Automatic video cassette changer

Abstract: An automatic cassette changer capable of selectively loading any of cassettes (1, 2) of various sizes upon a recording and/or playback unit (13), comprises cassette-housing racks (3) capable of selec­ tively storing any of large cassettes (1) and small cassettes (2), and having first guides for the large cassette and second guides for the small cassette so as to put the respective cassettes in their proper positions; and a cassette transfer (10) having third guides for the large cassette (2) and fourth guides for the small cassette (1) so as to have both sides of the respective cassettes guides, and capable of selectively moving any of the large cassette and the small cassette from the cassette-housing racks (3) to the recording and/or playback unit (13), and vice versa.

Description: This invention relates to an automatic cassette changer which is capable of selectively loading either large or small cassettes into a recording and/or playback unit and to draw the cassettes again from the unit. An automatic cassette changer having the features of the preamble of appended claim 1 corresponds to a combination of the teachings of the documents EP-A-227 446 and JP-A-62219358. From the former document, all the features of the preamble are known except those ones which deal with the guiding of cassettes of a second size. However, the latter document describes a means for exactly inserting a cassette of a large size or a cassette of a small size into a cassette holder. Therefore, from this document the features of the preamble concerning the guidance of cassettes of a second size are known. It is the object of the present invention to provide an automatic cassette changer with improved guidance for large and small cassettes. The automatic cassette changer of the present invention is defined by the features of claim 1. It comprises a mechanical detection means for detecting the external form of the cassette and a control means interlocked with said detection means. Guide means within cassette storage racks and guide means within a cassette transfer unit are moved by signals from said control means in dependence of the signal of said mechanical detection means which gives the information whether a large or a small cassette has to be changed. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front view of a automatic cassette changer according to this invention; Figure 2 is a plan view of a part of the automatic cassette changer according to an embodiment of this invention; Figure 3 is a perspective view of the housing rack in the automatic cassette changer, storing any of large cassettes and small cassettes; Figure 4 is a plan view of the housing rack shown in Figure 3, wherein a small cassette is accommodated; Figure 5 is a plan view of the housing rack shown in Figure 3, wherein a large cassette is going to be inserted; Figure 6 is a plan view of the housing rack shown in Figure 3, wherein a large cassette is accommodated; Figure 7 is a plan view of the housing rack shown in Figure 3, wherein a large cassette is going to be inserted; Figure 8 is a sectional view in the A-A direction in Figure 4; Figure 9 is a sectional view in the B-B direction in Figure 5; Figure 10 is a sectional view in the C-C direction in Figure 6; Figures 11 and 12 are fragmentary perspective views of the housing rack shown in Figure 3, wherein a large cassette is going to be normally inserted; Figures 13 and 14 are fragmentary perspective views of the housing rack shown in Figure 3, wherein a large cassette is going to be erroneously inserted; Figure 15 is a perspective view of the cassette ejection means provided in the housing rack shown in Figure 3; Figure 16 is an exploded perspective view of the cassette ejection means shown in Figure 15; Figure 17 is a schematic perspective view of a cassette transfer unit included in the automatic cassette changer according to this invention; Figure 18 is a side view of the cassette transfer unit shown in Figure 17; Figure 19 is a schematic perspective view of the cassette transfer unit included in the automatic cassette changer according to this invention; Figure 20 is a plan view of cassette guides provided in the cassette transfer unit shown in Figure 19; Figure 21 is a view of the cassette guides viewed in a direction D-D in Figure 20, wherein a small cassette is in its proper position; Figure 22 is a view of the cassette guides viewed in a direction D-D in Figure 20, wherein a large cassette is in its proper position; Figure 23 is a perspective view of the main part of the cassette guide shown in Figure 20; Figure 24 is a front view of a cassette transfer unit in the automatic cassette changer according to another embodiment of this invention; Figure 25 is a side view of the cassette transfer unit shown in Figure 17; Figure 26 is a front view of the cassette transfer unit shown in Figure 17; Figure 27 is a side view of the cassette transfer unit shown in Figure 17; and Figure 28 is a side view of the cassette transfer unit shown in Figure 17; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an automatic cassette changer for video cassettes embodying the present invention is hereinafter described. The automatic cassette changer shown in Figures 1 and 2 can handle any of cassettes of different sizes, large cassettes 1 and small cassette 2. The automatic cassette changer comprises a rack block 4 in which cassette-housing racks 3 selectively storing any of large cassettes 1 and small cassettes 2 are provided in several lines and in a few columns; three rack blocks 5, in each of which a plurality of racks are provided in several lines and in a few columns; a rack block 9 in which racks 7a for small cassettes insertion use and a rack 7b for small cassette ejection use; and others. These rack blocks 4, 6, and 9 are