JPH06242367A - Distance measuring equipment - Google Patents

Abstract

PURPOSE:To execute photographing in which more accurate focusing is realized by considering the intention of a photographer by detecting the focusing state of an eye and selecting a measured value the most approximate to a distance corresponding to the focusing state o the eye from among the measuring values of plural points in the case of selecting one of plural pieces of measured information. CONSTITUTION:This device is constituted of a plural distance measuring equipment detecting a distance, a focusing detecting device 5 detecting the focusing state of the eye 1, and a distance measuring point selection device 6 controlling the device 5, processing the signal of the eye and selecting an optimum value from the distance measuring signal of the device 4. Then, the device 5 is constituted of a pattern projection device 7, an eye detecting optical system 8 detecting the eyeground state of the eye 1 by projecting a pattern by the device 7, and a received light detecting device 9 detecting the pattern image of the eyeground of the eye 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance measuring device for selecting optimum distance measuring information from a plurality of distance measuring information by using information of a photographer's eyes.

[0002]

2. Description of the Related Art Conventionally, in a camera having a multi-point distance measuring function, an erroneous distance measurement (a hollowed-out state) has occurred due to the presence or absence of a near object at the time of photographing. To solve these problems, many means for selecting the optimum distance measurement information from the distance measurement information of a plurality of points have been proposed.

For example, JP-A-59-146028, JP-A-60-172008, and JP-A-60-2.
In Japanese Patent No. 33610 and the like, it is disclosed that the optimum point (closest distance, predetermined distance range) is selected from the distance measurement information by emphasizing the center point. Furthermore, JP-A-1-27610
No. 6, for example, discloses selecting various information by fuzzy processing.

There has also been proposed one that uses eye information for distance measurement. These are disclosed, for example, in JP-A-60-1942.
No. 37, etc. disclose a method of performing AF (autofocus) at the line-of-sight position, and Japanese Patent Application Laid-Open No. 63-40525 discloses a method of measuring the refractive index of the eye to measure the distance.

[0005]

By the way, when one piece of information is automatically selected from the distance measurement results of the multi-point distance measurement, camera information (focal length, photometric value, etc.), distance information, and priority of selected area are given. Although it is considered to use the ranking, the finished image may not be complete because the intention of the photographer is not taken into consideration.

Further, in order to more faithfully reflect the intention of the photographer, a method has been proposed in which a distance measuring area is determined by the line of sight and focus detection is performed in that area. However, since the position where the photographer looks into the viewfinder and the distance from the viewfinder are not fixed, a large sensor (area sensor) or the like is required, which results in an increase in cost and an increase in mounting size. It was

A method has also been proposed in which the refractive index of the photographer's eyes is measured and the focus position of the photographing lens is calculated based on the result. However, the amount of light reflected from the fundus of the eye is weak and the S value is higher. A signal of / N cannot be obtained (the phenomenon such as birefringence reflection occurs because the fundus has a thin transparent film structure). In addition, there is a problem that it is difficult to obtain accuracy corresponding to the focal length of the taking lens and the distance measuring range.

The present invention has been made in view of the above problems, and an object thereof is to complete a photograph produced without considering the intention of the photographer even if one is selected from a plurality of distance measurement information. Even if the photographer's intention is more faithfully reflected, the cost does not increase, the size of the mounting does not increase, and a high S / N signal can be obtained without decreasing the focal length of the photographing lens. An object of the present invention is to provide a distance measuring device capable of obtaining an accuracy corresponding to a distance measuring range.

[0009]

That is, the present invention provides a multi-point distance measuring means capable of outputting distance information for each of a plurality of points of an object, a focus detecting means for detecting a focus state of a user's eye, and It is characterized by further comprising: selecting means for selecting the distance information based on the output of the focus detecting means from among the plurality of distance information detected by the multi-point distance measuring means.

