JP2018005085A - Optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device capable of rotating a drive shaft of a drive source when a manual rotation ring is operated so that a transmission mechanism of a lens barrel smoothly switches in both of manual operation using the manual rotation ring and motor-driven operation using an electric drive source.SOLUTION: The optical device is configured so that, when a drive mechanism 4 is manually driven by driving manual operation means 2, a driving force by the manual operation means 2 is transmitted to the drive source 3 via the drive mechanism 4, and a drive shaft 3a constituting the drive source 3 is also driven simultaneously.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical apparatus such as a digital still camera, a digital video camera, and an interchangeable lens.

  Digital cameras are often used as tools for taking photographs. Digital cameras include a lens barrel having a photographing lens, and many lens barrels have a zoom mechanism.

  The zoom mechanism moves the photographic lens in the optical axis direction, and the image can be taken while changing the image from the wide angle to the telephoto region.

  In order to operate the photographing lens provided in the lens barrel in the optical axis direction, it is necessary to move the plurality of lens groups while holding the lens group so as not to rotate in the optical axis direction.

  As one configuration for this purpose, a cam cylinder having a cam groove is provided on the outer periphery of a fixed cylinder having a straight advance groove.

  Then, there is a method in which the lens group is moved to the optical axis by rotating the cam cylinder by following the cam groove while guiding the lens group linearly in the straight groove.

  There is also a demand to operate the lens barrel electrically.

  There is also a demand for determining the zoom position by manually rotating a manual ring attached to the outer periphery of the lens barrel in addition to the electric operation.

  The following proposals have been made for such problems.

  Patent Document 1 discloses a lens barrel that operates with a manual ring.

  When operating the manual ring, the lens barrel is operated manually by switching the connection using a separately prepared clutch mechanism.

Japanese Patent Laid-Open No. 9-15482

  In Patent Document 1, it is necessary to provide a separate clutch mechanism for switching between electric operation and manual operation.

  Furthermore, it is necessary for the user to switch the switch, which is troublesome during manual operation. In addition, the clutch mechanism must be inserted, and there is a problem that the number of parts increases and the equipment becomes large.

  There is a demand for a mechanism that can operate manually and electrically without any switching.

Therefore, in the present invention, a drive mechanism that drives the lens holding member in the optical axis direction, a drive source that is coupled to the drive mechanism and that electrically drives the drive mechanism, and a drive mechanism that is coupled to the drive mechanism and is manually operated. An optical instrument having manual means for driving,
When the driving mechanism is driven manually by driving the manual means, the driving force by the manual means is driven by the driving mechanism, and the driving shaft constituting the driving source is also driven simultaneously. It is characterized by that.

  According to the present invention, it is possible to smoothly switch between manual zooming and electric zooming without increasing the size of the optical apparatus and further increasing the number of components, and usability can be improved.

It is a perspective view which shows the structure of the photographic lens barrel comprised in the optical apparatus in the Example of this invention. (A) is a side view showing the configuration of the taking lens barrel and the manual operation ring provided in the optical apparatus in the embodiment of the present invention, and (b) is the shooting provided in the optical apparatus in the embodiment of the present invention. It is a conceptual diagram which shows the structure of a lens-barrel and a manual operation ring. (A) is detail drawing which shows the power transmission from the drive source with which the optical instrument in the Example of this invention is equipped, (b) is sectional drawing of the drive source with which the optical instrument in the Example of this invention is equipped. It is. (A) is a front perspective view of the optical apparatus in the Example of this invention, (b) is a rear view of the optical apparatus in the Example of this invention. It is a block diagram which shows the structure of the digital camera which is an optical apparatus in the Example of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  4 (a) and 4 (b) show a digital camera 12 as an optical apparatus having a photographic lens barrel according to the present embodiment.

  The digital camera 12 shown in the present embodiment is a camera having a zoom mechanism that can change the photographing magnification.

  FIG. 4A is a front perspective view of the digital camera 12. FIG. 4B is a rear view of the digital camera 12.

  FIG. 5 shows a block diagram of the digital camera 12.

  A front surface of the digital camera 12 according to the present embodiment includes an auxiliary light 15 that assists a light source in the case of performing photometric distance measurement, a strobe 17, and a photographic lens barrel 1.

