JP2005043857A - Imaging unit and portable terminal device equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an imaging unit having a simple structure, which is uninfluenced by the difference in attitude, in which an accurate positioning of an imaging device and an imaging optical system in the optical axis direction is realized, which is compatible with a larger pixels of the imaging device, and with which a macro imaging is realized, and also to obtain a portable terminal device equipped with the same. <P>SOLUTION: The imaging unit has: the imaging device, an imaging optical system which guides the light of an object into the imaging region of the imaging device; an elastic member which energizes the imaging optical system to the imaging device; and a cam member which dislocates the imaging optical system in the optical axis direction against the elastic member. The imaging optical system is characterized in that the system has a first abutting part which abuts to the imaging device and a second abutting part which abuts to the cam member. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to focus adjustment of an imaging device, and more particularly to a mechanism for close-up photography of an imaging device built in a portable terminal.

  Conventionally, a small and thin imaging device is mounted on a small and thin electronic device such as a mobile phone or a PDA (Personal Digital Assistant), so that not only audio information but also image information can be transmitted to a remote place. It is possible to transmit to each other.

  The imaging devices incorporated in these portable terminals have a very short focal length of the imaging optical system, and Fno. Is about 2 to 4, the depth of focus on the image side becomes very shallow, and strict accuracy is required for positioning the imaging optical system with respect to the imaging surface in the optical axis direction. For this reason, various proposals have been made regarding the position setting method of the imaging optical system of the imaging apparatus.

  For example, in order to eliminate the need for focus adjustment at the time of manufacturing the imaging device, the leg formed integrally with the optical member is brought into contact with the imaging element, and the optical member is biased toward the imaging element by an elastic member. An apparatus that positions an imaging element and an optical member in the optical axis direction is disclosed (for example, see Patent Document 1).

Also, the projection lens and the cylindrical holder are formed with protrusions and inclined grooves, and by rotating the photographic lens, the photographic lens is moved in the optical axis direction to adjust the focus during assembly. What enables close-up photography using a mechanism is disclosed (for example, see Patent Document 2).
JP 2003-37758 A JP 2002-82271 A

  Imaging devices mounted on the above-described mobile terminals are also required to have high image quality and multi-functionality as the penetration rate increases, and imaging devices capable of mounting an image sensor with a high number of pixels and performing close-up shooting (macro shooting) are available. It is requested.

  For high image quality, an image sensor with a large number of pixels is used, and in response to this, a plurality of optical members are made in order to make the image pickup optical system have high resolution, and the optical members are positioned with each other. Accurate positioning in the optical axis direction with respect to the image pickup element of the image pickup optical system composed of optical members is required.

  In addition, regarding macro photography, the amount of movement in the optical axis direction of the imaging optical system with respect to the imaging surface and the set position thereof are required to be extremely strict as described above.

  On the other hand, the image pickup apparatus described in Patent Document 1 does not require an adjustment process for positioning the image pickup element and the optical member in the optical axis direction, and is a simple and effective method. It has not yet been moved.

  Further, when the protrusion and the inclined groove are configured to be relatively movable as in the image pickup apparatus described in Patent Document 2, the inclined groove is necessarily formed with a clearance with respect to the size and shape of the protrusion. If the imaging device is facing upward, the projection will be in contact with the lower side of the inclined groove, and when the imaging device is downward, the projection will be in contact with the upper side of the tilting groove, and the focus will be shifted by the clearance. A difference problem occurs.

  In view of the above problems, the present invention has a simple configuration, does not cause a difference in posture, can accurately position the image sensor and the image pickup optical system in the optical axis direction, and can cope with an increase in the number of pixels of the image sensor. An object of the present invention is to obtain an imaging device capable of photographing and a portable terminal equipped with the imaging device.

  Said subject is solved by the following structures.

  1) an imaging device, an imaging optical system that guides subject light to an imaging region of the imaging device, an elastic member that urges the imaging optical system toward the imaging device, and the imaging optical system against the elastic member A cam member that displaces the cam in the optical axis direction, and the imaging optical system includes a first abutting portion that abuts on the imaging element and a second abutting portion that abuts on the cam member. An imaging device that is characterized.

  2) The imaging device according to 1), wherein the first contact portion is in contact with the imaging element when the second contact portion is not in contact with the cam member.

  3) When the second contact portion and the cam member are in contact with each other and the first contact portion is not in contact with the imaging device, the imaging optical system is set to the close-up shooting position 1) or 2) apparatus.

  4) The imaging apparatus according to any one of 1) to 3), wherein the imaging optical system includes a plurality of optical members, and the optical members are in contact with each other.

  5) The imaging apparatus according to any one of 1) to 4), which includes an outer frame member that includes an imaging optical system and an elastic member, and the cam member is disposed outside the outer frame member.

  6) The imaging apparatus according to any one of 1) to 5), which has a gas flow path that allows gas to flow on the object side and the image plane side of the imaging optical system.

  7) The imaging device according to any one of 1) to 6), wherein the space in which the imaging element is arranged is substantially sealed by an imaging optical system.

  8) The imaging device according to 6), wherein a dustproof filter is provided in the gas flow path.

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

  The imaging device of the present invention, an imaging optical system that guides subject light to the imaging area of the imaging device, an elastic member that urges the imaging optical system in the direction of the imaging device, and the optical axis of the imaging optical system against the elastic member An imaging optical system having a first abutting portion that abuts on the imaging element and a second abutting portion that abuts on the cam member. It is possible to obtain an imaging apparatus capable of macro photography that has a simple configuration, does not cause a posture difference, can accurately position the imaging element and the imaging optical system in the optical axis direction, and can cope with an increase in the number of pixels of the imaging element. It becomes possible.

  The imaging optical system has a first contact portion that contacts the imaging element and a second contact portion that contacts the cam member, and the second contact portion is not in contact with the cam member. By configuring the first abutting portion to abut on the image sensor, positioning of the image sensor and the imaging optical system in the optical axis direction can be performed without using intervening parts, It is possible to minimize focusing position errors and individual differences. Furthermore, when the second contact portion and the cam member are in contact, and the first contact portion is not in contact with the image sensor, the imaging optical system can perform close-up shooting by setting the close-up shooting position. can do.

Furthermore, when the imaging optical system is composed of a plurality of optical members, the optical members are assembled in contact with each other, so that the mutual lens interval can be assembled without any error without interposing other members. This eliminates the fluctuation element of the set focus position, enables accurate positioning of the image sensor and the imaging optical system in the optical axis direction, and eliminates focus adjustment. Also, the outer frame that contains the imaging optical system and the elastic member And the cam member is disposed outside the outer frame member, so that the imaging optical system movable in the optical axis direction and the outer frame member can be fitted, and the imaging optical system and the outer frame member It is possible to prevent external dust from entering the space where the image sensor is located through the gap.

  Further, the imaging optical system has a gas flow path that allows gas to flow between the object side and the image plane side, the space where the imaging element is arranged is substantially sealed by the imaging optical system, and a dustproof filter is provided in the gas flow path. Accordingly, it is possible to prevent dust entering from the outside or dust generated by operation from adhering to the light receiving surface. Furthermore, the negative pressure or the pressurized state due to the movement of the imaging optical system in the space can be eliminated by allowing the gas from which dust is removed to flow in and out by the gas flow path and the dustproof filter formed in the imaging optical system. .

  In addition, by using a mobile terminal including any of the above-described imaging devices, a mobile terminal including the imaging device having the above-described effects 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 a diagram showing an external appearance of a mobile phone T that is an example of a mobile terminal in which an imaging device of the present invention is built.

  In the mobile phone T shown in FIG. 1, an upper casing 71 as a case having a display screen D and a lower casing 72 having an operation button P are connected via a hinge 73. The imaging device S is built below the display screen D in the upper casing 71, and is arranged so that the imaging device S can capture light from the outer surface side of the upper casing 71.

  Below the display screen D of the upper casing 71, an arcuate opening 74 and the operation member 15 are disposed so as to be exposed from the opening 74. By moving the operation member 15 upward in the drawing within the opening 74, the focus position at the time of macro photography is set.

  Note that the position of the imaging device may be arranged above or on the side of the display screen D in the upper casing 71, and the same applies to the position of the operation member 15. Of course, the mobile phone is not limited to a folding type.

  FIG. 2 is a perspective view of the imaging apparatus 100 of the present invention. The imaging apparatus 100 in the figure corresponds to the imaging apparatus S in FIG.

  As shown in FIG. 2, the outer surface of the image pickup apparatus 100 includes a printed circuit board 11 on which an image sensor is mounted, a connect board 17 for connection to another control board of the mobile terminal, and the printed board 11 and the connect board 17. The flexible printed circuit board FPC to be connected, the outer frame members 12 and 12a, the lid member 13 incorporated on the upper surface of the outer frame member 12a, the cam member 14 incorporated on the outer periphery of the cylindrical portion of the outer frame member 12, and the outer frame member 12 The operation member 15 is rotatably mounted on the boss 12b formed in a conventional manner, and the stepped screw 16 is configured to fix the operation member 15 to be rotatable.

  FIG. 3 is a cross-sectional view of the imaging apparatus 100 according to the present invention cut along line FF shown in FIG.

  In FIG. 3, the outer frame members 12 and 12 a are arranged such that the first lens 1 from the subject side, the aperture stop 4 that determines the aperture F value of the imaging optical system, the second lens 2, the fixed aperture 5 for blocking unnecessary light, An imaging optical system 50 constituted by the third lens 3, an infrared light cut filter 7, an imaging element 8 mounted on the printed circuit board 11, a compression coil spring 9 that is an elastic member, and a lid member 13. . In addition, as described with reference to FIG. 2, the outside includes a cam member 14, an operation member 15, and a stepped screw 16 assembled on the outside of the outer frame member 12. The periphery of the outer frame member 12 and the printed board 11 is sealed with an adhesive B.

  As shown in the figure, the imaging optical system 50 is a unit in which the first lens 1, the second lens 2, and the third lens 3 are brought into contact with each other at a flange portion other than the optically effective surface and are fixed to each other with an adhesive or the like. By constructing it without using other members, the distance between the lenses can be assembled without error.

  In the figure, the third lens 3 constituting the imaging optical system 50 according to the present invention is formed with a contact portion 3d that contacts the imaging element 8. Further, as shown in the figure, an arm portion 3s is integrally formed on the side surface, and a contact portion 3t that contacts the cam member 14 is formed on the arm portion 3s. The arm portions 3s and the contact portions 3t are formed at intervals of approximately 120 degrees. As shown in the figure, when the contact portion 3d is in contact with the image sensor 8, the contact portion 3t of the arm portion 3s is set to be separated from the cam member 14.

  In a state in which the contact portion 3d is in contact with the image sensor 8, the height of the contact portion 3d is set so that the imaging optical system 50 is in focus on the far side such as infinity or hyperfocal distance. Has been.

  That is, the first contact portion according to the present invention corresponds to the contact portion 3d, and the second contact portion corresponds to the contact portion 3t.

  Further, the outer periphery 3r of the third lens 3 and the inner periphery 12r of the outer frame member 12 corresponding to the third lens 3 are fitted, and at least one of the outer periphery 3r and the inner periphery 12r is thinly coated with lubricating oil. The space on the image sensor 8 side is substantially sealed.

  Further, the third lens 3 has a hole 3p as a gas flow path, and a dustproof filter 3g is disposed in the hole 3p, and the image pickup device 8 is sealed by movement of the image pickup optical system 50 in the optical axis direction. Corresponding to the increase in the volume of the space on the side, gas can flow into the image sensor 8 side from the hole 3p. At least one such hole 3 p is formed in the third lens 3.

  The imaging optical system 50 configured as described above is urged toward the imaging element 8 by the compression coil spring 9, and the abutting portion 3 d is brought into contact with the imaging element 8 by this urging force.

  On the other hand, the cam member 14 disposed on the outer periphery of the cylindrical portion of the outer frame member 12 is rotatable along the outer periphery of the cylindrical portion of the outer frame member 12. A gear portion 14 g is formed on at least a part of the outer periphery of the cam member 14, and meshed with the gear portion 15 g formed on the operation member 15.

  Although described in detail later, the cam member 14 has a cam shape at a position corresponding to the contact portion 3t of the arm portion 3s of the third lens 3, and the illustrated state in which the contact portion 3t and the cam member 14 are separated from each other. Is rotated along the outer periphery of the cylindrical portion of the outer frame member 12 so that the imaging optical system 50 is moved away from the imaging element 8 against the urging force of the elastic member 9 by contacting the contact portion 3t. It is configured.

  FIG. 4 is a perspective view showing the shape of the cam member 14 used in the imaging apparatus 100 of the present invention.

  As shown in the figure, the cam member 14 is formed with a gear portion 14g that meshes with a gear portion 15g (see FIG. 3) of the operation member 15 in a part of the outer periphery, and three flat portions A having a low height, Three flat portions M having a high height and three inclined portions B that smoothly connect the flat portions A and M are formed at intervals of approximately 120 degrees.

  Among these cam shapes, the flat part A having a low height is set to a height that does not contact the contact part 3t of the arm part 3s of the third lens 3 when the flat part A is incorporated in the imaging device 100. The flat portion M having a high height is set to a height that abuts against the abutting portion 3t and moves the abutting portion 3t against the urging force of the elastic member 9.

  The height of the flat portion M is set such that the imaging optical system 50 is positioned on the optical axis that enables desired close-up photographing by moving the contact portion 3t.

  Returning to FIG. 3, in the imaging apparatus 100 configured as described above, by operating the operation member 15, the operation member 15 rotates around the stepped screw 16 and is engaged with the gear portions 15 g and 14 g. The member 14 is rotated. At this time, the inclined portion B of the cam member 14 and the abutting portion 3t first come into contact with each other, and the abutting portion 3t is moved along the inclined portion B against the urging force of the elastic member 9 in the optical axis direction. The flat portion M (see FIG. 4) having a high height of the member 14 comes into contact with the contact portion 3t. As a result, the imaging optical system 50 configured integrally with the third lens 3 can move in the direction away from the imaging element 8 in the optical axis direction.

  FIG. 5 is a cross-sectional view showing the positional relationship between the cam member 14 and the imaging optical system 50 of the imaging apparatus 100 of the present invention. This figure shows a state in which the right side is focused at a long distance with the optical axis O as a boundary, and the left side shows a state during close-up photography.

  In the state of focusing on a long distance on the right side of the figure, the contact portion 3d contacts the image sensor 8, and the contact portion 3t is separated from the low flat portion A of the cam member 14. On the other hand, when the cam member 14 is rotated and the high flat portion M and the contact portion 3t come into contact with each other, the contact portion 3d is separated from the image sensor 8. As a result, the imaging optical system of the imaging apparatus 100 moves to the object side and can perform close-up photography.

  As described above with reference to FIGS. 3 to 5, the compression coil spring 9, which is an elastic member, urges the imaging optical system 50 toward the imaging element 8 from the beginning. For this reason, the imaging optical system 50 can maintain a constant distance from the imaging element 8 in any posture without tilting, and obtain an imaging device capable of macro photography that solves the problem of the posture difference. be able to.

  In the state of focusing at a long distance, the contact portion 3d integrated with the imaging optical system is brought into contact with the image pickup device 8 and is configured without using any other intervening parts, so that the variation element of the set focus position Thus, accurate positioning of the image sensor and the imaging optical system in the optical axis direction is possible, and focus adjustment can be eliminated.

  Furthermore, by making the space on the image pickup device 8 side of the third lens 3 substantially sealed, the light receiving surface side of the image pickup device 8 can be enclosed, and dust entering from the outside or dust generated by operation Can be prevented from adhering to the light receiving surface. Further, the negative pressure or the pressurized state due to the movement of the imaging optical system in the space accompanying this is caused by the inflow and outflow of the gas from which dust is removed by the gas flow path 3p and the dustproof filter 3g formed in the imaging optical system. Can be resolved.

  Further, since the imaging optical system 50 is held in the outer frame member 12 via the compression coil spring 9 which is an elastic member, the outer frame member 12 is shocked when the imaging device 100 is transferred or incorporated into the portable terminal T. Even when an external pressure is applied, no force is transmitted directly to the internal imaging optical system 50, and the imaging optical system 50, which is the main part, can be made an imaging device with high reliability without any error.

  Similarly, the rotation of the operation member 15 is restricted by the opening 74 (see FIG. 1) of the portable terminal T, and even if a large acting force is applied to the operation member 15, the opening 74 receives the force, and the imaging optical system Since it is not transmitted to 50, it can be made into a structure which is hard to break down.

  Although the compression coil spring has been described as the elastic member, the present invention is not limited to this, and the use of a sponge-like elastic member or a leaf spring does not depart from the present invention.

  FIG. 6 is a cross-sectional view showing another example of the imaging apparatus 100 of the present invention. This figure shows a state in which the right side is in focus at a long distance with the optical axis O as the boundary, as in FIG. 5, and the left side shows a state during close-up photography. In order to avoid duplication of description, members having the same functions as those of the imaging apparatus shown in FIGS. 3 and 5 are denoted by the same reference numerals, and different portions will be described.

  In the figure, an outer frame member 12, an inner periphery 12r thereof, and an inner periphery 12s of the outer frame member 12a are formed in a shape having no step. On the other hand, the outer periphery 3r of the third lens 3 is extended so as to be fitted to the inner periphery 12s of the outer frame member 12a, and the outer periphery 3r is moved in the optical axis direction by the cam member 14 already described. Even if it moves, both inner circumferences 12r and 12s are formed to fit together. Similarly, a thin lubricating oil is applied to the outer periphery 3r and inner periphery 12r, 12s. The third lens 3 is formed with a gas flow path 3p that is divided by the third lens 3 between the space on the imaging element 8 side and the space on the infrared light cut filter 7 side.

  As described above, even when the third lens 3 moves in the optical axis direction, the inner circumferences 12r and 12s are configured to be fitted together, so that even if the arm portion 3s of the third lens 3 protrudes to the outside, the imaging device It is possible to prevent dust from entering the inside. As a result, the dust filter 3g described with reference to FIG. 3 can be eliminated, and costs can be reduced by reducing the number of parts while obtaining the same effects as described above.

  In FIG. 6, the change in volume due to the movement of the imaging optical system between the space on the imaging element 8 side and the space on the infrared light cut filter 7 side separated by the third lens 3 is a gas flow provided in the third lens 3. The pressure change is absorbed by the passage 3p, but it goes without saying that both spaces may be connected to the outside of the outer frame members 12 and 12a using a duct pipe or the like to form a gas flow path. Furthermore, a hole provided with a dustproof filter may be provided on the space side where the imaging element 8 of the outer frame member 12 is disposed, and a gas flow path to the outside may be used.

  FIG. 7 is a cross-sectional view showing another example of the imaging apparatus of the present invention. In order to avoid duplication of explanation, members having the same functions as those of the imaging apparatus shown in FIGS. Hereinafter, parts of the imaging device 150 shown in FIG. 7 that are different from the configuration of the imaging device 100 shown in FIG. 5 will be described.

  The image pickup apparatus 150 shown in the figure does not use the infrared light cut filter 7 (see FIG. 3), but has an infrared light cut coating applied to a part of the image pickup optical system. Since the characteristics of this infrared light cut coating change according to the incident angle of light, it is desirable to apply to the surface of the imaging optical system where the incident angle or the emission angle is small even if the image height changes. In the imaging optical system shown in the figure, it is desirable to apply to the object side surface of the third lens 3. Other configurations are the same as those shown in FIG.

  By doing in this way, the imaging device 150 can be configured to be thin by the thickness of the infrared light cut filter while obtaining the same effect as described above. Further, the lid member 13 shown in FIG. 3 can be eliminated, and the cost can be reduced by reducing the number of parts.

  In the present embodiment, the imaging optical system has been described as being moved to two positions, that is, the long-distance photographing and the close-distance photographing positions. Needless to say, shooting at an intermediate distance between the two is possible.

  Further, the first and second contact portions are integrally formed on the optical member constituting the photographing optical system. However, the contact portion may be integrated with the optical member as a separate part. Of course.

It is a figure which shows the external appearance of the mobile telephone which is an example of the portable terminal which incorporated the imaging device of this invention. It is a perspective view of the imaging device of the present invention. It is sectional drawing which cut | disconnected the imaging device of this invention by the FF line | wire shown in FIG. It is a perspective view which shows the shape of the cam member used for the imaging device of this invention. It is sectional drawing which shows the positional relationship of the cam member and imaging optical system of the imaging device of this invention. It is sectional drawing which shows the other example of the imaging device of this invention. It is sectional drawing which shows another example of the imaging device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st lens 2 2nd lens 3 3rd lens 4 Aperture stop 5 Fixed stop 7 Infrared light cut filter 8 Image sensor 9 Elastic member 11 Printed circuit board 12 Outer frame member 13 Lid member 14 Cam member 15 Operation member 16 Stepped screw 50 Imaging Optical System 100 Imaging Device

Claims (9)

An imaging element; an imaging optical system that guides subject light to an imaging region of the imaging element; an elastic member that urges the imaging optical system toward the imaging element; and A cam member for axial displacement,
The image pickup optical system includes a first contact portion that contacts the image sensor and a second contact portion that contacts the cam member. The imaging apparatus according to claim 1, wherein when the second contact portion is not in contact with the cam member, the first contact portion is in contact with the imaging element. When the second contact portion and the cam member are in contact with each other, and the first contact portion is not in contact with the imaging element, the imaging optical system is set to a close-up shooting position. The imaging apparatus according to claim 1 or 2. The imaging apparatus according to claim 1, wherein the imaging optical system includes a plurality of optical members, and the optical members are in contact with each other. 5. The apparatus according to claim 1, further comprising an outer frame member that encloses the imaging optical system and the elastic member, wherein the cam member is disposed outside the outer frame member. Imaging device. The imaging apparatus according to any one of claims 1 to 5, further comprising a gas flow path that allows gas to flow between the object side and the image plane side of the imaging optical system. The imaging apparatus according to claim 1, wherein a space in which the imaging element is arranged is substantially sealed by the imaging optical system. The imaging apparatus according to claim 6, wherein a dustproof filter is provided in the gas flow path. A portable terminal comprising the imaging device according to claim 1.

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