U.S. patent application number 10/437389 was filed with the patent office on 2003-10-16 for information recording-reproducing apparatus.
This patent application is currently assigned to Pioneer Corporation. Invention is credited to Matsuo, Kazunori, Takahashi, Teruo, Yoshida, Susumu.
Application Number | 20030193850 10/437389 |
Document ID | / |
Family ID | 18089459 |
Filed Date | 2003-10-16 |
United States Patent
Application |
20030193850 |
Kind Code |
A1 |
Matsuo, Kazunori ; et
al. |
October 16, 2003 |
Information recording-reproducing apparatus
Abstract
An information recording-reproducing apparatus includes carrier
rollers 1a, 2a arranged in a carriage path having a width almost
equal to a diameter of a large diameter disc, and a mechanical side
switch PSW at one peripheral end of the carriage path. First and
second optical detectors P1, P2 are arranged in the carriage path
at an interval smaller than a diameter of the small diameter disc.
The first optical detector P1 and the side switch PSW are arranged
at an interval larger than the diameter of the small diameter disc,
while the second optical detector P2 and the side switch PSW are
arranged at an interval smaller than the diameter of the small
diameter disc. The type of the disc as well as difference between
the disc and an object other than the disc are determined based on
the detection signals from the optical detectors P1, P2 and the
side switch PSW. As a result, the information recording-reproducing
apparatus can be applicable to discs having different formats, and
prevent an unexpected accident caused by insertion of a foreign
matter.
Inventors: |
Matsuo, Kazunori;
(Saitama-ken, JP) ; Takahashi, Teruo;
(Saitama-ken, JP) ; Yoshida, Susumu; (Saitama-ken,
JP) |
Correspondence
Address: |
ARENT FOX KINTNER PLOTKIN & KAHN
1050 CONNECTICUT AVENUE, N.W.
SUITE 400
WASHINGTON
DC
20036
US
|
Assignee: |
Pioneer Corporation
|
Family ID: |
18089459 |
Appl. No.: |
10/437389 |
Filed: |
May 14, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10437389 |
May 14, 2003 |
|
|
|
09433956 |
Nov 4, 1999 |
|
|
|
Current U.S.
Class: |
369/30.36 ;
369/53.22; G9B/19.017 |
Current CPC
Class: |
G11B 19/12 20130101;
G11B 17/0515 20130101 |
Class at
Publication: |
369/30.36 ;
369/53.22 |
International
Class: |
G11B 007/085 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 11, 1998 |
JP |
10-317545 |
Claims
What is claimed is:
1. A carrying apparatus for carrying an information recording
medium as an object to,be carried in an information
recording-reproducing apparatus, comprising: a carrying mechanism
for carrying a carried medium; a determining unit for determining
whether or hot said carried medium carried by said carrying
mechanism is the recording medium as the object to be carried; and
a controller for outputting an ejection signal to said carrying
mechanism when said carried medium is not the recording medium to
be carried, based on a result of determination by said determining
unit, wherein said carrying mechanism ejects said carried medium in
accordance with said ejection signal.
2. A carrying apparatus according to claim 1, wherein: said
determining unit determines which said carried medium carried by
said carrying mechanism is, a large diameter disc of recording
medium or a small diameter disc of recording medium; and said
controller outputs said ejection signal when said determining unit
determines that said carried medium is the small diameter disc.
3. A carrying apparatus according to claim 1, further comprising: a
bearing section for bearing said recording medium; a retaining
section for retaining said recording medium in cooperation with
said bearing section; a rotating mechanism for driving said bearing
section with rotation; and a driving unit for applying a driving
force onto said rotating mechanism, wherein said driving unit
determines said driving force to be applied on said rotating
mechanism, based on said result of determination by said
determining unit.
4. A method for carrying an information recording medium as an
object to be carried in an information recording-reproducing
apparatus, the method comprising the steps of: carrying a carried
medium from an insertion port; determining whether or not said
carried medium is the recording medium as the object to be carried;
outputting an ejection signal when said carried medium is not the
recording medium to be carried, based on a result of said
determination, and ejecting said carried medium in accordance with
said output of said ejection signal.
5. An information recording-reproducing apparatus comprising: a
carrying mechanism for carrying a carried medium; detectors for
detecting said carried medium; a determining section for
determining a kind of said carried medium based on detection
signals output from said detectors; and a controller for
controlling said carrying mechanism, wherein said controller
outputs a control signal for instructing an ejecting operation to
said carrying mechanism when said determining section determines
that said carried object is not said object to be installed, said
carrying mechanism performing said ejecting operation or a stopping
operation in response to said control signal.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to an information
recording-reproducing apparatus which records and/or reproduces
information on a recording medium, such as a CD (compact disc) and
a DVD (digital versatile disc), and more particularly to an
information recording-reproducing apparatus of this kind, which has
a slot-in type carrier mechanism provided therefor, for installing
and ejecting the recording medium.
[0002] There are known information recording-reproducing
apparatuses having a slot-in type carrier mechanism provided
therefor, among which is an information reproducing apparatus
mounted in vehicles, i.e. an in-vehicle information reproducing
apparatus. The conventional in-vehicle information reproducing
apparatus includes carrier mechanism composed of carrier rollers
which carry a recording medium into the interior of the apparatus
(loading) and eject the recording medium from the apparatus
(unloading), and photo sensors which detect the position of the
recording medium. The carrier rollers are controlled based on
detection signals output from the photo sensors, to thereby carry
out the above-mentioned loading and unloading of the recording
medium.
[0003] In these years, however, various types of recording media
have been developed which are the same in information recording and
reproducing method but different in standard. For instance, with
respect to CD's (compact discs), in addition to two conventionally
known discs, i.e. a 8-cm diameter disc and a 12-cm diameter disc, a
Maxi single disc has been standardized recently. To cope with the
variety of the types, it is a significant challenge for the
information reproducing apparatus to enhance its general
applicability, i.e. to be applicable to any discs irrespective of
their types.
[0004] FIGS. 14 to 16 show the formats of a 8-cm diameter disc, a
12-cm diameter disc, and a Maxi single disc, respectively. The 8-cm
diameter disc (see FIG. 14) includes a center hall having a bore
diameter of 15 mm, a clamping area having a diameter of 33 mm, and
a program area, on which information is recorded, at an outer
periphery thereof outside a circle having a diameter of 50 mm. On
the other hand, the 12-cm diameter disc (see FIG. 15) includes a
center hole and a clamping area which are the same in diameter as
the 8-cm diameter disc, and a program area at an outer periphery
thereof outside a circle having a diameter of 50 mm.
[0005] The Maxi single disc (see FIG. 16) which has been
standardized recently has a diameter of 120 mm, and includes a
center hole and a clamping area which are the same in diameter as
the 8-cm diameter disc, and a program area at an outer periphery
thereof defined by an inner circle having a diameter of 50 mm and
an outer circle having a possible maximum diameter of 82 mm. In
other words, the Maxi single disc is formatted to have both the
standards of the 8-cm diameter disc and the 12-cm diameter disc.
