JP3006480B2 - Automatic focusing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line image sensor.
To receive the image of the subject using
The point state is detected, and the shooting level is determined based on the detected focus state.
Automatic focus adjustment device that drives the lens to adjust the focus
You. 2. Description of the Related Art Conventional line image sensors as described above
Is used, for example, in a camera focus detection device. I
However, this line image sensor uses a unidirectional line
The following problems can be detected because only a light distribution in the shape of a circle can be detected.
was there. A video signal obtained by an image sensor
In the focus detection device of the type that analyzes the image on the image sensor
If there is no more than a certain amount of contrast in the
Cannot detect points. Line image as image sensor
When using a sensor, the image line on the image sensor
Focus detection cannot be performed if the contrast in the direction is low.
Of the image in a direction different from the sensor line
Trust is often sufficient. Take pictures of people and outside scenes
When shooting true, the horizontal contrast is vertical
Because the contrast is often higher than the
When using a line image sensor for
It is reasonable to arrange the sensors horizontally. But this
, The horizontal contrast happens to be low.
Focus on subjects that have high vertical contrast
No detection will be possible. Also use the camera in a vertical position
A similar problem arises in such a case. This problem is two-dimensional
The problem is solved by using a simple image sensor. This kind of
JP-A-59-174807 discloses a focus detection device.
Proposals have been made. The gist of this proposal is that two
So that they form a subject image on them
The arrangement of the light receiving elements in one row
If the contrast is insufficient after reading the output,
To read the output from the light receiving element array. Like this
Focus detection by searching for a direction that provides sufficient contrast
It performs calculations, but requires a two-dimensional image sensor.
It is expensive because it is used. Therefore, a plurality of line image sensors are
By changing the in-direction and replacing the two-dimensional image sensor
However, in this case, multiple line
The image sensor consists of the same chip on one plane,
Video signal from the sensor to the data processing circuit via the output circuit.
Enter the focus distance (from the current position of the taking lens
The amount of lens movement until the body is in focus, that is, the focus
State) and so on. [0005] As described above, a plurality of lasers
Considered an automatic focusing device using an in-image sensor.
Output characteristics of a line image sensor such as a CCD
Are well prepared, but the output circuit varies in the characteristics of each circuit.
Output circuit is provided for each image sensor.
As a result, variations in the characteristics of each image sensor result.
It has become big. Data processing from output circuit
As the area of wiring to the circuit increases and the power consumption increases,
There is a problem. The present invention solves such a problem.
Trying to do it. SUMMARY OF THE INVENTION A focus detecting device according to the present invention
Comprises: a first imaging unit having a pair of image sensors;
The second imaging means having a pair of image sensors is provided
Cross-shaped by being arranged in a direction orthogonal to
The subject image is formed separately for each imaging unit.
Optical means for forming and each image sensor of the first imaging means
From the output through different paths, and the second
Output from each image sensor of
A plurality of reading means for reading via a
Output from the output means to an external circuit from one output terminal.
Output means for reading, read by the reading means,
The output from the output means is used for predetermined focus adjustment.
It is characterized by that. According to the present invention, a plurality of image pickup means arranged in a cross shape are provided.
A pair of images of the imaging device with the automatic focus detection device used
Read the output from the sensor via different paths
Also, the output circuit is common. Like this
This simplifies the path of the readout means.
On the other hand, the effects of variations in output circuit characteristics are avoided.
You. FIG. 5 is a block diagram showing the contents of the present invention.
Mainly described in paragraph numbers 0017 to 0019
However, the plurality of reading means in the claims
Corresponds to the shift registers R1 and R2 in FIG.
Lexer 70 corresponds to output means in claims
However, one output terminal of the claims has a multiplex
The output terminal of the sensor 70 corresponds. FIG. 1 shows an optical system and an image according to an embodiment of the present invention.
FIG. 2 is a perspective view of the arrangement of the image sensor, and FIG.
It is an exploded perspective view. In FIG. 1, 1 is a photographing lens of a camera, 6 is
Condenser lens, 8 are four re-imaging lenses, 10 is
Image sensor. Condenser lens 6 has four reconnections
An image of the pupil mask placed in front of the image lens 8 for taking a picture
1. Dotted circle drawn on the taking lens in the figure
Is the projected image. The front of the condenser lens 6
A field mask 2 having a character-shaped opening is arranged.
The plane is the planned focal plane of the taking lens 1 and the film plane of the camera.
Is equivalent to. The re-imaging lens 8 is
An image of the surface is formed on the image sensor 10. With this configuration
For example, one of the re-imaging lenses 8a '
Image on lens 1 by lens 6
Is the area surrounded by the circle of the photographing lens 1
Formed on the visual field mask 2 by the passed subject light
The image is displayed on the image sensor 10 by the re-imaging lens A '.
Formed. Similarly, the area of b on the taking lens
Formed on the visual field mask 2 by the passed subject light
The image is formed on the image sensor by the re-imaging lens
Is done. Long rectangles arranged in a cross on the image sensor 10
In the shape, X1 is the cross of the field mask 2 by the re-imaging lens
X2 is the image of the horizontal part of the aperture, where X2 is the re-imaging lens
B 'is an image of the horizontal part of the cross-shaped aperture of the field mask.
You. Similarly, Y1 and Y2 form a pair of vertical reconnections.
Image of vertical part of cross-shaped aperture of field mask by image lens
It is. An image of the same part of the subject is formed on X1 and X2
But the image of the subject by the photographing lens 1 is just viewed.
Formed on the field mask 2, that is, in focus
Image of the same part of the subject on X1, X2
The subject image is taken from the field mask based on the position of
When near the lens (front pin), X1, X2
Are closer to each other, and conversely,
Keep away. Therefore, a line is drawn in the direction connecting X1 and X2.
The image sensor is placed, and X1
For the video signal of the object image above, X _Two Of the subject image above
The video signals are shifted little by little and overlapped, and the phase of both video signals is
By detecting the amount of displacement that maximizes the
How far from the correct focus position is the body image
Can be calculated. This is the focus detection in the present invention.
This is the principle of the video signal processing.
Japanese Patent Application Laid-Open No. 60-2472 filed by the patent applicant
No. 10. Image according to the above principle
On the surface of the sensor 10, the arrangement direction of X1 and X2 and the
Line images are respectively drawn along the orthogonal direction of Y1 and Y2.
Image sensor is disposed. In FIG. 2, the taking lens is not shown, and
Tilt 45 ° behind the transparent part in the center of the flex mirror
The transmitted light is red due to the mirror placed downward
Outside line cut filter 3, visual field mask 2, condenser lens
Mirror 6 turned by the mirror 4 at a 45 ° angle.
The pupil mask 7 and the re-imaging lens 8 (two
(Four pairs) and is projected onto the image sensor 10. 5
Is a frame that combines all the above elements into one unit
You. The image sensor 10 moves in the horizontal direction (X
1 and X2) and the vertical direction.
Image sensor, but the line image sensor
A CCD image sensor is used as the sensor. A CCD image sensor is a photo diode.
And a capacitor that integrates the output photocurrent for one pixel
And these elements are arranged in an array
Then, the product is integrated at the place where photocurrent integration is performed for a proper time
To apply a shift pulse to the minute control gate.
The light amount signal due to the accumulated charge of each element
To the shift register and then to the shift register
When a clock is applied, the charge in the shift register
By reading the signals sequentially as voltage signals, the video signal
Is to be obtained. FIG. 3 shows an embodiment of the present invention.
1 shows a circuit configuration around a CCD image sensor. In this figure
PD array I to PD array IV are used for CCD image sensor
An array of elements as described above, wherein PD array I is
At the position of X1 in FIG. 1, the PD array III
2 and PD Array II at Y1, PD Array
Ray IV is located at Y2. Also PD array
Photocurrent integration by the average brightness of the image projected above
To determine the time, monitor along the PD array I
A photodiode (PD) M1 is also
A monitor photodiode (PD) M2 is
It is. G1 to G4 correspond to PD array I to PD array IV.
Each element of PD array with corresponding integration control gate row
And one-to-one correspondence. R1 and R2 are shift registers
is there. Shift register R1 corresponds to PD arrays I and IV
And the shift is applied to the integration control gates G1 and G4.
When topazul is applied, each element in PD arrays I and IV is
The elementary photocurrent integrated charges are transferred in parallel to the shift register R1.
Sent. Applied to the integration control gates G1 and G4
The timing of the shift pulse is different. Shift
The register R2 corresponds to PD arrays II and III, and PD
The charge signals in the arrays II and III are transferred. These
The shift register applies two-phase transfer clock pulses φ1 and φ2.
Driven, and the information stored in the register is sequentially output.
Is forced. For the sake of convenience in the following description, some words have been decided.
Keep it. Figure 1 shows the direction of the line image sensor.
As shown, the x direction (horizontal) and the y direction (vertical) are determined.
These two directions are directions indicated by arrows x and y in FIG. Total
Contrast is the difference between adjacent signals in a video signal.
The sum of the absolute values of the data differences, where the difference between light and dark is large
The more contrast, the lighter and darker the mix
Is bigger. “LowCon” is LowConf
An abbreviation of "idence", meaning that the reliability of focus detection is low.
It is. Hereinafter, the configuration and operation of each unit of the device will be described in detail.
You. (CCD image sensor circuit) FIG.
The CCD analog shift registers R1 and R2 are two-phase
Charge transfer is performed by locks φ1 and φ2. The output terminal
A pressure conversion unit and a buffer are provided to store PD arrays I and IV.
The accumulated charge is supplied to the OSI terminal via the analog shift register R1.
And the accumulated charges of PD arrays II and III are
Output from OSII terminal via log shift register R2
You. The output side of the monitor PD is the accumulated charge of the PD array.
The configuration is the same as that of
Is the charge stored in the monitor (PD) M1 at the AGCOSI terminal?
The accumulated charge of the monitor (PD) M2 is
Output from Also, the reference voltage output of this monitor PD is
The PD is not connected or the aluminum is shielded from light
A voltage converter connected to a PD is provided.
DOS is output. This output is the output of the shift pulse
Used to control the timing of occurrence. The integration control gates G 1 and G 3 have x
Direction PD arrays I and III, and
Then, a common shift pulse SH1 is applied. Likewise
The integration control gates G2 and G4 are connected to the PD
Rays II and IV, common shift via terminal SH2
The pulse SH2 is applied. Also each
The integration control gates G1 to G4 are connected via terminals SH.
So that the shift pulse SH can be applied all at once.
It has become. Image obtained from CCD image sensor
The signal is suitable for focus detection regardless of the subject brightness.
Signal level, so the integration time is
Of photodiodes (PD) M1 and (PD) M2
Controlled by force. Where the x and y directions of the subject
Because the average brightness of the strips of
Pulses SH1 and SH2 can be applied separately.
ing. The PD arrays I to IV are integrated clear signals ICG.
The pulse is cleared all at once, and from that point the photocurrent
Integration begins. Here, for example, a band in the x direction of the subject
When the average luminance is higher in the minute than in the y direction, the shift pulse
SH1 is output first and the photocurrent of PD arrays I and III is output.
The integration signal is intermediate between the integration control gates G1 and G3.
Is held. After that, the video signals of PD arrays II and IV
When it reaches a positive value, a shift pulse SH2 is issued and PD
The photocurrent integration signals of arrays II and IV are integrated control gates.
G2 and G4. Then each gate G
The shift pulse SH is applied to 1 to G4 all at once.
And the video signals in the x and y directions are all shifted by the shift register R.
1 and R2. As described above, the integration control gate G
1 to G4 temporarily hold the outputs of PD arrays I to IV
A device for transferring this data in parallel to shift registers R1 and R2
FIG. 4 shows a circuit configuration for this purpose. FIG.
Indicates the configuration of one pixel, and indicates the electric power photoelectrically converted by the PD array.
The load is integrated by the clear pulse ICG through the barrier gate.
Barrier to the first storage unit C1 which is charged to almost power level
Stored through the gate. Average brightness of this PD array row
The integration signal whose degree is monitored by the monitor PD is appropriate integration
SH when level reached ₁ Or SH2 pulse is applied
The pixel charge is transferred from the storage section C1 to C2 in parallel.
At this time, charge transfer occurs due to the capacitance difference between V1, V2, C1, and C2.
Is performed almost completely. Thus, the application of ICG pulse
To the application of SHn (n = 1 or 2) pulse
The charge thus transferred is transferred from the storage section C1 to C2, and
Of the PD array on which the other image is projected in the state of
Wait for load accumulation to complete. In this second storage unit C2
No photocurrent is generated and the charge is almost maintained.
You. When the charge accumulation of the other PD array is completed, C
The charges of all the pixels of the CD image sensor are stored in the second storage section C2.
The states are aligned at a level suitable for the focus detection calculation.
Next, by applying an SH pulse to the SH gate,
Information of all pixels in the analog shift register at an appropriate level
Transfer in parallel, and then synchronize with OSI,
This charge is sequentially output from the OSII terminal. (Circuit for performing focus detection and focus adjustment)
FIG. 5 shows how the image sensor is driven to detect and adjust focus.
The circuit configuration to be performed is shown. 20 drives the image sensor 10
Input the information, perform focus detection calculation, and drive the motor.
The lens is driven through a circuit 90, and a focus state display circuit is provided.
Microcomputer for AF that controls the control through 100
Data. The AF microcomputer is an AF star
The operation starts when the switch SAFS is turned ON. 30 is x
Direction monitor output AGCOS1 is detected, and PD in x direction is detected.
A shift pad that completes integration for arrays I and III
A shift pulse generating circuit for generating a pulse SH1;
Direction monitor output AGCOS2 is detected, and PD in y direction is detected.
Shift pulse that completes integration for arrays II and IV
This is a shift pulse generation circuit for generating SH2. This time
The road is constituted by a circuit as shown in FIG. Reference voltage D
The OS is input to the buffer circuit Buf1, and from the output thereof
Lower by constant voltage ΔV1 by resistance R31 and constant current I31
The applied voltage is applied to the (+) input of the comparator Com1.
It is. The monitor output A is connected to the (-) input of this comparator.
GCOSn is applied. Integral clear pulse ICG
DOS and AGCOSn become equipotential by the application of
After that, the potential of AGCOSn becomes the electric charge in the monitor PD.
It decreases in proportion to the amount of generation, that is, the amount of incident light. Compa
Looking at the input level of the generator Com1, at the time of ICG application
Indicates that the (-) input is higher by ΔV1 but decreases with charge accumulation
When the (-) input falls below the (+) input, the comparator
The output is inverted. The average level of the video signal at the time of this inversion
When focus detection is performed, R is set so that an appropriate focus detection result is obtained.
31, I31, that is, ΔV1 is set. At this time
The inverted signal of the comparator COM1 is reset by the pulse ICG.
Set flip-flop FF31 that was turned on and output FF31
Power inversion is controlled by AND31, INV31 and delay circuit 32.
And output as SHn (n = 1 or 2) signal
Is done. Also, the SHn signal is generated from the application of the pulse ICG.
The time it takes to output is longer for lower brightness.
It is necessary to set a maximum integration time, and when this time elapses
A shift pulse SH is generated by a microcomputer.
It is also possible to limit the integration time
You. Regarding the handling at the time of low brightness, see
This is equivalent to that described in, for example, Japanese Patent No. 125817. The circuit 40 is a transfer clock generation circuit, and CK
The basic clock supplied from the microcomputer to the terminal
The clock is divided to generate φ1 and φ2 pulses. To Sφ terminal
Indicates that the signal for switching the transfer clock frequency is
Supplied from the computer 20, this signal is both x and y
High when inputting the output of the direction, the x, y direction
When inputting only one-way output of
The transfer clock frequency is set to Low for the input of the bidirectional output.
Input as double the power transfer time to reduce the charge transfer time.
ing. Also, the analog signal is obtained from the second storage means C2.
It is necessary to synchronize when transferring charge to the shift register.
Therefore, the SH signal is input. 50 and 51 are each drawing
Basic configuration with analog OSI and OSII processing circuits
Is shown in FIG. Each pixel output is sent to the differential amplifier Amp51.
And is output as a difference from the reference voltage V52. This out
The force is at the front of the output of each photodiode array PDI-IV
The dark output signal of the aluminum light-shielded pixel provided in the
SP1 output by the microcomputer 20 when
Or sampled with the signal of SP2, and
The difference between the optical output and the optical output
By using mp52, only the light output component is extracted. Here, the dark output is sampled by each of the PD arrays I to IV.
The pull hold is performed by the PD arrays I and III and II and IV.
Are controlled with different integration times, and there is no difference in the dark output voltage.
This is because it occurs. Pixel from which only the light component is extracted
The output is then input to sample and hold circuits 60 and 61
After that, it is input to the multiplexer 70. Here the multiplex
The lexer 70 outputs the sampled and held pixel outputs I1 and I1.
One of the two by the input data selection zone signal SZ.
And output it to the A / D conversion circuit 80 from the D1 terminal.
You. As described above, the microcomputer operates in both x and y directions.
When inputting data, the Sφ signal Hi is output and the transfer clock is
Lock is generated at normal speed and AND2, OR1
Transfer of the output of the multiplexer 70 via the
Switch in synchronization with clock φ1. As a result,
G As shown in FIG. 8A, the CCD shift registers R1,
The output signal of the CCD shift register R2 is output alternately.
Digitalized by the A / D conversion circuit 80, and
Input to the computer. On the other hand, only the x direction or the y direction
Signal, the Sφ signal is set to Low and AND2
The output of the multiplexer is turned off by setting one input to Low.
The change is based on the selection signal SZ of the microcomputer.
become. At this time, the CCD image sensor transfer lock
The frequency is doubled. The microcomputer is in the x direction
Input the reference unit output if it is in the y direction, then input the reference unit output
The signal is inverted, and the output x of the CCD shift registers I and II
Reference unit output in direction Input reference unit output in y direction. this
By making full use of the A / D conversion time,
Timing at this time when transfer time can be reduced
Is shown in FIG. (Automatic focus detection operation)
Several modes of operation are possible for focus detection.
You. Specific examples of operations in these modes
FIG. 9 to FIG. Fig. 9 focuses on x and y directions
Performs a detection operation and finds that the subject is closer to the camera as a result.
Lens based on the focus detection result for the determined direction
It is a flow for driving. FIG. 10 shows the total coordinates in both the x and y directions.
Compare contrast and prioritize the direction with higher contrast
The lens is driven by performing focus detection calculation on
Only when the other lens becomes in focus, the other focus detection
This is a flow for performing the operation. Here the contrast value is large
LowCon is used as a LowCon determination criterion.
The applicant proposed in Japanese Patent Application Laid-Open No. Sho 60-247210.
As shown, the evaluation function YM (XN) / C
It is also required that N is equal to or less than a predetermined value.
The evaluation function is significantly degraded in the case of subjects with perspective conflict
Cases are conceivable. FIG. 11 shows the focus detection function in the x direction.
Focus adjustment is performed, and the x direction becomes LowCon.
An example of using the focus detection function in the y direction only when
You. First, FIG. 9 will be described. AF switch
When SAFS is turned on, the microcomputer 20
Is activated. The microcomputer first starts with a CCD image
Initialize the disensor. This is before power supply or transfer
While the clock is stopped, it is stored in the register and photoelectric converter in advance.
Need to be performed once at startup
There is. Next, the microcomputer 20 reads the CCD image.
An ICG pulse is supplied to the disensor 10 to start integration. This
The application of the ICG pulse causes the image sensor to
While discharging the accumulated charge, the accumulated charge of the monitor output is
Are also discharged, and with the disappearance of this pulse,
Load accumulation starts. After that, the microcomputer
Inversion of both terminals INT1, TINT2, ie PD array
The average of the charge stored in each pixel of I and III and PD array II and IV is
When the shift pulses SH1 and S
H2 is generated and a PD array is stored in the second storage section C2 of each pixel.
The accumulated charges of I and III are stored in the second accumulation section C2 of each pixel by PD.
Wait until the transfer of the accumulated charges in the arrays II and IV is completed. this
When the microcomputer detects the completion,
The computer generates an SH pulse to generate the PD array I or IV.
Analog shift register (CCD register) for stored charge
R1 stores the charges stored in the PD arrays II and III in the analog shift mode.
To the register (CCD register) R2. Thereafter, in synchronization with the transfer clock, OSI, O
Each pixel signal is output from both SII terminals,
The A / D conversion completion signal A of one pixel signal thereafter
The number of output pixels is known by counting / DEOC.
Of the aluminum light-shielded pixels installed in each of the PD arrays I to IV
Outputs the output sample signals SP1 and SP2 and continues to output them
A / D conversion value of each light output pixel output in sequence
To obtain image information. This timing will be described later.
In this way, the digital output of all pixels necessary for focus detection
When you have stored the information in the microcomputer,
The microcomputer starts the focus detection calculation. My
The computer first performs a correlation operation in the x direction. First
x-direction difference data is created. This difference data is Ux
(K) = Sx (k) -Sx (k + 4), Vx (k) = T
x-Tx (k + 4)
Take the difference. This reduces low-frequency components that cannot be calculated for focus detection.
