JP4301383B2 - Tape cartridge - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tape cartridge having a pocket for accommodating a sensor for detecting a tape end at a front portion of a case, and a sensor window that allows a detection light to pass through a front wall of the case facing the pocket.
[0002]
[Prior art]
The detection light projected from the light source may be repeatedly reflected by the inner wall of the case and reach the sensor, resulting in a false detection state. In order to prevent this type of malfunction, Japanese Utility Model Laid-Open No. 5-8780 discloses that a case inner wall facing the detection optical path is formed with a matte surface to prevent the detection light from being unnecessarily reflected. In JP-A-5-89636, a plug body functioning as a concave lens is fitted into the sensor window to prevent light reflected from the case from reaching the sensor.
[0003]
There is a compatible type of tape cartridge that can be applied to the same VTR in large and small tape cartridges that are mainly applied to VTRs for business use, as disclosed in Japanese Patent Laid-Open No. 5-89636. Tape cartridges are the same. In a VTR to which this type of compatible tape cartridge is applied, the inventors have made it possible to detect a tape end in a large-sized tape cartridge with the same optical path length as that of a small-sized tape cartridge. In this tape cartridge, it is planned to stably detect the tape end.
[0004]
Specifically, as shown in FIG. 4, pockets 13 for accommodating the sensors C are formed in the left and right sides of the front surface of the case body 1 of the large-sized tape cartridge C1, and a sensor for the small-sized tape cartridge C2 indicated by a broken line is formed. C is shared, and the detection optical path length is made equal for both tape cartridges C1 and C2. In this way, when the sensor pocket is formed in the recess in the front part of the case, the sensor window 14 is opened in the case front wall facing the pocket.
[0005]
[Problems to be solved by the invention]
As described above, when the tape end is detected by the sensor arranged in the front part of the case, it is possible to avoid an increase in the optical path length and to prevent erroneous detection due to light repeatedly reflected in the case. However, since the sensor window opened facing the pocket faces the tape path at the same time, it is inevitable that the dust-proof property of the case body is impaired by opening the sensor window.
[0006]
In order to prevent dust and the like from entering from the sensor window, the present inventors have studied to provide a dust-proof wall on the inner surface of the lower end of the front lid for closing the opening on the lower surface of the pocket. At the same time, the presence or absence of problems when adding a dust barrier was examined. As a result, it was found that providing a dust-proof wall can prevent dust and the like from entering from the sensor window, but causes a new problem.
[0007]
First, in a state where the front lid is opened, the previous dust-proof wall protrudes substantially downward. For this reason, the distance from the bottom wall of the case to the protruding end of the dust-proof wall becomes abnormally small, and there is a possibility that the sensor entering the pocket and the dust-proof wall may contact and interfere with each other. Secondly, the dust-proof wall protrudes in a cantilevered manner from the front lid. However, since the protruding dimension is large, the dust-proof wall may be damaged by a drop impact or the like. The inventors of the present invention have proposed the present invention in consideration of a new problem that would be caused by adding the dust-proof wall as described above.
[0008]
An object of the present invention is to ensure that dust enters from a sensor window in a tape cartridge having a pocket for accommodating a tape end detection sensor at the front of the case and having a sensor window opened facing the pocket. In other words, the reliability of the tape cartridge is improved by preventing the erroneous detection when the tape end is detected. Another object of the present invention is to reliably prevent the dust-proof wall provided on the front lid from interfering with the sensor for detecting the tape end or being damaged by a drop impact. Another object of the present invention is to make it possible to prevent intrusion of dust from a sensor window opened in the front wall of the case while cleaning up erroneous detection at the time of tape end detection in a compatible large-sized tape cartridge. In other words, the reliability of the compatible tape cartridge is improved.
[0009]
[Means for Solving the Problems]
In the tape cartridge according to the present invention, pockets 13 for receiving the tape end detection sensor C are formed in the left and right sides of the front portion of the case body 1 so as to be recessed. A sensor window 14 that allows detection light to pass through is opened in the case wall facing the pocket 13. A lid mechanism including at least a front wall 5 that protects the tape 2 when not in use is provided at the front of the case body 1. The pocket 13 is formed in a multi-stage recess shape by the front-stage recess 16 and the rear-stage recess 17. A dust-proof wall 20 is provided on the inner surface of the front lid 5 so as to enter the pocket 13 and cover at least the outer surface side of the opening region of the sensor window 14.
[0010]
The sensor window 14 opens from the inner back inner corner of the front recess 16 to the front end corner of the rear recess 17. The dust-proof wall 20 is formed of a front-rear wall that simultaneously covers the lower surface side of the front recess 16 and the lower surface side of the opening area of the sensor window 14 facing the rear recess 17.
[0011]
Reinforcing walls 21 and 22 for the dust-proof wall 20 are provided integrally between the dust-proof wall 20 and the inner surface of the front lid 5.
[0012]
In the compatible large-sized tape cartridge C1, pockets 13 for the sensor C are formed in the left and right sides of the front portion of the case body 1, and a sensor window 14 is opened in the front wall of the case facing the pocket 13.
