JPH02293615A - Range finder - Google Patents

Abstract

PURPOSE:To accurately measure a distance without being affected by how a camera is held nor the arrangement of a subject by dividing the light beam from a light source into three vertically and moving the light source horizontally and mechanically. CONSTITUTION:A prism 11 is arranged on the projection side of a projection lens 2 and has a surface 11A perpendicular to the optical axis of the incident light and slanting surfaces 11B and 11D. The light beam from the light source 1 is therefore split into three light beams to generate measured distances Pa, Pd, and Pb in the center and upper and lower parts in a photography range 10. Further, the light source 1 is moved by a motor in parallel to the length of a base line, so distance measurement points are formed at Pa1, Pb1, and Pd1, and Pa2, Pb2, and Pd2. Consequently, the distance measurement points are distributed in two dimensions, so the distance accurately is measured even when the camera is held longitudinally or when right and left separate subjects are arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a distance measuring device that measures the distance to a subject in, for example, a camera. [Prior Art] As one of the autofocus devices in a camera, The infrared light active method is known. In this method, a small diameter infrared light beam is projected onto the subject.
The reflected light is received by a semiconductor optical position detection device (PSD), etc., and the distance to the subject is calculated from the detection output of the PSD, and the photographing lens is driven to a predetermined position according to the calculation result. This is for taking pictures. With such conventional devices, when photographing a scene in which two people are standing, for example, the light beam for distance measurement may not be projected onto the two people, but instead may pass between them. As a result, instead of the distance to the person as the original subject,
The distance to the background behind the person is measured, and the image of the person becomes out of focus.

In order to prevent such false detection, for example,
No. 3406 proposes a method of dividing an infrared light beam horizontally (linearly) into three beams. In this way, the distance measurement range is widened and the left or right light beam is projected onto the two people, reducing the possibility that the distance to the background will be measured incorrectly. [Problems to be Solved by the Invention] However, the method described in the above publication is good when taking pictures by holding the camera horizontally, but when taking pictures by holding the camera vertically, it still eliminates the drawbacks of the conventional method. I couldn't do it. This invention was made in view of this situation, and is intended to make it possible to accurately measure the distance to the actual subject without being affected by how the camera is held or the placement of the subject. [Means for Solving the Problems] The distance measuring device of the present invention includes a light source means for emitting a light beam for distance measurement, and a light beam emitted from the light source in a direction parallel to the base line length direction and a direction perpendicular to the base line length direction. an optical means for dividing the light source into a plurality of parts in one direction, a moving means for mechanically moving the light source in the other direction of the direction parallel to the base line length direction and the direction perpendicular to the base line length direction; The camera is equipped with a light projection means for projecting a light beam onto a subject, a light collecting means for collecting a light beam reflected by the subject, and a detection means for detecting the light collected by the light collecting means. [Operation] For example, one light beam emitted from an LED as a light source is split into three beams by a prism as an optical means in a direction perpendicular to the base line length direction. Additionally, this LED is mechanically moved by a predetermined distance in a direction parallel to the baseline length direction. This allows the distance measurement points to be distributed two-dimensionally. Therefore, the distance to the actual subject can be accurately measured regardless of the subject's placement or how the camera is held. [Example] Figure 2 shows the principle of distance measurement in this invention.
A light beam for distance measurement generated by a light source 1 made of, for example, an infrared LED is projected onto a subject 3 via a projection lens 2. The light beam reflected at the reflection point R of the subject 3 passes through the condenser lens 4? Semiconductor optical position detection element (PS
D) Injected into the predetermined position of 5. Assuming that the optical axis of the condensing lens 4 is located at the center of the PSD 5, when the subject 3 is located at an infinite distance due to the focus adjustment of the camera, the light beam will be incident on the center of the PSD 5 [M]. do. As the distance d between the subject 3 and the projection lens 2 becomes smaller, the spot position of the light beam on the PSDS [S] moves to the right in the figure. The distance between the right end A of PSD5 and position S is X, and the distance between position M and position I! Let the distance from S be ΔL. If the length from the left end B of PSD5 to the right end A is L, then the right end A of PSD5 is
Output current I from the left end B, and output current I2 from the left end B.
becomes as follows. I,=Ip(L-x)/L
... (1) I2 = engineering px/L
...(2) Here, Ip is a constant.

From the above equation, the following equation is obtained. ■. =(It-I,)/(I■+I2)=(I p(L
-x)/L-I p x/L)/(Ip(L-x)
/L+Ipx/L)=1-2x/L
・ ・ ・(3) Also, since the following equation (4) holds true, x = L / 2-ΔL ・・・(4)
By substituting this equation (4) into equation (3), equation (5) is obtained. ? ,=1-2x/L =1-2(L/2-ΔL)/L =2ΔL/L ・ ・
・(5) Center 0■ of the projecting lens 2, reflection point R of the subject 3
and the center O. of the condenser lens 4. The triangle formed by connecting the
Since the triangles formed by connecting position M, center 04, and position S are similar, equation (6) holds true. ΔL=Df/d・
...(6) Here, f is the focal length of the condenser lens 4 (distance between the condenser lens 4 and PSD 5), and D
is the base line length (distance between the optical axis of the projection lens 2 and the optical axis of the condenser lens 4). Therefore, by substituting equation (6) into equation (5), the following equation (7) is obtained. ? ．． =2Df/(dL) ・ ・
-(7) Rewriting equation (7), equation (8) is obtained.

d=2Df/(LI.)...(8)
In equation (8), the values D, f. L is known and the value I. can be calculated from the output currents I2 and I2 of the PSD 5 according to equation (3), so the distance to the subject can be calculated from equation (8).