[0010]

In the distance measuring device of the present invention, the distance information is output by the distance measuring means for each of a plurality of points on the object. The focus detecting means detects the focus state of the user's eyes. Then, the distance measuring value closest to the corresponding distance is calculated by the selecting means, and one distance measuring information is selected based on the detected distance measuring information of the plurality of points.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. First, before describing the embodiments, a method of detecting the focus state of the eye adopted in the present invention will be described with reference to FIG.

Generally, when a person looks at an object clearly,
The eye images the light flux from the subject on the retina by varying the refractive index with the crystalline lens. FIG. 2A shows a state where the eye 1 is in focus. At this time, the object O
The light flux from _one point is refracted by the crystalline lens 2 and imaged on the retina 3. 2B and 2C show a state in which the eye 1 is out of focus.

As a result, when the eye 1 is looking at the point O ₁ ((a) in the figure), when the contrast pattern is projected from the point O ₁ , the contrast pattern is not blurred on the retina 3. . Further, when the contrast pattern is projected from the O ₂ point or the O ₃ point in the state of the eye 1 in FIG. 2A, the contrast pattern is blurred on the retina 3. That is, if the contrast pattern is projected from different positions in the optical path in time division and the state of the contrast pattern of the retina 3 is detected, the focus state of the eye 1 can be detected.

FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention. In the figure, this distance measuring device comprises a plurality of distance measuring devices 4 for detecting distances, a focus detecting device 5 for detecting the focus state of the eye 1, control of the focus detecting device 5, and processing of eye signals. , And a distance measuring point selecting device 6 for selecting an optimum value from the distance measuring signals of the plurality of distance measuring devices 4. Then, the focus detection device 5 projects the pattern projection device 7 and the eye detection optical system 8 that projects the pattern by the pattern projection device 7 to detect the fundus state of the eye 1.
And a photodetection device 9 for detecting the pattern image of the fundus of the eye 1.
It is composed of. With the distance measuring device having such a configuration, the optimum value is selected based on the focus state of the eye 1 from the plurality of detected distance measuring information.

FIG. 3 is a block diagram showing a more detailed structure of FIG. Incidentally, the multi-distance measuring method generally used in the camera is known to be active or passive.
In this embodiment, the active distance measuring method will be described.

This range finder includes a multi range finder 10 and
A focus detection device 11 that projects light toward the eyes from positions with different optical distances, and an eye focus state is detected based on a signal detected by the focus detection device 11 to perform the multi-distance measurement. It is composed of a CPU 12 that detects an optimum value from the distance measurement information detected by the device 10.

The focus detecting device 11 is a projection optical system a.
13, pattern a14, IRED (infrared light emitting diode) a15, and projection optical system b16, pattern b17, I
A light projecting block having a REDb 18, a light receiving optical system 19 for receiving and detecting fundus light of the eye 1, a sensor 20, and an A / D converter 21 for A / D converting an output signal of the sensor 20 and supplying the same to the CPU 12. And a light receiving block having. Further, the CPU 12 detects the focus state of the eye 1 based on the signal detected by the light receiving block, and detects the optimum value from the distance measurement information detected by the multi-distance measuring device 10.

FIG. 4 shows a part of the structure of the finder, in which a finder optical system 22 for guiding a subject luminous flux and a part of the finder optical system 22 are shared by a mirror 23 for infrared light. , And a sensor 20 for detecting the state of the fundus of the eye 1. Further, this finder includes two sets of projecting optical systems 13 and 16 having different optical distances, a pattern a14 and a pattern b17, a projecting IREDa15 and a projecting IR.
It has an EDb 18. The light projecting system is configured to project light obliquely with respect to the finder optical axis. Further, the sensor 20 is configured by a line-shaped sensor CCD, and the patterns a14 and b17 are configured to be easily detected by the line sensor.

FIG. 5 is a diagram showing a state where the eyes are looking and the state of the light projection pattern of the fundus when the patterns a14 and b17 are projected from the equivalent positions (A, B). . Note that, here, the light projection pattern is shown for one line.

In this embodiment, the detection distance is divided into four, and I
Is farther than L1 (L0), II is in the range L2 to L1, III is in the range L4 to L3, and IV is closer than L4 (L5). The threshold levels of contrast corresponding to II and III are K1 and K2.

FIG. 5 (a) shows the optical positional relationship between A and B. In addition, FIGS. 5B to 5E show the state of the pattern projected from the point A and the pattern projected from the point B at the fundus when the focus position of the eyes is at each point. It is a thing. The figure (b) shows that the eye is looking far from the point A, the figure (c) shows that the eye is looking around the point A, and the figure (d) shows that the eye is between the points A and B. Is present in
And (e) is a case where the eyes are looking at the near side from the point B. The focus state of the eye can be estimated from the relationship between the projected position and the contrast. The active multi-AF is already known in the camera, but its configuration is briefly shown in FIG. An explanation will be given using the method of three points in the distance measuring area.

In FIG. 6A, an infrared light source AF_IREDa for AF is supplied through a light projecting optical system 24 of the camera.
b, c 25, 26, and 27 are time-divisionally projected toward the subject. Then, the reflected light from the subject is detected by the PSD 29 via the light receiving optical system 28. Figure 6 (b)
Indicates the position of the focus area in the viewfinder. Focus areas a, b, and c correspond to the projected position. Next, the operation of the camera to which this distance measuring apparatus is applied will be described with reference to the flowchart in FIG.

When the AF sequence is started, first initialization (setting the focus area as the center)
Is performed (step S1). Then, the first (1
st) Release “ON” is determined (step S)
2). Here, when the 1st release is “OFF”,
After the selective focus area is reset (step S
9) Then, the sequence ends.

In step S2, if the 1st release is "ON", the subroutine "A" for performing multi-distance measurement
F "is performed (step S3). Then, a subroutine" eye focus detection "for determining which distance the eyes are focused is performed (step S3).
4).

Then, a sub-routine "selection of AF data" for selecting the optimum value in the focusing state of the eyes from the multi-AF data is performed (step S5). And 1
st release is determined (step S6), 1st
If the release is "OFF", the process proceeds to step S9, and if it is "ON", the determination of the second (2nd) release is performed (step S7).

If the second release is "OFF" in step S7, the process returns to step S6. On the other hand, "O
In the case of N ″, the AF lens is driven based on the AF information (step S8), and then this AF sequence is ended.
FIG. 8 is a flowchart of a subroutine "AF" for detecting multi-AF data.

When the subroutine "AF" is started and the infrared light source AF_IREDb26 is projected (step S11), the PSD 29 detects the position of the reflected light (step S12). Then, the distance (Lb) of the focus area b is obtained from the position information of the PSD 29 (step S13). Next, focus areas a and c
For a similar sequence (corresponding AF_IRED
Is detected, the distance is calculated by PSD, and the distance (La) of the focus area a and the distance (Lc) of the focus area c are obtained (steps S14 to S19).
After that, this subroutine "AF" is ended. Next, referring to the flowchart of “eye focus detection” in FIG.
A subroutine for detecting the focus state of the eyes will be described.

When the subroutine "eye focus detection" is started, the sensor 20 is first reset (step S21). Then, the IREDa 15 is projected (step S22), and sensor integration is performed (step S2).
3). Next, at the end of the integration, the data is read (step S24), and the read data is A / D converted (step S25).

In this way, when the contrast is calculated (sum of absolute values of difference values of adjacent pixels: ΣA) (step S2)
6), the sensor is reset (step S27), and the infrared light source IREDb18 is projected (step S28).
Next, sensor integration is performed (step S29), and when the data is read at the end of the integration (step S30), the read data is A / D converted (step S31). When the contrast is calculated (ΣB) (step S32), this subroutine “eye focus detection” is ended. FIG. 10 shows a flowchart of a subroutine "AF data selection" for selecting an optimum value from multi-AF data.

The subroutine "selection of AF data" is started, and the contrast ΣA is first compared with the reference value K1 (step S41). Where ΣA <K1
If not, the process proceeds to step S42 and Lmax is set to L.
1 and L2 is substituted for Lmin. Step S41
When ΣA <K1, the contrast ΣA and the contrast ΣB are subsequently compared (step S4).
3).

If ΣA <ΣB is not satisfied in step S43, the process proceeds to step S44, where Lmax is L0 and L0 is L.
L1 is substituted for min. On the other hand, when ΣA <ΣB,
Next, the contrast ΣB and the reference value K2 are compared (step S45). In this step S45, Σ
If B <K2 is not satisfied, the process proceeds to step S46 and Lmax
Is assigned to L3, and L4 is assigned to Lmin. On the other hand, Σ
If B <K2, L4 is substituted for Lmax and L5 is substituted for Lmin (step S47).

Thus, the steps S42, S44,
When S46 and S47 are performed, it is next determined whether or not the distance measurement data Lb in the multi distance measurement is within the range of Lmin and Lmax (step S48). Where Lmin <
If Lb <Lmax, the process proceeds to step S50. On the other hand, when Lmin <Lb <Lmax is not satisfied, Lc is set to Lb.
However, after MAX (the maximum value of the detection distance) is substituted for Lb (step S49), it is determined whether or not the distance measurement data La is within the range of Lmin and Lmax (step S50).

In this step S50, Lmin <L
If a <Lmax, the process proceeds to step S52, and Lmin <
When La <Lmax is not satisfied, MAX is substituted for La (step S51) and the process proceeds to step S52. Then, in step S52, it is determined whether or not the distance measurement data Lc is within the range of Lmin and Lmax. Where Lmin
If <Lc <Lmax, the process moves to step S54 and Lmi
When n <Lc <Lmax is not satisfied, MAX is substituted for Lc (step S53).

Thereafter, the minimum value is substituted for LD from the distance measurement data La, Lb, Lc (step S54). Next, LD and MAX are compared (step S5).
5). Here, when LD = MAX is not satisfied, this subroutine is finished as it is. On the other hand, when LD = MAX,
After the LC data is assigned to the LD (step S5
6) The subroutine "AF data selection" is ended.
Although the embodiment of the present invention has been described above, the present invention is not limited to this, and it is needless to say that various improvements and modifications can be made. For example, if the eye focus detection area is 4
Although it is divided, it may be divided more finely. Further, the phase difference method or the contrast method may be used as the multi AF method. Further, the lens may be roughly initially driven in the eye focus state.

When there are distance measuring data of a plurality of points in the eye focus detection area, a flow chart as shown in FIG. 11 may be performed. The flowchart of FIG. 11 is almost the same as that of FIG. 10, and when the focus state of the eye is set so that the middle data of the three data is selected when the closest region is selected, the part different from FIG. Only the following will be described.

After MAX is substituted for Lc in step S53, Lmin is compared with L5 (step S57). Here, if Lmin = L5 is not satisfied, the process proceeds to step S54, and if Lmin = L5, La, Lb,
The middle value of the data is assigned to LD from Lc (step S58). Next, LD and MAX are compared (step S59). Here, if LD = MAX is not satisfied, this subroutine is terminated as it is, and if LD = MAX, the minimum value is substituted into LD from the distance measurement data La, Lb, and Lc (step S54), and then LD and MAX are again calculated. After the comparison is performed (step S55), when LD = MAX, the LC data is substituted into the LD (step S5).
6) The subroutine "AF data selection" is ended.
In this way, the data to be selected may be changed for each detection area. The selection of distance measurement data may be changed using the focal length information of the photographing lens. Further, the sensor for detecting the focus of the eyes is not limited to the accumulation type (CCD etc.) but may be a non-accumulation type (photodiode etc.). The pattern projection may be coaxial or off-axis, and the projection pattern may be a point image.

Regarding the determination of the focus state of the eyes, instead of projecting the light projection patterns from positions optically different in distance, as shown in FIG. The light may be projected from different angles. As the detection sensor, a position detection sensor 30 such as a PSD installed near the fundus to be in focus is used.

In the detection, instead of detecting the contrast state, the projection IRE is performed via the lens 31 and the infrared mirror 32.
D33 is projected in a time division manner, and is performed by both the position information of the corresponding PSD and the detection current of the PSD. That is, when the projected light IRED 33 is projected, it hits a position corresponding to the focus of the lens of the eye 1, and the reflected light is condensed on the PSD 30 via the lens of the eye 1, the infrared mirror 32, and the mirror 31. The focus position of the eye is detected from the received light value of the reflected light.

[0039]

As described above, according to the present invention, when the optimum value is selected from a plurality of pieces of distance measurement information, the focus state of the eyes of the user, which includes the intention of the user, is used, so that it is more accurate. It is possible to select distance measurement information and perform highly accurate focus detection.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention.

2A and 2B are diagrams for explaining a method of detecting an eye focus state, in which FIG. 2A is a diagram showing a state in which an eye is in focus, and FIGS. 2B and 2C are out of focus. It is the figure which showed the state.

FIG. 3 is a block diagram showing a more detailed configuration of FIG.

FIG. 4 is a diagram showing a part of a schematic configuration of a finder.

FIG. 5 is a diagram showing a state where the eyes are looking and a state of a light projection pattern of the fundus when pattern a and pattern b are projected from equivalent positions (A, B). Is A, B
Showing the optical positional relationship of the eye, (b) when the eye is looking far from the point A, (c) when the eye is looking near the point A, (d) when the eye is A, If it exists between points B,
(E) is a diagram showing a state at the fundus of a pattern projected from points A and B when the eye is looking closer to point B.

FIG. 6A is a diagram showing a schematic structure of active multi-AF, and FIG. 6B is a diagram showing positions of focus areas in a finder.

FIG. 7 is a flowchart illustrating an operation of a camera to which this distance measuring device is applied.

FIG. 8 is a flowchart of a subroutine “AF” that detects multi-AF data.

FIG. 9 is a flowchart of “eye focus detection” for explaining a subroutine for detecting an eye focus state.

FIG. 10 is a flowchart of a subroutine “AF data selection” for selecting an optimum value from multi-AF data.

FIG. 11 is another example of the flowchart of the subroutine “AF data selection” that selects the optimum value from the multi-AF data when the distance measurement data of a plurality of points exist in the eye focus detection area.

FIG. 12 is a diagram showing an example in which light projection patterns are optically projected at substantially the same distance from different angles with respect to the eyes for the focus state determination of the eyes.

[Explanation of symbols]

1 ... Eyes, 2 ... Lens, 3 ... Retina, 4 ... Multiple distance measuring devices,
5, 11 ... Focus detection device, 6 ... Distance measuring point selection device, 7 ...
Pattern projection device, 8 ... Eye detection optical system, 9 ... Receiving detection device, 10 ... Multi-range finding device, 12 ... CPU, 13 ... Projection optical system a, 14 ... Pattern a, 15 ... IRED (infrared light emitting diode) a, 16 ... Projection optical system b, 17 ... Pattern b, 18 ... IREDb, 19 ... Receiving optical system, 20 ... Sensor, 21 ... A / D converter, 22 ... Viewfinder optical system,
23 ... Mirror.

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Claims (1)

[Claims] 1. A multi-point distance measuring means capable of outputting distance information for each of a plurality of points of an object, a focus detecting means for detecting a focus state of a user's eye, and the multi-point distance measuring means. A distance measuring device comprising: a selecting unit that selects distance information from a plurality of distance information based on an output of the focus detecting unit.