JPH0618772A - Camera provided with function for detecting line of sight - Google Patents

Abstract

PURPOSE:To eliminate a concrete trouble occurring when a camera having a function executing focusing based on the detected information of the line of sight is used. CONSTITUTION:The camera is provided with a lens control means controlling the focusing of an objective lens 1, detection means for the line of sight 9 and 11-15 detecting the line of the sight of an observer and a means 6 detecting a focus as for plural detection areas in a picture. In a servo action mode in which the change of the position of the image forming surface of the lens 1 acompanied with the change of an object distance is followingly corrected, the position of the line of the sight is detected before a focus detecting action by the detection means for the line of sight. Besides, such an action that the image forming position of the lens 1 is continuously controlled as for a focus detection output at a part based on the positional information of the line of the sight is executed by the lens control means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera or a video camera using a silver salt film, or a photographing apparatus which cooperates with industrial equipment, and in particular, detects the line of sight of an operator and adjusts the focus on an object to which the line of sight is directed. It relates to cameras (including camera bodies) that can be obtained.

[0002]

2. Description of the Related Art A camera capable of focusing on an object located in a different area of a screen requires a so-called AF lock for re-framing after focusing like a camera for focusing an object in the center of the screen. Since this has no effect, there is an advantage that the quick-shooting property is improved and the degree of freedom of framing is increased especially for a moving object (moving object). In addition, even if the photographer is unfamiliar with the camera, it is possible to take a picture without worrying about focusing.

However, in order to take advantage of this kind of advantage, it is necessary to always select the optimum distance measuring area, and it is very troublesome to make the selection manually.

For example, Japanese Patent Application Laid-Open No. 2-332312 discloses a technique for focusing on the basis of the line-of-sight information of the operator. According to this technique, it is desired even in a scene where there is an obstacle in front of the main subject. This is convenient because the subject is subject to proper focus adjustment.

On the other hand, the conventional automatic camera is provided with so-called one-shot operation mode and servo operation mode.
It is used properly depending on the movement of the object. For example, the one-shot operation mode is mainly used for a stationary subject, the lens drive is prohibited (AF lock state) after focusing once, and if necessary, the framing is performed thereafter. Is a mode mainly used for a moving subject and is a mode in which continuous lens driving is accompanied with a change in subject distance.

As a technique for tracking a moving subject with a single-lens reflex camera, it is conceivable to arrange a large number of predictive controls or detection areas. In such a case, consider that it may take some time until the shutter lens travels after the shooting lens is driven through distance measurement calculation after obtaining subject information, and these tracking delays are predicted from past distance measurement data. To correct. Also, if you have a configuration that arranges a large number of detection fields,
It is a technology that enables focusing. A certain degree of improvement in tracking performance is realized by the combination of these two techniques.

However, when a large number of detection areas are arranged in parallel, object information other than the main subject is also detected, so that the background may be erroneously focused.

On the other hand, as one of the important techniques in automatic focus adjustment of a camera, there is an increase in focusing speed. This means how to shorten the time from the focus adjustment start instruction by pressing the release button or the like until the subject is in focus and photographing is possible. 2. Description of the Related Art Conventionally, speedup has been achieved by shortening the storage time by increasing the sensitivity of photoelectric conversion elements, shortening the calculation processing time by a high-speed microcomputer, and improving the actuator that drives the focusing lens.

By the way, in the automatic focus adjustment of the camera, focus detection and lens driving are repeated until focusing is achieved. Therefore, prior to each focus detection operation, the line of sight is detected, and the distance measuring field of view is determined based on the result. The operation of reselecting may significantly impair the high-speed focusing speed described above.

Apart from that, it has been mentioned that there is known a technique for detecting the line of sight of the operator and selecting the detection area based on the line of sight.
A device that irradiates the observer's eye with infrared light from the viewfinder of the camera and obtains the rotation angle of the eyeball according to the relative position between the reflection image of the light source (so-called Purkinje image) and the center of the pupil It is suitable for cameras because it is small and there are few restrictions on the position of the eyeball.

However, when the eyeball is optically observed in this way, the eyelids are often obstructed and the entire pupil cannot be seen. Therefore, the accuracy of detecting the center of the pupil may be inferior in the vertical direction with respect to the horizontal direction, and the accuracy of visual axis detection in the vertical direction by this method may be low. However, since the photographing screen of the camera is generally horizontally long, only lateral detection is practically sufficient. On the other hand, the line-of-sight detection in a specific direction can be realized by using only one array of photoelectric conversion elements as described later, which is extremely advantageous in terms of cost. Taking these things into consideration, it can be said that the visual line detection device that detects the lateral visual line position is optimal for a camera.

However, in this type of line-of-sight detection device, there is an unavoidable decrease in detection accuracy due to the attitude of the camera because of the structural drawbacks described above.
That is, since the aspect ratio of the screen of a normal camera is not 1, naturally, the camera may be rotated by 90 °. At this time, the eyeball rotation in the vertical direction is detected based on the line-of-sight detection position.

[0013]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems that occur when using a camera having a function of adjusting the focus based on the sight line detection information. In the present application, the camera to which the taking lens is fixed, the camera to which the taking lens is attached and detached, and the so-called camera body where the taking lens is detached are all referred to as cameras in order to avoid complication of words.

More specifically, the above-mentioned problem will be described firstly so that the main subject is accurately focused. Further, it is to realize stable follow-up even when detection cannot be performed due to the action of an inconvenient factor such as eyelashes, eyeblink blinking, eyeball jumping movement, and the like. Another object of the present invention is to provide a device in which the operator can focus on the intended position even in the large defocus state. Another object of the present invention is to provide a moving object detection function for enabling reliable switching of operation modes in a camera that selects a distance measuring field of view based on line-of-sight information. An object of the present invention is to provide a camera with a visual axis detection function that maintains a higher focusing speed. Further, the present invention provides a camera in which the focus adjustment operation is not affected by a decrease in detection accuracy due to the posture and a malfunction when detection is impossible.

[0015]

SUMMARY OF THE INVENTION The present invention comprises a lens control means for controlling the focus adjustment of an objective lens, a visual axis detection means for detecting the visual axis of an observer's eye, and a means for performing focus detection for different parts on the screen. In the provided camera, in the servo operation mode in which the change in the image plane position due to the change in the object distance is tracked and corrected, the line-of-sight detecting unit detects the line-of-sight position prior to the focus detection operation, and the lens control unit sets the line-of-sight position information. The operation of continuously controlling the image forming position of the objective lens is performed with respect to the focus detection output of the part based on.

Further, the present invention has a lens control means for controlling the focus adjustment of the objective lens, a visual axis detecting means for detecting the visual axis of the observer's eye, and a means for performing focus detection for different parts within the screen. If the line-of-sight cannot be detected by a camera that repeatedly detects the line-of-sight and focus detection, the lens control means is operated based on a new focus detection output regarding the previous line-of-sight position or its vicinity.

The present invention is also a camera provided with a lens control means for controlling the focus adjustment of an objective lens, a visual axis detection means for detecting the visual axis of the observer's eye, and a means for performing focus detection on different parts of the screen. The control means has a first operation mode for controlling only the moving direction of the image forming position of the objective lens and a second operation mode for controlling the moving direction and the moving amount. The control in the first operation mode is performed, and during the adjustment control of the objective lens in the first operation mode, the sight line detection and the focus detection at or near the sight line position are performed in a predetermined order.

Further, the present invention comprises a lens control means for controlling the focus adjustment of the objective lens, a visual axis detection means for detecting the visual axis of the observer's eye, a means for performing focus detection for a different portion in the screen, and a moving body detection means. In the camera, in response to a focus adjustment disclosure instruction operation, the control means is driven, and after the focus detection means outputs that the focus state is once in focus, driving of the control means thereafter is prohibited. Operating mode,
The moving object detecting means has a second operation mode in which the control means is continuously driven to correct the change of the image plane due to the change of the object distance, and the moving body detecting means obtains the focus detection output based on the visual line detection result. The first operation mode is switched to the second operation mode due to the fluctuation of the above, and until the second operation mode is switched after the focus state is once detected in the first operation mode. Re-selection of a site in the screen by the visual field detection means is suppressed.

The present invention is also a camera provided with a lens control means for controlling the focus adjustment of an objective lens, a visual axis detection means for detecting the visual axis of the observer's eye, and a means for performing focus detection with respect to different parts of the screen. In response to a disclosure instruction operation of focus adjustment, the lens control means is driven, and after the focus detection means outputs the focus state, the one-shot operation mode for prohibiting further driving is performed. The line-of-sight detection unit detects the line-of-sight position prior to the first focus detection operation, and the lens control unit is driven by the focus detection output detected based on the line-of-sight position. The lens control means is controlled based on the focus detection output based on the same line-of-sight position.

Further, according to the present invention, the lens control means for controlling the focus adjustment of the objective lens, the line of sight of the observer's eye are detected, the means for performing focus detection with respect to a different part of the screen, and the attitude in the direction of gravity. In a camera having a posture detection device for detecting, the line-of-sight detection means is capable of detecting the line-of-sight position with respect to the detection direction in the state where the camera is in the normal position by using the reflected light from the anterior segment.
When the output from the posture detecting means indicates that the posture of the camera is in the vertical position, the operation of the line-of-sight detecting means is prohibited, and the objective lens coupling is performed based on the focus detection output for a specific part in the screen. Determine the image state.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 11 are flowcharts for explaining the operation of the apparatus, and FIG. 12 shows a camera equipped with a sight line direction detecting apparatus. An optical arrangement is shown, and FIGS. 13 to 16 are views for explaining a method of detecting the line-of-sight direction. In addition, FIG.
To FIG. 20 are views for explaining the configuration of the focus detection apparatus,
FIG. 24 is a diagram mainly showing an electric system of the camera.

First, in FIG. 12, reference numeral 4 is a camera body of a single-lens reflex camera, and 5 is a lens barrel, which is detachable or fixed to the camera body 4. Reference numeral 1 schematically shows a photographic lens, which is housed in a lens barrel 5, and is moved in the optical axis x direction by a driving force of a drive motor (not shown) to perform focusing.

It is assumed that 2 is a quick return mirror (main mirror), 3 is a sub mirror, and the sub mirror 3 is supported by the main mirror 2. Reference numeral 6 is a focus detecting device, which will be described later in detail, and receives the light refracted and passed through the taking lens 1, the main mirror 2, and the light reflected by the sub mirror 3. On the other hand, the number 3 arranged on the reflection optical path of the main mirror 2 is a focusing screen, and the numeral 8 is bentagonal.
A prism and 15 are eyepieces, which form a finder system. Reference numeral 9 denotes a light splitter, in which a dichroic mirror that reflects infrared light and transmits visible light is obliquely installed and is provided in the finder optical path. Reference numeral 11 is a light emitting / receiving lens, 12 is a half mirror, and 13 is an illumination point light source such as an LED that emits infrared light. It is assumed that the light source 13 is at one focus position of the system in which the light emitting / receiving lens 11 and the eyepiece lens 15 are combined, and the light flux emitted from the light source 13 is half
After passing through the mirror 12, the light emitting / receiving lens 11, and the light splitter 9, the light exits as parallel light from the eyepiece lens 15. Reference numeral 14 denotes a photoelectric converter having an element array, which is arranged at a position where the anterior eye part is imaged by the eyepiece lens 15 and the light projecting / receiving lens 11, and receives an eyeball image and a corneal reflection image of the light source. Members 9, 11, 12,
13, 14 and the eyepiece lens 15 form an optical system of the visual axis detection device.

Next, a method of detecting the direction of the line of sight will be described with reference to FIG. In the figure, reference numeral 20 denotes a lens in which the light projecting / receiving lens 11 and the eyepiece lens 15 are combined, 22 denotes a model eye of an observer's eye, 21 is a cornea, and 23 is an iris.

The infrared light emitted from the LED 13 becomes parallel light by the lens 20 and illuminates the cornea 21 of the eyeball. At this time, the corneal reflection image d formed by a part of the infrared light reflected on the surface of the cornea 21 occurs near the iris 23 and the lens 2
The light is focused by 0, passes through the half mirror 12, and is re-imaged at the position d ′ on the photoelectric converter 14.

Light fluxes from the ends a and b of the iris 23 pass through the light receiving lens 20 and the half mirror 12 and the photoelectric converter 1 is provided.
The images of the end portions a and b are formed at the positions a ′ and b ′ on the position 4.
When the rotation angle θ of the optical axis a of the eyeball with respect to the optical axis a of the lens 20 is small, the Z coordinates of the ends a and b of the iris 23 are set to Za and Z.
Assuming b, the coordinate Zc of the center position c of the iris 23 is expressed as Zc≈ (Za + Zb) / 2.

Further, when the Z coordinate of the corneal reflection image generation position d is Zd and the distance between the center of curvature O of the cornea 21 and the center C of the iris 23 is OC, the rotation angle θ of the eyeball optical axis a is OC * SINθ. Almost satisfy the relational expression of Zc-Zd (1). Here, Z at the position d of the corneal reflection image
The coordinate Zd and the Z coordinate Zo of O at the center of curvature of the cornea 21 match. Therefore, the rotation angle θ of the eyeball optical axis a can be obtained by detecting the position of each singular point (corneal reflection image d and the edges a and b of the iris) projected on the photoelectric converter 14. At this time, the equation (1) can be rewritten as β * OC * SINθ≈ (Za ′ + Zb ′) / 2−Zd ′ (2). However, β is a magnification determined by the distance L1 between the corneal reflection image generation position and the lens 20, and the distance L0 between the lens 20 and the photoelectric converter 14.

Although a line-of-sight detection method using a reflection image on the cornea, a so-called Purkinje's first image, is shown here,
It is known that four Purkinje images such as a reflection image of the crystalline lens are formed from the structure of the human eye, and these images are also formed on the photoelectric converter 14, but other than the Purkinje first image, it is relatively large. Since the light intensity is low, detection will not be hindered by applying appropriate electrical processing. In addition, when a person actually sees an object, there is a deviation between the geometrical optical axis of the eyeball and the visual axis (line of sight) because the macula is in the center of the field of view, but there is a certain amount of correction during calculation. If there is no problem in practice by applying the above method and precise correction is required, the method described in JP-A-1-241511 can be adopted.

In the arrangement shown in FIG. 13, it is assumed that the photoelectric converter 14 has elements arranged one-dimensionally in the vertical direction in the figure, and each element 14 is vertically arranged as shown in FIG. 14 for simplification of the detection apparatus. The width of the strip is more than several times the width. This makes it difficult to detect in the vertical direction, but makes it almost insensitive to vertical translation or rotation of the eyeball and simplifies signal processing. In order to obtain a similar effect, a cylindrical lens having a refractive power in the direction perpendicular to the arrangement direction of the elements may be attached to the front surface of the photoelectric converter.

FIG. 14 shows a state in which a pupil image 61 and a Purkinje first image 62 are formed on the photoelectric converter, and FIG.
Shows the image of the observation eye when viewed from the front.

When the image of the observation eye is received by the photoelectric converter, FIG.
The outputs shown in FIG. 6 are obtained, 65 is the output corresponding to the first Purkinje image 62, 67 and 68 are the edges of the iris, and the high output values on both sides are the sclera (white eye).

The center of the pupil is obtained from the position information of the edge portions 67 and 68. In the simplest way, at the edge part, the pixel numbers that produce an output close to half the average of the iris part 81 are i ₁ , i
Position coordinates of the pupil center to ₂ is given by _{i 0 = (i 1 + i} 2) / 2. The position of the Purkinje's first image is obtained from the maximum peak that appears locally in the dark part of the pupil, so the relative positional relationship between this position and the center of the pupil above
It is possible to know the rotation state of the eyeball, and hence the direction of the line of sight. Reference numerals 82 and 83 are upper and lower eyelids. Next, the configuration of the focus detection device will be described with reference to FIG. 17, but the present focus detection device can select one of the blocks having a plurality of detection fields of view, respectively. FIG. 18 shows the optical action when the on-axis block is selected, and FIG. 19 shows the optical action when the off-axis block is selected.

In the figure, X is the optical axis, and the sub mirror 3 in FIG.
Hit the area after reflection at. A member 81 drawn with a broken line and shown in practice is a field mask, and rectangular openings 81a, 81b, 81c for the left off-axis block 81 that maximize the detection field of the on-axis block.
d, 81e, 81f, right off-axis blocks 81g, 81h,
81i, and is arranged at or near the planned image forming plane of the taking lens. A movable mask 80 has a rectangular opening 80a for selecting one of the on-axis block and the off-axis block, and is assumed to be slidably supported by a holding member (not shown) close to the field mask 81. . The movable mask 8
A drive piece 122 is fixed to the end portion of 0, and a female screw is formed on the drive piece. Reference numeral 121 is a stepping motor, and a lead screw 121a is connected to the rotation shaft of the motor. Since the lead screw 121a is screwed into the female screw of the drive piece, the lead screw 121a rotates when power is supplied to the stepping motor, and the drive piece 1
22 and the movable mask 80 moves in the direction of arrow A.

Therefore, by rotating the stepping motor 121 forward and backward, the opening of the movable mask can select three positions corresponding to the three blocks of the field mask 81.

Reference numeral 82 denotes a split field lens, which imparts different refracting powers to the light flux passing through the on-axis block and the light flux passing through the off-axis block, and a photoelectric conversion element 8 to be described later.
5 is adjusted so as to receive the luminous flux in a good state. 84
Is a secondary imaging lens group, and positive lenses 84a to 84d are integrally formed. Positive lenses 84a to 84d
Are three pairs, namely 84a and 84d, 84b and 84c,
84c and 84d are formed.

Reference numeral 83 denotes a porous mask, which has elliptical openings corresponding to the respective positive lenses for restricting the light flux passing through the positive lenses 84a to 84d. Reference numeral 85 is a photoelectric conversion element, which is an array of pixel pairs SNS3 and SNS4, SNS5 and SN.
It has S6, SNS7 and SNS8, and is enclosed in a package 86 made of transparent resin. The light fluxes passing through the upper, middle, and lower detection fields of each block of the field mask 81 are incident on the lower, middle, and upper arrays of photoelectric conversion elements 85, respectively.

FIG. 18 shows an example in which the opening 80a of the movable mask 80 is on the optical axis of the objective lens 1, and the light flux for focus detection is the movable mask opening 80a and the fixed mask opening 81.
After passing through b, the light enters the central portion 82a of the split field lens. In the central portion of the split field lens 82, the porous mask 83 and the exit pupil plane 38 of the objective lens are placed in a conjugate relationship, and in particular, the two openings 83 of the porous mask are arranged.
The centers of b and 83c are projected onto the center of the exit pupil. Further, the light flux passing through the openings 83b and 83c of the porous mask is
The lens portion 84 of the re-imaging lens 84 placed behind it
It is incident on b and 84c, respectively. The lenses 84b and 84c of the secondary image forming lens group place the planned image forming surface of the objective lens 1 and the light receiving surface of the photoelectric conversion element 85 in a conjugate relationship so that a secondary image of a pair of objects is formed on the light receiving surface of the photoelectric conversion element. Form on top. The back projection images of a pair of pixel rows SNS5 and SNS6, which are composed of a large number of pixels arranged on the photoelectric conversion element on which the image of the opening 81b of the fixed mask is formed by the secondary imaging lens, serve as a distance measuring field. Since the relative distance of the secondary image changes depending on the image forming state of the taking lens 1 with respect to the planned image forming surface,
After photoelectrically converting this, the image formation state of the photographing lens can be known by performing a predetermined calculation. 20 Ai and B
i is an example of a photoelectrically converted signal.

