U.S. patent application number 09/498382 was filed with the patent office on 2002-04-25 for tape cassette.
Invention is credited to Chiba, Hitomi, Sasaki, Kazuo.
Application Number | 20020048119 09/498382 |
Document ID | / |
Family ID | 12238430 |
Filed Date | 2002-04-25 |
United States Patent
Application |
20020048119 |
Kind Code |
A1 |
Sasaki, Kazuo ; et
al. |
April 25, 2002 |
Tape cassette
Abstract
In a tape cassette, an erroneous erasing preventive or write
protect device includes a plurality of discriminating detectable
portions provided in a cassette body or casing and a discriminating
plug for opening and closing at least one of the discriminating
detectable portions. The discriminating detectable portions are
formed collectively in a single indented part with no separating
walls.
Inventors: |
Sasaki, Kazuo; (Miyagi,
JP) ; Chiba, Hitomi; (Miyagi, JP) |
Correspondence
Address: |
FROMMER LAWRENCE & HAUG
745 FIFTH AVENUE- 10TH FL.
NEW YORK
NY
10151
US
|
Family ID: |
12238430 |
Appl. No.: |
09/498382 |
Filed: |
February 3, 2000 |
Current U.S.
Class: |
360/132 ;
G9B/23.064; G9B/23.087 |
Current CPC
Class: |
G11B 23/288 20130101;
G11B 23/287 20130101; G11B 23/08714 20130101 |
Class at
Publication: |
360/132 |
International
Class: |
G11B 023/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 5, 1999 |
JP |
11-028067 |
Claims
What is claimed is:
1. A tape cassette comprising: a case formed with a plurality of
discriminating detectable portions; and a discriminating plug
slidably disposed in the case, for moving into and out of at least
one of the discriminating detectable portions; wherein the
discriminating detectable portions are collectively formed in a
single cavity, and the discriminating plug faces at least one of
the discriminating detectable portions in the recess.
2. A tape cassette according to claim 1 wherein one of the
discriminating detectable portions is a write protect portion for
preventing erroneous erasure, and the discriminating plug is
arranged to move into and out of the write protect portion.
3. A tape cassette according to claim 2 wherein the discriminating
detectable portions are first, second and third detectable portions
which are aligned in the cavity, the third detectable portion is
located between the first and second detectable portions, and the
third detectable portion is the write protect portion for
preventing erroneous erasure.
4. A tape cassette according to claim 1 wherein the discriminating
plug is slidable in the case up and down between an upper position
and a lower position, and the discriminating plug comprises a lower
projection for closing said at least one of the discriminating
detectable portions by moving into said at least one of the
discriminating detectable portions in the lower position and for
opening said at least one of the discriminating detectable portions
by moving out of said at least one of the discriminating detectable
portions in the upper position.
5. A tape cassette according to claim 4 wherein the case comprises
first and second lock holes formed on a back side of the case, the
discriminating plug further comprises a lock portion projecting, in
the shape of a cantilever having a predetermined elasticity, to a
forward end formed with an engaging projection which is received in
the first lock hole, for locking the discriminating plug in the
upper position and which is received in the second lock hole, for
locking the discriminating plug in the lower position.
6. A tape cassette according to claim 5 wherein each of the first
and second holes is a through hole extending from an outside
surface of the case to an inside surface of the case, and exposing
the engaging projection of the lock portion therethrough when the
engaging projection is received therein.
7. A tape cassette according to claim 6 wherein the engaging
projection of the lock portion is colored.
8. A tape cassette comprising: a case having first and second
opposite faces and a discriminating cavity having first, second and
third space sections each opening in the first face of the case;
and a discriminating plug slidably disposed in the case, for moving
into and out of the discriminating cavity, the discriminating plug
comprising a closing portion for closing one of the space sections
of the discriminating cavity and leaving open the remaining two of
the space sections of the discriminating cavity.
