WO2016038917A1 - Focus control device, focus control method, focus control program, lens device, and imaging device - Google Patents

Abstract

The purpose of the present invention is to provide a focus control device capable of achieving both improved accuracy and lower power consumption during focus control when imaging a moving picture, a lens device and an imaging device equipped with the focus control device, and a focus control method and program. The focus control device comprises: a first imaging element (20) for outputting a pair of image signals deviated in one direction relative to one subject image; optical elements (a beam splitter (16), mirror (17), collecting lens (18), and a separator lens (19)) for introducing, onto a second imaging element (31) for imaging the subject image through an imaging optical system including a focus lens (11), a part of the subject light incident onto the imaging optical system and introducing the rest of the subject light onto the first imaging element (20); and a controller (26) for controlling the focusing of the focus lens (11) on the basis of the phase difference between the pair of image signals output from the first imaging element (20), and controlling the read out rate of the image signal from the first imaging element (20).

Description

Focus control device, focus control method, focus control program, lens device, and imaging device

The present invention relates to a focus control device, a lens device and an imaging device including the focus control device, a focus control method, and a focus control program.

In recent years, with the increase in resolution of image sensors such as CCD (Charge Coupled Device) image sensors and CMOS (Complementary Metal Oxide Semiconductor) image sensors, mobile phones such as digital still cameras, digital video cameras, and smartphones, PDAs (Personal Digital). , Portable information terminals) and other information devices having a photographing function are rapidly increasing. Note that an information device having the above imaging function is referred to as an imaging device.

In these imaging apparatuses, a contrast AF (Auto Focus) method or a phase difference AF method (see, for example, Patent Documents 1 and 2) is adopted as a focusing control method for focusing on a main subject. The phase difference AF method is effective for high-speed processing, and is effective for moving image capturing in which a subject is continuously imaged by an image sensor.

In Patent Document 1, a light beam that has passed through an imaging optical system is split by a half mirror and is incident on a pair of AF line sensors. A phase difference is detected by the pair of line sensors, and based on the detected phase difference. An imaging device that performs focus control is described.

Patent Document 2 describes an imaging apparatus including an imaging element including imaging pixels and phase difference detection pixels. When the defocus amount calculated based on the detection signal of the phase difference detection pixel is highly reliable, this imaging device increases the signal readout rate from the imaging device, thereby enabling the subject in live view image display to be displayed. The visibility of movement is improved.

In Patent Document 3, a part of a large number of pixels included in an image sensor is a first pixel group for AF, and the remaining pixels are a second pixel group for moving image capturing. An imaging device is described in which the signal readout speed is higher than the signal readout speed from the second pixel group.

JP-A-11-84221 JP 2014-88672 A JP 2014-143667 A

In recent years, demands for imaging performance of imaging devices are increasing, and the number of pixels mounted on an imaging element is increasing. For example, in order to generate a high-quality moving image with a resolution four times that of full high-definition used in television broadcasting or the like, the number of pixels of the image sensor is greatly increased and the signal readout rate from the image sensor is increased. There is a need.

As described above, focusing control by the phase difference AF method is effective during moving image capturing. However, when moving images are captured at a high signal readout rate, the phase difference is acquired at a higher speed than the high-speed signal readout rate in order to perform focus control with improved followability to the movement of the main subject. There is a need to. However, when the number of pixels of the sensor used to acquire the phase difference is large, a large amount of power is consumed for reading signals from the pixels.

The imaging apparatus described in Patent Document 3 sets a signal readout rate from the first pixel group for AF higher than a signal readout rate from the second pixel group for moving image imaging. However, this method requires a large number of pixels because the number of pixels that can be used for moving image capturing is reduced. There is also a limit to increasing the signal readout rate from the first pixel group. Further, since the signal readout rate from the first pixel group is increased, the power consumption is large.

The imaging apparatus described in Patent Document 1 cannot perform AF during moving image imaging. Further, since the phase difference information is detected using a line sensor, the above-described power consumption is not a problem.

The imaging apparatus described in Patent Document 2 cannot change the signal readout rate by the imaging pixels and the phase difference detection pixels. It is conceivable that signals are separately read out by the phase difference detection pixel and the imaging pixel. However, with this method, the sampling period of the phase difference becomes longer during moving image capturing, and it is difficult to perform focus control with improved followability to the movement of the main subject.

