JP2003202612A - Filter for quantity-of-light adjustment and quantity-of- light adjusting device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter for quantity-of-light adjustment having high dimensional accuracy of respective quantity-of-light adjustment regions and high performance in spite of the filter which is free of the degradation in optical performance by cracking, peeling, etc., of vapor-posited films and has a plurality of quantity-of-light adjustment regions. <P>SOLUTION: The filter is formed with the vapor-deposited films away from the segments constituting the outer peripheral ends of the filter of a transparent plastic sheet and therefore the cracking and peeling areas of the vapor-deposited films in subsequent cutting and fabricating can be decreased. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light amount adjusting filter and a light amount adjusting device used in a digital still camera, a video camera and the like, and a manufacturing method of the filter.

[0002]

2. Description of the Related Art Conventionally, in a light quantity adjusting device used in a digital still camera, a video camera or the like, in order to adjust the light quantity, a light quantity adjusting blade advances and retreats to face a light receiving opening to form a diaphragm opening, and at the same time, adjust the light quantity. In order to prevent problems such as hunting when the blade has a small aperture and reduction of resolution due to optical diffraction phenomenon, a light amount adjusting filter, for example, an ND filter (Neutral Density) is used.
It is well known that the filter is disposed so as to face the aperture opening.

This light quantity adjusting filter is made by mixing an organic dye or pigment into a plastic material to give it optical filter characteristics, forming it into a sheet shape, and then pressing it into the required filter shape. There is a method in which a vapor-deposited film is formed on the surface of a plastic sheet material, the vapor-deposited film is provided with optical filter characteristics, and then the filter is formed into a required filter shape by press working.

This latter filter has the effect of reducing the ghost in the lens optical system because the surface of the filter has an effect of preventing the surface reflection of light due to the combination of the vapor-deposited film layer due to its use and the structure of the vapor-deposited film. It has been used widely in recent years due to some advantages of optical characteristics such as the ability to make a plurality of light amount adjusting regions.

In the filter having the vapor deposition film formed thereon, conventionally, a transparent plastic sheet material is cut into a predetermined size, and thereafter, the vapor deposition film is formed by arranging them side by side in a vapor deposition tank of a vapor deposition apparatus. After that, it is taken out of the vapor deposition tank and the outer shape is cut into a filter shape using a pressing device or the like to manufacture it.

The reason for performing vapor deposition with the plastic sheet material of the predetermined size is that the vapor deposition is performed in such a manner that a vapor deposition film having a uniform film thickness can be formed on the entire surface of the material in the vapor deposition tank. If it is too small, or if it is too small, many plastic sheet materials must be lined up in the vapor deposition tank, which is troublesome and costly, and flexible. In order to fix the thin plastic sheet materials side by side, it is necessary to press and fix a certain area of the outer peripheral edge of the material with a pressing jig, etc. This is because the ratio of the area that can be used as a product decreases and the cost increases.

Further, in general, a dielectric film or a metal film is selected in order to obtain an optical filter characteristic by a vapor deposition film. For example, in an ND filter, in many cases, a metal film is selected as the light absorption layer and a dielectric film is selected to prevent reflection. This is because the reflectance increases with only the metal film, which causes ghost in the lens optical system as described above.

[0008]

However, the following problems have arisen here.

Since the dielectric film for preventing reflection is a hard and brittle material, when the transparent plastic sheet material on which the vapor deposition film is formed is cut into a filter shape by a press machine or the like, the cutting is performed. The surface will crack. Although a metal film is more ductile than a dielectric film, it is more likely to crack.

This crack causes diffuse reflection of light, causes flare in the lens optical system, and causes a reduction in optical resolution.

As shown in FIG. 4, the cross section at the time of cutting is deformed in the thickness direction when the transparent plastic sheet material 1 is pressed by the upper die 2 of the press die and cut.
The vapor-deposited film 3 formed on the surface is peeled off from the transparent plastic sheet material 1.

If the vapor-deposited film is cracked and then peeled off, the vapor-deposited film itself will fall off in the form of small pieces, which will cause dust in the lens optical system and not only cause optical problems. The dust may adversely affect the movable part such as the guide shaft of the movable lens.

Therefore, conventionally, an inspection process for cracks and peeling at the time of finishing the outer shape press working is indispensable,
This additional inspection process and poor yield have made it expensive. Further, this inspection process alone is not sufficient to prevent the removal of small pieces of the deposited film in the lens optical system afterward.

