JP4128895B2 - Lens barrel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a lens mirror in which the tube length can be freely changed between a storage state in which the tube length is relatively short and a shooting state in which the tube length is relatively long On the torso It is related.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a type of camera that takes a picture on a silver salt film has been widely used. In recent years, in addition to such a type of camera, a subject is imaged on a solid-state image sensor such as a CCD image sensor, and the subject. An electronic camera that obtains image data representing the image is rapidly spreading. Here, the conventional type of camera for taking a picture on a silver halide film and the electronic camera are collectively referred to as “camera”.
[0003]
Cameras generally require a high degree of portability, and the lens barrel that holds the taking lens is retracted to the camera body side when not in use, and is configured to protrude forward from the camera body side when taking a picture. Retractable, retractable lens barrels are widely used. Also, in conventional so-called compact cameras and recent electronic cameras, lens shutters and diaphragms arranged between photographing lenses are widely used.
[0004]
In such a retractable and retractable lens barrel and having a lens shutter or a diaphragm, how to improve portability becomes a problem.
[0005]
In this case, one of the points that greatly contributes to portability is the thinness in the optical axis direction of the lens barrel when retracted.
[0006]
FIG. 17 is a cross-sectional view along the optical axis S when the lens barrel of the conventional camera is retracted.
[0007]
Here, a collapsible and extended lens barrel 10 is shown. The lens barrel 10 has a three-group photographic lens including a first group lens 21, a second group lens 22, and a third group lens 23. 20 and a lens shutter 30 provided between the first group lens 31 and the second group lens of the photographing lens 20. The lens barrel 20 has a zoom lens configuration that allows the focal length to be adjusted when the lens barrel 20 is not simply retracted and extended. In addition, a CCD image pickup device 40 fixed on the camera body side is disposed at the rear of the lens barrel 20. That is, a lens barrel for an electronic camera is shown here.
[0008]
Here, as shown in FIG. 7, among the lens groups constituting the photographing lens 20, the second group lens 22 and the third group lens 32 are extremely close to each other in the retracted state shown in FIG. However, there is a lens shutter 30 between the first group lens 21 and the second group lens 22, so that the lens shutter 30 is sandwiched between them and they are separated to some extent from each other. It is in the state. This makes it impossible to further reduce the size when retracted.
[0009]
For example, in Patent Document 1, a camera that can move to an initial position where a single-focus imaging optical system composed of a plurality of lens groups can be photographed and a retracted position retracted from the initial position to the camera body side is photographed. A mechanism is described in which when the optical system is moved to the retracted position, the length occupied by the imaging optical system is changed by further shortening the plurality of lens groups from the lens group interval at the initial position.
[0010]
Further, Patent Document 2 shows a zoom lens that has been downsized by devising an aperture drive mechanism or the like, but this does not solve the problem that the aperture and the shutter itself are in the way, and it is still limited to downsizing. There is.
[0011]
[Patent Document 1]
JP-A-6-258702
[Patent Document 2]
JP-A-10-288873
[0012]
[Problems to be solved by the invention]
In view of the above circumstances, the present invention provides a lens barrel capable of further reducing the dimension (cylinder length) in the optical axis direction as compared with a conventional retractable lens barrel, a lens barrel that can be extended, and such a lens barrel. An object is to provide a camera having a lens barrel.
[0013]
[Means for Solving the Problems]
The lens barrel of the present invention that achieves the above object has a built-in photographing lens composed of a plurality of lens groups, and has a tube length between a relatively short tube length storage state and a relatively long tube length photographing state. A lens barrel that can be changed freely.
A light amount control member that is in a use state that controls the amount of photographing light that passes through the photographing lens when in a photographing state, and that is not in use when the opening is kept open to a predetermined opening diameter when in a retracted state When,
When moving from the shooting state to the retracted state, move at least part of the members that make up one of the lens groups that make up the taking lens into a state in which the light quantity control member enters the aperture. And a lens moving mechanism.
[0014]
Here, in the lens barrel of the present invention, the light amount control member may be a lens shutter, or a diaphragm member, or a member that serves as both the shutter member and the diaphragm member. .
[0015]
When the lens barrel of the present invention moves from the photographing state to the retracted state, at least a part of the members constituting any one of the plurality of lens groups constituting the photographing lens is in an unused state. Since it moves to the state which entered in the opening of the light quantity control member, the cylinder length in the accommodation state can be shortened conventionally.
[0016]
Here, in the lens barrel according to the present invention, when the light amount control member is in a non-use state, the light amount control member is held in an open state that is further open than a maximum opening in the use state. Is preferred.
[0017]
The maximum aperture when in the shooting state needs to be determined from the viewpoint of shooting performance, and the aperture diameter of the maximum aperture when in the shooting state is at least of the members constituting any lens group when in the retracted state. The diameter of the opening is not necessarily sufficient to allow a part to enter the opening. In such a case, when in the stowed state, by keeping the opening of the light quantity control member in an open state that is further opened larger than the maximum opening in the shooting state, both shooting performance and stowability are achieved. Can be satisfied.
[0018]
Further, in the lens barrel of the present invention, when the lens barrel moves from the photographing state to the retracted state, the light amount control member is not used prior to the partial contact with the light amount control member. It is preferable to have a configuration including a forced transition member that forcibly shifts to the position.
[0019]
By providing such a forced transition member, even if the lens control system malfunctions or a mechanical shock is applied during use, the lens group and the light quantity control member approach each other. Therefore, the light quantity control member moves to a non-use state, and mechanical destruction can be avoided.
[0020]
When the forcible transition member is provided, the forcible transition member is a rod-like member that is provided on the lens group side and protrudes toward the light amount control member,
When the lens barrel moves from the photographing state to the retracted state, the light amount control member contacts the forcible transition member before the part contacts the light amount control member, and the It is preferable that the lens barrel shifts to a non-use state upon receiving a driving force when moving toward the retracted state.
[0021]
By providing the rod-like member, there is no risk that the lens group will come into contact with the light amount control member with a simple mechanism, and the light amount control member can be easily put into an unused state in accordance with the movement of the lens barrel to the retracted state. Can be migrated.
[0022]
In the lens barrel of the present invention, when the lens barrel is in the retracted state, the light amount control member is held in a non-use state in which it is retracted to a predetermined retracted position, and the light amount control member is in the non-retracted position. In some cases, it is also a preferred aspect that a restricting means for controlling the approach of the lens group and its light amount control member in the optical axis direction is provided.
[0023]
The regulating means intervenes from outside the movement path of the engagement member into the movement path in conjunction with the engagement member provided on the lens group side and the light amount control member moving from the retraction position to the non-retraction position. It can comprise with a control member. In this case, the restricting member is configured to contact the engaging member and prevent contact before at least a part of the lens group comes into contact with the light amount control member in the non-retracted position.
[0024]
In the configuration including the regulating member, when the light amount control member is formed of a diaphragm blade, the regulating member can be configured integrally with the diaphragm blade.
[0025]
Further, the regulating member can be configured to be retracted from the moving path of the engaging member to the outside of the moving path when the shutter is opened in conjunction with the shutter blade.
[0026]
Further, the camera of the present invention that achieves the above object has a relatively short tube length that holds a photographing lens composed of a plurality of lens groups and a light amount control member that controls the amount of light passing through the photographing lens. In a camera that includes a lens barrel that is freely changeable in a tube length between a storage state and a relatively long photographing state, and that performs photographing using photographing light that has passed through a light amount control member, the lens barrel includes: When the lens barrel is in the retracted state, at least a part of the members constituting any one of the plurality of lens groups is held in the lens shutter opening. It is characterized by.
[0027]
Here, in the camera of the present invention, the light quantity control member may be a lens shutter, a diaphragm member, or a member that serves as both the lens shutter and the diaphragm member.
[0028]
The camera of the present invention holds the lens group in a state in which at least a part of the members constituting any of the lens groups has entered the opening of the light amount control member when in the stored state. By reducing the dimension in the thickness direction at a certain time as compared with the conventional one, a thin camera having excellent portability can be provided.
[0029]
Here, in the case of an electronic camera, there is no problem in placing the light quantity control member in a state where light can pass when the lens barrel is in the retracted state, but the conventional type in which photography is performed on a silver salt film In the case of this camera, if the light quantity control member is placed in a state in which light can pass, there is a possibility that the silver salt film is exposed by the light that has passed through the light quantity control member. However, this is a case where no particular measures are taken, and can be solved by, for example, providing a lens cover, a front cover, a lens barrier, or the like having excellent light shielding properties, or by providing a focal plane shutter.
[0030]
That is, the present invention can be applied not only to an electronic camera but also to a conventional camera of a type that takes a picture on a silver salt film.
[0031]
Here, in the camera according to the present invention, when the lens barrel is in the retracted state, the light amount control member is held in an open state that is further open than the maximum opening in the photographing state. Also good.
[0032]
The maximum aperture when in the shooting state needs to be determined from the viewpoint of shooting performance, and the aperture diameter of the maximum aperture when in the shooting state is that of the members that constitute any lens group when in the retracted state. The opening diameter is not necessarily sufficient to allow at least a portion to enter the opening. In such a case, when in the stowed state, the opening of the light quantity control member is held in an open state that is larger than the maximum opening in the state, thereby satisfying both photographic properties and stowability. can do.
[0033]
Further, in the camera of the present invention, the light amount control member includes a use state in which the light amount of the photographing light passing through the photographing lens is controlled, and at least a member constituting any one of the plurality of lens groups. The amount of photographic light passing through the photographic lens in the use state when the lens barrel is in the photographic state is freely changeable between the non-use state in which a part is allowed to enter the opening Which controls
When the lens barrel further moves from the shooting state to the retracted state, the camera forcibly shifts the light amount control member to a non-use state before the part contacts the light amount control member. It is preferable to have a configuration including a forced transition member to be moved.
[0034]
By providing the forcible transfer member, even if the lens control system malfunctions or the lens group and the light quantity control member approach due to mechanical shock during use, the forced transfer member The presence of the light quantity control member shifts to a non-use state, and mechanical damage can be avoided.
[0035]
When the forcible transition member is provided, the forcible transition member is a rod-like member that is provided on the lens group side and protrudes toward the light amount control member,
When the lens barrel moves from the photographing state to the retracted state, the light amount control member contacts the forcible transition member before the part contacts the light amount control member, and the It is preferable that the lens barrel receives the driving force when moving toward the retracted state and shifts to the non-use state.
[0036]
By providing the rod-like member, there is no risk that the lens group will come into contact with the light amount control member with a simple mechanism, and the light amount control member can be easily put into an unused state in accordance with the movement of the lens barrel to the retracted state. Can be migrated.
[0037]
In the camera of the present invention, when the lens barrel is in the retracted state, the light amount control member is not retracted to a retracted position that allows at least a part of the lens group to enter the opening of the light amount control member. It is also a preferable aspect to provide a configuration in which a restricting means for restricting the approach of the lens group and the light amount control member in the optical axis direction when the light amount control member is in the non-retracted position while being held in use.
[0038]
The restricting means includes, for example, a pin-shaped engagement member that is provided on the lens group side and extends in the optical axis direction, and the engagement member is interlocked with the movement of the light amount control member from the retracted position to the non-retracted position. It can comprise by the control member which intervenes in a movement channel from the movement channel outside. In this case, the restricting member is configured to contact the engaging member and prevent contact before at least a part of the lens group comes into contact with the light amount control member in the non-retracted position.
[0039]
In the configuration including the regulating member, when the light amount control member is formed of a diaphragm blade, the regulating member can be configured integrally with the diaphragm blade.
[0040]
Further, the regulating member can be configured to be retracted from the moving path of the engaging member to the outside of the moving path when the shutter is opened in conjunction with the shutter blade.
[0041]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0042]
1 and 2 are external perspective views of a first embodiment of the camera of the present invention.
[0043]
FIG. 1 shows the retracted state of the lens barrel 100 incorporating the zoom lens of the camera 1 of the present embodiment, and FIG. 2 shows the extended state of the lens barrel 100 of the camera 1. ing.
[0044]
The lens barrel 100 of the camera 1 shown in FIG. 1 and FIG. 2 incorporates a zoom lens composed of three groups similar to that described with reference to FIG. The focal length is adjusted by moving the lens to, and the focus is adjusted by moving the third lens group in the optical axis direction.
[0045]
An auxiliary light emission window 12 and a viewfinder objective window 13 are arranged at the upper front of the camera 1 shown in FIGS. A shutter button 14 is disposed on the upper surface of the camera 1.
[0046]
A zoom operation switch is provided on the rear surface (not shown) of the camera 1. When one of the zoom operation switches is pressed, the lens barrel 100 is extended to the telephoto side while the button is being pressed, and the zoom operation switch is When the other is pushed, the lens barrel 100 moves to the wide-angle side while keeping pushing.
[0047]
3 is a cross-sectional view of the lens barrel of the camera shown in FIGS. 1 and 2 in the retracted state along the optical axis S. FIG. 4 is a diagram of the same lens barrel as in FIG. 2 is a cross-sectional view along an axis S. FIG.
[0048]
The lens barrel 100 includes a photographing lens 200 including a first lens group 201, a second lens group 202, and a third lens group 203. The lens barrel 100 is in the retracted state shown in FIG. 3 and the maximum extension shown in FIG. It can be retracted and extended between the states.
[0049]
Further, the lens barrel 100 moves between a minimum extended state extended from the retracted state shown in FIG. 3 to some extent and a maximum extended state shown in FIG. The lens groups 201, 202, and 203 constituting the lens 200 move in the optical axis direction so that the focal length changes as a whole. That is, the photographing lens 200 is configured as a zoom lens. The focus adjustment is performed by moving only the third lens group 203 of the imaging lens 200 in the optical axis direction.
[0050]
Details of the retracting and feeding mechanism will be described later.
[0051]
Further, the lens barrel 100 is provided with a lens shutter 300 between a first group lens 201 and a second group lens 202 constituting the photographing lens 200. The lens shutter 300 is an example of a light amount control member according to the present invention. As shown in FIG. 4, the lens shutter 300 is attached to a second group lens holding frame 212 that holds the second group lens 202 while being biased forward by a coil spring 213. The coil spring 213 is compressed by being pushed by the holding frame of the first group lens 201, and the lens shutter 300 is moved to the second group lens side.
[0052]
Further, in the lens shutter 300, the maximum opening at the time of shooting is limited to a predetermined opening diameter shown in FIG. 4, and thus the shooting performance is maintained. In addition, as shown in FIG. 3, the lens shutter is opened to an open diameter that is wider than the maximum opening diameter (see FIG. 4) during photographing in the retracted state. As shown in FIG. 3, the opening diameter in the open state is larger than the outer diameter of the second group lens 202 of the photographing lens 200, and the second group lens enters the opening of the lens shutter 300 when retracted. As a result, the dimension in the optical axis direction in the retracted state in this embodiment is shorter than the dimension in the retracted state of the conventional example shown in FIG.
[0053]
Further, a CCD image pickup device 400 further fixed to a fixed frame 101 fixed to the camera body is provided at the rear of the photographing lens 200.
[0054]
Here, the operation of the lens barrel 100 between the retracted state shown in FIG. 3 and the maximum extended state shown in FIG. 4 will be described.
[0055]
The lens barrel 100 includes a fixed frame 101 fixed to the camera body and a drive cylinder 102 that is rotatable with respect to the fixed frame. The drive cylinder 102 is rotatable with respect to the fixed frame 101, but a protrusion 102 a provided in the circumferential direction is fitted in a groove extending in the circumferential direction of the fixed frame 101. On the other hand, movement in the direction of the optical axis is prohibited. The drive cylinder 102 is provided with a gear 102b on the outer peripheral surface thereof. A drive gear (not shown) is engaged with the gear 102b, and a driving force from a motor (not shown) is transmitted via the gear 102b. The drive cylinder 102b rotates.
[0056]
The drive cylinder 102 is further provided with a key groove 102c extending in the optical axis direction. A pin-like cam follower 104 fixed to the rotationally movable cylinder 103 is provided on the fixed frame 101 in the key groove 102c. It penetrates through the provided cam groove. Therefore, when the drive cylinder 102 rotates, the cam follower 104 enters the key groove 102c, so that the rotational movement cylinder 103 also rotates together with the drive cylinder 102, and the cam follower 104 passes through the cam groove of the fixed frame 101. Therefore, it moves in the optical axis direction according to the shape of the cam groove while rotating as the drive cylinder 102 rotates.
[0057]
In addition, a rectilinear movement frame 105 is provided inside the rotational movement cylinder 103. The rectilinearly moving frame 105 is engaged with the rotationally movable cylinder 103 so as to be freely rotatable relative to the rotationally movable cylinder 103, and the rotation is prohibited by fitting into the key groove 101 a of the fixed frame 101. Therefore, the moving frame 105 moves together with the movement of the rotationally moving cylinder 103 in the optical axis direction when the rotationally movable cylinder 103 rotates in accordance with the rotation of the driving cylinder 102 and moves in the optical axis direction. . However, the rectilinear movement frame 105 is prohibited from rotating by fitting the fixed frame 101 into the key groove 101 a, and moves linearly in the optical axis direction as the rotational movement cylinder 103 moves.
[0058]
The second group lens 202 is a second group lens holding frame 212, and the second group lens holding frame 212 has a cam follower 216 fixed to the second group lens holding frame 212. And the key full 105a extending in the optical axis direction of the rectilinear moving frame 105, so that the rotationally movable cylinder 103 moves in the optical axis direction while rotating as the drive cylinder 102 rotates. Then, the second group lens holding frame 212 and the second group lens unit 260 composed of the second group lens 202 held by the second group lens holding frame 212 are rotationally moved with the cam follower 216 fitted therein. It moves straight in the direction of the optical axis along the shape of the cam groove of the tube 103.
[0059]
As described above, since the lens shutter 300 is attached to the lens unit 260 in a state of being biased forward by the coil spring 213, the lens shutter 300 also moves in the optical axis direction together with the lens unit 260.
[0060]
Further, the lens barrel 100 is provided with a rectilinearly moving cylinder 106 that holds the first group lens 201. In the straight movement cylinder 106, a cam follower 107 fixed to the straight movement cylinder 106 enters a cam groove of the rotation movement cylinder 103, and also enters a key groove 105a of the straight movement frame 105 extending in the optical axis direction. Therefore, when the rotationally movable cylinder 103 rotates in accordance with the rotation of the drive cylinder 102 and moves in the optical axis direction, the cam follower 107 is fitted along the shape of the cam groove of the rotationally movable cylinder 103 in the optical axis direction. Go straight to.
[0061]
In this way, the feeding is performed, and the drive cylinder 102 is retracted by rotating in the reverse direction.
[0062]
The third group lens 203 of the photographic lens 200 is a nut that is integrally held by a third group lens holding frame 215 that holds the third group lens 203 as the lead screw 214 is rotated by a drive source (not shown). Since 217 is screwed into the lead screw 214, the lead screw 214 moves in the optical axis direction as the lead screw 214 rotates, and focus adjustment is performed.
[0063]
FIG. 5 is a block diagram showing a circuit configuration of the camera shown in FIG.
[0064]
The camera 1 includes the above-described photographing lens 200, lens shutter 300, and CCD image pickup device 400. A subject image formed on the CCD image sensor 400 via the photographing lens 200 and the lens shutter 300 is converted by the CCD image sensor 400 into an analog image signal. Here, the lens shutter 300 is for suppressing the occurrence of smear due to light when reading an analog signal from the CCD image pickup device 400.
[0065]
Moreover, the auxiliary light emission part 130 is provided here, This auxiliary light emission part 130 light-emits auxiliary light at the time of low illumination. In addition, the auxiliary light emitting unit 130 can emit light when necessary other than low illuminance.
[0066]
The camera 1 also includes an analog signal processing unit 501, an A / D unit 502, a digital signal processing unit 503, a temporary memory 504, a compression / decompression unit 505, a built-in memory (or memory card) 506, An image monitor 507 and a drive circuit 508 are provided. The CCD image pickup device 400 is driven at a timing generated by a timing generation circuit (not shown) in the drive circuit 508, and outputs an analog image signal. The drive circuit 508 also includes a drive circuit that drives the photographing lens 200, the lens shutter 300, the auxiliary light emitting unit 130, and the like. The analog image signal output from the CCD imaging device 400 is subjected to analog signal processing by the analog signal processing unit 501, A / D converted by the A / D unit 502, and digital signal processed by the digital signal processing unit 503. Data representing the digital signal processed signal is temporarily stored in temporary memory 504. The data stored in the temporary memory 504 is compressed by the compression / decompression unit 505 and recorded in the built-in memory (or memory card) 506. Depending on the shooting mode, the compression process may be omitted and the recording may be performed directly in the built-in memory 506. The data stored in the temporary memory 504 is read out to the image monitor 507, whereby an image of the subject is displayed on the image monitor 507.
[0067]
Further, the camera 1 is provided with a CPU 509 for controlling the entire camera 1, an operation switch group 510, and a shutter button 14. The operation switch group 510 is operated to set a desired photographing state. A photograph is taken by pressing the shutter button 14.
[0068]
Next, a second embodiment of the present invention will be described.
[0069]
The external appearance and circuit configuration of the camera of the second embodiment are the same as the external appearance (FIGS. 1 and 2) and circuit configuration (FIG. 5) in the first embodiment described above, and here, there are differences in the lens mirrors. Only the trunk will be described.
[0070]
6 is a cross-sectional view of the lens barrel according to the second embodiment along the optical axis when the lens barrel is in the retracted state, and FIG. 7 is a maximum extension state of the lens barrel according to the second embodiment as in FIG. It is sectional drawing in alignment with the optical axis at the time. The members having the same functions as those of the lens barrel (FIGS. 3 and 4) in the first embodiment described above have the same reference numerals as those in FIGS. Description will be omitted with reference numerals attached, and description will be made focusing on differences from the lens barrel of FIGS. 3 and 4. The same applies to each of the third and subsequent embodiments described later.
[0071]
The lens shutter 300 provided in the lens barrel 100 of the second embodiment is fixed to a second group lens holding frame 212 that fixes the second group lens 202 of the photographing lens 200 as shown in FIG. ing. Therefore, the second group lens 202 and the lens shutter 300 are always kept at a constant interval regardless of whether the lens barrel 100 is in the retracted state or in the extended state.
[0072]
Here, the maximum opening during the operation of the lens shutter is the opening diameter shown in FIG. 17, and when the lens is retracted, the opening further expands to the opening diameter in the open state shown in FIG. When the lens barrel is retracted, the first lens group 201 of the taking lens 200 enters the opening of the lens shutter 300 that has an open diameter. As a result, the dimension in the optical axis direction when retracted is shorter than the dimension of the conventional example shown in FIG.
[0073]
Thus, the lens group that enters the opening of the lens shutter when retracted may be either one of the lens groups on both sides of the lens shutter.
[0074]
Here, the description has been given of the photographic lens having the three-group configuration. However, the present invention can be applied to a photographic lens having a configuration other than the three-group configuration, for example, a two-group configuration or four or more groups.
[0075]
Further, although an example in which a zoom lens is provided as a photographing lens has been described here, the present invention does not necessarily require that the photographing lens is a zoom lens, and can be retracted and extended. It can also be applied to a camera or the like that maintains the above.
[0076]
Furthermore, here, a lens shutter in which the opening at the time of retraction is further widened than the maximum opening at the time of photographing is illustrated, but the maximum opening at the time of photographing is the opening at the time of retraction, and the lens group is in the opening. You may comprise so that it may enter.
[0077]
Further, here, the relationship between the shutter blades and the diaphragm was not mentioned regarding the lens shutter, but this lens shutter may be a lens shutter in which the shutter blades and the diaphragm blades are combined. Alternatively, a lens shutter provided with a diaphragm may be used.
[0078]
Alternatively, the light amount control member referred to in the present invention does not need to be a lens shutter, and is a diaphragm member having diaphragm blades, or a diaphragm member having a plurality of switchable openings or a single fixed opening. Also good.
[0079]
Next, a third embodiment of the present invention will be described.
[0080]
The appearance of the camera of the third embodiment is the same as that of the first embodiment described above (FIGS. 1 and 2). Here, the circuit configuration is the same as the circuit configuration (FIG. 5) of the first embodiment. In comparison, the only difference is that an aperture unit is provided in place of the lens shutter 300 and the drive circuit 508 drives the aperture blades of the aperture unit, and the appearance and circuit configuration are the subject of the present invention. Instead, only the lens barrel will be described here. Further, in each of the fourth and subsequent embodiments to be described later, illustration and description of the appearance and circuit configuration are omitted.
[0081]
FIG. 8 is a sectional view along the optical axis S showing the retracted state of the lens barrel of the camera of the third embodiment, and FIG. 9 shows the maximum extended state of the lens barrel in the same third embodiment as FIG. 2 is a cross-sectional view along the optical axis S. FIG.
[0082]
The lens barrel 100 includes a photographic lens 200 composed of three groups including a first group lens 201, a second group lens 202, and a third group lens 203 arranged in alignment along the optical axis S. The focus adjustment is performed by moving these lens groups in the optical axis direction, and the focus adjustment is performed by moving the third group lens 203 in the optical axis direction. A diaphragm unit 630 is disposed between the first group lens 201 and the second group lens 202, and a CCD image sensor 400 is disposed behind the photographing lens 200.
[0083]
The aperture unit 630 includes a guide rod 624 that protrudes in the optical axis direction from the back surface thereof. The guide rod 624 holds the second group lens 202 that holds the second group lens 202 behind the aperture unit 630. 212 is slidable in the optical axis direction. A stopper 624a is provided at the rear end of the guide rod 624, and a coil spring 213 is mounted between the diaphragm unit 630 and the second group lens holding frame 212. The second group lens unit 260 including the lens 202 and its holding frame 212 is held movably rearward in the optical axis direction in a manner in which it is spring-biased forward. When the lens barrel is retracted, the aperture unit 630 is configured to move toward the lens unit 260 while compressing the coil spring 213.
[0084]
The retracting and feeding mechanism of the lens barrel 100 is the same as that of the camera (FIGS. 3 and 4) of the first embodiment described above, and a description thereof is omitted.
[0085]
FIG. 10 is an exploded perspective view schematically showing the second lens unit 260 and the aperture unit 630 disposed in front of the second lens unit 260 when retracted.
[0086]
The second group lens unit 260 includes an engagement rod 629 (bar-shaped forced retraction) that extends in the optical axis direction from one corner of the surface of the holding frame 212 that holds the second group lens 202 on the diaphragm unit 630 side toward the diaphragm unit 630 side. Member).
[0087]
On the other hand, the aperture unit 630 includes a circular opening 631 centered on the optical axis S, and this opening 631 allows the second group lens 202 to enter inside as shown in FIG. 10 when retracted. Open to the size possible.
[0088]
The diaphragm unit 630 includes a notch 632 on the extension line of the engagement rod 629 that allows the engagement rod 629 of the lens unit 260 to be introduced during the retracting operation.
[0089]
Further, the aperture unit 630 includes an actuator 633 that rotates the aperture blade 634 (see FIG. 11) about the rotation axis.
[0090]
FIGS. 11A and 11B are schematic diagrams illustrating an example of the structure of the diaphragm blade 634 included in the diaphragm unit 630 and the operation thereof. The diaphragm blade 634 has an open position illustrated in FIG. That is, it is configured to be rotatable around the drive shaft 635 of the actuator 633 between the retracted position and the small aperture position shown in FIG.
[0091]
The drive shaft 635 of the actuator 633 is spring-biased so as to move the aperture blade 634 to the non-retracted position in FIG. 11B, and when energized, the aperture blade 634 is moved to the open position shown in FIG. When the power is cut off, the diaphragm blade 634 is moved again to the non-retracted position shown in FIG.
[0092]
The aperture blade 634 retracts to the side of the aperture 631 of the aperture unit 630 when opened, and does not interfere with the aperture 631, but the plate portion 634a having a size capable of shielding the aperture 631 at the small aperture position (non-retracted position). A small hole 636 that allows light to pass through is formed in the center of the plate portion 634a.
[0093]
Here, when the lens barrel 100 is in the extended state (see FIG. 4), the aperture unit 630 is in a use state for controlling the amount of photographing light passing through the photographing lens 200. When the object scene is relatively dark, the blade 634 moves to the open position retracted by the opening 631 as shown in FIG. 11A, and when the object scene is relatively bright, the blade 634 overlaps the opening 631. Move to the aperture position (non-retracted position). On the other hand, when the lens barrel 100 is in the retracted state (see FIG. 8), the aperture unit 630 is in the retracted state with the aperture blades 634 moved to the open position (retracted position).
[0094]
On the opposite side of the diaphragm blade 634 from the side of the plate 33a with respect to the shaft 635, it does not interfere with the notch 632 of the aperture unit 630 when opened, but moves to a position overlapping the notch 632 when retracted, and during the retracting operation A cam portion 634 b that interferes with the engagement rod 629 entering the notch 632 is provided.
[0095]
Here, as shown in FIG. 10, the engaging rod 629 of the lens unit 260 has a tapered portion 629a at its tip portion, and this engaging rod 629 enters the notch 632 when retracted, and the tapered portion 629a. Then, the cam portion 634b of the aperture blade 634 at the small aperture position is pushed. Then, the cam portion 634b rotates to the open position (retracted position) in FIG. 11 (a) against the spring biasing force of the drive shaft 635 of the actuator 633 to the small aperture position shown in FIG. 11 (b). The second group lens 202 enters the opening 631 thus opened.
[0096]
As described above, in the aperture unit 630, the aperture blade 634 is moved to the retracted position by the engagement rod 629 before the second group lens 202 enters the opening 631, and therefore the aperture is set by the contact of the second group lens 202. The wings will not be destroyed.
[0097]
As is apparent from the above description, according to the third embodiment, when the lens barrel 260 and the aperture unit 630 are retracted as shown in FIG. 8, the second group lens 202 enters the opening 631 of the aperture unit 630. Since it is held, the size when retracted can be shortened compared to the prior art, and a thin camera with excellent portability can be provided.
[0098]
As shown in FIG. 11B, when the diaphragm blade 634 is present in the opening 631 of the diaphragm unit 630, that is, when the diaphragm blade 634 is in the non-retracted position, the lens control system malfunctions or is in use. If the second lens group 202 tries to enter the aperture 631 of the aperture unit 630 due to mechanical impact of the lens unit 260, before the second lens group 202 contacts the aperture blade 634, the engagement rod 629 on the lens unit 260 side is moved. Since the diaphragm blade 634 is moved to the retracted position shown in FIG. 11A in contact with the cam portion 634b of the diaphragm blade 634, there is no possibility that the second lens group 202 contacts the diaphragm blade 634, and the structural strength is high. The retractable length can be shortened while ensuring reliability.
[0099]
The third embodiment is an embodiment in which the present invention is applied to a diaphragm of a digital camera. However, a shutter may be provided instead of the diaphragm, and the present invention may be applied to the shutter. Both of them may be provided, and the present invention may be applied to both of them.
[0100]
Next, a fourth embodiment of the present invention will be described.
[0101]
FIG. 12 is a sectional view along the optical axis S showing the retracted state of the lens barrel of the camera in the fourth embodiment, and FIG. 13 shows the maximum extended state of the lens barrel in the same fourth embodiment as FIG. 2 is a cross-sectional view along the optical axis S. FIG.
[0102]
The lens barrel 100 includes a photographic lens 200 composed of three groups including a first group lens 201, a second group lens 202, and a third group lens 203 arranged in alignment along the optical axis S. The focus adjustment is performed by moving these lens groups in the optical axis direction, and the focus adjustment is performed by moving the third group lens 203 in the optical axis direction. A shutter unit 730 is disposed between the first group lens 201 and the second group lens 202, and a CCD image sensor 400 is disposed behind the photographing lens 200.
[0103]
The shutter unit 730 includes a guide rod 624 that projects in the optical axis direction from the back surface thereof. The guide rod 624 holds the second group lens 202 that holds the second group lens 202 behind the shutter unit 730. 212 is slidable in the optical axis direction. A stopper 624 a is provided at the rear end of the guide rod 624, and a coil spring 213 is mounted between the shutter unit 730 and the second group lens holding frame 212, so that the shutter unit 730 has the second group. The second group lens unit 260 including the lens 202 and its holding frame 212 is held movably rearward in the optical axis direction in a manner in which it is spring-biased forward. When the lens barrel is retracted, the shutter unit 730 is configured to move toward the lens unit 260 while compressing the coil spring 213.
[0104]
The retracting and feeding mechanism of the lens barrel 100 is the same as that of the camera (FIGS. 3 and 4) of the first embodiment described above, and a description thereof is omitted.
[0105]
FIG. 14 is an exploded perspective view schematically showing the second lens unit 260 and the shutter unit 730 disposed in front of the second lens unit 260 when retracted. The second group lens unit 260 has an engagement rod 729 (engagement member) extending in the optical axis direction from one corner of the surface on the shutter unit 730 side of the holding frame 212 that holds the second group lens 202 toward the shutter unit 730 side. It has.
[0106]
On the other hand, the shutter unit 730 includes a circular opening 731 centered on the optical axis S. The opening 731 allows the second lens group 202 to enter the interior when retracted, as shown in FIG. Although it is open to the maximum size, it is closed by shutter blades (not shown) except for a predetermined short time for exposure during shooting. The shutter unit 730 includes a notch 732 on the extension line of the engagement rod 729 that allows the engagement rod 729 of the lens unit 260 to be engaged when retracted.
[0107]
FIGS. 15A and 15B are schematic views showing an example of the structure of the diaphragm blade 733 provided in the shutter unit 730 and its operation. The diaphragm blade 733 has an open position shown in FIG. That is, it is configured to be rotatable around the shaft 734 between the retracted position and the small aperture position shown in FIG. Note that a drive source for rotating the diaphragm blade 733 around the shaft 734 is not shown. The aperture blade 733 is retracted to the side of the opening 731 of the shutter unit 730 when opened, and does not interfere with the opening 731, but when the aperture is small (non-retracted state), the plate portion 733 a having a size capable of shielding the opening 731. Is formed on one side of the shaft 734, and a small hole 735 through which light passes is formed in the center of the plate portion 733a. On the opposite side of the diaphragm blade 733 from the plate 733a side with respect to the shaft 734, it does not interfere with the notch 732 of the shutter unit 730 when opened, but the notch 732 is closed when the aperture is small, and the lens unit 260 side is closed. A plate portion 733 b (regulation member) that regulates engagement of the engagement rod 729 into the notch 732 is provided. Further, a reinforcing plate 736 for increasing the strength of the plate portion 733b is attached to the plate portion 733b. Instead of providing the reinforcing plate 736 separately from the plate portion 733b, the plate portion 733b itself is thickened. It may be formed.
[0108]
By providing the engaging rod 729 and the diaphragm blade 733 having such a configuration in the lens unit 260 and the shutter unit 730, respectively, the diaphragm blade 733 is moved to the retracted position as shown in FIG. Since it moves to open the opening 731 and the notch 732 of the shutter unit 730, the second group lens 202 is allowed to enter the opening 731 and the engagement rod 729 to enter the notch 732. Therefore, the retractable length can be shortened.
[0109]
On the other hand, as shown in FIG. 15B, when the diaphragm blade 733 is in the non-retracted position, the shutter unit 730 is moved to the lens unit 260 due to malfunction of the lens control system or light quantity control system or mechanical shock during use. In the case of moving in the approaching direction, the plate portion 733b of the diaphragm blade 733 comes to the tip of the engagement rod 729 before the diaphragm blade 733 in the non-retreat position and the second group lens 202 come into contact with each other. Since the lens unit 260 and the shutter unit 730 are prevented from approaching each other by contact, there is no possibility of the diaphragm blade 733 being destroyed by the contact of the second lens group 202.
[0110]
As is clear from the above description, according to the fourth embodiment, the lens unit 260 and the shutter unit 730 are in a state in which the second lens group 202 enters the opening 731 of the shutter unit 730 when retracted as shown in FIG. Since it is held, the size when retracted can be shortened compared with the conventional one, and a thin digital camera with excellent portability can be provided.
[0111]
As shown in FIG. 15B, when the diaphragm blade 733 is present in the opening 731 of the shutter unit 730, that is, when the diaphragm blade 733 is in the non-retracted state, the light quantity control system malfunctions or the machine in use. Even if the second lens group 202 tries to enter the opening 731 of the shutter unit 730 due to a mechanical impact or the like, the engaging rod 729 on the lens unit 260 side is stopped before the second lens group 202 contacts the aperture blade 733. Since the second group lens 202 and the shutter unit 730 are prevented from coming into contact with the plate portion 733b of the blade 733, there is no possibility that the second group lens 202 contacts the diaphragm blade 733. The retractable length can be shortened while ensuring the reliability of the structural strength.
[0112]
In the fourth embodiment, the restricting portion is provided on the diaphragm blade 733. However, the restricting portion may be provided on the shutter blade or a member interlocked therewith.
[0113]
Next, a fifth embodiment of the present invention will be described. Each of the first to fourth embodiments described so far is an embodiment in which the present invention is applied to a digital camera. However, the present invention is not limited to a digital camera, and is a type for taking a photograph on a silver salt film. It can also be applied to other cameras. However, in this case, the diaphragm or the like is in an open state when retracted, so that it is necessary to configure so that light does not enter the silver salt film when retracted.
[0114]
FIG. 16 is a cross-sectional view along the optical axis S showing a fifth embodiment in which the present invention is applied to a camera for taking a photograph on a silver salt film.
[0115]
In the present embodiment, only the retracted state is shown, and only the characteristic portion to which the present invention is applied will be described.
[0116]
The camera 1 includes a retractable and extended lens barrel 810 that includes a two-group photographic lens 820 including a first group lens 821 and a second group lens 822. Further, a diaphragm unit 830 is provided between the first group lens 821 and the second group lens 822. Although the structure of the aperture unit 830 is not particularly limited, it will be described here as having the same structure as the structure described with reference to FIGS. 10 and 11. In the retracted state shown in FIG. 16, the aperture unit 830 is in a retracted state in which the aperture blade 34 (see FIG. 11) has moved to the retracted position shown in FIG. In the case of the camera shown in FIG. 16, the distal end portion of the second group lens 822 enters the opening 831 of the aperture unit 830 in the retracted state.
[0117]
This camera 1 is a type of camera that takes a picture on the silver salt film 900, so that the silver salt film 900 is not irradiated with light when it is in the retracted state shown in FIG. A focal plane shutter 840 is provided behind the lens barrel 810 to cover the front surface of the silver salt film 900 and shield it from light and open only during shooting.
[0118]
In addition, the camera 1 is provided with an optical viewfinder 850 at the top thereof.
[0119]
The embodiment shown in FIG. 16 is a type of camera that takes a picture on a silver salt film, and includes a focal plane shutter so that light is not incident on the silver salt film except when taking a picture, for example, when retracted. However, it is possible to avoid extra light from entering the silver salt film by providing a lens barrier having a light shielding performance, a front cover, or the like instead of providing the focal plane shutter. In this case, instead of the aperture unit 830, a unit including an aperture / shutter blade is disposed, and a mechanism for forcibly retracting the aperture / shutter blade to the retracted position is provided. Further, it is desirable to provide a mechanical coupling mechanism so that the lens barrier or the front cover is closed before the aperture / shutter blade starts to open even if there is a malfunction or a mechanical shock during use.
[0120]
In each of the above embodiments, the present invention is applied to a retractable camera. However, the present invention does not necessarily require the lens barrel to be completely retracted. Any lens barrel can be used as long as the tube length can be freely changed between the short storage state and the relatively long shooting state.
[0121]
Further, each of the above embodiments is an embodiment of a camera having a lens barrel as an embodiment of the present invention. However, the present invention is also applicable to a single lens barrel such as an interchangeable lens. Can do.
[0122]
【The invention's effect】
As described above, according to the present invention, the dimension in the optical axis direction when the lens barrel is in the retracted state can be further reduced, and the lens barrel having a short tube length and the thin portability are excellent. Camera can be provided.
[Brief description of the drawings]
FIG. 1 is an external perspective view of a first embodiment of a camera of the present invention.
FIG. 2 is an external perspective view of the first embodiment of the camera of the present invention.
3 is a cross-sectional view of the lens barrel of the camera shown in FIGS. 1 and 2 along the optical axis in the retracted state. FIG.
4 is a cross-sectional view of the same lens barrel as in FIG. 3 along the optical axis in a maximum extended state.
5 is a block diagram showing a circuit configuration of the camera shown in FIG. 1. FIG.
FIG. 6 is a cross-sectional view taken along the optical axis when the lens barrel in the second embodiment is in a retracted state.
FIG. 7 is a cross-sectional view along the optical axis when the lens barrel in the second embodiment is in a maximum extended state.
FIG. 8 is a sectional view taken along the optical axis in the retracted state of the lens barrel of the camera of the third embodiment.
FIG. 9 is a cross-sectional view along the optical axis in the maximum extended state of the lens barrel of the camera shown in the third embodiment.
FIG. 10 is an exploded perspective view schematically showing a second group lens unit and a diaphragm unit disposed in front of the second group lens unit.
FIG. 11A is a schematic diagram showing the structure of the aperture unit when the aperture blade is in the open position, and FIG. 11B shows the structure of the aperture unit when the aperture blade is in the small aperture position. FIG.
FIG. 12 is a cross-sectional view taken along the optical axis in the retracted state of the lens barrel of the camera of the fourth embodiment.
FIG. 13 is a cross-sectional view along the optical axis in the maximum extended state of the lens barrel of the camera of the fourth embodiment.
FIG. 14 is an exploded perspective view schematically showing a second group lens unit and a shutter unit disposed in front of the second group lens unit.
15A is a schematic diagram showing the structure of the shutter unit when the aperture blade is in the open position, and FIG. 15B is the structure of the shutter unit when the aperture blade is in the small aperture position. FIG.
FIG. 16 is a cross-sectional view along the optical axis showing a fifth embodiment in which the present invention is applied to a camera for taking a photograph on a silver salt film.
FIG. 17 is a cross-sectional view taken along the optical axis when a lens barrel of a conventional camera is retracted.
[Explanation of symbols]
1 Camera
12 Flash window
13 Viewfinder objective window
14 Shutter button
100 lens barrel
105 Straight movement frame
200 Photography lens
201 First lens group
202 Second lens group
203 Third lens group
212 Second lens group holding frame
213 Coil spring
260 Lens unit
300 Lens shutter
400 CCD image sensor
629 engagement rod
630 Aperture unit
631 opening
632 Notch
633 Actuator
634 Aperture blade
729 engagement rod
730 Shutter unit
731 Opening
732 Notch
733 aperture blade

Claims (7)

In a lens barrel that has a built-in photographic lens composed of a plurality of lens groups and can change the tube length between a relatively short tube length storage state and a relatively long tube length shooting state,
When in the shooting state, it is in a use state for controlling the amount of shooting light passing through the shooting lens, and when in the storage state, it is in a non-use state with the opening being opened to a predetermined opening diameter. A light quantity control member;
When moving from the photographing state to the retracted state, at least a part of a member constituting any one of the plurality of lens groups constituting the photographing lens enters the opening of the light amount control member. A lens moving mechanism for moving the lens
When the lens barrel moves from the photographing state to the retracted state, the light amount control member is forcibly shifted to the non-use state before the part contacts the light amount control member. A transition member ,
The forcible transition member is a rod-shaped member provided on the lens group side and protruding toward the light amount control member,
When the lens barrel moves from the shooting state to the retracted state, the light amount control member contacts the forcible transfer member prior to the partial contact with the light amount control member, and the forced transfer A lens barrel, wherein the lens barrel receives a driving force when the lens barrel moves toward the housed state via a member and shifts to the non-use state . In a lens barrel that has a built-in photographic lens composed of a plurality of lens groups and can change the tube length between a relatively short tube length storage state and a relatively long tube length shooting state,
When in the shooting state, it is in a use state for controlling the amount of shooting light passing through the shooting lens, and when in the storage state, it is in a non-use state with the opening being opened to a predetermined opening diameter. A light quantity control member;
When moving from the photographing state to the retracted state, at least a part of a member constituting any one of the plurality of lens groups constituting the photographing lens enters the opening of the light amount control member. A lens moving mechanism for moving the lens
When the lens barrel is in the retracted state, the light amount control member is retracted to a predetermined retracted position so that the opening remains open at a predetermined opening diameter. A lens barrel , comprising: a restricting unit that prevents the lens group and the light amount control member from approaching in the optical axis direction when the member is in a non-retracted position . The restricting means is a movement path from outside the movement path of the engagement member in conjunction with the engagement member provided on the lens group side and the light amount control member moving from the retraction position to the non-retraction position. A regulating member that intervenes in the inside, and the regulating member abuts on the engaging member before the at least part of the lens group comes into contact with the light amount control member in the non-retracted position. the lens barrel according to claim 2, characterized in that it is configured to prevent contact. 4. The lens barrel according to claim 3, wherein the light quantity control member is composed of a diaphragm blade, and the restricting member is formed integrally with the diaphragm blade . The lens barrel according to any one of claims 1 to 3, wherein the light amount control member is a lens shutter . The lens barrel according to claim 1, wherein the light amount control member is a diaphragm member . The said light quantity control member is hold | maintained in the open state opened more largely than the maximum opening in the said use state when it is in the said non-use state. The lens barrel according to claim 1.

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