JP2920383B2 - camera - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a camera having a photographing zoom lens.

[Related Art] In a camera having a photographing zoom lens, it is desired that the speed of lens driving be increased in a zooming operation. For example, when it is desired to capture the intended subject in the crowd from a long distance to the entire shooting screen. On the other hand, when pursuing a subtle movement of the captured subject through the finder until the intended photo opportunity, it is desirable to drive at a low speed. Therefore, a camera that can change the driving speed of a photographing zoom lens has been known.

[Problems to be Solved by the Invention] In such a camera, first, a photographing zoom lens is driven at a high driving speed. And waited for the intended shutter chance.

For this reason, switching is troublesome, and because of the switching operation, the user may look away from the viewfinder and miss a shutter chance, or may miss a subject from the viewfinder. Conversely, the user sometimes concentrates on the finder and misses the subject from the shooting screen due to an error in the switching operation.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and has as its object to provide a camera that can change the driving speed of the next shooting zoom lens depending on the operation time of the shooting zoom lens.

[Means for Solving the Problems] In order to solve the problems and achieve the object, the present invention is configured as follows.

The invention according to claim 1 is a camera capable of driving a photographing zoom lens at at least two different speeds, wherein a focal length switch operated to drive the photographing zoom lens at a first speed; The operation time of the focal length switch is measured, and it is determined whether the operation time is within a predetermined time.If the operation time is within the predetermined time, the driving of the photographing zoom lens by the focal length switch is performed. A camera comprising control means for performing the control at a second speed lower than the first speed. ].

According to the first aspect of the present invention, when it is determined that the operation time of the focal length changeover switch is within the predetermined time, it means that the photographer has approached a scene desired by the photographer in the vicinity, and the next time. By switching the driving of the shooting zoom lens to a low speed side by operating the focal length switch, it is easy to adjust by driving the shooting zoom lens at a low speed thereafter.For example, you can look away from the viewfinder to miss a shutter chance or from within the viewfinder. It is possible to prevent the subject from being missed, or conversely, concentrate on the finder and miss the subject from the shooting screen due to an error in the switching operation.

According to a second aspect of the present invention, there is provided the camera according to the first aspect, wherein the focal length changeover switch is a slide type. ].

According to the second aspect of the present invention, the switching operation can be easily performed by sliding the focus switching switch.

According to a third aspect of the present invention, there is provided the camera according to the first or second aspect, wherein a driving speed of the photographing zoom lens is changed according to a sliding amount of the focal length switch. ].

According to the third aspect of the present invention, the drive speed can be changed by a simple mechanism according to the slide amount of the focal length switch.

According to a fourth aspect of the present invention, there is provided an image forming apparatus, comprising: a release means for releasing the switching of the low-speed side when the driving of the photographing zoom lens by the operation of the focal length changeover switch is performed for a predetermined time or more or the photographing is completed. Claim 1
The camera according to claim 3. ].

According to the fourth aspect of the present invention, the low-speed switching can be canceled by operating the focus switching switch for a predetermined time or more or by ending the photographing, and the initial high-speed switching can be easily returned.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of a single-lens reflex camera provided with an automatic focusing device capable of converting a lens.

Reference numeral 1 in FIG. 1 denotes a camera, which includes a zoom lens barrel 2 and a release switch 3.

On the side of the zoom lens barrel 2, a focal length switch 4 for switching the focal length is provided at a position where the thumb of the left hand hits the camera.

This camera measures the distance with light passing through the lens system of the zoom lens barrel 2, and the photographer obtains a composition for photographing with the light.

The focal length changeover switch 4 can be slightly slid in the circumferential directions A and B of the zoom lens barrel 2. When the switch is slid in the direction A, a contact portion (not shown) is turned on, so that the zoom lens barrel 2 is turned on. When the focal length changeover switch 4 is slid in the B direction when the focal length change switch 4 is slid to the wide side, the contact portion is turned on to change to the telephoto side.

FIG. 2 shows a lens configuration diagram of the single-lens reflex camera.

In FIG. 2, reference numeral 11 denotes an optical axis of a magnification optical system, and reference numeral 12 denotes a magnification lens group which is movably disposed along the optical axis 11 and is a photographing zoom which is configured with the magnification optical system.

The magnification lens group 12 includes first to fifth lens groups 12a to 12e each including one or more lenses, and the first lens group 12a and the second lens group 12b form a focusing lens group. I have.

The light incident into the camera is further guided to a finder 15 via an optical system such as a main mirror 13 and a pentaprism 14 arranged on an optical axis 11. A part of the light projected on the main mirror 13 is transmitted through the main mirror 13 and the sub-mirror 16, guided to the film 18 through the shutter 17, and exposes the image of the subject on the film 18. Part of the light projected on the sub-mirror 16 is an optical system such as a condenser lens 19 and an AF sensor 20 composed of a CCD or the like which is a sensor array.
Are input to the focus detection means 21 composed of the above.

This embodiment is the same as the focus detection device of the TTL phase difference detection system disclosed in Japanese Patent Application Laid-Open No. 60-4914.

The focus detecting means 21 is operated by a first-stage pressing stroke of the release switch 3, and performs photographing by a next second-stage stroke. The focus can be selected between a manual mode and an AF mode by the mode selection switch 5.

Further, the variable power lens group 12 is driven by a variable power motor 23 forming a variable lens driving means 22, and the first lens group 12 a and the second lens group 12 b are driven by a focusing motor 25 forming a focusing lens driving means 24. Driven by

First and second lens groups which are detected by focusing detection means 21 for detecting the subject distance based on light information passed through the photographing zoom lens, and which are focused by focusing lens control means 26 based on the information.
Drives 12a and 12b.

Further, when the photographing zoom lens is zoomed, the focus detecting means 21 is automatically operated, and the magnification zoom lens driving means 22 is driven by the variable magnification lens control means 27 with respect to the subject, and the photographing zoom lens is always driven. Maintain the in-focus state.

Therefore, when the in-focus state and the zooming state are detected by the in-focus detection means 21, the photographing zoom lens is driven to an optimum focus position based on the detection results.

Further, when driving to the optimum focus position, both the movement of the focus position by zooming and the automatic focus adjustment are corrected by adjusting the shift amount.

Furthermore, the presence or absence of the zoom operation of the shooting zoom lens is detected, and when the shooting zoom lens is zoomed,
The operation of the focus detection means 21 automatically corrects the photographing zoom lens to a focus position based on the detection result.

As described above, the image in focus on the subject can be detected during zooming, so that the finder image can be visually recognized in a state that matches the subject.

In addition, after the photographing scene is determined by zooming, the amount of movement of the focusing lens to the focusing drive associated with the shutter release is reduced, so that the photographing can be performed instantaneously.

In this embodiment, the focal length switch 4 may be formed as a two-stage switch so that the zooming speed may be controlled by the magnitude of the slide amount. For example, the zooming operation time may be measured, and if the zooming operation is completed within a predetermined time, the movement of the variable power lens during the next zooming operation may be switched to the low speed mode. This means that a short zooming operation time means that the photographer has approached a scene desired by the photographer in the vicinity, and it becomes easier to adjust the zooming operation thereafter by slowing down. As a means for releasing the low-speed mode, the operation returns to the first high-speed mode when the focus switch is operated for a predetermined time or longer or when the photographing is completed.

FIG. 3 is a schematic block diagram of the automatic focusing device of the camera, and FIG. 4 is a flowchart.

Reference numeral 30 in FIG. 3 denotes a CPU provided in the camera, which is connected to a battery 32 via a power holding circuit 31.
At 31 a predetermined operating voltage is provided.

The CPU 30 includes a release unit 33 and a zooming unit 3.
4.Focus detection means 21, magnification lens position detection means 35, photometry means 36, focus lens control means 26, magnification lens control means 2
7, the exposure control means 37 and the finder LED 38 are connected,
These exchange information with the CPU 30 and operate.

The release means 33 turns on the switches S1 and S2 during the stroke by pressing the release button, and the switch S
At 1, photometry is performed, and at switch S2, shooting is performed by exposure control based on the information of switch S1.

By turning on the switch S1, the focus detection means 21 is operated,
The subject distance is detected, and based on the detected subject distance, the focusing lens control means 26 drives the focusing lens by the motor 25 to move it to the focusing position.

The zooming means 34 is a switch for setting the focal position of the photographing lens. By pressing this switch, the magnification lens of the photographing zoom lens is moved in the optical axis direction.

The variable power lens position detecting means 35 detects the position of the variable power lens by the zooming drive, moves the focusing lens corresponding to the position of the variable power lens, and detects the subject distance by turning on the switch S1, thereby detecting the focusing lens. Is moved to the in-focus position.

In the wide area ranging, the focus area is determined by pressing the zoom button with the switch S1. After the determination, the focusing starts when the switch S1 is turned off. A with zoom lens means
F is intermittent until the movement of the lens is completed even after the zoom lens is released. However, it stops when the switch S1 is released. AE photometry is performed during zooming, and the F-number of the lens changes depending on the focal length of the lens.

Next, the operation will be described with reference to FIG. 4. If the switch S1 is turned off in step a and the zoom switch is turned off in step b, the switch S1 is turned off in step a.
N willing to be. When the switch S1 is turned on, the distance measurement is performed (step c), the focusing lens is driven (step d), and when the focus is achieved by this operation, the photometry is performed (steps e and f).

Next, when the switch S2 is turned on (step g), exposure control is performed (step h). When this exposure is performed, one frame film is fed and the process ends (step i).

In step a, when the switch S1 is OFF, the input state of the zoom switch is determined. When the zoom switch is turned ON (step b), the driving of the variable power lens starts (step j).

Further, in step k, the ON state of the zoom switch is further determined. When the zoom switch is turned off (step k), the driving of the variable power lens is stopped and the process jumps to step a (step l). When the zoom lens reaches the zoom end (step m), the driving of the zoom lens is similarly stopped, and the process jumps to step a.

If the variable power lens is not at the zoom end, distance measurement is performed (step n). When a subject in a very dark place, a subject with extremely strong reflection, or a distant object and a close object is applied to the distance measurement unit, the distance is stabilized. In the case of a moving subject that cannot be measured or a subject having no contrast, a correct value may not be obtained as distance measurement data. Therefore, it is determined whether or not the information is successful (step o). The driving amount of the focusing lens is calculated (step p), the moving amount of the variable power lens is calculated (step q), and the focusing lens is driven (step r). When the switch is turned off, the driving of the variable power lens is stopped in the same manner as described above, and the process jumps to step a (step l).

In step a, when the switch S1 is turned on, the distance measurement is performed in the same manner as described above (step c), and the focusing lens is driven and corrected (step d). (Step f).

Next, when the switch S2 is turned on (step g), exposure control is performed (step h), and when this exposure is performed, one-frame film is fed and the process ends (step i).

In this embodiment, although not specifically shown, the manual mode and the AF mode can be selected by the mode selection switch 5. However, in the manual mode as well as the AF mode, the focus detecting means is provided during zooming. The zoom lens is actuated to keep the taking lens at the in-focus position, thereby facilitating focus correction after zooming.

[Effect of the Invention] As described above, according to the first aspect of the present invention, when it is determined that the operation time of the focal length changeover switch is within the predetermined time, the photographer approaches the desired scene near the predetermined time. That is, the driving of the photographing zoom lens by the next operation of the focal length changeover switch is switched to the low speed side, and the driving of the photographing zoom lens thereafter is facilitated by adjusting the driving speed to a low speed. Missing a chance, missing a subject from inside the viewfinder, or conversely, concentrating on the viewfinder and preventing the subject from being missed from the shooting screen due to an error in the switching operation can be prevented.

According to the second aspect of the present invention, the switching operation can be easily performed by sliding the focus switching switch.

According to the third aspect of the present invention, the driving speed can be changed by a simple mechanism according to the slide amount of the focal length changeover switch.

According to the fourth aspect of the invention, the low-speed switching can be canceled by operating the focus switching switch for a predetermined time or longer or by ending the shooting, and the initial high-speed switching can be easily performed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a single-lens reflex camera provided with an automatic focusing device capable of converting a lens, FIG. 2 is a lens configuration diagram of the single-lens reflex camera, and FIG. 3 is a schematic configuration block diagram of the automatic focusing device of the camera. FIG. 4 is a flowchart. In the figure, reference numeral 1 denotes a camera, 2 denotes a zoom lens barrel, 3 denotes a release switch, 4 denotes a focal length changeover switch, 12 denotes a photographing zoom lens, 21 denotes focus detection means, 26 denotes focus lens control means, and 27 denotes a variable lens. This is magnification lens control means.

Continuation of the front page (56) References JP-A-61-45212 (JP, A) JP-A-63-33720 (JP, A) JP-A-63-189817 (JP, A) JP-A-1-226281 (JP) JP-A-1-250912 (JP, A) JP-A-2-73320 (JP, A) JP-A-2-77054 (JP, A) JP-A-63-280208 (JP, A) JP-A-62-133029 (JP, A) JP-A-62-178915 (JP, A) JP-A-64-106006 (JP, A) JP-A-63-193118 (JP, A) A) JP-A-2-210410 (JP, A) JP-A-2-29610 (JP, A) JP-B-56-47533 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) ) G02B 7/09 G03B 5/00

Claims (4)

(57) [Claims] 1. A camera capable of driving a photographing zoom lens at at least two different speeds, comprising: a focal length switch operated to drive the photographing zoom lens at a first speed; The operation time of the switch is counted, and it is determined whether or not the operation time is within a predetermined time. If the operation time is within the predetermined time, the driving of the photographing zoom lens by the focal length switch is performed at the first speed. A camera having control means for performing the control at a second speed which is lower. 2. The camera according to claim 1, wherein said focal length switch is a slide type. 3. The camera according to claim 1, wherein a driving speed of the photographing zoom lens is changed according to a slide amount of the focal length switch. 4. The image forming apparatus according to claim 1, further comprising a canceling means for canceling the switching of the low-speed side when the driving of the photographing zoom lens by the switch operation of the focal length changeover switch is performed for a predetermined time or more or the photographing is completed. The camera according to claim 3.