JP4629275B2 - camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a camera including a zoom lens including a plurality of lens groups.
[0002]
[Prior art]
Conventionally, a camera equipped with a lens shutter type zoom lens has been widely used. In such a camera, focus adjustment is performed by changing the relative distance between the lenses built in the zoom lens at a plurality of zoom stages (a plurality of step-by-step zoom magnifications) determined in advance. Yes. For example, in a so-called two-group zoom lens, focus adjustment is performed by changing the relative distance between the front lens group and the rear lens group in a plurality of stepwise zoom stages (zoom magnifications). Focus adjustment performed by a camera equipped with the two-group zoom lens will be described with reference to FIGS.
[0003]
FIG. 1 is a diagram showing the movement of the front group and rear group lenses of a camera that performs focus adjustment by moving only the front group lens forward in the optical axis direction in a plurality of zoom stages determined in steps. is there.
[0004]
FIG. 1 shows a horizontal axis representing a rotation angle of a rotating member for rotating a lens barrel containing a front lens group and a rear lens group in the optical axis direction, and a vertical axis representing a distance to the film surface. Yes. As the lens barrel is extended in the optical axis direction, the front group lens and the rear group lens built in the lens barrel also move in the optical axis direction.
[0005]
In FIG. 1, the change in the distance of the front lens group relative to the film surface with the extension of the lens barrel in the optical axis direction is indicated by a solid line A, and the change in the distance of the rear lens group relative to the film surface is shown in FIG. This is indicated by the solid line B. In this camera, as the lens barrel is extended in the optical axis direction, the front lens group and the rear lens group move on the solid line A and the solid line B, respectively, so that the subject is in focus at infinity. Is set to
[0006]
Further, in FIG. 1, a change in the distance of the shutter blades that also serve as the diaphragm blades with respect to the film surface with the extension of the lens barrel in the optical axis direction is indicated by a solid line C. The shutter blades are located between the front lens group and the rear lens group. Therefore, a solid line C representing a change in the distance of the shutter blades relative to the film surface is shown between the solid line A and the solid line B. ing. The left side of FIG. 1 is the wide-angle (WIDE) side, the right side of FIG. 1 is the telephoto (TELE) side, and the solid line A representing the change in the distance of the front group lens with respect to the film surface is from the middle left to the top right of the figure. A solid line B, which is indicated by an extending straight line and represents a change in the distance of the rear lens group relative to the film surface, is indicated by a curve from the lower left of the figure to the upper right of the figure. The solid line C is indicated by a straight line parallel to the solid line A. The distance between the front group lens and the rear group lens is wide on the wide angle side and narrow on the telephoto side.
[0007]
In addition, FIG. 1 also shows a single two-dot chain line D extending from the middle left of the figure to the upper right of the figure. In this camera, when the front lens group and the rear lens group move on the two-dot chain line D and the solid line B as the lens barrel is extended in the optical axis direction, the focus is set to match the closest subject. ing. The two-dot chain line D is a straight line parallel to the solid line A, which is a straight line, and is shown above the solid line A.
[0008]
Here, FIG. 1 shows a part of rotation angles (Z1 to Z5) determined in a stepwise manner among continuous rotation angles of a rotating member that is rotated when the lens barrel is extended in the optical axis direction. ) In each case, a circle mark indicating the distance of the front lens group to the film surface is shown on a solid line A, and an arrow E is drawn from the circle mark to a two-dot chain line D. These arrows E indicate a subject at an intermediate distance in focus at an infinite distance at each of some rotation angles (Z1 to Z5) of the rotation angles determined stepwise, that is, at each zoom stage. It shows the change in the distance of the front lens group relative to the film surface until it is adjusted to the closest subject. That is, by rotating the rotation member of the lens barrel by any one of rotation angles (Z1 to Z5, etc.) determined stepwise according to the zoom magnification desired by the photographer, the lens is obtained. When the lens barrel is extended in the direction of the optical axis, at this point, the focus is in a state of being suitable for a subject at infinity. Thereafter, distance measurement is performed on the subject desired by the photographer, and the amount of movement of the front group lens forward in the optical axis direction (upward in FIG. 1) is determined according to the distance to the subject. By moving the front lens group forward in the optical axis direction, it is possible to adjust the focus from a subject at infinity to the closest subject at each zoom magnification determined stepwise. In a camera in which such focus adjustment is performed, the relative distance between the front lens group and the shutter blade that also functions as a diaphragm blade changes in the focus adjustment.
[0009]
FIG. 2 shows that the lens barrel is extended forward in the optical axis direction and the relative distance between the front group lens and the rear group lens incorporated in the lens barrel is changed at a plurality of stepwise zoom stages. It is a figure which shows the motion of the front group of a camera in which focus adjustment is performed, and a rear group lens.
[0010]
FIG. 2 also shows a horizontal axis representing the rotation angle of the rotating member rotated to extend the lens barrel, and a vertical axis representing the distance to the film surface, and a lens incorporating a front group lens and a rear group lens. A change in the distance of the front lens group relative to the film surface as the lens barrel extends in the optical axis direction is indicated by a solid line F, and a change in the distance of the rear lens group relative to the film surface is indicated by a broken line G ing. FIG. 2 also shows a dotted line I extending from the lower left of the figure to the upper right of the figure. In this camera, as the rotating member of the lens barrel rotates, the front group lens and the rear group lens are When moving on the solid line F and the dotted line I, respectively, the focus is set to be suitable for a subject at infinity. As shown in FIG. 2, this dotted line I and a polygonal solid line G representing a change in the distance of the rear lens group are part of rotation angles (Z11 to Z15) determined in a stepwise manner. Since they intersect each other, in this camera, the focus is set at a part of rotation angles (Z11 to Z15) of the stepwise determined rotation angles, that is, at the stepwise determined zoom steps. It is set to fit subjects at infinity. As in FIG. 1, the left side of FIG. 2 is the wide angle (WIDE) side, the right side of FIG. 2 is the telephoto (TELE) side, and the solid line F representing the change in the distance of the front lens group relative to the film surface is A solid line G, which is indicated by a straight line extending from the middle left to the upper right of the figure and representing a change in the distance of the rear group lens, is indicated by a broken line from the lower left of the figure to the upper right of the figure. The distance between the front lens group and the rear lens group is wide on the wide angle side and narrow on the telephoto side. The change in the distance from the film surface of the shutter blade also serving as a diaphragm blade, which is located between the front lens group and the rear lens group, is represented by a solid line H. This solid line H is a straight line parallel to the solid line F. It is shown.
[0011]
Further, in FIG. 2, a circle mark representing the distance of the rear group lens from the film surface at each of some rotation angles (Z11 to Z15) determined in a stepwise manner is shown on the broken line-like solid line G. An arrow J is drawn along the broken line-like solid line D from each of these circles. These arrows J indicate the change in the distance of the rear lens group from the film surface in accordance with the focusing from infinity to the closest distance at each of some rotation angles (Z11 to Z15) determined in a stepwise manner. Is shown. In other words, when the rotation member of the lens barrel further rotates from any one of the rotation angles (Z11 to Z15) of the rotation angles determined stepwise, that is, from a predetermined zoom stage, Focus adjustment is performed from the subject to the closest subject. In a camera in which such focus adjustment is performed, the relative distance between the front lens group and the shutter blade that also functions as a diaphragm blade is unchanged in the focus adjustment.
[0012]
Here, in the focus adjustment described with reference to FIG. 1, the relative distance between the front lens group and the shutter blades changes, so that the peripheral light amount is insufficient for the subject at the wide-angle side or the closest position, and the stable adjustment is achieved. On the other hand, it is difficult to ensure optical performance, but since only the front lens group is moved, a quick focusing operation can be realized.
[0013]
On the other hand, in the focus adjustment described with reference to FIG. 2, since the relative distance between the front lens group and the shutter blade is constant, it is easy to ensure stable optical performance even for a subject at a close position on the wide angle side. On the other hand, since the entire lens barrel is moved, it is difficult to realize a quick focusing operation.
[0014]
[Problems to be solved by the invention]
However, the focus adjustment performed by the camera needs to satisfy both contradictory conditions in the above-mentioned example of ensuring stable optical performance and realizing a quick focusing operation.
[0015]
This also applies to a camera having a zoom lens incorporating three or more groups of lenses.
[0016]
SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a camera equipped with a zoom lens that performs focus adjustment that ensures both stable optical performance and quick focusing operation.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, the camera of the present invention comprises:
A first lens group that moves relative to the stop when the focal length is changed, and a second lens group that moves while changing the relative distance between the first lens group when the focal length is changed; In a camera equipped with a zoom lens including
A first focus adjustment mechanism that performs focus adjustment by moving all or a part of the lenses of the first lens group while the second lens group and the aperture position are stationary;
A second focus for adjusting the focus by moving the first lens group so that the relative distance between the first lens group and the stop remains unchanged and moving the second lens group while changing the relative distance from the first lens group. And an adjusting mechanism.
[0018]
In order to realize a quick focusing operation, the camera of the present invention stops at least one lens group and the stop position, and the whole or a part of at least one lens group whose relative distance from the stop does not change when the focal length is changed. In order to ensure stable optical performance for the first focus adjustment mechanism that performs focus adjustment by moving the lens, and a subject on the wide-angle side or the closest position, the relative distance between the aperture is unchanged when the focal length is changed. At least one lens group and a second focus adjustment mechanism that performs focus adjustment with the relative distance from the aperture unchanged. Therefore, according to the camera of the present invention, it is difficult to secure stable optical performance by the focus adjustment by the first focus adjustment mechanism, the second focus is applied to the subject on the wide angle side or the subject on the close side. By performing focus adjustment by the adjustment mechanism, stable optical performance is ensured. For subjects other than the wide-angle side or subjects other than the closest side, focus adjustment by the first focus adjustment mechanism is performed. It is possible to realize a quick focusing operation, which is difficult with the focus adjustment by the second focus adjustment mechanism. In this way, it is possible to achieve both a stable optical performance and a quick focusing operation in total.
[0019]
Here, the zoom lens provided in the camera of the present invention is a zoom lens composed of two groups of lenses, a front group and a rear group, with a diaphragm interposed therebetween,
The first focus adjustment mechanism performs focus adjustment by moving the entire front group while keeping the rear group and the stop position stationary.
The second focus adjustment mechanism may perform focus adjustment by moving the front group so that the relative distance from the diaphragm remains unchanged and moving the rear group while changing the relative distance from the front group. Good.
[0020]
In this way, in a camera having a zoom lens composed of two groups of lenses, the front group and the rear group, with the stop interposed therebetween, two kinds of focus adjustments by the first focus adjustment mechanism and the second focus adjustment mechanism. If the camera is equipped with three or more zoom lenses, the effect is more remarkable than using these two types of focus adjustment.
[0021]
In the camera of the present invention, when the focal length of the zoom lens is adjusted to the telephoto side and the wide-angle side with respect to a predetermined focal length, the first focus adjustment mechanism and the second focus are respectively provided. It is also a preferred embodiment that a focus adjustment unit that performs focus adjustment using an adjustment mechanism is provided.
[0022]
The camera of the present invention performs focus adjustment by the first focus adjustment mechanism capable of realizing a quick focusing operation on the telephoto side of the predetermined focal length, rather than ensuring stable optical performance, and is more than the predetermined focal length. On the wide-angle side, focus adjustment is performed by the second focus adjustment mechanism that can ensure stable optical performance rather than realizing quick focusing operation. Therefore, according to the camera of the present invention, stable optical performance and quick focusing can be achieved. It is possible to carry out focus adjustment that achieves a total balance between the realization of the focal movement.
[0023]
Alternatively, the camera of the present invention has a focus using the first focus adjustment mechanism and the second focus adjustment mechanism, respectively, when the subject is beyond a predetermined distance and closer than the predetermined distance. It is also a preferred embodiment that a focus adjustment unit that performs adjustment is provided.