However, its program area is set almost the same area as the 8-cm
diameter disc, and therefore an outer peripheral area AR outside
the 82-mm diameter circle is not the program area. The outer
peripheral area AR may be formed of a transparent material or an
opaque material, on which pictures, letters, or graphics may be
drawn.
[0006] As mentioned hereinabove, since various types of the discs
exist which are the same in information recording and reproducing
method but different in format, it is a significant challenge to
impart general applicability to an information
recording-reproducing apparatus. Especially, to positively install
and eject the disc, the carrier mechanism is required to have
improved accuracy in sensing the difference between the types of
the discs.
[0007] In addition to the above mentioned discs in various types,
there is conventionally proposed a toroidal adapter (see FIG. 17)
with which the 8-cm diameter disc is treated as the 12-cm diameter
disc in appearance.
[0008] The adapter is formed to have a 12-cm diameter and therein a
circular hole BR having a diameter of 80 mm, in which the 8-cm
diameter disc is mounted. By mounting the 8-cm diameter disc in the
circular hole BR, the disc as a whole can be treated similarly to
the 12-cm diameter disc.
[0009] However, the adapter like this can cause the following
disadvantage: For example, the user can insert the adapter int the
information recording-reproducing apparatus without mounting the
8-cm diameter disc. In such a case, the adapter must be quickly
ejected as a foreign matter, to thereby prevent an unexpected
accident beforehand. The real discs should be discriminated from
not only the adapter shown in FIG. 17 but also any types of foreign
matters, and therefore when the foreign matter is inserted, it
should be positively ejected, to thereby prevent an unexpected
accident.
SUMMARY OF THE INVENTION
[0010] It is therefore an object of the invention to provide an
information recording-reproducing apparatus which has general
applicability to discs manufactured according to different
standards as well as be capable of preventing an unexpected
accident caused by insertion of a foreign matter.
[0011] To attain the object, the invention provides an information
recording-reproducing apparatus intended for carrying and
installing a large diameter disc-type recording medium and a small
diameter disc-type recording medium, including a carriage path, and
carrier means for carrying the recording medium along the carriage
path. The information recording-reproducing apparatus comprises
optical detecting means arranged in the carriage path at a location
close to the carrier means, for optically detecting the recording
medium when the recording medium passes through the carriage path,
mechanical detecting means arranged in the carriage path at a
location close to the carrier means and outside the optical
detecting means with respect to a center of the carriage path, for
mechanically detecting the recording medium when the recording
medium passes through the carriage path, and determining means for
determining whether an inserted object is the large diameter
disc-type recording medium, a small diameter disc-type recording
medium, or an object not to be installed, based on detection
signals output from the optical detecting means and the mechanical
detecting means.
[0012] Preferably, the carriage path has a width almost equal to a
diameter of the large diameter recording medium, the mechanical
detecting means being arranged at one peripheral end of the
carriage path.
[0013] More preferably, the optical detecting means are comprised
of a first optical detector and a second optical detector, the
first optical detector and the second optical detector being
arranged at an interval smaller than a diameter of the small
diameter recording medium, the first optical detector and the
mechanical detecting means being arranged at an interval larger
than the diameter of the small diameter recording medium, the
second optical detector and the mechanical detecting means being
arranged at an interval smaller than the diameter of the small
diameter recording medium.
[0014] According to the arrangement, the large diameter disc-type
recording medium is detected based on the detection signals output
from the first and second optical detectors and the mechanical
detecting means, while the small diameter disc-type recording
medium is detected based on the detection signals output from the
first and second optical detectors.
[0015] Further preferably, the information recording-reproducing
apparatus includes control means for controlling the carrier means,
wherein the control means output a control signal for instructing
an ejecting operation to the carrier means when the determining
means determine that the inserted object is the object not to be
installed, the carrier means performing the ejecting operation in
response to the control signal.
[0016] According to the arrangement, when a foreign matter other
than the real recording medium or the like is inserted into the
apparatus, the foreign matter is ejected out of the apparatus, and
the carrier means are stopped. As a result, the apparatus can be
prevented from being damaged.
[0017] The above and other objects, features and advantages of the
invention will be more apparent from the following detailed
description taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a perspective view showing the construction of the
essential part of an information recording-reproducing apparatus
according to an embodiment of the invention;
[0019] FIG. 2 is a side view schematically showing the construction
of an optical pickup mechanism and a clamping mechanism of the
information recording-reproducing apparatus;
[0020] FIG. 3(a) is a plan view showing disc carrier mechanisms of
the information recording-reproducing apparatus, in positions
assumed during loading and unloading of a disc;
[0021] FIG. 3(b) is a plan view showing the disc carrier mechanisms
in positions assumed when shifted toward the disc insertion port
and held on standby;
[0022] FIG. 4 is a plan view showing the arrangement of optical
detectors P1, P2, a side switch PSW, and a home switch HSW which
are arranged in a carriage path;
[0023] FIG. 5(a) is a circuit diagram showing the arrangement of
the first optical detector P1;
[0024] FIG. 5(b) is a circuit diagram showing the arrangement of
the second optical detector P2;
[0025] FIG. 5(c) shows a truth table showing a relationship in
level between detection signals output from the first and second
optical detectors P1, P2;
[0026] FIG. 5(d) is a circuit diagram showing the arrangement of
the side switch PSW;
[0027] FIG. 5(e) is a circuit diagram showing the arrangement of
the homes switch HSW;
[0028] FIG. 5(f) shows a truth table showing a relationship in
level between detection signals output from the home switch HSW and
the side switch PSW;
[0029] FIG. 6 is a block diagram showing the arrangement of a
control circuit for controlling an operation of carrier mechanisms
during installation of the disc;
[0030] FIG. 7 is a block diagram showing the arrangement of the
control circuit for controlling the operation of the carrier
mechanisms during ejection of the disc;
[0031] FIG. 8(a) is a descriptive drawing useful in explaining a
manner of insertion of a 12-cm diameter disc or an adapter mounting
therein a 8-cm diameter disc;
[0032] FIG. 8(b) is a timing chart showing changes in the detection
signals output from the first and second optical detectors P1, P2,
the side switch PSW, and the home switch HSW, according to the
above-mentioned insertion;
[0033] FIG. 9(a) is a descriptive drawing useful in explaining a
manner of insertion of a Maxi single disc;
[0034] FIG. 9(b) is a timing chart showing changes in the detection
signals according to the above-mentioned insertion;
[0035] FIG. 10(a) is a descriptive drawing useful in explaining a
manner of insertion of the adapter alone;
[0036] FIG. 10(b) is a timing chart showing changes in the
detection signals according to the above-mentioned insertion;
[0037] FIG. 11(a) is a descriptive drawing useful in explaining a
manner of insertion of a 8-cm diameter disc;
[0038] FIG. 11(b) is a timing chart showing changes in the
detection signals according to the above-mentioned insertion;
[0039] FIG. 12 is a timing chart showing changes in the detection
signals during ejection of the disc;
[0040] FIG. 13 is a flowchart showing a program for carrying out
ejection control of the control circuit of FIG. 7;
[0041] FIG. 14 is a plan view showing the format of the 8-cm
diameter disc;
[0042] FIG. 15 is a plan view showing the format of the 12-cm
diameter disc;
[0043] FIG. 16 is a plan view showing the format of the Maxi single
disc; and
[0044] FIG. 17 is a plan view showing the shape of the adapter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] The invention will now be described in detail with reference
to the drawings showing embodiments thereof. The term the
information recording-reproducing apparatus according to the
invention refers to an information recording apparatus which
records information on a recording medium, an information
reproducing apparatus which reads and reproduces information
recorded on the recording medium, and an information
recording-reproducing apparatus which records information and
reproduces the recorded information on the recording medium.
