in a direct relationship with the d,rection o~ rotation of the car-riage drive capstan shaft 40, thus imparting a motive force to the carriage 14 through the carriage drive cable 18 and its.associated points of attachment 43 and 44 to the carriage 14. The cooperation of carriage drive capstan 39, the carriage drive cable 18 and the carriage drive cable guides 20, form the carriage drive~ utilizable as means of imparting linear motion to the carriage.
The carriage drive cable 18 having a devica 41, such as a spring, which device supplies tension and dampen-ing to said carriage drive cable 18~ and having attachment ` to said carriage drive 18 at the point 42. The carriage ; drive cable 18 having a means of attachment to the car-.. rlage 14 at the points of attachment 43 and 44, said polnts of attachment 43 and 44 being accomplished by the
The accurate translation of the spindle and motor assembly 5 and the attached video disc 2, radially with respect to the video disc 2 ~eneath the optical bridge 8, is provided by 2 carriage 14 having a locator bearing assembly 15 and a support follower bearing assembly 16 allowlng an accurate linear translation of the spindle and motor assembly 5 and the attached video disc 2, and a restraining force is supplied by a resiliently attached rolling retainer 17. The means of resilient attachment is accomplished by a number of springs and grommets which will be discussed in detail in FIG. ll. Said resiliently attached rollin~ retainer 17 supplies a downward force to the locator b~ææing assembly 15 and the support follower bearing assembly 15.
The translational motion imparted to the carriage 14 is supplied by a carria~e drive capstan (not shown~ and dlrected to the carriage 14 by means of a carriage drive cable 18. The carriage drive cable 1~ is directed circum-: ferentially about a carriage drlve pulley l9 b~ means of a carriage drive cable guide 20. The carriage drive pulley l9 supplies a carriage posltion potentiometer 21 ;:
.
-6~
~' with a motive force directly relatable to the location of the carriage 14. The carrlage position potentiometer renders a direct current voltage proportional to the posi-tion o~ the carriage 14 at any given moment.
The carriage support plate 12 ls suppli~d with a number of structural support rlbs 22 utilized to strengthen the carrlage support plate 12, the carriage support plate 12 also having stif~ening ribs 23 located in the area of the locator bearing assembly 15, and the support ~ollower bearing assembly 15 where structural integrity has the highest degr~e of significance.
The carriage support plate 12 having an upper plane 24 and a lower plane 25 securel~J conjolned by means of a connecting angle 26 which cooperates wlth the upper plane 27 of the carriage 14, and the lower p~ane ?8 of the carriage 14 which are interconnected by means of a connec~
ing angle 29 to lorm a more compact video disc player unit 1. Also indlcated ,by FIG. 1 at the arrows 29A and 29B are two substantially parallel surfaces, which sur~aces cooperate to mainta1n the points of contact of the linear bearing which will be described in detail in FIG. 5.
The carriage support plate 12 forms a secure attachment to the base 30 by means of a carriage support post 31 through a shock mounting dead rubber grommet 32, and ls restrained by a threaded device, such as a stud ~, (not shown). The carriage support plate 12 cooperates with the carriage support post 31 to ~orm a rigid support ~or the carriage.
In order to conta-ln the rotating disc 2 and the collimated light source (not shown), to the area o~ the video disc player unit 1, the unit 1s aupplled with two side covers 33 and a cover 34 which is flrmly attached through a hinge 35 allowing access to the mechanical `; portion of the video disc player unlt 1. The cover 34 i.s supplied with a mechanical stop 36 which attaches to the ~ront cover 37 o~ the video disc player unit 1.
Now referring to FIG. 2 which indicates a bottom plan view o~ the carrlage support plate 12, and the car-- riage 14) and thelr relationship.
FIG. 2 shows the protective dust cover 13 and its aperture 38 allowing ~or the translatlon of the . carriage 14 throughout its range of tra-~lel.
The translation o~ the carrlage 14 is achieved by means of th0 carriage drive capstan 39 at which point the carr-Lage drive cable 18 is wound circumferentially about the carriage drive capstan shalt 40. The path o~
the carriage drive cable 18 is pre~cribed by a number of carriage drive cable guides 20.
It can be seen by a person skilled in the art~
that as the carriage drive capstan 39 and its associated carriage drive capstan shaft 40 are rotated, t'ne carriage drive cable 18 will be wound or ~nwound circumferentially about the carriage drive capstan shaft 4OJ in a direct relationship with the d,rection o~ rotation of the car-riage drive capstan shaft 40, thus imparting a motive force to the carriage 14 through the carriage drive cable 18 and its.associated points of attachment 43 and 44 to the carriage 14. The cooperation of carriage drive capstan 39, the carriage drive cable 18 and the carriage drive cable guides 20, form the carriage drive~ utilizable as means of imparting linear motion to the carriage.
The carriage drive cable 18 having a devica 41, such as a spring, which device supplies tension and dampen-ing to said carriage drive cable 18~ and having attachment ` to said carriage drive 18 at the point 42. The carriage ; drive cable 18 having a means of attachment to the car-.. rlage 14 at the points of attachment 43 and 44, said polnts of attachment 43 and 44 being accomplished by the
3 means of a ~hreaded device 45~ such as a screw. The threaded device 45 is restrained in lts position by mean~ :
of a threaded aperture (not shown) Continuing with FIG. 2, it can be seen that the stabilization plate 7 is supplied with a number of struc-: 35 tural ribs 46 greatly enhancing the structural integrity without appreciably increasing the mass o~ said stabiliza-tlon plate 7. ~he stabilization plate 7 ls rigidly attached to the carriage 14 by means o~ a number o~ adJu~t-able retaining screws 47. Due to this rigid attachment~
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-8~
the stabilization plate 7 is directed to move in con~unc-tion with the carriage 14. The maintalning of a low mass stabilization plate allows for faster ~orward and rev~erse speeds that might be utilized in a reJect or search mode.
The low mass carriage and stabilization plate assembly allow for the use of a lower energy capstan drive for said carriage drive, since the low mass assembly is incapable of storing as much inertia as an assembly utilizing a solid stabilization plate.
