JPH0722660Y2 - Lens shutter type zoom lens camera - Google Patents

Description

[Technical Field] The present invention relates to a lens shutter type camera having an autofocus function, and particularly to a zoom motor of a camera using a motor-driven zoom lens system as an image pickup optical system, and an autofocus. TECHNICAL FIELD The present invention relates to an arrangement structure of a light emitting unit and a light receiving unit of a distance measuring device for a vehicle.

"Prior Art and its Problems" Many autofocus lens shutter cameras are known, but conventional products generally cannot change the focal length of a photographing optical system. There is also known a two-focal length lens shutter camera in which a focal length changing lens is inserted and removed in the photographing optical system, but this camera is called, for example, wide angle and telephoto, standard and telephoto. Only two focal lengths can be used, not one in the middle. For this reason, in reality, the imaging using the zoom lens is limited to the single-lens reflex camera. However, the single-lens reflex camera is more expensive and heavier than the lens shutter type camera, and is a heavy burden for a beginner or an intermediate person to use. Especially for overseas travelers who want to make the weight as small as possible, or even for female users, the single-lens reflex camera is recognized as being large in size and heavy in weight, even if the excellent rendering is recognized. There is. In such cases, the user is light and compact,
A lens shutter type camera whose focal length cannot be changed or which can be changed in two steps is selected.

In other words, it is common sense that the current lens-shutter camera cannot change the focal length, or can only change the focal length in two steps. Looking for. However, if a lens shutter camera equipped with a zoom lens is put into practical use, it will have a great impact on society and is expected to cultivate more users.
That is, the user thinks that the single-lens reflex camera is too large and that the current lens shutter camera is not sufficient.

[Object of the Invention] The present invention is an autofocus lens shutter camera equipped with a zoom lens, which is a compact camera with power for zooming, based on the above-mentioned analysis of the current situation regarding a single-lens reflex camera and a lens shutter camera. Aim to get. The present invention, in particular, when a distance measuring device based on the triangulation principle is adopted as the distance measuring device,
An object of the present invention is to obtain an arrangement structure in which the light emitting unit and the light receiving unit can be arranged with high space efficiency in relation to a zoom motor for zooming.

[Summary of Device] The present invention is a distance measuring device based on the principle of trigonometric distance measurement. In consideration of the fact that the distance measurement accuracy increases, the distance between the two is made as large as possible, and the zoom motor is arranged in the space between the two resulting. That is, according to the present invention, the zooming motor, which is the driving source for zooming of the zoom lens system, is located in the upper part of the zoom lens system when viewed from the front of the camera and is disposed inside the camera body. The light emitting section and the light receiving section are arranged.

"Embodiment of the Invention" The present invention will be described below with reference to illustrated embodiments. The lens shutter camera of the present invention has a lens barrel block 1 of a zoom lens, a finder and a strobe block (hereinafter simply referred to as finder block) 2, and a distance measuring device (AF device) as shown in FIG. A light emitting unit 3, a light receiving unit 4, and a zoom motor 5 for zooming are provided. These elements are fixed on a base plate 6 (see FIGS. 2 to 4) which serves as a fixed portion of the camera body.

That is, the base plate 6 includes the lens barrel support plate portion 6a which is perpendicular to the optical axis.
And a horizontal support plate portion 6b in which the upper end of the lens barrel support plate portion 6a is bent at a right angle, and a motor support plate portion 6c forming a right angle with respect to the horizontal support plate portion 6b. The lens barrel block 1 is supported by the plate portion 6a. A zoom motor 5 located at the center of the upper portion of the lens barrel block 1 is fixed to the motor support plate portion 6c, and the light emitting portion 3 and the light receiving portion 4 fixed to the horizontal support plate portion 6b are provided on both sides of the zoom motor 5. Is located. The finder block 2 is fixed to the right front side of the horizontal support plate portion 6b. 6e is a gear train support plate fixed to the motor support plate portion 6c via a spacer 6f.

The present invention is thus characterized in that the zoom motor 5 for zooming is arranged between the light emitting portion 3 and the light receiving portion 4 of the distance measuring device.

