JPS59146028A - Camera - Google Patents

Abstract

PURPOSE:To bring the closest subject among plural subjects into focus and give priority thereto by selecting distance information on the closest subject among plural pieces of subject distance information obtained by a distance measuring means and specifying a lens position. CONSTITUTION:Distance measuring operation ends when light projecting element lever 13 finishes sliding to turn on distance measurement end signal contacts 25 and 26, and this completion is detected by a distance measurement completion detection part 109, which outputs a distance measurement completion signal. When the completion signal is inputted from the distance measurement completion detection part 198, a closest distance decision making circuit 110 operates decides on and output the smallest distance address among distance addresses No.1-No.15 stored in pulse counters M1-M9. A photodetecting element 111 for exposure starts preliminary photometry on the start of a releasing mechanism 104 and converts the quantity of light from the subject into an electric signal, which is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a camera having an automatic distance detection function that automatically detects a subject distance and automatically adjusts focus or displays the focus state based on the distance information. This is related to the improvement of.

Traditionally, automatic focus cameras have used an automatic distance detection method, but all of these cameras have a distance measurement mark near the center of the shooting screen, and the main subject is placed within the distance measurement mark. This camera was designed to focus only on the main subject, and as a result, everything except for compositions where the main subject was in the center of the frame would be out of focus, making it extremely difficult to use.

Some cameras have a built-in reflex focus mechanism that allows you to compose shots where the main subject you want to focus on is somewhere other than the center of the screen. However, with a camera equipped with such a prefocus mechanism, for example, a photographer who is not familiar with cameras can create a composition like the one shown in Figure 1 (two people with a stone monument behind them in the center, and then When photographing a place with a torii gate on the other side, I often made mistakes by aligning distance measurement mark 1 with the stone monument between two people (-7, which resulted in the person in the foreground being blurred. In normal photography, there is a main subject, such as a person, that you want to focus on first, and a secondary subject, such as an alpha view. In many cases, only the main subject is in focus, and the secondary subject is out of focus. However, in the case of a commemorative photo or other subject where the background has some weight, the photographer also has to focus on the person who is the main subject. There is a desire to photograph the background, which is the subject, in focus.Conventional autofocus cameras have not been able to satisfy this desire.

To overcome these shortcomings, we need to create a system that performs side-focusing movements toward multiple subjects one time at a time, stores multiple pieces of data, and focuses on a position that encompasses all of them. A camera with a pre-focusing mechanism has already been proposed in Japanese Patent Laid-Open No. 101128/1983.

Adjust the INK focus so that the depth of field is within the depth of field determined by the lens diameter, and if all subject information does not fit within the depth of field determined by the shooting lens aperture, focus only on the subject that falls within the depth of field. It is possible to determine the distance at which the photographing lens can be accurately focused (hereinafter referred to as the "focus distance") by taking other subject information into consideration.

However, in such an autofocus camera, the subject,
When taking pictures of a number of subjects at different distances within the field, in order to include as many subjects as possible within the depth of field, the focus distance of the photographic lens is set at a long distance (same - aperture). (The farther away the object is, the deeper the depth of field is.) There is a high probability that the closest object will be out of the depth of field and will be blurred. This is because in normal shooting scenes, the closest subject is often the main subject, so the main subject is blurred and only the background is in focus.3 The purpose of the present invention is to achieve the above-mentioned To provide a camera which can solve the problems and give priority to a nearby object in focusing among a plurality of measured objects.

In order to achieve this object, the present invention provides a lens position specifying means that selects the closest subject distance information from among a plurality of pieces of subject distance information provided by the distance measuring means and specifies the position of the photographing lens that matches the distance information. It is characterized by having the following.