The advantages of utilizing a belt type drive system having a capstan drive ~orming the motive force are such that the capstan drive allows for precise servo control of the carriage 14 speed~ This system also elim-inates problems with Qscillations and irregularities in 15 carriage speed due to the cooperation of the capstan and dampening spring in isolating said carriage 14 from these forms of irregularities.
It can be seen from FIG. 2 that the carriage 14 is supplied with an aperture 48 which provides a placement 20 point ~or the spindle and motor assembllJ 5. This aperture 48 cooperates with the dual planes 27 and 28 of the car-riage 14 and the dual planes 24 and 25 of the carriage support plate 12 to provide a means of lowerlng vertically the spindle and motor assembly which is the limiting factor 25 in reducing the ver~ical slze of the video disc player unit 1. The cooperation of the carriage 14~ the stabillzation plate 7 and the spindle and motor assembly 5 form the carriage assembly~ utilizable in the support, rotation and translation of the video disc 2.
Continuing with FIG. 2~ it can be seen that the resiliently mounted rolling retainer 17 is provided with a groove 49 allowing for a predetermined area of travel.
Also visible in FIG. 2 is a threaded aperture 50 which provides a restraining point for a threaded device 35 such as a stud (not shown).
Also shown in FIG. 2 is a limit switch 48a whlch will be further discussed in FIG. 3.
Now referring to FIG. 3~ indicated b~y the arrow 51 is the range of travel allowed the carriage 14. This travel is mechanically limited b~J the limit switch 48a and a limit switch 52g these limit switches 48a and 52 collectively operate to deflne the ~urther~ost boundaries o~ the carriage travel, and provide a positive means of sa~eguarding the video disc player unit 1 from unnecessary damage due to operator error or a mechanical malfunction.
Continuing with FI~. 3) it can be seen that the optical bridge 8 is provided with an optical bridge shield 53 which optical bridge shield 53 fully encloses the optical bridge 8. This is provlded for sa~ety reasons as the collimated light source 55, such as a laser) ls required to have such shielding to eliminate the occurrence of pre-ventible in~uries to the user.
The optical bridge 8 is ~ormed b~J the optical bridge base 54 and attachment of the associated optical bridge components~ such as mirrors 56 and 57 which direct the collimated light reflected from the sur~ace 3 o~ the video disc 2 in order to recover in~ormation stored thereon.
The optical bridge 8 is also proYided with a lens drlver assembl~J 58 which lens driver a.ssembly ~ocuses the read beam generated b~J the collimated light source 55 such that the read beam is maintained in critical ~ocu~
on the bumps and lands disposed upon the video disc 2 and in a manner such that the lens driver assembly will main-tain said critical ~ocus throughout any vertical excursionsthe video disc may undergo due to its own imperfections.
Continuing with FIG. 3, it can be seen that the lower plane 25 of the carriage support plate 12 forms a bend 59 thus directing the c~æriage support plate 12 ver-3 tically to form an upright 60, said upright ~0 directingthe carriage support plate 12 towards its upper plane 24 via an elbow 61. Disposed upon the upper plane 24 of the carriage support plate 12 is a threaded aperture 62 which cooperates with a threaded device 63, such as a screw~ to restrain the protective dust shield 13 in its required " pos~tion.
" Still re~erring to FIG. 3, it can be ~een that the threaded aperture 50 cooperates with a ,threaded dev~ce 64, such as a stud, and passing through an aperture 65 provided in the carriage support plate post 31 to form the restraining member o~ the carriage support plate post Continuing with FIG. 3, it can be seen that t'ne stabillzation plate 7 is provided wit'n a num'oer of threaded apertures 67 which apertures 67 cooperate witll a number of ad~ustable retaining screws 47 to provide an ad~ustable means of restraint such that the stabillzation plate con-~orms to a critical perpendicularity to the central axis 69 of the spindle and motor assembly 5 and havlng a number of threaded locking means 68, such as nuts, which nuts cooperate with the adjustable retaining screws 47 to insure said crltica]. perpendicularity to the central axis of the spindle and motor assembl~ 5.
Still referring to FIG. 3, it can be seen that a ` tachometer disc 70 is shown securely attached to the spindle and motor assembly 5. Sald tachometer disc 70 is utilizable in generating an electrical signal indicatlve of the spindle speed at any given moment. Said electrical signal provides an accurate representation to servo means such that the servo means will maintain the spindle speed with~n a critical limit of a desired speed of rotation.
Now referring to FIG. 4, a detailed diagram of the spindle and motor assembly 5, the clamp assembly 6 and the stabilization plate 7 is provided. Further, a novel centering means for use with the video disc player 1 and spindle and motor assembly 5 is illustrated and described.
FIG. 4 shows a motor 71 which motor i~ utilize-able for imparting a rotational motion to a video disc 2, 3 said motor retained in its location by means of a threaded device 73, such as a screw, which screw cooperates with a threaded aperture 75 and passes through an aperture 76 provided in a motor mount 72. Said motor mount 72 is vibrationally isolated from the remainder of the spindle 35 assembly by means Or a dead rubber mount 74. Said motor 71 is a pancake type and is commercially available.
The spindle 77 is securely connected to the motor 71 by means of a threaded device 78, such as a nut, which nut cooperates with a threaded lower portion 79 of the . .
. , spindle 77, said threaded lo~er portion 79 p~s~n~ th~ough an apertured spacer 80~ such as a washer.
The spindle 77 ls provided with a means accurately locating said spindle about its central axis 69, said means also providing a high degree o~ nearly ~rictionle3s rota-tlon This is accomplished by the implementation of the lower bearing 81 and the upper bearing 82. The lower bearing 81 ls retained by a means, such as a press ~it, ln a recess 83. The upper bearing 82 is also retained by 10 a means, ~uch as a press fit, in a recess 84. The lower bearing 81 i5 ~urther provided with a thrust washer 85, said thrust washer 85 llmiting the amount o.~ vertical motion o~ the spindle 77.
Continuing with FIG. 4, the spindle 77 is provided 15 with a video disc support ring 86 which video disc support ring ls axranged about the central axis 69 of the spindle 77 and having an upper plane 87 arranged in a critical : perpendlcularly ~o the central axis 69 and directly adja-cent to the plane of the second surface 4 o~ the video 20 disc 2. Said video disc support rlng 86 having a lower plane 88 in intimate contact with an upper plane 89 o~
the upper bearing 82, and provided with a lip 90 ~or the positloning of a compresslon spring 91.
