Automatic medium changing apparatus using an automatic regulator according to the disk type

In an automatic medium changing apparatus capable of storing a multiplicity of optical disks, the control parameters required for the drive control system of a drive unit for recording-reproducing are automatically regulated for all the combinations of the existing drive units and all the media held. The resulting values of the control parameters are stored in a control unit of the automatic medium changing apparatus and the apparatus is controlled by the corresponding control parameters transferred from the control unit at the time of processing the medium.

FIELD OF THE INVENTION AND RELATED ART STATEMENT 
1. FIELD OF THE INVENTION 
The present invention relates to an automatic medium changing apparatus and 
a recording-reproducing apparatus for a plurality of optical disk media 
which are used only for read operation or capable of both write and read 
operations such as a CD-ROM, an magneto-optical disk and a phase change 
optical disk. 
2. DESCRIPTION OF THE RELATED ART 
In recent years, recording capacity and the recording/reproducing 
(write/read) speeds of the optical disk medium have greatly increased. As 
a result, the optical disk medium has been closely watched as an external 
memory for computers and also as image processing medium. An automatic 
medium changing apparatus (hereinafter referred to as the auto-changer) 
capable of managing and operating a great amount of data using an optical 
disk medium has been commercialized. 
Limited installation space demands a compact auto-changer. In compliance 
with this demand, an auto-changer has been suggested so that a plurality 
of media are held in a tray for an improved holding efficiency and easier 
operation. 
A conventional auto-changer will be described below. 
FIG. 8 is a side view showing an internal structure of an example of a 
conventional auto-changer. In FIG. 8, a tray transport unit 101 takes out 
a tray 108 on which media (not shown) are held in a magazine 102 and moves 
in the direction of arrow a, so that the media are transported to a drive 
unit 103 for recording-reproducing the media. The tray transport unit 101 
is guided by a guide shaft 104, and driven by a drive motor 107 through a 
belt 105 and a pulley 106. 
FIG. 9 is a plan view of the tray 108. As shown in FIG. 9, the tray 108 is 
formed to have a medium holding recess 109. Also, the tray 108 is formed 
to have an opening 110 into which a turn table 113 and a pickup 114 of the 
drive unit 103 are adapted to be inserted. The tray 108 has a positioning 
hole 111 for setting the drive unit 103 in proper position, and a notch 
112 used by the tray transfer unit 101 to retrieve/insert the medium from 
and into the magazine 102. 
Also, the drive unit 103 provided in the auto-changer includes the turn 
table 113 adapted to rotate with a medium loaded on the turn table 113, 
the pickup 114 for reading a signal from the medium, and a positioning pin 
115 corresponding to the positioning hole 111 of the tray 108. 
A control unit 116 is arranged in the auto-changer. The control unit 116 
controls a drive motor 107, the tray transport unit 101 and the drive unit 
103. The control unit 116 also controls the operation of the auto-changer 
on the basis of the inputs entered by way of a host computer (not shown) 
or an operating button (not shown), and manages the medium information. 
Next, the operation of a conventional auto-changer will be explained. 
Explanation will be made on the case that a reproducing command for 
mounting a specific medium held in the magazine in the drive unit 103 is 
issued to the control unit 116 from an external source. First, the control 
unit 116 outputs a reproducing command signal to the drive motor 107 and 
the tray transport unit 101. As a result, the tray transport unit 101 is 
driven by the drive motor 107 through the belt 105 along the direction of 
arrow a or b and thus moves to a position corresponding to the designated 
tray 108. The tray transport unit 101 then takes out the designated tray 
108 from the magazine 102 using advantage of the notch 112. 
The tray transport unit 101 holding the designated tray 108 moves along the 
direction of arrow a, so that the positioning hole 111 of the tray 108 is 
caused to engage the positioning pin 115 of the drive unit 103. As a 
result, the tray 108 is set in position with respect to the drive unit 
103. In this stage, the control unit 116 outputs a reproducing command 
signal to the drive unit 103. Consequently, the turn table 113 and the 
pickup 114 of the drive unit 103 advance into the opening 110 of the tray 
108. At the same time, the medium placed on the tray 108 is arranged to be 
centered on the turn table 113. Then, the clamp unit (not shown) of the 
tray transport unit 101 fixes the designated medium on the turn table 113. 
After that, the turn table 113 rotates and signals are read out by the 
pickup 114. In this reproduction mode, the tray 108 is set in position by 
the drive unit 103, and held by the tray transport unit 101 at a position 
out of contact with the medium. 
The tray 108 is returned in the following manner after reproduction. 
As in the above-mentioned reproduction operation, the control unit 116 
outputs a return command signal and stops the turn table 113 of the drive 
unit 103. And the tray transport unit 101 is moved by the drive motor 107 
along the direction of arrow b. Then, the medium is released from the turn 
table 113, and the tray 108 with the medium placed thereon is transferred 
to a predetermined position in the magazine 102. The medium is thus 
returned to the magazine 102 using the notch 112. 
Next, explanation will be made on the management of the medium (the 
presence or absence of a medium, the type of medium, the contents recorded 
in the medium, etc.) conducted by the auto-changer. 
The user opens the door 122, inserts the magazine 102 and closes the door 
122. Then the control unit 116 detects the signal from a door sensor (not 
shown) and outputs a management command signal to the tray transport unit 
101. The tray transport unit 101 takes out all the trays 108 sequentially 
and detects by a sensor (not shown) whether a medium is placed on the tray 
108 or not. 