Further, in the above manufacturing method, as shown in FIG. 5, for example, the ND filter 8 having a plurality of light quantity adjusting regions.
In the case of making 9, the size b of each light quantity adjusting region of the ND filter, which is formed in the process of forming the vapor deposition film, is determined by the vapor deposition process, but the size a and the size c of the light amount adjusting regions A and C are determined later. Will be decided by the cutting process.

Positioning guide holes 102 during cutting
Transparent plastic sheet material 1
Is a material that is easily deformed, the guide hole 102 that was once used as a positioning reference in the vapor deposition process is easily deformed, and even if the guide hole 102 of this reference is used again during cutting, the cutting position accuracy is poor, and the dimension a And the accuracy of the dimension c was inferior.

Therefore, the present invention relates to a light quantity adjusting filter in which a vapor deposition film is formed on a transparent plastic sheet,
It is intended to provide a high-performance light quantity adjusting filter having a high dimensional accuracy of each light quantity adjusting area even if it is a filter having a plurality of light quantity adjusting areas without deterioration of optical performance due to cracking or peeling of a vapor deposition film.

[0017]

SUMMARY OF THE INVENTION The present invention relates to a light amount adjusting filter in which a vapor deposition film having a predetermined transmittance is formed on the surface of a plastic sheet for adjusting the light amount facing a diaphragm opening of a light amount adjusting device. Is a light quantity adjusting filter which is formed at least at a part of the outer periphery of the plastic sheet and is retracted from the outer peripheral end portion. And
The retracted portion is a light amount adjusting filter which is a portion facing the aperture opening, and the light amount adjusting filter is a light amount adjusting filter having a plurality of light amount adjusting regions in a plurality of ranges. .

Further, in the method for manufacturing the light quantity adjusting filter, a step of forming the vapor deposition film excluding at least a part of a portion which becomes an outer shape portion of the filter, and a step of cutting the outer shape portion of the filter thereafter And a method for manufacturing a light quantity adjustment filter.

By using the manufacturing method as described above, it is possible to reduce the number of sites where cracks and peeling of the vapor deposition film occur.

Further, even in the case of a filter having a plurality of light amount adjusting regions, if each light amount adjusting region is determined in the vapor deposition film forming step, a light amount adjusting filter having high dimensional accuracy of each light amount adjusting region can be obtained. be able to.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are exploded perspective views of a light amount adjusting device for a camera according to an embodiment of the present invention.

As shown in FIG. 1, the light quantity adjusting device E comprises a blade drive unit 10 and a diaphragm unit 50 which is driven to open and close by the blade drive unit 10.

As shown in FIG. 2, the diaphragm unit 50 is a blade drive unit 10.
A base plate 51 for attaching the first light amount adjusting blade E1 and
A second light amount adjusting blade E2 and a pressing plate 70 that covers one surface of the base plate 51 and sandwiches the light amount adjusting blades E1 and E2 between the base plate 51 and the light amount adjusting blade E1.
An operating lever 90 that engages with E2 and transmits the driving force of the blade drive unit 10 and an urging spring 95 that constantly biases the operating lever 90 in one direction are provided.

As shown in FIG. 1, the main plate 51 has a light receiving opening 52.
And a mounting portion 53 of the blade drive unit 10 and some engagement protrusions 55a, 55b formed on the mounting portion 53,
56a and 56b, fitting ribs 57a and 57b, a small hole 54 for penetrating the drive shaft, and locking projections 58a and 58b for holding the lead wire printed board 38 are provided. The light receiving opening 52 has an ND filter 8 to be described later.
An escape portion 52N is formed so as not to hinder the movement of 9.

Further, on the base plate 51, light quantity adjusting blades E1 and E2 are provided.
So that they can move without sliding contact with each other.
Engagement pins 59a and 59b slidably engaged with 1 and E2, and projections 61a to 61h for floating the blades E1 and E2 are provided.

The actuating lever 90 is provided with a hole 91 into which the drive shaft of the blade drive unit 10 is fitted, and pin portions 92a and 92b which engage with the light amount adjusting blades E1 and E2.

The light quantity adjusting blade E1 is made of PE colored in black.
A diaphragm opening forming portion 80 for restricting the amount of light and a pin portion 92 are formed of a thin piece of T or PEN or the like, as shown in FIG.
A small hole 82 for fitting with b and an elongated hole 83 for fitting with the engaging pin 59b are provided.

On the other hand, the light quantity adjusting blade E2 is also made of a thin piece of PET or PEN colored in black, and has a diaphragm opening forming portion 85 for regulating the light quantity, and a small hole 87 that fits into the pin portion 92a. Long hole 88 that engages with the engagement pin 59a
And are provided. The blade opening forming portion 85 forms a diaphragm opening together with the blade opening forming portion 80 of the blade E1.

As shown in FIG. 8, at the deepest part of the aperture opening forming portion 80 of the blade E1, a plastic light amount adjusting filter member such as an ND filter (Neutr) is provided.
Al Density Filter) 89 is adhesive 11
It is pasted by 0.

The ND filter has a vapor-deposited film formed on the surface of a transparent plastic sheet material, and the vapor-deposited film has optical filter characteristics. The manufacturing method will be described below.

As shown in FIG. 6, the transparent plastic sheet material 1 is cut into a predetermined size. In this embodiment, it is cut in a shape close to a square.

The transparent plastic sheet material 1 has positioning holes 102 provided in the vicinity of the diagonal, and the positioning holes 102 are inserted into the guide pins 104 provided on the substrate 103 and placed on the substrate 103. Then, in order to press the transparent plastic sheet material 1, the mask plate 105 is inserted with the positioning holes 106 aligned with the guide pins 104. The mask plate 105 is provided with a mask opening 107 so that a portion for forming a vapor deposition film is exposed when the transparent plastic sheet material 1 is superposed.

Next, the substrate 103, the transparent plastic sheet material 1 and the mask plate 105 are placed in a stacked state in a vapor deposition tank of a vapor deposition apparatus for forming a vapor deposition film.

The transparent plastic sheet material has a predetermined size. The reason for performing vapor deposition in the predetermined size is that the vapor deposition film is arranged in a vapor deposition tank so that a vapor deposition film having a uniform film thickness can be formed on the entire surface of the material, so that the vapor deposition film must have a certain size or less. If not, or if it is too small, many plastic sheet materials must be lined up in the vapor deposition tank, which is time consuming and costly, and is a flexible and thin plastic sheet material. In order to fix them side by side, it is necessary to press and fix a certain area of the outer peripheral edge of the material with a pressing jig, etc.Therefore, a vapor deposition film is not formed on the outer peripheral edge surface, and the ratio of the area that can be used as a filter is This is because it will decrease and the cost will increase.

In the vapor deposition tank, a vapor deposition film is formed on the surface of the transparent plastic sheet material 1 exposed at the mask opening 107. Then, after the vapor deposition film is formed, the above vapor deposition process is repeated by using the mask plate in which the size and the position of the mask opening are different, so that a filter having a plurality of light amount adjustment regions can be produced.

Then, as shown in FIG. 7, the transparent plastic sheet material 1 on which the vapor deposition film is formed is taken out from the vapor deposition tank after all the vapor deposition film forming steps are completed, and the ND filter 89 is used.
The portion that becomes the outer shape is cut and processed by a press device or the like. At this time, the vapor deposition film is formed so that the portion where the vapor deposition film is formed is retracted from the outer shape portion.

Since the ND filter 89 is manufactured as described above, when the transparent plastic sheet material on which the vapor deposition film is formed is cut into a filter shape by a press machine or the like, vapor deposition is performed from the cut surface. It is possible to prevent the film from cracking or to be generated, and by increasing the retreat distance at the time of cutting processing, the deposited film formed on the surface of the transparent plastic sheet material peels off from the transparent plastic sheet material. It is possible to prevent it.

In the ND filter 89, since a plurality of light amount adjustment regions are determined only by the vapor deposition film forming step, it is possible to obtain a light amount adjustment filter with high dimensional accuracy of each vapor deposition region.

Next, the pressing plate 70 is provided with a light receiving opening 71,
Slots 72a and 72b formed so that the pin portions 92a and 92b of the actuating lever 90 can rotate, coupling portions 74a and 74b that couple with the main plate 51, and engagement pins 59a and 59b.
Are provided with holes 75a and 75b, and projections 62a to 62d for floating the light amount adjusting blades E1 and E2.

It should be noted that the light receiving opening 71 has a light quantity adjusting blade E2.
ND filter 8 when attached to ND filter 89
An escape portion 71N is formed so as not to hinder the movement of 9.

Next, the structure of the blade drive unit 10 will be described. As shown in FIG. 3, the blade drive unit 10 includes a permanent magnet body 11 that is rotatably supported in the center as shown in FIG. 1, a coupling side bobbin 14 and a pin side bobbin 25 that surround the permanent magnet body 11. A driving coil 130A and a braking coil 130B wound around both bobbins 14 and 25, and a hollow cylindrical magnetic circuit member (yoke) fitted to the outer circumferences of both bobbins 14 and 25 to guide the magnetism of the permanent magnet body 11. 35, an end plate 36 that presses the end of the magnetic circuit member 35, and a magnetic sensor 37 that detects the rotational angle position of the permanent magnet body 11.
And a conductor printed board 38 connected to the coils 130A and 130B. The permanent magnet body 11 is composed of a cylindrical magnet 12 and a drive shaft 13 fixed through the cylindrical center of the magnet 12, and is rotatably supported inside a bobbin 14 and a bobbin 25. There is.

Above the bobbin 25, coils 130A, 1
Terminal pins 29a, 29b, 29 for winding the wire end of 30B
c and 29d are provided. And the magnetic circuit member 35
The end plates 36, and then the terminal pins 29a, 29 are inserted into the four small holes formed in the printed wiring board 38.
Place while passing b, 29c, 29d. Finally, by assembling the terminal pins 29a, 29b, 29c, 29d and the printed wiring board 38 with solder or the like, the assembly of the blade drive unit 10 is completed.

In the light quantity adjusting device constructed as described above, as shown in FIG.
The outer peripheral part of the ND filter formed more retracted,
The opening forming portion 80 of the light amount adjusting blade E1 of the light amount adjusting device
Since it is a portion facing the opening side, the occurrence of cracks in the vapor deposition film at this portion is eliminated, and the problem that flare occurs in the lens optical system due to irregular reflection of light due to cracks is solved.

Further, since the vapor-deposited film is free from cracks and peeling, the inspection process for this and the poor yield are solved, and the vapor-deposited film itself is subject to vibrations or impacts in a later use environment. It is also possible to reduce the possibility that the small pieces will fall off and become dust in the lens optical system.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing the overall structure of a diaphragm device for a camera according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the diaphragm unit of FIG.

FIG. 3 is an exploded perspective view showing the structure of the blade drive unit in FIG.

FIG. 4 is a partial cross-sectional view in which a transparent plastic sheet material on which a vapor deposition film is formed is cut and processed by a conventional technique.

FIG. 5 is an explanatory diagram of dimensional accuracy of each light amount adjustment region of an ND filter having a plurality of light amount adjustment regions according to a conventional technique.

FIG. 6 is an explanatory view of a method of fixing a transparent plastic sheet material when forming a vapor deposition film.

FIG. 7 is an explanatory view of cutting an ND filter from a transparent plastic sheet material on which a vapor deposition film is formed.

FIG. 8 is an example in which an ND filter is attached to a light amount adjusting blade.

[Explanation of symbols] 1 Transparent plastic sheet material 2 Upper mold 3 evaporated film 4 Lower mold 10 Blade drive 52 Light receiving aperture 80 Opening part 89 ND filter 100 connection 101 notch 102 Positioning hole 103 substrate 104 guide pin 105 mask plate 106 Positioning hole 107 mask opening 108 Notch 109 convex 110 adhesive E1 Light intensity adjustment blade

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H042 AA08 AA13 AA22                 2H080 AA10 AA31 DD01                 2H083 AA01

Claims (5)

[Claims] 1. A light quantity adjusting filter having a vapor deposition film having a predetermined transmittance formed on the surface of a plastic sheet for adjusting the light quantity facing the aperture opening of the light quantity adjusting device,
The light quantity adjusting filter, wherein the vapor deposition film is formed at least at a part of the outer periphery of the plastic sheet, and is retracted from an outer peripheral end portion. 2. The light quantity adjusting filter according to claim 1, wherein the retracted portion is a portion facing the aperture opening. 3. The light quantity adjusting filter according to claim 1, wherein the filter has a plurality of transmittance regions in a plurality of ranges. 4. A light quantity adjusting device comprising the light quantity adjusting filter according to claim 1. 5. A method for manufacturing a light quantity adjusting filter, comprising: forming a vapor deposition film having a predetermined transmittance on a surface of a plastic sheet that adjusts the light quantity by facing a diaphragm opening of a light quantity adjusting device; Manufacture of a light quantity adjusting filter, which comprises a step of forming at least a part of an outer shape part of the adjusting filter, and a step of cutting the outer shape part of the light quantity adjusting filter thereafter. Method.