JP2004177831A - Light shielding device for camera lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light shielding device for a camera lens, a device that makes temporary exposure interruption possible without being accompanied with frame feed during photographing by a bulb mode. <P>SOLUTION: A unit 10 is used that is detachably mounted in front of the camera lens. The unit 10 incorporates a light shielding blade 13 that mechanically opens and closes the front face of the camera lens through a manual operation by a user, with an exposure operation performed separately from the shutter in the camera lens. The light shielding blade 13 is of a rotary type that rotates along the front face of the camera lens, and is remote-controlled with a camera cable release 20. The unit 10 is provided with a switch that is linked with the opening/closing operation of the light shielding blade 13. With this switch, a timer connected to the unit 10 is remote-controlled. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a camera lens light-shielding device detachably mounted on a camera lens and performing an exposure operation separately from a shutter in the camera.
[0002]
[Prior art]
One of the uses of the camera is to shoot night scenes and celestial bodies. In these shootings, since a long exposure time is required, the bulb mode (B) is selected as the shutter mode. As is well known, the bulb mode (B) is a shutter operation mode in which the shutter keeps opening 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-A-2001-264844
[Problems to be solved by the invention]
However, when shooting night scenes or celestial bodies in the bulb mode (B), there is often a risk that disturbance light such as a car light may enter the lens during exposure. In such a case, it is effective to close the shutter temporarily, but in the bulb mode (B), once the shutter is closed, the shooting of that frame ends, and it is not possible to re-expose the same frame. It is.
[0005]
That is, in the shooting of night scenes and celestial bodies in the bulb mode, it is often convenient to temporarily suspend the exposure during the shooting, but such an exposure operation is impossible.
[0006]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a light blocking device for a camera lens that enables a temporary suspension of exposure without accompanying frame advance during shooting in a bulb mode.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a camera lens light-shielding device according to the present invention is a unit that is detachably attached to the front of the camera lens, and mechanically opens and closes the front of the camera lens by manual operation by a user. Built-in light-shielding blades.
[0008]
By using the camera lens light-shielding device according to the present invention, it becomes possible to perform an exposure operation and an exposure interruption operation at an arbitrary timing separately from the operation of the shutter in the camera.
[0009]
It is preferable that the light-shielding vane be a rotary type that rotates along the front surface of the camera lens, because the thickness can be reduced.
[0010]
It is preferable that the light shielding blade is remotely operated by a cable release from the viewpoint of preventing blurring.
[0011]
The unit has a filter frame on the front side or the rear side of the light-shielding blade, and the filter frame is arranged on the front side of the base plate supporting the light-shielding blade with the light-shielding blade interposed therebetween, and A configuration that also serves as a protective frame is preferable. With this configuration, the filter can be used without hindering the reduction in thickness.
[0012]
The unit also preferably has an opening / closing door at the forefront, and the opening / closing door preferably has a built-in aperture mechanism for opening and closing an opening provided on the front side of the camera lens with a slide plate. With this configuration, a diaphragm mechanism is added without hindering the reduction in thickness.
[0013]
It is preferable that the unit has a built-in switch that is linked to the opening and closing operation of the light-shielding blade, and a timer that is separated and independent from the unit and remotely operated by the switch. By remotely operating the timer separately and independently from the unit, a timer function is obtained, and blurring due to the operation of the timer is prevented.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an internal structure of a camera lens light shielding device according to an embodiment of the present invention. 2 (a) to 2 (d) are four views of the camera lens light-shielding 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. FIG. 3 is a front view showing a state in which the opening / closing door and the cover of the camera lens light blocking device are removed. 4 (a) to 4 (d) are four views showing the structure of an opening / closing mechanism section and a timer operating section of the camera lens light blocking 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 a structural explanatory view of a timer operation unit of the camera lens light shielding device.
[0015]
As shown in FIGS. 1 to 3, the camera lens light-shielding device according to the present embodiment includes a light-shielding unit 10 that is detachably attached to the front of a single-lens reflex interchangeable lens that is a camera lens.
[0016]
The unit 10, which is an apparatus body, is attached to a square base plate 11 held on the front side of the camera lens and a rear surface of the base plate 11 for holding the base plate 11 on the front side of the camera lens. An annular holding frame 12, a pivotable light-shielding blade 13 attached to the front surface of the base plate 11, and a square plate-shaped filter serving also as a protection frame attached to the front surface of the base plate 11 from the front side of the light-shielding blade 13. The frame includes a frame 14, a rectangular opening / closing door 15 attached to a further front side of the filter frame 14, and a mechanical case 16 for housing a mechanical unit for operating the light shielding blade 13.
[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 the diameter of the opening 11a, and is attached concentrically to the opening 11a. A plurality of tightening screws 17 are radially attached to the holding frame 12 at equal intervals in the circumferential direction. The plurality of tightening screws 17 press the pad against the outermost peripheral surface of the foremost part of the camera lens by the tightening operation, and fix the unit 10 concentrically to the front part of the camera lens by this pressing.
[0018]
The light-shielding blade 13 has a disk-shaped main body 13 a arranged parallel to the front side of the base plate 11. The main body 13a is integrally provided with a support portion 13b extending outward (here, obliquely upward) from a part of the circumferential direction of the main body 13a. The diameter of the main body 13a is set smaller than the length of one side of the base plate 11 so as not to protrude outside the base 11, while the opening is formed so as to completely shield the opening 11a provided in the base plate 11. It is set larger than the diameter of the portion 11a.
[0019]
The support portion 13b of the light-shielding blade 13 is rotatably supported at one corner of the base plate 11 by a support shaft 13c. As a result, the light-shielding blade 13 is moved between 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. Rotate around the support shaft 13c so as to reciprocate between them. A plurality of shock absorbing cushions 19a and spare cushions 19b for fixing the light shielding blade 13 at the shielding position and a shock absorbing cushion 19c for fixing the light shielding blade 13 at the open position are provided on the front surface of the base plate 10. It is mounted around the periphery of 11a.
[0020]
The opening and closing mechanism for opening and closing the light shielding blade 13 is housed in a mechanical case 16 together with a timer operating 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 of the base plate 11 so as to be located behind the support portion 13b of the light-shielding blade 13. The internal structure of the mechanical case 16 will be described later in detail.
[0021]
The filter frame 14 also serving as a protection frame is attached to the front surface of the base plate 11 via an L-shaped spacer 11b. The L-shaped spacer 11b is attached to two intersecting side edges of the base plate 11, and forms a thin space between the base plate 11 and the filter frame 14 for accommodating the light shielding blades 13. The filter frame 14 is configured such that a front plate 14a and a rear plate 14b are overlapped with a predetermined gap 14c therebetween, and various filters are detachably accommodated in the gap 14c. At the center of the filter frame 14, a circular opening 14d corresponding to the opening 11a of the base plate 11 is provided.
[0022]
An opening / closing door 15 provided further on the 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 upper and lower two-stage hinges 15a, 15a. The opening / closing 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 opening and closing door 15 forms a thin gap vertically communicating between the front plate and the rear plate having an opening, and the sliding plate 15c inserted into this gap is moved up and down to open the opening. 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, 15d are provided on the open side edge of the door 15.
[0023]
As described above, the mechanical case 16 is attached to the rear surface of one corner of the base plate 11 so as to be positioned behind the support portion 13b of the light-shielding blade 13, and the opening and closing operation of the light-shielding blade 13 therein. Opening / closing mechanism for operating the shutter and a timer operating 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 slidably supported in the mechanical case 16, and a pinion gear 16b meshing with the rack gear 16a. The rack gear 16a is urged in one direction by a spring 16c, and moves in the other direction against the urging force by operating the cable release 20 mounted on 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 rotates the rack gear 16a in one direction by operating the cable release 20 to move the light-shielding blade 13 from the shielding position. Move to open position. When the operating force applied to the rack gear 16a is removed, the rack gear 16a and the pinion gear 16b automatically return to their original positions by the urging force, the weight of the light shielding blade 13 and the spring 16c. Return to position. In this way, the light-shielding blades 13 open and close by remote control using the cable release 20.
[0026]
As shown in FIGS. 4 and 5, the timer operation section is provided in the mechanical case 16 alongside the opening and closing mechanism section described above. 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 switch cam 16e keeps the micro switch 16d in the off state, and the light-shielding blade 13 When the micro switch 16d is turned 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 microswitch 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 at both ends, and the plugs 31 at both ends are inserted into the jack 16f in the mechanical case 16 and the jack 41 in the timer 40, respectively. Connection. The timer 40 has a start / stop button 42, a reset button 43, and the like. By operating these buttons, the accumulated time of the ON state of the microswitch 16d is measured and displayed on the display unit 44.
[0028]
Next, a method of using and a function of the camera lens light blocking device according to the present embodiment will be described.
[0029]
The unit 10 is mounted on the front of the camera lens. Specifically, the holding frame 12 is fitted into the front part of the camera lens with the plurality of tightening screws 17 attached to the holding frame 12 loosened, and in this state, the plurality of tightening screws 17 are evenly tightened. At the same time as the mounting of the unit 10, the cable release 20 is attached to the unit 10. The timer 40 is connected via the signal cable 30. Further, a filter is mounted on the filter frame 14 as needed.
[0030]
After the above preparation, the shutter mode of the camera is set to the bulb 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, no blurring occurs even if the camera moves when operating the shutter of the camera.
[0031]
When the time to be exposed comes, the cable release 20 is operated in the opening direction to open the light shielding blade 13 in the unit 10. This starts the actual exposure. At the same time, the exposure time starts to be measured by the timer 40. Since the light-shielding blade 13 is remotely controlled using the cable release 20 and it is not necessary to touch the unit 10 during the operation, blurring at the start of exposure can be prevented. Further, since the timer 40 is not incorporated in the unit 10 and is separated and independent from the unit 10, there is no danger of the unit 10 and the camera being shaken even when the timer 40 is operated.
[0032]
When it becomes necessary to interrupt the exposure within the same frame, the cable release 20 is operated in the closing direction to close the light shielding blade 13 in the unit 10. This stops the exposure. Also, the measurement of the exposure time stops. However, since the camera is in a state where the shutter is kept open, no frame advance is involved. When it is time to restart the exposure, the cable release 20 is again operated in the opening direction to open the light shielding blade 13 in the unit 10. Thus, the exposure starts again. At the same time, the exposure time starts to be re-measured by the timer 40. In this way, it is possible to perform a predetermined exposure while interrupting the exposure at an arbitrary timing within the same frame without accompanying the frame advance. This prevents intrusion of disturbance light and the like.
[0033]
When the exposure is completed, the light-shielding blades 13 in the unit 10 are closed by operating the cable release 20 in the closing flat direction. Then, the shutter of the camera is closed.
[0034]
Although the opening and closing door 15 is opened at the time of exposure in the above usage example, the door itself can be closed and the opening 15b of the opening and closing door 15 can be opened to an arbitrary 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 having such a built-in 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 light-shielding device according to the present invention includes a light-shielding 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. The exposure operation can be performed at an arbitrary timing separately from the shutter operation in the camera, so that it cannot be performed in the bulb mode of the camera such that the exposure is temporarily interrupted during nighttime shooting. Enables exposure operation.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating an internal structure of a camera lens light blocking device according to an embodiment of the present invention.
FIGS. 2A and 2B are four side views of the camera lens light blocking device, wherein FIG. 2A is a plan view, FIG. 2B is a front view, FIG. 2C is a left side view, and FIG.
FIG. 3 is a front view showing the camera lens light blocking device with the open / close door and cover removed.
4A and 4B are four views showing the structure of an opening / closing mechanism and a timer operating part of the camera lens light blocking device, wherein FIG. 4A is a rear view, FIG. 4B is a left front view, and FIG. (D) is a bottom view.
FIG. 5 is a structural explanatory view of a timer operation unit of the camera lens light shielding device.
[Explanation of symbols]
Reference Signs List 10 Unit 11 Base plate 11a Opening 12 Holding frame 13 Light shielding blade 13c Support shaft 14 Filter frame 14d Opening 15 Opening / closing door 15b Opening 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 (6)

A light shielding device for a camera lens, which is a unit detachably attached to a front part of the camera lens and has a built-in light shielding blade for mechanically opening and closing the front surface of the camera lens by manual operation by a user. 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. The light shielding device for a camera lens according to claim 1, wherein the light shielding blade is remotely controlled by a cable release. The unit has a filter frame on the front side or the rear side of the light-shielding blade, and the filter frame is arranged on the front side of the base plate supporting the light-shielding blade with the light-shielding blade interposed therebetween, and 2. The light shielding device for a camera lens according to claim 1, which also serves as a protection frame. 2. The camera lens according to claim 1, wherein the unit has an opening / closing door at the forefront, and the opening / closing door has a built-in aperture mechanism that opens and closes an opening provided on the front side of the camera lens with a slide plate. Light shielding device. 2. The camera lens light-shielding device according to claim 1, wherein the unit has a built-in switch interlocking with the opening and closing operation of the light-shielding blade, and a timer separated and independent from the unit is remotely operated by the switch. 3.

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