[0024]
In the camera of the present invention, it is difficult to ensure stable optical performance. For a subject closer to a predetermined distance, focus adjustment is performed by the second focus adjustment mechanism, and stable optical performance is easily ensured. For a subject that is more than a predetermined distance, focus adjustment is performed by the first focus adjustment mechanism with an emphasis on realizing a quick focusing operation. For this reason, according to the camera of the present invention, it is possible to perform focus adjustment that totally balances securing of stable optical performance and realization of quick focusing operation.
[0025]
Further, in the camera of the present invention, the focus adjustment by the first focus adjustment mechanism out of the first focus adjustment mechanism and the second focus adjustment mechanism as the focal length of the zoom lens is closer to the telephoto side. And the second focus of the first focus adjustment mechanism and the second focus distance adjustment mechanism as the focal length of the zoom lens is on the wide-angle side. A focus adjustment unit that performs focus adjustment with a higher contribution ratio to the focus adjustment by the adjustment mechanism may be provided.
[0026]
The camera of the present invention mainly performs focus adjustment by the second focus adjustment mechanism, which focuses on ensuring stable optical performance rather than focus adjustment by the first focus adjustment mechanism, as it is at the wide angle side. The focus adjustment by the first focus adjustment mechanism that focuses on the realization of a quick focusing operation is mainly performed as compared with the focus adjustment by the second focus adjustment mechanism. For example, when the zoom magnification is on the telephoto side, focus adjustment by the second focus adjustment mechanism is performed only when the subject is in the vicinity of the closest distance, and when the subject is at the distance from the closest distance, the first focus adjustment mechanism is used. Adjust the focus. When the zoom magnification is on the wide-angle side, focus adjustment is performed by the first focus adjustment mechanism only when the subject is near infinity, and when the subject is closer to infinity, the second focus is all set. Adjust the focus using the adjustment mechanism. By doing so, it is possible to perform focus adjustment that achieves both stable optical performance and quick focusing operation.
[0027]
Further, in the camera of the present invention, as the subject is farther away, the contribution ratio to the focus adjustment by the first focus adjustment mechanism of the first focus adjustment mechanism and the second focus adjustment mechanism is increased. While performing the increased focus adjustment, the closer the subject is to the closer side, the higher the contribution ratio to the focus adjustment by the second focus adjustment mechanism of the first focus adjustment mechanism and the second focal length adjustment mechanism. It may be provided with a focus adjustment unit for performing an increased focus adjustment.
[0028]
The camera of the present invention realizes a quick focusing operation by increasing the rate of focus adjustment by the first focus adjustment mechanism as the subject is at infinity, rather than the focus adjustment by the second focus adjustment mechanism. Emphasis is placed on focusing on ensuring optical performance by increasing the proportion of focus adjustment by the second focus adjustment mechanism rather than focus adjustment by the first focus adjustment mechanism as the subject is closer. Make adjustments. For example, when the subject is between the closest and infinity, the focus adjustment is divided in half by the focus adjustment by the first focus adjustment mechanism and the focus adjustment by the second focus adjustment mechanism. Is close to the object, the ratio of focus adjustment by the first focus adjustment mechanism is reduced and the ratio of focus adjustment by the second focus adjustment mechanism is reduced compared to the case where the subject is between the closest and infinity. When the increased focus adjustment is performed and the subject is on the infinity side, the ratio of the focus adjustment by the first focus adjustment mechanism is increased as compared with the case where the subject is between the closest distance and the infinity, and the second The focus adjustment is performed by reducing the focus adjustment ratio by the focus adjustment mechanism. Even in this way, it is possible to perform focus adjustment that achieves both stable optical performance and quick focusing operation.
[0029]
Furthermore, in the camera of the present invention, as the focal length of the zoom lens is on the telephoto side and the subject is on the far side, the first of the first focus adjustment mechanism and the second focus adjustment mechanism described above. The first focus adjustment mechanism performs focus adjustment with a higher contribution ratio to the focus adjustment by the first focus adjustment mechanism, and the closer the focal length of the zoom lens is to the wide-angle side and the closer the subject is to the first focus adjustment mechanism. And a focus adjustment unit that performs focus adjustment with a higher contribution ratio to the focus adjustment by the second focus adjustment mechanism of the second focal length adjustment mechanisms.
[0030]
The camera of the present invention is quicker by increasing the rate of focus adjustment by the first focus adjustment mechanism than the focus adjustment by the second focus adjustment mechanism, as the object is at the telephoto side and the infinity side. Emphasis is placed on the realization of the focusing operation, and the closer the subject is to the wide-angle side and the closer the subject is, the more the focus adjustment by the second focus adjustment mechanism is increased than the focus adjustment by the first focus adjustment mechanism. Therefore, focus adjustment is performed with emphasis on ensuring stable optical performance. For example, when the subject is at a predetermined position, the focus adjustment ratio by the first focus adjustment mechanism is set higher on the telephoto side than the focus adjustment by the second focus adjustment mechanism, and the first angle is set on the wide angle side. The ratio of the focus adjustment by the second focus adjustment mechanism is higher than the focus adjustment by the focus adjustment mechanism, and at a predetermined zoom magnification, the first focus adjustment by the second focus adjustment mechanism is performed on the far side than the focus adjustment by the second focus adjustment mechanism. The ratio of focus adjustment by the focus adjustment mechanism is increased, and the focus adjustment ratio by the second focus adjustment mechanism is made higher than the focus adjustment by the first focus adjustment mechanism on the close side. By changing the focus adjustment ratio of the first focus adjustment mechanism and the second focus adjustment mechanism between the telephoto side and the wide angle side as described above, it is possible to secure stable optical performance. Quick match It is possible to achieve both the realization of the operation in good balance.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0032]
3 and 4 are external perspective views of the first embodiment of the camera of the present invention.
[0033]
3 shows the retracted state of the lens barrel 20 incorporating the zoom lens of the camera 1 of the present embodiment, and FIG. 4 shows the extended state of the lens barrel 20 of the camera 1. .
[0034]
The lens barrel 20 of the camera 1 shown in FIGS. 3 and 4 incorporates a zoom lens composed of two groups, a front group and a rear group. The front group and rear group lenses are arranged in the optical axis direction. Zoom and focus adjustments are performed by moving.
[0035]
A flash light emission window 12, a finder objective window 13, an AF light projection window 14a, an AF light reception window 14b, and an AE light reception window 15 are disposed on the upper front portion of the camera 1 shown in FIGS. A shutter button 16 is disposed on the upper surface of the camera 1.
[0036]
A zoom operation switch is disposed on the rear surface of the camera 1 (not shown). When one of the zoom operation switches is pressed, the lens barrel 20 is extended and the other zoom operation switch is pressed while the button is kept pressed. And the question that keeps pushing, the lens barrel 20 retracts.
[0037]
5 and 6 are sectional views of the lens barrel and the lens barrel driving mechanism of the camera shown in FIGS.
[0038]
FIG. 5 shows a cross section of the lens barrel 20 in the wide angle (WIDE) end state, and FIG. 6 shows a cross section of the lens barrel 20 in the telephoto (TELE) end state. The lens barrel 20 of the camera 1 shifts from the retracted state shown in FIG. 3 to the wide-angle end state shown in FIG. 5 when a power switch described later is turned on, and the power switch is turned off. The retracted state returns from the state extended beyond the wide-angle end state.
[0039]
5 and FIG. 6, a flat gear 120 that applies a rotational driving force to the lens barrel 20, a reduction gear system 110 that transmits the rotational driving force to the flat gear 120, and a pinion 100 that transmits the driving force to the reduction gear system 110 are shown. The provided lens barrel driving motor 10, the photo sensor 500 for detecting the rotation amount of the lens barrel driving motor 10, the contact brush 700 attached to the key plate 25 to be described later, and the encoder substrate 810 (see FIG. 9) is also shown, such as a bag portion 21e of the fixed cylinder 21 and the like. In addition, this bag part 21e is provided in the fixed cylinder 21 mentioned later.
[0040]
The lens barrel 20 is fitted into a fixed barrel 21 fixed to a holding member 90 provided inside the camera body, a first barrel 22 fitted inside the fixed barrel 21, and fitted inside the first barrel 22. The straight guide tube 23, the second lens barrel 24 fitted between the first lens barrel 22 and the straight guide tube 23, and the key plate fixed to the rear end surface of the straight guide tube 23 with screws (not shown). 25 or the like.
[0041]
The lens barrel 20 includes a rear group lens unit 30 including a rear group lens 300 and a rear group lens holding frame 310 that holds the rear group lens 300, a shutter unit 50 that also serves as a diaphragm blade, and a shutter unit. A sector actuator 600 for driving 50 is provided.
[0042]
Further, a front lens group guide mechanism is also provided inside the lens barrel 20, and the front lens group guide mechanism includes a front lens group 400 and a front lens group holding cylinder 410 that holds the front lens group 400. The front group lens unit 40, the front group lens drive motor 420 for moving the front group lens unit 40 in the optical axis direction, the drive gear 430 provided in the front group lens drive motor 420, and the outer peripheral surface mesh with the drive gear 430. The inner peripheral surface includes a rotating cylinder 440 that is screwed into the front group lens holding cylinder 410, a fixed cylinder 450 that serves as a detent for the front group lens holding cylinder 410, and the like. Next, these operations will be described.
[0043]
FIG. 7 is an exploded perspective view of the lens barrel.
[0044]
The fixed cylinder 21 shown in FIG. 7 has a helicoid screw 21 a formed on the inner peripheral surface thereof, and the helicoid screw 21 a is screwed with a helicoid screw 22 a formed on the outer peripheral surface of the first lens barrel 22. Further, the fixed cylinder 21 is provided with a longitudinal opening 21b that is an opening penetrating the inner wall and the outer wall, and key grooves 21c (three places) extending in the optical axis direction on the inner peripheral surface. Further, the fixed cylinder 21 has a spur gear 120 at a position sandwiching the bag portion 21e, which is a passage in the fixed cylinder 21 of the contact brush 700 attached to the key plate 25, and the vertical opening 21b of the fixed cylinder 21 in the front-rear direction. 21 d is also provided, and the spur gear 120 is attached to the bearing 21 d by a shaft 21 f shown in FIG. 7.
[0045]
The key plate 25 shown in FIG. 7 is a ring-shaped flat plate, and protrusions 25c (three places) for preventing rotation are provided on the outer periphery of the key plate 25.
[0046]
Here, as will be described in detail later, the key plate 25 is screwed to a rectilinear guide tube 23 covered with the first lens barrel 22, and has three protrusions 25 c provided on the key plate 25 and a fixed tube. The straight guide cylinder 23 in which the key groove 21 c of 21 is fitted and the key plate 25 is screwed is fitted in the fixed cylinder 21.
[0047]
The first lens barrel 22 shown in FIG. 7 includes a helicoid screw 22a formed on the outer peripheral surface, a driven gear 22b formed on the rear end of the outer peripheral surface, a cam groove 22c formed on the inner peripheral surface, and also on the inner peripheral surface. It has a formed helicoid screw 22d and a flange 22e formed on the rear opening surface. The helicoid screw 22a and the driven gear 22b coexist. As described above, the helicoid screw 22 a formed on the outer peripheral surface of the first lens barrel 22 is screwed with the helicoid screw 21 a formed on the inner peripheral surface of the fixed cylinder 21.
[0048]
The straight guide tube 23 shown in FIG. 7 includes a first flange 23b that contacts the key plate 25 on the rear opening surface, a second flange 23a provided on the outer peripheral surface in front of the first flange 23b, and an inner wall and an outer wall. There are three linear grooves 23c that pass through and extend in the optical axis direction, and three protrusions 23d that are provided on the outer peripheral surface and extend in the optical axis direction.
