JP2006153970A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus of which reliability can be raised by adjusting the focal position of the apparatus to a fixed lens group surely while it has very simple constitution, and the miniaturization can be promoted. <P>SOLUTION: The imaging apparatus of this invention is equipped with: a camera main body 1 consisting of a box body whose one end is opened; a lens barrel 2 which is provided at the opening part of the camera main body 1, and is equipped with a lens group 4 in its inside; and an imaging device 3 which is housed in the inside of the camera main body 1, and which is mounted on the optical axis of the lens group 4, and, moreover, the imaging apparatus is equipped with: freely elastically deformable substrates 6a, 6b which are attached and fixed to the camera main body 1, and on which the imaging device 3 is mounted; a wound coil part 7 which is provided near the imaging device 7 on the substrates 6a, 6b; and a magnet 8 which adjusts the focal position of the imaging device 7 to the lens group by moving the wound coil part 7 while elastically deforming the substrates by generating a electromagnetic field between the wound coil part 7 provided in the camera main body 1 and the magnet 8. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electro-optical image pickup apparatus called a so-called digital camera, and more particularly to an improvement of a focus adjustment mechanism for adjusting a focus position of an image pickup element with respect to a lens group.

An electro-optical imaging device called a so-called digital camera is composed of a lens barrel portion having a lens group and a camera body made of a box having an opening to which the lens barrel portion is attached. On the camera body side, a power button and a shutter button are exposed, and inside the shutter mechanism, an image sensor that converts a subject image captured via a lens group into an electrical signal, and this electrical signal as a video signal A video processing unit that converts the image data into a video signal and a control unit that performs these controls are accommodated.
In this type of imaging apparatus, a plurality of interchangeable lenses can be used for a single camera body, and a focus motor is provided for each interchangeable lens, as in a conventional silver salt film single-lens reflex camera. It was necessary to make it a structure that could move forward and backward.

That is, in order to adjust the focal position of the lens group with respect to the image pickup element, the heavy lens group must be moved back and forth, and a driving mechanism having a large driving force is provided. Inevitably, the drive mechanism becomes rugged and large, which is an obstacle to promoting the downsizing of the imaging apparatus itself.
Therefore, as disclosed in, for example, [Patent Document 1] or [Patent Document 2], the position of the lens group is fixed, and the image sensor side is movable forward and backward with respect to the optical axis of the lens group. An imaging apparatus having a mechanism for adjusting the focal position of the camera has been provided.
JP-A-62-276967 JP-A-5-203864

Specifically, in [Patent Document 1], a solid-state image sensor is arranged in a direction orthogonal to the optical axis of the lens, and this image sensor is supported by a vibration element. The solid-state image sensor vibrates in the lens optical axis direction, and the image sensor vibration device fixes the drive circuit board and the flexible printed circuit board at a predetermined distance from the optical axis in a direction perpendicular to the lens optical axis.
[Patent Document 2] is characterized in that, in an image capturing apparatus capable of exchanging lenses, the moving range of the image sensor is limited in accordance with the focal length of the lens to be mounted. The effective guide length of the guide member that guides the movement of the image sensor is set to a length that can correspond to all the lenses to be mounted.

By the way, in [Patent Document 1], in order to determine the focal point from the output change of the high-frequency component when the focus state is slightly changed by a sine wave, the solid-state imaging device is vibrated in the optical axis direction by the vibration element. Yes. And by fixing the flexible printed circuit board, the stress with respect to the vibration element of this board | substrate is eliminated, and the vibration element fully functions.
As described above, the technique of [Patent Document 1] is a device that determines whether or not the solid-state image sensor is at the in-focus position, and the solid-state image sensor is vibrated by the vibration device. Therefore, unlike the technique of adjusting the position of the solid-state imaging device to the focal position and holding the position with respect to the lens, it is difficult to refer to.

In the technique of [Patent Document 2], the elements constituting the imaging unit are accommodated and held in the imaging unit main body fixed to the exterior body. That is, an image sensor holder that holds the image sensor is movable along the optical axis in a state where the image sensor holder that holds the image sensor is slidably supported by the guide shaft and the guide shaft.
In the drive mechanism of the image sensor holder, a drive gear that meshes with an output gear of a drive motor that is a stepping motor is fixed to the feed shaft. Further, a feed screw portion is cut on the outer periphery of the shaft portion of the feed shaft, and a guide hole provided in one end portion of the image sensor holder is rotatably fitted on the outer periphery of the shaft portion of the feed shaft.

  As described above, in the technique of [Patent Document 2], the image pickup device holder, the feed shaft, the guide shaft, and the gear mechanism must be accommodated in the image pickup unit main body that is a box, and the structure is complicated and the assembly is performed. Work becomes troublesome. In addition, a drive motor must be attached to the outer surface of the imaging unit main body, and it is not possible to reduce the size of the exterior body that accommodates them, that is, the imaging device.

  The present invention has been made by paying attention to the above circumstances, and the object of the present invention is to adjust the focal position of the image pickup element with respect to a fixed lens group while being extremely simple in configuration. Therefore, an object of the present invention is to provide an imaging apparatus that can improve reliability and promote downsizing.

  In order to achieve the above object, an imaging apparatus according to the present invention includes a camera body having a box with one end opened, a lens barrel attached to the opening of the camera body and having a lens group therein, and a camera body. And an image sensor that is mounted on the optical axis of the lens group, and is an elastically deformable substrate that is mounted and fixed to the camera body and on which the image sensor is mounted, and a first provided near the image sensor on the substrate. The first electromagnetic generation means is moved while elastically deforming the substrate by generating an electromagnetic field between the electromagnetic generation means and the first electromagnetic generation means provided in the camera body, and the focus of the imaging device with respect to the lens group Second electromagnetic generation means for adjusting the position.

  According to the present invention, while having a simple configuration, the focus position of the image pickup element can be reliably adjusted with respect to the fixed lens group, so that the reliability can be improved and miniaturization can be promoted. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic cross-sectional view of an electro-optical imaging device (also called a camera module) that is a so-called digital camera, showing a first embodiment of the present invention. In the drawing, the image pickup apparatus is illustrated as a single unit, but may be incorporated into a so-called mobile phone.
This electro-optical imaging device is composed of a camera body 1 composed of a box having one end opened, and a lens barrel 2 attached to the opening end of the camera body 1. The mounting portion of the lens barrel 2 with respect to the camera body 1 is particularly subjected to complete waterproofing and dustproofing.

On the camera body 1 side, a power button and a shutter button are exposed so that a shutter mechanism, an image pickup device 3, a video processing unit for converting the electrical signal into a video signal, and control thereof are provided. A control unit (not shown except for the image pickup device 3) is accommodated.
The lens barrel 2 includes a lens group 4 composed of a plurality of lenses, and the image sensor 3 can convert a subject image captured through the lens group 4 into an electrical signal. Therefore, the image pickup device 3 is disposed on the optical axis of the fixed lens group 4, and the image pickup device is movably attached along the optical axis of the lens group 4 as will be described later, and adjusted so as to match the focal position. It is possible.

  The imaging element 3 is supported via a support mechanism 5 provided in the camera body 1. The support mechanism 5 is provided in the vicinity of the image pickup device 3 and flexible substrates 6a and 6b, which are a plurality of (two) elastically deformable substrates that are attached and fixed to the camera body 1 and on which the image pickup device 3 is mounted. Winding coil portion (first electromagnetic generation means) 7 and a magnet (second electromagnetic generation means) 8 provided at a position facing the winding coil portion 7 in the camera body 1.

  In other words, the flexible substrates 6 a and 6 b have their surface directions oriented in a direction perpendicular to the optical axis of the lens group 4, and their peripheral ends are closely attached and fixed to the camera body 1. Two flexible substrates 6a and 6b are stacked in the vertical direction in the figure, and the central portion of one (here, the lower surface side) flexible substrate 6b is opened. The image pickup device 3 is mounted on the flexible substrate 6a so as to face the opening, and is electrically connected to a control unit (not shown) to receive a control signal.

A color filter 9 is attached to a portion on the other (upper surface side) flexible substrate 6b and facing the image pickup element 3 through the opening of one flexible substrate 6a. The color filter 9 absorbs and removes harmful rays and the like for the image sensor 3.
The winding coil portion 7 is formed in an annular shape with a predetermined distance from the outer peripheral edge of the color filter 9, and is attached and fixed to the flexible substrate 6a on the upper surface side. That is, the winding coil unit 7 is disposed in the vicinity of the image pickup device 3, and is electrically connected to a control unit (not shown) to receive a control signal.

  The magnet 8 is embedded in the peripheral wall of the camera body 1 and is formed in an annular shape, and its inner peripheral surface is exposed to be flush with the inner peripheral surface of the camera body 1. And the inner peripheral surface of the magnet 8 has a predetermined gap with the outer peripheral surface of the winding coil portion 7, and the winding coil portion 7 An electromagnetic field is generated between the two.

The imaging apparatus configured as described above is configured such that when a power button provided on the camera body 1 is pressed for imaging and the lens group 4 is directed toward a subject, the winding coil unit 7 is energized and an electromagnetic field is generated between the magnet 8. Will occur.
While the magnet 8 is attached to the camera body 1 and the position thereof is fixed, the winding coil portion 7 is attached to the flexible substrate 6a, so that the winding coil portion 7 is accompanied by elastic deformation of the flexible substrates 6a and 6b. Is freely movable along the optical axis of the lens group 4.

  The intensity of the electromagnetic field formed between the coil 8 and the magnet 8 changes in accordance with the amount of current applied to the coil 7 and the amount of movement of the coil 7 along the optical axis of the lens group 4 is set. If the winding coil part 7 moves, naturally the flexible substrates 6a and 6b are elastically deformed, and the position of the image sensor 3 attached thereto is adjusted. That is, the focal position of the image sensor 3 with respect to the lens group 4 can be accurately obtained.

Next, when the shutter button is pressed to operate the shutter mechanism, the subject image is taken into the image sensor 3 through the lens group 4, and the subject image is converted into an electrical signal here. This electrical signal is sent to the video processing unit, converted into a video signal, and visualized.
As described above, in the imaging apparatus of the present invention, the image element 3 is attached to the flexible substrates 6 a and 6 b, the winding coil portion 7 is attached to the vicinity of the image element 3, and the camera body 1 is connected to the winding coil portion 7. While having a very simple configuration in which a magnet 8 that forms an electromagnetic field is attached between them, the focus position of the image pickup device 3 is reliably adjusted with respect to the fixed lens group 4 in a state where power consumption is suppressed. Thus, it is possible to promote downsizing of the imaging apparatus itself.

FIG. 2 is a schematic cross-sectional view of an electro-optical imaging device showing a second embodiment of the present invention.
The basic configuration of this electro-optical imaging device is the same as that described above. That is, the camera body 1 and the lens barrel 2 are configured, the image pickup device 3 and the like are accommodated in the camera body 1, and the lens group 4 including a plurality of lenses is provided in the lens barrel 2. There is no change.
The support mechanism 5 that supports the image pickup device 3 on the camera body 1 includes flexible substrates 6 a and 6 b that are attached and fixed to the camera body 1 and support the image pickup device 3, and a winding coil portion (first step) provided around the image pickup device 3. 1 (electromagnetic generating means) 7, a magnet (second electromagnetic generating means) 8 and a parallel guide mechanism (parallel guide mechanism) 10 provided at a position facing the winding coil portion 7 in the camera body 1. .

The configurations of the flexible boards 6a and 6b, the winding coil section 7 and the magnet 8 may be exactly the same as those described above with reference to FIG. Therefore, the parallel guide mechanism 10 will be described in detail here.
Auxiliary piece portions 11 made of a plurality of rigid bodies are integrally projected on the outer shape portion of the winding coil portion 7. The auxiliary piece portion 11 may be formed in an annular shape along the outer shape of the winding coil portion 7, but in order to avoid the influence of an increase in weight, at least at a symmetrical position around the optical axis of the lens group 4. Only one pair may be provided, or preferably three points may be provided at equal intervals on the circumference around the optical axis of the lens group 4.

Each auxiliary piece 11 is provided with a screw hole in the plate thickness direction, and a ball screw 12 is screwed into the screw hole. That is, the ball screw 12 passes through the auxiliary piece portion 11 and the through holes provided in the flexible substrates 6a and 6b. One end portion of the ball screw 12 is supported by a bearing portion a provided on the end surface of the lens barrel 2, and the other end portion is supported by a bearing portion b provided on the inner bottom portion of the camera body 1.
In the imaging apparatus configured as described above, an electromagnetic field is generated between the coil 8 and the magnet 8 by energizing the winding coil unit 7 by pressing the power button provided on the camera body 1 and directing the lens group 4 toward the subject. appear.

The strength of the electromagnetic field formed between the coil 8 and the magnet 8 changes according to the amount of current supplied to the coil 7 and the amount of elastic deformation of the flexible substrates 6a and 6b is adjusted along with the amount of movement of the coil 7. The Since the auxiliary piece portion 11 provided integrally with the winding coil portion 7 is screwed into the ball screw 12, the auxiliary piece portion 11 moves with the elastic deformation of the flexible substrates 6a and 6b, and the ball screw 12 is moved all at once. Rotate to.
Therefore, the ball screw 12 regulates the bias of the elastic force of the flexible substrates 6a and 6b, and the flexible substrates 6a and 6b, the image pickup device 3, and the winding coil portion 7 are guided by the ball screw 12, and the light of the lens group 3 is not tilted. Move parallel to the axis. That is, in addition to the effects of the first embodiment described above, accurate imaging without distortion can be obtained in the image sensor 3.

Although a plurality of ball screws 12 constituting the parallel guide mechanism 10 are arranged and rotated individually, the present invention is not limited to this. For example, the ball screws 12 are rotated and energized simultaneously and synchronously. By providing this means, the parallelism of the image sensor 3 can be maintained more accurately.
Further, instead of the ball screw 12, a combination of a simple cylindrical guide rod and an auxiliary piece portion 11 having a hole through which the guide rod is inserted may be used. At this time, since the guide rod does not rotate, the bearings a and b described above are not necessary. Instead of the ball screw 12, a combination of a rack and pinion may be used, and the bias of the elastic force of the flexible boards 6a and 6b is regulated by elastically pressing the leaf spring against the auxiliary piece 11 or the winding coil part 7. You may do it.

FIG. 3 is a schematic cross-sectional view of an electro-optical imaging device showing a third embodiment of the present invention.
The basic configuration of this electro-optical imaging device is the same as that described above. That is, the camera body 1 and the lens barrel 2 are configured. The camera body 1 houses the image pickup device 3 and the like, and the lens barrel includes a lens group 4 including a plurality of lenses. Absent.
The support mechanism 5 for supporting the imaging device 3 on the camera body 1 includes flexible substrates 6a and 6b, a winding coil portion (first electromagnetic generation means) 7, a magnet (second electromagnetic generation means) 8, A parallel guide mechanism (parallel guide means) 10 and a holding mechanism (holding means) 15 are included.

The configurations of the flexible boards 6a and 6b, the winding coil section 7, the magnet 8 and the parallel guide mechanism 10 excluding the holding mechanism 15 may be exactly the same as those described above with reference to FIG. Therefore, new explanation is omitted. Therefore, the holding mechanism 15 will be described in detail here.
The holding mechanism 15 includes a plurality (at least two) of holding pins 16 provided on the lower surface side flexible substrate 6b and an electromagnetic clamp body 17 provided on the inner bottom portion of the camera body 1 and the same number as the holding pins 16. The

The holding pin 16 is protruded by selecting a portion facing the winding coil portion 7 via the flexible substrates 6 a and 6 b, and the flexible substrates 6 a and 6 b move along the axial direction of the lens group 4. Sometimes, it can move together with the flexible substrates 6a and 6b.
The electromagnetic clamp body 17 has an opening that can be freely opened and closed. When the current is energized, the opening is closed, and the state is maintained even after the power is cut off. In order to reopen the opening, it is sufficient to energize it again, and the open state of the opening is maintained even if the power is turned off thereafter. Each holding pin 16 is set in a state of being inserted into the opening of the electromagnetic clamp body 17 and has a length within a range where it does not contact the inner bottom of the camera body 1 even if the holding pin 16 moves as will be described later. Is set.

The imaging apparatus configured as described above is configured such that a lens group 4 is directed to a subject by pressing a power button (not shown) provided on the camera body 1 for imaging, and the winding coil unit 7 is energized between the magnet 8. An electromagnetic field is generated.
The strength of the electromagnetic field formed between the coil 8 and the magnet coil 8 changes according to the amount of current supplied to the coil 7 and the amount of movement of the coil 7 and the amount of elastic deformation of the flexible substrates 6a and 6b. Is adjusted.
Since the auxiliary piece portion 11 provided integrally with the winding coil portion 7 is screwed to the ball screw 12, the auxiliary piece portion 11 moves as the flexible substrates 6a and 6b are elastically deformed, and the ball screw 12 is moved all at once. Rotate. As a result, the parallel guide mechanism 10 operates as described in the second embodiment, and an accurate image without distortion can be obtained by the image sensor 3.

Then, the holding mechanism 15 is energized at a timing after the image pickup device 3 is displaced to the normal focal position. When the electromagnetic clamp body 17 is energized once, the opening is closed and the holding pin 16 is clamped. Thereafter, the winding coil portion 7 and the electromagnetic clamp body 8 are set to be disconnected, and the focal position of the image pickup device 3 with respect to the lens group 4 is ensured.
That is, if the imaging is completed immediately after setting the focal position of the imaging element 3 with respect to the lens group 4, it is not necessary to hold the position of the imaging element 3 in that state, so the winding coil unit 7 is disconnected. That's fine.

However, imaging is not always completed immediately after setting the focal position, and it may take time. Originally, it is necessary to continue energization to the winding coil part 7 during that time, and the power supply may be consumed at an early stage.
On the other hand, by providing the holding mechanism 15 as in the above-described embodiment, after setting the focal position, no matter how long it takes, there is no adverse effect on the power supply, and usability can be improved.

In the first to third embodiments described above, the winding coil portion (first electromagnetic generating means) 7 is attached to the flexible boards 6a and 6b in the vicinity of the image pickup device 3 to be movable. Although the magnet (second electromagnetic generation means) 8 is attached and fixed to the camera body 1, the present invention is not limited to this, and the winding coil portion 7 is attached to the camera body 1 and the magnet 8 is located in the vicinity of the image sensor 3. You may make it attach to flexible substrate 6a, 6b.
Further, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments.

1 is a schematic cross-sectional view of an imaging apparatus according to a first embodiment of the present invention. FIG. 6 is a schematic cross-sectional view of an imaging apparatus according to a second embodiment of the present invention. FIG. 6 is a schematic cross-sectional view of an imaging apparatus according to a third embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Camera body, 4 ... Lens group, 2 ... Lens barrel, 3 ... Image pick-up element, 6a, 6b ... Flexible substrate, 7 ... Winding coil part (1st electromagnetic generation means), 8 ... Magnet (2nd electromagnetic) Generating means), 10... Parallel guide mechanism (parallel guide means), 15... Holding mechanism (holding means).

Claims (3)

A camera body comprising a box with one end open, a lens barrel mounted in the opening of the camera body and having a lens group therein, and mounted on the optical axis of the lens group housed in the camera body An imaging device comprising:
An elastically deformable substrate mounted and fixed to the camera body, on which the image sensor is mounted;
First electromagnetic generation means provided in the vicinity of the imaging element on the substrate;
A focal point of the imaging element with respect to the lens group is provided in the camera body, and the first electromagnetic generation unit is moved while elastically deforming the substrate by generating an electromagnetic field with the first electromagnetic generation unit. An image pickup apparatus comprising: second electromagnetic generation means for adjusting a position.   2. The imaging according to claim 1, further comprising parallel guide means for guiding the imaging element in parallel along the optical axis of the lens group via the substrate between the camera body and the lens barrel. apparatus. The imaging apparatus according to claim 1, further comprising a holding unit configured to hold a position of the imaging element via the substrate between the camera body and the substrate.

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