Still loo~ing at FI~. 4, it can be seen that the 25 spindle 77 ls provided wlth a centering device 92 which centering device ls arranged ln critical perpendlcularity to the central axis 69 of the spindle 77, said centering devlce 92 being of a subs~antially conical shape and resi~
lng in a recess 93 formed by the vertical connection 30 upright 94 of the video disc suppor~ ring 86, said center-ing device having a first position 95 and a second position 96. The centering device 92 cooperates with the central aperture 97 o~ the video disc 2 and the clamp ~ssembly 6 in providing an accurate means of locating said video disc 35 2 about the central axis 69 o~ the spindle 77.
In order to place a video disc 2 on a video disc player unit 1 the clamp assembly is removed ~rom the spindle 77. This will be de~cribed in detail further on.
The video disc 2 is placed on the spindle and motor .
; , -~a-assembly 5 such that the second surface ~ o~ the vldeo dlsc 2 contacts the upper plane 87 of the video disc support ring 8~. The central aperture g7 of the video disc 2 contacts the centering device 92 at a poin~ 100.
The centering device 92 at this point is residing in its first position 95~ said first po~itlon being described as the centering device's upper vertical limit o~ travel as de~ined by a retalning device 983 such as a snap ring, as it resides in a groove 99 about the central axis 69 of the 10 spindle 77. The centering device 92 receives an upward pressure from the compression spring 91 which maintains it vertically against the retaining device 98. The coope~
ation between the conical shape o~ the centering device 92 and the upward pressure of the compression spring 91 15 allow a wide variation in radial size o~ the central aper-ture 97 of the video disc 2, without substantially degrad-ing the centering device's ability to accurately locate the video disc 2 about the central axis 69 ol the spindle 77. As the clamp assembly 6 is replaced on the spindle 20 77, the clamp assembly 6 engages the video disc 2, and with the clamp assembly in its restrained position~ the video disc 2 is firmly held between the video disc sup-port ring 86 and the clamp assembly 6, allowing the video dlsc 2 to rest at a point of contact on the conical sur-2~ ~ace o~ the centering device 92 individually defined bythe radial si7.e of the central aperture 97 o~ the video disc 2.
Continuing with Figure 4, the clamp assembly 6 `will now be described in detail. The clamp a~sembly 6 is :3 provided with a main clamping portion 103 being primarily cylindrical in shape and having a conical base 104 and provided ~ith a flange 105 dlsposed upon its uppermost region. The main clamping portion 103 provides the re-straint for the video disc 2 when cooperating with the 35 video disc support ring 86 and the centering device 92.
The remainder o~ the clamp assembly 6 is provided to allow ease o~ operation yet insuring a secure restraint o~ both the clamp assembly 6 and the video disc 2. The clamp assembly 6 is provided with a release button 106 which is . `
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utll~zable ln the removal o~ the clamp assembly 6 ~rom the spindle 77. The release button 106 is pro~lided wlth a lip 109 and the main clamping portion 103 -ls provided with a ledge 110, sald lip 109 and said ledge 110 cooperate to form a cylindrical recess wherein resides a co~pression spring 111, said compression spring 111 retaining the release button 106 to its uppermost limit of travel. The relea~e button 106 ls provided with a threaded aperture arran~ed abou~ the central axis 69 of the spindle 77 and not shown in Figure 4. Said threaded aperture in the release button 106 cooperates wlth a threaded device, such as a screw to form a mechanlcal stop for a plunger 113.
The plunger is provided with a compression spring 114, said compression spring residing on a ledge 115 ~ormed on the plunger 113 and supplying a downward force to the plunger 113.
To secure the clamp assembly 6 to the spindle 77, a number o~ steel balls 107 are received in an equal -number of apertures 108 on the release button 106, and the balls engage an annular groove 120 in the spindle. By this arrangement, and as illustrated in FIG. 4, the release button 106 is secured to the spindle 77, and the main clamping portion 103 of the clamp assembly is urged into ^ clamping engagement with the disc 2 by the compresslon ` 25 spring 111.
To re~ove the clamp assembly 6 from the spindle 77, two fingers are placed under the flange 105, and the release button 106 is depressad with the thumb. This action pulls the main clamping portion 103 upwardly, 30 bringing a widened inside diameter portion 116 o~ the main portion 103 ad~acent the steel balls 1O7J thereby permitting the balls to move radially outwardly out of the annular groove 120. In this position, the clamp assembly 6 can be axially wi~hdrawn ~rom ~he spindle 77, 35 and as the clamp assembly is so withdrawn, the plunger 113 moves downwardly within the release button 106 until an outer surface 112 o~ the plunger 113 engages the balls 107 and retains them within the clamp assembly while lt is disengaged from the spindle.
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- Illustrated in FI~S. 5 and 6 is a novel locator and follower bearing arrangement for controlling the linear translation of the carriage 14 with respect to carriage support 12. Now referring to Figure 5 which is an enlarged sectional view of the locator bearing assembly, the loca-tor bearing assembly is formed by the cooperatlon of the lower plane 28, the connection angle 29, the upper plane 27, and a diverging angle 135, and thelr relatlve disposi-; tion on the carriage 14. The connecting angle 29 and the diverging angle 135 for~ a ~runcated a~sembl~ to which isattached a linear bearing 1220 The bearing 122 has a point of contact to a truncated rail 125 having an upper sur~ace 127 and a lower surface 126 which attaches to the carriage support plate 12 b~J means of a threaded device ~not shown). The truncated rail 125 has two slde connect-ing piece~s 128 and 129 and two working sur~aces 123 and 124. The diverging angle 135 has a second linear bearing 134 attached by means of a threaded device 133, such as a screw, cooperating with a second threaded aperture 130.
20 The locator bearing assembly is maintained in intimate contact with the truncated rail 125 b~ means of the resil-iently mounted rolling retainer 17. The locator bearing assembly provides an accurate means of frictionless trans-lation for the carriage 14 throughout its travel.
Now referring to Figure 6 which is an enlarged sectional view of the locator follower bearing assembly.