[0049]
The rear group lens holding frame 310 incorporating the rear group lens 300 shown in FIG. 7 has detachable cam pins 310 a (three pieces) on the circumference thereof, and these cam pins 310 a are linear grooves of the rectilinear guide tube 23. It arrange | positions in the rectilinear guide pipe | tube 23 so that 23c may be penetrated. Since the rectilinear guide tube 23 is screwed to the key plate 25 with the first lens barrel 22 covered as described above, the rear opening surface of the first lens barrel 22 covered with the rectilinear guide tube 23 The flange 22e is sandwiched between the key plate 25 and the second flange 23a of the rectilinear guide tube 23 so as to be freely rotatable.
[0050]
Further, the cam pin 310 a of the rear lens group holding frame 310 shown in FIG. 7 passes through the linear groove 23 c of the linear guide tube 23 and engages with the cam groove 22 c formed on the inner wall of the first lens barrel 22. .
[0051]
The second lens barrel 24 shown in FIG. 7 has a helicoid screw 24a on the outer peripheral surface, three linear grooves 24b extending in the optical axis direction, and a rear lens unit 30 that is extended forward in the optical axis direction (FIG. 7). 6) has a groove 24c for allowing the cam pin 310a of the rear lens group holding frame 310 to enter. The second lens barrel 24 enters between the outer wall of the rectilinear guide tube 23 and the inner wall of the first lens barrel 22 covered by the rectilinear guide tube 23. Thereby, the helicoid screw 24a on the outer peripheral surface of the second lens barrel 24 is screwed with the helicoid screw 22e on the inner peripheral surface of the first lens barrel 22, and the three linear grooves 24b of the second lens barrel 24 are rectilinear guide cylinders. 23 is slidably fitted to the protrusion 23d on the outer peripheral surface of 23.
[0052]
Here, when the lens barrel driving motor 10 shown in FIG. 5 rotates and the driving force is transmitted to the spur gear 120 via the gear train described above, the driving force is further driven by the driven gear 22b of the first lens barrel 22. To be told. Here, the protrusion 25c of the key plate 25 is fitted in the key groove 21c of the fixed cylinder 21, and the linear guide cylinder 23 and the key plate 25 are fixed with screws. No. 25 is prevented from rotating with respect to the fixed cylinder 21. Therefore, when the driving force is transmitted to the driven gear 22b of the first lens barrel 22 and the first lens barrel 22 rotates, the helicoid screw 22a on the outer peripheral surface of the first lens barrel 22 and the helicoid on the inner peripheral surface of the fixed barrel 21 Since the screw 21a is screwed, the first lens barrel 22 rotates and moves in the optical axis direction. Further, since the key plate 25 and the rectilinear guide tube 23 sandwich the flange 22e of the rear opening surface of the first lens barrel 22 between the second flange 23a of the rectilinear guide tube 23 and the key plate 25, the key plate 25 and the rectilinear guide tube 23 are rotatable. As the first lens barrel 22 rotates and moves in the optical axis direction, it moves linearly in the optical axis direction. At this time, the contact brush 700 attached to the key plate 25 moves while contacting on the encode substrate 810 provided on the bag portion 21e of the fixed cylinder 21.
[0053]
Further, the cam pin 310a of the rear lens group holding frame 310 is prevented from rotating by passing through the linear groove 23d of the rectilinear guide tube 23, and further enters the cam groove 22c of the first lens barrel 22. The rear lens group holding frame 310 also moves linearly in the optical axis direction.
[0054]
In addition, the second lens barrel 24 is prevented from rotating by fitting three linear grooves 24 b extending in the optical axis direction to the protrusions 23 d on the outer peripheral surface of the rectilinear guide tube 23. Therefore, the second lens barrel 24 has a helicoid screw 24 a on the outer peripheral surface of the second lens barrel 24 screwed into a helicoid screw 22 d on the inner peripheral surface of the first lens barrel 22. As the lens rotates and moves in the optical axis direction, it moves directly in the optical axis direction.
[0055]
FIG. 8 is an external perspective view of the guide mechanism for the front lens group.
[0056]
The front group lens holding tube 410 shown in FIG. 8 incorporates the front group lens 400 and has protrusions 410a (three places) at the rear part thereof. Further, the front group lens holding cylinder 410 has a helicoid screw 410b on the outer peripheral surface.
[0057]
The rotating cylinder 440 shown in FIG. 8 has a gear groove 440a that meshes with the drive gear 430 on the outer peripheral surface, and a helicoid screw 440b that engages with the helicoid screw 410b of the front group lens holding cylinder 410 on the inner peripheral surface. The rotating cylinder 440 is screwed onto the front group lens holding cylinder 410 and the helicoid screw 440b of the rotating cylinder 440 is screwed with a helicoid screw 410b provided on the outer peripheral surface of the front group lens holding cylinder 410. Yes. It should be noted that the movement of the rotating cylinder 440 covered at a predetermined position on the front lens group holding cylinder 410 in the optical axis direction is prevented by means not shown.
[0058]
A key groove 450a extending in the optical axis direction is formed on the inner peripheral surface of the fixed cylinder 450 shown in FIG. The fixed tube 450 is fixed to the second lens barrel 24, and a protrusion 410 a provided at the rear portion of the front lens group holding tube 410 is fitted in the key groove 450 a of the fixed tube 450. As a result, the front lens group holding cylinder 410 is prevented from rotating.
[0059]
Here, when the front group lens driving motor 420 shown in FIG. 5 is driven, the rotating cylinder 440 rotates via the driving gear 430, but the front group lens holding cylinder 410 is prevented from rotating by the fixed cylinder 450. The front lens group holding cylinder 410 moves linearly in the optical axis direction.
[0060]
FIG. 9 is a diagram illustrating the movement of the front group and rear group lenses of the camera of the present embodiment in which focus adjustment is performed from infinity to the closest distance at a plurality of zoom stages determined in steps. In FIG. 9, the horizontal axis represents the rotation angle of the first lens barrel 22, the vertical axis represents the distance to the film surface, the left side of the figure represents the wide angle side, and the right side of the figure represents the telephoto side.
[0061]
In FIG. 9, a solid line K representing a change in the distance of the front lens group 400 relative to the film surface as the first lens barrel 22 rotates, a solid line L representing a change in the distance of the rear lens group 300 relative to the film surface, and A dotted line M, which will be described later, is shown. The solid line K is a straight line extending from the middle left of the figure to the upper right of the figure, the solid line L is a broken line only on the left wide angle side, and the portions other than the broken line part are shown by curves from the lower left of the figure to the upper right of the figure Has been. As the first lens barrel 22 rotates, the rear group lens 300 that moves in the curved portion of the solid line L excluding the broken line portion, and the front group lens 400 that moves on the solid line K, In the camera 1 of the present embodiment, the focus is set to infinity. However, even if the rear lens group 300 moves on the dotted line M and the front lens group 400 moves on the solid line K as the first lens barrel 22 rotates, the camera 1 of the present embodiment is in focus at infinity. It is set to suit.
[0062]
FIG. 9 also shows a two-dot chain line N that is located above the solid line K and is parallel to the solid line K. In addition, as the first lens barrel 22 rotates, the rear group lens 300 that moves in the curved portion of the solid line L excluding the broken line portion, and the front group lens 400 that moves on the two-dot chain line N, Therefore, in the camera 1 of the present embodiment, the focus is set closest to the camera.
[0063]
Further, in FIG. 9, among the patterns on the encoder board 810, an arrow R drawn on a broken line portion of a dashed line Q and a solid line L extending upward through the center (P1) of the wide-angle side pattern, stepwise Also shown is a circle indicating the position of the front lens group 400 at each of some of the determined rotation angles (Z22 to Z25), an arrow S extending from the circle to a two-dot chain line N, and a contact brush 700. ing. 9 represents the shape of the cam groove 22c provided on the inner wall of the first lens barrel 22 shown in FIG.
[0064]
Here, as described above, the contact brush 700 is attached to the key plate 25 constituting the lens barrel 20, and the contact brush is rotated by the rotation of the first barrel 22 by the operation of a zoom operation switch (not shown). 700 moves on the encode substrate 810 shown in FIG. 9 as the key plate 25 moves in the optical axis direction. However, the contact brush 700 stops at one of the centers of the plurality of patterns on the encode substrate 810 (P1 to P5 in FIG. 9). Accordingly, in order to move the contact brush 700 stopped at an arbitrary position on the encode substrate 810 to the center of the nearest pattern by the end of the operation of the zoom operation switch, the rotation of the first lens barrel 22 is It continues even after the operation of the zoom operation switch is completed. The center of the pattern on the encode substrate 810 is a lens barrel standby position where the lens barrel 20 stands by for focus adjustment, and a method for detecting this lens barrel standby position will be described later. As described above, when the lens barrel 20 is stopped at the lens barrel standby position in preparation for focus adjustment, the lens barrel 20 waits for the shutter button operation, and the focus is based on the distance value to the subject obtained by the distance measuring function associated with the shutter button operation. Adjustments are made.
[0065]
Hereinafter, focus adjustment in the camera 1 of the present embodiment will be described.
[0066]
As a result of the operation of the zoom operation switch, when the lens barrel standby position is the center (P1) of the pattern on the wide angle side of the encoder board 810, the distance measurement value obtained by the distance measurement by half-pressing the shutter button 16 is used. The focus is adjusted by extending both the front group and rear group lenses. In the camera 1, the first lens barrel 22 is rotated until the rotation angle corresponding to the amount of extension of the lens barrel 20 determined according to the distance measurement value is obtained. Incidentally, when the first lens barrel 22 is rotated from the rotation angle Z20 corresponding to the lens barrel standby position P1 to the rotation angle Z21 which is the nearest rotation angle determined in a stepwise manner, it corresponds to the rotation angle Z21. The subject is in focus at infinity at the zoom magnification set as described above.
[0067]
Thereafter, the shutter is operated so as to obtain an appropriate exposure amount based on the measured subject light amount information, and photographing is performed. When the photographing is finished, the lens barrel 20 is returned to the lens barrel standby position P1, and the next Prepare for shooting.
[0068]
Next, as a result of the operation of the zoom operation switch, when the lens barrel standby position is located at any center (P2 to P5 in FIG. 9) other than the center (P1) of the wide-angle pattern of the encoder board, the shutter Focus adjustment is performed by extending only the front lens group 400 forward in the optical axis direction by the amount of extension calculated based on the distance value obtained by the distance measurement by half-pressing the button 16. Thereafter, the shutter is operated so as to obtain an appropriate exposure amount based on the measured subject light amount information, and photographing is performed. When the photographing is finished, the front lens group 300 is most lighted with respect to the second lens barrel 24. It is returned to the axially rear position (front group lens standby position) to prepare for the next shooting.
[0069]
That is, the focus adjustment performed by the camera 1 of the present embodiment is such that when the current zoom magnification is smaller than the predetermined zoom magnification (wide-angle side), the first lens barrel 21 is rotated to rotate the front group lens. 400 and the rear group lens 300 are fed out simultaneously, and the relative distance between the front group lens 400 and the rear group lens 300 is changed to perform focus adjustment (focus adjustment by the second focus adjustment mechanism in the present invention). When the zoom magnification is larger than the predetermined zoom magnification (on the telephoto side), only the front lens group 400 is extended, and the distance between the front lens group 400 and the rear lens group 300 is changed to adjust the focus (first focus adjustment according to the present invention). Focus adjustment by mechanism). For this reason, when the zoom lens is on the wide angle side, the relative distance between the front lens group 400 and the shutter blade that also serves as a diaphragm is unchanged, so that emphasis is placed on ensuring stable optical performance and the telephoto side. In this case, since only the front lens group 400 is extended, an emphasis is placed on realizing a quick focusing operation. Therefore, in the camera 1 equipped with the zoom lens in which the focus adjustment as described above is performed, it is possible to achieve both a stable optical performance and a quick focusing operation in total.