9. A tape cassette according to claim 8 wherein the discriminating
cavity is a single elongated continuous cavity having a bottom
formed with a hole, the discriminating plug is slidably received in
a receptacle chamber formed behind the bottom of the cavity in such
a manner as to allow the closing portion of the discriminating plug
to move into and out of one of the space sections of the
discriminating cavity through the hole formed in the bottom of the
cavity.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to tape cassettes for
recording audio or video signals or computer data, and more
specifically to a write protect device or erroneous erase
preventing device.
[0002] As shown in FIGS. 20.about.24, a tape cassette 101 includes
a pair of rotatable tape reels 103 and 104 winding magnetic tape
102, and a cassette body (or case) 105 enclosing the tape reels 103
and 104. At one corner of a lower face 106 of the cassette body
105, there is provided an erroneous erase preventing device (or
write protect device) 111 for discriminating a record enable state
enabling the recording on the magnetic tape 102 and for preventing
recorded data from being erased by error.
[0003] The erroneous erase preventing device 111 consists of a
detectable portion 112 for discrimination to prevent erroneous
erasing (which serves as a detectable portion formed in the bottom
106 of the cassette body 105), and an erroneous erase preventive
plug 113 serving as a discrimination plug for opening and closing
the detectable portion 112.
[0004] The detectable portion 112 is formed by opening a round hole
in the bottom 106 of the case 105.
[0005] As shown in FIG. 22, the erroneous erasing preventive plug
113 has an open-close portion 114 for opening and closing the
detectable portion 112, a slide operating portion 115, and a lock
portion 116.
[0006] As shown in FIG. 20, the erroneous erasing preventive plug
113 is right-left slidably attached in the cassette body 105 in the
state that the slide control portion 115 projects out of an
operation opening 108 on the back 107 of the cassette body 105.
Thus, the plug 113 is slidable in a right and left direction.
[0007] The erroneous erasing preventive plug 113, when the slide
operation element 115 is operated to slide to one direction, closes
the detectable portion 112 with the open-close portion 114 as shown
in FIG. 23, while the lock portion 116 engages in a first lock
opening 109 provided inside the case 105 to keep the closing state
of the detectable portion 112.
[0008] Also, the erroneous erasing preventive plug 113, when
operated to slide to direction A shown by an arrow from the state
shown in FIG. 23, opens the detectable portion 112 which was closed
by the open-close portion 114 as shown in FIG. 24, while the lock
element 116 hooks to a second lock opening 110 provided inside the
cassette body 105 to lock to keep the opening state of said
detectable portion 112.
[0009] Then, if the tape cassette 101 is loaded in the
recorder-player that is not shown in figures, while in the state
that the detectable portion 112 for discrimination to prevent
erroneous erasing is closed by the erroneous erasing preventive
plug 113, the erroneous erase detecting element provided on the
recorder-player is prevented by the erroneous erasing preventive
plug 113 from being lead into the cassette body 105 from the
detectable portion 112, which enables the recording on the magnetic
tape 102 in the tape cassette 101.
[0010] Also, if the tape cassette 101 is loaded in the
recorder-player, while in the-state that the detectable portion 112
is open, the erroneous erasing detection element provided on the
recorder-player is lead into the cassette body 105 from the
detectable portion 112, which disables the recording on the
magnetic tape 102 in the tape cassette 101 or, in other words,
prevents erroneous erasing.
[0011] By the way, in addition to the conventional tape cassette
(hereinafter called the first format tape cassette) 101 shown in
FIGS. 20-24, the tape cassette that enables high-density recording
on the magnetic tape (hereinafter called the second format tape
cassette) has also been developed.
[0012] As shown in FIG. 25, the second format tape cassette 201,
like the first format tape cassette 101, is provided with a pair of
tape reels 203 and 204 with magnetic tape 202 wound around them
that are rotatably accommodated in the cassette body 205, and, in
one corner in the bottom 206 of the cassette body 205, there is
provided with an erroneous erasing preventive device 211.
