JP3771897B2 - Shading device for camera lens - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a camera lens shading device that is detachably attached to a camera lens and performs an exposure operation separately from a shutter in the camera.
[0002]
[Prior art]
One of the ways to use the camera is to shoot night views and celestial bodies. Since these exposures require a long exposure time, the valve mode (B) is selected as the shutter mode. As is well known, the valve mode (B) is a shutter operation mode in which the shutter is kept open while the shutter operation button is pressed. Use of this mode enables exposure for an arbitrary time (for example, Patent Document 1 discloses a camera having a bulb mode).
[0003]
[Patent Document 1]
JP 2001-264844 A
[Problems to be solved by the invention]
However, when shooting night scenes and astronomical objects in the bulb mode (B), there is often a risk that ambient light such as car lights will enter the lens during exposure. In such a case, it is effective to temporarily close the shutter. However, in the valve mode (B), once the shutter is closed, shooting of the frame ends, and re-exposure on the same frame is impossible. It is.
[0005]
That is, in night scenes and celestial bodies in the bulb mode, it is often convenient to temporarily stop the exposure during the shooting, but such an exposure operation is impossible.
[0006]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a camera lens light-shielding device that enables primary exposure to be interrupted without frame advance during photographing in the bulb mode.
[0007]
[Means for Solving the Problems]
To achieve the above object, a camera lens shading device according to the present invention is a unit that is detachably attached to the front of a camera lens, and mechanically opens and closes the front of the camera lens by a user's manual operation. And has a filter frame on the front surface side or rear surface side of the light shielding blade, and the filter frame is disposed on the front surface side of the base plate supporting the light shielding blade with the light shielding blade interposed therebetween. Also serves as a protective frame for the light shielding blade.
[0008]
By using the light-shielding device for a camera lens according to the present invention, an exposure operation and an exposure interruption operation can be performed at an arbitrary timing separately from the operation of the shutter in the camera. Further, the filter can be used without hindering the reduction in thickness.
[0009]
The light-shielding blade is preferably a rotary type that rotates along the front surface of the camera lens because it can be thinned.
[0010]
In addition, it is preferable that the shading blade is remotely controlled by a cable release from the viewpoint of preventing blurring.
[0012]
The unit also has an opening / closing door in the foremost part, and the opening / closing door preferably has a built-in diaphragm mechanism that opens and closes an opening provided on the front side of the camera lens by a slide plate. With this configuration, the diaphragm mechanism is added without hindering the reduction in thickness.
[0013]
The unit also preferably includes a switch that interlocks with the opening / closing operation of the light-shielding blade, and a timer that is separated and independent from the unit is remotely operated by the switch. By remotely operating the timer separately from the unit, a timer function can be obtained, and shake associated with the operation of the timer can be prevented.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the internal structure of a camera lens shading device according to an embodiment of the present invention. 2A to 2D are four views of the camera lens shading device, where FIG. 2A is a plan view, FIG. 2B is a front view, FIG. 2C is a left side view, and FIG. FIG. FIG. 3 is a front view showing the camera lens shading device with the door and the cover removed. 4 (a) to 4 (d) are four views showing the structure of the opening / closing mechanism part and timer operation part of the camera lens shading device, where (a) is a rear view, (b) is a left front view, and (c). Is a right front view, and (d) is a bottom view. FIG. 5 is an explanatory view of the structure of the timer operation unit of the camera lens shading device.
[0015]
As shown in FIGS. 1 to 3, the camera lens light-shielding device according to this embodiment includes a light-shielding unit 10 that is detachably attached to the front portion of a single-lens reflex interchangeable lens that is a camera lens.
[0016]
This unit 10 which is an apparatus main body is attached to the rear surface of the base plate 11 in order to hold the base plate 11 on the front side of the camera lens, and a rectangular base plate 11 held on the front side of the camera lens. An annular holding frame 12, a rotating light shielding blade 13 attached to the front surface of the base plate 11, and a square plate filter that also serves as a protective frame attached to the front surface of the base plate 11 from the front surface side of the light shielding blade 13. A frame 14, a rectangular opening / closing door 15 attached to the front side of the filter frame 14, and a mechanical case 16 that houses a mechanical portion for operating the light shielding blade 13 are provided.
[0017]
The base plate 11 of the unit 10 has a circular opening 11a having a diameter sufficiently larger than the outer diameter of the frontmost part of a general interchangeable lens at the center. The holding frame 12 is a sleeve having a diameter larger than that of the opening 11a, and is concentrically attached to the opening 11a. A plurality of fastening screws 17 are attached to the holding frame 12 radially at equal intervals in the circumferential direction. The plurality of tightening screws 17 press the pad against the outermost peripheral surface of the front end of the camera lens by the tightening operation, and the unit 10 is concentrically fixed to the front portion of the camera lens by the pressing.
[0018]
The light shielding blade 13 has a disk-shaped main body portion 13 a arranged in parallel to the front side of the base plate 11. The main body part 13a is integrally provided with a support part 13b that extends from a part in the circumferential direction of the main body part 13a to the outside (in this case, obliquely upward). The diameter of the main body 13a is set to be smaller than the length of one side of the base plate 11 so as not to protrude outside the base 11, while the opening 11a provided in the base plate 11 is completely opened. It is set larger than the diameter of the portion 11a.
[0019]
The support portion 13 b of the light shielding blade 13 is rotatably supported at one corner portion of the base plate 11 by a support shaft 13 c. Thereby, the light-shielding blade 13 has a shielding position where the main body 13a completely shields the opening 11a of the base plate 11 and an upper open position where the main body 13a completely opens the opening 11a of the base plate 11. It rotates around the support shaft 13c so as to reciprocate between them. On the front surface of the base plate 10, a plurality of shock absorbing cushions 19a and a spare cushion 19b for fixing the light shielding blade 13 at the shielding position, and an impact absorbing cushion 19c for fixing the light shielding blade 13 at the open position are opened. It is attached to be located around 11a.
[0020]
An opening / closing mechanism for opening / closing the light shielding blade 13 is housed in the mechanical case 16 together with a timer operation unit for operating a timer in conjunction with the operation of the light shielding blade 13. The mechanical case 16 is attached to the rear surface of one corner portion of the base plate 11 so as to be positioned behind the support portion 13 b of the light shielding blade 13. The internal structure of the mechanical case 16 will be described in detail later.
[0021]
The filter frame 14 also serving as a protective frame is attached to the front surface of the base plate 11 via an L-shaped spacer 11b. The L-shaped spacer 11 b is attached to two side edges where the base plate 11 intersects, and forms a thin space for accommodating the light shielding blades 13 between the base plate 11 and the filter frame 14. The filter frame 14 is configured such that the front plate 14a and the rear plate 14b are overlapped with a predetermined gap 14c, and various filters are detachably accommodated in the gap 14c. A circular opening 14 d corresponding to the opening 11 a of the base plate 11 is provided at the center of the filter frame 14.
[0022]
The opening / closing door 15 provided on the further front side of the filter frame 14 is attached to the front surface of one side edge of the filter frame 14 in a single-opening manner by two upper and lower hinges 15a, 15a. The open / close door 15 has a circular opening 15b corresponding to the openings 11a and 14d at the center, and incorporates a slide plate 15c that opens and closes the opening 15b. That is, the open / close door 15 is formed by forming a thin gap in the vertical direction between the front plate and the rear plate having the opening, and moving the slide plate 15c inserted in the gap up and down. The portion 15b can be opened to any position from fully closed to fully open. In order to fix the slide plate 15c at an arbitrary position, set screws 15d and 15d are provided on the edge of the open / close door 15 on the open side.
[0023]
As described above, the mechanical case 16 is attached to the rear surface of one corner portion of the base plate 11 so as to be positioned on the back side of the support portion 13b of the light shielding blade 13 and opens and closes the light shielding blade 13 therein. And a timer operation unit that operates a timer in conjunction with the operation of the light shielding blade 13.
[0024]
As shown in FIGS. 1 and 4, the opening / closing mechanism includes a rack gear 16a that is slidably supported in the mechanical case 16, and a pinion gear 16b that meshes with the rack gear 16a. The rack gear 16a is biased in one direction by a spring 16c, and moves in the other direction against the biasing force by operating the cable release 20 attached to the release mounting portion 16g of the mechanical case 16.
[0025]
The pinion gear 16b that meshes with the rack gear 16a is attached to the support shaft 13c that supports the light shielding blade 13, and the light shielding blade 13 is moved away from the shielding position by the rotation accompanying the movement of the rack gear 16a in one direction by the operation of the cable release 20. Move to the open position. When the operating force applied to the rack gear 16a is removed, the rack gear 16a and the pinion gear 16b are automatically returned to their original positions by the biasing force, the weight of the light shielding blade 13 and the spring 16c, and accordingly the light shielding blade 13 is shielded from the open position. Return to position. Thus, the light shielding blade 13 is opened and closed by remote operation using the cable release 20.
[0026]
As shown in FIGS. 4 and 5, the timer operation unit is provided in the mechanical case 16 alongside the opening and closing mechanism. The timer operation unit includes a micro switch 16d fixed to the inner surface of the mechanical case 16, and a switch cam 16e for operating the micro switch 16d. The switch cam 16e is attached to the support shaft 13c that supports the light shielding blade 13 together with the pinion gear 16b. When the light shielding blade 13 is in the shielding position, the micro switch 16d is maintained in the off state, and the light shielding blade 13 is shielded. When the micro switch 16d is rotated from the position to the open position, the micro switch 16d is switched from the off state to the on state.
[0027]
The operating state of the micro switch 16d is transmitted to a timer 40 separated and independent from the unit 10 via a detachable signal cable 30. The signal cable 30 is a normal signal cable having plugs 31, 31 at both ends, and the plugs 31, 31 at both ends are respectively inserted into the jack 16 f in the mechanical case 16 and the jack 41 in the timer 40 to electrically connect both. Connect. The timer 40 has a start / stop button 42, a reset button 43, and the like, and measures the accumulated time of the on-state of the micro switch 16d by these button operations and displays them on the display unit 44.
[0028]
Next, the usage method and function of the camera lens shading device according to the present embodiment will be described.
[0029]
The unit 10 is attached to the front part of the camera lens. Specifically, in a state where the plurality of tightening screws 17 attached to the holding frame 12 are loosened, the holding frame 12 is fitted into the front portion of the camera lens, and in this state, the plurality of tightening screws 17 are evenly tightened. When the unit 10 is mounted, the cable release 20 is attached to the unit 10. In addition, the timer 40 is connected via the signal cable 30. Further, a filter is attached to the filter frame 14 as necessary.
[0030]
After the above preparation, the camera shutter mode is set to the valve mode (B). Then, the shutter of the camera is opened with the opening / closing door 15 of the unit 10 opened and the light shielding blade 13 closed. At this time, since the light shielding blade 13 is closed, actual exposure does not start. For this reason, even if the camera moves when operating the shutter of the camera, no blur occurs.
[0031]
When it is time for exposure, the cable release 20 is operated in the opening direction to open the light shielding blade 13 in the unit 10. Thereby, actual exposure starts. At the same time, the exposure time starts to be measured by the timer 40. Since it is not necessary to remotely operate the shading blade 13 using the cable release 20 and touch the unit 10 during the operation, blurring at the start of exposure is prevented. In addition, since the timer 40 is not incorporated in the unit 10 and is separated and independent from the unit 10, there is no risk that the unit 10 and the camera will be shaken even when the timer 40 is operated.
[0032]
When exposure needs to be interrupted within the same frame, the light shielding blade 13 in the unit 10 is closed by operating the cable release 20 in the closing direction. This stops the exposure. Also, the measurement of the exposure time is stopped. However, since the camera is in a state where the shutter is opened, frame advance is not involved. When it is time to resume the exposure, the cable release 20 is again operated in the opening direction to open the light shielding blade 13 in the unit 10. Thereby, the exposure starts again. At the same time, the exposure time starts to be measured again by the timer 40. In this way, it is possible to perform predetermined exposure while interrupting exposure at an arbitrary timing within the same frame without accompanying frame advance. As a result, intrusion of ambient light is prevented.
[0033]
When the exposure is completed, the light release blade 13 in the unit 10 is closed by operating the cable release 20 in the closing direction. Then close the camera shutter.
[0034]
In the above use example, the opening / closing door 15 is opened at the time of exposure. However, the door itself can be closed and the opening 15b of the opening / closing door 15 can be opened to any open state by the slide plate 15c. That is, it is possible to perform an aperture operation not only to open the entire opening 15b but also to open only the lower half thereof. By using the opening / closing door 15 incorporating such a diaphragm mechanism, the diaphragm operation can be performed without hindering the reduction in thickness.
[0035]
【The invention's effect】
As described above, the camera lens shading device according to the present invention is a shading blade that mechanically opens and closes the front surface of the camera lens by a user's manual operation on a unit that is detachably attached to the front of the camera lens. Since the exposure operation can be performed at an arbitrary timing separately from the shutter operation in the camera, it is impossible to execute in the bulb mode of the camera in which the exposure is temporarily interrupted during night shooting. Allows exposure operations.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an internal structure of a camera lens shading device according to an embodiment of the present invention.
FIG. 2 is a four-view diagram of the camera lens shading device, where (a) is a plan view, (b) is a front view, (c) is a left side view, and (d) is a right side view.
FIG. 3 is a front view showing the camera lens shading device with a door and a cover removed.
4A and 4B are four views showing the structure of an opening / closing mechanism and a timer operation unit of the camera lens shading device, where FIG. 4A is a rear view, FIG. 4B is a left front view, and FIG. 4C is a right front view; (D) is a bottom view.
FIG. 5 is an explanatory diagram of a structure of a timer operation unit of the camera lens shading device.
[Explanation of symbols]
10 Unit 11 Base plate 11a Opening portion 12 Holding frame 13 Shading blade 13c Support shaft 14 Filter frame 14d Opening portion 15 Opening / closing door 15b Opening portion 15c Slide plate 16 Mechanical case 16a Rack gear 16b Pinion gear 16c Spring 16d Micro switch 16e Switch cam 17 Tightening screw 20 Cable release 30 Signal cable 40 Timer

Claims (5)

A unit that is detachably attached to the front of the camera lens, and has a built-in light shielding blade that mechanically opens and closes the front of the camera lens by a user's manual operation, and a filter on the front or rear side of the light shielding blade. A camera lens shading device comprising a frame, wherein the filter frame is disposed on the front side of a base plate supporting the shading blade so as to serve as a protection frame for the shading blade .   The light shielding device for a camera lens according to claim 1, wherein the light shielding blade is a rotary type that rotates along a front surface of the camera lens.   2. The camera lens shading device according to claim 1, wherein the shading blade is remotely operated by a cable release. 2. The camera lens according to claim 1, wherein the unit has an opening / closing door in a foremost portion, and the opening / closing door incorporates a diaphragm mechanism that opens and closes an opening provided on a front surface side of the camera lens by a slide plate. Shading device. 2. The camera lens shading device according to claim 1, wherein the unit includes a switch that interlocks with an opening / closing operation of the shading blade, and is configured to remotely operate a timer separated and independent from the unit by the switch .

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