JP6765879B2 - Optical equipment - Google Patents

Description

The present invention relates to optical devices such as digital still cameras, digital video cameras, and interchangeable lenses.

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

The zoom mechanism moves the taking lens in the direction of the optical axis, allowing the image to be changed from a wide angle to a telephoto range for shooting.

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

As one of the configurations for that purpose, a cam cylinder having a cam groove is installed on the outer circumference of the fixed cylinder having a straight groove.

Then, there is a method of moving the lens group to the optical axis by rotating the cam cylinder by following the cam groove while guiding the lens group straight to the straight groove.

There is also a demand for electrically operating the lens barrel.

In addition to the electric operation, there is also a demand for determining the zoom position by manually rotating the manual ring attached to the outer circumference of the lens barrel.

The following proposals have been made to address such issues.

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

If you want to operate the manual ring, the lens barrel is operated manually by switching the connection using a separately prepared clutch mechanism.

JP-A-9-15481A

In Patent Document 1, a clutch mechanism for switching between electric operation and manual operation must be provided separately.

In addition, the user has to flip the switch, which is troublesome during manual operation. In addition, there is a problem that a clutch mechanism must be inserted, the number of parts increases, and the size of the device increases.

A mechanism capable of seamlessly operating manual operation and electric operation without switching is desired.

Therefore, in the present invention, a drive mechanism for driving the lens holding member in the optical axis direction, a drive source connected to the drive mechanism to electrically drive the drive mechanism, and a drive source connected to the drive mechanism to manually drive the drive mechanism. An optical instrument having a manual means of driving.
When the power is switched from the power OFF to the power ON, the lens holding member is driven in the optical axis direction from the non-photographing region to the photographing region by electric drive by the driving source.
When shooting in the shooting area, it is possible to switch between the electric drive and the manual drive without performing the switching operation between the electric drive and the manual drive.
When shooting in the shooting region, the lens holding member can be driven in the optical axis direction by the electric drive and the manual drive.
When the driving mechanism is manually driven by driving the manual means during shooting in the photographing region, the driving force by the manual means is transmitted to the driving source via the driving mechanism, and the driving source is transmitted. It is characterized in that the constituent drive shafts are also driven at the same time.

According to the present invention, it is possible to smoothly switch between manual zoom and electric zoom without increasing the size of the optical device and further without increasing the number of parts, and it is possible to improve usability.

It is a perspective view which shows the structure of the photographing lens barrel provided in the optical device in the Example of this invention. (A) It is a side view which shows the structure of the photographing lens barrel and the manual operation ring provided in the optical device in Example 1 of this invention, and (b) is the photographing provided in the optical device in Example 1 of this invention. It is a conceptual diagram which shows the structure of the lens barrel and the manual operation ring. (A) is a detailed view showing power transmission from a drive source provided in the optical instrument according to the embodiment of the present invention, and (b) is a cross-sectional view of the drive source provided in the optical instrument according to the embodiment of the present invention. .. (A) is a front perspective view of the optical device according to the embodiment of the present invention, and (b) is a rear view of the optical device according to the embodiment of the present invention. It is a block diagram which shows the structure of the digital camera which is an optical device in an Example of this invention. It is a conceptual diagram which shows the structure of the photographing lens barrel and the manual operation ring provided in the optical instrument in Example 2 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 device having a photographing lens barrel according to the present embodiment.

The digital camera 12 shown in the present embodiment is a camera having a zoom mechanism capable of changing the shooting 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.

In front of the digital camera 12 of the present embodiment, an auxiliary light 15, a strobe 17, and a photographing lens barrel 1 are configured to assist a light source when performing photometric distance measurement.

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

Operation buttons 19, 20, 21, 22, 23, 24, 25 are arranged on the back surface, and various function switching can be performed.

A display (liquid crystal means) 18 composed of an LCD is arranged.