[0013]
[Effects of the invention]
Since pockets 13 are provided at the front left and right of the case body 1 and the tape ends are detected by the sensors C accommodated in the pockets 13, the sensor C is increased by an amount corresponding to the shortening of the optical path length between the sensor C and the light source L. It is possible to detect the tape end in a stable and stable state by eliminating false detection due to. A dust-proof wall 20 that enters the pocket 13 is provided on the inner surface of the front lid 5, and covers the outer surface side of the sensor window 14, and dust or the like enters the sensor window 14 through the recessed opening of the pocket 13. Since shielding is performed, dust and the like can be well prevented from entering the case through the sensor window 14.
[0014]
The pocket 13 is formed as a multi-stage recess by a wide front recess 16 and a narrower rear recess 17 so that the left and right width dimensions on the protruding base end side of the dust-proof wall 20 protruding in a cantilever manner are as much as possible. This is to increase the strength by increasing the size. When all of the lower surface opening of the pocket 13 is covered with the dust-proof wall 20, it is possible to more reliably prevent dust and the like from entering the pocket 13. However, in this case, the dust-proof wall 20 interferes with the internal device of the tape drive such as the sensor C in a state where the front lid 5 is opened. In order to avoid such a situation and further prevent damage to the dust-proof wall 20 due to a drop impact or the like, the lower surface side facing the opening region of the sensor window 14, that is, the lower surface of the front recess 16 and the opening region of the sensor window 14 facing the rear recess 17. The dust-proof wall 20 is formed by a wall in the front-rear direction that covers the lower surface side, and the protruding dimension of the dust-proof wall 20 is suppressed.
[0015]
The reinforcing wall 21 provided between the dust-proof wall 20 and the front lid 5 is useful for preventing deformation of the dust-proof wall 20 and improving the strength. By providing the reinforcing wall 21, the space between the dust-proof wall 20 and the sensor window 14 is divided in the left-right direction. Therefore, the reinforcing wall 21 prevents the movement of the dust, so that the dust can reach the sensor window 14. Can be prevented.
[0016]
In a compatible type tape cartridge, the pocket 13 and the sensor window 14 as described above are provided at the front of the case of the large tape cartridge C1, and these are covered with the dust-proof wall 20 to ensure detection of the tape end. While improving the dust resistance, the reliability can be improved.
[0017]
【Example】
1 to 6 show an embodiment in which the present invention is applied to a compatible large-size tape cartridge C1. In FIG. 2, a tape cartridge C1 has a pair of left and right reels 3 around which a tape 2 is wound, a reel lock mechanism, and the like inside a case body 1 formed by joining upper and lower cases 1a and 1b. A tape loading pocket (hereinafter simply referred to as a tape pocket) 4 is formed in the center of the front surface of the case body 1 so as to guide the tape 2 in a state of crossing the front surface from side to side. A lid mechanism is provided on the front surface of the case body 1 to protect the tape 2 exposed on the front surface of the tape pocket 4 when not in use.
[0018]
As shown in FIG. 3, the lid mechanism is composed of a front lid 5, an upper lid 6, and a back lid 7, and the front lid 5 rotates upwardly about a support shaft 9 as indicated by an imaginary line. When this is done, each of the upper lid 6 and the back lid 7 moves backward so as to ride on the upper surface of the front portion of the case body 1 so that the front and lower surfaces of the tape pocket 4 can be opened. The front lid 5 is closed and urged by a torsion coil spring 10 fitted on the support shaft 9, and in the closed position, the front lid 5 is held in a locked state by a lid lock mechanism provided on both sides of the front portion of the case body 1. ing.
[0019]
In the small-sized tape cartridge C2 shown by a broken line in FIG. 4, a pair of left and right sensors C in which the detection light projected from the light source L located at the front center of the case main body faces the left and right outer walls of the front part of the case. The tape end is detected. The detection optical path is indicated by symbol P.
[0020]
In the large tape cartridge C1, a light source insertion hole 12 (see FIG. 2) is provided on the rear side of the tape pocket 4 in order to use the tape end detection means of the small tape cartridge C2 as it is. A pocket 13 for receiving the preceding sensor C is formed in the left and right sides. A sensor window 14 that allows detection light to pass is opened in the case front wall facing the pocket 13.
[0021]
As shown in FIGS. 2 and 6, the front lid 5 in the closed state is received and supported by receiving walls 15 whose main surface walls 5 a are positioned on the left and right of the tape pocket 4. The pocket 13 is formed in a multi-step recess shape with a front recess 16 that is recessed rearward from the front receiving wall 15 and a rear recess 17 that faces the rear of the case further than the inner inner surface of the front recess 16. To do. The sensor window 14 opens in an L shape from the inner back inner corner of the front recess 16 to the front corner of the rear recess 17. More specifically, as shown in FIG. 5, at the joint surface between the upper case 1a and the lower case 1b, the joint wall of the lower case 1b is cut out in an L shape, and the upper surface thereof is joined with the joint wall of the upper case 1a. The sensor window 14 is formed at a position slightly lower than the center of the thickness of the case main body 1. This is to reduce the size of the sensor C entering the pocket 13 upward.
