JPH02275420A - Camera - Google Patents

Abstract

PURPOSE:To improve the focusing accuracy and exposure adjustment accuracy and to make a camera main body compact by executing the photometry for the focus detection and automatic exposure adjustment of automatic focusing with a photographic lens system and composing finder systems of external light systems. CONSTITUTION:The finder systems 27 - 29 are arranged so that optical axes different from the optical axes of photographic lens systems 25 and 26 are provided and the photometric means 30 and 31 of the focus detecting means 22 and automatic exposure adjusting means of the automatic focusing means are arranged in the photographic lens systems. For the automatic focusing and automatic exposure, a range finding means 22 and photometric means 30 and 31 operate with the light from an object passing through the photographic lens system. Namely, so-called TTL system is obtained. The finder systems 27 - 29, on the other hand, are composed of the external light system without passing through the photographic lens system, so the capacity rate of the finder systems in the camera is small. Namely, none of a pentagonal prism, quick return mirror for a finder, etc., is required. Consequently, compact constitution is maintained and the camera capable of accurate focusing and accurate photometry is realized.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a camera equipped with an autofocus function and an automatic exposure adjustment function, and more particularly to a camera capable of TTL type autofocus and automatic exposure.

[Conventional technology]

As is well known, currently popular cameras can be roughly classified into single-lens reflex cameras and non-lens reflex cameras, based on the structure of their viewfinders, and the latter includes cameras that are generally called compact cameras. - Eye reflex cameras have advantages such as the subject image observed through the viewfinder matching the subject being photographed and the focus adjustment status being directly observable through the viewfinder. It has the advantage of being freely interchangeable and usable. In addition, recently, single-lens reflex cameras have become popular, with a device installed inside the camera that detects the light that has passed through the photographic lens (hereinafter referred to as the TTL method) and performs focus detection and photometry. Adjustments and exposure can be made. In other words, the TTL focus detection device detects the amount of defocus on the planned focal plane and can perform focusing operations until the focus is actually achieved, so it eliminates fluctuation errors caused by mechanical errors of the camera and temperature changes. This has the advantage that, in principle, it does not affect focus detection. Furthermore, with a TTL type photometer, there is no risk of receiving light from outside the photographing range, and changes in the effective aperture due to lens exchange or zooming, that is, changes in the amount of light passing through the lens, can be accurately detected. Furthermore, since the light that actually passes through the lens is detected, it is possible to perform photometry while taking into account the attenuation of the light when it passes through the lens and the error in the effective aperture. In this way, current single-lens reflex cameras are useful in making accurate focus adjustment and exposure based on the photographer's intentions.
On the other hand, it requires components such as a pentaprism and a mirror box, which inevitably results in an increase in size and weight. On the other hand, in the currently popular non-eye reflex cameras, the finder optical system, distance measurement device, and photometry device are installed separately from the photographic optical system (hereinafter referred to as non-TTL system), and the distance measurement device is equipped with a zone. Since it is a focus-based camera, it has the advantage of being compact and easy to use, although it is inferior to single-lens reflex cameras in terms of making use of the photographer's intentions and performing accurate focus adjustment and exposure. However, recently, more and more non-eye reflex cameras are equipped with zoom lenses. As a future trend in non-eye reflex cameras, it is expected that photographic lenses will have higher zoom magnification and longer focal lengths. As mentioned above, the distance measuring device of a non-eye reflex camera is a non-TTL camera.
Since it is a zone focusing method, there is a problem that it becomes difficult to ensure accuracy when the photographic lens becomes a high-power zoom or a long focal length, and it becomes unable to cope with the problem. That is, in the case of the non-TTL method, the actual focus adjustment state is not detected, so if there is an error in the mechanism for stopping the lens, it becomes an adjustment error. Such mechanical errors always exist, and focusing errors cannot be eliminated. Further, in the case of a zone focus method, the focus is not accurately adjusted near the edges of the focus zone. When a lens has a long focal point, the depth of field becomes extremely shallow, and this error appears as a large out-of-focus on the screen. In addition, in a camera equipped with a varifocal lens, that is, a variable magnification lens in which the amount of extension of the focusing lens changes depending on the focal length, the variable magnification area is divided into several areas, and each divided area is The amount of extension at a representative focal length of is determined as the representative amount of extension for the entire area and is adjusted. Therefore, at an intermediate focal length between the representative focal length of a certain region and the representative focal length of an adjacent region, the amount of extension is not accurate and defocus occurs. In addition, since the photometry device of a non-eye reflex camera is a non-TTL type, it cannot be used from a photometry perspective if the photographing lens becomes a high-power zoom lens. That is, when zooming is performed, the photographing range changes, so naturally the photometric value should change accordingly, but if the zooming range is narrow, this change is considered to be negligibly small. However, when high-magnification zooming is performed, a completely different range is photographed, so the photometric value may change significantly. If a non-TTL method is used, it will not be possible to accurately respond to such changes in photometric values.

