JP2007093711A - Optical module and mobile terminal equipped with the optical module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical module capable of increasing the degree of freedom of design related to reduction in thickness in the direction of an optical axis. <P>SOLUTION: The optical module is equipped with: a lens holder 22 holding a lens group 21; a motor 13 having an output shaft 13b extended in the direction orthogonal to the optical axis of the lens group 21 and rotating the output shaft 13b; and a transmission mechanism 53 converting the rotation of the output shaft 13b into a translational motion in the direction of the optical axis and transmitting it to the lens holder 22. Further, an object side cover 11, a shutter unit 12, a lens unit 14 and a substrate 16 are stacked in the direction of the optical axis in order from an object side. The substrate 16 on which an imaging element 35 is provided has a width approximately equal to those of the shutter unit 12 and the lens unit 14, and mounts electronic components only on a surface on which the imaging element 35 is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical module and a mobile terminal including the optical module.

  As a technique for driving a lens included in a camera or the like in the optical axis direction, for example, there are the following techniques.

  Patent Document 1 discloses an imaging apparatus that includes a focusing imaging lens that is driven along an optical axis by a drive motor, and an aperture stop that adjusts the amount of incident light of the imaging lens. Note that the arrangement of the lens, aperture, and motor is not disclosed.

  Patent Document 2 discloses an image pickup apparatus that opens and closes a shutter after driving an image pickup lens to a focus position by a driving force of a motor. The motor is arranged so that the output shaft is parallel to the optical axis.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a front stop second group zoom lens in which an aperture stop is disposed on the subject side of the lens group. Note that the arrangement of motors and the like is not disclosed.

There are also known technologies such as an imaging device that drives a lens and a diaphragm by a single drive source, and a portable terminal that puts an optical member for close-up photography into and out of an optical path by a motor.
JP-A 64-17030 Japanese Unexamined Patent Publication No. 03-38625 Japanese Patent Laid-Open No. 10-123418

  In the above technique, the motor is arranged so that the output shaft is parallel to the optical axis. Therefore, it is necessary to secure the arrangement area of each part in the optical axis direction by the amount obtained by integrating the moving range of the lens, the length of the motor output shaft, the length of the motor body, etc. Is limited. It is also required to accurately detect the lens position.

  An object of the present invention is to provide an optical module that is thin in the optical axis direction and that can accurately control the position of a lens.

 The optical module of the present invention is output from a lens, a lens base that holds the lens movably in the optical axis direction of the lens, a drive source having an output shaft that outputs a driving force, and the output shaft. A transmission mechanism that transmits a driving force to the lens base; a shutter blade; a shutter base that holds the shutter blade so that an optical path of the lens can be opened and closed; and an image sensor on which an optical image is formed by the lens; A substrate on which the image pickup element is provided, and is arranged in a stacked order of the shutter base, the lens base, and the substrate from one direction with respect to the optical axis direction, and the drive source is The shutter base and the lens base are arranged in parallel in a direction substantially perpendicular to the optical axis, and the substrate has substantially the same size as the shutter base and the lens base. And wherein the mounting the electronic component only on the surface where the imaging device is provided.

 More preferably, the substrate is provided with only a flexible printed wiring board extending along the surface on the surface opposite to the surface on which the image sensor is provided.

 More preferably, a cover member that covers the imaging element side of the substrate is provided, and the shutter base, the lens base, the cover member, and the substrate are stacked in this order, and the substrate includes the shutter base, It has the same area as the lens base and the cover member.

 More preferably, the drive source is arranged so that the output shaft is substantially perpendicular to the optical axis, and the transmission mechanism transmits a driving force output from the output shaft, to the optical axis. A worm that rotates about an axis that is substantially orthogonal to the worm, a gear portion that meshes with the worm or a gear that transmits rotation of the worm, and a cam portion that is inclined with respect to a plane orthogonal to the optical axis, And a cam gear that rotates about an axis substantially parallel to the lens, and the lens base is in contact with the cam portion and guided in the optical axis direction.

  More preferably, it has position detection means which has a detected part arranged in the cam gear, and a detection part arranged near the cam gear, and the position detection means is the cam gear by the detection part. The position of the lens is detected by detecting the rotation of the lens.

  More preferably, the cam gear is arranged in order of the detected portion and the cam portion from the inside of the cam gear. More preferably, the cam gear is characterized in that the cam portion and the gear portion are arranged concentrically with the cam gear.

  Furthermore, a portable terminal including the optical module of the present invention includes a housing that houses the above-described optical module and a battery, and the drive source is supplied with power from the battery.

  According to the present invention, it is possible to provide an optical module that is thin in the optical axis direction and that can accurately control the position of a lens.

  1 and 2 are external perspective views showing an embodiment of a mobile phone to which the present invention is applied. The mobile phone 1 is configured as a so-called foldable mobile phone. FIG. 1 shows an open state, and FIG. 2 shows a closed state.

  The mobile phone 1 includes a receiving case 2 and a transmitting case 3, and the receiving case 2 and the transmitting case 3 are connected to each other by a connecting portion 4 so as to be opened and closed. The receiving case 2 and the transmitting case 3 are provided with front side cases 2c and 3c on the side (front side) facing each other in the closed state and back side cases 2d and 3d on the back side. These cases are integrally formed, for example, with resin.

  The receiving case 2 is provided with a main display unit 5 that displays an image on the front side and a sub display unit 6 that displays an image on the back side along each surface. The main display unit 5 and the sub display unit 6 are configured by a liquid crystal display, for example. In addition, the receiver case 2 is provided with an optical module 7 for imaging a subject from an opening 2e provided in the back side case 2d, and a strobe 8 that emits light from the back side.

  The transmitter case 3 includes an operation unit 9 on the front side. Various buttons for operating the cellular phone 1 such as a numeric keypad 9a are arranged on the operation unit 9. The cellular phone 1 performs radio communication or imaging with the optical module 7 in response to an input operation to the numeric keypad 9.

  The mobile phone 1 is provided with a high-frequency circuit for radio communication, an antenna, a microphone and a speaker for telephone call, which are not shown. Similarly, although not shown in the figure, a cover is provided on the opposite surface of the operation unit 9, and when the cover is opened, the battery is accommodated and the battery is accommodated. In the present invention, the power supply is supplied from the battery to the drive source of the optical module 7, thereby reducing the number of parts and reducing the size of the mobile phone 1.

  FIG. 3A is a schematic perspective view of the optical module 7, and FIG. 3B is a cross-sectional view taken along the line III-III in FIG. Note that the y-axis direction in FIG. 3 is the optical axis direction, and the lower left side in FIG. 3A and the upper side in FIG. 3B are the subject side (upper side in FIG. 2).

  The optical module 7 includes a subject side cover 11, a shutter unit 12, a lens unit 14, a substrate cover 15, and a substrate 16 stacked in order from the subject side in the optical axis direction, and is generally formed into a thin rectangular parallelepiped thin in the optical axis direction. Is formed.

  Specifically, the subject side cover 11, the lens unit 14 (lens base 23 to be described later), the base cover 15 and the substrate 16 are formed in a substantially rectangular shape having substantially the same size in the optical axis direction. The side surfaces of these parts constitute side surfaces of the overall shape, and the subject side cover 11 and the substrate 16 constitute the subject side surface of the overall shape and the back surface thereof. The optical module 7 is configured as a relatively small module. For example, the width of the surface orthogonal to the optical axis is 22 mm × 16 mm, and the thickness in the optical axis direction is 6.9 mm.

  As shown in FIG. 3B, the optical module 7 has a built-in motor 13 for driving the lens in the optical axis direction, and the focus position can be adjusted by moving the lens in the optical axis direction. It is.

  4 is an exploded perspective view of the optical module 7 viewed from the subject side, and FIG. 5 is an exploded perspective view of the optical module 7 viewed from the opposite side of the subject side. In FIG. 5, the substrate cover 15 and the substrate 16 are omitted.

  The subject side cover 11 is formed in a rectangular box shape as a whole, and has a plate surface 11a on the subject side and a side surface 11b surrounding the outer periphery of the plate surface 11a. At one end side in the x-axis direction, a rectangular opening portion 11c that is approximately half the size of the subject-side cover 11 opens, and most of the shutter unit 12 is exposed. The subject side cover 11 is made of, for example, metal. In the optical module 7, the subject side cover 11 may be omitted.

  The outer shape of the shutter unit 12 is formed in a thin, substantially rectangular parallelepiped shape that has a width approximately half that of the lens unit 13 as a whole. As shown in FIG. 5, a circular recess 12a centered on the optical path is provided on the lens unit 14 side of the shutter unit 12. As shown in FIG. 3B, the recess 12a will be described later. The lens group 21 is inserted, and the concave portion 12 a can define a part of the moving region of the lens group 21.

  As shown in FIGS. 4 and 5, the motor 13 is a lens unit that is arranged in parallel with the shutter unit 12 with respect to the optical axis, that is, the shutter unit 12 and the motor 13 are arranged in a direction orthogonal to the optical axis. 14 on the subject side. Further, as shown in FIG. 3B, the motor 13 is located on the radially outer side of the lens group 21 to be described later.

  As shown in FIGS. 4 and 5, a flexible printed wiring board (FPC) 32 for electrically connecting the shutter unit 12, the motor 13 and the like to the substrate 16 is provided on the subject side of the motor 13. It has been.

  The lens unit 14 includes a lens group 21, a lens holder 22 that holds the lens group 21, and a lens base body 23 that holds the lens holder 22 movably in the optical axis direction of the lens group 21. .

  As shown in FIG. 4, the lens group 21 includes, for example, three optical lenses. From the subject side, the first lens 24, the mask 25, the second lens 26, the mask 27, and the third lens 28 are arranged in this order. Are stacked. The first lens 24, the second lens 26, and the third lens 28 are configured such that the diameter gradually increases from the subject side. A single lens may be held by the lens holder 22.

  As shown in FIG. 3B, the lens holding body 22 has a circular recess that is reduced in a step shape so that the lenses 24, 26, and 28 are fitted and inserted. The first lens 24, the second lens 26, and the third lens 28 are housed and stacked in the concave portion in this order, and further, a ring-shaped retainer 29 is stacked, and the retainer 29 is attached to the lens holder 22 with an adhesive. The lens group 21 is held by the lens holding body 22 by being fixed by a fixing means such as. The lens holder 22 is made of, for example, resin.

  As shown in FIGS. 4 and 5, the lens base 23 is formed of, for example, a resin, and the overall shape is a generally rectangular parallelepiped. The area of the lens base 23 is approximately the same as that of the subject-side cover 11, and the subject-side cover 11 is placed on the lens base 23 from above the shutter unit 12 and the motor 13 and is fitted to the lens base 23. The subject-side cover 11 and the lens base 23 are fixed by, for example, inserting the claw portions 11d provided on the subject-side cover 11 into a plurality of hole-like engaging portions 23a provided on the lens base 23. And being locked.

  A substantially rectangular recess 23b is provided on the subject side of the lens base 23 as a whole, and the shutter unit 12 is fixed to the lens base 23 in a state of being fitted and inserted into the recess 23b. Note that a part of the recess 23b is formed in a hole shape in order to secure an optical path. The shutter unit 12 and the lens base 23 are fixed by, for example, inserting a screw 101 into a through-hole of the lens base 23 and screwing it into the shutter unit 12.

  Further, a concave portion 23c is provided adjacent to the concave portion 23b on the subject side of the lens base 23, and the motor 13 is fixed to the lens base 23 while being accommodated in the concave portion 23c. Note that a part of the recess 23c may be formed in a hole shape. The motor 13 is fixed to the lens base 23 by, for example, fixing the motor 13 to the motor fixing member 31 by soldering or welding, and the screw 102 inserted into the through hole of the motor fixing member 31 is the screw of the lens base 23. This is done by being screwed into the hole. The motor fixing member 31 is made of, for example, a flat metal and is disposed on the subject side of the motor 13.

  The shutter unit 12 and the motor 13 are accommodated in the concave portion 23b or the concave portion 23c of the lens base 23, so that the subject side surface of the lens base 23, the subject side surface of the shutter unit 12, and the motor fixing member 31 The surface on the subject side has substantially the same position in the optical axis direction.

  The substrate cover 15 is formed of a resin, for example, and has a generally thin rectangular parallelepiped shape. The substrate cover 15 is provided with an opening 15a for securing an optical path. A plurality of recesses 15b (see FIG. 3B) that can accommodate various components provided on the substrate 16 are provided on the substrate 16 side of the substrate cover 15. An IR cut filter 33 is provided on the substrate cover 15 on the lens unit 23 side.

  As shown in FIG. 4, the substrate 16 is configured as a rigid substrate by a hard substrate material, and is formed in a substantially rectangular shape as a whole. The substrate 16 is a multilayer printed board in which a pattern layer, a ground layer, and a power supply layer are laminated on an insulating layer formed of, for example, a hard resin.

  A light image is formed by the lens group 21 on the subject-side surface 16a of the substrate 16, and an image sensor 35 that outputs a signal corresponding to the formed light image, and a connector portion connected to the connector portion 32b of the FPC 32. Various electronic components such as 36 are provided.

 On the other hand, as shown in FIG. 3 (b), the surface 16b of the substrate 16 opposite to the subject is only provided with an FPC 37 extending along the surface 16b and extending from the substrate 16. The 16b side is formed substantially flat. The FPC 37 may be connected to the subject-side surface 16a and nothing may be mounted on the surface 16b opposite to the subject. In this way, the electronic component is mounted only on the surface on which the image sensor 35 is provided with the image sensor 35, so that the back surface becomes flat and the substrate cover 15 and the lens unit 14 for stacking the mounting layout of the electronic components on the front surface Therefore, it is possible to reduce the thickness in the optical axis direction.

  As shown in FIGS. 3A and 3B, the substrate 16 forms a surface opposite to the subject side in the overall shape of the optical module 7, and the optical module 7 is attached to the mobile phone 1. When mounted, for example, the surface 16 b opposite to the subject side of the substrate 16 abuts on an appropriate member such as a substrate (not shown) provided inside the cellular phone 1 and is held by the cellular phone 1. The The FPC 37 is provided with a connector 38 for connecting to a substrate or the like provided inside the mobile phone 1. By connecting the connector 38, power can be supplied from the battery of the mobile phone 1.

  The image sensor 35 is a CCD, for example, and outputs a signal corresponding to the received light. The signal output from the image sensor 35 is output to the image processing unit provided on the substrate for the display unit of the mobile phone 1 through the substrate 16 and the FPC 37 and processed. The optical image is displayed on the main display unit 5 or the sub display unit 6.

  FIG. 6 is an exploded perspective view of the shutter unit 12, and the upper side of the drawing corresponds to the subject side. The shutter unit 12 includes a shutter base 41 formed in a box shape as a whole, a neutral density filter 42 accommodated in the shutter base 41, a neutral density filter pressing plate 43 that holds the neutral density filter 42, and a shutter base 41. A plurality of shutter blades 44A to 44D, and a pressing plate 45 for pressing the shutter blades 44A to 44D. Note that the shutter base 12 and the presser plate 45 substantially constitute the outer shape of the shutter unit 12.

  As shown in FIGS. 4 and 5, in the mobile phone 1, the shutter unit 12 and the lens unit 14 each have a shutter base 41 and a lens base 23. The shutter base 41 and the lens base 23 are combined to constitute a part of the optical module 7.

  As shown in FIG. 6, an opening for transmitting incident light to the lens unit 14 is provided on the bottom surface of the shutter base 41. The shape of the opening is appropriate, but is rectangular, for example. A plurality of fixed convex portions 41a and movable convex portions 41b are provided around the opening, and the fixed convex portions 41a and the movable convex portions 41b are inserted into through holes provided in the neutral density filter 42 and the shutter blades 44A to 44D, By driving the movable convex part 41b and rotating the neutral density filter 42 and the shutter blades 44A to 44D around the fixed convex part 41a, the optical filter is opened and closed and the optical path is opened and closed by the shutter blades 44A to 44D.

  An actuator (not shown) for driving the movable convex portion is housed in the shutter base 41. For example, it is accommodated in a convex portion 41c around the concave portion 12a (see FIG. 5). The operation of the actuator is controlled by a control unit (not shown) of the mobile phone 1 via the FPC 32, the substrate 16, and the FPC 37.

  FIG. 7 is a perspective view of the lens unit 12 as seen from the side opposite to the subject, and FIG. 8 is a perspective view of the internal configuration of the lens unit 12 as seen from the subject side.

  The lens holding body 22 includes guided portions 22 a and 22 b that protrude outward in the radial direction of the lens 21. A through hole 22c is provided in the guided portion 22a, and a guide shaft 51 is inserted through the through hole 22c. The guide shaft 51 extends in the optical axis direction and is fixed to the lens base 23, and guides the guided portion 22a in the optical axis direction. The guided portion 22 b is inserted into a concave rail portion 23 d provided on the lens base 23. The rail portion 23d is formed so as to extend in the optical axis direction, and guides the guided portion 22b in the optical axis direction.

  The motor 13 is composed of, for example, a stepping motor, and includes a motor main body 13a including a rotor and the like, and an output shaft 13b extending from the motor main body 13a and driven to rotate. The motor body 13a is formed in, for example, a substantially cylindrical shape, and the output shaft 13b extends from the end surface of the cylindrical shape.

  As shown in FIGS. 7 and 8, the motor body 13a has a length in the direction of the output shaft 13b larger than a width in a direction orthogonal to the output shaft 13b. The length obtained by integrating the length of the motor main body 13a and the length of the output shaft 13b is larger than the diameter of the lens group 21, and the width in the direction perpendicular to the output shaft 13b of the motor main body 13a is the optical axis of the lens group 21. It is smaller than the thickness in the direction (see FIG. 3B).

  The motor 13 extends so that the output shaft 13b extends in a direction orthogonal to the optical axis and in a direction orthogonal to the arrangement direction with the shutter unit 12 (z-axis direction, see also FIGS. 4 and 5). Has been placed. That is, the motor 13 is arranged with the longitudinal direction in the overall shape orthogonal to the optical axis and the short direction parallel to the optical axis.

  A terminal folder 52 is provided on the side of the motor body 13a opposite to the shutter unit 12, and the terminal 52a of the terminal folder 52 is connected to the FPC 32 (see FIGS. 4 and 5). The operation of the motor 13 is controlled by the control unit (not shown) of the mobile phone 1 through the FPC 37, the substrate 16, the FPC 32, and the terminal folder 52.

  As shown in FIGS. 7 and 8, the lens unit 12 is provided with a transmission mechanism 53 that converts the rotation of the output shaft 13 b of the motor 13 into a linear motion in the optical axis direction and transmits it to the lens holder 22. .

  The transmission mechanism 53 includes a worm 54 provided on the output shaft 13 b of the motor 13, a worm wheel 55 that meshes with the worm 54, and a cam gear 56 that meshes with the worm wheel 55. The worm 54, the worm wheel 55, and the cam gear 56 function as a cam drive unit that drives a cam unit 56b described later.

  The worm 54 and the worm wheel 55 constitute a worm gear device, and the rotation around the axis orthogonal to the optical axis of the output shaft 13b is converted into the rotation around the axis parallel to the optical axis. That is, the worm 54 rotates about an axis orthogonal to the optical axis, and the worm wheel 55 rotates about an axis parallel to the optical axis by the driving force transmitted by the worm 54.

  The worm wheel 55 includes a large-diameter gear portion 55 a that meshes with the worm 54 and a small-diameter gear portion 55 b that has fewer teeth than the large-diameter gear portion 55 a and meshes with the cam gear 56. The transmitted rotation is decelerated at a predetermined reduction ratio and transmitted. As shown in FIG. 5, the worm wheel 55 is inserted into a circular recess 23e provided in the lens base 23 and a shaft 31b protruding from the motor holding member 31. It is pivotally supported.

  9A is a perspective view of the cam gear 56 viewed from the subject side, and FIG. 9B is a front view of the cam gear 56 viewed in the direction of the rotation axis.

  The cam gear 56 includes a gear portion 56a at a part of the outer peripheral portion, and a cam portion 56b at another part of the outer peripheral portion. The gear part 56 a and the cam part 56 b are formed over substantially half the circumference of the cam gear 56. The gear portion 56a meshes with the worm wheel 55, and the cam gear 56 rotates about an axis parallel to the optical axis.

  The cam portion 56b has a cam surface 56c that is inclined with respect to a surface orthogonal to the rotation axis of the cam gear 56, that is, inclined to a surface orthogonal to the optical axis. On the other hand, as shown in FIG. 8, the lens holding body 22 has a contact portion 22 d that contacts the cam surface 56 c, and the contact portion 22 d can slide on the cam surface 56 c as the cam gear 56 rotates. It is. The lens holder 22 is biased toward the cam surface 56 c by a spring 57. Accordingly, the lens holder 22 is guided in the optical axis direction as the cam gear 56 rotates. The spring 57 is, for example, a coiled compression spring, and is sandwiched between the lens holding body 22 and the lens base 23 with a predetermined compression force.

  The inclination angle of the cam surface 56c may be set as appropriate. For example, as shown in FIG. 9, the inclination angle of the end-side cam surfaces 56e1 and 56e2 on both ends is set to the central cam between the ends. The movement of the lens holder 22 in the optical axis direction when the cam gear 56 overruns may be suppressed more gently than the inclination angle of the surface 56d or the inclination angle may be 0 °. The inclination angle of the central cam surface 56c may be about 9 ° ± 20%, that is, 7 to 11 °. This range takes into account the minimum required size and the amount of movement of the lens holder 22 in the optical axis direction while aiming for miniaturization of the cam gear 56 mounted in the optical module, and an appropriate drive resolution and drive speed. In this range, it can be driven smoothly. Specifically, if the angle is smaller than 7 °, the cam gear 56 is small, and the central cam surface 56c may not be sufficient for one round to secure the necessary movement amount of the lens holding body 22. The amount of rotation of the cam gear 56 increases, and a drive time is required for the lens holder 22 to reach a predetermined position. On the other hand, if the angle is larger than 11 °, the lens holder 22 cannot be held in fine increments, and the driving resolution is lowered. Also, the gravity of the lens holder 22 causes the contact between the contact portion 22d and the central cam surface 56c. Slip easily occurs.

  As shown in FIG. 8, the lens unit 12 is provided with a photoelectric sensor 61 for detecting the rotational position of the cam gear 56 and thus detecting the position of the lens holder 22 in the optical axis direction.

  As shown in FIG. 9, the photoelectric sensor 61 as a detection unit in the position detection unit is configured by a reflective photoelectric sensor, and includes a light emitting unit 61a and a light receiving unit 61b. The photoelectric sensor 61 is disposed so as to face the surface orthogonal to the rotation axis of the cam gear 56, the light emitting unit 61 a emits light to the cam gear 56, and the light receiving unit 61 b receives light reflected by the cam gear 56. Then, an electrical signal corresponding to the received light is output.

  Also, the position of the lens can be detected with the position where the received light quantity is a predetermined amount as a reference position. In particular, when the change in the received light quantity is not a sudden change but a gentle change, the lens position can be grasped with reference to the lens position at a predetermined light quantity in the middle of the gentle change.

  For example, the photoelectric sensor 61 is configured by a sensor that outputs an electrical signal (for example, a current value, a voltage value, or a power value) corresponding to the amount of light received by the light receiving unit 61b, and whether the amount of light exceeds a certain threshold value. Depending on whether or not, the output signal is switched between an on signal and an off signal.

  The photoelectric sensor 61 is connected to the substrate 16 by connecting the FPC 32 (see FIGS. 4 and 5) to a terminal 61c (see FIG. 8) provided on the side opposite to the side facing the cam gear 56. The operation of the photoelectric sensor 61 is controlled by a control unit (not shown) of the mobile phone 1 via the FPC 32, the substrate 16, and the FPC 37.

  As shown in FIGS. 9A and 9B, the position of the cam gear 56 facing the photoelectric sensor 61, that is, the position concentric with the cam portion 56b, causes the light from the light emitting portion 61a to enter the light receiving portion 61b. It functions as a detected portion 56f that reflects. The detected portion 56f is located, for example, on the inner peripheral side of the cam portion 56b. The detected portion 56f includes a first reflecting portion 56g and a second reflecting portion 56h.

  The first reflecting portion 56g is formed on a protrusion that protrudes closer to the photoelectric sensor 61 than the second reflecting portion 56h (hereinafter also referred to as a protrusion or protrusion). In the present embodiment, the first reflecting portion 56g is set to have a higher light reflectance than the second reflecting portion 56h. For example, the surface on the photoelectric sensor 61 side of the first reflecting portion 56g is subjected to mirror finishing or color coating (for example, white coating) by metal deposition or the like, or a member with high reflectivity (for example, a mirror) is attached. The reflectance of the first reflecting portion 56g is set higher than the reflectance of the second reflecting portion 56h, for example, by subjecting the surface of the second reflecting portion 56h to a satin finish. In addition, the cam gear 56 may be made of a resin, and the protrusion portion which is the first reflection portion 56g may be integrally formed to perform the above-described high light reflection processing, and has the first reflection portion 56g (protrusion portion). After that, the first reflecting portion 56g (projection portion) is manufactured with a light reflecting material rather than the cam gear 56, or the surface is subjected to light reflecting processing and bonded onto the second reflecting portion 56h. You may do it.

  As described above, the photoelectric sensor 61 (optical sensor) having the light emitting part 61a (light emitting element) and the light receiving part 61b (light receiving element) is used as the position detecting means, and the first reflecting part 56g formed on the protrusion is provided. As a result, the amount of light received by the light receiving portion 61b is increased by reducing the distance from the photoelectric sensor 61, so that the position of the lens that is the driving destination can be accurately detected. Specifically, the photoelectric sensor 61 has a distance from the detection target optimum for detection, but the height of the first reflecting portion 56g is set to the optimum distance, and the second reflecting portion 56h is further separated. By setting the distance to a large value, a large difference is generated in the output signal of the photoelectric sensor 61, so that erroneous detection can be prevented and detection accuracy can be improved.

  As in this embodiment, in order to reduce the size of the optical module, it is preferable to use a photoelectric sensor having a short optimum distance. For example, when the optimum distance is seen from the graph of the distance of the reflective photoelectric sensor and the relative output current, NJL5196 / 97K (manufactured by New Japan Radio) is approximately 0.6 mm, CNB1011 (manufactured by Matsushita) is approximately 0.8 mm, EE-SY125 (manufactured by OMRON) is approximately 0.7 mm, and PR-30-T (Citizen Electronics). Is approximately 0.4 mm, and the relative output current decreases as the optimum distance approaches and moves away from the peak. When the current value obtained at the optimum distance is 100%, when 60% is set as a threshold value and the signal to be output is switched between the on signal and the off signal depending on whether or not the threshold value is exceeded, In any of the photoelectric sensors described above, the object to be detected needs to be within a distance of 1.5 mm. However, for reasons such as the structure for fixing the photoelectric sensor of the optical module and the effect of preventing the rubbing debris between the cam portion 56b and the contact portion 22d, or the effect of scattering of the lubricant applied to the cam portion 56b. The photoelectric sensor 61 and the second reflecting portion 56h must be separated from each other by more than 1.5 mm. Therefore, in the present invention, the first reflecting portion 56g is formed to project, and thus the distance can be shortened to a position suitable for the photoelectric sensor 61 to switch to the ON signal, thereby preventing erroneous detection and improving detection accuracy. Can be planned. The photoelectric sensor 61 is preferably one that greatly reduces the current value obtained by the light receiving unit 61b when the distance to the object to be detected changes slightly. For example, when the current value obtained at the optimum distance is 100% It is preferable to reduce the distance by 50% or more when it is 1 mm away from the optimum distance.

  Furthermore, in order to accurately detect the position of the lens, the reflectance of the first reflecting portion 56g is made higher than that of the second reflecting portion 56h. Specifically, the first reflecting portion 56g is light as described above. You may comprise a highly reflective process or a light highly reflective material. When performing this high light reflection processing, it is only necessary to perform processing on the protruding portion, so that processing can be performed easily and accurately. The high light reflection of the present invention means that the first reflecting portion 56g has a higher reflectance when measured under the same conditions than the second reflecting portion 56h.

  Further, the first reflecting portion 56g serving as the detected portion is not limited to the one provided on the inner peripheral side of the cam portion 56b on the surface orthogonal to the optical axis of the cam gear 56. For example, on the outer peripheral side of the cam portion 56 It may be set. Further, in the present embodiment, the first reflecting portion 56g and the cam portion 56b are provided separately. However, the photoelectric sensor 61 is disposed on the protruding portion of the cam portion 56b, and the first reflecting portion 56g of the cam portion 56b. You may make it combine. Further, the first reflecting portion 56g detected by the photoelectric sensor 16 when the lens holding body 22 abuts between the end portions of the cam portion 56b does not overlap with the cam portion 56b. Good. For example, it may be provided at a position facing the cam portion 56b across the rotation shaft. Even in this case, the length of the first reflecting portion 56g is made shorter than the length of the cam portion 56b, and the amount of deviation between the photoelectric sensor 16 and the contact portion 22d of the lens holding body 22 is set to be different from that of the cam portion 56b. What is necessary is just to make it equal to the deviation | shift amount with 1 reflective part 56g.

  In this embodiment, the case where the photoelectric sensor 61 is used has been described. However, the photoelectric sensor includes a light emitting unit and a light receiving unit, and outputs an output signal according to a change in reflected light of light emitted from the light emitting unit. Any change may be used, and the present invention is not limited to outputting a signal corresponding to the amount of light. For example, a position sensor (PSD) or a photoelectric sensor having a two-divided photodiode may be used as the photoelectric sensor, and the position of the cam gear may be specified based only on the change in the distance between the photoelectric sensor and the cam gear. Alternatively, a mechanical switch sensor may be used in place of the photoelectric sensor, and the sensor may be in contact with only the ridge forming portion of the first reflecting portion 56g and may be turned on by the contact.

  The first reflecting portion 56g is shorter than the cam portion 56b in the circumferential direction and is formed so as to be within the range of the cam portion 56b. Specifically, the length of the first reflecting portion 56g is equal to the length of the central cam surface 56d. When the lens holder 22 is in contact with the central cam surface 56d, the photoelectric sensor 61 receives the reflected light from the first reflecting surface 56g and outputs a signal. When it abuts on the side cam surface 56e, that is, when the lens holder 22 reaches the end of the movement range in the optical axis direction, it receives the reflected light from the second reflecting surface 56h and outputs a signal. To do. The circumferential position between the first reflecting portion 56g and the central cam surface 56d is set to be shifted by an amount corresponding to the positional shift between the photoelectric sensor 61 and the contact portion 22d of the lens holding body 22. ing.

  Thus, it is preferable that the first reflecting portion 56g is located at a position facing the photoelectric sensor 16 when the lens holder 22 is located at the reference position or the reference area. The reference position may be a storage position (optical lens system non-driven, non-zoom position), a predetermined zoom position, an infinite focal position, a closest focal position, or an arbitrary focal position, A plurality of reference positions may be provided by combining these. The reference area may be an accommodation area, a zoom area, an arbitrary focal area, or the like, and a plurality of reference areas may be provided in combination.

  Further, the height of the cam portion 56b is determined according to the required amount of extension of the lens, and the height of the first reflecting portion 56g is determined according to the optimum condition with the photoelectric sensor 61. The protrusions of one reflecting portion 56g are formed higher than the cam portion 56b and the end-side cam surface 56e. As a result, when the first reflecting portion 56g is subjected to high light reflection processing (for example, white coating), the first reflection portion 56g is processed without affecting the cam portion 56b (for example, the cam portion 56b is also painted white). Can do.

  A control unit (not shown) of the mobile phone 1 specifies the origin position of the cam gear 56 based on the position when the signal from the photoelectric sensor 61 is switched between the on signal and the off signal, and based on the origin position. Thus, the rotational position of the cam gear 56 is controlled.

  According to the above embodiment, the motor 13 is disposed so that the output shaft 13 b extends in a direction orthogonal to the optical axis of the lens group 21, and the rotation of the output shaft 13 b is translated in the optical axis direction by the transmission mechanism 53. Since the lens group 21, the motor main body 13a, and the motor output shaft 13b are arranged in series in the optical axis direction, the thickness can be reduced. It becomes possible. In other words, in contrast to the conventional arrangement in which the output axis 13b is parallel to the optical axis, the number of options for making the output axis 13b orthogonal to the optical axis increases, and the degree of freedom in design is improved.

  For example, the motor 13 is provided on the outer side in the radial direction of the lens group 21 or arranged in parallel with the shutter unit 12 (shutter base body 41), so that the thickness can be reduced. The entire shape of the shutter base 41, the lens base 23, the substrate cover 15, and the substrate 16 stacked in this order can be configured to be thin and thin in the optical axis direction.

  The substrate 16 has a width equal to or greater than that of the shutter base 41, the motor 13, the lens base 23, and the substrate cover 15, and the surface 16b of the substrate 16 opposite to the surface 16a on which the imaging element 35 is provided is an optical module. 9, and the opposite surface 16 b is provided with only the FPC 37 extending along the surface. Therefore, when mounting the optical module 9, the substrate 16 is attached to the mobile phone 1. It can be placed in contact with an internal flat portion, for example, a main substrate. Therefore, the mounting of the optical module 9 is facilitated, and the fixing is performed reliably. As described above, according to the configuration of the present invention, the shutter blade can be formed in a thin shape even with respect to the optical module including the shutter base that holds the optical path of the lens so that the optical path of the lens can be opened and closed.

  The transmission mechanism 53 is provided with a cam portion 56b having a cam surface 56c that is inclined with respect to a surface orthogonal to the optical axis, and the lens holder 22 is moved along the surface orthogonal to the optical axis of the cam portion. Since it is guided in the axial direction, the movement characteristics of the lens holder 22 can be set by adjusting the inclination angle and height of the cam surface 56c. For example, even if the rotational speed of the motor 13 is constant, the lens holder It is possible to prevent the lens holder 22 from moving in the optical axis direction even if the moving speed of the motor 22 is changed or the motor 13 overruns. In other words, the control of the motor 13 can be facilitated and the control accuracy can be relaxed.

  By providing a spring 57 for urging the lens holding body 22 to the cam surface 56c, not only the lens holding body 22 is pushed up and guided by the raising of the cam surface 56c, but the lens holding body 22 follows the lowering of the cam surface 56c. Can guide you.

  Since the cam portion 56b is provided in the cam gear 56 that rotates about an axis parallel to the optical axis to guide the lens holder 22, the thickness can be reduced in the optical axis direction. In other words, since the cam gear is generally thin and thin in the direction of the rotation axis, the arrangement area in the direction of the optical axis is smaller when the rotation axis is parallel to the optical axis than in the case where the rotation axis is orthogonal to the optical axis, thereby reducing the thickness. It is done.

  Since the gear portion 56a is provided at a part of the outer peripheral portion of the cam gear 56 and the cam portion 56b is provided at the other portion of the outer peripheral portion of the cam gear 56, the shape is relatively simple. Setting and assembling of the arrangement area is relatively easy. In addition, since the cam portion 56b is provided on the outer peripheral portion, the cam portion 56b is longer with respect to the rotation angle than when the cam portion 56b is provided on the inner peripheral side. The lens holder 22 can be smoothly guided.

  Since the photoelectric sensor 61 is arranged and the position of the lens holding body 22 is detected based on the change in the reflected light accompanying the rotation of the cam gear 56, the position of the lens holding body 22 can be detected easily and accurately.

  For example, a photoelectric sensor 61 that outputs a different signal according to a change in the amount of reflected light is provided, and the light of the photoelectric sensor 61 is reflected by the first reflecting portion 56g when the lens holder 22 is in the central range of the moving range. Is reflected, and the light of the photoelectric sensor 61 is reflected by the second reflecting portion 56h in which the amount of reflected light is different from that of the first reflecting portion 56g when the lens holder 22 is at the end of the moving range. The end position of the movement range of the lens holder 22 can be easily detected.

  The first reflecting portion 56g is protruded to the photoelectric sensor side from the second reflecting portion 56h, and the surface of the first reflecting portion 56g is processed to have a higher reflectance than the second reflecting portion 56h. Therefore, the difference in the amount of light reflected to the photoelectric sensor 61 between the two becomes larger, and the boundary between the first reflecting portion 56g and the second reflecting portion 56h is detected more accurately.

  Further, the cam gear 56 is arranged in the order of the detected portion 56f, the cam portion 56b, and the gear portion 56a in this order from the concentric inner side, so that the cam gear 56 and the peripheral parts of the cam gear can be accommodated in the minimum necessary space. .

  In this embodiment, the cam gear 56 is arranged from the inside in the order of the detected portion 56f (the first reflecting portion 56g and the second reflecting portion 56h) and the cam portion 56b. This makes it possible to accurately control the position of the lens for a long period of time while accommodating the cam gear 56 and the peripheral parts of the cam gear 56 in the minimum necessary space. Specifically, by forming the detected portion 56f on the innermost side, the photoelectric sensor 61 disposed opposite to the detection portion 56f can be brought closer to the center side of the concentric circle of the cam gear 56. Can be realized. Further, since the cam portion 56b is formed on the outer side, the inclination angle described above can be made gentler than that formed on the inner side, so that the contact portion 22d and the central cam surface are caused by the gravity of the lens holder 22 described above. Sliding between 56c is less likely to occur.

The present invention is not limited to the above embodiment, and may be implemented in various aspects.
The target to which the optical module of the present invention is applied is not limited to a mobile phone, and may be applied to various devices such as a digital camera and a surveillance camera.
The drive source may be disposed at an appropriate position with respect to the lens, the shutter, the image sensor, etc., as long as the output axis is disposed in a direction orthogonal to the optical axis.
The transmission mechanism only needs to convert rotation about an axis orthogonal to the optical axis of the drive source into a translational motion in the optical axis direction and transmit it to the lens holder, and is not limited to one using a cam. For example, rotation about an axis orthogonal to the optical axis may be converted into translational movement in the optical axis direction by a slider link mechanism including a rack and a pinion.

  In addition, when the translational movement in the optical axis direction is realized by the cam, the cam surface only needs to change the height of the cam surface in the optical axis direction, and the cam is provided on the cam gear that rotates around the axis parallel to the optical axis. It is not limited to things. For example, it may be converted into a translational movement in the optical axis direction by a cam that rotates around an axis orthogonal to the optical axis and the distance from the rotation axis to the peripheral portion changes according to the position in the circumferential direction. The cam surface inclined to the plane orthogonal to the optical axis may be linearly driven along the plane orthogonal to the optical axis to convert into a translational motion in the optical axis direction.

 When converting into translational motion in the optical axis direction by a cam gear rotating about an axis parallel to the optical axis, the cam gear may mesh with the worm and the cam gear may also serve as the worm wheel. Further, another gear may be interposed between the worm wheel and the cam gear. For example, the worm may be provided on an axis parallel to the output shaft to which the rotation of the output shaft is transmitted without providing the worm on the output shaft. Further, the cam portion 56b is arranged at a place different from the gear portion 56a as in this embodiment, and the cam gear 56 can be reduced in size by concentrically arranging the cam portion 56b and the gear portion 56a. it can.

  In these inventions, there may be no configuration for moving the lens. Further, the overall shape may not be a thin shape. And also in the said invention, the various preferable aspects similar to invention of this application may be included.

It is a perspective view which shows the external appearance of the mobile telephone of embodiment of this invention in an open state. It is a perspective view which shows the external appearance of the mobile telephone of FIG. 1 in a closed state. It is the external appearance perspective view and sectional drawing of the optical module of the mobile telephone of FIG. It is the disassembled perspective view which looked at the optical module of FIG. 3 from the to-be-photographed object side. It is the disassembled perspective view which looked at the optical module of FIG. 3 from the opposite side to the to-be-photographed object side. It is a disassembled perspective view of the shutter unit of the optical module of FIG. It is a perspective view of the lens unit of the optical module of FIG. It is a perspective view which shows the internal structure of the lens unit of FIG. It is a figure which shows the cam gear of the lens unit of FIG.

Explanation of symbols

24, 26, 28 ... lens 22 ... lens holder 23 ... lens base 13 ... drive source 53 ... transmission mechanism.

Claims (8)

A lens, a lens base that holds the lens movably in the optical axis direction of the lens, a drive source having an output shaft that outputs a driving force, and a driving force output from the output shaft. And a shutter blade, a shutter base that holds the shutter blade in an openable / closable manner, an imaging element on which a light image is formed by the lens, and the imaging element. A substrate, and
The shutter base, the lens base, and the substrate are stacked in this order from one direction with respect to the optical axis direction, and the drive source is disposed on the shutter base and the lens base. Arranged in a direction substantially perpendicular to the optical axis,
The optical module is characterized in that the substrate has substantially the same area as the shutter base and the lens base, and an electronic component is mounted only on a surface on which the imaging element is provided.  2. The optical module according to claim 1, wherein the substrate is provided with only a flexible printed wiring board extending along a surface on a side opposite to a surface on which the imaging element is provided. A cover member that covers the imaging element side of the substrate;
The shutter base, the lens base, the cover member, and the substrate are laminated in this order.
3. The optical module according to claim 1, wherein the substrate has an area equivalent to that of the shutter base, the lens base, and the cover member. The drive source is arranged so that the output axis is substantially perpendicular to the optical axis,
The transmission mechanism transmits a driving force output from the output shaft, and rotates around an axis substantially orthogonal to the optical axis, and a gear portion that meshes with the worm or a gear that transmits the rotation of the worm. And a cam gear that has a cam portion that is inclined with respect to a plane orthogonal to the optical axis, and rotates around an axis substantially parallel to the optical axis.
The optical module according to claim 1, wherein the lens base is in contact with the cam portion and guided in the optical axis direction. A position detecting means having a detected portion disposed in the cam gear and a detecting portion disposed in the vicinity of the cam gear;
The optical module according to claim 4, wherein the position detection unit detects the position of the lens by detecting the rotation of the cam gear by the detection unit.  The optical module according to claim 5, wherein the cam gear is arranged in order of the detected portion and the cam portion from the inside of the cam gear.  The optical module according to claim 4, wherein the cam gear includes a cam portion and a gear portion that are concentrically arranged with the cam gear.   A portable terminal comprising: a housing that houses the optical module according to any one of claims 1 to 7; and a battery, wherein the drive source is supplied with power from the battery.

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