CN113940054B

CN113940054B - Imaging device and information terminal

Info

Publication number: CN113940054B
Application number: CN201980096761.2A
Authority: CN
Inventors: 米山厚司; 宇野胜
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-05-27
Filing date: 2019-05-27
Publication date: 2023-02-07
Anticipated expiration: 2039-05-27
Also published as: JP7324301B2; CN113940054A; WO2020237450A1; JP2022522306A

Abstract

An image forming apparatus is provided which is simple in configuration and lower in power consumption of a driving mechanism. The image forming apparatus includes: a first lens group; a second lens group through which light transmitted through the first lens group passes; a first drive shaft frictionally engaged with the first lens group and frictionally engaged with the second lens group with a frictional force smaller than that of the first lens group; a first piezoelectric element fixed to one end of the first driving shaft to expand and contract the first driving shaft; a second drive shaft frictionally engaged with the second lens group and frictionally engaged with the first lens group with a frictional force smaller than that of the second lens group; a second piezoelectric element fixed to one end of the second driving shaft to expand and contract the second driving shaft; a sensor receiving light transmitted through the first lens group and the second lens group.

Description

Imaging device and information terminal

Technical Field

The present invention relates to an imaging apparatus and an information terminal, and more particularly to a driving mechanism for realizing a zoom function and an Auto Focus (AF) function.

Background

A portable information terminal such as a smartphone generally includes an imaging function serving as a camera (imaging device). The imaging function realizes a desired zoom function and AF function by driving and operating a lens or the like.

Each of the portable information terminals is limited in the thickness of its housing, and it is desirable that the image forming function be realized by a mechanism having a simple structure that does not occupy much space. It is also desirable that the actuator constituting the drive mechanism for the imaging function has low power consumption.

An object of the present invention is to provide an image forming apparatus and an information terminal which are simple in configuration and whose driving mechanism has low power consumption.

Disclosure of Invention

In a first aspect of the present invention, there is provided an image forming apparatus comprising: a first lens group; a second lens group through which light transmitted through the first lens group passes; a first drive shaft frictionally engaged with the first lens group and frictionally engaged with the second lens group with a frictional force smaller than a frictional coefficient with the first lens group; a first piezoelectric element fixed to one end of the first driving shaft to expand and contract the first driving shaft; a second drive shaft frictionally engaged with the second lens group and frictionally engaged with the first lens group with a frictional force smaller than that of the second lens group; a second piezoelectric element fixed to one end of the second driving shaft to expand and contract the second driving shaft; a sensor receiving light transmitted through the first lens group and the second lens group.

In a second aspect of the present invention, there is provided an image forming apparatus comprising: a lens group; a sensor receiving light transmitted through the lens group; a mirror reflecting incident light toward the lens group; a control unit that performs optical anti-shake of components in a direction orthogonal to an optical axis of the lens group by causing vibration at the reflection position of the mirror.

Drawings

Fig. 1A is a perspective view of a rear surface of a smartphone provided by an embodiment of the present invention;

fig. 1B is a perspective view of a front surface of a smartphone provided by an embodiment of the present invention;

figure 2 (a) is a plan view of the internal mechanism of a smartphone according to an embodiment of the present invention,

fig. 2 (b) is a side view of the internal mechanism;

FIG. 3 is a view showing a layout relationship between a magnet on the mirror side and a coil on the sub chassis side;

FIG. 4 is a view of a core member with a coil mounted thereon;

fig. 5 is a graph of the change of magnetic poles of the core arm caused by the current supply of the coil in the rotational driving of the mirror;

fig. 6A is a diagram of a waveform of a hall element that detects the rotation of the mirror;

fig. 6B is a diagram of waveforms of hall elements detecting mirror rotation;

fig. 7 is a block diagram mainly showing a configuration for drive-controlling the smartphone of the present embodiment.

Detailed Description

Embodiments of the present invention will be described below with reference to the accompanying drawings. Fig. 1A and 1B are perspective views of a smartphone serving as an imaging device (camera) according to an embodiment of the present invention; fig. 1A shows a view of the back surface of the smartphone, and fig. 1B shows a view of the front surface of the smartphone.

In these drawings, the smartphone 100 includes an imaging mechanism serving as a camera (imaging device). More specifically, an opening 103 is provided on the rear surface 101B of the smartphone 100, and a lens is provided to close the opening 103. The opening 103 is provided inside with a mirror 3, and the direction of light incident through the opening 103 is changed by the mirror 3 so that the light enters the optical system of the imaging mechanism provided inside the smartphone 100. Therefore, the user can perform imaging by operating a predetermined imaging button while aligning the rear surface 101B with the photographic subject. In addition, as shown in fig. 1B, the reflecting mirror 3 is configured to be able to be ejected from the upper portion of the smartphone 100 by the ejection unit 102. A lens is disposed at the opening of the ejecting unit 102 so as to close the opening. When the ejecting unit 102 ejects, the mirror 3 is rotated by 90 degrees from the state shown in fig. 1A. This enables the user to perform imaging with the front surface 101A of the subject aligned. In this way, the smartphone 100 provided by the present embodiment can perform imaging using the rear surface 101B or the front surface 101A of the alignment photographic subject. Further, the eject mechanism provided for the mirror or the like can make almost the entire front surface 101A function as a display screen. In other words, it is not necessary to provide an incident light path for imaging, such as a lens, in a part of the display screen, so that the arrangement and size of the display screen are not limited.

Fig. 2 (a) and 2 (b) are a plan view and a side view, respectively, of a configuration of a camera (imaging) function inside a smartphone provided by an embodiment of the present invention.

The camera mechanism provided in the present embodiment roughly includes a zoom lens group 10, an automatic focus (hereinafter referred to as "AF") lens group 15, an aperture system 16, a sensor 18, and a mirror 3 for guiding light from a subject through these lens groups to the sensor 18. The zoom lens group 10 and the AF lens group 15 are provided on an AF/zoom chassis 17 together with their driving parts. The mirror 3 and the sensor 18 are provided on the sub chassis 2. The AF/zoom chassis 17 is movably provided on the sub chassis 2. In addition, the sub chassis 2 is provided movably with respect to the main chassis 1. The main chassis 1 constitutes a part of a chassis of the smartphone 100 of the present embodiment. Although the zoom lens group 10 and the AF lens group 15 in the present embodiment are each constituted by a plurality of lenses, the two lens groups or one of the two lens groups may be constituted by a single lens according to the specifications of the camera.

The smart phone of the present embodiment has a back side camera mode and a front side camera mode as described above with reference to fig. 1A and 1B. In the rear camera mode, as shown in fig. 2 (b), the rotational position of the mirror 3 is set to an angle at which light incident from the rear side of the smartphone is reflected to be guided to the lens group through the opening 103 (fig. 1A). On the other hand, in the front side camera mode, the sub chassis 2 is moved to the eject position, and the rotational position of the mirror 3 is set to an angle at which light incident from the front side of the smartphone through the eject unit 102 (fig. 1B) is reflected to be guided to the lens group.

The drive mechanisms of the zoom lens group 10 and the AF lens group 15 provided on the AF/zoom chassis 17 are as follows.

The driving shaft 141 (first driving shaft) supports one end of the zoom lens group 10 by moving the supporting member 151. The moving support member 151 and the driving shaft 141 are frictionally engaged with each other with a predetermined frictional force. More specifically, the moving support member 151 has a V-shaped section, an inner surface of which is in line contact with the driving shaft 141 at two points. Meanwhile, a flat spring (not shown) abuts on the driving shaft 141 and presses the driving shaft 141 against the V-shaped inner surface of the moving support member due to its elastic force. This pressing generates a predetermined frictional force. The other end of the zoom lens group 10 in the X-axis direction (opposite to one end of the zoom lens group 10) is supported on the drive shaft 142 (second drive shaft) by a support member 161. The support member 161 and the drive shaft 142 are engaged with each other with a frictional force smaller than that when the moving support member 152 of the AF lens group 15 is engaged with the drive shaft 142. Specifically, support member 161 has a U-shaped cross-section, and drive shaft 142 engages the U-shaped inner surface with a close tolerance. It should be noted that the cross-sectional shapes of the movement support member 151 and the support member 161 are not limited to the above-described shapes, and may be any shapes as long as the frictional force between the support member 161 and the drive shaft 142 is smaller than the frictional force between the movement support member 151 and the drive shaft 141. The same engagement relationship as described above also applies to the engagement relationship of the support member 162 and the drive shaft 141 and the corresponding engagement relationship of the movement support member 152 and the drive shaft 142.

With the zoom lens group 10, a weight 121 is connected to one end of the drive shaft 141, and one end of the piezoelectric element 131 (first piezoelectric element) is fixed to the weight 121. Further, one end of the driving shaft 141 is fixed to the other end of the piezoelectric element 131. The weight member 121 is attached to the vertical chassis 171 by a flexible adhesive. Therefore, the weight member 121 can be freely moved in the direction and range of the deformation of the piezoelectric element 131 based on the driving. The other end of the drive shaft 141 is slidably retained by a vertical chassis 172. It should be noted that the configuration for the action of the weight member 121 is not limited to the above adhesive, and may take any form as long as the weight member 121 can freely move within a predetermined range.

The AF lens group 15 further includes a drive mechanism similar to that of the zoom lens group 10 described above. That is, one end of the AF lens group 15 is supported by the drive shaft 142 via the moving support member 152. The moving support member 152 and the driving shaft 142 are frictionally engaged with each other by pushing the driving shaft 142 toward the moving support member 152 having a V-shaped section by a flat spring (not shown) contacting the driving shaft 142. Further, the other end of the AF lens group 15 opposite to the one end of the AF lens group 15 in the X-axis direction is supported on the drive shaft 141 by a support member 162. As described above, the support member 162 and the driving shaft 141 are engaged with each other with a tolerance that forms a slight gap between the driving shaft 141 and the U-shaped section of the support member 162.

With the AF lens group 15, a weight 122 is attached to one end of the drive shaft 142, and one end of the piezoelectric element 132 (second piezoelectric element) is fixed to the weight 122. Further, one end of the driving shaft 142 is fixed to the other end of the piezoelectric element 13. The weight 122 is attached to the vertical chassis 172 by a flexible adhesive. The other end of the drive shaft 142 is slidably retained by a vertical chassis 171.

The driving principle of the driving mechanisms of the zoom lens group 10 and the AF lens group 15 described above is based on a so-called smooth impact driving mechanism (hereinafter referred to as "SIDM"). The following is an explanation of the principle of driving the zoom lens group 10. When the driving shaft 141 is relatively slowly moved by driving the piezoelectric element 131 in the extension direction of the piezoelectric element 131 by the voltage applied to the piezoelectric element 131, the movement supporting member 151 moves together with the driving shaft 141 due to frictional engagement with the driving shaft 141. Then, the piezoelectric element 131 is driven in the opposite direction (i.e., in the contraction direction of the piezoelectric element) so that the driving shaft 141 is rapidly moved, thereby causing the movement support member 151 to stay at the current position due to the relationship between the inertia of the movement support member 151 and the kinetic friction with the driving shaft 141 a. Repeating the above-described slow and fast movements of the drive shaft 141 can move the movement supporting member 151 and thus the zoom lens group 10 in the negative direction of the Y-axis. Further setting the moving speed of extension and contraction in an inverse relationship to the above moving speed relationship makes it possible to move the zoom lens group 10 in the positive direction of the Y-axis.

According to the present embodiment, the zoom lens group 10 and the AF lens group 15 are driven as follows. The AF mode and the zoom mode are performed by connecting the movement of the zoom lens group 10 and the movement of the AF lens group 15 to each other. For example, when focusing at the same magnification as in the case of focusing the subject at the zoom magnification in the case of changing the subject, the AF lens group 15 is moved to perform focusing. Then, the zoom lens group 10 moves due to the change of the focus position. Further, when the zoom magnification is changed without changing the subject, the in-focus position changes with the movement of the zoom lens group 10, and thus the AF lens group is moved. As described above, the zoom lens group 10 and the AF lens group 15 are driven by the corresponding

piezoelectric elements

131, 132 in any one of the AF mode and the zoom mode. According to the present embodiment, the driving frequencies of the respective piezoelectric elements are set to respective appropriate frequencies in the range of about 200KHz to about 300 KHz.

In the movement of connecting the AF lens group 15 and the zoom lens group 10 to each other, a so-called "shake effect" is generated in each of the engagement relationships of the

support members

161, 162 and the

corresponding drive shafts

142, 141. More specifically, the connecting movement of the above two lens groups causes the respective drive shafts to move in an oscillating manner, and the engagement of the

corresponding support members

161, 162 with the respective drive shafts becomes a dynamic frictional engagement. Therefore, the resistance due to the engagement is small. As a result, the driving force of the

piezoelectric elements

131, 132, which are the driving sources of the AF lens group 15 and the zoom lens group 10, becomes small, and thus power consumption can be reduced.

Note that even if any one of the AF lens group 15 and the zoom lens group 10 does not move, a shake effect is caused. The drive shaft may become in an idle state in which the corresponding piezoelectric element vibrates the drive shaft for moving the non-moving lens group and has a sine curve of several kilohertz. This idle state causes a wobbling effect between the support member of the moving lens group and the vibrating drive shaft.

In addition, although in the above-described embodiment, the driving frequencies of the

piezoelectric elements

131, 132 are set to values in the range of about 200KHz to about 300KHz, the driving frequencies are of course not limited to these values. The respective driving frequencies of the two piezoelectric elements may be changed according to conditions such as specifications and product shapes of an imaging device or a smart phone, and may be determined according to a value of a connecting motion of the two lens groups and a shake effect between the two lens groups.

Although the above description is related to the driving of the zoom lens group and the AF lens group, the two lens groups (the first lens group and the second lens group) are of course not limited to the zoom lens group and the AF lens group. The above-described configuration and driving method can be applied to any type of lens groups as long as the target lens group is two lens groups constituting a camera mechanism driven in a linked manner.

The aperture system 16 is disposed in front of the AF lens group 15 along the optical axis, and adjusts the aperture in two stages of aperture sizes.

The magnet 11 is provided on the rear side of an AF/zoom chassis 17, and the above-described optical system is mounted on the AF/zoom chassis 17. The coil 20 is provided on the sub chassis 2 at a position where the coil 20 may face the magnet 11. The AF/zoom chassis 17 is provided movably with respect to the sub chassis 2 by three balls 4. This configuration can achieve optical anti-shake (hereinafter referred to as "OIS") described later.

The sensor 18 is positioned along the optical axis of the optical system at the rear of the optical system. The sensor 18 is held by a sensor holder 19 fixed to the sub chassis 2.

As described above, the mirror 3 changes its rotational position between the rear-side camera mode and the front-side camera mode. The mirror 3 takes an oscillating action in the direction of rotation to perform OIS, as described below. The mechanism for driving the mirror 3 is given below.

The mirror 3 is held rotatably about an axis parallel to the X axis by a support member 201 (not shown in fig. 2 (b)) provided on the sub chassis 2. A disc-shaped yoke 5 is attached to one side surface of the mirror 3, and a magnet 6 is attached to the yoke 5. This enables the mirror 3 and the magnet 6 to rotate together. The coil 7 is disposed on the sub chassis 2 at a position facing the magnet 6 of the mirror 3.

Fig. 3 is a diagram showing the arrangement relationship between the magnet 6 on the mirror 3 side and the coil 7 on the sub chassis 2 side, and fig. 4 is a diagram showing the core member 70 to which the coil 7 is attached.

As shown in fig. 3, the magnet 6 includes 12N-pole magnetized portions 6A and 12S-pole magnetized portions 6B. As shown in fig. 3 and 4, the coil 7 includes two types of

coils

7A and 7B wound to pass through a passage formed between the core arm 71 to the core arm 78 of the core member 70. Specifically, the coil 7A and the coil 7B are arranged on the core member 70 with a phase difference of 90 degrees. Further, both

coils

7A and 7B are arranged around the magnet 6. Input side terminals and output side terminals of these coils (not shown) are provided at predetermined positions. Note that the

coils

7A and 7B are present on each of the two layers of the coil substrate. Therefore, the currents flowing through the

coils

7A and 7B do not interfere with each other.

Fig. 5 is a graph of the change in magnetic pole of the core arm caused by the current supply of the coil 7 in the rotational driving of the mirror 3. When the rotation angle of the mirror 3 is 0 degrees (initial state), the current supply of the

coils

7A and 7B sets the magnetic poles of the core arms 71 to 78 to S, N, \8230, S, and N. When the current supply of the

coils

7A and 7B is controlled in this state so that the magnetic poles of the core arms 71 to 78 are set to S, N, 8230 \8230;, S, and N, the mirror 3 is rotated Clockwise (CW) by 15 degrees. Likewise, changing the magnetic poles of core arms 71 to 78 can rotate mirror 3 by 30 degrees, 45 degrees, 60 degrees, 75 degrees, and 90 degrees. When the N pole or S pole of the magnet 6 directly faces the core arms 71 to 78 at such a rotational position, the rotational position becomes a magnetic stabilization point. When the current supply of the

coils

7A and 7B is cut off in this state, the position of the magnet 6 to the coil 7 and thus the position of the mirror 3 to the coil 7 are fixed. According to the present embodiment, a mode at a fixed point where the rotation angle of the mirror 3 is 0 degree among the fixed points is referred to as a rear side camera mode, and a mode at a fixed point where the rotation angle of the mirror 3 is 90 degrees among the fixed points is referred to as a front side camera mode. When transitioning from the front camera mode to the rear camera mode, the mirror 3 is rotated counterclockwise (CCW) to change the rotational position of the mirror 3.

Fig. 6A and 6B are diagrams of waveforms of the

hall elements

28A and 28B that detect the above-described rotation of the mirror 3. Fig. 6A shows waveforms detected by the

hall elements

28A and 28B when the mirror 3 is rotated clockwise, and a combined waveform of these detected waveforms, and fig. 6B shows waveforms detected by the

hall elements

28A and 28B when the mirror 3 is rotated counterclockwise, and a combined waveform of these detected waveforms. In the present embodiment, the hall element 28A and the hall element 28B are disposed at positions separated from each other by an equivalent electrical angle of 90 degrees.

Whether the mirror 3 rotates clockwise or counterclockwise is determined by the phase difference between the combined waveform 28C and the waveforms detected by the

hall elements

28A and 28B. Further, the number of times the hall element passes through the magnetic poles of the magnet 6, that is, the number of times the waveform detected by the hall element 28A crosses "0", can be counted to detect the rotation angle.

According to the present embodiment, OIS is performed by using the driving of the mirror 3. That is, in the case where the mirror 3 is fixed at a position of 0 degree or 90 degrees or a rotational position of each of the rear side camera mode or the front side camera mode, the OIS in the Z-axis direction can be controlled by using the hall element 28A. More specifically, by supplying a current to the coil 7, the mirror 3 (magnet 6) is rotated, and the rotational position of the mirror 3 is detected by the hall element 28A. Under the condition that the range of the rotational position of the mirror 3 detected by the hall element 28A is set as the servo region shown in fig. 6A, OIS in the Z-axis direction can be performed by rotating (vibrating) the mirror 3 (magnet 6) within this range. The following is an example of a servo region. When the hall element 28A detects a size of 3.5mm, the opening angle of each magnetic pole is 360/24, i.e., 15 degrees. The angle is 0.46nm in terms of distance, and therefore, the range of the servo region where linearity is guaranteed becomes 0.32mm with a margin of 70%. In other words, assuming that the area is ± 0.16mm, ois can be controlled in angle to be within a range of ± 5.2 degrees. In this example of the range of servo control, assuming that the distance from the reflection point of the mirror 3 to the sensor 18 is 10mm, the moving distance of the light spot on the sensor 18 is about 1.835343446mm. This value has a sufficient margin compared to the spot movement distance of 150 μm in the normal OIS.

Referring again to fig. 2 (a) and 2 (b), the configuration of OIS will be described. OIS in the X-axis direction may be performed by moving the AF/zoom chassis 17 in a direction along the X-axis. Specifically, the AF/zoom chassis 17 is moved in the X-axis direction by a required distance by controlling the supply of current to the coil 20 provided on the sub-chassis 2 based on the image detected by the sensor 18. This may ensure that OIS is performed in the X-axis direction. In addition, as described above, OIS in the Z-axis direction is performed by control using a hall element in which the rotational position of the mirror 3 is fixed at 0 degrees or 90 degrees.

As is apparent from the above, the mirror 3 can be used for OIS as well as for optical path switching in the dual-side camera mode, so that OIS and the like functions can be realized in a simple configuration without requiring a large component space.

The above optical system including the mirror 3 is mounted on the sub chassis 2. When the sub chassis 2 is moved relative to the main chassis 1, a pop-up window associated with the front side camera mode will be enabled. The sub chassis 2 includes a bearing portion 29 on one side surface in the X-axis direction and a guide portion 30 on the other side surface. A bearing portion 29 is provided on the main chassis 1 and slidably engages with the main shaft 8 extending in the Y-axis direction. The guide portion 30 is slidably engaged with a guide rail (not shown) extending in the Y-axis direction. That is, the sub chassis 2 is supported on the main chassis 1 by the main shaft 8 and the guide rail, and is movable in the Y-axis direction.

Both ends of the main shaft 8 engaged with the bearing portions 29 on the sub chassis 2 are supported by respective support members of the main chassis 1. The spring 22 is provided between one of the two support members on the sensor side of the rear of the optical system and the bearing portion 29 to normally urge the bearing portion 29 toward the front of the optical system. The bearing 29 abuts against the nut 23, the nut 23 being screwed onto the screw 9, the screw extending in the Y-axis direction on the opposite side of the portion of the bearing 29 in contact with the spring 22. The elasticity of the spring 22 absorbs the force erroneously applied by the user to press the ejection unit 102 back into the smartphone in the ejection position, so that the influence on other members can be reduced.

The screw 9 is driven to rotate by using the piezoelectric actuator 21 as a drive source. In particular, the actuator 21 is abutted against the rotor 25 by a spring 24 surrounding the actuator 21. Then, a high-frequency voltage is applied to the actuator 21 to cause expansion/contraction, so that the metal sheet mounted on the distal end of the actuator 21 makes an elliptical motion, thereby enabling the rotor 25 to rotate due to friction between the metal sheet and the rotor 25. The rotor 25 can be rotated in the reverse direction by changing the phase relationship of the applied voltages. Rotation of the rotor 25 causes rotation of the coaxial first gear 26, which causes rotation of the second gear 27 engaged with the first gear 26. One end of the screw 9 is fixed to a second gear 27, which second gear 27 enables rotation of the screw 9. In the above configuration, when the lead screw 9 is rotated in a predetermined direction, the nut 23 is advanced in the positive direction of the Y-axis, so that the bearing portion 29 urged by the spring 22 can be moved in the same positive direction of the Y-axis when abutting against the nut 23. Therefore, the sub chassis 2 can move in the positive direction of the Y axis. The movement of the sub chassis 2 in the negative direction of the Y axis can be achieved by the reverse rotation of the rotor 25. As a result, the pop-up unit 102 may pop up through the top of the smartphone 100 and into the smartphone 100.

Fig. 7 is a block diagram mainly showing a configuration of the smartphone 100 for drive control of the present embodiment.

The smartphone 100 of the present embodiment includes a processing unit 111, and the processing unit 111 performs data processing and control on the operation of each component in the smartphone 100. The ROM 112 and the RAM 113 are storage units used when the processing unit 111 performs processing and control. The smartphone 100 also includes a display device 114 and an input device 115, and performs display on the display portion of the front surface 101A and input processing through the display portion.

The camera unit 180 includes a driving unit that controls the above-described driving of the respective units. That is, the zoom lens group driving unit 181 controls the driving of the above-described zoom lens group 10 under the control of the processing unit 111, and the AF lens group driving unit 182 also controls the above-described driving of the AF lens group 15 under the control of the processing unit 111. The mirror driving unit 183 controls the rotation of the reflecting mirror 3 as described above with reference to fig. 5, 6A, and 6B. In addition, an AF/zoom chassis driving unit 184 controls the above-described movement of the AF/zoom chassis 17, and a sub chassis driving unit 185 controls the above-described movement of the sub chassis 2.

Claims

1. An image forming apparatus, characterized by comprising:

a first lens group;

a second lens group through which light transmitted through the first lens group passes;

a first drive shaft frictionally engaged with the first lens group and frictionally engaged with the second lens group with a frictional force smaller than that frictionally engaged with the first lens group;

a first piezoelectric element fixed to one end of the first driving shaft to expand and contract the first driving shaft;

a second drive shaft frictionally engaged with the second lens group and frictionally engaged with the first lens group with a frictional force smaller than that of the second lens group;

a second piezoelectric element fixed to one end of the second driving shaft to expand and contract the second driving shaft;

a sensor receiving light transmitted through the first lens group and the second lens group.

2. The imaging apparatus of claim 1,

when the first lens group is moved by driving the first piezoelectric element to move the first drive shaft in the direction in which the first piezoelectric element expands and contracts, respectively, the second piezoelectric element is driven to move the second drive shaft in the direction in which the second piezoelectric element expands and contracts, respectively, so that the second drive shaft moves in conjunction with the movement of the first drive shaft; when the second lens group is moved by driving the second piezoelectric element to move the second drive shaft in the direction in which the second piezoelectric element expands and contracts, respectively, the first piezoelectric element is driven to move the first drive shaft in the direction in which the first piezoelectric element expands and contracts, respectively, so that the first drive shaft moves in conjunction with the movement of the second drive shaft.

3. The imaging apparatus according to claim 1 or 2, characterized by further comprising:

a lens group supporting member on which the first lens group, the second lens group, the first drive shaft, the first piezoelectric element, the second lens group, and the second piezoelectric element are mounted,

the lens group support member is disposed to be movable relative to the sensor.

4. The imaging apparatus according to claim 1 or 2, characterized by further comprising:

a mirror reflecting incident light toward the first lens group and guiding light incident from front and rear surfaces of the imaging device toward the first lens group by changing a rotational position of the mirror.

5. The imaging apparatus according to claim 4,

the imaging apparatus exhibits a zooming function by movement of the first lens group, an auto-focusing function by movement of the second lens group, an optical anti-shake function of a component in a direction orthogonal to an optical axis of the first lens group and the second lens group by movement of the lens group supporting member, and an optical anti-shake function of a component in a direction orthogonal to the optical axis and parallel to a surface of the sensor by causing vibration at the reflecting position of the mirror.

6. An image forming apparatus, characterized by comprising:

a lens group including a first lens group and a second lens group through which light transmitted through the first lens group passes;

a first drive shaft frictionally engaged with the first lens group and frictionally engaged with the second lens group with a frictional force smaller than that of the first lens group;

a sensor receiving light transmitted through the lens group;

a mirror reflecting incident light toward the lens group;

a control unit performing optical anti-shake of components in a direction orthogonal to an optical axis of the lens group by causing vibration at the reflection position of the mirror.

7. The imaging apparatus of claim 6,

by changing the rotational position of the mirror, the mirror guides light incident from the front and rear surfaces of the imaging device toward the lens group.

8. An information terminal characterized by comprising:

the imaging device of any one of claims 1 to 7.