The light flux that has entered the focus detection system through the upper and lower openings of the field mask 81b is the secondary imaging lens 84b,
By the action of 84c, the pixel column SNS3 of the photoelectric conversion element,
Image on SNS4, SNS7, SNS8, 2 of the object
Form the next image. These images can also be formed in the fixed masks 81a and 81c by utilizing the fact that the relative distance changes in accordance with the image formation state of the objective lens.

FIG. 19 shows an example in which the opening 80a of the movable mask 80 is located off the optical axis of the objective lens 1.
The light flux for focus detection passes through the movable mask opening 80a and the fixed mask opening 81e, and then the split field lens 8
The light is incident on the second peripheral portion 82b. The optical axis 88 of the peripheral portion 82b of the split field lens is different from the optical axis of the objective lens, the porous mask 83 and the exit pupil plane 38 of the objective lens 1 are placed in a conjugate relationship, and the aperture 83a of the porous mask,
The center of 83b is projected onto the center of the exit pupil. The light flux that has passed through the perforated masks 83a and 83b receives the secondary imaging lens 84.
Incident on the lens section of the photoelectric conversion element 84a and 84b, respectively, and on the pair of pixel rows SNS5 and SNS6 of the photoelectric conversion element, the object of
Form the next image. Therefore, as in the case of the on-axis detection field of view described with reference to FIG. 18, a pair of secondary images are displayed on the pixel array SNS.
5. The image formation state of the objective lens can be known by performing a predetermined calculation on the signal photoelectrically converted by the SNS6. The upper and lower openings of the field mask 81e can be detected by photoelectrically converting the images on the pixel columns SNS3, SNS4, SNS7, SNS8.

The field masks 81g, 81h, 81i
Since the detection system on the side is axisymmetric, the description is omitted.

As described above, the pixel columns SNS3, SNS4
Are used for focus detection at the positions of the field mask openings 81d, 81a, 81g, and the pixel columns SNS5, SNS6 are at the positions of the openings 81e, 81b, 81h, and the pixel columns SNS7, SN.
S8 is used for focus detection at the positions of the openings 81f, 81c, 81i. Focus detection at a total of nine positions is possible with three pairs of pixel rows. In each case, the back projection image by the secondary imaging lens of the pixel row is the actual detection visual field, and it is convenient for the operator to display these in the finder visual field as shown in FIG. However, the detection frames 94a to 94i may be written on one surface of the focusing screen of FIG. 4, or a liquid crystal display plate 16 may be provided adjacently above the focusing screen to display the detection field of view of the selected block. Is also good.

FIG. 22 is a detailed view of the porous mask 83, and particularly shows the positional relationship with the exit pupil image. 90 in the figure
Reference characters a, 90b, and 90c are images of the exit pupil of the objective lens 1 by the central portion 82a and the peripheral portions 82b and 82c of the split field lens, respectively, which are obtained through the nine openings of the visual field mask 81. Inside the exit pupil image 90a,
The porous mask openings 83b and 83c are formed inside the exit pupil image 90b, and the porous mask openings 83a and 83b are formed inside the exit pupil image 90b.
Porous mask openings 83c and 83d are placed inside 0c, respectively. The perforated mask openings 83b and 83c are located in a common area of the two exit pupil images, and the light beams from the two detection fields of view are selectively incident on the movable mask 80 depending on the position of the movable mask 80. Thus, by configuring one mask aperture to receive light flux from two detection fields,
By projecting the projected image formation surface of the photographing lens and the photoelectric conversion element into a reduced image, it is possible to further guide the light flux of the field masks 81a to 81i onto the photoelectric conversion element while reducing the sensor area.

Next, FIG. 23 shows a switch for detecting whether the camera is held horizontally or vertically. If a two-dimensional area sensor is adopted for the photoelectric converter 14 in the visual axis detection device shown in FIG. 12, the output of the vertical side and the output of the horizontal side of the area sensor can be switched according to the attitude of the camera so that the horizontal side is output. It is possible to detect the line-of-sight direction. However, in this embodiment, since the photoelectric converter 14 employs the one-dimensional sensor, when the camera is held vertically, an erroneous detection occurs, so that the detection is stopped.

This drawing is an example of a detection switch utilizing gravity, and 107 is a rotating shaft, which is constructed so that a weight 108 is provided at one end of a lever supported by the shaft and friction is reduced at the other end. A micro brush 106a is provided. 109, 1
Reference numerals 10 and 111 denote curved electrodes arranged on the same circle.
A horizontal position signal is generated when the microbrush 106a and the electrode 109 are in contact with each other, and a vertical position signal is generated when the microbrush 106a and the electrode 110 or 111 are in contact with each other.

FIG. 24 mainly shows the electric system. However, FLS
Corresponds to the lens barrel 5 in FIG. 12, and 1 corresponds to the LNS. Similarly, the LED corresponds to the illumination light source 13 of FIG. 12, and the SA corresponds to the photoelectric converter 14. The SNS corresponds to the member 6 of FIG. 12, specifically the photoelectric conversion element 85 of the focus detection device of FIG. 17, and the MTR 3 corresponds to the stepping motor 121 of FIG. By the way, MTR1 is a film feeding motor, MTR
2 is a shutter spring winding motor. SW1 and SW2 indicate switches that are sequentially closed by pressing down a release button (not shown), and SPC indicates a photometric sensor for exposure control. The DSP indicates a display board for displaying various information of the camera.

On the other hand, PRS is a control device of the camera, for example, a CPU (central processing unit), ROM, RAM,
EEPROM (Electrically Erasable Programmable RO
M), which is a 1-chip microcomputer having an A / D conversion function, according to the camera sequence program stored in the ROM, the automatic exposure control function, the automatic focus detection function, the film winding / rewinding, etc. It's working. EEPROM is a type of non-volatile memory,
Various adjustment data are written in the process. The camera control unit PRS uses communication signals SO, SI, SCL
K is used to communicate with the peripheral circuits and the lens to control the operation of each circuit and lens.

SO is a data signal output from PRS,
SI is a data signal input to PRS, and SCLK is a synchronization signal of signals SO and SI.

LCM is a lens communication buffer circuit,
When the camera is in operation, the lens power supply VL is applied to the lens, and when the signal CLCM from the PRS is at a high potential level, it serves as a buffer for communication between the camera and the lens.

PRS sets CLCM to "H", and SCL
When certain data is sent from SO in synchronization with K, LC
M outputs the buffer signals LCK and DCL of SCLK and SO to the lens via the camera / lens indirect point. At the same time, the buffer signal of the signal DLC from the lens is output to SI, and the PRS inputs the lens data from SI in synchronization with SCLK.

SDR1 is a drive circuit of the line sensor device SNS for focus detection, which is selected when the signal CSDR1 is "H" and controlled by the PRS using SO, SI and SCLK.

The signal CK1 is the CCD driving clock φ1.
Clock for generating 1 and φ12, signal IN
TEND1 is a signal notifying the PRS that the accumulation operation has been completed.

The output signal OS1 of the SNS is the clock φ1.
1, a time-series image signal synchronized with φ12, SDR1
After being amplified by the amplifier circuit inside, it is output to PRS as AOS1. The PRS inputs AOS1 from the analog input terminal and synchronizes with CK1 by using the internal A / D conversion function.
After the / D conversion, the data is sequentially stored in a predetermined address of the RAM.

Similarly, the output signal of SNS, AGC1
Is the output of the AGC control sensor in the SNS, and SD
It is input to R1 and used for SNS storage control.

One of the two photoelectric conversion outputs formed on the pair of sensor arrays is A (i) and the other is B.
It is shown in FIG. 12 as (i). In this example, the number of pixels of the sensor is 40 pixels (i = 0, ..., 39).

Image shift amount P from the image signals A (i) and B (i)
A signal processing method for detecting R is disclosed in Japanese Patent Laid-Open No. 58-142.
No. 306, No. 59-107313, No. 60-101513, or No. 63-1.
No. 8314 is disclosed.

SDR2 is a drive circuit of the line sensor device SA for detecting the line of sight, which is selected when the signal CSDR2 is "H" and is controlled by the PRS using SO, SI and SCLK.

The signal CK2 is the CCD driving clock φ2.
Clock for generating 1 and φ22, signal IN
TEND2 is a signal notifying the PRS that the accumulation operation has been completed.

The output signal OS2 of SA is clock φ21,
These are time-series image signals synchronized with φ22, and after being amplified by the amplifier circuit in SDR2, are output to PRS as AOS2. The PRS inputs AOS2 from the analog input terminal, synchronizes with CK2, and A / D by the internal A / D conversion function.
After conversion, the data is sequentially stored at a predetermined address in the RAM.

Similarly, AGC2 which is the output signal of SNS2
Is the output of the AGC control sensor in the SA, and SDR
2 is input and used for SNS storage control.

The LED (13 in FIG. 12) is an L for human eye illumination.
At the ED, the transistor TR3 is energized in synchronism with the accumulation of the photoelectric element SA (14 in FIG. 12) to be used for detecting the line of sight.

SPC is a photometric sensor for exposure control that receives light from the taking lens, and its output SSPC is P
It is input to the analog input terminal of RS, used for automatic exposure control (AE) after A / D conversion.

DDR is a switch sense and display circuit, which is selected when the signal CDRD is "H", and S
Controlled from PRS using O, SI, SCLK. That is, the display of the display member DSP of the camera is switched based on the data sent from the PRS, and the ON / OFF state of various operation members such as a release button (not shown) (interlocked with the switches SW1 and SW2) and mode setting buttons. Also, the state of the gravity detection switch SWC shown in FIG. 23 is notified to the PRS.

MDR1 and MDR2 are drive circuits for the film feeding and shutter spring hoisting motors MTR1 and MTR2, which carry out normal / reverse rotation of the motors by the signals M1F, M1R, M2F and M2R.

The MDR 3 is a movable mask 8 of the focus detection device.
Zero-moving stepping motor MTR3 (121 in FIG. 9)
Drive circuit, the number of drive steps by signal M3P, signal M3D
The drive direction instruction is received at, the pulse is distributed to each phase of the stepping motor, and current amplification for excitation is performed.