[0070]
FIG. 10 is a circuit block diagram of the camera of this embodiment.
[0071]
The camera 1 of the present embodiment is provided with a control circuit 51 including a microcomputer, and signals from various sensors and switches are input to the control circuit 51. The control circuit 51 receives these signals. Based on this, each part of the camera is controlled. Hereinafter, various sensors and switches that input signals to the control circuit 51 and various control targets of the control circuit 51 will be described.
[0072]
The zoom operation switch 56 is a switch for changing the zoom magnification between the wide angle (WIDE) side and the telephoto (TELE) side.
[0073]
The encoder 54 includes a contact brush 700 attached to the key plate 25 and an encoder substrate 810 provided on the bag portion 21e of the fixed cylinder 21. When the lens barrel 20 is extended, the contact brush 700 waits for the lens barrel. It is a sensor that detects that one of the positions has been approached.
[0074]
The photosensor 500 generates a pulse for detecting the amount of rotation of the lens barrel drive motor 10 by detecting the transmitted light. As described above, when the encoder barrel detects that the contact brush 700 has approached one of the lens barrel standby positions by the extension of the lens barrel 20, that is, when the contact brush 700 contacts the end of the pattern. The rotation amount of the lens barrel drive motor 10 is monitored by counting the pulses from the photosensor 500. When the amount of rotation of the lens barrel driving motor 10 becomes equal to a preset value, the control circuit 51 stops the lens barrel driving motor 10.
[0075]
The AE sensor 53 is a photometric sensor disposed inside the AE light receiving window 15 shown in FIG. 3, and the photometric value is used for exposure control.
[0076]
The AF sensor 55 is disposed inside the AF window shown in the front view of FIG. 3, and outputs a distance measurement value representing the distance to the subject.
[0077]
The shutter button 16 is a tact switch that is arranged on the upper surface of the camera 1 shown in FIG. Press halfway to perform photometry and distance measurement, and full press to open and close the shutter.
[0078]
The lens barrel drive motor control 59 represents that the lens barrel drive motor 10 shown in FIG. 5 is controlled. By controlling the lens barrel drive motor 10, the rotation of the first lens barrel 22 is controlled, and the lens The feeding amount of the lens barrel 20 is controlled.
[0079]
The front group lens drive motor control 57 represents that the front group lens drive motor 420 shown in FIG. 5 is controlled, and the amount of extension of the front group lens 400 is controlled by controlling the rotation of the front group lens drive motor 420. The The front group lens drive motor 420 is a pulse motor, and the amount of extension of the front group lens 400 is determined by controlling the number of pulses from the front group lens standby position.
[0080]
The flash control 52 represents controlling the flash function.
[0081]
The shutter control 58 sends a control signal to the sector actuator 600 that drives the shutter unit 50 shown in FIG. 5, and controls the opening and closing of the shutter blades that also serve as the diaphragm blades. Description of functions not directly related to the present invention, such as control of a film feeding motor, is omitted.
[0082]
FIG. 11 is a flowchart of a “power on” program that is started when the camera of the present embodiment is turned on.
[0083]
This program is executed in the control circuit 51 shown in FIG. When the power source of the camera 1 is turned on, in step S11, the lens barrel drive motor 10 shown in FIG. 5 is driven in the forward direction, and the rotational driving force transmitted through the gear train described above is not applied to the first lens barrel. The drive gear 22b is rotated forward. Thereby, the lens barrel 20 shifts from the retracted state shown in FIG. 3 to the wide-angle (WIDE) end state shown in FIG. Thereafter, this routine is terminated.
[0084]
FIG. 12 is a flowchart of a “zoom operation” program that is activated when an operation is performed on the zoom operation switch.
[0085]
By operating the zoom operation switch 56 (see FIG. 10), this 'zoom operation' program is started, and in step S21, it is determined whether or not the operation on the zoom operation switch 56 is finished.
[0086]
If it is determined in step S21 that the operation on the zoom operation switch 56 has not ended, step S21 is repeated.
[0087]
If it is determined in step S21 that the operation on the zoom operation switch 56 has been completed, the process proceeds to step S22.
[0088]
In step S22, it is determined whether or not the current zoom magnification is smaller than a predetermined zoom magnification.
[0089]
If it is determined in step S22 that the current zoom magnification is smaller than the predetermined zoom magnification, the process proceeds to step S23.
[0090]
In step S23, a “corresponding flag” indicating that the current zoom magnification is smaller than a predetermined zoom magnification is set. Thereafter, this routine is terminated.
[0091]
If it is determined in step S22 that the current zoom magnification is larger than the predetermined zoom magnification, this routine is also terminated.
[0092]
FIG. 13 is a flowchart of a “shutter button on” program that is activated when the shutter button of the camera is pressed.
[0093]
When the shutter button 16 of the camera 1 is pressed, first, in a half-pressed state, a photometric operation for measuring the brightness of the subject to be photographed is performed in step S31, and the aperture and shutter speed are determined. Thereafter, the process proceeds to step S32.
[0094]
In step S32, distance measurement to the subject is performed. Thereafter, the process proceeds to step S33.
[0095]
In step S33, as described above, it is determined whether or not “corresponding flag” is set in accordance with the zoom operation.
[0096]
In step S33, when it is determined that the “corresponding flag” is set, the process proceeds to step S34.
[0097]
In step S34, since the current zoom magnification is smaller than the predetermined zoom magnification (on the wide-angle side), focus adjustment is performed by extending the lens barrel 20, so that the distance measurement value and the zoom magnification already obtained are obtained. Based on this, the feeding amount of the lens barrel 20 is determined. Thereafter, the process proceeds to step S36.
[0098]
If it is determined in step S33 that the “corresponding flag” is not set, the process proceeds to step S35.
[0099]
In step S35, since the current zoom magnification is larger than the predetermined zoom magnification (on the telephoto side), focus adjustment is performed only by extending the front group lens 400, so that the front group lens is obtained from the distance measurement value already obtained. A feed amount of 400 is determined. Thereafter, the process proceeds to step S36.
[0100]
In step S <b> 36, focus adjustment is performed by extending the lens barrel 20 or extending the front lens group 400. Thereafter, the process proceeds to step S37.
[0101]
In step S37, it is determined whether or not the shutter button 16 is fully pressed.
[0102]
If it is determined in step S37 that the shutter button 16 is fully pressed, the process proceeds to step S39.
[0103]
If it is determined in step S37 that the shutter button 16 is not fully pressed, the process proceeds to step S38.
[0104]
In step S38, it is determined whether or not the shutter button 16 is half pressed.
[0105]
If it is determined in step S38 that the shutter button 16 is not half pressed, this routine is terminated.
[0106]
If it is determined in step S38 that the shutter button is half pressed, the process returns to step S37.
[0107]
In step S39, it is determined whether to perform flash emission based on the light quantity obtained by the photometric operation.
[0108]
If it is determined in step S39 that it is not necessary to perform flash emission, the process proceeds to step S41.
[0109]
In step S41, shooting is performed by opening and closing the shutter. Thereafter, the process proceeds to step S42.
[0110]
If it is determined in step S39 that it is necessary to perform flash emission, the process proceeds to step S40.
[0111]
In step S40, a series of operations of opening the shutter to emit flash and closing the shutter is performed, and then the process proceeds to step S42.
[0112]
In step S42, in preparation for the next shooting, the front lens group driving motor 420 is driven to return the front lens group 400 to the front lens group standby position, and the lens barrel driving motor 10 is driven to move the lens barrel 20 to the front lens group. Return to the lens barrel standby position before focus adjustment. Further, an electric motor (not shown) is driven to wind up the film by one frame, and this routine is finished.
[0113]
FIG. 14 is a flowchart of a power-off program that is activated when an operation to turn off the camera is performed.
[0114]
When an operation to turn off the power of the camera 1 is performed, in step S51, the lens barrel drive motor 10 is driven in the reverse direction, thereby moving the lens barrel 20 to the retracted state shown in FIG. This routine ends. Thereafter, the power supply of the camera 1 is turned off.
[0115]
Next, a second embodiment of the camera of the present invention will be described.
[0116]
Since the external appearance of the camera 2 of the present embodiment is the same as FIG. 3 and FIG. 4, illustration and description are omitted.
[0117]
Further, the lens barrel and the lens barrel driving mechanism provided in the camera 2 are the lenses of the camera 1 of the first embodiment except for the shape of the cam groove and the encoder formed on the inner wall of the first barrel. Since the same type and the same operation as the lens barrel and the lens barrel driving mechanism are performed, illustration and overlapping description are omitted.
[0118]
Hereinafter, the focus adjustment performed in the camera 2 will be described with reference to FIG. Here, for the sake of convenience, the same types as those constituting the camera 1 of the first embodiment are denoted by the same reference numerals as those used in the description of the camera 1.
[0119]
FIG. 15 is a diagram illustrating the movement of the front group and rear group lenses of the camera of the present embodiment in which focus adjustment is performed from infinity to the closest distance at a plurality of stepwise zoom stages. Note that the way of viewing FIG. 15 is the same as that of FIG.
[0120]
FIG. 15 shows the change in the distance of the rear group lens 300 with respect to the film surface, the solid line K2 representing the change in the distance of the front group lens 400 with respect to the film surface, as the first lens barrel 22 of the lens barrel 20 rotates. A solid line L2 is shown. The solid line K2 is a straight line extending from the middle left in the figure to the upper right in the figure, and the solid line L2 is shown in a shape in which curved parts and broken line parts alternate from the lower left in the figure to the upper right in the figure. As the first lens barrel 22 rotates, the rear group lens 300 that moves in the curved portion of the solid line L2 excluding the broken line portion, and the front group lens 400 that moves on the solid line K2, In the camera 2 of the present embodiment, the focus is set to infinity.
[0121]
FIG. 15 also shows an encoder substrate 820, a contact brush 710, a part of the lens barrel standby position (P11 to P15), an arrow R2 drawn on the broken line portion of the solid line L2, and a rotation determined in a stepwise manner. Also shown is a circle indicating the distance of the front lens group 400 to the film surface at each of some rotation angles (Z31 to Z35), and an arrow S2 extending upward from the circle. A solid line L2 representing a change in the distance of the rear lens group 300 with respect to the film surface shown in FIG. 15 indicates the shape of the cam groove 22c provided on the inner wall of the first lens barrel 22 shown in FIG. The description of the operation of the contact brush 710 attached to the key plate 25 of the camera 2 and the encoding substrate 820 is the same as that described in the camera 1 of the first embodiment, and will not be repeated.
[0122]
Hereinafter, focus adjustment in the camera 2 of the present embodiment will be described.
[0123]
As a result of the operation of the zoom operation switch, the subject obtained by the distance measuring operation by half-pressing the shutter button 16 regardless of whether the lens barrel standby position is at the center of the pattern of the encoder board 820 (P11 to P15 in FIG. 15). If the distance measurement value up to is compared with a predetermined value and it is determined that the position of the subject is farther than the position represented by the predetermined value, only the feed amount calculated based on the distance value The focus adjustment is performed by extending only the front lens group 400 forward (upward in FIG. 15) (arrow S2). When it is determined that the position of the subject is closer than the position represented by the predetermined value, the lens barrel 20 is moved forward by the amount of extension calculated based on the distance measurement value and the zoom magnification. The focus is adjusted by moving it upward (arrow R2 in FIG. 15). Thereafter, the shutter is operated so as to obtain an appropriate exposure amount based on the measured subject light amount information, and photographing is performed. When the photographing is completed, the front group lens 400 is returned to the front group lens standby position, or the lens barrel 20 is returned to the lens standby position before the focus adjustment to prepare for the next photographing.
