JPS6388532A - Single-lens reflex camera - Google Patents

Abstract

PURPOSE:To display a focus detecting function and a TTL light measuring function to their maximums by arranging a sensor for TTL light measurement at the position where reflected light from an object image formation surface is guided in through a field lens. CONSTITUTION:Part of luminous flux incident on a film is reflected by a film surface and incident on a sensor 14 for dimming through the field lens, and a light measurement signal obtained by photodetecting and converting the light photoelectrically is outputted to a control circuit 101 from a TTL strobe dimming circuit 109. The control circuit 101 compares light measurement information from a light measuring circuit 110 with light measurement information from the TTL strobe dimming circuit 109 and allows the trailing curtain of a shutter 15 to run through a shutter control circuit 103 on detecting their coincidence. Then the film is taken up and a series of photographing operations are completed. Consequently, the performance of a focus detection optical system and TTL light measurement optical system is displayed to the maximum.

Description

Detailed Description of the Invention (Field of Application of the Invention) The present invention relates to a focus detection optical system having a field lens, a secondary imaging lens, and a focus detection sensor, and a focus detection optical system that includes a field lens, a secondary imaging lens, and a focus detection sensor, and Or, it relates to the improvement of a single-lens reflex camera equipped with a TTL photometry optical system having a TTIJII light sensor (TTL light control sensor or TTL-AE sensor) that measures the light reflected from the shutter curtain surface at the bottom of the mirror box. It is.

(Background of the invention) In a single-lens reflex camera, focus detection function and TT
Providing both the L and L dimming functions is generally very difficult in terms of layout, as both optical systems are placed at the bottom of the mirror box. From the request to measure the center,
In addition, in the TTL light control optical system, it is ideal to arrange the centers of these optical paths on the center of the photographing optical axis in order to make the photometric sensitivity distribution even on the left and right sides. It is necessary to take measures such as dividing the optical path due to the I had to choose between shifting the optical system from the center of the photographic optical axis and sacrificing the photometric sensitivity distribution.

(Object of the invention) The object of the present invention is to solve the above-mentioned problems, reduce costs,
Focus detection function and TTL while achieving compactness
To provide a single-lens reflex camera that can maximize the performance of each photometry function.

(Characteristics of the Invention) In order to achieve the object L, the present invention arranges a TTL photometry sensor at a position t where it can take in the reflected light from the object image formation plane via a field lens, and The present invention is characterized in that the field lens is shared by both the detection optical system and the TTL photometry optical system, so that the centers of these optical paths are located on the center of the optical axis.

(Embodiments of the Invention) Hereinafter, the present invention will be described in detail based on illustrated embodiments.

1 to 3 show one embodiment of the present invention.
The figure is a cross-sectional view with a strobe attached. 1st
In the figure, 1 is a camera body, 2 is a lens barrel that holds a photographic lens 3 movably in the direction of an optical axis 4, and 5 is a sub-mirror 6 that converts the subject light transmitted through the photographic lens 3 into a finder system and AF@photometering. Main mirror that separates into systems, 7
10 is a focusing glass that constitutes a finder system together with a pentaprism 8 and an eyepiece 9; 10 is a field lens 11. Secondary imaging lens 12. AF-AE river sensor 13. has a sensor section 13a where an AFJTI line sensor and an AE sensor are arranged (details will be described later). Sensor part 1
4a, etc. (here, the TTL strobe light control system and the A
15 is a shutter, 16 is a strobe, 17 is a flash light emitting section, and 18 is a near-infrared auxiliary light emitting section for AF.

Figure 2.3 shows the AF-photometering unit 10 shown in Figure 1.
FIG. 2 is a sectional view thereof, and FIG. 3 is an exploded perspective view thereof.

On the upper surface side of the main body block 19, an infrared cut filter 21 having regions 21a and 21b with different transmittances of the field mask 2O1 and a field lens 11 are attached in that order, and on the lower surface side, an aperture 22 and a secondary The imaging lens 12, the pressing spring 23, the sensor block 24, the sensor holder 25, and the AF-AE sensor 13 are attached in this order. Furthermore, the main body block 19 is provided with a TTL strobe light control sensor 1 at a position where it can receive reflected light from the film surface via the field lens 11.
4 can be installed.

The diaphragm 22 has a pair of orthogonal openings 22a, 22b and 22c, 22d as shown in FIG. Part 22e.

22f, a spring portion 22g, and a long hole 22h.

