JP2003075718A - Focus detector and optical equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that a focus detector gets larger in the case of providing a pair of image reforming optical systems for every incident area for taking in focus detecting luminous flux. SOLUTION: This focus detector is provided with a plurality of incident areas 11-1 to 11-9 on which luminous flux from an objective optical system is made incident and a pair of image reforming optical systems 71-1 to 71-12 for every incident area, and detects the focusing state of the objective optical system based on the detected result of a pair of object images formed by a pair of image reforming optical systems. In the focus detector, one image reforming optical system is shared by a pair of image reforming optical systems respectively arranged in two incident areas extended in different directions from each other out of a plurality of incident areas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus detection device having a plurality of incident areas through which a light beam from an objective optical system is guided and a pair of re-imaging optical systems provided for each of these incident areas. .

[0002]

2. Description of the Related Art In many cases, a camera or an observation device is equipped with a focus detection device for detecting a focus adjustment state of a photographing optical system or an objective optical system. In recent focus detection devices, a plurality of focus detection areas are provided in the screen, and the camera / device automatically or automatically detects the area where the focus adjustment state of the objective optical system is detected from the plurality of focus detection areas. There is one that can be selected by a user operation (or a user's line of sight detection).

Such a so-called multi-point focus detection device has been proposed in Japanese Patent Laid-Open No. 11-281885 and Japanese Patent Laid-Open No. 5-142465.

Here, FIGS. 25 to 27 show the structure of the focus detection apparatus proposed in the above-mentioned Japanese Patent Laid-Open No. 11-281885. This device has a visual field mask 1141.
, Field lens 1142, and reflection mirror 1143
, Aperture mask 1144, and re-imaging optical panel 1145
And a light receiving sensor 1146.

A plurality of mask openings 1141a to 1141i formed in the field mask 1141 are provided corresponding to a plurality of focus detection areas set in the screen of the objective optical system. Among the light fluxes incident from the objective optical system, the light fluxes guided to the mask openings 1141a to 1141i are re-imaging lenses 1145a and 1145b (FIG. 27) provided on the re-imaging optical panel 1145 for each pair of mask openings.
(Refer to FIG. 26) and forms a pair of secondary images on the pair of light receiving regions 1146a and 1146b (see FIG. 26) of the light receiving sensor 1146.

However, in this focus detection device, since it is necessary to provide a pair of re-imaging optical systems for each mask aperture, when the number of mask apertures (that is, focus detection regions) increases,
There is a problem that the entire focus detection device becomes large.

FIG. 28 shows the above-mentioned Japanese Unexamined Patent Publication No. 5-142465.
1 shows the configuration of the focus detection device proposed in the publication. This apparatus includes a field mask 1051, a field lens 1052, a diaphragm 1053, and a re-imaging optical panel 1.
054 and a light receiving sensor 1055.

A detection field 1051-2-1, provided in the peripheral portion on the right side of the field mask 1051 as viewed in the drawing.
Light fluxes from 1051-2-2 are areas 1052-having different optical functions of the field lens 1052.
2-1 and 1052-2-2, and the same re-imaging lens pair 1054-2 in the re-imaging optical panel 1054.
a, 1054-2b, and sensor rows 1055-2-1a and 1055-2-1 in the light receiving sensor 1055.
b and the sensor array 1055-2-2a, 1055-2.
A secondary image is formed on 2b.

As described above, in the focus detection device of FIG.
For a plurality of incident areas having the same longitudinal direction (secondary image detection direction), since a pair of re-imaging optical systems are shared, the number of focus detection areas of the re-imaging optical system is different. The number can be reduced, which is effective for downsizing the focus detection device.

[0010]

However, even in the focus detecting device proposed in Japanese Patent Laid-Open No. 5-142465, a pair of re-imaging optical systems are separately provided for the incident areas extending in different directions. There is a need.
Therefore, when the plurality of incident areas (that is, the focus detection areas) are extended in various directions, this is not an effective means for downsizing the focus detection device.

[0011]

In order to solve the above-mentioned problems, the present invention provides a plurality of incident areas into which a light beam from an objective optical system is incident, and a pair of re-imaging optical systems for each of these incident areas. In the focus detection device for detecting the focus adjustment state of the objective optical system based on the detection result of the pair of object images formed by the pair of re-imaging optical system,
One re-imaging optical system is shared by a pair of re-imaging optical systems respectively provided for two incident areas extending in different directions among a plurality of incidence areas.

That is, the different direction is the longitudinal direction 2
Two pairs of re-imaging optical systems provided for one incident area share one re-imaging optical system of each pair of re-imaging optical systems, so that incidences extending in various directions can be achieved. Even if there is a region, the number of re-imaging optical systems can be reduced so that the focus detection device can be downsized.

In the present invention, the angle formed by the longitudinal axis of one of the two incident areas and the longitudinal axis of the other incident area and the angle of incidence with respect to the one incident area. The angle formed by the arrangement direction axes of the pair of re-imaging optical systems and the arrangement direction axis of the pair of re-imaging optical systems provided with respect to the other incident area is substantially the same, or the one incident area is formed. Angle formed by the longitudinal axis of the other incident area and the longitudinal axis of the other incident area, the arrangement direction axis of the pair of light receiving areas provided for the one incident area, and the pair provided for the other incident area. It is preferable that the angle formed by the light receiving area and the arrangement direction axis is substantially the same.

Thus, the re-imaging optical system used as a pair can prevent the formed object image from deviating, and prevent the detection accuracy from deteriorating.

Further, in the case where the re-imaging optical system is provided with a diaphragm aperture, when the pair of diaphragm apertures are provided with respect to the pair of re-imaging optical systems, the pair of diaphragm apertures are made symmetrical to each other. It is possible to maintain the required focus detection performance regardless of which pair of re-imaging optical systems is used.

Further, by making the diaphragm aperture circular,
The degree of blurring of the object image on each light receiving region is made uniform, and the focus adjustment state can be detected with the same accuracy by the object image formed by the incident light flux from any of the incident regions.

Further, it is preferable that at least one condenser lens is provided for each pair of re-imaging optical systems to configure an appropriate or optimum detection system for each of the plurality of incident areas.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is an exploded view of the overall structure of a focus detection unit (focus detection device) according to a first embodiment of the present invention. Note that a case where the focus detection device is mounted on a camera will be described here.

In FIG. 1, reference numeral 10 denotes only a light flux necessary for detecting the focus adjustment state of the photographing optical system, out of the subject light flux from a photographing optical system (objective optical system) (not shown). The field mask has a mask opening for removing).

Reference numeral 20 denotes a split field lens as a condenser lens for guiding an image to be formed on the primary image forming surface by the light flux passing through the mask opening of the field mask 10 to a light receiving sensor 90 described later.

Numeral 30 separates the light flux from the central mask opening and the light flux from the peripheral mask openings, and shields the light rays other than the effective light flux corresponding to each mask opening from entering the light receiving sensor 90. It is a plate.

Reference numeral 40 denotes a mirror which is a surface mirror for bending a light beam (hereinafter referred to as focus detection light beam) which has entered the focus detection unit through the mask opening toward the light receiving sensor 90, and 50 denotes infrared light. It is an infrared cut filter for removing.

Reference numeral 60 is a porous diaphragm for separating the focus detection light beam, and 70 is a re-imaging lens panel having a plurality of pairs of re-imaging lenses for forming an image on the sensor 90. The stop aperture formed in the perforated stop 60 and the re-imaging lens corresponding to this stop aperture form a re-imaging optical system in the claims. Further, the re-imaging lens panel 70 is provided with a pair of positioning dowels 72.

Reference numeral 80 is a sensor holder for holding the light receiving sensor 90, and 100 is a sensor support member for adjusting the inclination of the sensor 90. The light receiving sensor 90 is formed with a plurality of pairs of line sensors (light receiving regions), and these line sensors detect the light amount distribution of the image for performing the focus detection operation. In addition, each line sensor,
It is configured by arranging a plurality of photoelectric conversion elements.

Reference numeral 300 is a circuit board on which the light receiving sensor 90 is mounted. Reference numeral 110 is a light-shielding sheet that closes the gap between the focus detection unit and the focus detection unit mounting portion of the camera, and 120 is a main body block as a holding member that holds each component forming the focus detection unit and shields external light. Is.

Next, the mounting relationship of the above components will be described. The body block 120 includes a field mask 10, a split field lens 20, a light blocking plate 30, a mirror 40, an infrared cut filter 50, a porous diaphragm 60, a re-imaging lens panel 70, a sensor holder 80, and a sensor support member 10.
0, the light receiving sensor 90 and the light shielding sheet 110 are attached.

The field mask 10 is positioned and fixed to the main body block 120. Split field lens 20
Is adhered and fixed to the main body block 120, and the light shielding plate 30,
The mirror 40 and the infrared cut filter 50 are positioned on the body block 120 and then fixed by adhesion.

The porous diaphragm 60 is positioned and fixed to the re-imaging lens panel 70. In addition, the re-imaging lens panel 7
0 is positioned and fixed to the main body block 120.

Re-imaging lens panel 70 and body block 1
20 is fixed so as to sandwich the porous diaphragm 60 so that the porous diaphragm 60 is not displaced with respect to the main body block 120 and the re-imaging lens 70.

The light receiving sensor 90 is mounted on the circuit board 300 and is bonded and fixed to the sensor holder 80 in advance to form a sensor unit 200. The sensor unit 200 is provided with a main body block 120 via a sensor support member 100. Held in.

The sensor support member 100 comprises a body block 1
It is held by the main body block 120 so that tilts of a plurality of axes with respect to 20 can be adjusted.

The light shielding sheet 110 is positioned and held while being sandwiched between the visual field mask 10 and the main body block 120.

FIG. 2 shows a sectional view of the focus detection unit in an assembled state, and FIG. 3 shows a rear view of the focus detection unit with the infrared cut filter 50 attached. The mounting relationship of each component of the focus detection unit will be described in more detail with reference to FIG.

The main body block 120 is provided with a positioning shape part and a fixing shape part for positioning and fixing each component of the focus detection unit.

The infrared cut filter 50 is positioned with respect to the main body block 120 by being mounted on the infrared cut filter positioning and fixing portion 121 provided in the main body block 120. The main body block 1 is formed by a plurality of infrared cut filter adhesive portions 122 provided around 121.
It is adhesively fixed to 20.

The light blocking plate 30 includes a light blocking plate positioning and fixing portion 31 provided on the light blocking plate 30 and a body block 120.
It is positioned with respect to the main body block 120 by the light shielding plate positioning and fixing portion 123 provided in the main body block 120, is mounted inside the main body block 120, and is further adhesively fixed to the main body block 120.

The light shielding plate 30 is composed of the split field lens 20.
There are walls 32 and 33 for preventing unnecessary light fluxes other than the effective light fluxes from the respective detection fields of view that have passed through to enter the light receiving regions corresponding to other detection fields of view on the light receiving sensor 90. An opening 34 for passing the focus detection light flux is formed between the wall 33 and the wall 33.

After the various adjustments have been made, the split field lens 20 is adhesively fixed to the split field lens fixing portion 124 provided in the main body block 120.

The field mask 10 has a pair of field mask positioning fitting shafts 15 provided on the field mask 10.
The visual field mask positioning fitting hole 125 and the visual field mask positioning fitting slot 12 provided in the main body block 120.
6 is positioned with respect to the main body block 120.

The field mask positioning fitting hole 125
Prevents the planar movement within the mounting surface of the field mask 10, and the field mask positioning fitting slot 126 blocks rotational movement of the field mask 10 about the field mask positioning fitting hole 125.

The visual field mask 10 is provided with a pair of visual field mask fixing elastic claw portions 12, and the visual field mask 10 is provided.
This field mask fixing elastic claw portion 12 is attached to the main body block 12
It is fixed to the main body block 120 by being engaged with a pair of visual field mask fixing holes 127 provided at 0.

Further, in the visual field mask 10, even if the visual field mask fixing elastic claw portion 12 comes off from the visual field mask fixing hole 127 of the main body block 120 after the focus detection unit is attached to the camera, the visual field mask 10 is main body. In order to prevent the block 120 from rising, a visual field mask floating prevention portion 13 is provided. The field mask floating prevention unit 13 also has a role of reducing the gap formed between the mirror box of the camera and the focus detection unit.

The light-shielding sheet 110 is the light-shielding sheet 11
0 is positioned by inserting the pair of light shielding sheet positioning portions 14 provided in the visual field mask 10 into the pair of positioning hole portions 111 provided in the visual field mask 10, and is sandwiched between the visual field mask 10 and the main body block 120 to be the main body. It is fixed with respect to the block 120.

The mirror 40 is positioned by a mirror positioning and fixing portion 134 provided on the main body block 120, and is fixed to the main body block 120 by adhesion.

On the surface of the mirror 40, a light shielding mask portion 41 having a mask shape for shielding an unnecessary light flux for each detection visual field is added, and the light shielding mask portion 4 is added.
When the focus detection light flux is bent with respect to the light receiving sensor 90, the first light flux shields unnecessary light flux that passes through the gap between the light shield plate 30 and the mirror 40.

Further, the light-shielding mask portion 41 is formed substantially parallel to the sensor array direction of the line sensor corresponding to the peripheral detection visual field, whereby a light-shielding pattern exists in the light beam splitting direction of the focus detection light beam. Therefore, a ghost due to reflection at the pattern edge does not occur.

The re-imaging lens panel 70 has a pair of fitting shafts 72 provided on the re-imaging lens panel 70, and the re-imaging lens positioning hole portion 1 formed in the main body block 120.
31 and the re-imaging lens positioning elongated hole portion 132 are fitted to the main body block 120 so that they are positioned and adhesively fixed.

The perforated diaphragm 60 is recombined by engaging the hole portion 62 and the U groove portion 63 provided in the perforated diaphragm 60 with a pair of positioning dowels 72 provided in the re-imaging lens panel 70. It is positioned with respect to the image lens 70 and is held with respect to the main body block 120 by being sandwiched between the re-imaging lens panel 70 and the main body block 120.

The sensor support member 100 is positioned with the pair of convex spherical positioning adjustment parts 101 provided on the sensor support member 100 abutting on the pair of concave surface parts 151 provided on the main body block 120. To be done. Here, the positioning adjustment unit 101 has a curvature R1, and the concave surface portion 151 is composed of a curved surface having a plurality of curvatures (R1, R2).

Then, the sensor support member 100 is positioned on the curved surface 101 having the curvature R2 of the concave shape portion 151 and the positioning adjustment portion 1
01 is brought into contact so that it can be rockably positioned,
It is possible to adjust the tilt with respect to a plurality of axes. In this way, the sensor support member 100 is adhesively fixed to the main body block 120 after various adjustments such as sensor inclination adjustment are performed.

The light receiving sensor 90 is bonded and fixed to the sensor holder 80 in advance while being mounted on the circuit board 300, and the sensor block 200 and the sensor holder 80 are integrated into the sensor unit 200 to form the main body block 120.
The inclination is adjusted with respect to.

The sensor unit 200 is held by the main body block 120 via the sensor support member 100,
After the tilt adjustment of the sensor 90 with respect to the focus detection unit and other adjustments are performed between the main body block 120 and the sensor support member 100, the sensor block 90 is adhesively fixed to the sensor support member 100.

A groove for guiding the adhesive is formed on the surface of the sensor holder 80 that is bonded to the sensor support member 100.

Next, the optical operation in the focus detection unit will be described with reference to FIGS. 4 and 5. Of these focus detection units, only the field mask 10, the split field lens 20, the perforated diaphragm 60, the re-imaging lens panel 70 and the light receiving sensor 90 are shown in these figures.

The field mask 10 has a plurality of mask openings 1
1-1 to 11-9 are formed, and these mask openings 11-1 to 11-9 have a plurality of focus detection areas that can be selected automatically by the camera or by the operation of the photographer in the screen of the photographing optical system. It is arranged corresponding to. The mask opening 1
1-1, 11-3, 11-4, 11-6, 11-7, 1
Each of 1-9 corresponds to the incident area in the claims. Further, in the mask opening 11-2, a region extending in the vertical direction and a region extending in the horizontal direction, the mask apertures 11-5, 1
The outer region and the inner region of 1-8 correspond to the incident region in the claims.

The split field lens 20 is formed with a plurality of field lens portions 21-1 to 21-9.

Further, a plurality of aperture openings 61-1 to 61-12 are formed in the porous diaphragm 60, and a plurality of re-imaging lenses 71-1 to 7-1 are formed in the re-imaging lens panel 70.
1-12 are formed. Further, the light receiving sensor 90 has a plurality of line sensors 91-1 to 91-24.

Here, first, the optical action will be described focusing on the light flux passing through the mask openings 11-1 to 11-3 of the visual field mask 10.

In FIG. 4, the mask aperture 1 of the visual field mask 10 out of the luminous flux taken from the photographing optical system and guided to the focus detection unit via the quick return mirror or the like.
The light flux passing through 1-1 is the field lens unit 21-1.
Is guided to the perforated diaphragm 60.

Similarly, the light fluxes that have passed through the mask openings 11-2 and 11-3 are respectively in the field lens section 21-.
It is guided to the perforated diaphragm 60 by 2, 21-3.

Here, the light fluxes that have passed through the mask apertures 11-1 to 11-3 are respectively the aperture apertures 61 of the perforated aperture 60.
Go to -1 to 61-4. Then, the aperture openings 61-1 to 61-1
The light flux passing through 61-4 is projected onto the light receiving sensor 90 by the re-imaging lenses 71-1 to 71-4 corresponding to the respective diaphragm openings.

As a result, on the sensor 90, the light enters from the mask openings 11-1 to 11-3 and enters the diaphragm openings 61-1 to 61-1.
Four pairs of secondary images are formed by the light beams that have passed through 61-4 and the re-imaging lenses 71-1 to 71-4. Aperture openings 61-1 to 61-4 and re-imaging lens 7
1-1 to 71-4 are arranged so that these secondary images do not overlap each other.

Specifically, the light beam incident from the mask opening 11-1 passes through the aperture openings 61-3 and 61-4 and the re-imaging lenses 71-3 and 71-4, and the line sensor 91-.
A pair of secondary images is formed on 7, 91-8.

Further, the light beam incident from the vertically extending region of the mask opening 11-2 is limited to the aperture openings 61-1 and 6-1.
A pair of secondary images are formed on the line sensors 91-1 and 91-2 after passing through 1-2 and the re-imaging lenses 71-1 and 71-2.

Further, the light flux incident from the area of the mask opening 11-2 extending in the left-right direction is formed by the diaphragm openings 61-3 and 6-3.
A pair of secondary images are formed on the line sensors 91-5 and 91-6 by passing through 1-4 and the re-imaging lenses 71-3 and 71-4.

Further, the light flux incident from the mask opening 11-3 passes through the aperture openings 61-3 and 61-4 and the re-imaging lenses 71-3 and 71-4, and the line sensors 91-3 and 91-3.
A pair of secondary images is formed on 91-4.

In the arithmetic circuit (not shown), the focus detection area selected by the camera or photographer is the mask opening 1
When it corresponds to 1-1, line sensors 91-7, 9
Sensor output from 1-8 (line sensors 91-7, 91
The output signals corresponding to the light amount distributions of the secondary images formed on −8 are compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 11-1.

The detected focus adjustment state is sent as a signal to a camera microcomputer (not shown), and the camera microcomputer drives the photographing optical system (through a lens microcomputer or the like) in response to this signal to select the selected focus. The photographing optical system is focused on the subject in the detection area.

Further, the arithmetic circuit, if the focus detection area selected by the camera or the photographer corresponds to the mask opening 11-2, the line sensors 91-1 and 91-2 or the line sensors 91-5 and 91-5. The sensor output from -6 is compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 11-2.

When the focus detection area selected by the camera or photographer corresponds to the mask opening 11-3, the arithmetic circuit compares the sensor outputs from the line sensors 91-3 and 91-4. , The focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 11-3 is detected.

Next, referring to FIG. 5, the mask opening 11-4 is formed.
The optical action will be described by focusing on the luminous flux passing through 11-6.

In FIG. 5, the mask aperture 1 of the visual field mask 10 out of the luminous flux taken from the photographing optical system and guided to the focus detection unit via the quick return mirror or the like.
The light flux passing through 1-4 is the field lens unit 21-4.
Is guided to the perforated diaphragm 60.

Similarly, the light fluxes that have passed through the mask openings 11-5 and 11-6 are respectively the field lens section 21-.
5, 21-6 is guided to the perforated diaphragm 60.

Here, the light fluxes that have passed through the mask openings 11-4 to 11-6 are respectively the diaphragm openings 61 of the perforated diaphragm 60.
Go to -5 to 61-8. Then, the diaphragm aperture 61-5
The light flux passing through 61-8 is projected onto the light receiving sensor 90 by the re-imaging lenses 71-5 to 71-8 corresponding to the respective aperture openings.

As a result, on the sensor 90, the light enters from the mask openings 11-4 to 11-6 and enters the diaphragm openings 61-2 to 61-5.
Four pairs of secondary images are formed by the light flux that has passed through 61-8 and the re-imaging lenses 71-5 to 71-8. Aperture apertures 61-5 to 61-8 and reimaging lens 7
1-5 to 71-8 are arranged so that these secondary images do not overlap each other.

Specifically, the light beam incident from the mask opening 11-4 passes through the aperture openings 61-5 and 61-6 and the re-imaging lenses 71-5 and 71-6 and the line sensor 91-.
A pair of secondary images is formed on 9, 91-10.

Further, the light flux incident from the region extending in the vertical direction on the right side (outside) of the mask opening 11-5 has aperture openings 61-6 and 61-7 and the re-imaging lens 71-.
6, 71-7 and line sensors 91-13, 91
Form a pair of secondary images on -15.

Further, the light flux incident from the region extending in the vertical direction on the left side (inner side) of the mask opening 11-5 is the diaphragm openings 61-6 and 61-7 and the re-imaging lens 71-.
6, 71-7 and line sensors 91-14, 91
Form a pair of secondary images on -16.

Further, the light beam incident from the mask opening 11-6 passes through the aperture openings 61-7 and 61-8 and the re-imaging lenses 71-7 and 71-8, and the line sensor 91-1.
A pair of secondary images are formed on 1, 91-12.

In the arithmetic circuit (not shown), the focus detection area selected by the camera or photographer is the mask opening 1
In the case of corresponding to 1-4, the line sensors 91-9, 9
The mask output 1 is calculated by comparing the sensor outputs from 1-10.
The focus adjustment state of the photographing optical system in the focus detection area corresponding to 1-4 is detected.

Further, when the focus detection area selected by the camera or the photographer corresponds to the mask opening 11-5, the arithmetic operation circuit detects the line sensors 91-13, 91-15.
Alternatively, the sensor outputs from the line sensors 91-14 and 91-16 are compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 11-5.

Further, when the focus detection area selected by the camera or the photographer corresponds to the mask opening 11-6, the arithmetic circuit calculates the line sensors 91-11, 91-12.
The sensor output from is calculated and compared, and the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 11-6 is detected.

Next, with reference to FIG. 5, a mask opening 11-7 is formed.
The optical action will be described by focusing on the light flux passing through 11-9.

In FIG. 5, the mask aperture 1 of the visual field mask 10 out of the luminous flux taken from the photographing optical system and guided to the focus detection unit via the quick return mirror or the like.
The light flux that has passed through 1-7 is the field lens unit 21-7.
Is guided to the perforated diaphragm 60.

Similarly, the luminous fluxes passing through the mask openings 11-8 and 11-9 are respectively reflected by the field lens section 21-.
It is guided to the perforated diaphragm 60 by 8, 21-9.

Here, the light fluxes that have passed through the mask openings 11-7 to 11-9 are respectively the diaphragm openings 61 of the perforated diaphragm 60.
Head to -9 to 61-12. Then, the aperture opening 61-9
The light fluxes that have passed through .about.61-12 are received by the re-imaging lenses 71-9 to 71-12 corresponding to the aperture openings of the light receiving sensor 9.
0 is projected.

As a result, on the sensor 90, the light enters from the mask openings 11-7 to 11-9 and enters the diaphragm openings 61-9 to 61-9.
Four pairs of secondary images are formed by the light flux that has passed through 61-12 and the re-imaging lenses 71-9 to 71-12. The aperture openings 61-9 to 61-12 and the re-imaging lenses 71-9 to 71-12 are arranged so that these secondary images do not overlap each other.

Specifically, the light beam incident from the mask opening 11-7 passes through the aperture openings 61-9 and 61-10 and the re-imaging lenses 71-9 and 71-10, and the line sensor 9 is passed.
A pair of secondary images is formed on 1-17 and 91-18.

Further, the light flux incident from a region extending in the up-down direction on the left side (outside) of the mask opening 11-8 has aperture openings 61-10 and 61-11 and the re-imaging lens 7.
Line sensor 91-2 passing through 1-10 and 71-11
A pair of secondary images is formed on 1, 91-23.

Further, the light flux incident from the region extending in the vertical direction on the right side (inner side) of the mask opening 11-8 has aperture openings 61-10 and 61-11 and the re-imaging lens 7.
Line sensor 91-2 passing through 1-10 and 71-11
A pair of secondary images are formed on 2, 91-24.

Further, the light flux incident from the mask aperture 11-9 passes through the aperture apertures 61-11 and 61-12 and the re-imaging lenses 71-11 and 71-12 and the line sensor 9.
A pair of secondary images is formed on 1-19 and 91-20.

In the arithmetic circuit (not shown), the focus detection area selected by the camera or photographer is the mask opening 1
In the case of corresponding to 1-7, the line sensors 91-17,
The sensor output from 91-18 is compared and calculated, and the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 11-7 is detected.

Further, when the focus detection area selected by the camera or the photographer corresponds to the mask opening 11-8, the arithmetic operation circuit detects the line sensors 91-21, 91-23.
Alternatively, the sensor outputs from the line sensors 91-22 and 91-24 are compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 11-8.

Further, when the focus detection area selected by the camera or the photographer corresponds to the mask opening 11-9, the arithmetic circuit operates the line sensors 91-19, 91-20.
The sensor output from is calculated and compared, and the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 11-9 is detected.

Next, the arrangement of the diaphragm aperture, the re-imaging lens and the line sensor used in this embodiment will be described with reference to FIGS. 6 to 8. In addition, in FIG.
0, the re-imaging lens panel 70 is shown in FIG. 7, and the light receiving sensor 90 is shown in FIG.

As described above, the diaphragm aperture 61-6 and the re-imaging lens 71-6 form a pair with the diaphragm aperture 61-5 and the re-imaging lens 71-5 and enter the light flux entering from the mask aperture 11-4. The line sensors 91-9, 91-10
Form a pair of secondary images on top. Further, the diaphragm aperture 61-6
The re-imaging lens 71-6 also forms a pair with the aperture opening 61-7 and the re-imaging lens 71-7 to form the mask opening 11-7.
The line sensors 91-14,
A pair of secondary images is formed on 91-16 or line sensors 91-13, 91-15.

That is, the two pairs of diaphragm apertures and the re-imaging lens corresponding to the two mask apertures 11-4 and 11-5 having different detection component directions (longitudinal directions) are respectively the diaphragm aperture 61-6 and the recombining lens. The image lenses 71-6 are shared to form a pair.

The stop aperture 61-7 and the re-imaging lens 71-7 are paired with the stop aperture 61-6 and the re-imaging lens 71-6, as described above, and the stop aperture 61-8 is used. Also, a pair of secondary images is formed on the line sensors 91-11 and 91-12 by the light flux which is paired with the re-imaging lens 71-8 and enters from the mask opening 11-6.

That is, the above-mentioned two pairs of diaphragm apertures and re-imaging lenses corresponding to the two mask apertures 11-5 and 11-6 having different detection component directions (longitudinal directions) are respectively the diaphragm aperture 61-7 and the recombining lens. The image lenses 71-7 are shared to form a pair.

Then, as shown in FIG.
-5, 61-6 arrangement direction axis and diaphragm openings 61-6, 61
The angle θ1 formed by the arrangement direction axis of −7 and the arrangement direction axis of the line sensors 91-9, 91-10 and the line sensors 91-13, 91-15 (and the line sensor 91 shown in FIG.
-14, 91-16) and the arrangement direction axis are substantially the same as the angle θ3.

Further, similarly, the arrangement direction axes of the re-imaging lenses 71-5 and 71-6 shown in FIG.
An angle θ2 formed by the arrangement direction axes of −6 and 71-7 is also configured to be substantially the same as the angle θ3.

Further, the angle formed by the arrangement direction axes of the diaphragm openings 61-7 and 61-8 and the arrangement direction axes of the diaphragm openings 61-6 and 61-7 is the arrangement direction of the line sensors 91-11 and 91-12. The angle between the axis and the arrangement direction axis of the line sensors 91-13, 91-15 (and the line sensors 91-14, 91-16) and the arrangement direction axis of the re-imaging lenses 71-7, 71-8 are reconnected. The image lenses 71-6 and 71-7 are configured so as to have an angle substantially equal to the angle formed with the arrangement direction axis.

On the other hand, the aperture opening 61-10 and the re-imaging lens 71-10 are paired with the aperture opening 61-9 and the re-imaging lens 71-9, and the line sensor is formed by the light flux incident from the mask aperture 11-7. A pair of secondary images are formed on 91-17 and 91-18. Further, the aperture opening 61-10 and the re-imaging lens 71-10 form a pair with the aperture opening 61-11 and the re-imaging lens 71-11, and the line sensor 91-2 is formed by the light flux incident from the mask opening 11-8.
2, 91-24 or line sensor 91-21, 91-2
A pair of secondary images is formed on 3.

That is, the two pairs of diaphragm apertures and the re-imaging lens corresponding to the two mask apertures 11-7 and 11-8 having different detection component directions (longitudinal directions) are respectively the diaphragm aperture 61-10 and the recombining lens. The image lenses 71-10 are shared to form a pair.

Further, the aperture opening 61-11 and the re-imaging lens 71-11 are the aperture openings 61-10 as described above.
And the re-imaging lens 71-10 and a diaphragm aperture 61-12 and the re-imaging lens 71-12.
A pair of two beams are formed on the line sensors 91-19 and 91-20 by a light beam that forms a pair and is incident from the mask opening 11-9.
Form the next image.

That is, the two pairs of diaphragm apertures and the re-imaging lens corresponding to the two mask apertures 11-8 and 11-9 having different detection component directions (longitudinal directions) are respectively the diaphragm aperture 61-11 and the recombining lens. The image lenses 71-11 are shared to form a pair.

The angles formed by the arrangement direction axes of the diaphragm openings 61-9 and 61-10 and the arrangement direction axes of the diaphragm openings 61-10 and 61-11 are line sensors 91-17 and 91-1.
8 alignment direction axis and line sensors 91-21, 91-23
(And the angle formed by the arrangement direction axis of the line sensors 91-22, 91-24) and the re-imaging lenses 71-9, 71-
10 arrangement direction axis and re-imaging lenses 71-10, 71-1
It is configured to be substantially the same as the angle formed by the arrangement direction axis 1.

Further, the angles formed by the arrangement direction axes of the diaphragm openings 61-11, 61-12 and the arrangement direction axes of the diaphragm openings 61-10, 61-11 are line sensors 91-19, 91-2.
0 arrangement direction axis and line sensors 91-21, 91-23
(And line sensor 91-22, 91-24) and the re-imaging lens 71-11, 71 formed by the arrangement direction axis
-12 arrangement direction axis and re-imaging lenses 71-10, 71-
It is configured to be substantially the same as the angle formed by 11 with respect to the arrangement direction axis.

As described above, in this embodiment, two pairs of re-imaging optical systems corresponding to two mask apertures having different detection component directions (longitudinal directions) are provided. Since they are shared, the number of re-imaging optical systems can be reduced and the focus detection unit can be downsized.

Further, in the present embodiment, the diaphragm aperture 61-
6 and the re-imaging lens 71-6, the aperture opening 61-7 and the re-imaging lens 71-7 are the mask opening 11
A pair of secondary images is formed on the line sensors 91-14, 91-16 or the line sensors 91-13, 91-15 by the light fluxes incident from the outside incident area and the inside incident area of -5.

Further, the pair of the diaphragm aperture 61-10 and the re-imaging lens 71-10 and the diaphragm aperture 61-11 and the re-imaging lens 71-11 is a pair of an incident area on the outside of the mask aperture 11-8 and an inside region of the mask aperture 11-8. A pair of secondary images is formed on the line sensors 91-22, 91-24 or the line sensors 91-21, 91-23 by the light fluxes incident from the incident area.

That is, the mask openings 11-5 and 11-8.
A pair of common aperture openings and a re-imaging lens are used for the light fluxes incident from the outer region and the inner region having the same longitudinal direction as the incident region. Therefore, the number of re-imaging optical systems can be further reduced, and the focus detection unit can be further downsized.

Here, in the present embodiment, the pair of diaphragm openings are symmetrical with each other, and the shape of each diaphragm opening is circular. As a result, it is possible to prevent a difference in blurring of the secondary image formed on each line sensor, and the required and uniform focus detection can be performed regardless of the secondary image formed by the light flux incident from any mask opening. The accuracy can be maintained.

The line sensors 91-9 to 91-16
(Or 91-17 to 91-24), when the angle formed by the arrangement direction axes is 60 degrees, the aperture openings 61-5 to 61-8.
(Or 61-9 to 61-12) can be formed in a hexagon.

(Second Embodiment) FIG. 9 and FIG.
The optical structure in the focus detection unit which is 2nd Embodiment of this invention is shown. The overall basic configuration of the focus detection unit of this embodiment is the same as that of the first embodiment.

The focus detection unit of this embodiment comprises a field mask 510, a split field lens 520, a perforated diaphragm 560, a re-imaging lens panel 570, and a light receiving sensor 590.

In FIGS. 9 and 10, the field mask 5 is used.
In FIG. 10, a plurality of mask openings 511-1 to 511-9 are formed, and these mask openings 511-1 to 511 are formed.
-9 is arranged corresponding to a plurality of focus detection areas which can be selected by the camera automatically or by a photographer's operation within the screen of the photographing optical system.

The mask openings 511-1 and 511-
3,511-4,511-6,511-7,511-9
Each corresponds to the incident area in the claims. Further, in the mask opening 511-2, an area extending in the vertical direction and an area extending in the horizontal direction, the mask openings 511-5, 51.
The outer region and the inner region of 1-8 correspond to the incident region in the claims.

The split field lens 520 is formed with a plurality of field lens portions 521-1 to 521-9.

Further, a plurality of aperture openings 561-1 to 561-10 are formed in the perforated diaphragm 560, and a plurality of re-imaging lenses 57 are formed in the re-imaging lens panel 570.
1-1 to 571-10 are formed. Further, the light receiving sensor 590 includes a plurality of line sensors 591-1 to 591-1.
591-24 are present.

Here, first, the optical action will be described focusing on the luminous flux passing through the mask openings 511-1 to 511-3 of the visual field mask 510.

In FIG. 9, of the light fluxes taken from the photographing optical system and guided to the focus detection unit via the quick return mirror or the like, the light fluxes passing through the mask opening 511-1 of the field mask 510 are the field lens unit 52.
It is guided to the perforated diaphragm 560 by 1-1. Similarly, the light fluxes that have passed through the mask openings 511-2 and 511-3 are guided to the porous diaphragm 560 by the field lens units 521-2 and 521-3, respectively.

Here, the mask openings 511-1 to 511-
The light fluxes having passed through 3 are directed to the aperture openings 561-1 to 561-4 of the multi-hole aperture 560, respectively. Then, the light fluxes passing through the aperture openings 561-1 to 561-4 are projected onto the light receiving sensor 590 by the re-imaging lenses 571-1 to 571-4 corresponding to the aperture openings.

As a result, on the sensor 590, the light enters from the mask openings 511-1 to 511-3 and enters the diaphragm opening 56.
1-1-561-4 and re-imaging lenses 571-1-5
Four pairs of secondary images are formed by the light flux passing through 71-4. The aperture openings 561-1 to 561-4 and the re-imaging lenses 571-1 to 571-4 are the same as these two.
The next images are arranged so that they do not overlap each other.

Specifically, the light beam incident from the mask opening 511-1 passes through the aperture openings 561-3 and 561-4 and the re-imaging lenses 571-3 and 571-4, and the line sensors 591-7 and 591. Form a pair of secondary images on -8.

