JPH08195902A - Imaging device with switchable aspect ratio - Google Patents

Abstract

(57) [Abstract] [Purpose] The aspect ratio of the effective imaging surface is 16: 9 and 4:
To obtain an image pickup device capable of switching an aspect ratio suitable for a television camera or the like capable of switching to 3. [Structure] Extender switching means for inserting / removing the extender into / from the optical path of the photographing system for displacing the focal length range of the entire system, and for responding to effective screens with different aspect ratios with the imaging position fixed. An image pickup device capable of switching an aspect ratio of an effective screen, which has a conversion lens switching means for inserting and removing a conversion lens in an optical path of the photographing system, wherein the extender is switched in a predetermined range within one operation range of an operation member. And a conversion lens switching means are driven, and a first state in which the extender is inserted in the optical path, a second state in which neither the extender nor the conversion lens is inserted in the optical path, and an optical path The three states of the third state in which the conversion lens is inserted thereinto are continuously realized by one operation of the operation member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device capable of switching the aspect ratio, and for example, when reversibly converting the aspect ratio of an effective screen from 4: 3 to 16: 9, the aspect ratio is used as a part of a photographing system. It is suitable for an image pickup apparatus having a built-in extender such as a TV camera or a video camera in which a conversion conversion lens group is detachably provided.

[0002]

2. Description of the Related Art The aspect ratio, or so-called aspect ratio, of an effective image pickup surface (screen) of a general television camera or video camera is 4: 3. On the other hand, recently, an EDTV system having a screen aspect ratio of 16: 9 has been put into practical use as a next-generation broadcasting system. Therefore, recently, the aspect ratio is 4:
In order to support both the standard TV system of 3 and the EDTV system of 16: 9 aspect ratio, various cameras (imaging devices) can be used by selectively switching between both 16: 9 aspect ratio and 4: 3 aspect ratio. Is proposed.

For example, in an image pickup tube type camera, the aspect ratio is changed while electrically maintaining the diagonal length of the screen by electrically switching the deflection area of the electron beam. However, in order to perform this method using a solid-state image pickup device such as a CCD device, it is necessary to do the following.

As shown in FIG. 9, a camera which uses a CCD device whose original aspect ratio of the image pickup surface 91 is 16: 9 uses the entire area 92 of the 16: 9 aspect ratio screen. On the other hand, when shooting a screen with an aspect ratio of 4: 3, which is a partial area of an image sensor of this size, the left and right sides of the shooting surface 81 are not used as shown in FIG. Only the screen area 82 is used.

Thus, when the image pickup surface of the image pickup device is partially used, the image obtained by the taking lens cannot be effectively utilized because the diagonal length of the screen becomes short, and the diagonal angle of view becomes narrow. However, there is a drawback that the sensitivity decreases.

Conventionally, in a TV camera or the like, a method of changing the focal length range of the entire system by inserting / removing an extender in a part of a photographing system (zoom lens) has been used.
The fact that the diagonal screen becomes narrower by converting the aspect ratio means that in an extender configured for the purpose of extending the focal length of the entire system to the longer side, the apparent focal length is further extended. This is not a problem because the focal length tends to be longer when the extender is used, but when the extender is not used, the wide-angle focal length shifts to the telephoto side, which is a big problem. come.

On the other hand, in Japanese Unexamined Patent Publication No. 6-230279, a lens group for converting an image size (for example, a screen 83 shown by a two-dot chain line in FIG. 8) is arranged on a turret provided for an extender, and the turret is provided. There has been proposed a method for avoiding the above-mentioned drawbacks when the central part of the image pickup surface is used by inserting / removing the conversion lens group (hereinafter referred to as “shrinker”) to / from the optical path by rotating.

[0008]

[Patent Document 1] Japanese Patent Application Laid-Open No. 6-23027
The method proposed in Japanese Patent No. 9 uses the turret method for switching the extender. Therefore, this method is very effective for a large photographic lens such as a lens for studio cameras.

However, in a camera system such as a portable handy camera in which the photographer holds his / her shoulder to take a picture, it is common to manually switch the extender. Therefore, if the turret is newly provided, the following problems occur. Will occur.

(A) The weight of the handy camera system is greatly increased by adding the turret and its rotating mechanism to the photographing system.

(B) Conventionally, in a taking lens for a handy camera, switching of the extender is realized by switching the switching lever up / down or left / right. In order to rotate the turret, it is general to rotate the dial connected to the turret, a knob or the like. This operation will switch not only the shrinker but also the extender, which may cause a photographer who is accustomed to conventional lens operations to feel uncomfortable, but it takes time to switch, which is an obstacle for shooting fast-moving subjects. Will occur.

(C) Since the switching mechanism becomes large and the area of the orbit of the taking lens moves is enlarged, it becomes difficult to see the index provided on the circumference of the lens when manually performing the focus, zoom and iris operations, and Will cause problems.

(D) At the time of shooting, after once selecting the aspect ratio on the camera side, the photographer does not have to be aware of the presence / absence of a shrinker, but is conscious of only the same magnification and the selection of the extender as before. Regardless, if the selection is wrong, the screen may be cut off. For this reason, the photographer who manually operates must be careful about the relationship between the aspect ratio and the shrinker even during the shooting.

According to the present invention, in an image pickup system having a conversion lens (shrinker) for switching the aspect ratio and an extender, the drive mechanism for inserting and removing both lenses into and out of the optical path is appropriately set so that the optical path is changed. The extender or the shrinker can be easily positioned, or neither of them can be positioned, and the aspect ratio switchable imaging device can be easily photographed at the same aspect ratio or different magnification (focal length range) with a predetermined aspect ratio. For the purpose of providing.

[0015]

The aspect ratio switchable image pickup apparatus of the present invention comprises: (1-1) Extender switch for inserting / removing an extender into / from an optical path of a photographing system in order to displace the focal length range of the entire system. Means and a conversion lens switching means for inserting and removing a conversion lens into and out of the optical path of the photographing system in order to correspond to an effective screen having a different aspect ratio with the imaging position fixed. A switchable image pickup device, wherein the extender switching means and the conversion lens switching means are driven in a predetermined range within one operating range of an operating member, and the extender is inserted into an optical path in a first state. And a second state in which neither the extender nor the conversion lens is inserted in the optical path, and a third state in which the conversion lens is inserted in the optical path. It is characterized in that one state is continuously realized by one operation of the operating member.

In particular, (1-1-1) the driving force is intermittently transmitted to the extender switching means and the conversion lens switching means by one operation of the operating member, and the first, second, and second driving means are provided. It must have a selection drive means that realizes the state of 3. (1-1-2) One operation range of the operation member is limited by a stopper so that the operation member is switched to the first state or the second state. (1-1-3) An electric motor for driving the operation member is provided. (1-1-4) The drive of the electric motor is controlled by an input signal from the outside. And so on.

(1-2) Extender switching means for inserting / removing the extender into / from the optical path of the photographing system for displacing the focal length range of the entire system, and an effective screen having different aspect ratios with the image forming position fixed. Is an image pickup device capable of switching the aspect ratio of the effective screen, which has conversion lens switching means for inserting and removing the conversion lens in the optical path of the photographing system in order to correspond to In the range, the extender switching means and the conversion lens switching means are driven, and when the first aspect ratio is set by the aspect ratio setting means, a part of the operating member within the operating range is limited by the stopper. ,
The aspect ratio setting means is adapted to switch only between two states, a first state in which the extender is inserted in the optical path and a second state in which neither the extender nor the conversion lens is inserted in the optical path. When the second aspect ratio is set, the stopper is released, and the first state and the second state are continuously operated by one operation of the operating member, and the third state in which the conversion lens is inserted in the optical path is continued. The feature is that it is realized.

In particular, the present invention is characterized by including selective drive means for intermittently transmitting the driving force to the extender switching means and the conversion lens switching means by one operation of the operating member.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1, 3 and 5 are sectional views of the essential parts of a first embodiment of the present invention, FIG. 2 is a side view of the essential parts of FIG. 1, and FIG. 4 is an external view of the essential parts of an image pickup apparatus according to the present invention. Is.

FIG. 3 shows an aspect ratio 16: 9, 1: 1 mode (no extender 2a or shrinker (conversion lens) 3a in the optical path). FIGS. 1 and 2 show aspect ratio 16: 9, 2x mode (optical path). Figure 5 shows the aspect ratio of 4: 3 and 1x mode (shrinker is inserted in the optical path).

In the figure, reference numeral 1 denotes an extender main body, which accommodates and holds an extender 2a and a shrinker 3a, which will be described later, and serves as a base of the extender mechanism portion.
The extender body 1 is provided between a taking lens body 22 having a zoom lens and a camera body 23. Reference numeral 2 denotes an extender barrel, which holds the extender group 2a.

In the figure, the case is shown in which the image pickup magnification is composed of a magnifying lens with a magnification of 2 and the focal length range of the entire system is changed to double in the longer direction (double mode). Reference numeral 3 denotes a shrinker lens barrel, which holds a conversion lens (shrinker lens) 3a to be inserted into the optical path in correspondence with the image size (aspect ratio). The figure shows a case where the image pickup magnification is composed of a reduction system lens having a magnification of 0.824.

Reference numeral 4 denotes a rotary shaft, which is an extender lens barrel 2.
It corresponds to the center of rotation of. Reference numeral 5 denotes a rotation shaft, which corresponds to the rotation center of the shrinker barrel 3. A sector 6 fixes the rotating shaft 4 and the extender barrel 2. A sector 7 fixes the rotating shaft 5 and the shrinker barrel 3. Reference numeral 8 denotes a switching lever as an operating member, and the extender barrel 2 and the shrinker barrel 3 are mounted on the optical path so that they can be selectively inserted and removed. Reference numeral 9 denotes a lever shaft, to which the switching lever 8 is attached.

The lever shaft 9 is a gear 9 as a selective driving means.
a. Reference numeral 10 denotes a gear, which is fixed to the sector 6 and is shown in FIGS. 1 and 2 in which it is meshed with the gear 9 a of the lever shaft 9. Reference numeral 11 denotes a gear, which is fixed to the sector 7 and can be meshed with the gear 9a of the lever shaft 9 by rotating the lever shaft 8 of the switching lever 8. The rotary shaft 4, the sector 6, the gear 10, and the like constitute one element of the extender switching means. The rotary shaft 5, the sector 7, the gear 11 and the like constitute one element of the conversion lens switching means. The gear 9a is rotated by the turning operation of the switching lever 8 within one operation range.
The driving force is intermittently transmitted to No. 1.

A stopper 12 holds the sector 6 for holding the extender barrel 2 on the optical axis. A stopper 13 holds the sector 7 for holding the shrinker barrel 3 on the optical axis. Reference numeral 14 denotes a spring, which elastically holds the extender barrel 2 and the sector 6. Reference numeral 15 denotes a spring, which elastically holds the shrinker barrel 3 and the sector 7. Reference numeral 21 denotes a driving grip, which is provided on a part of the taking lens 22. Reference numeral 16 denotes a stopper (slide stopper) that limits and releases the rotation range within one operation range of the operation member 8. Reference numeral 17 is a click ball, and the stopper 1 is provided by a click spring 18.
It is pressed in the concave portion of 6.

In this embodiment, the zoom lens (photographing system)
For example, the aspect ratio conversion and the zoom range expansion (magnification) can be performed by attaching or detaching either one of the extender 2a and the shrinker 3a to a part of the relay lens 22 in the optical path of the relay lens, or with neither of them attached. ) Is supported.
Table 1 shows the configuration of the use states of the extender and the shrinker in each mode at this time.

[0027]

[Table 1] As shown in Table-1, there are a total of five modes (shooting conditions) for two aspect ratios desired by the photographer. Actually, there are three arrangements when there is no extender and a shrinker in the optical path, when the extender is arranged, and when the shrinker is arranged. This is because, as described in the related art, it is determined that it is not necessary to correct the extension direction of the focal length based on the use state of the extender. Therefore, even when the same 2x extender is used, in the use mode of the extender with an aspect ratio of 4: 3, 2 ÷ 0.824 = 2.427, so that the overall shooting system has an apparent focus of 2.427x. It becomes the distance.

Further, in the case of the mode with the aspect ratio of 4: 3, the reason why the shrinker is required if both the extender and the shrinker are retracted from the optical path is that the focal length extends to the telephoto side as described above. , Wide-angle shooting causes troubles. However, if a shrinker is formed and this problem is solved, it is possible to use the property as in the present embodiment, and it is possible to use it as an apparently low-magnification extender inserted. In this case, the apparent extender magnification is 1.214, which is the reciprocal of the shrinker magnification.

In the present embodiment, when the aspect ratio setting means (not shown) on the camera body side sets the mode with the aspect ratio of 16: 9 (aspect ratio 16: 9 mode), the shrinker barrel 3 is always It is in a state of being retracted from the optical axis La. At this time, the stopper 16 limits the rotation range within one operation range of the switching lever 8.

By operating the switching lever 8, only the extender lens barrel 2 is inserted / removed on / from the optical axis, and the focal length range of the entire system is set to the same magnification (equal magnification mode) of FIG. Change to double (double mode). In addition, a mode with an aspect ratio of 4: 3 (aspect ratio 4: 3 mode)
In this case, the stopper 16 is moved to the left as shown by the arrow to release the restriction of the turning range within the operating range of the switching lever 8.

Thus, the shrinker barrel 3 or the extender barrel 2 is located on the optical axis, or both of them are located outside the optical axis by one operation within the operating range of the switching lever 8. That is, the operation is changed to one of FIGS. 1, 3 and 5 by one operation of the switching lever 8.

Next, the operation at this time will be described according to the operation of the switching lever 8. 1 and 2 have an aspect ratio of 1
In the case of 6: 9, when the extender is used, the entire system is doubled (aspect ratio 16: 9, doubled mode). At this time, as shown in Table 1, the extender barrel 2 is on the optical axis and the shrinker barrel 3 is on the optical axis La.
It is placed in a position that is retracted from.

When the switching lever 8 is operated in this state, the lever shaft 9 to which the switching lever 8 is attached is attached.
Also rotates, and the gear 10 also rotates integrally via the gear 9a. Since the gear 10 is fixed to the sector 6, the sector 6 is rotated. Thereby, as shown in FIG. 3, the extender barrel 2 is retracted from the optical axis La. At this time, the aspect ratio is 16: 9 and the focal length range of the entire system is the same size mode (aspect ratio 16: 9, same size mode).

On the contrary, when the switching lever 8 is returned, the same member is reversed and the extender barrel 2 is positioned on the optical axis La. During this time, the gear 9 provided on the side of the shrinker barrel 3 does not touch the gear 9a at all, and thus the shrinker barrel 3 remains retracted from the optical path. At this time, the aspect ratio is 16: 9, and the focal length range of the entire system is a mode that is double (aspect ratio 16: 9, double mode).

In this embodiment, even if the switching lever 8 is further rotated in the same direction, the stopper 16 blocks the switching lever 8 and prevents further rotation. This prevents the shrinker barrel 3 from being arranged on the optical path in the mode of the aspect ratio 16: 9 using the stopper 16.

As described above, in the present embodiment, when the aspect ratio (first aspect ratio) 16: 9 mode is selected, the extender operation is switched by the switching lever 8 as in the case of a conventional photographing lens that does not form a shrinker. Only the operation is performed.

Next, the aspect ratio (second aspect ratio)
The case of the 4: 3 mode will be described.

When the aspect ratio 4: 3 mode is selected by the aspect ratio setting means (not shown) on the camera body side or the lens side, switching is performed by retracting the stopper 16 on the lens side to a position where the lever 8 is not blocked. It is carried out.

With respect to the retracting of the extender barrel 2 from the optical axis in FIGS. 1 to 3, the aspect ratio 1 described above is used.
As in the case of the 6: 9 mode, the switching lever 8 is rotated. However, as shown in Table-1, in the aspect ratio 4: 3 mode, 1.214 times when there is no extender in FIG. 3, and 2.14 times when there is an extender in FIG.
It is used as 427 times.

Next, the switching lever 8 is further rotated from the state shown in FIG. At this time, the gear 9a of the lever shaft 9 meshes with the gear 11 without being blocked by the stopper 16,
The sector 7 starts rotating around the rotating shaft 5. At this time, the gear 9 remains disengaged from the gear 10,
The extender barrel 2 remains retracted from the optical path.
That is, by using the gear 9a as the selection driving means when the switching bar 8 is rotated, the gear 9a shown in FIGS.
As shown in, the driving force is intermittently transmitted to the gear 10 and the gear 11.

Thereby, the shrinker barrel 3 is positioned on the optical axis as shown in FIG. At this time, the aspect ratio is 4: 3, and the unit mode is set.

FIG. 6 is a sectional view of the essential portions of Embodiment 2 of the present invention. In this embodiment, as compared with the first embodiment shown in FIGS. 1 to 5, instead of manually rotating the switching lever to rotate the lever shaft 9, the electric motor 25 is used to rotate the lever shaft 26. They are different, and other configurations are the same.

In the figure, 25 is a motor, 26 is a lever shaft similar to the lever shaft 9 of FIG. 1, and partially has teeth 26a. 27 is a position detection device. Although not shown in the figure, a dedicated drive circuit is connected to the position detecting device 27 and the motor 25. Motor 2
The rotation operation of 5 allows the switching operation.

In the present embodiment, the shrinker 3a may not be arranged on the optical path in the 16: 9 aspect ratio mode depending on the state detected by the position detecting device 27 and the command given to the drive circuit. The command signal to the drive circuit may be sent directly from the camera side when the mode is switched by a switch provided on the zoom lens.

In the present invention, the switching axis of the switching lever 8 is arranged to be left with respect to the optical axis when viewed from the camera side. However, when a motor is used, as shown in FIG. It may be configured to. As is clear from the figure, the optical axis and the outer shape of the extender main body and the interval (A dimension) can be reduced, and further improvement can be made so as not to disturb the line of sight of the photographer 24 shown in FIG.

In the first embodiment, the case has been described in which the magnification of the extender is 2. However, other magnifications may be used. In addition, with respect to the camera of the image pickup device whose aspect ratio of the image pickup surface is 4: 3, the aspect ratio which is a part of the area is 1
When shooting a 6: 9 screen, a part of the vertical direction of the screen is not used, but an area of 16: 9 in the central part is used, or in this case, the magnification of the shrinker is changed. 91
You may correspond to this as 7 times. Similarly, even when the aspect ratio is different, a shrinker magnification corresponding to the aspect ratio may be adopted to cope with this.

[0047]

As described above, according to the present invention, in the photographing system having the conversion lens (shrinker) for switching the aspect ratio and the extender, the driving mechanism for inserting / removing both lenses into / from the optical path is appropriate. By setting to, the extender or shrinker can be easily located in the optical path, or neither of them can be located, and the magnification is the same or different at a predetermined aspect ratio (focal length range).
Thus, it is possible to achieve an image pickup device capable of switching the aspect ratio that can be easily photographed.

In particular, in the present invention, an aspect ratio capable of performing a quick extender operation by operating the switching lever as in the prior art without giving a feeling of strangeness to a photographer who is accustomed to the shooting operation of the conventional zoom lens for a handy camera with an extender. It can be applied to cameras with switching function.

Further, since the photographer only needs to be aware of the same magnification and the selection of the extender as usual after once selecting the aspect ratio, these are new learning for the photographer to use the new function of switching the aspect ratio. Is unnecessary,
It is possible to effectively prevent a mistake that is absolutely unacceptable during shooting, such as vignetting of the shot image.

Further, in the aspect ratio 4: 3 mode photographing, an extender function of about 1.2 times can be realized without adding an optical system other than the shrinker prepared for equal magnification. This is because when shooting in a dark place, the amount of light will be halved by using a double extender, so even if it is difficult to increase the focal length, the decrease in light amount is minimized and the focal length on the telephoto side is reduced. It becomes possible to make the lens equivalent to a lens one class above, and it is possible to further extend the range of choice to the photographer with the extender of 2.4 times or more.

When the aspect ratio is 16: 9, the use of a stopper is prevented by using a stopper to prevent vignetting of a photographed image, which is an unforgivable mistake in photographing.

Also, the lens movement locus area is minimized,
Since the entire switching mechanism is extremely simplified, it is possible to reduce the weight of the entire imaging system as compared with the conventional turret type. At the same time, the shape which is smaller than that of the turret type has the effect of not impairing the visibility of the operating scales, index lines and the like arranged on the lens circumference.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part when an extender with an aspect ratio of 16: 9 according to a first embodiment of the present invention is used.

FIG. 2 is a side view of a main part of FIG.

FIG. 3 is a cross-sectional view of a main part of the embodiment 1 of the present invention, which has an aspect ratio of 16: 9 and is of the same size.

FIG. 4 is an external view of a main part of the first embodiment of the present invention.

FIG. 5 is a sectional view of an essential part when a shrinker having an aspect ratio of 4: 3 is used in Example 1 of the present invention.

FIG. 6 is a cross-sectional view of the essential parts of Embodiment 2 of the present invention.

FIG. 7 is a cross-sectional view of an essential part of another embodiment of the present invention.

FIG. 8 is an explanatory diagram showing the relationship between the imaging plane and the image circle when the aspect ratio is 4: 3.

FIG. 9 is an explanatory diagram showing the relationship between the imaging plane, the image circle, and their relationship when the aspect ratio is 16: 9.

[Explanation of symbols]

 1 Extender main body 2 Extender lens barrel 3 Shrinker lens barrel 4,5 Rotating shaft 6,7 Sector 8 Extender switching lever 9,26 Switching shaft (lever shaft) 10,11 Gear 12,13,16 Stopper 14,15 Spring 21 Lens grip 22 lens body 23 camera 24 photographer 25 motor 27 position detection device

Claims (7)

[Claims] 1. An extender switching means for inserting / removing an extender into / from an optical path of a photographing system for displacing a focal length range of the whole system, and an effective screen having different aspect ratios with a fixed image forming position. For this reason, there is provided an imaging device capable of switching the aspect ratio of an effective screen, which has conversion lens switching means for inserting and removing the conversion lens in the optical path of the photographing system. A first state in which the extender switching means and the conversion lens switching means are driven, and the extender is inserted in the optical path; and a second state in which neither the extender nor the conversion lens is inserted in the optical path. Further, the three states of the third state of inserting the conversion lens in the optical path are continuously realized by one operation of the operating member. Image pickup device with switchable image ratio. 2. A driving force is intermittently transmitted to the extender switching means and the conversion lens switching means by one operation of the operating member to realize the first, second and third states. 2. The aspect ratio switchable image pickup apparatus according to claim 1, further comprising: 3. The aspect ratio switching according to claim 1, wherein one operating range of the operating member is limited by a stopper so that the operating member is switched to only the first state or the second state. Possible imaging device. 4. The image pickup apparatus according to claim 2, further comprising an electric motor for driving the operation member. 5. The image pickup apparatus according to claim 4, wherein the drive of the electric motor is controlled by an input signal from the outside. 6. An extender switching means for inserting / removing an extender into / from an optical path of a photographing system for displacing a focal length range of the entire system, and an effective screen having different aspect ratios with a fixed image forming position. For this reason, there is provided an imaging device capable of switching the aspect ratio of an effective screen, which has conversion lens switching means for inserting and removing the conversion lens in the optical path of the photographing system. The extender switching means and the conversion lens switching means are driven, and when the first aspect ratio is set by the aspect ratio setting means, a part of the operating range of the operating member is limited by a stopper to allow the optical path to move. A first state in which the extender is inserted into the optical path, and a second state in which neither the extender nor the conversion lens is inserted into the optical path.
When the second aspect ratio is set by the aspect ratio setting means, the stopper is released, and one operation of the operating member causes the first state and the second state to be switched. An aspect ratio switchable image pickup device, which continuously realizes a state and a third state in which the conversion lens is inserted in the optical path. 7. The aspect ratio according to claim 6, further comprising a selection drive means for intermittently transmitting a driving force to the extender switching means and the conversion lens switching means by one operation of the operation member. Switchable imaging device.