arranged in two rows on both sides of the transfer route 11 for the cassette transfer unit 10, which is movable vertically in Figure 1 and laterally in Figure 2. On one side of not the rack block row 12a corresponding to the operator side (the front side) 12, but the rack block row 12b, recording/playback units 13 are vertically arranged in plural lines. Such a plurality of recording/playback units 13 are front-loading-type VTRs capable of selectively loading any of large cassettes and small cassettes used for recording or playback. The cassette inlets 13a of these recording/playback units 13 face to the operator side 12, and in front of the inlets, there are provided a plurality of cassette inserting/ejecting adaptors 14. The cassette transfer unit 10 has a cassette-housing unit 15 capable of selectively holding any of the large cassettes 1 and small cassettes 2. A control unit 8 is located above the uppermost recording/playback unit 13. This control unit 8 controls the cassette transfer unit 10 and recording/playback unit 13 according to information given by a predetermined operating program which consists of a playback or recording sequence of image signals, and so on. The cassette transfer unit 10 is movable between a desired position in the rack blocks 4, 6, and 9, and the recording/playback unit 13 according to the control signal supplied by the control unit 8, so as to selectively load any of cassettes stored in the rack blocks 4, 6, and 9 to the recording/playback unit 13 and vice versa. There are doors 16 in front of the rack block row 12a on the operator side 12. Before the automatic cassette changer is used, the large cassettes 1 and the small cassettes 2 are housed in the cassette-storage racks 3 and 5 beforehand. At that time, the operator inserts or ejects the large cassetes 1 and the small cassettes 2 to the cassette-storage rack 3 in a direction of arrows a and a′ from the operator side 12, but in the cassette-storage rack 5 used only for the small cassettes 2, the cassettes 2 inserted in turns into the insertion rack 7a by the operator are transferred in turns by the cassette unit 10, and inserted into the cassette storage rack 5 in the direction of arrow b from the transfer route 11 side, and on the contrary, the cassettes 2 drawn from the cassette-storage rack 5 onto the cassette transfer unit 10 in the direction of arrow b are ejected from the ejection rack 2b on the operator's side 12. Next, the cassette transfer unit 10 is controlled to transfer vertically and laterally along the moving route 11, so as to selectively receive the large cassette 1 or the small cassette 2 located at the designated rack address in the direction of arrow b′, and hold it in the cassette-housing unit 15. Then, after transferring the cassette 1 or 2 housed in the cassette transfer unit 10 to a specified recording/playback unit 13, it loads the large cassette 1 or small cassette 2 into the designated recording/playback unit 13 from the inlet 13a using the adaptor 14 in the arrow c direction to record or playback the large cassette 1 or small cassette 2. However, the large cassette 1 or small cassette 2 after completion of recording or playback by the recording/playback unit 13 is unloaded in the arrow c′ direction using the adaptor 14 and received by the cassette transfer unit 10 and returned to the original address in the reverse to the above sequence. By repeating the above operation continuously, long-time continuous video playback, image recording, etc. are possible. In addition, such a method to distinguish the length of the recording/playback time by the sizes of the large and small cassettes 1 and 2 can be used so that short-term commercials or other programs can be televised using the small cassette 2, while televising news or various long-term programs can use the large cassette 1. Next, referring to Figures 3 to 14, the rack 3 holding both large and small cassettes is described in detail. As shown in Figures 3, 4, and 8, the rack plate 19 is installed horizontally above the rack chassis 18 made of a metal plate, a pair of right and left large-cassette guide plates 20 are vertically installed on both right and left sides of the rack plate 19. A rack chassis 18 right above the above-mentioned rack chassis is installed nearly above both the large-cassette guide plates 20, and a cassette-housing unit (space) 21 is formed by these rack plates 19, both large cassette guide plates 20, and the above rack chassis 18. Front and rear ends of the cassette-housing unit 21 from the openings 21a and 21b, respectively. At the bottom of the cassette-housing unit 21, a pair of small-cassette guides 22 are installed in parallel and with symmetry on the right and left sides. Both small-cassette guides 22 are rail-like, having guide surfaces 22a in parallel with each other and slanted surfaces 22b and 22c formed at both their ends in the longitudinal direction. These small cassette guides 22 are formed of synthetic resin integrally on the inside of the pair of right and left oscillating plates 23. The outer ends of both oscillating plates 23 are installed on the bracket 24 fitted on the rack chassis 18 by the horizontal fulcrum shaft 25 so as to freely oscillate in the vertical direction (arrow mark d and d′ direction). On the right and left sides of the cassette-housing unit, a pair of detection rollers 26a and 26b (4 in total), for detecting large cassettes, are provided respectively. These detection rollers 26a and 26b are installed to rotate freely to one end of the part of L-shaped rotary arms 28a and 28b, which are installed to rotate freely to the upper part of the right and left sides of the rack chassis 18 through the vertical fulcrum shaft 27a and 27b in the arrow e and e′ directions respectively on the front and rear, 4 in total. The front and rear ends of the pair of right and