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

2 to 7 show one embodiment of the present invention.
FIG. 4 is a perspective view showing the structure of the automatic focus control mechanism. 2
2 is a lens barrel that houses a photographic lens (not shown) and is movable between a close end and an infinity end, and a convex portion integrally formed with the lens barrel 2; 2a, and moves back and forth while being guided by an insert par 3 that fits into the convex portion 2a and a structural member (not shown). Reference numeral 4 denotes a focusing screw screwed into the convex portion 2a of the lens barrel 2. Its tip 4a is in contact with a feeding cam portion of a distance adjustment ring, which will be described later, and by rotating the focusing screw 4, the photographing lens can be moved. The range can be adjusted. Reference numeral 5 denotes a spring that urges the lens barrel 2 in the direction of the arrow so that the tip 4a of the focusing screw 4 always comes into contact with the extension cam part of a distance adjustment ring, which will be described later. 6 indicates the inner diameter part 6a, the extension cam part 6b, and the charger. Locking portion 6C and locking portions 6d, 6e, 6f
(In this example, only 5 pieces are drawn, but actually the 10th piece is drawn.
The diameter part 6a of the distance adjustment ring is fitted with a structural member (not shown), and is rotatably held by the structural member. A focusing screw 4 screwed into the convex portion 2a of the lens barrel 2 is attached to the feeding cam portion 6b.
The lens barrel 2 is retracted or extended as the distance adjustment ring 60 rotates. The charge locking portions 6c are respectively provided at positions corresponding to s:ytm by being locked with the claws of the stop claws described later, and the claws of the stop claws described later are engaged with the claws of the stop claws 6c to 6h. By jumping into either position, the lens barrel 2 stops its retracting operation.

7 is a spring that urges the distance adjustment ring 6 in the counterclockwise IT direction (arrow direction); 8 is a lens movement amount monitor signal contact piece that slides on the pulse plate 9 as the distance adjustment ring 6 rotates; 1o
3 is a stop pawl, which is rotatably held by a structural member (not shown) fitted into the Yashiro 10 set, and is biased clockwise (in the direction of the arrow) by a spring (not shown). The claw 1o has a protrusion 10 that holds the claw portion 1ob and the armature 711.
c is provided. Reference numeral 12 denotes a distance adjustment start magnet, and when excited, the yoke 12a attracts the armature 11. As a result, the stop pawl 10 rotates counterclockwise against the biasing force of the spring, and the distance adjustment ring 6
Charge locking part 6c and claw part 1o1 of stop claw 10)
The engagement is released, and the claw portions 101) jump into the locking portions 6d to 6h again due to demagnetization of the distance adjustment start magnet 12. 13 are two long grooves 13a1 convex portion 131), gear portion 1
3c1 A throwing element lever equipped with a cam part 13d and a locking part 13e, with a long groove 13a, a structural member 14 and an adjusting member 1.
5 are fitted, and are slidably held by the structural member 14 and the adjustment member 15. The adjusting member 15 is used to adjust the positions of the light emitting element and the light receiving element, which will be described later. The light projecting element lever -13 g is finely adjusted.

Reference numeral 16 denotes a light emitting element lever position signal contact piece, which is fixed to the convex portion 13b of the light emitting element L/bar 13, and when the light emitting element lever 13 slides (travels), the comb-shaped electrode of the pulse plate 17 and the straight line are connected. slide over the shaped electrode. Reference numeral 18 indicates a lever for the light projecting unit: a spring that biases the lever in the direction of the arrow; 19.2o indicates a governor mechanism;
a is held at a rotational speed of η1, and the light emitting part lever]
3 gear part 13C and gear part 19c of the governor mechanism 19
The structure portion H (not shown) transmits the rotation to a known governor mechanism using a pallet (not shown), thereby equalizing the sliding movement of the light projecting element lever 13. 2
1 includes a hole 21a, a claw 211), and a protrusion 21C. ) is held rotatably by the structure part (not shown) fitted in the hole 21a, and the spring 2
2, it is directed counterclockwise. An armature 23 is fixed to the convex portion 21C, and the yoke 24a is moved to the armature 23 by excitation of the distance measurement starting magnet 24.
aspirate. As a result, the locking pawl 21 rotates in the direction of stiffness against the bias of the spring 22, and the locking portion 1:3e of the light emitting element lever 13 engages with the pawl portion 21b of the locking pawl 21. is solved. Reference numeral 25 and 26 indicate distance measurement completion signal contacts, which are turned on when the light emitting element lever 13 completes the sliding slide for 1 to 1 loaf, and are output to the distance completion detection section 6 (11), which will be described later.

Reference numeral 27 denotes a light projecting element holder, in which a shaft part 27a is rotatably held by a structural member 28, and a protrusion 27b and a light projecting element lever 13
The spring 29 is biased clockwise so that the cam portion 13d is always in contact with the cam portion 13d. A compression spring 27c serves to bias the shaft portion 27a of the light projecting element holder 27 in the direction of the arrow, thereby preventing the light projecting element boulder 27 from wobbling. 3
0 is a light projecting section, which is integrally constructed with the light projecting element boulder 27, and includes a light projecting element section consisting of nine light projecting elements:
1, 32 is a connector section, 33 is a light projection lens provided on the front side in the optical axis direction of the light projection section 300, 3
4 is a light receiving lens, and 35 is a light receiving element substrate, which holds a light receiving element section 36 consisting of nine light receiving elements and a peak detecting section 37 (details will be described later). , 38 is a connector part,
Reference numeral 39 denotes a board that holds a start position confirmation circuit, a light projecting element control circuit, an aperture value determination circuit, a pulse counter section, a nearest distance determination circuit, a lens position calculation circuit, a lens extension control circuit, etc., which will be described later.

FIG. 5 is a diagram showing the light projecting element section 31 and the light receiving element section 36. ■, ~■, are the light emitting parts f arranged in 3 vertical rows and 3 horizontal rows.S, ~S are the light receiving elements, and the light emitting elements I
,~1. are arranged in A1' devices corresponding to the respective A1' devices.

6(al) and (b) are diagrams showing the viewfinder field of view. 40 is the viewfinder field of view, Point) For the subject P, -P, the light emitting element I, ~■,
The reflected light is emitted from each of the light receiving elements S, ~S
9 respectively.

The number of distance measurement points is not limited to nine, but may be set as KN distance measurement points P, ~P1 as shown in FIG. 6(b). The numbers of elements and light receiving elements are also each N pieces.

FIG. 7 is a block diagram showing the electric circuit of the automatic focus control mechanism. Reference numeral 101 denotes a release button, which outputs a light level signal when the photographer presses the release button 101 (release operation). Reference numeral 102 denotes a start position confirmation circuit for checking whether or not the distance measurement can be started. If the distance measurement can be started, a high level signal is output to the AND gate 103. Reference numeral 104 denotes a release mechanism equipped with a known release operation holding mechanism, etc.
3, the operation starts when a signal of NO-I level is input manually. Reference numeral 105 denotes a light emitting element control circuit, and in synchronization with the pulse output from the light emitting element control circuit 105, the light emitting elements I to Il of the light emitting element section 310 sequentially emit light, which is transmitted to the light receiving element. S, ~S0 receives C. This light emitting operation is performed repeatedly as the light emitting element lever 13 slides, but the cycle of light emitting operations of the light emitting elements 11 to 1 is performed at a much higher speed than the sliding movement of the light emitting element lever 13. Therefore, the position of the light projecting element lever 13 is almost the same when the light projecting elements 11 to (1) rotate. Light receiving element 8
1 to S9, the amount of received light is converted into a current value and output to the peak detection section 37. The peak detection unit 37 is composed of nine peak detectors Kl'', I(, o, respectively. The output signal is rotated and input 110 times.Then, in each peak detector, the corresponding light receiving elements S, -S, respectively, are the light emitting elements (1), -2.

It is configured to detect the peak value of each of the five points 1) and 1) when the light is received by repeated light emission.Until the peak value is detected, the signal of No.1 is output, and at the same time as the peak value is detected. The output is inverted to a low level signal. 106%-1 As the light emitting element lever 13 slides, the light emitting cable moves on the pulse plate 17 and the position signal contact piece 16 ζ slides, thereby changing the pulse to the distance address 1'. ! A pulse generator 107 outputs a signal pointing to 11 to 15 (details will be described later),
) A and ~A are the AND gate parts consisting of Al~A, respectively. The gate will open until it flips over. Reference numeral 108 denotes a pulse counter section consisting of nine pulse counters M1 to M, each of which outputs the output from the AND gate section 107, that is, the o to the vinegar beak detector KI-. It has the role of counting the number of pulses from the pulse generator 106 and simultaneously recording the number until each detects a peak current (until it is reversed from 7 to low level to low level). There is.

109 is the light emitting element /<-13 has completed the slide,
A distance measurement completion detection section detects that the distance measurement operation is completed when the distance measurement completion signal contact pieces 25 and 26 become main, and upon detection, outputs a distance measurement completion signal. 1
10 is the nearest distance determination circuit that operates when the distance measurement completion signal is input from the distance measurement completion detection unit 109, and the distance-address% stored in the nockle counters M, ~M, is calculated.
Among 1 to 15, the smallest one is determined and output. 11
1 is a light receiving element for exposure, which starts pre-metering when the release mechanism 104 is started (7, converts the light stitches from the subject to be photographed into an electrical signal and outputs it; 112 is an aperture value determination circuit; the light receiving element for exposure 111 is converted into an aperture value F and outputted to the A/D conversion circuit 113.The A/D conversion circuit 113 converts the aperture value F into a digital signal and converts the aperture value information 1 to 62 into a digital signal (details will be described later). ) and outputs it. 114 is the distance address l'1&l*A, /D conversion circuit 11 output from the closest determination circuit 110.
A lens position arithmetic circuit adds the digitalized aperture information and outputs the aperture value information, and 115 is a Norculus generator, and as the distance adjustment ring 6 rotates, it generates a value of ℃ and on the Norculus plate 9. When the lens movement acid monitor signal contact piece 8 slides, a number of pulses corresponding to the lens movement amount are output as a lens movement amount monitor signal.

Reference numeral 116 denotes a lens extension control circuit which starts comparing the pulse signal from the pulse generator 115 and the output signal from the lens position calculation circuit 114, and at the same time starts energizing the distance adjustment start magnet 12. When the number of pulse signals from the lens position calculation circuit 115 matches the output signal from the lens position calculation circuit 114, the power supply to the distance adjustment start magnet 12 is turned off. 117 is an inverter that outputs a low-level signal when a high-level signal is input from the release button 101, and a high-level signal when a low-level signal is input; 118 is a memory cancel circuit that outputs a high-level signal from the inverter 117; Operation 1~ is triggered by a level signal input, and after a certain time delay, a high level signal is output to the pulse counter M, ~M, and the glue set terminal, and the pulse count 3' is activated M4~M.

It serves to reset the . 119, a lens position calculation circuit 114, a lens position designation signal and a pulse generator 11;
．． a comparator for comparing the number of pulse signals from 5 to 120;
is a display circuit that displays front defocus, in-focus, or rear refocus according to a signal input from the comparator 119. , Next, its operation will be explained. When the photographer decides on the composition of the subject as shown in Figure 1 and presses the release button 101,
When the power switch is turned on, the start position confirmation circuit 102,
A high level signal is output to the AND gate 103 and the inverter 11117. Start position confirmation circuit 102
Then, check whether the light emitting element lever 13 is in the charging position shown in FIG. ) Outputs a high level signal to 103. Since the high level signals from the release button 101 and the start position confirmation circuit 102 are missed, the anime game) 103 outputs a high level signal to start the operation of the release mechanism 104. Further, the high level signal inputted to the inverter 117 is inverted to low level, and the memory cancel circuit 118 inverts the high level signal outputted to each pulse counter M1 to M and the glue set terminal to low level, and the pulse The count preparation operations of the counters M1 to M are completed.

The process starts when the release mechanism 104 operates. The distance measurement starting magnet 24 is excited, the locking pawl 21 rotates clockwise against the biasing force of the spring 22, and the pawl portion 21b and the locking portion 13e of the light emitting element lever 13 are locked. Once released, the light emitting element lever 13 begins to slide at a constant speed from the position shown in FIG. 2 to the position shown in FIG. 4 by the force of the spring 18. As a result, the light projector 30 starts scanning in the distance direction from close range to infinity. On the other hand, in the light emitting element control circuit 105, the light emitting elements (1), to (2). starts synchronous blinking and synchronous light reception of light receiving elements 81 to S9 (state shown in Fig. 3)
do. As a result, the distance measurement points P, -P are scanned. The scanning speed of the ranging points P, ~P, that is, the light projecting element I.

