Patent Application
20090029063
The present invention relates to a resin film forming device for forming a resin film on a disc, a method of forming a resin film, and a program for controlling the resin film forming device. More particularly, the present invention relates to a resin film forming device, a method of forming a resin film and a program in which resin can be re-used.
Priority is claimed on Japanese Patent Application No. 2006-029211, filed Feb. 7, 2006, the content of which is incorporated herein by reference.
Optical discs have been developed from compact discs (CDs) into digital versatile discs (DVDs) and into next generation DVDs. The recording density has increased accordingly. In the optical discs, fine pits and lands are formed in a spiral groove on a surface of, for example, a polycarbonate substrate. When scanning the pits and lands with laser beam, recorded information is read out. If information is recorded on a single substrate as in a CD, a recording surface is protected with a resin coating. A DVD is fabricated by bonding two or more substrates together, each having a recording surface, using adhesive resin so as to increase recording density.
Application of coating resin or adhesive resin on a substrate surface generally includes applying the resin circularly near a center hole of the substrate, and making the substrate spin at high speed to spread the resin out into uniform thickness. The spread resin is then irradiated with light sequentially from a center side toward an outer circumference so as to cure the resin (see pages 11 to 13 and FIG. 1 of Patent Document 1).
When resin applied on a disc is to be spread out and cured while the disc is spinning at high speed, the resin spread and reached an outer circumference of the disc is partially blown off due to high-speed spinning. If the resin blown off has been subject to light irradiation, the characteristics, such as absorbance and viscosity, of the resin have varied. As a result, it is difficult to re-use the resin, and the resin is wasted. In view of the aforementioned, an object of the invention is to provide a resin film forming device, a method of forming a resin film, and a program readable by a control device for controlling the resin film forming device. In the device, method and program, resin can be re-used.
To achieve the above object, a resin film forming device according to a first aspect of the invention includes: as shown in
With this configuration, since the light irradiation is stopped before the irradiation unit reaches the outer circumference, the resin escaping from the disc is not irradiated with light. The characteristics, such as absorbance and viscosity, of the escaping resin are not influenced by the light, and thus the resin can be re-used. The concept of “curing resin” used herein includes complete curing of the resin. In addition, the concept may also include curing resin to an extent that the resin is not completely cured and is gelled and no more spread out toward the outer circumference by centrifugal force caused by further spinning of the disc (hereinafter, referred to as “semi-curing”).
In a resin film forming device according to a second aspect of the invention, as shown in
With this configuration, since the light irradiation position is continuously shifted from the inner circumference side toward the outer circumference side of the disc, the resin becomes gradually cured from the inside toward the outer circumference, and thus only the resin that has not been subject to light irradiation escapes from the circumference of the disc.
In a resin film forming device according to a third aspect of the invention, as shown in
With this configuration, the resin is spread quickly and uniformly on the disc while the disc is spinning at the first spin speed. After that, the spin speed is change from the first spin speed to the second spin speed which is slower than the first spin speed. Thus, the speed at which the resin moves toward the outer circumference of the disc decreases. Since the resin is irradiated with light in this state, the resin irradiated with light can be prevented from moving toward the outer circumference of the disc.
A resin film forming device according to a fourth aspect of the invention may further include, as shown in
With this configuration, two or more substrates having recording surfaces to increase recording density can be fabricated for, for example, a DVD. Also in this case, the adhesive resin for bonding the two or more substrates together having recording surfaces can be re-used.
A resin film forming device according to a fifth aspect of the invention may further include, as shown in
With this configuration, the resin escaping from the disc can be reliably collected, thereby increasing a re-use ratio of the resin.
A resin film forming device according to a sixth aspect of the invention may further include, as shown in
With this configuration, the light irradiation position is shifted from the inner circumference side toward the outer circumference side of the disc and irradiation of light is stopped before the irradiation unit reaches the outer circumference. Thus, the resin which has not been completely cured and the resin which is located at the outermost circumference of the disc and has not cured are cured by the moving irradiation light. The cured resin is used as adhesive resin, or cured resin as a protection film.
To achieve the above object, a method of forming a resin film according to a seventh aspect of the invention includes: as shown in
With this configuration, the circular disc with the resin applied thereon is spun at the first spin speed to spread the resin quickly and uniformly on the circular disc. Then the spin speed is reduced, and the resin is irradiated with light for curing while the irradiation position of the light is shifted from the center toward the outer circumference side of the disc. Then, irradiation of light is stopped before the outer circumference of the disc is irradiated with light. In this manner, the resin escaping from the circumference of the disc is not irradiated with light, and the characteristics, such as absorbance and viscosity, of the escaping resin are not influenced by the light. Thus, the resin can be re-used.
A method of forming a resin film according to an eighth aspect of the invention may further include, as shown in
With this configuration, since the resin escaping from the disc is collected, the resin can be re-used and is not wasted.
A ninth aspect of the invention may further include a second light irradiation process S100 after the light irradiation stopping process S70 in the above-described method of forming a resin film. As shown in
With this configuration, the light irradiation position is shifted from the inner circumference side toward the outer circumference side of the disc, and irradiation of light is stopped before the irradiation unit irradiates the outer circumference of the disc. Thus, the resin which has not been completely cured and the resin which is located at the outermost circumference of the disc and has not cured can be cured by the moving irradiation light. The cured resin is used as adhesive resin, or cured resin as a protection film.
