JPS607622A - Information signal recording medium - Google Patents

Abstract

PURPOSE:To obtain a magnetic drum which is free from the drop-out of signal in the butt part of a film and has high quality by winding spirally a magnetic tape with the side edges held in tight contact with each other on the inside surface of a cylindrical seamless tube. CONSTITUTION:A tube formed of a polyester terephthalate having heat shrinkability and resiliance is fitted onto a circular cylindrical handle jig 41 having a diameter D and the jig 41 is heated with a heater 42. The tube 40 shrinks and contacts tightly with the circumferential surface of the jig 41. The tube is removed from the jig 41 and a seamless tube 43 having an inside diameter D is thus obtd. A magnetic tape 44 with the magnetic layer faced on the inside is spirally wound on the inside circumferential surface of the tube 43 while the side edges 44a are butted to each other. Both ends 46a, 46b are adhered to each other and a magnetic drum body 45 is obtd. The magnetic drum which is free from the drop-out of signal in the butt part of the film and has high quality is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an information signal recording medium on which information signals are recorded.

PRIOR ART The present applicant has proposed an apparatus in which a drum having a magnetic layer on its circumferential surface rotates, and a magnetic head scans the magnetic layer relative to each other to record and reproduce images. -We proposed a device that is built into a body that is about the size of an eye reflex camera. Since the drum of this device has a magnetic layer on the outer peripheral surface, there is a risk that the magnetic layer may be damaged during handling, and there is a problem in protecting the magnetic layer. Furthermore, since the magnetic layer is located on the outer peripheral surface, the magnetic head is disposed outside the drum, which is not desirable in terms of miniaturization.

Means for Solving the Problems It is an object of the present invention to provide an information signal recording medium that solves the above-mentioned problems. Here, D is the inner diameter of the cylindrical recording medium), and the cylindrical recording medium is formed by winding a flexible band with a smooth surface and with its ends closely abutted. It consists of an inner circumferential layer formed on the inner circumferential wall surface of the medium body, the surface of which is mirror-like, and a recording layer formed on the surface of the inner circumferential layer, on which information signals are recorded by the υ signal conversion element. It is structured as follows.

Embodiment FIG. 1 schematically shows an image recording/reproducing apparatus to which an information signal recording medium according to the present invention is applied.

The outer casing 2 of the image recording/internal recording device 1 has a shape roughly similar to that of a 35 mm single-lens reflex camera.

Although the outer casing 2 is shown as transparent for convenience of explaining the internal configuration, it is actually opaque. The source from the subject (not shown) to be imaged and recorded is lens system 3.
The light passes through the D,/%-humirror 4 and enters a solid-state image sensor 5, such as a CCD, where it is converted into a video signal. A part of the light passing through the lens system 3 is reflected by the mirror 4, is reflected by the mirror 6, and reaches the viewfinder γ. The battery 8 is a power source for a circuit board 9 provided with a solid-state image sensor 5 and motors 2γ, 32, etc., which will be described later. On the top surface of the outer casing 2, a shutter button 10, a release button 11, and a further operation switch 12 are provided, as in a normal camera.

Further, a magnetic drum cartridge 13 is installed in the apparatus 1, and a magnetic drum 14 inside this cartridge 13 is installed.
Then, the video signal from the solid-state image sensor 5 is recorded by the magnetic head 15.

FIG. 2 shows the magnetic drum cartridge 13, and FIG. 3 shows the magnetic drum cartridge 13 together with the mechanism on the apparatus 1 side.

As shown in FIGS. 2 and 3, the magnetic drum cartridge 13 includes a magnetic drum 14 housed inside a cylindrical cartridge body 20 with a top plate.

The cartridge body 20 has the function of protecting the magnetic drum 14 and stabilizing the high-speed rotation of the magnetic drum 14. The magnetic drum 14 has a lower edge fitted inside the lower open end of the cartridge body 20 and is locked by a ring member 21, so that separation from the cartridge body 20 is restricted.

The magnetic drum 14 includes a seamless tube 22 having a cylindrical shape with a flexible outer side and an inner diameter of D, as shown in FIG.
A base layer 23 for a magnetic layer having a soft and mirror-like surface formed on this inner circumferential wall, and a magnetic layer 24 on the surface of the base layer 23, a bearing hole 25 & a magnetic adsorption plate in the upper end opening. The seamless tube 22 is kept in a cylindrical shape by cutting out several discs 25 having the same diameter.

Base layer 23 serves to provide a mirror-like surface for magnetic layer 24 . 5 to 7 show the base layer 23 taken out. As shown in each figure, base layer 2
3 has a structure in which a soft film 26 having a width W (<πD) is wound into a spiral πD shape with the side edges 26a and 26b closely abutting each other at a lead angle θ (==sin '''). By making the base layer 23 have this structure, the inner circumferential surface of the p1 base layer 23 becomes a sufficiently flat mirror surface without mirror finishing, and the surface of the magnetic layer 24 also becomes flat and magnetic. Recording and re-recording of video signals on the layer 24 is performed with almost no signal loss.

The method for manufacturing the above magnetic drum 14 will be described later.

As shown in FIG. 3, the magnetic drum cartridge 13 having this configuration is attached to the drum motor 2T and the magnetic head transfer mechanism 28 below the magnetic head transport mechanism 28 at The drum 14 is fitted into the bearing hole 25a and the motor shaft 2γa of the iX drum motor 27, and the disk 25 is attracted to the permanent magnet 29, and is mounted on the drum motor 27 in a state floating from the inside of the cartridge body 20. The magnetic throat 15 at the tip of the opening 30 is retracted by the action of the electromagnet 310, and the magnetic drum cartridge 13 is mounted without colliding with the magnetic throat 1-15.

During recording or reproduction, the magnetic drum 1 is moved by the drum motor 2γ.
4 rotates at high speed while the rotational phase is detected by the rotating pulse pickup head 3-6. In addition, the magnetic drum 14
rotates stably in a non-contact floating state with respect to the cartridge body 20 and in a state in which a hydrodynamic air bearing is formed between it and the cartridge body 20. Also, magnetic head 1
5 is attached to the magnetic layer 24 of the magnetic drum 14 and relatively scans it, so that video signals are recorded or reproduced without any omission.

Also, the feed motor 32 operates and the feed screw 3
3 rotates, and the rad mount section 34 is magnetically transferred upward or downward. Note that the magnetic rad mount section 34 is the eighth
As shown in the figure, the arm portion 34a"f has a frame 35 that supports the drum motor 21 and the feed screw 33.
The magnetic head 15 moves vertically together with the magnetic head 15 while being guided in a fixed manner by the elongated hole 35&, and its rotation is restricted.

Here, the magnetic head 15 is attached to the cylindrical magnetic layer 24, as shown in an enlarged view in FIG.
Since the head surface 15a of No. 5 and the magnetic layer 24 are curved surfaces in the same direction, the head surface 15a easily conforms to the magnetic layer 24,
So-called head touch becomes better.

Further, according to the above structure, there is no need to provide a head insertion hole in the cartridge body 20 as in the case where a magnetic head is attached to the outer peripheral surface of a drum, and the cartridge body 20 becomes suitable as a rotation stabilizing member. Furthermore, the magnetic drum 1
4, the drum motor 2γ as well as the magnetic head transport mechanism 28 are accommodated, and the drum periphery is compactly constructed.

In addition, since the seamless tube 22 has flexibility and the magnetic drum 14 rotates while being supported by a hydrodynamic air bearing, fine dust etc. may become trapped between the seamless tube 22 and the base layer 23. oh! Even if the magnetic layer 24 has a convex shape, when this portion passes through the magnetic head 15, the seamless tube 22 will close to the magnetic head 1.
The convex portion of the magnetic layer causes almost no adverse effects on recording and reproduction.

Next, a method for manufacturing the above magnetic drum 14 will be explained.

FIGS. 10(A) to 10(C) show the first manufacturing method. First, as shown in FIG. 4(A), a tube 40 made of heat-shrinkable and flexible polyester resin is fitted into a handle jig 41 having a cylindrical diameter.
is placed on the electric heat heater 42 and heated. This is it,
The tube contracts and comes into close contact with the circumferential surface of the jig 41, and is removed from the jig 41 to obtain a seamless tube 43 (22) with an inner diameter of D, as shown in FIG. 4(B). Next, as shown in the same figure (C), this seamless tube 43
A ready-made magnetic tape 44 is placed on the inner circumferential surface of the 7-Mules tube 43 in a spiral shape with the magnetic layer inside, the back side of the tape in close contact with the inner circumferential surface of the 7-Mures tube 43, and the side edges 44a closely abutted against each other. and glue both ends to form the magnetic drum body 4.
Get 5. 46a and 46b are adhesive parts. The parts of the magnetic tape 44 other than both ends tend to deform in the direction of expanding the warp diameter due to the elastic stress (strength) of the tape itself, which is spirally bent, and this action causes the inner peripheral surface of the tube to It is always in contact with the tube, and when the drum rotates at high speed, it comes into even closer contact with the inner circumferential surface of the tube due to centrifugal force.
4. There is no need to attach it, and it can be left unattached.

Finally, the first circular plate 25 is fitted into the opening at one end of the magnetic drum main body 45.

FIGS. 11(A) and 11(B) show the second manufacturing method.

First, as shown in FIG. 4A, a magnetic tape 44 is placed on the circumferential surface of a jig 41 with the magnetic layer inside (on the jig circumferential side).
The tll edges 44a are brought into close contact with each other and wound spirally, and both ends are temporarily fixed with adhesive tapes 47a and 4γbKJ. In this state, the tube 40 is fitted and heated and shrunk. This Q Teyori Seamless Tube 4
3 is spirally wound (formed in close contact with the circumferential surface of the magnetic tape 44. After this, it is seamlessly wound).
The magnetic tape 44 and the seamless tube 43 are bonded at the upper and lower ends of +3, and the magnetic tape protruding upward and downward from the bonded portions 46a and 46b is cut and analyzed.

Next, the tube 43 is removed from the jig 41 together with the spirally wound magnetic tape 44 inside, as shown in FIG.
) A magnetic drum body 4B shown in K is obtained, and finally a disk 25 is attached to it.

Here, the tube 4o contracts at a temperature of about 100 to 120°C, but the heat resistance temperature of the magnetic tape 44 is sufficiently higher than that, so when the tube 4o is heated and contracted, it is wound spirally. The inconvenience that the magnetic tape 44 is deformed or distorted does not occur.

FIG. 12 shows a modification of the magnetic drum body. This magnetic drum main body 49 does not have adhesive parts at the upper and lower ends. That is, the magnetic drum main body 49 is constructed with the magnetic tape 44 spirally wound around the jig 41 as shown in FIG. 1(A).
A thin layer of heat-adhesive hot melt or the like is applied to the circumferential surface, which is the back surface of the magnetic tape 44, and dried.
It is manufactured by adhering the magnetic tape 44 to the inner peripheral surface of the 7-mmless tube 43 when the tube is heated and shrunk. Note that the hot melt may be applied to the entire surface, or may be applied only to the abutting portions of the side edges 44a of the magnetic tape 44.

Note that the base of the magnetic tape 440 has a mirror surface, so when a magnetic layer is formed on the inner peripheral surface of the magnetic tape 44 as described above, the magnetic layer will be formed on a mirror surface, and the magnetic No finishing is required on the layers.

FIG. 13 shows yet another modification of the magnetic drum body. In each of the magnetic drum bodies described above, when a magnetic tape having a width W is used, the lead angle θ increases. The magnetic drum main body 50 in FIG. 13 has a magnetic tape 5 whose width W is close to πD.
1 is used, the lead angle θ is close to 90 degrees, and the abutting portion 52 between the tape side edges falls within a narrow angle range. Here, this butt part 52 i
If it is within the V and BLK range 53, even if the butt part 5
Even if signal loss becomes a problem in 2, the shadow of signal loss ~
I does not appear in the reproduced image, which is convenient.

It is also possible to use a magnetic tape with a tape width W of πD, in which case the lead angle θ will be 90 degrees, and the magnetic drum will have the abutting portion V, BLK, as in the above case.
Q: It can be kept within the enclosure and used.

Furthermore, the magnetic drum can also be manufactured by the method described below.

That is, in the manufacturing method shown in FIGS. 11(A) and 11(B)K, instead of the magnetic tape, a film having a sufficiently smooth surface on which a magnetic layer is formed is wound spirally around the jig 41. , a seamless tube 43 is formed in close contact with this, and these are extracted from the jig 41. In this state, an inner layer is formed inside the seamless tube 43 with a sufficiently smooth surface made of a spirally wound film that does not require mirror finishing. Next, a magnetic layer is formed on the surface of this inner layer. The magnetic layer is formed by applying a magnetic agent to the surface of a spirally wound film and finishing it with a coating. As a result, the magnetic drum main body is opened.

If necessary, after forming the magnetic layer, the surface of the magnetic layer is polished to a mirror-like finish, and the magnetic binder wraps around and fills the minute gap between the film butts. As a result, a high-quality magnetic drum can be obtained that has no signal dropout phenomenon at the butt portion of the film.

Furthermore, in the magnetic drum 14 described above, a rigid cylindrical body may be used instead of the seamless tube 22, and in this case, the surface precision of the inner surface of the cylindrical body may be poor.

Furthermore, in the magnetic drum cartridge 13 shown in FIGS. 2 and 3, if the cartridge body 20 is made of a resin molded member, the magnetic drum cartridge 13 will be inexpensive.