[0013] The erroneous erasing preventive device 211 consists of a
detectable portion 212 for discrimination or identification to
prevent erroneous erasing and an erroneous erasing preventive plug
213 which closes/opens the detectable portion 212.
[0014] The detectable portion 212 is formed by opening a round hole
in the bottom 206 of the cassette body 205.
[0015] The erroneous erasing preventive plug 213 is formed roughly
in the same way as the erroneous erasing preventive plug 113 of the
first format tape cassette 101, and when it is operated to slide to
one direction, closes the detectable portion 212, while when it is
operated to slide to the other direction, releases open the
detectable portion 212.
[0016] The cassette body 105 of the first format tape cassette 101
is also used as the cassette body 205 of the second format tape
cassette 201.
[0017] The detectable portion for identification to prevent
erroneous erasing 212 of the second format tape cassette 201 is
formed, near the detectable portion 112 for identification to
prevent erroneous erasing of said first format tape cassette 101,
with a predetermined spacing D between the portion 212 and the
portion 112.
[0018] Because of the development of magnetic materials and the
reduction in thickness of magnetic recording layers enabled by the
recent technological advances, the third format tape cassette that
enables higher-density recording than said second format tape
cassette 201 has also been developed.
[0019] By the way, in attempting to use, as the cassette body of
the third format tape cassette, the cassette body 205 of the second
format tape cassette 201, the following problems have been
arisen.
[0020] (1) As shown in FIG. 26, in attempting to form the
detectable portion for identification to prevent erroneous erasing
312 for the third format tape cassette between the detectable
portion for identification to prevent erroneous erasing 112 for the
first format tape cassette and the detectable portion for
identification to prevent erroneous erasing 212 for the second
format tape cassette provided on the bottom 306 of the cassette
body 305 of the third format tape cassette 301, these three
detectable portions 112, 212 and 312 become close in distance,
therefore, as shown in FIG. 27, the thickness t of the separating
walls 321 between the detectable portions 112, 212 and 312 become
thinner, which often results in defective products during forming
process and reduces efficiency in production. Moreover, the
separating walls 321 are easy to break during usage.
[0021] (2) If the detectable portion 312 for the third format tape
cassette of the cassette body 305 is formed sufficiently away from
the detectable portions 112 and 212, the above-mentioned first
problem (1) will be solved. However, the bottom plate 306 of said
cassette body 305 is formed with various holes such as detection
hole for magnetic tape type 331, cassette positioning holes 332 and
333, detection hole for recording format 334, detection hole for
tape end 335. Therefore, there are imposed constraints in space.
Also, in the case that the detectable portion 312 for the third
format tape cassette is formed at a distance from the detectable
portions 112 and 212, the position of the detection element for
erroneous erasing of the recorder-player unit must also be moved in
conformity with the position of the detectable portion 312 for the
third format tape cassette. Again, on the recorder-player unit, the
change of the position of the detection element for erroneous
erasing is also subjected to constraints in space, and difficulties
in terms of cost.
SUMMARY OF THE INVENTION
[0022] From the above viewpoints, it is desirable to form the
detectable portions for identification to prevent erroneous erasing
112, 212 and 312 for the first, second, and third format tape
cassettes together in a single space of the cassette body 305.
[0023] Therefore, it is an object of the present invention to
provide tape cassettes having a plurality of discriminating
detectable portions formed closed in a narrow area.
[0024] According to the present invention, a tape cassette
comprises: a casing formed with a plurality of discriminating
detectable portions; and a discriminating plug slidably disposed in
the casing, for moving into and out of at least one of the
discriminating detectable portions. The discriminating detectable
portions are collectively formed in a single cavity, and the
discriminating plug faces at least one of the discriminating
detectable portions in the recess.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a perspective view of a tape cassette according to
one embodiment of the present invention as view from the upper
side.
[0026] FIG. 2 is a perspective view of the tape cassette shown in
FIG. 1, as viewed from the lower side.
