APPARATUS FOR REPRODUCING RECORDING MEDIUM

Abstract: Even if a recorded medium is exchanged during the reproduction of another recorded medium, the contents of the exchange work can be confirmed easily. A stocker accommodates a plurality of recorded medium carriers each holding a recorded medium. A first transport unit transports a recorded medium carrier between the outside of an apparatus housing and the stocker. A second transport unit transports a recorded medium between the stocker and a reproduction unit. The stocker is moved up and down in order to align the position of the recorded medium carrier with the first or second transport unit. While a recorded medium carrier is transported from the outside of the housing to the stocker, light emitting and receiving elements detect a presence/absence of a recorded medium. A control unit stores information of a presence/absence of a recorded medium at each stage of the stocker, and displays the contents of the information on a display unit.

Description: Technical Field of the Invention The present invention relates to a recorded medium reproducing apparatus having a recorded medium exchanger, and more particularly to display means for displaying information of a presence/absence of a recorded medium in a recorded medium stocker of a recorded medium reproducing apparatus which can exchange a recorded medium even during the reproduction of another recorded medium. Related Background Art As a conventional recorded medium reproducing apparatus having a recorded medium exchanger, a disk reproducing apparatus such as shown in Fig. 26 disclosed in Japanese Patent Laid-open Publication No. 4-38673 is known in which a stocker houses a plurality of carriers each capable of placing a disk thereon and is raised or lowered by stocker transport means to a height at which a desired carrier is pulled out by a tray. Namely, the stocker is moved by a distance corresponding to the number of shelves for housing carriers. The tray is transported between a load position shown in Figs. 26(a) and 26(b) and an eject position shown in Figs. 26(c). As shown in Fig. 26(a), the carrier having a desired disk placed thereon is pulled out on the tray at the load position, and the disk is clamped by clamping means to reproduce the disk as shown in Fig. 26(b). As the tray with the carrier moves from the position shown in Fig. 26(a) to the position shown in Fig. 26(c), the carrier on the tray is exposed to the outside of the apparatus housing. In this state, the disk on the carrier is exchanged or a new disk is placed on the carrier. As the tray with the carrier moves from the position shown in Fig. 26(c) to the position shown in Fig. 26(a) and the carrier on the tray is moved back to the stocker, the disk can be exchanged or a new disk can be added to the apparatus. This disk reproducing apparatus is advantageous over a conventional disk reproducing apparatus with an exchanger in that a disk magazine is not used. The disk magazine is expensive, and if it is dismounted from the apparatus and placed at a different position, it takes some time to locate this disk magazine. This is inconvenient to use. However, this disk reproducing apparatus disclosed in the above-described Japanese Patent Laid-open Publication No. 4-38673 has only one means for pulling a carrier out of the stocker. Therefore, a disk in the stocker cannot be exchanged during the reproduction when the carrier is at the position of reproducing means. Fig. 27 shows a disk reproducing apparatus disclosed in Japanese Patent Laid-open Publication No. 3-71432 which can exchange a disk even during the reproduction of another disk. This disk reproducing apparatus is of a so-called carousel type. A tray 126 shown in Fig. 27 is driven by a motor and moved into and out of a reproducing apparatus main body 128 in the arrow direction A. A rotary table 130 is rotatively mounted on the tray to be driven by a motor in the arrow direction B. A plurality of disk holders 134 are formed on the rotary table 130 so as to hold disks 101 around the rotation center 132. Each disk holder 134 has a 12 cm CD groove 134a and an 8 cm CD groove 134b. The bottom of the disk holder 134 is inclined in the rotation direction so as to hold a disk in a slanted state. An opening 136 is formed in the disk holder 134 in the radial direction of the rotary table 130 so as to insert therethrough a turn table and a reproduction head. An opening 138 is formed in the tray 126 at the center back end thereof so as to communicate with the opening 136 of each disk holder 134. During the reproduction, the turntable and reproduction head are inserted into these openings 138 and 136. A subsidiary chassis 142 is supported under the tray at the center back of a mechanical chassis 140 of the reproducing apparatus main body 128 by a pivot shaft 144 which is pivoted in the arrow direction C by a motor. The subsidiary chassis 142 is mounted with the turntable 172 and an unrepresented reproduction head. A disk clamper 1466 is fixedly mounted on the mechanical chassis, facing the turntable 172 over the tray 126. As the subsidiary chassis 142 pivots upward while the tray 126 is housed in the reproduction apparatus main body 128, the turntable 172 and reproduction head rise and are inserted into the opening 136 of the disk holder 134. Therefore, the disk 101 is placed on the turntable 172, raised above the disk holder 134, and clamped by the disk clamper 146. In this state, the disk can be reproduced by the reproduction head. As the subsidiary chassis 142 pivots downward while the tray 126 is housed in the reproduction apparatus main body 128, the disk 101 is placed again on the disk holder 134 and the turntable 172 and reproduction head are retracted from the opening 136. Upon a disk ejection operation in the reproduction state, the turntable 172 and reproduction head are retracted from the openings 136 and 138 in the horizontal direction. Therefore, while the reproduction continues, the tray 126 can be pulled out of the reproduction apparatus main body and disks can be exchanged. A presence/absence of a disk on the tray can be detected by a signal from an optical pickup of the reproduction head. Specifically, after the tray 126 is housed in the reproduction apparatus main body 128 and the height of the optical pickup is adjusted so that light from the optical pickup can be focussed on the surface of the disk at some position, the tray 126 is rotated. A focus error signal of the optical pickup takes a zero value when light is focussed on the surface of the disk. Therefore, by checking the waveform of the focus error signal, information of a presence/absence of a disk on the disk holder 134 can be obtained. With this disk reproducing apparatus, even if a disk is exchanged or dismounted by opening the tray 126 during the reproduction, information of whether a disk was placed on or dismounted from a disk holder 134 cannot be displayed on a display device because the tray cannot be rotated during the reproduction even if the tray 126 is again closed. Since an "exchange or dismount work of a disk during the reproduction" cannot be displayed on a "display device", a user is required to perform cumbersome operations in order to confirm the contents of the work of opening the tray during the reproduction and exchanging or dismounting a disk. Namely, a user is required either (1) to "interrupt the reproduction, to rotate a corresponding disk holder to the reproduction position, and to confirm a presence/absence of a disk by using a pickup" or (2) to "visually confirm by opening the tray". This Japanese Patent Laid-open Publication No. 3-71432 discloses the structure that "a light emitting element and a light receiving element are mounted on the tray, facing the disk holder". Also with this structure, the disk holder cannot be rotated after the disk is exchanged and the tray is closed, so that a presence/absence of a disk cannot be confirmed. The disk holder cannot be rotated because the disk holder collides with the reproduction unit during the reproduction. Therefore, the contents of a disk exchange or dismount work during the reproduction cannot be displayed immediately on a display device. Although it is possible to make the contents of the exchange or dismount work be displayed on the "display device", achieving this configuration is very cumbersome and the control system thereof becomes complicated. Specifically, in order to achieve this configuration, it is necessary to rotate the disk holder after a user exchanges or dismounts a disk and before the tray is closed, and to close the tray after the check operation is performed during the rotation". More specifically: (3) A new key is required for instructing to "rotate the disk holder before the tray is closed". In this case, a user is required to operate the instruction key, and after it is confirmed that the work contents are displayed on the display device, the user is required to depress a close key. These operations are cumbersome. (4) The close key may be used also as the key for instructing to "rotate the disk holder before the tray is closed". In this case, however, even if the close key is operated, the tray cannot be closed until the disk holder stops rotating. This makes the apparatus not easy to use. (5) In both the cases (3) and (4), it is necessary to consider the "disk holder on which a presently reproduced disk is to be placed". Specifically, during