A light beam incident from a region of the mask opening 511-2 extending in the vertical direction is transmitted through the aperture opening 561-.
1,561-2 and reimaging lenses 571-1,571
-2 to form a pair of secondary images on the line sensors 591-1 and 591-2.

A light beam incident from a region of the mask opening 511-2 extending in the left-right direction is squeezed into the aperture opening 561-.
3, 61-4 and re-imaging lenses 571-3, 571-
4 to form a pair of secondary images on the line sensors 591-5 and 591-6.

Further, the light flux incident from the mask aperture 511-3 passes through the aperture apertures 561-3 and 561-4 and the re-imaging lenses 571-3 and 571-4 and then on the line sensors 591-3 and 591-4. To form a pair of secondary images.

In the arithmetic circuit (not shown), the focus detection area selected by the camera or photographer is the mask opening 5
11-1 corresponds to the line sensor 591-
Sensor output from 7,591-8 (line sensor 591
The output signals corresponding to the light quantity distributions of the secondary images formed on −7 and 591-8 are compared and calculated, and the mask aperture 5
The focus adjustment state of the photographing optical system in the focus detection area corresponding to 11-1 is detected.

Further, when the focus detection area selected by the camera or the photographer corresponds to the mask opening 511-2, the arithmetic circuit, the line sensors 591-1, 591-.
2 or the sensor outputs from the line sensors 591-5 and 591-6 are compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 511-2.

Further, the arithmetic circuit, if the focus detection area selected by the camera or the photographer corresponds to the mask opening 511-3, the line sensors 591-3 and 591-.
The sensor output from 4 is compared and calculated, and the mask opening 511-
The focus adjustment state of the photographing optical system in the focus detection area corresponding to 3 is detected.

Next, with reference to FIG. 10, a mask opening 511 is formed.
-4 to 511-6 will be focused on the light flux to describe the optical action.

In FIG. 10, among the light fluxes taken from the photographing optical system and guided to the focus detection unit via the quick return mirror or the like, the light fluxes that have passed through the mask opening 511-4 of the field mask 510 are the field lens unit 52.
It is guided to the perforated diaphragm 60 by 1-4. Similarly, the light fluxes passing through the mask openings 511-5 and 511-6 are guided to the porous diaphragm 60 by the field lens units 521-5 and 521-6, respectively.

Here, the mask openings 511-4 to 511-
The light fluxes having passed through 6 are directed to the aperture openings 561-5 to 561-7 of the multi-hole aperture 60, respectively. And aperture opening 5
The light flux that has passed through 61-5 to 561-7 is projected onto the light receiving sensor 90 by the re-imaging lenses 571-5 to 571-7 corresponding to the aperture openings.

As a result, on the sensor 590, the light enters from the mask openings 511-4 to 511-6 and enters the diaphragm opening 56.
1-5-561-7 and re-imaging lens 571-5-5
The luminous flux that has passed through 71-7 forms three pairs of secondary images. The diaphragm apertures 561-5 to 561-7 and the re-imaging lenses 571-5 to 571-7 are provided in these two positions.
The next images are arranged so that they do not overlap each other.

Specifically, the light beam incident from the mask aperture 511-4 passes through the aperture apertures 561-5 and 61-6 and the re-imaging lenses 571-5 and 571-6, and the line sensors 591-9 and 591. Form a pair of secondary images on -10.

Further, the light flux incident from the vertically extending region on the right side (outer side) of the mask opening 511-5 passes through the diaphragm openings 561-5, 561-7 and the re-imaging lenses 571-5, 571-7. Then line sensor 59
A pair of secondary images is formed on 1-13 and 591-15.

Further, the light flux incident from a region extending in the vertical direction on the left side (inner side) of the mask opening 511-5 passes through the diaphragm openings 561-5, 561-7 and the re-imaging lenses 571-5, 571-7. Then line sensor 59
A pair of secondary images is formed on 1-14 and 591-16.

Further, the luminous flux incident from the mask aperture 511-6 passes through the aperture apertures 561-6, 561-7 and the re-imaging lenses 571-6, 571-7 and then on the line sensors 591-11, 591-12. To form a pair of secondary images.

In the arithmetic circuit (not shown), the focus detection area selected by the camera or photographer is the mask opening 5
11-4, the line sensor 591-
The sensor outputs from 9,591-10 are compared and calculated, and the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 511-4 is detected.

Further, when the focus detection area selected by the camera or the photographer corresponds to the mask opening 511-5, the arithmetic circuit operates the line sensors 591-13, 591.
-15 or the sensor outputs from the line sensors 591-14 and 591-16 are compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 511-5.

Further, when the focus detection area selected by the camera or the photographer corresponds to the mask opening 511-6, the arithmetic circuit calculates the line sensors 591-11, 591.
The sensor output from −12 is compared and calculated, and the mask opening 51
The focus adjustment state of the photographing optical system in the focus detection area corresponding to 1-6 is detected.

Next, with reference to FIG. 10, a mask opening 511 is formed.
The optical action will be described by focusing on the light flux passing through −7 to 511-9.

In FIG. 10, the mask aperture 5 of the visual field mask 10 out of the luminous flux taken from the photographing optical system and guided to the focus detection unit via the quick return mirror or the like.
The light flux that has passed through 11-7 is the field lens unit 521.
It is guided to the perforated diaphragm 560 by -7. Similarly, the light fluxes that have passed through the mask openings 511-8 and 511-9 are guided to the perforated diaphragm 60 by the field lens units 521-8 and 521-9, respectively.

Here, the mask openings 511-7 to 511-
The light fluxes having passed through 9 are directed to the aperture openings 561-8 to 561-10 of the multi-hole aperture 560. Then, the light fluxes passing through the aperture openings 561-8 to 561-10 are re-imaging lenses 571-8 to 571-10 corresponding to the respective aperture openings.
The light is projected onto the light receiving sensor 590.

As a result, on the sensor 590, the light enters from the mask openings 511-7 to 511-9 and enters the diaphragm opening 56.
1-8 to 561-10 and re-imaging lens 571-8 to
The luminous flux that has passed through 571-10 forms three pairs of secondary images. Aperture apertures 561-8 to 561-
10 and the re-imaging lenses 571-8 to 571-10,
The secondary images are arranged so as not to overlap each other.

Specifically, the light beam incident from the mask aperture 511-7 passes through the aperture apertures 561-8, 561-9 and the re-imaging lenses 571-8, 571-9 and the line sensors 591-17, 591. Form a pair of secondary images on -18.

Further, the light flux incident from a region extending in the vertical direction on the left side (outside) of the mask aperture 511-8 passes through the aperture apertures 561-8, 561-10 and the re-imaging lenses 571-8, 571-10. Then, a pair of secondary images are formed on the line sensors 591-21 and 591-23.

Further, the light flux incident from the vertically extending region on the right side (inner side) of the mask opening 511-8 passes through the diaphragm openings 561-8, 561-10 and the re-imaging lenses 571-8, 571-10. Then, a pair of secondary images are formed on the line sensors 591-22 and 591-24.

Further, the light flux incident from the mask aperture 511-9 passes through the aperture apertures 561-9, 561-10 and the re-imaging lenses 571-9, 571-10 and then on the line sensors 591-19, 591-20. To form a pair of secondary images.

In the arithmetic circuit (not shown), the focus detection area selected by the camera or the photographer is the mask opening 5
11-7, line sensor 591-1
The sensor output from 7, 591-18 is compared and calculated, and the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 511-7 is detected.

Further, the arithmetic circuit, if the focus detection area selected by the camera or the photographer corresponds to the mask opening 511-8, the line sensors 591-21, 591.
-23 or the sensor outputs from the line sensors 591-22 and 591-24 are compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 511-8.

Further, the arithmetic circuit, if the focus detection area selected by the camera or the photographer corresponds to the mask opening 511-9, the line sensors 591-19, 591.
The sensor output from -20 is compared and calculated, and the mask opening 51
The focus adjustment state of the photographing optical system in the focus detection area corresponding to 1-9 is detected.

Next, the arrangement of the diaphragm aperture, the re-imaging lens, and the line sensor used in this embodiment will be described with reference to FIGS. 11 to 13. It should be noted that FIG. 11 shows a perforated diaphragm 560, and FIG. 12 shows a re-imaging lens panel 570.
In FIG. 13, a light receiving sensor 590 is shown.

As described above, the diaphragm opening 561-5 and the re-imaging lens 571-5 are paired with the diaphragm opening 561-6 and the re-imaging lens 571-6 to form the mask opening 51.
Line sensor 591-depending on the luminous flux incident from 1-4.
A pair of secondary images is formed on 9,591-10. Also,
The diaphragm aperture 561-5 and the re-imaging lens 571-5 are
A pair of the aperture opening 561-7 and the re-imaging lens 571-7 form a pair on the line sensor 591-14, 591-16 or the line sensor 591-13, 591-15 by the light flux incident from the mask opening 511-5. To form a secondary image of.

That is, the two pairs of diaphragm apertures and the re-imaging lens corresponding to the two mask apertures 511-4 and 511-5 having different detection component directions (longitudinal directions), respectively,
The diaphragm aperture 561-5 and the re-imaging lens 571-5 are shared to form a pair.

Then, as shown in FIG.
61-5 and 561-6 arrangement direction axis and diaphragm opening 561-
The angle θ1 formed by the arrangement direction axes of 5, 561-7 is shown in FIG.
The angle θ3 formed by the arrangement direction axes of the line sensors 591-9, 591-10 and the arrangement directions axes of the line sensors 591-13, 591-15 (and the line sensors 591-14, 591-16) shown in FIG. Is configured to be.

Further, similarly, an angle θ2 formed by the arrangement direction axes of the re-imaging lenses 571-5 and 571-6 and the arrangement direction axes of the re-imaging lenses 571-5 and 571-7 shown in FIG.
Is also configured to be substantially the same as the angle θ3.

Further, the diaphragm aperture 561-6 and the re-imaging lens 571-6 are, as described above, the diaphragm aperture 561-5.
And a re-imaging lens 571-5 and a diaphragm aperture 561-7 and a re-imaging lens 571-7.
A pair of secondary images are formed on the line sensors 591-11 and 591-12 by the light beams that form a pair and enter from the mask opening 511-6.

That is, the two pairs of diaphragm apertures and the re-imaging lens corresponding to the two mask apertures 511-4 and 511-6 having different detection component directions (longitudinal directions), respectively,
The diaphragm aperture 561-6 and the re-imaging lens 571-6 are shared to form a pair.

The angles formed by the arrangement direction axes of the diaphragm openings 561-5 and 561-6 and the arrangement direction axes of the diaphragm openings 561-6 and 561-7 are line sensors 591-9 and 591-.
10 arrangement direction axes and line sensors 591-11, 591
The angle formed by the -12 arrangement direction axis and the re-imaging lens 57
1-5 and 571-6 arrangement direction axis and re-imaging lens 571
It is substantially the same as the angle formed by the arrangement direction axes of -6 and 571-7.

Further, the aperture opening 561-7 and the re-imaging lens 571-7 are, as described above, the aperture opening 561-.
5 and the re-imaging lens 571-5, and the aperture opening 561-6 and the re-imaging lens 571-
It is paired with 6.

That is, the two pairs of diaphragm apertures and the re-imaging lens corresponding to the two mask apertures 511-5 and 511-6 having different detection component directions (longitudinal directions), respectively,
The diaphragm aperture 561-7 and the re-imaging lens 571-7 are shared to form a pair.

The angles formed by the arrangement direction axes of the diaphragm openings 561-5 and 561-7 and the arrangement direction axes of the diaphragm openings 561-6 and 561-7 are line sensors 591-13 and 591.
-15 (and line sensors 591-14, 591-1
6) Arrangement direction axis and line sensors 591-11, 591
The angle formed by the -12 arrangement direction axis and the re-imaging lens 57
1-5, 571-7 arrangement direction axis and re-imaging lens 571
It is substantially the same as the angle formed by the arrangement direction axes of -6 and 571-7.