The secondary imaging lens 12 having the lens parts 12a to 12d is positioned by the pins 12e and 12f with the diaphragm 22 for viewing each part as described above sandwiched between it and the main body block 19, and is fixed by a pressing spring 23. (Second
(see figure), in such a state, the lens portions 12a to 12d of the secondary imaging lens 12 are connected to the openings 22a to 12d.
22d (details will be described later), and the positioning parts 22e and 22f are provided with a secondary imaging lens 1.
2 bottles 12g and 12h are attached to the spring part 22g.
i is inserted respectively. Bin 1 is attached to the spring portion 22g.
2i, the spring portion 22g is deformed as shown in FIG.
It generates a force that urges in the direction of. Therefore, eccentric bin 2
6 into the hole of the main body block 19 through the elongated hole 22h of the aperture 22, and by rotating it, the aperture 22
The diaphragm 22 can be rotated by a minute angle (in the direction of arrow B in FIG. 2) about the center A of each opening.

As described above, the sensor block 24 and the sensor holder 25 are arranged below the secondary imaging lens 12, and these are attached using screws 27. The AF-AE sensor 13 is further arranged below the washer 28 and the eccentric bin 29.
It constitutes an inclination 3I adjustment mechanism. In the AF-AE sensor 13, a sensor holder 25 is attached to the surface 25a, and a sensor block 24 having holes 24a and 24b is attached to the arc-shaped sensor block 24, which is attached to the surface 24c. For installation, use screws 27° and washers 28
Fixed by

Here, for the arcuate mounting, the R center of the surface 24c is the axis C drawn assumingly in FIG. 2, and for mounting the sensor block 24, the hole 24a is elongated, so Directional tilt adjustment is possible. Furthermore, the sensor holder 25 is installed in hole 2, which is an elongated hole similar to hole 24a.
The sensor block 2 is also connected by the eccentric bin 29 via 4b.
4, and the thickness of the bent portion 25b of the sensor holder 25 is made sufficiently thin to provide flexibility.

By rotating the eccentric bin 29, it is possible to adjust the inclination in the direction of arrow F in FIG. 2 approximately around the axis E hypothetically drawn in FIG.

In the AF/photometering unit IO having the above configuration, each of the TTL strobe light control system, AF system, and AE system will be explained below.

First, a TTL strobe light control system (abbreviated as light control system in the following embodiments) will be described. The light control system captures reflected light from the film surface during flash photography into the sensor section 14a of the light control sensor 14 through the field lens 11, and stops the flash 16 from emitting light depending on the amount of light received. That is, main mirror 5. When the sub-mirror 6 is raised, the front curtain of the shutter 15 is moved, and the strobe 16 emits light with the film exposed, five subject images are formed on the film and their reflected light is generated. A part of the reflected light is reflected by the field mask 20 of AF/photometry 2) 10 shown in FIG.
．． It passes through the infrared cut filter 21 and the field lens 11 and enters the sensor section 14a of the dimming sensor 14,
For example, when a microcomputer (described later) detects that the amount of received light has reached a photometric amount predetermined by an AE sensor that performs spot photometry (described later), a light emission stop signal is output to the strobe 16, Light emission stops.

As can be seen from the above, since the field lens 11 used in the AF system and AE system is shared with the TTL light control system, the film sensitivity distribution is good while realizing a compact and low-cost camera. can be made into something.

Next, we will discuss the AF system. 4 and 5 are optical path development diagrams of the AF system. The secondary imaging lens 12 has a pair of lens parts 12a and 1 disposed perpendicularly as shown in FIG.
2b, 12c, and 12d, and the fourth one represents the cross section including the optical axis of the lens parts 12a and 12b.
FIG. 5 shows a cross section including the optical axis of the lens portions 12c and 12d. In order to simplify the diagram, only the rays passing through the aperture centers of the apertures of the diaphragm 22 and having an object height of O on the primary imaging plane are depicted, and the position of the arrow G in the diagram is the primary imaging plane. The surface and arrow H are the sensor surfaces of the AF/AF sensor 13. Lens portion 12a of the secondary imaging lens 12~
12d has openings 22a to 22 of the diaphragm 22 as described above.
d correspond to each other, so that the sensor part 13a
Four secondary images are formed above, the boundaries of these secondary images being separated by the aperture image of the field mask 20. A pair of openings 22a and 22b having the same shape as the diaphragm 22
The distance between them is narrower than the distance between the openings 22c and 22d, and these openings are projected by the field lens 11 onto the knee of the photographing lens 3. This situation is shown in Figure 6. In Figure 0, 30 is the exit pupil of the photographic lens 3.

31a to 31d are openings 22a to 2 of the diaphragm 22, respectively.
This is the area on the pupil plane corresponding to 2d.

In the case of a general camera lens, the M and N areas may be selected to be approximately F4 and F8, respectively.

FIG. 7 shows a secondary image on the sensor section 13a of the AF@AE sensor 13. On the sensor 13a is a line sensor S for AF that performs vertical distance measurement and horizontal distance measurement.
Two AE sensors SAE and SAF are arranged adjacent to the line sensors SAA and SAB (with the distance measurement area sandwiched therebetween), and the secondary images 32a to 32d are arranged above the line sensors AA, SAB, SAC, and SAD. is projected by the secondary imaging lens 12. The secondary images 32a and 32b are subject images formed by the light beams that have passed through the areas 31a and 31b above the knee of the photographic lens 3, and the secondary images 32c and 32d are the images of the subject formed by the area 31.
This is a subject image created by the light flux that has passed through e and 31d. Note that the broken line portions 32e and 32f are image areas that are omitted by the submirror 6. Further, 33a to 33d arranged on the sensor section 13a are the line sensors 5AA to 3AB.
In this sensor drive circuit, a light-shielding aluminum layer is formed on this part so that light incident on this part does not affect the sensor output.

FIG. 8 is an explanatory diagram of defocus amount calculation.

The track output of line sensors 5AA-3AD is shown in image A~
It is expressed as a D image. As explained in Figure 6, A, B
The image is formed by the light flux passing through the areas 31a and 31b above the knees, while the C and D images are formed by the more outer areas 31c and 31
Since images C and D are formed by the light flux that has passed through point d, the amount of image shift due to defocusing of the photographing lens 3 is larger in images C and D than in images A and B, that is, in FIG.

This phase difference X, where x2 is larger than the phase difference xl,
The X2 information is transmitted to a microcomputer (described later) via the sensor drive circuits 33a to 33d, where a defocus calculation is performed to control the focus of the photographing lens 3. S.A.A., S.A.A.
When performing distance measurement using both B, SAC, and SAD, the calculation results from C and D images have a larger amount of image shift, so using these results will result in higher focus detection accuracy. Become.

Figure 9 is a diagram showing the distance measurement area within the viewfinder field of the camera. In Figure 9, 34 is the camera's viewfinder field of view, 35 is a diagram assuming the distance measurement area within the finder field of view 34, and the horizontal The distance measurement area in the direction corresponds to the back projection image of the line sensors SAA and SAB, and the distance measurement area in the vertical direction corresponds to the back projection image of the line sensors SAC and SAD.

FIG. 1O shows the state on the sensor 13a of the AF-AE sensor 13 when a manufacturing error occurs in the secondary imaging lens 12. In other words, as shown in FIG. 11(a), the ideal positional relationship of each lens part in the secondary imaging lens 12 differs from the error (each opening 22a to 22d of the diaphragm 22) as shown in FIG. 11(b). It is assumed that the following occurs. In this way, the lens parts 12a, 12b and 12
c.

When the perpendicularity of 12d is not obtained, the secondary images 32a, 32b and 32c, 32dc7) also have poor perpendicularity, as shown in FIG. Therefore, when line sensors SAA and SAB are aligned with respect to secondary images 32a and 32b, line sensors SAC and SAB are aligned with respect to secondary images 32c and 32d.
, SAD alignment becomes impossible. As a result, different parts of the object are projected onto the line sensors SAC and 5ADh, and when the object image with the brightness pattern with diagonal lines is incident on the distance measurement area as shown in FIG. This causes a focusing error, which is inconvenient if left as is. Therefore, in such a case, the aperture 22 is rotated in the direction of arrow B in FIG. 3, and the line sensor SAC is activated.

The secondary images 32c and 32d are aligned with respect to the SAD.