FIG. 3 is a block diagram of the distance measuring device of the present invention. In the figure, numeral 21 is a control circuit composed of, for example, a microcomputer, which controls photographing operations including distance measuring operations.
22 is a switch operated in conjunction with the release button of the shirt shutter (not shown). 23 is a drive circuit that drives the light source 1, and 24 is an A/D conversion circuit that A/D converts the output of the PSD 5 and supplies it to the control circuit 21. 25 is a lens drive system that drives a photographic lens (not shown). 26 is a memory that stores programs, data, etc. 28 is a motor that is driven by a drive circuit 27 when moving the light source 1 in a predetermined direction. However, when the switch 22 is pressed, the control circuit? 1 drives the light source 1 via a drive circuit 23 to generate a light beam. This light beam is projected onto a subject 3 via a projection lens 2. The light beam reflected by the subject 3 is incident on the PSD 5 via the condenser lens 4. The output currents I and I2 of the PSD 5 are A/D converted by the A/D conversion circuit 24 and inputted to the control circuit 21. The control circuit 21 calculates the distance d according to the above-mentioned equations (3) and (8). Value required for calculation D. f
．． L, etc. are stored in the memory 26 in advance. Further, the calculation results are temporarily stored in the memory 26.

Next, the control circuit 21 drives the motor 28 via the drive circuit 27 to move the light source 1 by a predetermined distance in a predetermined direction. Then, a distance measurement operation is performed in the same manner as in the case described above, and the calculated value is compared with the previous calculated value stored in the memory 26. The larger value is then stored in the memory 26. Similar operations are repeated a predetermined number of times, and finally the largest calculated value is stored in the memory 26. This largest calculated value corresponds to the distance to the nearest distance measurement point. The control circuit 21 drives the photographic lens via the lens drive system 25 in accordance with the largest calculation result, and operates the shutter when the photographic lens is moved to a predetermined position. By the way, the light projection system of this invention is configured as shown in FIG. 1, for example. That is, the prism 11 is arranged on the output side of the light projecting lens 2. This prism 11 has a surface 11 inclined in a direction perpendicular to the base line length direction (vertical direction in II).
B, a surface 11A perpendicular to the optical axis of the incident light and an inclined surface 11
D in sequence. As a result, one light beam emitted from light g1 is divided into three light beams, which are emitted from three surfaces IIA, IIB, and IID, respectively. Therefore, as shown in FIG.
At approximately the center of 0 and above and below it, there is a WA distance Pa. Pd. Pb
are formed respectively. Also, in this embodiment, the light source 1
is moved by a predetermined distance in a direction parallel to the base line length direction (horizontal direction in the figure) by driving the motor 27.
As a result, the distance measuring point Pa. There are distance measuring points Pa on the left and right of Pb and Pd.
,,Pb. ．． Pd. and. Pa,, Pb2, and Pd, are respectively formed. In other words, the distance measurement points are distributed two-dimensionally (plane). The same thing can be achieved with the light projection system shown in Fig. 5. In this embodiment, the inclined surface 12C and the vertical surface 12A of the prism 12 disposed on the exit side of the projection lens 2
and an inclined surface 12E are arranged in a direction parallel to the base line length direction. As a result, one light beam emitted from the light source 1 is divided into three beams in a direction parallel to the base line length direction, and the beams are divided into three beams at the distance measuring points Pa, Pai. Pa, are formed respectively. Therefore, in this case, by moving the light [1 by a predetermined distance in a direction perpendicular to the base line length direction, the so-called focal point Pa
, Pax, Pa2, distance measuring points Pd, Pdi, Pd
, and pb. pb1. pb, are formed respectively.

Next, an example of a condensing system applicable to these light projecting systems will be described.

In FIGS. 6 to 9, light beams from a plurality of distance measuring points distributed in a direction parallel to the base line length direction are optically made incident on a PSD using a prism.

In the embodiment shown in FIG. 6, on the incident side of the condenser lens 40,
A prism 13 is arranged. This prism 13 is
It has a vertical surface 13A and inclined surfaces 13B to 13E. Surface 13G. 13A. 13E is sequentially arranged in a direction parallel to the base line length direction, and surfaces 13B, 13A, and 13D are arranged in a direction perpendicular thereto. Therefore, the distance measuring points Pa, Pb in FIG. Pa,,Pd. The reflected light beam from Pa2 hits surface 14A. of this prism 14. 14
B, 14C. The light enters from 14D and 14E, respectively, and is irradiated onto the PSD 5 via the condenser lens 4. Here one P
The operation of the PSD when light from multiple aperture points is simultaneously incident on the SD will be explained. For example, as shown in FIG. 10, if a person 17 is placed slightly to the right of the center of the shooting range 10, a tree 19 is placed to the left, and a mountain 18 in the background is placed in the center, the distance measurement point Pa2 Person 17 is 2lI! Tree 19 is created by distance point Pa, and mountain 1 is created by distance measurement point Pd (Pa.Pb).
8 are measured. Assuming that the person 17 is now closest to the camera, the mountain 18 is the farthest, and the tree 19 is located at a distance between the two, the distance measurement point on the PSDS is as shown in Figure 11. Pa. The distance ΔL2 from the position M of the spot Sa corresponding to the distance measuring point P
Distance ΔL from position M of spot Sa corresponding to a
Becomes greater than 1. Also, the spot Sd (Sa.Sb) corresponding to the distance measuring point Pd (Pa, Pb) is theoretically located at the position I
It will be placed in IM. However, since the distance between the distance measuring point Pd (Pa.Pb) and the camera is very long,
The light is attenuated on the way, and is essentially a spot Sd (Sa.
Sb) is not formed. The light energy of spots Sa and Sa2 is transferred from the camera to the distance measuring point Pa. , the distance to Pa2 is dd2, and the distance to the distance measuring point Pa is Pa2? The emissivity is R1, R2
Then, the following equation (9) holds true.

