JP2006337654A - Light-shielding blade and optical path switching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem, wherein conventional light shielding blades obtained by press-forming a sheet film cannot achieve high strength and stable quality at low cost. <P>SOLUTION: The light-shielding blade 32 has a substantially strip shape and has mounting parts 35a, 35b at one end part in the longitudinal direction. The thickness of the mounting parts 35a, 35b is larger than that of the rest of a light-shielding part 37. The light-shielding blade 32 is made by injection molding of a material, having a liquid crystal polymer as the main component. A gate 39 for material injection is provided to the mounting parts 35a, 35b or in the vicinity thereof. Thus, the light-shielding blade 32, by having high strength and stable quality at low cost and an optical path switching device by using the light-shielding blade 32, can be provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light shielding blade for opening and closing an optical path in an optical apparatus such as a camera and an optical path opening and closing device using the light shielding blade.

  In optical path opening and closing devices such as shutters and diaphragms that open and close the optical path of optical equipment such as cameras, the light shielding blades that make up the shutter blades and diaphragm blades must move and stop so as to cross the optical path in a very short time. In order to reduce the load on the drive source, it is desired to be lightweight and highly rigid. In addition, these light-shielding blades need to shield light from a photoconductor such as a film or a CCD. Therefore, the light-shielding blade is required to have a light-shielding property, a low surface reflectance, and a certain level of flatness. Furthermore, many optical path opening and closing devices are configured to operate with a plurality of light shielding blades being overlapped, and lubricity and antistatic properties of contact portions that overlap each other are required. The flatness of the surface of the light shielding blade described above is important in preventing damage due to collision with the adjacent light shielding blade during the operation.

  In order to satisfy the characteristics required for such light shielding blades, those using various materials have been proposed. For example, Patent Document 1 discloses a camera shutter that uses at least one metal layer between a plurality of film layers of a crystalline polymer compound such as polyester to shield light. Further, it teaches that a light shielding means is provided by sandwiching one or more coating layers of black paint or the like between plastic film layers. In addition, it is disclosed that at least one layer of the plastic film contains a black pigment or a black dye. In Patent Document 2, a thermosetting matte paint is coated on a biaxially stretched polyester film having a composition with a film thickness of about 100 μm or less, preferably 70 μm or less and an optical density of about 10 or more. Furthermore, a plastic blade for an optical device to which an antistatic material is attached is disclosed. Patent Document 3 uses a film mainly composed of a thermoplastic resin as a base film, and is provided with a light-shielding film by providing layers made of a thermosetting resin containing carbon black, a lubricant, and a matting agent on both sides. Configuration is disclosed. Patent Document 4 discloses a light-shielding blade for a camera made of an aluminum alloy, and Patent Document 5 applies a carbon fiber reinforced thermosetting resin thin plate (hereinafter referred to as CFRP) to the shutter blade. In addition, it is disclosed that light shielding properties can be obtained by mixing a black pigment containing carbon black or the like into the matrix resin. Further, Patent Document 6 discloses CFRP with less warping, and Patent Document 7 discloses that CFRP has light weight, high strength, high elasticity, impact resistance, and vibration damping.

JP 57-60315 A JP-A-57-118226 JP-A-9-274218 JP 57-24925 A JP 49-84232 A Japanese Patent Laid-Open No. 51-14969 JP-A-53-101080

  Conventional light-shielding blades mainly made of resin are processed into a predetermined contour shape from a sheet film with a substantially uniform thickness by a press or the like, so that the required strength of the part to which the member for driving the light-shielding blades is attached is satisfied. It is necessary to use a sheet film having such a thickness. As a result, the thickness of the light-shielding portion becomes excessively thick, which causes an increase in inertial mass that hinders improvement in curtain speed when used as a shutter.

  A light-shielding blade made of polyethylene terephthalate (hereinafter referred to as PET) is widely used in low-price cameras and the like because of its low manufacturing cost and low specific gravity. However, since PET has low mechanical strength such as tensile elastic modulus, the light shielding blades bend due to vibrations or shocks that occur during running or braking, and the light shielding blades tend to collide with each other and be damaged by them. It cannot be used with a focal plane shutter that travels on the road.

  In addition, a light-shielding blade made of a metal such as an aluminum alloy has high mechanical strength and can be incorporated into a high-speed shutter device, but the weight of the light-shielding blade itself is increased due to the large specific gravity of the material itself. , Requires large charge energy. Furthermore, vibrations that occur during running and braking, so-called undulations, are very large, and this undulation state is not easily settled.