Figure 13 is a diagram to help with the previous explanation (positioning).
The internuclear space is shown in FIG. 5, when the secondary imaging lens 12 is viewed from the direction of arrow 1. In FIG.
d, and in this way, the lens portions 12c, 12
The imaging plane d is located behind the sensor surface H of the AF-AE river sensor 13, and a defocused image is projected onto the sensor surface H. On the other hand, the imaging planes of the lens parts 12a and 12b coincide with the sensor surface H, and the focused image is the line sensor S.
Projected to AA and SAB. In other words, in order to make corrections due to manufacturing errors of the secondary imaging lens 12, the imaging planes of the lens parts 12a and 12b are made to coincide with the sensor surface H, and the imaging planes of the lens parts 12e and 12d are arranged at the rear ( In other words, a defocused image is projected onto the sensor surface H. In addition, between the nuclei, K is the axis determined by the lens portion 12a and the lens portion 12b, L is the axis of the lens portion 12e, and U is the position t of the aperture 22.
to the sensor surface H, and v is the distance from the sensor surface H to the secondary imaging surface J.

Here, when the axis of the lens portion 12c is eccentric by δ,
Image position on the secondary imaging plane J If this deviation occurs by ε, then the relationship ε = δ (1 + β) (1) holds, where the secondary imaging magnification is β. The deviation of the image position at is α (=ε・U/(U+V)). This deviation α is due to the defocusing of the image, so the aperture 2 of the diaphragm 22
It can be changed by moving the positions of 2c and 22d. Therefore, if the image with a positional shift of In order to do so, the aperture 22c of the diaphragm 22 only needs to be moved by C, and this amount of movement C can be determined by the following formula.In other words,
The amount of movement C is defined as the distances U, V, eccentricity δ, and secondary imaging magnification β.
Expressed as e / v = c / u c = u・ε/V (2) Above (1
), from the formula (2), c=uδ(1+β)/v (3) The diaphragm 22 (aperture 22c
, 22d).

This is possible by rotating the eccentric pin 26 shown in FIG. 2.3. At this time, the other secondary images 32a and 32b are not affected by the rotation of the aperture 22 because focused images are formed on the sensor surface. Even if the position of the sensor 13 in the optical axis direction is shifted, the secondary images 32a, 32
Since the apertures 22a and 22b of the diaphragm 22 forming the diaphragm 22 are located inside (relative to the apertures 22c and 22d), the movement of the apertures as the diaphragm 22 rotates is relatively small.
The amount of deviation in the image position due to this is also minute.

Next, we will discuss the AE system. Sensor SAE for AE,
As explained in FIG. 7, SAF is line sensor SA.
A, the aperture image of the field mask 20 is created by the light flux that has passed through the apertures 22a and 22b of the diaphragm 22, that is, the light flux that has passed through the areas 31a and 31b on the exit pupil shown in FIG. (The image of the subject passing through the aperture shape) is projected. Therefore, the combined photometry area of the AE sensors SAE and SAF is shaped like a spot as shown in FIG.
The rectangular area 35c corresponding to AA and SAB is excluded (35a in FIG. 14).

35b), the rectangular area 3
Since the area of 5c is quite small, the photometric sensitivity distribution can almost be considered as the aperture shape of the field mask 20. Therefore, when performing spot photometry photography, the exposure time is controlled based on the value measured by this photometry area. A microcomputer, which will be described later, controls the shutter 15 and an aperture (not shown).

By the way, in this embodiment, the light control system and the AF system.

Although the AE systems share the optical path, it is necessary to limit the wavelength range of light incident on each sensor for each system. In other words, it is desirable that the spectral sensitivity characteristics of the light control system and AE system match the spectral sensitivity characteristics of the film, while for the AF system, for example, near-infrared auxiliary light is used for low-brightness subjects, so Near-infrared light must be sensitive to outside light, and even if near-infrared auxiliary light is not used, we want to capture as much light as possible (increase distance measurement accuracy). Generally, sensors are sensitive to light with a wavelength of 11,000 nm or more, so it is necessary to cut out infrared light with an optical filter.

Figure 1n15 is a diagram showing the infrared cut filter 21 that made it possible to achieve the above requirements, and shows the infrared cut filter 21 shown between the nuclei.
36a and 36b are effective parts in the AE system, and 37 is an effective part in the dimming system. This infrared cut filter 21 consists of two regions 21a and 21b with different spectral transmittance characteristics, the region 21a has the characteristics as shown in FIG. 16, and the region 21b has the characteristics as shown in FIG. 17. . That is, the infrared cut wavelength of the region 21a is 700 nm, and the infrared cut wavelength of the region 21b is 700 nm.
The 15th infrared cut wavelength is 740 nm.
As shown in the figure, the effective parts of the light control system and the AE system are located across two areas, and in both areas 21a
Since the ratio occupied by the region 21b is small, it is possible to perform photometry with characteristics close to the spectral sensitivity characteristics (400 to 700 nm) of the film. On the other hand, as can be seen from the shape of the area 21a, the effective part of the AF system is
It is designed to be completely included in the line sensor surface, and is designed to ensure that there is no unevenness in illumination on the line sensor surface.

FIG. 18 is a block diagram schematically showing the main parts of the single-lens reflex camera constructed as described above.

Reference numeral 101 denotes a control circuit that controls various operations of the camera, and includes, for example, a CPU (central processing unit), RAM, ROM,
It is a one-chip microcomputer in which an EEFROM, an input/output board, etc. are arranged, and the ROM and EEF
1fAF in ROM.

A series of control software and parameters including photometry control are stored. 102 is a data bus, 103 i
tThe control gIIOIJ: Shutter control that accepts data input via the data bus 102 while the control signal 104 is input, and controls the running of the front curtain and rear curtain of the shutter 15 based on the data. A circuit 105 receives data input via the data bus 102 while a control signal 106 is input, and a diaphragm control circuit that controls an aperture mechanism (not shown) based on the data; 107 a control signal 1;
08 is a lens control circuit that receives data input via the data bus 102 and controls the position of the photographing lens 3 in the optical axis 4 direction based on the data. 109 is a TTL strobe light control circuit consisting of the light control sensor 14, etc., and 110 is the AE sensor SAE.
, SAF, etc., and the photometric signal photoelectrically converted by these is sent to the control circuit 101, which controls the above-mentioned shutter control circuit 103 and aperture control circuit. 105 and as data for controlling the strobe 16.

Further, 33 indicates the two sets of line sensors SAA consisting of COD according to each signal inputted from the control circuit 101.
, SAB, SAC, and SAD, and is the sensor drive circuit explained in FIG.

Next, a series of photographing operations will be briefly explained.

When the first stroke of the release button (not shown) is performed, the photographing lens 3. Main mirror 5. Sub-mirror 6° field lens 11. The light flux passing through the secondary imaging lens 12 etc. is AE
A photometric signal that is incident on the sensors SAE and SAF and photoelectrically converted from the photometric circuit 110, that is, subject brightness information, is sent to the control circuit 101.

Also, almost at the same time, control diagram 1tot shows A image, B image, C
In order to obtain the phase difference between the image and the D image, The line sensor SA on which the subject image is incident is driven.

Control circuit 101 at this time. To briefly explain each operation of the sensor drive circuit 33 and line sensor SA, the control circuit 10
11 When the accumulation start signal STR is generated, the sensor drive circuit 33 outputs a clear signal CL to the line sensor SA,
Clear the charge in each photoelectric conversion unit of line sensors SAA, SAB, SAC, and SAD.

Then, the line sensor SA starts photoelectric conversion and charge accumulation of the image projected by the secondary imaging lens 12 disposed at the front stage. When a predetermined period of time has elapsed after the start of the operation, the sensor drive circuit 33 transfers the transfer signal SH.
is output to the line sensor SA, and the charges accumulated in the photoelectric conversion section are transferred to the CCD section. At the same time, the sensor drive circuit 33 outputs an accumulation end signal END to the control circuit 101,
The sensor drive circuit 33 waits for the CCDCD drive clock C to be input from the control circuit 101. When the CCDCD drive clock C is input, the sensor drive circuit 33 generates CCD drive signals φ1 and φ2 and outputs the signals to the line sensor SA. When the CCD drive signals φ1 and φ2 are input, the line sensor SA sends the analog image signal SSA to the control circuit 101 according to these signals.
Output to.

As a result, the control circuit 101 uses the CCDCD drive clock C.
The analog image signal is A/D converted at intervals, and the image signal A (
i) to D (i) and calculate the phase difference X using a known calculation method.
I+X2, that is, a focus detection signal, is calculated and the data is output to the lens control circuit 107. Lens control circuit 1
In response to this, 07 moves the photographing lens 3 using a known drive method.
control.

Next, when the second stroke of the release button is performed, the main mirror 5. The sub-mirror 6 rises, the front curtain of the shutter 15 moves, and the strobe 16 starts emitting light. As a result, the strobe light is reflected by the subject surface, and this reflected light passes through the photographing lens 3 and enters the film, and the imprinting of the subject image onto the film is started. Also, a part of the luminous flux incident on the film is reflected on the film surface and enters the light control sensor 14 via the field lens 11,
A photometric signal received here and photoelectrically converted is output from the TTL strobe light control circuit 109 to the control circuit 101 . Then, the control circuit 101 compares the photometry information from the photometry circuit 110 with the photometry information from the TTL strobe light control circuit 109, and when it detects that they match, that is, that proper exposure has been reached, it controls the shutter. The rear curtain of the shutter 15 is caused to run via the circuit 103. Thereafter, the film is wound and the series of photographing operations is completed.

According to this embodiment, the A
By configuring the camera to guide the reflected light from the film to the dimming JTI sensor 14 via the field lens 11 of the F river, the following effects can be obtained.

1) Both the AF system and the light control system can be easily arranged on the center of the photographing optical axis (optical axis 4) of the camera.

2) In order to improve the photometric sensitivity distribution, only the part facing the field mask 20 (in this case, the part facing the field mask 20) is required, so the rigidity of the camera is improved.

4) Since only one lens is exposed inside the mirror box, internal reflection can be minimized.

5) The AF system and light control system can be integrated into a unit.

(Modified Example) In this embodiment, a case has been described in which the TTL strobe light adjustment sensor 14 is arranged, but the TTL sensor 14 measures the reflected light on the shutter 15 surface and controls the shutter 15 and aperture (not shown).
It is also applicable to cameras using the TL photometry method.

(Effects of the Invention) As explained above, according to the present invention, the TTL photometry sensor is arranged at a position where it can take in the reflected light from the object image formation plane via the field lens, and the focus detection optical By sharing the field lens with both the TTL photometry optical system and the TTL photometry optical system, the center of these optical paths is positioned on the optical axis center, thereby achieving cost reduction and compactness, while improving focus detection optics. It becomes possible to maximize the performance of each of the optical system and the TTL photometric optical system.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG.
FIG. 3 is a cross-sectional view of the illustrated AF-photometry unit. Figure 3 is a developed perspective view explaining the structure of the same <AF@photometering unit, Figure 4 is a developed view of one optical path of the AF system in the same <AF/photometering unit, and Figure 5 is a developed view of the other optical path. , FIG. 6 is an explanatory diagram of pupil region division, and FIG. 7 is an illustration of pupil region division.
Figure 8 is a diagram explaining the relationship between the illustrated AF/AE sensor and the secondary image, Figure 8 is a diagram explaining the image signal used when calculating the amount of defocus, and Figure 9 is the distance measurement area within the viewfinder field of view. Figure 1O is a diagram explaining the relationship between the AF@AE sensor and the secondary image when there is a manufacturing error in the secondary imaging lens shown in Figure 1, and Figure 11(a) is a diagram showing the relationship between the secondary image forming lens shown in Figure 1 A plan view showing an ideal secondary imaging lens with no errors, FIG. 11 (
b) is a plan view showing a secondary imaging lens with manufacturing errors; FIG. 12 is a diagram illustrating an unsuitable subject image when using the secondary imaging lens of FIG. 11(b); FIG. 13 The figure is a diagram illustrating the amount of position adjustment between the secondary image and the line sensor when the secondary imaging lens of FIG. 11(b) is used, and the figure 14
The figure shows the photometry area within the viewfinder field of view, Figure 15 is a top view showing each area of the infrared cut filter shown in Figure 2, and Figures 16 and 17 are each area of the infrared cut filter. FIG. 18 is a block diagram schematically showing an embodiment of the present invention. 3...Camera, 5...Main mirror, 6.
...Sub mirror, 10...A F -J
l Optical unit, 11...Field lens, 1
2... Secondary imaging lens, 13... AF
@AE sensor, 14...TTL strobe light control sensor, 33...sensor drive circuit, lOl.
...Control circuit, 109...TTL strobe light control circuit, 110...Photometering circuit, 5AA-3
AD...Line sensor, SAE, SAF...
...AE sensor. Patent Applicant Canon Co., Ltd. Representative Minoru Nakamura Figure 2 Figure 10 Figure 11 Wavelength (nm) Reverse length (nm) Teitokanneichi-JF (Spontaneous) November 4, 1986

Claims (1)

[Claims] (1) A focus detection optical system that includes a field lens, a secondary imaging lens, and a focus detection sensor, and a TTL photometry optical system that includes a TTL photometry sensor that measures light reflected from a subject image formation surface. A single-lens reflex camera equipped with a mirror box at the bottom of the mirror box, wherein the TTL photometry sensor is arranged at a position where reflected light from the object image formation plane can be taken in through the field lens. camera.