[0027] FIG. 3 is a perspective view of the tape cassette of FIG. 1
with a lid being open.
[0028] FIG. 4 is an exploded perspective view of the tape cassette
of FIG. 1.
[0029] FIG. 5 is a perspective view showing a bottom side of a
lower half of the tape cassette of FIG. 1.
[0030] FIG. 6 is a perspective view showing a front side of a
discriminating plug of the tape cassette shown in FIG. 1.
[0031] FIG. 7 is a perspective view showing a back side of the
discriminating plug of FIG. 6.
[0032] FIG. 8 is a perspective view showing the main portion of the
tape cassette which receives the discriminating plug shown in FIGS.
6 and 7.
[0033] FIG. 9 is a perspective view showing the discriminating plug
of FIGS. 6 and 7 in the main portion of the tape cassette.
[0034] FIG. 10 is a partly cutaway sectional view showing the
discriminating plug of FIGS. 6 and 7 in a first position.
[0035] FIG. 11 is a partly cutaway sectional view showing the
discriminating plug of FIGS. 6 and 7 in a second position.
[0036] FIG. 12 is a vertical sectional view showing the
discriminating plug of FIGS. 6 and 7 in the tape cassette.
[0037] FIG. 13 is a front view showing the main portion of the tape
cassette according to the embodiment.
[0038] FIG. 14 is a partly cutaway sectional view showing the main
portion of the tape cassette according to the embodiment in a first
operative state.
[0039] FIG. 15 is a partly cutaway sectional view showing the main
portion of the tape cassette according to the embodiment in a
second operative state.
[0040] FIG. 16 is a partly cutaway sectional view showing the main
portion of the tape cassette according to the embodiment in a third
operative state.
[0041] FIG. 17 is a partly cutaway sectional view showing the main
portion of the tape cassette according to the embodiment in a
fourth operative state.
[0042] FIG. 18 is a sectional view showing a first variation of the
embodiment.
[0043] FIG. 19 is a sectional view showing a second variation of
the embodiment.
[0044] FIG. 20 is a perspective view showing the upper side of a
conventional first-format tape cassette.
[0045] FIG. 21 is a perspective view showing the lower side of the
conventional first-format tape cassette.
[0046] FIG. 22 is a perspective view showing an erroneous erasing
preventive plug of the tape cassette shown in FIGS. 20 and 21.
[0047] FIG. 23 is a sectional view showing the erroneous erasing
preventive plug of FIG. 22 in a first position.
[0048] FIG. 24 is a sectional view showing the erroneous erasing
preventive plug of FIG. 22 in a second position.
[0049] FIG. 25 is a perspective view showing a conventional
second-format tape cassette.
[0050] FIG. 26 is a perspective view showing a conventional
third-format tape cassette.
[0051] FIG. 27 is a sectional view taken across a line A-A in FIG.
26.
DETAILED DESCRIPTION OF THE INVENTION
[0052] FIGS. 1.about.19 shows a tape cassette 1 according to one
embodiment of the present invention. FIG. 1 is a perspective view
from the top, FIG. 2 is a perspective view from the bottom, FIG. 3
is a perspective view with a lid open, FIG. 4 is an exploded
perspective view, and FIG. 5 is a perspective view of the lower
half from the bottom.
[0053] As shown in FIG. 2, the tape cassette 1 includes an
erroneous erasing preventive device (or write protection device) 41
serving as means for protecting recorded information from being
erased inadvertently, or as a cassette discriminating or
identification means. The device 41 is formed on the bottom
side.
[0054] The erroneous erasing preventive device 41 of this example
comprises an indented part (or cavity) 42 as a detectable element
unit which includes three discriminating detectable portions or
elements for discrimination or identification 42a-42c put together
(continuously without separating walls), and an erroneous erasing
preventive plug 43, as an discriminating or identification plug,
placed to face the indented part 42.
[0055] The first discriminating detectable portion 42a is formed at
the position corresponding to the first format detectable portion
112 of the first format tape cassette 101 shown in FIGS. 20-21.
[0056] The second discriminating detectable portion 42b is formed
at the position corresponding to the second format detectable
portion 212 of the second format tape cassette 201 shown in FIG.
25.
[0057] The third discriminating detectable portion 42c is formed at
the position that corresponds to the third format detectable
portion 312 of the third format tape cassette 301 shown in FIG.
26.
[0058] The erroneous erasing preventive plug 43 of this example is
provided at the position facing the third detectable portion 42c of
the indented part 42, and arranged to slide into the detectable
portion 42c to close it or slide out of the detectable portion 42c
to open it.
[0059] The tape cassette 1 of the present invention is explained in
detail in the following three sections: 1 . . . Overall Structure
of the Whole Cassette, 2 . . . Erroneous Erasing Preventive Means,
and 3 . . . Variations.
[0060] 1 . . . Overall Structure of the Whole Cassette
[0061] The tape cassette 1 has the cassette body or casing 4
including the upper half 2 and the lower half 3, a pair of tape
reels 5 and 6 rotatably installed in the cassette body 4, and the
magnetic tape 7 wound around those tape reels 5 and 6.
[0062] Each of the upper and lower halves 2 and 3 of said cassette
body 4 is integrally formed by injection molding of resin to have
enough size to rotatably accommodate the pair of tape reels 5 and 6
with the magnetic tape 7. The upper and lower halves 2 and 3 are
joined together with their respective openings butted against each
other, to form the box-shaped cassette body 4.
[0063] The upper face 4a of the cassette body 4 is formed with a
transparent window 4b for making visible the wound magnetic tape 7
in the cassette body 4.
[0064] In the bottom face 4c of the cassette body 4, as shown in
FIG. 2, portions of hubs 5a, 6a of the tape reels 5, 6 are exposed
to outside, and there are provided hub engagement holes 8 and 9 to
regulate the rotation of the tape reels 5 and 6. These hub
engagement holes 8, 9 are positioned to correspond to the tape
supply reel 5 and tape take-up reel 6, respectively, and formed as
round holes having the diameter approximately equal to the outside
diameters of the hubs of the tape reels 5 and 6.
[0065] The bottom face 4c of the cassette body 4 is further formed
with a light emitting element inserting hole 10 through which the
light emitting element of the light detection mechanism on the side
of recorder-player unit is aimed into this cassette body 4. The
light emitting element inserting hole 10 is a round hole positioned
to confront the light emitting element provided in the
recorder-player unit. In other words, the light emitting element
inserting hole 10 is positioned near the tape leading indented part
11 cut in the front face of the cassette body 4 where the tape
leading pin of the recorder-player unit is inserted, and the hole
11 is roughly in the middle between the tape reels 5 and 6.
[0066] The bottom face 4c of the cassette body 4 is further formed
with cassette positioning holes 12, 13 where the cassette
positioning pins of the recorder-player unit is inserted in order
to set the position of the tape cassette 1 in relation to the
recorder-player unit. These cassette positioning holes 12 and 13
are formed as a round hole and an elliptical hole respectively near
the left and right ends of the tape leading indented part 11.
[0067] The bottom face 4c of the cassette body 4 is further
provided with a recording format detection hole 14. The detection
hole 14 is positioned at the corner of the cassette body 4 near one
hub engagement hole 8, and formed as a small rectangle blind hole.
At the opposite corner of the cassette body 4, a detection hole 15
is provided to identify the tape type. This detection hole 15 is
formed as a small round hole. In the region adjacent to this
detection hole 15, there is formed the indented part 42 in which
the first to third detectable portions 42a-42c are collectively
formed as a single continuous cavity.
[0068] As shown in FIG. 4, each of the tape reels 5 and 6 has a
cylindrical hub 5a or 6a on which the magnetic tape 7 is wound, a
disk-shaped lower flange 5b or 6b at a lower end of the hub 5a or
6a, and a transparent upper flange 5c or 6c at an upper end of the
hub 5a or 6a . . . Each reel 5 or 6 is rotatable with the upper end
of the hub 5a or 6a provided in the corresponding hub engagement
hole 8 or 9 formed in the bottom face 4c of the cassette body 4.
Each tape reel 5 or 6 is pushed in the axial direction by a reel
holding spring 16 or 17 attached to the upper half 2 at the center
of rotation of said hub 5a or 6a, in order that the rattling of the
tape reels 5 and 6 is reduced.
[0069] The magnetic tape 7 is connected to each tape reel 5 or 6 by
a transparent leader tape 19 having one end connected with the tape
7 and the other end fixed on the hub 5a or 6a by a damper 18. The
magnetic tape 7 and leader tape 19 are connected by a transparent
thin connection tape 20, called splice tape, having a sticky layer
on one side.
[0070] The magnetic tape 7 is guided by semicircular tape guide
members 21 and 22 provided on both sides of the tape leading
indented part 11 of the cassette body 4 and stretched rectilinearly
across the tape leading indented part 11.
[0071] The magnetic tape 7 is stretched between a front lid 23 and
a back lid 24 for protecting the magnetic tape 7 from dust and an
external force when the tape cassette 1 is not in the loaded state
in the recorder-player unit. These front lid 23 and back lid 24,
when the cassette is not in the loaded state, cover the tape
leading indented part 11 with the magnetic tape 7 therebetween.
When the cassette is set in the recorder-player unit, the front and
back lids 23 and 24 are rotated in the direction A indicated by an
arrow in FIG. 1, to expose the magnetic tape 7 in the front of the
tape leading indented part 11 shown in FIG. 3.
[0072] As shown in FIG. 4, a return coil spring 25 urges the front
lid 23 in the direction to close the tape leading indented part 11.
A lid lock 26 is designed to lock the front lid 23 in the closed
position closing the indented
[0073] A reel lock 27 is for locking the tape reels 5 and 6
nonrotatable. A coil spring 28 urges the reel lock 27 in the
direction for reel locking.
[0074] The lower half 3 is provided with the erroneous erasing
preventive device 41 in one corner of the bottom.
[0075] A plug receiving cavity (or chamber) 29 is formed in the
cassette body 4 of the upper and lower halves 2 and 3. The
erroneous erasing preventive plug 43 is received in the plug
receiving cavity 29 so that the plug 43 can slide up and down. On
the back side of the cassette body 4, there is formed an operation
window 30 through which the erroneous-erasing preventive plug 43 is
operated from outside. There are further formed first and second
lock windows 31, 32 for locking the erroneous erasing preventive
plug 43 at record enable position and a record disable position,
respectively.
[0076] After assembled with the tape reels 5 and 6, reel holding
spring 16 and 17, front and back lid 23 and 24, return coil spring
25, lid lock 26, reel lock 27, coil spring 28, and erroneous
erasing preventive plug 431 the upper 5 and lower halves 2 and 3
are fastened together by screw members 33 into a tape cassette.
[0077] 2 . . . Erroneous Erasing Preventive Means
[0078] The erroneous erasing preventive device 41 of this example
includes the erroneous erasing preventive plug 43, and the first,
second and third detectable portions 42a, 42b and 42c that are
formed together as the continuous single indented part or cavity
42.
[0079] As shown in FIG. 5, the indented part 42 is formed by
arranging the first, second and third detectable portions 42a, 42b
and 42c consecutively in a line and uniting these three portions as
a single cavity. An opening 42e is formed in the middle of the
indented part 42. In this example, the third detectable portion 42c
is located between the first and second detectable portions 42a and
42b. The indented part 42 has a bottom 42d.
[0080] The opening 42e is formed in the middle of the bottom 42d of
the indented part 42, so that the third detectable portion 42c is
bottomless whereas the first and second detectable portions 42a and
42b are bottomed.
[0081] The erroneous erasing preventive plug 43 is installed in the
cassette body 4 at the position facing the third detectable portion
42c.
[0082] Through the opening 42e, an extension 44 of the erroneous
erasing preventive plug 43 moves into the third detectable portion
42c to close the same, and moves out of the third detectable
portion 42c to open the same, as detailed later.
[0083] As shown in FIGS. 6-7, the erroneous erasing preventive plug
43 includes a main body 44 in the form of a rectangular
parallelepiped, the extension (closing portion) 45 projecting from
the bottom of the body 44, a slide guide 46 provided on the front
side of the main body 44, a slide operating portion 47 provided in
the middle of the front side of the slide guide 46, and a lock
portion 48 extending from one side of the slide guide 46.
[0084] As shown in FIGS. 8-9, the erroneous erasing preventive plug
43 is inserted in the plug receiving part 29 of the lower half
3.
[0085] When the erroneous erasing preventive plug 43 is inserted in
the receiving part 29, both ends of said slide guide 42 are lead
into slide guide slots 35 each formed between a guide wall 34 and a
bottom wall section 3a of the lower half 3, and the slide operating
projection 47 is exposed to outside through the slide operating
window 30.
[0086] When the slide operating part 47 is pushed down manually
with the tip of a fingernail or the like, a protrusion 48a of the
lock portion 48 is fit into the first lock window 31 to lock the
erroneous erasing preventive plug 43 in the pushed-down state.
[0087] In the state in which the erroneous erasing preventive plug
43 is pushed down, as shown in FIG. 10, the extension 45 projects
into the third detectable portion 42c from the opening 42e in the
middle of the bottom 42d of the plug receiving part 42, and the
front face 45a of the extension 45 is approximately flush with the
bottom face 4d of the cassette body 4 so that the third detectable
portion 42c is entirely closed.
[0088] When, from the state shown in FIG. 10, the slide operating
portion 47 is pushed up manually, as shown in FIG. 11, the
protrusion 48a of the lock portion 48 is fit in the second lock
window 32 to lock the erroneous erasing preventive plug 43 in the
pushed-up state. In this state, the extension 45 is in the upper
position, out of the third detectable portion 42c, and the front
face 45a of the extension 45 is approximately flush with the bottom
42d of the indented part 42.
[0089] The extension 45 is so sized and shaped as to fit in the
opening 42e in the bottom 42d of the indented part 42 so that no
undesired gap is formed therebetween.
[0090] The front face of the slide guide 46 is so sized as to fully
close the operation window 30.
[0091] The slide operating portion 47 has a semicircular cross
sectional shape as shown in FIG. 6, and has such a height that the
operating portion 47 cannot project from the back of the cassette
body 4.
[0092] The lock portion 48 projects from one side of the slide
guide 46 like a cantilever, and has a moderate degree of
elasticity. The free end of the lock portion 48 is formed with a
semicircular engaging protrusion 48a for engaging in the first or
second lock window 31 or 32. In this example, the protrusion 48a is
colored with a conspicuous color such as red or yellow, to
facilitate recognition from outside as to whether the protruding
portion 48a is in the first lock window 31 or the second 32, or
whether the erroneous erasing preventive plug 43 is in the record
enable position or the record disable position. In this case, it is
optional to color only the protruding portion 48a, or the entirety
of the erroneous erasing preventive plug 43.
[0093] The erroneous erasing preventive plug 43 of this example is
a single plastic piece. In addition, as shown in FIG. 12, the upper
and lower edges of the operating window 30 of the cassette body 4
are chamfered to form an inclined surface 30a, to facilitate manual
operation of the slide operating portion 47 of the erroneous
erasing preventive plug 43.
[0094] The thus-constructed tape cassette 1 according to this
embodiment is operated as follows. When the tape cassette 1 is
loaded in the recorder-player in the state where the slide
operating part 47 is moved to the REC side at the lower end of the
operating window 30, as shown in FIG. 13, the under side 45a of the
extension 45 of the erroneous erasing preventive plug 43 abuts
against a first erroneous erasing detecting element 411 provided in
the recorder-player as shown in FIG. 14, and thereby holds the
detecting element 411 in the pushed down state to enable the
recording to the tape cassette 1. When the tape cassette 1 is
loaded in the recorder-player in the state where the slide
operating part 47 is moved to the SAFE side at the upper end of the
operating window 30, the first erroneous erasing detection element
411 is inserted into the third detectable portion 42c, as shown in
FIG. 15, so that the recording to said tape cassette 1 is
disabled.
[0095] FIGS. 16-17 show another example using, as the erroneous
erasing detection element 411 of the recorder-player, a photo
sensor consisting of a light emitting section 411a and a light
receiving section 411b. When the tape cassette 1 is loaded in the
recorder-player in the state where the slide operating portion 47
is to the REC side, the light emitting section 411a is inserted
into the first detectable portion 42a, and the light receiving
section 411b is inserted into the second detectable portion 42b as
shown in FIG. 16. However, the extension 45 of the erroneous
erasing preventive plug 43 intervenes between the light emitting
section 411a and the light receiving section 411b, and thereby
blocks sensing light emitted from the light emitting section 411a
toward the light receiving section 411b, thus, enabling the
recording to said tape cassette 1.
[0096] When the slide operating part 47 is to the SAFE side, the
extension 45 of the erroneous erasing preventive plug 43 is located
out of the intervening position between the light emitting section
411a and the light receiving section 411b as shown in FIG. 17, and
allows the sensing light emitted from said light emitting section
411a to reach the light receiving part 411b, thus, disabling the
recording to the tape cassette 1.
[0097] The recorder-player shown in FIGS. 14-15 is a so-called
downward compatible recorder-player that can accept a tape cassette
inferior in recording capacity to the tape cassette 1. This
recorder-player has a second erroneous erasing detecting element
412 on one side of the first erroneous erasing detecting element
411 and a third erroneous erasing detecting element 412 on the
other side.
[0098] When a first format tape cassette 101 as shown in FIGS.
20-21 is loaded in the recorder-player, the second erroneous
erasing detection element 412 works to detect if the recording to
said first format tape cassette 101 is enabled or disabled. When a
second format tape cassette 201 as shown in FIG. 25 is loaded in
the recorder-player, the third erroneous erasing detecting element
413 works in the same manner.
[0099] 3 . . . Variations
[0100] In the example of FIGS. 1-17, the erroneous erasing
preventive plug 43 is arranged to open and close the third
detectable portion 42c with the extension 45. However, it is
optional to arrange the erroneous erasing preventive plug 43 to
open and close the first detectable portion 42a, as shown in FIG.
18, or to open and close the second detectable portion 42b as shown
in FIG. 19.
[0101] In the illustrated embodiment, the indented part 42 consists
of the first to third detectable portions 42a-42c. However, it is
also possible to form four or more detectable portions in the
indented part 42.
[0102] The discriminating detectable portions can be used for
various purposes such as for discriminating tape type or other
conditions.
[0103] The tape cassette according to the illustrated embodiment is
easy to manufacture, and advantageous in that there are no
separation walls separating the detectable portions. The erroneous
erasing preventive plug makes it possible to detect the record
enable and disable states by moving into one of the detectable
portions. The tape cassette allows the use of both the plunger type
detecting elements of the recorder-player shown in FIGS. 14 and 15
and the photosensitive type detecting elements shown in FIGS. 16
and 17.
[0104] The discriminating plug 43 is arranged to slide up and down.
Therefore, as compared to a plug slidable left and right, it is
easier to operate and perceive the operating direction of the
plug.
[0105] The lock portion having the protrusion, the elasticity and
the color facilitates the lock and slide operations, and improves
the visibility.
* * * * *