MG1 and MG2 are shutter front and rear curtain running start magnets, respectively. Signals SMG1 and SMG2,
Power is supplied to the amplification transistors TR1 and TR2, and shutter control is performed by the PRS.

SW1 and SW2 are switches interlocked with the release button 87. SW1 is turned on when the release button 87 is pressed in the first step, and subsequently SW2 is turned on when the release button 87 is pressed in the second step. The control device PRS performs photometry, line-of-sight detection, and automatic focus adjustment when SW1 is on, and exposure control and subsequent film winding are triggered by SW2 on.

The SW2 is connected to the "interrupt input terminal" of the control device PRS, which is a microcomputer, so that even if the program is executed when the SW1 is on, an interrupt is generated by turning on the SW2, and control can be immediately transferred to a predetermined interrupt program. it can.

The switch / sense display circuit DD
Since R, motor drive circuits MDR1 and MDR2, and shutter control are not directly related to the present invention, detailed description thereof will be omitted.

In-lens control circuit LPR synchronized with LCK
The signal DCL input to S is the lens FLN from the camera.
This is command data for S, and the operation of the lens with respect to the command is predetermined.

The LPRS analyzes the command according to a predetermined procedure, and performs focus adjustment and aperture control operations and output DLC.
Various lens parameters (open F number, focal length, coefficient of defocus amount vs amount of extension, etc.) are output.

In the embodiment, an example of a single lens for the entire extension is shown. When a focus adjustment command is sent from the camera, the focus adjustment motor LMTR is driven in accordance with the drive amount and direction sent at the same time. Driven by the signals LMF and LMR, the optical system is moved in the optical axis direction to perform focus adjustment. The amount of movement of the optical system is monitored by the pulse signal SENC of the encoder circuit ENC, and is counted by the counter in the LPRS. When the predetermined movement is completed, the signal LM
F and LMR are set to "L", and the motor LMTR is S-controlled.

When a diaphragm control command is sent from the camera, a stepping motor DMTR known for driving the diaphragm is driven in accordance with the number of diaphragm stages sent at the same time. Since the stepping motor can be open-controlled, it does not need an encoder for monitoring the operation.

Next, the operation of the camera will be described with reference to FIGS. FIG. 1 is a flowchart showing the overall flow of the program stored in the PRS. When the execution of the program is started by the above operation, the state of the switch SW1 which is turned on by the first stroke of the release button is detected in step (002), and when the switch SW1 is off, in step (005), By sending a "drive stop command" to the lens, a drive stop instruction is given. In step (005), all the control flags set in the RAM in the PRS are cleared. The above steps (002) and (005) are repeatedly executed until the switch SW1 is turned on or the power switch is turned off. Therefore, even when the lens is being driven, the lens stops driving when SW1 is turned on. It will be. When SW1 is turned on, the process proceeds to step (003). Step (003) means a subroutine of "AE control". This "AE control"
In the subroutine, a series of camera operation controls such as photometric calculation processing, exposure control, shutter charging after exposure, film winding, and the like are performed. The "AE control" subroutine is not directly related to the present invention, so a detailed description thereof will be omitted, but the outline of the function of this subroutine is as follows.

While SW1 is on, this "AE control" subroutine is executed, and photometry and exposure control calculations are executed each time.
The display is done. When the switch SW2 is turned on by the second stroke of the release button (not shown), the release operation is started by the interrupt processing function of the microcomputer DRS, and the aperture or shutter speed is changed based on the exposure amount obtained by the exposure control calculation. After the exposure is completed, the shutter charge and the film feeding operation are performed to complete the photographing of one frame of the film.

The camera of the embodiment of the present invention has two AF modes, so-called "one-shot" and "servo", which are automatically switched according to the subject. When the AF mode is one-shot, once the focus is achieved, the lens drive operation is not performed again until the switch SW1 is turned off, and the release cannot be performed until the focus is achieved.

In the case of the servo mode, the lens drive that follows the pursuit of the object is continuously performed even after focusing, and the release is permitted when the lens drive by the moving body prediction control described later is completed.

As described above, the release operation is performed by turning on the switch SW2. However, even if the switch SW2 is turned on even after the shooting of one frame of film is completed,
The "AE control" is returned once it has been completed. Therefore, to explain the operation with the SW2 turned on, in the case of one shot, the release cannot be performed until the subject comes into focus, and the release is possible only after the subject comes into focus, and one frame is photographed. Focus adjustment is not performed, the next frame is shot with the same lens position,
Shooting is continuously executed while the switch SW2 is on.

In the servo mode, while the switch SW2 is turned on, "release operation", "AF control", "release operation" and "AF control" are alternately repeated.

Now, as described above, the step (00
When the "AF control" subroutine in 3) is completed,
The "AF control" subroutine of step (004) is executed.

FIG. 2 shows a flowchart of the "AF control" subroutine.

First, in step (108), the flag PRM is set.
The state of V is determined. As will be described later, PRMV is a flag related to lens control, and is a flag that is set to 1 when the lens is driven in the previous “AF control”. Since the first flow after the switch SW1 is turned on has been described, the flag PRMV is 0, and the process proceeds to step (112).

Although the state of the flag SRMV is detected in step (112), SRMV is also a flag related to lens control, and since SRMV = 0 now, step (1)
55). In step (155), the flag LM
VDI is detected, and since it is φ, step (15
Move to 0).

In step (150), the "line-of-sight detection" subroutine is executed. This subroutine is shown in FIG. Here, the position of the line of sight of the photographer is detected. The details of this subroutine and the subsequent subroutine will be described later.

In step (151), based on the line-of-sight detection result according to the range-finding visual field range setting subroutine shown in FIG. Is selected and the stepping motor 121 is controlled to set the opening of the movable mask 80 at a desired position.

In the next step (129), the "focus detection" subroutine is executed. The flow chart of this subroutine is shown in FIG. 5, and the focus state of the taking lens is detected in the three distance measuring fields in this subroutine. In the subsequent step (102), the AF mode is set by detecting whether the subject is moving or stationary in the subroutine shown in FIG. 3. In the first flow, AFOFLG is cleared as the one-shot mode. Will be returned.

In step (152), the flag AFOFL is set.
The state of G is detected, and since φ is φ in the first flow, the process proceeds to step (130).

In the next step (130), the "determination" subroutine is executed. The flowchart of this subroutine is shown in FIG. Based on the result of the "focus detection" subroutine, the "judgment" subroutine selects one of the three distance measuring fields of view to be used for focus adjustment, and determines whether focusing or focus detection is impossible. Further, when the lens drive is not required, the lens drive prohibition flag LMVDI (104) is set to 1.

Next, at step (131), a "display" subroutine for displaying the focus or the focus detection inability is executed. This is to communicate predetermined data to the display circuit DDR (FIG. 13) and display it on the display device DSP. However, since this operation is not directly related to the present invention, further description will be omitted. .

In step (132), the flag LMVDI is set.
Detect the state of. As described above, since LMVDI is set to 1 when lens driving is not necessary, if LMVDI = 1 in step (132), the process proceeds to step (133) and the "AF control" subroutine is returned. . If the flag LMVDI is 0, the process proceeds to step (134) to detect the state of the flag LCFLG.

LCFLG is a low contrast flag which is set in the "focus detection" subroutine of step (129), and is set to 1 when the contrast of the image signal is lower than a predetermined value. L in step (134)
If CFLG is 0, it means that the contrast is sufficient for focus detection, and after "lens driving" described later is performed in step (135), step (13) is performed.
The lens drive flag PRMV is set to 1 in 6), and the "AF control" subroutine is returned in step (137).

If LCFLG is 1 in step (134), it is determined that the contrast is low, and the process proceeds to step (138).

The steps after step (138) are the first control flow of the so-called "search operation".

Now, in step (138), the count value FCNT of the "distance ring counter" which communicates with the lens and counts the movement amount of the focus adjustment lens by the output pulse of the encoder which is interlocked therewith is set from the in-lens controller LPRS. input. This counter is reset to 0 at the start of supply of the power source VL for the lens, and it is determined that the feeding direction is up-counting and the feeding direction is down-counting.

Therefore, the count value FC of the range ring counter
It is possible to know the relative position of the focusing lens in the lens with respect to the optical axis direction by NT.

In the next step (139), the count value FCNT is set to RA in the microcomputer PRS.
This count value, which is stored and stored in the conversion area LPOS on M, represents the relative position of the lens when the search operation is started. As will be described later, the search operation could not detect a subject with sufficient contrast. When used to return the lens to this search start lens position.

Then, in step (140), a "close-up direction drive command" is sent to the lens, and the search operation is started. In response to this command, the lens drives the focus adjustment lens in the close-up direction. This command does not specify the drive amount, it is only a command for the drive direction,
When the focus adjustment lens reaches the mechanical limit at the closest end, the in-lens control circuit LPRS detects it and the lens itself stops driving. The detection of the mechanical limit position is recognized by the time interval of the encoder pulse SENC. In step (141), the variable SRCNT and the flag SRMV are set to 1
Set to. SRCNT is a variable indicating the state of the search operation, and is 0 when the search operation is not performed, 1 when the lens is driving in the closest direction, 2 when the lens is driving in the infinite direction, and is driven toward the search start lens position. Is set to 3 when Since the lens is driven in the close-up direction here, 1 is set to the variable SRCNT. SRMV is a flag indicating that the lens drive in the search operation has been performed.

The first control of the search operation is performed in steps (138) to (141), and the "AF control" subroutine is returned in step (142).

When the "AF control" subroutine of step (003) in FIG. 1 is completed, the step (00
In 2), the state of the switch SW1 is determined. If SW1 is off, a "drive stop command" is sent to the lens in step (003). That is, even if some lens driving command is issued in the previous "AF control" subroutine, the lens driving is stopped when the switch SW1 is turned off. Then, in the next step (005), all flags are cleared.

If the switch SW1 remains on in step (002), the "AE control" subroutine in step (003) is executed, and then "AF control" is executed again in step (005).
Start execution of the "control" subroutine.