In some cases, the tray 108 is transferred to the drive unit 103, and the 
medium is placed on the drive unit 103 to determine the type of medium, or 
write the recording data or the management information of the medium. 
These media information can be stored in the control unit 116, whereby the 
information about the holding position, type and content of the medium can 
be used to issue an operation command when exchanging the medium. This 
series of operations is called an initializing operation, which is 
performed when power is switched on, the user changes the magazine 102, or 
the host computer issues an operation command for the initializing 
operation. 
In addition to an auto-changer of magazine/tray type, another auto-changer 
for holding a plurality of cartridges each holding one medium is also 
widely used. 
In such an auto-changer, the cartridges are taken out and held one by one 
through a mail slot (as a mechanism for inserting/discharging the 
cartridge into or from the auto-changer) formed in the auto-changer. 
Therefore, the controller is kept informed of which cartridge is held in 
which position. As a consequence, the controller has performed the 
initializing operation only for the cartridges newly inserted. 
Next, the drive unit used for the conventional auto-changer will be 
explained with reference to FIG. 10. 
FIG. 10 is a diagram schematically showing an internal configuration of the 
drive unit 103 of FIG. 8. 
In FIG. 10, a disk 117 as a medium is mounted on the turn table 113 is 
rotated by a spindle motor 118, and a drive controller 119 controls the 
operation of the pickup 114 and the spindle motor 118. At the same time, 
the drive controller 119 receives a signal from the pickup 114. The drive 
controller 119 operates in accordance with the command from the control 
unit 116 of the auto-changer, transfers the data read in accordance with 
the command, and reports the current state of the drive unit 103. An 
automatic regulator 120 is performs automatic regulation of the drive 
controller 119 for accurately detecting the information on the disk 117. 
Next, the operation of the drive unit 103 will be explained in detail. 
When the disk 117 is clamped on the turn table 113 of the drive unit 103, 
the drive controller 119 drives the spindle motor 118 thereby to start 
rotating the disk 117. In this operation, the pickup 114 is driven 
according to the variations in reflectance or clamping position of the 
disk 117. In this drive control operation, the signal may not be read at 
all in some cases if fixed control parameters are used. Even if the signal 
can be read to some degree, it would be impossible to control the pickup 
114 accurately. As a result, error rate of the detected signal becomes 
high or repeated read operations are required. The conventional drive 
unit, therefore, has the problem that long time is consumed for reading or 
transferring the data. 
In view of this, various automatic regulation systems have been suggested 
to accommodate the variations of the disk etc. Examples are disclosed in 
the gazette of the Japanese unexamined patent application hei 1-89034 
(Tokkai hei 1-89034) and the gazette of the Japanese unexamined patent 
application hei 7-153106 (Tokkai hei 7-153106). 
The automatic regulator 120 shown in FIG. 10 is used for accommodating the 
variations mentioned above. This automatic regulator 120 has the function 
of automatically regulating the control parameter required for reading the 
data from the disk 117 with the highest accuracy by means of a learning 
algorithm. 
The drive controller 119 reads the data from the disk 117 after the optimum 
control parameter is set by the automatic regulator 120. 
The conventional auto-changer having the above-mentioned configuration, 
however, leads to the following problem. 
Specifically, in the above-mentioned conventional apparatuses, it is 
indispensable that automatic regulation is operated in consideration of 
reflectance of the disk or the clamping position. In this learning 
algorithm, however, the steps of applying a test signal and adjusting to 
an optimum parameter are required to be repeated several times. The result 
is the problem that it takes a very long time after the disk is clamped 
until data can be actually read. 
The auto-changer requires the time for the automatic regulation as long as 
for the tray transfer from the magazine to the drive unit no matter how 
rapidly the tray carrying the disk thereon is transferred to the drive 
unit. The overall operating efficiency of the apparatus, therefore, is 
unavoidably deteriorated. Also, since this operation is performed each 
time a disk is set, even if it has learned about a disk A, the drive unit 
must again learn about a disk B when it is set. Even when the disk A is 
set the second time, further learning is required again because the 
previous learning data has disappeared. Also, even when the control 
parameter is stored for the disk previously regulated, the data cannot be 
read from the disk before the automatic regulation is completed. It 
therefore cannot be known which of the loaded disks corresponds to the 
previously learned disk. 
Consequently, in the conventional drive unit, learning is required each 
time of automatic regulation, and therefore it takes a long starting time 
from setting a disk to reading data therefrom. The auto-changer using such 
an algorithm is low in operating efficiency. This problem presents itself 
very conspicuously especially in an environment where the apparatus is 
connected with a network for operation. 
Further, the conventional drive unit is a drive apparatus meeting the 
requirement of only one of the recording and reproducing operations. The 
auto-changer is adapted to drive either a medium which can be reproduced 
only or a medium which can be both recorded and reproduced. Demand is 
high, therefore, for an auto-changer which can operate with both a 
read-only medium such as the CD-ROM now closely watched and an optical 
disk medium capable of both read and write operations. 
OBJECT AND SUMMARY OF THE INVENTION 
The object of the present invention is to solve the above-mentioned 
problems and to provide an automatic medium changing apparatus and a 
recording-reproducing apparatus having a high operating efficiency capable 
of processing both a read-only medium and a read-write medium in a short 
time before reading data. 
In order to achieve the above-mentioned object, according to the present 
invention, the apparatus is provided with an automatic medium changing 
apparatus (hereinafter referred to as the auto-changer) which can manages 
the information about the media (disks) in the auto-changer, as well as 
information about recording-reproducing unit in the auto-changer. The 
auto-changer of the present invention comprises a recording-reproducing 
unit having the information manageable and capable of processing both a 
read-only medium and a read-write medium, a holding unit for holding the 
media, a medium transfer unit for transferring the medium from the holding 
unit to the recording-reproducing unit, and a management controller for 
controlling the recording-reproducing unit and the medium transfer unit 
and for managing the medium. The recording-reproducing unit includes an 
automatic regulator for automatically regulating control parameters 
required for reproducing or recording the medium signal and holding the 
regulated control parameters when the medium is placed on the 
recording-reproducing unit, and the management controller stores control 
parameters regulated and held by the automatic regulator and the 
corresponding management discrimination information on the corresponding 
media and the corresponding recording-reproducing unit. 
The above-mentioned configuration permits the control parameter once 
learned to be reused and therefore eliminates the time required for 
relearning the same combination. The starting time for processing the disk 
medium thus is shortened, thereby improving the overall operating 
efficiency of the apparatus and the system connected with the apparatus. 
The auto-changer in accordance with the present invention comprise a 
recording-reproducing unit capable of accommodating and processing both a 
read-only medium and a read-write medium, a holding unit for holding the 
media, a medium transfer unit for transferring a medium from the holding 
unit to the recording-reproducing unit, and a management controller for 
managing and controlling the recording-reproducing unit, the medium 
transfer unit and the medium. The recording-reproducing unit includes an 
automatic regulator which, when the medium is placed on the 
recording-reproducing unit, automatically regulates the control parameters 
required for reproducing or recording the signal of the medium and holds 
the control parameters thus regulated. The management controller is 
adapted to store the control parameters automatically regulated and held 
by the automatic regulator of the recording-reproducing unit for the 
medium transferred and placed by the medium transfer unit. The management 
controller also stores the management discrimination information on the 
corresponding medium and the corresponding recording-reproducing unit. By 
this configuration, a read-only medium and a read-write medium can both be 
processed, held and exchanged, and the starting time for processing the 
disk medium is reduced, with the result that the overall operating 
efficiency of the apparatus and the system connected with the apparatus 
can be improved. 
While the novel features of the invention are set forth particularly in the 
appended claims, the invention, both as to organization and content, will 
be better understood and appreciated, along with other objects and 
features thereof, from the following detailed description taken in 
conjunction with the drawings.

It will be recognized that some or all of the Figures are schematic 
representations for purposes of illustration and do not necessarily depict 
the actual relative sizes or locations of the elements shown. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
First embodiment! 
A first embodiment in accordance with the present invention will be 
described below with reference to FIGS. 1, 2, 3 and 4. FIG. 1 is a diagram 
showing a configuration of an automatic medium changing apparatus 
(hereinafter referred to as the auto-changer) of the first embodiment. 
FIG. 2 is a plan view of a tray 8 of the first embodiment. FIG. 3 is a 
block diagram showing a configuration of a recording-reproducing unit 3 of 
the first embodiment. FIG. 4 is a flow chart for explaining the 
initializing operation of the first embodiment. 
In FIG. 1, a medium or tray transfer unit 1 takes out the tray 8 carrying a 
medium (not shown) such as an optical disk, a magneto-optical disk or a 
phase change optical disk in a holding or magazine unit 2. The tray 
transfer unit 1 moves along the direction of arrow a and transfers the 
tray 8 to a recording-reproducing unit (hereinafter referred to as drive 
unit) 3. The drive unit 3 is guided by a guide shaft 4, and driven by a 
drive motor 7 through a pulley 6 and a belt 5. 
As seen from FIG. 2, the tray 8 is formed to have a recess 9 for holding a 
medium. Also, the tray 8 has an opening 10 which is inserted by a pickup 
14 and a turn table 13 of the drive unit 3 at recording-reproducing, a 
positioning hole 11 for setting the tray in position with respect to the 
drive unit 3, and a notch 12 used by the tray transfer unit 1 for taking 
out or inserting the medium from or into the magazine 2. 
Also, the drive unit 3 provided in the auto-changer has a turn table 13 
adapted to rotate with a medium mounted thereon, a pickup 14 for reading a 
signal from the medium, and a positioning pin 15 corresponding to the 
positioning hole 11 of the tray 8. 
A management control unit 16 in the auto-changer controls the driving 
operation of a drive motor 7, the tray transfer unit 1 and the drive unit 
3. The control unit 16 also controls the operation of the auto-changer and 
manages the medium information in accordance with the information from a 
host computer (not shown) or operating buttons (not shown). 
FIG. 3 is a diagram schematically showing an internal configuration of the 
drive unit 3 of FIG. 1. In FIG. 3, the same component parts as those in 
FIG. 1 are designated by the same reference numerals, respectively, and 
will not be described any further. 
In FIG. 3, a disk 17 is a medium, a spindle motor 18 rotates the turn table 
13, and a drive controller 19 controls the driving operation of the pickup 
14 and the spindle motor 18 and receives a signal from the pickup 14. The 
drive controller 19 operates in response to a command from the control 
unit 16 of the auto-changer, and has the functions of transferring the 
data read in accordance with the command and reporting the conditions of 
the drive unit 3. 
