JP3089592B2 - Camera ranging lens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance measuring lens for a camera, and more particularly to a distance measuring lens for a camera to which a triangular distance measuring method for measuring a distance based on a base line length is applied.

[0002]

2. Description of the Related Art Among auto-focusing devices mounted on a photographic camera or a video camera, those based on a triangulation method are either active type or passive type, and the distance to a subject is determined based on a preset base line length. Measure
The lens is moved to a position where focus is achieved with respect to the measured subject distance.

In such a triangulation method, since the distance is measured based on the base line length, the base line length is accurately determined in order to improve the distance measurement accuracy. It must not fluctuate. FIG.
FIG. 6 shows the optical module 1 for distance measurement in which the base line length is set to be constant. The distance measuring lenses 2 and 3 are positioned at the front end of the lens barrel 4 by engagement of a hole and a pin described later. An aperture cover 5 is put on the distance measuring lenses 2 and 3, and an end of the gabber 5 is engaged with a hook 6 formed on a side wall of the lens barrel 4 so that the distance measuring lenses 2 and 3 are attached to the lens barrel 4. Fixed.

An IC package 7 is fixed to the rear end of the lens barrel 4. In the IC package 7, a linear image sensor 8 and a silicon substrate on which a signal processing circuit is formed are sealed in a ceramic base and covered with a cover glass 9. Optical axes P1, P of the distance measuring lenses 2, 3, respectively.
2 are parallel, and the distance A between these optical axes is the base line length B. The ranging lenses 2 and 3 form images from the same subject on the image sensor 8, respectively, but these images are shifted from each other according to the subject distance. For example, when the subject distance is infinity, the images obtained by the distance measuring lenses 2 and 3 are shifted from each other by the base line length B, and the shift amount increases as the subject distance decreases. Therefore, a distance signal corresponding to the distance to the subject can be obtained by identifying the luminance distribution pattern of each image based on the photoelectric signal from the image sensor 8 and determining the amount of deviation between the respective luminance distribution patterns.

By the way, in the distance measuring optical module 1,
Four holes 2a, 2b,
2c, 2d, 3a, 3b, 3c, 3d are formed, of which the holes 2a, 2b, 3a, 3b are engaged with pins 10a, 10b, 11a, 11b protruding from the lens barrel 4 to measure the distance. The lenses 2 and 3 are positioned in the lens barrel 4. The positioning reference position by the hole and the pin is orthogonal to the direction of the base line length B shown in FIG. 6 (indicated by a two-dot chain line in the figure), and is a line segment 12a passing through the optical axis of each distance measuring lens 2, 3. 12b. For example, the positioning reference position of the distance measuring lens 2 is outside the optical axis P1 of the distance measuring lens 2 by a distance C,
Further, it is located at a distance D from the midpoint of the base length B.

The holes 2c and 2d are formed at positions symmetrical with respect to the line 12a with respect to the holes 2a and 2b, and the holes 3c and 3d are formed at positions symmetrical with respect to the line 12b with respect to the holes 3a and 3b. This is so that the lenses 2 and 3 made of the same molding die can be used even if the lenses 2 and 3 are interchanged. On the other hand, when the lens barrel 4 expands due to the influence of temperature and humidity and becomes “D → D + ΔD”, the distance measuring lens 2
Since the holes 0a and 10b and the holes 2a and 2b are tightly engaged with each other, the lens barrel 4 expands and moves to the left by ΔD, and the optical axis P1 also moves to the left by ΔD.

The distance measuring lens 2 is expanded with the expansion of the lens barrel 4.
Also expands. In the distance measuring lens 2, since the engagement portion between the pins 10a and 10b and the holes 2a and 2b serves as a base point of expansion, "C →
C + ΔC ”, and moves rightward by ΔC, and the optical axis P
1 also moves rightward by ΔC. Therefore, “ΔD = ΔC”
Is maintained, the optical axis of the distance measuring lens 2 does not change from the initial set position, and the same applies to the distance measuring lens 3, so that the base line length B is kept constant without being affected by changes in temperature or humidity. Can hold. Maintaining the relationship of “ΔD = ΔC” can be dealt with by setting the values of the base line length B and the distance D, and the linear expansion coefficients of the materials of the ranging lenses 2 and 3 and the lens barrel 4 with respect to the temperature and humidity. .

For example, assuming that the linear expansion coefficients of the distance measuring lenses 2 and 3 are α and the linear expansion coefficient of the lens barrel 4 is β, D and C are set so that α: β = D: C. The base length B can be kept constant.

