JPS6163813A - Focusing state detector - Google Patents

Abstract

PURPOSE:To obtain a device for detecting focusing state always correctly by providing the titled device with a means having a photoelectric converting element, a means for discriminating the focusing status from an electric signal outputted from said means and a means for detecting the contrast of light flux obtained from said discriminating means. CONSTITUTION:Light flux projected from a photographing lens system 1 is made incident upon an image sensor 4 having two right and left photoelectric converters through a half mirror 36 and a total reflection mirror 37. A dark current compensating circuit 43 removes the dispersion of signals obtained from the right and left converters which may be due to the reflective index and transmissibility of mirrors 36, 37 and a part of the dispersion-removed signal is outputted to a gain setting circuit 51 through an accumulation time appreciating circuit 50. The other part is sent to an integrator 48 through a bit delay circuit 45, a differential amplifier 8, an absolute circuit 9, a variable amplifier 47, and a (R) converter 10 and a signal detecting the contrast of two formed images is sent from the integrator 48 to the circuit 51 and a signal is sent from the circuit 51 to a driver 6 to focus the sensor 6 precisely. Thus the always correct focusing state is obtained.

Description

[Detailed description of the invention]

The present invention relates to an in-focus state detection device for detecting the (-in-focus state, i.e., focused state, adjustment state) of an optical system such as a camera.
The method of detecting the rl of 1//z of a camera, etc. 1) is the so-called leading 7M of CdS, CdSe shade, and the element surface illuminance lamp light of J<1'-. Many devices have been proposed that take advantage of the non-1n linearity of the resistance value. Improved sharpness detection by skillfully combining two different elements r-
- However, the responsiveness of such element r to changes in illuminance is low and! '-(-The first disadvantage is that the resistance value is extremely high and signal processing is not possible at the time of ilj signal processing?-(F
Recently, several methods have been proposed for detecting the brightness of an image using solid-state imaging. , and detecting the maximum jf+ of the differential signal level to detect the brightest point of the image, υ, is disclosed, and JP-A-51-60105 discloses a method υ as described in Section 1. From the signal, two successive output signal levels X: are detected, and the lens system is moved according to the f average value of the difference to find the general sharp point of the image. In addition, JP-A No. 5151
−2603(+, l:, I/, V body tiJ & , +;
t no CI 'E of bits fi spaced apart at regular intervals
* hl + output So to speak, a specific frequency; the method of detecting changes in the 8th component, as in Japanese Patent Application Laid-Open No. 113824/1983, 1. The maximum value in the previous series signal and the value between the maximum value and the maximum value of 1. Detection 1. A method has been proposed in which the image size is determined by changing the level. However, (as described above) i X' is achieved by converting the overlapping f-body light flux formed by optics such as a camera into an electrical signal and processing the electrical signal. Since the image is clearly visible, when the luminous flux is dull and dark, the level of the electrical signal is lowered accordingly, and the signal-to-noise ratio is lowered.
1 f,t,'ll! It was not possible to detect a state of high focus. Therefore, the 4S applied by Mizude-jin
Gankan No. 52-93998 (filing date August 50, 1978)
A technology has been developed in which a single light beam detects darkness and prevents photography from taking place when it is dark. However, since all of the advanced methods detect the level difference of the electrical signal with -1 changed to the signal, even if the subject light flux is not very dense, the overlap If the contrast of is low, 1S actual 1:
There is a drawback that the in-focus state cannot be detected, and for example, the in-focus state may be mistakenly determined. □In view of the drawbacks of the conventional art, the present invention provides a method for preventing erroneous detection of the focus state by detecting that the contrast of the subject light beam formed by the optical system is low. (1) The objective is to provide a device for detecting a matching state. The details of the unreleased 1!1 will be explained below according to the drawings. Figure i1, Figure 2, and Figure 3 are used to explain the general image sharpness improvement and the corresponding change in the image plane illuminance distribution, prior to a detailed explanation of the present invention. This is the second picture. Figure 1 shows - General light? The image of an object (not shown) is formed in the vicinity of the predetermined focal plane 2 by the imaging optical system 1. 'a) is the so-called imaged behind the predetermined focal plane. This is a rear bin state, and the image is in a blurred state in the T constant focal plane. Figure (b) shows the case where the image is correctly formed on the pre-i' focal plane.
The image becomes 1 bright, which is the so-called in-focus state (0th figure (C))
is imaged in front of the planned focal plane. This is a so-called iNj bin state, and the image becomes blurred on the two planned focal planes, similar to the case 1', a). Figure 2 (a) schematically shows an example of an object and changes in image clarity of the object.
It is an object with white lines on a black background, and the number 11121 of this object is
The imaging conditions are as follows: ', a) l', b) l', C) respectively: JS2 figure t
', b) (, c) (, d), 1-s, Figure 3 is the second
FIG. 1 is a diagram showing the illuminance distribution in the planned focal plane J- of the image of the object shown in FIG. ), (c) shows the Hi, 171 distribution of the image in the imaging state, and the X direction in the third leap corresponds to the X direction shown in FIG. 2 (a).
yS4 diagram is based on the above imaging optics +$1. The illuminance distribution 3 as shown in FIG. 3 is used as a time-series electric signal 5, and a solid-state image sensor (hereinafter referred to as an image sensor for aS) is used.
41 Examples are CCD and CID. FIG. 3 is a diagram illustrating an output from a BBD or photodiode type sensor. As an image fist sensor,
For example, the photosensitive part has N floating PN junctions,
For example, 4
CCD as Aino's analog fist shift register,
1. . As an example, consider a shift I pole that controls the transfer of signal charges to a shift register. This image sensor 4 receives a signal pulse SP to the rat electrode, an analog shift 1, a clock 2 bulk for transfer φ1゜ψ2, 43, υψ4 and υ output part 1L 荀1f
By adding RS for conversion = note / number M = reset number for electricity (RS), electricity +, i;
5, the time series of N hints is also output as No. 1 after adding Noft No. SP, but this is! 4, '<'-: ■ b: Generated and accumulated in the photosensitive area from the previous left shift key SP to the current shift key 12.
/; Sentence to f! 1 core electricity is also 1, and these are the time intervals or accumulation times that give the raft bulk after the market where 5 de 1 was present. FIG. 5 shows an example of the -tm form of the imaging state detection circuit according to the invention in a small model 1) L! I, and r- as shown in Figure 3.
1 jiao 1. ', The change in the imaging state of the illuminance 11 distribution on the - plane is expressed by the electric 4r using the image number sensor [,
In Figure 0, which is converted to No. 1 and sharply detects the clear melon in the 2″ shape φ, as shown in J), the l method is /1;
The imaging optical system 1 was arranged so that its light-receiving section was aligned with the focal plane having a constant f. Like image sensor 4, 4 marks l
'IA does not run straight in the J1 direction of J1.
．． However, for example, at 214f'a), an image of an object such as a small child is formed on or near the light receiving surface of the image sensor 4 (Z). The image sensor 4 is supplied with a shift bulk reset pulse of +tij l by a driver 6 and a transfer clock pulse φ1゜ψ2. φ3
．． As an example of 0 where ψ4 is added, Fig. 2 t', a)
The image of the object shown in Figure 6(a) is formed on the light receiving part of the image sensor in an unreliable state! Mi;
The operation of this method will be explained below. An image signal having a variable illuminance distribution is extracted from the image sensor 4 as a time S column signal as shown in the JSS diagram (b). The horizontal axis between (b) and (g) in FIG. 6 shows the time axis in J(, and the vertical axis shows the upper air output at the middle of α.
The reason why the signal in figure (b) is shifted toward the L side is that of the image sensor Ill'! This is the direct 'IAI component due to the current. The output from the image sensor ", 5: -17 is supplied to the 1" input terminal of the 4-operating lamp 8, and is simultaneously input to ξ and 3().