An automatic regulator 20 operates to automatically regulate the control 
parameters used by the drive controller 19 for controlling the driving 
operation of the spindle motor 18 and the pickup 14 in order to accurately 
detect the information on the disk 17. 
Next, explanation will be made about the operation of the auto-changer for 
exchanging the medium. 
Assume that an external command is input to the control unit 16 for 
mounting and processing a specific disk on the drive unit 3. First, the 
control unit 16 outputs a reproduction command signal to the drive motor 7 
and the tray transfer unit 1. Then, the tray transfer unit 1 is driven by 
the drive motor 7 along the direction of arrow a or b through the belt 5 
and moves to the position corresponding to the tray 8 carrying the 
designated disk. The tray transfer unit 1 takes out the tray 8 carrying 
the designated disk from the magazine 2 taking advantage of the notch 12. 
Next, the tray transfer unit 1 now holding the tray 8 moves in the 
direction of arrow a, and causes the positioning hole 11 of the tray 8 to 
engage with the positioning pin 15 of the drive unit 3. The tray 8 thus is 
set in position with respect to the drive unit 3. At this time, the 
control unit 16 outputs a command signal to the drive unit 3, so that the 
turn table 13 and the pickup 14 of the drive unit 3 advance into the 
opening 10. In this operation, the medium placed on the tray 8 is centered 
on the turn table 13, and fixed on the turn table 13 by means of a clamp 
(not shown) arranged on the tray transfer unit 1. After that, the turn 
table 13 rotates and the disk signal is read out by the pickup 14. 
In t his reproduction operation, the tray 8 is set in position by the drive 
unit 3 and held in the tray transfer unit 1 at a height not in contact 
with the disk. 
The tray 8 that has completed the reproduction operation is returned as 
described below. 
Like in the above-mentioned reproduction operation, the control unit 16 
outputs a return command signal and thus causes the turn table 13 of the 
drive unit 3 to s top. After that, the tray transfer unit 1 is moved by 
the drive motor 7 along the direction of b. The disk is released from the 
turn table 13, and transferred to a predetermined position in the magazine 
2 while being placed on the tray 8. The tray transfer unit 1 returns the 
disk to the magazine 2 taking advantage of the notch 12. 
Next, explanation will be made on the operation of the drive unit 3 and the 
control unit 16 for processing the disk as a medium. 
First, the medium management (as to the presence or absence of the medium, 
the medium type, the control parameters required for processing the 
medium, etc.) conducted in this auto-changer will be explained. 
After the user opens the door 22, inserts the magazine 2 and closes the 
door 22, the control unit 16 detects the signal from a door operation 
sensor (not shown) and outputs a command signal. The tray transfer unit 1 
supplied with this output signal takes out all the trays sequentially and 
detects the presence or absence of the medium therein by means of a sensor 
(not shown). The sensor detects whether a medium is placed on the tray 8 
on the one hand and whether the medium is of a type that can be reproduced 
only or can be both recorded and reproduced on the other hand. 
After that, the tray 8 on which the medium is placed is transferred to the 
drive unit 3 and placed on the drive unit 3. A command is issued to the 
drive controller 19 and the automatic regulator 20 of the drive unit 3 so 
that the control parameters are automatically regulated for the pickup 14 
to read, write or erase the data on the medium. In other words, the 
control parameters are corrected to accommodate various variations or 
irregularities in the drive unit 3 for the optical disk, including the 
medium shape (warping and the like), characteristics variations 
(reflectance and the like) or eccentricity variations caused at the time 
of clamping. 
In a regulation procedure, when the disk 17 constituting a medium is 
clamped to the turn table 13 of the drive unit 3, the drive controller 19 
rotates the disk 17 by starting the drive motor 18. At the same time, the 
automatic regulator 20 automatically regulates the control parameters 
required for reading the data from the disk 17 with the highest accuracy 
by a learning algorithm incorporated for accommodating the variations and 
irregularities described above. After the optimum control parameters are 
set by the automatic regulator 20, the drive controller 19 is capable of 
processing data on the disk 17. 
Then, among the control parameters to be regulated, those which are varied 
in accordance with the combination between the medium and the drive unit 
3, for example, the focusing of the pickup, the tracking control gain, the 
optical output power, the tracking offset or the like informations are 
stored in the management control unit 16 together with the management 
discrimination information on the combination of the medium and the drive 
unit 3. This storage operation is performed sequentially for all the 
combinations of the medium and the drive unit 3 thereby to store the 
above-mentioned information. This entire series of operations, which is 
called the initializing operation, is performed when an initializing 
command is issued from the host computer or the apparatus is switched on. 
Next, with reference to FIG. 4, explanation will be made on the procedure 
in which the medium is processed in the drive unit 3 in accordance with a 
command from an external source. FIG. 4 shows flow chart for initializing 
operation. 
First, the control unit 16 receives a command to read, write or erase a 
predetermined medium by using a predetermined drive unit 3, as shown in 
FIG. 4 (step 100). The control unit 16 then searches for corresponding 
control parameters from the management information on the combination of 
the medium and the drive unit 3 (step 101). 
The drive controller 19 of the drive unit 3 is adapted to select, in 
response to a command from an external source, either the automatic 
regulation mode or the drive control mode performed using the control 
parameter values held in the automatic regulator 20. 
