JPH10262167A - Still video camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of image surface precision based on the movement, etc., of a reflection mirror and also to simplify mechanism by arranging plural photograph optical systems with a different focal distance so as to permit an optical axis to be in parallel and also an image surface to be arranged on one plane, moving a photoelectric conversion element in a longitudinal direction as against the optical axis and aligning the desired photograph optical system to the optical axis. SOLUTION: Respective lenses 8-1 to 10-2 which are provided with a zoom function so as to constitute the photograph optical systems 8, 9 and 10 having a mutually different focal distance are held by a common holding frame at every lens group which constitutes zoom mechanism and moved in the optical axis direction by driving mechanism such as a piezoelectric actuator, etc., so as to form the image of desired magnification on the fixed plane. CCD (photoelectric conversion element) 25 is held by a holding unit 26 which is moved in the longitudinal direction as against the optical axes of the photograph optical systems 8, 9 and 10, moved along the fixed plane and controlled so as to meet the optical axes of the lenses 9-1, 9-2 and 9-3 which constitute the middle photograph optical system 9, for example.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a still video camera using a photoelectric conversion element as an image pickup element.
The present invention relates to a technique for switching an imaging optical system.

[0002]

2. Description of the Related Art Conventionally, as a mechanism for switching a photographing lens of a camera, there is provided a turret type in which a plurality of photographing lenses are provided on the circumference of a disk, and the photographing lens is exchanged by rotating the disk. However, this is not suitable for use with small cameras because of the large size of the device. Therefore,
2. Description of the Related Art There has been known an image pickup apparatus in which a plurality of photographing lenses are built in, and a photographing light beam is bent by a reflection mirror to switch the photographing lenses, thereby enabling multifocal switching. Further, by incorporating a plurality of photographing lenses and rotating the image pickup device (CCD) by 90 degrees to switch the photographing lenses,
There is an electronic still camera capable of performing photographing at a desired magnification (for example, see Japanese Patent Application Laid-Open No. 63-90972). According to these cameras, the configuration becomes simpler than achieving a high magnification zoom with one photographing lens, and
The overall length of the taking lens can be reduced.

[0003]

However, when the photographing lens is switched by using the above-mentioned reflecting mirror, it is difficult to make the image plane of the photographing lens coincide with the image pickup device, and the image plane accuracy is reduced. Tends to decrease. Also, CC
In the one that switches the taking lens by rotating the D,
There is a problem that the degree of perpendicularity of the imaging surface of the CCD with respect to the optical axis of the photographing light beam is not easily obtained, and the mechanism becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and the image plane accuracy is reduced by switching the photographing lens by moving the photoelectric conversion element in a direction perpendicular to the photographing optical system. It is another object of the present invention to provide a still video camera capable of simplifying a mechanism without using the same.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, a plurality of photographing optical systems each having a photographing lens having a different focal length from each other, and an image is formed through these photographing optical systems. In a still video camera including a photoelectric conversion element that converts an optical image into an electric signal,
The photographing optical system is arranged such that its optical axes are parallel to each other, and switches the photographing optical system by moving the photoelectric conversion element in a direction perpendicular to the optical axis.

[0006] In the above arrangement, the imaging optical system is switched by moving the photoelectric conversion element in a direction perpendicular to the optical axis of the imaging optical system, and the imaging light flux from the imaging lens to the photoelectric conversion element is reflected. Since the light enters the photoelectric conversion element without passing through the mirror, the deterioration of the imaging accuracy is less than that in the case where the imaging light beam is reflected by the reflection mirror. In addition, a mechanism for aligning the optical axis of the photoelectric conversion element surface with the optical axis of the imaging light beam can be simplified.

According to a second aspect of the present invention, in the still video camera according to the first aspect, each of the photographing optical systems is oriented in the optical axis direction such that the image planes of the plurality of photographing optical systems are on the same plane. The thing that moves to. In this configuration,
By moving the photoelectric conversion element on one plane, the imaging light flux from the imaging optical system can be captured, so that the mechanism for moving the photoelectric conversion element is simpler.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 5 show a still video camera according to a first embodiment. 1 is an external view of the camera, FIG. 2 is an exploded perspective view of a zoom lens mechanism built in the imaging block, FIG. 3 is an exploded perspective view of a CCD moving mechanism built in the imaging block, and FIG. FIG. 5 is an exploded perspective view of a cover forming the body of FIG.
FIG. 9 is a diagram for explaining a switching operation of a photographing optical system using a CD. In these figures, a still video camera 1
Is composed of a camera body 2 having a partial square shape, an imaging block 3 for photographing, and an LCD 4 for displaying a photographed image. The camera body 2 is provided with a power switch 5, a release switch 6, a control circuit, a battery power supply, and the like.

The imaging block 3 has a zoom function 3
A lens unit 12 consisting of a single holding frame for integrally holding photographing lenses 8-1, 9-1, 10-1 belonging to two photographing optical systems 8, 9, 10 having different focal lengths; A lens unit 13 for holding 2, 9-2, 10-2, and photographing lenses 8-3, 9-3, 10-
A zoom lens mechanism including a lens unit 14 that holds the camera 3 is provided.
10 for converting an optical image formed through the lens 10 into an electric signal
CD25 (photoelectric conversion element), these photographing optical systems 8,
Switch 11a for switching and selecting between 9 and 10
And a zoom switch 11b for changing the focal length of each of the photographing optical systems 8, 9, and 10.

The lens units 12, 13, and 14 constituting the zoom lens mechanism are arranged in the optical axis direction as shown in FIG. The three photographing optical systems 8, 9, and 10 have optical axes different from each other, and are arranged so that the respective optical axes are parallel to each other, and are respectively used for wide (W), middle (M), and tele (T). Has a focal length. These lens units 12, 13, and 14 are linearly zoom-driven in the optical axis direction by three piezoelectric actuators 15, 16, and 17 so that the image planes of the photographing optical systems 8, 9, and 10 are on the same plane. Is done. Photographing lens 8 with different optical axis
1, 9-1 and 10-1 are integrally formed with the lens unit 12, and similarly, the photographing lenses 8-2, 9-2 and 9-
Reference numeral 3 denotes a lens unit 13 and photographing lenses 8-3 and 9-3.
Is integrally formed with the lens unit 14. The glass plate 14 is located at the tele lens position of the lens unit 14.
d is fitted.

A driven piece 12a projecting in the horizontal direction is formed on the right side wall of the lens unit 12, and a support hole 12b is formed on both right and left side walls. Similarly, the lens unit 13 has a driven piece 13a and a support hole 13b, and the lens unit 14 has a driven piece 14a and a support hole 14b. A driving rod 18 of a piezoelectric actuator 15 that reciprocates slowly and rapidly by energization is fitted to the driven piece 12a in a frictionally engaged state. Similarly, the driving rod 19 of the piezoelectric actuator 16 is attached to the driven piece 13a,
The drive rods 20 of the piezoelectric actuator 17 are fitted in a in a frictional engagement state. Support holes 12b, 13
b and 14b include horizontal covers 36 and 37 of the imaging block 3 respectively.
The guide bars 21 and 22 held in (FIG. 4) are inserted, whereby the lens units 12, 13, and 14 are movably held.

The mechanism for moving the CCD 25 is as shown in FIG. 3, and the CCD 25 is provided with a photographing optical system 8, 9, 10
The CCD 25 is arranged so that the light receiving surface thereof is perpendicular to the optical axis. A unit 26 for holding the CCD 25 is formed with a driven piece 26a and a support hole 26b. A driving rod 30 of a piezoelectric actuator 27 for driving the CCD 25 in a direction perpendicular to the optical axes of the imaging optical systems 8, 9, and 10 is fitted in the driven piece 26a in a frictionally engaged state. Also, the support hole 31a of the support member 31 holding the piezoelectric actuator 27 is provided in the support hole 26b.
Is inserted into the guide bar 32,
The CCD 25 is movably held.

As shown in FIG. 4, the body of the imaging block 3 has a casing formed of a case 35, lateral covers 36, 37 and the like, and extends inside the case 35 in a direction perpendicular to the optical axis direction of the photographing optical system. The front and rear space 35 by the partition member 38
a, 35b, and the zoom lens mechanism shown in FIG. 2 described above is provided in the front space 35a.
The CCD moving mechanism shown in FIG. The front wall of the case 35 has three openings 33-.
1, 33-2, 33-3 are provided, and the partition member 38 is provided with three openings 38-1, 38-2, 38-3.

Here, the piezoelectric actuators 15, 16,
Driving operations of 17, 18 will be described. For example, when the lens unit 12 is moved in the direction in which the CCD 25 is located (referred to as the element direction: the direction of the white arrow in FIG. 2), the piezoelectric actuator 15 contracts slowly in the element direction and rapidly expands in the opposite direction. Reciprocate slowly and quickly. When the actuator 15 suddenly extends in the direction opposite to the element direction, the drive rod 18 also moves in the same direction as the movement of the actuator 15. At this time, the lens unit 12 does not move because the total inertia of the lens unit 12 and the total frictional force between the guide bars 21 and 22 and the support holes 12b are larger than the driving force applied to the driving rod 18 from the actuator 15. When the actuator 15 contracts slowly, the lens unit 12 moves in the element direction due to the frictional force between the lens unit 12 and the driving rod 18. When the contraction of the actuator 15 is completed, the movement of the drive rod 18 in the direction of the arrow stops, but the unit 12 still moves in the element direction due to its kinetic energy, and the unit 12 and the drive rod 18 cause the frictional force described above. When kinetic energy is exhausted,
The lens unit 12 stops. By repeating the above operation for each pulse, the unit 12 is driven in the element direction. On the other hand, when moving the lens unit 12 in the direction opposite to the element direction, the actuator 15 may be controlled so as to contract rapidly in the element direction and to slowly expand in the direction opposite to the element. Also, the lens unit 13,
By driving the actuators 16, 17 and 27 in the same manner as described above, the units 13 and 14 can be moved in the optical axis direction, and the CCD 25 can be moved in the direction perpendicular to the optical axis.

In the photographing optical systems 8, 9, and 10, as shown in FIG. 5, when the wide photographing optical system 8 is used, the photographing light flux passes through the photographing lenses 8-1, 8-2, and 8-3. To form an image on the CCD 25. Similarly, when the middle photographing optical system 9 is used, the photographing light beam passes through the photographing lenses 9-1, 9-2, and 9-3 and passes through the telephoto photographing optical system 10
Is used, the photographing light flux is changed to the photographing lens 10-.
All pass through 1, 10-2 and are imaged on the CCD 25. The switching from the wide state to the middle state and to the telescopic state is achieved by operating the zoom lens changeover switch 11a so that the CCD 25 is moved in a direction perpendicular to the optical axis directions of the photographing optical systems 8, 9, and 10. It is performed by

FIG. 6 is a perspective view showing one of the lens units according to a modification of the first embodiment. In each of the lens units 12, 13, and 14 shown in the first embodiment described above, the taking lens is integrally formed.
This lens unit 41 has three partitioned spaces 41a, 4
1b and 41c are formed in the frame, and each partitioned space 41
The lens frame holding the photographing lens is fitted in a, 41b and 41c. A ball frame 42 in which two lens frames 42a and 42b are connected by a connecting member 42c is fitted into the partitioned space 41a.
A ball frame 43 composed of two lenses is
A lens frame 44 in which two lens frames 44a and 44b are combined is fitted in c, and a plurality of such lens units 41 are arranged in the optical axis direction to form a photographing optical system.

FIG. 7 is a block diagram of a control circuit of the still video camera 1. The control circuit includes a CPU 46 and a power supply 47 for controlling the entire camera.
The piezoelectric actuators 15 of the zoom lens mechanism and the CCD moving mechanism (optical system drive: 48) receive operation signals from the power switch 5, the release switch 6, the zoom lens changeover switch 11a, and the zoom switch 11b.
The operations of 16, 17, and 27 are controlled. Also, the CPU 46
Receives an imaging signal from the CCD 25 which is an imaging device,
The captured image is displayed on the LCD 4 as a display device, and the image data is stored in a storage device 49 such as a memory card.

In the still video camera 1 according to the first embodiment, the movement of the CCD 25 in the direction perpendicular to the optical axes of the photographing optical systems 8, 9, 10 causes the photographing optical systems 8, 9, 10 to move. Switching can be performed. Therefore, a decrease in image plane accuracy can be reduced as compared with the case where the imaging light beam is reflected by the reflection mirror. Also, C
The rotation of the CD 25 does not switch the photographing optical systems 8, 9, and 10, so that the photographing light flux does not deviate from the optical axis of the CCD 25 surface. Further, the CCD 25 is moved on one plane to capture the photographic light beams from the photographic optical systems 8, 9, and 10, so that the mechanism can be simplified.

As shown in FIGS. 2 and 6, since one lens unit holds a plurality of photographing lenses of a photographing optical system, the positional relationship of the optical axes between different photographing lenses is kept constant. It becomes easier. In particular, as shown in FIG. 2, when the lens unit and the photographing lens are integrally molded, the variation in the position of the lens unit and the photographing lens is reduced, and the production and assembly are facilitated, and the productivity is improved. The number of parts can be reduced, and the cost can be reduced.

Further, the lens units 12, 9 and 10 are switched in accordance with the photographing optical systems 8, 9 and 10 which are switched and selected for photographing.
Since the optical drive is performed on the CCDs 13 and 14 by zoom driving to form an optical image on the CCD 25, the number of driving mechanisms for the photographing lens is three (in this embodiment, three), and a driving mechanism is provided for each photographing lens. The driving mechanism of the photographing lens can be simplified as compared with the conventional one. Also, the lens units 12, 1
Piezoelectric actuators 15, 1
Since the motors 6 and 17 are used, downsizing and weight reduction can be achieved as compared with a driving device using a conventional motor or gear.

FIG. 8 is an external view of a zoom lens provided in a still video camera according to the second embodiment. The zoom lens 50 includes two lens units 51 and 5
Three imaging optical systems 5 having different optical axes from each other
0a, 50b, and 50c. The lens unit 51 has three lenses 51a, 51b, 51c, and the lenses 51a, 51b are convex lenses,
Is a concave lens. The lens unit 52 includes six lenses 52a, 52b, 52c, 52d, 52e, 5
The lenses 52b, 52c, and 52d are convex lenses, and the lenses 52a, 52e, and 52f are concave lenses. Reference numeral 53 denotes a glass plate. These lens units 51 and 52 are driven in the optical axis direction by a piezoelectric actuator (not shown) as described above.

The photographing optical system 50a includes a photographing lens 51a,
52a and a glass plate 53, and has a telephoto focal length (25 to 50 mm). Similarly, the photographing optical system 50b includes photographing lenses 51b, 52b, and 52e, and sets the middle focal length (50 to 150 mm) for the middle. The photographing optical system 50c uses the photographing lenses 52d, 51c, 52c, and 52c.
52f, and a wide focal length (150 to 45).
0 mm). Note that these photographing optical systems 50
The same configuration as that of the above-described first embodiment can be applied to the CCD driving mechanisms disposed behind the a, 50b, and 50c.

In general, a zoom lens is composed of a two-component lens group of a component for changing the magnification and a component for ensuring the image plane. In the zoom lens according to the present embodiment, since the lens groups constituting each component are integrated as the lens units 51 and 52, the number of piezoelectric actuators constituting the zoom lens mechanism can be further reduced. The size of the zoom drive mechanism can be reduced, and the size of the camera including the drive mechanism can be reduced.

FIG. 9 is a perspective view of a CCD moving mechanism held in a still video camera according to the third embodiment. The CCD moving mechanism shown in FIG.
Is moved only in a direction perpendicular to the optical axis of the photographing optical system. However, the CCD moving mechanism according to the third embodiment moves the CCD 25 not only in the direction perpendicular to the optical axis but also in the optical axis direction. Is also moved to realize a focusing function. A focusing piezoelectric actuator 55 for moving the CCD 25 in the optical axis direction of the photographing optical system is provided at one rear end of the pedestal 56, and a driving rod 57 of the actuator 55 extends in the optical axis direction. The driving rod 57 is fitted in a hole 58a formed through one end of a moving table 58 for holding the CCD 25 in a frictional engagement state. A hole 58b is provided at the other end of the movable base 58 in the optical axis direction, and a guide bar 59 supported by the base 56 is inserted into the hole 58b. This allows
The moving table 58 is held movably in the optical axis direction.

On the movable table 58, there is provided a CCD moving actuator 60 for moving the CCD 25 in a direction perpendicular to the optical axis. The unit 26 for holding the CCD 25 has a hole 26a.
The drive rod 61 of the actuator 60 is fitted to 6a in a frictional engagement state. Thus, the CCD 25 is movably held in a direction perpendicular to the optical axis. Note that the zoom lens mechanism used in the still video camera may be the same as that in the first or second embodiment.

Thus, the two actuators 55,
By driving the CCD 60, the CCD 25 can be moved not only in the direction perpendicular to the optical axis of the photographing optical system but also in the optical axis direction, so that the focusing function can be realized. This makes it possible to more accurately match the image formation point of the zoom lens with the imaging surface of the CCD 25, and a sharper and more focused image as compared with the still video camera 1 shown in the first embodiment. Can be obtained.

FIG. 10 is a perspective view of a CCD moving mechanism according to a modification of the third embodiment. In this modification, the difference from the above is that the CCD 25 is configured to be able to move up and down.
It is used for a still video camera in which shooting lenses are arranged vertically. An actuator 66 for moving the CCD is provided on the moving table 65, and a driving rod 67 of the actuator 66 extends in the vertical direction. A drive rod 67 is fitted in a hole 26a formed through the unit 26 in a frictional engagement state. Thus, the CCD 25 is movably held. As described above, by driving the CCD 25 in the vertical direction by the piezoelectric actuator 66, even in a still video camera in which photographing lenses are arranged in the vertical direction, similarly to the above, it is possible to prevent a decrease in image plane accuracy and simplify the mechanism. be able to.

FIGS. 11 and 12 show a still video camera according to a fourth embodiment. FIG. 11 is an external view of the still video camera 1, and FIG. 12 is an exploded perspective view of the imaging block 3. In these drawings, members equivalent to those in the above-described first embodiment are denoted by the same reference numerals. The fourth embodiment is different from the first embodiment in the switching of the photographing optical system, that is, the CCD moving mechanism. Imaging block 3
Is composed of three photographing lenses 71, 72, and 73 having different focal lengths and integrally held by a lens unit 70, and a CCD 25 that is skewed with respect to the optical axis of the photographing optical system in accordance with the focal lengths. Have. Imaging block 3
A slide groove 74 is formed in the upper cover 3a, and the CCD protrudes from the slide groove 74 and is movable along the groove 74.
A moving lever 75 is provided. When the lever 75 is manually moved along the groove 74, the CCD 2
5 moves obliquely with respect to the optical axis, so that the photographing optical system is switched.

More specifically, the unit 26 holding the CCD 25 has a hole 26a penetrating therethrough in a direction oblique to the optical axis. A guide bar 78 supported between the walls is inserted. The skew angle of the guide bar 78 with respect to the optical axis is determined by the focal length of the photographing lenses 71, 72, 73. For example, if the photographing lenses 71, 72, and 73 have focal lengths of 25 mm, 50 mm, and 75 mm, respectively, the guide bar 78 may be arranged at an angle of 45 degrees with respect to the optical axis. , 7
Each of the focal positions 2 and 73 and the imaging surface of the CCD 25 can be matched. The skew angle can be freely changed by cutting the hole 26a or setting the angle of the guide bar 78 according to the focal length of the photographing lens.

As described above, in the still video camera 1 according to the fourth embodiment, the photographing lenses 71 and 7 are used.
Since the configuration is such that the CCD 25 is obliquely moved so that the focal positions of the CCDs 2 and 73 coincide with the imaging surface of the CCD 25, a focused image can be obtained with a simple configuration. Further, since the photographing optical system is switched by a manual operation, a driving source such as a piezoelectric actuator is not required, and the size and weight of the camera can be reduced.

The present invention is not limited to the configuration of the above embodiment, and various modifications are possible. For example, in each of the embodiments described above, one having three photographing optical systems has been described, but it is also possible to have more photographing optical systems.

[0032]

As described above, according to the still video camera according to the first aspect of the present invention, the photoelectric conversion element is moved in a direction perpendicular to the optical axis of the photographing optical system, whereby the photographing optical system is moved. Is switched, it is possible to reduce a decrease in image plane accuracy as compared with the case where a reflection mirror or the like is interposed. Further, a mechanism for aligning the photoelectric conversion element surface with the optical axis of the photographing light beam can be simplified.

According to the still video camera of the second aspect of the present invention, the photographic light beam from the photographic optical system can be captured by moving the photoelectric conversion element on one plane. Is simpler.

[Brief description of the drawings]

FIG. 1 is an external view of a still video camera according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of a zoom lens mechanism in the camera.

FIG. 3 is an exploded perspective view of a CCD moving mechanism.

FIG. 4 is an exploded perspective view of a cover forming a body of the imaging block.

FIG. 5 is a diagram for explaining a switching operation of a photographing optical system by moving a CCD.

FIG. 6 is a perspective view showing a lens unit according to a modification of the first embodiment.

FIG. 7 is a block diagram of a control circuit of the still video camera according to the first embodiment.

FIG. 8 is an external view of a zoom lens of a still video camera according to a second embodiment.

FIG. 9 is a perspective view of a CCD moving mechanism in a still video camera according to a third embodiment.

FIG. 10 is a perspective view of a CCD moving mechanism according to a modification of the third embodiment.

FIG. 11 is an external view of a still video camera according to a fourth embodiment.

FIG. 12 is an exploded perspective view of an imaging block of the camera.

[Explanation of symbols]

 1 Still video camera 8, 9, 10 Photographing optical system 8-1, 8-2, 8-3 Photographing lens 9-1, 9-2, 9-3 Photographing lens 10-1, 10-2 Photographing lens 25 CCD ( Photoelectric conversion element)

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tetsuo Kono 2-3-13 Azuchicho, Chuo-ku, Osaka City Inside Osaka International Building Minolta Co., Ltd. (72) Hiroyuki Matsumoto 2-chome Azuchicho, Chuo-ku, Osaka City 13 Osaka International Building Minolta Co., Ltd.

Claims (2)

[Claims] 1. A still video camera comprising: a plurality of photographing optical systems each having a photographing lens having a different focal length from each other; and a photoelectric conversion element for converting an optical image formed through these photographing optical systems into an electric signal. In the imaging optical system, the optical axes are arranged to be parallel to each other, and the imaging optical system is switched by moving the photoelectric conversion element in a direction perpendicular to the optical axis. A still video camera. 2. The still video camera according to claim 1, wherein each of the photographing optical systems moves in the optical axis direction such that the image planes of the plurality of photographing optical systems are on the same plane.