The display 18 is an image display means, and displays image data stored in the memory 36 and 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 a release button 13, an operation button 19 to 25, a display 18, a memory 36, and a memory card drive 38 are connected via a 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 a control system via a bus 40.

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

The ROM 41 stores a program that controls each of the above-mentioned functional components. Data required for each control program is stored in the RAM 43.

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

The A / D conversion unit 34 converts the captured analog data into digital data. This digital data is output to the digital signal processing means 35, and the digital data is processed here. Finally, the digital data will be 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 / decompression means 37.

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

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

FIG. 1 is a perspective view of the photographing lens barrel 1.

The photographing lens barrel 1 has a zoom mechanism, and the angle of view can be changed from the wide state to the tele state.

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

Due to the layout of the camera, if you try to make the main body as thin as possible, if the zoom motor is oriented in the same direction as the optical axis, the length of the motor will be thicker.

Therefore, a layout like the present embodiment is advantageous for miniaturization.

A manual drive ring 2 operated by a user is arranged on the outer circumference of the photographing lens barrel 1.

FIG. 2A shows a partial cross-sectional view showing the configuration of the photographing lens barrel 1 and the manual drive ring 2 as a manual means. The connection portion between the manual drive ring 2 and the drive ring 4 is displayed in cross section.
FIG. 2 (b) shows a conceptual diagram.

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, which is 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 hasba gear 6 as the second gear that meshes with the worm gear 5 rotates.

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

By rotating the drive ring 4, the cam ring 9 provided inside 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 be done.

Further, when the user rotates the manual rotary ring 2, the drive ring 4 is simultaneously rotated by the drive connecting means 8 between the manual rotary 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 moves in the optical axis direction to perform the zoom operation.

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

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

When the drive ring 4 constituting the drive mechanism is rotated by the manual rotation ring 2, the gear means is connected to the drive ring 4, so that the gear means also rotates at the same time.

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

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

Therefore, when electrically zooming, the zoom motor, which is the drive source 3, rotates by the drive circuit 39.

Further, even when the manual rotating ring is operated for manual zooming, the zoom motor, which is the drive source 3, is forcibly rotated by an external force.

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

It becomes possible to seamlessly operate by selecting the zoom changeover switch 14 and the manual drive ring 2 without changing the switch.

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

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

Normally, if the twist angle of the worm is small, the locking action works and it becomes difficult to operate from the direction of the Hasba gear. A small diameter gear of about φ3 mm or less is preferable.

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

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

There is a detailed description in the gear technical data of Kohara 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 detecting means 7 such as a photo interrupter.

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

When the zoom motor, which is the drive source 3, is energized and the drive shaft 3a rotates, the pulse plate 5a rotates, and the pulse detecting means 7 counts the rotation speed of the drive shaft 3a.

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

The zoom position of the lens holding member is detected by 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 rotation speed of the drive ring 4 can be counted.

The zoom position can be detected by the number of counts.

A focus drive mechanism 26 is provided inside the photographing lens barrel 1, and the focus lens 27 is operated to perform a focusing operation.

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

A drive connecting means 8 is arranged between the manual drive ring 2 and the drive ring 4.

The drive connecting means 8 as the first elastic body is formed of an elastic body, and has a structure in which a load is applied in the radial direction by being compressed between the manual drive ring 2 and the drive ring 4.

Further, a main body connecting means 11 as a second elastic body is arranged between the manual drive ring 2 and the main body main plate 10.

The main body connecting means 11 is also formed of an elastic body, and has a structure in which a load is applied in the radial direction by being compressed between the manual drive ring 2 and the main body main plate 10 as a fixing member.

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

The photographing lens barrel 1 itself as an exterior member also has a load required for rotation. The zoom motor, which is the drive source 3, needs to rotate with a torque larger than the load on the lens barrel of the photographing lens.

The relationship of the above load is defined as main body connecting means 11> drive connecting means 8> photographing lens barrel load.

That is, the relationship of the load amount of the second elastic body 11> the load amount of the first elastic body 8> the load amount of the lens holding member 1 is satisfied.

With this configuration, when the user operates the zoom changeover switch 14, the zoom motor, which is the drive source 3, is driven to rotate the drive ring 4 to operate the photographing lens barrel 1.

However, at this time, since the load of the main body connecting means 11 is the heaviest on the manual drive ring 2, sliding occurs between the drive ring 4 and the manual drive ring 2 without following the rotation of the drive ring 4.

That is, the manual drive ring 2 can be prevented from rotating during the electric zoom, and the user does not feel uncomfortable.

On the contrary, when the user operates the manual drive ring 2, the manual force of the user can rotate more than the load of the main body connecting means 11.

Therefore, the manual drive ring 2 rotates, and the drive ring 4 rotates via the drive connecting means 8 with the rotation, so that the photographing lens barrel 1 is operated.

Since the load on the lens barrel of the photographing lens is smaller than the load on the drive connecting means 8, no sliding occurs during this period.

Of course, at this time, the drive shaft 3a of the zoom motor, which is the drive source 3 connected to the gear, is rotated with the rotation of the drive ring 4.

In this embodiment, both the manual zoom and the electric zoom can be seamlessly operated without switching.

When the user operates the power switching button 16 when the power is turned on, the CPU 42 emits a start signal. The drive source 3 is operated via the drive circuit 39 based on the activation signal, and the photographing lens barrel 1 is operated by rotating the drive ring 4, and is operated from the storage to the imageable area (WIDE position). ..

After that, the photographing lens barrel 1 is operated by the user selectively selecting the electric and manual operations.

Further, when the power is off, the photographing lens barrel 1 can be operated regardless of the photographing position, and when the user operates the power switching button 16, a signal is emitted from the CPU 42.

Based on the signal, the drive source 3 is operated via the drive circuit 39, and the drive ring 4 is rotated to operate the photographing lens barrel 1 and operate it in the retracted state.

By doing so, the camera can be turned on and off electrically, so that the camera can be used without any discomfort from the operation of the conventional camera, and the operability of the user can be maintained.

Further, when the manual operation is performed, the drive ring 4 is operated, but at the beginning of turning the drive ring 4, static friction acts and the load becomes heavy.

Therefore, at the beginning of operation, the drive source 3 is also energized and operated to assist the drive ring 4 so that it can easily rotate. This configuration improves user operability.

As described above, in this embodiment, when the power is turned on and off, the lens holding member is driven in the optical axis direction by electric driving by the drive source 3.

Then, at the time of photographing, the lens holding member can be driven in the optical axis direction by electric drive by the drive source 3 and manual drive by the manual means 2.

When the drive is started by the manual means, the drive source 3 is driven to assist the manual drive by the manual means 2.

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

Since the shooting lens barrel is a retractable type, it is convenient for the user to turn the power on and off electrically. Therefore, the power ON and OFF are driven by the zoom motor as in the case of the electric zoom. Further, when the macro mode is separately installed, the photographing lens barrel may be electrically operated by operating the macro switch.

Further, when the photographing lens barrel 1 is operating in the imagenable area, it is desired not to easily move from the wide position (wide-angle end) of the zoom to the storage direction.

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

When the manual zoom is performed, the user rotates the manual drive ring 2 to rotate the drive ring 4, and the rotation causes the worm gear 5 to rotate to generate a count of the pulse plate 5a.

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

On the telephoto side of the zoom, the rotation of the drive ring 4 may be mechanically stopped.

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 as described above, and the drive source 3 is put into the rotation holding state at the telephoto position of the zoom.

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 holding energization, a holding energizing state can be achieved by using a stepping motor as the drive source 3 to be used.

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

In this embodiment, when the lens holding member is in the imaging region and the non-imaging region is operated by the manual means 2, the drive source 3 is electrically rotated and held at the boundary between the imaging region and the non-imaging region. To.