Specifically, in the following embodiment, description will be made
of an information reproducing apparatus to be mounted in vehicles,
which has provided therefor a slot-in type carrier mechanism and a
so-called auto-changer mechanism, and accepts and installs discs
having the same information reproducing method but being different
in standard (format), as well as an adapter, shown in FIGS. 14 to
17, by way of example.
[0046] Referring first to FIG. 1, there is schematically
illustrated the construction of an information reproducing
apparatus according to the embodiment, in which a housing thereof
is removed. The information reproducing apparatus is comprised of a
pair of disc carrier mechanisms 1,2, a clamping mechanism 3, an
optical pickup mechanism 4, a fixed chassis 5, and a plurality of
(e.g. 6) accommodating trays 12 (not shown in FIG. 1). The carrier
mechanisms 1, 2 function to install a disc DS which is inserted
into the interior of the information reproducing apparatus from a
disc insertion port (not shown) formed in a front panel of the
housing, and to eject the disc DS housed in the apparatus out of
the disc insertion port. The clamping mechanism 3 is arranged at a
rear region of the apparatus, and the optical pickup mechanism 4 is
arranged under a rear side of the clamping mechanism 3 such that
the clamping mechanism 3 is superposed on the pickup mechanism 4.
The fixed chassis 5 has a pair of columnar shafts 5a, 5b raised
thereon, and the accommodating trays 12, referred to hereinafter,
are vertically moved by means of an elevator mechanism, not shown,
supported by the columnar shafts 5a, 5b.
[0047] The front panel is provided thereon with an open/close door
which is driven by a predetermined actuator mechanism, for opening
and closing the disc insertion port, a display section, and
operation button switches. Further, a carriage path having a width
almost equal to a diameter of the 12-cm diameter disc DS is formed
in the apparatus at a location between the disc insertion port and
the disc carrier mechanisms 1, 2, along which a disc guide is
arranged for guiding the disc DS passing therethrough. These
component elements mentioned above are not shown in FIG. 1.
[0048] The clamping mechanism 3 and the optical pickup mechanism 4
are mounted on another chassis (hereinafter referred to as "the
mobile chassis") 6 arranged on the fixed chassis 5. In other words,
the clamping mechanism 3 is supported by a hinge mechanism 7 so as
to move up and down (in a direction indicated by an arrow Z), over
the optical pickup mechanism 4, and the optical pickup mechanism 4
is supported by a support shaft 8 raised on an end of the mobile
chassis 6 such that the mechanism 4 can move along a horizontal
plane (X-Y plane). Further, the mobile chassis 6 is provided
therein with an arc-shaped guide hole 9, the pickup mechanism 4 is
provided therein with a long hole 10, and a guide shaft 11 is
fitted into these holes. Therefore, the guide shaft 11 moves to and
fro in a predetermined direction by means of an actuator mechanism,
not shown, which enables the optical pickup mechanism 4 and the
clamping mechanism 3 to be shifted with respect to the support
shaft 8.
[0049] Further, as shown in a side view of FIG. 2, the clamping
mechanism 3 which can be shifted has an almost circular hub 3a for
clamping, so as to face downward. On the other hand, the optical
pickup mechanism 4 has a turn table 4b arranged thereon, so as to
be opposed to the hub 3a. The turn table is driven for rotation of
the disc DS by a thin motor 4d, such as a piezoelectric motor.
Further, the optical pickup mechanism 4 includes an optical pickup
main body 4c which can be moved to and fro in a horizontal plane
with respect to the turn table 4b by means of a spindle shaft, not
shown, which is interlocked to a spindle motor 4a.
[0050] Referring again to FIG. 1, the optical pickup mechanism 4 is
provided with a mechanical switch (hereinafter referred to as "the
home switch") HSW formed by a microswitch or the like, at an end
portion thereof. The home switch HSW is provided for detecting
arrival of the disc DS at a clamping position, and upon detection
that the delivered disc DS comes in contact therewith, the home
switch HSW outputs a detection signal S.sub.HSW.
[0051] FIGS. 3(a) and 3(b) each show the construction of the disc
carrier mechanisms 1, 2, the relationship in position between the
disc carrier mechanisms 1, 2 and the accommodating trays 12
disposed between the optical pickup mechanism 4 and the clamping
mechanism 3, and the shape of each accommodating tray 12.
[0052] In the figures, the accommodating tray 12 is a plate member
having a disc bearing surface 12b in which an almost V-shaped
recess 12a is formed. Further, formed in the accommodating tray 12
are through holes 12c, 12d at locations on both sides of the disc
bearing surface 12b, and the columnar shafts 5a, 5b are fitted into
the through holes 12c, 12d, respectively. The accommodating trays
12 are superposed to form six layers which are supported by the
columnar shafts 5a, 5b, and moved in the direction of Z by means of
the elevator mechanism.
[0053] The disc carrier mechanisms 1, 2 are arranged on both sides
of the six-layered accommodating trays 12 at respective locations
closer to the front panel. The disc carrier mechanisms 1, 2 are
almost in parallel with a direction indicated by an arrow Y, as
shown in FIG. 3(a), during so-called loading and unloading. On the
other hand, when some of the six-layered accommodating trays
accommodate therein the discs DS or when the six-layered
accommodating trays 12 move up and down along the columnar shafts
5a, 5b, the carrier mechanisms 1, 2 are shifted toward the disc
insertion port, as shown in FIG. 3(b).
[0054] The disc carrier mechanisms 1, 2 each include a carrier
roller 1a, 2a, a flat abutting member 1b, 2b arranged over the
carrier roller 1a, 2a, and a power transmission mechanism 1c, 2c
formed by a gear mechanism and a belt mechanism. Further, a driving
motor 13 is provided in the vicinity of the carrier mechanism 1,
and a driving force thereof is transmitted via the power
transmission mechanisms 1c, 2c to the carrier rollers 1a, 2a,
respectively, to thereby rotate the same.
[0055] The carrier rollers 1a, 2a carry out forward rotation during
loading such that the disc DS is carried toward the side of the
accommodating tray 12, while they carry out reverse rotation during
unloading such that the disc DS is ejected from the side of the
accommodating tray 12. The rotation and stoppage of the carrier
rollers 1a, 2a are synchronously controlled. Further, the carrier
rollers 1a, 2a each have a conical trapezoidal shape such that they
each taper at an end portion facing the other. By virtue of the
shape, the disc DS can be carried through the center of the
carriage path during the loading and unloading, i.e. the disc DS is
centered while being carried (so-called "centering").