The locator follower bearing is arranged upon the carriage 14 by means of a connecting angle 29 cooperating with the upper plane ~7 of the carriage 14. ~ttached to the upper 30 portion of the carriage 14 is a linear bearing 136 re-strained in this position by the cooperation o~ a threaded aperture 137 and a threaded device 138, such as a screw, passing through an aperture 139 in a linear bearlng 136.
The linear bearing 136 has a point of contact on the work-35 ing sur~ace of a substantially square rail 144 having aworking surface 140, a side connecting surface 141 and a second side connecting sur~ace 142. The support follower rail 144 is restra~ned in lts position through it3 surface 143 b~J means o~ a number o~ threaded device~, such as screws, not shown in Figure 6. The support follower bearing supplies support ~o the carriage 14 directly opposing the locator bearing assembly such that both sides of the carriage 14 are supported equally. The support follower bearing assembly provides the required support without imparting an angular direction to the plane of translation o~ the carrlage as def~ned by the locator bear~ng assembly.
In order to provide for smooth~ relatively frlc-tionless translatlon o~ ~he carriage 14 along the locator and follower rails3 the linear bearings 122, 134 and 136 of novel construction are provided. It will be appreciated that the linear bearings 122, 134 and 136 are o~similar construction, and accordingly~ one of these bear~ngs will be described in detail with reference to Figure 7, which is a cross-sectional view through khe support follower bearing 136. From this view, a number o~ steel balls 145 are indicated having a polnt of contact at the point 147 and the point 148, the point 147 forming a contact with the working surface 140 of the support follower rail and the p~int 148 having a point of contact wit'n a steel shoe 149. The steel ball 145 can be seen residing in a recess 146, henceforth referred to as the oval track. The steel balls 145 are retained within the linear bearing by a cover plate 150) the cover plate 150 being retained by a tab 151.
Now referring to Figure 8 whlch shows the steel shoe 149 residing in the slot 152 and havlng a point of contact with t~.e carriage at the point 1539 indicated at the points 148 are the points of contact with the steel shoe of the balls 145. Indicated at the points 147 are the points of contact of the steel balls with the working surface 140 of the support follower rail 144. Indicated at 154 can be seen a radlus on the opposite side of the steel shoe 149 from the steel balls 145. This radius allows the linear bearing to be self-aligning. This marks one improvement over the normal linear bearings available today, in that this linear bearing is capable of main-taining a crit~cally accurate translat~on desplte irregu-larities in worlcing surface3 provided for the linear '.~, `~, ` . ' '' .
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bearing.
; Mow referring to Figure 9 showlng an elev~tional view o~ the linear bearing ~artially cut away to show the relationship of the parts) indlcated at 145 are the steel balls residing in the oval track 14~. The cover 150 has been cut away to show the path of the oval track 146. The tab 151 i5 still indicated. The steel shoe 149 is lndi cated in the slot 152.
Now referring to Figure 10 showing the resiliently mounted rolling retainer from a bottom plan view. A shaft is indicated at the point 153 which retains a roller 154 by means of a retaining device, such as a sn~p ring. The shaft 153 passes through a truck 156 where it is restrained by a retain device~ such as snap ring 157. A threaded device such as a screw is lndicated at 158 and a rubber bushing 159 is retained by the screw 158.
Now referring to Figure 11 which is an elevation-al view of the resiliently mounted rolling retainer 17, the roller is indicated at 154, said roller being main-tained by the shaft 153 and restrained by the snap ring155. The truck 156 supplies a mounting platform for the roller and is provided with an aperture (not shown), through which a threaded device 158, such as a screw, passes vertically towards the carriage 14 where it cooper-ates with a threaded aperture 160 to restrain the resili-ently mounted rolling retainer 17. The threaded device 158 passes through a spring 161, which spring 161 supplies a downward force to the carriage 14. The spring 161 and : the rubber bushing cooperate to provide the resilient attachment of the rolling retainer 17. This resiliently mounted rolling retainer allows for a high degree of re-straint and provides ~or reliable self-alignment of the locator bearing assembl~y and the support follower bearing assembly without impairing their frictionless translation.
Another novel feature of the present invention resides in a method and means by which the rotating disc 2 is stabilized. More specifically, referring again to " Figure 4~ it can be seen that the stabilization plate 7 is provided with an upright 204, this upright 204 is provided .
:
~ 17-with the aperture 75 wherein the threaded device 73 is retained. The upright 204 cooperates wlth the motor mount 72 forming a cavity 205, the cavity 205 employing an aper-ture (not shown) provided for ingress o~ air to the cavity 205. The cavity serves as a storage rneans for a volume of air~ which volume of air is provided as a ready supply such that a portion o~ thls volume o~ air is available at an annular ~ir exit point 201. ~he air supplied at the air exit point 201 is employed in a region 203 which ls formed lO by interaction o~ the stabilization plate 7 and the second sur~ace 4 o~ the video disc 2. The video disc 2 and the stabilization plate 7 are arranged about t~e central axis 69 of the spindle 77 and maintain a crltical perpendicu-larity to the central axis ~9 o~ the spindle 77.
The use of a stabilization plate is well known in prior art. However; it has been determined experimentally that the vertical distance between the stabilization plate 7 and the second surface 4 of the video disc 2 is of a critical nature such that the interaction of the stabili-20 zatlon plate 7, and the video disc 2 will cooperate to provide a degree of stability to the video disc 2 not normally inherent in the video disc. It has been deter-mined that a video disc can have a nature such that it is substantially unflat. This unflatness is generated 25 at the time of the manufacture of the video disc and is individually variable video disc to video disc. This unflatness is detrimental to the optimum operation of the video disc player unit in that an unflat video disc will scrape or in other ways, contact the sur~ace of the 30 stabilization plate or other components of the video disc player unit when the disc is rotated about the central axis of the spindle. An obvious means of rectifying this problem is to e~tend vertically the distance between the ~" video disc 2 and the stabilization plate 7. However, it ` 35 was determined that the cooperation between the stabili-zation plate and the video di~c no longer existed, and the ` dampening effect provided by the region 203 of air between '` the lower surface 4 o~ the vldeo disc 2 and the ~tabiliza-~ tion plate 7 acted in a manner such that it no longer : .
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.
.
.
dampened the oscillations to which the video disc 2 is prone. Through experlmentation, the air exit polnt 201 and its available areas were identifled as coopera~ing wlth other factorsg well known to a person skilled in the art, such that the available area of the air exit point was contrlbuting to this lack of dampening of the oscilla-tions to which the video disc is prone. It was further determined by limiting the available area to a mathe-matically ascertainable amount that this detrimental effect could be eliminated. The area of the air exit point 201 in the present embodiment is approximately 6 tenths of a square centimeter This effectively elimlnates the problem b~y allowing an extended vertical distance between the stabilization plate and the video disc such ~hat an unflat vldeo disc no longer scrapes or contacts the stabiliza-tion plate or other components in the video disc player unit upon impartlng rotation to the video disc.
l~hile the invention has been particularly shown and described with reference to a preferred embodiment and alterations theretoJ it would be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
of a threaded aperture (not shown) Continuing with FIG. 2, it can be seen that the stabilization plate 7 is supplied with a number of struc-: 35 tural ribs 46 greatly enhancing the structural integrity without appreciably increasing the mass o~ said stabiliza-tlon plate 7. ~he stabilization plate 7 ls rigidly attached to the carriage 14 by means o~ a number o~ adJu~t-able retaining screws 47. Due to this rigid attachment~
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the stabilization plate 7 is directed to move in con~unc-tion with the carriage 14. The maintalning of a low mass stabilization plate allows for faster ~orward and rev~erse speeds that might be utilized in a reJect or search mode.
The low mass carriage and stabilization plate assembly allow for the use of a lower energy capstan drive for said carriage drive, since the low mass assembly is incapable of storing as much inertia as an assembly utilizing a solid stabilization plate.
The advantages of utilizing a belt type drive system having a capstan drive ~orming the motive force are such that the capstan drive allows for precise servo control of the carriage 14 speed~ This system also elim-inates problems with Qscillations and irregularities in 15 carriage speed due to the cooperation of the capstan and dampening spring in isolating said carriage 14 from these forms of irregularities.
It can be seen from FIG. 2 that the carriage 14 is supplied with an aperture 48 which provides a placement 20 point ~or the spindle and motor assembllJ 5. This aperture 48 cooperates with the dual planes 27 and 28 of the car-riage 14 and the dual planes 24 and 25 of the carriage support plate 12 to provide a means of lowerlng vertically the spindle and motor assembly which is the limiting factor 25 in reducing the ver~ical slze of the video disc player unit 1. The cooperation of the carriage 14~ the stabillzation plate 7 and the spindle and motor assembly 5 form the carriage assembly~ utilizable in the support, rotation and translation of the video disc 2.
Continuing with FIG. 2~ it can be seen that the resiliently mounted rolling retainer 17 is provided with a groove 49 allowing for a predetermined area of travel.
Also visible in FIG. 2 is a threaded aperture 50 which provides a restraining point for a threaded device 35 such as a stud (not shown).
Also shown in FIG. 2 is a limit switch 48a whlch will be further discussed in FIG. 3.
Now referring to FIG. 3~ indicated b~y the arrow 51 is the range of travel allowed the carriage 14. This travel is mechanically limited b~J the limit switch 48a and a limit switch 52g these limit switches 48a and 52 collectively operate to deflne the ~urther~ost boundaries o~ the carriage travel, and provide a positive means of sa~eguarding the video disc player unit 1 from unnecessary damage due to operator error or a mechanical malfunction.
Continuing with FI~. 3) it can be seen that the optical bridge 8 is provided with an optical bridge shield 53 which optical bridge shield 53 fully encloses the optical bridge 8. This is provlded for sa~ety reasons as the collimated light source 55, such as a laser) ls required to have such shielding to eliminate the occurrence of pre-ventible in~uries to the user.
The optical bridge 8 is ~ormed b~J the optical bridge base 54 and attachment of the associated optical bridge components~ such as mirrors 56 and 57 which direct the collimated light reflected from the sur~ace 3 o~ the video disc 2 in order to recover in~ormation stored thereon.
The optical bridge 8 is also proYided with a lens drlver assembl~J 58 which lens driver a.ssembly ~ocuses the read beam generated b~J the collimated light source 55 such that the read beam is maintained in critical ~ocu~
on the bumps and lands disposed upon the video disc 2 and in a manner such that the lens driver assembly will main-tain said critical ~ocus throughout any vertical excursionsthe video disc may undergo due to its own imperfections.
Continuing with FIG. 3, it can be seen that the lower plane 25 of the carriage support plate 12 forms a bend 59 thus directing the c~æriage support plate 12 ver-3 tically to form an upright 60, said upright ~0 directingthe carriage support plate 12 towards its upper plane 24 via an elbow 61. Disposed upon the upper plane 24 of the carriage support plate 12 is a threaded aperture 62 which cooperates with a threaded device 63, such as a screw~ to restrain the protective dust shield 13 in its required " pos~tion.
" Still re~erring to FIG. 3, it can be ~een that the threaded aperture 50 cooperates with a ,threaded dev~ce 64, such as a stud, and passing through an aperture 65 provided in the carriage support plate post 31 to form the restraining member o~ the carriage support plate post Continuing with FIG. 3, it can be seen that t'ne stabillzation plate 7 is provided wit'n a num'oer of threaded apertures 67 which apertures 67 cooperate witll a number of ad~ustable retaining screws 47 to provide an ad~ustable means of restraint such that the stabillzation plate con-~orms to a critical perpendicularity to the central axis 69 of the spindle and motor assembly 5 and havlng a number of threaded locking means 68, such as nuts, which nuts cooperate with the adjustable retaining screws 47 to insure said crltica]. perpendicularity to the central axis of the spindle and motor assembl~ 5.
Still referring to FIG. 3, it can be seen that a ` tachometer disc 70 is shown securely attached to the spindle and motor assembly 5. Sald tachometer disc 70 is utilizable in generating an electrical signal indicatlve of the spindle speed at any given moment. Said electrical signal provides an accurate representation to servo means such that the servo means will maintain the spindle speed with~n a critical limit of a desired speed of rotation.
Now referring to FIG. 4, a detailed diagram of the spindle and motor assembly 5, the clamp assembly 6 and the stabilization plate 7 is provided. Further, a novel centering means for use with the video disc player 1 and spindle and motor assembly 5 is illustrated and described.