In this case, the cartridge body 20 becomes tapered at a slight angle due to the relationship with the mold, and the magnetic drum 1 corresponds to this.
4 is also required to be a tapered cylinder in order to form the entire hydrodynamic air bearing. This tapered magnetic drum is manufactured by using a magnetic tape whose tape width changes slightly in the direction of increasing, and by winding the magnetic tape helically around a tapered cylindrical jig.

Effects As mentioned above, according to the information signal recording medium of the present invention,
It has the following features.

(2) Since the recording layer is formed on the inner peripheral surface of the cylindrical recording medium, the recording layer can be sufficiently protected.

■ The inner circumferential layer, which is the base layer of the recording layer, is a band-shaped body with a smooth surface placed on the inner circumferential wall surface of the hollow cylindrical recording medium body.
Since the layer is formed by winding the raw ends closely butted together, a sufficiently smooth mirror surface can be obtained just by closely butting the ends, and it is then plated to form the inner peripheral layer. This eliminates the need for a mirror finishing process, which is advantageous in manufacturing.

■ The signal conversion element is placed inside the internal space of the recording medium, making it possible to downsize the recording device compared to the case where the signal conversion element is placed outside the recording medium. In the case of a magnetic head in which the signal conversion element is attached to the recording layer, the head surface of the magnetic head and the recording layer are curved surfaces in the same direction, so that they are easily conformed to each other and the so-called head touch is good. In addition, 1. When the recording medium is housed in a case, there is no need to provide a magnetic head insertion hole in the case.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of an imaging recording/reproducing device to which the information signal recording medium of the present invention is applied, as an external @fully transparent figure, and FIG. 2 is an embodiment of the information signal recording medium of the present invention. The third picture shows the magnetic drum cartridge shown in Fig. 2 installed in the device shown in Fig. 1.
A vertical cross-sectional view showing the structure of the magnetic drum cartridge and the mechanism housed in the internal space of the magnetic drum cartridge; FIG. 4 is an enlarged view of a part of the magnetic drum; FIGS. 5 and 6; , FIG. 1 is a perspective view, front view, and exploded view showing the base layer of the magnetic drum with the base layer removed, and FIG. 8 is a perspective view showing the drum motor and part of the magnetic head transport mechanism shown in FIG. 3. Figure 9 is an attachment to the magnetic layer of the magnetic head]
10 (A) to (C) are perspective views showing the concubine state in an enlarged manner.
) is a diagram explaining the first manufacturing method of the magnetic drum, the 11th
12 and 13 are perspective views showing modified examples of the drum body, respectively. 1...Image recording/playback device, 3...Lens system, 5...
・Solid-state image sensor, 13...Magnetic drum cartridge＼
14...Magnetic drum, 15...Magnetic head 120°
°゛force-torture body, 21-... ring member, 22.
43...Seamless tube, 23...Base! ,
24... Magnetic layer, 25... Disc, 26... Film, 26a. 26b...Side edge, 21...Drum motor, 28...
Magnetic head transfer mechanism, 32... Feet motor, 3
3... Feed screw, 34... Magnetic rad mount part, 35... Frame, 40... Polyester terephthalate tube, 41... Jig, 42...
Electric heater, 44, 51--Magnetic tape, 44a
+・+ (l'llll edge, 45°4B, 49.50=-
6M magnetic drum body, 46a, 46b...adhesive part,
52... Butt part, 53... V, B'LK range. Figure 1 Upper Figure 5 Figure 6 132- Figure 8 Figure 9 1 (A) (B) However, Figure 10 (C) 9th

Claims (3)

[Claims] (1) Hollow cylindrical recording medium body and width dimension W (≦πD
, where D is the inner diameter of the cylindrical recording medium main body), and the cylindrical recording medium body is wound by winding a belt-like body having a smooth surface and flexibility with its ends closely abutted. It consists of an inner circumferential layer formed on the inner circumferential wall surface of the recording medium main body, the surface of which is mirror-like, and a recording layer formed on the surface of the inner circumferential layer, on which information signals are recorded by a signal conversion element. An information signal recording medium characterized by: (2) The cylindrical recording medium body is made by fitting a heat-shrinkable synthetic resin tube into a cylindrical jig with a diameter and heating it, thereby shrinking the cylindrical jig. 2. The recording medium according to claim 1, wherein the recording medium is a seamless tube made of synthetic resin and has a diameter corresponding to the diameter of the recording medium. (3) The recording layer is a magnetic layer, and the strip is a magnetic tape with the magnetic layer pre-formed on one side (/), and the magnetic tape is spirally wound and coated inside the strip. The recording medium according to claim 1, characterized in that a peripheral layer and the magnetic layer are formed.