It is to cut. Difference data 27 of reference part and reference part
When 35 and 35 pieces are available, the microcomputer displays the image
Increasing the amount one pitch at a time,
The correlation value YM (l) is obtained from the quantity. Also the total contrast
A value, that is, a sum of adjacent data of the difference data is obtained. This
Of the correlation value YM (l)
When the image shift amount is high, that is, the value of the correlation value YM (l) is minimum.
Is obtained. This lx is the lens defocus amount
Was involved, but the system used here
In order to obtain more accuracy, the correlation value at the time of
The interpolation calculation is performed using the correlation value at the image shift amount. This supplement
A detailed description of the inter-operation is given in JP-A-60-247211.
Please refer to the explanation by the applicant. Thus accuracy
Good and detailed image thread amount XM, correlation evaluation function YM (XM)
/ CX is required. This correlation evaluation function YM (XM) /
CX, total contrast value CX, and all output raw data values
Low Con determination is performed at three points. This LowCon discrimination
Is also described in JP-A-60-247210.
Therefore, the description is omitted here. Note that both ends of lx = 1 or 9
If the correlation value at is minimum, it is set to LowCon. When it is determined that the state is not LowCon,
XM-5 as the PX value, that is, the difference from the in-focus image shift amount
And store it in memory. Also, assuming lmin = lx-1
Restrict the image shift range of the correlation operation in the y direction
You. On the other hand, if it is determined to be LowCon, the phase in the y direction is determined.
There is no image shift range for the related operation, and correlation is performed over the entire range.
Perform the calculation. In this way, note the limitation of the correlation calculation range in the y direction.
After that, the difference data in the y direction is
To create. Uy (k) = Sy (k) -Sy (k +
4), Vy (k) = Ty (k) -Ty (k + 4)
The same as in the x direction based on the difference data created by
The calculation of the correlation value is performed. However, here, the correlation calculation in the x direction
Only for the image shift amount of lmin or more obtained from the result
Perform correlation calculation. This is because the closer the subject is,
Is large, the phase in both x and y directions is large.
The one with the larger image shift amount of the function result is selected. So ahead
The correlation calculation is performed only for the portion larger than the image shift amount in the x direction
It is sufficient to perform the calculation, and the correlation calculation can be shortened. This
Thus, the correlation value is obtained also in the y direction, and
Calculate the high part. Next, an interpolation operation is performed in the same manner as in the x direction.
The image shift amount xN and the correlation
The evaluation function YM (XN) / Cy is calculated. This evaluation function
YM (XN) / Cy, total contrast value Cy in the y direction,
Determines the raw data peak value in the y direction and calculates the correlation image
The calculated minimum correlation value image interval lx is added to both ends lmin and 9 of the shift amount.
Determines whether there is 1 or not, and is not LowCon
Is determined as PY, the image is shifted from the in-focus state.
Store the quantity xN-5. Thus, in both the x and y directions
When the correlation calculation is completed, the microcomputer
The lens is driven based on the result of the correlation operation in both the x and y directions.
U. First, it is determined that both directions are LowCon.
Microcomputer drives lens if separated
To find the lens position where the contrast can be detected
(Low Con Scan). This action is
Lens after scanning the lens drive range at least once
Stop the drive and use the lens position as it is
Lens drive in the state where contrast is detected.
In this mode, the operation is restarted. At least one is LowC
If it is not on, the magnitude of the obtained image shift amount in the x direction is large or small.
Compare and use the larger one as P for subsequent lens drive
Is adopted as the image interval amount. Here at the time of LowCon
The values of Px to Py are set to the Min value (-4).
Shall be. Despite adding restrictions when calculating in the y direction
Dare to compare the size here is the image deviation amount one pitch
Has a considerable defocus amount within
This is because a large difference occurs in the amount of defocus. This performance
The calculated image shift amount P is converted into a defocus amount, and the
Multiply by different lens drive amount conversion coefficients
The drive amount is calculated, and focus determination is performed. Extreme lens drive
When the lens is small and does not need to be driven,
Display, if not, according to the lens drive amount
Drive the lens, and then perform the focus detection operation again.
Re-integrate the page sensor. Next, referring to the flowchart of FIG.
Excellent correlation calculation in the direction where the contrast amount is large.
Go ahead and drive the lens, and the direction will be the subject
When it becomes LowCon state due to the effect of
First, the other focus detection correlation calculation is performed, and according to the result,
The operation of the focus detection device that drives the lens will be described.
