JP2801016B2 - camera - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly, to a camera having a finder optical system independent of a photographic optical system and interlocking the finder optical system with the photographic optical system. The present invention relates to a camera configured as a zoom optical system.

[Prior Art] A non-interchangeable autofocus camera equipped with a zoom lens as a photographing optical system has been commercially available for several years. Recently, in this type of camera, the zoom lens has been increased in magnification and the shooting distance has been reduced, and the zoom ratio of about 2 times in a conventional similar camera has been reduced to 3 to 3 in a recently released similar camera. The focal length of the lens is four times larger and the focal length of the lens is longer than that of the conventional product, and the closest shooting distance is about 0.6 m. Some cameras of this type employ a range finder, and the zoom ratio of the range finder has been increased with an increase in the zoom ratio of the photographing optical system.

[Problems to be Solved by the Invention] In general, the rangefinder mounted on the camera is infinite if it is adjusted to focus on a subject at a distance of about 3 m in consideration of the focusing ability of the eyes. A subject in a range from a distance to a close distance can be seen without blurring.

However, when the zoom ratio of the viewfinder optical system increases and the focal length increases, the depth of field becomes shallower and the range in which the subject is in focus becomes smaller. As a result, on the long focal length side, the focus of the viewfinder is reduced by about 3 m. When adjusted to match the subject, the subject that can be seen without blurring is a subject at a distance from infinity to about 1 m, and a subject at a distance shorter than that will appear blurred when viewed through the viewfinder.

On the other hand, if the focus adjustment range of the taking lens is from infinity to about 0.6 m, a subject at a distance of 1 m to 0.6 m appears blurred when viewed through the viewfinder, but when taking a picture, a focused photograph can be taken. become. This is because the photographer mistakenly believes that the subject in this range (0.6 to 1 m) is out of focus, so the photographer may retreat to a distance where the subject can be seen without blur through the viewfinder, or the subject may be blurred. That is, the user is required to take an action such as shortening the focal length of the zoom lens until the image is visible. Therefore, there is a defect that the conventional camera with a large zoom ratio of the finder optical system cannot realize this, although the subject can be photographed larger near the subject.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a new camera which does not have the above-mentioned disadvantages of the conventional camera.

[Means for Solving the Problems] In order to achieve the above object, a camera according to the present invention includes a variable focal length photographing optical system having a zoom lens and a focusing lens. A variable focal length finder optical system having an interlocking finder variable power lens and a finder focusing lens interlocked with the focusing lens; a variable power lens of the photographing optical system and the finder variable power lens; A first drive source for driving the lens, a second drive source for driving the focusing lens of the photographing optical system and the finder focusing lens, and a zoom operation member for performing a zoom operation.
First control means for controlling the driving of the first drive source in accordance with the operation of the operation member, focus signal generating means for generating an output signal corresponding to the subject distance, and generating the focus signal A second control means for calculating a moving amount or a moving position of the focusing lens according to an output signal of the means and controlling the driving of the second driving source based on the calculation result. It is characterized by the following.

[Operation] In the camera according to the present invention, during zooming, the variable power lens of the photographic optical system and the variable power lens of the finder optical system are interlocked. Since the focusing lens and the focusing lens of the finder optical system are interlocked, the appearance of the image in the viewfinder matches the appearance of the image in the photographing optical system, and therefore,
The camera user can decide the composition with ease, and there is no risk of failure in close-up shooting.

[Embodiment] An embodiment of a camera according to the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a schematic structure of an optical system of a camera according to the present invention and a driving structure of the optical system. As shown in FIG. 1, in the camera of the present invention, the photographing optical system 10 is a first group lens.
3 having 11 and second group lens 12 and third group lens 13
It is composed of a group zoom lens. The second lens group 12 and the third lens group 13, which are variable power lenses, are driven by a first motor M1, and the first lens group 11, which is a focusing lens, is a second lens element. 2 motor
It is driven by M2.

