JPH0618958A - Shutter for camera - Google Patents

Abstract

PURPOSE:To provide shutter speed <=1/8000 second and further, to attain manufacture at cost for the market by making plural division blades of the fiber reinforced plastic material of specific thickness. CONSTITUTION:A shutter is primarily composed of a fist blind 10 and a second blind 20, a shutter substrate 30, and a driving mechanism for driving these blinds. The first blind 10 is composed of four division blades, and the division blades are called first blade 11, second blade 12, and third blade 13, and fourth blade 14, in the order of the large moving amount. Then, the division blades of the second blind 20 are called first blade 21, second blade 22, third blade 23, and fourth blade 24, in the order of the large moving amount, as well. Then, the first blades 11 and 21 or the first and second blades 11 and 21, and 12 and 22, are composed of a fiber reinforced plastic plate (FRP) whose thickness is 65-80mum, and the third and fourth blades 13 and 23, and 14 and 24 are composed of the FRP whose thickness is 90-110mum. As fiber, the continuous fiber of aromatic polyamide fiber or ultra-high molecular weight polyethylene, etc., can be used, besides the continuous fiber of carbon fiber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera shutter (for example, a vertically running type focal plane shutter). In particular, the present invention relates to a shutter that can realize a shutter speed exceeding 1/8000 second.

[0002]

2. Description of the Related Art The maximum shutter speed of camera shutters (vertical running type focal plane shutters) currently on the market is 1/8000 second. This shutter is composed of four or five divided blades (light-shielding blades) and a drive mechanism for driving them. The light-shielding blades are composed of a fiber-reinforced plastic plate (hereinafter referred to as FRP), an aluminum plate, two of the four blades that have a large amount of movement, the former, and two that have a small amount of movement. There is one that is composed of the latter.

In general, in order to realize a high shutter speed, the plate material used for the light-shielding blade should be light and have high bending rigidity. In order to reduce the weight, it is generally necessary to reduce the plate thickness. However, since the bending rigidity is proportional to the cube of the plate thickness, when the bending rigidity is reduced, the bending rigidity extremely decreases. Shading vanes with low bending stiffness undulate during running and immediately after stopping. When the blades are wavy or wavy, when the next shutter operation is performed, the blades collide with each other or the blades and the aperture (which determines the angle of view) collide. Therefore, the blades are damaged and the shutter becomes inoperable. Even if the FRP blades are wavy, the wavy (vibration) state of the FRP blades quickly subsides. Therefore,
The next shutter operation is immediately possible.

One of the blades used for a maximum shutter speed of 1/8000 is made of FRP having a thickness of 90 μm. As disclosed in Japanese Patent Application Laid-Open No. 59-61827, FRP uses continuous fibers of carbon fibers as fibers and epoxy resin as matrix resin. FRP is a precursor, prepreg sheet (p
It is manufactured by laminating a plurality of repreg sheets (laminating so that the fiber directions thereof are orthogonal or substantially orthogonal to each other), and heating and curing the entire laminated body while pressing. The thickness of the manufactured FRP material is 90 as described above.
It has a rectangular shape measuring 80 mm long and 400 mm wide in μm.

In the prepreg sheet, continuous fibers of carbon fibers are aligned in one direction and thinly arranged on a plate material, which is impregnated with "uncured epoxy resin liquid" which is a precursor of a matrix resin, and the resin liquid B It is a stage condition. The B stage state is a state in which it is solidified and has no apparent fluidity, but can be finally cured by heating. In order to manufacture FRP, it is necessary to prepare at least one prepreg sheet on each of the front and back sides for the surface material layer and at least one prepreg sheet for the intermediate layer.

The FRP material is cut into the desired shape of the light-shielding blade. Cutting is generally punching with a press.
The cutting is performed so that the direction of the continuous fibers of the surface material layer coincides with the longitudinal direction of the blade. Next, the cut blades are painted black (dry lube coating) on both front and back surfaces and the cut surface. In this way, 20-40 blades can be obtained from one material. Since the diameter of the fiber is 3 to 10 μm, if the amount of the fiber is reduced in order to make the FRP material thin, the fibers are likely to be locally gathered.
Therefore, conversely, the number of fibers locally decreases. Looking at the FRP material with a small amount of fibers, the plate thickness there is thinner than 90 μm, the bending rigidity is low, and the toughness is also poor. In addition, the blade including that part will warp after long use. The warped blade causes the above-mentioned collision. Also, for some reason, some blades will warp after being used for a long time. Such a blade having poor durability has a large variation in plate thickness and can be known in advance. With further painting, some blades will warp. This also throws away the warped blade. Therefore, when the prepreg sheet is used as a reference, the non-defective rate of the light-shielding blade becomes extremely low.

Further, when the FRP material is thinned, there are some fibers which are already warped when finished and cannot be sent to the next punching step because the amount of fibers is small. This also causes the yield rate to be extremely low. The extremely low yield rate makes the manufacturing cost of the shutter considerably high. Therefore, in the current shutter, the thickness of the FRP shading blade is 90
It has stopped at μm.

[0008]

Recently, camera users have been demanding shutter speeds exceeding 1/8000 second for new image representations. To achieve a high speed exceeding 1/8000 second, the thickness of the FRP shading blade should be 80μ.
Although it may be thinned to m or less, as described above, the yield rate is extremely low. Therefore, at present, no camera having a shutter exceeding 1/8000 second is commercially available.

An object of the present invention is to provide a shutter which can realize a shutter speed exceeding 1/8000 second and which can be manufactured at a commercially available cost.

[0010]

As a result of earnest research, the present inventors have found that the yield rate is extremely low, but the plate thickness is 65 to 80 μm.
FRP material can be manufactured, and the most important thing to make light is the No. 1 blade with the largest movement amount. The No. 1 blade requires FRP compared to other blades.
Since the area of the material (hereinafter referred to as the effective area) is small, the non-defective rate is higher than other blades, and the final blade (No. 4 or 5 blade) with the smallest amount of movement has a large effective area. "FR with a plate thickness of 65 to 80 μm
You have to avoid "P material", the last blade is
Since the amount of movement is the smallest, even if the thickness is as thick as 90 to 110 μm (heavy), it is permissible. The final blade needs to be strong because the shape is complicated and large, and the plate thickness 90 Since the FRP material of ~ 110 μm has already been mass-produced as a commercial product, I learned that the price is considerably low. The effective area means the smallest rectangular area in which the blades fit, as indicated by the one-dot chain line in (4) of FIG.

Based on these information, the present inventors
In the case of a single-piece (or five-piece) shutter, at least the first (or first to second) blade is a FRP with a plate thickness of 65 to 80 μm.
FRP with a final blade thickness of 90 to 110 μm
It was found that a shutter speed exceeding 1/8000 second can be realized and the shutter can be manufactured at a commercially available cost, and the present invention has been completed.

Therefore, the first aspect of the present invention is that, in a camera shutter including four divided blades and a drive mechanism for driving the divided blades, the first to third counted blades in descending order of movement amount. A shutter (claim 1), characterized in that the number blade is made of FRP having a thickness of 65 to 80 µm and the rest is made of FRP having a thickness of 90 to 110 µm. Second
According to the present invention, "in a camera shutter including four divided blades and a drive mechanism for driving these, the first to second blades of the blades counted in descending order of movement amount,
Consists of FRP with a thickness of 65-80 μm, and the rest with a thickness of 90-110
A shutter (claim 2) characterized in that it comprises a FRP of μm.

Thirdly, according to the present invention, in a camera shutter comprising four divided blades and a drive mechanism for driving them, one of the blades is counted in descending order of movement amount.
A shutter (claim 3), characterized in that the number blade is composed of an FRP having a thickness of 65 to 80 µm and the rest is composed of an FRP having a thickness of 90 to 110 µm. Fourth, the present invention is
"In a camera shutter including five divided blades and a drive mechanism for driving the divided blades, among the blades, the first to fourth blades counted from the largest moving amount have a thickness of 65 to 80 μm.
A shutter (claim 4), characterized in that the shutter is constituted by the FRP of (1) and the rest is constituted by the FRP having a thickness of 90 to 110 µm (claim 4).

Fifth, according to the present invention, in a camera shutter comprising "five divided blades and a drive mechanism for driving them, one of the blades is counted in descending order of movement amount.
No. 3 to No. 3 blades are made of FRP having a thickness of 65 to 80 μm, and the rest are made of FRP having a thickness of 90 to 110 μm. Sixthly, the present invention provides a camera shutter comprising "five divided blades and a drive mechanism for driving the divided blades.
The first to second blades counted from the largest moving amount, the thickness 65 to
It is composed of 80μm FRP, and the rest is 90 ~ 110μm thick F
A shutter (claim 6) characterized in that it is made of RP.

Seventh, the present invention provides: "In the camera shutter according to the first to sixth aspects, the FRP is carbon fiber,
There is provided a shutter (claim 7), characterized in that it comprises a fiber selected from aromatic polyamide fiber or ultra high molecular weight polyethylene and a matrix resin containing the fiber.

[0016]

In the present invention, as the fibers, continuous fibers such as carbon fibers, continuous fibers such as aromatic polyamide fibers or continuous fibers such as ultra high molecular weight polyethylene can be used. In particular, other than carbon fiber can be used for the intermediate layer. Further, short fibers may be used instead of continuous fibers for the intermediate layer.

The matrix resin includes (1) celluloid, cellulose acetate, cellulose propionate, cellulose butyrate, 6-nylon, 6,6-nylon, ABS, AS resin, high density polyethylene, polypropylene, polyacetal, polycarbonate, Polyethylene terephthalate, polybutylene terephthalate,
Thermoplastic resins such as polyetherketone, polyetheretherketone, polysulfone, polyethersulfone, polyetherimide, polyarylate, polyamide elastomer, ionomer, liquid crystal polymer, polyimide, polyamideimide, fluororesin, PPS, modified polyphenylene oxide, etc., Alternatively, (2) a thermosetting resin such as epoxy resin, unsaturated polyester, polyurethane or polyimide can be used.

When the carbon fiber is used, the carbon fiber is black, so that the FRP has a temporary light shielding property. However, in order to improve the light-shielding property, carbon black may be previously added and dispersed in the resin liquid that is a precursor of the matrix resin when the prepreg sheet is manufactured. Alternatively, a resin solution in which carbon black is mixed at a high concentration is separately prepared, and this may be press-fitted and permeated into an ordinary prepreg sheet by using a roll coater or the like. Carbon black also has the effect of improving the sliding of the blades. Even if the blade rubs, it will wear less if it is slippery.

Carbon black has an average particle size of 0.07 μm.
It is particularly preferably 0.01 μm or less. The compounding amount of carbon black is 3 to the resin liquid (100 parts by weight of solid content).
15% by weight is preferred. If it is 15% by weight or more, the arrangement of the fibers becomes too bad and the flatness is adversely affected. In addition, since the fluidity of the resin liquid becomes too poor, voids may be formed inside or delamination may occur. The amount of resin in the prepreg sheet is
30 to 50% by weight, especially 38 to 48% are suitable. When the amount of resin is small, voids and fine cracks are visible on the appearance, and the coatability is deteriorated. Furthermore, since the surface of the material has irregularities, the wear resistance and lubricity of the blades are inferior, and further the aesthetic appearance is deteriorated. In addition, when the amount of resin is small, a striped pattern may appear during resin flow, which also deteriorates the appearance.

The fiber basis weight of the prepreg sheet (how many g of fiber is contained per 1 m ² ) is 10 g / m ^{2 to} 60 g / m.
^{Is 2} . The thickness of one layer of prepreg sheet is 15-70μ
m. The prepreg sheets need not all have the same plate thickness. If they are used so as to be plane-symmetric with respect to the neutral plane in the thickness direction, it is possible to combine various plate thicknesses and various basis weights. If the plate thickness is within the specified value, increase the bending rigidity of the whole by changing the plate thickness and weight of the intermediate layer to the surface material layer (in this case,
It is advantageous to make it thicker or more than just the layers).

In the prepreg sheet, the surface material layer and the intermediate layer are so arranged that the directions of the fibers are orthogonal or substantially orthogonal to each other.
In addition, at least three or more sheets, for example, three, four, or five sheets are superposed so as to be plane-symmetric in the thickness direction from the center plane, and heat press molding is performed on them to obtain a plate material. As a result, the uncured thermosetting resin liquid is crosslinked and hardened. The material obtained is then punched into the shape of a blade. After that, dry lube painting is applied. Film thickness of dry lube coating (after dry hardening)
Is generally 0.1 to 10 μm, preferably 0.5 to 5 μm. If thickened, the blades will warp.

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited thereto.

[0023]

[Example 1 ... FRP material] (1) prepreg sheet a: carbon fiber in which the precursor of the matrix resin is "uncured epoxy resin liquid" and the fibers are aligned in one direction (average diameter 6 to A prepreg sheet a which is a continuous fiber of 7 μm) was prepared. It has a resin content of about 40 to 45% by weight and a fiber basis weight of 20 g / m ² . The thickness of the sheet is 20-25 μm.

(2) Prepreg sheet b: a matrix resin precursor is an "uncured epoxy resin liquid", and carbon fibers in which the fibers are aligned in one direction (average diameter 6 to 7 .mu.m).
A prepreg sheet b which is a continuous fiber of m) was prepared. It has a resin content of about 40 to 45% by weight and a fiber basis weight of 20 g / m ² . The thickness of the sheet is 20-25 μm. Furthermore, 10% by weight of carbon black in the resin liquid
It is compounded.

(3) Prepreg sheet c: The matrix resin precursor is "uncured epoxy resin liquid", and the carbon fibers are aligned in one direction (average diameter 6 to 7 .mu.m).
The prepreg sheet c which is the continuous fiber of m) was prepared. This has a resin content of about 38% by weight and a fiber basis weight of 22.
It is g / m ² . The thickness of the sheet is 25-30 μm.

(4) Prepreg sheet d: The precursor of the matrix resin is "uncured epoxy resin liquid", and the fibers (average diameter 6 to 7 μm) are short carbon fibers having a length of 1 to 30 mm. A prepreg sheet d having one direction was prepared. This has a resin content of about 80 to 95% by weight and a fiber basis weight of 5 to 10 g / m ² . Sheet thickness is 20-30
μm.

(5) Prepreg sheet e: A prepreg sheet e was prepared in which the matrix resin precursor was "uncured epoxy resin liquid" and the fiber direction was unidirectional Kevlar fiber. The sheet e has a resin content of about 85 to 95% by weight and a fiber basis weight of 5 to 10 g / m ² . The thickness of the sheet is about 30 μm.

(6) Prepreg sheet f: a prepreg sheet f which is a continuous fiber of ultrahigh molecular weight polyethylene fibers in which the matrix resin precursor is "uncured epoxy resin liquid" and the fibers are aligned in one direction. Prepared. The sheet f has a resin content of about 50% by weight and a fiber basis weight of 20 g /
m ² . The thickness of the sheet is 20-30 μm.

(7) Prepreg sheet g: A prepreg sheet g was prepared in which the precursor of the matrix resin was "uncured epoxy resin liquid" and the fiber direction was unidirectional ultrahigh molecular weight polyethylene fiber. The sheet g has a resin content of about 85 to 95% by weight and a fiber basis weight of 5 to 10 g / m ² . The thickness of the sheet is 20-30 μm.

(8) FRP material A having a thickness of 70 μm: Two sheets a and one sheet b were prepared, and the fiber directions were 0 ° surface layer / 90 ° intermediate layer / 0 ° surface layer, and So that the type of the sheet is surface material layer a / intermediate layer b / surface material layer a,
The above 3 sheets are laminated in plane symmetry, and 5 to 15 at a temperature of 130 ° C
FRP material A was obtained by applying a pressure of kg / cm ² and curing for 1 to 2 hours, and then slowly cooling it under pressure. Material A
Is a rectangle measuring 80 mm in length and 400 mm in width.

(9) 90 μm thick FRP material B: Two sheets a and two sheets b were prepared, and the fiber directions were as follows: surface material layer 0 ° / intermediate layer 90 ° / intermediate layer 90 ° / surface material layer 0 °. And the type of sheet is as follows: surface material layer a / intermediate layer b / intermediate layer b
/ The above four sheets are laminated plane-symmetrically so as to be the surface material layer a,
Apply a pressure of 5 to 15 kg / cm ² at a temperature of 130 ° C,
Cure in 2 hours, then slowly cool under pressure to FRP
Material B was obtained. Material B is a rectangle measuring 80 mm in length and 400 mm in width.

(10) FRP material C (short fibers) having a thickness of 70 μm: An FRP material was manufactured in the same manner as in the above (8) except that the sheet used for the intermediate layer was replaced by the sheet d. (11) FRP material D (short fibers) having a thickness of 90 μm: An FRP material was produced in the same manner as in (9) above except that the sheet used for the intermediate layer was replaced by the sheet d.

(12) FRP material E (polyethylene continuous fiber) having a thickness of 70 μm: An FRP material was produced in the same manner as in the above item (8) except that the sheet used for the intermediate layer was replaced by the sheet f. (13) FRP material F (polyethylene continuous fiber) having a thickness of 90 μm: An FRP material was produced in the same manner as in the above item (9) except that the sheet used for the intermediate layer was replaced with the sheet f.

(14) FRP material G (polyethylene short fiber) having a thickness of 70 μm: An FRP material was produced in the same manner as in the above item (8) except that the sheet used for the intermediate layer was replaced by the sheet g. (15) FRP material H (polyethylene short fiber) having a thickness of 90 μm: An FRP material was produced in the same manner as in the above item (9) except that the sheet used for the intermediate layer was replaced by the sheet g.

(16) FRP material I (continuous fiber) having a thickness of 70 μm: In the same manner as in (8) above except that the sheet used as the surface material layer is replaced by the sheet b and the sheet used as the intermediate layer is replaced by the sheet c. Manufactured FRP material. (17) FRP material J (continuous fiber) having a thickness of 90 μm: FR except that the sheet used for the surface material layer is replaced by the sheet b and the sheet used for the intermediate layer is replaced by the sheet c.
P material was manufactured.

(18) FRP material K (Kevlar short fibers) having a thickness of 70 μm: An FRP material was manufactured in the same manner as in the above item (8) except that the sheet used for the intermediate layer was replaced by the sheet e. (19) FRP material L (Kevlar short fiber) with a thickness of 90 μm:
An FRP material was manufactured in the same manner as in the above item (9) except that the sheet e used as the intermediate layer was replaced with the sheet e.

[0037]

[Embodiment 2 ... Four-blade light-shielding blades (for front curtain)] (1) From the FRP material A having a thickness of 70 μm, the first blade to the fourth blade (see FIG. 1) for the front curtain are pressed. Punched by. At this time, the punching was performed so that the longitudinal direction of the blade and the longitudinal direction of the carbon fiber of the surface material layer were parallel to each other. In the case of "punching" in the following examples, punching is also performed. Next, the punched blades were subjected to dry lube coating on both front and back surfaces with a film thickness of 4 μm on each side. After this, the warped wings were discarded. Based on the prepreg sheet, the non-defective rate was 20 to 50%.

(2) From the FRP material B having a thickness of 90 μm, the first blade to the fourth blade (see FIG. 1) for the front curtain were punched out.
After that, the same treatment as in the above item (1) was performed. Non-defective rate is 60 to 90
%Met.

[0039]

[Embodiment 3 ... Four-bladed light-shielding blade (for rear curtain)] (1) From FRP material A having a thickness of 70 μm, as in (1) of Example 2, first blade for rear curtain- The fourth blade (see FIG. 2) was punched out and painted. The non-defective rate was 20 to 50%. (2) From FRP material B having a thickness of 90 μm, the first blade to the fourth blade (see FIG. 2) for the trailing blade were punched out and coated in the same manner as in (2) of Example 2. The non-defective rate was 60 to 90%.

[0040]

[Embodiment 4 ... four-element light-shielding blade (for front curtain)] (1) Instead of the FRP material A having a thickness of 70 μm, FRP materials C, E, G, I, and K are used. Similar to (1) of No. 2, blades 1 to 4 for the front curtain were manufactured. (2) Instead of the FRP material B having a thickness of 90 μm, FRP materials D, F, H, J, and L were used, and the first blade to the fourth blade for the front curtain were used as in (2) of Example 2. Was produced.

[0041]

[Embodiment 5 ... Four-element light-shielding blade (for rear curtain)] (1) Instead of the FRP material A having a thickness of 70 μm, FRP materials C, E, G, and K are used, Similar to (1), No. 1 to No. 4 blades for the rear curtain were manufactured. (2) Instead of the FRP material B having a thickness of 90 μm, the FRP materials D, F, H, and L were used, and the first blade to the fourth blade for the rear curtain were used in the same manner as in (2) of Example 3. I made it.

[0042]

[Example 6 ... Five-blocked light-shielding blade (for front curtain)] (1) First blade to fifth blade for front curtain (not shown) were punched out from FRP material A having a thickness of 70 μm. After that, the same treatment as in (1) of Example 2 was performed. (2) From FRP material B having a thickness of 90 μm, blades 1 to 5 for the front curtain (not shown) were punched out. After that, the same treatment as in (1) of Example 2 was performed.

[0043]

[Embodiment 7 ... 5-shield blade (for rear curtain)] (1) From FRP material A having a thickness of 70 μm, blades 1 to 5 for rear curtain (not shown) were punched out. After that, the same treatment as in (1) of Example 2 was performed. (2) From FRP material B having a thickness of 90 μm, the first blade to the fifth blade for the trailing curtain (not shown) were punched out. After that, the same treatment as in (1) of Example 2 was performed.

[0044]

[Embodiment 8: 4-sheet shutter] [Shutter Configuration] FIGS. 3 to 5 are front views of a four-plane focal plane shutter according to the present embodiment. The shutter is roughly divided into a front curtain 10, a rear curtain 20, a shutter substrate 30, and a drive mechanism (not shown) for driving these curtains. The front curtain 10 is composed of four divided blades, and the divided blade is the first blade 1 counting from the largest moving amount.
The blades are numbered 1st, 2nd blade 12, 3rd blade 13 and 4th blade 14. The trailing blade 20 is also composed of four divided blades, and the divided blades are numbered in descending order of the amount of movement and are named first blade 21, second blade 22, third blade 23, and fourth blade 24.

The shutter comprises two arms 15 for the front curtain.
16 is also included, and these arms 15 and 16 are rotatably connected to the axes X ₁ and X ₂ that are implanted in the shutter substrate 30. The split blades 11 to 14 are rotatably connected to the arms 15 and 16 by caulking pins 17 _{1 to} 17 ₄ and 18 ₁ to 18 ₄ , respectively. A drive shaft 31 is attached to the hole 16a of the arm 16, and the front curtain 10 can be driven by moving the shaft 31 up and down by a drive mechanism.

The shutter also includes two arms 25, 26 for the rear curtain.
Are rotatably connected to axes X ₃ and X ₄ planted on the shutter substrate 30. Then, the divided blades 21 to 24
Are caulking pins 27 _{1 to} 27 ₄ and 28 ₁ to 2 respectively.
It is rotatably connected to the arm 25, 26 by 8 _4. A drive shaft 32 is attached to the hole 26a of the arm 26, and the front curtain 10 can be driven by moving the shaft 32 up and down by a drive mechanism.

The arms 15, 16, 25, 26, the axes X ₁ , X ₂ , the axes X ₃ , X ₄ , the crimp pins 17 ₁ to _{1 are} attached.
7 ₄ , 18 ₁ to 18 ₄ , 27 _{1 to} 27 ₄ , 28 _{1 to} 28
₄ , the drive shafts 31, 32, etc. form part of a drive mechanism in a broad sense. In this embodiment, as the divided blades of the front curtain and the rear curtain,
The blades produced in Examples 2 and 3 were selected and used as shown in Table 1 below. Table 1 shows the selected blade thickness.

[0048]

[Table 1]

[Description of Shutter Operation] Next, the operation of the shutter of this embodiment will be described. FIG. 3 is a diagram showing a state in which the front curtain 10 is expanded and the exposure window (aperture) 30a is closed. That is, the divided blades 11 to 14 are respectively expanded to close the exposure window 30a, and the divided blades forming the rear curtain 20 are retracted upward from the exposure window 30a and folded.

When the driving force from the driving mechanism is transmitted to the driving shaft 31 attached to the arm 16, the arm 16 is driven.
Rotates about the axis X ₂ in the clockwise direction in FIG. As a result, the front curtain 10 starts to open and exposure is started. After a predetermined time, the driving force from the driving mechanism is applied to the arm 26.
When transmitted to the drive shaft 32 attached to the arm 26, the arm 26 rotates about the axis X ₄ in the clockwise direction in FIG. As a result, the rear curtain 20 follows the front curtain 10, and exposure is performed while forming a slit having a predetermined width between the divided blades 11 and 21. That is, the opened front curtain 10 is closed and the closed rear curtain 20 is expanded. At the end of the exposure, the rear curtain 20 is expanded and the exposure window 3 is opened as shown in FIG.
0a is closed, and the front curtain 10 is retracted in a state of being overlapped below the exposure window 30a.

In FIG. 4, the front curtain 10 and the rear curtain 20 are the exposure window 3.
It is a diagram showing a state in which both are retracted from 0a, and the shutter speed is in the state of the valve (B).

[0052]

[Embodiment 9: Shutter of four-element structure] The shutter of this embodiment is the same as the shutter of Embodiment 8, except that the divided blades of the front and rear curtains are manufactured in Embodiments 2 and 3. The selected blades were used as shown in Table 2 below. Table 2 shows the selected blade thickness.

[0053]

[Table 2]

[0054]

[Embodiment 10 ... Shutter of four-element structure] The shutter of this embodiment is the same as the shutter of Embodiment 8, except that the divided blades of the front and rear curtains are manufactured in Embodiments 2 and 3. The blades were selected and used as shown in Table 3 below. Table 3 shows the thickness of the selected blades.

[0055]

[Table 3]

[0056]

[Embodiment 11: Shutter of four-element structure] The shutter of this embodiment is the same as the shutter of Embodiments 8 to 10, except that the divided blades have the same thickness manufactured in Embodiments 4 and 5. Various blades of Sano were used.

[0057]

[Embodiment 12 ... Shutter of five-sheet structure] The shutter of this embodiment is the same as the shutter of the eighth embodiment, except that the front curtain and the rear curtain are each composed of five divided blades. For each blade, the blades produced in Examples 2 and 3 were selected and used as shown in Table 4 below. Table 4 shows the selected blade thickness.

[0058]

[Table 4]

[0059]

[Embodiment 13: 5-sheet shutter] The shutter of this embodiment is the same as the shutter of embodiment 12, except that the divided blades of the front curtain and the rear curtain are manufactured in the second and third embodiments. The selected blades were used as shown in Table 5 below. Table 5 shows the thickness of the selected blades.

[0060]

[Table 5]

[0061]

[Embodiment 14: 5-sheet shutter] The shutter of the present embodiment is the same as the shutter of the embodiment 12, except that the divided blades of the front and rear curtains are manufactured in the embodiments 2 and 3. The blades were selected and used as shown in Table 6 below. Table 6 shows the selected blade thickness.

[0062]

[Table 6]

[0063]

[Comparative Example 1 ... Shutter of four-sheet structure] The shutter of this example is the same as the shutter of Example 8, except that the divided blades of the front and rear curtains are the same as those of Examples 2 and 3. The manufactured blade was selected and used. Table 7 shows the thickness of the selected blades.

[0064]

[Table 7]

[Test Example] Two sets of shutters of Example 8 and Comparative Example 1 were prepared and subjected to a durability test. The first blade
The time to go up and down the angle of view of 24 mm is called the running speed. In the durability test, the first set had a running speed of 2.2 msec and the second set had a running speed of 2.9 msec. A traveling speed of 2.9 msec corresponds to a shutter speed of 1/8000 second, and a traveling speed of 2.2 msec corresponds to 1/1200 second. The endurance test continuously raises and lowers the angle of view for both the leading and trailing curtains.

The results of this test are shown in Table 8.

[0067]

[Table 8]

[0068]

As described above, according to the present invention, the first blade is made of "FRP having a plate thickness of 65 to 80 µm, which is light but has a very low yield rate, which increases cost."
The last blade (4th or 5th blade) has a high quality rate,
Therefore, by using an inexpensive FRP with a plate thickness of 90 to 110 μm, a shutter speed exceeding 1/8000 second can be realized, and a shutter can be manufactured at a commercially available cost. Since the final blade has a small amount of movement, it may be thick and therefore heavy.

All the blades are made of F having a plate thickness of 90 to 110 μm.
In the conventional shutter composed of RP, the blade chamber for accommodating the blades must be made thick when retracted. Therefore, there is a drawback that miniaturization of the camera is hindered. Moreover, since the charge energy increases, it is necessary to increase the number of batteries. Further, since the total weight of the blades becomes too heavy, the impact at the end of traveling of the blades becomes too large, which deteriorates the durability performance. However, with the shutter of the present invention, such drawbacks are alleviated.

[Brief description of drawings]

FIG. 1 is an exploded view showing divided blades of a front curtain of a focal plane shutter according to the present invention.

FIG. 2 is an exploded view showing the divided blades of the rear curtain of the focal plane shutter according to the present invention.

FIG. 3 is a front view showing a state where the front curtain of the focal plane shutter according to the present invention is expanded to cover the exposure window.

FIG. 4 is a front view showing a state where the front curtain of the focal plane shutter according to the present invention is retracted and the exposure window is fully opened.

FIG. 5 is a front view showing a state where the rear curtain of the focal plane shutter according to the present invention is expanded to cover the exposure window.

FIG. 6 is a schematic cross-sectional view of FRP material I of Example 1.

FIG. 7 is a schematic cross-sectional view of FRP material A of Example 1.

[Explanation of symbols]

1 ... Carbon fiber 2 ... Matrix resin 3 ... Surface material layer 4 ... Carbon black 5 ... Carbon fiber 6 ... Matrix resin 7 ... Intermediate layer 10 ... Front curtain 11・ ・ ・ 1st blade for front curtain 12 ・ ・ ・ 2nd blade for front curtain 13 ・ ・ ・ 3rd blade for front curtain 14 ・ ・ ・ 4th blade for front curtain 15, 16 ・ ・ ・ Arm for front curtain 17 _{1 to} 17 ₄・ ・ ・ Crimping pin (for first curtain) 18 ₁ to 18 ₄・ ・ ・ Crimping pin (for first curtain) 20 ・ ・ ・ Rear curtain 21 ・ ・ ・ Rear curtain first blade 22 ・ ・ ・ Rear curtain 2nd blade 23 ・ ・ ・ 2nd blade for rear curtain 24 ・ ・ ・ 4th blade for rear curtain 25,26 ・ ・ ・ Arm for rear curtain 26a ・ ・ ・ ・ Arm hole 27 _{1 to} 27 ₄・ ・ ・ Crimping pin (post for curtain) 28 _{1-28 4} ... caulking pin (for the rear curtain) 30 ... shutter plate 30a · · exposing window 31, 32 ... drive shaft X ₁ to X ₄ ... shaft

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[Procedure amendment]

[Submission date] August 10, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

[0027] (5) prepreg sheets e: precursor of the matrix resin is "uncured epoxy resin solution", fiber
A prepreg sheet e was prepared in which the fibers were short fibers having a length of 1 to 30 mm and the fiber direction was unidirectional. The sheet e has a resin content of about 85 to 95% by weight and a fiber basis weight of 5 to 10 g / m ² . The thickness of the sheet is about 30 μm
Is.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

[0029] (7) prepreg sheet g: precursor of the matrix resin is "uncured epoxy resin solution", fiber
A prepreg sheet g was prepared in which the fibers were short fibers having a length of 1 to 30 mm and the fiber direction was unidirectional ultrahigh molecular weight polyethylene fibers. The sheet g has a resin content of about 85 to 95% by weight and a fiber basis weight of 5 to 10 g / m ² . The thickness of the sheet is 20-30 μm.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0065

[Correction method] Change

[Correction content]

[Test Example] Two sets of shutters of Example 8 and Comparative Example 1 were prepared and subjected to a durability test. The first blade
The time to go up and down the angle of view of 24 mm is called the running speed. In the durability test, the first set had a running speed of 2.2 msec and the second set had a running speed of 2.9 msec. Running speed 2.9msec corresponds to one second of the shutter speed 8000 min, the running speed 2.2msec corresponds to one second of 12000 minutes. The endurance test continuously raises and lowers the angle of view for both the leading and trailing curtains.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masayuki Kinmuro 1-6-3 Nishioi, Shinagawa-ku, Tokyo Nikon Oi Manufacturing Co., Ltd.

Claims (7)

[Claims] 1. A camera shutter comprising four divided blades and a drive mechanism for driving the divided blades. Among the blades, the first to third blades counted from the largest moving amount have a thickness of 65 to 80 μm. The shutter is characterized in that it is composed of the fiber-reinforced plastic plate of, and the remaining blades are composed of the fiber-reinforced plastic plate with a thickness of 90 to 110 μm. 2. A camera shutter comprising four divided blades and a drive mechanism for driving the divided blades. Among the blades, the first to second blades counted from the largest moving amount have a thickness of 65 to 80 μm. The shutter is characterized in that it is composed of the fiber-reinforced plastic plate of, and the remaining blades are composed of the fiber-reinforced plastic plate with a thickness of 90 to 110 μm. 3. A camera shutter comprising four divided blades and a drive mechanism for driving the divided blades. Among the blades, the first blade counted from the largest moving amount is the fiber reinforced having a thickness of 65 to 80 μm. A shutter comprising a plastic plate, and the rest made of a fiber-reinforced plastic plate having a thickness of 90 to 110 μm. 4. A shutter for a camera comprising five divided blades and a drive mechanism for driving the divided blades. Among the blades, the first to fourth blades counted from the largest moving amount have a thickness of 65 to 65. A shutter characterized by being composed of a fiber-reinforced plastic plate having a thickness of 80 μm and the rest being composed of a fiber-reinforced plastic plate having a thickness of 90 to 110 μm. 5. A camera shutter comprising five divided blades and a drive mechanism for driving the divided blades. Among the blades, the first to third blades counted from the largest moving amount have a thickness of 65 to A shutter characterized by being composed of a fiber-reinforced plastic plate having a thickness of 80 μm and the rest being composed of a fiber-reinforced plastic plate having a thickness of 90 to 110 μm. 6. A camera shutter comprising five divided blades and a drive mechanism for driving the divided blades. Among the blades, the first to second blades counted from the largest moving amount have a thickness of 65 to 65. A shutter characterized by being composed of a fiber-reinforced plastic plate having a thickness of 80 μm and the rest being composed of a fiber-reinforced plastic plate having a thickness of 90 to 110 μm. 7. The shutter for a camera according to claim 1, wherein the fiber-reinforced plastic plate is a fiber selected from carbon fiber, aromatic polyamide fiber or ultra high molecular weight polyethylene, and a matrix resin containing the fiber. A shutter comprising: