JPH11337796A - Imaging device - Google Patents

Abstract

(57) [Summary] To highly precisely adjust the position of the optical axis of an imaging optical system with respect to an imaging means. An imaging optical system for imaging a subject is provided.
3 and an imaging unit 101 arranged in an image forming unit, a parallel plane plate 102 made of a transparent member arranged in front of the imaging unit, and the parallel plane plate Optical axis changing means 107 and 106 for adjusting the image forming position on the image pickup means by being inclined with respect to the optical axis of the image pickup means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an image pickup apparatus having an image forming optical system and image pickup means.

[0002]

2. Description of the Related Art Hitherto, the adjustment of the optical axis of an image pickup device in an image pickup apparatus depends on the precision of components such as a lens unit and an image pickup device holder, and in many cases, the image pickup device itself is not adjusted. In the case of the adjustment, as shown in FIG. 3, when the image sensor 121 is mounted on the lens block 122, the position is adjusted while swinging the image sensor 121 right and left and up and down.

[0003]

However, in recent years, the miniaturization of the imaging device has been advanced, and it has become impossible to guarantee the center of the device and the optical axis only by the accuracy of the components.

Also, in the case of performing the adjustment as shown in FIG. 3, it is difficult to perform high-precision adjustment by directly moving the image pickup device 121, and there is a deviation when the screws 123 and 124 after adjustment are used. And the like.

[0005] Further, in this type of image pickup apparatus, since a vibration isolator such as a variable apex angle prism is mounted on the front surface of the lens, there is a problem that the apparatus becomes large.

(Object of the Invention) A first object of the present invention is to provide an image pickup apparatus capable of adjusting the position of an optical axis of an image forming optical system with respect to an image pickup means with high accuracy.

[0007] A second object of the present invention is to provide an image pickup apparatus which can be provided with an image stabilizing function while achieving downsizing of the apparatus.

[0008]

According to a first aspect of the present invention, there is provided an image forming optical system for forming an image of an object, and an image pickup apparatus arranged in an image forming section. And a parallel plane plate made of a transparent member disposed in front of the imaging unit, and the parallel plane plate is tilted with respect to the optical axis of the imaging optical system, Optical axis variable means for adjusting the imaging position is provided, and by inclining the parallel plane plate with respect to the optical axis of the imaging optical system, a light beam passing through the parallel plane plate is refracted, and It is characterized in that the center and the imaging position are adjusted.

[0009] In order to achieve the second object,
According to a third aspect of the present invention, there is provided the image pickup apparatus according to the first aspect, further comprising: an anti-vibration unit that supplies an anti-vibration signal to the optical axis changing unit so as to suppress a vibration applied to the device. Driving the optical axis varying means to incline the plane-parallel plate with respect to the optical axis of the imaging optical system so as to correct a change in an imaging position on the imaging means due to a shake of the apparatus. It is characterized by the following.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments. (First Embodiment) FIG. 1 is a cross-sectional view showing a main configuration of an imaging apparatus according to a first embodiment of the present invention.

In FIG. 1, reference numeral 101 denotes an image sensor, 101
a is a photoelectric conversion surface, and 102 is a crystal low-pass filter including an IR cut (infrared cut) filter. Reference numeral 107 denotes a filter holder that holds the quartz low-pass filter 102. The filter holder 107 includes a rotation shaft 107a fitted to the shaft 104 and a position adjustment unit 107b. The position adjustment unit 107b is a screw hole of the fixing unit 105. The adjustment screw 106 is sandwiched between the spherical tip 106a of the adjustment screw 106 and the spring 109 pressed from the fixing portion 108, and the position thereof, that is, the angle of the quartz low-pass filter 102 with respect to the lens optical axis 112 is adjusted. Will be.

Reference numeral 103 denotes (the final lens surface of) the imaging lens;
110a is a principal ray on the lens optical axis 112, 110b, 1
Reference numeral 10c denotes light rays above and below the F number. 111a, 11
Reference numerals 1b and 111c denote principal rays, upper and lower rays at the corners of the screen.

In the above configuration, after the image pickup device 101 such as a CCD is attached to a lens unit (not shown), the adjusting screw 1
By moving the screw portion 06, the crystal low-pass filter 102 can obtain an inclination with respect to the lens optical axis 112 around the axis 104.

Here, assuming that the refractive index of the crystal low-pass filter 102 is n and the thickness is d, the amount of shift の of the lens optical axis 112 depending on the incident angle i, when i is small, Δ = i × (n−1) ) / N × d.

Therefore, for example, by shifting the optical axis by 0.1 mm, an inclination of about 4 ° is generated at a thickness d = 4.5 mm and n = 1.5. In this case, the filter rotation center (axis 104) If the distance from to the tip of the screw (spherical tip 106a) is assumed to be 10 mm, the screw-in amount is 0.7 mm, and extremely fine adjustment can be performed with a large moving amount.

The above is an adjustment in only one direction with respect to the optical axis and only in one direction (for example, the vertical direction). However, by adding an inclination perpendicular to this, adjustment in two directions is possible.

Also, the case where an image pickup device (CCD) is used as the image pickup unit has been described. However, even when the image pickup unit is a silver halide film or the like, a similar effect can be obtained by disposing a parallel flat plate on the front surface of the film. Needless to say. (Second Embodiment) FIG. 2 is a sectional view showing a main part of an image pickup apparatus according to a second embodiment of the present invention.
The same reference numerals are given to the same parts.

The position adjusting unit 107 of the filter holder 107
“b” is abutted by a tension spring 113 on the distal end 114 a of a linearly moving actuator 114 such as a voice coil motor. The distal end portion 114a is configured to move back and forth with the operation of the rectilinear actuator 114.

In the above arrangement, the camera shake state detected by the acceleration sensor (not shown) is controlled by the microcomputer (not shown) and the actuator drive circuit so that the linear
By driving the camera 14, the parallel flat plate-shaped crystal low-pass filter can be tilted to cancel the camera shake state.

According to the above-described first and second embodiments, the parallel plane plate disposed immediately before the image pickup unit is inclined with respect to the optical axis, so that the center of the image pickup unit and the light of the image pickup optical system are changed. The adjustment between the shafts can be performed accurately with a simple structure, and an anti-vibration function can be provided by using an actuator.

[0021]

As described above, according to the first aspect of the present invention, the position of the optical axis of the image forming optical system with respect to the image pickup means can be adjusted with high accuracy.

Further, according to the third aspect of the present invention, it is possible to provide an anti-vibration function while miniaturizing the apparatus.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a main configuration of an imaging device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a main configuration of an imaging device according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view for explaining position adjustment of an imaging element in a conventional imaging device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 101 Image sensor 102 Crystal plane low-pass filter in parallel plane 103 Imaging lens 104 Axis 105 Fixed part 106 Adjusting screw 107 Filter holder 108 Fixed part 109, 113 Spring 112 Lens optical axis 114 Linear actuator

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Harunobu Ichise Canon Inc. 3- 30-2 Shimomaruko, Ota-ku, Tokyo

Claims (4)

[Claims] An imaging optical system for imaging an object;
In an image pickup apparatus provided with an image pickup unit disposed in an image forming unit, a parallel plane plate made of a transparent member disposed in front of the image pickup unit, and the parallel plane plate with respect to an optical axis of the image forming optical system. An optical axis changing means for tilting and adjusting an image forming position on the imaging means. 2. The imaging apparatus according to claim 1, wherein the plane-parallel plate has an optical low-pass function. 3. The image pickup apparatus according to claim 1, further comprising: a vibration control unit that supplies a vibration control signal to the optical axis changing unit in order to suppress a shake applied to the device. 4. The imaging apparatus according to claim 1, wherein the plane-parallel plate has an IR cut function.