Do? It is assumed that the optimum t is determined by setting=1. The signal from the image sensor fed into the same delay circuit is as follows. In this example, a detailed configuration example of the 20-hit delay circuit, which is extended by n hira) and is fed together to the load output terminal of the differential amplifier 8, will be described later. The signal indicated by the broken line in Fig. 6(C) is a signal that does not receive the same ff[ as t' b ) in the same figure, and the signal indicated by the solid line receives the ν section in the n hit and extension circuit. Figure 6 (
d) Ninisu, 4° No. 1 is a draw! 1 is then passed to the absolute value circuit 9 and converted into a signal as shown in FIG. 6(e). For a detailed configuration example of the absolute value circuit, the differential output described later is 1. Through the absolute value circuit shown below. The conversion to in 4f:ji is done at the later J+- minute,
This is to prevent the integral value from being canceled out due to the presence of the negative signal ζ. The output of the absolute &41〆1 circuit 9 is mechanically sent to a gamma conversion circuit 10. The example of the AT jig A'' configuration of the gamma conversion 111Iv8 will be discussed in detail.The output signal of the gamma conversion circuit IO is in a form that is emphasized by 1 compared to the 4-power signal level as shown in FIG. 6(f). One of the five major features of the present invention is that the same circuit is included, and this allows the signal to be assigned according to the level of the signal. , and the integrated value is stored by the hold circuit 12.
For example, an electric cable 1. ;1
The signal is supplied to a display 13 consisting of. An example of an intra-community JlII and a halt circuit is described below. FIG. 6(g) shows how the signal is integrated and fielded. The maximum p' pressure V5 is the output signal indicating the sharpness of the difference. In this way, the imaging state detection circuit of this example takes the difference between the image sensor output multiplied by 'N and the one not multiplied by ai=, in other words,
The outline of the image is extracted, the sharpness of the outline is gamma-converted, and the sharper the sharpness, the more it is emphasized. Next, by applying this to the entire J11 constant field and integrating it, we get the following:
+ me 17+! It is a Z-type device that can sensitively detect light 18. , FIG. 7 is a diagram showing an example of a silica-like structure of Vδ7 once per n-day. Image 4 from
No. 91 or mechanical. 15 is an l hinotoshi crazy circuit in which n pieces are connected in a canucate, and n tips are extended or 9 pieces are connected to input lIV,)Il,, $H1 from an O-end amplifier with a return resistor R connected to the terminal. As already mentioned, the signal shown in FIG. 6(, d) is outputted to the output terminal 16 of the zero-time amplifier 8 mechanically connected to the negative mechanical terminal r of the X-movement amplifier 8. Pl. P2 is a ten-de-barne added to the l-hit spread circuit. FIGS. 8 and 9 are signal waveform diagrams showing a practical example of the above-mentioned 1-pin circuit 14 and how the signal is slowed down by 1 hit in the same circuit. In FIG. 8, by applying the hold pulses P1 and P2 at the timing of skipping 91.4, it is possible to achieve the 1-pi)W extension of No. 4L1. That is, from the mechanical end 17 to the point 18. Point 18
to the output i19 are constructed as well-known circuits, and the input terminal 17 has a 9th output.
When the time-series signal from the image processor 4 as shown in figure (a) is added λ, Samblinogbarnu P! By Voino l
-18 output is shown in Figure 9 1. 'b) A seven-note signal is generated. Similarly, No. 4Y in the same figure (b) is processed by the sample hold circuit in the latter stage by the sublink pulse P2, as shown in (C) in the same figure (°1, i.e., (
a) As No. 1 and No. 4-+, which was delayed by one hit,
It is outputted to the output terminal 19 and is a Z signal. Figures 10 and 11 respectively show one of the absolute 411 circuits.
An example of a physical configuration and its solicitation power characteristics are shown. The signal input to the input end 20 of the circuit shown in FIG. Ru. 12 and 13 are concrete examples of the conversion circuit 10 using multipliers. 22 is a block diagram of the same circuit using a multiplier, and 22 is a mechanical end of the multiplier;
3 times? This is the output terminal of the calculator, and this circuit is the 1314th
Since input 1 to the same circuit has a square characteristic similar to that of a child,
．． By adding IC1 to the level of No. 1, an output No. 0 which is linearly increased by 1+2 is obtained. , i14 and 15 show a known broken line approximation circuit as another simple example of the comma conversion circuit, and the output characteristics of the same circuit. A timing diagram showing how the input signal is integrated and held for 1111 times in a diagrammatic circuit configuration of the hold circuit 12 is shown. Figure 17 ([a
), the gamma subscript shall be replaced with 41, and the number shall be entered)). In FIG. 17, 1', a), 32 represents the temporal length of the measurement field, and 33 represents the 11 h hour of the image or sensor.
Switch S1.52.33 consisting of ET analog switch sugar electronic switch or Figure 17 1. 'b),
It is configured to turn on at the timings indicated by t', c), f', and d). The output amplifier 27 has a capacitor 28 and a switch S2 connected in series to the negative mechanical terminal and the output terminal, and once the switch S2 is in the OFF state jJ11
Now, integrate Mecha No. 1 and send the integrated value via switch S3. It is supplied to the capacitor 29 as a charging voltage. The change in the output voltage of the capacitor 29 is as shown in FIG.・Halt once via sofa amplifier 30 (/
i is input to the voltmeter 31, and according to the instruction from the voltmeter 31,
You can know the sharpness of the image at that time. Figure 17 (f) shows the changes in the number 3. In other words, the signal ('
The fourth
In the figure, the sharp spatial change in the illumination component 41 of the predetermined focal plane due to the imaging optical system is large.
This is clear from the method of detecting the imaging state shown in the figure. That is, as shown in FIG. 18, the focus signal is at its maximum when the imaging optical system is focusing on the predetermined focal plane. This is a sentence for that object, 11-τ result 2゛ optics, Y or combination j
, ji state. &llll Image optical system or focus! Poor appearance, even in +iii pinot condition, or in a/bi/condition 1. However, the focus signal will be extremely reduced, and the image state will be clearly detected by the extremely sharp precision IB. FIG. 19 is a diagram showing changes depending on the aperture ratio of the imaging optical system of No. 1 Huoichi Kanui No. 11; the imaging optical system with a small aperture ratio,
? When using ・, the focus signal becomes a gentle curve of 1 in 35, and conversely, the focusing signal has a large aperture ratio.
When using the F' system, the fork angle is 1 in 34, resulting in a very sharp curve. However, in an imaging optical system with a small aperture ratio,

[More than the image optics R, which has a large ratio of 1: The depth of field of the surface is large, so the image formation is good! Even if the detection accuracy of the system is low, the negative points will be canceled out. In this way, the imaging state detection method shown in Fig. 5, t, can be used as a focus detection system for optical equipment such as a camera.・Even in the case, the difference between the focus signals of the 5-focused state f1 and the 1-focused state can be increased by intensifying the Ji line 1 and Z9 of the comma conversion circuit 10. It is possible to achieve extremely high accuracy. Nu, parable. Even if the output of the comma conversion circuit is small, the difference between the focus signal between the 1st focus state and the 41st focus state can be made extremely large because the integration or addition is performed over the entire measurement field of view range. In addition, even if there is noise in the mechanical signal to the integrator circuit, due to the high frequency component removal effect of the jh divider, a stable Fourcanu V1 bow with no noise can be obtained in the integrator output to some extent. It will be done. Below 1. As shown in the figure, this method emphasizes the blur corresponding to the sharpness 11 of the image formed by the imaging optical system, and adds σ over the entire 4 constant visual fields, thereby making it possible to detect the imaging state with high precision. On the other hand, in the detection method of the image formation f; shown in the fjSS diagram,
*Since only the sharpness of the - image is detected, even if the in-focus point can be detected correctly, it is not possible to add m1 even if the imaging state is in the front bin or back bin when out of focus.・. ν, object?1. If the system moves relative to an optical device such as a camera, the measurement field of view will be obscured, and even with the same sharpness, the focus will be 4L. The focus signal may fluctuate, and the focus signal may fluctuate if the brightness of the same object changes.
Oh,! I will explain 1g+ to To. Figure 20 shows 1. Note 1
! This is an example of l in which improvements were made by changing j to old L^-.
In the same figure, the light flux passing through the imaging optical system l in the manner f, is /, -
The light is divided into two parts by the humirar 36, and the transmitted light is divided into two parts.
Fixed 1. It is applied to the left half of the image φ sensor 4 placed at the +iii force of the one-point surface 39. On the other hand, the light weight reflected by the half mirror 36 is parallel to the half mirror 36 once.
The Y-air, which is optically equivalent to the plane 39, is reflected by the total reflection mirror 37 arranged at The distance between the 1st surface 39.40 and the image sensor 4 is 11.6419υ42 is the imaging optical S.
