JP2004280952A - Floating optical head and optical recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a floating optical head which can prevent its floating surface from being damaged and be reused even if the floating surface is damaged. <P>SOLUTION: The floating optical head 1 is provided with an objective lens 4 which condenses light on an optical disk. In this case, the optical head 1 has a coated layer 7, which can be exfoliated, on a face facing the optical recording medium. By this, the floating optical head can repeatedly be used by exfoliating the coated layer 7 and then forming the layer again even if the floating surface of the floating optical head 1 is damaged. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a floating optical head having an objective lens for condensing at least an optical recording medium such as an optical disk, and an optical recording / reproducing apparatus that performs at least one operation of reproducing, recording, and erasing information using the same. It concerns the device.
[0002]
[Prior art]
At present, an optical disk as a recording medium on which information can be reproduced and / or recorded / erased by using a laser beam is commercially available and widely used for consumer use and data backup. These optical disks include, for example, a rewritable type, a write-once type and a read-only type.
[0003]
On the other hand, there is a great demand for increasing the capacity of these optical discs, and research and development of larger-capacity optical discs have been carried out, with the aim of putting them to practical use.
[0004]
In order to increase the capacity of the optical disc, it is conceivable to increase the recording density of data on the optical disc. To cope with this increase in density, a method of recording and reproducing smaller recording bits by reducing the spot diameter of the light beam can be considered.
[0005]
The spot diameter of a light beam applied to an optical disk is proportional to λ / NA, where λ is the wavelength of the light and NA is the numerical aperture of an objective lens used for focusing. Therefore, the spot diameter of the light beam can be reduced by shortening the wavelength of light and increasing the NA of the objective lens.
[0006]
Here, when the NA of the objective lens is increased, the depth of focus of the objective lens becomes shallower. Therefore, in consideration of the fact that the influence of the tilt (tilt) of the optical disk is increased, light is not incident from the substrate side as in the related art, but the surface side of the information film or the like laminated on the substrate (hereinafter, the film surface). From the side).
[0007]
As described above, in order to make light incident from the film surface side of the optical disk, it has been proposed to use a floating optical head in which an objective lens is provided on a floating slider. When the floating optical head is used, the distance between the floating slider or the objective lens and the optical disk, that is, the flying height, can be maintained constant by keeping the linear velocity of the optical disk facing the floating optical head constant. Therefore, the focus can be adjusted by adjusting the interval to a predetermined value.
[0008]
Here, the floating optical head will be described more specifically with reference to FIG. In FIG. 1, the flying optical head 101 reproduces and / or records / erases information on the optical disk 102. The floating optical head 101 has a configuration in which a slider 105 provided with an objective lens 104 is attached to a suspension 103. The optical disc 102 includes an information layer on at least a substrate for reproducing and / or recording / erasing information. Although not shown, the light beam 106 is emitted from the semiconductor laser, and after being formed, is condensed on the optical disk 102 by the objective lens 104 on the floating optical head 101. Then, the light beam reflected from the optical disc 102 returns in the same process in the opposite direction, and is detected by a reproduction signal detection system (not shown) to read out information.
[0009]
[Patent Document 1]
JP-A-2000-251340 (release date: September 14, 2000)
[0010]
[Problems to be solved by the invention]
However, when the floating optical head is used as described above, the distance between the floating optical head and the optical disk is several μm or less, so that the floating optical head collides with the optical disk due to some external factors, thereby damaging or floating the optical disk. The optical head may be damaged. For example, when the optical disk is damaged, if the damage reaches the information layer of the optical disk, there is a possibility that the information in the damaged portion is destroyed. For this reason, it has been studied to provide a lubricating layer having a small friction coefficient on the outermost surface side of the optical disk to protect or reduce the impact at the time of collision of the floating optical head.
[0011]
However, similarly, if the flying surface of the floating optical head is damaged, the flaw may change the floating characteristics of the floating optical head, causing the floating to become unstable, making it impossible to collect light on the optical disk. There is. As a result, there is a problem that it becomes impossible to reproduce or record information on the optical disk by the floating optical head.
[0012]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a floating type that can prevent the flying surface from being damaged and can be reused even if the flying surface is damaged. An object of the present invention is to provide an optical head.