[0009]

By the way, such an optical module 1 for distance measuring uses an image sensor 8 to be used.
The baseline length B is determined by the sensor baseline length of
C and D dimensions for positioning are determined based on the base line length B. However, in the conventional ranging lenses 2 and 3, when the small image sensor 8 is used, that is, when the base line length B is very short, the facing side portions of the ranging lenses 2 and 3 which are a common molded product are used. The distance measuring lenses 2 and 3 cannot be attached to the lens barrel 4 due to collision.

The present invention has been made in view of such circumstances, and has as its object to provide a distance measuring lens for a camera which can be attached to a holding member without any trouble even if the base line length is very short. And

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a plurality of positioning holes in a single holding member such that the distance between optical axes becomes a base length for distance measurement. In the distance measuring lens of the camera which is individually positioned via the pin, when positioning the distance measuring lens to the holding member,
The fitting protrusion is fitted on one end of the distance measuring lens, and the fitting protrusion is fitted on the other end of the distance measuring lens such that ends of adjacent distance measuring lenses are fitted in a telescopic manner. Fitting recesses to be
Is formed.

[0012]

According to the present invention, a fitting convex portion is formed at one end of each distance measuring lens and a fitting concave portion is formed at the other end, and the distance measuring lens is positioned when the distance measuring lens is positioned on the holding member. The fitting projection of the lens and the fitting recess of the distance measuring lens adjacent to the distance measuring lens are arranged so as to fit in a telescopic manner. Thereby, even when the base line length is very short, the distance measuring lens can be positioned on the holding member without the ends of the distance measuring lens colliding with each other.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a distance measuring lens of a camera according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows a first embodiment of a distance measuring optical module 20 to which a distance measuring lens of a camera according to the present invention is applied. The distance measuring optical module 20 includes a pair of distance measuring lenses 22 and 24,
It comprises a lens barrel 26 and an IC package 28. Since the IC package 28 is the same as the conventional IC package 7 shown in FIG. 5, its description is omitted. Further, since the distance measuring lenses 22 and 24 are the same lens made using a common molding die, the distance measuring lens 22 will be described in detail below.

As shown in FIG. 2, the distance measuring lens 22 has protrusions 30, 32 formed on the upper and lower sides on the right side. Protruding pieces 30, 3
2 is formed at an asymmetrical position with respect to the base line 34, and positioning pins 36 and 38 are fixed to the surface thereof. Also, a protruding piece 40 is provided on the left side of the distance measuring lens 22.
42 are formed. The protruding pieces 40 and 42 are formed at positions symmetrical to the protruding pieces 30 and 32 with respect to the lens optical axis P, and positioning pins 44 and 46 are fixed to the surfaces thereof. When the distance measuring lenses 22 and 24 are attached to the lens barrel 26, the protruding pieces 30, 32, 40 and 42
The projections, which are arranged so as to be alternately arranged on a line segment 48 orthogonal to 4 and the projections, and the recesses formed by the projections, are fitted in a nested manner.

The pins 36 and 38 are formed at a position inward of the line L by a distance S, and the pins 44 and 46 are formed at a position of a distance S outward from the line L. Is done. Further, a pair of positioning pins 50, 5
2 is fixed on a line segment L passing through the lens optical axis P and orthogonal to the base line 34. The distance measuring optical module 20
Is that the base lengths B and S, and the linear expansion coefficients of the distance measuring lenses 22, 24 and the lens barrel 26 are different even if the temperature or the like changes.
Is set to be constant.

On the other hand, as shown in FIG.
The IC package 28 is adhered to the rear end of a rectangular tube formed in parallel. Also, long holes 54, 56, 58, 6 for lens positioning are provided at the front end of the lens barrel 26.
0, 62A, 62B and fool holes 64A, 64B are respectively formed. As shown in FIG. 2, the long holes 54 to 60 are long in the up-down direction in the figure, and the diameter in the left-right direction is formed so as to allow a pin to be press-fitted. , 44 and the long holes 58, 60 are engaged with the pins 36, 38 of the distance measuring lens 24. As a result, the distance measuring lenses 22 and 24 are positioned in the left-right direction with respect to the lens barrel 26, and the distance between the optical axes of the lenses 22 and 24 becomes the base line length B. This base line length B matches the base line length of the IC package 28 sensor shown in FIG.

The elongated holes 62A and 62B are long in the left-right direction in the drawing, and have a diameter in the up-down direction that is large enough to allow a pin to be press-fitted. The pin 5 of the distance measuring lens 22 is provided in the elongated hole 62A.
0 and the pin 50 of the distance measuring lens 24 is fitted in the long hole 62B. Thereby, the distance measurement lenses 22 and 24
Are positioned vertically with respect to the lens barrel 26. still,
The fool hole 64A is formed to have a size that allows the pin to be sufficiently displaced when it is expanded, and the pin 36 of the distance measuring lens 22 and the pin 46 of the distance measuring lens 24 are loosely fitted. I have.

The fool hole 64B is formed in a substantially T-shape and has a size sufficient to allow the pin to be displaced when inflated and expanded. Pins 38 and 52 of distance measuring lens 22 and pin 4 of distance measuring lens 24
4 and 52 are loosely fitted. Next, a description will be given of a method of positioning the distance measuring lenses 22 and 24 configured as described above.

First, the pins 44, 46 of the distance measuring lens 22,
50, as shown in FIG. 2, the long holes 56, 54,
The distance measuring lens 22 is positioned in the lens barrel 26 by engaging with the lens 62A. Next, the pins 36, 38, 50 of the distance measuring lens 24
Are engaged with the long holes 58, 60 and 62B of the lens barrel 26 to position the distance measuring lens 24 in the lens barrel 26. At this time, the projections 30 and 32 of the distance measuring lens 22 and the projection 4
0 and 42 alternately overlap on the line segment 48. As a result, the distance S of the distance measurement lenses 22 and 24 is increased by the width E where the projections 30 and 32 and the projections 40 and 42 overlap.
Dimensions can be given a margin in design. Therefore,
Even when the base line length B is very short as compared with the conventional distance measuring lenses 2 and 3 shown in FIGS.
Can be attached to the lens barrel 26 without the ends thereof colliding with each other.

Further, the lens 2 is changed by a change in temperature or humidity.
When the lens 2 is expanded, the engagement portion between the pins 44 and 46 and the elongated holes 56 and 54 of the distance measuring lens 22 becomes a base point of the lateral expansion.
Lateral expansion relative to this base point is achieved with pins 36, 38, 5
0 and 52 escape by the long hole 62A and the fool holes 64A and 64B. The base point of the vertical expansion of the distance measuring lens 22 is the pin 5
0 and the long hole 62A, the pin 44, 46 escapes at the long holes 56, 54, and the pins 36, 38, 52 escape at the fool holes 64A, 64B. escape. Thereby, the lens 22 expands without receiving any resistance. The escape effect due to this expansion is the same for the distance measurement lens 24.

FIG. 3 shows a second embodiment of the distance measuring optical module 70 according to the present invention. The distance measuring optical module 70 includes three distance measuring lenses 22, 24, and 72.
The lens is positioned in the lens barrel 74. The lens 72
Are the same lenses made by a common molding die with the distance measuring lenses 22 and 24, and therefore the description thereof is omitted.

An IC package 76 is fixed to the rear end of the lens barrel 74. At the front end of the lens barrel 74, a positioning round hole 80, a long hole 82, 84, 86, 88, 90,
92, 94 and fool holes 96, 98, 100, 102 are formed. The round hole 80 has an inner diameter formed so that a pin can be press-fitted, and the pin 50 of the distance measuring lens 24 is engaged.

The long holes 82, 84, 88, 92 and 94 are long in the vertical direction in FIG. 4, and the diameter in the left and right directions is formed so as to be able to press-fit a pin. The pins 46 and 44 of the lens 22 are engaged with the pins 88 of the distance measuring lens 24 in the long holes 88, and the pins 36 and 38 of the distance measuring lens 72 are engaged in the long holes 92 and 94. This allows
The distance measurement lenses 22, 24, 72 are positioned in the left-right direction with respect to the lens barrel 74.

The long holes 86 and 90 are long in the left-right direction, and the diameter in the up-down direction is formed so as to allow the pins to be press-fitted. The long holes 86 have the pins 50 of the distance measuring lens 22 and the long holes 9.
At 0, the pin 50 of the distance measuring lens 72 is engaged. As a result, the distance measuring lenses 22 and 72 are positioned vertically with respect to the lens barrel 74, and the distance between the optical axes of the lenses 22, 24 and 72 becomes the base line length B. This baseline length B is I
It matches the base length of the C package 76 sensor.

The fool holes 96 to 102 are formed in a size sufficient to allow the pins to be displaced when the pins are inflated and expanded.
The pins 38 and 52 of the distance-measuring lens 22 and the pin 44 of the distance-measuring lens 24 are loosely fitted into the pins 46 and 52 of the distance-measuring lens 24 and the L-shaped fool hole 98, respectively. Also, stupid hole 1
00 is the pin 36 of the distance measuring lens 24 and the pin 46 of the distance measuring lens 72, and the L-shaped flap 102 is the pin 38 of the distance measuring lens 24 and the pins 44 and 52 of the distance measuring lens 72, respectively. It is fitted.

The optical module for distance measurement 70 thus constructed is also the optical module for distance measurement 20 shown in the first embodiment.
Similarly, when the distance measuring lenses 22, 24, 72 are attached to the lens barrel 74 as described above, the projections 30, 32 of the distance measuring lens 22 and the projections 40, 42 of the distance measuring lens 24 Wrapped width E and projection 3 of distance measuring lens 24
(S × 2) dimensions of the distance measuring lenses 22, 24, 72 by (E × 2) by adding the width dimension E, at which the protruding pieces 40, 42 of the distance measuring lens 72 overlap with 0, 32. A margin can be given in design.

Therefore, the distance measuring lenses 22, 24, 72 are
Even when two or more lenses are used, when the base line length B is very short, the distance measuring lenses 22, 24, and 72 can be attached to the lens barrel 74 without their ends being bumped. When the distance measurement lens 22 expands due to a change in temperature or humidity, the distance measurement lens 22 is connected to the pins 44 and 46 and the long holes 84 and 82.
Is the starting point of the lateral expansion. The expansion of the distance measuring lens 22 in the lateral direction with respect to this base point can escape through the long hole 86 and the fool holes 96 and 98. Further, in the distance measuring lens 22, an engagement portion between the pin 50 and the elongated hole 86 serves as a base point of expansion in the vertical direction. The expansion of the distance measuring lens 22 in the vertical direction with respect to this base point can be escaped by the slots 82 and 84 and the holes 96 and 98. Thereby, the lens 22 expands without receiving any resistance. The escape effect due to this expansion is the same for the distance measuring lens 72.

On the other hand, when the distance measuring lens 24 expands, the engaging portion between the pin 50 and the round hole 80 of the distance measuring lens 24 becomes a base point of expansion in the vertical and horizontal directions. The distance measuring lens 24 expands in the horizontal direction with respect to this base point, and expands in the vertical direction with the slot 8.
Run away at 8. Thereby, the lens 24 expands without receiving any resistance. Accordingly, the optical module for distance measurement 70 of the second embodiment is also the optical module for distance measurement 2 shown in the first embodiment.
Similarly to 0, the base length B can be kept constant without being affected by changes in temperature or humidity.

[0029]

As described above, according to the distance measuring lens of the camera according to the present invention, a fitting convex portion is formed at one end of each of the distance measuring lenses, and a fitting concave portion is formed at the other end thereof. When the lens is positioned on the holding member, the fitting convex portion of the distance measuring lens and the fitting concave portion of the distance measuring lens adjacent to the distance measuring lens are arranged so as to fit in a nested manner, so that the base line length is set. Is very short, the distance measuring lens can be positioned on the holding member without the ends of the distance measuring lens colliding with each other.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a distance measuring optical module to which a distance measuring lens of a camera according to the present invention is applied.

FIG. 2 is a plan view of the optical module for distance measurement shown in FIG. 1;

FIG. 3 is a perspective view showing a second embodiment of a distance measuring optical module to which the distance measuring lens of the camera according to the present invention is applied.

FIG. 4 is a plan view of the optical module for distance measurement shown in FIG. 3;

FIG. 5 is a sectional view of a distance measuring optical module to which a distance measuring lens of a conventional camera is applied.

FIG. 6 is a plan view of the optical module for distance measurement shown in FIG. 5;

[Explanation of symbols]

 20, 70 ... distance measuring optical module 22, 24, 72 ... distance measuring lens 26, 74 ... lens barrel 28, 76 ... IC package 30, 32, 40, 42 ... projecting piece 36, 38, 44, 46, 50, 52 ... Pin

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-241508 (JP, A) JP-A-2-213810 (JP, A) JP-A-4-190210 (JP, A) JP-A-4- 306607 (JP, A) JP-A-6-130261 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B ^7/ 28-7/40 G02B 7/02 G03B 13/36

Claims (1)

(57) [Claims] A distance measuring lens of a camera which is individually positioned via a plurality of pins in a positioning hole of a single holding member so that each optical axis distance becomes a base length for distance measurement. In positioning the distance measuring lens to the holding member, a fitting projection is provided at one end of the distance measuring lens such that ends of adjacent distance measuring lenses are nested with each other, and a distance measuring lens. A distance measuring lens for a camera, comprising: a fitting concave portion fitted to the fitting convex portion on the other end side of the lens.