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 adjusted position, the drive source 3 is electrically rotated and held at the boundary between the photographing region and the non-imaging region. To.

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 photographing region and the non-photographing region. To.

If the camera is retractable and the lens barrel extension position is different when not in use and when in use, it is effective to be able to experience the stop position at that boundary. Further, even when switching between the actual use area and the optical macro area, it is possible to give the load fluctuation by the motor and notify the user.

FIG. 6 shows a diagram in the case where the clutch mechanism 6a is provided between the zoom motor which is the drive source 3 and the drive ring 4. By rotating the clutch mechanism 6a around the gear 6, the power of the zoom motor can be disconnected from the drive ring 4.

Even in this case, when the user operates the zoom changeover switch 14, the clutch gear 6a is connected to the drive ring 4, the zoom motor which is the drive source 3 is driven, and the drive ring 4 is rotated to operate the photographing lens barrel 1.

However, at this time, since the load of the main body connecting means 11 is the heaviest on the manual drive ring 2, sliding occurs between the drive ring 4 and the manual drive ring 2 without following the rotation of the drive ring 4.

That is, the manual drive ring 2 can be prevented from rotating during the electric zoom, and the user does not feel uncomfortable.

On the contrary, when the user operates the manual drive ring 2 as shown in FIG. 6, the manual force of the user can be rotated stronger than the load of the main body connecting means 11 by disengaging the clutch gear 6a.

Therefore, the manual drive ring 2 rotates, and the drive ring 4 rotates via the drive connecting means 8 as the manual drive ring 2 rotates, so that the photographing lens barrel 1 is operated.

Since the load on the lens barrel of the photographing lens is smaller than the load on the drive connecting means 8, no sliding occurs during this period.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and modifications can be made within the scope of the gist thereof.

It is clear that it can be used industrially.

1 Photograph lens barrel 2 Manual rotating ring 3 Drive source 3a Drive shaft 4 Drive ring 5 Worm gear 5a Pulse plate 6 Hasba gear 7 Pulse detection means

Claims (7)

A drive mechanism that drives the lens holding member in the optical axis direction, a drive source that is connected to the drive mechanism and electrically drives the drive mechanism, and a manual means that is connected to the drive mechanism and manually drives the drive mechanism. It is an optical device that has
When the power is switched from the power OFF to the power ON, the lens holding member is driven in the optical axis direction from the non-photographing region to the photographing region by electric drive by the driving source.
When shooting in the shooting area, it is possible to switch between the electric drive and the manual drive without performing the switching operation between the electric drive and the manual drive.
When shooting in the shooting region, the lens holding member can be driven in the optical axis direction by the electric drive and the manual drive.
When the driving mechanism is manually driven by driving the manual means during shooting in the photographing region, the driving force by the manual means is transmitted to the driving source via the driving mechanism, and the driving source is transmitted. An optical device characterized in that the constituent drive shafts are also driven at the same time. The optical device according to claim 1, wherein when the drive is started by the manual means, the drive source is driven to assist the manual drive by the manual means. Further, it is provided with a detection means for detecting the rotation of the drive shaft even when the drive is driven by the drive source and when the drive is driven by the manual means.
When the lens holding member is in the imaging region and the non-imaging region is operated by the manual means, the drive source is electrically rotated and held at the boundary between the imaging region and the non-imaging region. The optical device according to claim 1 or 2. 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 by the manual means at the adjusted position, the drive source is electrically operated at the boundary between the imaging region and the non-imaging region. The optical device according to claim 3, which is held in rotation. 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 by the manual means at the adjusted position, the drive source is electrically operated at the boundary between the imaging region and the non-imaging region. The optical device according to claim 3, which is held in rotation. The optical device according to any one of claims 1 to 5, wherein the manual drive ring constituting the manual means does not rotate during the electric drive. The optical device according to any one of claims 1 to 6, wherein the non-photographing region is a collapsible region.

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