The blinking transition speed of ~■ is determined to be faster than the scanning speed in the distance direction by changing the angle of the light projecting section 300. Incidentally, in this embodiment, in order to simplify the explanation, the light projecting elements 11 to 1 are arranged as shown in FIG.

and light-receiving elements S, ~S, are combined into nine combinations, and the positions detected by the light-receiving elements S, ~S in the finder field of view 40 are determined by nine ranging points P as shown in FIG. 6 (al).
1 to P, but the number may be less than this, or it may be N distance measuring points P1 to P as shown in FIG. 6(b). Further, the arrangement IN may also be, for example, in a concentric circular shape. Furthermore, the light emission 1 of the light emitting elements ■1 to ■,
First, in order to prevent interference between neighboring elements on the object surface, it is preferable to use an order in which adjacent elements do not emit light, rather than from light emitting element I to light emitting element I. In the embodiment, for convenience, the synchronous flashing is performed sequentially starting from the light projecting element (1), and when it reaches the light projecting part (f), the next flashing is performed again by the light projecting element I, and so on.

In the process of sliding the light emitting element lever 13, the light emitting elements 11 to 1 sequentially emit the light emission signal 121 at a speed considerably faster than the sliding speed of the light emitting element lever 13, as shown in FIG. The light is irradiated toward distance measurement points PI to Po, and the light receiving elements S and S9 convert the amount of light received into a current value of 122 and output it to the peak detector. Bi--The current value while emitting light is the light reception signal 123
(shown with diagonal lines in FIG. 8), and outputs a high-level signal to the AND gate section 107 until the peak value is detected as shown in FIG. Inverts to a - level signal. On the other hand, the pulse generator 106 outputs a pulse indicating distance attation/distance as the light projecting element lever 13 slides. That is, the pulse No. 1 [] points to the distance address NcL1, the second pulse points to the distance address %2, and the pulse No. 15 ['' points to the distance address Nl i 5, respectively.

As shown in FIG. 1I, distance RIL address collections 1 to 15 are assigned to predetermined distances from 0.8 m to infinity (υ).
At~A, represents each peak (1~I on the moxibustion device).

While the output from the pulse generator 106 is at a high level, the pulse counter MI~Mg''\tsure is counted [7, and the d count value is memorized. The object distance at point l-1', ~P, is the subject distance 1 (corresponds to the address %. For example, in the example of figure ~' 0, distance measurement point ■) 1
The count values of pulse counters M and ~M3 corresponding to ~P are], 0, 51 values of pulse counter M4 corresponding to 6111 distance points 1) 4,..., measurement h'l-1
point) Pulse counter M corresponding to P. of itj
The numerical value is 9.

Next, when the sliding of the light emitting element lever 13 is completed (distance measurement operation is completed), the distance measurement completion signal contact piece 25 and the distance measurement completion signal contact piece 26 are turned on by pressing the light emitting element lever 13 at the same time. The distance measurement completion detection unit 109 detects that the distance measurement operation is completed, and outputs a distance measurement completion signal to the closest distance determination circuit 110. When the distance measurement completion signal is input, the closest determination circuit 10 determines the minimum value among the counted values stored in the pulse counters M1 to M. For example, according to the example in FIG. , the count value 4 of pulse counters M4 and M6 is selected and outputted to the lens position regulator circuit 114.

On the other hand, the exposure ring element f111 starts photometry in response to a signal input from the release mechanism 104, converts the brightness of the subject into a current value, and converts the aperture value determination circuit I~, Al1) conversion circuit 1
13-\Output. Al1) The conversion circuit 113 is connected to the aperture value determining circuit 112.

For example, if the aperture value F2==;==8 is input, the aperture color information is 1, and if the aperture value F4 is input, the aperture color information is 2.
,..., aperture value F32 is input 1. If so, the aperture color information is converted to f digital number 1-1, such as aperture color information 8, and outputted to the lens position calculation circuit 114.

Note that here, the distance measurement point P of the finder field of view 40,
Considering that all of .about.P are to be in focus, it is desirable that the aperture value determined by pre-metering be as small as possible.

Therefore, the shutter used in the camera of this embodiment is set at a shutter speed that is ``C'' for a given subject's EV value, and the aperture is set as small as possible without blurring due to photography. The lens position calculation circuit 114 adds the distance address from the closest determination circuit 110 and the aperture color information from the A/D conversion circuit 113, and uses this calculation value as the lens position designation signal and L2. and outputs the lens extension control circuit 116 and the comparator 119. For example, as shown in FIG.
Calculate 7 1-1 If the aperture value information is 7 (F22), 1.
Calculate i+7=i1''.The calculated value specifies the lens position that is in focus at the distance corresponding to that value.
For example, the calculated value 5 is the distance 1 corresponding to the distance address 5.
．． 6 Specify the lens position that focuses on m. The lens extension control circuit 116 starts energizing the distance adjustment start magnet 12 at the same time as the signal input from the lens position calculation circuit 114, and the distance adjustment start magnet 12 is energized. 10 claws 101
) is released.

Therefore, the distance M ili'J joint ring 6 begins to rotate counterclockwise according to the biasing force of the spring 7. Distance adjustment ring 6
With the zero rotation, the lens movement amount monitor signal contact piece 8 slides 12 on the pulse plate 9, and the movement amount is input from the pulse generator 115 to the lens feeding control circuit 116 in the form of a pulse number. At the same time, the lens movement amount is inputted from the pulse generator 115 to the comparator 119 in the form of the number of pulses, and the comparator 119 compares the calculated value from the lens position calculation circuit 114 with the number of pulses. The front defocus or rear defocus can be displayed.

Further, the lens extension control circuit 116 compares the information from the lens position calculation circuit 114 and the information from the pulse generator 115, and if they match, the energization to the distance adjustment start magnet 12 is turned off. That is, when the number of pulses from the pulse generator 115 reaches the same value as the information from the lens position calculation circuit 114 (for example, if 4+1=5, when the number of pulses is counted 5), the distance adjustment is performed. The excitation of the starting magnet 12 is released. Due to this operation, the stop claw 10 jumps into the locking portion 6c of the lens barrel 2, and the rimming operation of the lens barrel 2 is completed, and the photographing lens is
To bring the nearest object into the depth of field and stop with the object further away in focus. As a result, the display circuit 120 will display that the focus is on, and at the same time, a known exposure operation will be activated. When a series of photographic operations is completed, the film is wound up by a motor or manually, and one frame is advanced. Each member necessary for photographing is charged and the state shown in FIG. 2 is restored.

Here, a comparison between the method of this embodiment for determining the retracted position of the lens barrel 2 and the conventional method will be explained with reference to FIG. 10.11. In this embodiment, the aperture value information is outputted as a numerical value 2.3, .
The smallest numerical value among the counted values stored in O is determined and outputted by the nearest distance determination circuit 110, and each numerical value is added by the lens position calculation circuit 114 and outputted as a lens position designation signal. It has become. This means that the depth of field of the photographing lens is t, the allowable inner diameter of confusion is δ,
Since there is a relationship between the aperture value F and the depth of field t increasing by narrowing down the aperture value F, use the fact that the depth of field t increases by narrowing down the aperture value F. The idea is to expand further away. .

In other words, as shown in FIG. 11(a), in the conventional example, when the distance signal to the object is output from the distance measuring device 115, the retraction of the photographing lens is stopped in accordance with the output object distance. In other words, the subject distance is 1.35
If the focus signal was output at a time of 1.35 m, the retraction of the photographic lens would also have stopped at a position corresponding to 1.35 m.

However, in this embodiment, as shown in FIG. 11 (bl),
Assuming that the distance address 4 is output from the closest distance determination circuit 110, the lens position calculation circuit 114 specifies the retraction position of the lens barrel 2 to match the position of the distance address %5 (1.6 m). do. Note that this calculation may be performed, for example, by determining the nearest object and determining a position signal to stop the lens barrel 2 at the focused position, or by determining a position signal that is determined in advance. The depth of field is determined according to the aperture value information provided, and the near point of the depth of field range is compared with the nearest object distance signal, and the nearest object is at least the near point of the depth of field range. It is also possible to stop at a retracted position of the photographing lens which is further away than the above distance and closest to the near point.