Therefore, first, the structure of the lens barrel block 1 driven by the zoom motor 5 will be described with reference to FIGS. 6 to 8.
A rear fixing plate 11 is fixed to the lens barrel supporting plate portion 6a of the base plate 6 via fixing screws 10. Four guide rods 12 parallel to the optical axis and located around the optical axis are fixed to the rear fixing plate 11, and a front fixing plate 13 is fixed to the tip of the guide rod 12. The above is the main fixing element of the lens barrel block 1.

A cam ring 14 is rotatably supported between the rear fixed plate 11 and the front fixed plate 13, and the pinion 7 fixed to the drive shaft 5a of the zoom motor 5 and the gear train are directly attached to the outer periphery of the cam ring 14. The gear 15 that meshes with is fixed by a fixing screw 15a (Fig. 6). This gear 15 has a cam ring 14
Is a sector gear that covers the rotation range of the. Cam ring
The zooming cam grooves 20 and 21 for the front group and the rear group are formed in the front group 14.

FIG. 7 is a development view of the zooming cam grooves 20 and 21. The zooming cam grooves 21 for the rear group are the wide-angle end fixed section 21a and the variable magnification section 21.
b, has a fixed section 21c at the telephoto end. On the other hand, the zooming cam groove 20 for the front group is the barrier 31 of the barrier block 30.
Barrier opening and closing section 20a, lens storage section 20b, wide angle end fixed section 20c, variable magnification section 20d, telephoto end fixed section 20e,
It has a macro feeding section 20f and a macro end fixed section 20g. The rotation angle of each of these sections depends on the zooming cam groove.
The total angle θ1 of the barrier opening / closing section 20a, the lens storing section 20b, and the wide-angle end fixing section 20c of 20 is the zooming cam groove 2
The angle θ1 of the wide angle end fixed section 21a of 1 is the same, the angle θ2 of the variable power section 20d and the variable power section 21b are the same, the telephoto end fixed section 20e, the macro feeding section 20f, and the macro fixed section.
The total angle θ3 of 20 g is the same as the angle θ3 of the fixed section 21c at the telephoto end. The specific zooming range of this embodiment is
35 mm to 70 mm.

The roller 17 of the front group frame 16 and the roller 19 of the rear group frame 18, which are movably fitted to the guide rod 12, are fitted in the zooming am groove 20 and the zooming cam groove 21. The decorative frame 22 is fixed to the front group frame 16 via fixing screws 22a, and the shutter block 23 is further fixed. The front group lens frame 24 holding the front group lens L1 is screwed to the shutter block 23 by the helicoid 25, and has an arm 24a that engages with the lens feeding lever 23a of the shutter block 23. Therefore, when the lens feeding lever 23a rotates in the circumferential direction and the front lens group frame 24 rotates accordingly, the front lens group frame 24 moves in the optical axis direction according to the helicoid 25.
The rear lens group L2 is directly fixed to the rear lens frame 18.

The shutter block 23 itself is well known. With the built-in pulse motor, the lens feeding lever 23a is rotated by an angle according to the distance measuring signal from the distance measuring device having the light emitting unit 3 and the light receiving unit 4, and the shutter (sector) 23b that is closed is opened. After opening for a certain time and closing again,
The lens feeding lever 23a is returned to the original position.

Next, the distance measuring device (AF device) will be described with reference to FIGS. Various types of distance measuring devices having a light emitting portion 3 and a light receiving portion 4 are conventionally known, but in the present invention, a type based on the triangulation distance measuring principle using a position detecting element (for example, PSD) as a light receiving element is used. To use. FIG. 9 is a conceptual diagram thereof, in which the light emitting section 3 is provided with a light source 3a such as an LED and a light projecting lens 3b, and the light receiving section 4 is a PSD 4a separated from the light source 3a by a baseline length L,
The light receiving lens 4b is provided. While the CCD is composed of a large number of light receiving elements, the PSD 4a is, as is well known, a long and narrow light receiving element, and has one common terminal (cathode) C and two terminals (polarity different from that of the common terminal C). Anode) A,
I have B.

When the distance measuring device emits the light source 3a and makes the reflected light reflected by the subject enter the PSD 4a, the position of the light hitting the light receiving surface varies depending on the distance of the subject 0, and the light spot from the terminals A and B A photocurrent is generated corresponding to the position of. Therefore, by measuring this photocurrent, the subject distance can be known. More than
This is the principle of distance measurement of a triangular path using PSD4a.

By applying an operation signal to the above-mentioned shutter unit 23 based on the distance measurement data, automatic focusing can be performed in the entire zooming range. That is, when a drive pulse based on the distance measurement data is applied to the pulse motor of the shutter unit 23, the lens feeding lever 23a rotates by an angle corresponding to the pulse and rotates the front lens group frame 24 together. Therefore, the helicoid 25 moves in the optical axis direction so that the front lens group frame 24 (front lens group L1) is at the in-focus position.

The distance measuring accuracy of the distance measuring device based on the triangular distance measuring principle depends on the distance between the light emitting unit 3 and the light receiving unit 4, that is, the base line length L. Therefore, the distance between the two should be as large as possible.
In the present invention, this base line length is increased and
The zoom motor 5 is arranged between the light emitting portion 3 and the light receiving portion 4 which are generated as a result of the enlargement. The position of the zoom motor 5 is effective for increasing the base length of the distance measuring device and at the same time reducing the size of the entire camera.

As described above, in the lens shutter camera of the present invention, the cam ring 14 is provided with the zooming cam groove 20f that moves (feeds) the front lens group L1 further forward from the telephoto end. At the time of this macro photography, if the distance measuring device including the light emitting unit 3 and the light receiving unit 4 is operated as it is,
Reflected light from a subject at a close position does not enter PSD4a. That is, since the distance cannot be measured, the shutter block
No drive signal (distance measurement data) can be given to 23.
The distance measuring apparatus of this embodiment has a novel structure for correctly detecting the subject position even during this macro photography. The distance measuring device at the time of macro photography will be described with reference to FIGS. 10 to 12.

On the front surface of the light receiving unit 4 of the distance measuring device,
A short-distance correction optical element 4e consisting of a prism 4c having two total reflection surfaces and a mask 4d advances. The prism 4c has an effect of optically extending the base length of the distance measuring device and an effect of refracting the light beam. The mask 4d is for blocking light other than the required optical path, and it includes the aperture 4f on the subject side and the light receiving lens 4b.
It has a side opening 4g. The opening 4f is formed in a slit shape with a distance l apart from the optical axis of the light receiving lens 4b on the side away from the optical axis of the light projecting lens 3b. Correspondingly, it is opened like a slit.

According to this structure, at the time of close-up photography, as shown in FIG. 11, due to the effect of the prism 4c, the light receiving lens 4b of the distance measuring device is obtained.
The optical axis of the light receiving lens 4b and the optical axis of the light projecting lens 3b can be crossed at a finite distance while the optical axis of the optical axis is translated by 1 in the direction of the base line length L.

As described above, according to the near distance correction device that not only refracts the distance measuring light beam but also translates it in the direction of the base line length L by 1, the PSD 4a with respect to the object distance is set with the base line length being L + 1.
By increasing the shift amount of the upper spot image and appropriately setting the angle δ1, the refractive index, etc. of the prism 4c, the correct subject distance can be detected. Therefore, if the shutter block 23 is driven on the basis of the distance measurement data, it is possible to obtain a photograph with correct focus even in macro photography.

As shown in FIGS. 1 to 4, this short distance correction optical element 4e is fixed to one end of an arm 42 pivotally attached to the base plate 6 by a shaft 41 located below the light receiving section 4. An interlocking protrusion 43 is integrally provided at the other end of the arm 42. The arm 42 maintains linearity when no external force is applied, but has flexibility to elastically deform when an external force is applied. The short-distance correction optical element 4e is a tension spring.
By 46, it is normally urged to rotate in the direction of retracting from the front of the light receiving section 4. Further, the cam ring 14 is provided with an advancing protrusion 44 which engages with the interlocking protrusion 43 to advance the short-distance correction optical element 4e to the front surface of the light receiving portion 4 when the cam ring 14 is rotated to the macro photographing position. The protrusion 44 is an optical element
The position and shape are determined so as to rotate the 4e larger than the front surface of the light receiving unit 4, but the rotating end of the short distance correction optical element 4e by the advancing protrusion 44 is a gear support plate integral with the base plate 6.
The side surface of 6e regulates, and the overcharge due to the advancing protrusion 44 is absorbed by the flexibility of the arm 42.

According to the above structure, when the cam ring 14 is rotated to the macro photographing position, the short distance correction optical element 4e can be automatically positioned on the front surface of the light receiving unit 4.

A drive signal from the distance measuring device having the optical unit 3 and the light receiving unit 4 to the shutter block 23 is sent via a flexible printed circuit board (FPC board) not shown. This flexible printed circuit board is bent and arranged inside the cam ring 14 so that it can be extended and folded with a margin in the entire movement range of the front lens group L1 and the rear lens group L2.

The zoom motor 5 is used not only as a driving source for zooming, but also as a driving source for driving the finder device 8 and the strobe device 9 of the finder block 2 in association with zooming. That is, as shown in FIG.
Both the finder device 8 and the strobe device 9 included in the finder block 2 change the finder field and the strobe irradiation angle (light intensity) in conjunction with the change in the focal length of the lens barrel block 1. is there. A pinion 50 different from the pinion 7 is meshed with the gear 15 of the cam ring 14, and a shaft 51 of the pinion 50 is extended to the rear of the base plate 6 and a reduction gear train 52 is provided at the rear end thereof. There is. The final gear 52a of the reduction gear train 52 meshes with the rack 53a of the cam plate 53. The cam plate 53 is slidable in the left-right direction, and a rack 53a is integrally provided at the tip (lower end) of the lower bent portion 53b at the rear end. The reduction gear train 52 is
The rotation of the gear 15 is decelerated, and the movement of the cam ring 14 is reduced to be given to the cam plate 53. The cam plate 53 has a variable magnification cam groove 55 for the finder device 8 and a parallax correction cam groove.
56 and a strobe cam groove 57 for the strobe device 9 are provided.

The lens system of the finder device 8 basically comprises a fixed subject-side lens unit L3, an eyepiece lens unit L4, and a movable variable-magnification lens unit L5, and further includes a deflection prism P1 for micro photography. I have it. The variable-magnification lens unit L5 is used to match the photographing screen by the variable-magnification operation of the lens barrel block 1 with the visual field of the finder device 8.
Only moves to the optical axis during macro shooting to correct parallax. That is, in the lens shutter type camera, parallax is unavoidable, and the amount thereof becomes larger in short-distance shooting, but in the zoom lens camera of this embodiment, macro shooting is possible, and at this time, the amount of parallax becomes large. Therefore, only in macro photography, a wedge-shaped deflection prism P1 having a thick lower portion and a thin upper portion is inserted into the optical path to bend the optical path downward so that a portion closer to the photographed portion can be observed. FIG. 20 shows an outline of the optical path when the deflection prism P1 is inserted.

Further, the strobe device 9 narrows the irradiation angle as the focal length of the photographing lens is longer, that is, as the lens is extended,
During macro photography, the irradiation angle is widened to reduce the light amount to the subject. Therefore, in this embodiment, the Fresnel lens L6 is fixed and the reflection shade 59 holding the xenon lamp 58 is moved in the optical axis direction.

Therefore, a specific structural example for giving the above-described movements to the finder device 8 and the strobe device 9 will be described with reference to FIGS. 13 to 20. A finder main plate 60 is fixed on the finder block 54 fixed to the base plate 6, and a guide pin 62 fitted in a straight guide groove 61 of the cam plate 53 is fixed to the finder main plate 60. The cam plate 53 has a straight guide groove 61, a guide pin 62, and a restraining guide 60a formed as a cut-and-raised piece in the finder main plate 60 that restrains the cam plate 53 from rising in front of the cam plate 53. The direction is restricted (Figs. 13 and 14).