[0013]
[Means for Solving the Problems]
In order to solve the above problem, a floating optical head according to the present invention includes a floating optical head having an objective lens for condensing light on an optical recording medium. It is characterized by having a possible coat layer.
[0014]
According to the above configuration, the coating layer can prevent the floating optical head from being damaged due to contact with the optical recording medium. Further, even if the coating layer is damaged due to the contact between the optical recording medium and the floating optical head, it is possible to prevent damage to the optical path portion of the floating optical head. Therefore, by peeling the coating layer, the floating characteristics of the floating optical head due to the scratches can be improved, and the floating optical head can be reused.
[0015]
Further, the coat layer is preferably made of an acrylic UV curable resin. According to the above configuration, the coat layer can be easily peeled off with a solvent such as alcohol. Therefore, peeling can be easily performed without requiring a complicated device. Further, when the coating layer is peeled off, the coating layer can be easily formed again. Thereby, it is possible to eliminate the damage of the portion of the optical path on the surface of the flying optical head, and it is possible to improve the flying characteristics. Therefore, the flying optical head can be reused repeatedly.
[0016]
Furthermore, the floating optical head of the present invention preferably has a first protective layer on the coat layer in addition to the above configuration.
[0017]
According to the above configuration, by providing the first protective layer on the coat layer, it is possible to further prevent damage to the optical path portion in the floating optical head. Further, the first protective layer can be peeled at the same time when the coat layer is peeled, and the floating optical head can be reused repeatedly by forming the coat layer and the first protective layer again.
[0018]
Further, it is preferable that a first protective layer is provided between the coat layer and the facing surface.
[0019]
According to the above configuration, the provision of the first protective layer can further prevent damage to the optical path portion of the flying optical head. Also, by forming the first protective layer from a material that is not peeled off from the floating optical head, only the coat layer is peeled off, and the first protective layer is left on the surface of the floating optical head facing the optical recording medium. Can be. The first protective layer can protect the optical path portion of the floating optical head because the optical path portion of the floating optical head is not exposed during and after the coating layer is stripped. Further, damage to the optical recording medium can be prevented. Further, when the coat layer is peeled off, the flying characteristics can be improved by forming the coat layer again, and the flying optical head can be reused repeatedly as a floating optical head capable of preventing damage.
[0020]
The thickness of the first protective layer is preferably 1 nm or more and 6 nm or less. By setting the film thickness as described above, it is possible to prevent the light-collecting characteristics of the floating optical head from being focused on the optical recording medium. That is, light can be accurately focused on the optical recording medium.
[0021]
Further, the floating optical head of the present invention preferably includes a second protective layer between the facing surface and the coat layer.
[0022]
According to the above configuration, the provision of the second protective layer can further prevent damage to the optical path portion of the flying optical head. Further, by forming the second protective layer from a material that is not peeled off from the floating optical head, only the coat layer and the first protective layer are peeled off, and the second protective layer faces the optical recording medium of the floating optical head. Can be left on the surface. Since the optical path portion of the floating optical head is not exposed during and after the separation of the coat layer and the first protective layer by the second protective layer, the optical path portion of the floating optical head can be protected. Further, damage to the optical recording medium can be prevented. Further, when the coat layer and the first protective layer are peeled off, the coat layer and the first protective layer are formed again, so that the flying characteristics are improved and the flying optical head can be prevented from being damaged. Can be used.
[0023]
The total thickness of the first protective layer and the second protective layer is preferably 1 nm or more and 6 nm or less. By setting the film thickness as described above, it is possible to prevent the light-collecting characteristics of the floating optical head from being focused on the optical recording medium.
[0024]
An optical recording / reproducing apparatus according to the present invention includes the above-mentioned floating optical head. According to the above configuration, since the floating optical head can be used repeatedly, it is possible to provide an optical recording / reproducing apparatus that can be used for a long time.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
[Embodiment 1]
An embodiment of an optical disk device (optical recording / reproducing device) using a floating optical head according to the present invention will be described below with reference to FIGS.