1, the image plane is focused to the real left. In FIG. 20, the imaging plane 41, 42 of the imaging optical system l
shows the case where the object is in front of the planned focal plane 3940. Here, suppose the object is Batano as shown in Figure 2+'a).・Sensor■
The illuminance distribution of the image is as shown in FIG. 21(a). This is because the image-forming surface 41 at the tip of the eight-view mirror 36 is closer to the light-receiving surface of the image sensor than the image surface 42 of 1/q1 light. This is because the image on the left side, that is, the one that is created by the transmitted light of the humira 36, is clearer than the image that is created on the right side, that is, that is created by the reflected light. : PS21 diagram (°b) shows the case where the planned focal planes 39 and 40 and the imaging planes 41 and 42 of the imaging optical system coincide, that is, the two imaging planes and the image sensor light receiving surface are both in the diagram. Since they are separated by Δ, the illuminance distribution of the image of the image sensor l- is the same. Figure 1', c) is the opposite of (a), where the image formation surface of the reflected light is formed closer to the light receiving part of the image sensor than the image formed by the 4-pass light, and the image number sensor The illuminance distribution of the image on the light receiving surface is on the right side, that is, on the half mirror.
The image is clear due to 36 reflected lights! L or entry side, i.e.
I.--The image is sharper than that of the image formed by the light transmitted through the mirror 36. Like this &1. A concrete method for detecting the imaging state of the imaging optics S.1 by comparing time-series image signals of an image sensor having first and second light receiving sections arranged after rifting across a predetermined focal plane. The method will be described below. FIG. 22 is a schematic diagram showing an embodiment of an imaging state detection method according to an uninvented invention. The reflected light is further reflected Q4 by the total reflection mirror 37 and enters the image sensor 4 in left and right directions, and the distribution of the light 4 on the light receiving surface is as shown in FIG. 23(a). The broken line in the figure shows the illuminance distribution when both the reflectance and transmittance are set correctly to 50%, and the solid line is the reflectance, !
Such an imbalance is observed in an actual I-fum mirror, which shows a deviation from the ideal state shown by the dashed line when using a half-mirror in which the over-I: is not formed with ir', L, < 50%. Since this is unavoidable, □1 In the present invention, 1. J! This will be explained in detail later. For image sensor 4. From driver 6, shift valve, reset pulse, transfer lock pulse 2φ1. φ2. φ3° and φ4 are applied from the driver 6, and the image sensor LrrJ image signal is converted into a time series signal as shown in FIG. 23(b). = The figure shown by the broken line shows the signal when there is no variation in the reflectance and transmittance of the I... mirror, as in (a).The shift of the signal towards the side has already been explained As shown in FIG. 23, this is caused by a rectangular current in the photosensitive part of the image sensor, and can be reduced by passing it through the dark current compensation circuit 43, resulting in a signal as shown in FIG. 23(C). (
Also in C), the signal indicated by #IIw is a diagram corresponding to the case where there is no reflectance of the half mirror and the transmittance 5. Dark J+: lk compensation circuit 43! An example of an L-body configuration is shown in FIG. 24, and it is assumed that the signal from the small-sized image sensor shown in FIG. This corresponds to ff523 diagram (b). ] The signal No. 4 is passed through a known peak old circuit constituted by an O/R amplifier 58 and an O/R amplifier 59, and the switches 34 and 35 are connected to each other as shown in FIG. 25(b).
By turning ON and OFF at the timings shown in FIG. '+jj pressure value is held. The bits output when the switch S5 is in the ON state are the bits output from the image sensor 1. It is constructed so that it moves at the speed of light, and the output at the same time corresponds to the dark current level of the image fist sensor at that time. By subtracting this output voltage from the time-series signal by a differential amplifier constituted by an amplifier 60, a dark current compensated 5 signal such as
is output from the output terminal 61. The signal in the same figure is as shown in Figure 23 1.
', c). 62 in Figure 25.
64 and 63.65 respectively indicate time widths corresponding to the measurement field of view of the first image and the second image. The dark current compensated signal shown in FIG. 123 (C) is reflected by the half mirror 36. In order to correct the imbalance between the image and the second image, w4 due to the imbalance in transmittance is removed by the gain section f#I + width filter 44, and tR
23rla (d) Mr. f) fxjR number 2 conversion 1'LL
. As a specific variable gain widening base, for example, the 26th
A circuit as shown in the figure is given. The gain IIT variable amplifier 10 shown in FIG. 26 has a configuration in which input resistors R1, I and feedback resistors R2, R3, R4 are connected to the negative input terminal of an operational amplifier 67. Of the resistances listed above, R3 and R4 are the switches 56, respectively.
．． It functions as a feedback resistor depending on the open/closed state of 37. 6. Since the gain of the wood widening device is made variable in accordance with the open/closed state of s6.37. 271ml', a) is the first image and υ from the image sensor 4 when the imaging light = 7: #-1 or r is imaged on a constant imaging plane, that is, in the focused state.
It accepts the signal of the second image. If the half mirror is ideally made, the 4'i combination of the above two images will be
However, due to the actual eight-fumiller subequilibrium,
The two images will be slightly different, and this situation is minimized in the figure. 69.70 indicates the field of view of the first image and the second f#, respectively. When such signals are supplied to the Nuka #i66 of the variable gain amplifier, the above switch is actually switched to St with the FET analog switch. Turn on S6 and S at the timing shown in Figure 27 (b) and (:C),
The R2. If R3 and R4 are set to 5 in advance, the imbalance of the 29 signals mentioned in L can be avoided and the in-focus position l can be detected with certainty. That is, Fig. 27 (
As shown in d). The unbalanced 2K'47'/ shown by the dashed line is converted into the iE two-image signal shown by the solid line, and this corrected signal becomes the signal shown in fR23 figure (d). It is equivalent. In addition, 71 in fJS27 figure (a)
represents the length of the charge JM time of the image fist sensor. The output of the variable gain amplification JA44 in which the imbalance between the two images is eliminated in this way is input to the accumulation time evaluation circuit 50, and the evaluation signal, specifically, the accumulation time when there are too many bright lights, is sent to the accumulation time evaluation circuit 50. On the contrary, the shortening command signal is inputted to the J81 time extension command signal when the light visibility is too small.The signal line 52 inputs the extension command signal to the gain setting circuit 51. In the same figure, when a signal t) as shown in FIG. O at timings like (b), (c) and (d)
By turning N and OFF, it becomes a known peak hold circuit configured with operational amplifiers 73 and 74 as shown in the figure. The peak value 85 in the measurement field of view 83 of the ta-th and the measurement field of view 83 of the second image is as shown in FIG.
2, and when 310 is turned ON, a sample hold circuit constituted by an operational amplifier 75 operates, and the peak value is held in capacitor C3 as shown at 84 in FIG. 29(e). In the figure, 80 indicates the width of the storage time of the image sensor, and 81 indicates the time during which the N-bit time series signal is output. The held peak values are input to comparators 76 and 77, and the respective reference voltages are applied to the other input terminals of the comparators. Each of these JjJ voltages is connected to the maximum value h It f of the time series signal and the variable resistor 86 to the maximum value H It f of the time series signal.
．． 87, and if this limit value is exceeded, the output terminal 78 of the comparator 76 goes high; similarly, if the lower limit value is exceeded, the output terminal 79 of the comparator 77 goes high. become the level. In FIG. The signal of this comparator is input to the gain setting circuit 51, and the 8-integration time is changed so that the outputs of the comparators 76 and 77 both become low level. Specifically, the accumulation time is changed by changing the timing at which the driver 6 applies a shift pulse to the image sensor in accordance with the output of the gain setting circuit 51. This signal is conveyed to the image sensor 4 via line 53. Variable gain amplification shown in Figure 23(d)! 4
The output of 4 is input to the accumulation time jf*l+11 path described above, and is also applied to the negative input terminal of the differential amplifier 17-, while at the same time, it is sent once to the differential amplifier 8 via the n-bit delay circuit 45. Appended to positive input. n pip)i! ! [The circuit can be easily realized as explained in FIG. 7, but in this example, the number of delay bits is changed according to the maximum aperture ratio of the imaging optical system 1, 19th by taking the difference between belief t'>
Fluctuations in the focus signal due to the aperture ratio described in the figure can be suppressed as much as possible. In other words, when the aperture ratio is large,
Since the sharpness changes relatively rapidly, the two-way hit g is reduced, and when the other aperture ratio is small, it is reduced to one bag.
This method attempts to suppress the change in the focus signal by increasing the number of fl bits, and the method using only one stick is the third method.