To achieve the above object, a program according to a tenth aspect of the invention is a program for controlling the resin film forming device 100 which forms a resin film on a circular disc having a center hole as shown in
With this configuration, since irradiation of light is stopped before the outer circumference of the disc is irradiated with light. In this manner, the resin escaping from the circumference of the disc is not irradiated with light, and the characteristics, such as absorbance and viscosity, of the escaping resin are not influenced by the light. Thus, the resin can be re-used.
The resin film forming device includes: a spinner on which a circular disc having a center hole is mounted, the spinner spinning the disc about the hole; a resin supply unit which applies resin onto the disc around the hole; a light irradiation unit which irradiates the resin on the disc mounted on the spinner with light for curing the resin, the light irradiation unit shifting a light irradiation position from an inner circumference side toward an outer circumference of the disc mounted on the spinner, and stopping irradiation of light before the irradiation point reaches the outer circumference of the disc. With this configuration, since irradiation of light is stopped before the irradiation unit reaches the outer circumference, the resin escaping from the disc is not irradiated with light, and the characteristics, such as absorbance and viscosity, of the escaping resin are not influenced by the light. Thus, the resin can be re-used.
The method of forming a resin film includes: a resin supply process in which resin is applied on a circular disc, around a hole formed at the center of the disc; a first spinning process in which the disc with the resin applied thereon in the resin supply process is spun at first spin speed; after the first spinning process, a reduction process in which the spin speed is reduced; during or after the reduction process, a light irradiation process in which the resin is cured while an irradiation position at which the resin is cured by light is shifted from the center toward an outer circumference side of the disc; and a light irradiation stopping process in which irradiation of light is stopped before the outer circumference of the disc is irradiated with light. With this configuration, the circular disc with the resin applied thereon is spun at the first spin speed to spread the resin quickly and uniformly on the circular disc. Then the spin speed is reduced, and the resin is irradiated with light for curing while the irradiation position of the light is shifted from the center toward the outer circumference side of the disc. Then, irradiation of light is stopped before the outer circumference of the disc is irradiated with light. In this manner, the resin escaping from the circumference of the disc is not irradiated with light, and the characteristics, such as absorbance and viscosity, of the escaping resin are not influenced by the light. Thus, the resin can be re-used.
In addition, the program readable by a control device for controlling the resin film forming device which forms a resin film on a circular disc having a center hole executes the following steps: a resin application step in which the resin is applied around a hole of a disc; a spinning step in which the spinner on which the disc with resin applied thereon is mounted is spun at first spin speed; after the spinning step, a reduction step in which the spin speed of the spinner is reduced; after the reduction step, a light irradiation step in which the disc is irradiated with light from the inner circumference side toward the outer circumference side of the disc; and a light irradiation stopping step in which irradiation of light is stopped before the outer circumference of the disc is irradiated with light. With this configuration, since irradiation of light is stopped before the outer circumference of the disc is irradiated with light. In this manner, the resin escaping from the circumference of the disc is not irradiated with light, and the characteristics, such as absorbance and viscosity, of the escaping resin are not influenced by the light. Thus, the resin can be re-used.
The invention may alternatively include the following structures. The invention is a resin film forming device in which the light irradiation unit includes: a light irradiation portion; an arm which supports the light irradiation portion; and a pivot driver which supports the arm, makes the aim pivot and travel from the inner circumference side toward the outer circumference side of the spinning disc.
With this configuration, an effect is advantageously provided that the pivotal movement facilitates continuous movement, in its precise sense, of the light irradiation unit. In addition, an effect is also advantageously provided that the shifting speed of the light irradiation position can be adjusted by the speed of the pivotal movement.
The invention is the above-described resin film forming device, in which the light irradiation unit includes: a light irradiation portion; an arm which supports the light irradiation portion; a pivot driver which supports the arm, makes the arm pivot and travel from the inner circumference side toward the outer circumference side of the spinning disc; and a vertical driver connected to the pivot driver, for moving the arm upward to move the light irradiation portion upward when the light irradiation portion reaches the outer circumference of the disc.
In this configuration, since the distance between the disc and the light irradiation portion becomes long when the arm is moved upward, similar effect to the stopping of light irradiation can be obtained.
The invention is a method of forming a resin film, which includes: a process of mounting a circular disc having a center hole on a spinner, and making the disc spun about the hole; a process of applying resin onto the disc around the hole; a process of irradiating the disc with light while an irradiation position is shifted from an inner circumference side toward an outer circumference side of the disc mounted on the spinner; and a process of stopping irradiation of light before the light irradiation reaches the outer circumference of the disc.
With this configuration, since irradiation of light is stopped before the light irradiation reaches the outer circumference, the resin escaping from the disc is not irradiated with light, and the characteristics, such as absorbance and viscosity, of the escaping resin are not influenced by the light. Thus, the resin can be re-used.
