JPH0268479A - Device for drying original plate of optical disk by heating - Google Patents

Abstract

PURPOSE:To enable more accurate control about temperature distribution without damaging space efficiency and hence improve a product quality by controlling the distribution of radiant quantities of infrared radiation from a heating means to an original plate for optical disk based on a control means. CONSTITUTION:A heating value per unit area of a glass-made original plate is generally determined by such factors as facing time to a heater element 13, the distribution of heating value processed by the element 13 itself, and cooling efficiency subject to surroundings. Therefore, it is possible to obtain a uniform temperature distribution all over the entire surfaces from the inner periphery to the outer periphery by providing a radiation heat control panel 12 having an opening section and correcting all factors which are related with the heating value per unit area based on an opening 11 which is generally fan-shaped. It is also possible to raise the surface temperature of the original plate in the uppermost outer periphery higher than the other sections by forming the opening section 11 in terms of the unit area of the original plate 1 so that the heat transferred time by way of the opening section 11 may exceed that in the other sections in the outer most peripheral part.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a heating drying apparatus that radiantly heats an optical disk master using a far-infrared or infrared heater.

BACKGROUND ART A so-called heat tunnel shown in FIG. 6 is known as a conventional heating drying device. In this heating drying device, the heated object 61 is transferred by a belt conveyor 62 and is heated and dried by heat conduction due to the atmospheric temperature inside the tunnel when the heated object 61 passes through an L-tunnel composed of a heater 63. The structure is such that this is carried out.

In this heating drying device, the temperature distribution on the heating surface of the object to be heated 61 depends on the amount of heat of the heater 62, the transfer speed of the belt conveyor 62, and the thermal properties and shape of the object to be heated 6]. The disadvantage was that it was impossible to control the distribution.

In addition, since the heating is conducted by conduction due to the atmospheric temperature inside the tunnel, the temperature distribution on the surface of the heated object is reduced as shown in Figure 6 (B
), as shown by the dashed line, the center and outermost parts are low;
The middle part becomes high and the illumination is not uniform on the other side. For this reason, when the object to be heated is a glass master disk for optical recording whose negative side is coated with photoresist, as shown in Fig. 5 (C
), the surface temperature increases from the inner circumference to the 21st circumference, and decreases at the outermost circumference. As described above, if there are variations in the heating temperature during heating and drying, there will be variations in the sensitivity of the resist, which will adversely affect the shape of the pits when information is recorded as pits. Furthermore, the present applicant also acknowledges that if the heating temperature at the outermost peripheral portion is low, the glass master disc will be fragile.

A conventional heating drying apparatus capable of controlling the temperature distribution' is shown in FIG. In this heating and drying apparatus, heating and drying is carried out by a heater 63 provided at a variable distance from the object to be heated 6 and the object to be heated 61. In this case, even if the object to be heated 6 is moving, rotating, or stationary, the heating and drying process can be carried out i+J.

According to this heating drying device, it is possible to control the temperature distribution to a certain extent, but since the control is based on distance, the space efficiency of the device is poor, and depending on the size of the object to be heated 61, the size of the heater 63 may be However, there were drawbacks such as the fact that precise control of temperature distribution was impossible due to the relationship with the temperature.

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the drawbacks of the conventional ones as described above, and provides a heating drying device for optical disc masters that increases space efficiency and allows more precise control of temperature distribution. With the goal.

In the heating drying apparatus for an optical disk master according to the present invention, the optical disk master is supported so as to face the heating means that performs radiant heating using infrared rays, and the distribution of the amount of infrared rays radiated to the optical disk master by the heating means is controlled by the thermal control means. It is configured to control.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is an external view of an apparatus showing an embodiment of the present invention, and FIG. 2 is a structural diagram thereof. In each of these figures, a glass master disk 1, which is an optical disk master disk, has one surface coated with a photoresist, and is supported by a spindle 2 so that the surface coated with the photoresist is the lower surface. The spindle 2 is rotationally driven by a spindle motor 4 housed in a housing 3. The spindle 2 and the spindle motor 4 are attached to a spindle base 5, and are guided by a linear slide 6 and driven and transferred on a main base 7 by a spindle base drive motor 8, so that the spindle 2 is attached to the housing 3. It moves between the position shown by the solid line and the position shown by the dashed-dotted line in the figure along a long hole 9 formed on the top surface of the glass master disk 10 with a length approximately equal to the radius of the glass master disk 10.

The positions of the glass master disk 1 and the spindle 2 indicated by solid lines are standby positions, and at this standby position, the low-definition ink and unrope of the glass master disk 1, the ink, and the cooling treatment after the heat treatment are performed. Further, the position indicated by the - dotted chain line is the heating drying (baking) position, and the heating drying process is performed at this position.

This device is installed in a horizontal airflow type clean bench and used in a clean room, but the left side of the diagram is the operator side,
It is arranged so that the right side is the clean bench side. This positional relationship makes it possible to minimize contamination during the drying process, which is most susceptible to contamination. In other words, in a clean room, workers who are the source of dust generation always work downwind, and particles that settle due to the influence of gravity are prevented by clean air flow as shown by the arrow in Figure 2. By setting the heated surface of the glass master 1 on the lower side, and by exhausting the inside of the casing 3 with the exhaust tube 10 to prevent dust from the mechanical part, We are dealing with pollution. In addition, the housing 3
The top surface is essentially flat, except for some openings, which prevents the accumulation of contaminant particles and facilitates cleaning.

A part of the upper surface of the housing 3 on the clean bench side is a radiant heat control plate 12 having a substantially fan-shaped opening 11 .

The radiant heat control board 12 is made of stainless steel, for example.
It may be configured integrally with the housing 3. A heater unit 4 including a far-infrared or infrared heater element 13 is arranged below the opening 11 to radiantly heat the glass master through the opening 11 . As is particularly clear from FIG. 3, in this heater mounting plate I.]4,
The heater element 13 is mounted on the heater mounting plate 15 so as to face a part of the radial area of the glass master in the heating drying position.
and is fixed to the outer panel 16 by a support (not shown). A radiant heat control plate] 2 is fixed to the upper part of the outer panel 16 via a spacer 17 which also serves as heat insulation. The jacket portion formed by the heater mounting plate [5] and the outer plate 16 is exhausted by the exhaust tube [8], whereby the heater element 13 is maintained at negative pressure to prevent heat diffusion type contamination from occurring due to heating. There is.

Further, by exhausting the heater unit 14, unnecessary heat transfer is prevented and the temperature of the device is prevented from rising. The temperature of the heater element 13 is measured by a thermocouple (not shown) attached to the heater element 13.

A radiation thermometer 19 is provided inside the housing 3, and this radiation thermometer 19 is inserted into the measurement window 2 formed on the top surface of the housing 3.
0 to measure the surface temperature of the glass master 1. The measured output of this radiation temperature=119 is supplied to the controller 21. The controller 2] is composed of, for example, a microcomputer, and performs a series of operations such as controlling the temperature of the heater element 13, controlling the rotation start and stop of the spindle 2, and controlling the transfer of the spindle 2, for heating and drying the glass master disk. control.

Next, the basic sequence of the heat drying procedure executed by the processor of the controller 21 will be explained according to the flowchart of FIG. 4.

When the device is powered on, the processor first
Preheating of the heater element 13 is started (step Sl). For example, the temperature of the heater element 1B is 215
℃, and preparation is completed at 215±5℃. The purpose of preheating is that due to the large time constant of heater heating, heating and drying time will be longer if the heater element 13 is not heated in advance.Temperature measurement is performed by a thermocouple attached to the heater element 13. .

When the glass master disc] is set on the spindle 2 and the start switch (not shown) is turned on (step S
2), the processor controls the spindle 2 by e.g. 3[r,
p, m, ] (step S3), and when it is detected that the temperature of the heater element 13 has reached the set temperature T1 based on the measurement output of the thermocouple (step s4)
, by driving and controlling the spindle base drive motor 8, the spindle 2 is advanced from the standby position to the heating drying position (step S5). Then, at this position, the photoresist on the glass master 1 is heated and dried by radiation heating from the heater element 13 (step S6).

In this heating drying process, when it is detected that the surface temperature of the glass master 1 has reached a predetermined temperature T2, for example, 90±0.5°C based on the measurement output of the radiation thermometer 19 (step S7), the spindle base drive motor 8, the spindle 2 is moved back from the heating drying position to the standby position (step S8). At this standby position, the glass master 1 after heating is cooled (step S9).
), in this cooling step, the surface temperature of the glass master disc] reaches a predetermined temperature T3 based on the measurement output of the radiation temperature if19.
For example, when it is detected that the temperature is below 550.5° C. (step 5IO), the rotation of the spindle 2 is stopped (step S]1). Then, by removing the glass master disk from the spindle 2, the series of processes is completed.

In the heating drying process described above, the heater element 13
The infrared rays generated have the property of traveling in a straight line like visible light, and reach the opposing glass master 1 through the opening 1 of the radiant heat control plate 12, where they are absorbed by the photoresist and generate heat.

The amount of heat generated per unit area is approximately determined by various conditions such as the time the heater element 13 faces the heater element 13, the distribution of the amount of heat generated by the heater element 13 itself, and the cooling efficiency received from the surroundings. Therefore, radiant heat control board 1
2, the temperature distribution on the resist surface of the glass master is low in the center and low in temperature, as shown in FIG. 5(b).
It becomes higher toward the outer periphery, and becomes lower again at the outermost periphery due to the large cooling effect. In contrast, by providing a radiant heat control plate 12 having an opening 11 and correcting the amount of heat generated per unit area by the substantially fan-shaped shape of the opening 11, including all related factors, As shown in a), a uniform temperature distribution can be obtained over the entire surface from the inner circumference to the outer circumference.

In addition, by forming the fan-shaped opening 11 so that the time for heat transfer through the opening 11 per unit area of the glass master 1 is longer in the outermost portion than in other parts, As shown in FIG. 5(a), the surface temperature of the outermost portion of the glass master disk 1 can be made higher than that of the other portions.

Note that in the above embodiment, the radiant heat control plate 12 having a fan-shaped opening 11 is used as a heat control means for controlling the distribution of the amount of infrared rays radiated to the glass master 1 by the heater element 13i. I explained, but
The shape of the opening] 1 can be any shape depending on the use and purpose.

Further, the heat control means is not limited to the radiant heat control plate 12 having the opening 11, but may also be a radiant heat control plate made of a combination of materials with different thermal properties,
A radiant heat control plate having partially different thermal properties may be used, and the distribution of the amount of infrared rays radiated to the glass master 1 can also be controlled by changing the calorific value distribution of the heater element 13.

Further, in the above embodiments, the purpose was to make the temperature distribution uniform, but it goes without saying that the temperature distribution can be adjusted to any desired temperature distribution within the possible range by the heat control means. Similarly, it is also possible to arbitrarily adjust the temperature and temperature distribution by combining some kind of temperature and temperature distribution detection means and thermal control means.

Effects of the Invention As explained above, in the heating drying device for optical disc masters according to the present invention, the optical disc master is supported so as to face the heating means that performs radiant heating using infrared rays,
Since the configuration is such that the distribution of the amount of infrared rays radiated from the heating means to the optical disk master is controlled by the thermal control means.
This enables more precise control of temperature distribution without sacrificing space efficiency, which can improve product quality.

As a result, in the case of a glass master disk whose negative side is coated with photoresist, the heating temperature can be made uniform from the inner circumference to the outer circumference, so that variations in the sensitivity of the photoresist can be minimized.

Furthermore, since the heating temperature of the outermost peripheral portion can be made higher than that of the other portions, cracking of the glass master disc can be prevented.

[Brief explanation of the drawing]

Fig. 1 is an external view of a device showing an embodiment of the present invention, Fig. 2 is a structural diagram thereof, Fig. 3 is an enlarged sectional view of the dryer unit in Fig. 2, and Fig. 4 is a drying process performed by a processor. A flowchart showing the basic sequence of processing steps,
Fig. 5 is a characteristic diagram showing the temperature deviation of each radius with respect to the reference temperature, Fig. 6 (A) is an external view of a conventional device, (B) is a front cross-sectional view thereof, and Fig. 7 is a configuration showing another conventional device. It is a diagram. Description of main parts No. n 1...Glass master 2...Spindle 4...Spindle motor 8...Spindle base drive motor 1.0,1
．． 8... Exhaust tube 11... Opening 12... Radiant heat control board 13...
... Heater element 14 ... Heater unit 19 ... Radiation thermometer 21 ... Controller applicant Pioneer Co., Ltd. Pioneer Video Co., Ltd.

Claims (7)

[Claims] (1) A heating means for heating an optical disc master by infrared rays, a supporting means for supporting the optical disc master so as to face the heating means, and controlling the distribution of the amount of infrared radiation radiated by the heating means to the optical disc master. What is claimed is: 1. A heating drying device for optical disc masters, comprising: a heat control means for controlling the temperature of the optical disc. (2) The apparatus for heating and drying an optical disk master according to claim 1, wherein the heat control means controls the distribution of the radiation amount so that the surface temperature of the optical disk master becomes uniform over the entire surface. . (3) The optical disc master according to claim 2, wherein the thermal control means controls the distribution of the radiation amount so that the surface temperature of the outermost peripheral part of the optical disc master is higher than other parts. heating drying equipment. (4) The apparatus for heating and drying optical disc masters according to claim 1, wherein the heat control means comprises a radiant heat control plate having an opening, and heat transfer is controlled depending on the shape of the opening. (5) The heating drying device for optical disk masters according to claim 1, wherein the heat control means is comprised of a radiant heat control plate made of a combination of materials having different thermal properties. (6) The heating drying apparatus for optical disk masters according to claim 1, wherein the heat control means is comprised of a radiant heat control plate having partially different thermal properties. (7) A heating means for heating an optical disc master by infrared rays, and a supporting means for supporting the optical disc master so as to face the heating means, and distribution of the amount of infrared rays radiated by the heating means to the optical disc master. A heating drying device for an optical disc master, characterized in that the temperature is controlled by the calorific value distribution of the heating means.