On the other hand, in the camera of the present invention, the finder optical system 20 also includes the first group lens 21, the second group lens 22, and the third group lens.
The first group lens 21 as a focusing lens is driven by a motor M2, and the second group lens 22 and the third group lens 23 as zooming lenses are configured as a focusing lens. It is designed to be driven by a motor M1.
That is, in the camera of the present invention, the zoom lenses 12 and 13 of the photographing optical system 10 and the zoom lens of the finder optical system 20
22 and 23 are linked to each other,
Focusing lens 11 and finder optical system 20 of shooting optical system 10
And the focusing lens 21 are linked to each other.

FIG. 2 is a schematic diagram showing a part of an electric configuration of the camera of the present invention having the optical system shown in FIG. In FIG. 2, 1 is a control circuit having an arithmetic function, a sequence control function, and a storage function, 2 is a first motor driving circuit for driving the motor M1, and 3 is a second motor driving circuit for driving the motor M2. The motor drive circuit 4 detects the absolute value of the rotation amount of the motor M1 and feeds it back to the control circuit 1. First motor rotation amount detection means 5 detects the absolute value or relative value of the rotation amount of the motor M2. The second motor rotation amount detecting means 6 for feeding back to the control circuit 1 is a known distance measuring device (focusing signal generating means), and 9 and 14 are zoom switches operated by the photographer, one of which is pressed. When the other switch is depressed, zooming to the wide angle side is performed.

Reference numeral 15 denotes a first release switch that is turned on in response to a half-press stroke of a shutter release button (not shown), 16 denotes a second release switch that is turned on in response to a full-press stroke of the shutter release button, and 17 denotes a shutter of the camera. And various mechanism control circuits for controlling the aperture mechanism and other mechanisms.

In the above configuration, the first control means 18 (ie, the first control means 18 for controlling the zooming operation of the photographing optical system and the finder optical system)
The control means for the motor M1 is represented by a block surrounded by a dashed line in FIG. 2, and a second control means 19 for controlling the focusing operation of the photographing optical system and the finder optical system.
(That is, the control means of the motor M2) is represented by a block surrounded by a two-dot chain line in FIG.

FIG. 3 is a flowchart of a control operation executed in the control circuit 1 shown in FIG.

Hereinafter, the operation of the camera of the present invention will be described with reference to FIGS.

When the camera user turns on the power switch (not shown),
The operation of the control circuit 1 becomes possible, and the control circuit 1 enters the START state in the flowchart of FIG. When the camera user shoots at the subject toward the subject and presses the zoom switch 9 or 14 while looking at the viewfinder to determine the composition, the control circuit 1 detects which switch is pressed, The photographing lens is zoomed to the telephoto side or the wide-angle side by rotating the motor M1 forward or backward through the motor drive circuit 2 accordingly.
When the motor M1 is driven, the second group lenses 12 and 13 of the photographing optical system are moved along the optical axis, and at the same time, the second group lens 21 and the third group lens 23 of the finder optical system 20.
Is also moved along the optical axis. At this time, the absolute value of the rotation amount of the motor M1 is detected by the motor rotation amount detection means 4,
The control circuit 1 can detect the focal length (magnification) of the photographing lens based on the position signal generated from the detecting means 4, and changes control conditions such as a shutter at the time of photographing based on the focal length information. The control circuit 1 drives the motor M1 while the switch 9 or 14 is pressed, detects that the switch 9 or 14 has been released, or detects the telephoto end point position or the wide angle The drive of the motor M1 is stopped when any of the end point positions is detected. When the image in the viewfinder matches the image intended by the camera user, the switch 9 or 14 is released, so that the control circuit 1 stops the motor M1.
Of the second group lenses 12 and 13 and the finder optical system 20
The group lens 21 and the third group lens 23 are stopped.

