JPS62239041A - Surface inspecting device for magnetic recording medium - Google Patents

Abstract

PURPOSE:To perform efficient inspection with less man-hours by providing a surface inspecting function for monitoring the defect state and polished state of the surface of a magnetic layer formed on the surface of a magnetic recording medium. CONSTITUTION:A film 1 is supported and run under the surface inspecting device 5 by a backup roller 6 in contact and laser light 8 from the light emitting device 7 consisting of a laser light source and a scanner is made incident on the coating surface on the surface of the film 1. A defect state detector 10 is provided opposite diffuse reflected light 9 which forms a dark visual field as to reflected light of the laser light 9 from the film surface 1 and a polished state detector 12 is provided opposite regularly reflected light 11 which forms a light visual field respectively. Then, the film 1 after surface inspection is guided to a downstream-side pushing device 13, but a sizing roll 16 is provided between the devices 5 and 14 and the operation of the device 13 is stopped until a detected defect part reaches the device 13; and the film is sent to the downstream side without being punched and only a film 1 having no defect is blanked in a specific shape.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a surface inspection device for magnetic recording media such as surface-polished flexible magnetic disks, and particularly for efficiently inspecting the polished state and defect state of the surface. The present invention relates to a surface inspection device for magnetic recording media that is capable of inspecting the surface of a magnetic recording medium.

(Prior Art) Floppy disks (hereinafter referred to as Fr) are widely used as external storage media for computers and word processors.

Conventionally, the method for manufacturing this Fr) is to use a strip-shaped substrate (hereinafter simply referred to as a film) on which a magnetic material is coated and dried.
A method has been used since then, in which the surface of a disk is beaten into an annular shape using a mold, polished, and then the surface of each disk is inspected for defects one by one to complete the product.

Surface polishing of the magnetic layer formed on the surface of the film is carried out with the main purpose of removing defects such as protrusions on the surface, but defects that cannot be removed by this polishing alone often remain. Furthermore, this surface polishing may not be uniformly performed over the entire surface.

When such defects or incomplete surface polishing occur, they become a cause of recording/reproduction failures, so they must be detected and eliminated in the defective product inspection process. As a method for inspecting this defect state, as disclosed in Japanese Unexamined Patent Publication No. 59-52775, a method is widely used in which magnetic disks are rotated one by one and a specific pattern is recorded and reproduced. . In addition, a common method for inspecting the polishing state is to visually inspect an FD punched into a disk shape, visually inspecting glossiness, reproduction output voltage, and the like. In the conventional FD manufacturing method as described above, the surface polishing and surface inspection are carried out in a ring shape and then separated one by one, which requires a large number of man-hours and reduces productivity.

In order to solve this problem, JP-A-60-1!1183
As disclosed in Publication No. 8, the surface of a strip-shaped film coated with a magnetic material is polished while the film is running, and then continuously punched into a predetermined shape using a die to form Fr). A method is proposed. According to this proposal, the efficiency of the surface polishing process is improved, but it requires a process of inspecting each FD punched into a predetermined shape to check for defects, which is the same as the conventional process. There is a problem in that productivity cannot be sufficiently increased because inspection is performed. Furthermore, when surface polishing is performed in the form of a strip film, the productivity is extremely high, so conventionally the surface polishing state has been inspected by sampling. Therefore, in order to guarantee the quality of the product, the number of products handled must be increased, resulting in a large number of defective products being produced during evaluation and an increase in the number of man-hours required for sampling inspections. Furthermore, since surface polishing is performed on the strip film, it is not possible to guarantee the quality of the surface polishing under transient conditions such as speeding up and deceleration of the conveyance system, and in this state, it is necessary to inspect all parts or discard many parts. □There was also the problem of increased losses.

(Object of the Invention) The present invention has been made in view of the above circumstances, and provides a surface inspection device for a magnetic recording medium that can efficiently inspect the polishing state and defect state after surface polishing of a film with a small number of man-hours. The purpose is to

(Structure of the Invention) A surface inspection apparatus for a magnetic recording medium according to the present invention includes a surface inspection apparatus for a magnetic recording medium whose surface has been polished. This feature is characterized by the provision of a function to monitor each of the following.

According to the above configuration, it is possible to simultaneously inspect the surface defect state and polishing state of the magnetic layer formed on the surface of the magnetic recording medium, and the film strip is inspected almost synchronously with the moving speed on the line along which the strip film moves. Both of the above tests can be performed. As a result, the man-hours required for conventional sampling inspections are no longer necessary, and by detecting the occurrence of defective products and providing rapid feedback to the punching process, it is possible to prevent the production of unnecessary defective products, and to prevent the production of excessively large quantities during acceleration/deceleration. The number of discarded sheets can be minimized.

(Embodiment) Hereinafter, one embodiment of the magnetic recording medium surface inspection apparatus according to the present invention will be described with reference to the drawings.

An embodiment of the present invention is shown in FIGS. 1 and 2. FIG.

In FIG. 1, a strip-shaped film 1 with a magnetic material coated and dried on one side travels in the six directions of arrows and is guided to a polishing device 4 consisting of two polishing rolls 2 and 3 rotating at high speed. The film 1 is held between these polishing rolls 2 and 3 under appropriate pressure, and the surface of the film 1 coated with the magnetic material and dried is polished. In this case, the roll 2 in contact with the coated surface of the film 1 becomes a polishing roll, and the roll 3 on the opposite side becomes a backup roll. Subsequently, the film 1 is guided to a surface inspection device 5 provided downstream of the polishing device 4, and the film 1 is
The coating surface is inspected for defects and polishing.

This surface inspection device 5 is constructed as shown in FIG. That is, the film 1 is traveling while being supported in contact with the backup roller 6. A laser beam 8 is incident on the front coated surface of the film 1 in contact with the backup roller 6 from a light emitter 7 consisting of a laser light source and a scanner.

Of the reflected light from the film 1 surface of this laser beam 8, a defect state detector 10 is placed at a position corresponding to the diffuse reflected light 9 which becomes a dark field, and a defect state detector 10 is placed at a position corresponding to the specularly reflected light 11 which becomes a bright field. A state detector 12 is provided respectively.

After the surface inspection, the film 1 is led to a punching device 13 provided further downstream, and is punched into a predetermined shape by fitting a known punch 14 and die 15 together. At this time, in order to eliminate the defective portion detected by the surface inspection device 5, a measuring roll 16 is provided between the surface inspection device N5 and the punching device 13, and the detected defective portion is removed from the punching device. 13, the operation of the punching device 13 is stopped, and the film 1 is sent downstream without being punched. Then, the punching machine @ 13 operates normally and punches out parts of the film 1 in which no defects are detected into a predetermined shape. This punched FD
17 are accumulated in an accumulation section 18 provided at the lower part of the punching device 13 and sent to the next process. If a defect is detected, the film 1 may be punched out by the punching device 13 and then not sent to the stacking section 18 using known means.

Next, the operation of the surface inspection device 5 according to this embodiment will be explained.

If there is a defect such as a hole in the polished magnetic layer formed on the surface of the film 1, diffused light is more sensitive as a light beam for detecting this defect. Furthermore, when detecting the polishing state of the surface, it is effective to detect the average amount of specularly reflected light. For this reason, in this embodiment, the surface inspection device 5 is provided with a detector 10 that receives diffused light 9 to inspect the defect state, and a detector 12 that receives specularly reflected light 11 is provided to inspect the polishing state. This is what I did.

According to this embodiment, since surface polishing of the FD, surface inspection of the polished surface, and punching into a predetermined shape can be performed continuously as a series of operations, a significant improvement in productivity can be realized. Furthermore, as a surface inspection, defect state inspection and polishing state inspection can be performed on the line along which the film 1 moves, almost in synchronization with this moving speed. As a result, the conventional sampling inspection becomes unnecessary and all products can be inspected continuously, thereby reducing the number of man-hours and costs. Moreover, since defects in the surface condition of the film 1 can be detected before the punching process, it is possible to prevent wasteful production of defective products and to minimize the number of discarded sheets in the case of excessive conditions when increasing or decelerating the feed speed of the film 1. .

In this embodiment, a case has been described in which the defect state and polishing state of the surface of the film 1 are inspected using diffuse reflected light and specularly reflected light, respectively. However, the defect state is inspected using laser reflected light, and the polishing state is inspected using white light. The measurement may also be carried out by measuring the reflected light needle. Furthermore, in this embodiment, a case has been described in which a magnetic film is formed on one side of the film 1, but even when a magnetic film is formed on both sides of the film 1, the polishing layer 4 and the surface inspection device 5 can be installed independently on each of the front and back sides. This can be achieved by providing a similar effect. Furthermore, the surface inspection device 5 according to this embodiment is also effective when applied to inspection of sheet-like films on which magnetic films are formed other than continuous films.

-〇- (Effects of the Invention) As described above, according to the present invention, a surface inspection device for a magnetic recording medium can monitor the defect state and polishing state of the surface of the magnetic layer formed on the surface of the magnetic recording medium. Since this function is provided, the surface of a magnetic recording medium can be inspected efficiently and with fewer man-hours.

[Brief explanation of drawings]

FIG. 1 is a perspective view schematically showing a manufacturing apparatus equipped with a magnetic recording medium surface inspection apparatus according to the present invention, and FIG. 2 is a configuration diagram without showing the surface inspection apparatus of FIG. 1.

Claims (2)

[Claims] (1) After polishing the surface of a strip-shaped magnetic recording medium on which a magnetic layer is formed by coating and drying a magnetic material on the surface of a substrate, the surface of the magnetic recording medium is inspected. 1. A surface inspection apparatus for a magnetic recording medium, characterized in that the inspection apparatus is provided with means for respectively monitoring the defect state and polishing state of the surface of the magnetic layer. (2) The means for monitoring the defect state and polishing state of the surface of the magnetic layer includes a light emitter that makes light incident on the surface of the magnetic layer, and a detector that detects diffusely reflected light and specularly reflected light, respectively. An apparatus for inspecting the surface of a magnetic recording medium according to claim 1.