1, 1′: disc substrates, 2: hole, 3: resin, 4, 5: optical disc, 10: disc mounting arm, 11: turn table, 11a, 11b: receiving part, 12: inversion unit, 13: resin supply unit, 13a: supply nozzle, 14: disc alignment unit, 15: transfer unit, 16 (16A, 16B): spinner, 16a: receiver, 16b: spinning axis, 16c: spin driver, 17 (17A, 17B): light irradiation unit, 18: receiver, 19: transfer unit, 20: turn table, 21: curing unit, 22: turn table, 23: inversion unit, 24: electric discharger, 25: transfer unit, 26: inspection unit, 27: lifting stage, 28: transfer unit, 29; non-defective article table, 30: defective article table, 40: coater house, 41: suction pipe, 42: resin reservoir, 43: suction unit, 46: shutter, 60: control unit, 111: disc receiver, 112: projection, 113: notch, 140: column, 141: arm, 142: suction unit, 143: suction surface, 144: vacuum section, 145: Suspending portion, 146: vacuum tube, 171: irradiation unit, 172: irradiation arm, 173: vertical driver, 174: pivot driver, 175: optical fiber, 176: ultraviolet light source, 178: irradiation control unit, 180: light irradiation unit, 181: LED, 188: LED control unit, R1: position at inner circumference side of disc where ultraviolet light irradiation is started, R2: position at outer circumference side of disc where irradiation of ultraviolet light is stopped, V1, V2, V3: spin speed of disc
Hereinafter, embodiments of the invention will be described with reference to the drawings. In the drawings, identical reference numerals are given to the identical or corresponding devices, and repeated description thereof will be omitted.
First, a resin film forming device 100 according to the invention will be described with reference to
The resin film forming device 100 also includes a receiver 18, a transfer unit 19, a turn table 20, a curing unit 21, a turn table 22, an inversion unit 23, an electric discharge unit 24, a transfer unit 25, an inspection unit 26, a lifting stage 27, a transfer unit 28, a non-defective article table 29 and a defective article table 30. The disc 4 irradiated with light is temporarily placed on the receiver 18. The transfer unit 19 transfers the disc 4 from the receiver 18 to the turn table 20 and from the turn table 20 to the turn table 22. The turn table 20 transfers the disc 4 to the curing unit 21. The curing unit 21 re-irradiates the disc 4 on the turn table 20 with light, thereby completely curing the entire resin 3. The turn table 22 moves the disc 4 to the inversion unit 23 and to the electric discharge unit 24. The electric discharge unit 24 discharges the disc 4 and the inversion unit 23 which inverts the disc 4. The transfer unit 25 transfers the disc 4 from the turn table 22 to the inspection unit 26 and from the inspection unit 26 to the lifting stage 27. The inspection unit 26 inspects the disc 4. The lifting stage 27 lifts the disc 4 to the height of the transfer unit 28. The transfer unit 28 transfers the disc 4 from the lifting stage 27 to the non-defective article table 29 and to the defective article table 30. Discs 4 defined as non-defective articles in the inspection are placed on the non-defective article table 29. Discs 4 defined as defective articles in the inspection are placed on the defective article table 30.
The disc substrates 1 and 1′ are typically polycarbonate resin-made discs, but not limited thereto. Other materials that transmit laser beam may be used suitably. The disc substrate 1 is a circular thin board, which has a circular hole 2 in the center thereof. The disc is typically circular-shaped, but not limited thereto. For example, the disc substrate 1 is 120 mm in diameter and 0.6 mm in thickness. The center hole is 15 mm in diameter. However, the size may vary depending on application. Fine grooves constituting spiral grooves or signals are formed on one side of the disc substrate 1. The disc substrate 1 and the disc substrate 1 have different grooves. These disc substrates are temporary placed near the turn table 11. The disc substrate 1 and the disc substrate 1′ are alternately placed on the receiving part 11a of the turn table 11 by the disc mounting arm 10 with the groove-formed surfaces facing upward. The disc mounting arm 10 places the disc substrates 1 and 1′ on the receiving parts 11a by holding them at the hole from the inside or at the outer circumference from the outside so that the arm 10 does not contact the groove-formed surfaces.
The turn table 11 has twelve receiving parts 11a. The number of the receivers is not limited to twelve, but twelve is preferred in that the receivers come to the same position by turns as the turn table 11 intermittently rotates by 30 degrees. A central portion of the receiving part 11a is empty space, of which circular periphery is recessed to receive the disc substrate 1. The circular recess of the receiving part 11a opens to outside at the outer circumference of the turn table 11. With this structure in which the receiving part 11a opens to outside, a later-described arm of the inversion unit 12 can be inserted from the underside of the disc substrate 1 placed in the receiving part 11a.
The inversion unit 12 inverts the disc substrate 1′ placed in the receiving part 11a. In order that the two disc substrates 1 and 1′ are aligned with the groove-formed surfaces facing with each other as shown in
The resin supply unit 13 applies resin circularly on the disc substrate 1 around the hole 2. In the resin film forming device 100, since the two disc substrates 1 and 1′ are bonded together, ultraviolet curing resin is used as a liquid adhesive. The resin supply unit 13 applies the resin circularly by moving a nozzle 13a over a peripheral circumference of the hole 2 to supply resin. However, the nozzle 13a may alternatively be fixed and the disc substrate 1 may rotate slowly. The resin is applied to the non-inverted disc substrate 1 by the disc inversion unit 12. That is, the resin is applied to the groove-formed surface of the disc substrate 1. The resin supply unit 13 may be provided separately form the turn table 11 so that the resin supply unit 13 applies the resin to the disc substrate 1 before the disc substrate 1 is placed in the turn table 11.
As shown in
Here, with reference to
In the foregoing description, the disc alignment unit 14 includes two suction units 142, and the arm 141 rotates by 180 degrees to move to the next receiver 11a. However, the disc alignment unit 14 may alternatively include only one suction unit 142 that is fixed and supported by the arm 141. The suction unit 142 may suck and hold the disc substrate 1′, and the turn table 11 may be rotated by 30 degrees. When the next disc substrate 1 is positioned directly below the suction unit 142, the suction unit 142 may align the disc substrate 1′ with the disc substrate 1 at that position. While the disc substrates 1′ is sucked, held and lifted, the turn table 11 rotates by 30 degrees and aligns the disc substrate 1′ with the disc substrate 1 placed in the next receiving part 11a. In this manner, the two disc substrates 1 and 1′ are aligned with each other. In this manner, since the disc substrate 1′ to be aligned with the disc substrate 1 from upward without moving, the disc substrate 1 and the disc substrate 1′ cannot be misaligned or rotated with each other. In a structure with two suction units 142, operating time can be reduced. In that structure, the aim 141 is rotated 180 degrees without waiting for the rotation of the turn table 11 to move the disc substrate 1′, and the disc substrate 1′ is aligned on the disc substrate 1. Note that, the structure of the disc alignment unit 14 is not limited to that illustrated to
The transfer unit 15 transfers the aligned disc substrates 1 and 1′ (referred to as “disc 4” altogether with the resin 3) from the receiver 11a of the turn table 11 to the spinners 16A and 16B, and from 16A and 16B to the receiver 18. The transfer unit 15 includes three arms extending perpendicularly to one another. With this configuration, the transfer unit 15 can transfer the disc 4 from the receiver 11a to the spinner 16A, from the spinner 16A to the receiver 18, and from the receiver 11a to the spinner 16B at a time. At the same time, the transfer unit 15 can transfer the disc 4 from the spinner 16B to the receiver 18. The receiver 11a, the spinner 16A, the receiver 18 and the spinner 16B are circumferentially disposed at 90 degrees from one another counterclockwise in this order. The transfer unit 15 may transfer two discs 4 at a time by two arms. However, three arms may reduce a rotation angle required to transfer the disc 4. If the transfer unit 15 has four arms, the rotation angle may further be reduced since operation for returning the transfer unit 15 to the original position can be omitted.
The spinner 16 makes the disc 4 spin in order to spread the resin 3 uniformly on the disc 4 while spinning the disc 4 at high speed, and to irradiate light from the light irradiation unit 17 on the entire surface of the disc 4. The light irradiation unit 17 is assembled to the spinner 16.
Here, also referring to
The Spinner 16 includes a receiver 16a, a spinning axis 16b, and a spin driver 16c. The receiver 16a receives the disc 4 and makes the disc 4 spin. The receiver 16a. Includes a circular plate on which the disc 4 is mounted, and a pillar-shaped projection at the center of the plate. The projection is inserted in the holes 2 of the disc substrates 1 and 1′. In this manner, the center of the disc 4 and the center of rotation of the receiver 16a are aligned with each other. Other than being shaped as a pillar, the projection may also be tapered to facilitate insertion in the hole 2. A pillar-shaped spinning axis 16b is disposed directly below and at an opposite side of the receiver 16a cocentrically with the receiver 16a. The other end of spinning axis 16b is connected to the spin driver 16c. The receiver 16a spins about the projection when the spin driver 16c spins. The spin driver 16c includes, for example, a motor and a gearbox for varying the spin speed of the receiver 16a. Instead of the gearbox, the spin driver 16c may include an inverter motor. Any mechanism may be employed which can rotate the receiver 16a with varying spin speed.
The coater house 40 is a container formed to surround the receiver 16a. The coater house 40 catches on the surrounding wall the resin 3 scattering from the disc 4 spinning on the spinner 16 and collects the resin 3. In addition, the coater house 40 collects the resin 3 escaping from the disc 4. The coater house 40 has an opening at the bottom thereof. A suction pipe 41 is connected with the opening to suck the resin 3 collected in the coater house 40. The other end of the suction pipe 41 is connected to a resin reservoir 42. The resin reservoir 42 is a sealed container which has an opening connected to the suction pipe 41 and an opening to be connected with a suction unit 43. The resin reservoir 42 may also include a discharge port (not shown) for sometimes discharging the resin collected in the resin reservoir 42. The discharge port is closed for normal operation. The suction unit 43 sucks air through the suction pipe 41 to such the resin reservoir 42 from the interior of the coater house 40. The suction unit 43 is typically a draft fan. The air sucked from the resin reservoir 42 by the suction unit 43 is emitted to the atmosphere. A demister (not shown) may be provided at a position where the air is sucked from the resin reservoir 42 by the suction unit 43.