[0026]
FIG. 2 is a schematic diagram of an optical disk device that reproduces and / or records / erases an optical disk by irradiating light from the film surface side of the optical disk (optical recording medium). The optical disc has an information layer for at least reproducing and / or recording / erasing information on a substrate.
[0027]
In the optical disk device, as shown in FIG. 2, a light beam (incident light) 6 emitted from a light source (not shown) is applied to the information layer side (film) of the substrate of the optical disk 2 by the floating optical head 1. (On the side of the optical disk 2). As a light source of the light beam 6, for example, a semiconductor laser may be used.
[0028]
The flying optical head 1 has a configuration in which a slider 5 is attached to a suspension 3 made of a leaf spring or the like. The slider 5 is provided with an objective lens 4 for condensing a light beam 6 on the optical disk 2. The floating optical head 1 flies at a constant distance from the optical disk 2 by a floating pressure caused by the optical disk 2 rotating at a predetermined linear velocity (for example, 5 m / s). Therefore, if the linear velocity of the optical disk 2 is constant, the floating amount of the floating optical head 1 is also constant. Therefore, the flying height is set in advance so that the focus of the light beam (incident light) 6 is focused on the information layer of the optical disc 2. Further, a separate focus function may be provided.
[0029]
The optical disk 2 is not particularly limited, and may be any type such as a read-only type, a write-once type, and a recording / reproducing type.
[0030]
FIG. 1 is a schematic diagram more specifically showing the configuration of the flying optical head 1 in the optical disk device shown in FIG. As shown in FIG. 1, a flying optical head 1 according to the present embodiment has a configuration in which a coating layer 7 and a protective layer (first protective layer) 8 are sequentially provided on a surface facing an optical disk (not shown). is there. The incident light is applied from above (the side on which the coat layer 7 and the protective layer 8 are not formed) in FIG.
[0031]
Next, a method for forming the coating layer 7 and the protective layer 8 on the slider 5 having the objective lens 4 will be described. Usually, a plurality of floating optical heads are manufactured by cutting a plurality of floating optical heads on a single substrate so that a large number of them can be taken out at once. Therefore, after manufacturing a plurality of sliders 5 having the objective lens 4 on the substrate, the coating layer 7 and the protective layer 8 are applied and formed, and these are cut out individually to manufacture. The material of the substrate is preferably glass, resin, or the like.
[0032]
First, the coat layer 7 is formed on the slider 5 having the objective lens 4 (coat layer forming step). In this coat layer forming step, first, a resin is applied onto the slider 5 having the objective lens 4 and cured to form the resin. The above optical disk device is designed to be focused on the information layer of the optical disk 2 by the objective lens 4. However, if the coating layer 7 is applied too thick, the intensity of the light hitting the original information layer becomes weaker. In other words, if the coating layer 7 is too thick, the laser light focusing characteristics of the objective lens 4 may be affected. If the thickness of the coat layer 7 is approximately 3 μm, the strength is reduced by about 10%. The thickness of the coating layer 7 where the intensity of light reaching the information layer of the optical disk 2 hardly deteriorates is 1 μm or less. Therefore, the thickness of the coat layer 7 is preferably, for example, 1 μm or less, though it depends on the type and properties of the resin.
[0033]
The method of applying the resin is not particularly limited, but a spin coating method can be used. Further, when the spin coating method is used, the viscosity of the resin is preferably 30 to 100 cps, preferably about 50 cps, and the thickness of the coating layer 7 can be controlled by the number of rotations during spin coating. . In addition, although it does not specifically limit as said resin, For example, an acrylic UV curing resin is mentioned. The acrylic UV-curable resin can be cured by irradiating ultraviolet rays after application, and is preferable because of its easy handling. The acrylic UV curable resin preferably has a hardness of 20 to 30 in Vickers hardness. This hardness is effective in preventing damage due to contact between the optical disk and the floating optical head.
[0034]
Subsequently, a protective layer 8 is formed on the coat layer 7 (protective layer forming step). In this protective layer forming step, a resin is applied on the coat layer 7 and hardened, as in the case of forming the coat layer 7. The method of applying the resin is not particularly limited, but a spin coating method can be used. Further, when the spin coating method is used, the viscosity of the resin is preferably 1 to 10 cps, preferably about 5 cps, and the thickness of the protective layer 8 can be controlled by the number of rotations during spin coating. . The resin is not particularly limited, but examples include a hard UV-curable resin. In particular, the hard UV-curable resin preferably has a Vickers hardness of 50 or more. If the hardness is at least this, it is possible to prevent scratches due to contact between the optical disk and the floating optical head. Further, a Si oil-based resin may be mixed with the above resin. By mixing and curing this Si oil-based resin, lubricity can be improved, and scratches due to contact between the optical disc and the floating optical head can be further prevented.
[0035]
As with the coat layer 7, if the thickness of the protective layer 8 is too large, the laser light focusing characteristics of the objective lens 4 will be affected, and depending on the type and properties of the resin, for example, 6 nm or less. It is desirable that the thickness be 1 nm or more and 6 nm or less. The protective layer 8 needs to have a certain thickness in order to obtain the hardness described above, and preferably has a thickness of at least 1 nm. If the thickness of the protective layer 8 is 6 nm or more, the hardness is almost the same. Therefore, the thickness of the protective layer 8 is preferably 1 nm or more and 6 nm or less.
[0036]
Finally, the substrate on which the coat layer 7 and the protective layer 8 are formed is cut out one by one to manufacture a floating optical head.
[0037]
As described above, in the present embodiment, the coat layer 7 is formed on the surface of the floating optical head 1 facing the optical disk 2. The coating layer 7 can prevent the objective lens 4 (optical path) in the floating optical head 1 from being damaged. Thereby, it is possible to prevent the optical characteristics of the flying optical head 1 from deteriorating. Further, it is preferable that the coat layer 7 be peelable. For example, when an acrylic UV curable resin is used as the coat layer 7, the coat layer 7 can be peeled off by dipping in a solvent such as an alcohol such as ethanol or isopropyl alcohol. In other words, the coating layer 7 can weaken the adhesion of the floating optical head 1 to the opposing surface of the optical disk 2 with a solvent such as alcohol, and can be peeled off. At this time, glass is preferable as a material of the substrate (slider 5, objective lens 4) in order to obtain peeling characteristics. Thus, even if the coating layer 7 is damaged and the floating characteristics of the flying optical head 1 are deteriorated, the coating layer 7 is peeled off and the coating layer 7 is formed again. Therefore, the flying characteristics of the flying optical head 1 can be improved, and the flying optical head 1 can be reused.
[0038]
Further, it is preferable to form the protective layer 8 on the coat layer 7. Further, the protection layer 8 preferably has a higher hardness than the coat layer 7. Since the coating layer 7 emphasizes the characteristic that the floating type optical head 1 can be peeled off on the surface facing the optical disk 2, it is difficult to increase its hardness. Therefore, the coating layer 7 alone may not be able to completely prevent the floating optical head 1 from being damaged by contact with the optical disk 2. Thus, by forming the protective layer 8 on the coat layer 7, damage due to contact between the flying optical head 1 and the optical disk 2 (particularly damage in the optical path of the objective lens 4 and the like) can be further prevented. Further, even when the protective layer 8 is scratched and the floating characteristics of the floating optical head 1 are deteriorated, the protective layer 8 is formed on the coat layer 7, so that the coat layer 7 is peeled off. At the same time, the protective layer 8 can be peeled off. Further, even if the coat layer 7 and the protective layer 8 are damaged, the coat layer 7 and the protective layer 8 are peeled off, and the coat layer 7 and the protective layer 8 are formed again. Since the flying characteristics can be improved, the flying optical head 1 can be reused.
[0039]
[Embodiment 2]
Another embodiment of the flying optical head according to the present invention will be described below with reference to FIG. The flying optical head 10 according to the present embodiment is a flying optical head that can be used in the optical disk device shown in FIG. 2 described in the first embodiment.
[0040]
As shown in FIG. 3, the floating optical head 10 according to the present embodiment has a configuration in which a protective layer 8 and a coat layer 7 are sequentially formed on the surface of the floating optical head 10 facing the optical disc 2. is there.
[0041]
The floating optical head 10 can be manufactured by reversing the manufacturing order of the coat layer 7 and the protective layer 8 described in the first embodiment.
[0042]
As described above, in the present embodiment, the protective layer 8 and the coat layer 7 are sequentially formed on the surface of the floating optical head 10 facing the optical disk 2. The coating layer 7 can prevent the objective lens 4 (optical path) in the floating optical head 10 from being damaged. Thus, it is possible to prevent the optical characteristics of the flying optical head 10 from deteriorating. Further, since the protective layer 8 is provided between the facing surface of the floating optical head 10 and the coat layer 7, it is possible to further prevent the objective lens 4 (optical path) from being damaged.
[0043]
Further, since the adhesion between the protective layer 8 and the substrate is strong against alcohol, even when the coat layer 7 is peeled using alcohol, it is not peeled from the substrate. Accordingly, since the objective lens 4 (optical path) of the floating optical head 10 does not become exposed during and after the coating layer 7 is peeled off, the protection of the surface of the floating optical head 20 facing the optical disk can be strengthened. . In addition, it is possible to prevent the optical disc 2 from being damaged.
[0044]
Furthermore, even if the coating layer 7 and the protective layer 8 are damaged, the coating layer 7 is peeled off, and the coating layer 7 is formed again, thereby eliminating the surface damage and improving the floating characteristics of the floating optical head 1. Therefore, the floating optical head 1 can be reused.
[0045]
[Embodiment 3]
Another embodiment of the flying optical head according to the present invention will be described below with reference to FIG. The floating optical head 20 according to the present embodiment is a floating optical head that can be used in the optical disk device shown in FIG. 2 described in the first embodiment.
[0046]
As shown in FIG. 4, the floating optical head 20 according to the present embodiment is different from the floating optical head 1 according to the first embodiment in that a cover is provided between the facing surface of the floating optical head 1 and the coating layer 7. The configuration includes a layer (second protective layer) 9.
[0047]
In the floating optical head 20, before forming the coat layer 7 and the protective layer 8 described in the first embodiment, the cover layer 9 can be formed by the same method as that for forming the protective layer 8. . That is, the cover layer 9 is formed by applying a hard UV curing resin similarly to the protective layer 8. At this time, the thickness of the cover layer 9 is preferably set so as not to affect the light-collecting characteristics on the optical disk. Depending on the type and properties of the resin, the thickness is preferably 6 nm or less together with the thickness of the protective layer 8. It is desirable that the thickness be 1 nm or more and 6 nm or less.
[0048]
In the present embodiment, by forming the cover layer 9, the combined effects of the first and second embodiments can be obtained. That is, since the cover layer 9 made of a hard UV curable resin is newly formed, the coating layer 7 and the protective layer 8 can be peeled off at the same time to efficiently perform the peeling operation, and the surface of the floating optical head 20 facing the optical disk. Can be firmly protected. In other words, after the coating layer 7 and the protective layer 8 are peeled off, the surface of the floating optical head 20 facing the optical disk 2 (the portion that becomes the optical path of the objective lens 4, etc.) is not exposed by the cover layer 9. The protection of the surface facing the optical disk can be strengthened.
[0049]
Further, in this configuration, a hard UV curable resin is newly added as a material of the cover layer 9 in the configuration of the first embodiment, but the thickness and the type of material of the cover layer 9 are not particularly limited.
[0050]
Further, for example, after forming the protective layer, it is also possible to form a lubricating layer having a small friction coefficient in order to further reduce damage when the floating optical head collides with the optical disk.
[0051]
According to the present invention, in a floating optical head for performing reproduction or recording and erasing using light, a protective layer for protecting a light incident surface on a light incident surface side of an optical disc and a protective layer for protecting a light incident surface from scratches are repeatedly formed. Form a coat layer that can be peeled and formed. With this configuration, even if the surface of the floating optical head facing the optical disk is damaged, the protective layer and the coating layer can be repeatedly formed, so that the floating optical head can be reused.
[0052]
Further, since the above-mentioned coat layer can be peeled off with a solvent such as alcohol, it can be easily peeled off without requiring a complicated apparatus.
[0053]
In addition, since the coating layer and the protective layer are formed in this order on the floating optical head, the optical disk can be protected by the protective layer, and the protective layer can be peeled simultaneously with the peeling of the coat layer, so that the peeling operation can be performed efficiently. I can do it. In addition, by controlling the thickness of the protective layer to 1 to 6 nm, the laser light focusing characteristics of the optical disk are not impaired.
[0054]
In another floating optical head, the coating layer and the protective layer are formed on the floating optical head in the order of the protective layer and the coating layer. Accordingly, the surface of the floating optical head facing the optical disk is not exposed by the protective layer when the coat layer is damaged and peeled off, so that the floating optical head can be protected during the coating layer peeling operation.
[0055]
In the case of a floating optical head having an objective lens that focuses light on an optical disk, the floating optical head has a cover layer for protecting the optical disk from damage caused by contact with the optical disk, and protecting and repeatedly protecting the damage caused by contact with the optical disk. By providing a coating layer that can be peeled and formed and a protective layer that protects the damage caused by contact with the optical disk in this order, the coating layer and the protective layer can be peeled at the same time, and the optical disk of the floating optical head can be peeled off during the peeling. This has the effect that the floating optical head can be protected during the peeling operation of the coat layer since the surface facing the substrate does not become exposed.
[0056]
Further, by controlling the thickness of the cover layer to 1 to 6 nm in accordance with the thickness of the protective layer, the laser beam can be accurately focused on the optical disc.
[0057]
In addition, by forming a protective layer for protecting at least damage due to contact with the optical disk and a coat layer for protecting damage due to contact with the optical disk and capable of being repeatedly peeled and formed on the surface of the floating optical head facing the optical disk. The floating optical head can be used repeatedly.
[0058]
【Example】
(Example 1)
Hereinafter, the flying optical head 1 according to the first embodiment will be described in detail with reference to specific examples.
[0059]
First, the flying stability of the flying optical head manufactured by the above method was examined.
[0060]
In the optical disk device shown in FIG. 2, the optical disk 2 was rotated at a predetermined linear velocity of 5 m / s, and the manufactured floating optical head 1 was floated for one hour. Thereafter, scratches were confirmed on the surface (protective layer 8) of the floating optical head facing the optical disk, but no particular scratches were found.
[0061]
Next, the surface of the protective layer 8 of the floating optical head is intentionally scratched so as not to reach the optical disk 2, and the optical disk 2 is rotated again at a predetermined linear velocity of 5 m / s to cause the floating optical head 1 to float. I tried it, but I couldn't fly it stably, and I scratched the optical disc 2 as well. That is, when the protective layer 8 has a flaw, the predetermined floating characteristics cannot be obtained.
[0062]
Here, the portion of the coating layer 7 and the protective layer 8 in the floating optical head having the abrasion was immersed in ethanol and allowed to stand for a while to peel off the coating layer 7 and the protective layer 8. Since the protective layer 8 was formed on the coat layer 7, it could be peeled off at the same time by peeling off the coat layer 7. In addition, even when isopropyl alcohol was used at the time of peeling, the film could be similarly peeled.
[0063]
After peeling, the surface facing the optical disk was observed to check for dirt and scratches on the surface. No dirt or scratches were found.
[0064]
Next, the coating layer 7 and the protective layer 8 were applied again by dipping on the surface facing the optical disk by the above-described method. That is, the coat layer 7 was formed by immersing the surface of the floating type optical head facing the optical disk in a tank containing an acrylic UV curable resin, applying the immersion, and irradiating with ultraviolet light to cure. After forming the coat layer 7, the protective layer 8 was formed by immersing and applying the protective layer 8 in a tank containing a hard UV curable resin, and then irradiating and curing the ultraviolet ray.
[0065]
After forming the coat layer 7 and the protective layer 8, the new disk was rotated at a predetermined linear velocity (5 m / s), and the flying optical head was floated for 1 hour. As a result, stable flying characteristics were obtained. Here, the surface of the protective layer of the floating optical head and the surface of the optical disk were observed once, but no particular damage was found. Therefore, the flying optical head 1 was floated again for about 2 hours, and it was confirmed that the floating optical head 1 was stably flying.
[0066]
(Example 2)
Hereinafter, the flying optical head 10 according to the second embodiment will be described in detail with reference to specific examples.
[0067]
First, the flying stability of the flying optical head 10 was examined.
[0068]
The flying stability of the flying optical head 10 was confirmed in the same manner as in Example 1. Thereafter, scratches on the surface (coat layer 7) of the flying optical head 10 facing the optical disk were confirmed, but no particular scratches were found.
[0069]
Next, the extent that the protective layer 8 does not reach the surface of the coat layer 7 of The optical disk 2 was rotated at a predetermined linear velocity of 5 m / s to try to levitate the flying optical head 10, but it was not possible to stably fly, and the optical disk 2 was also damaged. Was. That is, when the coat layer 7 has a flaw, the predetermined floating characteristics cannot be obtained.
[0070]
Here, the portion of the coating layer 7 of the floating optical head having the abrasion was immersed in ethanol and allowed to stand for a while, and the coating layer 7 was peeled off. Note that the protective layer 8 was not peeled.
[0071]
After the coating layer 7 was peeled off, the surface of the protective layer 8 was observed to check for dirt and scratches on the surface. No dirt or scratches were found. Next, the coating layer 7 was formed by applying the coating layer 7 again by dipping on the surface of the floating optical head facing the optical disk, that is, on the protective layer 8. That is, the coating layer 7 was formed by immersing the coating layer 7 in a tank containing an acrylic UV curing resin, applying the coating, and irradiating ultraviolet rays to cure the coating.
[0072]
After the formation of the coat layer 7, the new optical disc 2 was rotated at a predetermined linear velocity (5 m / s), and the flying optical head 10 was floated for one hour. As a result, stable flying characteristics were obtained. Here, the surface of the coating layer 7 of the flying optical head 10 and the surface of the optical disk were observed once, but no particular damage was found. Therefore, the flying optical head 10 was floated again for about 2 hours, and it was confirmed that the flying optical head 10 was stably flying.
[0073]
(Example 3)
Hereinafter, the floating optical head 20 according to the third embodiment will be described in detail with reference to specific examples.
[0074]
First, the flying stability of the flying optical head 20 was examined.
[0075]
The flying stability of the flying optical head 20 was confirmed in the same manner as in Examples 1 and 2. Thereafter, scratches on the surface (coat layer 7) of the flying optical head 10 facing the optical disk were confirmed, but no particular scratches were found.
[0076]
Next, a scratch was made to such an extent that it did not reach the cover layer 9 and the optical disk 2 was rotated again at a predetermined linear velocity of 5 m / s to try to float the flying optical head 20, but it was possible to stably fly. Instead, the optical disk was also damaged. That is, when the cover layer 9 has a flaw, the predetermined floating characteristics cannot be obtained.
[0077]
Here, the portion of the coating layer 7 and the protective layer 8 of the floating optical head 20 having the abrasion was immersed in ethanol and left for a while, and the coat layer 7 and the protective layer 8 were peeled off. Since the protective layer 8 was formed on the coat layer 7 as in Example 1, the protective layer 8 could be peeled off simultaneously by peeling off the coat layer 7. Note that the cover layer 9 was not peeled off.
[0078]
After the coating layer 7 and the protective layer 8 were peeled off, the surface of the cover layer 9 was observed and checked for dirt and scratches. No dirt or scratches were found. Next, in the same manner as in Example 1, the coat layer 7 and the protective layer 8 were again applied by dipping and formed.
[0079]
After forming the coat layer 7 and the protective layer 8 again, the new optical disc 2 was rotated at a predetermined linear velocity (5 m / s), and the flying optical head 20 was floated for 1 hour. As a result, stable flying characteristics were obtained. . Here, the surface of the protective layer 8 of the flying optical head 20 and the surface of the optical disk 2 were observed once, but no particular damage was found. Therefore, the flying optical head 20 was floated again for about 2 hours, and it was confirmed that the flying optical head 20 stably floated.
[0080]
【The invention's effect】
As described above, the floating optical head of the present invention has a configuration in which a releasable coat layer is provided on the surface facing the optical recording medium.
[0081]
According to the above configuration, the coating layer can prevent the floating optical head from being damaged due to contact with the optical recording medium, and even if the coating layer is damaged, the coating layer is peeled off. As a result, the flying characteristics of the flying optical head due to the scratches can be improved, and the flying optical head can be reused.
