JP4451865B2 - Imaging apparatus having a plurality of optical systems - Google Patents

Description

  The present invention relates to an imaging apparatus having a plurality of optical systems, and more particularly to a zooming or focusing drive mechanism.

  In an imaging apparatus such as a digital camera, zooming and focusing of a lens are performed by separate drive mechanisms and separate drive motors, which hinders downsizing and cost reduction particularly in a compact digital camera.

  The following patent document discloses a configuration in which zooming and focusing can be performed with a single drive motor by configuring the front group lens and the rear group lens so that they can be moved independently of each other by rotation of the drive ring. ing.

JP-A-5-249362

  On the other hand, a digital camera having a plurality of imaging optical systems instead of a single imaging optical system is assumed, and it is possible to cover a wide imaging range without changing lenses by changing the focal length of each. However, there is a problem that the internal configuration is complicated as compared with a single imaging optical system.

  4A and 4B show an example of the appearance of a digital camera including a plurality of imaging optical systems, and FIG. 5 shows an example of the internal structure. The first imaging optical system 200 has a zoom lens having a focal length range of 39 mm to 117 mm in terms of 35 mm film. The user operates the zoom button 120 to set the zoom position. When the desired zoom position is reached, the shutter button 130 is operated to take a picture. The flash 150 is appropriately controlled to emit light according to the brightness of the subject, and the captured image is displayed on the LCD 160. The zoom lens is a so-called bending optical system as shown in FIG. 5, and subject light incident from the first lens group 201 is bent at a right angle by the prism 202, and is applied to the first image sensor 204 via the lens group 203. The image is formed.

  The lens group 203 includes a zooming lens group 203a and a focusing lens group 203b. These are each guided by a rod 210 and configured to be movable in the optical axis direction. The variable power lens group 203a is driven by a feed screw 212 and a nut 213 that are directly connected to the rotation shaft of the drive motor 211, and the combined focal length of the entire lens is changed by its movement. The lens group 203b of the focus adjustment system is driven by a feed screw 215 and a nut 116 that are directly connected to the rotation shaft of the drive motor 214, and the focus of the first imaging optical system 200 is adjusted by the movement.

  The second imaging optical system 300 includes a zoom lens having a focal length range of 130 mm to 390 mm in terms of 35 mm film. This zoom lens is also a bending optical system, and the subject light incident from the first lens group 301 is bent at a right angle by the prism 302 and forms an image of the subject on the second image sensor 304 via the lens group 303.

  The lens 303 includes a zoom lens group 303a and a focus adjustment lens group 303b. These are each guided by a rod 310 and configured to be movable in the optical axis direction. The variable power lens group 303a is driven by a feed screw 312 and a nut 313 that are directly connected to the rotation shaft of the drive motor 311 and changes the total focal length of the entire lens by the movement. The lens 303b of the focus adjustment system is driven by a feed screw 315 and a nut 316 that are directly connected to the rotation shaft of the drive motor 314, and the focus of the second imaging optical system 300 is adjusted by the movement.

  As described above, in the digital camera including the first imaging optical system 200 and the second imaging optical system 300, a total of four drive motors 211, 311, 214, and 314 are required, which increases the size and cost of the digital camera. I will invite you. As disclosed in the above prior art, it is conceivable to share the drive motors 211 and 214 of the first imaging optical system 200 or to share the drive motors 311 and 314 of the second imaging optical system 300. Further simplification of the configuration is desired.

  An object of the present invention is to realize a low cost by reducing the number of drive motors and simplifying the configuration in an imaging apparatus including a plurality of imaging optical systems.

The present invention is an image pickup apparatus having a plurality of optical systems including a first image pickup optical system and a second image pickup optical system having a different angle of view from the first image pickup optical system, the first image pickup optical system and the first image pickup optical system. Sharing the at least one of a zooming drive motor of the two imaging optical systems or a focusing drive motor of the first imaging optical system and the second imaging optical system , and the second imaging optical system is the first imaging optical system And the first imaging optical system and the second imaging optical system are selectively switched according to the zoom position, and the first imaging optical system is selected when zooming up. The zooming drive motor is driven in a direction to increase the focal length of the first imaging optical system and is driven in a direction to decrease the focal length of the second imaging optical system. A driving motor for the zooming when the serial second imaging optical system is selected and drives in the direction of increasing the focal length of the second imaging optical system.

The present invention is also an imaging apparatus having a plurality of optical systems including a first imaging optical system and a second imaging optical system having a different angle of view from the first imaging optical system, the first imaging optical system and The zooming drive motor of the second imaging optical system or at least one of the first imaging optical system and the focusing drive motor of the second imaging optical system is shared, and the second imaging optical system is the first imaging optical system. The angle of view is set to be narrower than that of the optical system, and the first imaging optical system and the second imaging optical system are selectively switched according to the zoom position, and the second imaging optical system When selected, the zooming drive motor drives in a direction to decrease the focal length of the second imaging optical system and drives in a direction to increase the focal length of the first imaging optical system. It said first imaging optical system is a drive motor for the zooming when the selected and drives in the direction of decreasing the focal length of the first imaging optical system I.

The present invention is also an imaging apparatus having a plurality of optical systems including a first imaging optical system and a second imaging optical system having a different angle of view from the first imaging optical system, the first imaging optical system and The zooming drive motor of the second imaging optical system or at least one of the first imaging optical system and the focusing drive motor of the second imaging optical system is shared, and the first imaging optical system is a first variable magnification The second imaging optical system has a second zoom lens group, and the first zoom lens group is screwed into a first feed screw that is rotationally driven by the zooming drive motor. The second zoom lens group is connected to a nut screwed to a second feed screw that is driven to rotate in a direction opposite to the first feed screw by the zooming drive motor. the shall be the feature.

  According to the present invention, since a zooming drive motor or a focusing drive motor is shared by a plurality of imaging optical systems, the configuration can be simplified to reduce the size of the imaging apparatus and the cost can be reduced. Further, by controlling the zooming direction or focusing direction of the plurality of imaging optical systems to a predetermined direction, the plurality of imaging optical systems can be switched smoothly.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The external configuration of the digital camera according to the present embodiment is the same as the configuration shown in FIGS. 4A and 4B, and includes two imaging optical systems including zoom lenses having different focal lengths.

  FIG. 1 shows the internal configuration of the digital camera of this embodiment. The difference from FIG. 5 is that only two zooming drive motors 400 and focusing drive motor 410 are provided.

  A feed screw 401 is directly connected to the zooming drive motor 400, and nuts 213 and 313 are screwed into the feed screw 401. Further, a feed screw 411 is directly connected to the focusing drive motor 410, and nuts 216 and 316 are screwed into this.

  The zooming drive motor 400 performs zooming by rotating in the forward and reverse directions in response to a command from a control circuit (not shown) by operating the zoom button 120 (see FIG. 4B). Zooming is performed by moving both the zoom lens group 203a of the imaging optical system 200 and the zoom lens group 303a of the second imaging optical system 300. At this time, the first imaging optical system 200 and the second imaging optical system 300 are set so that the directions in which the focal lengths change are opposite to each other. That is, when the zooming drive motor 400 rotates in one direction, the first imaging optical system 200 changes in the direction in which the focal length increases from the wide end (39 mm in terms of 35 mm film) to the tele end (117 mm). The second imaging optical system 300 changes in a direction in which the focal length decreases from the tele end (390 mm) toward the wide end (130 mm).

  The focusing drive motor 410 rotates in the forward and reverse directions in response to a command from the control circuit and performs an autofocus operation. At this time, the in-focus subject distances of both imaging optical systems are set to be the same. The That is, when the first imaging optical system 200 is in focus at infinity, the second imaging optical system 300 is also focused at infinity, and the first imaging optical system 200 is focused at a subject distance of 2 m. Is set so that the second imaging optical system 300 is also focused on a subject distance of 2 m.

  When the power of the digital camera is turned on, the digital camera is set to the initial state by the control circuit. In this initial state, the first imaging optical system 200 is in an operating state, the zoom position of the first imaging optical system 200 is set to the wide end (39 mm), and the zoom position of the second imaging optical system 300 is the tele end (390 mm). ).

  There are two methods for the user to select the zoom position or shooting angle of view. The first is to operate the switching button 110 to switch between the first imaging optical system 200 and the second imaging optical system 300. When the imaging optical system is switched using the switch button 110, either the widest angle of view or the telescopic angle of view is often necessary within the range possible with the camera. Setting is effective. Second, the zoom button 120 is operated. When the tele side of the zoom button 120 is operated from the initial state, the zooming drive motor 400 rotates and moves in a direction to increase the focal length of the first imaging optical system 200 (zoom up), and at the same time, the second imaging optical system 300 Move in the direction to decrease the focal length (zoom down).

  Since the first imaging optical system 200 is operating in the initial setting, the image displayed on the LCD 160 is an image obtained by the first imaging optical system 200, and this is changed to an image zoomed up from the wide end (39 mm). I will do it. If the tele side of the zoom button 120 is continuously operated, the tele end (117 mm) of the first imaging optical system 200 is reached, but if the operation is continued further, an image obtained by applying electronic zoom to the image of the first imaging optical system 200 is obtained. Is displayed. Then, when the setting reaches the wide end (130 mm) of the second imaging optical system 300, the imaging optical system is automatically switched, and the second imaging optical system 300 enters an operating state and the image is displayed on the LCD 160.

  At this time, as described above, the first imaging optical system 200 and the second imaging optical system 300 perform zooming so that the directions in which the focal lengths change are opposite to each other, so the first imaging optical system 200 has reached the tele end. At that time, the second imaging optical system 300 has reached the wide end, and can be switched smoothly without moving the zoom lens group 303a of the second imaging optical system again at the time of switching.

  If the zoom button 120 is further operated to the tele side, the zooming drive motor 400 will reversely move and move in the direction to increase the focal length of the second imaging optical system 300 (zoom up).

  When the zoom button 120 is operated to the wide side, the operation is the reverse of the above zoom-up operation. That is, the zooming drive motor 400 rotates and moves in a direction to increase the focal length of the first imaging optical system 200 (zoom up), and moves in a direction to decrease the focal length of the second imaging optical system 300 (zoom down). ). If the wide side of the zoom button 120 is continuously operated, the wide end of the second imaging optical system 300 is reached. However, if the operation is continued further, the imaging optical system is automatically switched, and the first imaging optical system 200 is in the operating state. The image is displayed on the LCD 160. Since the first imaging optical system 200 and the second imaging optical system 300 perform zooming so that the directions in which the focal lengths change are opposite to each other, when the second imaging optical system 300 reaches the wide end, the first imaging optical system 200 reaches the telephoto end, and can be switched smoothly without moving the zoom lens group 203a of the first imaging optical system 200 again at the time of switching. If the zoom button 120 is further operated to the wide side, the zooming drive motor 400 will reversely move and move in the direction to reduce the focal length of the first imaging optical system 200 (zoom down).

  When the shutter button 130 is operated when a desired angle of view is set, an autofocus operation is performed by a known method. An image signal from the operating image sensor is read out and processed, and the focusing drive motor 410 rotates in accordance with the result to adjust the focus of both imaging optical systems. As described above, since the subject distances of both imaging optical systems are set to be the same, even when the imaging optical system is switched by operating the switch button 110 in this state, the autofocus operation is performed from the beginning. There is no need to redo, and it is possible to proceed to the next sequence as it is.

  When the shutter button 130 is further operated in this state, the image signal from the imaging optical system that is operating at that time is processed and stored in a storage medium such as a memory card.

  In the present embodiment, both imaging optical systems are driven by a single feed screw 401, 411. However, both imaging optical systems are controlled so that the directions in which the focal lengths change are opposite to each other. Or if it is difficult to control the distance between the objects of both imaging optical systems to be the same, a separate drive mechanism such as a feed screw is provided for each imaging optical system. You may comprise so that the motive power of the motors 400 and 410 may be transmitted with a gear train or a belt.

  In addition, the drive motors 400 and 410 in the present embodiment are disposed adjacent to each other in the vertical direction at the approximate center of the bending optical system.

  FIG. 2 shows another internal configuration of the digital camera. Also in this example, only the zooming drive motor 400 and the focusing drive motor 410 are provided, and the first imaging optical system 200 and the second imaging optical system 300 share the drive motor. The zooming drive motor 400 is disposed in the vicinity of the lens group 303 a in the bending optical system, and the focusing drive motor 410 is disposed in the vicinity of the first image sensor 304. That is, they are arranged at both ends of the bending optical system.

  FIG. 3 shows still another internal configuration of the digital camera. Also in this example, only the zooming drive motor 400 and the focusing drive motor 410 are provided, and the first imaging optical system 200 and the second imaging optical system 300 share the drive motor. The zooming drive motor 400 is disposed at the same position as in FIG. 1, but the focusing drive motor 410 is disposed at the substantially center of the bending optical system and on the opposite side across the bending optical system.

  FIG. 6 shows still another internal configuration of the digital camera. A feed screw 350 is directly connected to the zooming drive motor 400, and a feed screw 250 is connected to the zooming drive motor 400 via gears G1 and G2. The feed screw 250 and the feed screw 350 are positioned in parallel with each other, and rotate in opposite directions with the rotation of the zooming drive motor 400. The feed screw 250 is a feed screw for driving the zoom lens group 203a of the first imaging optical system 200, and the feed screw 350 is for driving the zoom lens group 303a of the second imaging optical system. It is a feed screw. The lens group 203a is screwed onto the feed screw 250 via a nut, and moves in the axial direction of the feed screw 250 as the feed screw 250 rotates. Further, the lens group 303 a is screwed into the feed screw 350 via a nut, and moves in the axial direction of the feed screw 350 according to the rotation of the feed screw 350. Since the feed screws 250 and 350 rotate in reverse, the moving directions of the lens groups 203a and 303a are also reversed. That is, when the lens group 203a moves in the direction A in the figure, the lens group 303a moves in the direction B in the figure. When the lens group 203a is located at the wide end, the lens group 303a is located at the tele end. When the lens group 203a moves from the wide end toward the tele end, the lens group 303a is directed from the tele end toward the wide end. Moving. Note that a difference in optical design occurs between the movement amounts of the lens group 203a and the lens group 303a, but this difference can be eliminated by making the pitches of the feed screw 250 and the feed screw 350 different. The difference that cannot be eliminated by the pitch can be eliminated by adjusting the gear ratio of the gears G1 and G2. By using the feed screws 250 and 350 in the first imaging optical system 200 and the second imaging optical system 300, respectively, it is possible to reduce the size of the lens barrel in the length direction. Further, by reversing the moving directions of the lens group 203a and the lens group 303a, when the lens group 203a reaches the tele end, the lens group 303a reaches the wide end. Therefore, the tele end of the first imaging optical system To the wide end of the second imaging optical system 300 can be smoothly performed.

  On the other hand, a feed screw 360 is connected to the focus drive motor 410 via a gear, and a lens guide ring 260 is connected via a gear. The feed screw 360 is a feed screw for driving the focus adjustment system lens group 303b of the second imaging optical system. The lens group 303b is screwed onto the feed screw 360 via a nut, and moves in the axial direction of the feed screw 360 as the feed screw 360 rotates. The lens guide ring 260 has a hollow cylindrical shape, and a gear 260a that meshes with the gear of the focus drive motor 41 is formed on the outer periphery. A screw is formed on the inner circumference of the lens guide ring 260, and the inner circumference screw holds the lens group 203b of the focus adjustment system of the first imaging optical system and moves it in the axial direction. The lens guide ring 260 is rotated by the rotation of the focus drive motor 410, and the lens group 203b is moved by the inner peripheral screw. The variable power lens group of the first imaging optical system may be composed of a lens group 204a in addition to the lens group 203a. The lens group 203a is disposed on the front side (subject side) of the shutter / aperture assembly 500, The lens group 204 a can be disposed on the rear side (image sensor side) of the shutter / aperture assembly 500. In this case, the lens group 203a is driven together with the lens group 303a by the zoom lens drive motor 400 as described above, but the lens group 204a may be driven by another drive motor 420 and a feed screw 370.

  As described above, in this embodiment, the zooming drive motor of the first imaging optical system 200 and the zooming drive motor of the second imaging optical system 300 are shared, and the focusing drive motor of the first imaging optical system 200 and the second driving motor are shared. By sharing the focusing drive motor of the imaging optical system 300, the number of drive motors can be reduced.

It is an internal block diagram of the digital camera concerning an embodiment. It is another internal block diagram of the digital camera concerning an embodiment. FIG. 5 is still another internal configuration diagram of the digital camera according to the embodiment. It is an external view (front) of the digital camera which has two imaging optical systems. It is an external view (back surface) of the digital camera which has two imaging optical systems. It is an internal block diagram of a digital camera. FIG. 5 is still another internal configuration diagram of the digital camera according to the embodiment.

Explanation of symbols

  201 first lens group (first imaging optical system), 202 prism (first imaging optical system), 203 lens group (first imaging optical system), 203a variable power lens group (first imaging optical system), 203b Adjustment system lens group (first imaging optical system), 204 first imaging element, 301 first lens group (second imaging optical system), 302 prism (second imaging optical system), 303 lens group (second imaging optical system) ), 303a Variable magnification lens group (second imaging optical system), 303b Focus adjustment system lens group (second imaging optical system), 304 Second imaging element, 400 Zooming drive motor, 401 Feed screw, 410 Focusing drive Motor, 411 feed screw.

Claims (6)

A first imaging optical system;
A second imaging optical system having a different angle of view from the first imaging optical system;
An imaging apparatus having a plurality of optical systems comprising:
Sharing at least one of a zooming drive motor for the first imaging optical system and the second imaging optical system or a focusing drive motor for the first imaging optical system and the second imaging optical system ;
The second imaging optical system is set to have a smaller angle of view than the first imaging optical system,
The first imaging optical system and the second imaging optical system are selectively switched according to a zoom position,
When zooming up and the first imaging optical system is selected, the zooming drive motor drives in a direction to increase the focal length of the first imaging optical system and the focal length of the second imaging optical system. When the zoom is up and the second imaging optical system is selected, the zooming drive motor drives in a direction to increase the focal length of the second imaging optical system. An imaging apparatus having a plurality of optical systems. A first imaging optical system;
A second imaging optical system having a different angle of view from the first imaging optical system;
An imaging apparatus having a plurality of optical systems comprising:
Sharing at least one of a zooming drive motor for the first imaging optical system and the second imaging optical system, or a focusing drive motor for the first imaging optical system and the second imaging optical system;
The second imaging optical system is set to have a smaller angle of view than the first imaging optical system,
The first imaging optical system and the second imaging optical system are selectively switched according to a zoom position,
When zooming down and the second imaging optical system is selected, the zooming drive motor drives in a direction to decrease the focal length of the second imaging optical system and the focal length of the first imaging optical system. When the zoom is down and the first imaging optical system is selected, the zooming drive motor drives in a direction to decrease the focal length of the first imaging optical system. An imaging apparatus having a plurality of optical systems. The apparatus according to claim 1,
An imaging apparatus having a plurality of optical systems, wherein the focusing drive motor drives the first imaging optical system and the second imaging optical system so that focusing distances thereof coincide with each other . The apparatus according to claim 1,
The first imaging optical system has a first variable power lens group,
The second imaging optical system has a second variable power lens group,
A plurality of optical systems, wherein the first zoom lens group and the second zoom lens group are connected to nuts that are screwed into a common feed screw that is rotationally driven by the zooming drive motor. An imaging apparatus having the same. The apparatus according to claim 1,
The first imaging optical system has a first focus adjustment lens group,
The second imaging optical system has a second focus adjustment lens group,
A plurality of optical systems, wherein the first focus adjustment lens group and the second focus adjustment lens group are each connected to a nut screwed into a common feed screw that is rotationally driven by the focusing drive motor. An imaging apparatus having the same. A first imaging optical system;
A second imaging optical system having a different angle of view from the first imaging optical system;
An imaging apparatus having a plurality of optical systems comprising:
Sharing at least one of a zooming drive motor for the first imaging optical system and the second imaging optical system, or a focusing drive motor for the first imaging optical system and the second imaging optical system;
The first imaging optical system has a first variable power lens group,
The second imaging optical system has a second variable power lens group,
The first zoom lens group is connected to a nut that is screwed into a first feed screw that is rotationally driven by the zooming drive motor;
The second variable power lens group is connected to a nut screwed into a second feed screw that is driven to rotate in a direction opposite to the first feed screw by the zooming drive motor. An imaging apparatus having

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