The viewfinder base plate 60 has a variable magnification lens guide groove in the front-rear direction.
63, declination prism guide groove 64, and strobe guide groove
65 is cut, the guide projection 66a of the variable power lens frame 66 supporting the variable power lens group L5 is fitted in the variable power lens guide groove 53, and the declination prism guide groove 64 is engaged in the declination prism operation. The guide protrusion 67a of the plate 67 fits into the strobe guide groove 65.
A guide protrusion 68a of a strobe case 68 to which a reflection shade 59 is fixed is fitted into this to regulate the movement direction of these elements in the front-rear direction. The guide protrusions 66a, 67a, 68a are provided with driven pins 69, 70, 71, respectively, which are driven by the variable magnification cam groove 55, the parallax correction cam groove 56, and the strobe light. It fits in the cam groove 57. Therefore, when the cam plate 53 moves to the left and right, the variable power lens frame 66, the deflection angle prism operating plate 67, and the strobe case 68
However, according to the shapes of these cam grooves 55, 56, 57, they will move back and forth.

The sections of the variable magnification cam groove 55, the parallax correction cam groove 56, and the strobe cam groove 57 correspond to the sections described for the zooming cam grooves 20 and 21 of the cam ring 14 in FIG. That is, the variable power cam groove 55 has a wide-angle end fixed section 55a, a variable power section 55b, and a telephoto end fixed section groove 55c,
The angles θ1, θ2, and θ3 in each of these sections have a corresponding relationship with FIG. 7. On the other hand, the parallax compensation cam groove 56
Is a non-protruding section 56a, a projecting motion section (macro feeding section)
It has a projecting motion section 56b and a projecting position fixing section (macro end fixing section) 56c. The strobe cam groove 57 has a wide-angle end fixed section 57a, a variable magnification section 57b, a telephoto end fixed section 57c, a macro feeding section 57d, and a macro end fixed section 57e.

The variable power lens frame 66 that supports the variable power lens group L5 is movably supported in a suspended manner on the guide surface 54a of the finder block 54, as shown in FIG. Then, when this moves according to the zooming cam groove 55, the subject side lens unit L3,
The magnification of the finder optical system including the eyepiece lens group L4 and the magnification varying lens group L5 changes, and the photographing range by the lens barrel block 1 and the finder field of view substantially match. Such an optical system can be obtained by a simple lens design technique.

The deviation prism P1 is operated by a deviation prism operating plate 67 as shown in FIGS. 18 to 20. First, in the deflection prism P1 made of synthetic resin, fulcrum pins 74 at both lower ends thereof are rotatably supported by the finder block 54. A biasing torsion spring 75 is wound around the fulcrum pin 74, and one end of the torsion spring 75 is hooked on a position regulating piece 76 fixed to the side surface of the deviation prism P1 to keep the deviation prism P1 constantly. Is the subject side lens group L3 to the zoom lens group L5
It is urged to be located in the optical path of. Position control piece
76 is an arc-shaped relief groove formed in the finder block 54
Located within 79. The declination prism operating plate 67 is sandwiched between the finder block 54 and the guide plate 80 fixed to the finder block 54, and the guide pin 81 planted on the side surface of the declination prism operating plate 67 directs the guide groove 82 formed in the finder block 54. Fit in.

The position control piece 76 can be engaged with the rotation blocking surface 77 and the rotation surface 78 of the deflection angle prism operating plate 76. Deflection prism working plate 67
When the driven pin 70 is in the non-projecting section 56a of the parallax correction cam groove 56, the rotation blocking surface 77 of the driven pin 70 is used as the position regulating piece 7.
The deflection angle prism P1 is retracted from the optical path against the force of the torsion spring 75, but when the driven pin 70 reaches the protruding movement section 56b, the turning surface 78 corresponds to the position regulating piece 76. Let Then, the force of the torsion spring 75 causes the deflection angle prism P1 to rotate in the optical path, and the position regulating piece 76 thereof has a rotation surface 78.
While coming into contact with, gradually project into the optical path as shown in FIGS. 19 and 20, and bend the finder optical path as shown in the figure to bring the subject below into the field of view. In other words, reduce parallax during macro shooting.

As shown in FIG. 22, a guide block 85 is provided on the side surface of the strobe case 68 so as to be fitted in a straight guide groove 84 formed in the guide plate 80 in the front-rear direction. Height adjusting pins 86 (Figs. 15 and 21) that prevent the strobe case 68 from falling are fixed to the top and bottom of the strobe case 68. Therefore, the strobe case 68 moves back and forth according to the shape of the strobe cam groove 57 when the cam plate 53 moves left and right. The variable magnification section 57b of the strobe cam groove 57 is a section for retracting the xenon lamp 58 with respect to the Fresnel lens L6, narrowing the range of the irradiation angle emitted from the Fresnel lens 16 in accordance with the retreat and increasing the focal length. No guide number acts to substantially increase the number. On the other hand, in the macro feeding section 57d, the irradiation angle is widened conversely to substantially reduce the guide number in macro photography.

