JP4971709B2 - Imaging device - Google Patents

Description

  The present invention generally relates to an imaging apparatus, and more particularly, to an imaging apparatus having a lens barrel that extends and retracts an imaging lens.

  Imaging devices such as a film camera using a silver salt film and a digital camera using an imaging element have been widely used. The imaging device is, for example, a zoom camera that can change the focal length of the imaging lens or a single focal camera with a fixed focal length. Such an imaging apparatus generally enables downsizing during non-imaging (i.e., when the camera is turned off) and change of focal length during imaging (i.e., when the camera is turned on). For this purpose, a lens barrel capable of extending and retracting the imaging lens is provided.

  In recent years, in order to improve the portability and the like of the imaging device, the technological development of an internal mechanism for reducing the thickness of the imaging device (miniaturization) and increasing the focal rate change rate (zoom magnification) has progressed. Various mechanisms have been proposed that focus on making the imaging device thinner. For thinning the imaging device, not only thinning (downsizing) the battery and liquid crystal display device provided in the imaging device, but also thinning the lens barrel is an important factor. Thinning the lens barrel means reducing the retractable length of the lens barrel. Accordingly, not only the imaging lens is thinned, but also internal mechanisms such as a shutter mechanism, a diaphragm mechanism, and a focus adjusting mechanism disposed inside the lens barrel are thinned, that is, the thickness of the internal structure of the lens barrel when retracted. It is important to make the technology smaller.

For example, Patent Document 1 discloses a technique for retracting the imaging lens from the optical axis and reducing the thickness of the lens barrel when retracted. Patent Document 2 discloses a technique for reducing the retractable length by making the opening of the optical element arranged on the subject side of the imaging element larger than the imaging lens immediately before it.
JP 2003-315861 A JP 2003-131108 A

  However, since the technique of Patent Document 1 requires a retracting mechanism for retracting the imaging lens, the cost increases. Further, by retracting the imaging lens, the thickness of the lens barrel when retracted is reduced, but a space for storing the retracted imaging lens is required, and the diameter of the lens barrel is increased. As a result, the entire imaging device (left and right direction) is increased in size.

  Patent Document 2 discloses a technique for reducing the distance between the imaging lens and the optical element, but does not disclose the configuration of the entire lens barrel, and relates to thinning (miniaturization) of the lens barrel. Is insufficient disclosure.

  Accordingly, an object of the present invention is to provide an imaging apparatus that can reduce the thickness (collapse length) of the lens barrel when retracted and can realize a reduction in thickness (miniaturization) of the apparatus.

An imaging apparatus according to an aspect of the present invention includes an imaging lens having a plurality of lens groups, an imaging element that converts light from the imaging lens into an electrical signal, a substrate connected to the imaging element, and the imaging lens Provided between the lens group closest to the image sensor and the image sensor, a light amount adjusting means for adjusting the amount of light incident on the image sensor, an actuator for driving the light amount adjuster, and the image sensor A close lens group, a unit on which the light amount adjusting means and the actuator are mounted, and a cam ring having a cam that engages with a cam pin provided in the unit, and by rotating the cam ring, a unit imaging apparatus retractable Before moving in the direction of the optical axis of the imaging lens, when collapsed, at least a portion of said actuator, said shooting In the direction perpendicular to the optical axis of the lens overlaps with the imaging device, at least a portion of said actuator, characterized in that it is disposed in the optical axis direction so as not to overlap with the substrate.

  Further objects and other features of the present invention will become apparent from the preferred embodiments described below with reference to the accompanying drawings.

  According to the present invention, it is possible to provide an imaging apparatus that can reduce the thickness (collapse length) of the lens barrel when retracted, and can realize thinning (miniaturization) of the apparatus.

  Hereinafter, an imaging apparatus according to an aspect of the present invention will be described with reference to the accompanying drawings. In addition, in each figure, the same reference number is attached | subjected about the same member and the overlapping description is abbreviate | omitted. Here, FIG. 1 is a schematic perspective view showing the configuration of the imaging apparatus 1 of the present invention.

  The imaging device 1 is an imaging device that images a subject, and is embodied as a digital camera in the present embodiment. As shown in FIG. 1, the imaging apparatus 1 includes a camera housing 10, a lens barrel 20, a lens barrier unit 30, a light emitting window unit 40, a finder window 50, and a release button 60.

  The camera housing 10 houses components of the imaging device 1 such as an imaging device 70 described later. The lens barrel 20 can change the focal length of the imaging lens and is disposed on the front surface of the camera housing 10. The lens barrier unit 30 is disposed in front of the lens barrel 20 and opens and closes the optical path of the imaging lens in accordance with the power supply state (that is, ON or OFF) of the imaging device 1. The light emitting window 40 constitutes a part of a strobe device that irradiates the subject with illumination light, and is disposed on the front surface of the camera housing 10. The finder window 50 is disposed in the vicinity of the light emitting window 40. The release button 60 is disposed on the upper surface of the camera housing 10 and is a button for starting an imaging preparation operation (focus adjustment operation and photometry operation) and an imaging operation (exposure to an image sensor such as a film or a CCD). The configuration shown in FIG. 1 is a typical configuration of a camera, and the configuration of the imaging apparatus 1 of the present invention is not limited to the configuration shown in FIG.

  Here, a specific configuration of the imaging apparatus 1 will be described. In the following, a characteristic configuration relating to the present invention will be described.

  FIG. 2 is a developed perspective view showing the main part of the imaging apparatus 1, particularly the vicinity of the lens barrel 20. In FIG. 2, reference numeral 70 denotes an image sensor that converts light from the imaging lens into an electrical signal. Reference numeral 80 denotes an optical member that is disposed on the subject side of the image sensor 70 and is a so-called low-pass filter that suppresses generation of a false signal included in an electrical signal output from the image sensor 70. Reference numeral 90 denotes a flexible printed circuit board for connecting an electric signal output from the image sensor to an electric circuit such as a central processing unit. Reference numeral 100 denotes a holding plate for holding the image sensor 70 and the flexible printed board 90. Reference numeral 110 denotes a support plate for attaching the holding plate 100 to the housing of the lens barrel 20. Reference numeral 22 denotes a second group lens unit having a shutter mechanism SM described later. Reference numeral 24 denotes a moving cam ring for moving (advancing and retracting) the second group lens unit 24 in the optical axis direction.

  The lens barrel 20 rotates the movable cam ring 24 by a barrel drive motor (not shown), and the cam provided between the cam provided in the movable cam ring 24 and a cam pin provided in the second group lens unit 22 is connected via a cam. The second group lens unit 22 is moved in the optical axis direction. The specific driving method of the lens barrel 20 is a well-known technique in the industry, and thus detailed description thereof is omitted here.

  FIG. 3 is a schematic cross-sectional view of the second group lens unit 22. As shown in FIG. 3, the second group lens unit 22 has an imaging lens 221 inside. The position of the imaging lens 221 with respect to the imaging element 70 changes according to the rotation (drive) of the movable cam ring 24. As a result, the imaging apparatus 1 (lens barrel 20) can change the focal length (that is, perform zooming) to capture an image.

  In FIG. 3, SS is an area in which shutter splashes and ND splashes are stored. Since the configuration and arrangement of the shutter springs and ND springs are well known in the art, detailed description thereof is omitted here.

  FIG. 4 is a schematic perspective view from the image pickup element 70 side of the second group lens unit 22. In FIG. 4, reference numeral 222 denotes a support plate for pressing a shutter spring or the like. The support plate 222 also holds a shutter mechanism SM described later. Reference numeral 223 denotes a coil unit around which a coil (not shown) is wound. The coil unit 223 energizes the soldering part 223a in accordance with a signal from the central processing unit of the imaging device 1 to generate a magnetic field. Reference numeral 224 denotes a yoke plate for transmitting a magnetic field generated by the coil unit 223 to a rotating magnet 225 described later.

  FIG. 5 is a schematic perspective view showing the shutter mechanism SM including the coil unit 223, the yoke plate 224, the rotating magnet 225, and the shutter spring 226. In the present embodiment, the shutter mechanism SM comprises the coil unit 223, the yoke plate 224, and the rotating magnet 225 as a single unit. This is because the coil unit 223, the yoke plate 224, and the rotating magnet 225 are actuators having one function.

  The magnetic field generated by the coil unit 223 is transmitted to the yoke plate 224 and rotates the rotating magnet 225. Thereby, the rotary magnet 225 can rotate in the X direction shown in FIG. The rotating magnet 225 is coupled (pin coupled) to the shutter spring 226. The shutter spring 226 rotates in the Y direction shown in FIG. 5 in conjunction with the rotating magnet 225. As a result, the shutter splash 226 blocks the imaging optical path, and the imaging apparatus 1 ends imaging (exposure). The shutter mechanism SM is not limited to the configuration shown in FIG. 5, and any configuration known in the art can be applied, and thus further detailed description is omitted. In the present embodiment, the drive mechanism that is driven so that the position with respect to the image sensor 70 at the time of imaging differs from the position with respect to the image sensor 70 at the time of non-imaging is the shutter mechanism SM in the present embodiment.

  FIG. 6 is a schematic cross-sectional view showing the lens barrel 20 when the imaging apparatus 1 is not imaging (when the imaging apparatus 1 is powered off, that is, when the lens barrel 20 is retracted). In FIG. 6, the second group lens unit 22 is disposed inside the area indicated by the broken line. In particular, the coil unit 223, the yoke plate 224, and the rotating magnet 225 are disposed in the region indicated by α in the region indicated by the broken line.

  At least a part of the unit (shutter mechanism SM) including the coil unit 223, the yoke plate 224, and the rotating magnet 225 is imaged with respect to the optical axis direction (OD direction in the drawing) in the shaded area β as shown in FIG. It arrange | positions so that the full length L of the element 70 may overlap. In other words, the unit (shutter mechanism SM) including the coil unit 223, the yoke plate 224, and the rotating magnet 225 and the image sensor 70 are at least partially along the optical axis direction of the image sensor 70 (imaging lens 221). Arranged to overlap. Thereby, the retractable length of the lens barrel 20 can be reduced. In the present embodiment, such a unit is disposed so as to straddle the imaging plane of the image sensor 70.

  Here, the reason why the retractable length of the lens barrel 20 can be reduced in the imaging device 1 of the present invention will be described in detail with reference to FIG. 7A and 7B are diagrams showing the positional relationship between the image sensor 70 and the second group lens unit 22 (lens barrel 20). FIG. 7A shows the positional relationship in the prior art, and FIG. The positional relationship in the invention is shown.

Referring to FIG. 7A, in the prior art, the unit including the coil unit, the yoke plate, and the rotating magnet and the image sensor 70 are not arranged so that at least a part thereof overlaps along the optical axis direction. . Therefore, the second group lens unit 22 (lens barrel 20) cannot be retracted more than the image plane of the image sensor 70. Incidentally, L _A is the length between the imaging plane and the second group lens unit 22 of the image sensor 70.

On the other hand, as described above, the image pickup apparatus 1 of the present invention is such that the unit including the coil unit 223, the yoke plate 224, and the rotating magnet 225 and the image pickup element 70 overlap at least partially along the optical axis direction. Be placed. Accordingly, as shown in FIG. 7 (b), the second group lens unit 22 (lens barrel 20) by the length of at least L _B than the image plane of the image pickup element 70 2 group lens unit 22 (lens barrel 20 ) Can be retracted.

Comparing FIG. 7A and FIG. 7B, the imaging apparatus 1 of the present invention has at least the length of L _C (the length between the imaging element 70 and the optical member 80) as the lens barrel 20. The retractable length of can be reduced. As described above, the imaging apparatus 1 can reduce the retractable length of the lens barrel 20 as compared with the related art, and as a result, the imaging apparatus 1 can be thinned (the entire imaging apparatus can be downsized). be able to.

  In the imaging apparatus 1, as shown in FIG. 8, the flexible printed circuit board 90 and the shutter mechanism SM composed of the coil unit 223, the yoke plate 224 and the rotating magnet 225 are rotated with respect to the optical axis of the imaging element 70. May be arranged. In the present embodiment, the flexible printed circuit board 90 and the shutter mechanism SM are rotated 180 degrees. Here, FIG. 8 is a diagram for explaining the effect when the flexible printed circuit board 90 and the shutter mechanism SM are rotated with respect to the optical axis of the imaging device 70 in the imaging device 1.

FIG. 8A is a projection view showing the lens barrel 20 from the front of the imaging apparatus 1. In FIG. 8 (a), areas where the imaging element 70 and the flexible printed circuit board 90 is not disposed γ are hatched with respect to the diameter L _D of the lens barrel 20. In the present embodiment, a shutter mechanism SM including a coil unit 223, a yoke plate 224, and a rotating magnet 225 is disposed in the region γ.

  In the prior art, as shown in FIG. 8B, a shutter mechanism including a coil unit, a yoke plate, and a rotating magnet is disposed in an area where the flexible printed circuit board 90 exists. Such a configuration requires a space (gap) indicated by E in FIG. 8B in order to avoid interference between components when the second group lens unit 22 (lens barrel 20) is retracted. Accordingly, the lens barrel 20 cannot be retracted by the length of the gap E, and as a result, the thinning of the imaging device is hindered.

On the other hand, as shown in FIG. 8C, the imaging device 1 of the present invention has a shutter mechanism SM composed of a coil unit 223, a yoke plate 224, and a rotating magnet 225 disposed in an area where the flexible printed circuit board 90 does not exist. To do. Thereby, when the lens barrel 20 is retracted, the flexible printed circuit board 90 can be prevented from obstructing the collapse of the lens barrel 20 (shutter drive mechanism SM). Therefore, it is possible to only increase the collapsed length L _F from the image plane of the way, the image pickup device 70 of the lens barrel 20 shown in Figure 8 (c). In other words, the imaging apparatus 1 can retract the lens barrel 20 by a length LG larger than that of the conventional technique.

Thus, the imaging device 1 can reduce the retractable length of the lens barrel 20, and as a result, the imaging device 1 can be thinned (the entire imaging device can be downsized).
In the present embodiment, the flexible printed circuit board 90 and the shutter mechanism SM including the coil unit 223, the yoke plate 224, and the rotating magnet 225 are rotated 180 degrees with respect to the image sensor 70. However, the rotation angle is not limited to 180 degrees as long as the shutter mechanism SM can be disposed in the region γ (the region where the flexible printed circuit board 90 does not exist) illustrated in FIG.

  As described above, according to the present invention, the retractable length of the lens barrel can be reduced, and as a result, the imaging device can be thinned (downsized). Further, by applying the present invention to a camera, the size of the lens barrel in the radial direction is not affected.

  In this embodiment, the shutter mechanism is described as an example of the drive mechanism. However, the drive mechanism is a shutter mechanism or an operation mechanism that operates an optical member such as a diaphragm or an ND filter that adjusts the amount of light from the imaging lens. It may be. Further, it may be an operation mechanism that operates a focus mechanism that focuses the focus of the imaging lens and the imaging element (imaging plane thereof). Also in this case, as described above, an effect of reducing the retractable length of the lens barrel can be obtained. That is, the present invention does not depend on the shape or the like of the shutter mechanism, but can be applied to all driving mechanisms (aperture mechanism, operating mechanism, etc.) inside the lens barrel.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist.

1 is a schematic perspective view illustrating a configuration of an imaging apparatus as one aspect of the present invention. FIG. 2 is a developed perspective view showing the main part of the image pickup apparatus shown in FIG. 1, particularly the vicinity of a lens barrel. It is a schematic sectional drawing of the 2 group lens unit of the lens-barrel shown in FIG. It is a schematic perspective view from the image pick-up element side of the 2 group lens unit shown in FIG. It is a schematic perspective view which shows the shutter mechanism comprised with a coil unit, a yoke board, a rotation magnet, and a shutter spring. It is a schematic sectional drawing which shows the lens barrel at the time of the non-imaging of an imaging device (The state where the power supply of an imaging device is OFF, ie, the time of a lens barrel retracting). FIG. 2 is a diagram illustrating a positional relationship between an imaging element and a second group lens unit (lens barrel) in the imaging apparatus shown in FIG. 1. In the imaging device shown in FIG. 1, it is a figure for demonstrating the effect at the time of rotating and arrange | positioning a flexible printed circuit board and a shutter mechanism with respect to the optical axis of an imaging device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Imaging device 10 Camera housing | casing 20 Lens barrel 22 2nd group lens unit 221 Imaging lens 222 Support plate 223 Coil unit 223a Soldering part 224 Yoke board 225 Rotating magnet 226 Shutter spring 24 Moving cam ring 30 Lens barrier part 40 Light emission window 50 Finder window 60 Release button 70 Image sensor 80 Optical member 90 Flexible printed circuit board 100 Holding plate 110 Support plate SM Shutter mechanism

Claims (5)

An imaging lens having a plurality of lens groups ;
An image sensor that converts light from the imaging lens into an electrical signal;
A substrate connected to the image sensor;
A light amount adjusting means that is provided between a lens group closest to the image sensor of the image pickup lens and the image sensor, and adjusts the amount of light incident on the image sensor;
An actuator for driving the light amount adjusting means;
A lens group closest to the image sensor, a unit equipped with the light amount adjusting means and the actuator;
A cam ring having a cam that engages with a cam pin provided in the unit;
Have
Wherein an imaging device of collapsible Before moving in the direction of the optical axis of the imaging lens of the unit by rotating the cam ring,
When retracted, at least a portion of the actuator overlaps the image sensor in a direction perpendicular to the optical axis of the imaging lens,
At least a part of the actuator is arranged so as not to overlap the substrate in the optical axis direction. 2. The imaging apparatus according to claim 1, wherein at the time of retracting, at least a part of the actuator overlaps the entire length of the imaging element and the imaging element in a direction perpendicular to the optical axis of the imaging lens. The light amount adjusting means, imaging apparatus according to claim 1 or 2, characterized in that a shutter mechanism. The light amount adjusting means, imaging apparatus according to claim 1 or 2, characterized in that a throttle mechanism. Before Symbol light amount adjusting means, imaging apparatus according to claim 1 or 2, characterized in that the ND filter.