On the other hand, the aperture opening 561-8 and the re-imaging lens 571-8 are paired with the aperture opening 561-9 and the re-imaging lens 571-9, and the line sensor is formed by the light flux incident from the mask aperture 511-7. 591-17,591
Form a pair of secondary images on -18. Also, the aperture opening 5
61-8 and the re-imaging lens 571-8 are connected to the aperture opening 5
61-10 and the re-imaging lens 571-10 form a pair, and a pair of two on the line sensor 591-21, 591-23 or the line sensor 591-22, 591-24 by the light flux incident from the mask opening 511-8. Form the next image.

That is, the two pairs of diaphragm apertures and the re-imaging lens corresponding to the two mask apertures 511-7 and 511-8 having different detection component directions (longitudinal directions), respectively,
The diaphragm aperture 561-8 and the re-imaging lens 571-8 are shared to form a pair.

Then, the aperture openings 561-8, 561-9
The angle formed by the arrangement direction axis of the line sensors and the arrangement direction axis of the aperture openings 561-8, 561-10 is equal to the line sensors 591-17, 5
91-18 placement direction axis and line sensor 591-21,
591-23 (and line sensors 591-22, 59
1-24) and the angle formed by the arrangement direction axis of the re-imaging lenses 571-8 and 571-9 and the arrangement direction axis of the re-imaging lenses 571-8, 571-10. It is configured to be substantially the same.

Further, the aperture opening 561-9 and the re-imaging lens 571-9 are the aperture openings 561-8 as described above.
And a re-imaging lens 571-8 and a diaphragm aperture 561-10 and a re-imaging lens 571-.
A pair of secondary images is formed on the line sensors 591-19 and 591-20 by the light flux which forms a pair with 10 and enters from the mask opening 511-9.

That is, the two pairs of diaphragm apertures and the re-imaging lens corresponding to the two mask apertures 511-7 and 511-9 having different detection component directions (longitudinal directions) are respectively
The diaphragm aperture 561-9 and the re-imaging lens 571-9 are shared to form a pair.

The angles formed by the arrangement direction axes of the aperture openings 561-8 and 561-9 and the arrangement direction axes of the aperture openings 561-9 and 561-10 are line sensors 591-17 and 59.
Arrangement axis of 1-18 and line sensor 591-19, 5
The angle formed by the arrangement direction axis of 91-20 and the arrangement direction axis of the re-imaging lenses 571-8 and 571-9 and the re-imaging lens 5
It is substantially the same as the angle formed by the arrangement direction axes of 71-9 and 571-10.

Furthermore, the diaphragm aperture 561-10 and the re-imaging lens 571-10 are connected to the diaphragm aperture 561 as described above.
1-8 and the re-imaging lens 571-8, and a diaphragm aperture 561-9 and the re-imaging lens 57.
It is also paired with 1-9.

That is, the two pairs of diaphragm apertures and the re-imaging lens corresponding to the two mask apertures 511-8 and 511-9 having different detection component directions (longitudinal directions) are respectively
Aperture aperture 561-10 and reimaging lens 571-10
Share a pair.

The aperture openings 561-8, 561-10
The angle formed by the arrangement direction axis of the line sensors and the arrangement direction axes of the aperture openings 561-9, 561-10 is equal to the line sensors 591-21, 5
91-23 (and line sensors 591-22, 591)
-24) Arrangement direction axis and line sensor 591-19, 5
The angle formed by the arrangement direction axis of 91-20 and the angle formed by the arrangement direction axes of the re-imaging lenses 571-8, 571-10 and the re-imaging lenses 571-9, 571-10 are substantially the same. Is.

As described above, in this embodiment, two pairs of re-imaging optical systems corresponding to two mask apertures having different detection component directions (longitudinal directions) are provided. Since they are shared, the number of re-imaging optical systems can be reduced and the focus detection unit can be downsized.

Further, in the present embodiment, the diaphragm aperture 561
-5, the re-imaging lens 571-5 and the diaphragm aperture 561-
7 and the re-imaging lens 571-7, the line sensors 591-14, 5 are formed by the light fluxes incident from the outer incident area and the inner incident area of the mask opening 511-5.
91-16 or line sensor 591-13, 591-
A pair of secondary images is formed on 15.

The pair of the diaphragm aperture 561-8 and the re-imaging lens 571-8 and the diaphragm aperture 561-10 and the re-imaging lens 571-10 is the mask aperture 511-8.
A pair of secondary images is formed on the line sensors 591-22, 591-24 or the line sensors 591-21, 591-23 by the light fluxes incident from the outer incident region and the inner incident region.

That is, the mask openings 511-5 and 511.
A common pair of diaphragm apertures and a re-imaging lens are used for the light fluxes incident from the outer portion and the inner portion having the same longitudinal direction as the incident region of −8.
Therefore, the number of re-imaging optical systems can be further reduced, and the focus detection unit can be further downsized.

Here, in the present embodiment, the pair of aperture openings are symmetrical with each other, and the shape of each aperture opening is circular. As a result, it is possible to prevent a difference in blurring of the secondary image formed on each line sensor, and the required and uniform focus detection can be performed regardless of the secondary image formed by the light flux incident from any mask opening. The accuracy can be maintained.

The line sensors 591-9 to 591-
When the angle formed by the 16 (or 591-17 to 591-24) arrangement direction axes is 60 degrees, the diaphragm apertures 561-5
It is also possible to configure 561-7 (or 561-8 to 561-10) with a hexagon.

(Third Embodiment) FIGS. 14 and 15 show the optical construction of a focus detection unit according to a third embodiment of the present invention. The overall basic configuration of the focus detection unit of this embodiment is the same as that of the first embodiment.

The focus detection unit of this embodiment comprises a field mask 710, a split field lens 720, a perforated diaphragm 760, a re-imaging lens panel 770, and a light receiving sensor 790.

14 and 15, the field mask 710 has a plurality of mask openings 711-1 to 711-9.
Are formed, and these mask openings 711-1 to 71-1 are formed.
Reference numerals 1-9 are arranged corresponding to a plurality of focus detection areas which can be selected by the camera automatically or by a photographer's operation within the screen of the photographing optical system. Note that the mask openings 711-1 and 7
11-3, 711-4, 711-6, 711-7, 71
Each of 1-9 corresponds to the incident area in the claims. Further, of the mask opening 711-2, an area extending in the vertical direction and an area extending in the horizontal direction, the mask opening 711-
The outer region and the inner region of 5,711-8 correspond to the incident region in the claims.

The split field lens 720 is formed with a plurality of field lens portions 721-1 to 721-9.

Further, a plurality of aperture openings 761-1 to 761-12 are formed in the perforated diaphragm 760, and a plurality of re-imaging lenses 77 are provided in the re-imaging lens panel 770.
1-1 to 771-12 are formed. Furthermore, the light receiving sensor 790 includes a plurality of line sensors 791-1 to 791-1.
791-24 are present.

Here, first, the optical action will be described focusing on the luminous flux passing through the mask openings 711-1 to 711-3 of the visual field mask 710.

In FIG. 14, of the luminous flux taken from the photographing optical system and guided to the focus detection unit via the quick return mirror or the like, the luminous flux passing through the mask opening 711-1 of the field mask 710 is the field lens unit 72.
It is guided to the perforated diaphragm 760 by 1-1. Similarly, the light fluxes passing through the mask openings 711-2 and 711-3 are guided to the porous diaphragm 760 by the field lens units 721-2 and 721-3, respectively.

Here, mask openings 711-1 to 711-
The light fluxes having passed through 3 are directed to the aperture openings 761-1 to 761-4 of the perforated aperture 760, respectively. Then, the light fluxes passing through the aperture openings 761-1 to 761-4 are projected onto the light receiving sensor 790 by the re-imaging lenses 771-1 to 771-4 corresponding to the aperture openings.

As a result, on the sensor 790, the light enters from the mask openings 711-1 to 711-3 and enters the diaphragm opening 76.
1-1 to 761-4 and reimaging lens 771-1 to 77-1
Four pairs of secondary images are formed by the light flux passing through 71-4. The diaphragm apertures 761-1 to 761-4 and the re-imaging lenses 771-1 to 771-4 have these two components.
The next images are arranged so that they do not overlap each other.

Specifically, the light beam incident from the mask opening 711-1 passes through the aperture openings 761-3 and 761-4 and the re-imaging lenses 771-3 and 771-4 and the line sensors 791-7 and 791. Form a pair of secondary images on -8.

Further, the light flux incident from the area of the mask opening 711-2 extending in the vertical direction is limited to the aperture opening 761-.
1,761-2 and reimaging lenses 771-1, 771
-2 to form a pair of secondary images on the line sensors 791-1 and 791-2.

A light beam incident from a region of the mask opening 711-2 extending in the left-right direction is a diaphragm opening 761-.
3,761-4 and reimaging lenses 771-3,771
-4 to form a pair of secondary images on the line sensors 791-5 and 791-6.

Further, the luminous flux incident from the mask aperture 711-3 passes through the aperture apertures 761-3 and 761-4 and the re-imaging lenses 771-3 and 771-4 and then on the line sensors 791-3 and 791-4. To form a pair of secondary images.

In the arithmetic circuit (not shown), the focus detection area selected by the camera or photographer is the mask opening 7
11-1 corresponds to the line sensor 791-
7, 791-8 sensor output (line sensor 791
-7, 791-8), output signals corresponding to the light amount distributions of the secondary images respectively formed on the mask apertures 7
The focus adjustment state of the photographing optical system in the focus detection area corresponding to 11-1 is detected.

Further, when the focus detection area selected by the camera or the photographer corresponds to the mask opening 711-2, the arithmetic operation circuit detects the line sensors 791-1 and 791-.
2 or the sensor outputs from the line sensors 791-5 and 791-6 are compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 711-2.

Further, the arithmetic circuit, when the focus detection area selected by the camera or the photographer corresponds to the mask opening 711-3, the line sensors 791-3 and 791-.
The sensor output from 4 is compared and calculated, and the mask opening 711-
The focus adjustment state of the photographing optical system in the focus detection area corresponding to 3 is detected.

Next, with reference to FIG. 15, a mask opening 711 is formed.
-4 to 711-6 will be focused on the light flux to describe the optical action.

In FIG. 15, of the luminous flux taken from the photographing optical system and guided to the focus detection unit via the quick return mirror or the like, the luminous flux passing through the mask aperture 711-4 of the field mask 710 is the field lens unit 72.
It is guided to the perforated diaphragm 760 by 1-4. Similarly, the light fluxes that have passed through the mask openings 711-5 and 711-6 are guided to the porous diaphragm 760 by the field lens units 721-5 and 721-6, respectively.

Here, mask openings 711-4 to 711-
The light fluxes having passed through 6 are directed to the aperture openings 761-5 to 761-8 of the perforated aperture 760, respectively. Then, the light flux that has passed through the aperture openings 761-5 to 761-8 is projected onto the light receiving sensor 790 by the re-imaging lenses 771-5 to 771-8 corresponding to the respective aperture openings.

As a result, on the sensor 790, the light enters from the mask openings 711-4 to 711-6 and enters the diaphragm opening 76.
1-5-761-8 and re-imaging lens 771-5-7
Four pairs of secondary images are formed by the light flux passing through 71-8. The diaphragm apertures 761-5 to 761-8 and the re-imaging lenses 771-5 to 771-8 have these two positions.
The next images are arranged so that they do not overlap each other.

Specifically, the light beam incident from the mask aperture 711-4 passes through the aperture apertures 761-7, 761-8 and the re-imaging lenses 771-7, 771-8 and the line sensors 791-12, 791. Form a pair of secondary images on -11.

Further, the light flux incident from the vertically extending region on the right side (outer side) of the mask opening 711-5 passes through the aperture openings 761-5 and 761-8 and the re-imaging lenses 771-5 and 771-8. Then line sensor 79
A pair of secondary images is formed on 1-13 and 791-15.

Further, the light flux incident from the region extending in the vertical direction on the left side (inner side) of the mask aperture 711-5 passes through the aperture apertures 761-5, 761-8 and the re-imaging lenses 771-5, 771-8. Then line sensor 79
A pair of secondary images are formed on 1-14 and 791-16.

Further, the light flux incident from the mask aperture 711-6 passes through the aperture apertures 761-5, 761-6 and the re-imaging lenses 771-5, 771-6 and then on the line sensors 791-10, 791-9. To form a pair of secondary images.

In the arithmetic circuit (not shown), the focus detection area selected by the camera or photographer is the mask opening 7
11-4, the line sensor 791-1
The sensor outputs from 1, 791-12 are compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 711-4.

Further, the arithmetic circuit, if the focus detection area selected by the camera or the photographer corresponds to the mask opening 711-5, the line sensors 791-13, 791.
-15 or the sensor outputs from the line sensors 791-14 and 791-16 are compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 711-5.

Further, the arithmetic circuit, if the focus detection area selected by the camera or the photographer corresponds to the mask opening 711-6, the line sensors 791-9, 791-.
The sensor output from 10 is compared and the mask opening 711 is calculated.
The focus adjustment state of the photographing optical system in the focus detection area corresponding to −6 is detected.

Next, with reference to FIG. 15, a mask opening 711 is formed.
The optical action will be described by focusing on the light flux passing through −7 to 711-9.

In FIG. 15, of the luminous flux taken from the photographing optical system and guided to the focus detection unit via the quick return mirror or the like, the luminous flux passing through the mask opening 711-7 of the field mask 710 is the field lens unit 72.
It is guided to the perforated diaphragm 760 by 1-7. Similarly, the light fluxes passing through the mask openings 711-8 and 711-9 are guided to the perforated diaphragm 760 by the field lens units 721-8 and 721-9, respectively.

Here, mask openings 711-7 to 711-
The light fluxes having passed through 9 are directed to the aperture openings 761-9 to 761-12 of the perforated aperture 760, respectively. Then, the light fluxes passing through the aperture openings 761-9 to 761-12 are re-imaging lenses 771-9 to 771-12 corresponding to the aperture openings.
The light is projected on the light receiving sensor 90.

As a result, on the sensor 790, the light enters from the mask openings 711-7 to 711-9 and enters the diaphragm opening 76.
1-9 to 761-12 and re-imaging lens 771-9 to
Four pairs of secondary images are formed by the light flux that has passed through 771-12. Aperture openings 761-9 to 761-
12 and the re-imaging lenses 771-9 to 771-12,
The secondary images are arranged so as not to overlap each other.

Specifically, the light beam incident from the mask opening 711-7 passes through the aperture openings 761-11, 761-12 and the re-imaging lenses 771-11, 771-12 and the line sensors 791-20, 791. A pair of 2 on -19
Form the next image.

Further, the light flux incident from a region extending in the vertical direction on the left side (outer side) of the mask aperture 711-8 passes through the aperture apertures 761-9, 761-12 and the re-imaging lenses 771-9, 771-12. Then, a pair of secondary images are formed on the line sensors 791-21 and 791-23.

Further, the light flux incident from the region extending vertically in the right side (inside) of the mask opening 711-8 passes through the aperture openings 761-9, 761-12 and the re-imaging lenses 771-9, 771-12. Then, a pair of secondary images are formed on the line sensors 791-22 and 791-24.

Further, the light flux incident from the mask aperture 711-9 passes through the aperture apertures 761-9, 761-10 and the re-imaging lenses 771-9, 771-10 and then on the line sensors 791-18, 791-17. To form a pair of secondary images.

In the arithmetic circuit (not shown), the focus detection area selected by the camera or photographer is the mask opening 7
11-7, the line sensor 791-1
The sensor outputs from 9, 791-20 are compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 711-7.

Further, the arithmetic circuit, if the focus detection area selected by the camera or the photographer corresponds to the mask opening 711-8, the line sensors 791-21, 791.
-23 or the sensor outputs from the line sensors 791-22 and 791-24 are compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 711-8.

Further, the arithmetic circuit, if the focus detection area selected by the camera or the photographer corresponds to the mask opening 711-9, the line sensors 791-17, 791.
The sensor output from -18 is compared and calculated, and the mask opening 71
The focus adjustment state of the photographing optical system in the focus detection area corresponding to 1-9 is detected.

Next, the arrangement of the diaphragm aperture, the re-imaging lens, and the line sensor used in this embodiment will be described with reference to FIGS. It should be noted that FIG. 16 shows a porous diaphragm 760, and FIG. 17 shows a re-imaging lens panel 770.
18 shows a light receiving sensor 790.

As described above, the diaphragm aperture 761-5 and the re-imaging lens 771-5 are paired with the diaphragm aperture 761-6 and the re-imaging lens 771-6 to form the mask aperture 71.
Line sensor 791-1 by the light flux incident from 1-6
A pair of secondary images is formed on 0,791-9. Further, the aperture opening 761-5 and the re-imaging lens 771-5 form a pair with the aperture opening 761-8 and the re-imaging lens 771-8, and the line sensor 791-14 is generated by the light flux incident from the mask aperture 711-5. , 791-16 or line sensors 791-13, 791-15 to form a pair of secondary images.

That is, the two pairs of diaphragm apertures and the re-imaging lens corresponding to the two mask apertures 711-6 and 711-5 having different detection component directions (longitudinal directions), respectively,
The diaphragm aperture 761-5 and the re-imaging lens 771-5 are shared to form a pair.

Further, the diaphragm aperture 761-8 and the re-imaging lens 771-8 are, as described above, the diaphragm aperture 761-5.
And a re-imaging lens 771-5 and a diaphragm aperture 761-7 and a re-imaging lens 771-7.
A pair of secondary images are formed on the line sensors 791-12 and 791-11 by the light beams that form a pair and enter from the mask opening 711-4.

That is, the two pairs of diaphragm apertures and the re-imaging lens corresponding to the two mask apertures 711-5 and 711-4 having different detection component directions (longitudinal directions), respectively,
The diaphragm aperture 761-8 and the re-imaging lens 771-8 are shared to form a pair.

Then, as shown in FIG.
61-5 and 761-6 arrangement direction axis and diaphragm aperture 761-
The angle θ1 formed by the arrangement direction axes of 5,761-8 is shown in FIG.
Of the line sensors 791-11, 791-12 and the line sensors 791-13, 791-15 shown in FIG.
(And the line sensor 791-14, 791-16) and the arrangement direction axis are substantially the same as the angle θ3.

Further, similarly, an angle θ2 formed by the arrangement direction axis of the re-imaging lenses 771-5 and 771-6 and the arrangement direction axis of the re-imaging lenses 771-5 and 771-8 shown in FIG.
Is also configured to be substantially the same as the angle θ3.

The angles formed by the arrangement direction axes of the diaphragm openings 761-7 and 761-8 and the arrangement direction axes of the diaphragm openings 761-5 and 761-8 are line sensors 791-9 and 791-.
10 arrangement direction axis and line sensor 791-13, 791
-15 (and line sensors 791-14, 791-1
6) The angle formed by the arrangement direction axis and the re-imaging lens 771
-7, 771-8 arrangement direction axis and re-imaging lens 771-
It is configured to be substantially the same as the angle formed by the arrangement direction axis of 5,771-8.

On the other hand, the diaphragm aperture 761-9 and the re-imaging lens 771-9 are paired with the diaphragm aperture 761-10 and the re-imaging lens 771-10 to form a mask aperture 711-9.
Line sensor 791-18, 7
A pair of secondary images is formed on 91-17. Further, the diaphragm aperture 761-9 and the re-imaging lens 771-9 form a pair with the diaphragm aperture 761-12 and the re-imaging lens 771-12, and the line sensor 791-22 is formed by the light flux incident from the mask aperture 711-8. , 791-24 or line sensors 791-21, 791-23 to form a pair of secondary images.

That is, the two pairs of diaphragm apertures and the re-imaging lens corresponding to the two mask apertures 711-9 and 711-8 having different detection component directions (longitudinal directions), respectively,
The diaphragm aperture 761-9 and the re-imaging lens 771-9 are shared to form a pair.

Further, the diaphragm aperture 761-12 and the re-imaging lens 771-12 are arranged in the diaphragm aperture 761 as described above.
-9 and the re-imaging lens 771-9, and forms a pair with the diaphragm aperture 761-11 and the re-imaging lens 77.
1-11 and the line sensors 791-20 and 791-1 by the light flux incident from the mask opening 711-7.
A pair of secondary images is formed on 9.

That is, the two pairs of diaphragm apertures and the re-imaging lens corresponding to the two mask apertures 711-8 and 711-7 having different detection component directions (longitudinal directions), respectively,
Aperture aperture 761-12 and reimaging lens 771-12
Share a pair.

Then, the aperture openings 761-9, 761-1.
The angle formed by the arrangement direction axis of 0 and the arrangement direction axes of the aperture openings 761-9, 761-12 is the line sensor 791-20,
Arrangement axis of 791-19 and line sensor 791-2
1, 791-23 (and line sensors 791-22,
The angle formed by the arrangement direction axis of the re-imaging lenses 771-9, 771-10 and the arrangement direction axis of the re-imaging lenses 771-9, 771-12. It is configured to be the same.

Further, the aperture openings 761-11 and 761-1.
The angle formed by the arrangement direction axis of No. 2 and the arrangement direction axis of the aperture openings 761-9, 761-12 is equal to the line sensor 791-17,
Arrangement axis of 791-18 and line sensor 791-2
1, 791-23 (and line sensors 791-22,
The angle formed by the arrangement direction axis of the re-imaging lenses 771-11, 771-12 and the arrangement direction axis of the re-imaging lenses 771-9, 771-12. It is configured to be the same.

As described above, in this embodiment, two pairs of re-imaging optical systems corresponding to two mask apertures having different detection component directions (longitudinal directions) are provided. Since they are shared, the number of re-imaging optical systems can be reduced and the focus detection unit can be downsized.

Furthermore, in the present embodiment, the diaphragm aperture 761
-5 and the re-imaging lens 771-5 and the diaphragm aperture 761-
8 and the re-imaging lens 771-8, the line sensors 791-13, 7 are formed by the light fluxes incident from the outer incident area and the inner incident area of the mask opening 711-5.
91-15 or line sensor 791-14, 791-
A pair of secondary images is formed on 16.

The pair of the diaphragm aperture 761-9 and the re-imaging lens 771-9 and the diaphragm aperture 761-12 and the re-imaging lens 771-12 is the mask aperture 711-8.
A pair of secondary images is formed on the line sensors 791-21, 791-23 or the line sensors 791-22, 791-24 by the light fluxes incident from the outer incident area and the inner incident area.

That is, the mask openings 711-5 and 711.
A common pair of diaphragm apertures and a re-imaging lens are used for the light fluxes incident from the outer region and the inner region having the same longitudinal direction as the incident region of −8.
Therefore, the number of re-imaging optical systems can be further reduced, and the focus detection unit can be further downsized.

Here, in the present embodiment, the pair of aperture openings are symmetrical with each other, and the shape of each aperture opening is circular. As a result, it is possible to prevent a difference in blurring of the secondary image formed on each line sensor, and the required and uniform focus detection can be performed regardless of the secondary image formed by the light flux incident from any mask opening. The accuracy can be maintained.

Further, in the present embodiment, since θ1, θ2, and θ3 shown in FIGS. 16 to 18 are all set to about 90 degrees, each mask opening (that is, focus detection area) is set large. It becomes possible to do.

(Fourth Embodiment) FIG. 19 shows the arrangement of line sensors on the light receiving sensor in the focus detection unit according to the fourth embodiment of the present invention. The optical configuration and the optical action of the focus detection unit of this embodiment are the same as those of the third embodiment.

In the third embodiment, the mask opening 711-
4, 711-6, 711-7 and 711-9 are respectively connected to the mask openings 711-5 and 711.
Although it is arranged above and below the line sensor corresponding to −8, in the present embodiment, the mask opening 711-4 is provided between the upper and lower line sensors corresponding to the mask openings 711-5 and 711-8.
Line sensors corresponding to 711-6, 711-7, and 711-9 are arranged.

(Fifth Embodiment) FIGS. 20 and 21 show the optical construction of a focus detection unit according to a fifth embodiment of the present invention. The overall basic configuration of the focus detection unit of this embodiment is the same as that of the first embodiment.

The focus detection unit of this embodiment comprises a field mask 810, a split field lens 820, a perforated diaphragm 860, a re-imaging lens panel 870, and a light receiving sensor 890.

