JPH11281866A - Lens device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens device by which the position of a master lens group can be immediately returned to an initial flange back position and by which the present position of the master lens group is compared with a position on which flange back adjustment is performed, so that a user can be easily know the present position of the master lens group by storing the initial flange back position at the time of factory delivery. SOLUTION: The optimum initial flange back position of the master lens group 20 on a photographic lens system is stored on a storing device 66 at the time of the factory delivery. The user can return the group 20 to the initial flange back position by turning on a returning switch 56 even when a flange back adjusting knob 42 is turned and operated so that the flange back adjustment is performed on the group 20. An LED displays how much the position of the group 20 is deviated from the initial flange back position on a display device 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens device,
More particularly, the present invention relates to a lens device capable of adjusting the position of a master lens group of a photographing lens system by flange back.

[0002]

2. Description of the Related Art Conventionally, in a lens device used for a broadcast television camera or the like, in order to make the imaging position of a photographic lens system coincide with the position of an image pickup surface of a camera, a manufacturer installs the lens device before shipment from a factory. The position of the master lens group of the photographing lens system is adjusted (flange back adjustment) by operating the provided flange back adjustment knob. However, an optical member such as a color separation prism and a filter is actually inserted into the camera, and the distance to the image plane varies depending on the thickness and material of the optical member or the position where the image sensor is attached. For this reason, even if a manufacturer ships a lens in which the reference position of the master lens group is determined by adjusting the flange back, if the lens is attached to the camera on the user's side, the master lens will be connected at a position shifted from the reference position. There is a problem that the image may be formed and the resolution may be lowered. Therefore, a flange back adjustment knob is provided at a position (for example, a side surface of the lens) that can be easily adjusted so that the user can perform the flange back adjustment. Then, the user operates the flange back adjustment knob to move the master lens group to an optimal position in the camera to which the lens is attached, and fixes the knob so that the master lens group does not move from that position.

Incidentally, the position of the master lens group may be changed during photographing for the purpose of macro photographing or the like. In this case, the master lens group must be returned to the tracking position again when the operation such as macro shooting is completed. For this reason, a device which has a storage means for storing the position of the master lens group to facilitate this return has been conventionally known (Japanese Patent Publication No. 60-46405, Japanese Patent Application Laid-Open No. 10-20179).

[0004]

However, conventionally, if the user performs flange back adjustment on the user side,
The position of the master lens group (initial flange back position) at the time of factory shipment was lost. Therefore, for example, when the user wants to readjust the flange back position from the initial flange back position after performing the flange back adjustment, the user cannot return to that position. Further, even when the flange back adjustment knob is inadvertently moved, it cannot be returned to the initial flange back position again, and the flange back adjustment has to be performed again. In addition, when the knob moved so much that the flange back adjustment was not successful, it had to be sent back to the manufacturer again and re-adjusted at the factory.

Further, the position of the conventional master lens group can be known only from the approximate position by the rotation position of the flange back adjustment knob. Could not be known exactly from the position. For this reason, when performing the flange back adjustment, it is difficult to make the adjustment because it is only possible to know how much the lens moves with respect to the reference. Also,
Even if a defect such as low resolution occurs, it was not possible to immediately determine whether the position of the master lens group was bad. For example, if it is found that the position of the master lens group is greatly deviated from the flange back position, the user can immediately determine that the connection between the camera and the lens device is bad, and reconnect the camera and the lens device. Then, such a problem can be solved.

The present invention has been made in view of such circumstances, and a lens apparatus which can immediately return the position of the master lens group to the initial flange back position by storing the initial flange back position. The purpose is to provide. It is another object of the present invention to provide a lens device that can easily know the position of the master lens group subjected to flange-back adjustment and the current position of the master lens group.

[0007]

According to the present invention, in order to achieve the above object, the position of a master lens group of a photographing lens system is adjusted, and the position of an optical image formed by the photographing lens system is adjusted. In a lens device capable of adjusting a flange back to be positioned on an imaging surface of a camera, a flange back adjusting means for adjusting a position of the master lens group and an initial flange back position of the master lens group in the lens device alone are stored. And an initial flange back position storage means.

[0008] Further, a storage instructing means for instructing to store the flange back position of the master lens group in the initial flange back position storing means is provided. Further, a return instructing means for instructing to return the master lens group to the initial flange back position is provided.

According to the present invention, since the flange back position (initial flange back position) at the time of shipment from the factory is stored, the master lens group is immediately stored in the initial flange back position even after the user performs the flange back adjustment. You can go back. Therefore, even if the flange-back adjustment knob is inadvertently moved, the adjustment can be performed after returning to the initial flange-back position first, so that the adjustment is easy.

In order to achieve the above object, the position of the master lens group of the photographing lens system is adjusted, and the image forming position of the optical image formed by the photographing lens system is aligned with the imaging plane of the camera. In a lens device capable of adjusting the flange back, a flange back adjusting unit for adjusting the position of the master lens group, a flange back position storing unit for storing the position of the master lens group, and an adjustment by the flange back adjusting unit. Display means for displaying the position of the master lens group relative to the flange back position stored in the flange back position storage means.

[0011] Further, a storage instructing means for instructing to store the flange back position of the master lens group in the flange back position storing means is provided. Further, a return instructing means for instructing to return the master lens group to the flange back position is provided.

According to the present invention, the current position of the master lens group is displayed relative to the position of the master lens group whose flange back has been adjusted. For example, when the position of the master lens group is greatly deviated from the flange back position, it is possible to prevent the occurrence of a trouble due to this before shooting, and When a problem occurs due to this, the cause can be immediately known.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a lens device according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a side view of a lens device according to the present invention,
The internal structure is partially shown. Hood 1 on the left side of the figure
The portion covered by 1 corresponds to the front of the lens device 10, and the television camera is fixedly connected to the right end face in the figure. The lens device 10 is covered with a substantially rectangular cover 12, and the cover 12 is detachably fixed to the lens device 10 by fixing screws 14 provided on the left and right side surfaces. A concave portion 16 serving as a handle for carrying the lens device 10 is formed in the center of the upper side of the cover 12, and a tally lamp window 18 is formed in front of the concave portion 16.

Although the interior of the lens device 10 is not shown in detail, a fixed focus lens group, a movable focus lens group, a first movable zoom lens group, and a second movable A zoom lens group, a master lens group 20, and the like are provided. The master lens group 20 of the taking lens system includes a lens holding cylinder 2
2 and is connected to the rearmost part of the fixed lens barrel 24 so as to be movable in the front-rear direction. A guide hole parallel to the axis is formed on the peripheral surface of the fixed lens barrel 24, and a pin 26 implanted in the lens holding tube 22 is fitted into the guide hole. A cam groove having a constant width is formed in a cam cylinder 28 rotatably mounted on the outer peripheral surface of the fixed lens barrel 24 in a direction oblique to an axis. The cam groove is fitted.

The lens device 10 is provided with a drive motor 30 for driving the master lens group 20 and a potentiometer 32 for detecting the position of the master lens group 20. The driving force of the motor 30 is the gear 3
4 and 35 are transmitted to the cam cylinder 28. When the cam barrel 28 rotates, the lens holding barrel 22 moves back and forth with respect to the fixed lens barrel 24. The potentiometer 32 outputs a position detection signal indicating the position of the master lens group 20 according to the rotation amount.

Behind the cover 12, the mount frame 40
A rotary flange back adjustment knob 42 for adjusting the position of the master lens group 20 is provided at a lower portion of the side surface of the lens. As will be described in detail later, when the flange back adjustment knob 42 is rotated, the motor 30 is driven according to the operation amount. When the motor 30 rotates, the rotational force is transmitted to the potentiometer 32 and the cam barrel 28 via a gear, and the lens holding barrel 22 moves back and forth along the optical axis.

Accordingly, by rotating the flange back adjustment knob 42, the master lens group 20 is moved forward and backward along the optical axis, and the image forming position of the lens on the image pickup surface of the television camera is adjusted (flange back adjustment). You can do it. A fixed knob 44 is provided coaxially with the flange back adjustment knob 42. The fixing knob 44 locks the rotation of the flange back adjustment knob 42 so that the flange back position adjusted by the flange back adjustment knob 42 does not shift. That is, by operating the flange back adjustment knob 42 to adjust the position of the master lens group 20 and then turning the fixed knob 44 clockwise, the rotation of the rotation axis of the flange back adjustment knob 42 is fixed, The position of the master lens group once adjusted can be prevented from moving due to an unexpected external force.

A display 50 for displaying the position of the master lens group 20 is provided at the lower part of the side surface of the lens device 10. The display 50 is composed of a large number of LEDs 50A, 50A,... Arranged in a horizontal line, and only the LED 50A corresponding to the position of the master lens group 20 is turned on. By the way, LE of the display 50
The LED located at the center of D50A, 50A,... (Indicated by 50B to distinguish it from other LEDs 50A) is indicated by an arrow mark, and this LED 50B has a predetermined flange back position set by the manufacturer at the time of factory shipment. Lights up when the master lens group 20 is set at the (initial flange back position). Although the initial flange back position will be described later, when the master lens group 20 is set forward of the initial flange back position, the set position is set to the center corresponding to the amount deviated from the initial flange back position. LED
The LED 50A that is shifted forward (left side in the figure) from 50B is turned on. When the master lens group 20 is set rearward with respect to the initial flange back position, the center LE corresponds to the amount deviated from the initial flange back position.
LED 50A biased backward (right side in the figure) from D50B
Lights up.

By providing the display 50 in this manner, the current position of the master lens group 20 can be easily known, and the magnitude of the deviation of the master lens group 20 from the initial flange back position can be easily determined. You can know. The display 50 may be provided at any position without being limited to the side surface of the lens device 10. Also, behind the cover 12,
A display switch 54 is provided on the lower side of the mount frame 40.
The display switch 54 allows the display of the display unit 50 to be turned on or off.

A return switch 56 is provided above the display switch 54. The return switch 56 is for returning the master lens group 20 to the initial flange back position, and its operation will be described later. FIG. 2 is a diagram showing a configuration of a control circuit for controlling the master lens group 20, the display 50, and the like. Lens device 1
0 is the CPU 6 for controlling the position of the master lens group 20.
The CPU 60 has a rotary encoder 62 for rotating the flange back adjustment knob 42.
Is to be entered via Also, the CPU 6
To 0, a position detection signal from the potentiometer 32 for detecting the position of the master lens group 20 is input.

The rotary encoder 62 is mounted on the flange back adjustment knob 42. When the flange back adjustment knob 42 is rotated, for example, a two-phase pulse signal consisting of an A phase and a B phase is applied in accordance with the rotation direction. The phase is input to the CPU 60 at every predetermined rotation angle. When receiving the pulse signal, the CPU 60 counts up or down according to the phase of the pulse signal, and detects the operation amount of the knob 42. Then, the current position of the master lens group is detected by the position detection signal input from the potentiometer 32, and a position displaced from this detected position by a distance corresponding to the operation amount of the flange back adjustment knob 42 is set to the master lens group 20. Set position (target position).

On the other hand, a drive motor 30 for driving the master lens group 20 is connected to the CPU 60 via a drive circuit 64. After determining the set position of the master lens group 20 based on the rotation operation of the flange back adjustment knob 42 as described above, the CPU 60
And outputs a drive signal to drive the drive motor 30 to move the master lens group 20 to the set position. As a result, the position of the master lens group 20 can be flange-back adjusted by rotating the flange-back adjustment knob 42 as described above.

The CPU 60 has, for example, EEP
A storage device 66 including a memory such as a ROM is connected, and the storage device 66 stores an initial flange back position of the master lens group 20. The initial flange back position is
The optimum position of the master lens group 20 is shown in relation to the focus lens group and the zoom lens group of the photographing lens system, and is stored in the storage device 66 by the manufacturer at the time of factory shipment or the like. Specifically, the master lens group 20 is set to an optimum position (initial flange back position) with the flange back adjustment knob 42 at the time of shipment from a factory, and the storage switch 68 connected to the CPU 60 is turned on. The CPU 60 detects the position of the master lens group 20 input from the potentiometer 32 when the storage switch 68 is turned on, and records the detected position in the storage device 66 as an initial flange back position. This allows the storage device 66 to store the correct flange back position for each product.

The storage switch 68 is provided in advance so that the initial flange back position can be accurately set for each product at the time of factory shipment or the like, and the contents of the storage device 66 can be easily rewritten by a user's erroneous operation. In order to prevent the operation from being performed, it is desirable to provide the device at a position where it cannot be normally operated. The return switch 56 shown in FIG.
Is connected to the CPU 60, and when the return switch 56 is pressed, an ON signal is input from the return switch 56 to the CPU 60.
When receiving the ON signal, the CPU 60 inputs the initial flange back position from the storage device 66, outputs a drive signal to the drive circuit 64 to move the master lens group 20 to this position, and drives the drive motor 30. . When the position detection signal input from the potentiometer 32 matches the initial flange back position, the output of the drive signal of the drive circuit 64 is stopped, and the master lens group 20 is stopped at that position. Thus, even after the master lens group 20 is moved to an arbitrary position by the flange back adjustment knob 42, the return switch 56
Is turned on, the master lens group 20 can be easily and quickly returned to the initial flange back position. After the master lens group 20 is returned to the initial flange back position, the master lens group 2 is again rotated by rotating the flange back adjustment knob 42.
0 can be adjusted from the initial flange back position.

The display 50 and the display switch 54 shown in FIG.
Turning on and off of the ED 50A is controlled by the CPU 60. The CPU 60 switches the display of the display 50 on and off every time the display switch 54 is pressed, and when the display is off, all the LEs of the display 50 are turned off.
Turn off D50A. On the other hand, if the display is on,
The CPU 60 reads the initial flange back position from the storage device 66, detects the current position of the master lens group 20 from the potentiometer 32, finds the difference between the current position of the master lens group 20 and the initial flange back position, and obtains the difference. The LED 50A at the position corresponding to is turned on. That is, when the master lens group 20 is set at the initial flange back position as described above, the central LED 50B (see FIG. 1) is turned on, and the master lens group 20 is moved forward with respect to the initial flange back position. When the LED 5B is deviated forward (left side in FIG. 1) from the center LED 50B by an amount corresponding to the amount deviated from the initial flange back position,
Turn on 0A. When the set position is deviated rearward from the initial flange back position, the position is similarly shifted rearward from the center LED 50B by an amount corresponding to the deviated amount (right side in FIG. 1).
The LED biased to is turned on.

The display on the display unit 50 allows the user to easily and accurately know how much the current position of the master lens group 20 deviates from the initial flange back position. It is possible to determine that the mechanical connection between the device 10 and the television camera is bad. As described above, in the above-described embodiment, a case has been described in which only the initial flange back position set at the time of shipment from the factory can be stored in the storage device 66. In addition to the initial flange back position, the user can further adjust the flange back position. The flange back position adjusted by the knob 42 may be stored. FIG.
FIG. 3 is a diagram illustrating a configuration of a control circuit in this case. FIG.
2, the same or similar components as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG.
Similarly to the storage device 66, a storage switch 70 for instructing storage of the flange back position and a storage device 71 for storing the flange back position are provided. This allows
The user operates the flange-back adjustment knob 42 to adjust the flange-back of the master lens group 20 and then turns on the storage switch 70, so that the position can be stored in the storage device 71. still,
Since the memory switch 70 is operated by the user, it is desirable to install the memory switch 70 in a location that is easy to operate, such as the side surface of the lens device 10.

Then, the CPU 60 causes the display 50 to display the flange back position stored in the storage device 71.
The display of the flange back position corresponds to the difference between the initial flange back position adjusted by the manufacturer and the flange back position adjusted by the user, for example, as in the case of displaying the current position of the master lens group 20 as described above. The LED 50A at the position to be turned on is turned on. Note that the display colors of these positions may be changed so as not to confuse the display of the flange back position adjusted by the user with the current position of the master lens group 20. Further, each time the display switch 54 is turned on, the flange back position and the current position of the master lens group 20 may be switched and displayed.

Thus, the difference between the initial flange back position and the current position of the master lens group 20, the difference between the initial flange back position and the flange back position adjusted by the user, and the difference between the initial flange back position and the current flange back position adjusted by the user. Of the master lens group 20 can be easily known. Further, in FIG. 3, similarly to the return switch 56, a return switch for returning the master lens group 20 to the flange back position stored in the storage device 71 may be provided. Thereby, for example, when the lens device 10 enables the movement control of the master lens group 20 for the special effect, after returning the master lens group 20 from the flange back position for the special effect, The switch allows the master lens group 20 to quickly and accurately return to the flange back position.

As described above, in the above embodiment, the current position of the master lens group 20 (or the flange back position adjusted by the user) is displayed by the lighting positions of the LEDs 50A arranged in a line, and the current position of the master lens group 20 is displayed. The magnitude of the deviation between the (or flange back position) and the initial flange back position is displayed by the magnitude of the deviation between the lighting position of the LED 50A and the center position. However, the present invention is not limited to this. The magnitude of the deviation may be displayed by a numerical value, and the display method may be any method. Further, in the embodiment shown in FIG. 3, especially, the initial flange back position adjusted by the maker, the flange back position adjusted by the user, and the magnitude of the deviation of the current position of the master lens group 20 are all displayed. It is not necessary to display the magnitude of the deviation between the initial flange back position and the current position of the master lens group 20 or the flange back position adjusted by the user and the current master lens group 20 may be displayed. Only the magnitude of the deviation from the position may be displayed.

In the above embodiment, the storage device 66 and the storage device 71 for storing the initial flange back position or the flange back position are stored in a memory such as an EEPROM. However, the present invention is not limited to this. It may be stored in an analog manner by a resistor or the like. In this case, the storage switch 68 and the storage switch 70 are unnecessary.

In the above-described embodiment, the display on the display unit 50 is enabled only when the display switch 54 is turned on. However, the present invention is not limited to this, and the display unit 50 always displays the position of the master lens group 20 and the like. You may do so. Further, in the above embodiment, when the storage switches 68 and 70 are turned on, the initial flange back position or the flange back position is stored in the storage devices 66 and 71. However, the present invention is not limited to this. Without setting
Other switches (display switch 54, return switch 56
, Etc.) for more than a predetermined time, the memory switches 68, 7
The same effect as turning on 0 may be provided.

[0033]

As described above, according to the lens apparatus of the present invention, the flange back position (initial flange back position) at the time of shipment from the factory is stored, so that even after the user makes the flange back adjustment. The master lens group can be immediately returned to the initial flange back position. Therefore, even if the flange-back adjustment knob is inadvertently moved, the adjustment can be performed after returning to the initial flange-back position first, so that the adjustment is easy.

Also, the current position of the master lens group is
Since the relative position is displayed with respect to the position of the master lens group adjusted by the flange back, it is easy to know how much the master lens group is from the flange back position. If there is a large deviation from the flange back position, it is possible to prevent this from occurring before shooting, and if this occurs, it is possible to know the cause immediately. it can.

[Brief description of the drawings]

FIG. 1 is a side view of a lens device according to the present invention.

FIG. 2 is a configuration diagram showing an embodiment of a control circuit of the lens device according to the present invention.

FIG. 3 is a configuration diagram showing another embodiment of the control circuit of the lens device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Lens apparatus 20 ... Master lens group 30 ... Drive motor 32 ... Potentiometer 42 ... Flange back adjustment knob 50 ... Display 54 ... Display switch 56 ... Return switch 60 ... CPU 66 ... Storage device 68 ... Storage switch 70 ... Storage switch 71 …Storage device

Claims (6)

[Claims] 1. A lens device capable of adjusting a position of a master lens group of a photographing lens system and adjusting a focal position of an optical image formed by the photographing lens system to an image pickup surface of a camera. , Wherein flange back adjustment means for adjusting the position of the master lens group, and initial flange back position storage means for storing an initial flange back position of the master lens group in the lens device alone are provided. Lens device. 2. The lens apparatus according to claim 1, further comprising storage instruction means for instructing the initial flange-back position storage means to store the flange-back position of the master lens group. 3. The lens apparatus according to claim 1, further comprising a return instructing unit that instructs to return the master lens group to the initial flange back position. 4. A lens device capable of adjusting a position of a master lens group of a photographing lens system and adjusting a focal position of an optical image formed by the photographing lens system on an image pickup surface of a camera. In the above, flange back adjustment means for adjusting the position of the master lens group, flange back position storage means for storing the position of the master lens group, and the position of the master lens group adjusted by the flange back adjustment means, Display means for displaying relative to the flange back position stored in the flange back position storage means. 5. The lens apparatus according to claim 4, further comprising storage instruction means for instructing the flange-back position storage means to store the flange-back position of the master lens group. 6. The lens apparatus according to claim 4, further comprising a return instructing unit for instructing the master lens group to return to the flange back position.