[Problems to be solved by the invention]

As mentioned above, in conventional cameras, both eye reflex cameras and non-eye reflex cameras have advantages and disadvantages, and there is no camera that is suitable for all of them. The present invention provides a camera that combines the advantages of both the conventional single-lens reflex camera and non-lens reflex camera, that is, a camera that is capable of accurate focus adjustment and accurate photometry without losing compactness as much as possible. The purpose is to

[Means for Solving the Problems and Effects] (Means) In order to achieve the above object, the present invention is configured as follows. That is, the camera of the present invention is a camera having a photographic lens system, a finder system, an autofocus means, and an automatic exposure adjustment means, the finder system having an optical axis different from the optical axis of the photographic lens system. placed,
The focus detection means of the autofocus means and the photometry means of the automatic exposure adjustment means are arranged in the photographic lens system. (Function) According to the above configuration, autofocus and autoexposure are
This is a so-called TTL method in which the distance measuring and photometering means each operate using light from the subject that has passed through the photographic lens system. On the other hand, the finder system is constructed using an external light system without going through a photographic lens system, so it occupies a small volume ratio in a finder-based camera. In other words, there is no need for a pentaprism or a quick return mirror for the finder.

【Example】

EMBODIMENT OF THE INVENTION Below, based on FIGS. 1-14, the Example based on the camera of this invention is demonstrated concretely. FIG. 1 is a camera according to a first embodiment of the present invention, and shows a part of the light-shielding shutter that feeds directly to the film when looking inside the camera from the front. The light-shielding shutter 18 prevents the film surface from being exposed during focus detection, which will be described later. 18a is a holding plate of the light-shielding shutter 18, and I9 is a light-shielding shutter blade composed of four blades. 20 is an arm for moving the light-shielding shutter blade 19 up and down, and the light-shielding shutter 18 turns on and off a magnet (not shown).
The link mechanism is turned off and energized to move the light-shielding shutter blades 19 of the opening up and down. 2
■It is a mirror that is rotatably attached integrally to the light-shielding shutter blade 19, and the light from the lens is transferred to the distance measuring means 22.
It serves as a guide to That is, the mirror 21 is installed at the second blade from the bottom in the approximate center of the screen in order to bend the optical axis of the lens and guide the light from the lens to the distance measuring means 22. Although it is in a state of protruding from the blade 19, when the opening is opened, by setting the rising speed of the lowermost blade among the four blades to be faster than the other blades, the lowermost light-shielding shutter blade It is pushed up at the upper end and rotated, and is housed above the holding plate 18a together with the second light-shielding blade 19 from the bottom. Furthermore, when the light-shielding shutter blade I9 is lowered to close the opening again after exposure, the mirror 21 is brought into a protruding state again by the bias of a spring (not shown). 23 is a photometric window located in front of the photometric lens 30, and 24 is a finder window. FIG. 2 is a diagram showing the internal configuration and layout of the camera when viewed from above. 25 and 26 indicate a positive front group and a negative rear group of a two-group zoom lens, respectively, which perform zooming by moving back and forth at different speeds in the optical axis direction. Note that focusing is performed by the front group lens 25. Reference numeral 27 denotes an objective lens of a real image finder, which is configured to move a negative lens and a positive lens back and forth in the optical axis direction at different speeds, change the magnification with the positive lens, and adjust the diopter with the negative lens to perform zooming. ing. still. This configuration will be explained in detail later. 28
is a Porro prism for converting an inverted real image into an erected normal image. 29 indicates an eyepiece. 32 is a shutter/aperture mechanism explained in FIG. Figure 3A is a side view of the camera, and when measuring distance, the light from the photographing lens 25, 26 with the optical axis: Q is reflected by mirror 2! The figure shows how the light is guided to the focus detection means 22. 30 is a photometric lens for photometry, and 31 is a photometric element. FIG. 3B is an enlarged view of a portion of the mirror 21, showing the state of reflection at a portion of the mirror. Note that this focus detection means 22