This idea is based on the fact that most of the current 71 SLRs use so-called aperture metering, so when using lenses with various maximum aperture ratios, the focus signal is stabilized and operability is improved. The direction F is aimed at. In the ff130 diagram, when a signal as shown in FIG. 23 (cl) is applied to the input terminal 86, this human input signal and the 1-bit Y extension circuit 15 explained in FIG. 1. Corresponds to the diameter and diameter of the imaging optical system. The delay signal as shown in FIG.
The transmission signal is applied to each input terminal of a differential amplifier constituted by an operational amplifier 89 as shown in the figure, and the signal shown in FIG. 23(f) is outputted to the output terminal 9o. Figure a'$31 is the same figure (
Enlarge the circled part of the image signal shown in a).
This is an explanatory diagram that partially shows the difference output between the transmitted signal and the non-spread signal, that is, the signal in FIG. 23(f). FIG. By comparing (C) and (d), the output of the X・÷h7 amplifier when bit extension is applied and (d) of the same figure shows the output of the differential amplifier when 3 bit iY14 is applied. , it can be seen that the output value t) of the differential amplifier 8 changes by changing the number of slow bits. As mentioned above, Figure wS32 shows an example of the reciprocal of the maximum aperture ratio of the imaging optical system, that is, FN, and the number of delay bits suitable for it.In other words, the smaller the FNQ, the smaller the number of delay bits can be set. be. In FIG. The output of the differential amplifier 8 is input to an absolute value circuit 9 as shown in FIG.
! The signal is manually controlled by a width filter 47 to an appropriate signal level, and is converted by a gamma conversion circuit IO. That is, a large level of the output of the variable gain amplifier 47 is converted to a larger level, and a smaller level is converted to a smaller level. The change in the signal due to the signal processing in 1- below is absolutely 111 in Fig. 23 (g).
The output of the circuit 9 is shown as the output of the gamma conversion circuit in FIG. The output of the gamma conversion circuit is input to the h1 divider 4B, and the I of the first image is input as the 231st threshold (i).
It is added in the N+1 constant field and subtracted in the J11 constant field of the second image. Depending on whether the terminal value vs is positive or negative, which of the first and second images has greater clarity? is determined as r1. That is, if the first image is nil compared to the second image, the final integral value will be positive and L!
If the second image in I is clearer than the first image, the final integral value will be negative.0 If the sharpness of the images is equal, that is, when the image of the imaging optical system I is formed on the plane to the predetermined focus. The final integral value becomes O, and it is determined that the image is in focus. In this way, it is clearly determined whether the image of the imaging optical system is in the front focus, the back focus, or in focus with respect to the predetermined focal plane, depending on the positive or negative value or O of the output of the integrator 48. can. Since the signal processing for detecting the image formation state is in accordance with the Nomotogyori force method described in Figure 5, it is obvious that the ability to detect 11 degrees is extremely sensitive, as shown in Figure 22. Reference numeral 49 is a 1-display circuit that gives a warning when focus is before focus, after focus is detected, or when focus detection is difficult or impossible.
#Be controlled. Reference numeral 56 is a line for transmitting an i notification signal, which will be described later, from the gain setting circuit. X weight integral! ! An example of the hold circuit and display circuit is shown in FIG. 33.
The signal shown in FIG. 4(a) is input to the input terminal 91, and the signal shown in FIG.
At the timing shown in FIGS. (b) and (c), the switch S11
, S12 is ON, 0FFt! Therefore, the same figure (d
) As shown in <,: In the JS1 image-side fixed field 115,
The signal as it is is inputted from the operational amplifier 96 to the integrator 411 as shown in the figure as a signal inverted by the inverting amplification circuit constructed as shown in the figure by the operational amplifier 92 in the ff12 image side fixed field l16. Furthermore, the switch 313S14 is connected to the switch t1 as shown in FIGS. 34(e) and (f).
Integration is performed as shown in FIG. 4(g) by the IS, which is turned on and off at four timings, and the integration effect is held in the capacitor 100. This situation is shown in FIG. 34(h), and the hold outputs are then manually input to comparators 101 and 102, respectively. Let this Holt City Ha: be VS. On the other hand, the switches S 15 and 316 are set to the 341st+4(i)(
By turning ON and OFF at the timing shown in f),
An integrator configured as shown in the diagram with an operational amplifier 93 has a first
The image signal and iR2 image signal are shown in Figure 34 (k
), and then switch S 17 ,
S IB is shown in Figure 34 (cross). By turning ON and OFF at the timing indicated by (1+), the peak hold circuit composed of operational amplifiers 94.95 as shown in the figure generates the L first image signal or the second image signal.
The larger image signal integration result is detected as shown in FIG. 34(m) and held in the hold circuit constituted by the operational amplifier 97 as shown in FIG. 34A(0). Let this hold voltage be VT. vt is an external signal. For example, the aperture tt of the imaging optical system is controlled by a variable resistor 9, which is controlled by various conditions such as the light focusing aperture value or whether the aperture is 1E or not, and whether or not a flash is used.
8 and becomes the reference voltage of the comparator 101 as it is, and at the same time is inverted by the inverting amplifier constituted by the operational amplifier 99 and becomes the reference voltage of the comparator 102. In other words, +j (if the output attenuation rate is D due to variable resistance, the comparator 101.1
Both outputs of 02 become low level, NOR game) 10
The output of No. 3 becomes high level. In the case of vs<-v7o, only the comparator 102 becomes high level, and v5
>VTD, only the comparator 101 becomes high level. As can be seen from the explanation in section L, hereafter, the pair of comparators 101 and 102 operating under the conditions of H are used as so-called window comparators, and the OR gates 104, 105 and 106 are one of them becomes high level and accordingly,
Each of the LEDs 107a, 107b, or 107c will be lit. Therefore, the state of focus, front focus, or rear focus can be determined by the output voltage of the integrator vs. O, 1F, or negative sign as described above. Since the above output attenuation rate 〇 changes accordingly, the window comparators LO1, 1
02, the lower limit range changes. Even in this one-time focusing state, the single-focus accuracy may be loose to some extent under shooting conditions, such as conditions where the aperture value is expected to increase due to the aperture setting or the use of a flash. If the sharpness of the photograph α is not a problem and is practical,
By widening the focus discrimination range, it is possible to more stably find a single point of focus.On the other hand, when shooting a dark object, when the aperture is opened, the focus discrimination range is narrowed, and the shallow field density at that time can be achieved. The focus adjustment of the photographic lens is within a range that does not exceed . The tree structure allows the realization of a camera that is easy to adjust focus for various usage conditions. LED10
7b is for display when focusing. The LED 107a is for displaying the rear bin.
107c is a small front pin for the front pin. On the other hand, depending on the subject, if the hardness is extremely low or the contrast is very low, it may be difficult to detect the image formation state. In such cases, please send a notice to that effect. Record L
It is necessary to make the user aware of this using the ED107. Furthermore, it is also necessary to always control the value of v7 to be as constant as possible so that sharpness detection can be easily performed. This method will be explained below. In the tjS33 diagram, the hold voltage VT is also input manually to the comparators 111 and 112, and is compared and evaluated with the set voltage using variable resistors 109 and 110. If VT is not within the set voltage range, ?
Since the t' signal is determined to be inappropriate for sharpness detection, the output terminal 113 outputs a signal to notify that the human power is excessive. On the contrary, from the output terminal 114, a signal 1] is applied to the #iso gain and the immersion chamber circuit 51 via the line 54 to notify that the human power is too small. Gain, iQ constant 1ii11
'ft 511itu I:f)Ll'->*Use It
The gain of the variable gain amplification filter 47 is controlled so that T is always at a level a''I. In this case, the entire system is brought to a stable gain state close to Ft with as much flexibility as possible. Therefore, in the evaluation of VT, the above-mentioned accumulation time evaluation result can be added to the conditions for changing the Kabu Lv. Even if this is done, if a signal indicating an excessive input or an insufficient input is generated from the comparator 111 or 112, it is determined by the gain setting circuit, and the high level output is sent to the OR gate shown in FIG. 33 via the line 56. )104,105.1
By specifically transmitting the same information to LEo 06, all of the LEo 107 are turned on in the lighting state a, allowing the user to visually recognize that it is difficult or impossible to detect the condensation state. As shown in I-, the overall accuracy is shown in FIG. 22, and according to this method, the accuracy is greater than that of the method shown in FIG.
7: It is not only possible to determine the state of the 1-in-focus III pin or the back-focus without moving the system, but also to detect changes in the working object or brightness. Even for objects, the degree of resolution can be stably detected by evaluating the degree of resolution using two images. Furthermore, consideration is being given to automatically adjusting the gain of each part of the system in accordance with the brightness and contrast of the object, thereby making it possible to detect AA resolution under various usage conditions. R35ll shows the change in vs with respect to the position of the imaging optical system near the focal point when each part of the system is set to gain.As can be understood from this, the sign of Vs suddenly reverses at the focal point. The in-focus state can be detected with high precision for the first time, and it is possible to stably distinguish between the first and second bins at points other than the first in-focus point. Figure 36 shows how Vs changes with respect to the position of the imaging optical system when the gain is optimized in each part of the system. In the figure, vth is defined by the 1-lower limit voltage of the window comparator 1G1.102. I [area, and the image f that corresponds to this range;
Imaging light by one-time detection'? - System JI constant accuracy! be. Next, we will explain a method for inspecting the image formation state according to the j+1 method according to the present invention.
An image sensor with a light receiving part of #! It is the same as the S method in that the images in the ml and second light receiving sections are subjected to gamma conversion, respectively, in order to compare and evaluate the sharpness of the images received by each light receiving section. Photoelectric conversion t'! corresponding to the position in the same light receiving section! That is, a bit output difference signal 1) is formed, and the signal written by sequentially integrating this signal is used to determine the focus after focusing. A detailed explanation will be given below in the order of the figures F. FIGS. 37, 38, and 391!4 are schematic diagrams showing the arrangement relationship between the image sensor and the illuminance distribution of the insert in this method. As shown in Fig. 37, the imaging optical system 1 is divided into two beams by a half mirror 3B, and image sensors 4 and 4' are placed behind the chest of the planned focal plane. - Form an image of an object not shown in the figure. The example shown in FIG. This is a case where two image sensors 4.4 are arranged on the same plane, and in this case, by providing a total reflection mirror 37, such arrangement becomes possible. In this example, 4.
4: is a separate image sensor, - may also be used, but 11
! Preferably, 4, 4' are the first and second receiving X, a
1ll image sensor - For example, in the figure, it is qt@ to have a line sensor whose light-receiving surface lying on the plane of the paper is also 1, so that the optical position 2ts becomes tA.
It will be easier than the 31m approval example. In the examples of FIGS. 37m and 38, if the object 1 is assumed to be an S pattern as shown in FIG. 2(a), then when the imaging optical system 1 is in the rear focus state, When the S hoe illuminance distribution occurs and the image is in one focus state, the illuminance distribution of the image is as shown in (b), and conversely, when the front focus is on, the illuminance distribution of the image is as shown in (@). Figure 27140 is a block diagram of this method, in which the light weight passing through the imaging optical system 1 is divided into 2 light beams by the half mirror 36, and the light beams are separated into 2 light beams by the half mirror 36, which are then brought to a predetermined focal point across the fixed focal plane. At one optical distance from the surface, l'j! image sensor 4,4
′. Assuming that the image sensor 4.4' is supplied with the necessary pulses as already described by the driver 6, and that the slope distribution at the light receiving section is as shown in FIG. 41(a), the image sensor 4.4' sensor 4, go
>The time-series image signal becomes as shown in Figure N (b). In this case, since two image signals are simultaneously taken out from two image sensors, the @ signs of 2ffi overlap. This corresponds to the example of No. 37511, but in the example of FIG.
By forming a tap for taking out ItIR, it is possible to take out the two compensated signals at the same time. ! - The second image signal is the dark current compensation circuit 43. The seven-time signal that passes through <r and is converted into a signal with the dark current component removed, as shown in FIG.
In order to eliminate the non-uniformity between the two signals due to variations in J4*, a gain of 19 is applied to the %γ.
18 and 118' respectively to the gamma 9 conversion circuit 11.
9. Manually operated at 119'. The output signal from the same circuit is
The result will be as shown in FIG. 41(d). This signal is the differential amplifier 8
This results in a time-series signal of the difference between the two signals as shown in FIG. 41(e). The operations of the gamma conversion circuits 119 and 119' are the same as those described above, but in this example,
The gamma conversion characteristic is changed by Δ to the tq ability according to the maximum t+PI ratio of the imaging optical system, and this (therefore!!!) is characterized in that the brightness detection characteristic is changed.
A specific example of the configuration of the circuit will be explained in No. 4254. The image signal is manually inputted from λ Mandan 123 and then transferred to a known logarithmic compression circuit 124.
A separate input signal corresponding to the Ell ratio of the operational amplifier 125 and the imaging optical system 1 is received from the input terminal 120, and a'! 4 = 19
The gain is amplified by a gain amplifier, and further a known grain expansion circuit 1 is added.
27 and output from an output end 128. Thereby, the gamma conversion characteristics can be changed according to the characteristics of the imaging optical system, and changes in the focus signal due to the characteristics of the optical system can be suppressed as much as possible, and stable sharpness detection can be performed. FIG. 43 shows an example of the comma value that should be set for the FNo of a variety of imaging optical systems, if the FNo becomes small in this way. If the gamma value is small, and conversely the FNo is large, the gamma fl is increased to support strong nonlinear transformation of the image signal and sharpen the focus signal. In FIG. 40, the output of the amplifier 118 is inputted manually to the accumulation time, if value circuit 121, and is inputted to the accumulation time, at value circuit 12 in this example.
A concrete CO circuit configuration example of No. 1 can be considered as shown in FIG. 44. In the same figure, the input ends are increased in width at 129° and 130° respectively! When the outputs of 118' and 118 are input, the comparator 131 always closes the switch S20 to the higher level of the two inputs, which is shown by the solid line in FIG. As it is,
2tj7. Only the always large level of the signal of the second
It will be input to the J-1U11 evaluation circuit 50 as described in FIG. The operation of the circuit 50 is the same as described above, and if the accumulation time is too short and the signal level is small, the output terminal 79 will issue an instruction to extend the accumulation time, but conversely, if the accumulation time is too long, When the signal level is large, an accumulation time reduction command signal is output from the output terminal 78, and the gain setting circuit 51
is input. The output signal of the differential amplifier 8 is appropriately level-corrected by an Iff gain amplifier 47 controlled by a gain setting circuit 51, and is input to an integrator 122. The output signal of the integrator is as shown in Fig. 41 (f), and the image formation shape E can be detected by the winter integral 1pVB. This is the table of contents. A specific circuit example from the A-body integrator 122 to the table subcircuit 49 is shown in FIG.
The same numbers as those in Figure 3 are replaced by ``7'' and ``I'', which have the same functions as those described in Figure 33, so their explanation will be omitted. The output signal from the X' dynamic amplifier 8, which is input to the a71!4 (a), is input to the switches 521 and 322 by the integrator constituted by the operational amplifier 133 at the timing shown in Fig. 47 (b) and (c). ON. By turning OFF, it becomes an integrated signal as shown in Fig. 47(d). Historically, in a hold circuit consisting of an operational amplifier 134 and a capacitor C5, switch S23 is the fourth
'7 It turns on and off at the timing shown in Figure (e). −
It is held in a form similar to: jrJ471'4 (f). This halt value is Vs shown in Figure (f) of fS41. The integral signal enters the other absolute value circuit 135, and the absolute value +
G, (V), and the peak hold circuit consisting of operational amplifiers 94 and 95 holds the maximum (fi) of the signal.The hold value is VT as described in No. 3314.