"Effects of the invention" As described above, according to the present invention, the taking lens system is composed of the zoom lens system to increase the power of the zooming.
In a lens shutter zoom lens camera that uses a distance measuring device based on the principle of triangulation as a distance measuring device, it is positioned on the left and right of a zoom motor for zooming that is placed inside the camera body, and the light emitting unit and light receiving device Parts are provided. Therefore, it is possible to sufficiently lengthen the base line length that greatly affects the distance measurement accuracy in the triangulation distance measuring device, that is, the distance between the light emitting unit and the light receiving unit, and effectively use the space between the two that results from the lengthening to reduce the space Therefore, it is possible to obtain a lens shutter zoom lens camera which is highly efficient and therefore has a small size as a whole.

[Brief description of drawings]

FIG. 1 is a conceptual perspective view of main elements showing an embodiment of a lens shutter type camera of the present invention, and FIG. 2 is mainly a lens barrel block, a light emitting part and a light receiving part of a distance measuring device, and a short distance correction optical element, And a front view showing the arrangement of the zoom motor, FIG. 3 is a plan view of FIG. 2, and FIGS. 4 and 5 are cross-sectional views taken along lines IV-IV and VV of FIG. 2, respectively. 6 is a longitudinal sectional view of the lens barrel block, FIG. 7 is a development view of front group cam grooves and rear group cam grooves of the cam ring, FIG. 8 is an exploded perspective view of the lens barrel block, and FIG. 9 is triangulation. Fig. 10 is a conceptual diagram of a distance measuring device based on the distance principle, Fig. 10 is a conceptual diagram of the distance measuring device of Fig. 9 with a short-distance correcting optical element inserted, and Fig. 11 is a diagram of the short-distance correcting optical element of Fig. 10. Enlarged view, Fig. 12 is the same front view, Fig. 13 is a plan view of the cam plate of the finder block, and Fig. 14 is taken along the line XIV-XIV in Fig. 13. Sectional view, FIG. 15 is a rear view of FIG. 13, FIG. 16 is a plan view of FIG. 13 with the cam plate and finder master plate removed, and FIG. 17 is a front view of FIG. 17 is a sectional view taken along line XVIII-XVIII in FIG. 17, FIG. 19 is a sectional view in an operating state different from FIG. 18, and FIG. FIG. 21 is a vertical sectional view when the prism is inserted, FIG. 21 is a front view similar to FIG. 17 showing a state when the deflection prism is inserted, and FIG. 22 is a sectional view taken along line XXII-XXII of FIG. 1 ... Lens barrel block, 2 ... Finder and strobe block, 3 ... Light emitting unit, 4 ... Light receiving unit, 5 ... Zoom motor, 6 ... Base plate, 6a ... Lens barrel supporting plate unit, 6b ... … Horizontal support plate part, 6c …… Motor support plate, 7 …… Pinion, 14…
… Amring, 16 …… front group frame, 18 …… rear group frame, 20, 21…
… Zooming cam groove, 23… Shutter block, 25…
… Helicoid, 53 …… Cam plate, 55 …… Variable magnification cam groove, 56…
… Parallax compensation cam groove, 57 …… Strobe cam groove.

Claims (1)

[Scope of utility model registration request] 1. A light emitting section for providing distance measuring light to an object,
A distance measuring device based on a trigonometric distance measuring principle, which has a light receiving portion that receives reflected light from a subject and detects a subject distance; and a photographing optical system that is automatically focused according to the subject distance detected by this distance measuring device In the lens-shutter camera equipped with, the photographing optical system is composed of a zoom lens system that continuously changes the focal length, and the zooming motor that is the driving source for zooming of the zoom lens system is viewed from the front of the camera. A lens-shutter type zoom lens camera characterized in that it is positioned above a zoom lens system and disposed inside a camera body, and the light emitting unit and the light receiving unit of the distance measuring device are disposed on the left and right of this zooming motor.