E■:E-=R-7Cdi)":Rz/(dz)"・
・ ・(9) From equation (9), equation (10) holds true. E■/E,=R(d2)"/(R,・(dl)")・
- (10) If the positions of the centers of gravity of spots 3a and Sa are respectively aL and a2, then the positions of the centers of gravity of the light energy of both spots! g. is the gland component ae, a2 is the ratio of light energy E
This is the point divided internally by 2 vs. E2. Therefore, the distance ΔLg from the position M of the center of gravity Mg is determined by the following equation (11).

ΔLg=ΔL2-(ΔL2-ΔLt)/(1+Ei/E
W ・ ・ ・ (1 1) PSD5 is this (11)
It outputs the electric current, , and 2 corresponding to the formula, so if there are two or more objects within the distance measurement range, their optical center of gravity positions will be measured. In general, the light reflected from the object at a closer distance (spot Sa2 in the example) has stronger optical energy than the light reflected from the object at a farther distance (spot Sai in the example). , regardless of the distance of the far object, it is possible to obtain a close focus on the near object. Furthermore, in general (as the closest subject near the center of the shooting range is often the main subject, this prevents the main subject from becoming out of focus. In the embodiment shown in Fig. 7, , the prism 14 disposed on the incident side of the condensing lens 4 has only a vertical surface 14A and inclined surfaces 14C and 14E. Instead, the PSDs 5 are arranged in a direction parallel to the base line length direction. However, the distance measurement points in the direction perpendicular to the baseline length direction are measured at different timings.In contrast, the implementation of Fig. 8 In the example, above and below (perpendicular to the baseline length direction) the PSD 5a placed in the center
Are PSD5b and 5d placed? , This eliminates the need to move the PSD 5 up and down unlike the embodiment shown in FIG.

On the other hand, in the embodiment shown in FIG. 9, the length of PSD5A in the direction perpendicular to the base line length direction is set to approximately three times that of PSD5 shown in FIG. 7. In other words, in the embodiment shown in FIG. Three PSDs 5b, 5a, and 5d are formed from one PSD 5A. Therefore, in this case, when the projection system has a configuration as shown in FIG. 1, for example, distance measurement is performed in a direction perpendicular to the base line length direction by detecting the optical center of gravity position. In addition, in the case of a light projection system configured as shown in Fig. 5,
Distances are measured in chronological order. That is, for example, first the distance measurement point P
a, Pa,, Pa2, then distance measuring points pb, pb. pb,
, and then the distance measuring point Pd. The distances of Pd■ and Pd are measured in sequence.

Next, the embodiments shown in FIGS. 12 to 15 are for mechanical scanning in a direction parallel to the base line length direction. In the embodiment shown in FIG. 12, the prism 15 arranged on the incident side of the condenser lens 4 has a vertical surface 15A, an inclined surface 15B. It has 15D. This surface 15B, 15
Since A and 15D are sequentially arranged in a direction perpendicular to the base line length direction, the PSD 5 is moved in a direction parallel to the base line length direction.

On the other hand, in the embodiment shown in FIG. 13, the prism 15 in the embodiment shown in FIG. It looks like this.

Furthermore, in the embodiment shown in FIG. 14, in order to eliminate the need for movement in the direction perpendicular to the baseline length direction, the three PSDs 5b,
a and 5d are arranged in a direction perpendicular to the base line length direction. Further, in the embodiment shown in FIG. 15, a PSD5A having a length approximately three times as long in the direction perpendicular to the base line length direction is used. When using the projection system shown in Figure 1, the distance in the direction perpendicular to the baseline length direction is determined by determining the optical center of gravity. Next, FIGS. 16 to 19 show an embodiment in which a plurality of PSDs are arranged in a direction parallel to the base line length direction. In the embodiment shown in FIG. 16, three PSDs 5c. 5a. 5a are sequentially arranged, and in order to make the light beam from the lasing point in the direction perpendicular to the base line length direction enter these PSDs, on the incident side of the condenser lens 4, in the direction perpendicular to the base line length direction. A prism 15 having sequentially arranged surfaces 15B, 15A, and 15D is arranged.

On the other hand, in the embodiment shown in FIG. 17, the prism 15 in the embodiment shown in FIG. ing. On the other hand, in the embodiment shown in FIG. 18, in addition to PSDs 5a, 5C, and 5e arranged in a direction parallel to the base line length direction, there are PSDs 5b and 5d arranged in a direction perpendicular to the base line length direction. Therefore, in this case, there is no need to move not only in the direction parallel to the baseline length direction but also in the perpendicular direction. In the embodiment shown in FIG. 19, PSDs 5B and 5C are placed on the left and right sides of the PSD 5A in the embodiment shown in FIG. This eliminates the need to move the PSD in a direction parallel to the base line length direction.

Next, FIGS. 20 to 23 show an embodiment in which the PSD is elongated in a direction parallel to the base line length direction and electrically scanned. In the embodiment shown in FIG. 20, a PSD5D is used in which the length in the direction parallel to the base line length direction of the PSD5 in the embodiment shown in FIG. 12 is set to be about three times as long. In other words,
The three PSDs 5a, 5G, and 5e in Fig. 16 are combined into one PSD.
It has been replaced with the SD5D. In this way, the light beams from the ranging points (for example, Pa. Pa, Pa,) arranged in the direction parallel to the base line length direction are
is input to D in a time-sharing manner. So in this case, PSD
It is necessary to electrically scan 5D in a direction parallel to the baseline length direction.