This will be explained in detail later (see Figure 7). In the figure, the left side corresponds to the camera's sky, and the right side corresponds to the camera's ground. Also, in the figure, the top corresponds to the front of the camera. By the way, the optical path for photometry will be explained with reference to FIG. 3B. The central part "b" of mirror 21 is a mirror surface, and the angle of part "b" is set to have an angle of approximately 45 degrees with respect to the axial light beam of the lens, and the light reflected at part "b" is measured. While guiding the light to the distance element 22, the portion of the mirror 21 other than the "b" portion and the "a" portion is used as a diffusing surface, and the light is guided to the photometric element 31 at a different angle from the "b" portion.In this embodiment, Although we have shown an example in which the light flux that has passed through the photographic lens 25 and 26 is divided into the ranging system and the photometric system by changing the shape and optical characteristics of the mirror 2, there are other ways to divide the light flux that has passed through the photographic lens 25 and 26 by changing the shape and optical characteristics of the mirror 2. It is also possible to divide the luminous flux into the distance measurement system and photometry system by time division, wavefront division using a slit mirror, diffraction grating, etc., signal division that shares the output from the same element, etc. Figure 4 shows the shutter and aperture. This is an enlarged view of the mechanism 32, where I is the first motor, and the rotation of the motor I is directly transmitted to the arm 8. 8a is a shaft provided at the other end of the arm 8, and the shutter blade 3 Long hole 3 formed in .4
b, 4 It fits in b. The blades 3 and 4 are each rotatably supported by a sleeve A on the base plate, and have a substantially symmetrical shape with respect to a line connecting the axis A and the center of an exposure aperture 5 formed on the base plate. Each blade 3.4
The long holes 3b and 4b formed in the holes 3b and 4b extend in different directions and are fitted with a shaft 8a at their intersection, so that when the arm 8 rotates, it is driven by the shaft 8a and the blades 3.4 operate in opposite directions. At this time, the V'-shaped notches 3a and 4a formed in the blades 3.4 intersect on the exposure aperture 5 to open and close the exposure aperture 5, thereby determining the aperture diameter (the figure shows a closed state). ). Note that numeral 5 indicates the aperture of the photographing lens. By the way, the configuration and operation of the above-mentioned photographic lenses 25 and 26 for zooming will be explained with reference to FIG.
This will be explained below. Calculating the driving amount of the photographing lens from the defocus amount based on the focus detection result of the focus detection device 22, which is a focusing focus detection means of the photographing lens,
The focus motor MF is rotated until it reaches that amount. That is, when the front group holding cylinder 53 is rotated via the gear 52, the front group holding cylinder 53 is moved back and forth on the optical axis by the helicoid 54, and the front group lens 25 reaches the in-focus position. Focusing of the photographic lens is performed in this manner. Note that the focus motor MF is fixed to the front group moving cylinder 58. When the gear 55.degree. 56 rotates by energizing the zoom motor MZ, the zoom cam barrel 57 also rotates. The cam '7fIt57a1 of the cam cylinder 57, the rectilinear groove 51a of the fixed cylinder 51, and the pin 58a of the front group movable cylinder 58 fitted therein cause the front group movable cylinder 58 to move in a predetermined straight line according to the lead of the cam groove 57a. Note that the front group holding cylinder 53 also moves in the same manner. At this time, the rear group cam cylinder 59 also moves in the optical axis direction together with the front group moving cylinder 58, but also rotates. That is, when the front group movable barrel 58 moves in the optical axis direction, the rear group cam barrel 59 moves through the cam groove 51b of the fixed barrel 51, the cam groove 58b1 of the front group movable barrel 58, and the pin of the rear group cam barrel 59 that fits therein. 59b. The rear group holding cylinder 60 moves by the amount of movement of the front group moving cylinder 58 and further by the amount of movement corresponding to the shape of the cam '7R59c of the rear group cam cylinder 59. That is, when the rear group cam cylinder 59 rotates, the cam groove 59c of the rear group cam cylinder 59, the pin 60c of the rear group holding cylinder 60 that fits therein, the key 51d fixed to the fixed cylinder 51, and the key groove that fits therewith. 