FIG. 4 shows a motor 71 which motor i~ utilize-able for imparting a rotational motion to a video disc 2, 3 said motor retained in its location by means of a threaded device 73, such as a screw, which screw cooperates with a threaded aperture 75 and passes through an aperture 76 provided in a motor mount 72. Said motor mount 72 is vibrationally isolated from the remainder of the spindle 35 assembly by means Or a dead rubber mount 74. Said motor 71 is a pancake type and is commercially available.
The spindle 77 is securely connected to the motor 71 by means of a threaded device 78, such as a nut, which nut cooperates with a threaded lower portion 79 of the . .
. , spindle 77, said threaded lo~er portion 79 p~s~n~ th~ough an apertured spacer 80~ such as a washer.
The spindle 77 ls provided with a means accurately locating said spindle about its central axis 69, said means also providing a high degree o~ nearly ~rictionle3s rota-tlon This is accomplished by the implementation of the lower bearing 81 and the upper bearing 82. The lower bearing 81 ls retained by a means, such as a press ~it, ln a recess 83. The upper bearing 82 is also retained by 10 a means, ~uch as a press fit, in a recess 84. The lower bearing 81 i5 ~urther provided with a thrust washer 85, said thrust washer 85 llmiting the amount o.~ vertical motion o~ the spindle 77.
Continuing with FIG. 4, the spindle 77 is provided 15 with a video disc support ring 86 which video disc support ring ls axranged about the central axis 69 of the spindle 77 and having an upper plane 87 arranged in a critical : perpendlcularly ~o the central axis 69 and directly adja-cent to the plane of the second surface 4 o~ the video 20 disc 2. Said video disc support rlng 86 having a lower plane 88 in intimate contact with an upper plane 89 o~
the upper bearing 82, and provided with a lip 90 ~or the positloning of a compresslon spring 91.
Still loo~ing at FI~. 4, it can be seen that the 25 spindle 77 ls provided wlth a centering device 92 which centering device ls arranged ln critical perpendlcularity to the central axis 69 of the spindle 77, said centering devlce 92 being of a subs~antially conical shape and resi~
lng in a recess 93 formed by the vertical connection 30 upright 94 of the video disc suppor~ ring 86, said center-ing device having a first position 95 and a second position 96. The centering device 92 cooperates with the central aperture 97 o~ the video disc 2 and the clamp ~ssembly 6 in providing an accurate means of locating said video disc 35 2 about the central axis 69 o~ the spindle 77.
In order to place a video disc 2 on a video disc player unit 1 the clamp assembly is removed ~rom the spindle 77. This will be de~cribed in detail further on.
The video disc 2 is placed on the spindle and motor .
; , -~a-assembly 5 such that the second surface ~ o~ the vldeo dlsc 2 contacts the upper plane 87 of the video disc support ring 8~. The central aperture g7 of the video disc 2 contacts the centering device 92 at a poin~ 100.
The centering device 92 at this point is residing in its first position 95~ said first po~itlon being described as the centering device's upper vertical limit o~ travel as de~ined by a retalning device 983 such as a snap ring, as it resides in a groove 99 about the central axis 69 of the 10 spindle 77. The centering device 92 receives an upward pressure from the compression spring 91 which maintains it vertically against the retaining device 98. The coope~
ation between the conical shape o~ the centering device 92 and the upward pressure of the compression spring 91 15 allow a wide variation in radial size o~ the central aper-ture 97 of the video disc 2, without substantially degrad-ing the centering device's ability to accurately locate the video disc 2 about the central axis 69 ol the spindle 77. As the clamp assembly 6 is replaced on the spindle 20 77, the clamp assembly 6 engages the video disc 2, and with the clamp assembly in its restrained position~ the video disc 2 is firmly held between the video disc sup-port ring 86 and the clamp assembly 6, allowing the video dlsc 2 to rest at a point of contact on the conical sur-2~ ~ace o~ the centering device 92 individually defined bythe radial si7.e of the central aperture 97 o~ the video disc 2.
Continuing with Figure 4, the clamp assembly 6 `will now be described in detail. The clamp a~sembly 6 is :3 provided with a main clamping portion 103 being primarily cylindrical in shape and having a conical base 104 and provided ~ith a flange 105 dlsposed upon its uppermost region. The main clamping portion 103 provides the re-straint for the video disc 2 when cooperating with the 35 video disc support ring 86 and the centering device 92.
The remainder o~ the clamp assembly 6 is provided to allow ease o~ operation yet insuring a secure restraint o~ both the clamp assembly 6 and the video disc 2. The clamp assembly 6 is provided with a release button 106 which is . `
, ~
utll~zable ln the removal o~ the clamp assembly 6 ~rom the spindle 77. The release button 106 is pro~lided wlth a lip 109 and the main clamping portion 103 -ls provided with a ledge 110, sald lip 109 and said ledge 110 cooperate to form a cylindrical recess wherein resides a co~pression spring 111, said compression spring 111 retaining the release button 106 to its uppermost limit of travel. The relea~e button 106 ls provided with a threaded aperture arran~ed abou~ the central axis 69 of the spindle 77 and not shown in Figure 4. Said threaded aperture in the release button 106 cooperates wlth a threaded device, such as a screw to form a mechanlcal stop for a plunger 113.
The plunger is provided with a compression spring 114, said compression spring residing on a ledge 115 ~ormed on the plunger 113 and supplying a downward force to the plunger 113.
To secure the clamp assembly 6 to the spindle 77, a number o~ steel balls 107 are received in an equal -number of apertures 108 on the release button 106, and the balls engage an annular groove 120 in the spindle. By this arrangement, and as illustrated in FIG. 4, the release button 106 is secured to the spindle 77, and the main clamping portion 103 of the clamp assembly is urged into ^ clamping engagement with the disc 2 by the compresslon ` 25 spring 111.
To re~ove the clamp assembly 6 from the spindle 77, two fingers are placed under the flange 105, and the release button 106 is depressad with the thumb. This action pulls the main clamping portion 103 upwardly, 30 bringing a widened inside diameter portion 116 o~ the main portion 103 ad~acent the steel balls 1O7J thereby permitting the balls to move radially outwardly out of the annular groove 120. In this position, the clamp assembly 6 can be axially wi~hdrawn ~rom ~he spindle 77, 35 and as the clamp assembly is so withdrawn, the plunger 113 moves downwardly within the release button 106 until an outer surface 112 o~ the plunger 113 engages the balls 107 and retains them within the clamp assembly while lt is disengaged from the spindle.
, . .
- Illustrated in FI~S. 5 and 6 is a novel locator and follower bearing arrangement for controlling the linear translation of the carriage 14 with respect to carriage support 12. Now referring to Figure 5 which is an enlarged sectional view of the locator bearing assembly, the loca-tor bearing assembly is formed by the cooperatlon of the lower plane 28, the connection angle 29, the upper plane 27, and a diverging angle 135, and thelr relatlve disposi-; tion on the carriage 14. The connecting angle 29 and the diverging angle 135 for~ a ~runcated a~sembl~ to which isattached a linear bearing 1220 The bearing 122 has a point of contact to a truncated rail 125 having an upper sur~ace 127 and a lower surface 126 which attaches to the carriage support plate 12 b~J means of a threaded device ~not shown). The truncated rail 125 has two slde connect-ing piece~s 128 and 129 and two working sur~aces 123 and 124. The diverging angle 135 has a second linear bearing 134 attached by means of a threaded device 133, such as a screw, cooperating with a second threaded aperture 130.
20 The locator bearing assembly is maintained in intimate contact with the truncated rail 125 b~ means of the resil-iently mounted rolling retainer 17. The locator bearing assembly provides an accurate means of frictionless trans-lation for the carriage 14 throughout its travel.
Now referring to Figure 6 which is an enlarged sectional view of the locator follower bearing assembly.
The locator follower bearing is arranged upon the carriage 14 by means of a connecting angle 29 cooperating with the upper plane ~7 of the carriage 14. ~ttached to the upper 30 portion of the carriage 14 is a linear bearing 136 re-strained in this position by the cooperation o~ a threaded aperture 137 and a threaded device 138, such as a screw, passing through an aperture 139 in a linear bearlng 136.
The linear bearing 136 has a point of contact on the work-35 ing sur~ace of a substantially square rail 144 having aworking surface 140, a side connecting surface 141 and a second side connecting sur~ace 142. The support follower rail 144 is restra~ned in lts position through it3 surface 143 b~J means o~ a number o~ threaded device~, such as screws, not shown in Figure 6. The support follower bearing supplies support ~o the carriage 14 directly opposing the locator bearing assembly such that both sides of the carriage 14 are supported equally. The support follower bearing assembly provides the required support without imparting an angular direction to the plane of translation o~ the carrlage as def~ned by the locator bear~ng assembly.
In order to provide for smooth~ relatively frlc-tionless translatlon o~ ~he carriage 14 along the locator and follower rails3 the linear bearings 122, 134 and 136 of novel construction are provided. It will be appreciated that the linear bearings 122, 134 and 136 are o~similar construction, and accordingly~ one of these bear~ngs will be described in detail with reference to Figure 7, which is a cross-sectional view through khe support follower bearing 136. From this view, a number o~ steel balls 145 are indicated having a polnt of contact at the point 147 and the point 148, the point 147 forming a contact with the working surface 140 of the support follower rail and the p~int 148 having a point of contact wit'n a steel shoe 149. The steel ball 145 can be seen residing in a recess 146, henceforth referred to as the oval track. The steel balls 145 are retained within the linear bearing by a cover plate 150) the cover plate 150 being retained by a tab 151.
Now referring to Figure 8 whlch shows the steel shoe 149 residing in the slot 152 and havlng a point of contact with t~.e carriage at the point 1539 indicated at the points 148 are the points of contact with the steel shoe of the balls 145. Indicated at the points 147 are the points of contact of the steel balls with the working surface 140 of the support follower rail 144. Indicated at 154 can be seen a radlus on the opposite side of the steel shoe 149 from the steel balls 145. This radius allows the linear bearing to be self-aligning. This marks one improvement over the normal linear bearings available today, in that this linear bearing is capable of main-taining a crit~cally accurate translat~on desplte irregu-larities in worlcing surface3 provided for the linear '.~, `~, ` . ' '' .
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bearing.
; Mow referring to Figure 9 showlng an elev~tional view o~ the linear bearing ~artially cut away to show the relationship of the parts) indlcated at 145 are the steel balls residing in the oval track 14~. The cover 150 has been cut away to show the path of the oval track 146. The tab 151 i5 still indicated. The steel shoe 149 is lndi cated in the slot 152.
Now referring to Figure 10 showing the resiliently mounted rolling retainer from a bottom plan view. A shaft is indicated at the point 153 which retains a roller 154 by means of a retaining device, such as a sn~p ring. The shaft 153 passes through a truck 156 where it is restrained by a retain device~ such as snap ring 157. A threaded device such as a screw is lndicated at 158 and a rubber bushing 159 is retained by the screw 158.
Now referring to Figure 11 which is an elevation-al view of the resiliently mounted rolling retainer 17, the roller is indicated at 154, said roller being main-tained by the shaft 153 and restrained by the snap ring155. The truck 156 supplies a mounting platform for the roller and is provided with an aperture (not shown), through which a threaded device 158, such as a screw, passes vertically towards the carriage 14 where it cooper-ates with a threaded aperture 160 to restrain the resili-ently mounted rolling retainer 17. The threaded device 158 passes through a spring 161, which spring 161 supplies a downward force to the carriage 14. The spring 161 and : the rubber bushing cooperate to provide the resilient attachment of the rolling retainer 17. This resiliently mounted rolling retainer allows for a high degree of re-straint and provides ~or reliable self-alignment of the locator bearing assembl~y and the support follower bearing assembly without impairing their frictionless translation.
Another novel feature of the present invention resides in a method and means by which the rotating disc 2 is stabilized. More specifically, referring again to " Figure 4~ it can be seen that the stabilization plate 7 is provided with an upright 204, this upright 204 is provided .