Also, the control parameters held in the automatic regulator 20 can be read 
or written from an external source. In the case where a control parameter 
is found to exist as a result of search by the control unit 16, such a 
control parameter is transferred to the automatic regulator 20 of the 
drive unit 3 (step 105). The control unit 16 issues a command to the drive 
controller 19 to cancel the automatic regulation and perform the control 
operation using the value transferred (step 106). 
On the other hand, in the case where a control parameter conforming to a 
particular combination of the medium and the drive unit 3 cannot be 
extracted as a result of the search by the control unit 16, a command is 
issued to transfer the medium by the tray transfer unit 1 to the drive 
unit 3 and perform the automatic regulation (step 103). 
A command is issued also to transfer the control parameter thus obtained to 
the control unit 16. After that, the medium is actually processed. Assume, 
however, that the medium cannot be normally processed under the control of 
the drive unit 3 using the control parameter held in the automatic 
regulator 20 and an error occurs. The control unit 16 issues a command to 
the drive controller 19 and the automatic regulator 20 to carry out the 
automatic regulation again (step 108). Then the medium is processed, and 
the control parameter newly obtained is stored together with the 
information on the medium and the drive unit 3. 
When the disk 17 is actually processed as a medium on the drive unit 3, the 
time required for automatic regulation can be reduced considerably by the 
operation shown in FIG. 4. As a result, it is possible to provide an 
auto-changer which has a high overall operating efficiency of the system 
and thus saves the user waiting time considerably. 
The present invention is not necessarily limited to a single drive unit as 
a recording-reproducing unit used in the embodiment, but a plurality of 
recording-reproducing units may be used with equal effect. In such a case, 
exactly the same effect as the above-mentioned embodiment can of course be 
obtained, the only difference being that the control parameters are 
learned for all the combinations of the medium and the 
recording-reproducing units. 
Second embodiment! 
Next, an auto-changer of a second embodiment in accordance with the present 
invention will be explained with reference to FIG. 5. FIG. 5 is a side 
view showing a configuration of the auto-changer of the second embodiment. 
In FIG. 5, the same component parts as those in FIG. 1 will not be 
described in detail. 
The tray transfer unit 1 takes out the tray 8 carrying the medium (not 
shown) in the upper and lower magazines 2 (2a, 2b), and transfers along 
the arrow a to the drive unit 3. The tray transfer unit 1 is guided by the 
guide shaft 4, and driven by the drive motor 7 through the pulley 6 and 
the belt 5. The magazines 2 (2a, 2b) contains a plurality of trays 8, and 
is so configured that the magazine can be freely replaced by the user 
opening and closing the door 22. Also, the upper and lower magazines 2a, 
2b are provided with replacement sensors 21a, 21b for detecting the 
mounting and demounting of the magazines 2a 2b. 
The initializing operation performed in this auto-changer when power is 
switched on or when a command is received from an external source is 
already described above with reference to the first embodiment of the 
present invent ion. 
Next, explanation will be made on the operation performed when only the 
magazine 2a has been replaced by the user. In the case where the magazine 
2a is replaced, the control unit 16 detects a signal from a replacement 
sensor 21a. At the same time, the signal of the replacement sensor 21b is 
monitored by the control unit 16, and control unit 16 confirms that the 
magazine 2b is not replaced. When confirming that the magazine 2b is not 
replaced, the control unit 16 performs the aforementioned initializing 
operation only on the tray 8 and the medium held in the replaced magazine 
2a. The control unit 16 thus updates only the information on the medium 
contained in the magazine 2a (as to the presence or absence of the medium, 
the medium type, etc.) and the information on the control parameters for 
the combination of the medium and the drive unit 3. The existing 
information about the magazine 2b that has not be replaced is held as it 
is. 
As described above, since the initializing operation is performed and the 
data are updated only for the magazine replaced, the time required for the 
initializing operation is considerably reduced. In addition, the starting 
time for processing the medium is greatly shortened. It is thus possible 
to improve the operating efficiency of the auto-changer and the overall 
operating efficiency of the system connected with the auto-changer. 
Although a replacement sensor is used for detecting the replacement of the 
magazine of the second embodiment, the present invention is not 
necessarily confined to such a configuration. Instead, a replaced magazine 
replaced is designated by a host computer to give a command so as to 
perform the initializing operation only for that magazine. 
Further, the starting time for processing the medium can be shortened by 
performing the initializing operation again for all the magazines and 
media, though not useful for reducing the time of the initializing 
operation. Such a method is effective especially when only a few number of 
magazines can be stored, since there is no need of adding a replacement 
sensor and the total time required of the initializing operation is not 
very long. 
Also, instead of replacing the medium by a magazine in the second 
embodiment, the medium in an auto-changer can be held or managed by a tray 
or a cartridge. In such a case, the control parameters are updated each 
time of replacing a tray or a cartridge, as the case may be, thereby to 
shorten the starting time for disk processing and also the time required 
for the initializing operation. 
As another alternative, the auto-changer may be equipped with a mail slot 
which the medium can be inserted into or removed from. This makes it 
possible for the control unit to determine which medium is replaced. The 
initializing operation, therefore, can be readily performed for the 
medium, cartridge or the magazine containing the medium replaced, and only 
the related control parameters can be updated. 
Even with a plurality of drive units, the process similar to that for the 
above-mentioned embodiment is possible for a shorter starting time. 
Third embodiment! 