20 and 21, the field mask 810 has a plurality of mask openings 811-1 to 811-9.
Are formed, and these mask openings 811-1 to 81-1 are formed.
Reference numerals 1-9 are arranged corresponding to a plurality of focus detection areas which can be selected by the camera automatically or by a photographer's operation within the screen of the photographing optical system. The mask openings 811-1 and 8
11-3, 811-4, 811-6, 811-7, 81
Each of 1-9 corresponds to the incident area in the claims. Further, of the mask opening 811-2, an area extending in the vertical direction and an area extending in the horizontal direction, the mask opening 811-
The outer region and the inner region of 5,811-8 correspond to the incident region in the claims, respectively.

The split field lens 820 is formed with a plurality of field lens portions 821-1 to 821-9.

Further, a plurality of aperture openings 861-1 to 861-16 are formed in the perforated diaphragm 860, and a plurality of re-imaging lenses 87 are formed in the re-imaging lens panel 870.
1-1 to 871-12 are formed. Further, the light receiving sensor 890 includes a plurality of line sensors 891-1 to 891-1.
891-24 are present.

First, the optical action will be described by focusing on the light flux passing through the mask openings 811-1 to 811-3 of the visual field mask 810.

In FIG. 20, of the luminous flux taken from the photographing optical system and guided to the focus detection unit via the quick return mirror or the like, the luminous flux passing through the mask opening 811-1 of the field mask 810 is the field lens unit 82.
It is guided to the perforated diaphragm 860 by 1-1. Similarly, the light fluxes that have passed through the mask openings 811-2 and 811-3 are guided to the perforated diaphragm 860 by the field lens units 821-2 and 821-3, respectively.

Here, mask openings 811-1 to 811-
The light fluxes having passed through 3 are directed to the aperture openings 861-1 to 861-4 of the multi-hole aperture 860. Then, the light fluxes that have passed through the aperture openings 861-1 to 861-4 are projected onto the light receiving sensor 890 by the re-imaging lenses 871-1 to 871-4 corresponding to the aperture openings.

As a result, on the sensor 890, the light enters from the mask openings 811-1 to 811-3 and enters the diaphragm opening 86.
1-1 to 861-4 and reimaging lens 871-1 to 87-8
Four pairs of secondary images are formed by the light flux passing through 71-4. The aperture openings 861-1 to 861-4 and the re-imaging lenses 871-1 to 871-4 are the two
The next images are arranged so that they do not overlap each other.

Specifically, the light beam incident from the mask opening 811-1 passes through the aperture openings 861-3 and 861-4 and the re-imaging lenses 871-3 and 871-4, and the line sensors 891-7 and 891. Form a pair of secondary images on -8.

A light beam incident from a region of the mask opening 811-2 extending in the vertical direction is stopped by the aperture opening 861-.
1,861-2 and reimaging lens 871-1,871
-2 to form a pair of secondary images on the line sensors 891-1 and 891-2.

A light beam incident from a region of the mask opening 811-2 extending in the left-right direction is stopped by the aperture opening 861-.
3,861-4 and reimaging lenses 871-3,871
-4 to form a pair of secondary images on the line sensors 891-5 and 891-6.

Further, the luminous flux incident from the mask aperture 811-3 passes through the aperture apertures 861-3 and 861-4 and the re-imaging lenses 871-3 and 871-4, and then on the line sensors 891-3 and 891-4. To form a pair of secondary images.

In the arithmetic circuit (not shown), the focus detection area selected by the camera or photographer is the mask opening 8
11-1 corresponds to the line sensor 891-
Sensor output from 7,891-8 (line sensor 891
The output signals corresponding to the light amount distributions of the secondary images formed on −7 and 891-8 are compared and calculated, and the mask aperture 8
The focus adjustment state of the photographing optical system in the focus detection area corresponding to 11-1 is detected.

The detected focus adjustment state is sent as a signal to a camera microcomputer (not shown), and the camera microcomputer drives the photographing optical system (through a lens microcomputer or the like) in response to this signal to select the selected focus. The photographing optical system is focused on the subject in the detection area.

Further, the arithmetic circuit, if the focus detection area selected by the camera or the photographer corresponds to the mask opening 811-2, the line sensors 891-1 and 891-.
2 or the sensor outputs from the line sensors 891-5 and 891-6 are compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 811-2.

Further, the arithmetic circuit, if the focus detection area selected by the camera or the photographer corresponds to the mask opening 811-3, the line sensors 891-3, 891-.
The sensor output from 4 is compared and calculated, and the mask opening 811
The focus adjustment state of the photographing optical system in the focus detection area corresponding to 3 is detected.

Next, with reference to FIG. 21, a mask opening 811 is formed.
-4 to 811-6 will be focused on the light flux to describe the optical action.

In FIG. 21, of the luminous flux taken from the photographing optical system and guided to the focus detection unit via the quick return mirror or the like, the luminous flux passing through the mask opening 811-4 of the field mask 810 is the field lens unit 82.
It is guided to the perforated diaphragm 860 by 1-4. Similarly, the light fluxes passing through the mask openings 811-5 and 811-6 are guided to the perforated diaphragm 860 by the field lens units 821-5 and 821-6, respectively.

Here, mask openings 811-4 to 811-
The light fluxes having passed through 6 are directed to the aperture openings 861-5 to 861-10 of the multi-hole aperture 860. Then, the light flux passing through the aperture openings 861-5 to 861-10 is projected onto the light receiving sensor 890 by the re-imaging lenses 871-5 to 871-8 corresponding to the respective aperture openings.

As a result, on the sensor 890, the light enters from the mask openings 811-4 to 811-6 and enters the diaphragm opening 86.
1-5 to 861-10 and reimaging lens 871-5
Four pairs of secondary images are formed by the light flux that has passed through 871-8. Aperture apertures 861-5 to 861-1
0 and the re-imaging lenses 871-5 to 871-8 are arranged so that these secondary images do not overlap each other.

Specifically, the light beam incident from the mask aperture 811-4 passes through the aperture apertures 861-5 and 861-6 and the re-imaging lenses 871-5 and 871-6, and the line sensors 891-9 and 891. Form a pair of secondary images on -10.

The light flux incident from the vertically extending region on the right side (outer side) of the mask opening 811-5 passes through the aperture openings 861-7, 861-8 and the re-imaging lenses 871-6, 871-7. Then line sensor 89
A pair of secondary images is formed on 1-13 and 891-15.

Further, the light flux incident from the region extending in the vertical direction on the left side (inner side) of the mask opening 811-5 passes through the aperture openings 861-7, 861-8 and the re-imaging lenses 871-6, 871-7. Then line sensor 89
A pair of secondary images is formed on 1-14 and 891-16.

Further, the light flux incident from the mask aperture 811-6 passes through the aperture apertures 861-9 and 861-10 and the re-imaging lenses 871-7 and 871-8, and then on the line sensors 891-11 and 891-12. To form a pair of secondary images.

In the arithmetic circuit (not shown), the focus detection area selected by the camera or photographer is the mask opening 8
11-4, the line sensor 891-
The sensor output from 9,891-10 is compared and calculated, and the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 811-4 is detected.

Further, the arithmetic circuit, if the focus detection area selected by the camera or the photographer corresponds to the mask opening 811-5, the line sensors 891-13, 891.
-15 or the sensor outputs from the line sensors 891-14 and 891-16 are compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 811-5.

Further, when the focus detection area selected by the camera or the photographer corresponds to the mask opening 811-6, the arithmetic circuit calculates the line sensors 891-11, 891.
The sensor output from −12 is compared and calculated, and the mask opening 81
The focus adjustment state of the photographing optical system in the focus detection area corresponding to 1-6 is detected.

Next, with reference to FIG. 21, a mask opening 811 is formed.
The optical action will be described by focusing on the luminous flux passing through −7 to 811-9.

In FIG. 21, of the luminous flux taken from the photographing optical system and guided to the focus detection unit via the quick return mirror or the like, the luminous flux passing through the mask opening 811-7 of the field mask 810 is the field lens unit 82.
It is guided to the perforated diaphragm 860 by 1-7. Similarly, the light fluxes that have passed through the mask openings 811-8 and 811-9 are guided to the perforated diaphragm 860 by the field lens units 821-8 and 821-9, respectively.

Here, mask openings 811-7 to 811-
The light fluxes that have passed through 9 are directed to the aperture openings 861-111 to 861-16 of the multi-hole aperture 860. The light fluxes that have passed through the aperture openings 8611-11 to 861-16 are re-imaging lenses 871-9 to 871-corresponding to the aperture openings.
It is projected on the light receiving sensor 890 by 12.

As a result, on the sensor 890, the light enters from the mask openings 811-7 to 811-9 and the diaphragm opening 86.
1-111 to 861-16 and reimaging lens 871-9
The pair of secondary images is 4 due to the light flux that has passed through 871-12.
A set will be formed. Aperture openings 8611-11 to 86
1-16 and re-imaging lenses 871-9 to 871-12
Are arranged so that these secondary images do not overlap each other.

Specifically, the light beam incident from the mask opening 811-7 passes through the aperture openings 861-11 and 861-12 and the re-imaging lenses 871-9 and 871-10, and the line sensors 891-17 and 891. Form a pair of secondary images on -18.

Further, the light flux incident from the vertically extending region on the left side (outer side) of the mask opening 811-8 passes through the aperture openings 861-13, 861-14 and the re-imaging lenses 871-10, 871-11. Then, a pair of secondary images are formed on the line sensors 891-21 and 891-23.

Further, the light flux incident from the region extending in the vertical direction on the right side (inside) of the mask opening 811-8 passes through the diaphragm openings 861-13 and 861-14 and the re-imaging lenses 871-10 and 871-11. Then, a pair of secondary images are formed on the line sensors 891-22 and 891-24.

Further, the light flux incident from the mask aperture 811-9 passes through the aperture apertures 861-15 and 861-16 and the re-imaging lenses 871-11 and 871-12, and then on the line sensors 891-19 and 891-20. To form a pair of secondary images.

In the arithmetic circuit (not shown), the focus detection area selected by the camera or photographer is the mask opening 8
11-7, line sensor 891-1
The sensor output from 7,891-18 is compared and calculated, and the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 811-7 is detected.

Also, the arithmetic circuit, if the focus detection area selected by the camera or the photographer corresponds to the mask opening 811-8, the line sensors 891-21, 891.
-23 or the sensor outputs from the line sensors 891-22 and 891-24 are compared and calculated to detect the focus adjustment state of the photographing optical system in the focus detection area corresponding to the mask opening 811-8.

Further, the arithmetic circuit, if the focus detection area selected by the camera or the photographer corresponds to the mask opening 811-9, the line sensors 891-19, 891.
The sensor output from -20 is compared and the mask opening 81 is calculated.
The focus adjustment state of the photographing optical system in the focus detection area corresponding to 1-9 is detected.

Next, the arrangement of the diaphragm aperture, the re-imaging lens, and the line sensor used in this embodiment will be described with reference to FIGS. 22. FIG. 22 shows a multi-hole diaphragm 860, and FIG. 23 shows a re-imaging lens panel 870.
24 shows a light receiving sensor 890.

As described above, the diaphragm aperture 861-6 and the re-imaging lens 871-6 are paired with the diaphragm aperture 861-5 and the re-imaging lens 871-5 to form the mask aperture 81.
Line sensor 891-based on the luminous fluxes incident from 1-4.
A pair of secondary images is formed on 9,891-10. Also,
The aperture opening 861-7 and the re-imaging lens 871-6 are
A pair is formed on the line sensor 891-14, 891-16 or the line sensor 891-13, 891-15 by the light flux which is paired with the diaphragm aperture 861-8 and the re-imaging lens 871-7 and is incident from the mask aperture 811-5. To form a secondary image of.

That is, the two pairs of re-imaging lenses corresponding to the two mask openings 811-4 and 811-5 having different detection component directions (longitudinal directions) are re-imaging lenses 871-6.
Share a pair.

The re-imaging lens 871-7 is paired with the re-imaging lens 871-6 as described above, and is also paired with the re-imaging lens 871-8 to form the mask opening 811-6. Line sensor 89
A pair of secondary images is formed on 1-11 and 891-12.

That is, the two pairs of re-imaging lenses corresponding to the two mask openings 811-5 and 811-6 having different detection component directions (longitudinal directions) share the re-imaging lens 871-7 and form a pair. I am doing it.