[0124]
In other words, the focus adjustment performed by the camera 2 of the present embodiment is the focus adjustment (first focus adjustment mechanism referred to in the present invention) when only the front lens group 400 is extended when the subject is far from a predetermined distance. When the subject is closer than a predetermined distance, focus adjustment (focus adjustment by the second focus adjustment mechanism according to the present invention) is performed by extending the lens barrel 20. For this reason, an emphasis is placed on ensuring stable optical performance on the side closer to the predetermined distance, and an emphasis is placed on realizing a quick focusing operation on the infinity side than the predetermined distance. Therefore, even in the camera 2 equipped with the zoom lens, in which the focus adjustment as described above is performed, it is possible to ensure both stable optical performance and quick focusing operation in total.
[0125]
Since the circuit block diagram of the camera 2 of the present embodiment is the same as the circuit block diagram of the camera 1 of the first embodiment shown in FIG. 10, illustration and description thereof are omitted.
[0126]
The flowcharts of the “power on” program that is activated when the power is turned on and the “power off” program that is activated when the power is turned off are activated in the camera 1 of the first embodiment. Since the operation is the same as that described above, illustration and description are omitted. In the camera 2, a program that is activated by operating the zoom operation switch in the camera 1 is omitted. Hereinafter, a “shutter button on” program started when the shutter button is pressed will be described with reference to FIG.
[0127]
FIG. 16 is a flowchart of a “shutter button on” program that is activated when the shutter button of the camera is pressed.
[0128]
When the shutter button 16 of the camera 2 is pressed, first, in a half-pressed state, a photometric operation for measuring the brightness of the subject to be photographed is performed in step S131, and the aperture and shutter speed are determined. Thereafter, the process proceeds to step S132.
[0129]
In step S132, distance measurement to the subject is performed. Thereafter, the process proceeds to step S133.
[0130]
In step S133, it is determined whether or not the distance measurement value obtained by the distance measurement operation performed in step S132 is a value representing that it is closer to a predetermined position in the object scene.
[0131]
If it is determined in step S133 that the distance measurement value represents close distance, the process proceeds to step S134.
[0132]
In step S134, since the subject is at a position closer to the predetermined position, the focus adjustment is performed by extending the lens barrel 20, so that the lens is determined based on the distance measurement value and the zoom magnification already obtained. The feeding amount of the lens barrel 20 is determined. Thereafter, the process proceeds to step S136.
[0133]
If it is determined in step S33 that the distance measurement value does not indicate that it is close, the process proceeds to step S135.
[0134]
In step S135, since the subject is at a position farther than the predetermined position, the focus adjustment is performed by the extension of only the front group lens 400. Therefore, the extension amount of the front group lens 400 is determined from the distance measurement value already obtained. Is determined. Thereafter, the process proceeds to step S136.
[0135]
The description after step S136 is omitted because it overlaps with the description in FIG.
[0136]
Furthermore, a third embodiment of the camera of the present invention will be described.
[0137]
Since the external appearance of the camera 3 of the present embodiment is the same as FIG. 3 and FIG. 4, illustration and description thereof are omitted.
[0138]
Further, the lens barrel and the lens barrel driving mechanism provided in the camera 3 are the lenses of the camera 1 of the first embodiment except for the shape of the cam groove and the encoder formed on the inner wall of the first barrel. Since the same type and the same operation as the lens barrel and the lens barrel driving mechanism are performed, the illustration and repeated description are omitted.
[0139]
Hereinafter, the focus adjustment performed in the camera 3 will be described with reference to FIG. Here, for the sake of convenience, the same reference numerals as those used in the description of the camera 1 are given to the same types as those constituting the camera 1 of the first embodiment.
[0140]
FIG. 17 is a diagram showing the movement of the front group and rear group lenses of the camera of the present embodiment in which focus adjustment is performed from infinity to the closest distance at a plurality of stepwise determined zoom stages. is there. The way of viewing FIG. 17 is the same as that of FIG.
In FIG. 17, the solid line K3 representing the change in the distance of the front group lens 400 with respect to the film surface as the first lens barrel 22 of the lens barrel 20 rotates, and the change in the distance of the rear group lens 300 with respect to the film surface. A solid line L3 is shown, and a discontinuous dotted line M3 is shown. The solid line K3 is a straight line extending from the middle left in the figure to the upper right in the figure, and the solid line L3 is shown in a shape in which curved parts and broken line parts alternate from the lower left in the figure to the upper right in the figure. As the first lens barrel 22 rotates, the rear group lens 300 that moves on the curved line portion excluding the broken line portion of the solid line L3 and the dotted line M3, and the front group that moves on the solid line K3. With the lens 400, the camera 3 of the present embodiment is set to focus at infinity.
[0141]
FIG. 17 also shows the encoder substrate 830, the contact brush 720, a part of the lens barrel standby position (P21 to P25), the arrow R3 drawn on the broken line portion of the solid line L3, and the rotation determined stepwise. Also shown is a circle indicating the distance of the front lens group 400 to the film surface at each of some rotation angles (Z41 to Z45), and an arrow S3 extending upward from the circle. A solid line L3 representing a change in the distance of the rear lens group 300 with respect to the film surface shown in FIG. 17 indicates the shape of the cam groove 22c provided on the inner wall of the first lens barrel 22 shown in FIG. The description of the operation of the contact brush 720 and the encoding substrate 830 attached to the key plate 25 of the camera 3 is the same as that described in the camera 1 of the first embodiment, and will be omitted.
[0142]
Hereinafter, focus adjustment in the camera 3 of the present embodiment will be described.
[0143]
As a result of the operation of the zoom operation switch, when the lens barrel standby position is the center (P21) of the wide-angle pattern of the encoder board 830, based on the distance value obtained by the distance measurement by half-pressing the shutter button 16, Focus adjustment is performed by extending the lens barrel 20. In the camera 3, the first lens barrel 22 is rotated until the rotation angle according to the amount of extension of the lens barrel 20 determined according to the distance measurement value is obtained. Incidentally, when the first lens barrel 22 is rotated from the rotation angle Z40 corresponding to the lens barrel standby position P21 to the rotation angle Z41 which is the nearest rotation angle determined in a stepwise manner, it corresponds to the rotation angle Z41. The subject is in focus at infinity at the zoom magnification set as described above.
[0144]
Thereafter, the shutter is operated so as to obtain an appropriate exposure amount based on the measured subject light amount information, and photographing is performed. When photographing is completed, the lens barrel 20 is returned to the lens barrel standby position P21, and the next Prepare for shooting.
[0145]
Next, when the lens barrel standby position is located at the center (P22) of the wide-angle pattern of the encoder board as a result of the operation of the zoom operation switch, the distance value obtained by the distance measurement by half-pressing the shutter button 16 Based on the above, focus adjustment is performed by both the extension of the front lens group 400 and the extension of the lens barrel 20. First, the predetermined position represented by the predetermined value a set corresponding to the rotation angle Z42 is compared with the position of the subject represented by the current distance measurement value, and is the subject farther than the predetermined position? It is determined whether or not. When the subject is far from the predetermined position, focus adjustment is performed by extending the front lens group 400 as indicated by an arrow S3 shown in FIG. When the subject is closer than the set distance, focus adjustment is performed by extending the lens barrel 20 as indicated by an arrow R3 shown in FIG.
[0146]
Hereinafter, as a result of the operation of the zoom operation switch, when the lens barrel standby position is located at the center of the pattern further on the telephoto side from the center of the pattern on the wide angle side (P22) of the encoder board, the measurement is performed by half-pressing the shutter button. The distance value obtained by the distance is compared with a predetermined value set corresponding to each rotation angle. The closer to the telephoto side, the predetermined position represented by this predetermined value is closer to the near side. Move on. Thereby, the arrow S3 becomes longer and the arrow R3 becomes shorter as it goes to the telephoto side.
[0147]
Thereafter, the shutter is operated so as to obtain an appropriate exposure amount based on the measured subject light amount information, and photographing is performed. When the photographing is completed, the front group lens 400 is returned to the front group lens standby position, or the lens barrel 20 is returned to the lens standby position before the focus adjustment to prepare for the next photographing.
[0148]
In other words, in the camera 3 of the present embodiment, the first focus adjustment referred to in the present invention is performed when the position of the subject is far from the predetermined position represented by the predetermined value a set for each zoom magnification. The focus adjustment by the mechanism is performed, and if close, the focus adjustment by the second focus adjustment mechanism according to the present invention is performed. For this reason, an emphasis is placed on ensuring stable optical performance on the side closer to the predetermined distance, and an emphasis is placed on realizing a quick focusing operation on the infinity side than the predetermined position. Therefore, even with the camera 3 equipped with a zoom lens that performs the focus adjustment as described above, it is possible to achieve both a stable optical performance and a quick focusing operation in total.
[0149]
Since the circuit block diagram of the camera 3 of the present embodiment is the same as the circuit block diagram of the camera 1 of the first embodiment shown in FIG. 10, illustration and description thereof are omitted.
[0150]
The flowcharts of the “power-on” program that is activated when the power is turned on and the “power-off” program that is activated when the power is turned off are activated by the camera 1 of the first embodiment. Since the operation is the same as that described above, illustration and description are omitted. In this camera 3 as well, the program activated by operating the zoom operation switch is omitted. The “shutter button on” program that is activated when the shutter button is pressed has the same description as the camera 2 of the second embodiment, and thus illustration and description thereof are omitted.
[0151]
In addition, a fourth embodiment of the camera of the present invention will be described.
[0152]
Since the external appearance of the camera 4 of the present embodiment is the same as FIGS. 3 and 4, illustration and description thereof are omitted.
[0153]
Further, the lens barrel and the lens barrel driving mechanism provided in the camera 4 are the lenses of the camera 1 of the first embodiment, except for the shape of the cam groove formed on the inner wall of the first barrel and the encoder. Since the same type and the same operation as the lens barrel and the lens barrel driving mechanism are performed, the illustration and repeated description are omitted.
[0154]
Hereinafter, the focus adjustment performed in the camera 4 will be described with reference to FIG. Here, for the sake of convenience, the same reference numerals as those used in the description of the camera 1 are given to the same types as those constituting the camera 1 of the first embodiment.
[0155]
FIG. 18 is a diagram illustrating the movement of the front group and rear group lenses of the camera of the present embodiment in which focus adjustment is performed from infinity to the closest distance at a plurality of stepwise zoom stages. is there. The way of viewing FIG. 18 is the same as that of FIG.
In FIG. 18, the solid line K4 representing the change in the distance of the front group lens 400 with respect to the film surface as the first lens barrel 22 of the lens barrel 20 rotates, and the change in the distance of the rear group lens 300 with respect to the film surface. A solid line L4 is shown, and a discontinuous dotted line M4 is shown. The solid line K4 is a straight line extending from the middle left in the figure to the upper right in the figure, and the solid line L4 is shown in a shape in which curved portions and broken line portions alternate from the lower left in the figure to the upper right in the figure. As the first lens barrel 22 rotates, the rear group lens 300 that moves on the curved line portion excluding the broken line portion of the solid line L4 and the dotted line M4, and the front group that moves on the solid line K4. With the lens 400, the camera 4 of the present embodiment is set to focus at infinity.
[0156]
FIG. 18 also shows the encoder board 840, the contact brush 730, a part of the lens barrel standby position (P31 to P35), the arrow R4 drawn on the broken line portion of the solid line L4, and the rotation determined stepwise. Also shown is a circle indicating the distance of the front lens group 400 to the film surface at each of some rotation angles (Z51 to Z55), and an arrow S4 extending upward from the circle. A solid line L4 representing a change in the distance of the rear lens group 300 with respect to the film surface shown in FIG. 18 indicates the shape of the cam groove 22c provided on the inner wall of the first lens barrel 22 shown in FIG. The description of the operation of the contact brush 730 and the encoding substrate 840 attached to the key plate 25 of the camera 4 is the same as that described in the camera 1 of the first embodiment, and is therefore omitted.
[0157]
Hereinafter, focus adjustment in the camera 4 of the present embodiment will be described.
[0158]
As a result of the operation of the zoom operation switch, when the lens barrel standby position is located at one of the centers of the encoder board pattern (P31 to P35 in FIG. 18), the distance is obtained by half-pressing the shutter button 16. Based on the distance value and the zoom magnification, the focus adjustment by both the extension of the front lens group 400 and the extension of the lens barrel 20 is performed in the same manner regardless of the wide angle side or the telephoto side. . Two predetermined values (b, c) that have been set are compared with the distance measurement values obtained at the respective rotation angles. Based on two predetermined values (b, c) that have been set, the range from the closest distance to infinity is divided into three ranges. The three ranges are composed of a range X on the infinity side including infinity, a range Y near the middle distance, and a range Z on the close side including the closest distance. When the subject is in the range X, That is, when it is in the vicinity of infinity, focus adjustment is performed by extending only the front lens group 400 as represented by S4 shown in FIG. When the subject is in the range Y, that is, in the vicinity of the middle distance, as shown by S4 and R4 in FIG. 18, the focus adjustment is performed by both the extension of the front lens group 400 and the extension of the lens barrel 20. It is. When the subject is in the range Z, that is, in the vicinity of the close range, the focus adjustment is performed only by extending the lens barrel 20, as represented by R4 shown in FIG.
[0159]
Thereafter, the shutter is operated so as to obtain an appropriate exposure amount based on the measured subject light amount information, and photographing is performed. When the photographing is completed, the front group lens 400 is returned to the front group lens standby position, or the lens barrel 20 is returned to the lens standby position before the focus adjustment to prepare for the next photographing.
[0160]
In other words, in the camera 4 of the present embodiment, it is determined which of the three ranges from infinity to the nearest object the subject belongs to, and the first focus adjustment mechanism according to the ratio set for each belonging range. The focus adjustment is performed by the focus adjustment by, and the focus adjustment by the second focus adjustment mechanism. For this reason, emphasis is placed on securing stable optical performance on the close side, emphasis is placed on realizing a quick focusing operation on the infinity side, and focus adjustment is performed at a rate of half in the vicinity of the intermediate distance. Therefore, also in the camera 4 having the zoom lens in which the focus adjustment as described above is performed, stable optical performance is ensured and a quick focusing operation is realized.
[0161]
Since the circuit block diagram of the camera 4 of the present embodiment is the same as the circuit block diagram of the camera 1 of the first embodiment shown in FIG. 10, illustration and description thereof are omitted.
[0162]
The flowcharts of the “power-on” program that is activated when the power is turned on and the “power-off” program that is activated when the power is turned off are activated by the camera 1 of the first embodiment. Since the operation is the same as that described above, illustration and description are omitted. In this camera 4 as well, a program started by operating the zoom operation switch is omitted. Hereinafter, a “shutter button on” program started when the shutter button 16 is pressed will be described.
[0163]
FIG. 19 is a flowchart of a “shutter button on” program that is activated when the shutter button of the camera is pressed.
[0164]
When the shutter button 16 of the camera 4 is pressed, first, in a half-pressed state, a photometric operation for measuring the brightness of the subject to be photographed is performed in step S231, and the aperture and shutter speed are determined. Thereafter, the process proceeds to step S232.
[0165]
In step S232, distance measurement to the subject is performed. Thereafter, the process proceeds to step S233.
[0166]
In step S233, a “comparison” is a subprogram that compares the distance measurement value obtained by the distance measurement operation performed on the subject in step S232 with the two values (b, c) set in the camera 4. Run 'routine'.
[0167]
Here, FIG. 20 is a diagram showing a flowchart of the subprogram “comparison routine”.
[0168]
First, in step S61, the distance measurement value obtained in step S232 is compared with a value b which is one of two values set in the camera 4.
[0169]
If it is determined in step S61 that the distance measurement value is greater than the value b, the process proceeds to step S63.
[0170]
If it is determined in step S61 that the distance measurement value is not greater than the value b, the process proceeds to step S62, and a “closeness flag” indicating that the subject is on the near side is set. Thereafter, the process exits from this subprogram and returns to the “shutter button on” program.
[0171]
In step S63, the distance measurement value is compared with a value c which is another value set in the camera 4.
[0172]
If it is determined in step S63 that the distance measurement value is greater than the value c, the process proceeds to step S65.
[0173]
If it is determined in step S63 that the distance measurement value is not greater than the value c, the process proceeds to step S64, and in step S64, a “medium distance flag” indicating that the subject is in the middle distance is set. Thereafter, the process exits from this subprogram and returns to the “shutter button on” program.
[0174]
In step S65, an “infinity flag” indicating that the subject is near infinity is set. Thereafter, the process exits from this subprogram and returns to the “shutter button on” program.
[0175]
Returning to the “shutter button on” program again, the explanation will be continued from the point of proceeding to step S234.
[0176]
In step S234, a sub-program “feed amount determination routine” for determining the feed amounts of the front lens group 400 and the lens barrel 20 for focus adjustment is executed.
[0177]
Here, FIG. 21 is a diagram showing a flowchart of the subprogram 'feeding amount determination routine'.
[0178]
First, in step S71 and step S72, it is detected which flag is set among "close", "medium distance", and "infinity".
[0179]
From step S73 to step S75, based on the distance measurement value and zoom magnification, data representing the amount of extension of the front lens group 400 and the lens barrel 20 is extracted from the table corresponding to the set flag. Thereby, the amount of extension of the front lens group 400 and the lens barrel 20 for focus adjustment is determined. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0180]
The description will be continued from the point of proceeding again to step S235 of the shutter button on program.
[0181]
In step S235, focus adjustment is performed by feeding according to the determination. Thereafter, the process proceeds to step S236.
[0182]
The description after step S236 is omitted because it overlaps with the description after step S37 in FIG.
[0183]
A fifth embodiment of the camera of the present invention will be described.
[0184]
Since the appearance of the camera 5 of the present embodiment is the same as that shown in FIGS. 3 and 4, illustration and description thereof will be omitted.
[0185]
The lens barrel and the lens barrel drive mechanism provided in the camera 5 are also the lenses of the camera 1 of the first embodiment except for the shape of the cam groove formed on the inner wall of the first barrel and the encoder. Since the same type and the same operation as the lens barrel and the lens barrel driving mechanism are performed, the illustration and repeated description are omitted.
[0186]
Hereinafter, the focus adjustment performed in the camera 5 will be described with reference to FIG. Here, for the sake of convenience, the same reference numerals as those used in the description of the camera 1 are given to the same types as those constituting the camera 1 of the first embodiment.
[0187]
FIG. 22 is a diagram showing the movement of the front group and rear group lenses of the camera of the present embodiment in which focus adjustment is performed from infinity to the closest distance at a plurality of stepwise determined zoom stages. is there. Note that the way of viewing FIG. 22 is the same as that of FIG.
FIG. 22 shows a solid line K5 representing a change in the distance of the front lens group 400 with respect to the film surface with the rotation of the first lens barrel 22 of the lens barrel 20, and with respect to the film surface with the rotation of the first lens barrel 22. A solid line L5 representing a change in the distance of the rear lens group 300 and a discontinuous dotted line M5 are shown. The solid line K5 is a straight line extending from the middle left in the figure to the upper right in the figure, and the solid line L5 is shown in a shape in which curved portions and broken line portions alternate from the lower left in the figure to the upper right in the figure. As the first lens barrel 22 is rotated, the rear group lens 300 that moves on the curved line portion except the broken line portion of the solid line L5 and the dotted line M5, and the front group that moves on the solid line K5. With the lens 400, the camera 5 of the present embodiment is set to focus at infinity.
[0188]
Further, FIG. 22 shows a dot-and-dash line Q5 extending upward through the center (P41) of the wide-angle side pattern among the patterns on the encoder board 850, one of the encoder board 850, the contact brush 740, and one of the lens barrel standby positions. Part group (P61 to P65), the arrow R5 drawn in the broken line portion of the solid line L5, and a part of the rotation angles (Z61 to Z65) determined in a stepwise manner with respect to the film surface, the front group lens A circle mark representing a distance of 400 and an arrow S5 extending upward from the circle mark are also shown. Note that a solid line L5 representing a change in the distance of the rear lens group 300 with respect to the film surface shown in FIG. 22 indicates the shape of the cam groove 22c provided on the inner wall of the first lens barrel 22 shown in FIG. The description of the operation of the contact brush 740 and the encoding substrate 850 attached to the key plate 25 of the camera 5 is the same as that described in the camera 1 of the first embodiment, and is therefore omitted.
[0189]
Hereinafter, focus adjustment in the camera 5 of the present embodiment will be described.
[0190]
As a result of the operation of the zoom operation switch, when the lens barrel standby position is the center (P41) of the wide-angle pattern of the encoder board 850, based on the distance value obtained by the distance measurement by half-pressing the shutter button 16, Focus adjustment is performed by extending the lens barrel 20. In the camera 5, the first lens barrel 22 is rotated until the rotation angle corresponding to the extension amount of the lens barrel 20 determined according to the distance measurement value is obtained.
Incidentally, when the first lens barrel 22 is rotated from the rotation angle Z60 corresponding to the lens barrel standby position P41 to the rotation angle Z61 which is the nearest rotation angle determined in a stepwise manner, it corresponds to the rotation angle Z61. The subject is in focus at infinity at the zoom magnification set as described above.
[0191]
Thereafter, the shutter is operated so as to obtain an appropriate exposure amount based on the measured subject light amount information, and photographing is performed. When photographing is completed, the lens barrel 20 is returned to the lens barrel standby position P41, and the next Prepare for shooting.
[0192]
Next, when the lens barrel standby position is located at the center (P42) of the encoder board pattern as a result of the operation of the zoom operation switch, the distance value obtained by the distance measurement by half-pressing the shutter button 16 is used. The focus adjustment is performed by both the extension of the front lens group 400 and the extension of the lens barrel 20. First, a predetermined value d set corresponding to the rotation angle Z62 is compared with a distance measurement value, and it is determined whether or not the subject is farther than a predetermined position represented by the predetermined value d. When the subject is far from the predetermined position, focus adjustment is performed by extending the front lens group 400 as shown by an arrow S5 in FIG. When the subject is closer than a predetermined distance, focus adjustment is performed by extending the lens barrel 20 as indicated by an arrow R5 shown in FIG.
[0193]
Next, as a result of the operation of the zoom operation switch, when the lens barrel standby position is located at the center (P43) of the encoder board pattern, the distance value obtained by the distance measurement by half-pressing the shutter button 16 is used. The focus adjustment is performed by sharing the extension of the front lens group 400 and the extension of the lens barrel 20. First, the two values e and f set corresponding to the rotation angle Z63 are compared with the distance measurement value, and the subject is set at two positions represented by the two set values, respectively. Which of the three ranges belongs is determined. The three ranges include a range X on the infinity side including infinity, a range Y near the middle distance, and a range Z on the close side including the closest distance. In the ranges X, Y, and Z, ratios in focus adjustment between the focus adjustment by extending the front lens group 400 and the focus adjustment by extending the lens barrel 20 are set. When it is determined that the subject belongs to the range X, as indicated by the arrow S5 shown in FIG. 22, the focus adjustment is performed only by extending the front lens group 400 over a wider range than that performed at the rotation angle Z62. Is done. When it is determined that the subject belongs to the range Y, for example, the focus adjustment by the extension of the lens barrel 20 is mainly performed at the ratio set in the range Y, and the focus adjustment by the extension of the front lens group 400 is slightly performed. The focus adjustment is performed as shown by the arrows S5 and R5 shown in FIG. When it is determined that the subject belongs to the range Z, focus adjustment is performed only by extending the lens barrel 20 as indicated by an arrow R5 shown in FIG.
[0194]
Next, as a result of the operation of the zoom operation switch, even when the lens barrel standby position is located at the center (P44) of the wide-angle pattern of the encoder board, the distance obtained by the distance measurement by half-pressing the shutter button 16 Based on the value, focus adjustment is performed by sharing the extension of the front lens group 400 and the extension of the lens barrel 20. First, the three values g, h, i set corresponding to the rotation angle Z64 are compared with the distance measurement value, and the subject is set at the position represented by each of the three set values. Which of the four ranges belongs is determined. Also, these four ranges are a range W1 that is near infinity including infinity, a range X1 that is from infinity to the middle distance, a range Y1 that is from the middle distance to the near distance, and a near vicinity that includes the closest distance. It consists of the range Z1 which is. Further, in the ranges W1, X1, Y1, and Z1, ratios in focus adjustment between the focus adjustment by extending the front lens group 400 and the focus adjustment by extending the lens barrel 20 are set. When it is determined that the subject belongs to the range W1, as indicated by the arrow S5 shown in FIG. 22, the focus adjustment is performed only by extending the front lens group 400 over a wider range than that performed at the rotation angle Z63. Is done. When it is determined that the subject belongs to the range X1, for example, the focus adjustment by the extension of the lens barrel 20 is slightly performed at the ratio set in the range X1, and the focus adjustment by the extension of the front lens group 400 is mainly performed. The focus adjustment is performed as shown by the arrows S5 and R5 shown in FIG. When it is determined that the subject belongs to the range Y1, the rate of focus adjustment due to the extension of the lens barrel 20 is increased compared to the case where the subject is determined to belong to the range X1, and instead due to the extension of the front lens group 400. Focus adjustment is performed at a reduced rate of focus adjustment. If it is determined that the subject belongs to the range Z1, focus adjustment is performed only by extending the lens barrel 20 as indicated by an arrow R5 shown in FIG.
[0195]
Thereafter, the shutter is operated so as to obtain an appropriate exposure amount based on the measured subject light amount information, and photographing is performed. When the photographing is completed, the front group lens 400 is returned to the front group lens standby position, or the lens barrel 20 is returned to the lens standby position before the focus adjustment to prepare for the next photographing.
[0196]
In other words, in the camera 5 of the present embodiment, it is determined whether the subject belongs to a number of ranges corresponding to the number of predetermined values set for each zoom magnification, and is set to each of the ranges to which the subject belongs. In accordance with the ratio in the focus adjustment, the focus adjustment by the first focus adjustment mechanism according to the present invention and the focus adjustment by the second focus adjustment mechanism according to the present invention are performed. Accordingly, since the focus adjustment by the first focus adjustment mechanism and the focus adjustment by the second focus adjustment mechanism can be finely performed, stable optical performance and realization of a quick focusing operation are well balanced. It is possible to achieve both.
[0197]
Since the circuit block diagram of the camera 5 of this embodiment is the same as the circuit block diagram of the camera 1 of the first embodiment shown in FIG. 10, illustration and description thereof are omitted.
[0198]
The flowcharts of the “power-on” program that is activated when the power is turned on and the “power-off” program that is activated when the power is turned off are activated by the camera 1 of the first embodiment. Since the operation is the same as that described above, illustration and description are omitted. In this camera 5 as well, the program activated by operating the zoom operation switch is omitted. In the camera 5 of the present embodiment, when the shutter button 16 is pressed, the “shutter button on” program is started. The flowchart of the “shutter button on” program is the flowchart of the camera 4 of the fourth embodiment. The flowchart is the same as FIG. 19 showing the flowchart of the shutter button on 'program.
[0199]
When the shutter button 16 of the camera 5 is pressed, first, in a half-pressed state, a photometric operation for measuring the brightness of the subject to be photographed is performed in step S231, and the aperture and shutter speed are determined. Thereafter, the process proceeds to step S232.
[0200]
In step S232, distance measurement to the subject is performed. Thereafter, the process proceeds to step S233.
[0201]
In step S233, a “comparison routine” which is a subprogram for comparing the distance measurement values obtained by the distance measurement operation performed in step S232 with a plurality of values set in the camera 5 is executed. .
[0202]
FIG. 23 is a flowchart of the subprogram “comparison routine”. Here, Z61 to Z64 in zoom steps (rotation angles) set stepwise as shown in FIG. 22 will be representatively described.
[0203]
First, in step S81, the rotation angle of the first lens barrel 22 representing the zoom stage selected this time and set in a stepwise manner is detected. Thereafter, the process proceeds to step S82.
[0204]
In step S82, it is determined whether or not the rotation angle detected in step S81 is Z61.
[0205]
If it is determined in step S82 that the detected rotation angle is the same as Z61, the process proceeds to step S83, and the 'Z61 flag' is set. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0206]
If it is determined in step S82 that the detected rotation angle is not the same as Z61, the process proceeds to step S84.
[0207]
In step S84, it is determined whether or not the detected rotation angle is the same as Z62.
[0208]
If it is determined in step S84 that the detected rotation angle is the same as Z62, the “Z62 flag” is set in step S85. Thereafter, the process proceeds to step S86, and it is determined whether or not the distance measurement value is larger than the value d.
[0209]
If it is determined in step S86 that the distance measurement value is greater than the value d, this subprogram is exited and the process returns to the 'shutter button on' program.
[0210]
If it is determined in step S86 that the distance measurement value is smaller than the value d, the process proceeds to step S87, and the “closeness flag” is set. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0211]
If it is determined in step S84 that the detected rotation angle is not the same as Z62, the process proceeds to step S89, and it is determined whether or not the detected rotation angle is the same as Z63.
[0212]
If it is determined in step S89 that the detected rotation angle is the same as Z63, the 'Z63 flag' is set in step S90. Thereafter, the process proceeds to step S91, and it is determined whether or not the distance measurement value is larger than the value e.
[0213]
If it is determined in step S91 that the distance measurement value is smaller than the value e, the process proceeds to step S92, and the 'Z flag' is set. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0214]
If it is determined in step S91 that the distance measurement value is greater than the value e, the process advances to step S93 to determine whether or not the distance measurement value is greater than the value f.
[0215]
If it is determined in step S93 that the distance measurement value is smaller than the value f, the process proceeds to step S94, and the 'Y flag' is set. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0216]
If it is determined in step S93 that the distance measurement value is greater than the value f, the subprogram is exited and the process returns to the “shutter button on” program.
[0217]
If it is determined in step S89 that the detected rotation angle is not the same as Z63, the process proceeds to step S96, and it is determined whether or not the detected rotation angle is the same as Z64.
[0218]
If it is determined in step S96 that the detected rotation angle is the same as Z64, the 'Z64 flag' is set in step S97. Thereafter, the process proceeds to step S98, and it is determined whether or not the distance measurement value is larger than the value g.
[0219]
If it is determined in step S98 that the distance measurement value is smaller than the value g, the process proceeds to step S99, and the 'Z1 flag' is set. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0220]
If it is determined in step S98 that the distance measurement value is greater than the value g, the process proceeds to step S100, and it is determined whether or not the distance measurement value is greater than the value h.
[0221]
If it is determined in step S100 that the distance measurement value is smaller than the value h, the process proceeds to step S101, and the 'Y1 flag' is set. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0222]
If it is determined in step S100 that the distance measurement value is larger than the value h, the process proceeds to step S102, and it is determined whether or not the distance measurement value is larger than the value i.
[0223]
If it is determined in step S102 that the distance measurement value is smaller than the value i, the process proceeds to step S103, and the “X1 flag” is set. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0224]
If it is determined in step S102 that the distance measurement value is greater than the value i, the subprogram is exited and the process returns to the 'shutter button on' program.
[0225]
The description will be continued from the point of proceeding again to step S234 of the “shutter button on” program shown in FIG.
[0226]
In step S234, a sub-program “feed amount determination routine” for determining the feed amounts of the front lens group 400 and the lens barrel 20 for focus adjustment is executed.
[0227]
Here, FIG. 24 is a diagram showing a flowchart of the subprogram “feeding amount determination routine”. In this case as well, Z61 to Z64 of zoom steps (rotation angles) set in a stepwise manner will be representatively described.
[0228]
First, in step S110, it is determined whether or not the Z61 flag indicating that the current rotation angle is Z61 is set.
[0229]
If it is determined in step S110 that the Z61 flag is set, the process proceeds to step S111, and the distance measurement value and the rotation are obtained from the 'Z61 data table' which is a data table referred to when the rotation angle is Z61. Data representing the feed amount is extracted based on the zoom magnification corresponding to the angle Z61. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0230]
If it is determined in step S110 that the Z61 flag is not set, the process proceeds to step S112, and it is determined whether or not the Z62 flag indicating that the current rotation angle is Z62 is set.
[0231]
If it is determined in step S112 that the Z62 flag is set, the process proceeds to step S113, where the subject is closer to the predetermined position set at the zoom magnification corresponding to the rotation angle Z62. It is determined whether or not the “closeness flag” is set.
[0232]
If it is determined in step S113 that the “close-up flag” is set, from the “Z62 close-up data table” for the side closer to the predetermined position set at the zoom magnification corresponding to the rotation angle Z62, Data representing the feed amount is extracted based on the distance measurement value and the zoom magnification corresponding to the rotation angle Z62. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0233]
If it is determined in step S113 that the “close-up flag” is not set, from the “Z62 remote data table” for the far side of the predetermined position set at the zoom magnification corresponding to the rotation angle Z62, Data representing the feed amount is extracted based on the distance measurement value and the zoom magnification corresponding to the rotation angle Z62. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0234]
If it is determined in step S112 that the Z62 flag is not set, the process proceeds to step S116, and it is determined whether or not the Z63 flag indicating that the current rotation angle is Z63 is set.
[0235]
If it is determined in step S116 that the Z63 flag has been set, the process proceeds to step S117, and the subject moves closer to the close side of the predetermined three ranges set at the zoom magnification corresponding to the rotation angle Z63. It is determined whether or not the 'Z flag' indicating that it belongs is set.
[0236]
If it is determined in step S117 that the 'Z flag' has been set, the process proceeds to step S118, and measurement is performed from the closest-side 'Z63Z data table' set at the zoom magnification corresponding to the rotation angle Z63. Data representing the feed amount is extracted based on the distance value and the zoom magnification corresponding to the rotation angle Z63. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0237]
If it is determined in step S117 that the “Z flag” has not been set, the process proceeds to step S119, where the subject is in the middle of the predetermined three ranges set at the zoom magnification corresponding to the rotation angle Z63. It is determined whether or not the 'Y flag' indicating that it belongs to the vicinity of the distance is set.
[0238]
If it is determined in step S119 that the 'Y flag' is set, the process proceeds to step S120, and from the 'Z63Y data table' for the middle distance set at the zoom magnification corresponding to the rotation angle Z63, Data representing the feed amount is extracted based on the distance measurement value and the zoom magnification corresponding to the rotation angle Z63. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0239]
If it is determined in step S119 that the 'Y flag' is not set, the process proceeds to step S121, where the subject is infinite among the predetermined three ranges set at the zoom magnification corresponding to the rotation angle Z63. Based on the distance measurement value and the zoom magnification corresponding to the rotation angle Z63 from the “Z63X data table” for the infinity side set at the zoom magnification corresponding to the rotation angle Z63, as belonging to the far side. The data representing the feed amount is extracted. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0240]
If it is determined in step S116 that the Z63 flag is not set, the process proceeds to step S122, and it is determined whether or not a Z64 flag indicating that the current rotation angle is Z64 is set.
[0241]
If it is determined in step S122 that the Z64 flag is set, the process proceeds to step S123, where the subject is closest to the predetermined four ranges set at the zoom magnification corresponding to the rotation angle Z64. It is determined whether or not the 'Z1 flag' indicating that it belongs to is set.
[0242]
If it is determined in step S123 that the 'Z1 flag' is set, the process proceeds to step S124, and from the closest-side 'Z64Z1 data table' set at the zoom magnification corresponding to the rotation angle Z64, Data representing the feed amount is extracted based on the distance measurement value and the zoom magnification corresponding to the rotation angle Z64. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0243]
If it is determined in step S123 that the 'Z1 flag' is not set, the process proceeds to step S125, and the subject is slightly out of the predetermined four ranges set at the zoom magnification corresponding to the rotation angle Z64. It is determined whether or not the 'Y1 flag' indicating that it belongs to the closest side is set.
[0244]
If it is determined in step S125 that the 'Y1 flag' is set, the process proceeds to step S126, and from the slightly close side 'Z64Y1 data table' set at the zoom magnification corresponding to this rotation angle Z64, Data representing the feed amount is extracted based on the distance measurement value and the zoom magnification corresponding to the rotation angle Z64. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0245]
If it is determined in step S125 that the 'Y1 flag' is not set, the process proceeds to step S127, and the subject is slightly out of the predetermined four ranges set at the zoom magnification corresponding to the rotation angle Z64. It is determined whether or not the 'X1 flag' indicating that it belongs to the closest side is set.
[0246]
If it is determined in step S127 that the 'X1 flag' is set, the process proceeds to step S128, and from the slightly close side 'Z64X1 data table' set at the zoom magnification corresponding to the rotation angle Z64, Data representing the feed amount is extracted based on the distance measurement value and the zoom magnification corresponding to the rotation angle Z64. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0247]
If it is determined in step S127 that the 'X1 flag' is not set, the process proceeds to step S129, and the subject is infinite among predetermined four ranges set at the zoom magnification corresponding to the rotation angle Z64. Based on the distance measurement value and the zoom magnification corresponding to the rotation angle Z64 from the “Z64W1 data table” for the infinity side set at the zoom magnification corresponding to the rotation angle Z64 as belonging to the far side. The data representing the feed amount is extracted. Thereafter, this subprogram is exited, and the program returns to the “shutter button on” program.
[0248]
In the camera of the above embodiment, the following method is adopted in order to feed the lens barrel 20 to the lens barrel standby position with high accuracy. When the lens barrel is extended to an arbitrary position by the operation of the zoom switch, the first state is detected until contact between the contact brush and the end of the pattern on the encode substrate provided on the camera body side is detected. The lens barrel is rotated. In the camera, the amount of rotation of the lens barrel drive motor necessary to move the contact brush from the end of the pattern on the encode substrate to the center is known. After contact, that is, when the conduction timing is detected, counting of the rotation amount of the lens barrel driving motor 10 is started, and when the determined rotation amount is reached, an instruction to stop the lens barrel driving motor is issued. By doing so, the lens barrel 20 can be always stably extended to a predetermined lens barrel standby position (pattern center).
Moreover, although the above embodiment demonstrated using the camera which employ | adopts a roll-shaped film, the camera of this invention may be an electronic camera, an instant camera, etc. Furthermore, although the above embodiment has been described using a camera including a zoom lens configured by a two-group lens, the camera of the present invention is a camera including a zoom lens configured by three or more groups. There may be. In addition, although the above embodiment has been described using a camera having an autofocus function, the camera of the present invention is a camera having only a manual focus function or both an autofocus function and a manual focus function. There may be.
[0249]
【The invention's effect】
As described above, according to the camera of the present invention, it is possible to perform focus adjustment that achieves both stable optical performance and quick focusing operation.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating the movement of a front group lens and a rear group lens of a camera in which focus adjustment is performed by extending only a front group lens forward in the optical axis direction in a plurality of stepwise zoom stages. is there.
FIG. 2 shows that the lens barrel is extended forward in the optical axis direction and the relative distance between the front group lens and the rear group lens incorporated in the lens barrel is changed in a plurality of stepwise zoom stages. It is a figure which shows the motion of the front group of a camera in which focus adjustment is performed, and a rear group lens.
FIG. 3 is an external perspective view of the first embodiment of the camera of the present invention.
FIG. 4 is an external perspective view of the first embodiment of the camera of the present invention.
FIG. 5 is a cross-sectional view of a lens barrel and a lens barrel driving mechanism of a camera in a wide-angle end state.
FIG. 6 is a cross-sectional view of a lens barrel and a lens barrel driving mechanism of a camera in a telephoto end state.
FIG. 7 is an exploded perspective view of a lens barrel.
FIG. 8 is an external perspective view of a front lens group guide mechanism;
FIG. 9 is a diagram illustrating the movement of the front group and rear group lenses of the camera according to the present embodiment in which focus adjustment from infinity to the closest distance is performed in a plurality of zoom stages determined stepwise.
FIG. 10 is a circuit block diagram of the camera of the present embodiment.
FIG. 11 is a flowchart of a power-on program that is activated when the camera of the present embodiment is turned on.
FIG. 12 is a flowchart of a zoom operation program that is activated when an operation is performed on the zoom operation switch.
FIG. 13 is a flowchart of a shutter button on program activated when a shutter button of the camera is pressed.
FIG. 14 is a flowchart of a power-off program that is activated when an operation to turn off the power of the camera is performed.
FIG. 15 is a diagram illustrating the movement of the front group and rear group lenses of the camera according to the present embodiment in which focus adjustment is performed from infinity to the closest distance at a plurality of stepwise determined zoom stages.
FIG. 16 is a flowchart of a shutter button on program started when a shutter button of the camera is pressed.
FIG. 17 is a diagram showing the movement of the front group and rear group lenses of the camera of the present embodiment in which focus adjustment is performed from infinity to the closest distance at a plurality of stepwise determined zoom stages. is there.
FIG. 18 is a diagram showing the movement of the front group and rear group lenses of the camera of the present embodiment in which focus adjustment is performed from infinity to the closest distance at a plurality of stepwise zoom stages. is there.
FIG. 19 is a flowchart of a shutter button on program activated when a shutter button of the camera is pressed.
FIG. 20 is a flowchart of a subprogram “comparison routine”.
FIG. 21 is a view showing a flowchart of a subprogram 'feeding amount determination routine'.
FIG. 22 is a diagram showing the movements of the front group and rear group lenses of the camera of the present embodiment in which focus adjustment is performed from infinity to the closest distance at a plurality of stepwise determined zoom stages. is there.
FIG. 23 is a flowchart of a subprogram “comparison routine”.
FIG. 24 is a view showing a flowchart of a subprogram “Feedout amount determination routine”.
[Explanation of symbols]
1, 2, 3, 4, 5 camera
10 Lens barrel drive motor
100 pinions
110 Reduction gear system
12 Flash window
120 spur gear
13 Viewfinder objective window
14a AF projection window
14b AF light receiving window
15 AE light receiving window
16 Shutter button
20 Lens barrel
21 Fixed cylinder
21a helicoid screw
21b Vertical opening
21c Keyway
21d Bearing
21e Bag part
21f axis
22 First lens barrel
22a helicoid screw
22b Driven gear
22c Cam groove
22d helicoid screw
22e Flange
23 Straight guide tube
23a Second flange
23b 1st flange
23c straight groove
23d ridge
24 Second lens barrel
24a helicoid screw
24b Straight groove
24c groove
25 key plate
25b Bearing
25c protrusion
251 Drive gear
30 Rear lens unit
300 Rear lens group
310 Rear lens group holding frame
310a Cam pin
40 Front lens unit
400 Front lens group
410 Front lens barrel
410a protrusion
410b helicoid screw
420 Front lens drive motor
430 Drive gear
440 Rotating cylinder
440a Gear groove
440b helicoid screw
450 fixed cylinder
450a keyway
50 Shutter unit
51 Control circuit
52 Flash control
53 AE sensor
54 Encoder
55 AF sensor
56 Zoom operation switch
57 Front lens drive motor
58 Shutter control
59 Control of lens barrel drive motor
500 Photosensor
600 sector actuator
700, 710, 720, 730, 740 Contact brush
810, 820, 830, 840, 850 Encoder board
90 Holding member

Claims (4)

A first lens group that moves relative to the stop when the focal length is changed, and a second lens group that moves while changing the relative distance between the first lens group when the focal length is changed; In a camera equipped with a zoom lens including
A first focus adjustment mechanism that performs focus adjustment by moving all or a part of the lenses of the first lens group while keeping the second lens group and the stop position stationary;
The first lens group is moved so as not to change the relative distance from the stop, and the second lens group is moved while changing the relative distance from the first lens group, thereby adjusting the focal length as well as changing the focal length. A second focus adjustment mechanism to perform;
A distance measuring unit that measures the distance to the subject;
As a result of the measurement by the distance measuring unit , the first focus adjustment mechanism and the second focus adjustment mechanism are used when the subject is more than a predetermined distance and closer than the predetermined distance, respectively. A camera comprising a focus adjustment unit for performing focus adjustment. A first lens group that moves relative to the stop when the focal length is changed, and a second lens group that moves while changing the relative distance between the first lens group when the focal length is changed; In a camera equipped with a zoom lens including
A first focus adjustment mechanism that performs focus adjustment by moving all or a part of the lenses of the first lens group while keeping the second lens group and the stop position stationary;
The first lens group is moved so as not to change the relative distance from the stop, and the second lens group is moved while changing the relative distance from the first lens group, thereby adjusting the focal length as well as changing the focal length. A second focus adjustment mechanism to perform;
As the focal length of the zoom lens is closer to the telephoto side, the focus adjustment increases the contribution ratio to the focus adjustment by the first focus adjustment mechanism of the first focus adjustment mechanism and the second focus adjustment mechanism. As the focal length of the zoom lens is on the wide-angle side, the contribution ratio of the second focus adjustment mechanism to the focus adjustment of the first focus adjustment mechanism and the second focus adjustment mechanism is increased. A camera comprising a focus adjustment unit for performing an enhanced focus adjustment. A first lens group that moves relative to the stop when the focal length is changed, and a second lens group that moves while changing the relative distance between the first lens group when the focal length is changed; In a camera equipped with a zoom lens including
A first focus adjustment mechanism that performs focus adjustment by moving all or a part of the lenses of the first lens group while keeping the second lens group and the stop position stationary;
The first lens group is moved so as not to change the relative distance from the stop, and the second lens group is moved while changing the relative distance from the first lens group, thereby adjusting the focal length as well as changing the focal length. A second focus adjustment mechanism to perform;
A distance measuring unit that measures the distance to the subject;
As a result of the measurement by the distance measuring unit, the farther the subject is, the contribution rate to the focus adjustment by the first focus adjustment mechanism of the first focus adjustment mechanism and the second focus adjustment mechanism. As the subject is closer to the subject, the contribution ratio to the focus adjustment by the second focus adjustment mechanism of the first focus adjustment mechanism and the second focus adjustment mechanism is increased. A camera comprising a focus adjustment unit for performing an enhanced focus adjustment. A first lens group that moves relative to the stop when the focal length is changed, and a second lens group that moves while changing the relative distance between the first lens group when the focal length is changed; In a camera equipped with a zoom lens including
A first focus adjustment mechanism that performs focus adjustment by moving all or a part of the lenses of the first lens group while keeping the second lens group and the stop position stationary;
The first lens group is moved so as not to change the relative distance from the stop, and the second lens group is moved while changing the relative distance from the first lens group, thereby adjusting the focal length as well as changing the focal length. A second focus adjustment mechanism to perform;
A distance measuring unit that measures the distance to the subject;
As the focal length of the zoom lens is on the telephoto side and the subject is on the far side as a result of the measurement by the distance measuring unit , the first focusing mechanism and the second focusing mechanism among the first focusing mechanism and the second focusing mechanism. In addition to performing focus adjustment with an increased contribution ratio to the focus adjustment by the first focus adjustment mechanism, the focal length of the zoom lens is on the wide-angle side, and as a result of measurement by the distance measuring unit, the subject is closer to the near side. A focus adjustment unit that performs focus adjustment with a higher contribution ratio to the focus adjustment by the second focus adjustment mechanism of the first focus adjustment mechanism and the second focus adjustment mechanism. Camera characterized by.

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