Next, a schematic diagram showing an auto-changer of a third embodiment in 
accordance with the present invention is shown in FIG. 6. FIG. 6 is a side 
view showing a configuration of an auto-changer of the third embodiment. 
The third embodiment is different from the first embodiment in that this 
embodiment comprises two drive units 3 (3a, 3b) which can be easily 
replaced by opening the door 22. Also, the auto-changer of the third 
embodiment comprise replacement sensors 23a, 23b for detecting the 
replacement of the drive units 3a, 3b to output a signal to the control 
unit 16 indicating whether the drive units 3a, 3b have been replaced. The 
auto-changer also comprises loading mechanism 24a, 24b for holding and 
setting the tray 8 in position with respect to the drive units 3a, 3b. 
Next, the operation of the auto-changer of the third embodiment will be 
explained. 
The explanation will be made only about the loading mechanisms 24a, 24b 
used for replacing the medium, in which the third embodiment is different 
from the first and second embodiments. 
First, the tray transfer unit 1 carrying the tray 8 moves along the 
direction of arrow a and inserts the tray 8 into the loading mechanism 24a 
or 24b. The loading mechanism 24a or 24b causes the positioning hole 11 of 
the tray 8 to engage with the positioning pin 15 of the drive unit 3a or 
3b, thereby setting the tray 8 in position with respect to the drive unit 
3a or 3b. In this stage, the control unit 16 outputs a command signal to 
the drive unit 3a or 3b, so that the turn table 13 and the pickup 14 of 
the drive unit 3a or 3b advance into the opening 10 (FIG. 2). At the same 
time, the medium placed on the tray 8 is centered on the turn table 13, 
and is fixed on the turn table 13 by means of a clamp (not shown) of the 
loading mechanism 24a or 24b. After that, the turn table 13 rotates and 
the pickup 14 reads out the signal. 
In this reproduction mode, the tray 8 is set in position on the drive unit 
3a or 3b, and is held in the loading mechanism 24a or 24b at a height 
keeping out of contact with the medium. 
The operation of returning the tray 8 is performed in the following manner 
upon completion of the reproduction operation. As in the reproduction 
operation mentioned above, the control unit 16 stops the turn table 13 on 
the basis of a return command signal, and thus releases the medium thus 
far clamped to the turn table 13. Also, the tray transfer unit 1 withdraws 
the tray 8 and the medium from the loading mechanism 24a or 24b. The tray 
8 with the medium placed thereon is transferred to a predetermined 
position in one of the magazines 2 and thus returned to the magazine 2 
using the notch 12. 
The initializing operation performed for the auto-changer when power is 
switched on or in response to a command from an external source is the 
same as in the case of the aforementioned first embodiment. 
Next, explanation will be made about the operation of replacing only the 
drive unit 3a. In the case where the drive unit 3a is replaced, the 
control unit 16 detects a signal from the replacement sensor 23a. At the 
same time, the signal of the replacement sensor 23b is monitored by the 
control unit 16. After confirming that the drive unit 3b is not replaced, 
the control unit 16 performs the initializing operation for all the 
combinations of the drive unit 3a and all the media contained therein. And 
only the information about the control parameters for the combinations of 
the respective media and the drive unit 3a are updated. In this process, 
the information about the drive unit 3b not replaced is held as it is. 
As described above, the initializing operation is performed and data 
updated only for the drive unit 3a or 3b replaced. The time required for 
the initializing operation thus can be shortened considerably as well as 
the starting time for processing the medium. In this way, the operating 
efficiency of the auto-changer and hence the overall operating efficiency 
of the system connected to the auto-changer can be improved. 
Although a replacement sensor is used for detecting the replacement of the 
drive units 3 (3a, 3b) in the third embodiment, the present invention is 
not necessarily limited to such a configuration. Instead, the drive unit 3 
(3a, 3b) replaced may be designated by a host computer, for example, 
without using the replacement sensor, as in the case of the second 
embodiment. 
Further, though not contributive to a shortened time of the initializing 
operation, the starting time for medium processing can be reduced by 
repeating the initialing operation for all the drive units 3 (3a, 3b). 
Such a method is especially effective as it eliminates the need of adding 
a replacement sensor when only a small number of drive units 3 (3a, 3b) 
are installed and also as it involves a comparatively short time for the 
initializing operation as a whole. 
Fourth embodiment! 
Next, a fourth embodiment of the present invention will be described with 
reference to FIG. 7. The configuration and the medium-changing operation 
of the fourth embodiment are the same as those of the aforementioned first 
embodiment and will not be described. The auto-changer of the fourth 
embodiment, however, is configured in such a manner that the control unit 
16 stores both the control parameters and the time they are updated. FIG. 
7 shows a flow of operation for the case in which the control unit 16 is 
instructed by an external device (such as a host computer) to process a 
predetermined medium in a predetermined drive unit 3. 
First, as shown in FIG. 7, upon receipt of a command from an external 
source to process a predetermined medium by a predetermined drive unit 3, 
the control unit 16 searches the related management discrimination 
information for a corresponding control parameter and the latest update 
time tu (step 201). 
In the presence of a corresponding control parameter, the control unit 16 
checks that the time of lapse t-tu (from the latest update time tu and the 
current time t) is not longer than a predetermined time length (longest 
update interval: .DELTA.t)(step 205). After this check, the result is 
transferred to the automatic regulator of the drive unit 3 while at the 
same time cancelling the automatic regulation (step 207). The control unit 
16 then issues a command to control the drive unit 3 by using the control 
parameter transferred (step 208). 
On the other hand, in the absence of a corresponding control parameter in 
step 202 or in the case where .DELTA.t or more has passed from the 
previous time of updating or storing the control parameter in the presence 
of the control parameter, then the tray transfer unit 1 transfers the 
medium to the drive unit 3, and mounting the medium on the drive unit 3, 
issues a command for automatic regulation (step 203). The resulting 
control parameter is transferred and data updated. 
The subsequent flow of operation is similar to that for the aforementioned 
first embodiment. As described above, secular or environmental variations 
can be accommodated by eliminating the use of the control parameter data 
that have passed a predetermined length of time. More specifically, an 
error occurring when old data are used for drive control without automatic 
regulation can be prevented, thereby providing a highly reliable 
auto-changer that can process a medium most quickly after all. 
Though not shown in FIG. 7, the fourth embodiment can be configured to 
involve the following flow of operation. In the case where the control 
unit 16 has a buffer memory and the control parameter value is updated 
after the lapse of a predetermined time following the previous update, the 
value updated is compared with the previous value not updated. In the case 
where the difference is not less than a predetermined value, the medium or 
the drive unit 3 may be deteriorated. The result, therefore, is indicated 
on the display section of the auto-changer or transferred as a message to 
the host computer to call its attention. 
Further, according to the above-mentioned fourth embodiment, the time that 
has elapsed from the latest update of the control parameters is calculated 
only after receiving a medium-processing command from an external host 
computer. The present invention is not necessarily confined to such a 
configuration. Instead, the control unit 16 may check the latest update 
time of the stored control parameters at regular time intervals of 
.DELTA.tc, for example, and if there are any data that has elapsed a 
predetermined time (.DELTA.t) or more before the current time, the 
automatic regulation is conducted again for the particular combination 
thereby to update the control parameter data. 
Fifth embodiment! 
Next, a fifth embodiment in accordance with the present invention will be 
explained. The configuration and the medium-changing operation of the 
fifth embodiment are the same as those of the aforementioned first 
embodiment, but the difference of the fifth embodiment lies in the 
initializing operation. According to the first embodiment, the 
initializing operation is performed when power is switched on or in 
compliance with an external command, and automatic regulation is performed 
by the number of combinations of all the media contained in the 
auto-changer and the drive unit. And, in the first embodiment, the control 
parameters are stored in the control unit 16 in advance. 
In the fifth embodiment, by contrast, the control parameters are never 
automatically regulated during the initializing operation. Assume that an 
external host computer or the like issues a command to process a specific 
medium in a predetermined drive unit. The operation is the same as when 
the control parameters are absent as shown in FIG. 4, if the particular 
combination has not been experienced and has been realized for the first 
time. In such a case, the control unit 16 performs the automatic 
regulation and stores the control parameters at the that time. 
As described above, according as the process proceeds, the control unit 16 
steadily comes to learn the control parameters for various combinations of 
the medium and the drive units. 
Also, according to the fifth embodiment, in the case where the magazine, 
the medium (including the cartridge) or the tray is replaced as described 
in the second or third embodiment or in the case where the drive unit is 
replaced, the control unit 16 clears the data stored therein in relation 
to the control parameters for the magazine or the drive unit replaced. The 
above-mentioned automatic regulation is performed only at the time of 
processing for the combination using a newly-held medium or a new drive 
unit. 
Even when a predetermined time has passed from the learning of the control 
parameters as described in the fourth embodiment, the only related 
operation is to clear the corresponding data. This configuration makes it 
unnecessary to perform the time-consuming practice for mounting the medium 
on the drive unit, conducting automatic regulation and acquiring the 
control parameters for all the combinations at regular time intervals, at 
the time of changing the medium or the drive unit or at the time of the 
first initializing operation. As a result, an auto-changer configuration 
is made possible in which the user can immediately start operating the 
auto-changer with the operating efficiency progressively improved as the 
starting time is steadily shortened. 
Sixth embodiment! 
Next, a sixth embodiment of the present invention will be described. The 
component elements and the medium-changing operation of the sixth 
embodiment are exactly the same as those for the aforementioned third 
embodiment. According to the sixth embodiment, the initializing operation, 
the control parameters to be stored in the initializing operation and the 
method for generating the control parameters in the processing operation 
of the medium are different from those for the third embodiment. More 
specifically, according to the third embodiment, the control parameters 
are automatically regulated first during the initializing operation for 
all the combinations of the media stored and the drive units in the same 
manner as for the first embodiment, and the resulting control parameters 
are stored. With the increase in the number of drive units installed for 
holding the media or the number of media held, however, the more control 
parameters are used, resulting in an increased memory consumption, often 
leading to an increased cost or an increased apparatus size. The sixth 
embodiment will be described with reference to a method for producing the 
same effect as the aforementioned embodiments with a smaller capacity of 
memory in spite of an increased number of media held or the number of 
drive units used. 
In the sixth embodiment, assume that N drive units are mounted on the 
auto-changer and M media are held. 
In the first to fifth embodiments described above in which the initializing 
operation is performed somewhat differently from each other, it is 
basically necessary to acquire and store the control parameters for all 
the combinations of media and the drive units by automatic regulation. The 
management information thus stored are as many as N.times.M sets, of which 
the control parameters are represented as following Matrix 1 with (drive 
unit No. and medium No.): 
##EQU1## 
A corresponding method in accordance with the sixth embodiment will be 
described below. 