Next, is there an electrical current in a direction parallel to this baseline length direction? The principle of the channel will be explained with reference to FIG. Now light source 1
a■ and la2 are separated by a distance q from the light source 1a, and when the subject 3 is located at an infinite distance for focus adjustment, the light source 1
The light beams emitted from a, 1ad, and 1a2 are routed through path B.
a. Point Sa,,Sa, passing through Bayu and Ba2. ,Sa
! ．． , respectively. It is also assumed that the optical axis of the condenser lens 4 is separated from the position M by a distance Q. Ra
．． Ra ■. Ra, and S a 1 - S a xx ,
S a11 is the reflection point on the subject 3 and the incident point on the PSDS of the light beams from the lights g1a, 1a and la, respectively. Assuming that the reflection points Ra and Ra are both within a plane at a distance d from the projection lens 2, the points Sao and SaS
a■. and Sa,1,Sa,. The distances between and Sa and ■ are all equal to ΔL. Point Sa, Sa, Sa. L
and the right end A of PSD5 are x1, x2, x, respectively.
3, the following equation holds true.

xl=L/2-Δl+Q-
- -(1 2)? 2=L/2-Δl+Q-q
* + + (1 3)
x3=L/2-ΔL+Q+9 ・
・ ・(14) Therefore, the calculation value of equation (3) for each xi. (xi) are as follows.

■. (xl)=1- (2/L) (xi)=2ΔL/
L-20/L...(15)I, (
x2)=1-(2/L) (x2)=2ΔL/L-2Q
/L+2q/L...(16)I. (x3)
=1-(2/L) (x3)=2ΔL/L-2Q/L-
2q/L (17) That is, as is clear from these equations, the calculated value I, (x2) and I. (x3
) is I. It increases or decreases by 2q/L from (xi). This value 2q/L is the distance q of the light source in the baseline length direction,
Since it is determined by the length L of PSD5, it is a known value.

Therefore, the distance measuring points P a■, P b, . Pd. Or Pa
w, Pb2. When measuring the distance to Pd, the distance measuring points Pa,
Compared to the case of distance measuring Pb and Pd, by subtracting or adding this value 2q/L (=k) from the calculated value of equation (3), the distance measuring point Pa. Pb. The distance d can be found in the same way as when measuring Pd. Electrically scanning in a direction parallel to the base line length direction is nothing but adding and subtracting this value k to correct the distance d.

In the embodiment of FIG. 21, the prism 15 in the embodiment of FIG. 20 is omitted. For this reason, PSD5D
is moved in the direction perpendicular to the baseline length direction. On the other hand, in the embodiment shown in FIG.
Above and below the PSD5E. The 5th floor is located. Therefore, there is no need to move the PSD in the direction perpendicular to the baseline length direction. In the embodiment of FIG. 23, three PSD50.5E and 5F in the embodiment of FIG. 22 are replaced with one PSD5G.
The configuration has been replaced with . Therefore, in this case, the first
Using the projection system shown in the figure, scan in the direction parallel to the baseline length direction, and measure the distance by finding the optical center of gravity in the perpendicular direction. FIG. 25 is a flowchart when the light projecting system shown in FIG. 1 and the condensing system shown in FIG. 12 are combined. ．． The control circuit 21 first executes initialization processing (
Step S1), light source 1 is turned on (S2). As a result, the light beam emitted from the light source 1 is incident on the prism 11 via the projection lens 2, and is split into three light beams. This light beam is transmitted to the distance measuring point Pa of the subject 3. Pb. P
d is irradiated. Each distance measurement point Pa, Pb. The reflected light beam from Pd is applied to the prism 15 on its surfaces 15A, 15B, 1
5D, and pass through the condenser lens 4 to the PSD 5.
is incident on the The output of PSD5 is A/D conversion circuit 24
The signal is input to the control circuit 21 via (s3).

The control circuit 21 performs the calculation of equation (3) from this input data, and calculates the calculated value. Find ■ (S4). This calculated value is set to variable A (S5). Next, the control circuit 21 drives the motor 28 via the drive circuit 27 to move the light source 1 a predetermined distance to the left in FIG. 1, and at that position, lights the light source 1 via the drive circuit 23. (s6).

At this time, the PSD 5 is also moved to the left in conjunction with the light source 1. As a result, the distance measuring point Pa. , Pb1, and Pd are irradiated with a light beam, and the reflected light beam is incident on the PSD5. The output of PSD5 is read and the calculated value is calculated. , are calculated (S7, S8). Then, the calculated value I11m and variable A are compared, and the larger one is set to variable A (S9
, SIO).

Next, light source 1 is moved in the opposite direction to read data and perform calculations. , are executed (S11, S12, S 1
3). Then, the calculated value 1a3 and variable A are compared, and the larger one is set to variable A (S14, S15). In this way, variable A is given the largest calculated value (the closest distance d
) is set, and focus control is performed according to this value.

Next, we will explain the mechanism for moving one or both of the light projection system and the light collection system. 26 and 27 show a first embodiment of such a drive mechanism. A rod-shaped screw 32 is rotatably supported on the fixed substrate 31. This screw 32 has a nut 33
, 34 are screwed together, and these nuts 33 and 34 are
It is connected to protrusions 37 and 38 of a base plate 39 via links 35 and 36. The light source 1 and PSD 5 are fixed to this base plate 39. A gear 41 is coupled to the screw 32 and is driven by the motor 28 via a speed regulating mechanism 43.

42 is a detection unit that detects the rotational position of the gear 41.