60d, the rear group holding cylinder 60 moves straight on the optical axis. As a result, the front group lens 25 and the rear group lens 26 move in a predetermined manner on the optical axis to perform zooming. The diaphragm/shutter mechanism 32 is located between the front and rear lens groups 25 and 26 of the photographing lens, and is held in the front group moving barrel 58, and moves together with the front lens group 25 during zooming. When the gear 55, 61 rotates by energizing the variable magnification zoom motor MZ of the finder lens, the finder cam cylinder 62 also rotates. Reference numeral 27 indicates a finder objective lens, and a positive lens 27B, which is one component lens of the objective lens 27, is the cam 162b of the finder cam tube 62. The straight groove 63b1 of the fixed cylinder 63 and the pin 6 that fits into them
When the finder cam cylinder 62 is rotated by the lens 4b, the positive lens holding cylinder 64 is moved along its optical axis, and the magnification is changed. Similarly, the negative lens 27A, which is the other constituent lens of the objective lens 27, has a cam groove 62a1 and a straight groove 6.
3a and a pin 65a, the negative lens holding cylinder 65 is moved along the optical axis, and the diopter is adjusted in accordance with the power change. Note that the amount of movement of the finder lens is different from that of the photographing lens. Therefore, the finder lens is driven by the zoom motor MZ together with the photographic lens, and the reduction ratio of the finder gear group is made different from that of the photographic lens gear group to accommodate the difference in the amount of movement. Next, the finder system will be explained based on FIG. 6. FIG. 6 shows an optical system 28 corresponding to a Porro prism.
shows an example in which the mirrors are configured using four mirrors 28a to 28d. 33 is a condenser lens. 3
Reference numeral 4 denotes a field frame, which is located at the focal point of an objective lens 27 composed of a zoom lens. Reference numeral 29 indicates an eyepiece. By the way, the focus detection device (distance measurement device) 22 mentioned above is a device using a so-called phase difference detection method, and its optical system includes a seventh
It is configured as shown in the figure. That is, in FIG. 7, mirror 2! is located in front of the expected imaging plane (F). The mirror 21 is provided with a rectangular opening 21a that defines a field of view for detecting focus. A condenser lens L0 is provided behind the expected imaging plane (F) of the photographic lens TL (25, 26), which is equivalent to the film surface, and a pair of condenser lenses symmetrically to the optical axis (σ) of the photographic lens TL are provided behind it. re-imaging lens L
, , Lt are provided, and a pair of re-imaging lenses L, , L re-form the image formed by the photographic lens TL on its expected imaging plane (F). A mirror MI is arranged with an inclination of 45 degrees between the condenser lens L0 and the re-imaging lenses L, Lt. It is bent to be parallel to the optical axis (C) (see Figure 3A). (A), (B), and (C) respectively show a front focus image, a focused image, and a back focus image formed by the photographing lens TL, and the re-imaging lenses L and Lt are used to focus these front focus images. Images corresponding to the six images: image (A), focused image (B), and back-focused image (C) = (Aυ, (A, ), (B , ), (B t
), (C, ), and (Ct) are formed as the eleventh and second images, respectively. Here, when (A), (B), and (C) are formed as images indicated by upward arrows in the figure, the corresponding first and second images are both images indicated by downward arrows. The distance between the first and second images changes depending on the focus adjustment state of the photographic lens TL. Therefore, with respect to the re-imaging lenses L, , Lx, light-receiving element arrays are arranged at positions conjugate with the intended image-forming plane of the re-imaging lenses L, , Lx, or in the vicinity thereof, and the positions (intervals) of the first and second images are ), it is possible to detect the focus adjustment state of the photographic lens TL. Note that M, , M are re-imaging lenses L3. Lt
This is an aperture mask for image segmentation provided in front of the. FIG. 8 is a circuit diagram of a camera system to which the present invention is applied. DT (22) is a light receiving part for focus detection, and CCD
It has an image sensor array, controls the operation of the CCD image sensor array, and transmits signals read from the CCD image sensor array to A.
/D conversion and the microcomputer CO through the data bus DBAF.