Next, when the camera user presses a shutter release button (not shown), the button is first depressed by a first stroke to turn on the first switch 15 in FIG. 2, and the control circuit 1 responds accordingly. It causes the device 6 to perform a distance measuring operation and causes a photometric device (not shown) to perform a photometric operation. Then, the distance measurement result is fetched from the distance measurement device 6 to calculate a lens movement amount corresponding to the distance measurement result, and the motor M2 is driven via the motor drive circuit 3 based on the calculation result. When the motor M2 is driven, the amount of rotation of the motor M2 is detected by the detection means 5 and fed back to the control circuit 1. Further, the first lens group 11 of the photographing optical system 10 and the first lens group 21 of the finder optical system 20 are connected. By being moved along the optical axis by the motor M2, focus adjustment (focusing) in the photographing optical system and the finder optical system is performed simultaneously. When the output signal of the rotation amount detecting means 5 coincides with the lens movement amount calculated by the control circuit 1, the control circuit 1 outputs the motor M2.
Is stopped, and the focusing in the photographing optical system 10 and the finder optical system 20 is ended at the same time. Thereafter, the control circuit 1 checks the ON state of the first switch 15, and if the switch 15 is not ON, returns to its own initial state.

On the other hand, if the first switch 15 has been turned on after the focusing of the photographing optical system and the viewfinder optical system has been completed, the control circuit 1 checks the turned-on state of the second switch 16 and turns on the second switch 16. If not, the camera waits in a state after completion of focusing. Thereafter, the camera user further presses the shutter release button to operate the second switch.
When the shutter 16 is turned on, the control circuit 1 operates the mechanism control circuit 17 to operate the shutter mechanism and the like to perform exposure, and the photographing ends.

In the above-described embodiment, the motor rotation amount detection unit 5 is used as the detection unit of the movement amount of the focusing lens.
When a stepping motor is used as the motor M2, the detection means 5 is unnecessary.

[Effects of the Invention] As described above, according to the present invention, the focusing lens of both the photographing and finder optical systems are driven by a common drive source, and the zoom lens of both optical systems is also common. Since the image is driven by the drive source, even if the magnification is high, the appearance of the image in the viewfinder (degree of focus) and the appearance of the image in the photographing optical system can be made to coincide with each other. Can be achieved with a simple configuration while minimizing the increase.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a structure of an optical system and a driving structure of the optical system in the camera of the present invention, FIG. 2 is a schematic diagram showing a part of an electric configuration in the camera of the present invention, and FIG. Second
3 is a flowchart of a control operation executed by the control circuit 1 shown in FIG. DESCRIPTION OF SYMBOLS 1 ... Control circuit 2 and 3 ... Motor drive circuit 4 and 5 ... Rotation amount detecting means 6 ... Distance measuring device, 9 and 14 ... Switch 15 ... Release first switch 16 ... Release second switch 17 ... Various mechanism control circuits, 18... First control means 19... Second control means 10... Photographing optical system 11... First group lens 12... Second group lens 13. 20: finder optical system 21: first group lens, 22: second group lens 23: third group lens

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G02B 7/10 G03B 13/12 G03B 5/00

Claims (1)

(57) [Claims] 1. A variable focal length photographing optical system having a zoom lens and a focusing lens, a finder interlocking with the zoom lens, and a finder interlocking with the focusing lens. A variable focal length finder optical system having a focusing lens, a first drive source for driving the zoom lens of the photographic optical system and the finder zoom lens, and focusing of the photographic optical system A second drive source for driving the zoom lens and the finder focusing lens, a zoom operation member for performing a zoom operation, and controlling the driving of the first drive source in accordance with the operation of the operation member A first control means for performing the operation, a focusing signal generating means for generating an output signal corresponding to the subject distance, and calculating a moving amount or a moving position of the focusing lens according to the output signal of the focusing signal generating means. And the second drive based on the operation result. Camera, characterized in that it comprises a second control means for controlling the driving source, a.