the check operation while the disk holder is rotated, the "disk holder on which a presently reproduced disk is to be placed" is also checked and it is judged as an "absence of a disk" since this disk holder has no disk. Therefore, an indication is made to the effect that the disk holder for the presently reproduced disk has no disk. In order to avoid this, complicated control becomes necessary so as to memorize the position of this disk holder and not to change the contents displayed on the display device. An alternative configuration of the carousel type that "light emitting elements and light receiving elements are provided at the positions of all disk holders of the tray" may be thought of. In this case, however, the number of light emitting and receiving elements increases and manufacture cost rises. Since a number of components requiring interconnection wires are required to be mounted on the tray which moves by a large distance, the structure becomes complicated and assembly works may be greatly obstructed. Namely, in a conventional disk reproducing apparatus of the carousel type, it is practically impossible to "immediately display on the display device the contents of a disk exchange or dismount work performed during the reproduction". Document EP 0 541 208 A discloses a recorded medium reproducing apparatus according to the preamble of claim 1. The invention has been made under the above circumstances. It is an object of the present invention to provide a recorded medium reproducing apparatus capable of immediately confirming the contents of a recorded medium exchange or dismount work performed during the reproduction. A recorded medium reproducing apparatus according to the invention comprises the features of claim 1. A display method for a recorded medium reproducing apparatus according to the invention comprises the features of claim 3. The recorded medium reproducing apparatus may comprise a recorded medium carrier with a recorded medium placing part, wherein the stocker accommodates the recorded medium carrier, and the first or second transport means transports the recorded medium carrier. According to the recorded medium reproducing apparatus of this invention, even while a recorded medium transported by the second transport means from the stocker to the recorded medium reproducing means is reproduced, a recording medium can be exchanged or dismounted by position aligning a desired recorded medium carrier with the position of the first transport means by the positioning means and by transporting the recorded medium carrier between the inside of the stocker and the outside of the housing. During the recorded medium exchange work, while the first transport means transports a recorded medium from the outside of the housing to the inside of the stocker, a presence/absence of a recorded medium on the recorded medium carrier at the position of the first transport means can be immediately displayed on the display unit in accordance with the information detected by the recorded medium detecting means. The structure that a recorded medium is transported by using the recorded medium carrier with the recorded medium placing part, can realize easily recording medium engaging means for the first and second transport means. In the rest of the description the subject-matter disclosed in Figures 22(a) - 22(c) and 24(a) - 24(e) and the related description, mentioned as related art, does not fall under the scope of protection of the claims and is disclosed in EP 0 709 841 A, which is an Article 54(3) EPC prior art. Brief Description of The Drawings Fig. 1 is a broken perspective view showing part of a recorded medium reproducing apparatus according to an embodiment of the invention. Fig. 2 is a broken perspective view showing part of the recorded medium reproducing apparatus according to the embodiment of the invention. Fig. 3 is a broken perspective view showing part of the recorded medium reproducing apparatus according to the embodiment of the invention. Fig. 4 is a broken perspective view showing part of the recorded medium reproducing apparatus according to the embodiment of the invention. Fig. 5 is a cross sectional view showing part of the recorded medium reproducing apparatus according to the embodiment of the invention, the cross section being stepwise so as to take the view along the centers of a stocker cover 6 and a disk position detecting member 26. Fig. 6 is a cross sectional view showing another state of the portion shown in Fig. 5. Fig. 7 is a plan view showing part of the recorded medium reproducing apparatus according to the embodiment of the invention. Fig. 8 is a plan view showing another state of the portion shown in Fig. 7. Fig. 9 is a plan view partially broken showing part of the recorded medium reproducing apparatus according to the embodiment of the invention. Fig. 10 is a plan view showing another state of the portion shown in Fig. 9. Fig. 11 is a plan view showing another state of the portion shown in Fig. 9. Fig. 12(a) is a plan view showing part of the recorded medium reproducing apparatus according to the embodiment of the invention, and Fig. 12(b) is a side view showing the part shown in Fig. 12(a). Figs. 13(a) to 13(c) are partial side views illustrating the operation of the recorded medium reproducing apparatus according to the embodiment of the invention. Figs. 14(a) and 14(b) are partial plan views illustrating the operation of the recorded medium reproducing apparatus according to the embodiment of the invention, Fig. 14(c) is a cross sectional view taken along line C-C of Fig. 14(a), Fig. 14(d) shows the details of a D portion shown in Fig. 14(a), and Fig. 14(e) shows the details of an E portion shown in Fig. 14(b). Fig. 15 is a cross sectional view taken along the centers of gears, illustrating a meshing relationship between gears of the recorded medium reproducing apparatus according to the embodiment of the invention. Fig. 16(a) is a plan view showing part of the recorded medium reproducing apparatus according to the embodiment of the invention, Fig. 16(b) a plan view showing another part of the recorded medium reproducing apparatus in the state shown in Fig. 16(a), and Fig. 16(c) is a cross sectional view taken along line C-C of Fig. 16(b). Figs. 17(a) to 17(c) are diagrams showing another state of the part shown in Fig. 16. Figs. 18(a) to 18(c) are diagrams showing another state of the part shown in Fig. 16. Figs. 19(a) to 19(h) are charts illustrating the operation of the recorded medium reproducing apparatus according to the embodiment of the invention. Fig. 20(a) is a schematic diagram showing the structure of the recorded medium reproducing apparatus according to the embodiment of the invention, Fig. 20(b) is a schematic diagram showing the partial outline structure of the recorded medium reproducing apparatus, and Fig. 20(c) is a diagram showing another state of the part shown in Fig. 20(b). Fig. 21 is a block diagram of a control unit of the recorded medium reproducing apparatus according to the embodiment of the invention. Fig. 22(a) is a plan view showing the structure of a carrier of the recorded medium reproducing apparatus, Fig. 22(b) shows a waveform of a signal from a light receiving element obtained when the carrier of the recorded medium reproducing apparatus traverses light fluxes from a light emitting element, and Fig. 22(c) is a circuit diagram showing interconnection between the light emitting and receiving elements of the recorded medium reproducing apparatus, these figures disclosing related art. Fig. 23(a) is a plan view showing the structure of a carrier of the recorded medium reproducing apparatus according to the invention, and Fig. 23(b) shows a waveform of a signal from a light receiving element obtained when the carrier of the recorded medium reproducing apparatus traverses light fluxes from a light emitting element. Figs. 24(a) to 24(e) show examples of displays of a display device of a recorded medium reproducing apparatus, these figures disclosing related art. Figs. 25(a) to 25(f) show examples of displays of a display device of the recorded medium reproducing apparatus according to the invention. Figs. 26(a) to 26 (c) are schematic diagrams showing the structure of a conventional recorded medium reproducing apparatus. Fig. 27 is a perspective view of another example of a conventional recorded medium reproducing apparatus. Description of The Embodiments Recorded medium reproducing apparatus according to the embodiments of the invention will be described with reference to the accompanying drawings. First, with reference to Figs. 20(a) to 20(c), the outline of the recorded medium reproducing apparatus of the embodiments will be described. Obviously, as a recorded medium, various types of media can be used. In the following embodiments, a compact disk (merely called a disk) is used as a recorded medium. A carrier for carrying a disk is housed in a shelf at each stage (in the embodiment, six stages) of a stocker 21 disposed in a housing. First transport means transports a disk between the inside of the stocker 21 and the outside of the housing, and second transport means transports a disk between the inside of the housing and reproducing means. As the first transport means transports a carrier to the inside of the housing, a presence/absence of a disk is detected by a light emitting unit and a light receiving unit, and a presence/absence of a disk at the corresponding stage of the stocker 21. The first and second transport means are not driven in an up/down direction. The stocker 21 is moved up and down in order to align a desired disk with a pull-out height of the first or second transport means. As shown in Fig. 20(a), the first transport means is disposed lower than the second transport by one stage of disk in the stocker 21. Fig. 20(b) shows the state wherein the stocker 21 is moved to the lowest position. In this state, the first transport means couples to the uppermost disk, and the second transport means is at the position corresponding to an upper space of the stocker 21. Fig. 20(c) shows the state wherein the stocker 21 is moved to the highest position. In this state, the second transport means couples to the lowermost disk, and the first transport means is at the position corresponding to a lower space of the stocker 21. Although the stocker 21 has six stages of shelves for housing disks, it is driven by a stroke corresponding to seven stages of disks. Reproducing means is driven in an up/down direction. As a disk is transported by the second transport means to a reproducing position, the reproducing means rises to clamp the disk between a turntable and a clamper Then, the disk is rotated to reproduce it. In order to confirm a normal position of disks in the stocker 21, a disk position detecting member 26 is provided being inserted into the center holes of disks in the stocker 21, this member 26 being movable up and down and always energized upward by the force of a spring. The up/down stroke of the disk position detecting member 26 corresponds to two stages of disk. When the disk position detecting member 26 is at the lower position, the disk to be transported by the first or second transport means does not interfere with the disk position detecting member 26. After the disk is transported into the stocker 21 by the first or second transport means, the disk position detecting member 26 rises. Disks not inserted with the disk position detecting member 26 are inserted by a member fixed at the higher position than the disk position detecting member 26. A second motor drives the second transport means and stocker moving means, and a first motor drives the first transport means and disk clamping means of the disk reproducing means. The rotation force of the second motor is switched between the second transport means and the stocker moving means. The first transport means pulls a disk out of the stocker 21 in the direction opposite to the disk reproducing means. Therefore, irrespective of whether the disk reproducing means holds a disk or not, disks in the stocker 21 can be exchanged or a new disk can be added to the stocker 21. Next, with reference to Figs. 1 to 19, the details of the embodiment will be described. Figs. 1 to 4 are broken perspective views showing parts of a disk reproducing apparatus according to an embodiment of the invention. The positive directions of X-, Y-, and Z-axes shown in Fig. 1 are called in the following description, back, right, and up directions, respectively. The relative postures of each component shown in Figs. 2 to 4 are the same as those shown in Fig. 1. A main chassis 1 shown in Fig. 1 supports all components shown in Figs. 1 to 4. A right side chassis 2 is fixed to the right side of the main chassis 1. A gear train support member 3 and a guide plate 4 are fixed to the right side chassis 2. A first motor 7 is fixedly mounted on the gear train support member 3. The gear train support member 3 supports a transmission mechanism constituted of belts and idler gears. The transmission mechanism transmits a rotation force of the first motor 7 to a gear 8 supported by the gear train support member 3. A clamper support member 5 is fixed to the upper back surface of the main chassis 1 and holds a clamper 10 rotatively. A guide groove 5a for guiding a carrier 20 shown in Fig. 2 is formed in the left side inner wall of the clamper support member 5. Switches SW2, and SW4 to SW9 are mounted on a switch board 12 which is fixed to the bottom surface of the main chassis 1. A stocker cover 6 for covering the upper portion of the stocker 21 shown in Fig. 2 is fixed to the upper front surface of the main chassis 1. The positional relationship between the stocker cover 6 and stocker 21 is detailed in Figs. 5 and 6. Fig. 5 is a cross sectional view showing the state that all carriers 20 are housed in the stocker 21. Fig. 6 is a cross sectional view showing the state that a carrier 20 is partially pulled out of the stocker 21. As shown, a switch activating rod 11 is supported movably up and down by a cylindrical portion 6a extending downward from the central area of the stocker cover 6. A switch SW10 is fixed to the stocker cover 6 via a board, facing the switch activating rod 11. At the right front of the stocker cover 6, a stopper rod 6b is provided at the position corresponding to a hole 21c of the stocker 21 shown in Fig. 2. The height of the lower end of the stopper rod 6b is generally flush with the height of the lower end of the cylindrical portion 6a. A stopper portion 6c is provided at the lower front of the stocker cover 6. A light receiving element 74 is mounted via a board on the stopper cover 6. A light emitting element 73 projecting light toward the light receiving element 74 is mounted via a substrate on the main chassis 1. As detailed in Fig. 14(c), a loading slider 9 engages with a guide plate 4 and is supported by the guide plate 4 to become capable of sliding back and forth. At the lower left side of the loading slider 9, a rack 9a is mounted which meshes with outer teeth 52a of an inner teeth gear 52 shown in Figs. 4 and 15. The rack 9a meshes with the inner teeth gear 52 so that the loading slider 9 is driven in back and forth directions upon rotation of the inner teeth gear 52. As shown in Fig. 14(a), projections 13a, 13a of a switch activating slider 13 engage with elongated holes 1s, is of the main chassis 1. The switch activating slider 13 is supported movably right and left by the main chassis 1. As shown in Figs. 14(a), 14(d), 14(b), and 14(e) in detail, the projections 13a of the switch activating slider 13 abut against projections 9b, 9c of the loading slider 9. As shown in Figs. 14(a) and 14(d), as the loading slider 9 moves forward, i.e., toward the carrier housing position, the projection 9b of the loading slider 9 pushes via the projection 13a the switch activating slider 13 to the left to activate the switch SW8. As shown in Figs. 14(b) and 14(e), as the loading slider 9 moves backward, i.e., toward the loading position, the projection 9c of the loading slider 13 pushes via the projection 13a the switch activating slider 13 to the right to activate the switch SW7. While the projection 9b or 9c of the loading slider 9 does not push the projection 13a of the switch activating slider 12, the switch activating slider 13 is at an intermediate position because it is pushed by the switches SW7 and SW8. The carrier 20 shown in Fig. 2 can place thereon a disk with its position being alignment by a large diameter disk recess 20e or small diameter disk recess 20f. A hole 20c is formed at the outer position of the large diameter recess 20e of the carrier 20. This hole 20c is formed at the position corresponding to a hole 21c of the stocker 21 when the carrier 20 is housed in the stocker 21. Therefore, the above-described stopper rod 6b of the stocker cover 6 is inserted into the hole 20c of the carrier 20 via the hole 21c of the stocker 21. Grooves 21a, 21a,... formed in the inner wall of the stocker 21 support the carriers 20, the stocker 21 housing six carriers 20. As stated earlier, the stocker 21 has the hole 21c formed at the position corresponding to the hole 20c of the carrier 20 in the stocker 21. A hole 20h is partially formed in the small diameter disk recess 20f of the carrier 20. As will be later described, this hole 20h allows light from the light emitting element 73 to pass therethrough while the carrier 20 moves from the outside of the housing to the inside of the stocker 21. A plate spring 24 fixed to the stocker 21 shown in Fig. 2 engages with a recess 20g of the carrier 20 to thereby lightly position the carrier 20. A first hook engaging notch 20b of the carrier 20 engages with a first hook 36a of a carrier pull-out member 36 shown in Fig. 3. Therefore, the carrier 20 can be transported by the carrier pull-out member 36 between the stocker 21 and the outside of the housing. A second hook engaging notch 20a of the carrier 20 engages with a second hook 40a of a loading hook 40 shown in Fig. 3. Therefore, the carrier 20 can be transported by the loading hook 40 between the stocker 21 and the reproducing position. The carrier pull-out member 36 and its drive mechanism constitute the first transport means, and the loading hook 40 and its drive mechanism constitute the second transport means. Shafts 21b, 21b of the stocker 21 are fitted in vertical grooves 1a, 1a formed in the main chassis 1. A front plate 22 and a back plate 23 are fixed to the lower portion of the stocker 21. Shafts 22a, 22a are mounted upright on the front plate 22. A shaft 23a is mounted upright on the back plate 23, and a tongue 23b is provided. A guide rod 1c of the main chassis 1 is inserted into an elongated hole 25e of a stocker lift slider 25, and shafts 1r, 1r of the main chassis 1 are inserted into grooves 25b, 25b. Therefore, the stocker lift slider 25 is supported by the main chassis 1 to become capable of sliding right and left. The stocker lift slider 25 is provided with stepwise grooves 25c, 25c,... having seven horizontal portions and a rack 25a. The rack 25a of the stocker lift slider 25 meshes with a gear 56 shown in Figs. 4 and 15. The shafts 22a, 22a of the front plate 22 and the shaft 23a of the back plate 23 are inserted into the stepwise grooves 25c, 25c,.... Specifically, as the gear 56 rotates, the stocker lift slider 25 moves to make the stocker 21 move up and down. The stocker lift slider 25 and its drive mechanism constitute stocker transport means. When the stocker 21 is at the home position which is the lowest position, the tongue 23b activates the switch SW2. In this state, the carrier 20 on the shelf of the stocker 21 at the uppermost stage is at the position where the carrier 20 is moved to the outside of the housing by the carrier pull-out member 36. Whether there is a carrier 20 at the position (in this case, on the shelf at the uppermost stage) corresponding to the carrier pull-out member 36 can be detected by the switch SW9 to be later described. Also in this state, a loading hook 40 is at the upper space over the uppermost stage. A switch activating arm 28 is supported rotatively via its hole 28a by a shaft 1g of the main chassis 1. The right side end of the switch activating arm 28 abuts against the switch SW6. The switch activating arm 28 is pushed by the switch SW6 and energized in the counter-clockwise direction. A projection 28b of the switch activating arm 28 is at the position corresponding to holes 25d, 25d,... of the stocker lift slider 25. As the stocker lift slider 25 moves and each time it passes near the hole 25d, the projection 28b enters the hole 25d so that the switch activating arm 28 swings. The switch SW6 turns on and off each time the stocker lift slider 25 passes near the hole 25d. A pitch between the holes 25d and 25d is equal to a motion distance of the carrier by one stage. The position of the stocker 21 at the lowermost position is represented by "0", and while the stocker 21 is raised, the stocker position is counted up each time the switch SW6 turns on and off, whereas while the stocker 21 is lowered, the stocker position is counted down each time the switch SW6 turns on and off. In this manner, a control circuit can store the position of the stocker 21. The stocker can be raised to a height corresponding to seven shelf stages from the home position. When the stocker is at the uppermost position, the lowermost shelf is at the position where a carrier can be pulled into and out of the stocker by the loading hook 40. Specifically, the carrier pull-out member 36 is at the lower space under the lowermost shelf. As described earlier, in order to temporarily stop the stocker when the shelf at each stage of the stocker is at the height position corresponding to the loading hook 40 and carrier pull-out member 36, the seven horizontal portions are formed on the stepwise groove 25c of the stocker lift slider 25. The disk position detecting member 26 has rod-like protrusions 26a and 26b whose insides are hollow portions opening at the bottoms. The guide rods 1c and 1d of the main chassis 1 shown in Fig. 1 engage with the hollow portions of the rod-like protrusions 26a and 26b so that the disk position detecting member 26 can move up and down. A compression coil spring 27 squeezed between the main chassis 1 and disk position detecting member 26 energizes upward the disk position detecting member 26. A recess 58a formed at the end portion of an arm 58 shown in Fig. 4 couples to the base portion of the rod-like protrusion 26a of the disk position detecting member 26. The arm 58 makes the disk position detecting member 26 move up and down. Fig. 5 shows the state that the disk position detecting member 26 is at the raised position, and Fig. 6 shows the state that the disk position detecting member 26 is at the lowered position. As the disk position detecting member 26 rises, the switch activating rod 11 activates the switch SW10. The rod-like protrusion 26a is inserted into the center holes of disks in the stocker 21, and the rod-like protrusion 26b is inserted into the holes 20c of the carriers 20 in the stocker 21. A switch activating arm 29 shown in Figs. 2, 5, and 6 is rotatively supported via its shaft 29a by a boss 1h formed on the main chassis 1 at the central bottom surface on the slightly right side thereof, the lower back portion of the switch activating arm 29 abutting against the switch SW9 and being energized by this switch SW9. A protrusion 29b of the switch activating arm 29 is at the position corresponding to the stage where the carrier pull-out member 36 pulls out the carrier 20, and is in contact with the back portion of the carrier 20 at this position. The switch activating arm 29 therefore rotates when the carrier 20 is pulled out of the stocker or moved back to the stocker, and turns on and off the switch SW9 which detects that the carrier 20 is moved back to the stocker 21 by the carrier pull-out member 36. The switch SW9 also detects whether there is a carrier at the stage where the carrier pull-out member 36 operates. A switch holding member 38 shown in Fig. 3 is fixed in such a manner that a channel-shaped projection 38b formed on the bottom of the member 38 is fitted in a channel-shaped recess 2d formed on the front portion of the right side chassis 2 shown in Fig. 1. A slider tray 31 is supported by the main chassis 1 and switch holding member 38 to become capable of sliding back and forth. Specifically, the projection 38a of the switch holding member 38 engages with a groove 31d formed in the right side wall of the slider tray 31, and a projection lj formed in the left side wall of the main chassis 1 engages with a groove 31e formed in the left side wall of the slider tray 31. The positional relationship between the slider tray 31 and stocker 21 is shown in Figs. 7 and 8. Fig. 7 shows the state that the carrier 20 is in the housing, and Fig. 8 shows the state that the carrier is out of the housing. As shown, the slider tray 31 is formed and disposed so as to sandwich the stocker between the right and left sides thereof. Therefore, the slider tray 31 can form therein grooves 31e and 31d serving as a support portion long in the right and left direction. The stocker can therefore be supported stably to become capable of sliding back and forth, and as will be later described, a main slider 34 and carrier pull-out member 36 can be stably supported. Furthermore, since the slider tray 31 accommodated in the housing surrounds the stocker 21 when the slider 31 is accommodated in the housing, a stroke of the slider tray 31 can be made large in a narrow space so that the carrier 20 can be pulled out a long distance. An operating piece of the switch SW3 fixed to the switch holding member 38 is pushed to the right side surface of the slider tray 31, when the slider tray 31 is accommodated in the housing as shown in Fig. 7 or while it is transported during a motion stroke to the outside of the housing (to the front direction). As shown in Fig. 8, at the end of the motion stroke of the slider tray 31 to the outside of the housing, a slanted back portion 31c of the slider tray 31 faces the operating piece of the switch SW3 to release the pressure of the operating piece. Namely, the switch SW3 detects the open position of the slider tray 31. A guide plate 33 shown in Fig. 3 is fixed to the bottom of the slider tray 31. The guide plate 33 and slider tray 31 support the guide plate 33 and slider tray 31 to be made capable of moving back and forth, by sandwiching the guide plate 33 and slider tray 31. A rack 34a is formed on the bottom of the main slider 34 in the back and forth direction. The rack 34a meshes with the gear 8 shown in Fig. 1. Therefore, as the first motor 7 rotates in the normal and reverse directions, the main slider 34 moves back and forth. The main slider 34 moves the slider tray 31 and carrier pull-out member 36 and rotates a gear 62 shown in Figs. 4, 7, and 8. Specifically, as the main slider 34 moves back, the slider tray 31 can be moved to the inside of the housing. The main slider 34 can move back further after the slider tray is moved to the inside of the housing. The main slider 34 moved back further rotates a gear 62 shown in Figs. 4, 7, and 8. The carrier pull-out member 36 shown in Figs. 3 and Figs. 9 to 11 rotatively supports a rotary member 37. The shaft 37a of the rotary member 37 engages with a J-shaped groove 31a of the slider tray 31 and can engage also with a recess 34c of the main slider 34. The slider tray 31 shown in Figs. 3 and Figs. 9 to 11 rotatively supports a rotary member 35. The shaft 35a of the rotary member 35 engages with a J-shaped groove 2a of the right side chassis 2 shown in Fig. 1 and can engage also with a recess 34d of the main slider 34. Figs. 9 to 11 show a change in the relationship of the relative position of the main slider 34, slider tray 31, and carrier pull-out member 36. As shown in Fig. 9, while the main slider 34 moves back, the shaft 37a engages with the right protrusion of the J-shaped groove 31a and does not engage with the recess 34c. Therefore, the main slider 34 does not drive the carrier pull-out member 36. Also in this case, the shaft 35a engages with the right protrusion of the J-shaped groove 2a and does not engage with the recess 34d. Therefore, the main slider 34 does not drive the slider tray 31. Namely, in the state shown in Fig. 9, although the main slider 34 moves, the carrier pull-out member 36 and main slider 34 will not move. As the main slider 34 moves forth to the position shown in Fig. 10, the recess 34c makes the shaft 37a enter therein, the shaft 37a engages with a straight portion of the J-shaped groove 31a, and the carrier pull-out member 36 is driven. In this state, the main slider 34 is not moved as yet. As the main slider 34 moves forth to the position shown in Fig. 11, the recess 34d makes the shaft 35a enter therein, the shaft 35a engages with a straight portion of the J-shaped groove 2a, and the slider carrier pull-out member 36 is driven. The main slider 34 first moves forth to thereafter move forth the slider tray 31 along with the carrier pull-out member 36. As the carrier pull-out member 36 moves forth, the carrier 20 in the stocker 21 is pulled forth to place the end portion thereof on tongues 32a and 32a of a lower plate 32 fixed to the slider tray 31. Fig. 6 shows the state that the carrier 20 is placed on the tongues 32a and 32a of the lower plate 32. As shown in Fig. 6, in the state while the carrier 20 is pulled out of the stocker 21 toward the outside of the housing, a distance C between the disk on the carrier 20 and the stopper portion 6c of the stocker cover 6 is made smaller than the thickness of the disk. In the state that the slider tray 31 is in the housing, the tongues 32a and 32a are fitted in recesses 1f and 1f formed in the upper frame 1e of the main chassis 1 and are near at the carrier 20 in the stocker 21. As the carrier 20 is pulled out in the above manner, recesses 20d and 20d at the top end of the carrier 20 engage with protrusions 31b and 31b of the slider tray 31 so that the right and left positions at the top end of the carrier 20 can be fixed. The rear portion of the carrier 20 is supported by the upper frame 1e of the main chassis 1, and the right and left positions of the carrier 20 are determined by the right and left vertical surfaces of the upper frame le. A shaft 61 shown in Fig. 4 is supported by being fitted in a hole 1p formed in the bottom of the main chassis shown in Fig. 1 and in a hole formed on the left bottom on a slightly back side of a support member 39 shown in Fig. 3. The shaft 61 rotatively supports a cam gear 63 and the gear 62. A protrusion 63a of the cam gear 63 is fitted in a recess 62b of the gear 62 so that the cam gear 63 and gear 62 rotate together. As described previously, the gear 62 is rotated by the main slider 34. Fig. 7 shows the state that the main slider 34 starts rotating the gear 62. As the main slider 34 moves back, its rear end pushes the protrusion 62a of the gear 62 so that the gear 62 rotates and meshes with the rack 34b of the main slider 34. Since the positional relationship between the gear 62 and main slider 34 is constant, the gear 62 smoothly meshes with the rack 34b. The support member 39 show in Fig. 3 is fixed to the right side chassis 2 in such a manner that shafts 2b and 2c of the right side chassis 2 are fitted in holes 39c and 39d of the support member 39. A guide groove is formed in the left side wall of the support member 39 for guiding the carrier 20 together with the guide groove 5a of the clamper holding member 5 described previously with reference to Fig. 1. A rotary member 41 is rotatively supported by the loading hook 40. The shaft 41a of the rotary member 41 engages with the L-shaped groove 39a of a support member 39. The shaft 41b engages with a slanted groove 8d of the loading slider 9 shown in Fig. 1. In the above manner, the loading hook 40 is supported by the support member 39 and loading slider 9 to be movable back and forth. Figs. 12(a) and 12(b) show an assembly state of the support member 39, loading slider 9, loading hook 40, and rotary member 41. Figs. 13(a) to 13(c) show the state that the loading slider 9 drives the loading hook 40. Fig. 13(a) shows the intermediate drive state of the loading hook 40. In this state, the shaft 41a (hidden by the shaft 41b) engages with the horizontal portion of the L-shaped groove 39a, the rotary member 41 does not rotate, and the loading hook 40 moves together with the loading slider 9. Fig. 13(b) shows the state that the shaft 41a engages with the end of the horizontal portion of the L-shaped groove 39a, and Fig. 13(c) shows the state that the loading slider 9 is at the end of the motion stroke. While the loading slider 9 moves from the position shown in Fig. 13(b) to the position shown in Fig. 13(c), the rotary member 41 rotates and the loading hook 40 moves less. Even if the loading slider 9 bounds and the motion position changes, the stop position of the loading hook 40 is stabilized. As described earlier, the second hook engaging notch 20a of the carrier 20 engages with the second hook 40a of the loading hook 40. Therefore, as the loading hook 40 moves back, the carrier 20 in the stocker 21 is pulled out by the loading hook 40. The carrier is guided by the guide groove 5a of the clamper support member 5 previously described with Figs. 1 and 3 and the guide groove 39b of the support member 39, and transported to the position just above the turntable 70a shown in Fig. 4 and Figs. 7 and 8, i.e., to the loading position. As above, since the carrier 20 is guided by the members fixed to the main chassis 1, it does not vibrate during transportation and can be pulled in the guide portions reliably. The carrier 20 is transported between the stocker 21 and turntable 70a as the loading slider 9 moves as in the above manner. The end of the motion stroke of the loading slider 9 is detected by the switches SW7 and SW8 as previously described with Fig. 14. Both the carrier pull-out member 36 and loading hook 40 pull the carrier 20 out of the stocker 21, and the height positions thereof differ by one stage of carrier as shown in Figs. 20 and 6 so that the carrier 20 will not be pulled by both the carrier pull-out member 36 and loading hook 40. A driving gear 51, inner teeth gear 52, and carrier gear 54 shown in Figs. 4 and 15 are rotatively supported by the shaft 1h. The upper and lower ends of the shaft 1h are supported by a hole 1k of the main chassis 1 shown in Fig. 1 and a hole 55a of a holding member 55 fixed to the main chassis 1. The holding member 55 is fixed to the main chassis 1 in such a manner that the hole 55a faces the hole 1k of the main chassis 1. Planetary gears 53, 53 rotatively supported by the shaft of the carrier gear 54 mesh with the inner teeth 52b of the inner teeth gear 52 and a sun gear 51b formed on the driving gear 51. These gears constitute a planetary gear mechanism. A second motor 50 is fixed to a boss 1m of the main chassis 1 shown in Fig. 1. A deceleration mechanism driven by the second motor meshes with a large gear 51a of the driving gear 51 so that the second motor 50 rotatively drives the driving gear 51. A rotation force of the second motor 50 is transmitted to the carrier gear 54 while the inner teeth gear 52 stops and to the inner teeth gear 52 while the carrier gear 54 stops. As described earlier, the outer teeth 52a of the inner teeth gear 52 mesh with the rack 9a of the loading slider 9a (as shown in Fig. 15) to drive the loading slider 9. The carrier gear 54 is coupled to the rack 25a of the stocker lift slider 25 via gears 56 and 57 rotatively supported and sandwiched between the main chassis 1 and holding member 55, to thereby drive the stocker lift slider 25. A slider 59 shown in Fig. 4 and Figs. 16 to 18 is supported at the upper portion of the holding member 55 via a plurality of elongated holes extending in the back and forth directions to become capable of sliding back and forth, and is energized forth by an extension coil spring 72. A cam follower 59b of the slider 59 engages with a protrusion 63a of a cam gear 63, and the slider is driven back and forth by the cam gear 63. A cam-shaped protrusion 59a formed on the bottom of the slider 59 engages with a fringe of an arm 58 rotatively supported by the holding member 55 to rotate the arm 58 as shown in Figs. 16 to 18. Specifically, the main slider 34 raises and lowers the disk position detecting member 26 shown in Fig. 2, and raises it while the carrier 20 is not transported into and from the stocker 21. For example, if an 8-cm disk is accommodated in the stocker 21 of the carrier 20 in a displaced manner, the displaced disk hinders the rise of the disk position detecting member 26 and the switch SW10 does not operate so that displacement of a disk or carrier can be detected. The disk position detecting member 26 is formed to have a lift stroke corresponding to the carriers 20 engaged with the carrier pull-out member 36 and loading hook 40. In other words, the lift stroke of the disk position detecting member 26 corresponds to two stages of carrier. While the disk position detecting member 26 rises, the rod-like protrusions 26a and 26b are inserted into the center holes of disks in the stocker and into the holes 20c of the carriers 20. In this case, the rod-like protrusion 26a abuts against the switch activating rod 11 to activate the switch SW10, whereas the rod-like protrusion 26b abuts against the stopper rod 6b on the back surface of the stopper cover. There is a case wherein while the stocker 21 is raised, the carrier 20 is above the loading hook 40. In this case, because of the lift stroke of the disk position detecting member 26, the rod-like protrusion 26a is not inserted into the center holes of disks above the loading hook 40, and the rod-like protrusion 26a is not inserted into the holes 20c of the carriers 20. In such a case, however, as shown in Fig. 5, the cylindrical portion 6a is inserted into the center holes of disks above the loading hook 40, and the stopper rod 6b on the back surface of the stocker cover is inserted into the holes 20c of the carriers 20. Therefore, irrespective of the position of the stocker 21, even if vibration is applied while the disk position detecting member 26 rises, the carrier 20 and the disk on the carrier will not be displaced. As shown in Fig. 6, as the disk position detecting member 26 lowers, the carrier 20 in the stocker 21 can be pulled out in respective directions by the carrier pull-out member and loading hook 40. Even if vibration is applied while the disk position detecting member 26 lowers, the carrier 20 will not be displaced because the carrier pull-out member 36 and loading hook 40 engage with the carriers 20 at the position where the rod-like protrusion 26b is not present. If tapers are provided at the top ends of the rod-like protrusions 26a and 26b of the disk position detecting member 26, a small position displacement of a disk or carrier can be corrected while the disk position detecting member 26 rises. It is therefore possible to prevent the carrier 20 from contacting the loading hook 40 or carrier pull-out member 36 while the stocker 21 is moved up and down. A brake member 60 shown in Fig. 4 and Figs. 16 to 18 is supported to become capable of sliding back and forth, by being sandwiched between the main chassis 1 and holding member 55. A cam follower 60a of the brake member 60 engages with the cam 63b of the cam gear 63, and the brake member 60 is driven back and forth by the cam gear 63. A protrusion 60b of the brake member 60 stops the carrier gear 54 and a protrusion 60c thereof stops the inner teeth gear 52. As described earlier, while the carrier gear 54 is stopped, the inner teeth gear 52 is rotatively driven, and while the inner teeth gear 52 is stopped, the carrier gear 54 is driven. Therefore, in accordance with a motion of the brake member 60, the transmission destination of the rotation force of the second motor 50 is switched. Specifically, the main slider 34 switches the transmission destination of the second motor 50. The brake member 60, its drive mechanism, and the planetary gear mechanism constitute transmission switching means. The cam gear 63 shown in Fig. 4 and Figs. 16 to 18 meshes with a gear 64 rotatively supported by the chassis 1 on a slightly right back side thereof. The gear 64 meshes with teeth 65a formed on a rotary member 65 rotatively supported by a shaft In of the main chassis 1. The shaft 65c of the rotary member 65 engages with a J-shaped groove 71a of a slider 71 supported at the rear portion of the main chassis 1 to become capable of sliding. A radius of the arc portion of the J-shaped groove 71a is equal to the rotation radius of the shaft 65c so that the slider 71 moves or stops while the rotary member 65 rotates. Shafts 69a, 69a,... of a lift member 69 engage with vertical guide grooves 1b, 1b,... of the main chassis 1 and slanted lift guide grooves 71b, 71b,... of the slider 71. Therefore, the lift member 69 is moved up and down by the main slider 34 via the gear 62 to slider 71. A mechanism chassis 70 is mounted on the lift member 69 by using springs and dampers. A disk motor is fixed to the mechanism chassis 70, and the turntable 70a is fixed to the rotary shaft of the disk motor. An optical pickup 70b is mounted on the mechanism chassis 70 to be fed in the radial direction of the disk placed on the turntable 70a. When the optical pickup 70b is at the home position remotest from the turntable 70a, an unrepresented switch SW1 is activated and the home position of the optical pickup is detected. As the mechanism chassis 70 rises and the turntable 70a rises, the disk on the carrier 20 is clamped by the turntable 70a and clamper 10 and rotatively driven by the disk motor. While the disk rotates, the optical pickup 70b is fed in the radial direction of the disk to reproduce signals recorded in the disk. Components mounted on the mechanism chassis 70, clamper 10, and drive mechanism for the mechanism chassis 70 constitute reproducing means. Levers 66 and 67 shown in Fig. 4 and Figs. 16 to 18 at the position near the rotary member 65 are rotatively supported by the main chassis 1 in such a manner that holes 66a and 67a of the levers engage with the shaft of the main chassis 1. The levers are energized by an extension coil spring 68 and the rear ends thereof abut against the cam 65b of the rotary member 65. The front ends of the levers 66 and 67 abut against the switches SW4 and SW5, respectively. As the rotary member 65 rotates, the levers 66 and 67 swing about the shaft fitted in the holes 66a and 67a. The levers 66 and 67 activate the switches SW4 and SW5. The switch SW4 turns on when the mechanism chassis 70 rises or immediately before it starts lowering, whereas the switch SW5 turns on when the mechanism chassis 70 lowers or immediately before it starts rising. Figs. 16(a) to 16(c) show the state before the cam gear 63 is rotated by the main slider 34. In this state, the disk position detecting member 26 is at the lower position and the inner teeth gear 52 is stopped by the brake member 60. The turntable 70a is at the raised position. The switches SW4 and SW5 are off. Figs. 17(a) to 17(c) show the state that the cam gear 63 is rotated by the main slider 34 to the intermediate position. In this state, the disk position detecting member 26 is at the raised position and the inner teeth gear 52 is stopped by the brake member 60. The turntable 70a is at the raised position. The switch SW4 is on and the switch SW5 is off. Figs. 18(a) to 18(c) show the state that the cam gear 63 is rotated by the main slider to the maximum rotation angle. In this state, the disk position detecting member 26 is at the lower position and the carrier gear 54 is stopped by the brake member 60. The turntable 70a is at the lower position. The switch SW4 is off and the switch SW5 is on. Figs. 19(a) to (h) are chart showing operation timings of each component. The abscissa of each of Figs. 19(a) to 19(h) represents a main slider stroke of the same scale. The motion start point A of the main slider indicates that the main slider is at the most advanced position. The main slider motion end point B indicates that the main slider is at the most retracted position. Figs. 19(b) and 19(c) show the motion periods of the slider tray 31 and carrier 20, respectively. The motion end point C of the slider tray 31 is earlier in time than the motion end point D of the carrier 20. Fig. 19(d) shows the up/down state of the disk position detecting member 26. Fig. 19(e) shows the up/down state of the turntable. The point G of the raised position of the turntable is detected by the switch SW4 as described previously. Fig. 19(f) shows the rotation state of the cam gear 63. Fig. 19(g) shows the rotation enabled state of the components of the planetary gear mechanism. Before the point H, the carrier gear can rotate and after the point J the inner teeth gear can rotate. Fig. 19(h) shows the stocker up/down state and the motion state of the loading slider. Before the carrier gear rotation limit point H, the stocker is moved up and down. The loading slider is driven after the point F when the disk position detecting member 26 is lowered. Next, the operation of the disk reproducing apparatus constructed as above will be described. A control circuit shown in Fig. 21 has a microcomputer, a memory, input/output interface units, a drive circuit, and the like. Signals from operation keys, switches SW1 to SW10, and a reproducing unit are input to the control circuit to drive the first motor 7 (M1) and second motor 50 (M2), to output a play signal to the reproducing unit, to drive the disk motor and a pickup feed motor of the reproducing unit, and to control a display device. The apparatus is controlled by the control circuit in accordance with the operations of the switches SW1 to SW10 and inputs from unrepresented keys mounted on a front panel of the housing. In the initial stage, as shown in Fig. 7, the carrier pull-out member 36 and loading hook 40 are engaged with the carriers 20, 20 of the stocker 21. The main slider 34 is at the position just before it departs from the gear 62 which rotates in the clockwise direction as viewed down. The turntable 70a is at the raised position. The stocker 21 is the lowermost position. The brake member 60 is at the back position as shown in Fig. 16(a) and the protrusion 60c engages with the inner teeth gear 52 to stop it (in this state, the switches SW2, SW4, and SW8 are on, and the switches SW5 and SW7 are off). Therefore, the second motor 50 can rotate only the carrier gear 54. The stocker lift slider 25 is therefore moved by the second motor so that the stocker 21 shown in Figs. 2, 5, and 6 is moved up and down. In this state, the stocker 21 is moved up and down to align the loading hook 40 with the height position of the carrier of a disk to be reproduced so that the disk to be reproduced can be selected. Specifically, the second motor raises the stocker 21, and the counter of the control circuit for storing the stocker position in accordance with on/off of the switch SW6 is counted up starting from "0" to align the height position of the carrier of the disk to be reproduced with that of the loading hook 40. The height position of the carrier 20 for exchanging disks may be aligned with that of the carrier pull-out member 36. First, the disk exchange operation will be described. Disk exchange may be performed at the initial stage. Disk exchange can also be performed in the reproducing state that the loading hook 40 moved the carrier 20 onto the turntable 70a (in this state, the switch SW7 is on and the switch SW8 is off). Specifically, as described earlier, when the main slider 34 is at the position shown in Fig. 7, the turntable 70a is at the raised position. If the carrier 20 is moved onto the turntable 70a by the loading hook 40 before the turntable 70a rises, the disk on the carrier 20 is held by the turntable 70a and clamper 10 and is in the reproducing state. Even if the main slider 34 moves from the position shown in Fig. 7 toward the front side (lower side in Fig. 7), the state of the brake member 60 does not change so that the gear 52 does not rotate without any change in the reproducing state. After the second motor 50 moves the stocker lift slider 25 and moves up and down the stocker 21 to align the height position of the carrier 20, whose disk is to be exchanged, with that of the carrier pull-out member 36, the main slider 34 is moved forward by the first motor 7. At the initial stage of the motion stroke of the main slider 34, the rotary member 35 shown in Fig. 3 rotates in the clockwise direction as viewed down, and its shaft 35a engages with the J-shaped groove 2a of the right side chassis shown in Fig. 9 at the portion perpendicular to the motion direction of the slider tray 31. Therefore, the back and forth motion of the shaft 35a of the rotary member 35 is stopped so that the slider tray 31 supporting the rotary member 35 does not move. Similarly, the carrier pull-out member 36 does not move at the initial stage of the forward stroke of the main slider 34. At the intermediate stage of the forward stroke of the main slider 34, the rotary member 37 shown in Fig. 10 rotates by being guided by the recess 34c of the main slider 34, and the shaft 37a of the rotary member 37 enters the straight portion of the J-shaped groove 31a so that the carrier pull-out member 36 is driven forth. The front end portion of the carrier 20 is transported and placed on the tongues 32a, 32a of the lower plate 31 and supported by the slider tray 31. As the main slider 34 moves further, as shown in Fig. 11 the recess 34d of the main slider 34 engages with the shaft 35a so that the rotary member 35 rotates in the counter-clockwise direction. Then, the shaft 35a engages with the J-shaped groove 2a at the portion extending to the motion direction of the slider tray 31 so that the slider tray 31 becomes movable and the shaft 35a is pushed by the recess 34d. Therefore, the slider tray 31 moves forward, i.e., in the direction of protruding from the housing. Specifically, the slider tray 31 moves from the position shown in Fig. 7 to the position shown in Fig. 8. At this time, the switch SW3 turns off. In the state shown in Fig. 8, the slider tray 31 protrudes from the housing and also the carrier 20 is pulled out together with the slider tray 31 by the carrier pull-out member 36. In the state shown in Fig. 8, the disk on the carrier 20 can be exchanged or a new disk can be placed on the carrier 20. In accommodating the carrier 20 in the stocker 21, the motor 7 is rotated in the reverse direction. In this case, the shaft 35a is guided by the J-shaped groove 2a and the rotary member 35 rotates in the clockwise direction. Therefore, after the slider tray 31 is retracted (which is detected from an on-state of the switch SW4), the main slider 34 can be retracted further. A presence/absence of a disk on the carrier 20 is detected from a signal from the light receiving element 74 which signal is generated when the slider tray 31 is retracted and the carrier 20 is accommodated in the stocker 21. In accordance with this detected information, a control circuit operates to store information of a presence/absence of a disk at each stage of the stocker 21. How a presence/absence of a disk is detected will be described with reference to Figs. 22(a) to 22(c), these figures disclosing related art. Fig. 22(a) shows the configuration of the carrier 20, Fig. 22(b) shows the waveform of a signal from the light receiving element 74 when the carrier 20 traverses light fluxes from the light emitting element 73, and Fig. 22(c) is a circuit diagram showing interconnection between the light emitting and receiving elements 74 and 73. Reference character L in Fig. 22(a) indicates a locus of the carrier transversing light fluxes from the light emitting element 73. As light fluxes are intercepted by the carrier 20 or disk, the light receiving element becomes non-conductive and the signal from the light receiving element 74 becomes "H". If there is no disk on the carrier 20, a signal from the light receiving element 74 becomes "L" when the light fluxes pass through a hole 20h. The signal from the light receiving element 74 in this case is indicated at (1) in Fig. 22(b). If there is a disk on the carrier 20, the signal from the light receiving element 74 becomes "H" over the whole period while the carrier 20 traverses the light fluxes. The signal from the light receiving element 74 in this case is indicated at (2) in Fig. 22(b). A presence/absence of a disk on the carrier 20 can be checked by observing the signal from the light receiving element 74 while the carrier 20 is transported from the outside of the housing to the inside of the stocker 21. The light emitting and receiving elements 73 and 74 may be disposed on the same side of the carrier transport path. In this case, a reflection surface is formed on the tray to detect a presence/absence from reflected light. Reflection is intercepted by a disk, and the signal from the light receiving element 74 is an inverted signal of the signal shown in Fig. 22(b). The state of the carrier 20 in the stocker 21 is shown in Fig. 6. Since the distance C shown in Fig. 6 is shorter than the thickness of a disk, it is possible to prevent two disks on the carrier from being moved into the housing. By repeating the operations of selecting a carrier by moving up and down the stocker and protruding the selected carrier from the housing to exchange disks, disks of all carriers can be exchanged. Next, the operation of reproducing a desired disk on the carrier, starting from the initial stage, will be described. In the initial stage shown in Fig. 7, when a key is entered to instruct to reproduce a disk at an optional stage of the stocker 21, a disk reproduction operation is executed if the disk is present at that stage. In the disk reproduction operation, the stocker is moved up and down to align the carrier 20, whose disk is to be reproduced, with the loading hook 40. Thereafter, the first motor 7 retracts the main slider 34 so that the teeth of the gear 62 mesh with the rack 34b and the gear 62 and cam gear 63 rotate in the counter-clockwise direction. Then, the turntable 71a lowers from its raised position and the brake member 60 moves forth to stop the carrier gear 54. This is detected from an on-state of the switch SW5. This state is shown in Fig. 18(a). While the cam gear 63 rotates from the point D to point B shown in Fig. 19(f), the disk position detecting member 26 rises once and then lowers as shown in Fig. 19(d). The inner teeth gear 52 is therefore rotated by the second motor 50 and the loading slider 9 is moved back. The carrier 20 is moved onto the turntable 70a by the loading slider 9 via the loading hook 40 (this state is detected from an on-state of the switch SW7). Thereafter, by the rotation opposite in the direction to the preceding state of the first motor 7, the main slider 34 is moved forth (toward the position shown in Fig. 7) to the position just before it departs from the gear 62, and the turntable 70a rises to clamp the disk and the reproducing state starts (this state is detected from an on-state of the switch SW4). In this state, the first motor 7 is under the conditions that it moves the main slider 34 so that disks can be exchanged as described above. Namely, with this apparatus, disks can be exchanged during the reproducing state. After the disk reproduction, the disk is moved back to the stocker 21. This operation is performed by rotating the first and second motors 7 and 50 in the directions opposite to those when a disk is mounted on the turntable. Specifically, the main slider 34 is first moved by the motor 50 from the point D to point B shown in Fig. 19(f)(the main slider 34 is retracted from the position shown in Fig. 7 and this state is detected from an on-state of the switch SW5). Thereafter, the second motor 50 moves forth the loading slider 9 from the reproducing position to the position shown in Fig. 14(a) to accommodate the carrier 20 in the stocker 21. This state is the initial stage shown in Fig. 7. In the above manner, reproduction of a disk or exchange of disks in the stocker is carried out. When the slider tray 31 is moved from the outside of the housing to the inside of the housing, i.e., when the carrier 20 is moved from the outside of the hosing into the stocker 21, the main slider 34 moves to the point G shown in Fig. 19(e)(this is detected from an on-state of the switch SW4). By moving the main slider 34 in the above manner, the disk position detecting member 26 rises. However, if the disk position detecting member 26 is hindered to move up by a displaced disk or carrier 20, the switch SW10 is not activated. In this case, the slider tray 31 is moved to the outside of the housing. After the position displacement of the disk is corrected, the slider tray 31 is moved to the inside of the housing. Also when the carrier 20 is moved back to the stocker 21 from the reproducing position, the disk position detecting member 26 is raised, and if there is a position displacement of a disk or carrier 20, the returned carrier is ejected to the outside of the housing. In this case, after the height position of the carrier to be ejected is aligned with that of the carrier pull-out member 36 by lowering the stocker 21 by one stage of carrier, the main slider 33 is moved to the outside of the housing. In stopping the apparatus after disk reproduction or disk exchange, the disk position detecting member 26 is moved up and the stocker 21 is lowered to make the disk position detecting member 26 insert into holes of all the disks and carriers in the stocker. With this arrangement, even if a force is applied to a disk and carrier in the stocker while the apparatus is moved or the like, the position displacement of the carrier and disk does not occur. Next, examples of displays on the display device will be described with reference to Figs. 24(a) to 24(e), these figures disclosing related art. Fig. 24(a) shows an example of a display during the reproduction. Numerals 1 to 6 in the upper column indicate the stages of shelves having a disk, a turned-on numeral indicating a presence of a disk. The lower column indicates a disk during the reproduction. This display example indicates that all the shelves at the 1st to 6th stages have disks and that the disk at the 2nd stage is under the reproduction. The display example shown in Fig. 24(b) indicates that the shelves at 1st, 3rd, 5th, and 6th stages have disks and that the disk at the 5th stage is under the reproduction. The display example shown in Fig. 24(c) indicates that the shelves at 1st, 3rd, 5th, and 6th stages have disks and that the disk at the 3rd stage is being removed while the disk at the 5th stage is reproduced. The numeral at the shelf from which a disk is being removed is flashed as above. The display example shown in Fig. 24(d) indicates that a user displaced the disk at the 3rd stage with another disk after the state shown in Fig. 24(c) and the slider tray was closed. Since a disk is placed on the shelve at the 3rd stage, the numeral "3" is again turned on. The display example shown in Fig. 24(e) indicates that a user removed the disk from the carrier after the state shown in Fig. 24(c) and the slider tray was closed. Since a disk is not detected on the shelf at the 3rd stage, the numeral "3" is turned off. As above, since a presence/absence of a disk is displayed immediately after the slider tray 31 is closed, a disk exchange or dismount work can be performed quite easily. Fig. 23 shows a carrier according to the invention. In this example, the carrier 20 is formed with a 8 cm CD detecting hole 20h and a 12 cm CD detection hole 20k. Fig. 23(b) shows the waveforms of signals from the light receiving element 74 while the carrier traverses light fluxes from the light emitting element 73. A waveform indicated at (1) stands for an 8 cm CD placed on the carrier, and a waveform indicated at (2) stands for a 12 cm CD placed on the carrier. A waveform indicated at (3) stands for no disk placed on the carrier. In this modification, information of the type of a disk accommodated in the stocker can be obtained. Next, examples of displays according to the invention will be described with reference to Figs. 25(a) to 25(f). Fig. 25(a) shows an example of a display during the reproduction. The upper and lower columns have the same meaning as the above embodiment. Characters S and L displayed under each numeral at the upper column indicates an 8 cm DC and a 12 cm DC, respectively. This display example indicates that all the shelves at the 1st, 4th, and 6th stages have 8 cm CDs and the shelves at the 2nd, 3rd, and 5th stages have 12 cm CDs and that the disk at the 3rd stage is under the reproduction. The characters S and L are juxtaposed under each numeral and one of them is turned on. The display example shown in Fig. 25(b) indicates that the shelve at the 2nd stage has an 8 cm CD and the shelves at the 4th and 5th stages have 12 cm CDs and that the disk at the 4th stage is under the reproduction. The display example shown in Fig. 25(c) indicates that the shelve at the 5th stage is being removed after the state shown in Fig. 25(b). The numeral of the shelf from which the carrier is being removed is flashed as above. The display example shown in Fig. 25(d) indicates that a user replaced the disk at the 5th stage with another 12 cm CD and the slider tray was closed. Since the 12 cm CD is placed on the shelf at the 5th stage, "5, L" are again turned on. The display example shown in Fig. 25(e) indicates that a user placed an 8 cm CD on the carrier and the slider tray was closed. Since the 8 cm CD is placed on the shelf at the 5th stage, "5, S" are turned on. The display example shown in Fig. 25(f) indicates that a user removed the disk after the state shown in Fig. 25(c) and closed the slider tray. Since no disk is detected on the shelve at the 5th stage, "5 and S, L" are turned off. According to this invention, even if recorded media are exchanged during the reproduction, the content of the exchange work can be easily confirmed. A recorded medium reproducing apparatus easier to use can therefore be provided to users.

Claims: A recorded medium reproducing apparatus comprising: a stocker (21) capable of accommodating recorded media; reproducing means (70a) for reproducing a recorded medium; first transport means (36) for transporting the recorded medium between the inside of said stocker (21) and the outside of an apparatus housing; second transport means (40) for transporting the recorded medium between the inside of said stocker (21) and a reproduction position; positioning means (SW1 to SW10) for determining a relative position between the recorded medium and said first or second transport means (36, 40); and recorded medium detecting means (20h, 20k) provided on a transport path of the recorded medium being transported by said first transport means (36), for discriminating between different sizes of recorded media; characterized by a display unit for displaying information supplied from said recorded medium detecting means (20h, 20k) and relating to the size of the recorded medium. The recorded medium reproducing apparatus of claim 1, comprising: a control unit for controlling the recorded medium detecting means (20h, 20k) to detect a presence/absence of the recorded medium transported to said stocker (21) by said first transport means (36) and controlling said display unit to display information detected by said recorded medium detecting means (20h, 20k), if said first transport means (36) transports the recorded medium between the inside of said stocker (21) and the outside of the housing while said second transport means (40) has transported the recording medium to the reproduction position. A display method for a recorded medium reproducing apparatus comprising: a stocker (21) capable of accommodating recorded media; reproducing means (70a) for reproducing a recorded medium; first transport means (36) for transporting the recorded medium between the inside of said stocker (21) and the outside of an apparatus housing; second transport means (40) for transporting the recorded medium between the inside of said stocker (21) and a reproduction position; positioning means (SW1 to SW10) for determining a relative position between the recorded medium and said first or second transport means (36, 40); recorded medium detecting means (20h, 20k) provided on a transport path of the recorded medium being transported by said first transport means (36), for discriminating between different sizes of recorded media; and a display unit for displaying information supplied from said recorded medium detecting means (20h, 20k), the method comprising: a first step of driving said first transport means (36) to transport the recording medium to the outside of the apparatus housing; a second step of driving said first transport means (36) to transport the recording medium to the inside of said stocker (21); a third step of causing said recorded medium detecting means (20h, 20k) to detect a presence/absence of the recorded medium to be transported by said first transport means (36) and the size of the recorded medium; and a fourth step of displaying the results detected by said recorded medium detecting means (20h, 20k) on said display unit. The display method according to claim 3, the method comprising: a further step of driving said second transport means (40) to transport the recorded medium to the reproduction position, said further step being performed prior to said step of driving said first transport means (36) to transport the recording medium to the outside of the apparatus housing.

Inventors: YOSHIMURA MASAKI, YOSHIMURA, MASAKI
Applicants: KENWOOD CORP, KABUSHIKI KAISHA KENWOOD
Application year: 1996
Main classification: G11B17
IPC codes: G11B17, G11B33, G11B15