  A release button 13, a zoom changeover switch 14, and a power supply changeover button 16 are disposed on the upper surface.

  Operation buttons 19, 20, 21, 22, 23, 24, and 25 are arranged on the back, and various functions can be switched.

  A display (liquid crystal means) 18 comprising an LCD is disposed.

  The display 18 is an image display means, and displays the image data stored in the memory 36 and the image data read from the memory card on the screen.

  The control unit includes a CPU 42, a ROM 41, and a RAM 43.

  Various components such as the release button 13, the operation buttons 19 to 25, the display 18, the memory 36, and the memory card drive 38 are connected via the bus 40.

  The zoom mechanism 3 and the focus drive mechanism 26 are connected to the drive circuit 39 connected to the control system via the bus 40.

  Further, a shutter drive mechanism 28, an aperture drive means 30, an image sensor 32 such as a CCD or CMOS, and a strobe 17 are connected to a drive circuit 39 connected to the control system via the bus 40.

  The drive circuit 39 controls each drive by a signal from the control system.

  The ROM 41 stores a program for controlling each functional component described above. The RAM 43 stores data necessary for each control program.

  The analog signal processing means 33 performs analog processing on the captured image data and outputs it to the A / D converter 34.

  The A / D converter 34 converts the captured analog data into digital data. This digital data is output to the digital signal processing means 35, where the digital data is processed. Finally, the digital data is stored in the memory 36.

  The image data stored in the memory 36 and the image data stored in the memory card drive 38 are decompressed by the compression / expansion means 37.

  The image data can be displayed on the display 18 via the bus 40. When the user views the data on the display 18 and determines that the image is unnecessary, the user can delete the image by operating the operation button 19.

  Next, the configuration of the taking lens barrel 1 as a lens holding member provided in the digital camera 12 according to the present embodiment will be described.

  FIG. 1 is a perspective view of a photographic lens barrel 1.

  The taking lens barrel 1 has a zoom mechanism and can change the angle of view from a wide state to a tele state.

  The drive shaft 3a of the zoom motor, which is the drive source 3, is arranged perpendicular to the optical axis of the photographic lens barrel.

  When trying to make the main unit as thin as possible due to the camera layout, if the zoom motor is set in the same direction as the optical axis, the motor will become thicker.

  Therefore, the layout as in this embodiment is advantageous for downsizing.

  A manual drive ring 2 that is operated by a user's hand is disposed on the outer periphery of the taking lens barrel 1.

  FIG. 2A is a partial cross-sectional view showing the configuration of the taking lens barrel 1 and the manual drive ring 2 as manual means. A connection portion between the manual drive ring 2 and the drive ring 4 is shown in cross section.

  A conceptual diagram is shown in FIG.

  FIG. 3A shows a zoom mechanism showing the connection from the drive source 3 to the drive ring 4.

  FIG. 3B shows a cross-sectional view of the drive source 3.

  When the user operates the zoom changeover switch 14, the zoom motor as the drive source 3 is energized and the drive shaft 3a rotates.

  As the drive shaft 3 rotates, the worm gear 5 as the first gear rotates, and the helical gear 6 as the second gear meshing with the worm gear 5 rotates.

  As it is, the gears are coupled to transmit power, and finally connected to the drive gear 4a integrally provided with the drive ring 4, so that the drive ring 4 rotates.

  As the drive ring 4 rotates, the cam ring 9 provided in the photographing lens barrel 1 is rotated, and the lens group provided in the photographing lens barrel 1 moves in the optical axis direction to perform a zoom operation. Can do.

  When the user rotates the manual rotation ring 2, the drive ring 4 is simultaneously rotated by the drive connecting means 8 between the manual rotation ring 2 and the drive ring 4.

  Then, the cam ring 9 provided inside the photographing lens barrel 1 is rotated, and the lens group provided in the photographing lens barrel 1 can move in the optical axis direction to perform a zoom operation.

  The manual drive ring 2 is held via a main body connecting means 11 on a main body base plate 10 that is connected and fixed to the optical device 12.

  The drive connecting means 8 and the main body connecting means 11 are made of an elastic body such as rubber, and are arranged in a ring shape so as to hold the periphery. The drive connecting means 8 is disposed between the manual rotary ring 2 and the drive ring 4 so as to be slightly compressed. The main body connecting means 11 is disposed between the manual drive ring 2 and the main body base plate 10 so as to be slightly compressed.

  When the driving ring 4 constituting the driving mechanism is rotated by the manual rotating ring 2, the gear unit is rotated at the same time because the gear unit is connected to the driving ring 4.

  As a result, the helical gear 6 rotates and the worm gear 5 rotates. Eventually, the drive shaft 3a inside the drive source 3 to which the worm gear 5 is connected rotates.

  That is, the manual rotation ring 2 and the drive ring 4 and the zoom motor which is the drive ring 4 and the drive source 3 are directly connected.

  Therefore, when electrically zooming, the zoom motor as the drive source 3 is rotated by the drive circuit 39 itself.

  Further, even when manual zooming is performed by operating the manual rotation ring, the zoom motor as the driving source 3 is forcibly rotated by an external force.

  With the above configuration, it is not particularly necessary for the user to switch the switch in order to perform a zoom operation with a manual ring.

  Without switching the switch, the zoom switch 14 and the manual drive ring 2 can be selected and operated seamlessly.

  An important configuration in the present embodiment is the relationship between the worm gear 5 and the helical gear 6, and the rotational force of the worm gear 5 rotates the helical gear 6.

  Similarly, the worm gear 5 must be rotated by the rotational force of the helical gear 6.

  Usually, when the twist angle of the worm is small, the locking action works and the operation from the helical gear direction becomes difficult. A small diameter gear with a diameter of about 3 mm or less is preferable.

  Generally, the number of self-locking strips is 3 or less, and when the helix angle is increased, it is desirable to use 4 or more worm teeth. Normally, reverse driving is possible if the twist angle of the worm is larger than the angle of repose (friction angle).

  Therefore, the twist angle is preferably 14 degrees or more. For this purpose, the screw of the worm gear 5 is preferably four or more worm teeth. In order to reversely drive, it is necessary to reduce the frictional resistance, and it is necessary to use high-performance lubricating oil.

  There is a detailed description in the gear technical data of Ohara Gear Industry Co., Ltd.

  The worm gear 5 is provided with a pulse plate 5a, and the pulse of the pulse plate 5a can be detected by a pulse detection means 7 such as a photo interrupter.

  The first gear includes a pulse plate 5a, and the optical apparatus detects the rotation of the drive shaft 3a even when driven by the drive source 3 and when driven by the manual means 2.

  When the zoom motor as the drive source 3 is energized and the drive shaft 3a rotates, the pulse plate 5a rotates, and the pulse detection means 7 counts the number of rotations of the drive shaft 3a.

  By counting the pulses, the drive ring 4 can be moved to an appropriate position to determine the zoom position.

  The zoom position of the lens holding member is detected based on the count number of the pulse plate 5a, and the focus lens provided in the lens holding member is driven based on the detection result.

  In the present invention, since the driving force of the manual drive ring 2 is also transmitted to the worm gear 5, the pulse plate 5a can be rotated and the number of rotations of the drive ring 4 can be counted.

  The zoom position can be detected based on the count number.

  A focus driving mechanism 26 is provided inside the taking lens barrel 1 and operates a focus lens 27 to perform a focusing operation.

  By using the pulse count detected by the rotation of the manual drive ring 2 and operating the focus lens 27 in conjunction with the zoom position, the focus is not lost even during manual zooming.

  In addition, when the photographing lens barrel 1 is operating in the photographing region, it is desired that the photographing lens barrel 1 is not easily moved from the zoom wide position (wide angle end) in the storage direction.

  At the time of the electric zoom, the rotation to the zoom motor as the driving source 3 is detected by the pulse plate 5a, and the operation can be stopped by stopping the energization at the wide position of the zoom.

  When manual zooming is performed, the user rotates the driving ring 4 by rotating the manual driving ring 2, and the rotation of the worm gear 5 by the rotation causes the count of the pulse plate 5a to be generated.

  The count of the pulse plate 5a is detected, and the drive source 3 is brought into the rotation holding state at the zoom wide position. In this way, the user feels that the operation of the manual drive ring 2 has become heavy, and stops the operation.

  It is only necessary to mechanically stop the rotation of the drive ring 4 on the telephoto side of the zoom.

  However, the telephoto side may adjust the zoom stop position by correcting the angle of view.

  In this case as well, the count of the pulse plate 5a is detected based on the angle-of-view zoom stop position adjustment value in the same manner as described above, and the drive source 3 is brought into the rotation holding state at the zoom telephoto position.

  In this way, the user feels that the operation of the manual drive ring 2 has become heavy, and stops the operation.

  As a method of generating the holding energization, the holding energization state can be achieved by using a stepping motor as the driving source 3 to be used.

  Further, the drive source 3 is a DC motor, and reverse energization is performed when the stop position is reached, so-called short brake energization is performed to make the user feel that the operation is stopped.

  In this embodiment, when the lens holding member is in the shooting area and the manual means 2 is operated to the non-shooting area, the drive source 3 is electrically rotated and held at the boundary between the shooting area and the non-shooting area. The

  Further, when the stop position of the lens holding member on the wide angle side is adjusted and the zoom operation is further performed on the wide angle side at the adjustment position, the drive source 3 is electrically rotated and held at the boundary between the imaging region and the non-imaging region. The

  Further, when the stop position of the lens holding member on the telephoto side is adjusted, and the zoom operation is further performed on the telephoto side at the adjusted position, the drive source 3 is electrically rotated and held at the boundary between the imaging region and the non-imaging region. The

  When the camera is retractable and the lens barrel is extended when not in use and used, it is effective to experience the stop position at the boundary. Further, even when switching between the actual use area and the optical macro area, it is possible to notify the user by giving a load fluctuation by the motor.

  With the above configuration, the electric zoom and the manual zoom can be performed without adding any parts or enlarging them, and can be achieved seamlessly without switching.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  It is clear that it can be used industrially.

DESCRIPTION OF SYMBOLS 1 Shooting lens barrel 2 Manual rotation ring 3 Drive source 3a Drive shaft 4 Drive ring 5 Worm gear 5a Pulse plate 6 Hasuba gear 7 Pulse detection means

Claims (11)

A drive mechanism for driving the lens holding member in the optical axis direction;
A drive source coupled to the drive mechanism and electrically driving the drive mechanism;
Manual means coupled to the drive mechanism for manually driving the drive mechanism;
An optical instrument comprising:
When the driving mechanism is driven manually by driving the manual means, the driving force by the manual means is driven by the driving mechanism, and the driving shaft constituting the driving source is also driven simultaneously. An optical apparatus characterized by that.   The drive shaft of the drive source is perpendicular to the optical axis of the lens holding member, the first gear provided on the drive shaft of the drive source, the first gear, and the first gear. The optical apparatus according to claim 1, wherein power of the drive source is transmitted to the drive mechanism by a second gear meshing with the gear.   The optical apparatus according to claim 2, wherein the twist angle of the first gear is 14 degrees or more.   The optical apparatus according to claim 2, wherein the first gear has four or more worm teeth.   5. The device according to claim 2, wherein the first gear includes a pulse plate, and the optical device detects the rotation of the drive shaft during driving by the driving source and driving by the manual means. An optical device according to any one of the above.   The optical apparatus according to claim 5, wherein a zoom position of the lens holding member is detected based on a count number of the pulse plate, and a focus lens provided in the lens holding member is driven based on the detection result.   The lens holding member is in an imaging region, and the driving source is electrically rotated and held at a boundary between the imaging region and the non-imaging region when the manual means is operated to the non-imaging region. Item 7. The optical apparatus according to any one of Items 1 to 6.   The stop position of the lens holding member on the wide-angle side is adjusted, and when the zoom operation is further performed on the wide-angle side at the adjusted position, the drive source is electrically rotated and held at the boundary between the imaging area and the non-imaging area The optical apparatus according to any one of claims 1 to 7.   The stop position of the lens holding member on the telephoto side is adjusted, and when the zoom operation is further performed on the telephoto side at the adjusted position, the drive source is electrically rotated and held at the boundary between the imaging area and the non-imaging area The optical apparatus according to any one of claims 1 to 8.   The optical device according to claim 7, wherein the driving source is a stepping motor and performs holding energization when rotating.   The optical apparatus according to claim 7, wherein the drive source is a DC motor and short brake energization is performed when the drive source is rotated.

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