JPS58194007A - Focusing detector - Google Patents

Abstract

PURPOSE:To detect the relative position relation of an object image formed through at least three light shielding plates which are not arrayed in a straight line at or near a pupil position and placed in a transmission state selectively by a two-dimensional photoelectric converting element in two different directions precisely with simple constitution. CONSTITUTION:Luminous flux passing through one light transmission part of a pupil splitter 21 equipped with light transmission parts 21a, 21b, 21c, and 21d which are controlled into a transparent state successively is passed through an image forming lens 22 to form its image on an optical position detector 23. The detector 23 is equipped with electrodes 23a and 23b for vertical detection and electrodes 23c and 23d for horizontal detection and currents IA and IB, and I'A and I'B from the opposite electrodes are processed similarly. A subtracter 25 and an adder 26 find the sum and difference and a divider 27 finds (IA-IB)/ (IA+IB); and a comparator 30 compares its value with a synchronizing signal to discriminate between a front and a rear focus and a control circuit 31 performs display and lens driving.

Description

[Detailed description of the invention] do.

It is known that by dividing one frame of an optical system in general 7, when it is out of focus, it will be divided into different parts, and the images formed by the light beams will move in different directions.This principle can be explained using Figure 1. For example, in FIG. 1(, 1), 1071 imaging lens has an aperture 2a disposed near the pupil with iiJ of 1, 2 to 1, and 1 to 2; i! M ff; +#, 3 i
r. I: f'4r (') When in focus, the image Q is formed on the image plane 31. A blurred image Q++ is formed into an image IJν4 at a position perpendicular to the axis Ovc in the opposite direction.

Figure 1 (1) shows the opening of the light plate 2] 2;
h (If moved to the opposite side with respect to 1, 71<1~
During combined use, an image Q' is formed on the image plane 3.
The valve stand U (sometimes a blurred image Qf + Q'z is formed on the image plane 3 corresponding to the front bin and the rear bin, respectively; , I) to position (1)), when focusing (
c11 dust (and (λ') are in the same position, so the image does not move, but on the lifting platform of the 01 bottle: J: 1 dust (tj pulled.

From the beginning of Q'I's rise to the end of Q'2, I was on the verge of hyperactivity, and the dust on the lifting platform of the bottle was transferred from Q2 to the first stage of Q'2.

A device f that uses this principle to emit one moxibustion line
rIi, for example, according to Japanese Patent Publication No. 5 (U-13929), ``The phase shift of the image is steep only in one direction. For example, this vertical direction e
(Only in the case of an image with a strong jψ change, focusing could not be detected. This is because the phase shift of the two-dimensional image can be detected by using 11 C1 secondary Kerr solid-state sensors and performing two-dimensional pupil division accordingly. In the case of ``dimension'', v4 victory: Compared to the case of ``i-dimensional'' (
Since the number of vertices increases with the square of the number of pixels), the number of vertices increases significantly, making it difficult to implement. It was iMG. 1 Present invention I:l1, taking into consideration the following points, light f as a photodetector
)′1. By using the l + qI ejector, we aim to provide a highly focused detection device with a 1' top illumination structure and only one unit at the top.
The detector (f) is shown in Figure 2.
Lateral in semiconductor point curve] 1st... effect (
L+1lcrdl I'l+(Jt.

1] Shield of potential position detector using NecL)
f<, 10Q, quotient resistance board, 110:J,
1) to jJ (antilayer, 12 is n' single layer, 13kl, both) 1
@'Qi rare, 14 and 15 are '@poles, and the surface layer is provided with yt and an electric cup due to the n junction.

Therefore, when the light proboscis enters, the electric current f depends on the incident position.
ifn14. 'I and others + L + gradient direct current ■ A, '13
3, where city] distance a between 14 and 150
, the resistance is 1(1t, the distance t at the incident position of the light from the electric current Jm I 4 is X, and the part J'!t
If the likelihood current generated by the incident light with h'+□ as -R,
A -"'(,1,'l:(-,"'. ・(2
) 7 Therefore, city; pole 14. By performing a performance consisting of the output weights 1'A and 'n of Is, the incident position of the circle is 1!, regardless of the input M' energy (ie, incident light) meter. The distance X is found. Incidentally, the incident light l is 1o- to 1'n-...(4
) is required. The above question has been made for the case of a one-dimensional (one-dimensional) viewing position, but the principle is the same for a two-dimensional optical position detector. Thus, for example O'#: (X'7 equipment as shown in Figure 3) ' A (x) + ' 1) (X) (', J1, I
Eight (X) = -10 (X) , II,, (X) --
'-10(X)-(5)7,
1, and the flow IAl'11 for the output from the electrodes 1 and 15 by the entire image is as follows. K is expressed by the expression (+il, (7J), so the equation (8) is:
□You can now find the center of gravity of the image.

Next, the focus detection device according to the present invention using a two-dimensional optical position detector will be explained with reference to an embodiment shown in FIGS. 4 and 5. The transparent parts 21a and 2 are controlled to become transparent sequentially by a pupil divider using an electrochromic device or the like.
] 1st, 21c and 21d. 22 is an imaging lens; 21: J is an electrode 2 for performing vertical detection with a quadratic multiplier i)"r li detector placed at the focal position of the imaging lens 22; and horizontal force. It is equipped with electrodes 2, 2 and 3d for detecting the direction, and 1 (transparent part 2.1 of the acid content ifU device 2j).

21 l), 2 'I c '! ) da 4: J' 21
A beam of light entering d passes through the entire unit 1//z 22 and forms an LVC image on the original position detector 23. Figure 5 shows optical 1, device detector 2;・
The position of the optical position detector 23 (2:3:+, 2
:31) or 1. The output' current [Al'H and 75 (blood 2
:3 c, 23 (output current 1'A from I
I′+3 is treated similarly, t], so the output′ current I
A, Regarding II3” Sodo d) 1. I will clarify. 24.2
CB light 1η position detector 2:3'11 pole 23;l,
23 A/f that amplifies the output current from +1, 25 a reducer that calculates (IA'''II), 26'l-
1Jll calculator that calculates “(IA +”n), 270
J: R(R)'s Performance 181 - Exerting Threatening Device, 28d,
Pupil split i! A drive circuit that sequentially makes the transparent parts of i 21 transparent, and simultaneously connects them to the comparator 30]
- Lever system 1i111 same lever j17-C transparent part 2141
When is in the transparent state (→) level and when the transparent part 21 (is in the transparent state is at (-) level
- Eyes /) Grate: 3 (same as 1-i4 self-control j1111 for y) υ] When the translucent part 211) is in the transparent state (→) Section 21 [1] When in transparent state, issue a pulse at (-) level/J-. 29shi1
3 Fl, a filter that removes the Ias component from the output of the desensitizer 27;

30' is the same 11J outputted from the drive circuit 28 as 71'j.
I bow and filter 2! ] via [7 to remove the clock from 27 to Tsuno 5\:11. 1. It is a converter that determines whether it is the front bin or the back bin by comparing it with the sprouting signal.

To be clear, in FIG.
:(With 1-, the center of gravity of the squad is -1, the force is not equal)] If we take the time when it is on the (+) side of the output J of the remover 27, then the front edge + DlljM
28 (hereinafter referred to as "Signal A-1")
．． ) and the output signal of the fish remover 27 or 1-) (hereinafter 1 Shinyumi 13
” 1. ) and when the ratio is 1~, the (
-1) and A8 bow 1('s (-1) match (1,
(': 7!i: Eyes 1 dark light position 1r! Output device 1 knee'c-1-force G' (2sfl Koi?, the corner is in Figure 1 (2)) It shows the state of the channel Q2, and the (→) of the IN channel matches the (-) of the fi number I4. (1 large scale of λ1/] is 1.・co/・millerator is σ
) to detect whether the state is
3 + 6:1 1st 1st order': 1, 1-J-rudo both figure small (, 7 no clothing device d chitaba? 1 signal command output to the old image lens drive turning part The control circuit detects the level of the amplitude of the amplitude of 13": 4' + 4' and 7], and detects the intensity of the amplitude of the amplitude of 13, and 1: The in-focus state is determined by the signal from the rear bin or the rear bin, and the display device or drive device (=C effect JL) outputs the necessary amber signal. When focused, the amplitude of the U1 signal sensor 13 becomes dO.Furthermore, from the output of the adder 26, the radiation light -
can be detected, so this can be used for the first time in Numakawa Bay, for example, as shown in Figure 5'! 1 is there” 2 sea urchin υldo]
The output of the θ device 2 () is sent back to the drive circuit 28 by "Noy IS" and the transparent part 21 of the pupil divider 21; l, 2111
, 2+ (', and white 11 by adjusting the transmittance of 21d.
iIJ ga... ゛Ha is rounded up? 1j rope 2 main I ask. Own Hgb
The amount of light may be adjusted by controlling the opening area of the light-transmitting portion by other means.

This embodiment is structured as follows: 1 and 1-; Author'i ('To make a comparison'), each of the vertical and horizontal directions
, ((state ie front pinot, small beam 2 in focus f1j ■ or switch pinout) - can detect the deviation lk and this rl, l') 4-, Rzle L fiM i( '
J Cityll IflII L+ jW VCJ: Rihaku! 1
v1 focal beam - 1 focus can be performed.

As described above, according to the present invention, focusing is sharply focused in the vertical direction and the horizontal direction. 1. Ut'(
', Jinoko.

6: [, imitation unnecessary 1'J1
f-knee: or difficult to reach Mlt)': Connected in one direction, it is possible to detect focus even on small objects, and extremely (
f(@effective1, also, in the following explanation-4,
Two-dimensional bi(8r position detector is used, so it is very easy to use)
A 1fi-i photodetector may also be used. Furthermore, the pupil divider 1 may be a light-shielding plate that disturbs at least E openings 1'l that are not on the -plane line G. In this case, J: is used to detect the movement of the image in two directions. Detects char and swallows 7. Therefore, the present invention can be applied to the 7th automatic focusing device of the optical equipment of the camera NI'- (if tC is 7'1, then 1-
It is possible to use a high autofocus device with +t'flΩ.

In addition, the transparent part of the pupil divider &:j:I closes as if it were a remaining stock. Equipment i/(m
JL・Iteji 11vJ, 1. I will do 1.
It goes without saying that the control circuit would be used to drive and adjust the stage rather than the imaging lens.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the principle of horizontal focusing of the present invention, Fig. 2 is a schematic sectional view showing an example of the optical position detector used in the present invention, and Fig. 3 is an optical position detection diagram. FIG. 4 is a perspective view showing the optical system of the two-dimensional focus detection device according to the present invention, and FIG. It is a block diagram. 1.22...Imaging lens, 2 Light shielding plate, 3... Image surface, 1
0 High resistance 8 plate substrate, 11 P type resistance layer, 12...-1
11 layers, 13 - common electrode, ] /1, ] 5-electrode, 21 - 1 node divider, 23 - light f~shi position detection, 2
4. 24' amplifier, 25, reducer, 26, adder, 27
Divider, 28 Drive time j clear, 29... Filter h
30. 30'・Controller: 31・Control circuit. Agent Masuriju Shinohara

Claims (1)

[Claims] The object images formed by the light beams passing through different paths of the imaging optical system are received by a photoelectric conversion element disposed on the regular imaging plane or its conjugate plane, and are focused based on the relative positional relationship of the object images. 1. In a focus detection device configured to perform detection. a light-shielding plate having at least three 111-order transparent parts disposed at or near the pupil device of the imaging optical system or at a conjugate position thereof and which are not in a straight line and which selectively transmit light; A device comprising a two-dimensional photoelectric conversion element provided as a conversion element, and capable of focusing in two different directions connecting the light-transmitting portion.