JP3466718B2 - Optical scale molding die and method of manufacturing optical scale - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scale, and more particularly to a mold used for molding an optical scale suitable for use in an optical encoder and the like, and a method for manufacturing an optical scale using the mold.

[0002]

2. Description of the Related Art Conventionally, in information devices such as printers, optical encoders have often been used to detect the position and speed of movable parts such as carriages. Such an optical encoder is usually fixed to a movable part, projects light on an optical scale on which an optical code is recorded, and photoelectrically converts the modulated light to encode the position information of the movable part. It was configured to take out as a converted electric signal.

The optical scale includes (1) a metal plate provided with slits by etching, (2) silver, copper, etc. on a transparent substrate such as glass or plastic.
A metal such as chrome or aluminum is vapor-deposited, and only the metal layer is removed by etching into a slit shape (3) A slit pattern is drawn on the mask blanks using a resist, and the photomask removed by etching into a slit shape is used as a master mold. A silver salt film that has been exposed to light and patterned by a development process has been used.

However, in (1), the width of the slit that can be etched is limited to twice the metal thickness or more, and it is difficult to record a fine code. In addition, the other ones have a drawback that the manufacturing process is complicated and the cost is high because an expensive photosensitive resin is used for etching. Further, even if the method using a silver salt film is used, the cost of the silver salt film is high, so that there is a limit to cost reduction.

Therefore, Igaki et al. Disclose that an inexpensive optical scale can be provided by injection molding or compression molding by using a scale having the shape disclosed in Japanese Patent Laid-Open No. 62-3616. When the optical encoder having the above-mentioned shape is mounted on the printer in order to detect the position and speed of the movable part such as the carriage, the scale length is required to be 210 mm or more for A4 portrait. The width is usually about 3 to 15 mm. When molding such a slender-shaped scale by the injection method, it is necessary to increase the thickness, and the productivity is not good because it is a single-wafer process. On the other hand, in the compression method, a large number of patterns can be arranged on one die, but since the transfer time is long and the single wafer processing is used, this also has low productivity.

As described above, the conventionally used optical scale cannot be mounted on a low-priced general-purpose printer or the like because of high manufacturing cost regardless of which manufacturing method is used.

[0007]

Therefore, as a result of studying a method of manufacturing an optical scale having high productivity and low cost, the roller grooving method (RG method) of the present invention has been reached.

That is, a light-transmitting member has a marking portion, and the marking portion has a light-transmitting portion and an optical non-lighting surface which is an inclined surface whose incident angle is set to a critical angle or more with respect to an incident light ray. In a method of manufacturing an optical scale in which transmissive portions are alternately formed, 1. 1. The first step of making a roll stamper by mounting a mold on the roll that is larger than the corresponding pattern of the desired optical scale. 2. The second step of melting a thermoplastic resin having a light transmittance of 50% or more at a wavelength to be used with an extruder and extruding it from a T-die. The molten resin is sandwiched between the roll-shaped stamper and the mirror-like roll to form a sheet, and the scale pattern is transferred at the same time.
It has been found that by using the optical scale manufacturing method for manufacturing the sheet-shaped optical scale, it is possible to dramatically reduce the cost, which was impossible in the past.

For example, in the case of producing a thin plate-shaped molded product, the conventional compression method has a cycle of heating and cooling, and the molding tact per one time takes at least about 3 minutes. Even if 60 scale patterns are provided, the production amount per minute is only 20.

On the other hand, in the above-mentioned RG method, one mold has 15
Even if the scale pattern of the book is provided, two rolls can be attached to one roll die and the molding speed is 1 to 1.
Since high-speed molding is possible at 7 m / min, the production amount per minute is 30 to 210 and the productivity is 1.5 to 10.5 times that of the compression method. Further, in the RG method, molding is performed in a state where the resin is molten,
Since the molding pressure is smaller than that of the compression method, there is also an advantage that the mold has good durability.

[0011] As described above, the RG method can provide a low-cost molded product because of its extremely high productivity and good mold durability. Various measures are required to reduce the defect rate and further reduce the cost. For that purpose, it is necessary to analyze the factors that affect the cost and eliminate the factors that increase the cost.

When the above-mentioned optical scale is manufactured by this method, it is the depreciation cost due to the price of the molding machine and the defective rate of the molded product that have the greatest influence on the cost. In order to reduce the apparatus price, it is effective to narrow the width of the roll and make the apparatus compact. In addition, a smaller device is more advantageous in terms of accuracy, ease of installation, ease of handling, safety, reduction of costs of incidental equipment, and the like.

On the other hand, when a long optical scale is manufactured by using a narrow device, the rows of the scale grooves are arranged so as to be orthogonal to the molding direction. As a result of various studies, it has been found that there is a problem that air is entrapped at the time when the resin is sandwiched between the concave portions on the mold, bubble defects occur, and the defective rate increases.

Therefore, preventing the occurrence of bubble defects has been a technical problem for manufacturing an optical scale of good quality and low cost by using a narrow device.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and it is possible to manufacture a long optical scale with high precision and at low cost by an extrusion molding method. An object of the present invention is to provide a mold for molding a scale and a method for manufacturing an optical scale using the mold.

[0016]

That is, the present invention is an optical type
Used to manufacture scales by extrusion
In a mold that is continuous parallel to the conveying direction of the molded sheet
Optical type characterized by having a groove for exhausting air
This is a scale molding die.

Further , the present invention extrudes an optical scale.
Smell used for manufacturing by sushi molding method
The air discharge on the boundary line between the light-transmitting part and the light-shielding part of the scale.
For optical scale molding, which is provided with a groove for
It is a type. Further, the present invention is an optical scale extruder.
In the mold used to manufacture by the molding method,
The groove that discharges air is on the back side of the pattern on the scale.
The scale pattern of the mold is convex due to the provided undercoat layer
Light that has a mechanism that deforms so that
This is a mold for academic scale molding.

[0018]

[0019]

Further , according to the present invention, a roll type having a scale pattern on its peripheral surface and a roll arranged opposite to the roll type are heated at a predetermined temperature from a means for extruding a thermoplastic resin while rotating each at a desired speed. A step of supplying the thermoplastic resin thus prepared between the roll mold and the roll;
In a method for continuously producing an optical scale by an extrusion molding method, which comprises a step of pressing the thermoplastic resin between the roll mold and the roll to transfer the scale pattern , a molded sheet is conveyed to the roll mold. Mold using a mold that has grooves for continuous air discharge parallel to the direction
It is a method of manufacturing an optical scale characterized by the above.

Further , according to the present invention, a roll die having a scale pattern on its peripheral surface and a roll arranged opposite to the roll die are heated at a predetermined temperature from a means for extruding a thermoplastic resin while rotating the roll die at a desired speed. A step of supplying the thermoplastic resin thus prepared between the roll mold and the roll;
In a method for continuously producing an optical scale by an extrusion molding method, which comprises a step of pressing the thermoplastic resin between the roll mold and the roll to transfer the scale pattern , the scale of the roll mold is transparent. Using a mold that has a groove for air discharge on the boundary between the light shielding part and the light shielding part
It is a method of manufacturing an optical scale characterized by the above.

Further , according to the present invention, a roll die having a scale pattern on its peripheral surface and a roll arranged opposite to the roll die are heated to a predetermined temperature from a means for extruding a thermoplastic resin while rotating the roll die at a desired speed. A step of supplying the thermoplastic resin thus prepared between the roll mold and the roll;
In a method for continuously producing an optical scale by an extrusion molding method including a step of pressing the thermoplastic resin between the roll mold and the roll to transfer the scale pattern, a pattern of a scale portion on the roll mold. A mechanism for discharging the air that has been deformed so that the scale pattern of the mold becomes convex by the undercoat layer provided only on the back surface of
Of an optical scale characterized by molding using a mold
It is a manufacturing method.

[0023]

[0024]

Further , according to the present invention, a roll die having a scale pattern on its peripheral surface and a roll arranged opposite to the roll die are heated to a predetermined temperature from a means for extruding a thermoplastic resin while rotating the roll die at a desired speed. A step of supplying the thermoplastic resin thus prepared between the roll mold and the roll;
In a method for continuously producing an optical scale by an extrusion molding method having a step of pressing the thermoplastic resin between the roll mold and the roll to transfer the scale pattern, the surface of the roll used for molding is heat-resistant. Of the roll mold used in the molding is used, and the rotary shaft of the roll mold and the rotary shaft of the roll are tilted within a range of 30 degrees or less. Optics characterized by molding using a device placed in parallel
It is a manufacturing method of a formula scale.

Next, the present invention will be described in detail with reference to the drawings. The mechanism for discharging the air of the optical scale molding die of the present invention is, for example, as shown in FIG.
In the mold 1 arranged so that the longitudinal direction of the mold coincides with the molding direction (the direction of the arrow in the figure), for continuous air discharge between the scale part 2 and the scale part 2 in parallel with the conveying direction of the molded sheet. It is configured by providing the groove 3.

If the depth of the air discharge groove 3 is too shallow, the air discharge effect is weakened, and if it is too deep, it causes defective release of the molded product. Therefore, the depth is preferably 5 to 100 μm, preferably 1
0-80 μm is preferable.

If the width of the air discharge groove is too narrow, the effect of preventing bubble defects becomes weak, and if it is too wide, unnecessary parts of the molded product increase and the cost of the scale increases, so the width is 0.1 to 10 m.
m is good, and preferably 0.3 to 8 mm.

Another mechanism for discharging air according to the present invention is, for example, as shown in FIG. 2, air is provided at the boundary between the light shielding portion 4 and the light transmitting portion 5 of the scale portion 2'of the mold 1 '. Discharge groove 6
By providing, it is possible to prevent the occurrence of bubble defects. In this case, the inclined surface of the air discharge groove 6 is preferably an inclined surface whose incident angle is set to a critical angle or more with respect to the incident light ray.

Further, as shown in FIG. 3 (a), when the thickness of the mold 1 "is 0.3 mm or less, if the undercoat layer 7 is thickly provided below the scale portion 2", molding is performed. Figure 3 (b)
As described above, the scale portion 2 ″ of the mold 1 ″ is deformed into a semi-cylindrical mold by the molding pressure of the resin, and the bubble defect can be prevented. In this case, the undercoat layer 7 is preferably located at the center of the scale portion 2 ″, but the position of the undercoat layer 7 in FIG. 3 may be offset to the left or right, and the height of the scale portion 2 ″ is continuous. It may be arranged so as to change.

Further, as a mechanism for discharging air, as shown in FIG. 4, the mold 11 is arranged so that the direction of the scale pattern (the direction of the light transmitting portion or the light shielding portion) and the molding direction are inclined by an angle φ. By manufacturing, the groove of the transparent portion or the light shielding portion of the scale pattern itself may be used as the air discharge groove. The angle φ at this time is 90
If it is close to 0 degree, the effect of preventing bubble defects is small, and if it is close to 0 degree, the sensitivity in the lateral direction becomes large and the performance as a scale deteriorates, so that it is preferably 25 to 80 degrees.

FIG. 4 shows an example in which a pattern is arranged on the entire surface of the mold 11, but if an air discharge groove as shown in FIG. 1 is provided in this pattern to form a divided pattern parallel to the molding direction. Further, the effect of preventing bubble defects is further increased.

Further, as shown in FIG.
It is also possible to prevent the lack of air bubbles by forming the light-shielding portion 4 ′ into two or more ridges and providing an air discharge groove in the light-shielding portion 4 ′. At this time, the depth of each groove (height of peak) is 10 μm or less, preferably 6 μm.
It is preferable that the number be less than that, and the larger the number of grooves, the greater the effect of preventing bubble defects.

Further, as shown in FIG. 14, a molding roll 19 'coated with a heat-resistant resin such as silicone rubber or fluorine resin is used, and the rotation axis of the molding roll 19' is set to 30 with respect to the rotation axis of the roll die 18. The effect of preventing bubble defects is further enhanced by molding using a device that is installed with a tilt within a range of not more than 100 degrees.

In the method for producing the optical scale forming die used in the present invention, a master die having a predetermined scale shape is produced by cutting a metal plate, a replica is taken with a resin, and the replica surface is electrically conductive. After the chemical treatment, a method of forming a work stamper by electroforming, polishing, trimming, and welding a fixture is preferably used. Further, a predetermined scale shape may be engraved by a direct cutting process on a thin metal plate having a uniform thickness.

Further, the method for producing an optical scale of the present invention is a method for continuously producing an optical scale by an extrusion molding method as shown in FIG. Roll type 1 equipped with a mechanism for discharging
8, a molding roll 19 is provided so as to face each other, and a thermoplastic resin heated to a predetermined temperature is extruded from the T die 20 while rotating each at a desired speed, and is supplied between the roll die 18 and the molding roll 19. An optical scale sheet 22 can be obtained by pressing the thermoplastic resin to transfer the scale pattern, and then passing the scale pattern between the roll mold 18 and the transport roll 21.

The thermoplastic resin used in the production of the optical scale of the present invention may have a light transmittance of 50% or more at the wavelength of the light used, but 70 from the viewpoint of the light utilization rate. % Or more is preferably used. Among them, polyimide resin, polysulfone resin, polyether ether ketone resin, polycarbonate resin, amorphous polyolefin resin, acrylic resin, styrene resin, PET resin, ABS resin, vinyl resin, etc. are preferably used from the viewpoint of mechanical strength and optical characteristics. To be

In the present invention, the base material of the roll type and the opposing roll has a high hardness and a good thermal conductivity,
Further, it is preferable that the peripheral mirror surface is easily processed, and, for example, steel, chrome steel, aluminum, aluminum alloy, steel for molds (maraging steel), phosphor bronze, stainless steel and the like can be used.

[0039]

In the conventional method for continuously producing a long optical scale by the extrusion molding method, the thermoplastic resin is provided between the roll mold provided with the optical scale molding die having the scale pattern and the molding roll facing the roll die. The scale pattern is transferred by pinching through the resin, but the rows of the scale grooves are arranged so as to be orthogonal to the molding direction, and in order to perform the molding as it is, the translucent part or the light-shielding part is concave on the mold. Air is caught when the resin is sandwiched between the
A bubble defect had occurred.

According to the present invention, by providing the optical scale molding die with a mechanism for discharging air as described above, the air trapped in the concave portion of the mold during molding can be discharged, and the long scale can be discharged. The optical scale can be manufactured accurately and at low cost.

[0041]

EXAMPLES The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to this embodiment.

Example 1 A phosphor bronze plate of 450 × 200 × 80 mm was prepared as a material for the master mold. It was attached to a grinding machine, and first, as shown in FIG.
1m by using a diamond grindstone with a groove of m and a width of 6 mm parallel to the long side at an interval of 10 mm (the pitch between the crest and the groove is 10 mm)
Six pieces were provided to obtain a grooved phosphor bronze plate 13.

Next, as shown in FIG. 7, the tip is 35.3 μm.
Using a trapezoidal diamond tool 14 with a flat width of m,
As shown in FIG. 8, the feed pitch 7 is perpendicular to the air discharge groove 3.
4700 trapezoidal grooves 5 ″ with 0.6 μm are used as air exhaust grooves 3
The master mold 15 having a shape as shown in FIG. 8 was manufactured by grinding so that the height from the to the trapezoidal groove 5 ″ was 30 μm.

30 g of urethane acrylate, 67 parts by weight of neopentyl glycol-modified trimethylolpropane diacrylate, and 3 parts by weight of 1-hydroxycyclohexyl phenyl ketone were thoroughly degassed, and 30 g of UV-cured resin was dropped. did.

Next, 1 v of silane coupling agent was applied on one side.
An ol% metamail solution (trade name: A-174; manufactured by Nippon Unicar Co., Ltd.) was spin-coated and baked in an oven at 70 ° C. for 2 hours to obtain a size of 480 × 250 × 15.
mm glass plate is prepared, and the silane coupling treatment surface is faced down on the UV curable resin, and the UV curable resin is slowly overlapped from the end, and when the UV curable resin spreads to the outer peripheral portion, a metal halide lamp (trade name: UVC- 2533; Ushio Denki Co., Ltd.) was used to irradiate ultraviolet rays under the conditions of 160 W / cm ² and a lamp distance of 130 mm to cure the resin.

Then, this was peeled off to obtain a glass master having an uneven scale pattern formed of an ultraviolet curable resin on a glass substrate. The glass master was placed on a sample stage of a sputtering device (trade name: SPF-530H; manufactured by Nichiden Anelva Co., Ltd.). The chamber is evacuated and the ultimate vacuum is 4.0 × 10 ^-3 Pa, Ar gas pressure is 1.2 Pa, RF
Reverse sputtering was performed for 5 minutes under the conditions of a power of 1 kW and a glass master disk rotation speed of 10 rpm.

Next, under the same conditions, a DC power of 0.5 kW was used to sputter-deposit nickel to a thickness of 0.11 μm. Then, nickel was electroformed to a thickness of 200 μm, and the back surface was polished. This nickel mold is peeled off in a clean room, a protective film is attached to the effective portion of the pattern, cut into a size of 440 × 180 mm, and fixing tools 16 and 16 ′ are attached to the short sides of both ends, as shown in FIG. A molding die 17 having a shape as shown was obtained.

Thereafter, the protective film was peeled off, and the size 4
After mounting two molding dies of the above shape through a polyimide film of 40 × 178 mm and a thickness of 100 μm on a grooved roll having a diameter of 300 mmφ provided with two fixing tool mounting grooves, the groove between the fixing tools is made of silicone resin. (Product name: KE1
204A, B; 10 by filling with Shin-Etsu Chemical Co., Ltd.
After curing at 0 ° C. for 30 minutes, the excess resin that had been squeezed out was removed by a cutter to produce a roll mold 18 as shown in FIG.

The roll die 18 is attached to an extrusion molding apparatus as shown in FIG. 11, and the pressing force of the molding roll 19 against the roll die 18 is adjusted to 2500 Kgf to adjust the bisphenol A-based polycarbonate (trade name: S) from the T die 20. -2000R: Mitsubishi Gas Chemical Co., Ltd. resin sheet is extruded, thickness 0.3 mm x width 250 m
m continuous optical scale sheet 22 was produced.

As molding conditions, the temperature of the T die 20 is 32
0 ° C., surface temperature of roll die 145 ° C., resin sheet conveying speed 5 m / min, resin extrusion amount 27 Kg / h
Was adjusted so that continuous molding was performed for 4 hours. With respect to the optical scale formed in this manner, bubble defects were examined at 3 locations within a range of 4 × 4 mm for each scale pattern. The number of defects was 10 or less, and the performance as an optical scale was hardly affected. There wasn't.

Further, the transfer accuracy was 95% or more, and a very high quality optical scale could be obtained in a short time and in a large amount. In this embodiment, the transfer accuracy is 3 mg with a stylus type step measuring device (trade name: Alphastep 200; manufactured by Tencor Instruments Inc.).
A value of the ratio a / A with the measured value a of the width of the light transmission part on the molded scale, with the value A obtained by measuring the width of the light transmission part of the glass master under the setting of the scanning range of 400 μm and the scanning time of 40 seconds. It was evaluated by.

Comparative Example 1 Two molding dies were produced by the same steps as in Example 1 except that the air discharge groove was not provided when the master die was produced, and a roll die was produced. Using this roll mold, an optical scale was molded under the same conditions as in Example 1 and the number of bubble defects was examined. Each scale pattern was inspected at 3 points within a range of 4 × 4 mm, but the number of defects was 100 or more, and when the performance as an optical scale was evaluated, the fluctuation range of the signal amplitude was 10% or more, which was insufficient. there were. Also,
Regarding the transfer accuracy, there was a portion where the value of a / A was 0.8 or less.

Example 2 First, similarly to Example 1, a phosphor bronze plate 13 having an air discharge groove 3 as shown in FIG. 6 was prepared. Using a cutting tool 14 'having a tip shape as shown in FIG.
The trapezoidal groove 5 ″ shown in FIG. 8 and the air discharging groove 3 have a height difference of 30 μm at a right angle to the air discharging groove 3 at 6 μm, and the air discharging provided at the boundary with the transparent portion 5 shown in FIG. The height difference from the groove 6 is 5 μm, and the width of the flat portion of the light transmitting portion is 35.3 μm.
The master mold of the shape of was manufactured.

Next, after washing, hard nickel plating was applied to the surface to a thickness of 0.1 μm to obtain a master mold for the purpose of preventing corrosion and improving the surface hardness. Thereafter, two glass masters and two molding dies were manufactured in the same manner as in Example 1, and after being mounted on a grooved roll via a polyimide sheet, the grooves between the fixtures were filled with silicone resin to manufacture a roll mold. .

Using this, the same apparatus as in Example 1 was used and the pressing force of the forming roll against the roll mold was 2000 K.
Adjusted to gf and changed from T-die to amorphous polyolefin (trade name: ZEONEX 250; manufactured by Nippon Zeon Co., Ltd.)
Extruding the resin sheet of, 0.25mm thickness, width 24
A 0 mm continuous optical scale sheet was produced.

As molding conditions, a T-die temperature of 330
C., the surface temperature of the roll mold was 145.degree. C., the resin sheet conveying speed was 4 m / min, and the resin extrusion amount was 14.5 Kg / h, and continuous molding was performed for 3 hours. With respect to the optical scale formed in this manner, bubble defects were examined at 3 locations within a range of 4 × 4 mm for each scale pattern. The number of defects was 10 or less, and the performance as an optical scale was hardly affected. There wasn't. Further, the transfer accuracy was 95% or more, and a very high quality optical scale could be obtained in a large amount in a short time.

Example 3 A width of 3 mm, a length of 430 mm, and a thickness of 1 were formed on all the back surfaces of the 17 pattern portions of each of the two stampers used in Example 1.
Instant adhesive with 00 μm polyimide film (trade name:
SC-55: Sony Chemical Co., Ltd. was used for attachment.

Using the above two stampers, a bisphenol A type polycarbonate (trade name: Panlite L-1225; Teijin Kasei Co., Ltd.) was used as the resin, and the thickness was 0.3 mm under the same conditions as in Example 1. A continuous optical scale having a width of 250 mm was manufactured. When the same evaluation as in Example 1 was performed, the number of defects was 8 or less, and the transfer accuracy was 95% or more, and a very high quality optical scale was manufactured in a short time and in a large amount. I was able to.

Example 4 A phosphor bronze plate having the same size as that of Example 1 and having the same groove processing as that of Example 1 as shown in FIG. 6 was prepared. This was reattached with an inclination of 45 degrees with respect to the cutting direction of the cutting tool of the grinding machine.

Next, the tip as shown in FIG.
Using a trapezoidal diamond tool 14 with a flat width of m,
Feed pitch 70.6μ at an angle of 45 degrees with the air exhaust groove 3
After grinding a trapezoidal groove 5 ″ on the entire surface of the phosphor bronze plate so that the height from the air discharge groove 3 to the trapezoidal groove 5 ″ is 25 μm, wash it and apply a hard nickel plating (thickness 0.1 μm). Then, a master mold 24 having a shape as shown in FIG. 13 was produced.

30 g of urethane acrylate, 67 parts by weight of neopentyl glycol-modified trimethylolpropane diacrylate, and 3 parts by weight of 1-hydroxycyclohexyl phenyl ketone were thoroughly degassed, and 30 g of UV-cured resin was dropped. did.

Next, 1 v of silane coupling agent was applied on one side.
An ol% metamail solution (trade name: A-174; manufactured by Nippon Unicar Co., Ltd.) was spin-coated and baked in an oven at 70 ° C. for 2 hours to obtain a size of 480 × 250 × 15.
mm glass plate is prepared, and the silane coupling treatment surface is faced down on the UV curable resin, and the UV curable resin is slowly overlapped from the end, and when the UV curable resin spreads to the outer peripheral portion, a metal halide lamp (trade name: UVC- 2533; Ushio Denki Co., Ltd.) was used to irradiate ultraviolet rays under the conditions of 160 W / cm ² and a lamp distance of 130 mm to cure the resin.

Then, this was peeled off to obtain a glass master disk having an uneven scale pattern formed of an ultraviolet curable resin on a glass substrate. The glass master was placed on a sample stage of a sputtering device (trade name: SPF-530H; manufactured by Nichiden Anelva Co., Ltd.). The chamber is evacuated and the ultimate vacuum is 4.0 × 10 ^-3 Pa, Ar gas pressure is 1.2 Pa, RF
Reverse sputtering was performed for 5 minutes under the conditions of a power of 1 kW and a glass master disk rotation speed of 10 rpm.

Next, under the same conditions, a DC power of 0.5 kW was used to sputter-deposit nickel to a thickness of 0.11 μm. Then, nickel was electroformed to a thickness of 200 μm, and the back surface was polished. This nickel mold is peeled off in a clean room, a protective film is attached to the effective portion of the pattern, then cut into a size of 440 × 180 mm, and fixing tools 16 and 16 ′ are attached to the short sides of both ends, as shown in FIG. Two molding dies 23 each having a trapezoidal groove formed obliquely were obtained.

Example 1 using the two stampers
A roll type is prepared in the same manner as above, and bisphenol A-based polycarbonate (trade name: H-3000R; manufactured by Mitsubishi Gas Chemical Co., Inc.) is used as the resin, and the resin sheet conveying speed is 1.2 m.
/ Min, the resin extrusion rate was 13 kg / h, and the conditions were the same as in Example 1 except that the thickness was 0.6 mm and the width was 250 mm.
Of continuous optical scales were manufactured. When the same evaluation as in Example 1 was performed, the number of defects was 3 or less, and the transfer accuracy was 95% or more, and a very high quality optical scale was manufactured in a short time and in a large amount. I was able to.

Example 5 A copper plate having a size of 470 × 220 × 60 mm was prepared as a material for the master mold, and subjected to the same groove machining as in Example 1 and attached to a grinding machine.

Next, a sword bite having a right-angled tip was prepared, and the entire surface of the copper plate was cut in parallel with the short side direction at a pitch of 70.6 μm to obtain a copper plate having a washing plate shape on the entire surface. Next, the trapezoidal cutting tool used in Example 1 was replaced, and until the triangular peak disappeared with the feed pitch of 70.6 μm (about 3.5 μm from the top of the peak).
After polishing the copper plate to a depth of (1), washing and hard nickel plating (thickness 0.1 μm) were performed to obtain a master mold. A schematic diagram of the shape of this mold is shown in FIG.

30 g of urethane acrylate, 67 parts by weight of neopentyl glycol-modified trimethylolpropane diacrylate and 3 parts by weight of 1-hydroxycyclohexyl phenyl ketone were thoroughly degassed, and 30 g of UV-cured resin was dropped. did.

Next, 1 v of silane coupling agent was applied on one side.
An ol% metamail solution (trade name: A-174; manufactured by Nippon Unicar Co., Ltd.) was spin-coated and baked in an oven at 70 ° C. for 2 hours to obtain a size of 480 × 250 × 15.
mm glass plate is prepared, and the silane coupling treatment surface is faced down on the UV curable resin, and the UV curable resin is slowly overlapped from the end, and when the UV curable resin spreads to the outer peripheral portion, a metal halide lamp (trade name: UVC- 2533; Ushio Denki Co., Ltd.) was used to irradiate ultraviolet rays under the conditions of 160 W / cm ² and a lamp distance of 130 mm to cure the resin.

Then, this was peeled off to obtain a glass master having a concave-convex scale pattern formed of an ultraviolet curable resin on a glass substrate. The glass master was placed on a sample stage of a sputtering device (trade name: SPF-530H; manufactured by Nichiden Anelva Co., Ltd.). The chamber is evacuated and the ultimate vacuum is 4.0 × 10 ^-3 Pa, Ar gas pressure is 1.2 Pa, RF
Reverse sputtering was performed for 5 minutes under the conditions of a power of 1 kW and a glass master disk rotation speed of 10 rpm.

Next, under the same conditions, a DC power of 0.5 kW was used to sputter-deposit nickel to a thickness of 0.11 μm. Then, nickel was electroformed to a thickness of 160 μm, and the back surface was polished. This nickel mold is peeled off in a clean room, a protective film is attached to the effective portion of the pattern, then cut into a size of 440 × 180 mm, and fixing tools 16 and 16 ′ are attached to the short sides of both ends, as shown in FIG. Two molding dies 23 each having a trapezoidal groove formed obliquely were obtained.

A roll mold was prepared in the same manner as in Example 1 except that the thickness of the polyimide sheet was 125 μm using the two stampers, and the conditions were the same as in Example 1 with a thickness of 0.3 mm and a width of 250 mm. Of continuous optical scales were manufactured. When the same evaluation as in Example 1 was performed, the number of defects was 3 or less and the transfer accuracy was 95% or more, and it was possible to manufacture a very high quality optical scale in a short time and in a large amount. .

Example 6 A roll die 18 as shown in FIG. 10 was produced by the same steps as in Example 1. This roll die 18 was attached to a forming apparatus as shown in FIG. 14, and a forming roll 19 'covered with silicone rubber was attached at an angle of 15 degrees with respect to the roll die 18. At this time, the forming roll 19 'has a thickness of 20 mm.
The silicone rubber whose surface was coated with was used.

As shown in FIG. 11, the pressing force of the molding 19 'against the roll mold 18 was adjusted to 1300 Kgf, and the bisphenol A-based polycarbonate (trade name: S-2000R; manufactured by Mitsubishi Gas Chemical Co., Inc.) The resin sheet of 1) was extruded to manufacture a continuous optical scale sheet having a thickness of 0.25 mm and a width of 240 mm.

As molding conditions, the temperature of the T die 20 is 33
0 ° C., surface temperature of roll mold 18 138 ° C., resin sheet conveying speed 6 m / min, resin extrusion amount 26.0 Kg
It was adjusted to be / h.

For the optical scale thus molded, three bubble defects were examined for each scale pattern within a range of 4 × 4 mm. The number of defects was 5 or less, and the performance as an optical scale was It had almost no effect. The transfer accuracy was 95% or more, which was very good.

[0077]

As described above, in the optical scale molding die of the present invention, it is difficult to reduce the cost in view of the low yield because the mechanism for discharging the air is provided. Using a device with a narrow roll width, it has become possible to manufacture a long optical scale accurately and at low cost.

Further, by continuously extruding the optical scale using the above-mentioned optical scale molding die, it becomes possible to provide an accurate and very inexpensive optical scale. It became possible to install optical encoders in popular printers that could not be installed because of the above, and it became possible to provide high-quality, high-reliability products at low cost.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an example of an optical scale molding die of the present invention.

FIG. 2 is a schematic perspective view showing an example of another configuration of the optical scale molding die of the present invention.

FIG. 3 is a schematic cross-sectional view showing an example of another configuration of the optical scale molding die of the present invention.

FIG. 4 is a schematic view showing an example of another configuration of the optical scale molding die of the present invention.

FIG. 5 is a schematic perspective view showing an example of another configuration of the optical scale molding die of the present invention.

FIG. 6 is a schematic perspective view showing an example of a master mold material used for manufacturing the optical scale molding mold of the present invention during processing.

FIG. 7 is a schematic view showing an example of the shape of a diamond bite used for producing the optical scale molding die of the present invention.

FIG. 8 is a schematic perspective view showing an example of the shape of a master mold used for manufacturing the optical scale molding mold of the present invention.

FIG. 9 is a schematic view showing an example of the overall shape of the optical scale molding die of the present invention.

FIG. 10 is a schematic perspective view showing an example of a roll mold to which the optical scale molding mold of the present invention is attached.

FIG. 11 is a schematic view showing an example of a method for continuously producing an optical scale using a roll die to which an optical scale molding die of the present invention is attached.

FIG. 12 is a schematic view showing an example of another configuration of the overall shape of the optical scale molding die of the present invention.

FIG. 13 is a schematic view showing another example of the shape of the master mold used for manufacturing the optical scale molding mold of the present invention.

FIG. 14 is a schematic view showing an example of the arrangement of rolls in a method for producing an optical scale using a roll die to which an optical scale molding die of the present invention is attached.

FIG. 15 is a schematic view showing another example of the shape of the diamond bite used for producing the optical scale molding die of the present invention.

[Explanation of symbols]

1,1 ', 1 "Optical scale mold 2,2 ', 2 "Scale part 3 Air discharge groove 4 Light shield 5,5 ', 5 "translucent part 6 Air exhaust groove 7 Undercoat layer 8-roll base material Type 11 12 Scale section 13 Master type phosphor bronze plate for manufacturing 14 Diamond Bit for Trapezoid Grooving 14 'diamond tool 15 Master type 16,16 'Fixture 17 Mold 18 roll type 19 Forming roll 19 'forming roll 20 T die 21 Conveyor roll 22 Optical scale sheet 23 Mold 24 master type

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-107503 (JP, A) JP-A-6-182855 (JP, A) JP-A 59-78811 (JP, A) JP-A 62- 163917 (JP, A) Actual Kaihei 5-16270 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01D 5/00-5/62 B29C 47/00-47/96 B29C 53/00-67/00

Claims (7)

(57) [Claims] 1. An optical scale is extruded by a molding method.
In the mold used for manufacturing, it is necessary to provide a groove for continuous air discharge parallel to the conveying direction of the formed sheet.
An optical scale molding die characterized by and . 2. An optical scale is extruded by a molding method.
In the mold used for manufacturing, it is necessary to provide a groove for air discharge on the boundary line between the translucent part and the light shield part of the scale.
An optical scale molding die characterized by and . 3. An optical scale is extruded by a molding method.
In the mold used for manufacturing, the groove that discharges air is a mechanism that deforms the scale pattern of the mold so that it is convex by the undercoat layer provided only on the back surface of the pattern of the scale part. optical scale molding die to. 4. A roll having a scale pattern on its peripheral surface.
The mold and the rolls arranged to face the roll, respectively.
A means for extruding a thermoplastic resin while rotating it at a desired speed
The thermoplastic resin heated to a predetermined temperature from the roll
Supplying between the mold and the roll, and the thermoplastic resin
Is pressed by the roll mold and the roll to produce the scale pattern.
By the extrusion molding method including the step of transferring
A method for continuously producing an optical scale, comprising the steps of:
Continuous air exhaust parallel to the conveying direction of the molded sheet
Characterized by molding using a mold with a groove for protrusion
Method of manufacturing the optical scale that. 5. A roll having a scale pattern on its peripheral surface.
The mold and the rolls arranged to face the roll, respectively.
A means for extruding a thermoplastic resin while rotating it at a desired speed
The thermoplastic resin heated to a predetermined temperature from the roll
Supplying between the mold and the roll, and the thermoplastic resin
Is pressed by the roll mold and the roll to produce the scale pattern.
By the extrusion molding method including the step of transferring
A method for continuously producing an optical scale, comprising the steps of:
The air is exhausted on the boundary line between the translucent and light-shielding parts of the scale.
Characterized by molding using a mold with a groove for protrusion
Optical scale manufacturing method. 6. A roll having a scale pattern on its peripheral surface.
The mold and the rolls arranged to face the roll, respectively.
Desired rotated at a speed while means starts to press the thermoplastic resin
The thermoplastic resin heated to a predetermined temperature from the roll
Supplying between the mold and the roll, and the thermoplastic resin
Is pressed by the roll mold and the roll to produce the scale pattern.
By the extrusion molding method including the step of transferring
A method for continuously producing an optical scale, comprising the steps of:
Molding using a mold scale pattern of the mold is provided with a mechanism for discharging the air is deformed in a convex by an undercoat layer provided only on the back surface of the pattern of the scale portion Lumpur type
A method for manufacturing an optical scale, comprising: 7. A roll having a scale pattern on its peripheral surface.
The mold and the rolls arranged to face the roll, respectively.
A means for extruding a thermoplastic resin while rotating it at a desired speed
The thermoplastic resin heated to a predetermined temperature from the roll
Supplying between the mold and the roll, and the thermoplastic resin
Is pressed by the roll mold and the roll to produce the scale pattern.
By the extrusion molding method including the step of transferring
In a method for continuously producing an optical scale, a roll provided with a heat-resistant resin layer on the surface is used as a roll used for molding, and a roll type used for molding is provided with a mechanism for discharging air, A method for manufacturing an optical scale, which comprises molding using a device in which a roll type rotation axis and a rotation axis of the roll are tilted within a range of 30 degrees or less.