The flow of the "AF control" subroutine (FIG. 2) when the switch SW1 is on will be described below by dividing it into cases.

(A) First, in the past "AF control" subroutine, the contrast is not low (flag LCFLG (1
34) is 0), the lens is driven (flag PRMV).
The case where (108) is 1) will be described.

When the "AF control" subroutine is executed, the state of the flag PRMV is discriminated at step (108), and the routine proceeds to step (109). Step (1
09) communicates with the lens to control the lens internal control circuit LPR
Information on the lens driving state is input from S. Here, if the predetermined driving is completed and the lens is already stopped, the process proceeds to step (110) to clear the flag PRMV,
A new focus adjustment operation after step (129) is started. However, if the handling of determining the distance measuring field is different between the one-shot mode and the servo mode, and if the flag AFOFLG is 1 in step (156), then step (15)
0), the line-of-sight detection is performed again, and if φ, the process proceeds to step (129) and focus detection is performed in the same range-finding visual field range the previous time. If the lens has not stopped, the process proceeds to step (111) and the "AF control" subroutine is returned. That is, the new focus adjustment operation is not performed until the driving of the amount instructed to the lens in the step (135) of the past “AF control” is completed.

(B) Next, in the previous "AF control" subroutine, with low contrast (flag LCFLG is 1),
A case where the search operation is performed (the flag SRMV is 1) will be described.

When the "AF control" subroutine is executed, the state of the flag SRMV is detected at step (112), and the routine goes to step (113).

In step (113), information on the lens driving state is input from the lens. If the lens is already stopped, the process proceeds to step (119), and if it is being driven, the process proceeds to step (153). As described above, the search operation drives the lens in the close-up direction (variable SRCNT = 1), and if a subject with contrast cannot be found and the focusing lens reaches the mechanical limit on the close-up side, the lens will be used in the future. To the infinite direction (variable SRCNT =
If a subject with contrast cannot be found during the driving of 2) and the focusing lens reaches the infinite side mechanical limit, the lens is driven to the search start lens position from now on (variable S
RCNT = 3) is controlled.

During the search operation, line-of-sight detection is always performed before focus detection, and the range-finding visual field range is reset each time. This is because the result of focus detection was low contrast even though the distance measurement field range was set based on the line-of-sight position in the first flow, and the search operation started means that the initial defocus of the taking lens was This is because it is extremely large, which indicates that the photographer may not have perceived the subject accurately, and the gaze detection result in this state has no meaning. This operation is the subroutine for detecting the line of sight and setting the range of the visual field for distance measurement in steps (153) and (154).

At step (114), the "focus detection" subroutine is executed. In this subroutine, the defocus amount and the contrast of the subject are detected. Next, in step (115), the state of the low contrast flag LCFLG is determined. If LCFLG is 1 and the contrast is low, the "AF control" subroutine is returned in step (117). That is, when focus detection is performed in the search operation, nothing is done if the contrast is low.

If it is determined that the flag LDFLG is 0 and the contrast is not low, then the step (116)
Then, a “drive stop command” is sent to the lens. Next, after clearing the flag SRMV in step (118), new focus adjustment control is performed in step (129). That is, when the focus detection during the search operation is not low contrast, that is, when the contrast sufficient for focus detection is detected, the lens is stopped and the search operation is ended (SRMV is set to 0), and the same distance measuring field of view is obtained. A new focus adjustment is performed within the range.

When the contrast cannot be detected by the above-described operation, the "AF control" subroutine is executed every time the "AF control" subroutine is executed until the focus adjustment lens of the lens reaches the mechanical limit on the near side. It will return the subroutine.

When the lens reaches the closest end, step (1
In 13), the lens stop is detected and the process proceeds to step (119). Since the above case has been described, the process proceeds to step (120). In the case of, the process shifts from step (119) to step (123), and then shifts to step (124). In the case of, the process proceeds to step (118) to end the search operation, but the case of will be described later.

Now, in step (120), the variable SRC is set.
Adding 1 to NT. This is because the lens has reached the closest end, so that it is driven in the infinite direction next time. In the next step (121), the "infinite direction drive command" is sent to the lens.
The search operation is started. And step (12
The "AF control" subroutine is returned in 2). The control when the contrast is not obtained during the operation is the same as in the case described above, each time the "AF control" subroutine is executed, the process returns at step (117) and the contrast is detected when the contrast is detected. It is the same.

When the focus adjustment lens of the lens reaches the mechanical limit on the infinite side, the lens stop is detected in step (113), and the process proceeds to step (123) via step (119). Since the search operation is now, SRCNT is 2, and step (123) to step (124)
Move to. At step (124), 1 is added to the variable SRCNT, and the search operation is performed.

At step (125), the distance ring counter value FCNT described above is input, and at step (126), the value of LPOS-FCNT is stored in the variable FP. Variable LPO
S stores the value of the distance ring counter when the search operation is performed, and FP obtained by subtracting the current counter value from this value
Represents the distance ring counter value from the current lens position to the search start position. This FP is step (12
In step 7), the light is sent to the lens, and the lens driving is commanded by the distance ring counter value of FP. That is, the lens is driven to the search start position. And step (12
The "AF control" subroutine is returned in 8). The control during the search operation is the same as that described above.

When the focus adjustment lens reaches the search start position, the lens stop is detected in step (113), and after steps (119) and (123), step (11)
After the flag SRMV is cleared in 8) to end the search operation, a new focus adjustment operation is started in step (129) and thereafter.

Next, the flow of AF control from the second time onward will be described. For that purpose, first, the moving body detection subroutine of step (102) will be described in detail.

FIG. 3 shows a moving body detection subroutine. This flow has a function of changing the AF mode to the servo by detecting the continuous movement of the subject on the image plane after focusing in the one-shot mode or when the one-shot mode fails to achieve the focusing. .

First, at step (624), the state of the flag AFOFLG is detected.
23) and immediately returns from the subroutine. This is to prevent returning to the one-shot mode once the servo mode is entered, and is a measure to prevent a hunting phenomenon between the modes.

In step (602), it is determined whether or not focus detection is possible in the focus detection field selected in the previous flow in the focus detection in step (129) of FIG. 2, and if focus detection is possible. If the process does not proceed to step (603), the process proceeds to step (620) to return the motion detecting operation to the initial state.

In the following description, the defocus amount is a value in the selected distance measuring field in the flow of the previous time or the time before the previous time.

In step (603), the defocus amount DF2 detected before before is set to DF3, the defocus amount DF3 is set to DF2 at the previous time, and the current defocus amount DEF is set to D.
Input to F3 to update the data. Next step (6
In 04), it is determined whether or not focus detection can be performed three times in succession. If ACNT = 3, the process proceeds to step (607), and if not, the process proceeds to step (605).

In step (605), the counter AC
NT is incremented by 1 and the process proceeds to step (606). In the next step (605), focus detection is set to 3 again.
It is determined whether or not the operation can be performed consecutively, and if ACNT = 3, the process proceeds to step (607) to perform the motion detection operation,
If not, the process proceeds to step (623) and this subroutine is returned.

At step (607), the defocus change amount DFA from the focus detection two times before to the focus detection last time.
Also, the defocus change amount DFB from the previous focus detection to the current focus detection is calculated.

In the next step (608), the defocus change amount DF from the previous focus detection to the current focus detection is calculated.
It is determined whether or not B is smaller than a predetermined value AD. If it is smaller than AD, the process proceeds to step (609), and if not, the process proceeds to step (620). Therefore, when the defocus change amount DFB is larger than the predetermined value AD, it is considered that the defocus amount has changed due to the entry of the obstacle into the visual field or the change of the framing, not the movement of the subject. To reset step (620). 0.5m as an example of the value of AD
Although a value of about m is used, if the above determination is performed based on the defocus change speed in consideration of the time factor, the influence of the time interval of focus detection can be removed, and a more accurate determination can be made.

In step (609), the focal length of the taking lens is input to LF2, and in the next step (610), the focal length LF1 of the taking lens at the time of focusing.
And the change rate AIZ of the current focal length LF2 is calculated.

In the step (611), the step (61
It is determined whether the focal length change rate AIZ calculated in 0) is smaller than 0.2, and if it is smaller, the process proceeds to step (612), and if not, the process proceeds to step (620) to reset the moving object detection operation. To do. If the rate of change in focal length is large, that is, if the shooting lens is partially focused or if the zoom lens is used for large zooming, the defocus amount may change due to zooming. This is to prevent it from being mistakenly determined to be a moving body.

In step (612), it is determined whether or not the defocus change amounts DFA and DFB are the same. If DFA / DFB> 0, it is determined that they are in the same direction, and step (613) follows. Transition, otherwise
Proceeding to step (620), the motion detection operation is reset. This is because if the subject is moving in one direction, the direction in which the defocus amount changes is the same, so it is determined to be a moving object, and if it is not, the moving object detection is redone.
Reset each parameter.

At step (613), the parameter MOVECNT for judging the moving body is incremented by 1, and the routine proceeds to step (614).

At step (614), it is judged if the defocus change amount DFB is larger than a predetermined value BD,
If it is larger than BD, the process proceeds to step (615). If not, the process proceeds to step (616). At step (615), MOVECNT is incremented by 1, and the process proceeds to step (616). This is because the defocus change amount DFB is larger than a predetermined value BD (for example, 0.08 mm), that is, MOVECN for a fast subject.
This is to increase the count speed of T and speed up the transition to servo control. If this determination uses a parameter other than the defocus change amount, for example, the focus change speed, the influence of the focus detection time interval can be removed, and a more accurate determination can be performed.

At step (616), the defocus amount DF3 detected this time is a predetermined value CD (for example, 0.2 mm).
It is determined whether or not it is larger (post pinning). If it is larger than CD, the process proceeds to step (617), and if not, the process proceeds to step (618). In step (617), MOVECNT is counted up by 1 and then step (61)
Proceed to 8). Here, if the subject in the center of the screen is in the rear focus state to some extent or more, the shift to the servo control is accelerated, so that the count-up speed of MOVECNT is increased.