It has the function of transmitting information to M. MF is a lens drive motor for autofocus, MDA is a motor control circuit, and is the output port P of the microcomputer COM. , Pl performs various controls such as forward rotation, reverse rotation, braking, and OFF. DPA is a display section for displaying the moving direction of the lens, focusing, and a warning that focus cannot be detected based on signals from the output ports Pz and P3 of the microcomputer COM. ENL is an encoder that outputs pulses for monitoring the lens drive amount (motor rotation amount) by the lens drive motor MF, and does not send pulses from the autofocus encoder ENL to the event counter input terminal CNTR. Sl is a switch for starting the camera, detecting focus, and starting photometry, which is closed at the first step of pressing the release button, and the closing signal of this switch Sl is sent from the microcomputer COM.
is input to the input port P. S is a release switch that is closed in the second step of pressing the release button,
The closing signal of this switch S is manually input to the input port P6. S is a reset switch that is closed upon completion of the exposure control operation and opened upon completion of winding/charging, and the closing signal of this switch S is input to the input port P7. GV is a power supply circuit, which operates when power control signal PWC output from output port P8 is at "Low" level. This power supply circuit GV outputs a high voltage HV and a low voltage LV based on the output of the power supply battery BA. The high voltage HV serves as a power source for the light receiving section DT. The low voltage LV is the aforementioned display section DPA. Encoder ENL and film sensitivity reading circuit I described below
SD, lens circuit LEC, photometry and A/D conversion circuit ME
It serves as the power source for the C1 load drive circuit DDR, and the motor control circuits MDA, MDF, display circuit DSP, and microcomputer COM.
It receives power directly from the power supply battery BA via the power line EV. The film sensitivity reading circuit ISD reads the ISO data indicating the film sensitivity on the film container and sends it to the output port P.
, the film sensitivity reading circuit selection signal C9IS from “L”
ow" level, the film sensitivity data is serially sent to the serial input terminal SIN in synchronization with the serial clock SCK from the microcomputer COM. LEC is a lens circuit. The lens circuit selection signal CSL from the output port P1o is "ow" level. When the level becomes “Low”, the serial
The ROM in the lens circuit LEC is synchronized with the clock SCK.
Various data stored in the serial input terminal SI
Send serially to N. The DSP is a display circuit and performs display based on display data sent from the microcomputer COM. MEC is a photometry and A/D conversion circuit, and the low voltage L from the power supply circuit GV
When the power supply to V is started, the photometry operation starts and the A/D conversion enable signal ADEN from the output boat pH becomes “Lo”.
w" level, A/D conversion is repeated at a constant cycle. Then, when the photometry and A/D conversion circuit selection signal CSME from the output port P becomes "Low" level, the A/D conversion
The converted and latched data is sent to the microcomputer COM in synchronization with the serial clock SCK. D
DR is a load driving circuit that decodes data sent from the microcomputer COM through the data bus DBDR and drives a load according to the decoded result. The loads include a release magnet RLM, a magnet APM for controlling the shutter/aperture mechanism 32, a magnet SHM for controlling the light shielding shutter 18, a charging motor MOCI for the film advance and exposure control mechanism, and its driver MDF.
, zoom lens drive motor MZ and its driver M
There is a DF. X is an oscillator. FIG. 9 is a flow chart showing the operation of the camera of this embodiment. In step #I, when the release button is pressed down one step, the switch S of the first step of the release button
, turns on, so this is detected and the camera starts up. Next, in step #2, the light-shielding shutter 18 is closed. This operation is performed because the initial state of the camera is unknown, and this ensures that the film remains unexposed. In step #3, the mirror 21 is lowered to a state where it projects from the shutter blade 19. This allows the light from the lens to be guided to the focus detection device 22. In step #4, the shutter/aperture mechanism 32 is opened to allow light from the lens to reach the focus detection device 22 and photometric element 31. In step #5, desired zooming is performed, and in step #6, lens specific information such as the focal length of the zoom lens is manually input to the microcomputer COM. Furthermore, in step #7, set the film sensitivity (ISO) to DX.
Input to microcomputer COM by code or manual setting. Next, focusing is performed in step #8 using the light that has passed through the lens. Also, in step #9, similarly,
It captures photometric information from the light that passes through the lens and calculates and determines the aperture value and shutter speed to obtain the correct exposure. Preparation for shooting is now complete. In this state, when the release button is pressed down one step further, the release switch S is turned on, so in step #10, the operating state of the switch S is determined. Release switch S,
When the on state is detected, the process proceeds to step #11. If switch S is not turned on, the process returns to step #5. When the switch S is turned on, first, the shutter diaphragm mechanism 32 is closed in step #ll. Accordingly, the mirror 21 is raised in step #12, and then the mirror 21 is raised in step #12.
At step 13, the light shielding shutter 18 is opened to make the film ready for exposure. Then, in step #14, the shutter/diaphragm mechanism 32 is used to open and close the shutter blades 3.4 so that the previously calculated aperture value and shutter speed are achieved, thereby performing proper exposure. After proper exposure is given, the light-shielding shutter 18 is closed in step #15. In steps #16 and #17, steps #3. The same operation as #4 is performed, and a series of exposures is completed. Next, a second embodiment of the present invention will be described below. FIG. 1O is a top view of the inside of the camera of the second embodiment. Lenses designated by numerals 117, 118, and 119 constitute a triplet type photographic lens. The intermediate and rear lenses t+s, tt9 are fixed to the lens barrel, and the shutters 3 and 4 are connected to the intermediate lens +18 and the rear lens 1.
It is located between 19 and 19. The front lens 117 is held at the center of the fan-shaped gear 7 shown in FIG. 11.13, and upon focusing, moves in the optical axis direction to perform focusing, as will be described later. Figure 1I is an internal view of the camera as seen from the target.
A shutter portion having the same structure as that in FIG. 4 of the embodiment is shown. Therefore, the explanation thereof will be omitted here. Note that in the figure, reference numeral 5 indicates the open aperture of the photographing lens. Further, 109 is a finder, which is arranged at a position different from the optical axis of the photographing lens. FIG. 12 is a view of the camera from the rear, showing a state in which film is loaded. FIG. 13 is a side view of the camera. In the figure, the left side corresponds to the camera's sky, and the right side corresponds to the camera's ground. 109a is a negative lens of the finder objective lens, 109
b is a positive lens of the finder eyepiece, and both lenses constitute a reverse Galilean off-eye viewfinder. The optical axis of the finder is above and parallel to the optical axis of the photographic lens. A second motor 6 is used for focusing. The rotation of the motor 6 is controlled by the sector gear 7.
can be conveyed to. The other end 7a of the sector-shaped gear 7 and the lens outer cylinder I
I6 has a helicoid configuration, and the front lens 117 held by the sector gear 7 is focused by sliding in the optical axis direction while the sector gear 7 rotates. A third motor 100 drives a shutter 112 located just in front of the film during exposure. The shutter 112 is a light shielding member that prevents light from reaching the film during focus detection. 111 is a fan-shaped gear that drives the shutter 112 (from the state shown in FIG. 13 to the state shown in FIG. 14). Reference numerals 113, 114, and 115 are distance measuring mechanisms (devices) that measure distance using light that has passed through a lens, and are integrally formed with the shutter 112 (7th
(The configuration is similar to the one shown in the figure). Reference numeral 113 denotes a mirror that bends the light traveling in the optical axis direction upward by 90 degrees (to the left in the figure), focuses the light with a lens 114, and guides the light to the distance measuring element 115. The photographing state will be explained using FIGS. 13 and 14. An electrical circuit (not shown) opens the shutter 3.4 to an open state when the switch S1 is on. As a result, the light that has passed through the photographic lens reaches the distance measuring element +15
The distance to the object is measured by the distance measuring means. Next, the front lens +17 moves to a predetermined focus position based on the distance measurement signal. First, by operating the release switch S,
Shutter 3.4 is closed, then blackout shutter 1
12 is rotated and retracted to a position where it does not obstruct the optical path of the photographing lens (the state shown in FIG. 14). Next, the shutter 3.4 is opened and the photographing lens is exposed, and the shutter 3.4 is opened.
is closed and the light-shielding shutter 112 returns to its original position (
13), exposure is completed. In Figure 13, the symbol! 20 is a photometric element, and mirror 11
By using 3 as a semi-transmissive mirror, photometry is performed using the light that has passed through the photographic lens.