You. Start the operation until the data input is completed
As in the case of FIG. 9, the image in both the x and y directions
Sensor data is stored in the microcomputer.
You. The microcomputer first calculates the difference data in the x direction.
Created in the same manner as in FIG. 9 and calculate the sum of adjacent differences of the difference data.
To calculate the x-direction total contrast value Cx
You. Subsequently, the difference data in the y direction is created, and
The total contrast value Cy is calculated. Thus both x and y
After calculating the total contrast values Cx and Cy of the two directions,
Is compared. Here the total contrast value becomes large
The correlation calculation result for the direction shows that the total contrast value is small.
Is more reliable than the result of the correlation operation in the direction
Usually considered. Therefore, in the direction Z where the total contrast value is large,
Is preferentially calculated. About this correlation operation
This is performed using the same method as the method shown in FIG. Correlated
The calculation of the high part and the interpolation calculation are performed, and the image shift amount xM and the correlation evaluation
The value function YM (XM) / CZ is calculated. Using this result
To determine LowCon, and determine that it is not LowCon.
In this case, the image shift amount XM is used to determine the image
Calculate the amount of deviation and calculate the amount of defocus and lens drive.
Go out. Focus indication is displayed at the time of in-focus determination.
When out of focus, the lens is driven according to the lens drive amount.
U. On the other hand, if it is determined to be LowCon, this time
Performs a correlation operation in the reverse direction. This results in a correlation
Is calculated and interpolation calculation is performed to obtain the image shift amounts XM, Y
M (XM) / CZ is calculated. Again using this result
Performs LowCon determination, and determines that it is not LowCon.
If the image is out of focus, the image shift amount XM
Calculate the defocus amount and calculate the defocus amount and lens drive amount
I do. Focus indication is displayed at the time of in-focus determination.
When out of focus, the lens is driven according to the lens drive amount.
U. If it is determined to be LowCon, this time
Both x and y directions were determined to be LowCon.
Is performed in the Low Con Scan. Finally the contrast
X-direction (horizontal direction) where the high-frequency part is frequently arranged
Focus detection calculation, and determines that the x direction is LowCon.
Focusing that performs focus detection calculation in the y direction only when separated
The detection device will be described with reference to the flowchart of FIG.
I do. In this focus detection apparatus, two examples shown in FIGS. 9 and 10 are used.
Unlike this, only data in the x direction is preferentially input. product
Minutes and data transfer time, and
After the AF operation starts, the CCD
When the rise is completed, the microcomputer
Set the lock frequency to the double speed of the above example and set Sφ = Lo
FIG. 8 (b) shows the output in only one direction at high speed.
It is carried out in such a form. An integration clear pulse is marked to start integration.
After the addition, the microcomputer determines that the integration in the x direction is completed.
Wait for the inverted signal of the INT1 signal. Inversion of TINT1 signal
Microcomputer detects the completion of the integration in the y direction.
Generates a shift pulse regardless of whether the
Of the pixel output data is started. First, P from OS1
D array I, x-direction reference portion pixel output is output, so S
Z = Hi and outputs D1 of the multiplexer 70 to I
1 signal, that is, OS1 processed signal,
A / D conversion of output of sub-pixels to microcomputer
input. During this time, the y-direction reference portion output from OS2 is output.
Power is ignored. When the input of this x direction reference part is completed
The microcomputer outputs Sz = Low and outputs
The D1 output of the lexer 70 is connected to the I2 signal,
Output of the reference part in the x direction by using the OS2 processing signal
A / D converted and input. Thus, the reference portion in the x direction,
Once the reference section has been entered,
Creation of difference data, calculation of correlation value, highest phase
Seki extraction, interpolation calculation, and LowCon determination are performed. The above two
As a result of the same LowCon determination as shown in the example,
Reliable data with the amount of image shift calculated instead of Con
Is determined, the in-focus image shift amount is calculated from the image shift amount.
The difference P = XM-5 is calculated. The defocus amount PF, the lens
The drive amount is calculated, and when the lens drive amount is extremely small,
Determined to be in focus and display focus, otherwise calculated
The lens is driven according to the lens drive amount, and each image in the x direction is
The reintegration and refocus detection calculation are repeated for the element. On the other hand, the focus detection calculation result in the x direction is LowC
If it is determined that the
Next, the integration of the image sensor in the y direction and the focus detection calculation
To start. Microcomputer is one-way data input
Output Sφ = Low to perform the force
Signal ICG is generated, and thereafter the integration completion signal TI in the y direction is generated.
Wait for the inversion of NT2. This inversion of TINT2 is detected.
SH pulse regardless of completion of x-direction integration
And input of y-direction data is started. At this time
First, SZ = Low is output and the x direction
While ignoring the output of the reference unit for the direction, only the output of the y-direction reference unit is I
2 is passed through the multiplexer and the data input after A / D conversion
When this is completed, SZ = Hi is output and the x-direction reference
While ignoring the illumination output, only I1
The data input after A / D conversion
U. In this way, all data in only the y direction is input and the
The microcomputer creates difference data in the y direction.
Calculation, correlation value calculation, extraction of highest correlation, interpolation calculation, LowC
ON determination is performed in the same procedure as that performed in the x direction.
U. As a result of the LowCon judgment, it is calculated instead of the LowCon
Image shift amount is determined to be highly reliable data
And the difference P = xM-5 between the image shift amount and the focused image shift amount
Calculation of the defocus amount DF and the lens drive amount
If the lens drive amount is extremely small, the
If not, follow the calculated lens drive amount.
Drive the lens, and the x-direction refocus detection
Re-integration and refocus detection for each pixel in the y direction without performing
Repeat the operation. On the other hand, in the y direction,
If it is determined that there is, the LowCo in both the x and y directions
n, and LowCon Scan is executed.
While re-producting the image sensor in both x and y directions
Minute, the refocus detection is repeated,
wait. According to the present invention, a plurality of photographers arranged in a cross shape
An automatic focus detection device using image means, and a pair of imaging devices.
Output from the image sensor via different paths
Since the readout and output circuit were shared,
The complexity of the step path is prevented and miniaturization is achieved.
On the other hand, there is no
As a result, the reliability of the operation increases.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an optical configuration of the present invention. FIG. 2 is an exploded perspective view of an optical part of one embodiment. FIG. 3 is a circuit diagram around an image sensor in the embodiment. FIG. 4 is a circuit diagram of an integration control gate in the embodiment. FIG. 5 is a circuit diagram of a portion for performing image sensor driving, focus detection, and focus adjustment in the embodiment. FIG. 7 is a detailed circuit diagram of another part of the circuit. FIG. 8 is a time chart of the operation of the circuit. FIG. 9 is a flowchart of one operation mode in the embodiment. Flowchart [FIG. 11] Flowchart of another operation mode [Description of reference numerals] 1 shooting lens 2 field mask 6 condenser lens 8 re-imaging lens (two to four) 10 image sensor

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Nobuyuki Taniguchi               2-3-13 Azuchicho, Chuo-ku, Osaka-shi Osaka               Kokusai Building Minolta Co., Ltd.                    Panel     Referee Masayuki Mori     Judge Akira Watanuki     Referee Masao Kashiwazaki                (56) References JP-A-55-115020 (JP, A)                 JP-A-59-174807 (JP, A)                 JP-A-60-247210 (JP, A)

Claims (1)

(57) [Claims] A first imaging unit including a pair of image sensors;
A second imaging unit having a pair of image sensors and a second imaging unit arranged in a direction perpendicular to each other to form a cross shape, and an optical unit for forming a subject image separately for each of the imaging units And a plurality of reading means for reading outputs from the respective image sensors of the first imaging means via different paths and reading outputs from the respective image sensors of the second imaging means via different paths. Output means for outputting an output from the read means to an external circuit from one output terminal, wherein the output read by the read means and output from the output means is subjected to a predetermined focus adjustment An automatic focus detection device, characterized in that: 2. 2. The automatic focus detection device according to claim 1, wherein said output means is a multiplexer. 3. The reading means reads the output from one image sensor of the first imaging means, the output from one image sensor of the second imaging means, and the other of the first imaging means. 2. The focus detection device according to claim 1, further comprising a second reading unit that reads an output from the image sensor and an output from the other image sensor of the second imaging unit. 4. One image sensor of the first image pickup means and one image sensor of the second image pickup means are disposed adjacent to each other, and the other image sensor of the first image pickup means and the second image pickup means 4. The focus detection device according to claim 3, wherein the other image sensors are disposed adjacent to each other.