JPH03219478A - Disk cartridge - Google Patents

Abstract

PURPOSE:To reduce the wear of a cartridge case by giving stability to a shutter plate in a way of forming the plate into an outward protruding shape in the longitudinal direction. CONSTITUTION:A head access opening in a long hole shape is formed on an upper case of the cartridge case. Moreover, a sliding recessed part 4 in an approximately rectangular shape is provided in approximately left half of the area including this opening. An optical disk is rotatively housed in the cartridge case. A shutter 54 consists of the shutter plate 55 and a slider. The shutter plate 55 is composed of upper and lower closed parts 57 and a connecting part 58 for connecting one end to one end of both closed parts 57. This shutter plate 55 is specified for its burr to be formed in a punching process as to be projected out of the outer surface of the shutter plate 55 in the punching direction. That is, the shutter plate 55 is provided with the stability by way of forming an outward protruding shape in the longitudinal direction. By this method, the wear of the cartridge is reduced, and trouble caused by worn particles is alleviated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to disk cartridges such as optical disk cartridges, magneto-optical disk cartridges, and magnetic disk cartridges.

[Prior Art] Conventionally, this type of disk cartridge consists of an upper case and a lower case, and recesses are provided at predetermined positions on the upper and lower case surfaces, and head access openings are formed in the recesses to prevent curling. However, the edge of the image side end extending in the longitudinal direction of the shutter plate faces the surface of the cartridge case. When this happens, the surface of the cartridge case is scraped by the opening and closing operations of the shutter, and the abrasions enter the inside of the cartridge case through the head access opening and adhere to the recording disk, causing signal recording and
It has a negative effect on playback and has reliability problems.

The purpose of the present invention is to eliminate such drawbacks of the prior art,
To provide a highly reliable disk cartridge that generates almost no abrasions.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a cartridge case having a recess on at least one side and a head access opening formed in the recess, and a rotatable cartridge inside the cartridge case. A recording disk stored therein, a shutter provided with a shutter plate on at least one side, an elastic cartridge case that elastically urges the shutter to a closed position, a recording disk rotatably stored in the cartridge case, The shutter is made of a thin metal plate with shutter plates on both sides and has an approximately mouth-shaped side surface, and an elastic biasing means such as a coil spring for elastically biasing the shutter to a closed position is provided inside the recess of the cartridge case. The structure is such that the cartridge case is sandwiched between the U-shaped shutter plates, and the head access opening is opened and closed by the shutter plates.

[Problems to be Solved by the Invention] By the way, a rolled metal plate is used as the shutter plate, but in the conventional shutter plate, the rolling direction coincides with the short direction of the shutter plate, that is, the sliding direction of the shutter plate. was.

Since the thin metal plate has the property of curling along the rolling direction, when the rolling direction of the shutter plate coincides with the sliding direction of the shutter plate as described above, the cartridge case is In a disk cartridge in which a shutter plate is disposed in a recess and a head access opening is opened and closed by the shutter plate, the rolling direction of the shutter plate is adjusted so that the longitudinal direction of the shutter plate becomes convex outward. It is characterized by having restorability by applying external force mechanically, regardless of the rolling direction.

[Function] As mentioned above, even if the shutter plate curls in the longitudinal direction,
Only the free end edge in the transverse direction will come into contact with the cartridge case. Therefore, the amount of abrasions generated on the cartridge case due to the sliding of the shutter is extremely small compared to conventional cartridge cases, and troubles caused by abrasions can be greatly reduced.

[Embodiment] Next, an optical disk cartridge according to an embodiment of the present invention will be explained with reference to the drawings.

1, 2, 3, 4, and 5 are a plan view, a side view, a front view, a rear view, and a bottom view of an optical disk cartridge according to this embodiment. 6 and 7 are a plan view and a front view of this optical disk cartridge with the shutter open.

The optical disk cartridge according to this embodiment mainly includes an upper case, a lower case, a recording disk, and a shutter.

The cartridge case 31 consisting of the upper case 1 and the lower case 17 is made of synthetic resin such as polycarbonate, ABS resin, a mixture of polycarbonate and ABS resin, or polypropylene.