(1) A reference drive unit (called the drive unit K for the sake of 
convenience) is selected from all the N drive units, and all the media (1 
to M) are sequentially transferred to the drive unit K, so that the 
related control parameters are automatically regulated and stored. The 
medium information (medium No., presence or absence of the medium, the 
medium type, etc.) are also of course stored at the same time. At this 
timing, therefore, M sets of management information are stored, for which 
the control parameters are given as 
Matrix! 
EQU (K,1), (K,2), . . . (K,M) 
(2) Next, one reference medium (medium L) is selected and transferred 
sequentially to the drive units 1 to M (except for K), and the control 
parameters described below are obtained by automatic regulation and 
stored. 
Matrix! 
EQU (1,L), (2,L), . . . (K-1,L), (K+1,L), . . . (N,L) 
Only those parameters having the values listed in Matrixes 2 and 3 above 
are stored, and constitute data in the number of M+N-1. This indicates 
that memories required in the sixth embodiment are (N-1).times.(M-1) fewer 
than in the method shown in the first to fifth embodiments. 
(3) Next, in the case where a medium j is processed by a drive unit i, for 
example, a control parameter (i,j) is obtained in the following-described 
manner. Specifically, 
EQU (i,j)=(K,j)+(i,L)-(K,L) (1) 
The control parameter (i,j) is forwarded to the automatic regulator of the 
corresponding drive unit and is used for drive unit as in the first to 
fifth embodiments, thereby shortening the starting time remarkably. 
As described above, according to the method of the sixth embodiment, the 
same effect is obtained with a fewer memory capacity. Also, a fewer number 
of media are actually mounted and used for automatic regulation at the 
time of initializing operation, and therefore the initializing operation 
can be completed within a shorter time. 
Also, unlike the sixth embodiment in which the control parameter is 
obtained by a difference as shown in Equation 1 above, the control 
parameter may alternatively be obtained in the following manner. 
EQU (i,j)=(K,j).times.(i,L)/(K,L) (2) 
The control parameter can be generated even more accurately by 
appropriately changing the method depending on drive characteristics and 
the medium variations. 
Also, instead of the linear computation as in Equation 1 or 2 described 
above, nonlinear equations may be used incorporating the respective 
features depending on the drive unit and medium variations and 
characteristics. As a result, the accuracy of the control parameters is 
further improved. 
In the above-mentioned embodiment, the control parameters were stored in 
the form of Matrix 2 or 3 above and the control parameters used for 
processing media are acquired from Equation 1 or 2. Without using Matrix 
3, however, the control parameters can alternatively be stored as 
difference information in advance as given below. 
EQU .delta.(i,L)=(i,L)-(K,L) (3) 
In this way, when a control parameter is generated, the following equation 
may 4 be used. 
EQU (i,j)=(K,j)+.delta.(i,L) (4) 
This fact becomes apparent by comparing Equations 1 and 4. Many other 
variations of the method of storing and acquiring the control parameters 
are considered available. For example, control parameters are variously 
generated for combinations of a reference medium and a plurality of drive 
units on the one hand and combinations of a reference drive unit and a 
plurality of media on the other. When the control parameters are generated 
in this way, the starting time is reduced while decreasing the memory 
capacity used. The use of the resulting parameters can complete the 
initializing operation within a short time. 
According to the first to fourth embodiments and the sixth embodiment, the 
control parameters are automatically regulated for each combination of 
drive units and media at the time of initializing operation. In the fifth 
embodiment, by contrast, the control parameters are automatically 
regulated by progressive learning. The present invention is not limited to 
either mode, however, but one of the two modes can be incorporated 
selectively. In this way, the configuration is changed appropriately in 
accordance with the application and propensity of each user or the number 
of drive units or media used. The optimum operation can thus be realized 
to meet various operating environments for an improved operating 
efficiency. 
The storage means used for storing the control parameters or the like data 
in the control unit in the first to sixth embodiments may be configured of 
a nonvolatile memory. Then the memory contents are not erased at the time 
of power failure or the like happening but can still be used as they are. 
Consequently, the time-consuming initializing operation is not required 
and the time before the system is restored is shortened, leading to an 
improved operating efficiency. 
Further, apart from the auto-changer of tray/magazine type described with 
reference to the first to sixth embodiments, the invention is applicable 
with completely equal effect to a tray-type or a cartridge-type 
auto-changer without any magazine. 
Furthermore, the first to sixth embodiments use the drive unit capable of 
processing both a read-only medium and a read-write medium. The present 
invention, however, is not necessarily limited to such a configuration. 
The use of a reproduction apparatus capable of processing only a read-only 
medium or a recording-reproducing apparatus capable of processing only a 
read-write medium, even though the advantage is lost of the possibility of 
processing the two types of media in a single apparatus, considerably 
shortens the starting time and improves the overall operating efficiency 
of the system including the recording-reproducing apparatus. 
Although the present invention has been described in terms of the presently 
preferred embodiments, it is to be understood that such disclosure is not 
to be interpreted as limiting. Various alterations and modifications will 
no doubt become apparent to those skilled in the art to which the present 
invention pertains, after having read the above disclosure. Accordingly, 
it is intended that the appended claims be interpreted as covering all 
alterations and modifications as fall within the true spirit and scope of 
the invention.