Then, as shown in FIG.
61-5 and 861-6 arrangement direction axis and diaphragm opening 861-
The angle θ1 formed by the arrangement direction axis of 7,861-8 is shown in FIG.
The angle θ3 formed by the arrangement direction axes of the line sensors 891-9, 891-10 and the arrangement directions axes of the line sensors 891-13, 891-15 (and the line sensors 891-14, 891-16) shown in FIG. Is configured to be.

Further, similarly, the angle θ2 formed by the arrangement direction axes of the re-imaging lenses 871-5 and 871-6 and the arrangement direction axes of the re-imaging lenses 871-6 and 871-7 shown in FIG.
Is also configured to be substantially the same as the angle θ3.

Further, the diaphragm apertures 861-9, 861-10
Of the line sensors 891-11, 89.
1-12 Arrangement Direction Axis and Line Sensors 891-13, 8
91-15 (and line sensors 891-14, 891)
-16) and the re-imaging lens 8 formed by the arrangement direction axis
71-7, 871-8 Arrangement Direction Axis and Reimaging Lens 87
1-6 and 871-7 are formed to be substantially the same as the angle formed by the arrangement direction axis.

On the other hand, the re-imaging lens 871-10 is paired with the re-imaging lens 871-9 to form a mask opening 811-7.
Line sensor 891-17,8 by the light flux incident from
A pair of secondary images is formed on 91-18. Further, the re-imaging lens 871-10 forms a pair with the re-imaging lens 871-11, and the line sensor 891-22, 891-24 or the line sensor 891-21, 891 is formed by the light flux incident from the mask opening 811-8. Form a pair of secondary images on -23.

That is, the two pairs of re-imaging lenses corresponding to the two mask openings 811-7 and 811-8 having different detection component directions (longitudinal directions) are re-imaging lenses 871-1.
They share 0 and make a pair.

The re-imaging lens 871-11 is paired with the re-imaging lens 871-10 as described above, and is also paired with the re-imaging lens 871-12 to form the mask opening 811-9. A pair of secondary images is formed on the line sensors 891-19 and 891-20 by the light flux incident from the.

That is, the two pairs of diaphragm openings and the re-imaging lens corresponding to the two mask openings 811-8 and 811-9 having different detection component directions (longitudinal directions) share the re-imaging lens 871-11. And paired up.

Then, the aperture openings 861-11, 861-
12 arrangement direction axis and aperture openings 861-13, 861-1
The angle formed by the arrangement direction axis of 4 is the line sensor 891-1.
7, 891-18 arrangement direction axis and line sensor 891-
21,891-23 (and line sensor 891-2
2, 891-24) and the angle formed by the re-imaging lenses 871-9, 871-10 and the re-imaging lenses 871-10, 871-11. It is configured to be substantially the same as.

Further, the aperture openings 861-15 and 861-1.
6 arrangement direction axis and diaphragm openings 861-13, 861-14
The angle formed by the line sensor 891-1
9,891-20 Arrangement Direction Axis and Line Sensor 891-
21,891-23 (and line sensor 891-2
2, 891-24) and an angle formed by the re-imaging lenses 871-11 and 871-12 and the re-imaging lenses 871-10 and 871-11. It is configured to be substantially the same as.

As described above, in this embodiment, two pairs of re-imaging optical systems corresponding to two mask apertures having different detection component directions (longitudinal directions) are provided. Since they are shared, the number of re-imaging optical systems can be reduced and the focus detection unit can be downsized.

Further, in the present embodiment, the diaphragm aperture 861
-7 and re-imaging lens 871-6 and diaphragm aperture 861-
8 and the re-imaging lens 871-7, the line sensors 891-14, 8 are formed by the light fluxes incident from the outer incident area and the inner incident area of the mask opening 811-5.
91-16 or line sensor 891-13,891-
A pair of secondary images is formed on 15.

The pair of the diaphragm aperture 861-13 and the re-imaging lens 871-10 and the diaphragm aperture 861-14 and the re-imaging lens 871-11 is the mask aperture 811.
The line sensors 891-22 and 891-24 are formed by the light fluxes incident from the outside incident area and the inside incident area of −8.
A pair of secondary images is formed on the top or the line sensors 891-21 and 891-23.

That is, the mask openings 811-5 and 811.
A common pair of diaphragm apertures and a re-imaging lens are used for the light fluxes incident from the outer region and the inner region having the same longitudinal direction as the incident region of −8.
Therefore, the number of re-imaging optical systems can be further reduced, and the focus detection unit can be further downsized.

Here, in the present embodiment, the pair of aperture openings are provided independently of each other. For this reason, it is possible to make the aperture stop optimal for the secondary image formed on each line sensor, and it is possible to achieve both miniaturization and optimal formation of the secondary image.

The present invention is not limited to the configurations of the respective embodiments described above, and two pairs of re-imaging optical systems corresponding to two incident areas having different longitudinal directions form one re-imaging. Any optical system can be shared.

In each of the above embodiments, the case where the line sensor provided on the light receiving sensor is used for detection has been described, but it goes without saying that the case where the area sensor is used is also applicable.

In each of the above embodiments, the case where the focus adjustment state of the photographing optical system of the camera is detected has been described. However, the present invention focuses on the focus of the objective optical system in the observation equipment such as binoculars or other optical equipment. It can also be applied when detecting the adjustment state.

[0301]

As described above, according to the present invention,
Two pairs of re-imaging optical systems provided for two incident regions having different longitudinal directions are made to share one re-imaging optical system of these pairs of re-imaging optical systems. Therefore, the number of re-imaging optical systems can be reduced and the focus detection device can be miniaturized even when it has the incident regions extending in various directions.

The angle formed by the longitudinal axis of one of the two incident areas and the longitudinal axis of the other of the two incident areas, and a pair of reconnections provided for the one incident area. The angle formed by the arrangement direction axis of the image optical system and the arrangement direction axis of the pair of re-imaging optical systems provided with respect to the other incident area is substantially the same, or the longitudinal direction axis of the one incident area. The angle formed by the longitudinal axis of the other incident area, the arrangement direction axis of the pair of light receiving areas provided for the one incident area, and the arrangement of the pair of light receiving areas provided for the other incident area. If the angle formed by the direction axis and the angle formed by the direction axis are made substantially the same, it is possible to prevent the re-imaging optical system used as a pair from causing a deviation in the formed object image, which deteriorates the detection accuracy. Can be prevented.

When a pair of diaphragm apertures are provided for a pair of re-imaging optical systems, which pair of re-imaging optical systems is used by making the pair of diaphragm apertures symmetrical to each other. However, the characteristics of the object image can be matched and the required focus detection performance can be maintained.

Further, by making the diaphragm aperture circular,
The degree of blurring of the object image on each light receiving area is made uniform, and the focus adjustment state can be detected with the same accuracy by the object image formed by the light flux from any incident area.

Furthermore, if at least one condenser lens is provided for each pair of re-imaging optical systems,
A suitable or optimum detection system can be configured for each of the plurality of incident regions.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a focus detection unit that is a first embodiment of the present invention.

FIG. 2 is a sectional view of the focus detection unit.

FIG. 3 is a rear view showing a state in which an infrared cut filter is attached to the focus detection unit.

FIG. 4 is a perspective view showing an optical configuration of the focus detection unit.

FIG. 5 is a perspective view showing an optical configuration of the focus detection unit.

FIG. 6 is a diagram showing a perforated diaphragm used in the focus detection unit.

FIG. 7 is a diagram showing a re-imaging lens panel used in the focus detection unit.

FIG. 8 is a diagram showing a light receiving sensor used in the focus detection unit.

FIG. 9 is a perspective view showing an optical configuration of the focus detection unit according to the second embodiment of the present invention.

FIG. 10 is a perspective view showing an optical configuration of the focus detection unit of the second embodiment.

FIG. 11 is a diagram showing a perforated diaphragm used in the focus detection unit of the second embodiment.

FIG. 12 is a diagram showing a re-imaging lens panel used in the focus detection unit of the second embodiment.

FIG. 13 is a diagram showing a light receiving sensor used in the focus detection unit of the second embodiment.

FIG. 14 is a perspective view showing an optical configuration of the focus detection unit according to the third embodiment of the present invention.

FIG. 15 is a perspective view showing an optical configuration of the focus detection unit of the third embodiment.

FIG. 16 is a view showing a perforated diaphragm used in the focus detection unit of the third embodiment.

FIG. 17 is a diagram showing a re-imaging lens panel used in the focus detection unit of the third embodiment.

FIG. 18 is a diagram showing a light receiving sensor used in the focus detection unit of the third embodiment.

FIG. 19 is a diagram showing a light receiving sensor used in a focus detection unit according to a fourth embodiment of the present invention.

FIG. 20 is a perspective view showing an optical configuration of the focus detection unit according to the fifth embodiment of the present invention.

FIG. 21 is a perspective view showing an optical configuration of the focus detection unit of the fifth embodiment.

FIG. 22 is a view showing a perforated diaphragm used in the focus detection unit of the fifth embodiment.

FIG. 23 is a view showing a re-imaging lens panel used in the focus detection unit of the fifth embodiment.

FIG. 24 is a view showing a light receiving sensor used in the focus detection unit of the fifth embodiment.

FIG. 25 is a diagram showing a conventional focus detection device.

FIG. 26 is a diagram showing a conventional focus detection device.

FIG. 27 is a diagram showing a conventional focus detection device.

FIG. 28 is a diagram showing a conventional focus detection device.

[Explanation of symbols]

10, 510, 710, 810 Field-of-view mask 20, 520, 720, 820 Split field lens 30 Shading plate 40 Mirror 50 Infrared cut filter 60, 560, 760, 860 Porous diaphragm 70, 570, 770, 870 Re-imaging lens 80 Sensor holder 90, 590, 790, 890 Light receiving sensor 100 Sensor support member 110 Light shielding sheet 120 Main body block 200 Sensor unit 300 Circuit board 11, 511, 711, 811 Mask opening 21, 521, 721, 821 Field lens part 61, 561, 761,861 Aperture openings 71,57
1,771,871 Re-imaging lens panel 91,591,791,891 Line sensor

Claims (12)

[Claims] 1. A plurality of incident areas on which a light beam from an objective optical system is incident, a pair of re-imaging optical systems are provided for each of these incident areas, and a pair of re-imaging optical systems is provided. In a focus detection device for detecting a focus adjustment state of the objective optical system based on a detection result of an object image, the focus detection device extends in different directions among the plurality of incident regions.
A pair of re-imaging optical systems respectively provided for one incidence area share one re-imaging optical system mutually, The focus detection apparatus characterized by the above-mentioned. 2. A pair of light-receiving regions for detecting the pair of object images are provided for each of the two incident regions without having a light-receiving region shared with each other. The focus detection device according to 1. 3. An angle formed by a longitudinal axis of one of the two incident areas and a longitudinal axis of the other of the two incident areas, and a pair of reconnections provided for the one of the incident areas. 3. The angle formed by the arrangement direction axis of the image optical system and the arrangement direction axis of the pair of re-imaging optical systems provided with respect to the other incident area is substantially the same. Focus detection device. 4. The angle formed by the longitudinal axis of one of the two incident areas and the longitudinal axis of the other of the two incident areas, and a pair of light receiving areas provided for the one incident area. 4. The focus detection device according to claim 2, wherein an angle formed by the arrangement direction axis of 1 and an arrangement direction axis of the pair of light receiving regions provided with respect to the other incident region is substantially the same. . 5. A common pair of re-imaging optical systems is provided for two incident areas extending in the same direction among the plurality of incident areas.
The focus detection device according to any one of 1 to 3. 6. The focus detection device according to claim 1, wherein each of the re-imaging optical systems is composed of a lens. 7. The focus detection device according to claim 1, wherein each of the re-imaging optical systems has a diaphragm aperture. 8. The focus detection device according to claim 7, wherein the pair of aperture openings included in the pair of re-imaging optical systems have mutually symmetrical shapes. 9. The focus detection device according to claim 8, wherein the aperture opening is circular. 10. The focus detection device according to claim 1, wherein at least one condenser lens is provided for each pair of re-imaging optical systems. 11. The image forming apparatus according to claim 1, wherein the pair of re-imaging optical systems form an object image by light fluxes passing through different regions of the objective optical system. Focus detection device. 12. An optical apparatus comprising the focus detection device according to claim 1. Description: