JPS59162408A - Distance measuring unit - Google Patents

Abstract

PURPOSE:To obtain a broad range wherein adjustment can be performed, by displacing a light receiving block having a light receiving element in the direction of the length of a base line by the rotation of an eccentric shaft, which is compressed to an optical block having a light receiving lens. CONSTITUTION:An optical block A supports a light receiving lens 6. A light receiving block C supports a light receiving element. A coupling means couples the light receiving block C and the optical block A so that the light receiving block C can be displaced in the direction of the length of a base line with respect to the optical block A. An adjusting member 15 devices the light receiving block C, so that the light receiving block C is displaced in the direction of the length of the base line, and adjusts the position.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a projection light type triangular distance measuring device that measures the distance at a distance measuring object 1 by projecting light onto a distance measuring object and receiving the light reflected by the distance measuring object. .

Prior Art Conventionally, in order to measure the distance to an object (in the case of a camera, the subject) using a camera, light is projected onto the object, and this light reflected by the object is measured. 2. Description of the Related Art Projection light type triangulation distance measuring devices that measure the distance to an object by receiving light are known. In this device, the accuracy of the baseline length between the light emitting light source section and the light receiving section affects the distance measurement accuracy, so this baseline length must be set accurately.

Projection light triangulation distance measuring devices perform measurements by utilizing the fact that the angle of incidence of the light reflected from the object differs depending on the distance to the object. There is a known configuration in which a light-receiving element is provided with photovoltaic elements arrayed, and detection is performed depending on which element the light is incident on. In this configuration, if the relative positions of the light-receiving lens and the light-receiving element that receive the light reflected by the object are not accurate, the light incident at the angle of incidence defined by the distance will be
The element that should originally receive the incident light cannot receive it, and a different element receives the light, resulting in inaccurate distance measurement.

Therefore, an adjustment device is required to adjust the relative position of the light receiving lens and the light receiving element.

- By the way, when assembling such a distance measuring device, it is difficult to avoid a certain degree of error in the relative positions of the light receiving lens and the light receiving element, and the above adjusting device needs to have a large adjustment range.

An example of this adjusting device is one in which a transparent homogeneous flat plate having a uniform thickness is provided between a daylight lens and a light receiving element and is tilted with respect to the incident optical path from the light receiving lens. This is because the light incident obliquely on the flat plate surface is refracted, and when it exits obliquely from the back surface, it is refracted again and passes along a different optical path that is parallel to the optical path before incidence, and the angle of the flat plate with respect to the incident optical path. Adjust the exit optical path by changing .

However, with this adjustment device, the amount of adjustment tends to be limited by the thickness of the transparent flat plate, and if the required amount of adjustment becomes too large, it cannot be adjusted completely, and countermeasures such as replacing it with a thicker flat plate are required.

Furthermore, if the adjustment range is increased, there is also the problem that fine adjustment becomes difficult.

OBJECT An object of the present invention is to obtain a distance measuring unit in which the base line length can be adjusted over a wide range.Embodiments Next, seven embodiments of the present invention will be described with reference to the accompanying drawings.

In this embodiment, the present invention is applied to a distance measuring device used in an automatic focusing device of a camera.

Figure 1 shows the distance measuring unit as seen from above, and Figure 2 shows the distance measuring unit as shown in Figure 1.
Figure 3 shows the view from above when cut along the horizontal plane including x', Figure 3 shows the view from the left when cut along the vertical plane including the finder optical axes X and X/ in Figure 1, and Figure 4 shows the view from the left. 1 as seen from the left, and FIG. 5 shows the state as seen from the left when cut along a vertical plane including the light receiving optical axis Z--Z/ in FIG.

The distance measuring unit includes a projection light type triangulation distance measuring device and a finder device, and the projection light type triangulation distance measuring device includes a projection light source section and a light receiving section. The projection light source section includes a light source and a projection optical system that project a single beam of light toward the subject for distance measurement, and the light receiving section includes a light receiving element that receives light reflected by the subject, and a light receiving optical system. and an electric circuit that processes the output signal of the light receiving element and measures the distance.

The distance measuring unit has a mounting hole (A13) on the top of the camera body.
It is fixed with a mounting screw through the i, and in this mounted state, the finder optical axis
is parallel to the optical axis of a photographic lens (not shown) installed on the camera. Furthermore, after being fixed to the top of the camera, the electric circuit of the light receiving section is connected to the terminal of the camera body, allowing distance measurement signals to be transmitted to the camera body.

The distance measuring unit consists of an optical system block (A) consisting of the optical systems of the projection light source section and the light receiving section and a finder device, a light source block (■) in which the projection light source is installed, and a tongue tip block (C) in which the light receiving element and electric circuit are installed. The blocks (A), (B), and (C) are connected so that their relative positions can be changed by adjustment.

Next, the configuration of each block (A), (B), and (C) will be explained.

As shown in Figures 1 to 3, optical system gloss (A)
is formed into a substantially T-shape when viewed from above.

The base of the optical system block (A) is a plastic molded product made of a material such as polycarbonate reinforced with glass fiber, and has cavities penetrating in the front and back direction in the center and left and right parts. .

The central cavity of the optical system block (A) contains a finder objective lens (1), a concave lens (2), and a flat glass (
3), an eyepiece lens (4) is supported, a light projecting lens (5) is provided in the left cavity, and a light receiving lens (6) is provided at a predetermined base length distance from the light projecting lens (5) in the right cavity. is supported. The finder optical system has a rectangular shape when viewed from the front.

The objective lens (1) is a T-shaped optical system block)
The upper and lower edges (1a) of the lens are attached to the peripheral frame of the cavity and the lens front frame (7) at the front end of the cavity that penetrates the body (A1) extending from the front to the rear in the center of the lens. Attached by being pinched. The front lens frame (7) also supports the light emitting lens (5) and the light receiving lens (6), and as shown in Fig. 1, Fig. 4, and Fig. 5, A protrusion (7a) protruding in the front frame mounting hole (A) formed in the front part of the optical system block (A)
4), it is connected to the optical system block (A).

A substantially rectangular concave lens (2) when viewed from the front is attached to the rear of the objective lens (1). The concave lens (2) is arranged between the concave lens (2) and a stepped surface (A5) formed perpendicularly to the optical axis of the objective lens in the body (A1) by making the cavity slightly narrower. It is a rectangular frame shape that matches the shape of the frame, and the plate springs (9) are bent in a dogleg shape so that the center part of each frame edge protrudes from the frame surface.
Furthermore, it is pressed and supported from the front by a rectangular lens frame (8). As shown in Fig. 3, the lens frame (8) has bent portions (8a) formed at the top and bottom, and these bent portions (8a) support the concave lens (2) vertically between them. The lower end of the frame (8)
b) is inserted into the hole (86) which is opened so as to pass through the bottom of the body (AI), and comes into contact with the protrusion (A,) which protrudes rearward from the front edge of the hole (A6). There is.

Further, an adjustment eccentric shaft (10) is press-fitted from the outside to the inside of the trunk (A1) and passes through the upper part of the trunk (A1), and the eccentric pin (10IL) of the adjustment eccentric shaft (10) ) resists the biasing force of the leaf spring (9) and the lens frame (8) and concave lens (
The concave lens (2) is positioned by pressing the lens (2) from the front to the rear. Incidentally, the eccentric pin (10a) is a pin formed at a position eccentric from the axis of the press-fit portion of the adjustment eccentric shaft (10). Therefore, by rotating the adjustment eccentric shaft (10), the front and rear positions of the eccentric pin (LOa) change, and the lens frame (8) and concave lens (2) are aligned with the protrusion (A,) and the lower end of the lens frame (8b). ) can be used as a fulcrum to swing, and by adjusting the angle of the optical axis of the concave lens (2), it is possible to adjust the position of a display such as a shooting range frame within the field of view of the finder, which will be described later.

Incidentally, as shown in Fig. 1, a pair of eccentric shafts (10) for adjustment are provided at substantially symmetrical positions with respect to the finder optical axis x-x'. It can be adjusted vertically, horizontally, and horizontally.

Here, the adjustment eccentric shaft (10) is a plastic motor/
The body (A) of the optical system block (A) formed by the lid
□) is press-fitted from the top by so-called t and b fitting, and although it is rotatable, it is semi-fixed with uniform hardness. Therefore, although it is possible to rotate the adjusting eccentric shaft (10) with a tool such as a screwdriver, it cannot be easily rotated by vibration or contact alone.

A flat glass (3) is attached to the grip of the concave lens (2), and an eyepiece (4) is attached to the rear of the flat glass (3). The flat glass (3) and the eyepiece (4) also have a substantially square shape, and fit into the mounting groove (A9) formed on the inner wall side of the body (A1) of the optical system block (A). and is fixed using adhesive as appropriate.

Incidentally, on the opposing surfaces of the concave lens (2) and the flat glass (3), there is a total reflection or translucent reflective mirror surface (2).
a) (8a) is provided, a part of the light incident from the objective lens (1) is reflected on the reflective mirror part (3a) of the flat galanu (3), and the reflective mirror part (3a) on the concave lens (2) side is attached to the body. By being reflected by 2a) and guided to the eyepiece lens (4), it is possible to display the photographing range frame, distance measurement range, and other characters, patterns, etc. within the field of view of the finder. This display can be made by adjusting the angle of the concave lens (2) as described above.
- and flat glass (3) respective reflective mirror surfaces (2aX8a)
The correct position can be adjusted by changing the relative position of the .

(Light-emitting diodes made by 11 manufacturers are used for various camera displays, such as low-luminance warnings that are issued when subject brightness is low and proper exposure cannot be performed, displays that the flash device has been charged, and displays that the distance measurement operation has completed. Ru.

The light emitting part of the light emitting diode (11) slightly protrudes inside the body part (A1) of the optical system block (A), and the connecting terminal (11)
11) penetrates the body side wall (AI) and is integrally attached to the optical system block body by soldering a contact piece (llb) to the portion that protrudes to the outside of the body.

Therefore, by looking into the finder device through the finder eyepiece frame (A, . . . ), the photographer can simultaneously observe the subject image, the photographing range frame, the distance measuring range frame, the display by the light emitting diode (11), etc.

In FIG. 1, the finder device is open at the top, that is, at the front in the figure, but this portion is covered when it is assembled into the camera body.

Finder optical axis of optical system block (A) KfAX7X
'To the left is the light emitting lens (5), and to the right is the light receiving lens (5).
6) is installed. The light emitting lens (5) and the light receiving lens (6) are attached to the front ends of the left and right cavities of the optical system block (A), and the edges of the lenses (
5a) (6a) are supported by being pinched.

As shown in FIGS. 1 and 2, the light source block CB)
It is connected to the optical system block (A) at a position on the left side of the distance measuring unit with respect to the finder optical axis XX/ and behind the light projecting lens (5). The light source block (B) has a cavity passing through it, and in the cavity, a light emitting diode (12) that emits infrared light is pressed against the inner wall of the cavity by a plate spring (2c), so that a light projection lens is installed. (5) It is positioned and installed on the projection light optical axis Y-Y/.

As shown in FIGS. 2 and 4, the light source block (B) has a vertically elongated guide hole (B2) extending in the front-to-back direction at the left side position, and the left end is located at the front side. It protrudes to form a sliding piece (B3). On the other hand, optical system block G
The rear side of the left side of A) is slightly concave and the sliding piece (B3)
A guide groove (AJ) is formed with a vertical stepped surface that can be fitted into the guide groove (A12), and a protruding portion is formed so that the stepped surface of the guide groove (A12) is extended and extends to the rear of the lens support block (A). The tip of the protruding portion is divided into upper and lower parts to form a fork-shaped guide piece (A, □).In the part having such a shape, the fork-shaped guide piece of the optical system block body (An) is elastically fitted into the guide hole (B4., ) of the light source block (B) so that it presses in the vertical direction ζ
The sliding piece (B3) of the light source block (B) fits into the guide groove (A□) of the optical system block (A). As a result, the fork-shaped guide piece (AI1) and the guide hole (B2) and the sliding piece (B8) and the guide groove (All) slide on each other, so that the light source block CB) is moved relative to the optical system block (A). It can move forward and backward.

Further, an eccentric shaft for adjustment (13) is press-fitted into the protruding portion where the fork-shaped guide piece (All) is formed, and an eccentric head (13a) forming the head of the eccentric shaft for adjustment (13)
) is fitted into a vertically elongated oblong slot (B4) formed in the sliding piece (B3). When the adjustment eccentric shaft (13) is rotated, the light source block (B) is displaced in the front-rear direction according to the displacement of the eccentric head (13a).

Therefore, by rotating the adjustment eccentric shaft (13), the light emitting diode (12) is positioned at the focal point of the light emitting lens (5), and thereby the light emitted from the light emitting diode (12) is directed to the light emitting lens (5). 5), the light becomes a parallel beam of light and is projected to the object to be measured. In addition, since the amount of vertical displacement of the eccentric head (1'la) is smaller than the length of the elongated hole groove (B4) in the long axis direction, no force acts on the light source block (B) to displace it vertically. .

The eccentric shaft for adjustment (13) is press-fitted into the base of the protruding part forming the fork-shaped guide piece (A11) of the optical system block (A) formed of plastic mold by a stripe fit, and is rotatable. However, it is pivoted semi-solidly. Therefore, although it is possible to rotate the adjustment eccentric shaft (13) with a tool such as a screwdriver,
It cannot be easily rotated by vibration or contact alone.

The light-receiving block (C) has a penetrating cavity, and as shown in FIGS. 1 and 2, the light-receiving lens in the optical system processor (A) K is the cloth part of the distance measuring unit with respect to the finder optical axis (6) Attached to the rear.

In other words, the optical system block, (
A) and the light receiving block (C) are pivoted so as to pass through it.
The pin (14) is press-fitted by a so-called interference fit, and both blocks (A) and (C) are connected to each other so as to be able to swing in a semi-fixed manner. Press-fit the shaft (15) and make the head part of the shaft (15).
By fitting the B head (15a) into a longitudinally elongated oblong groove (C,) formed in the light receiving block (C), both blocks (A) and (C) are connected to each other so that they can be displaced. has been done.

When the adjustment eccentric shaft (15) is rotated, the amount of eccentricity @1S (
15a), the long hole groove (C1) is pushed left and right, and the light receiving block (C) swings about the pivot pin (14). This oscillation causes the aforementioned light emitting diode (12
) is emitted by the projecting lens (5), reaches the subject as a flat beam, and is reflected.The so-called base line length π is trimmed so that the infrared light crab J reaches a predetermined light receiving element (16).
S will be carried out.

Reference numeral (22) denotes an optical axis adjustment plate disposed behind the light-receiving lens (6), which is a transparent plastic molded member having a certain thickness. The rotation shaft portion (22b) is press-fitted from the right side of the light receiving block (C) by a so-called interference fit, and the optical axis adjustment plate (22) is rotatable but semi-fixedly supported. The optical axis adjustment plate (22) is connected to the rotation shaft part (2
By rotating the transparent plane plate part (22a)
) rotates around the axis PP', and can vertically displace the optical path of the light incident from the light receiving lens (6).

As shown in FIGS. 2 and 5, the light receiving element (16) is a semiconductor piece that is located at the rear end of the cavity formed in the light receiving block (C) and is composed of a plurality of photovoltaic element arrays, and is mounted on a ceramic substrate ( 17) Mounted on top. Ceramic substrate (17
) is equipped with an integrated circuit (18) for processing the signal from the light receiving element (16), and a ceramic substrate (17).
) is pasted on the back side of the epoxy resin circuit board (19) on which electric circuit elements for signal processing are assembled. These circuit boards (17) (19) fit the positioning protrusions (C2) formed on the light receiving block (C) into the receiving holes (19a), and the light receiving block is installed by screwing in the screws (20). It is attached to (C).

In addition, a filter (21) is installed on the front surface of the light-receiving element (16), which transmits only infrared light into the cavity and absorbs other light. Infrared light reaches the light receiving element (16), but other light does not reach the light receiving element (16).

In the distance measuring unit configured as described above, the light reflected from an object at a predetermined distance is incident on the light receiving lens (6) at an incident angle corresponding to the distance, and the light is reflected at an incident angle corresponding to the distance. 11] of the reflected light on the light receiving element (16) depending on the distance of the subject in order to reach the light receiving element (16).
The points are different. Therefore, in order to perform accurate distance measurement, the position of the light receiving element (16) with respect to the light receiving lens (6) must be correct.
5), rotate the light-receiving block (C) around the pivot pin (14), and move the light-receiving element-T (16) in the left-right direction so that light can be received correctly by the element according to the subject distance. It can be adjusted as follows.

As described above, when the adjustment eccentric shaft (15) is rotated in the distance measuring unit of the present invention, the light receiving block (C) rotates around the pivot pin (14), and the light receiving element (16) is connected to the distance measuring unit. Move approximately left and right. At this time, the adjustment range can be selected by setting the eccentricity of the adjustment eccentric shaft (15), and by increasing the eccentricity, a wide adjustment range can be obtained. Therefore, even if there is a large error in the mounting positions of the light receiving element (16) and the light receiving lens (6) during assembly of the distance measuring device, the baseline length can be adjusted.

In addition, in the above-mentioned embodiment, the adjustment eccentric shaft (10) ('1
3) (15) and the pivot pin (14) are press-fitted into the base of the ranging unit, which is made of plastic molding, and are semi-fixed due to their moderate hardness, so they cannot be adjusted using the tool. If you rotate it using other methods, it will not rotate easily.

As described above, in the distance measuring unit of the present invention, the light receiving block having the light receiving element is displaced in the base line length direction by rotation of the press-fitted eccentric shaft with respect to the blower of the optical system having the light receiving lens. Because of this configuration, it is possible to provide a distance measuring unit with a wide adjustable range.

[Brief explanation of the drawing]

Fig. 1 is a top view showing an embodiment of the present invention, Fig. 2 is a sectional view of the above embodiment taken along a horizontal plane, and Fig. 3 is a longitudinal section of the above embodiment taken along a vertical plane including the finder optical axis. FIG. 4 is a side view of the same embodiment, and FIG. 5 is a longitudinal sectional view of the above embodiment taken along a vertical plane including the light receiving optical axis. 16. Light receiving element, 22... Optical axis adjustment plate, A... Optical system block. B--Light source block, C-Light receiving block. Applicant: Minolta Camera Co., Ltd. Figure 3 Figure 4 Figure 5 a

Claims (1)

[Scope of Claims] 1. A light source that emits light for distance measurement, a light projection lens that projects the light from the light source onto a distance measurement target, and a light source that is installed at a predetermined baseline length from the light projection lens, An optical system that supports the light receiving lens in a projection light type triangular ranging device comprising a light receiving lens that receives light projected from a light projecting lens and reflected by a distance measurement target, and a light receiving element that receives light that has passed through the light receiving lens. a light-receiving block that supports a light-receiving element; a connecting means that connects the light-receiving block and the optical system block so that the light-receiving block can be displaced in the baseline length direction with respect to the optical system block; A distance measuring unit comprising: an adjustment member that adjusts the position by driving the light receiving block so as to displace it in the baseline length direction. 2. The distance measuring unit according to claim 1, wherein the connecting means is a rotating shaft that passes through the optical system block and the light receiving block and is press-fitted in a semi-fixed manner. 3. The distance measuring unit according to claim 1, wherein the adjustment member is a rotatable eccentric shaft member that is semi-fixedly press-fitted into the optical system block and engages with the light receiving block. 4. The light projection lens is supported by the optical system block, and the light source is supported by the light source block, and the light source block is movable parallel to the optical axis of the projection lens, and the relative position of the light source block with the optical system block is displaceable. 2. The distance measuring unit according to claim 1, further comprising an adjusting member that is driven to adjust the distance.