JPH0578811B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Field of Application> The present invention relates to a photographic lens moving device for a camera in which a zoom finder and a photographic lens whose focus can be switched are linked. <Prior Art> Cameras with zoom lenses and cameras in which the magnification of the photographic lens can be switched are generally known. If this type of camera is a single-lens reflex camera, there is no problem because even if the magnification of the photographing lens changes, the magnification of the viewfinder changes at the same time, but there are cameras in which the photographic lens system and the viewfinder system are completely independent, so-called mid-range cameras. In this case, when the magnification of the photographic lens is changed, the magnification of the viewfinder must also be changed accordingly. For this reason, in conventional cameras in which the magnification of the photographic lens can be switched, when the magnification of the photographic lens is switched, the magnification of the viewfinder can be integrally changed in conjunction with the switching operation. Therefore, when you change the magnification of the viewfinder to determine the composition, the magnification of the photographic lens changes each time. I had to switch the camera to the stowed state. This makes the operation extremely troublesome, and there is also the problem of power loss when switching the magnification of the photographic lens using a motor or the like. <Object of the Invention> The present invention has been made in view of the above-mentioned circumstances, and includes a photographing lens that can freely change the magnification of an image, a viewfinder that can change the magnification of an image, an operating means that can change the magnification of the image of the viewfinder, and By comprising a detection means for detecting the magnification state of the viewfinder, and a drive means for driving the photographing lens according to a detection signal from the detection means through a release operation, the magnification of the viewfinder can be adjusted after the magnification setting operation of the viewfinder is performed. It is an object of the present invention to provide a photographing lens moving device for a camera, which determines the magnification of the image of the photographing lens according to the above. <Example> An example of the present invention will be described below with reference to the drawings. Figure 1 schematically shows the movement of the photographic lens. 1 is a convex lens unit, 2 is a shutter blade that also serves as an aperture, 3 is a concave lens unit, and 4 is a photographic screen. The image drawn at the top of the screen shows the lens in the WIDE state. The image shows the focus at ∞, and the bottom is
The optical axis of each lens unit 1 and 3 for each rotation angle of the zoom ring, with the arrows C to H shown in the middle drawn on the right side, when the lens is focused at its closest point in the TELE state. It represents the upper position. That is, arrows C to H are graphs showing the movement progress (trajectory) of each lens group when the horizontal axis is the amount of movement of the lens and the vertical axis is the amount of rotation of the drive ring. In this example, the concave lens unit 3 moves in a complicated manner, but as will be described later, this can actually be achieved with a very simple configuration. First, when the zoom ring is rotated 30 degrees from the WIDE and ∞ position shown in the figure above, convex lens unit 1, shutter 2, and concave lens unit 3 move together as shown in the figure. Therefore, there is no change in the magnification of the photographic lens system between arrow D, and the focus is adjusted in the WIDE state by rotating the zoom ring.
The closest distance is at 30°. If the photographer wants to increase the magnification a little more, he or she can stop the zoom ring at a position between 90° and 135°. When the zoom ring rotates 90 degrees, the lens will be in focus at ∞ in its normal state (intermediate magnification between TELE and WIDE). Furthermore, when the zoom ring is rotated, the entire lens system extends from 90° to 135°, just as in WIDE, and focus can be adjusted by simply rotating the zoom ring in NOM. In the same way when using TELE, rotating the zoom ring 180 degrees will bring it to the ∞ position of TELE, and rotating it further will bring the lens to a position where it can focus on short distances in TELE mode. With this configuration, both magnification and focus can be adjusted by simply rotating a single zoom ring. Figure 2 is a lens configuration diagram of a camera whose focal length can be changed from 35mm to 70mm.
It has seven focal lengths that can be switched between 70 mm. The configuration is the same as in Figure 1, so I will omit it and only explain the operation.The diagram above is when the lens system is 35mm, and the zoom ring has already been rotated 60°, and the zoom ring 0° storage position is at the front The convex unit forms a recessed area. zoom ring