[0082]
Further, the coat layer is preferably made of an acrylic UV curable resin. Thereby, the coat layer can be easily peeled off with a solvent such as alcohol. Further, when the coating layer is peeled off, the coating layer can be easily formed again. Therefore, the floating characteristics of the floating optical head can be improved, and the floating optical head can be reused repeatedly.
[0083]
Furthermore, the floating optical head of the present invention preferably has a first protective layer on the coat layer in addition to the above configuration. This can further prevent damage to the optical path portion of the flying optical head. Also, by peeling the coat layer,
Further, it is preferable that a first protective layer is provided between the coat layer and the facing surface.
[0084]
According to the above configuration, the provision of the first protective layer can further prevent damage to the optical path portion of the flying optical head. Further, since the first protective layer is formed of a material that is not peeled off from the floating optical head, the optical path portion of the floating optical head is not exposed during and after the coating layer is peeled off by the first protective layer. The optical head of the optical head can be protected and the optical recording medium can be prevented from being damaged. Further, by forming the coat layer again, there is an effect that the flying characteristics are improved, and the flying optical head can be reused repeatedly as a floating optical head capable of preventing damage.
[0085]
In addition, by controlling the thickness of the first protective layer to 1 to 6 nm, the light-collecting characteristics of the laser light on the optical disk are not impaired.
[0086]
Further, the floating optical head of the present invention preferably includes a second protective layer between the facing surface and the coat layer.
[0087]
According to the above configuration, the provision of the second protective layer has an effect that damage to the optical path of the flying optical head can be further prevented. Further, by forming the second protective layer from a material which is not peeled off from the floating optical head, the optical path portion of the floating optical head is exposed during and after the peeling of the coat layer and the first protective layer by the second protective layer. Therefore, the optical recording medium can be prevented from being damaged. Further, by forming the coat layer and the first protective layer again, there is an effect that the flying characteristics can be improved and the flying optical head can be reused repeatedly as a floating optical head capable of preventing damage.
[0088]
The total thickness of the first protective layer and the second protective layer is preferably 1 nm or more and 6 nm or less. By setting the film thickness as described above, it is possible to prevent the light-collecting characteristics of the floating optical head from being focused on the optical recording medium.
[0089]
An optical recording / reproducing apparatus according to the present invention is configured to include the above-mentioned floating optical head. According to the above configuration, since the floating optical head can be used repeatedly, it is possible to provide an optical recording / reproducing apparatus that can be used for a long time.
[Brief description of the drawings]
FIG. 1 is a sectional view of a main part of a flying optical head according to an embodiment of the present invention.
FIG. 2 is a sectional view of a main part showing an optical disk device using the floating optical head.
FIG. 3 is a cross-sectional view of a main part of a flying optical head according to another embodiment of the present invention.
FIG. 4 is a sectional view of a main part of a floating optical head according to still another embodiment of the present invention.
FIG. 5 is a sectional view of a main part showing an optical disk device using a conventional floating optical head.
[Explanation of symbols]
1,10,20 Floating optical head
2 Optical disk (optical recording medium)
3 suspension
4 Objective lens
5 Slider
6 light beam
7 Coat layer
8 Protective layer (first protective layer)
9 Cover layer (second protective layer)

Claims (8)

What is claimed is: 1. A floating optical head having an objective lens for condensing light on an optical recording medium, comprising a peelable coat layer on a surface facing the optical recording medium. . The floating optical head according to claim 1, wherein the coat layer is made of an acrylic UV curable resin. The floating optical head according to claim 1, further comprising a first protective layer on the coat layer. The floating optical head according to claim 1, further comprising a first protective layer between the coat layer and the facing surface. 5. The floating optical head according to claim 3, wherein the thickness of the first protective layer is 1 nm or more and 6 nm or less. The floating optical head according to claim 3, further comprising a second protective layer between the facing surface and the coat layer. The floating optical head according to claim 6, wherein the total film thickness of the protective layer and the second protective layer is 1 nm or more and 6 nm or less. An optical recording / reproducing apparatus comprising the flying optical head according to any one of claims 1 to 7.

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