Therefore, in the initial state, nuts 33 and 34 are in the 26th position.
It is located in the position shown in the figure. At this time, the optical axes of the light source 1 and the light projection lens 2 coincide, and the optical axis of the condenser lens 4 coincides with P.
It is located at a predetermined reference position (for example, the center) of SD5. Therefore, as shown in FIG. 28(a), at this time, the light source 1
and the projection lens 2 are directly facing each other. In this state, for example, the fourth
The center distance measurement point Pa in the figure is measured. Next, when the control circuit 21 rotates the motor 28, for example, clockwise via the drive circuit 27, the gear 41 is rotated counterclockwise via the speed regulating mechanism 43, and the screw 32 is also rotated counterclockwise. The nut 33 is attached to the right-hand thread 32A of the screw 32,
Since the nuts 34 are respectively screwed into the left-hand threads 32B of the screws 32, the nuts 33 and 34 move to the left and to the right in FIGS. 26 and 27, respectively. As the nuts 33 and 34 move apart from each other in this way, the nuts 33 and 34 are moved apart from each other through the links 35 and 36.
34 (therefore the base plate 39
) moves upward in FIG. 27 (upward perpendicular to the page in FIG. 26). The movement of the base plate 39 at this time is guided by the fixed base plate 31. The control circuit 21 monitors the output of the detection unit 42, and stops the rotation of the motor 28 when the gear 41 rotates to a predetermined position (when the base plate 39 moves to a predetermined position). In this way, as shown in FIG. 28(b), the light source 1 is placed above the projection lens 2, and the distance measurement point Pb in FIG. 4 is measured. Similarly, when motor 28 is rotated clockwise, nuts 33 and 34 move toward each other. As a result, the base plate 39 moves downward in FIG. 27 (downward perpendicular to the page in FIG. 26), so the light source 1
As shown in Figure 8(c), it is placed below the projection lens 2. As a result, the distance measurement point Pd in FIG. 4 is measured. FIG. 29 shows another embodiment of the drive mechanism. In this embodiment, a magnet 51 is coupled via a shaft 52 to a base plate 56 on which the light source 1 and PSD 5 are attached. A spring 54 is arranged between the magnet 51 and the case 53. 55 is an electromagnet that replaces the motor. 57 is a fixed board that guides the vertical movement of the base plate 56. When the electromagnet 55 is not excited, as shown in FIG. 30(a), the light source 1 faces the projecting lens 2 with its optical axis aligned. In this state, the distance measurement point Pa is measured. When ranging the distance measuring point pb, the electromagnet 55 is magnetized by the drive circuit 27 so that the arrangement of the magnetic poles matches that of the magnet 51. In other words, in this embodiment, the magnet 5
1 is excited so that its left end side becomes the north pole and its right end side becomes the south pole, so the electromagnet 55 is also excited so that the left side becomes the north pole and the right side becomes the south pole. This causes the same polarities to repel each other, causing the magnet 51 and therefore the shaft 52 to
The base plate 56, which is connected via the base plate 56, is moved upward in FIG. 29 against the biasing force of the spring 54.

As a result, as shown in FIG. 30(b), the light source 1 is moved above the optical axis of the projection lens 2, and the light beam emitted from the light source 1 is directed downward through the projection lens 2.

When the electromagnet 55 is de-energized after distance measurement, the biasing force of the spring 54 causes the magnet 51 and, therefore, the base plate 56
is returned to its original position. When ranging the distance measuring point Pd, the electromagnet 55 is excited so that its left side becomes the south pole and its right side becomes the north pole. As a result, the different polarities attract each other, and the magnet 51 and the base plate 56 are moved downward in the figure. As a result, as shown in FIG. 30(c), the light source 1 is placed below the optical axis of the projection lens 2, and the light beam is emitted upward through the projection lens 2.

In the drive mechanism shown in FIG. 31, the light gi and P
SD5 is installed. The white board 64 is a fixed board 66
It can move freely in the left and right directions in the figure (parallel to the direction of the base line length). 61 is a speed regulating mechanism that transmits the rotation of the remoter 28 to the gear 62. 63 is a cam plate having a cam groove 63B as shown in FIG. 32, and a gear 63A formed on the outer periphery of the cam plate meshes with the gear 62.

65 is a pin planted in the base plate 64, and the cam groove 63B
It is fitted with. In the initial state, the pin 65 is in the third position relative to the cam plate 63.
It is located at the position shown in Figure 2(a). At this time, as shown in FIG. 33, the light source 1 is directly facing the projection lens 2 so that their optical axes are aligned. In this state, for example, the center distance measuring point Pa
is measured.

When distance measuring point Pai is measured, the motor 28 is rotated. When the rotation of the motor 28 is transmitted to the gear 62 via the speed regulating mechanism 61, the cam plate 63 rotates counterclockwise in FIG. 32 because the gear 63A is meshed with the gear 62. As a result, the bin 65, and thus the base plate 64, are moved to the right in FIG. 31 (downward perpendicular to the plane of the paper in FIG. 33) while being guided by the cam groove 63B. Figure 32 (
As shown in b), when the pin 65 moves to the rightmost position, the rotation of the motor 28 is stopped and distance measurement is performed. At this time, since the light source 1 is placed on the right side of the optical axis of the projection lens 2, the light beam emitted from it is irradiated to the ranging point Pa1 on the left side of the optical axis of the projection lens 2. When distance measuring points Pa on the right side of the central distance measuring point Pa are to be measured, the cam plate 63 is rotated to the position shown in FIG. 32(c). At this time, the bin 65 is moved to the leftmost position (in the upper direction perpendicular to the plane of the paper in FIG. 33), and the light source 1 is placed to the left of the optical axis of the projection lens 2 6 Therefore, the light source 1
A light beam emitted from the distance measuring point Pa is irradiated with the light beam.

As shown in FIG. 34, instead of the cam plate 63, the cam groove 6
A similar operation can be performed using a cam cylinder 67 having a diameter of 8.

Figures 35 and 36 show other embodiments of the drive mechanism. The light source 1 and the PSD 5 are fixed to a base plate 71. The base plate 71 is guided by a fixed base plate 75. It is movable in the direction parallel to the baseline length direction. As shown in FIG. 35(a), in the initial state, the toothless pinion 74 meshes with the substantially central portion of the rack 72 below the base plate 71. As shown in FIG. At this time, the light source 1 is directly facing the projection lens 2 so that its optical axis coincides with the light source 1, so that a light beam is irradiated to the central ranging point Pa. When distance measuring point Pa on the right side of distance measuring point Pa is to be measured, the motor 28 rotates the pinion 74 clockwise in FIG. 35(a) via the speed regulating mechanism 76. As a result, the rack 73, and therefore the base plate 71, are moved to the left in FIG. 35(a) (upward perpendicular to the plane of the paper in FIG. 36). The detection unit 77 detects the rotational position of the pinion 74 and outputs a position signal to the control circuit 21. Figure 35 (
As shown in b), when the gear portion 74A of the pinion 74 rotates to a position where it separates from the rack 73, the rotation of the pinion 74 is stopped. At this time, the base plate 71 is located at the leftmost position, and the light source 1 is located at the left side of the optical axis of the projection lens 2.

When distance measuring point Pa to the left of lflg distance point Pa is to be measured, the pinion 74 is rotated clockwise from the state shown in FIG. 35(b). As a result, as shown in FIG. 36(c), the gear portion 74A engages with the upper rack 72, and the rack 72 and therefore the base plate 71 are moved to the right (downward perpendicular to the plane of the paper in FIG. 36). As shown in FIG. 35(d), when the gear portion 74A is separated from the rack 72, the base plate 71 is located at the rightmost position. At this time, the light source 1 is located on the right side of the optical axis of the projection lens 2, and the light beam emitted from it is irradiated to the distance measuring point Pa. In the embodiment shown in FIG. 37, the light source 1 and the PS are mounted on the base plate 81.
D5 is fixed. The base plate 81 is urged by a spring 84 so as to come into contact with a stopper 83 provided on the slide plate 82. A spring 86 is arranged between the slide plate 82 and the fixed base plate 85. Therefore the 37th
As shown in Figure (a), in the initial state, the slide plate 82 is in contact with a stopper 87 fixed to a fixed base plate 85 by the biasing force of a spring 86.

When distance measurement is performed at the central distance measurement point Pa, the cam plate 88 is rotated counterclockwise by the motor 28.

As a result, the lever 89 is rotated clockwise about the fixed fulcrum 90 against the biasing force of the spring 91. As a result, as shown in FIG. 37(b), the pin 92 at the tip of the lever 89 presses the right end of the slide plate 82, and the slide plate 82 moves to the left against the urging force of the spring 86. be done. At this time, the base plate 81 pressed against the stopper 83 by the biasing force of the spring 84 moves to the left together with the slide plate 82. When moved to a predetermined position, as shown in FIG. 37(b), the base plate 8
1 comes into contact with the right end of the locking lever 93, so the base plate 81 stops at that position. However, since the slide plate 82 is pressed by the bottle 92, it moves further to the left.

At this time, the movement of the slide plate 82 is guided by the elongated hole 103 of the slide plate 82 and the fixed pin 104 fitted therein. Further, since a long hole 95 is formed in the base plate 81 and a pin 94 implanted in the slide plate 82 is fitted therein, movement of the slide plate 82 is permitted. When the predetermined position is reached, as shown in FIG. 37(C), the hook 96 formed at the left end of the slide plate 82
It abuts against the pin 97 at the right end of the locking lever 98. A magnet 100 is fixed to the left end of the locking lever 98, and this magnet 100 is attached to the iron core 1 of the electromagnet 101.
It's just adsorbed to 02. hook 96 is pin 97
, the locking lever 98 is slightly rotated clockwise about the fulcrum 99 against the biasing force of the magnet 100. After the hook 96 is locked to the pin 97, the locking lever 100 is rotated counterclockwise again by the biasing force of the magnet 100, and the locking operation is completed. At this time, the suppression by the cam plate 88 is released, and the lever 89 is rotated counterclockwise about the fulcrum 90 by the biasing force of the spring 91 and returns to its original position. In this way, the state shown in Figure 37 (Q) is reached. A distance measurement operation for the center aperture point Pa is executed. Next, when opening the distance measuring point Pa2 on the right side, as shown in FIG. 37(d), the switch 107 is switched to the lower side in the figure, and the electromagnet 1
A battery 106 is connected to 01. At this time, the electromagnet 101
is excited so that a magnetic pole different from that of the magnet 100 is generated on the magnet 100 side. This allows magnet 1
00 remains attracted to the iron core 102, the iron piece 108 fixed to the left end of the locking lever 93 is attached to the iron core 102.
It is adsorbed to. As a result, the locking lever 93 is moved by the spring 1.
It is rotated clockwise about the fulcrum 1o9 against the urging force of 10. As a result, the right end of the locking lever 93 is lowered to release the locking of the base plate 8l, and the base plate 81 is moved to the left by the biasing force of the spring 84, and the stopper 8l is moved to the left by the biasing force of the spring 84.
It stops at the position where it touches 3. At this time, the light source 1 is placed on the left side of the optical axis of the projection lens 2, and a light beam is irradiated to the distance measuring point Pa2. When distance measuring point Pa on the left side is to be measured, the switch 107 is switched to the upper side in the figure, and the battery 105 of opposite polarity is connected to the electromagnet 101, as shown in FIG. 37(a). As a result, the electromagnet 101 is excited with a polarity opposite to that shown in FIG. 37(d). As a result, due to the repulsive force, the magnet 10
0 is separated from the iron core 102, and the locking lever 98 rotates clockwise about the fulcrum 99. Therefore, the locking of the hook 96 by the pin 97 is released, and the slide plate 82 is moved to the right by the biasing force of the spring 86.