At 60°, it is simply a 35mm ∞ position, and if you turn the zoom ring further from there, it will move as if the entire zoom ring is being extended, and depending on the amount of rotation of the zoom ring.
Up to the 100° position is used for focus adjustment. In this way, the range from the solid line to the dotted line where each focal length is written is the range used for focus adjustment from ∞ to close range. The difference between FIG. 2 and the principle diagram of FIG. 1 is that the convex lens unit also moves intermittently and that the number of switching points is increased by increasing the rotation angle of the zoom ring. Note that it is also easy to adjust the focus by moving only the front group or the rear group without moving the entire lens. Here, Figures 3a and 3b specifically show Figure 2, 1 and 3 are the convex lens and concave lens unit shown in Figure 2, 1a is the convex lens frame, 1
1c is a notch provided in the frame, and 1c is a part that fits into a straight groove 5b of a fixed frame 5, which will be described later, and is a zoom ring 6.
3a is a concave lens frame, 3b is a protrusion of the frame 3a, and 3c is a pin that also fits into a straight groove 5b of the fixed frame 5 and a lead cam groove 6c of the zoom ring 6. . These cam grooves 6b, 6c form the loci of the lens units 1, 2 as shown by the arrows in FIG. Further, the outer circumferences of the lens frames 1a and 3a are slidably fitted into the inner circumferences of a fixed frame 5, which will be described later. Reference numeral 5 denotes a fixed frame, the inner peripheral portion of which is the aforementioned lens frame 1a,
3a, and the outer peripheral part 5a is fitted with the inner diameter part 6a of a zoom ring 6, which will be described later.A straight groove 5b is cut in the optical axis, and the above-mentioned pin 1c and 3c is fitted. In this example, one groove 5a has two pins 1c,
3c is fitted, but these may be fitted into separate grooves. 6 is a zoom ring whose inner diameter 6a is the aforementioned fixed frame 5
It is fitted onto the outer circumferential part of the lens unit and rotatably supported, has a lead cam groove 6b for the convex lens unit 1 and a lead cam groove 6c for the concave lens unit 3, has a contact piece or terminal 6d for a known encoder, and has a gear part 6e. Therefore, it meshes with gear 7. The gear 7 is rotatably supported by a shaft 7a, and the gear portion 7
b is engaged with the gear portion 6e of the zoom ring 6 described above, and at the same time is interlocked with the motor 8 through a known reduction gear train. 9 is a pulse plate having a donut-shaped disc-shaped surface with a pattern formed thereon; 10 is a pulse detection circuit 10; 11 is a motor control circuit, which is an energizing circuit for forward rotation of the motor according to the output of the comparator 12a;
The output of the comparator 12b is configured to form a reverse energization circuit. Reference numeral 13 denotes a calculation circuit for rotating the zoom ring, which performs calculations as shown in Table 1 based on signals from the subject distance detection circuit 14 and the zooming signal processing circuit 15, and determines when the photographer presses the first stroke of the release button. A signal outputted from the logic control circuit 16 causes the motor forward rotation circuit of the motor control circuit 11 to be ready for operation. The logic control 16 also puts the motor reversal circuit into a ready state when the release button is cut off.

【table】

Claims (1)

[Scope of Claims] 1. A photographic lens that can freely change the magnification of an image, a viewfinder that can change the magnification of an image, an operation means that changes the magnification of the image of the viewfinder, and a detection means that detects the magnification state of the viewfinder. and a drive means for driving the photographing lens according to the detection signal of the detection means through a release operation, so that after setting the magnification of the viewfinder, the image of the photographic lens is adjusted according to the magnification of the viewfinder. A photographic lens moving device for a camera, characterized by determining magnification. 2. A photographic lens that can freely change the magnification of an image, a viewfinder that can freely change the magnification of an image, a first detection means that detects the magnification state of the photographic lens, and a second detection means that detects the magnification state of the viewfinder. a comparison means for comparing a detection signal of the first detection means and a detection signal of the second detection means, and a drive means for driving the photographic lens according to an output signal of the comparison means. The photographing lens moving device for a camera is characterized in that, after setting the magnification of the viewfinder, the magnification of the image of the photographic lens is determined in accordance with the magnification of the viewfinder.