As shown in FIG. 6, an elongated head assessment opening 2 is formed in the substantially central portion of the upper case 1 (lower case 17), and is co-located with a drive shaft insertion opening.

Furthermore, as shown in FIG.
The left half region including the upper case 1 (lower case 17) is slightly stepped down from the upper surface 3 of the upper case 1 (lower case 17), and is composed of an outer peripheral spacer.

Next, the structure of the shutter 54 is shown in FIGS. 7 to 14.
This will be explained using figures. This shutter 54 is composed of a shutter plate 55 and a slider 56.

The shutter plate 55 is made of a metal plate such as a stainless steel plate, and as shown in FIG.
7, and a connecting portion 58 that connects one end of both closing portions 57 to each other.
It is composed of , and its side profile is almost U-shaped. The closing portion 57 is connected to the drive shaft insertion opening 2a (18a).
The length is sufficient to close the combined head access opening 2 (18). The longitudinal direction of this closing portion 57 coincides with the rolling direction 59 of the roller plate 55. Metal plates have the property of curling along the rolling direction.

Therefore, if the short side direction of the closing part 57 is made to match the rolling direction 59 of the shutter plate 55 as in the conventional case, when the closing part 57 curls in that direction, the entire length of the edges of both sides of the closing part 57 will be The surface of the case 31 will be scraped. A substantially rectangular sliding recess 4 is provided.

Next to the sliding recess 4, an arrow indicating the insertion direction of the disk cartridge and an A-side (B-side) display section 7 are provided. Further, reference holes 8a and 8b consisting of a long hole and a round hole are formed on the left and right sides near the rear of the upper case 1, and further behind these reference holes 8a and 8b is a recording layer for side A (first side). An operation port 9 for preventing accidental erasure and an operation port 10 for preventing accidental erasure for the B side (second surface) recording layer are provided at symmetrical positions.

The operation port 9 and the detection port 10 are protected by a protector (
It is formed in a rectangular shape to allow movement of the M erasure prevention member).

An optical disc 32 (sixth
(see figure) is rotatably housed. This optical disc 32
Although not shown, it consists of a transparent disk-shaped substrate that has a recording layer with minute irregularities such as pre-groups and pre-pits formed on one side, and a hub that is fixed with adhesive to a through-hole in the inner circumference of the substrate. , an inner peripheral spacer 8 for bonding two substrates with the recording layer inside with a predetermined gap, and shavings (abrasion powder) enter the inside through the head access openings 2 and 18 of the cartridge case 31. , optical disc 3
If it adheres to the surface of 2, it will adversely affect the recording and reproducing characteristics.

In this regard, if the longitudinal direction of the closing portion 57 is made to match the rolling direction 59 of the shutter plate 55 as in the present invention, even if the closing portion 57 curls along that direction, one side of the closing portion 57 Since the end portion of the closing portion 57 is connected to the connecting portion 58, there is no edge, and only the free end side edge of the closing portion 57 comes into contact with the cartridge case 31. Since the length of this free end side edge is extremely short compared to the entire length of the edges on both sides of the closed portion 57, the amount of cutting powder (wear powder) generated is extremely small, and almost no adverse effects as described above occur.

Note that this shutter plate 55 is formed by punching a thin metal plate to a predetermined size and bending it, but the burrs formed in the above-mentioned punching process will not stick to the outer surface of the shutter plate 55. The punching direction is determined.

If this burr protrudes inside the shutter plate 55, the slidability of the shutter 54 will deteriorate and the surface of the cartridge case 31 will be scraped.

Therefore, the burr direction of the shutter plate 55 is regulated as described above.

As shown in FIGS. 8 and 9, at least one pair of engaging pawls 60 for engaging with the slider 56 are formed near the base portions of both the closing portions 57 that communicate with the communicating portions 58. .

The slider 56 is made of, for example, polyacetal (product name: Duracon), polyamide (product name: nylon), fluororesin (product name:
It is composed of self-lubricating molded materials such as Teflon (trade name), ultra-high molecular weight polyethylene, and synthetic resins mixed with appropriate amounts of various solid lubricants.

When polycarbonate is used as the cartridge case 31 and polyacetal is used as the slider 56 that comes into sliding contact with the cartridge case 31, the properties of each material are shown below.

1 (3) Bending strength (4) Bending modulus (5) Izot impact strength (notched) (6) Rockwell hardness (M scale) (7) Heat distortion temperature (18.6 kg/cm2) ( 8) Vicat softening point (9) Coefficient of linear expansion (10) Specific gravity (11) Water absorption rate (24 hours in 23°C water) (12) Molding shrinkage rate approximately 0.02 [mm/mm]
11 sail'C] 0 +62 ['Cko10-'[cm/cm/'C] 41 Q, 22[:] 980[kg/cm2] 2.64X10'[kg/cm2] 5. 4 [kg g-cm/cm] As shown in FIGS.

The engaging claws 60 of the shutter plate 55 are fitted into the intermediate positions of the shutter plate mounting portion 61 (polycarbonate) 620 [kg/cm"] 920 [%Co2.3XIC1'[kg/cm"] 85 [kg g-c m/cm] Cartridge case 31 (1) Tensile strength (2) Tensile elongation at break (3) Bending modulus (4) Izot impact strength (notched) (5) Rockwell hardness (M Scale) (6) Heat distortion temperature (18.6 kg/crn2) (7) Linear expansion coefficient (8) Specific gravity (9) Water absorption rate (24 hours in 23°C water) (10) Molding shrinkage rate 05-0.7 [ X] (flow direction) 20 8 x 101 [cm/cm/'C] 7 134°C 0.20 [X] Slider 56 (polyacetal) (1) Tensile strength (2) Tensile elongation at break 620 [kg /am2] 4o[Z] 2 Engagement grooves 63 for insertion are formed on both sides. Further, an inclined portion 64 is formed at the end of the shutter plate mounting portion 61 on the opposite side from the narrow width portion 62 .

A shutter opening arm 65 (recording and reproducing device) is provided at the end of the narrow portion 62 opposite to the shutter plate mounting portion 61.
A contact portion 65 is formed, the tip of which contacts the rock.

As shown in FIGS. 11 to 14, a retaining groove 67 that engages with the front portion of the cartridge case 31 extends from the shutter plate mounting portion 61 to the entire length of the narrow portion 62 on both sides. Furthermore, a protrusion 6 is provided below this retaining groove 67.
9 is provided, and this protrusion 69 connects the upper and lower cases 1.
It is designed to be inserted into the guide groove 14.29 of No. 17. Further, as shown in FIGS. 11 and 12, a spring hook hole 68 is formed below the inclined portion 64.

Insert the shutter plate attachment part 61 of the slider 56 between the closing parts 57 and 57 of the shutter plate 55, and insert the engaging claw 60 provided in the closing part 57 into the engagement groove 63 of the shutter plate attachment part 61. By fitting and deforming the shutter plate 55 inward, the shutter plate 55 is attached to the slider 56, thereby forming the shutter 54.

A coil spring 70 is used to elastically bias the shutter 54 to the closed position of the cartridge case 31 (
(See Figure 18).

15 to 17 show head access opening 2 (1
8) is a diagram for explaining the relationship between the closing portion 57 of the shutter 54 and the sliding recess 4 (19) @ dimensions.

As shown in these figures, head access opening 2 (18
) is the width of Ll, the width of the closing part 57 is L2, and the width of the sliding recess 4 (19) is L3, then Ll<L2<L3
There is a relationship between

As shown in FIG. 16, when the closure part 57 is in the closed position, the head access opening 2 (18) is connected to the closure part 57.
However, one side end 79 of the closing part 57 does not directly collide with one side end 80 of the sliding recess 4 (19). Therefore, the present invention is designed to form gaps G1 and G2. Especially when closing the shutter 54, the restoring force of the coil spring 70 causes the shutter 54 to close.
The formation of the gap G1 is important because the impact force at the side ends 79 and 80 is large because the force returns instantaneously with a strong pressing force.

FIGS. 18 and 19 are diagrams showing the closed position of the shutter 54 and the state of the coil spring 7o that can be placed in the closed position. One end of the coil spring 7o is engaged with the spring hook hole 68 of the slider 56, and the other end is engaged with the spring hook pin 15, thereby always elastically biasing the shutter 54 toward the closed position.

When this optical disk cartridge is inserted into a recording/reproducing device, the shutter opening arm 65 on the device side comes into contact with the contact portion 66 of the slider 56, as shown in FIG. Further, when the optical disk cartridge is inserted, the shutter opening arm 65 rotates clockwise relative to the drawing in accordance with the insertion. As a result of this rotational movement, the shutter 54 moves in the direction of the arrow as shown in FIG. 19, and a gap G1 is formed between both ends 79.8o of the head housing. Note that the upper and lower cases 1 are
．． The position of the starting end of the guide groove 14.29 in 17 is determined. In other words, this starting end serves as a stopper for the shutter 54 (occluding portion 57) at the closed position.

Further, as shown in FIG. 17, when the closing part 57 is in the closed position, the head access opening 2 (18) is completely open, and the other side end 82 of the closing part 57 is in the sliding recess 4 ( 19), and a gap G2 is formed between the two side ends 82 and 83. In addition, as this gap G2 is formed,
The stroke of the shutter 54 has been determined.

As mentioned above, since the cartridge case 31 is molded from synthetic resin, and the closing part 54 is made of metal,
When the shutter 54 is closed, the side edges 79 and 80 collide, or when the shutter 54 is opened, the side edges 80
2 and the side end 83, abrasion powder of the synthetic resin is generated. Therefore, preferably, the recess opening 2 (18) is opened. This shutter 54
As the slider 5 moves, the coil spring 70 is compressed as shown in FIG. 19, and when the shutter 54 is in the closed position, the slider 5
6 corresponds to the head access opening 2 (18) and allows insertion of an optical head (not shown).

As shown in FIGS. 1 and 5, upper and lower cases 1.
The upper surface 3 of the disk cartridge 17 is textured to prevent the disk cartridge from slipping easily when held in the hand, and to have a surface roughness Rz of approximately 25 μm from the design point of view.3 However, If the sliding recess 4.19 also has such a surface roughness, it is not preferable because abrasion powder is likely to be generated due to the sliding contact of the shutter 54. Therefore, as a result of various studies by the present inventors regarding the appropriate surface roughness of the sliding recesses 4 and 19, we found that when the surface roughness Rz is set to 15 μm or less, preferably 10 ALm or less, the generation of abrasion powder due to the sliding contact of the shutter 54 is almost eliminated. I found out that there is no.

In order to prevent the generation of abrasion powder as described above, it is preferable to make the surface roughness of the four sliding parts 4.19 as small as possible, but if it is too small, the appearance of the sliding recessed parts 4.19 is unfavorable. That is, since the inner surfaces of the upper and lower cases 1.17 are provided with arcuate ribs 12.27, etc., the upper and lower cases 1.17 are
A sink mark (dent) may occur on the surface side of the lower case 1.17 due to molding. The upper surface 3 of the upper and lower case surfaces 1.170 has a textured pattern, so even if a sink mark occurs, it is not so noticeable, but the sliding recess 4.19 has a textured pattern for the reason mentioned above. However, if the surface roughness is made as small as possible, sink marks will become noticeable, which is unfavorable in terms of appearance.

Therefore, the present inventors conducted various studies on the lower limit value of the surface roughness Rz at which sink marks are not noticeable, and the lower limit value was found to be 5 μm.
I found that. Therefore, by regulating the surface roughness Rz of the sliding recess 4.19 within the range of 5 to 15 μm, it is possible to prevent the generation of abrasion powder and to make sink marks less noticeable.