Conversely, for all subjects within the photographable range,
It is also possible to determine the aperture value such that the closest position and the farthest position are within the depth of field, and determine the retracting position of the photographic lens.

Gum To explain in more detail, if you shoot a composition with an aperture value of F5=;==a and the closest subject is located at a distance of 1.35 m, according to the conventional example, the range that appears in focus on the film surface is The object distance is between 0°6m and 4.8m.
3. Therefore, the secondary subject (subject distance) is up to 4.8 m and 7 is out of focus, and the background located further away becomes blurred. However, in this example, the subject distance is 0.78 m or more. The camera will be able to focus up to 17m. Also,
As shown in FIG. 11, the amount of blur of the image at infinity is also considerably smaller than that of the conventional one.

Next, the operations described so far will be briefly explained using the flowchart shown in FIG. First, the photographer decides on the composition of the subject and presses the first stroke of the release button 1°1 (
As a result of step 201), power is not supplied to each circuit, the camera becomes ready for shooting (step 2o2), and at the position pushed to the second stroke (step 203)
, the magnet 24 for starting distance measurement is turned on (step 204). When the distance measurement start magnet 24 is turned on, the light emitting element lever 13 begins to slide (step 205), and at the same time, a synchronous blinking command is issued for the light emitting element section 3, causing the light emitting elements (1), to (2). starts blinking synchronously (step 206), and the light receiving element S of the light receiving element section 36
, ~S9 (step 207). next,
Of the current values output from the light receiving elements S, ~S, only the portion that synchronizes with the light emission of the light projecting elements (2), ~2, is converted into a synchronizing signal as a light receiving signal (step 208). The peak value of the light reception signal, which is an analog value, is detected by a known means (step 209), and at the same time, the position signal is output in the form of pulses by sliding the light emitting element lever 13 (step 210). , it is determined at what distance the peak value was obtained as described above.

On the other hand, by operating an exposure control mechanism (not shown), pre-metering starts (step 211), and the exposure light receiving element 1
11, and the aperture value is determined (step 2
12). The aperture value is A/D converted (step 213).
, the number of pulses until the aforementioned peak value is detected and the first
The signals are added as shown in FIG. 0 (step 214) and stored in the lens extension control circuit 116 as a final lens position designation signal (step 215).

When the object distance measurement operation is completed using the light emitting element lever 13,
The distance measurement completion signal contacts 25 and 26 are turned on in step 216.
), the distance measurement start magnet 24 is turned off (step 217), and the distance adjustment start magnet 12 is turned on (step 21.8). When the distance adjustment start magnet 12 is excited, the lens The lens barrel 2 begins to retract (step 219), and a lens movement amount monitor signal is output in conjunction with the retracting operation (step 220).

A lens position 1 designation signal is stored in the lens extension control circuit 116, and compared with the lens movement amount monitor signal 1 to 1 described above (step 221), when they match, the -7 magnet 12 for starting distance adjustment is turned off. (Step 22
2).

By demagnetizing the distance adjustment start magnet 12,
The rotation of the locking ring 6 is stopped by the stop claw 10, and the retracting operation of the lens barrel 2 is stopped (step 223). At the same time, the exposure operation is started by known means by turning the second distance and f/M adjustment start magnet 12 (step 224), and the series of photographing operations is completed.

According to this embodiment, by measuring the distance points P, to P9, it is possible to perform focusing that takes into account not only the main subject but also the sub-subject in one distance measurement operation.
Further, by eliminating the distance measurement mark 1, etc. in the viewfinder field of view 40, the complication of the viewfinder field of view and the time required for the photographer to make decisions are eliminated, making the camera resistant to photo opportunities.

Furthermore, a plurality of light projecting elements ■1 to ■. and light receiving element 81~
Compared to measuring the same range using a large projection image of a single element, placing S not only improves the resolution of distance measurement, but also enables distance measurement of even small objects, making it possible to take high-precision photographs. becomes possible.