[0022]
As described above, if the tape end is detected by the sensor C entering the pocket 13 on the front surface of the case, the optical path length of the detection optical path P becomes the same as that of the small-sized tape cartridge C2. It is possible to prevent erroneous detection due to reflected light on the inner surface and erroneous detection due to disturbance. However, since the sensor window 14 is always open and opened in a recessed position of the pocket 13, the outer surface of the sensor window 14 cannot be covered with the main surface wall 5a even if the front lid 5 is closed. There is a concern that dust may enter from the sensor window 14.
[0023]
In order to prevent dust from entering from the sensor window 14, a dustproof wall 20 is provided on the inner surface of the front lid 5. As shown in FIGS. 1 and 6, the dust-proof wall 20 is formed by a wall in the front-rear direction that enters the pocket 13 from the lower end of the main surface wall 5 a and covers the lower surface side of the opening region of the sensor window 14. It is almost aligned with the recessed shape of the pocket 13. However, in order to prevent the protruding end of the dustproof wall 20 protruding downward from contacting and interfering with the sensor C in the state where the front lid 5 is opened, the position of the protruding end is the inner end of the opening of the sensor window 14 facing the rear-stage recess 17. It is restrained to the dimension that covers.
[0024]
According to the dust-proof wall 20 formed in a terrace shape along the recessed shape of the pocket 13, the ratio of the left and right widths of the protruding base end portion with respect to the protruding dimension can be increased to enhance the strength of the wall itself. Further, in order to increase the structural strength of the dust-proof wall 20, a pair of left and right reinforcing walls 21 and 22 are provided between the dust-proof wall 20 and the main surface wall 5a. These reinforcing walls 21 and 22 are provided so as to face both side edges of the opening of the rear-stage recess 17, but the reinforcing wall 22 on the side adjacent to the sensor window 14 has a rear-stage recess as shown in FIG. 6. It is provided at a position covering the window opening facing 17 so that dust can be more effectively prevented. In addition, as shown in FIG. 1, both the reinforcing walls 21 and 22 are provided so as to protrude above the upper edge of the opening of the sensor window 14.
[0025]
In the above-described embodiment, the dust-proof wall 20 is formed of a front-rear direction wall on the premise that the mold dividing surface when forming the front lid 5 is a vertical plane passing through the center of the support shaft 9. 7, as shown in FIG. 7, the dust-proof wall 20 is formed in a reverse L shape with a first wall 20 a facing forward and backward and a second wall 20 b facing vertically, and a reinforcing wall 21. 22 can be provided.
[0026]
In addition to the above, the planar view shape of the pocket 13 and the dust-proof wall 20 can be formed in an arbitrary shape such as a multistage cone shape, a trapezoidal shape, or a semicircular shape. The present invention can be applied to all tape cartridges provided with a pocket 13 for the sensor C on the front surface of the case other than a compatible tape cartridge. The lid mechanism may be different from the structure described in the embodiment, but it needs to include at least the front lid 5.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view taken along line AA in FIG.
FIG. 2 is a cross-sectional plan view of the tape cartridge.
3 is a cross-sectional view taken along line BB in FIG.
FIG. 4 is a schematic bottom view simultaneously showing compatible type large and small tape cartridges.
FIG. 5 is a perspective view showing the structure of a pocket.
6 is a sectional view taken along line DD in FIG. 1. FIG.
FIG. 7 is a cross-sectional view equivalent to FIG. 1 showing another embodiment of the dust-proof wall.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Case main body 5 Front cover 13 Pocket 14 Sensor window 16 Front stage recessed part 17 Rear stage recessed part 20 Dust-proof wall C1 Large size tape cartridge C2 Small size tape cartridge C Sensor P Detection optical path

Claims (4)

A pocket 13 for receiving the sensor C for detecting the tape end is formed on the left and right sides of the front portion of the case body 1.
A sensor window 14 that allows detection light to pass through the case wall facing the pocket 13 is opened.
A tape cartridge in which a lid mechanism including at least a front wall 5 for protecting the tape 2 when not in use is provided at the front portion of the case body 1,
The pocket 13 is formed in a multi-stage recess shape with a front recess 16 and a rear recess 17.
A tape cartridge, wherein a dustproof wall 20 is provided on the inner surface of the front lid 5 so as to enter the pocket 13 and cover at least the outer surface side of the opening region of the sensor window 14. The sensor window 14 is opened from the inner back inner corner of the front recess 16 to the front end corner of the rear recess 17.
2. The tape cartridge according to claim 1, wherein the dustproof wall is formed of a wall in the front-rear direction that simultaneously covers the lower surface side of the front recess portion and the lower surface side of the opening area of the sensor window facing the rear recess portion. The tape cartridge according to claim 1 or 2, wherein reinforcing walls (21, 22) for the dust-proof wall 20 are integrally provided between the dust-proof wall (20) and the inner surface of the front lid (5). This is a compatible large-sized tape cartridge C1, in which a pocket 13 for the sensor C is formed in the front left and right sides of the case body 1, and a sensor window 14 is opened on the front wall of the case facing the pocket 13. The tape cartridge according to claim 1, 2 or 3.

Images