FIG. 20 is a diagram for explaining the second embodiment of the present invention,
1 to 19 are for explaining the optical disk cartridge according to the first embodiment of the present invention, which is different from the first embodiment shown in FIG. 9. 2 is a side view of the optical disk cartridge, FIG. 3 is a front view of the optical disk cartridge, FIG. 4 is a rear view of the optical disk cartridge, and FIG. 5 is a bottom view of the optical disk cartridge. Figure 6 is a plan view of the optical disk cartridge with the shutter open, Figure 7 is a front view of the optical disk cartridge with the shutter open, and Figure 8 is a plan view of the shutter plate. , FIG. 9 is a sectional view of the shutter plate, FIG. 10 is a plan view of the slider, FIG. 11 is a side view of the slider, and FIG. 12 is an enlarged front view of the slider.

FIG. 13 is an enlarged rear view of the slider, FIG. 14 is an enlarged sectional view taken along line I'-I in FIG. 11, and FIGS. The shape of 57 is a middle bulge, that is, the central part of the closing part 57.57 is curved outward in a convex manner.

By adopting such a shape, the slidability of the slider 56 becomes even better.

In the above embodiment, the case of an optical disk cartridge was explained, but the present invention is not limited to this.
For example, it is also applicable to other disk cartridges such as optical-magnetic disk cartridges and magnetic disk cartridges.

[Effects of the Invention] As described above, the present invention, in the case of a thin metal plate, can be rolled in the longitudinal direction of the shutter plate by aligning the rolling direction with the longitudinal direction of the shutter plate, or by mechanically bending it by applying an external force. By providing resilience so that it becomes convex toward the outside, the wear of the cartridge case is reduced.
Trouble caused by abrasion powder is reduced, and a disk cartridge with excellent operational reliability can be provided.

[Brief explanation of drawings]

Figure 18 is a partially exploded plan view showing the state of the coil spring in the shutter closed position; Figure 19 is the shutter closed position. FIG. 3 is a partially exploded plan view showing the state of the coil spring in FIG. FIG. 2o is a sectional view of a shutter plate according to a second embodiment of the present invention. 1. Upper case, 2. Head access opening,
14...Guide groove, 17...Lower case, 1
8... Head access opening, 29... Guide groove,
31. Cartridge case, 32. Optical disc, 5
4...Shutter, 55...Shutter board,
56...Slider, 70...Coil spring. Figure 8 Figure 9 Figure 5 Figure 15 Field 0 Figure 16 Figure 18 Figure 19 Figure 20

Claims (6)

[Claims] (1) A cartridge case having a recess on at least one side and a head access opening formed in the recess, a recording disk rotatably housed in the cartridge case, and a shutter having a shutter plate on at least one side; and an elastic biasing means for elastically biasing the shutter to a closed position, wherein a shutter plate is disposed in a recess of the cartridge case, and a head access opening is opened and closed by the shutter plate. A disc cartridge characterized in that it is resilient so that its longitudinal direction is convex outward. (2) In claim (1), the shutter plate is composed of a thin metal plate, and the rolling direction of the thin metal plate coincides with the longitudinal direction of the shutter plate, and the thin metal plate is curled outward in a convex shape. 1. A disk cartridge, wherein the shutter plate is arranged in a direction perpendicular to the rolling direction and a sliding direction of the shutter plate. (3) The disk cartridge according to claim (1), wherein the burr formed by punching the shutter plate faces outward from the shutter plate. (4) In claim (1), the shutter plate is composed of upper and lower closing portions and a connecting portion connecting one end of both closing portions, and has a substantially U-shaped side surface. , a slider is disposed inside the connecting portion of the shutter plate, and at least one pair of locking pawls formed near the connecting portion of the upper and lower closing portions are connected to at least one pair of locking portions provided on the slider. A disc cartridge characterized in that a shutter plate and a slider are integrated by engaging with the disc cartridge. (5) The disk cartridge according to claim (1), wherein the side surface of the shutter plate is substantially U-shaped, and the shutter plate and the slider are integrated by screwing. . (6) The disk cartridge according to claim (1), wherein a central portion of the shutter plate in the longitudinal direction is curved outward in a convex manner.