In step (618), it is determined whether the moving object determination parameter MOVECNT is 6 or more. If it is 6 or more, it is determined to be a moving object, and the process proceeds to step (619).
Otherwise, it proceeds to step (623) and returns from this subroutine.

At step (619), 1 is input to AFOFLG in order to set the focus detection control mode to servo control, and at step (623) this subroutine is returned. Next, steps (620) to (622) are for returning the motion detection operation to the initial state.
In 0), the ACNT that counts the number of times of focus detection is reset, and then in step (621), the current focal length of the taking lens is input to LF1. And step (6
In 22), MOVECNT is reset, and this subroutine is returned in step (623). Then, this subroutine is repeated until a moving object is detected or the release switch SW2 is turned on or SW1 is turned off.

In addition, after focusing once according to the flow of FIG. 2, in the moving object detection subroutine described above, AF
Until the OFLG is set to 1, the lens drive prohibition flag LMVDI is set to 1 and the step (1
After step 55), step (129) is executed to detect a moving object based on the focus detection result of the same distance measuring visual field without performing the visual axis detection.

AFOLFL is detected as a moving object.
When 1 is set in G, the process branches to step (152) and proceeds to step (104). In step (104), the lens drive prohibition flag LMVDI is cleared, and in step (157), calculation of predictive drive of the photographing lens necessary for servo operation is performed.

In step (158), the lens is driven based on the result of the prediction calculation, and in step (159), the flag PRMV is set to 1 and step 16
When 0, the subroutine is returned.

Next, the flow chart of the "visual axis detection" subroutine of FIG. 4 will be described.

First, in step (201), the vertical / horizontal detection switch SW of the camera shown in FIGS.
The posture of the camera is determined by detecting the state of C. As a result, if the position is the vertical position, the line-of-sight detection operation is not performed and the process proceeds to step (214). If it is in the lateral position, the process proceeds to step (203) to start the sight line detection. At step (214), 0 which means on the optical axis is input to the line of sight VP, and the process returns at step (213).

In step (203), the LED (see FIG.
No. 13) is turned on to illuminate the eyeball, and at the same time, accumulation of the line-of-sight detection photoelectric conversion element SA (14 in FIG. 12) is started. Specifically, the control device PRS of FIG. 15 sends an accumulation start command to the sensor drive circuit SDR2,
Changes the clear signal CLR of the photoelectric conversion element SA to "L", and the accumulation of charges starts.

In step (204), the input I of the PRS is input.
The state of the NTEND2 terminal is detected and it is checked whether the accumulation is completed. The sensor drive circuit SDR2 sets the signal INTEND2 to “L” at the same time as the start of accumulation, and the AG from SA
The C signal SAGC2 is monitored, and when the SAGC2 reaches a predetermined level, the signal INTEND2 is set to "H", and at the same time, the charge transfer signal SH2 is set to "H" for a predetermined time to transfer the accumulated charge to the CCD unit. Have

If the INTEND2 terminal is "H" in step (204), it means that the accumulation is completed and the process proceeds to step (205). If it is "L", it means that the accumulation is not completed. Run.

In step (205), the photoelectric conversion element S
The A / D conversion of the signal AOS2 obtained by amplifying the image signal OS2 of A by the sensor drive circuit SDR2 and the storage of the digital signal in the RAM are performed. More specifically, SDR2
Generates the clocks φ21 and φ22 for driving the CCD in synchronization with the clock CK2 from the PRS and gives them to the control circuit inside the SA. SA drives the CCD section by φ21 and φ22, and the charge in the CCD is the image signal. Is output in time series from the output OS2. This signal is amplified by the amplifier in SDR2 and then input as AOS2 to the analog input terminal of PRS. The PRS performs A / D conversion in synchronization with the clock CK2 output by itself, and A / D
The converted digital image signal is sequentially stored in a predetermined address of the RAM.

In step (206), the edge of the pupil is detected based on the eyeball information obtained in step (205). As mentioned above, this is done by extracting the pixels that produce an output close to half the average of the iris output average.

In step (207), the contrast value of the image obtained during the processing in step (206),
Also, the reliability of the pupil diameter detection result is determined by the difference between the predicted pupil diameter calculated from the finder brightness corresponding to the SPC (FIG. 21) output and the detected pupil diameter. The predicted pupil diameter is a standard value of the pupil diameter that contracts and expands according to the brightness of the outside world. That is, it is possible to eliminate the case where the image of the pupil is unclear due to accumulation during the leap motion of the eyeball, the case where the reduction of the image output due to the eyelashes is mistaken for the pupil, and the like. When it is judged that the reliability is sufficient, the step (20
When it is determined that the reliability is insufficient, the process proceeds to step (212).

Next, in step (208), the first Purkinje image is extracted. This is done by detecting the brightness peaks that appear on the pupil or iris.

In step (209), by comparing the detected contrast of the first Purkinje image with a predetermined value, when the ghost light from glasses or the like overlaps with the Purkinje image, or when the Purkinje image is half missing due to blinking, etc. Is detected, the reliability is insufficient at this time, the process branches to step (212), and when the reliability is sufficient, the process proceeds to step (210).

In the following step (210), the rotation angle of the eyeball is calculated based on the equation (2).

In step (211), step (21
The viewpoint (line) VP on the focus plate is calculated from the rotation angle of the eyeball obtained in 0) and the default value of the finder optical system, and the subroutine is returned in step (213).

In the extraction of the first Purkinje image and the pupil edge, if it is determined that the reliability is insufficient, the branched step (212) sets 1 to the flag VLNG indicating that the line of sight cannot be detected, and the subroutine in step (212). It is supposed to return.

Next, FIG. 11 shows a flow chart of the "distance measuring visual field range setting" subroutine. This subroutine
Based on the line-of-sight detection result, it is determined which of the three blocks having the distance measuring field of view should be selected.

First, at step (902), the visual axis detection impossible flag VL set in the visual axis detection subroutine is set.
The state of NG is detected, and if it is 0, step (903)
If it is 1, branch to step (906),
Return the subroutine. This means that when the line-of-sight cannot be detected, the range-finding visual field range is set at the same position as in the previous flow.

In step (903), the viewpoint VP information (distance from the optical axis) on the focusing plate and a predetermined value a, for example, 1 in the case of a half 35 mm camera of the viewfinder.
Compare with 8 mm. If it is larger than a, it is judged that the photographer was looking at the photographing information other than the subject image, and the range-finding visual field range based on the line-of-sight position at this time is not set, and the process returns at step (906).

In step (904), the range-finding visual field range closest to the viewpoint VP is selected from the three.

In step (905), the movable mask 80
Drive control of the moving stepping motor MTR3 of
Enables focus detection for a selected field of view range.

FIG. 5 shows a flowchart of the "focus detection" subroutine. In steps (802) to (804), the defocus amounts DF (1) and D of the photographing lens are set for the upper, central, and lower distance measuring fields in the selected block.
The contrast between F (2) and DF (3) and the image signal is calculated.

In step (805), if all the contrasts calculated in steps (802) to (804) are less than a predetermined value, the process branches to step (806). If any one of them has a contrast equal to or higher than the predetermined value, the process proceeds to step (807) and the subroutine is returned.

Next, the "determination" subroutine and the "prediction calculation" subroutine will be described. These are subroutines for using the information of a plurality of distance measuring fields within that range for focus adjustment after the distance measuring field block is determined by the result of the line-of-sight detection, and are selectively used according to the focus adjusting operation mode of the camera. .

First, the flow chart of the "determination" subroutine will be described with reference to FIG.

At step 701, whether or not it is the first distance measurement calculation is determined here. Step 7 for the first distance measurement calculation
If not 02, branch to step 704.

At step 702, communication between the lens and the FLNS is carried out to input lens information into the microcomputer. Information such as focal length, close-up distance, sensitivity coefficient, and comb tooth pitch is read from the lens.

On the basis of the information read in steps 703 and 702, the close threshold value is calculated for each distance measuring field (TH (1), TH (2), TH (3)).

Different values are set for these threshold values depending on the distance measuring points. For example, the threshold values for the upper and lower focus detection points are set to TH (1) = TH (3) = 20f using the focal length f of the lens at that time. The threshold for the center is set closer to the thresholds of the upper and lower focus detection points, for example, TH (2) = 10f. This is because it is unlikely that a photographer does not intend to enter in the center of the screen or at a short distance. Further, when it is assumed that the microlens is in a close-up state, this threshold value is multiplied by a certain magnification (less than 1) to lower the threshold value.

In step 704, when the current absolute lens position (focus value) is read from the lens and there is no information on the absolute position of the lens, the lens is once brought to the infinite end at an appropriate time such as when the power is turned on, and the movement of the lens from that point onward is performed. By storing it in a predetermined memory, the current lens position can be obtained.

At step 714, the defocus amount DF is set for the distance measuring field whose contrast is equal to or more than the predetermined value.
(1) to DF (3) and the absolute distances AD (1) to AD for detecting the focus of each distance measuring point from the lens positions stored in S4
Find (3). Also, the number of absolute distance data is stored in NN.

At step 715, AD (1) to AD
(3) is compared and the order of the closer distance is given. A to N1
The distance measuring point number of the closest distance of D (1) to AD (3) is input to the distance measuring point number of the second distance to N2, and the distance measuring point number of the farthest distance is inserted to N3.

If NN = 1 in step 724, the process branches to step (719).

In step 716, the threshold value is compared with the closest distance measured point. Step 715
Since the distance measuring point number (N1) of the closest distance is obtained in the above, the distance measuring distance of the distance measuring point N1 and the threshold value AD (N1) and TH
(N1) is compared. If the distance measurement distance AD (N1) is smaller than the threshold value TH (N1), the process branches to step 717. If so, the process branches to step 720.

If NN = 2, step 725 branches to step (719).

At step 720, it is determined whether or not the distance measurement distance is continuously increasing. Since the distance measuring points are numbered in order from the top, it is possible to determine that the distance measuring is continuously distant if the arranged N1 to N3 are arranged in ascending order or in descending order in the order of short distance. If the distance is continuous, branch to step 718; otherwise, step 7
Branch to 19.

At step 717, since the short distance point is smaller than the threshold value, the second closest point is selected. The focus detection point number N2 of the second distance is stored in OP.

In step 718, when the subjects are lined up continuously, the distance measuring point is set to the center (distance measuring point number 2). The selected distance measuring point number 2 is stored in OP.

In step 719, the closest distance point is stored in OP when the branch is not made in the determination in steps 716 and 720.

In step 721, when the selection of the selected point is completed, it is determined whether or not the selected focus detection point is in focus. If in focus, the process branches to step 722. If not in focus, the process branches to step 723.

In step 722, the focus flag JFF is set.
LD is set to 1, and the subroutine returns in step 723.

Next, the flow of the "prediction calculation" subroutine will be described with reference to FIG. FIG. 3 (e) shows the flow of the "prediction calculation" subroutine, in which whether or not the prediction calculation is possible is determined, and if it is predictable, the lens drive amount in consideration of the AF time lag and the release time lag is calculated. is there.

The step (302) determines whether or not to count up a counter COUNT for determining whether or not the data necessary for prediction has been accumulated. In the present embodiment, when the distance measurement data and lens drive data are accumulated three or more times, that is, if COUNT> 2, it is possible to perform a predictive calculation, and no further count-up is necessary. Step (3
Go to 04). If COUNT <3, the COUNT is incremented in step (303) and then the process proceeds to step (304).

At step (304), the data for the current prediction calculation is updated. That is, the prediction calculation is performed in JP-A-1-288816 (6), (7), (8), (9).
Since it is performed based on the equation, the data is the defocus amounts DF ₂ , DF of the previous and the previous two times in FIG.
₁ , previous lens drive amount DL ₁ , current lens drive amount D
L ₂ , pre-previous and previous time intervals TM ₁ , TM ₂ , expected time lag TL are required. Therefore, step (30
In 4), each time focus detection is performed, the previous defocus amount is input to the storage area DF ₂ , and the previous _two defocus amounts are input to the storage area DF _1, and the lens drive amount DL converted to the previous image plane movement amount is input. Is input to the storage area DL ₂ and the lens drive amount DL ₁ in terms of the amount of movement of the image plane _two times before is input to the storage area DL _1, and the data in each storage area is updated to the data required for the current prediction calculation.

In step (305), it is determined whether AFP representing the position of the distance measuring point being used is "0". Here, when AFP is "-1", the lower distance measuring field of view, "0"
In the case of, the center distance measuring point is used, and in the case of "1", the upper distance measuring visual field is used. That is, in step (305), it is determined whether or not the central distance measuring visual field is being used, and if the central distance measuring visual field is being used, step (30)
6), otherwise move to step (307).

In step (307), step (30
In the same manner as 5), it is determined whether or not the lower distance measuring visual field is used, and if the lower distance measuring visual field is used, the process proceeds to step (308), and the upper distance measuring visual field is used. If so, the process proceeds to step (309).

Steps (306), (308), (30
In 9), the defocus amount measured this time in the distance measuring field used this time is input to the storage area DF ₃ on the RAM to update the data. Here, in step (306), the defocus amount DFB based on the image signal of the sensor of the central distance measuring field,
In step (308), the defocus amount DFA based on the sensor image signal of the lower distance measuring point is input, and in step (309), the defocus amount DFC based on the image signal of the sensor of the upper distance measuring point is input. When the above steps are completed, the process proceeds to step (310).

At step (310), it is determined whether or not the data required for the prediction calculation is input to each of the storage areas. As described above, the prediction calculation requires the defocus amount of the last time, the last time before and the lens drive amount of the last time before,
The condition is that the focus adjustment operation has been performed three or more times in the past. Therefore, in step (303), the counter COUNT is incremented by 1 each time the focus adjustment operation is performed, and the counter is made to count the number of times the focus adjustment operation is performed, and whether or not the number is greater than 2, that is, three or more times. Is performed 3 times or more, and if the prediction calculation is possible, go to step (312).
If it is impossible, the process proceeds to step (319).

At the step (312), it is judged whether or not the updated defocus amount is suitable for the prediction about the "continuity of the image plane position". If it is judged that there is continuity, the process proceeds to the step (313). If not, the process proceeds to step (314). Here, a method of determining "continuity of image plane position" will be described later.

When it is determined in step (312) that there is no continuity of the image plane position, and the process moves to step (314), the distance measuring field used in the "distance measuring field changing" subroutine is changed in this step. A detailed description of this subroutine will be given later.

At step (315), it is determined whether or not prediction is possible by ANG after changing the distance measuring field of view, and if possible, the process proceeds to step (313), and if unpredictable (inappropriate data). If so, the process proceeds to step (316).

At step (316), since the prediction control is once stopped, the COUNT for counting the number of times data has been accumulated is reset. And step (31
In 7), the flag ANG for determining whether or not the prediction is possible is reset.

In step (318), the defocus amount D of the central distance measuring field is added to the lens driving amount DL converted into the image plane movement amount.
Enter FB. This is once unpredictable,
The range-finding field used when starting AF again is the central range-finding field, but this does not have to be the central range-finding field, and, for example, the initially selected range-finding field,
Alternatively, the distance measuring field used last may be used.

In the first and second distance measurement, the process proceeds to step (319), and in step (319), the defocus amount DF ₃ updated this time is input to the lens drive amount DL converted into the image plane movement amount.

If it is determined in step (312) that the prediction is possible and the process proceeds to step (313), the estimated time lag TL is calculated in step (313).
As described above, the time from the previous focus detection operation to the current focus detection operation is stored in the memory area TM ₂ , and the time required for the current focus adjustment is assumed to be the same as TM _2. Calculate the time lag TL = TM ₂ + TR. Here, TR is the release time lag.

In the next steps (320) and (321), the respective storage areas DF _{1 to} DF ₃ , DL ₁ , DL ₂ , TM ₁ ,
Based on the data stored in TM ₂ , A and B representing the a and b terms of the equations (6) and (7) are obtained, and the process proceeds to step (322).

At step (322), the data of each storage means and step (313) and step (32).
0), the calculated value of the expression (9) is calculated based on the calculated values of (321), and this is calculated as the lens drive amount DL in terms of the current image plane movement amount.
Ask for.

In the next step (323), the lens drive amount DL obtained in steps (322), (318) and (319), the open F number FN of the taking lens and the predetermined coefficient δ (in this embodiment, 0. 035 mm) product FN
δ is compared, and if DL <FN · δ, step (32
If not so, the process returns to step (325).

In step (324), the previous step (3
In 23), it is determined that the lens drive amount DL is smaller than the depth of field FN · δ, that is, there is no need for lens drive,
The lens drive amount DL = 0 is set, and the lens drive is prohibited.
As a result, unnecessary microlens driving is not performed, and both usability and power consumption can be improved. Further, although FN is the open F number of the taking lens in this embodiment, there is no problem even if this is used as the taking aperture value, and δ is not limited to 0.035 mm. When this step is completed, the next step (32
This subroutine is returned in 5).

Next, the flow of the "distance measuring point change" subroutine will be described with reference to FIG. The figure shows the flow of the "distance changing field of view" subroutine. This time, it was determined that the defocus amount of the selected distance measuring field was not suitable for predictive control. It is a subroutine to change to.

At step (402), it is judged by AFP whether or not the distance measuring visual field used this time is the central distance measuring visual field, and if the central distance measuring visual field is used, the process proceeds to step (403), Otherwise, step (41
Go to 3).

In step (413), step (40
In the same manner as 2), it is determined whether or not the range-finding field used is the lower range-finding field this time, and if the lower range-finding field is used, the process proceeds to step (414), and the upper side If the distance measuring field of is used, the process proceeds to step (425).

Steps (403) to (412) and (41
4) to (423) and (425) to (434) change the image plane position close to the previous image plane change from the defocus amount of the distance measurement visual field other than the distance measurement visual field used this time. This is for selecting the distance measuring field.

At step (403), the image plane moving speed V1 from the distance measurement two times before to the distance measurement last time is calculated. Then, in the next step (404), the defocus amount DFA of the left distance measuring field is used to calculate the image plane moving speed V2 from the last distance measurement to the current distance measurement.

In step (405), step (40
3), the absolute value VA of the difference between V1 and V2 calculated in (404) is calculated. This is the image plane moving speed V1
And the image plane mobility V2 in the new left-side distance measuring field, that is, the continuity, and the smaller the value of VA, the higher the continuity.

In step (406), the defocus amount DFC of the upper distance measuring field is used to calculate the image plane mobility V3 from the last distance measurement to the current distance measurement. Then, in step (407), VC representing the continuity when the upper distance measuring field is used in the same manner as in step (405).
To calculate.

At the next step (408), VA and VC for evaluating continuity of image plane position change are compared, and VA <V
C, that is, if the continuity in the lower distance measuring visual field is higher, the process proceeds to step (411), and if not, the process proceeds to step (409).

At step (409), since the upper distance measuring visual field has higher continuity, the defocus amount DFC of the upper distance measuring visual field is input to the storage area DF ₃ on the RAM. Then, in step (410), "1" representing the upper distance measuring field is input to AFP representing the distance measuring point to be used.

At step (411), since the lower distance measuring visual field has higher continuity, the defocus amount DFA of the lower distance measuring visual field is input to the storage area DF ₃ on the RAM. Then, in step (412), "-1" representing the lower distance measuring field of view is input to the AFP.

Upon completion of step (410) or (412), the process proceeds to step (435). Further, steps (414) to (423) and (425) to (43)
Similarly, 4) is also used to change the image plane position from the time before the last time to the time before, and selects a distance measuring point with high continuity. The operation is the same as steps (403) to (412). Detailed description is omitted.

At step (435), it is judged from the changed defocus amount of the distance measuring field whether or not the continuity of the image plane position is suitable for the predictive control, and if it is suitable, the process proceeds to step (438) to make it suitable. If not, step (43
Go to 6).

At step (436), it is determined that the distance measuring field of view is not suitable for the predictive control even though the distance measuring visual field is changed to the most suitable point. Therefore, the flag ANG for temporarily stopping the predictive control is set to "1". input. And step (43
In 7), "0" is input to AFP in order to return the distance measuring field to be used to the central distance measuring field. When this step is completed, the process proceeds to step (438), and this subroutine is returned.

In the above-described predictive calculation and distance measuring point changing subroutine, when the continuity of images is not recognized in step (312) in the defocus data of the distance measuring point used first, the distance measuring visual field is changed, The defocus data in the distance measuring field having the highest continuity among the three distance measuring points is detected, and the presence / absence of continuity is determined again in step (435) based on this data. The prediction calculation based on the defocus data with the highest continuity is (31
Execution continues in steps 3) to (322). In addition,
At this time, the AFP indicating the focus detection point of the defocus data
Becomes a value corresponding to the distance measuring point of the data, and the focus detection thereafter is performed according to the defocus data from the changed distance measuring point, and the distance measuring point is changed. Also, when continuity is not recognized even in step (435), ANG =
Then, the prediction process is temporarily stopped, and the lens is driven according to the data of the central distance measuring field.

Next, the "image plane position continuity determination" subroutine will be described with reference to FIG.

In step (502), an operation of (DF ₂ + DL ₁ −DF ₁ ) / TM ₁ is performed based on the data in each storage area. This calculation is a step of calculating the average value V1 of the image plane moving speed between the times t ₁ and t ₂ in FIG. Similarly, the calculation in the next step (503) is a step of calculating the average value V2 of the image plane moving speeds between the times t ₂ and t ₃ . After this, the process proceeds to step (504).

In step (504), step (50
2) Calculate the absolute value VA of the difference between the image plane movement velocities V1 and V2 calculated in (503), and move to step (505).

In step (505), step (50
The VA obtained in 4) is compared with a preset number AX. When VA is larger than AX, it is determined that there is no continuity of the image plane position, and when VA is smaller than AX, there is continuity.

The principle of determination of presence / absence of continuity based on the above flow is based on the fact that the moving speed of the image plane at that time also changes continuously if the same subject is being followed. Therefore, the image plane moving speeds that are adjacent in time are calculated, and if this difference is small, it is considered that the image plane moving speeds are continuously changing, and it is determined that the same subject is being measured. Perform prediction calculation. On the other hand, when the change in the image plane moving speed is sufficiently large, it is considered that the image plane moving speed does not continuously change.

FIG. 10 shows a flowchart of the "lens drive" subroutine.

When this subroutine is executed, in step (1502), communication with the lens is made and the two data "S" and "PTH" are input. “S” is a “coefficient of the defocus amount versus the focus adjustment lens extension amount” peculiar to the taking lens. For example, in the case of the whole extension type single lens, S = 1 because the entire taking lens is the focus adjustment lens.
In the case of a zoom lens, S changes depending on each zoom position. “PTH” is the amount of extension of the focus adjustment lens per pulse output from the encoder ENC that is interlocked with the movement of the focus adjustment lens LNS in the optical axis direction.

Therefore, the current defocus amount DEF of the taking lens, a value obtained by converting the amount of extension of the focus adjusting lens into the number of output pulses of the encoder by S and PTH, so-called lens drive amount FP, is given by the following equation. .

FP = DEF × S / PTH Step (1503) executes the above equation as it is.

In step (1504), step (50
The FP calculated in 3) is sent to the lens and the focus adjustment lens (in the case of a single lens with a total extension, the entire shooting lens)
Order to drive.

In the above description, an example in which there are three independent distance measuring fields in the vertical direction in the selected distance measuring field blocks is used. However, these distance measuring fields connect a plurality of distance measuring fields. Alternatively, a continuous range-finding field may be used, and the same processing as described above can be applied by dividing this into a plurality of original areas and replacing right, center and left with upper, center and lower.

Although the embodiments described above show the passive type focus detecting device, the active type focus detecting device may be used. On the other hand, there are cases where the parallax can be ignored and the distance is relatively long, or the external distance detection device can be used in a camera model that can compensate for it.

[Brief description of drawings]

FIG. 1 is a flowchart schematically showing the overall operation of a camera.

FIG. 2 is a flowchart for explaining a control operation according to the embodiment of the present invention.

FIG. 3 is a flowchart for explaining a moving object detection subroutine.

FIG. 4 is a flowchart for explaining a visual axis detection subroutine.

FIG. 5 is a flowchart for explaining a focus detection subroutine.

FIG. 6 is a flowchart illustrating a determination subroutine.

FIG. 7 is a flowchart for explaining a prediction calculation subroutine.

FIG. 8 is a flowchart for explaining a detection point changing subroutine.

FIG. 9 is a flowchart for explaining a subroutine regarding continuity of image plane positions.

FIG. 10 is a flow chart for explaining a subroutine relating to lens driving.

FIG. 11 is a flowchart for explaining a subroutine for setting a distance measuring visual field range.

FIG. 12 is a sectional view of the single-lens reflex camera according to the embodiment.

FIG. 13 is a diagram for explaining a method of detecting a line of sight.

FIG. 14 is a diagram showing an optical relationship between a reflected image of an anterior segment and a pixel row of a photoelectric conversion element.

FIG. 15 is a diagram showing an optical relationship between an anterior segment and a Purkinje reflection image.

FIG. 16 is a diagram showing an output of a photoelectric conversion element.

FIG. 17 is a perspective view of a focus detection device.

FIG. 18 is a diagram showing an optical behavior when an on-axis detection visual field is detected.

FIG. 19 is a diagram showing an optical behavior when an off-axis detection visual field is detected.

FIG. 20 is a diagram showing an example of an output signal regarding an arbitrary visual field of the focus detection device.

FIG. 21 is a view showing a state in which a detection visual field is displayed in the finder visual field of a single-lens reflex camera.

FIG. 22 is a front view of a porous mask of the focus detection device.

FIG. 23 is a front view of the attitude detection switch of the camera.

FIG. 24 is a block diagram of an electric system of the camera.

[Explanation of symbols]

 2 Main mirror 3 Sub mirror 4 Camera body 5 Lens barrel 6 Focus detection device 9 Light splitter 13 Light source 14 Photoelectric converter 80 Movable mask 81 Field mask 83 Perforated mask 84 Secondary imaging lens group

Claims (6)

[Claims] 1. A camera provided with a lens control means for controlling focus adjustment of an objective lens, a visual axis detection means for detecting a visual line of an observer's eye, and a means for performing focus detection on a different portion in a screen, wherein a change in object distance. In the servo operation mode in which the change of the image plane position accompanying the correction is tracked and corrected, the line-of-sight detecting unit detects the line-of-sight position prior to the focus detecting operation, and the lens control unit relates to the focus detection output of the part based on the line-of-sight position information. A camera having a line-of-sight detection function, which is characterized by performing an operation of continuously controlling an imaging position of an objective lens. 2. A lens control means for controlling focus adjustment of an objective lens, a visual axis detection means for detecting a visual line of an observer's eye, and a means for performing focus detection on a different portion in a screen, the visual axis detection being performed. A camera having a line-of-sight detection function characterized by operating the lens control means based on a new focus detection output regarding the previous line-of-sight position or its vicinity when the line-of-sight detection is impossible in a camera that repeatedly performs focus detection. . 3. A camera comprising lens control means for controlling focus adjustment of an objective lens, line-of-sight detection means for detecting the line-of-sight of an observer's eye, and means for performing focus detection on different parts of the screen. It has a first operation mode for controlling only the moving direction of the image formation position of the objective lens and a second operation mode for controlling the moving direction and the moving amount, and the first operation when focus detection is impossible. A camera having a line-of-sight detection function, characterized in that the line-of-sight is detected and the focus of the line-of-sight position or its vicinity is detected in a predetermined order during the control of adjusting the objective lens in the first operation mode. 4. A camera comprising lens control means for controlling focus adjustment of an objective lens, visual line detection means for detecting a visual line of an observer's eye, means for performing focus detection for different parts in a screen, and moving body detection means. A first operation mode in which the control means is driven in response to a focus adjustment disclosure instruction operation, and after the focus detection means outputs the focus state, driving of the control means thereafter is prohibited. , A second operation mode in which the control means is continuously driven to correct the change of the image plane due to the change of the object distance, and the moving body detection means has a focus obtained based on the line-of-sight detection result. Switching from the first operation mode to the second operation mode due to fluctuations in the detection output, and until detecting the in-focus state in the first operation mode until switching to the second operation mode Is the above A camera having a line-of-sight detection function, characterized in that re-selection of a part in the screen by the field detection means is suppressed. 5. A camera comprising lens control means for controlling focus adjustment of an objective lens, line-of-sight detection means for detecting the line-of-sight of an observer's eye, and means for performing focus detection on different parts of the screen. In response to the disclosure instruction operation, the lens control means is driven, and after the focus detection means outputs that the focus state is once in-focus, the line-of-sight detection means is set in the one-shot operation mode in which further driving is prohibited. Detects the line-of-sight position prior to the first focus detection operation, and the lens control means is driven by the focus detection output detected based on the line-of-sight position. In the second and subsequent focus detection operations, the same line-of-sight position as before is detected. A camera having a line-of-sight detection function, characterized in that the lens control means is controlled in accordance with the focus detection output based on. 6. A lens control unit for controlling focus adjustment of an objective lens, a line of sight of an observer's eye, a line of sight detection unit, a unit for performing focus detection with respect to a different portion in a screen, and a posture for detecting a posture in the direction of gravity. In the camera having a detection device, the line-of-sight detection unit can detect the line-of-sight position in the inspection direction by using the reflected light from the anterior segment of the eye, and the posture detection unit can detect the line-of-sight position. When the output indicates that the posture of the camera is in the vertical position, the operation of the line-of-sight detecting means is prohibited, and the image formation state of the objective lens is determined based on the focus detection output for a specific part in the screen. A camera having a line-of-sight detection function.