In this embodiment, the light emitting element lever 13, the light emitting element 11
~■0, light receiving element S, ~S9, pulse counter M, ~M
9, etc. correspond to the distance measuring means of the present invention, and the nearest determination circuit 1
10 and the lens position calculation circuit 114 correspond to the lens position specifying means of the present invention.1 In this embodiment, an active type automatic distance detection method has been described, but even if it is a badge-ive type, for example, a visual distance detection method may be used. In the tronic method, the movable mirror is scanned in the distance direction and the distance measurement point is simultaneously scanned at a faster scanning speed) I? ,~■).

In conjunction with the movable mirror, the fixed mirror is also moved to scan the distance measurement points 1) 1 to P, thereby moving the distance measurement points 7).

~■), it is also possible to measure the distance. Also, it is composed of nine light emitting elements and nine light receiving elements;! , ) Y' is made up of a light projecting element and a light receiving element, but is not limited thereto.

It is also possible to continuously operate the element part and the light receiving element part to measure distance points P, ~P, in the viewfinder field of view.
3] It is Noh. Furthermore, in this embodiment, the information from the center and the periphery of the viewfinder field of view was processed with the same weight, but it is also possible to give weight to this information, in other words, to perform something like center-weighted photometry in photometry. It is.

The present invention is also applicable to a camera in which only distance measurement is performed automatically, and distance adjustment is performed manually while viewing the focus state display. Furthermore, the present invention is not limited to cameras that perform distance measurement in one distance measurement operation, but can also be applied to cameras with a prefocus mechanism that performs distance measurement operations one time at a time toward multiple subjects. .

As explained above, according to the present invention, the lens position specifying means selects the closest object distance information from among the plurality of object distance information provided by the distance measuring means and specifies the position of the photographing lens that matches the distance information. Since this is provided, priority can be given to the closest subject among the plurality of subjects whose distances have been measured.

[Brief explanation of the drawing]

Figure 1 shows the viewfinder field of view of a conventional camera;
4 is a perspective view showing the structure of an automatic focus control mechanism of a camera which is an embodiment of the present invention, FIG. 5 is a layout diagram of a light emitting element and a light receiving element, and FIG. Figure 7 is a block diagram showing the electric circuit, Figure 8 is the same diagram showing the operation of the light emitting element and light receiving element, Figure 9 is a diagram showing the light receiving signal, and Figure 10 is the same diagram showing the distance points. 11(a) is a diagram showing the calculation method, FIG. 11(a) is a diagram showing the depth of field in a conventional camera, and FIG. 11(b) is a diagram showing the depth of field in a camera according to an embodiment of the present invention. 12 are flowcharts showing the same operation. 1... Distance measurement mark, 2... Lens barrel, 4... Focusing screw, 6... Distance adjustment ring, 8... Lens movement. Quantity monitor signal contact, 9...Pulse plate, 10...Stop claw, 12...Distance adjustment start magnet, ]3
... Light emitting element lever, 16... Light emitting element lever position signal contact piece, 21... Locking claw, 24... Distance measurement start magnet, 25.26... Distance measurement completion 1 signal contact piece, 31
... Light emitting element section, 36... Light receiving element section, 37...
Peak detection unit, 101... Release button, 104-
...Release mechanism, 105...Light emitter control circuit, 1
06...Pulse generator, 108...Pulse counter section, 109...Distance measurement completion detection section, 110...Closest point determination [-■ path, 112...Aperture value determination circuit, 113
. . . A, /D conversion circuit, 114 . . . Lens position calculation circuit, 115 . . . Pulse generator, 116 . S. ...Photodetector, K1-, ...Peak detector, A,
~A,...AND gate, M+~M,...Pulse counter, R~P9, Pn...Distance measurement point. Patent Applicant: Canon Co., Ltd., Minoru Naka, Figure 1] C'SJ Mandai 5
Prisoner ÷ Fig. 6 (a) (b) Fig. 8 121 Fig. 9 ← 7 ← High pressure Y Toss No. - Sho Eson
Jeong Kyo Ri Figure 10 Tsujino CRI S1j

Claims (1)

[Claims] 1. In a camera equipped with a distance measuring means that automatically measures distances to a plurality of subjects within a shooting screen, the closest subject distance information is selected from among the plurality of subject distance information provided by the distance measuring means, and the distance information is A camera characterized in that it is provided with a lens position specifying means for specifying a position of a photographing lens suitable for the camera.