It is. The following five signal processing methods and their α'is
Since it is exactly the same as that described in FIG. 33, the explanation will be omitted. tJS40 diagram (22nd page)
The difference from the image forming state detection method described centering on b4 is that the first and second R signals are first subjected to gamma conversion by 91, and then the difference between the two signals for each bit corresponding to the digit is calculated. , the time series signal of such difference is integrated to obtain the shipboard N
Focusing of the imaging optical system, +1 at the integral set Vs and sign
Pin-like after iI! When applying the 0-hydraulic system, which discriminates E, to a camera, as in the method described above, it is important to always set optimal conditions according to the usage status of the camera. Noh No. 35. Extremely high focus detection accuracy as shown in No. 3614 can be achieved. Next, an example of a case where a focusing adjustment system for a photographic lens in an optical device of a camera rod is constructed using the image forming state detection method according to the present invention described in 7 will be described below.・Explain using a camera as an example. Examples are '
It goes without saying that the method of the present invention is also effective in application to other types of cameras, although it is an LLN+ reflex camera. :Figure B48 is a focusing system that uses an uninvented image forming state detection method for a normal single-lens reflex camera. In Figure 0, which is a schematic diagram showing the cross section when the t-da is incorporated, 1
5.0 is a lens barrel including optical aperture 152! 51 is a photographic lens held in the camera. A light beam from an object (not shown) passing through the photographing lens 150t is reflected by a quick-return mirror 153 and deflected into a single force. Ventabris L, 154. Finder eyepiece 15
5 and 91 reaches the photographer's eye without indicating 4. This allows the person to aim the object to be photographed, adjust the focus of the photographic lens, and expose! lSM's death
It becomes an ability to do this, and it becomes a glossy one.
57, when performing a full shadow, the quick return fist mirror 153 is bounced to one side using a known method:
By moving, it retreats from the optical path of the 1-ship shadow lens. 158 is a film, and 158 is a camera body that holds each of the elements listed in 1-(2) and shields disturbance light other than the photographing light beam. 159 is a camera body that uses the method of the present invention. ?C position is made into a unit (hereinafter abbreviated as AE unit), and in this example, the same unit 1
59 is a support member '160 that is rotatably supported in a part of the camera body 156, and the quick return
In conjunction with the bouncing action of the mirror 153, the illumination is moved away from the photographing optical path in the direction indicated by the 14-width broken line. When adjusting the focus of the photographic lens 150, the AF unit 159 is held in the optical path of the photographic lens. The quick return fist mirror 153 is set to 1 when adjusting the focus.
As shown in the figure, it is in a diagonal state in the photographing optical path, so
The mirror 153 must be a half mirror configured so that its part or the entire surface has an appropriate transmittance.
The light beam reflected at 3 is deflected to the fine sensor, and the transmitted light is deflected to the light receiving part of the image sensor in the AF unit. This is a display that informs the photographer of the adjustment status of the photograph/focus at the time of display.
9 and click return temple mirror 153 are taken at the same time!
Along with leaving the company. When 111 is finished and the quick return mirror returns to its original position, the AF unit 159 also rhythmically moves +
It is now in a state where it is held in the photographing optical path. An example of a mechanism that implements the rhythmic relationship shown in letter L between the quick-return self-mirror and the AF unit is shown in FIG. 49. The AF unit applies a shock in the opposite direction to the shock that occurs when the camera rotates, thereby effectively reducing the equivalently harmful mirror noise. L I'll. Figure 49 shows 1-. ? - is charged with a force in the direction indicated by the mark 161, and due to this force, the energy storage 8-174 of the quick return/working mirror 153 rotates in the clockwise direction around +h175, and the quick return 7@ Quick shaft supported by mirror hook 181
At the 0th time when the return mirror hook 180 is in the Q-in engagement state iE by the action of the spring +82, the quick-return mirror drive hook 177 is 1. Memory lever 17
Rotation B (rotated by the shaft 178 at the same time as the spring 1
79, the quick return mirror drive hook 177 is installed so that it always rotates to the right in the figure.
The drive lever drive shaft 173 can be moved in the direction (in the figure) by being guided by the slope of the protrusion 177a formed in a part of the drive lever 170, which is pivotally supported around the shaft 171 so as to be rotatable. is rotated to the right by the force of /Henne 172. 174a is where the quick return mirror drive hook 177 is located! Prevent from rotating further 11
This is a stopper formed in a part of the power storage/<-174. Reference numeral 176 denotes a spring for always attaching the energy storage lever 174 to the left. When the drive lever 170 is rotated to the right in the figure, the pin 163 fixedly installed on the return mirror 153 is driven, and the pin 163 is moved to the right of the slope 170a formed in a part of the 8-170. The mirror 15 becomes movable in conjunction with the movement in the direction.
3 rotates to the left around the same axis by the force of the 7 hene 164 around the fixed @ 162, and hits the stopper 165 and rotates 45 degrees.
It is made to be in a diagonal state. On the other hand, since the slope 170b formed at the do side end of A-170 is separated from the pin 169 installed in the support member 160 of the AF unit 159,
The AF unit 15 is rotated to the right in the j direction of the same 8-170.
9 is rotated to the right around the axis 167 by the force of the lens 2168, resulting in a state IF held in the optical path of the lens. 166, when the AF unit is held in the optical path of the lens, the light-receiving surface of the AF unit determines the exact position, distance, and angle in terms of There is a fine adjustment screw at the bottom of the adjustment to hold it accurately. When a shirt release is performed from such a state, a force in the direction indicated by 183 in the figure is applied to the quick return mirror hook 180 by a member not shown fA, so that the quick return mirror hook 180 is released.
The lever rotates to the right around the mirror fist book 181, P5 is released, and the state of engagement with -174 is released, and the same lever 174.1ffl and the quick
Since the return mirror movement hook instantaneously rotates to the left around the rotating shaft 175, the drive lever 5-170 rotates to the left around the shaft 171, which causes the n of Itj, the engagement relationship of the structure. At the same time as the quick return 9 mirror 153 springs up, the AF unit 159 rotates to the left around the axis +67 and immediately moves out of the optical path of the photographing lens in the direction shown in Fig. 48. . This kind of situation! Exposure of the fills l and \ is performed at this point. When the exposure is H (then, for example, the focus is -), the force in the direction indicated by 184 out of 14 is applied to the quick return mirror drive hook +77 by the control force of the rear curtain of the photographer, and the force is applied to the quick return mirror drive hook +77 to the left around the axis 178. At the same time, the engagement between the drive lever drive shafts 173 and 177a is released, and the drive lever is released! 70 is rotated to the right by the force of the spring 172. When the quick return mirror 153 returns to the position 4511 as described in the description of the charging of the wooden structure,
Then, the AF unit 159 is again held in the photographing optical path. If you want to take a picture again, apply a force in the direction of decreasing I! The mechanism is charged and the process described above is repeated. Below is a quick
This is an example of an embodiment in which the return mirror moves with the AF unit, but in general, an AF unit is not used and the focus of the photographing lens is adjusted using an optical focusing device such as a normal micro prism. Sometimes I want to do
In addition, if focusing is difficult even with the imaging state detection method of the present invention due to reasons already mentioned, 1. Ordinary optical focusing [Since it is necessary to use ambiguity, the following is a selection of names used. By A
Keep the F unit in the optical path or evacuate it from the entire optical path, II! To prevent malfunctions, please set the “
Dynamically J: The mechanism for retracting from the foot path will be explained. FIG. 50 is a diagram showing an example of a mechanism that can realize I: article retrieval. The same numbered parts as in Fig. 49 have the same functions and structures as those already mentioned, so their explanation will be omitted. In other words, the quick return mirror 153 is held at 45@ in the optical path of the photographing lens. The force in the direction indicated by 204, that is, the shooting 114 is applied to the button 203.
To describe the holding mechanism of the AF unit, which shows a state in which the AF unit is held in the optical path of the photographic lens by the action of the mechanism described next by the force pushing the button to the right, in the charged state shown in FIG. Illustrated It!
WAfh lever 18 with a slightly different shape from lever 170
AF unit hook disassembly lever installed 1-4 on 5 +8
6 is in the locked position, the AF unit hook member 189, which is loosely fitted to the shaft 190, is attached 9 downward by the action of the spring 188. AF unit hook member 18
9, the exposure flux is determined by the drive lever 185 as mentioned above.
It is in a state of being rotated to the left around axis 171. Therefore, the AF unit hook release lever 186 is
Then, since the AF unit hook member 189 is pushed, it can be rotated by 6 f around the AF unit first drive lever 193 and the lever 193 and the lever 194 in a coaxial relationship, and the spring 197 allows the AF unit hook member 189 to be rotated by 6 f if AF unit:t
<The ZS moving lever 196 is attached to the spring 19 around the shaft 194ty>
Because rM effects on the right side of 14 due to 50 action, rrII
The hook/191 embedded in the lever 193 moves the AF unit hook member 189 by 1° and comes into contact with the right side surface 189h of the member, and the AP unit: fS 29 moving lever! 11A of 96 I 96
Since the engagement between a and the end of the AF unit holding member 160 is released, the AF unit 159 rotates to the left around the shaft 167 by the action of the spring 187. It is in a state where it is retracted out of the photographing optical path. Even if the quick return mirror 153 is held at 45" from this state as shown in the figure, the AF unit remains out of the optical path. In this state, the button 203
When the lever 199 is pushed to the right by the photographer, the lever 199 is guided by the guide pins 200m and 200b against the spring 201 and slides to the right.The right end of the lever 199 pushes the AF unit first drive lever 193 to the left. Because it is rotated in the direction of A
F unit 2nd! [One end 196a of the single-motion lever 196 enters into engagement with the retaining member 160 of the AF unit 159. The AF unit (AF unit) 159 is held in the optical path against the force of the mirror J187. Also, the hook pin 191 is attached to this and 3Apr.
Move along the right side #189b of the unit hook member and
It is hooked to Y island as shown. Therefore, from now on, even if the button 203 is released, the AF unit remains held in the photographing optical path. This situation! The switch 198 is closed +l at ε;, but since this switch is a dynamic n switch of the focus detection system, focusing continues as it is, and the shutter is released as necessary. Photography is carried out, but during exposure the above-mentioned L ta Ikl < AF
unit, the quick return mirror is illuminated from the optical path.
I'm avoiding it. At the end of the exposure, a force acts in the direction indicated by 184 in the same way as described above, and the guinocrite/mirror moves at 45°.
However, the AF unit will not be held in the optical path again unless activated via button 203. The protrusion 185b formed on a part of the movable lever 185 is not used for the p-time exposure flux, and the button 203 is pressed at a,
In order to prevent the F unit 159 from entering the optical path, the exposure beam is a stopper that engages with the AF unit second drive lever 196 and prohibits movement of the lever. On the other hand, in r motion, move the AF unit) 159 out of the photographing optical path i1!
You can also avoid it with +i il, in this case press the button /203
When pressed again, the lever 199 moves to position 44, rotates the AF unit first drive lever 193 to the left, and the hook bin 191 moves from the hook position of the AF unit hook member to the tapered portion 189a provided on a portion thereof. By pushing up the same member to release the hook and releasing the button 203, note 6: When the Sl lever 193 and the second lever 196 rotate to the right and the AF unit retreats out of the optical path, the switch is switched to 8. 198 is opened and the power of the AF unit is turned off. When the shirt release is performed while the button 203 is pressed, this can be detected by the switch 202 and a voice effect or warning for the release can be given. Figure 51 shows the buttons 203 and <-19 in Figure 50.
Perform the operation in step 9 using the known self-timer lever and press the release button. FIG. 7 is a diagram illustrating a mechanism that prevents erroneous operations due to a non-pressed state. 199' in the door 4 corresponds to the lever 199 in Fig. 50, and is <-, with a protruding H' at one end of the same lever.
fl l 99'a is provided, and the same lever 199
' rotates the self-timer lever 209 provided on the camera body 210 in the direction of arrow 21, and when it is pushed to the right by shaft 2Q8 and arm 207, that is, when using the AF unit, the release button 206 is rotated in the direction of arrow 205. The press is locked by l99'a. In the state iL where the release button 206 is normally pressed and exposure is performed, 199'a is the
06, the self-timer lever 209 cannot be moved in the right direction, and rotation of the self-timer lever 209 is prohibited, so that the above-mentioned malfunction can be prevented. Earlier, I mentioned the change in focus signal due to the 1 diameter ratio of the imaging optical system, but in order to suppress this as much as possible, the imaging system of the present invention uses a signal corresponding to the aperture rI ratio of the cedar lens used in the camera. The circuit parameters of the state sensing method can be controlled. Hereinafter, for this purpose, the concrete implementation for forming a signal with a ratio of W'Fl and 7z p, l u is 1f≦, and −(J7
When the ten-cus signal is displayed on the 11L pressure gauge T, the maximum aperture ratio of the photographic lens used at that time, taking into account conditions such as lens aperture number, etc. 1. The display sensitivity of the small output shown. 52 is a schematic diagram quantitatively explaining the general relationship between the aperture ratio of the imaging optical system and the image clarity. , the elephant of the object 212 is the image forming optical system 213: Q, , fj,
The degree that satisfies the relationship by distance f; i'J a, b
A real image 214 is formed at 7A. In this case, the spatial frequency of the object is determined by the image multiplier −11b/a and the circumferential line;
alΔ is performed. Here, a surface 215 .6 near the imaging surface 214 .
Space 1 due to image blur at 216°217.218
,',L wave g('s low'#1. is the distance D from the image plane
/b and 1.7·z injection 1111 +i are proportional to R. L
! II, the image formation may be 2!4 1i,' III The spatial frequency inner paper II 7 is (, 7) ((j outl
,,': If H: is small, R, "b j A'
That is, L nof' (proportional to the r+ l l l'F ratio. - for +-1; In Ito Zhan 1r11 or its 61st sentence, the crab (like H'r l!II Chi... Knee opening) of the present invention Indirectly put Maki on the side of J1 and Ki-gu-men]”+
i,' j+1.1. The power to detect i blood
'*D is inversely proportional to the closure ratio. , for the second time, we have already given up t-/II+' This practically proves that printing is necessary in the IC position of a practical camera, etc. Figure 53 shows an example of a specific 4a structure for performing such compensation 11. First, the aperture value is input from the aperture ring provided on the lens barrel, and in aperture priority EE, which performs E E'yW light by the aperture setting that is set, it is used. The lens diaphragm ring 219 shows 71.
Ru. In this state V, due to the tapered part 219a formed in a part of the turning/ri 219,
By 221, the power in the figure is J! PIJL, EE signal The camera side detects that the lens is in manual aperture mode f5 using the switch 222 and sets the aperture signal control IIa.
Set the operating power 223 to Jl, f + dynamic state i. This causes the No. 11 ring 224 to stop the lens. The projection 219 of the aperture ring is rotated to the right by the spring 225.
The aperture signal ring is stopped at a point where the aperture signal ring protrusion 224b is cut off, and the aperture setting value is transmitted to the camera side by the l ring protrusion 224a as the number of aperture steps from the IY ratio on the photographic lens side. On the camera side, this 12 fixed aperture Ift is received by a weak spring 226 and an aperture signal lever 227 in contact with a protrusion 224a of an aperture signal ring. This aperture value information is converted by mechanisms 227, 228 and 230 formed in the camera body with axes 228 and 229 set to rotate i + l, and is converted by aperture signal plano 231 ', l' + (i % L Chang-1 and 1
), (Place the aperture of 12 mm from the h-co-large-ui-i ratio of the 1.
The main 111 ratio is the open aperture on the /s side (11'i 4
Due to the length of pin/233, the rotational force is leaked from the spring 234 on the camera side around +j235 and is transmitted to the nileper 236, and is transmitted to the nileper 236 by the brake 237. As No. 1, '(#i23 B to lI'1
A11 A ratio is conveyed, and with this 41) t;, Figure 22 and Figure 40 show that the child has not yet been born! 11 imaging state detection/:2
41 above with 1-manpower. +1! is what is to be done. Horn aperture, Δmi IhX'! Or j11! '9 (curricularly large to 1) i diameter ratio or setting aperture (da ratio)
], narrow down by moving towards 24
1 is force-rotated around the car 243 against the pi 242, and the lock 1. Refinement link 241
The clockwise rotation is made by using the aperture lever 246 as a signal to indicate the aperture condition, and by using the aperture lever 247 as a signal.
8, the kite member 249 moves it to Φ and F in the figure like an automatic aperture. The automatic aperture lever 250 on the photographing lens side is moved against the spring 251 by force direction movement of the aperture lever 247 to narrow down the lens. At other EE times, i.e., when the lens is set to EE, program EE, tire input aperture end EE, and strobe EE, the lens aperture is closed); By setting the ring to EE, the number of aperture stages determined by the known AE1 Or, the aperture-less stop is converted to 1 and 2 apertures by the maximum 111-i ratio d mechanism described in 1111, and the servo formed by the aperture signal control I, 1-river movement force 223 and the aperture signal-)), (4h 232). , by Y, press 1st (cedar/nu's aperture, 1st/nu's aperture, 1st/nu's aperture, 224) and finger the aperture to the photographic lens. The maximum weight of the shadow/s (I) and the signal of the number of aperture stages are obtained and the imaging of the present invention I1. And No. 551.1 is No. 1, durable result 1% = JL +Q test) 11 Output from power formula, Chirui is this kind of equipment; In order to control the output by a signal closed to the shadow and shadow characteristics such as 1.l, tejV) and achieve an IPIJh suitable for h6 as a camera, the following formula is used: First of all, in Fig. 54, the external All
Controlling the output of 1 IN range equipment by the formula; 252 ill
In this example, the object distance signal emitted from the device twice is the photographing lens jQ 'II:' distance (no. 11 emission) 1 circuit 2
The output of 53 is compared with the 1'1 moving up 254, and the vertical magnification of the photographing lens - ← The extraction II signal generation circuit 255 corrects the ML magnification, and the meter 255 shows the image plane, the planned plane, and the η point plane. Possible is reduced. Then, the outputs of the maximum ratio signal generator circuit 256 and the aperture stage number signal generator circuit 257 of the photographing lens are input to the square cutter amplifier 258 in a form that is supplemented by a comparison nf function. The output IJ of the amplifier is 6
This corresponds to the lens aperture ratio at the time of shooting 1'J, and the same value -: is used to correct the focusing accuracy.
59 K/ control (wholesale and photo small note 260 IJ#
, , and S draw 11, Section 1.1 is displayed. Note that the display is limited to a meter, but it can also be done using an anamig or deinotal method using an LED liquid crystal display, etc.
Being Noh is something that goes without saying. No. 551Δ
shows an example of a similar method when using a TTL force formula such as an uninvented method, 261 is a TTL focusing 161 control, and its output book No. 1 is an increaser 11" device 262fr, If r is open side light, l + & wide open [” ratio signal is emitted) 1
In the case of the aperture A-light, the aperture switch 267 is closed based on the signal from the circuit 256, and the output of the aperture number t1/1 circuit 257 is manually controlled by the angular movement up 268.
Control is performed by generating a signal corresponding to the aperture value actually set. The result is displayed on the meter 263. The meter displays the difference between the actual imaging plane and the planned focal plane. 269 is an operating amplifier that emits a signal corresponding to the output difference between the circuits 256 and 257, that is, the lens aperture ratio at the darkest moment.
! 1 and then ← Ino to the 11th IHL finally to Eta 270 r・〃, °me, jj 3. '4 To the blur of the statue in the blood bank, 1's A, 1's face is small. As shown in , iTl 1=li, depending on the method of the present invention, the image formed by the C forming optical system is C
CD, BBD, CCD) 10-to-tai auto array V or MOS image sensor etc. The imaging state of the l11+1 image is determined by the second scan No. 1.
jlchi iki尤'γ, 11i of Su, 'j, l, mountain face or this]! , it is possible to extremely sensitively control I/i + ff1l for 11L image TQll flood on a useful surface.
Therefore, the 211
I'm in the field! It is beneficial. Also, the embodiment described in I below is like a target object / 7 stripes 1ψhi'? Lens aperture 11 ratio, 1 slit I+t at the time of shooting
i Kiride Moto Furano/Yu or Strobe Senyoyuki By controlling the system to always keep it in its best condition in accordance with various shooting situations, the focusing performance of l:H and accuracy can be improved to 41. In history, it is also possible to detect one brightness level without requiring any mechanical drive or vibration part in the detection system.
It is extremely difficult to use 11 (1
1 form iE. In addition, as an example, a general photographic camera was used for the explanation. can be,
4-screen RIffff without being followed by a general photo fH camera
Both μ'' formed in an ordinary optical system can be widely used in various optical devices that concern the image state. A photoelectric sensor (corresponding to ! shown in Figure 2214) having a universal conversion element that generates an air signal according to the luminous flux formed by the system (corresponding to ! shown in Figure 22) From the side corresponding to image sensor 4) and -1111+il', '+lI/A signal, the focal state of the optical system is determined.
(Rahe comparator 112 of the circuit shown in No. 33F4)
．． Corresponds to the circuit other than resistor 110) and ll1Ikikoichihen! II Ryoshi's two sweet-hearted orders ``-'s electric signal 2''
A signal corresponding to the minute (corresponding to the output of operational amplifier 97)
Contrast detection r for detecting that the contrast test of the luminous flux formed by the optical system is lower than a predetermined value from
R (33rd MniLrin/?I/-9112. Corresponds to resistance 110)! 1. II So,
When the contest test of the subject is low,! l! It is possible to prevent 1- from accidentally detecting the in-focus state. 4, L4 plane fmtF', /x explanation Fig. 1, Fig. 2
Figures 3 and 3 show the &Il images of a general optical system f and 4.
Each image formation 13 for a fixed putter/: I! FIG. 4 is a schematic diagram showing an image pattern in the image formation state and an image view 1a/4i in each imaging state. 414 is a schematic diagram for explaining scanning of an image by the image 1 sensor; 5 to 1714 show the first embodiment of the present invention, FIG. 5 shows the configuration of the electric circuit system of the device according to the first embodiment, and FIG. is an output waveform diagram showing the output waveform of each circuit block in the circuit system shown in FIG. FIG. 18 and 19 are signal waveform diagrams showing a focus signal obtained when the first embodiment described above is applied to a focusing system and changes in the focus signal depending on the aperture ratio of the imaging optical system. It is. Figures 2014 to 0'i3B illustrate the second embodiment of the present invention, and Figure 20 is a schematic diagram showing an example of the optical arrangement in this second embodiment. The figure shows each image formation state in the arrangement configuration shown in 2014! Diagram 2214 showing the illuminance distribution of the image at L is based on this second embodiment? The configuration of cii'i's electrical circuit system is 7 grams from the Small Nablock Association. FIG. 23 is an output waveform diagram showing the output waveform of each circuit block in the circuit system shown in FIG. 22, FIGS. 24 to 31,
33 and 34 are diagrams showing the detailed configuration of each circuit block in the bar circuit system and its human output signal, and FIG. 34 is the relationship between the image shift bit ln and the FNo of the lens. , FIG. 35, and FIG. ff136 are signal waveform diagrams for reducing the focus signal obtained by the device according to the second embodiment. 371A to 47 show the third embodiment of the present invention, and FIGS. 37 and 38 are schematic diagrams 11 showing two examples of the optical arrangement in this third embodiment.
4. Fig. 39 is a diagram showing the illuminance distribution of the image in each imaging state in the configuration of Fig. 37 and Fig. 38 A block diagram showing the configuration of the system, FIG. 41 is an output waveform diagram showing the output waveform of each circuit block in the circuit system shown in FIG.
47IM from FIGS. 2 and ff144 is a diagram showing the detailed configuration of each circuit block in the circuit system shown in FIG. 40 and its human output signal. FIG. 43 is a diagram illustrating the relationship between the γ value and the FNo of the lens. Figures 48 to 51 show an example of a focus detection system for a single-lens flex camera by applying the method of the present invention, and Figure 48 shows a schematic diagram of the camera M4.
FIG. 49, FIG. 5, and FIG. 51 are side views showing an example of the configuration of the main mechanical parts that can be used for power distribution. Figure 52 shows the image formation state of the optical system and the state of image blur 1! It is a schematic diagram for explaining the relationship between ; FIG. 53 is a side view showing the IMI-related configuration of the i'-output system i11 in the camera system L including the photographic lens. Figures 54 and 55 show two examples of circuit systems for optimizing the focus signal with the aperture ratio of the photographing lens centered on the aperture 1/11. 1 --- Image forming optical system 2.41.42 --- One constant focal plane or its conjugate plane. 4, 4' --- One photoelectric f conversion device, 6 --- Circuit to trie. 7 , 45---n hit detour, 8-111 operational amplifier, 9~---absolute value conversion circuit. 10.119.119'----γ conversion circuit. 11.48, 122- ---1 integration circuit. 12--1 hold circuit, 13--display meter. 49--1 display circuit. (b) Olull Plh. [2] N Suiou Figure 26 Figure 27 Jiyi Figure 4i-7 Lf3 Figure Chrysanthemum 14-7

Claims (1)

[Claims] A focus state detection device for detecting a focus state of an optical system includes a photoelectric conversion means having a photoelectric conversion element that receives a light beam formed by the optical system and generates an electric signal according to the light beam; A determining means for determining the focusing state of the optical system from a signal and a signal corresponding to a difference between electric signals of two corresponding elements of the photoelectric conversion element, and determining that the contrast of the light flux formed by the optical system is higher than a predetermined value. 1. A focus state detection device comprising: a contrast detection means for detecting a low contrast.