At this time, the base plate 81 is pressed against the stopper 83 of the slide plate 82 by the biasing force of the spring 84, so that it moves integrally with the slide plate 82. The slide plate 82 stops at the position where it abuts against the stopper 87. At this time, light source 1
is arranged on the right side of the optical axis of the projection lens 2.

In the drive mechanism shown in FIG. 38, a block 128 houses a light projecting system including a light source 1 and a PSD 5, and a light receiving system.
When measuring the distance to the central distance measuring point Pa, the switch 124 is in the neutral position, as shown in FIG. Both solenoids 121 and 122 are in a non-energized state.

Since the spring 146 is disposed between the slide plates 133 and 141, the slide plate 133 is inserted into its elongated hole 134.
The slide plate 141 is stopped at a position where the left end of the slide plate 141 abuts the fixing pin 135 and a right end of the elongated hole 142 abuts the fixing pin 143. At this time, the pin 132 is held between the protrusion 136 of the slide plate 133 and the protrusion 144 of the slide plate 141. Since the block 128 is attached to the other end of the lever 131 where the pin 132 is installed, the block 128 is oriented toward the front of the camera, and the center focus point P
a is measured.

When distance measuring the left distance measuring point Pad, the switch 124 is switched to the right side and the solenoid 122 is energized by the battery 123, as shown in FIG. 38(b). As a result, the iron core 125 is attracted to the solenoid 122. A lever 127 is fixed to the iron core 125 via a pin 126, and a block 128 is fixed to the other end of this lever 127. At this time, the block 128 is centered around the fulcrum 129. Rotate counterclockwise. As a result, one end is block 1
Pin 132 at the other end of lever 131 fixed to 28
presses the protrusion 136 of the slide plate 133 to the left, so the slide plate 133 moves to the left against the biasing force of the spring 146.

This movement is guided by a fixing pin 135 into which the elongated hole 134 of the slide plate 133 is fitted. When a predetermined position is reached, the pin 137 implanted in the slide plate 133 comes into contact with the left side wall of the stopper 138, so that the slide plate 133 is stopped at that position. At this time, the block 128 points slightly to the left of the front of the camera, so the distance measurement point Pa
■ is measured.

On the other hand, when measuring the distance measuring point Pa2 on the right side, FIG.
), the switch 124 is switched to the left, and the solenoid 121 is energized.

As a result, the iron core 125 is attracted to the solenoid 121,
Block 128 is rotated clockwise about fulcrum 129. At this time, the pin 132 presses the protrusion 144 of the slide plate 141 to the right, so the slide plate 141
is moved to the right against the urging force of the spring 146. This movement is carried out through the elongated hole 14 formed in the slide plate 141.
It is guided by a fixing pin 143 that is fitted in 2.

When moved to a predetermined position, the pin 145 implanted in the slide plate 141 comes into contact with the right side wall of the stopper 138, so the slide plate 141 stops at that position. At this time, since the block 128 is directed slightly to the right of the front of the camera, the distance measurement point Pa2 becomes available for distance measurement. FIGS. 39 to 42 show still another drive mechanism of the distance measuring device. In the embodiment of FIG. 39, the block 151 includes a light source 1.
It has a built-in projector lens 2, a condensing lens 4, and a PSD 5. This block 151 is rotated in a direction perpendicular to the base line length direction about an axis 152 that is parallel to the base line length direction. This results in
It is possible to measure distances from the center distance measuring point Pa and the distance measuring points Pd and pb above and below it.

The embodiment of FIG. 40 has a mirror 1 in front of the block 151.
61, and the mirror 161 is rotatable about an axis 162 parallel to the base line length direction. Even in this case, the same operation as in the embodiment shown in FIG. 39 can be performed. In the embodiment shown in FIG. 41, a plano-convex cylindrical lens 171 and a plano-concave cylindrical lens 172 are arranged in front of the block 151 so that their curved surfaces having the same curvature join together. By rotating the block 151 and the cylindrical drill lens 171 integrally about the axis 152, the direction of the light beam emitted from the cylindrical drill lens 172 can be changed. In the embodiment shown in FIG. 42, parallel plane plates 181 and 183 are arranged in front of block 151 at a predetermined distance apart, and a liquid layer 182 is inserted between them. Therefore, the direction of the light beam can be changed by rotating the flat plate 181 about the axis 184.

In addition, the number of distance measuring points can be adjusted by forming prisms in various shapes, or by combining a plurality of prisms with the same shape or different shapes.

Furthermore, in addition to prisms, it is also possible to use diffraction gratings and other optical elements. Furthermore, in the above, a PSD was used as the detection element.
COD etc. can also be used. [Effects of the Invention] As described above, according to the present invention, a light beam is optically split in one of a direction parallel to the base length direction and a direction perpendicular to the base line length direction, and the light beam is split in the other direction by a prism or the like. By mechanically moving the mirror and light source in the direction of This makes it possible to accurately measure the distance to the actual subject without being affected by the direction or position of the subject.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a first embodiment of a light projection system of a distance measuring device according to the present invention, FIG. 2 is a principle diagram of the distance measuring device according to the present invention, and FIG. 3 is a block diagram of the distance measuring device according to the present invention. 4 is an explanatory diagram of the distance measuring point of the distance measuring device of the present invention, FIG. 5 is a perspective view of a second embodiment of the light projection system of the distance measuring device of the present invention, and FIG. 6 is a diagram of the distance measuring device of the present invention. FIG. 7 is a perspective view of a second embodiment of the focusing system of the distance measuring device of the present invention, and FIG. 8 is a perspective view of the second embodiment of the focusing system of the distance measuring device of the present invention. FIG. 9 is a perspective view of the fourth embodiment of the focusing system of the distance measuring device of the present invention; FIG. 10 is a perspective view of the fourth embodiment of the focusing system of the distance measuring device of the present invention; FIG. FIG. 11 is an explanatory diagram of the semiconductor optical position detection element of the distance measuring device of the present invention, and FIG. 12 is a diagram of the fifth embodiment of the focusing system of the distance measuring device of the present invention. A perspective view, FIG. 13 is a perspective view of a sixth embodiment of a condensing system of a distance measuring device of the present invention, and FIG. 14 is a perspective view of a seventh embodiment of a condensing system of a distance measuring device of this invention. , FIG. 15 is a perspective view of an eighth embodiment of the condensing system of the distance measuring device of the present invention, and FIG. 16 is a perspective view of the ninth embodiment of the condensing system of the distance measuring device of the present invention. FIG. 17 is a perspective view of a tenth embodiment of the condensing system of the distance measuring device of the present invention, FIG. 18 is a perspective view of the eleventh embodiment of the condensing system of the distance measuring device of the present invention, and FIG. The figure is a perspective view of a twelfth embodiment of the condensing system of the distance measuring device of the present invention, FIG. 20 is a perspective view of the thirteenth embodiment of the condensing system of the distance measuring device of the present invention, and FIG. 22 is a perspective view of a 15th embodiment of the focusing system of the distance measuring device of the present invention; FIG. 23 is a perspective view of the 15th embodiment of the focusing system of the distance measuring device of the present invention; FIG. FIG. 24 is an explanatory diagram of the semiconductor optical position detection element of the distance measuring device of the present invention, and FIG. 25 is a block diagram of the distance measuring device of the present invention. 26 is a plan view of the first embodiment of the drive mechanism of the distance measuring device of the present invention, FIG. 27 is a front view of the first embodiment of the drive mechanism of the distance measuring device of the present invention, and FIG. Figures (a), (b), and (c) are side views of a first embodiment of the drive mechanism for a range finder according to the present invention, and Fig. 29 is a side view of a second embodiment of the drive mechanism for a range finder according to the present invention. Example front view, Figure 30(a). (b) and (c) are side views of the second embodiment of the drive mechanism of the distance measurement device of the present invention, and FIG. 31 is a front view of the third embodiment of the drive mechanism of the distance measurement device of the present invention. Figure 32(a). (b) and (c) are plan views of the cam plate of the drive mechanism of the distance measuring device in FIG. 31, FIG. 33 is a side view of the third embodiment of the driving mechanism of the distance measuring device of the present invention, and FIG. The figure is a front view of another driving source of the third embodiment of the driving mechanism of the distance measuring device of the present invention, and FIGS. FIG. 36 is a side view of the fourth embodiment of the driving mechanism of the distance measuring device of the present invention, and FIGS. 37(a) to (e) are views of the driving mechanism of the distance measuring device of the present invention. Front view of the fifth embodiment, FIGS. 38(a) and 38(b). (c) is a plan view of the sixth embodiment of the drive mechanism of the distance measuring device of the present invention, FIG. 39 is a perspective view of the seventh embodiment of the drive mechanism of the distance measuring device of the present invention, and FIG. FIG. 41 is a perspective view of an eighth embodiment of the driving mechanism of the distance measuring device of the present invention; FIG. 42 is a perspective view of the ninth embodiment of the driving mechanism of the distance measuring device of the present invention; It is a perspective view of the 10th Example of the drive mechanism of a distance device. 1... Light source 2... Light projection lens 4 ・ ・ 5 ・ ・ 1 0 ・ 1 1, 1 7 ・ 1 8 ・ 1 9 ・ 2 1 ・ 2 3 ・ 24 ・ 2 5 ・ 2 6 ・ 2 7 ・2 8 ・ 3 2 ・ 3 3, 4 1 ・ 4 2 ・ Subject condensing lens Semiconductor optical position detection element (PSD) ・Distance measurement range 2, 13, 14.15... Prism, person, mountain, tree・Control circuit ・Drive circuit ・A/D conversion circuit ・Lens drive system ・Memory ・Drive circuit ・Motor ・Screw 4...Nut ・Base plate ・Gear ・Detection part 55...Electromagnet 56...Base plate 63 ...Cam plate 64...Cam groove 65...Pin 67...Cam tube 71...Bed plate 72.73...Rack 74...Pinion 77...Detection section 81... Base plate 82...Slide plate 83.87...Stopper 88...Cam plate 89...Lever 93.98...Locking lever 100...Magnet 108...Iron pieces 121, 122... Solenoid 128...Block 133, 1 5 1 ・ 1 6 1 ・ 1 7 1 ・ 1 7 2 ・ 1 8 1 ・ 1 8 2 ・ 1 8 3 ・ 141... Slide plate... Block 8 Il Fu... Plano-convex cylindrical lens...Plano-concave cylindrical lens...Parallel plane plate...Liquid layer...Parallel plane plate and above Patent applicant Asahi Kogaku Kogyo Co., Ltd.

Claims (1)

[Scope of Claims] Light source means for emitting a light beam for distance measurement, and dividing the light beam emitted from the light source into a plurality of parts in one of a direction parallel to the base line length direction and a direction perpendicular to the base line length direction. a moving means for mechanically moving the light source in the other direction of a direction parallel to the base line length direction and a direction perpendicular to the base line length direction; and a moving means for projecting the light beam emitted from the light source onto a subject. A distance measuring device comprising: a light projecting means that emits light; a condensing means that condenses a light beam reflected by the object; and a detection means that detects the light condensed by the condensing means.