【Effect of the invention】

As is clear from the above description, in the camera of the present invention, the light for autofocus focus detection and automatic exposure adjustment is performed using the TTL method, and the finder system is configured using an external light method. Therefore, it is possible to improve focusing accuracy and exposure adjustment accuracy, and it is also possible to make the camera body more compact. In other words, even when a zoom lens is attached to a camera, good focusing accuracy can be obtained regardless of the zoom position of the zoom lens. Furthermore, deterioration in focusing accuracy due to the effects of lens errors and mechanical errors is also prevented. Moreover, since the photometric angle of view corresponds to the zoom, the accuracy of exposure adjustment is improved. For example, if we compare the camera of the present invention with a conventional non-eye reflex camera (compact camera), we will find that: 1) it has excellent focusing accuracy and exposure adjustment accuracy, and 2) it has less focus error due to lens error and mechanical error. Its advantages include small size, and ease of use with varifocal lenses. Furthermore, compared to conventional single-lens reflex cameras, it is possible to make the camera more compact while maintaining the same focusing and exposure adjustment accuracy. This is because, in the camera of the present invention, the finder system is an external light system, so the pentaprism,
This is because there is no need for a quick return mirror for the finder, and there is no need for a long lens back due to the tilting of the mirror, which is unique to an eye reflex camera. As described above, the present invention provides a suitable camera that has the excellent characteristics of conventional single-lens reflex cameras and non-lens reflex cameras.

[Brief explanation of drawings]

1 to 14 show embodiments of the camera of the present invention, FIGS. 1 to 9 show the first embodiment, FIGS. 1O to 14 show the second embodiment, and FIG. FIG. 2 is a front view showing the inside of the camera of the first embodiment as seen from the front and shows a part of the light-shielding shutter just in front of the film; FIG. Figure 3A is a side view of the camera and shows the autofocus, Figure 3B is an enlarged view of a portion of the mirror in Figure 3A, and Figure 4 is an enlarged view of the shutter/aperture mechanism. , 5th
The figure is a configuration diagram showing the optical system of the camera, FIG. 6 is a perspective view showing the optical system configuring the finder of the camera, and FIG. 7 is an explanatory diagram of the optical system configuration for explaining the distance measuring mechanism of the camera. Figure 8 is a circuit diagram of the camera system, Figure 9 is a flow chart explaining the exposure operation of the camera, and Figure 10 is a second
An internal layout and configuration diagram of the camera of the embodiment as seen from above, FIG. 11 is a diagram showing a part of the shutter of the camera as seen from the front, and FIG. 12 is a diagram showing the rear of the camera. Figure 13 is a diagram showing the internal layout and configuration of the camera when viewed from the side, and Figure 14 is a diagram showing the camera in Figure 13 during exposure operation. be. 1.6,100...Motor, 2...Hole, 3.4...
・Shutter, 7...Sector gear, 8...Arm, 1
8- Light-shielding shutter 19... Shutter blade, 20
...Arm, 21,113...Mirror 22...Distance measuring means (distance measuring device), Q, Q'...Optical axis, 25...Front group lens for photography, 26...For photography Rear group lens, TL (25,26+l+7,118.119)...
・Photographing lens, 27...Finder objective lens, 28
... Porro prism, 29... Finder eyepiece, 30... Photometric lens, 31... Photometric element, 32...
・Shutter/aperture mechanism, 109a, 109b...finder lens, Ill
... Sector gear, 114 ... Condensing lens, 116 ...
・Lens outer cylinder, COM...Microcomputer, MF...Focus motor. Patent applicant Minolta Camera Co., Ltd. Agent
Patent attorney: 1 person: Figure 3B Figure 4 Figure 3A Figure 5 Figure 9

Claims (1)

[Claims] 1. Photographic lens system (25, 26) and finder system (
27, 28, 29) and autofocus means (22,
COM, MF) and automatic exposure adjustment means (31, COM,
APM), the finder system (27, 28, 29) is the photographic lens system (25,
The focus detection means (26) included in the autofocus means is arranged so as to have an optical axis (l') different from the optical axis (Q) of the focus detection means (26).
2) is a photometry means (31) disposed in the photographic lens system (25, 26) and included in the automatic exposure adjustment means;
A camera characterized in that it is arranged in the photographing lens system (25, 26).