JPH04340532A - Trimming adapter for camera - Google Patents

Abstract

PURPOSE:To thin an adapter by holding the adapter at a position where the adapter is attached to a main body and a position where it is detached by click force. CONSTITUTION:Holes 11a and 12a to hook a holder dwels are provided by two on the lock members 11 and 12, and holes 11b and 12b for sliding and projections 11c and 12c for clicking are provided by two on the members 11 and 12, respectively, then the lock members 11 and 12 can slide only by as much as the looseplay of a shaft 10 in the holes 11b and 12b. Namely, mechanisms for generating the click force are provided at the position where the adpater is attached to the main body and the position where it is detached in the actuating direction of the members 11 and 12. In such a case, the thickness of the adapter is made thin by positioning the adapter at each position by the click force. By energizing the dowels of a adapter holder 15 in a direction where the gap between them is narrowed by force stronger than the click force, the adpater is held by the holder 15 in a state where the finger force of an operator is lost, so that an accident that the adpater drops from the holder 15 carelessly is prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trimming adapter that partially covers the exposure aperture of a camera, thereby making the exposed area on the film smaller than the original format.

0002

2. Description of the Related Art Conventionally, there are two general screen sizes for still cameras: a full size, 36 mm x 24 mm, and a so-called half size, 24 mm x 18 mm. However, in recent years, a size of 36 mm x 13 mm (hereinafter abbreviated as new size) has become popular. For a camera dedicated to this new size, the exposure aperture of the camera may be formed to the above dimensions. However, the new size and full size have the same horizontal dimension of 36 mm, so the vertical dimension is 24 mm by covering the aperture of the camera with a full size aperture by 5.5 mm on the top and bottom.
If you shorten it to 13mm, you can use it as a new size camera. For this purpose, a new size adapter that can be attached to and detached from the camera's exposure opening (hereinafter simply referred to as adapter)
has already been proposed.

FIG. 5 is a schematic perspective view of one example. 10
Reference numerals 1 and 102 are masks made of thin plates with light-shielding properties, and the vertical dimension is 5.5 mm larger than the exposure aperture of the camera, as described above.
There are as many holes as necessary to cover each mm, and the lateral dimension is larger than the lateral dimension of the opening. Further, holes 101a and 102a are provided for holders to be described later. 103
, 104 is a guide member having a U-shaped cross section, and has holes 103a and 104a approximately in the center. The vertical dimension of the guide members 103 and 104 is the same as that of the masks 101 and 10.
2, and the horizontal dimension is slightly smaller than the exposure aperture of the camera.

[0004] Further, the guide members 103 and 104 are fixed to the masks 101 and 102, respectively, by adhesion, welding, or the like. Reference numerals 105 and 106 indicate locking levers having a substantially U-shape, and are slidably housed in the gaps between the guide members 103 and 104 and the masks 101 and 102.
6a are holes 103a and 10 of guide members 103 and 104.
Since it is in 4a, it will not fall off. Further, holes 105b and 106b are provided at positions corresponding to the holes 101a and 102a of the masks 101 and 102. 107,
A compression spring 108 is incorporated to bias the locking members 105 and 106 away from each other.

FIG. 6 shows a cross section of the adapter attached to the camera body. Reference numeral 1 denotes a main body having an exposure aperture 1a, with the film at the bottom and the photographic lens at the top in the figure. 109 is the aforementioned adapter holder. Inside the holder 109 are slide levers 110 and 1.
11, which are biased away from each other by a compression spring 112, and are stopped in the state shown in the figure by a stopper (not shown). Further, the slide levers 110 and 111 are fixedly provided with dowels 110a and 111a having small diameter portions near their tips. Although there is one each in the figure, there are a total of four in each of 110a and 111a, one set at the top and one at the top. The mask 101 is in close contact with the surface of the main body 1 on the film side, and the locking members 105 and 106 are moved away by the compression spring 107, and the locking members 105 and 106 are moved away from each other by a compression spring 107, and the locking members 105 and 106 are moved away from each other by the slope 16 of the main body 1 on the side opposite to the surface where the masks 101 and 102 are located. I'm running into this. Therefore, the adapter is locked to the main body by the biasing force of the compression spring 107. On the other hand, in the state shown in the figure, the dowels 110a of the slide levers 110, 111
, 111a penetrate the hole 101a of the mask 101, and further penetrate the holes 105b, 106 of the locking members 105, 106.
It is invading b.

When the slide levers 110 and 111 are moved toward each other against the compression spring 112, the dowels 110a and 1 of the slide levers 110 and 111 are moved.
The locking members 105 and 106 also connect to the compression spring 1 via 11a.
07 and move toward each other. Locking member 1
05 and 106, which were in contact with the inclined portion 1b of the main body 1, are moved until they become smaller than the exposure opening 1a, and the adapter can be removed downward in the figure. Conversely, when attaching the adapter to the camera body, just do the opposite operation.

[0007]

However, in the above conventional example, the locking members 105 and 106 are connected to the compression springs 107.
The disadvantage is that it is not possible to reduce the total thickness because it is energized by . The thickness of the main body 1 is usually about 1.2 to 1.3 mm, but the outer diameter of the compression spring to obtain sufficient operating force is 1.5 m.
It ends up being about m. Also, since the compression spring deforms in an undulating manner in the operating state, it moves upward in the figure from the main body 1 by 0.
It will protrude by about 3 to 0.5 mm.

However, in most single-lens reflex cameras, a focal plane shutter is provided above and adjacent to the main body 1. Focal plane shutters have a group of blades made up of multiple thin pieces that move at high speed.
For example, if the compression spring comes into contact with the traveling blade group, there is a risk that the shutter speed will be incorrect, or worse, the blade group will be damaged or damaged.

In addition, in the conventional example, after removing the adapter from the main body using the holder, if the operator does not always press the slide lever, the compression spring 112
There is also a drawback that the adapter may fall due to the gap between the dowels 110a and 111a.

Furthermore, conventionally, the entire adapter has been painted black. This is because if the reflection of photographing light is large, it will become stray light into the photographing screen, resulting in a decrease in image quality. However, there is a problem in that the photometry (light control) sensitivity changes when so-called film surface photometry (light control) is performed. This will be explained with reference to FIGS. 7 and 8. FIG. 7 shows a central vertical section of a general single-lens reflex camera with an adapter attached. 2 is a front plate forming a mirror box, 3 is an interchangeable lens mount, 4 is the aforementioned focal plane shutter unit, 5 is a mirror unit that reflects light to the finder system except when shooting, and the solid line is directed out of the shooting optical path when shooting. In the retracted state, the two-dot chain line indicates the state in which the light beam is reflected to the finder. Reference numeral 6 denotes a light receiving element, which faces the direction of the film 7. l1 and l2 are approximate light receiving angles of the light receiving element 6. In this figure, A is the shooting screen size with the adapter attached, which is 13 mm, and B is the normal size of 24 mm without the adapter attached.
It is. When the shutter unit 4 is opened during shooting, the light-receiving element 6 receives the shooting light reflected by the film, and when the amount of received light corresponds to the appropriate exposure amount of the shooting light on the film, it detects the strobe light. If the camera is shooting with an image, the camera is configured to stop the strobe light and start closing the shutter unit.

FIG. 8 shows the sensitivity distribution of the light-receiving element 6 with respect to the photographic screen expressed as contour lines, and it can be seen that the light part in the center has the highest sensitivity and the sensitivity decreases as the surrounding areas become darker and lighter. Recognize. Here, A and B are A and B in FIG.
Corresponds to the dimensions.

[0012] If the adapter is black, its reflectance is lower than that of the film, so that reflected light from outside the range of dimension A is reduced. Therefore, when the appropriate exposure amount is obtained within the A dimension range, the light receiving element 6 can only receive light from outside the A dimension, or an amount smaller than the amount of light received when the adapter is not attached. In other words, as a result, the area within dimension A is always slightly overexposed.

[0013]

[Means for Solving the Problems] According to the present invention, a mechanism is provided for generating a click force at a position where the adapter is attached to the main body and a position at which the adapter is detached in the operating direction of the locking member. By positioning the adapter, the thickness of the adapter can be reduced. Also,
By biasing the dowels of the adapter holder in the direction of narrowing the gap with a force stronger than the above-mentioned click force, the holder can hold the adapter with the operator's fingers relaxed. This also eliminates the accident of accidentally dropping the adapter from the holder.

Furthermore, by making the surface of the adapter on the light-receiving element 6 side closer to the reflectance of the film than the black color, the influence on photometry when the adapter is attached is reduced.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view of a first embodiment of the present invention. Masks 8 and 9 each have two holes 8a and 9a, as in the conventional example. It also has three surfaces 8b and 9c that are recessed one step toward the other side (left side) in the figure, and holes 8c and 9c at these positions, respectively. The locking members 11 and 12 have holes 1 for hanging holder dowels.
1a and 12a, two each, and slide holes 11b,
12b and click protrusions 11c and 12c. The guide members 13 and 14 each have a substantially U-shaped cross section and have holes 13a and 14a at three locations. There are six shafts 10, which pass through the masks 8, 9 and the locking members 11, 12, and are fixed to the guide members 13, 14.

Therefore, the locking members 11 and 12 are connected to the shaft 10 and the hole 1.
It becomes possible to slide only by the play (longer length) of 1b and 12b. On the other hand, the adapter holder 15 has built-in slide levers 16 and 17. The compression spring 18 is installed between the slide levers 16 and 17, and presses the slide levers 16 and 17 in the longitudinal direction. In addition, dowels 16a, 16b, 17a, 17 are attached to the slide levers 16, 17.
b is planted. In other words, slide levers 16 and 17
When you press and slide the compression spring in the direction of compressing it,
The dowels 16a, 16b and 17a, 17b will move away from each other.

Further, the masks 8 and 9 are colored black, and the guide members 13 and 14 are colored in a color (for example, gray) having a reflectance close to that of the film.

The operation of the first embodiment will be explained with reference to FIG. FIG. 2(a) shows the adapter before it is attached to the camera body 1, that is, the adapter is held by the adapter holder. FIG. 2(b) shows a state in which the adapter is attached to the camera body 1. First, in FIG. 2(a), the locking members 11 and 12 are located at the closest position to the center where they abut against the left and right dowels 10. This is the click protrusion 11c of the locking members 11 and 12.
, 12c and the shaft 10 are stably maintained, and the dowels 16a, 16b, 17a, 1 of the holder
7b is also urged toward the center by the compression spring 18, and stops against the holes 11a and 12a of the slide levers 11 and 12. Dowels 16a, 16b, 1 in the diagram
7a and 17b have a small diameter portion and a large diameter portion near the tip, so the adapter will not fall off from the holder. Furthermore, the slide levers 11 and 12 are smaller than the exposure opening 1a of the main body 1, and in this state they can be attached to the exposure opening from the back of the camera.

Here, slide levers 16, 1 of the holder
7, the dowels 16a, 16b, 17a, 17b are moved away from each other by the compression spring 18, and the slide levers 11, 12 are moved away from each other against the click force. Dowels 16a, 16b, 17a, 17
b is fixed by an unillustrated stopper in the holder 15 as shown in FIG.
Although it stops at the position (b), the slide levers 11 and 12
Since it has already crossed the click mountain, it moves further due to the click force and stops at the position shown in FIG. 2(b). At this time, the adapter cannot be removed because the masks 8, 9 and the locking members 11, 12 are sandwiching the main body 1, and the dowels 16a, 16b, 17a, 17b of the slide levers 16, 17
Since it is not touching anything and is in a idle state, if you pull the holder back, only the adapter will be attached to the main body 1.

In this embodiment, three shafts 10 for unitizing the adapter are used for each mask, and the center is used as the sliding part for clicking the shaft, so the overall rigidity is increased and the cost is reduced. It has a click mechanism.

(Other Embodiments) (Embodiment 2) FIG. 3 shows an example of another click mechanism. In this embodiment, the center shaft of the shaft 10 is eliminated, and the click protrusions 11c and 12c of the locking members 11 and 12 are in direct contact with each other. Other configurations and operations are the same as in the previous embodiment. Therefore, in this embodiment, the center shaft is eliminated, resulting in cost reduction.

(Embodiment 3) FIG. 4 shows an example using yet another click mechanism. Click notches 13b, 13c, 14b, 14c are provided on the vertically bent sides of the guide members 13, 14.
are provided, and click protrusions 11c of the locking members 11 and 12,
12c is engaged with this notch. In the illustrated state, the locking members 11 and 12 are in positions where they protrude left and right, so the click protrusions 11c and 12c of the locking members 11 and 12 are in contact with the outer notches, respectively.

In this embodiment, the locking members 11, 12
Since they have the same shape, two of the same parts can be used. This not only reduces mold costs but also prevents mistakes during assembly. Further, the central axis 10, which is not related to clicking, may be abolished.

[0024]

[Effects of the Invention] As explained above, (1) Since the locking member of the adapter is held by click force at the main body attachment position and the detachment position (two positions), it is possible to make the adapter thinner than before.

[0025]Furthermore, the adapter holder has a biasing means that biases the locking member of the adapter in the direction of the release position with a force stronger than the click force, so if the operator does not consciously push the slide lever, the adapter will not move. The holder never leaves the adapter, so there is no chance of dropping the adapter.

[0026] By making at least part of the surface of the adapter on the photographing lens side have a reflectance close to that of film, it is possible to reduce the amount of light on the exposed area when the adapter is attached or not attached when performing so-called film surface photometry (flash control). The impact can be reduced.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a first embodiment according to the invention.

FIG. 2 is an operational plan view of the first embodiment.

FIG. 3 is a main plan view of a second embodiment according to the present invention.

FIG. 4 is a main plan view of a third embodiment of the present invention.

FIG. 5 is a perspective view of a conventional example.

FIG. 6 is a cross-sectional view of a conventional example.

FIG. 7 is a longitudinal sectional view of a typical camera equipped with a conventional example.

FIG. 8 shows the photometric sensitivity distribution of the camera in FIG. 7.

[Explanation of symbols]

1 Main body 2 Front plate 3 Mount 4 Shutter 5 Mirror 6 Photometric element 7 Film 8, 9 Mask 10 axis 11, 12 Locking member 13, 14 Guide member 15 Holder 16, 17 Slide lever 18 Compression spring

Claims (3)

[Claims] 1. An adapter that can be attached to and detached from a camera and has a mask that covers a predetermined amount of the upper and lower parts of the exposure opening of the camera, in which a locking member for attaching the adapter to the camera has two parts, one in the attached position and one in the non-attached position. 1. A camera trimming adapter characterized by having a click mechanism that is movable between the two positions and that maintains the locking member at each position with a click force. 2. A holder for holding the adapter is provided, the holder has an engaging part that engages with the locking member, and the locking member is moved by the click force through the engaging part. 2. The camera trimming adapter according to claim 1, further comprising biasing means for biasing the trimming adapter to the non-attached position with a strong force. 3. The camera trimming adapter according to claim 1, wherein a surface of the adapter on the photographing lens side is configured so that its reflectance is at least partially close to that of the film.