The light irradiation unit 17 includes an irradiating section 171, an ultraviolet light source 176, an irradiation control unit 178 and an optical fiber 175. The irradiating section 171 emits the ultraviolet light in a spot manner as light beam to irradiate the disc with. The ultraviolet light source 176 generates the ultraviolet light to be irradiated from the irradiating section 171. The irradiation control unit 178 controls generation of the ultraviolet light in the ultraviolet light source 176. The optical fiber 175 transmits the ultraviolet light generated in the ultraviolet light source 176 to the irradiating section 171. The irradiating section 171 irradiates a surface of the disc 4 with ultraviolet light, while travelling from the position R1 at the inner circumference side around the hole 2 toward the outer circumference side of the disc 4. That is, travelling of the irradiating section 171 shifts the irradiation position of the ultraviolet light on the disc surface. The irradiating section 171 stops at a position R2 before it travels further toward the outer circumference. The irradiation of the ultraviolet light to disc 4 is completed at the position R2. Travelling of the irradiating section 171 and the irradiation of the ultraviolet light, i.e., generation of the ultraviolet light in the ultraviolet light source 176, are controlled by the irradiation control unit 178. Here, if a disc substrate having a radius of 60 mm (a diameter of 120 mm) is used, the position R1 at the inner circumference side is typically located within a range of 10 to 25 mm in radius (16 to 42% of the disc substrate radius) from the center. The position R2 at the outer circumference side is typically located within a range of 40 to 58 mm in radius (66 to 97% of the disc substrate radius) from the center.
The control unit 60 controls the timing and the spin speed at which the spin driver 16c of the spinner 16 makes the receiver 16a spin, the timing of the light irradiation unit 17 irradiate the disc with ultraviolet light, the position of the irradiating section 171 (including travelling speed), and irradiation amount. The spinner 16 spins and the light irradiation unit 17 irradiates light in a cooperative manner. The control unit 60 may control operation of the entire resin film forming device 100, and, may also control operation and stopping of the suction unit 43, for example.
Referring again to
Referring again to
Four receiving parts are provided in the turn table 20 for receiving the disc 4. When the turn table 20 rotates, the disc 4 placed on the receiving parts is transferred to the curing unit 21. The turn table 20 rotates intermittently by 90 degrees to transfer the disc 4 placed thereon to the curing unit 21. The curing device 21 irradiates the entire surface of the disc 4 with ultraviolet light to completely cure the resin 3 on the disc 4. Unlike the case where the resin 3 is cured by the spinner 16 and the light irradiation unit 17, in the curing unit 21, the disc 4 can be irradiated with ultraviolet light without rotating the disc 4. The curing unit 21 has a xenon lamp which generates the ultraviolet light in pulses, or a UV generating lamp which generates the ultraviolet light continuously on one or both of the upper and lower surfaces of the turn table 20. After the resin 3 is completely cured by the curing unit 21, the disc 4 is transferred to the turn table 22 by the transfer unit 19.
Similar to the turn table 11, the turn table 22 also includes cylindrical receiving parts which open to outside at outer circumferences thereof. The turn table 22 includes four receiving parts and rotates intermittently by 90 degrees. The turn table 22 is rotated to transfer the disc 4 sequentially to the inversion unit 23 and the electric discharge unit 24. The inversion unit 23 has a similar structure to that of the inversion unit 12. The disc 4 is optionally inverted when required for later inspection process. For this reason, the receiving part of the turn table 22 also opens to outside. The electric discharge unit 24 blows ionized air off to remove dust or the like adhering to the surface of the disc 4.
The disc 4 after removing the dust or the like is transferred from the turn table 22 to the inspection unit 26 by the transfer unit 25. The transfer unit 25 includes two arms opened at a predetermined angle. By rotating the two arms, the transfer unit 25 can transfer the disc 4 from the turn table 22 to the lifting stage 27 to the inspection unit 26, and from the inspection unit 26 to the next lifting stage 27 at the same time. That is, the position at which the disc 4 is removed from the turn table 22, the position of the inspection unit 26, and the position of the lifting stage 27 are placed at equal intervals on a circle about the center of rotation of the arm of the transfer unit 25.
The disc 4 is mounted on the inspection unit 26, which inspects the disc 4 from the underside. The inspection unit 26 inspects, for example, existence of blemish on the disc substrates 1 and 1′, misalignment of the two disc substrates 1 and 1′, uniformity in the spread resin 3, and warping of the disc 4. The inspected disc 4 is transferred to the lifting stage 27 by the transfer unit 25. The lifting stage 27 includes a stage which moves up and down between the height in which the foregoing processes are performed and the height at which the product is taken out. That is, in the resin film forming device 100, the product disc 4 is taken out from an upper port. In this manner, the disc 4 is easily transferred to subsequent processes. The lifting stage 27 moves upward with the disc 4 placed thereon, and continues moving until the disc 4 contacts the suction surface (not shown) of the transfer unit 28. The transfer unit 28 includes a pivoting arm, and a suction surface for sucking the disc 4 below a distal end of the arm. According to the inspection result, the transfer unit 28, by sucking the disc 4 at the suction surface at the distal end of the arm and pivoting the arm, transfers discs 4 that passed the inspection to the non-defective article table 29, and transfers discs 4 that did not pass the inspection to the defective article table 30. The non-defective article table 29 includes eight receiving parts, and rotates intermittently by 45 degrees to receive the disc 4 as a product one at a time in each receiving part. The defective article table 30 receives the discs 4 that failed to pass the inspection and thus cannot be used as products. The discs 4 may be stacked, and the defective article table 30 may include a guide for supporting the outer periphery of the discs 4.
Next, a method of fabricating a disc 4 will be described. A resin film is formed using a resin film forming device 100, and two disc substrates 1 and 1′ are bonded together to form a disc 4. The disc substrates 1 and 1′ are separately fabricated and recording grooves are also formed separately. Then, the disc substrate 1 and the disc substrate 1′ are separately conveyed to the vicinity of the resin film forming device 100. The disc substrates 1 and 1′ are stored within the reach of the disc mounting arm 10 with the groove-formed surfaces facing upward. The disc substrate 1 and the disc substrate 1′ are alternately placed in the receiving part 11a of the turn table 11 by the disc mounting arm 10. That is, the disc substrate 1 and the disc substrate 1′ are alternately placed in the receiving part 11a of the turn table 11.
The turn table 11 rotates intermittently by 30 degrees. The inversion unit 12 does not invert the disc 1 when the disc 1 comes to the position of the inversion unit 12. The inversion unit 12 inverts the disc 1′ only when the disc 1′ comes to the position of the inversion unit 12. The resin supply unit 13 supplies resin around the hole 2 of the disc 1, when the disc 1 comes to the position of the resin supply unit 13. The resin 3 is circularly applied around the hole 2 while the supply nozzle 13a moving around the hole 2. Then, in the disc alignment unit 14, the disc 1′ which has been inverted by the inversion unit 12 is placed to align with the disc 1 having the resin 3 applied thereto. In this manner, the disc 4 is fabricated. Since the disc 1′ had been inverted, when the alignment unit 14 moves the disc 1′ to be aligned with the disc 1 in the next receiving part 11a, two discs 1 and 1′ are aligned together with the groove-formed surfaces facing with each other. Then, the disc 4 is transferred from the turn table 11 to the spinner 16 by the transfer unit 15.
When the disc 4 is mounted on the spinner 16, the spinner 16 begins to spinning with the disc 4. As shown in
Now, also referring to
At time t2, the spin speed V begins to decrease, and the spin speed V becomes low spin speed V1 at time t3. The low spin speed V1 is slower than the high spin speed V3, and is a spin speed at which the resin 3 is spread toward the outer circumference by centrifugal force becomes slow. The low spin speed V1 is, for example, several hundreds to 7000 (min−1). A second spin speed does not necessarily represent the low spin speed V1, but represents all the spin speed V reduced from the high spin speed V3. That is, the spin speed V which begins to decrease from the high spin speed V1 is also the second spin speed. When the spin speed V begins to decrease, ultraviolet irradiation will begin from the position R1 at the inner circumference side by the light irradiation unit 17. It is when the thickness of the resin 3 i.e., the distance between the disc substrate 1 and the disc substrate 1′ at the inner circumference side becomes a predetermined length, the irradiation of the ultraviolet light is started. Since the resin 3 is an ultraviolet curing resin, it begins curing when irradiated with ultraviolet light. The resin 3 may be completely cured by the ultraviolet light from the light irradiation unit 17. The resin 3 is not necessarily cured completely, but may be gelled, and cured to such an extent that the resin 3 does not spread over the outer circumference by centrifugal force caused by the subsequent spinning (i.e., thickness of the resin 3 does not become thinner).
While spinning at the low spin speed V1, the resin 3 in a position other than that irradiated with ultraviolet light continues spreading toward the outer circumference side by centrifugal force. When the thickness of the resin 3 at a position adjacent to the position where the resin 3 has been cured at the side of the outer circumference becomes thinner to a predetermined thickness, the irradiation arm 172 is made to pivot by the pivot driver 174 to move the irradiating section 171, i.e., the position where the resin 3 is irradiated with ultraviolet light, is shifted toward the outer circumference side, and resin 3 at that position is cured. In this manner, by shifting the position at which the resin 3 is irradiated with ultraviolet light from light irradiation unit 17 toward the outer circumference side while confirming that the thickness of the resin 3 has become a predetermined thickness, the resin 3 can be cured with uniform thickness. Actually, the time when the thickness of the resin 3 becomes a predetermined thickness is determined depending on viscosity of the resin 3, the spin speed V, and other factors. Thus, the shifting speed of the position at which ultraviolet light is irradiated from the light irradiation unit 17 toward the outer circumference side can be determined in advance. That is, the film thickness of the resin 3 can be kept more uniform by continuously shifting the ultraviolet irradiation position from the inner circumference side toward the outer circumference side while rotating the disc 4, and by adjusting the movement speed appropriately. The shift of the ultraviolet irradiation position toward the outer circumference side is achieved by the pivotal movement of the pivot driver 174, and the movement speed is also adjusted by the speed of the pivoting movement.
Here, also referring to
Since points at the side of the outer circumference on the disc 4 moves faster than those at the side of the inner circumference, when the irradiating section 171 is moved at a constant travelling speed, irradiation of the ultraviolet light decreased in amount as the irradiating section 171 moves toward the outer circumference side. However, since the amount of ultraviolet light decreases gradually, the degree of curing of the resin 3 does not vary rapidly and not cause unevenness in thickness of the resin 3. That is, the irradiation intensity of the ultraviolet light is determined such that the resin is gelled and cured even at the outer circumference side to an extent that it no more spread from the outer circumference by centrifugal force due to further spinning. Alternatively, the travelling speed of the irradiating section 171 may decrease as it moves toward the outer circumference side. In this case, the degree of curing of the resin 3 can be uniform at both the outer and inner circumferences. Alternatively, the irradiation intensity of the ultraviolet light may be increased as the irradiating section 171 moves toward the outer circumference side, and the travel irradiating section 171 may travel at a constant speed. In this case, the resin 3 can be cured uniformly with the controlled irradiation intensity of the ultraviolet light. When the film thickness of the resin 3 is tend to become thin as the irradiating section 171 approaches the outer circumference, it is required to increase the travelling speed of the irradiating section 171 as it approaches the outer circumference side. Also in this case, the curing state of the resin 3 can be controlled to increase the irradiation intensity of the ultraviolet light as the irradiating section 171 approaches the outer circumference. The irradiation intensity of the ultraviolet light may be controlled by altering generating amount of the ultraviolet light in an ultraviolet light source 176. When the irradiating section 171 has a lens mechanism, the irradiation intensity of the ultraviolet light may be controlled by adjusting the lens. Alternatively, the irradiation intensity of the ultraviolet light may be controlled by a vertical movement of the vertical driver 173. Referring again to
Once the resin 3 is irradiated with ultraviolet light, the ultraviolet light absorbance characteristic, viscosity, and other characteristics of the resin 3 varies and it is thus difficult to mix the irradiated resin with new resin to re-use the same. Thus, the ultraviolet irradiation is stopped at the position R2 slightly before the irradiation unit reaches the outer circumference of the disc 4 so that the resin 3 at the outermost side is not irradiated with ultraviolet light. Spinning is controlled to prevent scattering of the irradiated resin due to further spinning of the disc 4. In this manner, mixing of the resin irradiated with ultraviolet light with the resin scattering from the disc 4 can be prevented. As described above, the resin 3 which receives slight ultraviolet irradiation is prevented from spreading toward the outer circumference and scattering from the outer circumference of the disc 4. Thus, mixing of the resin irradiated with ultraviolet light with the resin scattering from the disc 4 can be prevented.
As shown in
As shown in
Now, referring again to
The turn table 20 rotates intermittently by 90 degrees to transfer the disc 4 to the curing unit 21 and returns the disc 4 to the position at which the disc 4 is placed. Since the disc 4 is placed and removed at the same position on the turn table 20, a single transfer unit 19 can be used to place and remove the disc 4. The curing unit 21 irradiates the entire disc 4 with ultraviolet light so as to completely cure the resin 3 that has not received irradiation of the ultraviolet light by the light irradiation unit 17, and also completely cure semi-cured resin. Here, when the resin 3 is completely cured, it is solidified. The disc 4 with completely cured resin 3 is transferred to the turn table 22 by the transfer unit 19. The positional relationship of the receiver 18, the turn table 20 and the turn table 22 corresponds to the angle made by two arms of the transfer unit 19. For this reason, like the transfer unit 15, transfer of the disc 4 from the receiver 18 to the turn table 20 and transfer of the disc 4 from the turn table 20 to the turn table 22 can be efficiently performed at the same time.
The turn table 22 sends the disc 4 to the inversion unit 23 and the electric discharge unit 24 by rotating intermittently by 90 degrees. The inversion unit 23 inverts the disc 4 for later inspection depending on the state of the film formed on the disc 4. Then, ionized air is blown off from the electric discharge unit 24 to the upper and lower surfaces of the disc 4 to remove any dust or other material adhering on the surface of disc 4, thereby cleaning the surface. The disc 4 with clean surface is transferred to the inspection unit 26 by the transfer unit 25. The inspection unit 26 inspects the disc 4 as a product. The inspection unit 26 inspects, for example, misalignment between the disc substrate 1 and the disc substrate 1′ and existence of blemish. Since dust or other material is removed by the electric discharge unit 24, the dust or other material cannot be wrongly considered as blemish, or the disc substrates 1 and 1′ cannot be misaligned. Thus, reliability is improved.
The disc 4 inspected by the inspection unit 26 is transferred to the lifting stage 27 by the transfer unit 25. The positional relationship among the position at which the disc 4 is taken out on the turn table 22, the position of the inspection unit 26 and the position of the lifting stage 27 also corresponds to the angle made by the two arms of the transfer unit 25. In this manner, like the transfer units 15 and 19, transfer of the disc 4 from the turn table 22 to the inspection unit 26 and transfer of the disc 4 to the lifting stage 27 from the inspection unit 26 can be performed efficiently at the same time. The disc 4 is lifted by the lifting stage 27, made to abut the undersurface of the distal end of the arm of the transfer unit 28, and is sucked and held by the suction unit provided at the undersurface of the arm. The disc 4 sucked and held by the transfer unit 28 is transferred to the non-defective article table 29 if the disc 4 passed the inspection, and to the defective article table 30 if the disc 4 failed to pass the inspection. The discs 4 placed on the non-defective article table 29 are fed to subsequent processes and then shipped. The discs 4 placed on the defective article table 30 are processed as defective articles. In order to prevent that the height of the discs 4 transferred to the non-defective article table 29 or the defective article table 30 by the lifting stage 27 becomes too large, the discs 4 may be stacked on the non-defective article table 29 or the defective article table 30. Since the position at which the disc 4 is taken out from the resin film forming device 100 by the lifting stage 27 is high, subsequent processes are easy to conduct. Devices required with high positional accuracy, such as the turn table 11, the spinner 16 and the light irradiation unit 17 can be arranged at low, stable positions. However, the non-defective article table 29, the defective article table 30 and the like may be placed at the same height. In this case, the lifting stage 27 may be omitted.
Next, with reference to
The shutter 46 may be rotatable with the side wall of the coater house 40 as a rotation support. The shutter 46 may also be foldable or retractable. With these configurations, the shutter 46 is preferably retracted so as not to interfere with the transfer of the disc 5 at the time of mounting and removal of the disc 5. Alternatively, the shutter 46 may only be disposed directly under the linear or circular path of the irradiating section 171. For this reason, the disc 5 may be inclined during mounting and removal so as not interfere with the shutter 46.
Next, with reference to
In the light irradiation unit 180, each of the LEDs 181a to 181j is turned on every 0 second. That is, when the LED at the inner circumference side is turned off, the LED at the outer circumference side is turned on simultaneously. There may be slight interval of lighting time such as shorter than 0.1 seconds. The lighting time may also be slightly overlapped. In any case, the resin 3 is irradiated with ultraviolet light sequentially from the inner side toward the outer side so that the film thickness of the resin 3 becomes uniform at predetermined thickness. Turning-on and turning-off of the LEDs 181a to 181j are controlled by the LED controller 188. The LED controller 188 is preferably controlled by the control unit 60 to adjust timing with spinning of the spinner 16 or mounting of the disc 4. The light irradiation units 180 has a structure for sequentially turning the LEDs on and off from the inner circumference side toward the outer circumference side, so as to continuously shift the irradiation position from the inner circumference side toward the outer circumference side. With the structure, mechanical moving parts decrease in number, and thus the device can be simplified to reduce occurrence of mechanical malfunction. In a structure in which the irradiating section 171 travels via the irradiation arm 172 by pivotal movement of the pivot driver 174 as in the light irradiation unit 17, it is easy to continuously, in its precise sense, shift the ultraviolet irradiation position. It is easy to retract the irradiating section 171 and the irradiation arm 172 from the position above the spinner 16, and the disc 4 is easily mounted on and removed from the spinner.
It has been described that, in the resin film forming device 100 as shown in
It has been described in the resin film forming device 100 that the resin film is formed as an adhesive for bonding the disc substrates 1 and 1′ together with the resin 3 interposed therebetween. However, the resin film forming device 100 may be used as a device for forming a resin film as a protective layer of the disc substrate 1 as the disc 5 shown in
Here, with reference to
The disc is made to spin at high speed on the spinner (Step S30), and then the spin speed is reduced (Step S40). During or after the reduction in spin speed, irradiation of the ultraviolet light is started at a position at the inner circumference side of the disc (Step S50). The irradiation position of the ultraviolet light is shifted from the inner circumference side toward the outer circumference side of the disc (Step S60). Irradiation is stopped before the irradiation position of the ultraviolet light reaches the outer circumference of the disc (Step S70). The resin escaping from the disc while the disc is spinning is collected (Step S80). In the flow chart of
The above-described method of forming the resin film may be performed not in the resin film forming device 100 but a resin supply unit, a spinner, and an ultraviolet light irradiation unit of any structure. For example, independent devices may be used employed. The resin film may be formed by a program incorporated in a control device for controlling the above-described method of forming the resin film.
Here, the distribution at radius positions of the resin film on the disc formed in accordance with a conventional method means the distribution obtained in the following manner: as described in JP-A No. 2004-280927, the resin is circularly applied to a disc substrate around a hole; the resin is spread due to high-speed spinning of the disc substrate, then the disc substrate is made to spin at low spin speed at which the resin is no more spread out; at the same time, the resin of predetermined thickness is irradiated with ultraviolet light from the inner circumference side; after the resin is spread again while spinning the disc substrate at high speed, the resin of predetermined thickness is irradiated with ultraviolet light while the disc substrate spins at low spin speed; and the thickness of each radius positions is measured on a cocentric circle of the resin film formed by repeating the process. Whereas the distribution at radius positions of the resin film on the disc formed in accordance with the invention means the distribution of thickness of the formed resin film obtained in the following manner: after circularly applying resin to a disc substrate around a hole, the resin is spread due to high-speed spinning of the disc substrate; the spin speed is reduced to reduce the spreading speed of the resin; the disc substrate is irradiated with ultraviolet light, while the irradiation position is shifted from the inner circumference side to the outer circumference side so that the resin film obtains predetermined thickness; and irradiation is stopped before the irradiation unit reaches the outer circumference.
Even in the resin film formed by the conventional technology shown in
As described above, a resin film forming device is provided in which escaping resin can be re-used while characteristics such as absorbance and viscosity of the resin remain static.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-029211 | Feb 2006 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2007/051934 | 2/5/2007 | WO | 00 | 8/5/2008 |