  On the other hand, the light-shielding blade made of CFRP is lightweight and has a high elastic modulus, and even when the shutter speed is high, there is very little waving during running and braking, and even if undulation occurs, it quickly decays. It has the characteristic to end. Accordingly, there is no possibility of collision between the light shielding blades and damage due to this, and extremely high durability can be realized. However, CFRP is expensive in material itself and needs to be manufactured in a very laborious process in which a plurality of prepreg sheets, which are precursors at the time of manufacturing, are stacked and heated while being pressed. is there. In addition, the sheet thus obtained is also prone to defects such as openings due to variations in carbon fibers, and has a high defect generation rate due to variations in strength and warpage, which requires time and effort for quality control. In combination with this, the manufacturing cost becomes very high.

  By the way, when a liquid crystal polymer (hereinafter sometimes referred to as LCP), which is known as an engineering plastic and has a low density similar to that of general polymer substances, is formed into a film by extrusion molding, each domain (polymer chain) Each molecule oriented in a random direction is aligned along the extrusion direction and exhibits orientation. Thereby, LCP exhibits high strength and high elasticity not found in general polymer materials. In other words, since the mechanism of high elasticity in LCP depends on the orientation of domains in the molding direction, the elastic modulus shows anisotropy and has a high elastic modulus along the molding direction. In most cases, the elastic modulus in the orthogonal direction is extremely low. As a result, an LCP film that can be easily split along the forming direction is often produced. Considering the use of LCP as a structural material, the remarkable anisotropy of the elastic modulus as described above causes a lack of reliability and makes its practical use difficult.

  The present invention has been made to solve such problems, and an object thereof is to provide an inexpensive light-shielding blade having high strength and stable quality, and an optical path switching device using the light-shielding blade.

  According to a first aspect of the present invention, there is provided a light shielding blade having an attachment portion, wherein the thickness of the attachment portion is set to be thicker than the thickness of the other portions.

The bending strength W of a homogeneous material having a length L that supports both ends is expressed as follows: W = (48yEI) / L ³ where y is the displacement of the material, E is the elastic modulus, and I is the moment of inertia of the section. Become. However, cross-sectional secondary moment I, when the width of the material to h, and the thickness of the material is h, is expressed by I = bh ^3/12. Therefore, it can be seen that the bending strength W of the material is proportional to the cube of its thickness. For example, when the thickness of the attachment portion is 150 μm and the thickness of the other portion is 100 μm, the bending strength of the attachment portion is (150/100) ^three times the bending strength of the other portions, that is, about 3. It will have about four times the strength.

  In the present invention, the thickness of the attachment portion is set to be thicker than the thickness of the other portions, and the bending strength thereof is higher than the bending strength of the portions other than the attachment portion.

  The second embodiment of the present invention is a light-shielding blade having a substantially strip shape, having an attachment portion at one end in the longitudinal direction thereof, and the thickness of the attachment portion being set larger than the thickness of the other portions. An optical path opening / closing device to be used, wherein the light shielding blade is formed by injection molding a material mainly composed of LCP, and a gate for material injection is arranged at or near the attachment portion. .

  In the present invention, at the time of injection molding, the material is injected from the thickly attached portion to the other portion from the material injection gate, and the LCP molecules are oriented along the longitudinal direction of the light shielding blade.

  According to the light shielding blade of the present invention, the thickness of the attachment portion that requires mechanical strength is set to be thicker than the thickness of the other portions where mechanical strength is not so necessary, Optimum strength can be provided, and the durability of the light shielding blade itself can be remarkably improved.

  According to the optical path opening and closing device of the present invention, the light-shielding blade has a substantially strip shape, has an attachment portion at one end in the longitudinal direction thereof, and the thickness of this attachment portion is set to be thicker than the thickness of the other portions, Since the material mainly composed of LCP is injection-molded, and the material injection gate is arranged at or near the mounting portion, the filling property of the material into the mold cavity at the time of injection molding can be improved. Moreover, it is possible to reliably prevent the strength of the attachment portion from being lowered due to the influence of the weld. Further, since the LCP molecules can be oriented along the longitudinal direction, the elastic anisotropy preferable as the light shielding blade for opening and closing the optical path by running the light shielding blade in the direction intersecting the longitudinal direction of the light shielding blade. Can be given.

  In addition, when the light shielding blade is cut out from the sheet film by a press or the like, there is a possibility that fine chips generated when the sheet film is cut may adhere to the surface of the light shielding blade. The light-shielding blade of FIG. 5 hardly causes such problems, and is particularly advantageous for use in a shutter unit of a digital camera that dislikes adhesion of dust or the like to the image sensor.

  An embodiment in which the optical path opening and closing device according to the present invention is applied to a focal plane shutter of a camera will be described in detail with reference to FIGS. 1 to 8. However, the present invention is not limited to such an embodiment, and is claimed. Any change or modification included in the concept of the present invention described in the scope of the present invention can be made, and can naturally be applied to other techniques belonging to the spirit of the present invention.

  The front shape of the focal plane shutter unit according to the present embodiment is shown in FIG. 1, and the sectional structure taken along the line II-II is shown in FIG. That is, the focal plane shutter unit 10 is called a so-called vertical running type. In FIG. 1, a plurality of sheets overlapping each other as a front curtain 11 and a rear curtain 12 that run in the vertical direction (in the illustrated example, Five and four light-shielding blades 13, 14, 15, 16, 17, 18, 19, 20, 21 are used. Between a frame-shaped cover plate 23 and a frame-shaped shutter base plate 24 assembled in parallel with each other via a plurality of spacers 22, a frame-shaped partition plate 25 that partitions the front curtain 11 and the rear curtain 12 is provided. It is assembled in an inclined state. The front curtain 11 is disposed between the cover plate 23 and the partition plate 25, and the rear curtain 12 is disposed between the partition plate 25 and the shutter base plate 24. A front curtain support arm 26 and a front curtain drive arm 27 are respectively pinned to one longitudinal end side (left side in FIG. 1) of the light shielding blades 13 to 17 constituting the front curtain 11. The rear curtain support arm 28 and the rear curtain drive arm 29 are also pinned to one end side in the longitudinal direction of the light shielding blades 18 to 21 constituting the frame 12. The front curtain drive arm 27 and the rear curtain drive arm 29 are slidably engaged with arc-shaped guide grooves 30 and 31 formed in the cover plate 23 and the shutter base plate 24, respectively, and the base end portions thereof. Are connected to driving sources (not shown) for opening and closing the front curtain 11 and the rear curtain 12, respectively.

  The specific configuration of the focal plane shutter unit 10 itself is well known in Japanese Patent Laid-Open Nos. 10-186448, 2002-229097, 2003-280065, and the like.

  FIG. 3 shows a disassembled state of one of the light shielding blades 13 to 21 in the present embodiment (hereinafter, these are represented as 32 for convenience), and FIG. 4 shows a sectional structure thereof. That is, in order to pin the front curtain or rear curtain support arms 26 and 28 and the front curtain or rear curtain drive arms 27 and 29 on one end side in the longitudinal direction of the light shielding blade 32 of the present embodiment having an elongated rectangular plate shape. A pair of attachment portions 35a and 35b each having through holes 33 and 34 are formed, and the other end side of these attachment portions 35a and 35b functions as a light shielding portion 37 having a constant thickness of 100 μm, for example. The thicknesses of the attachment portions 35a and 35b each having a boss shape are set to be thicker than other portions, that is, the thickness of the light shielding portion 37, for example, 150 μm. The attachment portions 35 a and 35 b in the present embodiment are in a state of protruding from one surface of the light shielding portion 37. A black paint having at least one function of improving the light shielding property, preventing electrification and reducing friction is applied as a functional layer 38 to a thickness of 5 μm on both the front and back surfaces of the light shielding blade 32.

  The thickness of the light shielding portion 37 of the light shielding blade 32 is set in the range of 50 to 200 μm, and more preferably in the range of 70 to 120 μm. When the wall thickness is less than 50 μm, the mechanical strength as the light shielding blade 32 is insufficient and the light shielding property is also lowered. On the other hand, if the thickness exceeds 200 μm, the mechanical strength increases, but the weight of the light shielding blade 32 increases more than necessary, and the increase in inertial mass becomes an obstacle to improving the shutter curtain speed. In addition, in the case of the focal plane shutter unit 10 as in this embodiment, the distance between the front curtain 11 and the rear curtain 12 increases, which affects the slit formation accuracy and lowers the shutter efficiency.

  The thickness of the attachment portions 35a and 35b needs to be set so as to satisfy the mechanical strength required for these portions, and is generally 300 μm or less, more preferably 200 μm or less.

  The resin used for the injection molding of the light shielding blade 32 is not particularly limited as long as the thickness of the light shielding portion 37 can be formed to about 0.1 mm. However, in consideration of thin film moldability and material strength, LCP, particularly polyester called thermotropic LCP is preferable. Thereby, the high intensity | strength and highly elastic light-shielding blade 32 can be obtained. It is possible to add another resin to the LCP. The resin that can be blended may be either a thermoplastic resin or a thermosetting resin, but a so-called thermoplastic engineering plastic such as a polyamide resin, a polycarbonate resin, a polyethylene terephthalate resin, a polybutylene terephthalate resin, a polyphenylene sulfide resin, a poly Examples thereof include ether sulfone resin. The compounding quantity of the other resin with respect to LCP is 1-400 weight part with respect to 100 weight part of LCP, Preferably it is 10-200 weight part, More preferably, it is 30-100 weight part.

  When a resin containing LCP is injection-molded, longitudinal tearing and curling associated with the molecular orientation of LCP are likely to occur. Therefore, it is desirable to reduce the elastic modulus anisotropy by adding a filler. As such a filler, a general fibrous or powdery filler and a mixture of both can be used. Examples of the fibrous filler include glass fiber, carbon fiber, ceramic fiber, and whisker. Examples of the powder filler include mica, talc, clay, silicon carbide, alumina, boron nitride, and graphite. In particular, if the function as the light shielding blade 32 is taken into consideration, it can be said that whisker and graphite are preferable. In the case of graphite, it is more preferable because it can further improve the light shielding property. If the filling rate is too high, the fluidity of the material at the time of injection molding is lowered and the moldability is deteriorated. On the other hand, if the filling rate is too low, the effect of the filler is not exhibited, and tearing and curling are likely to occur. From such a viewpoint, the blending amount of the filler is 10 to 100 parts by weight, preferably 15 to 40 parts by weight with respect to 100 parts by weight of the LCP composition described above.

  As is well known, LCP is more opaque to light and has better light blocking properties than PET and the like. Specifically, the optical density of PET alone can be regarded as almost zero, but in the case of a 25 μm thick LCP, the optical density reaches about 0.5. Further, a light shielding material such as carbon black can be dispersed in the material. For example, when 2 wt% of carbon black is added to a LCP having a thickness of 25 μm, the optical density can be increased to 6 or more. . When such a light-shielding material is added to the molded resin, from an industrial standpoint, a method of kneading each component in a molten state in the same step as the mixing of the filler described above is preferable. For this melt-kneading, commonly used kneading apparatuses such as a single-screw or twin-screw extruder and various kneaders can be adopted, but a twin-screw high kneader is particularly preferable. At the time of kneading, each component may be mixed uniformly in advance with a device such as a tumbler or a Henschel mixer, or a method in which such mixing is omitted and a fixed quantity is separately supplied to the kneading device may be used. Is possible. The addition amount of the light shielding material relative to the resin is 0.1 to 10% by weight, preferably 0.5 to 5%. If the addition amount is small, the effect of improving the light shielding property cannot be obtained. Conversely, if the addition amount is too large, the fluidity of the material at the time of injection molding deteriorates.

The molding conditions for such an injection material are set such that the injection speed is high, the injection pressure is high, and the resin temperature and mold temperature are increased. For example, the injection speed is 200 mm / sec or more, preferably 500 mm / sec or more, the injection pressure is 1000 kg / cm ² or less, the resin temperature is 200 to 350 ° C., and the mold temperature is 60 to 150 ° C. Should. A molding machine capable of high pressure and high speed injection is preferable, and a molding machine equipped with a backflow prevention mechanism is particularly preferable.

  A known gate shape can be adopted as the gate at the time of injection molding, and the gate can be properly used according to the shape of the light shielding blade 32. In the case of the focal plane shutter unit 10 as in the present embodiment, a film gate 39 preferably having a short axis width (length along the vertical direction in FIG. 3) of the light shielding blade 32 is attached to the attachment portion where the light shielding blade 32 is thick. Set to 35a and 35b. Thereby, the LCP molecules are oriented in the longitudinal direction of the light shielding blade 32, and the light shielding blade 32 having preferable elastic modulus anisotropy can be obtained.

  In particular, when an LCP is injection-molded, the strength of the mounting portion may be reduced due to the influence of the weld due to the presence of the through hole of the mounting portion depending on the location and shape of the gate, but in the present invention, the mounting portions 35a and 35b By increasing the wall thickness, the influence can be reduced.

  The injection-molded light-shielding blade 32 is subjected to heat treatment as necessary. This heat treatment can be performed under stress or in a free state, and can be performed at a suitable temperature ranging from room temperature to the heat distortion temperature in a known atmosphere such as air, nitrogen, or a vacuum. .

  Usually, LCP has poor adhesion and paintability, and when the functional layer 38 is formed on the surface, it is difficult to obtain sufficient adhesion strength. Therefore, it is preferable to perform a known hydrophilic surface treatment such as corona discharge before the functional layer 38 is formed.

  In the above-described embodiment, the attachment portions 35a and 35b are protruded only from one surface side of the light shielding blade 32. However, as shown in FIG. It is. It is also possible to integrate the pair of attachment portions 35a and 35b so that a thin portion is not formed between these through holes.

  FIG. 6 shows the front shape of another embodiment of the light-shielding blade according to the present invention, and FIG. 7 shows the sectional structure taken along the arrow VII-VII. Only the same reference numerals are used, and duplicate descriptions are omitted. That is, two through holes 33 and 34 are formed on one end side in the longitudinal direction of the light shielding blade 32 in the present embodiment, and the thickness of the mounting portion 36 surrounding them is set to 150 μm, and the other light shielding portions The thickness of the portion 37 is set to 100 μm. Thereby, the intensity | strength of the attachment part 36 can further be raised.

  In the above-described embodiment, the thickness of the light shielding portion 37 is set to be constant. However, the thickness of the light shielding portion 37 can be set to be thin stepwise or continuously as the distance from the attachment portion 36 increases. FIG. 8 shows a cross-sectional structure of another embodiment of such a light-shielding blade according to the present invention. Elements having the same functions as those of the previous embodiment are designated by the same reference numerals, and redundant descriptions are omitted. And In other words, the light shielding blade 32 in the present embodiment has a thinner thickness toward the other end in the longitudinal direction, and the thickness of the light shielding portion 37 becomes the same as the thickness closer to the attachment portion 36 at the one end in the longitudinal direction. The thickness varies continuously along its longitudinal direction.

  It is also possible to change the thickness of the light shielding portion 37 stepwise as it moves away from the mounting portion 36. When the thickness of the light shielding portion 37 is changed stepwise or continuously in this way, Optimum strength can be given to each portion, and stress applied to the attachment portion 36 can be reduced to further improve durability.

  Next, the bending elastic modulus and coating strength of the light shielding blade 32 according to the present invention are shown in Table 1 below as Examples 1 to 4 together with Comparative Examples 1 to 3 for comparison. The flexural modulus is obtained from the load when a tensilon universal testing machine is used to support both ends of the light-shielding portion 37 in each sample with a distance of 30 mm and a displacement of 4 mm is applied to the central portion.

  Further, the light-shielding blades 32 obtained in Examples 1 to 4 and Comparative Examples 1 to 3 are incorporated as the front curtain 11 and the rear curtain 12 of the focal plane shutter unit 10 shown in FIGS. Evaluation of light leakage when irradiated with light of brightness was performed. Further, an open / close test was conducted 150,000 times at room temperature and humidity at a shutter speed of 1/8000 second, and the durability was examined. These results are shown together in Table 1.

Using a high-speed injection type injection molding machine with a check valve, the temperature in the injection cylinder is set to 370 ° C., the mold temperature is set to 120 ° C., and a high fluidity LCP containing 15% by weight of glass fiber as a filler. For example, from a material obtained by adding 2 parts by weight of carbon black to 100 parts by weight of Zyder (trade name) manufactured by Nippon Petrochemical Co., Ltd., the thickness of the light shielding part 37 is 100 μm, and the thickness of the attachment parts 35a and 35b A light-shielding blade having a thickness of 150 μm as shown in FIGS. 3 and 4 is injection-molded at an injection pressure of 600 kgf / cm ² , and the molded product is taken out and the resin injection gate (film gate 39) is cut and removed. The light shielding blade 32 was subjected to a known surface hydrophilization treatment, for example, a corona discharge treatment, to form a functional layer 38 of black coating having a thickness of 5 μm.

  Example 1 is the same as Example 1 except that the blending ratio of the glass fibers in the Zyder made by Nippon Petrochemical Co., Ltd. was set to 30% by weight.

  100 parts by weight of Zyder made by Nippon Petrochemical Co., Ltd., 30 parts by weight of aluminum borate whisker, for example, Arborex (product name: about 20 μm in length and about 1 μm in diameter) made by Shikoku Kasei Kogyo Co., Ltd., carbon The same as Example 1 except that a material consisting of 2 parts by weight of black was used.

  The same as Example 1 except that 100 parts by weight of Zyder manufactured by Nippon Petrochemical Co., Ltd., 30 parts by weight of artificial graphite manufactured by Nippon Graphite Industries Co., Ltd., and 2 parts by weight of carbon black were used. .

(Comparative Example 1)
The thickness of the attachment portions 35a and 35b is the same as that of Example 1 except that the thickness is set to 100 μm, which is the same as the thickness of the light shielding portion 37.

(Comparative Example 2)
Example 1 is the same as Example 1 except that the compounding ratio of the glass fibers in the Zyder made by Nippon Petrochemical Co., Ltd. was set to 0%.

(Comparative Example 3)
Example 1 is the same as Example 1 except that the functional layer 38 is formed without performing surface hydrophilization treatment.

  In the case of Comparative Example 2 that does not include a reinforcing material as a filler for LCP, the obtained light-shielding blade was fibrillated, and the bending elastic modulus could not be measured, and warping also occurred.

  In terms of coating strength, the “occurrence of peeling” in the case of Comparative Example 3 where the surface hydrophilization treatment is not performed indicates that the coating film (functional layer 38) has been peeled from the cross-cut portion.

  “None” in light leakage indicates that light leakage hardly occurs, and it was confirmed that the light shielding blade 32 according to the present invention has sufficient light shielding properties. In the case of Comparative Example 1, the amount of carbon black added was too small, indicating that light leakage often occurred. In the case of Comparative Example 2 where no filler was added, light leakage was caused by fibrillation of the light shielding blade. Indicates that it happened frequently.

  In terms of durability, “breakage” in the case of Comparative Example 1 indicates that a crack has entered from the weld portion formed in the light-shielding blade ejected through the gate, and “breakage” in the case of Comparative Example 2 Indicates that cracks occurred along the flow direction of the material during injection molding. Regarding this durability, it was confirmed that the light-shielding blade 32 of the present invention has a performance equal to or higher than that of the conventional product.

1 is a front view of an embodiment in which an optical path opening and closing device according to the present invention is applied to a focal plane shutter of a camera. It is II-II arrow sectional drawing in FIG. It is a front view of one Embodiment of the light-shielding blade | wing by this invention used for the focal plane shutter shown to FIG. 1 and FIG. FIG. 4 is a cross-sectional view taken along arrow IV-IV in FIG. 3. It is sectional drawing of other embodiment of the light-shielding blade | wing by this invention. It is a front view of another embodiment of the light-shielding blade | wing by this invention. FIG. 7 is a cross-sectional view taken along arrow VII-VII in FIG. 6. It is sectional drawing of other embodiment of the light-shielding blade | wing by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Focal plane shutter unit 11 First curtain 12 Rear curtain 13-21 Light shielding blade 22 Spacer 23 Cover plate 24 Shutter base plate 25 Partition plate 26 Front curtain support arm 27 Front curtain drive arm 28 Rear curtain support arm 29 Rear curtain drive arm 30, 31 Guide groove 32 Light-shielding blade 33, 34 Through-hole 35a, 35b, 36 Attaching part 37 Light-shielding part 38 Functional layer 39 Film gate

Claims (6)

  A light-shielding blade having an attachment portion, wherein the thickness of the attachment portion is set to be thicker than the thickness of other portions.   The light-shielding blade according to claim 1, wherein the light-shielding blade has a substantially strip shape, and the attachment portion is formed at one end in the longitudinal direction.   3. The light shielding blade according to claim 2, wherein a resin-based material is injection-molded, and a resin injection gate is disposed at or near the attachment portion.   The light-shielding blade according to claim 3, wherein the resin is a liquid crystal polymer.   The light shielding blade according to claim 1, wherein at least one of a light shielding property improving layer, an antistatic layer, and a friction reducing layer is formed on a surface. An optical path opening and closing device using a light shielding blade having a substantially strip shape, having an attachment portion at one end in the longitudinal direction thereof, and the thickness of this attachment portion being set thicker than the thickness of the other portion,
The light shielding blade is formed by injection molding a material mainly composed of a liquid crystal polymer, and a gate for material injection is arranged at or near the attachment portion.

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