[0056] When the user operates the operation button switch on the
front panel to selectively designate a desired one of the
accommodating trays 12, the designated accommodating tray 12 is
automatically positioned with respect to the carrier rollers 1a, 2a
by means of the elevator mechanism. Then, as soon as the user
inserts the disc DS into the disc insertion port, the carrier
roller 1a and the abutting member 1b cooperate with the counter
ones 2a, 2b in retaining the disc DS for loading, to thereby place
the disc DS on the designated accommodating tray 12.
[0057] When the user designates sound reproduction, the tray 12
accommodating the designated disc DS is automatically positioned
with respect to the optical pickup mechanism 4 and the clamping
mechanism 3 by means of the elevator mechanism, then the clamping
mechanism 3 is slightly shifted upward away from the optical pickup
mechanism 4, and therefore the optical pickup mechanism 4 and the
clamping mechanism 3 enter the recess 12a of the accommodating tray
12. Thereafter, the clamping mechanism 3 is closed toward the
optical pickup mechanism 4, followed by clamping the disc DS
between the hub 3a and the turn table 4b, whereby recorded
information is read and reproduced by the optical pickup main body
4c of the optical pickup mechanism 4.
[0058] On the other hand, when the user provides an instruction to
eject the disc DS which has been already accommodated in the tray
12, the optical pickup mechanism 4 and the clamping mechanisms 3
return to predetermined standby positions, respectively, as shown
in FIG. 1, and the tray 12 accommodating the designated disc DS is
automatically positioned with respect to the carrier rollers 1a, 2a
by means of the elevator mechanism. Then, the disc DS is unloaded
by the carrier rollers 1a, 2a such that the disc DS is retained by
the abutting members 1b, 2b, to thereby eject the disc DS out of
the disc insertion port.
[0059] Next, description will be made of a control mechanism for
controlling the disc carrier mechanisms 1, 2, with reference to
FIGS. 4 to 13.
[0060] As shown in a plan view of FIG. 4, in addition to the home
switch HSW mentioned above, there are arranged a first optical
detector P1 in front of the carrier roller 1a, and a second optical
detector P2 behind the carrier roller 2a, respectively. Further, a
mechanical switch (hereinafter referred to as "the side switch")
PSW formed by a microswitch or the like, is arranged along with a
carrier surface of the carrier roller 2a.
[0061] The first and second optical detectors P1 and P2 are spaced
less than 8 cm away from each other, i.e. arranged at an interval
smaller than a diameter of the 8-cm diameter disc DS. Further, the
first optical detector P1 is provided mainly for detecting
insertion of the disc to activate the carrier rollers 1a, 2a, while
the second optical detector P2 is provided mainly for detecting a
rear end portion of the disc when ejected to terminate rotations of
the carrier rollers 1a, 2a.
[0062] The side switch PSW is arranged at a location at which the
12-cm diameter disc DS allows its peripheral edge to come in
contact with the same when the disc DS is carried by being retained
between the carrier rollers 1a, 2a and the abutting members 1b, 2b.
The distance between the first optical detector P1 and the side
switch PSW is set to a value larger than the diameter of the 8-cm
diameter disc DS.
[0063] As shown in circuit diagrams of FIGS. 5(a) and 5(b), the
first and second optical detectors P1, P2 are applications of photo
interrupters each including a photo diode and a photo transistor
facing each other. Further, as understood from a truth table of
FIG. 5(c), when an object such as the disc DS passes between the
photo diode and the photo transistor (hereinafter referred to as
the "CLOSE level"), the voltage levels of respective detection
signals S.sub.P1 and S.sub.P2 are at logic H (high), whereas when
no object passes between the photo diode and the photo transistor
(hereinafter referred to as the "OPEN level"), the voltage levels
of the respective detection signals S.sub.P1 and S.sub.P2 are at
logic L (low).
[0064] On the other hand, as shown in circuit diagrams of FIGS.
5(d) and 5(e), the side switch PSW and the home switch HSW are each
formed by a normally open microswitch and a transistor. Further, as
understood from a truth table of FIG. 5(F), when an object such as
the disc DS does not come in contact with the microswitch
(hereinafter referred to as the "OFF level"), the voltage levels of
detection signals S.sub.PSW and S.sub.HSW are at logic H (high). On
the other hand, when the object comes in contact with the
microswitch (hereinafter referred to as the "ON level"), the
voltage levels of the detection signals S.sub.PSW and S.sub.HSW are
at logic L (low).
[0065] In regard of this point, the first and second optical
detectors P1 and P2 are each formed by a transmission-type optical
detector, according to the present embodiment, which detects
interception and transmission of beams depending on presence or
absence of the object such as the disc DS, but this is not
limitative. Alternatively, a reflection-type optical detector which
detects reflected beams of incident light from the object may be
employed for detecting presence or absence of the object such as
the disc DS.
[0066] Next, description will be made of the arrangement of a
control circuit for controlling the disc carrier mechanisms 1, 2,
based on the detection signals S.sub.P1, S.sub.P2, S.sub.HSW,
S.sub.PSW which are output from the optical detectors P1, P2, the
home switch HSW, and the side switch PSW, respectively, with
reference to FIGS. 6 and 7.
[0067] The control circuit shown in each figure is mounted on an
electric circuit substrate which is attached to a rear surface of
the fixed chassis 5 or the like, and comprised of a central control
unit 14 having a microprocessor unit (MPU), and a driving section
15 for supplying power to the driving motor 13 which drives the
carrier rollers 1a, 2a, according to an instruction from the
central control unit 14.
[0068] Further, the control circuit is comprised of first to ninth
state monitoring sections 16 to 24 and timeout monitoring sections
25 to 27 which are each formed as the firmware according to a
system program previously stored in a read only memory (ROM).
[0069] More specifically, the ROM is connected to the central
control unit 14, and the system programs stored in the ROM is
executed by the microprocessor unit (MPU) in the central control
unit 14, to thereby realize the first to ninth state monitoring
sections 16 to 24 and the timeout monitoring sections 25 to 27 each
having a function equivalent to the hardware.
[0070] In actuality, the detection signals S.sub.P1, S.sub.P2,
S.sub.HSW, S.sub.PSW output from the first and second optical
detectors P1, P2, the home switch HSW, and the side switch PSW,
respectively, are supplied to the central control unit 14 which
then controls the carrier rollers 1a, 2a in response to these
signals S.sub.P1, S.sub.P2, S.sub.HSW, S.sub.PSW. To make clearer
and more understandable the description of the invention, it is
assumed, for the sake of convenience, that the state monitoring
sections 16 to 19 each having an individual function are supplied
with the detection signals S.sub.P1, S.sub.P2, S.sub.HSW,
S.sub.PSW. Further, the arrangement of the control circuit for
executing the loading operation of the carrier rollers 1a and 2a is
shown in FIG. 6, while the arrangement of the same for executing
the unloading operation is shown in FIG. 7.
[0071] As understood from FIG. 6, when the user provides an
instruction to insert the disc DS, the central control unit 14
supplies a start signal S.sub.T to the first state monitoring
section 16 in synchronization with the instruction. Further, the
central control unit 14 supplies a control signal S.sub.MO to the
driving section 15 in synchronization with the start signal
S.sub.T, which allows the carrier rollers 1a, 2a to start forward
rotation.
[0072] Then, the first state monitoring section 16 starts its
operation in synchronization with the start signal S.sub.T, i.e. to
check changes in the detection signals S.sub.PSW and S.sub.P1
output from the side switch PSW and the first optical detector P1,
respectively, to thereby determine which one of the 8-cm diameter
disc DS, the 12-cm diameter disc DS, the Maxi single disc DS, and
the adapter is inserted. At the same time, the first state
monitoring section 16 returns a determination signal S.sub.CD to
the central control unit 14.
[0073] More specifically, if the first state monitoring section 16
detects, after starting of the forward rotation of the carrier
rollers 1a, 2a, that the detection signal S.sub.PSW is changed from
the OFF level to the ON level while the detection signal S.sub.P1
remaining in the CLOSE level, the monitoring section 16 determines
that one of the 12-cm diameter disc DS, the Maxi single disc DS,
and the adapter mounting therein the 8-cm diameter disc has been
inserted.
[0074] On the other hand, if the detection signal S.sub.P1 has been
changed from the CLOSE level to the OPEN level before the detection
signal S.sub.PSW is changed from the OFF level to the ON level, it
is determined that either the 8-cm diameter disc or the adapter
without mounting the 8-cm diameter disc has been inserted.
[0075] The first state monitoring section 16 carries out the above
determination process over a time period .tau.1 from the time the
user provided the instruction to insert the disc DS to the time the
type of the disc DS inserted into the apparatus is identified.
[0076] The second state monitoring section 17 starts its operation
in synchronization with a time point at which the first state
monitoring section 16 returns the determination signal S.sub.CD to
the central control unit 14, and monitors the state of disc
carriage, based on the detection signals S.sub.PSW and S.sub.P1
from the side switch PSW and the first optical detector P1,
respectively. That is, the second state monitoring section 17
monitors the state of the disc carriage immediately after the lapse
of the time period .tau.1, based on changes in the detection
signals S.sub.PSW and S.sub.P1.
[0077] If the detection signal S.sub.PSW is changed from the OFF
level to the ON level while the detection signal S.sub.P1 remaining
in the CLOSE level, the second state monitoring section 17 detects
the change, thereby issuing an instruction to start an operation to
the third state monitoring section 18. Accordingly, the second
state monitoring section 17 executes the above determination
process over a time period .tau.2, i.e. immediately after the lapse
of the above-mentioned time period .tau.1 to the determination of
the above change.
[0078] The third state monitoring section 18 monitors the state of
the disc carriage immediately after the lapse of the
above-mentioned time period .tau.2. Herein, the timeout monitoring
section 26 formed by a program timer is started immediately after
the lapse of the time period .tau.2.
[0079] Further, if it is determined that the detection signal
S.sub.P1 has been changed from the CLOSE level to the OPEN level,
the third state monitoring section 18 issues an instruction to
start an operation to the fourth state monitoring section 19.
Accordingly, the third state monitoring section 18 monitors the
state of the disc carriage over a time period .tau.3, i.e.
immediately after the lapse of the above-mentioned time period
.tau.2 to the time the detection signal S.sub.P1 is changed to the
OPEN level.
[0080] The fourth state monitoring section 19 supplies a brake
control signal S.sub.BK to the central control unit 14 immediately
after the lapse of the time period .tau.3.
[0081] Upon reception of the brake control signal S.sub.BK, the
central control unit 14 issues an instruction, to the driving
section 15, to rotate the carrier rollers 1a, 2a at a slightly high
rotational speed over a short time period, whereby the rollers 1a,
2a delivers the disc DS in a manner pressing the same toward the
accommodating tray 12.
[0082] When the leading end of the disc DS comes in contact with
the home switch HSW to change the level of the detection signal
S.sub.HSW of the home switch HSW from the OFF level to the ON
level, the fourth state monitoring section 19 determines that the
level of the home switch HSW has been changed, and then supplies a
result of determination to the timeout monitoring section 26. At
the same time, the fifth state monitoring section 20 is started to
execute its operation.
[0083] Herein, if the detection signal S.sub.HSW is not changed
from the OFF level to the ON level even when a measured time period
T.sub.O1 exceeds a first predetermined timeout period of 500 msec,
the timeout monitoring section 26 outputs a timeout signal
S.sub.TO1 indicative of occurrence of abnormality to the central
control unit 14, to thereby terminate the operation of the carrier
rollers 1a, 2a.
[0084] Upon reception of the above-mentioned determination result
from the fourth state monitoring section 19, the fifth state
monitoring section 20 determines that the disc DS has been loaded
normally on the accommodating tray 12, and therefore, it outputs a
confirmation signal S.sub.AK1 to the timeout monitoring section 25
formed by a program timer or the like.
[0085] If the timeout monitoring section 25 receives the
confirmation signal S.sub.AK1 after the output of the start signal
S.sub.T and before the lapse of a second timeout period of 8 sec,
it supplies a signal indicative of the fact that the carriage
operation has been carried out normally, to the central control
unit 14, and then the central control unit 14 forcibly terminates
the operation of the carrier rollers 1a, 2a, based on the
signal.
[0086] On the other hand, if the timeout monitoring section 25 does
not receive the confirmation signal S.sub.AK1 even if a time period
T.sub.02 measured after the output of the start signal S.sub.T
exceeds the predetermined second timeout period of 8 sec, it
supplies a timeout signal S.sub.TO2 indicative of occurrence of
abnormality to the central control unit 14, and then the central
control unit 14 forcibly terminates the operation of the carrier
rollers 1a, 2a.
[0087] More specifically, the timeout monitoring section 25
monitors the processing time periods required for the first state
monitoring section 16 to the fourth state monitoring section 19,
based on the timeout period (8 sec), to thereby determine whether
or not abnormality has occurred and whether or not the disc DS has
been inserted. On the other hand, the timeout monitoring section 26
monitors whether or not the disc DS has been positively delivered
from the positions of the carrier rollers 1a, 2a to the
accommodating tray 12, based on the timeout period (500 msec).
Further, upon reception of the timeout signals S.sub.TO1, S.sub.TO2
from the timeout monitoring sections 25, 26, the central control
unit 14 outputs the control signal S.sub.MO to the driving section
15, to thereby terminate the operation of the carrier rollers 1a,
2a, or the like. As a result, an accident such as intrusion of a
foreign matter into the interior of the apparatus can be
prevented.
[0088] If the determination signal S.sub.CD indicates that either
the 8-cm diameter disc DS or the adapter alone has been inserted,
the central control unit 14 outputs the control signal S.sub.MO to
the driving section 15, so that the carrier rollers 1a, 2a carry
out reverse rotation and hence unloading operation.
[0089] Next, the loading operation will be more specifically
described with respect to the respective types of the discs DS and
the adapter, with reference to FIGS. 8 to 11. FIGS. 8(a) and 8(b)
schematically show a case where the 12-cm diameter disc DS or the
adapter mounting therein the 8-cm diameter disc DS is inserted,
FIGS. 9(a) and 9(b) a case where the Maxi single disc DS is
inserted, FIGS. 10(a) and 10(b) a case where the adapter alone is
inserted without mounting the 8-cm diameter disc DS, and FIGS.
11(a) and 11(b) a case where the 8-cm diameter disc DS is inserted,
respectively.
[0090] Further, in each of FIGS. 8(b), 9(b), 10(b), and 11(b),
changes in voltage level of the optical detection signals S.sub.P1,
S.sub.P2, S.sub.HSW, S.sub.PSW output from the first and second
optical detectors P1, P2, the home switch HSW, and the side switch
PSW, respectively, are shown according to the change in operation
of each of the discs DS, and the adapter. Further, .tau.1 to .tau.3
in each figure represent the monitoring time periods .tau.1 to
.tau.3 for the first to third state monitoring sections 16 to 18,
respectively.
[0091] As shown in FIGS. 8(a) and 8(b), when the 12-cm diameter
disc DS is inserted from the disc insertion port, the first optical
detector P1 detects the leading end of the 12-cm diameter disc DS
before detection of the same by the second optical detector P2, and
therefore the detection signal S.sub.P1 changes from the OPEN level
to the CLOSE level prior to the change of the detection signal
S.sub.P2.
[0092] The first state monitoring section 16 monitors that the
detection signal S.sub.P1 has been changed to the CLOSE level and
sequentially monitors whether or not the detection signal S.sub.PSW
from the side switch PSW is changed from the OFF level to the ON
level. Upon the change of the detection signal S.sub.PSW to the ON
level, the first monitoring section 16 determines that one of the
12-cm diameter disc DS, the Maxi single disc DS, and the adapter
mounting therein the 8-cm diameter disc DS is inserted, and
therefore supplies the determination signal S.sub.CD to the central
control unit 14.
[0093] The time period .tau.1 from the time the first optical
detector P1 detects the leading end of the disc DS to the time the
determination signal S.sub.CD is output corresponds to the
monitoring time period .tau.1 described above. Thereafter, the
loading operation is carried out under monitoring by the second to
fifth state monitoring sections 16 to 20, and it is completed when
the detection signal S.sub.HSW from the home switch HSW is inverted
from the OFF level to the ON level.
[0094] Herein, individual identification of the 12-cm diameter disc
DS, the Maxi single disc DS and the adapter mounting therein the
8-cm diameter disc DS is not performed, since they have
substantially the same diameter. As a result, the first state
monitoring section 16 substantially determines that the 12-cm
diameter disc DS has been inserted.
[0095] In this manner, the first state monitoring section 16
monitors the detection signals S.sub.P1 and S.sub.PSW and when the
detection signal S.sub.PSW is changed from the OFF level to the ON
level while the detection signal S.sub.P1 remaining at the CLOSE
level within the timeout period of 8 sec, the first state
monitoring section 16 determines that the 12-cm diameter disc DS
has been inserted.
[0096] Further, if the adapter mounting therein the 8-cm diameter
disc DS is inserted, identification thereof is carried out under
the same monitoring operation, and therefore the adapter with the
disc DS is also loaded at the predetermined clamping position
without fail.
[0097] Next, as shown in FIGS. 9(a) and 9(b), when the Maxi single
disc DS is inserted from the disc insertion port, the detection
signal S.sub.P1 from the first optical detector P1 assumes the
CLOSE level over a long time period, as well.
[0098] In regard of this point, if the Maxi single disc DS has a
transparent area AR at an outer periphery thereof, the detection
signals S.sub.P1, S.sub.P2 from the first and second optical
detectors P1, P2 are changed as indicated by the solid lines,
respectively. On the other hand, if the area AR is entirely opaque,
or partially includes opaque portions due to a pattern, etc., the
detection signals S.sub.P1, S.sub.P2 are changed from the OPEN
level to the CLOSE level during time periods each inclusive of
hatched portions in the figure. In both the cases, however, the
detection signal S.sub.P1 from the first optical detector P1 is
changed to the CLOSE level before the change of the detection
signal S.sub.P2 from the second optical detector P2.
[0099] The first state monitoring section 16 monitors that the
detection signal S.sub.P1 has been changed to the CLOSE level and
sequentially monitors whether or not the detection signal S.sub.PSW
from the side switch PSW is changed from the OFF level to the ON
level. Upon the change of the detection signal S.sub.PSW to the ON
level, the first monitoring section 16 determines that one of the
Maxi single disc DS, the 12-cm diameter disc DS, and the adapter
mounting therein the 8-cm diameter disc DS is inserted, to thereby
supply the determination signal S.sub.CD to the central control
unit 14.
[0100] The time period .tau.1 from the time the first optical
detector P1 detects the leading end of the disc DS to the time the
determination signal S.sub.CD is output corresponds to the
monitoring time period .tau.1 described above. Thereafter, the
loading operation is carried out under monitoring by the second to
fifth state monitoring sections 17 to 20, and when the detection
signal S.sub.HSW of the home switch HSW is inverted from the OFF
level to the ON level, the loading is completed.
[0101] In this case as well, individual identification of the Maxi
single disc DS, the 12-cm diameter disc DS, and the adapter
mounting therein the 8-cm diameter disc DS is not carried out,
since they have substantially the same diameter. As a result, the
first state monitoring section 16 substantially determines that the
Maxi single disc DS has been inserted.
[0102] In regard of this point, as shown in FIG. 9(b), timing at
which the detection signal S.sub.P1 is changed from the CLOSE level
to the OPEN level may be varied depending on an opacity degree of
the outer peripheral area AR, i.e. whether or not the outer
peripheral area AR is entirely opaque. Therefore, the monitoring
time period .tau.3 may be varied in the range of .tau.3'. Even if
the monitoring time period .tau.3 is varied, however, the variation
in the time period .tau.3 within the fist timeout period (500 msec)
is not regarded as abnormality occurrence, and therefore the Maxi
single disc DS can be surely loaded on the predetermined clamping
position.
[0103] Next, as shown in FIGS. 10(a) and 10(b), when the adapter
alone without mounting therein the 8-cm diameter disc DS is
inserted from the disc insertion portion, the first optical
detector P1 detects the leading end of the adapter before the
detection thereof by the second optical detector P2, and therefore
the detection signal S.sub.P1 is changed from the OPEN level to the
CLOSE level prior to the change of the detection signal S.sub.P2.
Further, the first optical detector P1 detects a circular opening
BR of the adapter, and therefore the detection signal S.sub.P1 is
inverted again from the CLOSE level to the OPEN level.
[0104] The side switch PSW is arranged at a location where the
outer peripheral edge of the adapter can be detected, and
therefore, after the detection signal S.sub.P1 is inverted again
from the CLOSE level to the OPEN level, the detection signal
S.sub.PSW is changed from the OFF level to the ON level.
[0105] If the detection signal S.sub.P1 is inverted again from the
CLOSE level to the OPEN level (at a time point t.sub.AD) while the
detection signal S.sub.PSW remaining in the OFF level, the first
state monitoring section 16 determines that the adapter alone is
inserted. Therefore, the unloading operation is carried out based
on a result of determination, whereby the adapter is ejected to the
disc insertion port (forcible ejection).
[0106] In this manner, in case of insertion of the adapter alone,
the adapter is ejected, which leads to prevention of an unexpected
accident beforehand.
[0107] Next, a case where the 8-cm diameter disc DS is inserted
will be described with reference to FIGS. 11(a) and 11(b). As shown
in the figures, when the 8-cm diameter disc DS is inserted from the
disc insertion port into an intermediate area between the carrier
rollers 1a, 2a, i.e. a central area in the carriage path, the 8-cm
diameter disc DS is delivered without contact with the side switch
PSW, and therefore the detection signal S.sub.PSW from the side
switch PSW assumes the OFF level during the delivery of the disc
DS. On the other hand, the first optical detector P1 detects the
leading end and the rear end of the 8-cm diameter disc DS.
Therefore, the detection signal S.sub.P1 thereof is changed once
from the OPEN level to the CLOSE level, and then inverted again
from the CLOSE level to the OPEN level.
[0108] The first state monitoring section 16 determines that the
8-cm diameter disc DS alone is inserted when the second inversion
of the detection signal S.sub.P1 from the CLOSE level to the OPEN
level has occurred while the detection signal S.sub.PSW remaining
in the OFF level. Then, unloading is carried out based on a result
of determination, and therefore the 8-cm diameter disc DS is
ejected to the disc insertion port (forcible ejection).
[0109] The information reproducing apparatus according to the
present embodiment is applicable to the 12-cm diameter disc DS, the
Maxi single disc DS, and the adapter mounting therein the 8-cm
diameter disc DS. Therefore, when the 8-cm diameter disc DS is
inserted, the disc DS is forcibly ejected. However, as described
hereinafter in a variation of the present embodiment, the
information reproducing apparatus may be configured to be
applicable to the 8-cm diameter disc DS.
[0110] Next, description will be made of the arrangement of the
control circuit for controlling the unloading operation, with
reference to FIG. 7.
[0111] In the figure, the sixth state monitoring section 21 starts
its operation in synchronization with a start signal S.sub.T'
output from the central control unit 14. Further, when the carrier
rollers 1a, 2a are started to carry out reverse rotation in
synchronization with the start signal S.sub.T', the sixth
monitoring section 21 monitors whether or not the detection signal
S.sub.PSW from the side switch is changed from the OFF level to the
ON level, and when the change to the ON level is detected, the
sixth state monitoring section 21 issues an instruction to start an
operation to the seventh state monitoring section 22.
[0112] Thereafter, the seventh state monitoring section 22 monitors
whether or not the detection signal S.sub.PSW from the side switch
PSW is changed again from the ON level to the OFF level, and when
the change to the OFF level is detected, it issues an instruction
to start an operation to the eighth state monitoring section
23.
[0113] Thereafter, when the eighth state monitoring section 23
detects that the detection signal S.sub.P2 from the second optical
detector P2 has been changed from the CLOSE level to the OPEN
level, it determines that the rear end of the disc DS is out of
contact, followed by supplying a brake control signal S.sub.BK' to
the central control unit 14 in order to terminate the operation of
the driving motor 13. Then, the carrier rollers 1a, 2a are stopped
while receiving an inertial force, and finally they are stopped
with one end of the disc DS retained therebetween. As a result,
even if the carrier mechanisms of the reproducing apparatus
according to the present invention is of a slot-in type as, the
disc DS can be ejected without being slipped out of the disc
insertion port.
[0114] Further, the eighth state monitoring section 23 supplies a
termination signal S.sub.AK2 to the timeout monitoring section 27
to indicate that the carrier rollers 1a, 2a are stopped.
[0115] When the instruction to carry out the unloading is provided
by the user, the timeout monitoring section 27 starts to measure a
time period in synchronization with the start signal S.sub.T'
supplied from the central control unit 14. If the timeout
monitoring section 27 receives the termination signal S.sub.AK2
within a predetermined third timeout period of 8 sec, the timeout
monitoring section 27 determines that the unloading is carried out
normally, followed by issuing a notification of the normal
unloading to the central control unit 14. On the other hand, if the
section 27 does not receive the termination signal S.sub.AK2 within
the predetermined third timeout period of 8 sec, it issues a
notification that the carrier rollers 1a, 2a should be stopped, to
the central control unit 14. In this manner, by forcibly stopping
the carrier rollers 1a, 2a, occurrence of an accident, such as
presence of a foreign matter in the apparatus can be prevented
beforehand.
[0116] When the user pulls the disc DS out of the disc insertion
port, the detection signal S.sub.P1 output from the first optical
detector P1 is changed from the CLOSE level to the OPEN level. Upon
detection of the change of the detection signal S.sub.P1, the ninth
state monitoring section 24 determines that ejection of the disc DS
has been finally completed, followed by output of a completion
signal S.sub.OK to the central control unit 14.
[0117] Next, the unloading operation of the control circuit of FIG.
7 will be more specifically described according to a timing chart
shown in FIG. 12 and a flowchart shown in FIG. 13.
[0118] FIG. 13 shows the operation of the central control unit 14
executed before the operations of the sixth to ninth state
monitoring sections 21 to 24 are started.
[0119] First, at a step 101 in FIG. 13, it is checked whether or
not a power circuit, not shown, for supplying electric power to the
first and second optical detectors P1, P2 are stable. If the power
circuit is stable, then measurement of the time period is started
at the timeout monitoring section 27, at a step 102.
[0120] Next, a memory preset in the central control unit 14, which
stores a state of disc accommodation, is referred to, and then it
is determined at a step 103 whether or not the disc DS is
accommodated in the accommodating tray 12. If the disc DS is not
present, then it is determined at a step 104 whether or not the
detection signal S.sub.P2 from the second optical detector P2 is in
the OPEN level. If the detection signal S.sub.P2 is in the CLOSE
level, the program proceeds to a step 105, wherein the carrier
rollers 1a, 2a are started to carry out reverse rotation, followed
by execution of the unloading of the disc DS under monitoring by
the sixth to ninth state monitoring sections 21 to 24, as shown in
FIG. 7.
[0121] On the other hand, if it is determined at the step 104 that
the detection signal S.sub.P2 is in the OPEN level, the program
proceeds to a step 106. Then, the carrier rollers 1a, 2a are forced
to carry out reverse rotation over a predetermined time period
without presence of the disc DS, followed by being held on
standby.
[0122] On the other hand, if it is determined at the step 103 that
the disc DS is present, the program skips to the step 105, wherein
the above-mentioned unloading process is executed.
[0123] When the unloading process of the step 105 is started, the
detection signals S.sub.P1, S.sub.P2, S.sub.PSW, S.sub.HSW from the
first and second photo sensors P1, P2, the side switch PSW, and the
home switch HSW, respectively, are changed in a manner shown in the
timing chart of FIG. 12.
[0124] In this manner, the control circuit of FIG. 7 carries out
the monitoring, based on the detection signals S.sub.P1, S.sub.P2,
S.sub.PSW, S.sub.HSW, and therefore the unloading operation is
carried out normally.
[0125] As described hereinabove, according to the information
reproducing apparatus of the present embodiment, installation and
ejection of the disc DS and the adapter are controlled based on the
detection signals S.sub.P1, S.sub.P2, S.sub.PSW, S.sub.HSW output
from the first and second optical detectors P1, P2, the side switch
PSW, and the home switch HSW, respectively, a real disc can be
installed and ejected in a correct manner without fail. Further, if
the adapter alone or a foreign matter is inserted, it can be
forcibly ejected, which leads to enhanced reliability of the
information reproducing apparatus of the present invention.
[0126] In the above embodiment, the 8-cm diameter disc DS is
forcibly ejected, but this is not limitative. Alternatively,
according to a variation of the present embodiment, the information
reproducing apparatus may be configured so as to accept and install
the 8-cm diameter disc DS.
[0127] In this variation, when the 8-cm diameter disc DS is
inserted from the disc insertion port toward the carrier rollers
1a, 2a, the detection signal S.sub.PSW from the side switch PSW
always assumes the OFF level during the delivery of the disc DS, as
shown in FIG. 11. On the other hand, the first optical detector P1
detects the leading end and the rear end of the 8-cm diameter disc
DS, and therefore its detection signal S.sub.P1 is changed once
from the OPEN level to the CLOSE level, and then inverted again
from the CLOSE level to the OPEN level.
[0128] Accordingly, the first state monitoring section 16
determines that the 8-cm diameter disc DS alone is inserted when
the second inversion of the detection signal S.sub.P1 from the
CLOSE level to the OPEN level has occurred while the detection
signal S.sub.PSW remaining in the OFF level.
[0129] Further, to cope with insertion of the 8-cm diameter disc DS
in a fashion being out of alignment with the center of the disc
insertion port, a mechanism for placing the 8-cm diameter disc DS
at the center of the carrier rollers 1a, 2a, i.e. for centering the
disc between the carrier rollers is provided
[0130] The centering mechanism is realized, for example, by
providing biasing members on both sides of the disc guide at a
location between the disc insertion port and the disc carrier
rollers 1a, 2a. The biasing members function to elastically bias
side edges of the disc DS irrespective of disc size in diameter,
with a force which does not hinder the disc DS from passing
therethrough. By virtue of the elastically biasing force, the disc
can be positioned at the center of the carriage path irrespective
of its type.
[0131] In addition, to accommodate the disc DS carried by the
carrier rollers 1a, 2a to the predetermined clamping position, a
well-known positioning member may be provided. By virtue of this
positioning member, any of the 8-cm diameter disc DS, the 12-cm
diameter disc DS, the Maxi single disc DS, and the adapter mounting
therein the 8-cm diameter disc can be positioned at the
predetermined clamping position.
[0132] In the above described embodiments, the first and second
optical detectors P1, P2, the side switch PSW, and the home switch
HSW are arranged, and therefore positive loading and unloading are
carried out by the carrier mechanisms 1, 2. Alternatively, a
mechanically fallable type switch SWn may be arranged in addition
to the optical detectors P1 and P2, as shown in FIG. 4, on one side
of the carrier rollers 1a, 2a closer to the front panel and at the
center between the same. Thus, the carrier rollers 1a, 2a may be
started to rotate forward upon as soon as the switch SWn detect the
contact of the disc DS with the fallable type switch SWn.
[0133] According to this arrangement, the carrier rollers 1a, 2a
are started to perform forward rotation as soon as the leading end
of each disc DS comes in contact with the fallable type switch SWn,
and therefore the rollers can smoothly and positively carry out the
loading of the disc DS. Especially, if the Maxi single disc DS has
the transparent outer periphery AR, the peripheral edge of the Maxi
single disc DS is detected not optically but mechanically, which
leads to positive loading of the disc.
[0134] Further, as shown in FIG. 4, an optical detector Pn may be
additionally arranged on one side of the carrier rollers 1a, 2a
closer to the front panel such that an interval between the optical
detector Pn and each carrier roller 1a, 2a may be larger than a
radial width of the outside peripheral area AR of the Maxi single
disc DS.
[0135] In this arrangement, prior to insertion of the Maxi single
disc DS between the carrier rollers 1a, 2a, the optical detector Pn
can detect the program area of the Maxi single disc DS, to thereby
carry out the forward rotation of the carrier rollers 1a, 2a. As a
result, the loading of the Maxi single disc DS can be positively
carried out by the carrier rollers 1a, 2a irrespective of the
transparency or opacity of the outer peripheral area AR, whereby
the Maxi single disc DS can be positively carried to the
predetermined clamping position.
[0136] In addition, when information is reproduced by the optical
pickup mechanism 4 and the clamping mechanism 3, an initial
rotational force of the turntable may be controlled in a variable
manner depending on the types of the discs DS borne by the bearing
surface 12b of the accommodating tray 12, based on a result of the
determination as to the types of the discs. More specifically, when
information recorded on the 12-cm diameter disc DS having a large
weight or information on the adapter mounting therein the 8-cm
diameter disc DS is to be reproduced, the initial rotational force
may be set to a larger value, based on the determination result,
while when information on the 8-cm diameter disc DS is to be
reproduced, the initial rotational force may be set to a smaller
value, according to its small weight. By virtue of this setting, a
time period required for the disc DS to reach a reproducible linear
scanning speed can be set to an almost equal value irrespective of
the types of the disc DS etc.
[0137] Although in the present embodiment, the carrier rollers 1a,
2a are rotated in synchronization with the timing at which the user
provides an instruction to insert the disc DS, this it not
limitative. Alternatively, the carrier rollers 1a, 2a may be
rotated upon detection of the leading end of the disc DS by means
of the first optical detector P1 arranged at the frontward location
of the carrier rollers 1a, 2a. In this setting as well, the carrier
rollers 1a, 2a are started to carry out the loading in a manner
pulling the disc DS, and therefore a so-called slot-in type
information reproducing apparatus can be realized.
[0138] In the present embodiment, the description has been made of
an information reproducing apparatus with a so-called auto-changer
mechanism, but this is not limitative. Alternatively, the invention
may be applicable to an information reproducing apparatus which can
accommodate a single disc.
[0139] As described hereinabove, according to an information
recording-reproducing apparatus of the invention, first and second
optical detectors, and a mechanical detector are arranged in a
carriage path of the apparatus so as to conform to the shapes and
formats of a large diameter recording medium and a small diameter
recording medium. Therefore, each recording medium can be
discriminated from the other, based on detection signals output
from the detectors. Further, a foreign matter other than the real
recording medium can be discriminated. As a result, the information
recording-reproducing apparatus can carry out recording and/or
reproduction of the real recording medium irrespective of their
shapes and formats, which leads to enhanced reliability of the
apparatus.
[0140] Further, the information recording-reproducing apparatus of
the invention is comprised of a central control unit which outputs
a control signal to carrier mechanisms in order to carry out an
ejecting operation or a stopping operation. Therefore, when a
foreign matter other than the real recording medium or the like is
inserted into the apparatus, the foreign matter is ejected out of
the apparatus, and the carrier mechanisms are stopped. As a result,
the apparatus can be prevented from being damaged, leading to
enhanced reliability.
[0141] While there has been described what are at present
considered to be preferred embodiments of the present invention, it
will be understood that various modifications may be made thereto,
and it is intended that the appended claims cover all such
modifications as fall within the true spirit and scope of the
invention.
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