JP2774472B2 - Optical reflection mirror and its manufacturing method - 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 reflecting mirror formed by filling a molding die with a plastic material and a method of manufacturing the optical reflecting mirror for forming the optical reflecting mirror.

[0002]

2. Description of the Related Art A method of molding an optical component using a plastic material as a molding material is widely used, and a method of obtaining a high-precision optical surface is to fill a molding die with a plastic material at a high pressure. A method of molding by inverting the shape of the molding surface in the entire inner surface region of the molding die by pressure has been widely adopted.

[0003] Further, the molding surface of the molding die is subjected to a surface treatment for the purpose other than the improvement of the molding accuracy, for example, for the purpose of the strength and heat resistance of the die itself, or a method for realizing the same.
As in the mold described in Japanese Patent Application Laid-Open No. 102608, a mold for an oil seal and the like, in which a minute projection is formed by metal spraying on a surface of a mold corresponding to a sliding surface of an oil seal to be manufactured, has been developed.

[0004]

However, in the above-mentioned conventional method for molding an optical reflecting mirror, the entire area of the molding surface of the molding die is inverted by filling the plastic material with a high pressure to form a plane with high accuracy. In the molding technology to obtain on all surfaces, it is possible to invert the plane with good accuracy in the mold, but if this is released, the internal stress caused by the influence of the high pressure during the molding will cause In some cases, deformation occurs, causing distortion that is difficult to apply to a plane required for an optical reflecting mirror. Such a drawback has caused the yield in molding to be poor and the manufacturing cost of the optical reflecting mirror to be high.

Further, in the case where the molding surface has minute projections as in a molding die described in Japanese Utility Model Application Laid-Open No. 62-102608, it has been attempted to improve the reversibility of the molding surface by high-pressure filling of the plastic. In such a case, since the minute projections increase the biting force of the molded product on the mold, the deformation is caused at the time of release from the mold, resulting in distortion of the molding surface.

Accordingly, the present invention has been developed in view of the above-mentioned drawbacks in the conventional molding technique, and can manufacture an optical reflecting mirror having a desired flatness with high precision, at low cost, and efficiently. An object of the present invention is to provide an optical reflecting mirror and a method of manufacturing the optical reflecting mirror.

[0007]

The invention according to claim 1 is
In an optical reflecting mirror formed of a plastic material, a mirror surface which is flat and has a mirror surface, a back surface which is opposed to the mirror surface and is rough and has a sink mark, and a mirror surface which is continuous with the mirror surface And a surface surrounding the optical reflection mirror.

According to the first aspect of the present invention, since the back surface has a rough surface and a sink is formed, the flatness and the mirror surface of the mirror surface facing each other are reliably ensured. Since there is no need to mirror-finish (mirror finish) the molding surface of the molding die for molding the surrounding surface, a highly accurate and inexpensive optical reflecting mirror can be obtained.

According to a second aspect of the present invention, there is provided a method for manufacturing an optical reflecting mirror for injecting a plastic material into a molding die to form an optical reflecting mirror. Immediately before the filling is completed, the filling of the material is stopped, the plastic material is brought into close contact with the molding surface formed of the mirror surface for molding the mirror surface in the molding die, and the molding material faces the molding surface for molding the mirror surface. The surface to be adhered to the plastic material, the adhesion strength to the molding surface for forming the mirror surface is lower than the adhesion strength,
In this state, the plastic material injected into the molding die is cooled and solidified to cause sink marks on the molding surface having low adhesion strength, thereby producing an optical reflecting mirror.

This method will be described in more detail with reference to FIG. 1. A mirror-side mold 2 having the mirror forming surface 1 formed of a mirror surface and a mirror surface facing the mirror forming surface 1 having less slimness than the mirror surface. In a molding die 5 constituted by a rough surface side mold 4 having a molding surface 3 formed of a lowered rough surface,
A state in which the plastic material 7 filled in the cavity 6 is apparently filled in the cavity 6 (a state in which a slight gap 8 is formed at the bottom of the unevenness on the rough surface 3 side compared to the mirror surface 1 side, In the case of illustration, the rough surface 3
The air gap 8 on the side is extremely shown), and the cooling starts in the cavity 6 without applying the holding pressure, and the shrinkage starts.

At this time, the resin on the mirror surface 1 side is cooled faster than the rough surface 3 side, and the resin mirror surface 1
As a result, the resin is solidified on the side and the remaining resin is pulled toward the mirror surface 1, resulting in sink marks on the rough surface 3 side. Therefore, the high transferability is exhibited by the adhesion of the plastic material 7 to the mirror surface 1 side, and the shrinkage of the plastic material 7 occurs with reference to the mirror surface 1 side. It is transcribed.

The molding die used in the practice of the present invention is a molding die in which a plastic material is filled into a molding die to form an optical reflecting mirror. Of the optical reflecting mirror, or providing a minute unevenness on a molding surface facing the mirror molding surface of the optical reflecting mirror, or in place of this,
Porous as a means capable of interposing a surface treatment layer or a sheet-like member having a low wetting property as compared to the wetting property of the mirror forming surface, and further reducing the wetting property as compared to the wetting property of the mirror forming surface By providing a material layer, the operation of the method of the present invention in producing an optical reflecting mirror can be obtained properly.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIGS. 2 to 4 show Embodiment 1 of the present invention.
FIG. 2 is a sectional view of a molding die, and FIGS.
FIG. 4B is a plan view and a side view of a molded product, and FIGS. 4A, 4B and 4C are explanatory views showing a molded state of the molded product.

Now, the injection mold 10 shown in FIG.
A fixed-side mold part 14 comprising a fixed-side mold plate 12 provided with a fixed-side insert 11 and a fixed-side mounting plate 13 to which the fixed-side insert 11 is attached, and a movable-side insert 15 opposed to the fixed-side insert 11 are provided. The movable mold plate 16 is supported by a movable mold plate 16, a movable support plate 17 supporting the movable mold plate 16, and a spacer block 18.
Movable side mold part 2 comprising movable side mounting plate 19 with
0.

Also, the molding surface 11a of the fixed side insert 11 is provided.
Is formed of a grain surface, and the molding surface 15a of the movable-side insert 15 disposed opposite to the fixed-side insert 11 has a flatness required for the mirror surface of the optical reflecting mirror which is a molded product. Mirror finish (mirror finish finish) is applied. Further, forming surfaces 11a and 15a of the fixed-side insert 11 and the movable-side insert 15 and the protruding pins 23 supported by the movable-side mold plate 16 and the upper and lower protruding plates 21 and 22.
And 24 form a cavity 25.

The molding surface 16a of the movable mold plate 16 and the end surfaces 23a and 24a of the protruding pins 23 and 24 in the cavity 25, which are continuous between the molding surface 11a and the molding surface 15a, are mirror-finished. Not. Then, a sprue bush 27 having a sprue 26 is fixed to the fixed-side template 12 and is connected to the sprue 26 of the sprue bush 27 so that a sprue pool 28, a runner 29 and a gate 30 are arranged on the movable-side template 16. The end faces of the protruding pins 31 supported by the upper and lower protruding plates 21 and 22 are viewed through the sprue pool 28.

When the optical reflecting mirror as a molded product shown in FIG. 3 is formed by the injection molding die 10 having the above-described configuration, the sprue bushing 27 of the sprue bushing 27 and the sprue bushing 27 are spun from a cylinder nozzle of a molding machine not shown. Pool 2
8. Fill the cavity 25 with the plastic material through the runner 29 and the gate 30. At this time, immediately before the filling of the plastic material into the cavity 25 is completed, the filling from the cylinder nozzle is stopped, and thereafter the molding is performed without applying pressure to the cavity 25.

Therefore, the plastic material filled in the cavity 25 is cooled and solidified, and the molded product 32 shown in FIG.
Is molded. Thereafter, the movable mold 20 is opened from the fixed mold 14 via the parting surface 33 and the projecting pins actuated by the upper and lower projecting plates 21 and 22 pressed by the projecting rod (not shown) of the molding machine. 2
The molded product 32 is protruded out of the mold by 3, 24 and 31 to be released.

That is, FIG. 3 shows the molded product 32 after release from the mold, and the molded product 32 shown in the drawing includes a product portion 34, a molded product gate portion 35 connected thereto, a molded product runner portion 36,
It comprises a molded product sprue portion 37. Now, according to the above-described method of molding the molded product 32 using the injection molding die 10, the filling of the plastic material into the cavity 25 from the cylinder nozzle of the molding machine is stopped immediately before the completion thereof, As a result of molding without applying pressure thereafter, the molding surface corresponding to the mirror surface 15a of the movable-side insert 15 has a grained surface 11a and a mirror surface 15a of the fixed-side insert 11 having a poorer wetting property. The other molding surface 16a and the protruding pins 23, 2 which are located between the grain surface 11a and extend outside the mirror surface 15a.
4 is cooled faster than the end surfaces 23a and 24a, and the plastic material in the cavity 25 starts to shrink with the cooling on the mirror surface 15a side, thereby forming the outside of the grain surface 11a and the mirror surface 15a. Surface 16a,
Sinks occur on the end faces 23a and 24a.

On the other hand, on the surface corresponding to the mirror surface 15a, the mirror surface 15a is transferred with high precision without sink marks. FIGS. 4A and 4B show such a molded state.
In the product part 34 of FIG. 2, the sink surface 39a is generated on the surface 38 corresponding to the grain surface 11a of the fixed-side insert 11 and the outer surface of the movable-side mold plate 16 is continuous with and surrounds the mirror surface 15a. Forming surface 16a, and projecting pins 23, 2
The surface 39 corresponding to the end surfaces 23a and 24a of the surface 4 has a sink mark 39b.
Is generated, no sink mark is generated on the surface corresponding to the mirror surface 15a of the movable side insert 15, that is, the mirror surface 41 of the optical reflecting mirror.

However, as shown in Table 1 below, according to the above-described molding method, as described above, according to the molding without applying the holding pressure to the cavity 25, the mirror surface 41 corresponding to the mirror surface 15a is formed. Mirror surface 1 without sink marks
5a, a high-accuracy transfer property is exhibited, but when molding is performed by holding a pressure, no sink marks 39a on the fixed side and sink marks 39b on the movable side are generated, and as shown in FIG.
It has been found that sink marks 39c occur on the surface 41 corresponding to 5a.

[0022]

[Table 1]

(Embodiment 2) FIGS. 5 to 11 show Embodiment 2 of the present invention. FIG. 5 is a sectional view of a molding die, and FIGS. 6 and 7 are enlarged views of essential parts of the same. 8 to 10
Is a partially enlarged view of the molding surface of the fixed nest, and FIG. 11 is a partially enlarged sectional view of the movable nest. As for the molding die 10 in the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted, and corresponds to the injection molding die of the first embodiment. Only the components other than those described above will be described below.

Therefore, the fixed-side insert 11 and the movable-side insert 15 are attached to the fixed-side mold plate 12 and the movable-side mold plate 16 via the fixed-side sleeve 42 and the movable-side sleeve 43, respectively. The molding surface 11a of the nest 11 is formed by providing minute irregularities 44 as shown in FIG. 6 and FIG. 7 showing the irregularities of FIG. 6 in an enlarged manner, and the molding surface 15a of the movable nest 15 is a molded product. In order to transfer the mirror surface required for the mirror surface of the optical reflection mirror as above, a mirror finish finish with extremely high flatness is applied.

In the drawing, reference numeral 45 denotes a core pin, and reference numeral 46 denotes a runner projecting pin. In the case where a molded product as an optical reflecting mirror is molded by the molding die 10 having the above configuration, the sprue 26, the runner 29, and the gate 30 are formed by the cylinder nozzle of the molding machine as in the first embodiment. The plastic material is filled into the cavity 25 through the above, and the filling is stopped immediately before the completion, and no pressure is applied to the cavity 25 thereafter.

In this state, the plastic material filled in the cavity 25 is apparently filled in the cavity 25 (the irregularities 4 on the rough surface 11a side with respect to the mirror surface 15a side).
4 has a small gap at the bottom 44a). At the same time, the inside of the cavity 25 starts to be cooled without applying pressure and the shrinkage starts at the same time as being full. At this time,
Since no holding pressure is applied, the plastic material is not tightly adhered to the entire molding surface 11a of the fixed-side insert 11,
At the same time as the shrinkage starts, the close contact surface with the molding surface 11a starts peeling and causes sink marks.

For this reason, the shrinkage is caused by the molding surface 1 of the movable side insert 15.
5a, the mirror surface 15a of the movable insert 15 formed of a high-precision plane is directly transferred to the molded product. Thereafter, after the completion of the molding in the cavity 25, the mold is opened from the parting line 33, and the molded product is released through the core pin 46, the runner projecting pin 47, and the sprue projecting pin 31 supported by a projecting plate (not shown). And take out the molded product.

As described above, it is possible to obtain a molded product having a highly accurate flat surface for an optical reflecting mirror. Further, instead of the minute irregularities 44 shown in FIG. 7 on the molding surface 11a of the fixed side insert 11, as shown in FIG.
By blowing (blasting) a steel ball ball 48 on the 1a by air pressure or liquid pressure to form a smooth unevenness 49, the biting of the plastic material on the molding surface 11a is further reduced as compared with the unevenness 44, There is an advantage that the peeling at the time of shrinkage can be made to be in a state of being more easily peeled.

Further, as shown in FIG. 10, a coating layer 50 of several tens μm of electrolytic or electroless nickel plating or the like is formed on the surface of the fine irregularities 44 shown in FIG. By applying the same, the same operation and effect as those of the unevenness 49 can be obtained. In addition, as shown in FIG. 11, the movable side insert 15 is formed of an aluminum or copper material having good thermal conductivity, and the molding surface 15a of the movable side insert 15 is subjected to mirror finish as described above. In addition, by providing the thin film layer 51 of TiN, CrN or the like on the mirror finish surface 15a, the heat of the skin layer forming the mirror surface can be quickly removed by the action of the good thermal conductivity to reverse the mold. On the contrary, the temperature of the rough surface due to the minute irregularities 44 of the fixed-side insert 11 on the opposing surface is
If the height is higher than the mirror surface 15a, the sink phenomenon due to shrinkage will in principle always go to the higher temperature side.
In relation to the molding surface 11a of the fixed side insert 11 of 0,
Molding in a state in which the above-described functions and effects are further promoted is realized, and it is possible to mold a reflecting mirror with high optical surface accuracy.

The thin film layer 51 shown in FIG.
Corrosion resistance of the molding surface 15a of the movable insert 15 is improved, and the surface of the movable insert 15 is prevented from being damaged.
Can extend the life of the product. Further, the molding surface 11a of the fixed-side insert 11 shown in FIGS. 7 to 10 described above was measured to reduce the wetting property of the molding surface 15a of the movable-side insert 15 with respect to the mirror surface by the minute unevenness 44, 49, and 50. In addition to the configuration, when the molding surface 11a of the fixed-side insert 11 is formed of an oil-containing metal layer, the molding surface 11a is subjected to a self-cleaning process used in a commercially available gas range or the like, and is brought into contact with a plastic material. Embodiments such as a configuration in which the area is reduced as much as possible can be given.

(Embodiment 3) FIGS. 12 and 13 show Embodiment 3 of the present invention. FIG. 12 is an enlarged sectional view of a main part of a molding die, and FIG. It is an expanded sectional view shown. The molding die 10 of the present embodiment is the same as the molding die 10 of the second embodiment except that
For the purpose of reducing the wetting of the molding surface 11a of the fixed-side insert 11 against the wetting of the molding surface 15a of No. 5, a sheet-like sheet made of a Teflon sheet or the like is provided in the support recess 53 (see FIG. 13) provided in the movable sleeve 43. It is configured by covering the molding surface 11a of the fixed-side insert 11 while supporting the member 52. Other configurations are the same as those of the second embodiment, and the same components are denoted by the same reference numerals. Therefore, the description is omitted.

Accordingly, the molding die 1 having the above-described structure is used.
0, the plastic material filled in the cavity 25 is molded by the same method as the molding method of the second embodiment.
a, the same effect as that of the molding surface 11a of the fixed-side insert 11 of the second embodiment is exerted by the sheet-like member 52 interposed therebetween. As a result, the plastic material filled in the cavity 25 is cooled. The shrinkage is started, and the shrinkage is generated with reference to the molding surface 15a of the movable side insert 15. As a result, it is possible to mold the optical reflecting mirror on which the mirror surface of the molding surface 15a is transferred with high precision.

The sheet-like member 52 is peeled off from the molded product. However, if the sheet-like member 52 cannot be peeled off after being integrated with the molded product, no problem occurs, and the molded product does not become defective. Can be used.

(Embodiment 4) FIG. 14 is a sectional view of a main part showing Embodiment 4 of the present invention. In the molding die 10 of the present embodiment, the fixed-side insert 11 is formed of a porous material, for example, a ceramic material, and the air outlet 55 is fixed to the back of the fixed-side insert 11 to form an air generator. The other configuration is the same as that of the molding die 10 of the second embodiment, and the same components are denoted by the same reference numerals and description thereof is omitted.

Now, the molding die 10 having such a configuration.
Accordingly, when molding by the same method as the molding method of the second embodiment, the plastic material filled in the cavity 25 is formed on the molding surface 11a side of the fixed-side insert 11.
When the air from the air generator 54 is blown into the fixed side insert 11 through the air outlet 55, an air layer is interposed between the molding surface 11a and the plastic material, and as a result, the fixed side insert 11 of the plastic material is removed. Is prevented from contacting with the molding surface 11a.

Therefore, the shrinkage caused by cooling the plastic material in the cavity 25 occurs on the basis of the molding surface 15a of the movable side insert 15 as in the above-described embodiments, and the movable side The mirror surface on the molding surface 15a of the child 15 is transferred to the molded product with high precision, and a desired optical reflecting mirror can be molded. In each of the embodiments described above, the example in which the molding surface of the mirror surface required for the optical reflecting mirror is formed on the molding surface of the movable mold portion has been described. The present invention can also be implemented by a configuration provided in the side mold portion. For example, in the arrangement configuration of the molding die, it can be implemented while selecting one of the configurations according to the arrangement status such as the gate position and the like. .

[0037]

According to the present invention, it is possible to manufacture an optical reflecting mirror with high precision and efficiency at low cost. In addition, the obtained optical reflecting mirror can obtain a mirror surface having desired flatness and specularity without fail.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for explaining the concept of the present invention.

FIG. 2 is a sectional view of a molding die according to the first embodiment of the present invention.

FIG. 3 shows the first embodiment of the present invention, wherein a is a plan view of a molded product, and b is a side view of the molded product.

FIG. 4 shows Embodiment 1 of the present invention, wherein a, b, and c
FIG. 3 is an explanatory view showing a molded state of a molded product.

FIG. 5 is a sectional view of a molding die according to a second embodiment of the present invention.

FIG. 6 is an enlarged view of a main part of a molding die according to a second embodiment of the present invention.

FIG. 7 is an enlarged view of a main part of a molding die according to a second embodiment of the present invention.

FIG. 8 is a partially enlarged view of a molding surface of a fixed-side insert according to the second embodiment of the present invention.

FIG. 9 is a partially enlarged view of a molding surface of a fixed-side insert according to the second embodiment of the present invention.

FIG. 10 is a partially enlarged view of a molding surface of a fixed-side insert according to the second embodiment of the present invention.

FIG. 11 is a partially enlarged cross-sectional view of a movable-side insert according to a second embodiment of the present invention.

FIG. 12 is an enlarged sectional view of a main part of a molding die according to a third embodiment of the present invention.

FIG. 13 is an enlarged sectional view showing a receiving portion of a sheet-like member according to a third embodiment of the present invention.

FIG. 14 is a sectional view of a main part according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mirror molding surface (mirror surface) 2 Mirror side mold 3 Molding surface (rough surface) 4 Rough surface mold 5 Mold 6 Cavity 7 Plastic material 8 Air gap 10 Mold 11 Fixed side insert 11a Fixed Forming surface of side insert 12 Fixed side mold plate 13 Fixed side mounting plate 14 Fixed side mold part 15 Movable side insert 15a Forming surface (mirror surface) of movable side insert 16 Movable side mold plate 17 Movable side receiving plate 18 Spacer Block 19 Movable-side mounting plate 20 Movable-side mold 21, 22 Projecting plate 23, 24, 31, 46, 47 Projecting pin 25 Cavity 44, 49 Fine irregularities 50 Coating layer 52 Sheet member 54 Air generator

──────────────────────────────────────────────────の Continuing on the front page (51) Int.Cl. ⁶ Identification symbol FI // B29L 11:00 (72) Inventor Kenji Haga 2-43-2 Hatagaya, Shibuya-ku, Tokyo O-limpus Optical Industry Co., Ltd. ( 72) Inventor Hiroaki Kobayashi Examiner, Olympus Optical Industry Co., Ltd. 2-43-2 Hatagaya, Shibuya-ku, Tokyo Tomoya Kato (56) References JP-A-62-208919 (JP, A) JP-A-61- 188120 (JP, A) JP-A-61-254319 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 45/26-45/38 B29C 45/00 B29D 11/00 G02B 5/08 B29L 11:00

Claims (2)

(57) [Claims] 1. An optical reflecting mirror formed of a plastic material, comprising: a mirror surface which is flat and has a mirror surface; a rear surface which is opposed to the mirror surface and is rough and has a sink mark; And a surface surrounding the mirror surface in series. 2. A method of manufacturing an optical reflecting mirror, comprising: injecting a plastic material into a molding die to form an optical reflecting mirror, wherein the molding material is filled with the plastic material immediately before the filling of the plastic material is completed. Stopping the filling of the material, bringing the plastic material into close contact with a molding surface formed of a mirror surface for forming a mirror surface in the molding die, and forming a surface of the plastic material opposite to the molding surface for forming the mirror surface. The adhesion strength is set to be lower than the adhesion strength to the molding surface for forming the mirror surface, and in this state, the plastic material injected into the molding die is cooled and solidified, and the molding surface having a low adhesion strength is shrunk. And a method of manufacturing an optical reflecting mirror.