JP2005351948A - Imaging apparatus and personal digital assistant equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an imaging apparatus capable of accurately positioning an imaging optical system at a macro-photograph position without an attitude difference problem and further without the need for a detection member. <P>SOLUTION: In the imaging apparatus comprising an imaging element for photo-electrically converting object light, and the imaging optical system which has at least one optical element movable in the direction of the optical axis and guides the object light to an imaging area of the imaging element, a 1st abutment part to which a part of the optical elements is abutted when it moves to the imaging element side, and a 2nd abutment part to which a part of the optical elements is abutted when it moves to the object side are formed, and the 1st abutment part and the 2nd abutment part are located to face each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image pickup apparatus, and more particularly to an image pickup apparatus suitable for being incorporated in a portable terminal and capable of adjusting a focus according to a subject distance.

  Conventionally, small and thin imaging devices have been mounted on small and thin portable terminals such as mobile phones and PDAs (Personal Digital Assistants), which allows not only audio information but also image information to a remote location. It is possible to transmit to each other. As an image pickup element used in these image pickup apparatuses, a solid-state image pickup element such as a CCD (Charge Coupled Device) type image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) type image sensor is used.

  Various types of imaging devices mounted on mobile phones and PDAs have been proposed that can support macro photography.

  As an imaging device that enables macro photography, a projection lens and a cylindrical holder are formed with protrusions and inclined grooves, and the photographing lens is rotated to move the photographing lens in the optical axis direction for assembly. There is disclosed an apparatus that adjusts the focus of time and enables close-up photography using this inclined groove (see, for example, Patent Document 1).

In addition, a lens unit is disclosed that uses a piezoelectric element that expands and contracts in the optical axis direction as an actuator for moving a lens group for zooming or macro photography (see, for example, Patent Document 2).
JP 2002-82271 A JP 2002-107612 A

  The above-described imaging device built in the portable terminal corresponds to the fact that the imaging element used is miniaturized, the focal length of the imaging optical system is very short, and Fno. Therefore, the depth of focus on the image plane side is very shallow, and strict accuracy is required for the amount of movement and the set position of the imaging optical system relative to the imaging plane in the optical axis direction.

  On the other hand, when the projection and the inclined groove are configured to be relatively movable as in the imaging device described in Patent Document 1, the inclined groove necessarily has a clearance with respect to the size and shape of the projection. If the imaging device is facing upward, the protrusion will contact the lower part of the inclined groove, and when the imaging device is downward, the protrusion will contact the upper part of the inclined groove. The problem of the posture difference that only shifts occurs.

  Further, in the lens unit described in Patent Document 2, there is an advantage that a simple configuration can be obtained because the piezoelectric element is driven by open loop control. However, when trying to know whether the lens has moved to a predetermined position, Some kind of detection member for detecting the lens group is necessary.

  In view of the above problems, an object of the present invention is to obtain an imaging apparatus that can accurately position an imaging optical system at a macro imaging position without a problem of a posture difference and without requiring a detection member.

  Said subject is solved by the following means.

  1) An imaging apparatus comprising: an imaging element that photoelectrically converts subject light; and an imaging optical system that includes at least one optical element that can move in an optical axis direction and guides subject light to an imaging region of the imaging element. A first abutting portion that abuts when a part of the optical element moves to the imaging element side and a second abutting portion that abuts when a part of the optical element moves to the subject side are formed. The imaging device, wherein the first contact portion and the second contact portion are disposed to face each other.

  2) The imaging apparatus according to 1), further comprising: a pedestal formed with a leg portion that abuts on the imaging element, wherein the first abutment portion and the second abutment portion are formed on the pedestal.

  3) a first pedestal formed with a leg that contacts the imaging element; and a second pedestal that contacts the first pedestal; the first abutment on the first pedestal; The imaging apparatus according to 1), wherein the second contact portion is formed on the second pedestal.

  4) It has the 1st base and the 2nd base in which the leg part contact | abutted to the said image pick-up element was formed, said 1st contact part in said 1st base, said 2nd in said 2nd base The imaging device according to 1) in which a contact portion is formed.

  5) The imaging apparatus according to 3), further including an urging member that urges the second pedestal toward the imaging element.

  6) The imaging device according to any one of 1) to 5), wherein the optical element movable in the optical axis direction is moved in the optical axis direction by an actuator.

  7) The imaging device according to 6), wherein a piezoelectric element is used for the actuator.

  8) The imaging device according to 6), wherein an electrostatic actuator is used as the actuator.

  9) A portable terminal including the imaging device according to any one of 1) to 8).

  The optical element that can move in the optical axis direction of the present invention forms a first abutting portion that abuts when moving to the image sensor side and a second abutting portion that abuts when moved to the subject side. In addition, the first and second abutting portions are arranged facing each other, so that there is no problem of posture difference, and the imaging optical system is accurately positioned at the macro photographing position without the need for a detection member. A possible imaging device can be obtained.

  Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not limited thereto.

  FIG. 1 is an external view of a mobile phone T which is an example of a mobile terminal according to the present invention.

  In the mobile phone T shown in the figure, an upper housing 41 as a case having one display portion D1 and a lower housing 42 having an operation button P are connected via a hinge 43. An imaging device S (hereinafter also referred to as a camera module) that is an imaging unit is built under the other display unit D2 in the upper housing 41, and the imaging device S is an outer surface of the upper housing 41. It is arranged to capture light from the side.

  The display unit D1 displays various information when the portable terminal is opened as shown in the figure, and the display unit D2 displays information when the portable terminal is folded.

  Note that the position of the imaging device may be arranged above or on the side of the display unit D2 in the upper housing 41. Further, the mobile phone is not limited to a folding type.

  FIG. 2 is a perspective view of the imaging apparatus 100 according to the present invention. This imaging device 100 is built in the position of the imaging device S shown in FIG.

  As shown in the figure, an imaging apparatus 100 includes a printed circuit board 11 on which an imaging element is mounted, an outer frame member 12, and an opening 13 through which the subject light is incident. A lid member 14 is used. Further, a connection unit 17 for connecting the imaging apparatus 100 to another substrate of the mobile terminal, and a flexible printed circuit board FPC for connecting the printed circuit board 11 and the connection unit 17 are connected.

  Hereinafter, the inside of the imaging apparatus 100 will be described. In addition, in the following drawings, in order to avoid duplication of explanation, the same reference numerals are given to the same members.

  FIG. 3 is a diagram showing a cross section of the imaging apparatus 100 according to the present invention. This figure shows a cross section of the imaging apparatus 100 taken along line FF shown in FIG.

  In the figure, O is an optical axis, 1 is a first lens which is an optical element, 2 is a second lens which is an optical element, 3 is a third lens which is an optical element, 7 is a pedestal, 8 is an image sensor, and 9 is This is an infrared light cut filter that is an optical element, and is fixed to the base 7. This pedestal 7 is formed in a shape that covers the upper surface of the image sensor 8 with a material that blocks infrared light, or is formed with a translucent material and an infrared light cut coat is applied to the object light transmitting surface. For example, the infrared light cut filter 9 may be omitted. Reference numeral 22 denotes a guide axis A, 23 denotes a piezoelectric element, and 24 denotes a guide axis B, which are fixed to the end face of the piezoelectric element 23. The guide axis A22 and the guide axis B24 are disposed substantially parallel to the optical axis O.

  The outer frame member 12 is bonded and fixed to the printed circuit board 11 with the adhesive B around the entire periphery, and the outer periphery of the pedestal 7 is bonded with the adhesive B on the inner surface of the outer frame member 12 to seal the space where the image sensor 8 is located. It has stopped.

  As shown in the figure, the second lens of the imaging optical system 50 including a first lens 1, a second lens 2, a third lens 3, and a diaphragm arranged in each lens previously unitized by bonding or the like. 2 is integrally formed with a slider portion 2s configured to generate a constant frictional force on a contact surface between the guide tube portion 2t fitted to the guide shaft A22 and the guide shaft B24. In this example, the guide lens portion 2t and the slider portion 2s are integrally formed on the second lens. However, the first lens 1, the second lens 2, and the third lens 3 are held by a lens frame, The structure which formed the guide cylinder part and the slider part in the lens frame may be sufficient.

  The piezoelectric element 23 is composed of laminated piezoelectric ceramics or the like, and functions as an electric actuator that expands and contracts in the direction of the optical axis O when a voltage is applied. The guide shaft B24 receives light along with the expansion and contraction of the piezoelectric element 23. Excited in the direction of the axis O. By this vibration, the slider 2s is moved along the guide axis B24 in the subject direction and the image sensor direction. Thereby, the imaging optical system 50 is movable in the direction of the optical axis O while being guided by the guide axis A22.

  The pedestal 7 is built in such a manner that the integrally formed leg portion 7k is in contact with the image sensor 8. The pedestal 7 is formed with a contact portion 7b on the image sensor 8 side and a contact portion 7c on the subject side. On the other hand, a protrusion 3t is formed on the outer periphery of the third lens 3 of the imaging optical system 50 at a position corresponding to this. The contact portion 7b on the imaging element 8 side is the first contact portion according to the present invention, and the contact portion 7c on the subject side corresponds to the second contact portion according to the present invention.

  As described above, the first contact portion that comes into contact when a part of the optical elements constituting the image pickup optical system moves to the image pickup device side, and the second contact portion that comes into contact when moved to the subject side are provided. By forming the first contact portion and the second contact portion so as to face each other, driving the piezoelectric element 23 that is an actuator and moving the slider portion 2s, the imaging optical system 50 is The position is moved along the guide axis A22 in the direction of the optical axis O, and there are two types of positions when the protrusion 3t is in contact with the contact portion 7b and when the protrusion 3t is in contact with the contact portion 7c. To stop it forcibly. The position of the imaging optical system 50 when the protrusion 3t comes into contact with the contact portion 7b is set so as to focus on the far side such as infinity or hyperfocal distance, and the protrusion 3t is in contact with the contact portion 7c. By setting the position in contact with the lens so as to focus on the closest distance, the imaging optical system 50 can be accurately set to the position on the far distance side and the position for macro photography without using a detection member for detecting the lens position. It becomes possible to position.

  The piezoelectric element 23 is driven so as to move the slider portion 2s beyond the amount of movement of the imaging optical system 50, that is, the amount of movement of the protrusion 3t between the contact portions 7b and 7c. Is forced to stop by the protrusion 3t and the contact portions 7b and 7c as described above, so that there is no difference in posture and there is no need to perform complicated drive control. It becomes possible to accurately position the distance side position and the macro photographing position.

  Note that the arrangement of the first contact portion and the second contact portion facing each other means that the contact portion disposed on the surface facing the subject and the surface disposed on the surface facing the image sensor. This means that the contact portion has a contact portion, and the contact portions may be arranged so as to be shifted from each other.

  FIG. 4 is a schematic view showing the inside of the imaging apparatus in which the first contact portion and the second contact portion are formed according to the present invention.

  In the figure, the leg portion 7k and the contact portions 7b, 7c are integrally formed on the pedestal 7, and the pedestal 7 is bonded and fixed to the outer frame member 12.

  FIG. 6A shows a state in which the projection 3t formed on the third lens is in contact with the contact portion 7b of the base 7 and the imaging optical system 50 is in a position where it is focused on the long distance side. FIG. 7B shows a state where the projection 3t is in contact with the contact portion 7c of the pedestal 7 and the imaging optical system 50 is at a position that is in focus at a close distance.

  As described above, the leg portion 7t and the contact portions 7b and 7c that are in contact with the image pickup device 8 are integrally formed, whereby the distance from the contact surface between the image pickup device 8 and the leg portion 7t to the contact portion 7b and the image pickup device. It is possible to guarantee the distance from the contact surface between the contact surface 8 and the leg 7t to the contact portion 7c with a single component, so that the stop position accuracy of the imaging optical system 50 can be improved, and there is no variation due to assembly. The position adjustment of the imaging optical system can be made unnecessary during manufacture.

  FIG. 5 is a schematic diagram showing the inside of another example of the imaging apparatus in which the first contact portion and the second contact portion are formed according to the present invention.

  The figure shows that the contact portion 7 b is formed on the pedestal 7 having the leg portion 7 k that contacts the image sensor 8, and the contact portion 7 c is formed on another pedestal 10 that contacts the pedestal 7. The pedestal 10 is fixed to the pedestal 7 by bonding or the like.

  FIG. 6A shows a state in which the projection 3t formed on the third lens is in contact with the contact portion 7b of the base 7 and the imaging optical system 50 is in a position where it is focused on the long distance side. FIG. 7B shows a state in which the projection 3t is in contact with the contact portion 7c formed on the pedestal 10 and the imaging optical system 50 is in a position that is in focus at a close distance.

  FIG. 6 is a diagram illustrating a configuration in which another pedestal 10 that contacts the pedestal 7 illustrated in FIG. 5 is pressed and held by an elastic member.

  This figure shows a state in which the projection 3t formed on the third lens is in contact with the contact 7b of the pedestal 7 and the imaging optical system 50 is in a position where it is focused on the long distance side. In the configuration shown in the figure, the pedestal 10 that contacts the pedestal 7 is pressed and held in the direction of the image sensor 8 by the elastic member 25. In this case, the arm-shaped portion connected to the guide tube portion and the slider portion described with reference to FIG. 3 is provided closer to the image sensor than the pressing portion by the elastic member 25 of the base 10.

  Similarly, the protrusion 3t formed on the third lens contacts the second contact 7c formed on the pedestal 10 held in this manner, and is in a position that is in focus at a close distance.

  In addition, although this elastic member 25 was illustrated with the compression coil spring, elastic members, such as a leaf | plate spring and urethane, are applicable. Further, the pedestal 7 may be bonded and fixed in the same manner as described above. However, the pedestal 7 may be pressed and held without using the pressing force applied to the pedestal 10.

  FIG. 7 is a schematic diagram showing the inside of another example of the imaging apparatus in which the first contact portion and the second contact portion are formed according to the present invention.

  In the figure, the contact portion 7b is formed on the pedestal 7 having the leg portion 7k that contacts the image sensor 8, and the contact portion 7c is formed on the other pedestal 10 having the leg portion 10k that contacts the image sensor 8. Shows things. The base 7 and the base 10 are fixed to the outer frame member 12 by adhesion or the like. With such a configuration, the first contact portion and the second contact portion may be formed.

  Even in the configuration shown in FIGS. 5 to 7, as described above, the imaging optical system 50 is accurately positioned at the far-side position and the macro shooting position without using a detection member that detects the lens position. It becomes possible to position.

  FIG. 8 is a diagram showing a cross section of the imaging apparatus 200 according to the present invention. The imaging apparatus 200 shown in the figure is configured such that the imaging optical system 50 is moved in the optical axis direction by an electrostatic actuator composed of stators 31a and 31b and a mover 32. Only the parts different from the imaging apparatus 100 shown in FIG. 3 will be described.

  As shown in the figure, the second lens 2 of the imaging optical system 50 is integrally formed with an engaging portion 2k, and the movable element 32 and the engaging portion 2k are engaged. The mover 32 is configured to be movable in the direction of the optical axis O while being alternately attracted and vibrated between the stator 31a and the stator 31b.

  The stator electrodes formed on the stators 31a and 31b, the mover electrodes formed on the mover 32, and driving thereof are described in, for example, Japanese Patent Application Laid-Open Nos. 2003-92890 and 10-239578. Applied method is applied.

  From the state in which the protrusion 3t of the third lens shown in the figure is in contact with the first contact 7b formed on the pedestal 7 (in a state of focusing on a long distance), the movable element 32 of the electrostatic actuator is moved. When moving in the direction away from the image sensor 8 along the optical axis O, the imaging optical system 50 is also moved in the direction away from the image sensor 8 by the engaging portion 2k, and the protrusion 3t of the third lens is moved. When abutting against the second abutting portion 7c formed on the pedestal 7, the imaging optical system 50 cannot move any further and is in a state of focusing on a close distance.

  As described above, the first contact portion that comes into contact when a part of the optical elements constituting the image pickup optical system moves toward the image pickup device, and the second contact portion that comes into contact when moved toward the subject side. The first abutting portion and the second abutting portion are arranged to face each other, and the imaging optical system is moved by an actuator so as to abut on the first and second abutting portions to capture an image. By positioning the optical system in the optical axis direction, it is possible to obtain an imaging apparatus that can accurately position the imaging optical system at the macro imaging position without any difference in posture without the need for a detection member.

  In the imaging apparatus 100 shown in FIG. 3, the guide axis A22 is used as an example. However, when the tilt of the imaging optical system 50 does not occur only with the guide axis B24, the guide axis A22 may be omitted. . Although the present invention has been described using a piezoelectric element and an electrostatic actuator as an actuator, it is needless to say that a DC motor, a shape memory alloy, or the like may be used.

  In addition, the focus adjustment is performed by taking the entire image pickup optical system as an example, but the focus adjustment may be performed by extending a part of the lenses of the image pickup optical system.

  Further, in the above-described embodiment, the example in which the contact portion is configured by a surface has been described. However, the contact portion is formed by a protrusion or the like, and contacts a part of the optical element constituting the imaging optical system at a point. Needless to say, what is configured as described above does not depart from the present invention.

1 is an external view of a mobile phone T that is an example of a mobile terminal according to the present invention. FIG. 1 is a perspective view of an imaging apparatus 100 according to the present invention. It is a figure showing the section of imaging device 100 concerning the present invention. It is a schematic diagram which shows the inside of the imaging device which formed the 1st contact part and the 2nd contact part based on this invention. It is a schematic diagram which shows the inside of another example of the imaging device which formed the 1st contact part and the 2nd contact part based on this invention. It is a figure which shows the structure which pressed and hold | maintained another base contact | abutted to the base shown in FIG. 5 with the elastic member. It is a schematic diagram which shows the inside of the other example of the imaging device which formed the 1st contact part and the 2nd contact part based on this invention. It is a figure which shows the cross section of the imaging device 200 which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st lens 2 2nd lens 3 3rd lens 7 Base 8 Imaging device 9 Infrared light cut filter 11 Printed circuit board 12 Outer frame member 14 Lid member 22 Guide shaft A
23 Piezoelectric element 24 Guide shaft B
50 Imaging Optical System 100 Imaging Device

Claims (9)

In an imaging apparatus comprising: an imaging element that photoelectrically converts subject light; and an imaging optical system that has at least one optical element that can move in an optical axis direction and guides subject light to an imaging region of the imaging element.
A first abutting portion that abuts when a part of the optical element moves toward the imaging element side and a second abutting portion that abuts when a part of the optical element moves toward the subject side are formed. And
The imaging apparatus, wherein the first contact portion and the second contact portion are disposed to face each other. The imaging according to claim 1, further comprising: a pedestal formed with a leg portion that contacts the imaging element, wherein the first contact portion and the second contact portion are formed on the pedestal. apparatus. A first pedestal formed with a leg that contacts the imaging element; and a second pedestal that contacts the first pedestal, wherein the first abutment part, the first The imaging apparatus according to claim 1, wherein the second contact portion is formed on a second pedestal. A first pedestal and a second pedestal formed with legs that abut against the image sensor; the first abutment on the first pedestal; and the second abutment on the second pedestal. The imaging apparatus according to claim 1, wherein a contact portion is formed. The imaging apparatus according to claim 3, further comprising an urging member that urges the second pedestal toward the imaging element. The imaging device according to claim 1, wherein the optical element movable in the optical axis direction is moved in the optical axis direction by an actuator. The imaging apparatus according to claim 6, wherein a piezoelectric element is used for the actuator. The imaging apparatus according to claim 6, wherein an electrostatic actuator is used as the actuator. A portable terminal comprising the imaging device according to claim 1.

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