JPH07154703A - Image pickup device - Google Patents

Abstract

PURPOSE:To provide an image pickup device for high definition images which is provided with high responsiveness and durability by eliminating necessity to install the optical system of any new mechanism and is being constituted without any mechanical contact part. CONSTITUTION:A second lens group 1b is made movable in an optical axis direction over a prescribed range for zooming, and a fourth lens group 1d is made movable similarly for focus control. A cabinet 4 holds a first lens group la and an imaging device 3 or the like. A diaphragm member 6 changes the opening diameter of a diaphragm corresponding to a motive force source 7 such as a motor. This device is provided with a magnetic force generating member 101 composed of a permanent magnet or the like for holding the second and fourth lens groups 1b and 1d of movable lens groups respectively vertically to an optical axis with no contact to the cabinet 4 and a magnetic force generating member 102 composed of a permanent magnet or the like for respectively moving the second and fourth lens groups 1b and 1d of the movable lens groups in the optical axis direction with no contact to the cabinet 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state image pickup device for picking up a high-definition image by displacing an optical system holding means by a magnetic force so that an incident light image of an object to be imaged is relatively minutely moved. Regarding the device.

[0002]

2. Description of the Related Art In recent years, due to the increase in the number of pixels of solid-state image pickup devices used in home-use compact video cameras, still video cameras, etc., it has become possible to obtain sufficient image quality in the television standards such as NTSC. However, the current number of pixels is not sufficient to obtain the resolution required for a large-screen image, hard copy, computer graphics, and the like. The number of pixels of the solid-state image pickup device is usually 400,000, and even for high definition, the limit is 2 million, and further improvement is said to be difficult.

Therefore, as another method for realizing a higher pixel count, a method for synthesizing a high-definition image by shifting pixels has been disclosed. This is Japanese Patent Publication Sho 57-31701
No. 63-16064, etc., a method of picking up images by slightly changing the position of the input image light incident on the solid-state image sensor on the solid-state image sensor is used. More information than the number of pixels of the area sensor can be obtained.

In Japanese Patent Laid-Open No. 1-184410, a wedge-shaped polarizing member is inserted in a photographing optical system, an image is moved by rotation of a polarizing portion, the image is periodically taken, and information of more than the number of pixels is obtained. Proposals to get are made.

[0005]

However, these methods have the drawback of being costly because a mechanism for shifting the pixels is required in addition to the driving mechanism of the photographing optical system. Furthermore, the one having an optical system for shifting pixels in the middle of the photographing optical system has a drawback that the entire length of the optical system becomes long. In addition, the above-mentioned mechanism that causes friction such as rotating the polarizing member has drawbacks such as poor response, time required for starting, lack of durability, and sound.

The present invention has been made in order to solve the above problems, and it is not necessary to provide an optical system having a new mechanism, and the structure having no mechanical contact portion allows the responsiveness,
An object is to provide a high-definition image pickup device having excellent durability.

[0007]

The present invention relates to a solid-state image sensor, an optical member for converging an incident light image of an object to be imaged, and a magnetic force acting at least in a plane perpendicular to the photographing optical axis with respect to the photographing optical axis. An optical member holding unit that holds at least a portion of the optical member that is held in a non-contact manner in a vertical plane direction, and the optical system that moves the incident light image of the image-captured object relative to the solid-state image sensor minutely It is an imaging device that shifts pixels by a magnetic force control unit that displaces the holding unit by the magnetic force.

[0008]

By virtue of the above construction, the photographing optical system for shifting the image has no mechanical contact portion, and the structure is simple, and a high-definition image excellent in responsiveness and durability can be obtained.

[0009]

FIG. 1 shows the first embodiment of the present invention. Reference numeral 1a is a first lens group, 1b is a second lens group, 1c is a third lens group, and 1d is a fourth lens group. Among them, the second lens group 1b is movable for zooming, and the fourth lens group 1d is movable in a predetermined range in the optical axis direction for focus adjustment. Reference numeral 2 is an optical low-pass filter, and 3 is an image pickup device such as a CCD. Reference numeral 4 denotes a housing that holds the first lens group 1a, the third lens group 1c, the image pickup device 3, and the like. Reference numeral 5 is a lens holding member of the second lens group, and 6 is a diaphragm member, and the aperture diameter of the diaphragm is changed by a power source 7 such as a motor. Reference numeral 101 denotes a magnetic force generating member made up of a permanent magnet or an electromagnet for holding the second lens group 1b and the fourth lens group 1d, which are movable lens groups, in a direction perpendicular to the optical axis without contacting the housing 4. In addition, at least one place is installed on the circumference of the movable lens group. 102 is a second movable lens group
It is a magnetic force generating member composed of a permanent magnet or an electromagnet for moving the lens group 1b and the fourth lens group 1d in the optical axis direction in a non-contact manner with respect to the housing 4. less than,
A method of controlling the second lens group 1b by the magnetic force generating member of the present invention will be described.

FIG. 2 is a block diagram of the present invention for the second lens group 1b. In FIG. 2, 201 and 202 are permanent magnets, which are fixed to the housing. An electromagnet 203 is composed of a coil and an iron core, and is fixed to the lens holding member of the second lens group. Using these magnets, the second lens group 1b is moved in the optical axis direction in a non-contact manner by a method described later. Reference numerals 204 and 206 denote permanent magnets, which are fixed to the lens holding member of the second lens group. 205, 20
An electromagnet 7 is fixed to the housing. 208, 2
Reference numeral 09 denotes a gap sensor, each of which is an electromagnet 20.
The gap between 5, 207 and the second lens group 1b is detected magnetically or electrically and converted into an electric quantity. A magnetic force control unit 210 controls the magnetic forces of the electromagnets 205 and 207 based on the signals of the gap sensors 208 and 209. The structure of the magnetic force control means 210 is as follows. Reference numeral 211 is an AD converter that converts the signals of the gap sensors 208 and 209 from analog to digital, 212 is a computer including ROM and RAM, and 213 is a DA that converts the digital signals of the computer 212 to analog.
A converter, 214 is a current amplifier, and is composed of electromagnets 205, 2
Supply current to 07. With these configurations, the second lens group 1b is held in the direction perpendicular to the optical axis in a non-contact manner by the method described later.

A method of moving the second lens group 1b in the optical axis direction is described in JP-A-59-198409, so a brief description will be given here. The facing surfaces of the permanent magnet 201 and the permanent magnet 202 have the same polarity (N pole in FIG. 2). When a current is applied to the electromagnet 203 and the polarity becomes as shown in FIG. 2, the second lens group 1b moves in the direction of the third lens group (right side in FIG. 2), and when a current is applied to the electromagnet 203 in the opposite direction, The second lens group 1b moves in the first lens group direction (left side in FIG. 2). Therefore, the position of the second lens group 1b in the optical axis direction can be controlled by controlling the current flowing through the electromagnet 203 by the control means such as a computer.

Next, a method for holding the second lens group 1b in a direction perpendicular to the optical axis direction without contact will be described. Electromagnet 20
Current is applied to 5 in a current direction such that the facing surfaces of the permanent magnet 204 and the electromagnet 205 have the same polarity. Similarly,
The electromagnet 207 is energized in a current direction such that the opposing surfaces of the permanent magnet 206 and the electromagnet 207 have the same polarity. Permanent magnet 204, electromagnet 205, and permanent magnet 206
And the electromagnet 207 repel each other due to the magnetic force, and the repulsive force depends on the magnitude of the current flowing through the electromagnets 205 and 207. Therefore, it can be held in a non-contact manner at a predetermined position perpendicular to the electromagnetic direction. Further, in the plane perpendicular to the optical axis direction, the electromagnets 205, 207
By controlling the magnetic forces of the magnetic force generating members that act in directions different from the direction of the magnetic force of, for example, 90 degrees, the magnetic forces can be combined in any direction within the plane perpendicular to the optical axis. , The movable lens group can be moved by any distance in any direction within the vertical plane.

Next, a current control method for the electromagnets 205 and 207 for slightly moving the second lens group 1b in the direction perpendicular to the optical axis will be described. When the optical axis is the X axis, the decentering sensitivity of each lens group is a function of the position on the x axis, and the decentering sensitivity of the second lens group 1b is α (x), which is perpendicular to the optical axis of the second lens group. If the amount of movement in the direction is w and the amount of shift of the incident light image on the solid-state image sensor is p, then p = α (x) × w
Therefore, the second lens group may be moved (that is, decentered) in the direction perpendicular to the optical axis by w = p / α (x). Therefore, the magnetic force control means 210 determines the position x of the second lens group 1b in the optical axis direction, for example, as disclosed in Japanese Patent Laid-Open No.
No. 181049, a computer reads or calculates α (x) corresponding to x from a ROM table after detection by a lens position detecting device, and the gap sensors 208, 2 are set so that the movement amount becomes w.
The signal from 09 is detected to control the amount of current applied to the electromagnets 205 and 207.

After the photographing is finished, a current is passed through the electromagnet 203 to move the second lens group in the direction of the first lens group (left side in FIG. 2) or in the direction of the third lens group (right side in FIG. 2).
By moving the lens group 1b, the electromagnet 203 and the permanent magnet 201 are moved.
Alternatively, after the permanent magnet 202 is attracted, the electromagnet 20
Even if the power supply to 3, 205 and 207 is stopped, the electromagnet 203
Since the iron core and the permanent magnet 201 or the permanent magnet 202 are attracted to each other, the lens holding member of the second lens group is fixedly held to the housing.

What has been described above is exactly the same for the fourth lens group 1d. If the decentering sensitivity of the fourth lens group 1d is β (x), the fourth lens group is w = p / β (x). If it is decentered, the image on the solid-state image sensor can be shifted by p. Therefore, for example, if p is the pixel pitch of the solid-state image sensor, the number of pixels in the horizontal direction can be doubled by shifting in the horizontal direction of the solid-state image sensor by p / 2, and only p / 2 in the vertical direction. By shifting, the number of pixels in the vertical direction can be doubled. In this way, the signals of different optical images photoelectrically converted by the solid-state image sensor 3 are stored and combined, so that an image with high resolution can be obtained.

[0016]

As described above, according to the present invention, the magnetic force acting in the plane perpendicular to the photographing optical axis so as to slightly move the incident light image of the image pickup object with respect to the solid-state image pickup element. An optical member holding means including at least a part of the optical member held in a non-contact manner in a direction perpendicular to the photographing optical axis,
By displacing in a direction perpendicular to the photographing optical axis by magnetic force, it is possible to obtain a high-definition image pickup device having no mechanical contact portion and having excellent responsiveness and durability.

Further, since the optical member performs zooming or focus adjustment by moving in the optical axis direction,
It is not necessary to add a new mechanism and an optical system for the pixel shift, so that the cost can be reduced, and the total length of the optical system can be shortened as compared with the conventionally proposed photographing optical system for the pixel shift.

Further, even if the optical member moves in the optical axis direction, the amount of displacement in the direction perpendicular to the photographing optical axis can be changed according to the position, so that the object to be imaged can be zoomed or combined. Even if the position of the optical member is changed by performing the focusing operation, it is possible to capture an image in which the pixels are shifted by a predetermined amount.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a main part of an embodiment of the present invention.

FIG. 2 is a configuration diagram of a second lens group shown in FIG.

[Explanation of symbols]

 1a 1st lens group 1b 2nd lens group 1c 3rd lens group 1d 4th lens group 2 Optical low pass filter 3 CCD 4 Housing 5 Lens holding member 6 Aperture member 7 Power source 101,102 Magnetic force generation member

Claims (3)

[Claims] 1. An optical member for collecting an incident light image of an image pickup object on a solid-state image pickup element, and a non-contact holding member in a direction perpendicular to a photographing optical axis by a magnetic force acting at least in a plane perpendicular to the photographing optical axis. The optical member holding means including at least a part of the optical member, and the optical system holding means by the magnetic force so as to slightly move the incident light image of the object to be imaged with respect to the solid-state imaging device. An image pickup apparatus comprising: a magnetic force control unit that displaces in a direction perpendicular to a photographing optical axis. 2. The image pickup apparatus according to claim 1, wherein zooming or focus adjustment is performed by moving the optical member in a photographing optical axis direction. 3. The image pickup apparatus according to claim 2, wherein the position of the optical member in the photographing optical axis direction is adjusted so that the relative minute movement amount of the incident light image of the image pickup object with respect to the solid-state image pickup element becomes equal. An imaging apparatus, wherein the magnetic force control means is used to control the amount of displacement of the optical system holding means in the direction perpendicular to the photographing optical axis.