left cam levers 29 are interconnected between the above-described pairs of front and rear rotary arms 28a and 28b by the pins 30a and 30b so as to rotate freely. The front and rear pairs of rotary arms 28a and 28b and the right and left pair of cam levers 29 form parallel four link mechanisms which oscillate around the fulcrum axes 27a and 27b. A pair of cam drive units 31 are provided integrally above the front and rear ends of the right and left pair of cam levers 29 and a pair of cam followers 32 are provided integrally on the lower surfaces at the front and rear ends of the pair of right and left oscillating plates 23. The cam drive units 31 form a square, the upper end surface 31a is formed level, the cam followers 32 approximately form a crest, and the front and rear sides of the level lower end surface 32a form tapered surface 32b. The pair of right and left cam levers 29 are forced in the f direction by the pair of right and left return springs 33 installed between the rack chassis 18 and the cam lever 29. Thereby the cam follower 32 is pushed upward by the cam driving unit 31, the pair of right and left oscillating plates 23 are pushed up in the arrow d direction, and the pair of right and left small cassette guides 22 are forced from below towards the inside of the cassette-housing unit 21 as shown in Figure 8. The four rotary arms 28a and 28b are forcedly rotated in the direction by the pair of right and left return springs 33 and the four detection rollers 2a and 26b are forced from right and left sides towards the inside of the cassette-housing unit 21. The operation to insert selectively the large and small cassette 1 or 2 into the cassette-housing unit 21 is described below. Figures 4 and 8 show the small cassette 2 is inserted into the cassette-housing unit 21 through the opening 21a on the above-described operator side 12 in the arrow g direction. At this time, as shown in Figure 8, since both the small cassette guides 22 are positioned in the cassette-housing unit 21, the right and left sides 2a of the small cassette 2 are guided by the slanted surface 22b and guide surface 22a of both small cassette guides 22 and inserted precisely to the specified position in the cassette-housing unit 21. When the small cassette 2 is inserted into the cassette-housing unit 21 through the opening 21b from the above-described cassette transfer unit 10 in the g′ direction, they are guided by the slanted surface 22c of both cassette guides 22 and guide surface 22a. Next the large cassette 1 is inserted into the cassette-housing 21 from the opening 21a on the above-described operator side 12 in the g direction. As shown in Figure 5 and 9, when large cassette 1 is inserted into the cassette-housing 21 from the opening 21a side while being guided between the cassette guide plates 20 by a constant distance 1 in the g direction, (which is possible since a guide groove is provided as described later to prevent improper inserting of a cassette), the right and left side surfaces 1a are brought into contact with the pair of right and left detection rollers 26a. Then, as shown in Figure 6, both detection rollers 26a are moved in the e′ direction from the inside to the outside of the cassette-housing 21 against both return springs 33. (The external form of the large cassette 1 is detected by this.) At this time, both rotary arms 28a and 28b are rotated in the e′ direction against both return springs 33 and both cam levers 29 are moved in the f′ direction. Then the four cam driving units 31 are released from below the four cam follower units 32 in the f′ direction. As shown in Figure 10, both oscillating plates 23 rotate in the mark d′ direction by their own weight, and both cassette guides 22 automatically retract from the inside of the cassette-housing unit 21 to the outside downwards. Therefore, both small cassette guides 22 do not interfere with insertion of the large cassette 1. The large cassette 1 is guided between both large cassette guide plates 20, inserted correctly to the specified position in the cassette-housing unit 21. As shown in Figure 7, when the large cassette 1 is inserted into the cassette-housing unit 21 from the above-described cassette transfer unit 10 through the opening 21b in the g′ direction, upon slight insertion of the large cassette 1 into the opening 21b, the external form of the large cassette 1 is detected by the pair of right and left detection rollers 26b on the opening 21b side. Both small cassette guides 22 retract automatically in the d′ direction as shown in Figure 10. To prevent improper inserting of the large cassette 1 by both small cassette guides 22 is described below. As shown in Figures 9 and 11, a pair of right and left guide grooves 35 are provided in parallel with each other opposite the end 22d on the opening 21a side of both small cassette guides 22 on both the right and left sides of the bottom surface 1a of the large cassette 1. Both guide grooves 35 are slightly wider than both small cassette guides 22, so that the front cover 1c side of the large cassette 1 is composed at the open end 35a side and the opposite side is formed at the closed end 35b. The length 2 of both guide grooves 35 is slightly longer than the distance 1 shown in Fig. 5. Figure 11 shows the large cassette 1 is correctly inserted into the cassette-housing unit 21 in the g mark direction. At the insertion starting time point (meaning the distance at which it is inserted by the distance 1 in Figure 5 in the g direction), both guide grooves 35 have been inserted to both small cassette guides 22 from the open end 35a and both small cassette guides 22 guide the large cassette 1 through both guide grooves 35. As shown in Figure 12, when the large cassette 1 is inserted more than the distance 1 as shown in Figure 5 and the detection roller 26a is pushed in the e′ direction on the side surface 1a of the large cassette 1, the small cassette guide 22 retracts from the inside of the guide groove 35 in the d′ direction as described above. Figure 13 shows the large cassette 1 inserted improperly in the g direction, that is upside down. At this time, the front surface 1d of the front cover 1c of the large cassette 1 touches the end 22d of both small cassette guides 22 to prevent the improper insertion of the large cassette in the g direction. Figure 14 shows the large cassette is inserted with its front side in the g direction. The rear end 1e of the large cassette 1 touches the end 22d of both small cassette guides 22 to prevent improper insertion of the large cassette 1 in the g direction. As shown in Figure 15, a cassette ejection means 36 is provided at the center of the rack chassis 18. When the push lever 37 provided for the cassette transfer unit 10 pushes the rack ejection member 38 of the cassette ejection means 36, the large cassette 1 or small cassette 2 held in the large and small cassette-housing rack 3 is ejected from the cassette transfer unit 10. The cassette ejection means 36 is described below referring to Figures 15 and 16. The cassette ejection means 36 comprises a rack ejecting member 38 which is moved from the returning position on the side of the opening 21b of the cassette-housing unit 21 to the forward position on the opening 21a side, first rack member 39 which is installed above the rack chassis 18 in the g and g′ directions so as to freely move and is moved from the returning position on the opening 21b side of the cassette-housing unit 21 towards the forward position on the opening 21a side, second rack member 40 which is installed above the first rack member 39 in the g and g′ directions so as to be move freely, and the third rack member 41 for ejecting the cassette which is installed above the second rack member 40 in the g and g′ direction so as to be moved freely and moved from the returning position on the opening 21a side of the cassette-housing unit 21 exactly opposite the first rack member 39 to the forward position on the opening 21b side. A nearly L-shaped cassette ejecting member 42 is installed so as to rotate freely in the n and n′ directions through the horizontal fulcrum axis 43 above the third rack member 41. This cassette ejection means 36 is incorporated with the first rack and pinion mechanism 48 comprising the first and second racks 44 and 45 provided for the first rack member 39 and second rack member 40, and the first pinion 47 which is engaged between them and installed so as to rotate freely to the specified position above the rack chassis 18 through the vertical installing shaft 46, and the second rack and pinion mechanism 53 comprising the third and fourth racks 49 and 50 provided for the first rack member 39 and third rack member 41 and the second pinion 52 which is engaged between them and is installed to the above of the second rack member 40 so as to rotate freely thorough the installing shaft 51. The first pinion 47 comprises the lower small gear 47a and upper large gear 46b with the small gear 47a inserted into the rectangular opening 39a formed in the first rack 39 and engaged with the first rack 44 formed along one internal edge of the opening 39a. The section of the second rack member 40 is formed in "U" shape approximately, and a pair of guide rails 40a formed in parallel along both edges are fitted into the pair of guide grooves 39b formed in parallel along both upper edges of the first rack member 39. The large gear 47b of the first pinion 47 is engaged with the second rack 45 formed along the inside of the guide rail 40a on one side on the lower surface of the second rack member 40. The second pinion 52 comprises the lower large gear 52a and upper small gear 52b. The large gear 52a is engaged with the third rack 49 formed at a higher position than the rack member 40 along the side engaged on one side of the first rack member 39 and the small gear 52b is engaged with the fourth rack 50 formed along the side edge on one side of the third rack member 41. The guide pin 41a provided on the lower surface of the third rack member 41 is fitted to the guide groove 40b provided in the rack member 40. The cassette ejecting member 42 is positioned at the lower part of the lifting prevention plate 41b provided horizontally at the end of the third rack 41. This cassette ejecting member 42 is provided with a pair of guide pins 42a which are projected on the right and left sides and fitted with the guide groove 59b provided in the shutter 59 and the projection 42b provided on the lower surface. The shutter 59 turns in the arrow q direction when the cassette is housed completely in the cassette-housing unit 21 and causes the cassette ejecting member 42 to turn in the q direction around the fulcrum axis 43. The rack pushing member 38 is formed in a nearly L-shape by the horizontal plate 38a and vertical plate 38b. The horizontal plate 38a is inserted into the chassis 18 and the horizontal notch 39c provided on the lower surface of the first rack member 39 so as to be positioned above the rack chassis 18. The guide grooves 55a and 55b provided respectively in this horizontal plate 38a and first rack member 39 are fitted to the guide pin 54 installed above the rack chassis 18. The guide pin 56 provided on the lower surface of the first rack member 39 is fitted to the guide groove 57 provided in the rack chassis 18. There is a through hole 38C on the vertical plate 38b of the rack pushing member 38 to which the end of the third rack member 41 can be inserted. The rack pushing member 38 is forced towards the arrow g direction by the return spring installed between the rack chassis 18 and the rack pushing member 38. Now the operation of the cassette ejection means 36 is described below. When the rack pushing member 38 is pushed in the g′ direction by the pushing lever 37 provided in the cassette transfer 19, the first rack member 39 moves in the g′ direction and the first pinion 47 is turned in the h direction. By the rotation of the first pinion 47 in the h direction, the second rack member 40 moves in the g direction and resultantly the second pinion 52 is turned in the h direction. By the rotation of the second pinion 52 in the h direction, the third rack member 41 and the cassette ejecting member 42 are moved in the g direction. The large cassette 1 or small cassette 2 housed on the rack board 19 is ejected towards the cassette transfer 10. On the contrary, when the large cassette 1 or small cassette 2 is housed in the large and small cassette-housing rack 3 from the cassette transfer unit 10, the cassette is ejected to the large and small cassette-housing rack 3 by the cassette ejecting arm provided in the cassette transfer unit 10. At this time, the cassette ejecting member 42 and the third rack member 41 are moved in the g′ direction by the cassette and the first rack member 39 is moved in the g direction by the action reverse to the above-described cassette ejection action. In this way, cassettes are handed over between the large and small cassette-housing rack 3 and the cassette transfer unit 10. As the large and small cassette-storage rack 3 according to this invention is composed as described above, large and small cassettes can be selectively enhoused in the same cassette-storage rack. As the small cassette guide can be automatically retracted to the cassette-housing unit when the large cassette is inserted to the cassette-housing unit, the movement of the small cassette-guides can be automatically controlled. Therefore, an operator does not need to retract the small cassette guide by hand every time when inserting a large cassette. Large and small cassettes can then be selectively inserted into the cassette-housing unit very easily and quickly. Since the small cassette guide also serves to prevent improper insertion of a large cassette, a large cassette can always be inserted correctly into the cassette-housing unit. The composition of the cassette transfer unit 10 is described below referring to Figures 17 to 28. As shown in Figure 17, the cassette transfer unit 10 is provided with a cassette-housing unit 15 horizontally, which is composed referring to the large cassette 1. Both ends; 15a and 15b of the cassette-housing unit 15 in the longitudinal direction are open. A pair of right and left cassette transfer means comprising the transfer belt 61 and cassette ejection means 62 are provided respectively above and below the cassette-housing unit 15. The lower pair of right and left transfer belts are stretched between a pair of pulleys 64 installed to the pair of right and left vertical frames 63 so as to rotate freely. As shown in Figure 18, a multiple number of guide rollers 65 installed to the right and left frames 63 so as to rotate freely are arranged in the right and left transfer belt 61. The upper pair of right and left cassette ejection means 62 comprises four 4 push-up rollers 68 installed respectively to the pair of right and left frames 67, eight in total. As shown in Figure 18, these multiple number of push-up rollers 68 are installed to the right and left frames 67 so as to move freely in the vertical direction through the roller arm 69 and forced downwards by the spring 70. A drive shaft 71 to drive the right and left transfer belts 61 at the same time are driven by the motor 72 installed to the frame 63 on one side as shown in Figure 18 through the reduction gear mechanism 73. As shown in Figure 19, in the cassette-housing unit 15, there are pairs of right and left cassette guides 74 and large cassette guides 75, in total four, are provided and the large cassette guide 75 is fixed to the right and left horizontal frame 76 as shown in Figure 20. The pair of right and left small cassette guides 74 are provided with guide surface 74a on the right and left opposing surfaces. These small cassette guides 74 are installed to the fulcrum axis 78 installed horizontally by the bracket 77 on the horizontal frame 76 as shown in Figure 21 so as to rotate freely in the j and j′ directions respectively and is forced to turn in the j′ direction by the return spring 79. As shown in Figure 20, a pair of right and left cam levers 80 are installed on the horizontal frame 76 by the vertical fulcrum axis 81 so as to rotate freely in the t and t′ directions, respectively. As shown in Figure 21, the cam 80a provided at one end of the pair of right and left cam levers 80 controls the projection 74b provided on the lower surface of the pair of right and left small cassette guides 74. As shown in Figures 20 and 23, a plunger solenoid 83 is installed in the middle between the pair of right and left small cassette guides 74 on the horizontal frame 76 and the plunger 83a is interconnected with the other end of the pair of right and left cam levers 81 through a pin 84 and long hole 85. This plunger solenoid 83 is controlled by the control unit 8 according to the information on the cassette size given by the operating program. As shown in Figure 21, a pair of projections 74C provided on the lower surface on the guide surface 74a side of the pair of right and left small cassette guides 74 are inserted below the multiple number of floating-prevention stoppers 86 provided on the horizontal frame 76. The guide driving mechanism 87 to move the small cassette guide 74 comprises a cam lever 80, plunger solenoid 83, return springs 79 and 82, and others. Positioning operation of the large and small cassettes 1 and 2 in the cassette-housing unit 15 of the cassette transfer unit 10 is described below. As shown in Figure 20, when receiving the large cassette 1 or small cassette 2 selectively from the enhousing racks 3 or 5, etc. to the inside of the cassette-housing unit 15 in the k or k′ direction, the large cassette or small cassette 2 selectively inserted from either the front or rear ends 15a or 15b into the cassette-housing unit 15 is placed on the cassette transfer belt 61, transferred on it, pulled into the position shown by the 1-dot or 2-dot line in Figure 20 in the k or k′ direction and housed. At this time, when the large cassette 1 is received, the plunger solenoid 83 is controlled by the controller 8 so that the plunger 83a is moved in the extending direction. As shown in Figure 22, a pair of right and left small cassette guides 74 are turned in the j′ direction by the return spring 79 and retracted to the cassette-housing unit 15. Therefore, the large cassette 1 is guided by the pair of right and left large cassette guides 75 on both its right and left ends 1a, housed in the cassette-housing unit 15, and positioned at the position shown by 1-dot dash line in Figure 20. When the small cassette 2 is received, the plunger solenoid 83 is controlled by the controller 8, and as shown by the solid line in Figure 20, power is supplied to both plunger solenoids 83, and the plunger 83a is retracted in the S direction. Then each pair of right and left cam levers 80 are turned in the arrow t direction against the return spring 82, the projection 74b of each pair of right and left small cassette guides 74 is pushed up by each pair of right and left cams 80a, each pair right and left small cassette guides 74 is turned in the j direction against the return spring 7 as shown in Figure 21, and each pair of right and left small cassette guides 74 are inserted from below into the cassette-housing unit 15. The small cassette 2 inserted from the k and k′ directions into the cassette-housing unit 15 is guided by the guide surface 74a of the pair of right and left small cassettes guide 74 at the right and left both ends 2a, housed into the cassette housing unit 15, and positioned at the position shown by the 2-dot-line in Figure 20. At this time, as shown in Figure 21, the projection 74C of the small cassette guide 74 which was pushed upwards by the cam 80a is pushed from below by the stopper 86, and the position of the small cassette guide 74 is restricted to a horizontal position. The projection 74b of the small cassette guide 74 is completely dislocated on the cam 80a, the small cassette guide 74 does not escape downwards even though load is given from above to the small cassette guide 74 and is kept level. Therefore such a trouble that the small cassette 2 is dislocated on the small cassette guide 74 accidentally so that positioning becomes impossible does not occur at all. A modification is described referring to Figure 24. In this modification, the cassette transfer 10 is provided with the housing unit 89 for the large cassettes only and the housing unit 90 for small cassettes use only in vertical positions so that the large cassette 1 and small cassette 2 are housed respectively in the housing units 89 and 90 for specific use and transferred. As described above, two types of cassettes of different sizes can be transferred by the cassette transfer unit according to this invention. Therefore such an application is also possible that a short-term commercials or other programs is televised using a small cassette or news or other various long-term programs can be televised using the large cassette by one automatic cassette changer. It is very convenient when handling cassettes that length of televising time, etc. can be distinguished by the sizes of the cassettes. The mechanism to correct the cassette direction is described in detail referring to Figures 25 to 28. As shown in Figure 25, a pair of right and left cassette stoppers having cassette receiving surface 91a 91 are provided at the one-sided position 15a at the bottom in the cassette-housing unit 15. These cassette stoppers 91 are installed to the fulcrum pin 92 fixed horizontally to the pair of right and left frames 63 so as to rotate freely in the vertical u and u′ directions and forced by the return spring 93 so as to rotate in the upward u direction. A pair of right and left plunger solenoids 95 are fixed to the pair of right and left frames 63 through the installing plate 94 and the plunger 95a is interconnected with the pair of right and left cassette stoppers 91 through the link 96. The pin 97 projected from the plunger 95a is fitted into the long hole 98 provided on the installing plate 94 and the vertical movement of the cassette stopper 91 is restricted by the restriction of the vertical movement range of the pin 97 by this long hole 98. As shown in Figure 26, four sensors 99a, 99b, 99c and 99d are installed to detect the positions of the large and small cassettes 1 and 2 at four points, two near both ends 15a and 15b in the cassette-housing unit 15 and two on the inner side. These sensors 99a to 99d are photosensors comprising light emitting element 100 and light receiving element 101 respectively as shown in Figure 25. As shown in Figure 26, sensor 102 comprising bar code reading reflection type photosensor is provided at one end 15a in the cassette-housing unit 15. This sensor 102 is guided by a horizontal running guide (not illustrated) perpendicular to the pair of right and left transfer belts 61 to run (reciprocating) between the returning position shown by one-dot dash line and returning position shown by 2-dot dash line. The operation to correct the direction of the large and small cassettes by the cassette direction correction mechanism is described below. When the large and small cassettes 1 and 2 are selectively taken out from the large and small cassette-storage rack 3 into the cassette-housing unit 15 of the cassette transfer unit 10, at the initial stage, as shown in Figure 27, the plunger solenoid 95 is locked due to the applied power supply, the plunger 95a is retracted downwards and locked, the pair of right and left cassette stoppers 91 have been turned in the u′ direction against the return spring 93, and the cassette receiving surfaces 91a have been pulled down below the upper surface of the pair of right and left transfer belts 61. Figure 27 shows large and small cassettes 1 and 2 are selectively pulled into the cassette-housing unit 15 from one end 15a of the cassette-housing unit 15 and the pair of right and left transfer belts 61 have been driven in the w direction by the motor 72 by a speed reducer 73. The large and small cassettes 1 and 2 which were sent out of the housing racks 3 and 5 in the k direction are inserted in one end 15a of the cassette-housing unit 15, interposed from above and below by the pair of right and left transfer belts 61 and multiple number of push-up rollers 68, by the force of the spring 70, and pulled in via the w direction. The sensors 99a and 99b detect the large and small cassettes 1 and 2 in succession. As shown in Figure 25, when the large cassette 1 is pulled into the position shown by the 1-dot dash line and the sensor 99d detects the large cassette 1, or when the small cassette 2 is pulled into the position shown by the solid line and the sensor 99c detects the small cassette 2, power supply to the plunger solenoid 95 is cut off so that locked plunger solenoid 95 is released, the locked plunger 95a is released, the pair of right and left cassette stoppers 91 are turned in the u direction by the return spring 93, and the cassette receiving surface 91a is moved upwards higher than the top surface of the pair of right and left transfer belts 61. At this time, the cassette receiving surface 91a of the stopper 91 becomes vertical. At the same time, the motor is reversely driven, the pair of right and left transfer belts 61 are driven in the w′ direction, and the large and small cassettes 1 and 2 are transferred reversely in the w′ direction. As shown in Figures 18 and 26, the side 103 of the large and small cassettes 1 and 2 which were transferred reversely in the w′ direction come into contact with the vertical cassette receiving surface 91a of the pair of right and left cassette stopper 91 and is stopped. As a result, the inclination of the cassettes as shown by the 2-dot dash line in Figure 26, for instance, is corrected and the large and small cassettes 1 and 2 are positioned correctly. As shown in Figures 18 and 26, when the positioning of the large and small cassettes 1 and 2 between the sensor 99b and 99c is detected by these sensors, the motor 72 is stopped. Then the bar code reading sensor 102 runs in the v direction between the returning position shown by 1-dot dash line and the forward position shown by the 2-dot dash line in Figure 26. The sensor 102 at this time can move at a constant distance G to the side 103 of the large and small cassettes 1 and 2 along the side 103 in complete parallel with it so that the sensor 103 can read the bar codes (not illustrated) provided on the side 103 correctly. Upon completion of bar code reading by the sensor 103, power is supplied to lock the plunge solenoid 95, the plunger 95a is retracted downwards and locked, the pair of right and left cassette stoppers 91 is turned in the u′ direction against the return spring 93 as shown in Figure 27, and their cassette receiving surface 91a is moved again below the top surface of the pair of right and left transfer belts 61. Figure 28 shows the large and small cassettes 1 and 2 are selectively pulled into the cassette-housing unit 15 from the other end 15b of the cassette-housing unit 15 and in this case, the pair of right and left cassette transfer belts 61 are driven in the w′ direction by the motor 72. When the sensor 99d detects the large and small cassettes 1 and 2, the cassette receiving surface 91a of the pair of right and left cassette stopper 91 is moved above the top surface of the pair of right and left transfer belts 61 by the same action as described above, side surface 103 of the large and small cassettes 1 and 2 which were pulled in the w′ direction by the pair of right and left transfer belts 61 touches the cassette receiving surface 91a of the pair of right and left cassette stoppers 91 as shown in Figure 18 and is stopped, so that the inclination of the large and small cassettes 1 and 2 is corrected as described before. In this embodiment, respectively the pairs of right and left cassette transfer means and cassette stoppers are provided. When the width of the cassette transfer means and cassette stoppers in the lateral direction to the width of the cassettes in the lateral direction is sufficiently large, respectively one cassette transfer means and cassette stopper is enough. The cassette transfer device according to this invention is composed as described above and inclination of a cassette which is ejected in the cassette-housing unit of the cassette transfer means from the cassette-housing can be corrected easily. Therefore, when bar codes provided on the side surface of the cassette are read by a sensor reciprocating in the cassette-housing unit, the sensor can be moved at a constant interval from the cassette side surface, along and in parallel to the cassette side surface so that bar codes can be read correctly using a sensor having a narrow depth of focus. Also when sending out a cassette to the recording/playback unit or cassette-housing rack from the cassette-housing unit on the cassette transfer unit, it can be sent out easily and smoothly without inclination. In addition, only a cassette stopper is added making use of the cassette transfer means which is usually provided for the cassette transfer unit and resultantly the structure is simple. 1. Large cassette 2. Small cassette 3. Large and small cassette-storage rack 4. Rack block 5. Rack for small cassette use 6. Rack block 8. Control unit 9. Rack block 10. Cassette transfer unit 11. Transfer route 12. Operator's side (front side) 13. Recording/reproducing unit 14. Cassette loading/discharging adaptor 15. Cassette-housing unit 16. Opening/closing door 18. Rack chassis 19. Rack stay 20. Large cassette guide plate 21. Cassette-housing unit (space) 22. Small cassette guide 23. Oscillating plate 24. Bracket 25. Fulcrum axis 29. Cam lever 31. Cam drive shaft 32. Cam follower 33. Return spring 35. Guide groove 36. Cassette push-out means 37. Pushing lever 38. Rack pushing member 39. First rack member 40. Second rack member 41. Third rack member 42. Cassette push-out member 43. Fulcrum axis 44. First rack 45. Second rack 46. Installing shaft 47. First pinion 48. First rack & pinion mechanism 49. Third rack 50. Fourth rack 51. Installing shaft 52. Second pinion 53. Second rack & pinion mechanism 54. Guide pin 56. Guide pin 57. Guide groove 58. Return spring 59. Shutter 61. Transfer belt 62. Cassette push-up means 63. Vertical frame 64. Pulley 65. Guide roller 67. Frame 68. Push-up roller 69. Roller arm 70. Spring 71. Driving shaft 72. Motor 73. Reduction gear mechanism 74. Small cassette guide 75. Large cassette guide 76. Frame 77. Bracket 78. Fulcrum axis 79. Return spring 80. Cam lever 81. Fulcrum axis 82. Return spring 83. Plunger solenoid 84. Pin 85. Long hole 86. Stopper 87. Guide driving mechanism 89. Enhousing unit for large cassette use 90. Enhousing unit for small cassette use 91. Installing stay 95. Plunger solenoid 96. Link 97. Pin 98. Long hole 100. Light emitting element 101. Light receiving element 102. Sensor 103. Side surface 7a. Rack for insertion use 7b. Rack for discharge use 12a. Rack block row 12b. Rack block row 13a. Cassette inlet 21a. Opening 21b. Opening 22a. Guide surface 22b. Inclined surface 22c. Inclined surface 26a. Detection roller 26b. Detection roller 27a. Fulcrum axis 27b. Fulcrum axis 28a. Rotary arm 28b. Rotary arm 30a. Pin 30b. Pin 31a. Upper end surface 32a. Lower end surface 32b. Tapered surface 2a. Right and end sides 1a. Right and left side surface 1b. Bottom surface 22d. End 1c. Front cover 35a. Opened end 35b. Closed end 1d. Front surface 1e. Rear and surface 47a. Small gear 47b. Large gear 39a. Opening 40a. Guide rail 39b. Guide groove 52. Large gear 52b. Small gear 41a. Guide pin 40b. Guide groove 41b. Lifting prevention plate 59b. Guide groove 42a. Guide pin 42b. Projection 38a. Horizontal plate 38b. Vertical plate 39c. Notch 55a. Guide groove 55b. Guide groove 38c. Through hole 15a. Front end 15b. Rear end 74a. Guide surface 80a. Cam 74b. Projection 83a. Plunger 74c. Projection 91a. Cassette receiving surface 95a. Plunger 99a. Sensor 99b. Sensor 99c. Sensor 99d. Sensor Arrow mark 1. Constant distance 2. Length 3. Interval

Claims: An automatic cassette changer capable of selectively loading any of cassettes of various sizes into a recording and/or playback unit comprising: (a) cassette storage racks (3) for storing said cassettes, each cassette storage rack (3) comprising: first guides (20) for guiding cassettes of a first size to their stored position, and second guides (22) for guiding cassettes of a second size, which differs from said first size, to their stored positions; (b) a cassette transfer unit (10) comprising: a cassette housing unit (15) for carrying said cassettes of the first or the second size, means (37,61,71,72,73) for drawing a cassette from said cassette storage racks (3) and said recording and/or playback unit (13) so as to transfer said cassette (1,2) to said recording and/or playback unit (13) and said cassette storage racks (3) respectively, third guides (75) for guiding both sides of said cassette (1) of the first size, and fourth guides (74) for guiding both sides of said cassette (2) of the second size; (c) a control unit (8) for controlling motions of said cassette transfer unit (10) with information supplied under a predetermined operating program; characterized in that: each of said cassette storage racks (3) further comprises mechanical detection means (26a,26b) for detecting the external form of said cassette of the first size when said cassette is inserted in the cassette housing unit, control means (28a,28b,31) interlocked with said detection means so that said second guides (22) are retracted under or elevated above the surface of the cassette stay upon insertion of said cassette of the first size or second size respectively; and, the said cassette transfer unit (10) further comprises drive means (87) for moving said fourth guides (74), upon control signals from the control unit (8), from the inside to the outside of the cassette housing unit (15) and vice versa upon transfer of said cassette of the first size or the second size respectively. An automatic cassette changer according to claim 1, characterized in that said cassette transfer unit (10) has solenoid operated plungers (83) for moving said fourth guides (74) by being controlled by said control unit (8). An automatic cassette changer according to claim 1 or claim 2, characterized in that said means (37, 61, 71, 72, 73) for drawing a cassette from said cassette storage racks (3) in said recording and/or playback unit (13) comprise a pair of transfer belts (61). An automatic cassette changer according to claim 3, characterized by a sensor (102) movable perpendicularly to the travel direction of said pair of transfer belts (61) to read the bar code on a label that is stuck to said cassette (1, 2).

Inventors: IIDA OSAMU, INOUE YASUO, SATO KEIJI, TAKEDA HARUO, YAMAZAKI NORIYUKI, IIDA,, OSAMU, INOUE, YASUO, SATO, KEIJI, TAKEDA, HARUO, YAMAZAKI, NORIYUKI
Applicants: SONY CORP, SONY CORPORATION
Application year: 1989
Main classification: G11B25
IPC codes: G11B25, G11B15