:
~ 17-with the aperture 75 wherein the threaded device 73 is retained. The upright 204 cooperates wlth the motor mount 72 forming a cavity 205, the cavity 205 employing an aper-ture (not shown) provided for ingress o~ air to the cavity 205. The cavity serves as a storage rneans for a volume of air~ which volume of air is provided as a ready supply such that a portion o~ thls volume o~ air is available at an annular ~ir exit point 201. ~he air supplied at the air exit point 201 is employed in a region 203 which ls formed lO by interaction o~ the stabilization plate 7 and the second sur~ace 4 o~ the video disc 2. The video disc 2 and the stabilization plate 7 are arranged about t~e central axis 69 of the spindle 77 and maintain a crltical perpendicu-larity to the central axis ~9 o~ the spindle 77.
The use of a stabilization plate is well known in prior art. However; it has been determined experimentally that the vertical distance between the stabilization plate 7 and the second surface 4 of the video disc 2 is of a critical nature such that the interaction of the stabili-20 zatlon plate 7, and the video disc 2 will cooperate to provide a degree of stability to the video disc 2 not normally inherent in the video disc. It has been deter-mined that a video disc can have a nature such that it is substantially unflat. This unflatness is generated 25 at the time of the manufacture of the video disc and is individually variable video disc to video disc. This unflatness is detrimental to the optimum operation of the video disc player unit in that an unflat video disc will scrape or in other ways, contact the sur~ace of the 30 stabilization plate or other components of the video disc player unit when the disc is rotated about the central axis of the spindle. An obvious means of rectifying this problem is to e~tend vertically the distance between the ~" video disc 2 and the stabilization plate 7. However, it ` 35 was determined that the cooperation between the stabili-zation plate and the video di~c no longer existed, and the ` dampening effect provided by the region 203 of air between '` the lower surface 4 o~ the vldeo disc 2 and the ~tabiliza-~ tion plate 7 acted in a manner such that it no longer : .
:`` `
.
.
.
dampened the oscillations to which the video disc 2 is prone. Through experlmentation, the air exit polnt 201 and its available areas were identifled as coopera~ing wlth other factorsg well known to a person skilled in the art, such that the available area of the air exit point was contrlbuting to this lack of dampening of the oscilla-tions to which the video disc is prone. It was further determined by limiting the available area to a mathe-matically ascertainable amount that this detrimental effect could be eliminated. The area of the air exit point 201 in the present embodiment is approximately 6 tenths of a square centimeter This effectively elimlnates the problem b~y allowing an extended vertical distance between the stabilization plate and the video disc such ~hat an unflat vldeo disc no longer scrapes or contacts the stabiliza-tion plate or other components in the video disc player unit upon impartlng rotation to the video disc.
l~hile the invention has been particularly shown and described with reference to a preferred embodiment and alterations theretoJ it would be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
Claims (9)
1. A player for optically readable discs, comprising: a housing including fixed support means having at least one linear rail member; a movable carriage having at least one linear bearing means in operative engagement with said rail member; means for controlling movement of said carriage with respect to said housing along said rail; a motor and spindle assembly mounted on said carriage for movement therewith, said spindle having a central axis and said assembly including means for mounting an information bearing disc about said spindle in a plane generally perpendicular to the axis of said spindle, said mounting means including a videodisc support ring having a generally flat surface disposed in a plane generally perpendicular to said spindle axis and arranged to abut one side of said disc; and means for centering said disc about said spindle, said centering means being disposed about said spindle, said centering means being disposed about said spindle and having an outer surface generally forming a frustum of a cone, which surface is arranged to engage a central aperture in said disc thereby centering said disc with respect to said spindle axis.
2. The disc player as claimed in Claim 1, wherein said centering means is disposed in a central recess in said support ring and resiliently mounted with said conical surface extending beyond said flat surface of said support ring.
3. The disc player as claimed in Claim 1, further including a releasable clamping device arranged to rigidly engage said spindle and resiliently engage a second side of said disc.
4. The disc player as claimed in Claim 1, wherein: said linear rail member includes a first and a second side surface, at least a portion of said first side surface lying in a first plane, and at least a portion of said second side surface lying in a second plane; and said linear bearing means includes a support plate having a first side member, and a second side member, said first side member lying in a third plane spaced from and parallel to said first plane and carrying bearing means for providing rolling engagement with said first plane, and said second side member lying in a fourth plane spaced from and parallel to said second plane and carrying bearing means for providing rolling engagement with said second plane, whereby said linear bearing means is constrained to roll along said linear rail member.
5. The disc player as claimed in Claim 4, further including a retaining means resiliently mounted on said carriage for rolling engagement with said fixed support means and arranged to resiliently urge said linear bearing means into contact with said linear rail member.
6. The disc player as claimed in Claim 1, further including a second linear rail member on said fixed support means and a second linear bearing means on said carriage arranged to operatively engage said second rail member.
7. The disc player as claimed in Claim 6, further including a retaining means resiliently mounted on said carriage for rolling engagement with said fixed support means and arranged to resiliently urge said second linear bearing means into contact with said second linear rail member.
8. A disc support assembly comprising: a motor and spindle means for driving an information bearing disc in a predetermined plane, said spindle means having a central axis positioned perpendicular to said plane; a disc support means positioned about said central axis and having a generally flat annular surface lying in a plane parallel to said predetermined plane; and means carried by said spindle for centering said disc about said spindle, said centering means being received in a central recess in said support means and having an outer surface generally forming a frustum of a cone, said surface being arranged to engage a central aperture in said disc, thereby centering said disc with respect to said spindle axis.
9. The disc support assembly as claimed in Claim 8, wherein said centering means is slidably mounted on said spindle for axial movement thereon, and resiliently urged axially out of said recess and beyond said generally flat annular surface of said support means toward a position where said conical surface engages said central aperture of said disc prior to engagement between said disc and said generally flat annular surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000336259A CA1142644A (en) | 1979-09-25 | 1979-09-25 | Video disc player |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000336259A CA1142644A (en) | 1979-09-25 | 1979-09-25 | Video disc player |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1142644A true CA1142644A (en) | 1983-03-08 |
Family
ID=4115199
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000336259A Expired CA1142644A (en) | 1979-09-25 | 1979-09-25 | Video disc player |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1142644A (en) |
-
1979
- 1979-09-25 CA CA000336259A patent/CA1142644A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |