JP4785452B2 - Lens barrel and imaging apparatus having the same - Google Patents

Description

  The technology disclosed in the present application relates to a lens barrel technology such as a digital camera and a film camera or a video camera.

  In recent years, digital cameras that can capture an image in a memory without using a film are rapidly spreading. Some digital cameras include a zoom mechanism that moves a plurality of optical lenses in the optical axis direction to change a photographing magnification. An example of the configuration of the zoom lens barrel is shown in Patent Document 1.

  As a first technique, a plurality of lens holding means for holding a plurality of lenses are moved in the optical axis direction by a cam ring, and the movement of the lens holding means in the rotation direction is restricted by the rotation restricting means. With this configuration, the optical lens can be moved to a designated position. When a mechanism for moving the optical lens is provided, the movement accuracy of the optical lens greatly affects the optical performance of the digital camera, and various measures are taken to ensure the accuracy. The optical lens holder that holds the optical lens is provided with a spring so that each position faces the front and rear in the optical axis direction. Accordingly, there is one method of eliminating the backlash when the optical lens holder and the cam are moved and stabilizing the accuracy.

  As a second technique, the optical lens holder includes a plurality of follower pins that follow the cam. There is also a method in which one of the follower pins is movable so that the follower pins can always come into contact with the cam to stabilize the accuracy.

In the case of the first technique, it is necessary to provide a spring inside, and it is necessary to provide a space, which increases the size of the camera. In addition, workability during assembly is also a problem. In the case of the second technique, a method of moving the follower pin with a spring is generally used as means for moving the follower pin. In that case, it is necessary to provide a space for inserting the spring into the optical lens holder, and at least the plurality of lens holders cannot approach each other.
Japanese Patent Application Laid-Open No. 07-027962

  In the case of the conventional first technique, it is necessary to provide a spring inside, and a space must be provided, which increases the size of the camera. In addition, workability during assembly is also a problem. In the case of the second technique, a method of moving the follower pin with a spring is generally used as means for moving the follower pin. In that case, it is necessary to provide a space for inserting the spring into the optical lens holder. Accordingly, at least a plurality of lens holders cannot be accessed. As a result, miniaturization of the camera is hindered.

  On the other hand, cameras are currently being miniaturized, and it is necessary to reduce even a small space.

In order to achieve the above object, a lens barrel according to the present invention has a plurality of lens holding means that drive following a cam means having a plurality of cams, and each of the plurality of lens holding means includes tracking means for tracking the cam means are a plurality equipped with a plurality of follow-up means for each provision of the plurality of lens retaining means is at least partially larger diameter than the other follow-up means, a plurality of adjacent Each of the lens holding means has a large-diameter following means that is not aligned in the optical axis direction .

  According to the invention disclosed in the present application, it is possible to provide a camera that is smaller than the conventional one.

  The best mode for carrying out the present invention is as described in Examples described later.

  Hereinafter, the present invention will be described in detail based on the illustrated embodiments.

  6 to 10 show a digital camera as a photographing apparatus having an aperture structure according to this embodiment. The digital camera 15 shown in this embodiment covers the front surface of a lens barrel as a lens movement support device on the front surface of the camera with a large barrier 18. When using the camera, the photographing lens barrel 10 is opened (sent out) by sliding the barrier sideways. This is a so-called slide barrier type.

  FIG. 6 is an external perspective view showing the barrier 18 of the digital camera 15 opened with respect to the camera body. FIG. 7 is an external perspective view showing a state in which the barrier 18 of the digital camera 15 is closed with respect to the camera body.

  FIG. 8 shows a top view of the digital camera 15. FIG. 9 shows a bottom view of the digital camera 15. FIG. 10 shows a rear view of the digital camera 15.

  FIG. 11 shows a configuration of a main part of the digital camera 15.

  A finder 14 for determining the composition of the subject is provided in front of the digital camera of this embodiment. Further, a photometric distance measuring sensor 13 for performing photometric distance measurement, a red-eye lamp 16, a strobe 17, and a first lens group 10a are arranged. Further, a photographing lens barrel means 10 is configured.

  There is a release button 11 on the top surface. Further, there is a flash light emission mode button 12 and a strap holding means 20 on the side surface. There is a tripod mounting portion 21 on the bottom surface. A memory card drive 36, a card battery cover 22 having a battery insertion portion (not shown) provided therein, and an external input / output terminal mounting portion 19 are disposed.

  An operation button 24, an LCD display 25, a zoom button 23, and a viewfinder eyepiece 14a are arranged on the back.

  The operation button 24 selects an operation mode of the digital camera, for example, a shooting mode, a playback mode, a moving image shooting mode, and the like.

  The display 25 is image display means, and displays image data stored in the memory 34 and image data read from the memory card on the screen. When a mode is selected, a plurality of shooting data can be reduced and displayed on the screen.

  The control unit includes a CPU 40, a ROM 39, and a RAM 41. The control unit is connected to various components such as the release button 11, the operation button 24, the display 25, the memory 34, and the memory card drive 36 via the bus 38.

The drive circuit 37 connected to the control system via the bus 38 includes the following. A zoom motor driving unit 26, a focus motor driving unit 28, a shutter driving unit 29, a photometric sensor 13a, and a distance measuring sensor 13b are connected. Similarly, an imaging device 42 such as a CCD or CMOS that converts light passing through the lens barrel into an electrical signal is connected to the drive circuit 37. Further, the strobe 17 is connected to the drive circuit 37. Each of these drives is controlled by a signal from the control system.

  The ROM 39 stores a program for controlling each functional component described above. The RAM 41 stores data necessary for each control program.

  Here, an example of the operation is shown. For example, when the user slides the barrier 18, the power button linked to the barrier 18 is turned from OFF to ON. In response to this, the CPU 40 reads a necessary control program from the ROM 39 and starts an initial operation. That is, after the barrier opening operation is performed, the photographic lens barrel is moved to a predetermined shootable region, and a shooting standby state is set.

  When the release button 11 is pressed to take a picture, the brightness of the subject is detected by the photometric sensor 13a. Based on the photometric value, an aperture value, a shutter speed, and whether or not to emit a strobe are determined. In addition, the user can select whether the strobe light is forcibly emitted or not emitted by the operation button 24 in advance. Next, distance measurement is performed by the distance measurement sensor 13b. The focus motor drive means 28 is driven by measuring the distance to the subject. Thereby, the focus means 27 is moved to a predetermined focus position. Next, the shutter unit 30 is opened and closed, and a desired image is taken into the imaging device 42.

  The imaging device 42 accumulates electric charges according to the amount of light incident through the lens barrel based on the exposure control value. The charge becomes an image signal and is output to the analog signal processing means 31.

  The analog signal processing unit 31 performs analog processing on the captured image data and outputs it to the A / D conversion unit 32. The A / D converter 32 converts the captured analog data into digital data. This digital data is output to the digital signal processing means 33, where the digital data is processed. Finally, the digital data is stored in the memory 34.

  The data stored in the memory 34 is subjected to compression processing such as JPEG or TIFF by the compression / expansion means 35 by the operation of the operation button 24, and is output and stored in the memory card.

  In the case of a digital camera without the memory 34, the digital data processed by the digital signal processing means is output to the compression / expansion means 35 and stored in the memory card drive 36.

  The image data stored in the memory 34 and the image data stored in the memory card drive 36 are decompressed by the compression / expansion means 35. The image data can be displayed on the display 25 via the bus 38. When the user views the data on the display 25 and determines that the image is unnecessary, the user can delete the image by operating the operation button 24.

  A zoom button 23 is arranged on the back. By operating the zoom button 23, the zoom motor driving means 26 is controlled via the drive circuit 37. As a result, the photographing lens barrel 10 is moved in the optical axis direction of the lens. Further, the stored image displayed on the display 25 can be enlarged and reduced by the operation of the zoom button 23, so-called digital zoom.

  Next, the configuration of the lens barrel provided in the digital camera 15 will be described. FIG. 1 is a schematic perspective view of the configuration of the lens barrel unit of the digital camera of this embodiment.

  The first lens holding means 10 holding the first lens group 10a, the second lens holding means 2 and the third lens holding means 3 perform optical zooming. The first lens holding means 10 can be moved in the optical axis direction by a first cam provided inside the first cam means 1, and the rotation is restricted by the straight advance restriction means 4. The first cam means 1 can be extended by a cam provided inside the straight travel restricting means 4, and a rotational force is obtained by the cam means 5.

  Next, the second lens holding means 2 and the third lens holding means 3 are linearly guided by the straight movement restricting means 4 and can be moved in the optical axis direction by a cam provided inside the cam means 5. At this time, the cam means 5 can move integrally with the straight-travel regulating means 4. The cam means 5 can be moved in the optical axis direction by a cam provided in the second cam means 6, and the zoom motor driving means 26 rotates the lens barrel rotating means 7 via a plurality of gears to rotate the cam means 5. .

  The lens barrel is zoomed as described above. In the case where there are three lens holders as in this embodiment, for example, the size of the lens barrel when the second lens holding means 2 and the third lens holding means 3 are retracted as much as possible is reduced as much as possible. Can be reduced. This is because the space in which other members can enter can be increased by reducing the interval.

  Some of the lens holders inside the lens barrel, such as the second lens holding means 2 and the third lens holding means 3, are provided with a mechanism for shifting to be described later.

  FIG. 2 shows the shifting mechanism of this embodiment. In order to follow the drive of the cam means 5 in one lens holder, three follower pins are provided. One of them is movable as shown in FIG. 2, and a spring 9 is provided inside so that the movable follower pin 8 can be loaded on the outer periphery. The movable follower pin 8 can come into contact with a cam provided inside the cam means 5. The movable follower pin 8 can apply weight to the cam means 5 to prevent the lens holder and the cam from rattling.

  Here, the conventional state is shown in FIG. The second lens holding means 2 and the third lens holding means 3 restrict the rotation direction by the straight advance restriction means 4. Conventionally, as shown in FIG. 3, the movable follower pin 2a 'and the movable follower pin 3a' are regulated by the same linear guide 4a '. The other follower pin 2b 'and follower pin 3b' are regulated by a straight guide 4b ', and the follower pin 2c' and follower pin 3c 'are regulated by a straight guide 4c'. In this case, since the movable follower pin has mechanical parts inside than the other follower pins, the distance A between the second lens holding means 2 and the third lens holding means 3 is not reduced beyond a certain fixed distance.

  On the other hand, FIG. 4 is a diagram for explaining a technique corresponding to FIG. As in FIG. 3, a development view of the straight travel regulating means 4 is shown. A movable follower pin 2a having a diameter larger than that of the follower pin 2c and a movable follower pin 3c having a diameter larger than that of the follower pin 3a are provided in different phases so that the phases do not coincide with each other. In this way, the distance between the second lens holding means 2 and the third lens holding means 3 can be made closer to the extent that the movable follower pins do not overlap. Therefore, the mutual distance B can be made smaller than the above-mentioned distance A. As a result, the length of the lens barrel in the optical axis direction when the camera barrel is housed can be shortened, which contributes to further miniaturization of the camera. This is because the space in which other members can enter can be increased by reducing the interval.

  If this state is shown in three dimensions, it becomes like FIG. 5, and the movable follower pin 2a and the follower pin 3a can be brought closer.

  FIG. 12 shows a flowchart from the power-on to the end of photographing of a digital camera which is a photographing apparatus having the lens barrel mechanism described above.

  When the user turns on the power of the photographing apparatus (step S1201), the CPU 40 sends a command to the zoom motor driving means 26 to rotate the lens barrel driving motor CW (step S1202). Thereafter, a predetermined operation is performed, and when it is confirmed that the photographing lens barrel means has moved to the photographing position, it is stopped (step S1203).

  Next, when the user turns on the release button (step S1204), photometry is performed by the photometry means 13a to obtain luminance information of the subject (step S1205). It is determined whether or not the obtained luminance information is higher than a predetermined luminance (step S1206). When the obtained luminance information is higher than the predetermined luminance, the amount of incident light is changed by causing the diaphragm means 43 to enter the optical axis (step S1207). When the obtained luminance information is lower than the predetermined luminance, the diaphragm means 43 is not operated and is kept away from the optical axis.

  After that, the focusing unit 27 is operated (step S1208), and the subject is moved to a position where the subject is in focus, and image capture is started there (step S1209). Next, the shutter means 30 is moved from the open state to the closed state (step S1210). As a result, the amount of incident light is blocked, and the image capturing ends (step S1211). Thereafter, the aperture means 1 is retracted from the optical axis (step S1212), the focus means is moved to the initial position, and the operation ends (step S1213).

  FIG. 13 shows a flowchart when the user turns off the power of the photographing apparatus. When the user turns off the power of the photographing apparatus (step S1301), first, the shutter means 30 is moved to the closed position (step S1302). Next, after confirming that the aperture means 43 is in the retracted position (step S1303), the lens barrel drive motor is rotated in the CCW direction (step S1304). The photographing lens barrel is housed in a predetermined position, and the process ends (step S1305).

  By adopting the above configuration, the distance between the lens holders can be made closer, which can contribute to the recent miniaturization of cameras.

  In this embodiment, an example of a digital camera is shown, but a video camera having a similar lens barrel structure, an analog camera using a silver salt film, and the like can have the same configuration.

  The present invention can be used as a device that supports a lens holder of a digital camera, a silver salt camera, a video camera, binoculars, and other optical devices so as to be movable in the lens optical axis direction.

It is a disassembled perspective view which shows the structure of the lens-barrel structure in one Example of this invention. It is a figure which shows the structure of the movable follower pin of the lens-barrel structure in one Example of this invention. It is a figure which shows the structure of the conventional lens-barrel structure. It is a figure which shows the lens-barrel structure in one Example of this invention. It is a figure which shows the lens-barrel structure in one Example of this invention. 1 is a perspective view of a photographing apparatus having a lens barrel structure in an embodiment of the present invention in a power-on state. 1 is a perspective view of a photographing apparatus having a lens barrel structure in an embodiment of the present invention in a power-off state. 1 is a top view of a photographing apparatus having a barrel structure according to an embodiment of the present invention in a power-on state. It is a bottom view of the imaging device which has a lens-barrel structure in one Example of this invention. It is a rear view of the imaging device which has a lens-barrel structure in one Example of this invention. It is a block diagram which shows the principal part of a structure of the digital camera which is an imaging device which has a lens-barrel structure in one Example of this invention. It is a flowchart which shows the sequence at the time of imaging | photography from the power supply ON of the digital camera which is an imaging device which has a lens-barrel structure in one Example of this invention. It is a flowchart which shows the sequence at the time of the power supply OFF of the digital camera which is an imaging device which has a lens-barrel structure in one Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st cam means 2 2nd lens holding means 3 3rd lens holding means 4 Rectilinear advance restriction means 5 Cam means 6 2nd cam means 7 Lens barrel rotating means 8 Movable follower pin 9 Spring 10 First lens holding means 11 Release button 12 Flash emission mode button 13 Metering distance measuring sensor 14 Viewfinder 14a Viewfinder eyepiece 15 Digital camera 16 Red eye lamp 17 Strobe 18 Barrier 19 External input / output terminal mounting portion 20 Strap holding means 21 Tripod mounting portion 22 Card battery cover 23 Zoom button 24 Operation Button 25 Display 26 Zoom motor drive means 27 Focus means 28 Focus motor drive means 29 Shutter drive means 30 Shutter means 31 Analog signal processing means 32 A / D converter 33 Digital signal processing means 34 Memory 35 Compression / Expansion Means 36 Memory Card Drive 37 Drive Circuit 38 Bus 39 ROM
40 CPU
41 RAM
42 Imaging device 43 Aperture means 44 Aperture drive means 45 Battery insertion part (not shown)

Claims (5)

A plurality of lens holding means for driving following the cam means having a plurality of cams;
Wherein the plurality of lens retaining means are tracking means is a plurality equipped to follow the cam means, a plurality of tracking means, each of said plurality of lens holding means comprises rather than at least some other tracking means A lens barrel having a large diameter , and each of a plurality of adjacent lens holding means having a large diameter does not line up in the optical axis direction . A regulating means provided with a plurality of regulating portions for regulating the movement of each of the plurality of tracking means provided in the lens holding means in the optical axis direction;
2. The lens barrel according to claim 1, wherein the tracking means having a large diameter included in each of the plurality of adjacent lens holding means is not restricted by the same restriction portion. The tracking means having a large diameter included in each of the plurality of adjacent lens holding means is regulated by the same regulating unit as the tracking means different from the tracking means having a large diameter included in each of the plurality of adjacent lens holding means. The lens barrel according to claim 2. 4. The follow-up means having a large diameter has an elastic member provided therein, and a tip portion is urged toward the cam means by the elastic member. The lens barrel according to the item.   An imaging apparatus comprising: the lens barrel according to any one of claims 1 to 4; and imaging means that receives light passing through the lens barrel.

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