The present invention has been made in view of the above circumstances, and a focusing control device capable of achieving both improvement in focusing control accuracy and low power consumption during moving image shooting, and a lens device and imaging device including the focusing control device. It is an object to provide a focusing control method and program.

The focus control apparatus of the present invention captures a subject light image through an imaging optical system including a first imaging element that outputs a pair of image signals shifted in one direction with respect to one subject light image and a focus lens. An optical element that causes a part of subject light incident on the imaging optical system to be incident on a second imaging element, and that the remaining part of the subject light except the part is incident on the first imaging element; A focus control unit that performs focusing control of the focus lens based on a phase difference between the pair of image signals output from one image sensor, and controls a readout rate of the image signal from the first image sensor A read rate control unit.

The focus control method of the present invention captures a subject light image through an imaging optical system including a first imaging element that outputs a pair of image signals shifted in one direction with respect to one subject light image and a focus lens. An optical element that causes a part of the subject light incident on the imaging optical system to be incident on the second imaging element and causes the remaining part of the subject light other than the part to be incident on the first imaging element. A focus control method by a focus control device, the focus control step for performing focus control of the focus lens based on a phase difference between the pair of image signals output from the first image sensor, and A read rate control step for controlling a read rate of the image signal from the first image sensor.

The focus control program of the present invention captures a subject light image through an imaging optical system including a first imaging element that outputs a pair of image signals shifted in one direction with respect to one subject light image, and a focus lens. An optical element that causes a part of the subject light incident on the imaging optical system to be incident on the second imaging element and causes the remaining part of the subject light other than the part to be incident on the first imaging element. A focus control step for controlling the focus lens based on a phase difference between the pair of image signals output from the first image sensor; And a readout rate control step for controlling the readout rate of the image signal.

The lens device of the present invention includes the focusing control device and the imaging optical system.

The imaging device of the present invention includes the focusing control device and the second imaging device.

According to the present invention, there is provided a focus control device capable of achieving both improvement in focus control accuracy and low power consumption at the time of moving image capturing, a lens device including the focus control device, an imaging device, a focus control method, and a program. can do.

It is a figure which shows schematic structure of the camera system for describing one Embodiment of this invention. It is a block diagram which shows the internal structure of the lens apparatus 1 shown in FIG. It is a figure which shows the modification of the camera system of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of a camera system for explaining an embodiment of the present invention. This camera system is suitable for a camera system for business use such as broadcasting or movie.

1 includes a lens device 1 and a camera device 3 as an imaging device to which the lens device 1 is attached.

The lens device 1 includes a focus lens 11, zoom lenses 12 and 13, a diaphragm 14, and a master lens group 15, which are arranged in order from the subject side.

The focus lens 11, the zoom lenses 12, 13, the diaphragm 14, and the master lens group 15 constitute an imaging optical system. The imaging optical system includes at least a focus lens 11.

The focus lens 11 is a lens for adjusting the focus of the imaging optical system, and is constituted by a single lens or a plurality of lenses. Focus adjustment is performed by moving the focus lens 11 in the direction of the optical axis K of the imaging optical system.

The lens apparatus 1 further includes a beam splitter 16 including a reflecting surface 16a, a mirror 17, an AF unit 21 including a condenser lens 18, a separator lens 19, and a first image sensor 20. The first image sensor 20 is an image sensor such as a CCD image sensor or a CMOS image sensor having a plurality of pixels arranged two-dimensionally.

The beam splitter 16 is disposed on the optical axis K between the stop 14 and the master lens group 15. The beam splitter 16 transmits a part of the subject light that has entered the imaging optical system and passed through the aperture 14 (for example, 80% of the subject light) as it is, and removes a part of the subject light (for example, 20% of the subject light). %) Is reflected by the reflecting surface 16a in a direction orthogonal to the optical axis K. The position of the beam splitter 16 is not limited to that shown in FIG. 1, and it is sufficient that the beam splitter 16 is disposed behind the lens closest to the subject of the imaging optical system on the optical axis K.

The mirror 17 is disposed on the optical path of the light reflected by the reflecting surface 16 a of the beam splitter 16, and reflects this light so as to enter the condenser lens 18 of the AF unit 21.

The condensing lens 18 condenses the light reflected by the mirror 17.

The separator lens 19 includes two lenses arranged in one direction and two lenses arranged in a direction orthogonal to the one direction.

The subject light condensed by the condensing lens 18 passes through each of these four lenses and forms an image at different positions on the light receiving surface (surface on which a plurality of pixels are arranged) of the first image sensor 20. . That is, a pair of subject light images shifted in one direction and a pair of subject light images shifted in a direction orthogonal to one direction are formed on the light receiving surface of the first image sensor 20.

The beam splitter 16, the mirror 17, the condensing lens 18, and the separator lens 19 are used for one of the subject light incident on the imaging optical system to the second imaging element 31 of the camera device 3 that captures the subject light image through the imaging optical system. The optical element functions as an optical element that causes the first imaging element 20 to enter the remaining part of the subject light. In addition, the structure which deletes the mirror 17 and makes the light reflected by the beam splitter 16 inject into the condensing lens 18 directly may be sufficient.

The first image sensor 20 is an area sensor in which a plurality of pixels are two-dimensionally arranged on the light receiving surface, and outputs an image signal corresponding to each of four subject light images formed on the light receiving surface. That is, the first image sensor 20 has a pair of image signals shifted in one direction and a pair of image signals shifted in a direction orthogonal to one direction with respect to one subject light image formed by the imaging optical system. Are output. By using an area sensor as the first image sensor 20, it is possible to avoid the difficulty of precisely aligning the positions of the line sensors as compared to a configuration using four line sensors.

The camera device 3 captures a subject light image with a second image sensor 31 such as a CCD image sensor or a CMOS image sensor disposed on the optical axis K of the lens device 1 and the second image sensor 31. An image processing unit 32 that processes the obtained image signal and generates captured image data.

FIG. 2 is a block diagram showing an internal configuration of the lens apparatus 1 shown in FIG.

In addition to the components described in FIG. 1, the lens device 1 includes an image sensor driving unit 22, a lens driving unit 23, a diaphragm driving unit 24, an operation unit 25, and a control unit 26 that performs overall control. Is provided.

The image sensor driving unit 22 drives the first image sensor 20 in accordance with a command from the control unit 26. The image sensor driving unit 22 controls the exposure time of the first image sensor 20, or the first readout rate of the image signal from the first image sensor 20 (how many times the image signal is read out per second). Control the value shown).

The first readout rate can be set to a value larger than the second readout rate of the image signal from the second image sensor 31. For example, if the second read rate is 60 times / second, the first read rate can be set between 60 times / second and 120 times / second.

The lens drive unit 23 performs focus adjustment by driving the focus lens 11 in the optical axis K direction or changes the zoom magnification by driving the zoom lenses 12 and 13 in the optical axis K direction in accordance with instructions from the control unit 26. To do.

The diaphragm driving unit 24 adjusts the exposure amount by controlling the opening amount of the diaphragm 14 in accordance with a command from the control unit 26.

The lens device 1 includes a zoom ring, a focus ring, and an aperture ring (not shown). The zoom ring is for manually changing the position of the zoom lenses 12 and 13 in the optical axis K direction. The focus ring is for manually changing the position of the focus lens 11 in the optical axis K direction. The aperture ring is for manually changing the opening amount of the aperture 14.

The operation unit 25 is a user interface for inputting an instruction signal to the control unit 26. The operation unit 25 includes buttons for changing mode settings. Modes that can be set in the lens apparatus 1 include an AF mode that automatically performs focus control and an MF (manual focus) mode that manually performs focus control.

The control unit 26 outputs a phase difference between a pair of image signals output from the first image sensor 20 (a phase difference between two image signals shifted in one direction and two image signals shifted in a direction orthogonal to one direction). It functions as a focus control unit that performs focus control of the focus lens 11 based on the phase difference of the focus lens 11.

Specifically, the control unit 26 calculates a phase difference between the pair of image signals by performing a correlation operation between the pair of image signals output from the first image sensor 20 and shifted in one direction. A first defocus amount is obtained from the phase difference. Similarly, the control unit 26 calculates a phase difference between the pair of image signals by performing a correlation operation of the pair of image signals shifted in a direction orthogonal to the one direction output from the first image sensor 20. A second defocus amount is obtained from the calculated phase difference.

The control unit 26 generates a final defocus amount using the first defocus amount and the second defocus amount. For example, the control unit 26 determines the average of the first defocus amount and the second defocus amount or the larger value of the first defocus amount and the second defocus amount as the final defocus amount. And Then, the control unit 26 sets the drive direction and drive amount of the focus lens 11 based on the defocus amount. The control unit 26 controls the focus by causing the lens driving unit 23 to drive the focus lens 11 according to the set driving direction and driving amount. As described above, the control unit 26 performs focusing control by the phase difference AF method.

Further, the control unit 26 functions as a read rate control unit that controls the first read rate of the image signal from the first image sensor 20.

Hereinafter, an example of the first read rate control method (control methods 1 to 6) will be described.

(Control method 1)
The control unit 26 controls the first readout rate according to the brightness of the subject light image formed by the imaging optical system. Specifically, the control unit 26 decreases the first readout rate as the subject light image is darker. The brightness of the subject light image is one of the conditions related to the subject light image formed by the imaging optical system.

For example, the control unit 26 calculates an average value or an integrated value of output signals for each pixel for any of four image signals output from the first image sensor 20, and uses the calculated value as the brightness of the subject light image. It is information indicating this. Alternatively, an average value or an integrated value is calculated for each of the four image signals, and a value obtained by averaging the calculated four values is used as information indicating the brightness of the subject light image.

The dark subject light image means that the amount of light incident on the first image sensor 20 is reduced, and the accuracy of focusing control by the phase difference AF method is reduced. For this reason, the darker the subject light image, the lower the first readout rate and the control to extend the exposure time of the first image sensor 20, thereby increasing the amount of light incident on the first image sensor 20. It is possible to prevent the accuracy of focusing control from being lowered. Moreover, the power consumption of the lens apparatus 1 can be reduced by reducing the reading rate.

(Control method 2)
The control unit 26 controls the first readout rate according to the variation in the phase difference between the pair of image signals obtained by imaging with the first imaging element 20. Specifically, the control unit 26 increases the first reading rate as the variation in the phase difference increases. Since this phase difference changes depending on the subject light image formed by the imaging optical system, it is one of the conditions relating to the subject light image.

For example, after calculating the phase difference between the pair of image signals output from the first image sensor 20, the control unit 26 stores the phase difference in the internal memory. The internal memory is configured to store a phase difference for a past predetermined period (for example, 1 second). And the control part 26 calculates the fluctuation amount (for example, dispersion | distribution of a phase difference) of the phase difference for the past 1 second using the several phase difference memorize | stored in the internal memory at arbitrary timings.

The large fluctuation of the phase difference means that the distance between the main subject and the lens apparatus 1 is finely changed. That is, the followability of focusing control for the main subject is important. For this reason, when the fluctuation of the phase difference is large, the focus control with high accuracy following the movement of the main subject can be performed by increasing the first reading rate and finely controlling the focus. On the other hand, when the fluctuation of the phase difference is small, the accuracy of the focus control can be ensured without performing the fine focus control. Therefore, power consumption can be reduced by lowering the first reading rate.

(Control method 3)
The control unit 26 controls the first readout rate according to the speed of the moving object included in the subject light image formed by the imaging optical system. Specifically, the control unit 26 increases the first reading rate as the moving body speed increases. The speed of the moving object is one of the conditions regarding the subject light image formed by the imaging optical system.

For example, the control unit 26 performs a known moving object detection process on any of the four image signals output from the first image sensor 20. When detecting the motion, the control unit 26 detects the speed of the moving body, and sets the first read rate higher as the detected speed is higher.

The high speed of the moving object means that the distance between the main subject and the lens apparatus 1 or the position of the main subject in the subject optical image is finely changed. That is, the followability of focusing control for the main subject is important. For this reason, when the speed of the moving object is high, the first readout rate is increased and fine focusing control is performed, thereby enabling highly accurate focusing control following the movement of the main subject. On the other hand, when the speed of the moving body is low, the accuracy of the focus control can be ensured without performing the fine focus control. Therefore, power consumption can be reduced by lowering the first reading rate.

It should be noted that when no moving object is detected, it can be predicted that the fluctuation of the in-focus position is small. Therefore, the first reading rate may be set to a value lower than the settable maximum value to reduce power consumption.

(Control method 4)
The control unit 26 controls the first readout rate according to changes in the operating state of movable optical elements such as the focus lens 11, the zoom lenses 12 and 13, and the diaphragm 14 included in the imaging optical system. Specifically, when the control unit 26 controls the first readout rate to a first value lower than the maximum value that can be set, the operation state of the movable optical element changes. Controls the first read rate to a value larger than the first value.

For example, when the control method 2 is applied, the first reading rate is set to the first value in a situation where the position of the focus lens 11 hardly fluctuates. From this state, when the distance between the main subject and the lens apparatus 1 changes greatly and the phase difference fluctuates greatly, the moving distance of the focus lens 11 becomes greater than or equal to the threshold value.

The control unit 26 determines that the operation state of the focus lens 11 has changed when the moving distance of the focus lens 11 is equal to or greater than the threshold value. The fact that the movement distance changes by more than the threshold means that the situation where the movement of the main subject is stable has changed to the situation where the movement of the main subject becomes active. In such a situation, it can be determined that priority should be given to the accuracy of focus control over power consumption. For this reason, it is effective to make the first read rate larger than the first value.

Also, when the control methods 1 to 3 are applied, the first read rate may be set to the first value. From this state, let us consider a case where the positions of the zoom lenses 12 and 13 are changed by the operation of the zoom ring, or the opening amount of the stop 14 is changed by the operation of the aperture ring. The fact that the zoom magnification and the aperture opening amount change means that there is a possibility that the focus position so far may change greatly. That is, in such a situation, it can be determined that priority should be given to the accuracy of focus control over power consumption. For this reason, it is effective to make the first read rate larger than the first value.

(Control method 5)
The control unit 26 controls the first readout rate according to a change in the direction of the optical axis K of the imaging optical system. Specifically, when a change occurs in the direction of the optical axis K, the control unit 26 controls the first read rate to a value larger than the first value.

For example, when the control methods 1 to 3 are applied, the first read rate may be set to the first value. From this state, consider a case where the user of the camera system greatly moves the camera system in the horizontal direction or moves the camera system largely in the vertical direction.

The movement of the camera system means that the subject light image to be captured changes greatly. That is, in such a situation, it can be determined that priority should be given to the accuracy of focus control over power consumption. For this reason, it is effective to make the first read rate larger than the first value.

The control unit 26 determines whether or not the captured subject light image has changed significantly due to the change in the direction of the optical axis K. The direction of the optical axis K can be determined based on detection information of the motion detection unit provided with a motion detection unit such as an azimuth sensor, an acceleration sensor, and a gyro sensor in the lens device 1. Further, the control unit 26 performs pattern matching between two image signals continuously output from the first image sensor 20, and determines whether or not the direction of the optical axis K has greatly changed from the result. Good.

(Control method 6)
When the lens device 1 is set to the MF mode, the control unit 26 sets the first readout rate to a first value (preferably the lowest value among settable values). As described above, even in the MF mode, the first imaging device 20 is activated with low power consumption, so that it is possible to immediately shift to the AF mode.

Note that the control methods 1 to 6 may be implemented in combination as appropriate.

The optical elements (the beam splitter 16, the mirror 17, the condensing lens 18, and the separator lens 19), the first imaging element 20, and the control unit 26 in the lens apparatus 1 described above constitute a focusing control apparatus. .

In the camera system of FIG. 1, the focusing control device is provided in the lens device 1, but the focusing control device may be included in the camera device 3.

FIG. 3 is a diagram showing a configuration example of a camera system in which the focusing control device is built in the camera device.

In the camera system shown in FIG. 3, the lens device 1 includes the lens driving unit 23 and the aperture driving unit 24 shown in FIG. 2, and the focusing control device built in the camera device 3 and the lens device 1 can communicate with each other. The The camera system shown in FIG. 3 can be applied to both a digital camera with a replaceable lens device and a digital camera with an integrated lens device. In the case of a digital camera, unlike the professional camera system, the battery capacity is limited, so it is effective to employ the control methods 1 to 6 described above.

The configuration of the AF unit 21 is not limited to that shown in FIG. For example, as the first image sensor 20, an area in which a pair of phase difference detection pixels that are pupil-divided in one direction are two-dimensionally arranged on the light receiving surface as exemplified in Japanese Patent Application Laid-Open No. 2013-201466. A sensor may be used and the separator lens 19 may be omitted. Alternatively, an area sensor in which a pair of phase difference detection pixels that are pupil-divided in one direction and imaging pixels that are not pupil-divided are two-dimensionally arranged on the light receiving surface may be used.

As described above, the following items are disclosed in this specification.

The disclosed focus control apparatus captures a subject light image through an imaging optical system including a first imaging element that outputs a pair of image signals shifted in one direction with respect to one subject light image, and a focus lens. An optical element that causes a part of subject light incident on the imaging optical system to be incident on a second imaging element, and that the remaining part of the subject light except the part is incident on the first imaging element; A focus control unit that performs focusing control of the focus lens based on a phase difference between the pair of image signals output from one image sensor, and controls a readout rate of the image signal from the first image sensor A read rate control unit.

With this configuration, since the readout rate of the image signal from the first image sensor is controlled, for example, by making the readout rate faster than the readout rate of the image signal from the second image sensor, high accuracy can be achieved. Focus control can be performed. For example, in the case of a dark subject, the exposure time for obtaining a pair of image signals can be extended by slowing the readout rate, and focusing accuracy for a dark subject can be ensured. Also, for example, in a situation where the focus position of the focus lens does not change, power consumption can be reduced by slowing the readout rate. As shown in these examples, by controlling the reading rate of the first image sensor, it is possible to achieve both improvement in focusing control accuracy and reduction in power consumption.

In the disclosed focus control device, the readout rate control unit controls the readout rate according to a condition relating to a subject light image formed by the imaging optical system.

In the disclosed focus control device, the condition relating to the subject optical image includes the brightness of the subject optical image, and the readout rate control unit lowers the readout rate as the subject optical image becomes darker. .

The dark subject light image means that the amount of light incident on the first image sensor is reduced, and the focusing accuracy is reduced. For this reason, by setting it as the said structure, the light quantity which injects into a 1st image pick-up element can be increased, and the fall of a focusing precision can be prevented. Further, power consumption can be reduced by reducing the reading rate.

In the disclosed focus control device, the condition relating to the subject optical image includes a phase difference between the pair of image signals output with respect to the subject optical image, and the readout rate control unit is configured to change the phase difference. The larger the is, the higher the reading rate is.

The fact that the fluctuation of the phase difference is large means that the followability of focusing on the subject is important, so that the focusing accuracy can be increased by using the above configuration. On the other hand, when the fluctuation of the phase difference is small, the reading rate is lowered, so that power consumption can be reduced.

In the disclosed focus control device, the condition relating to the subject light image includes the speed of the moving object included in the subject light image, and the reading rate control unit increases the reading rate as the speed of the moving object increases. To do.

The high speed of the moving object means that the followability of focusing on the subject is important, so that the focusing accuracy can be increased by the above configuration. On the other hand, when the speed of the moving object is low, the reading rate is low, so that power consumption can be reduced.

In the disclosed focus control device, the readout rate control unit controls the readout rate in accordance with the state of the imaging optical system.

In the disclosed focus control device, the readout rate control unit controls the movable optics included in the imaging optical system in a state where the readout rate is controlled to a first value lower than a maximum value that can be set. When a change occurs in the operation state of the element, the read rate is controlled to a value larger than the first value.

Assuming that the movable optical element is a focus lens, zoom lens, diaphragm, etc., these may be changed by a user's manual operation. In such a situation, there is a possibility that the subject light image to be captured may change greatly, so that it can be determined that the focusing accuracy should be prioritized over power consumption. Therefore, it is effective to make the reading rate larger than the first value.

In the disclosed focusing control device, the readout rate control unit controls the readout rate to the first value lower than the maximum value that can be set, and the direction of the optical axis of the imaging optical system When the change occurs, the reading rate is controlled to a value larger than the first value.

For example, if there is a change in the optical axis direction due to panning and tilting operations of an imaging device equipped with a focus control device, the subject optical image to be captured may change significantly, so that it is more suitable than the power consumption. It can be determined that the focus accuracy should be given priority. Therefore, it is effective to make the reading rate larger than the first value.

When the disclosed focus control device is set to a manual focus mode in which the position of the focus lens is manually changed, the readout rate control unit sets the readout rate to a value lower than a maximum value that can be set. To control.

Thus, in the manual focus mode, the power consumption can be reduced by lowering the reading rate of the first image sensor 20. Further, it is possible to instantaneously shift from the manual focus mode to the auto focus mode in which the focus control unit performs the focus control.

In the disclosed focus control device, the first imaging element is an area sensor in which a plurality of pixels are two-dimensionally arranged on a light receiving surface, and a pair of the first imaging elements arranged in the one direction and arranged to face the light receiving surface. The separator lens is further provided.

In the disclosed focus control device, the first imaging element includes an area sensor in which a pair of phase difference detection pixels that are pupil-divided in the one direction on the light receiving surface are two-dimensionally arranged. .

The disclosed lens device includes the focusing control device and the imaging optical system.

According to this configuration, it can be used in combination with a high-quality image pickup device for business use used in television broadcasting, movies, etc., and can fully meet the demand for higher image quality.

The disclosed imaging device includes the focusing control device and the second imaging device.

According to this configuration, a compact digital camera or the like can sufficiently meet the demand for higher image quality.

The disclosed focus control method captures a subject light image through an imaging optical system including a first imaging element that outputs a pair of image signals shifted in one direction with respect to one subject light image, and a focus lens. An optical element that causes a part of the subject light incident on the imaging optical system to be incident on the second imaging element and causes the remaining part of the subject light other than the part to be incident on the first imaging element. A focus control method by a focus control device, the focus control step for performing focus control of the focus lens based on a phase difference between the pair of image signals output from the first image sensor, and A read rate control step for controlling a read rate of the image signal from the first image sensor.

In the disclosed focus control method, in the readout rate control step, the readout rate is controlled in accordance with a condition relating to a subject light image formed by the imaging optical system.

In the disclosed focus control method, the condition relating to the subject optical image includes the brightness of the subject optical image, and in the readout rate control step, the readout rate is lowered as the subject optical image is darker. .

In the disclosed focus control method, the condition relating to the subject optical image includes a phase difference between the pair of image signals output with respect to the subject optical image, and in the readout rate control step, the variation in the phase difference is performed. The larger the is, the higher the reading rate is.

In the disclosed focus control method, the condition relating to the subject optical image includes the speed of the moving object included in the subject optical image. In the readout rate control step, the higher the speed of the moving object, the higher the readout rate. To do.

In the disclosed focus control method, the readout rate control step controls the readout rate according to the state of the imaging optical system.

In the disclosed focus control method, in the read rate control step, the movable optical included in the imaging optical system in a state where the read rate is controlled to a first value lower than a maximum value that can be set. When a change occurs in the operation state of the element, the read rate is controlled to a value larger than the first value.

In the disclosed focus control method, in the readout rate control step, the orientation of the optical axis of the imaging optical system is controlled in a state where the readout rate is controlled to a first value lower than a maximum value that can be set. When the change occurs, the reading rate is controlled to a value larger than the first value.

In the disclosed focus control method, when the manual focus mode in which the position of the focus lens is manually changed is set, the readout rate control step sets the readout rate to a value lower than the maximum value that can be set. To control.

In the disclosed focus control method, the first image sensor is an area sensor in which a plurality of pixels are two-dimensionally arranged on a light receiving surface, and the focus control device is disposed to face the light receiving surface. And a pair of separator lenses arranged in the one direction.

In the disclosed focus control method, the first imaging device includes an area sensor in which a pair of phase difference detection pixels that are pupil-divided in the one direction are arranged two-dimensionally on a light receiving surface. .

The disclosed focus control program captures a subject light image through an imaging optical system including a first imaging element that outputs a pair of image signals shifted in one direction with respect to one subject light image and a focus lens. An optical element that causes a part of the subject light incident on the imaging optical system to be incident on the second imaging element and causes the remaining part of the subject light other than the part to be incident on the first imaging element. A focus control step for controlling the focus lens based on a phase difference between the pair of image signals output from the first image sensor; And a readout rate control step for controlling the readout rate of the image signal.

The present invention is particularly convenient and effective when applied to a commercial television camera system or a compact digital camera.

DESCRIPTION OF SYMBOLS 1 Lens apparatus 3 Camera apparatus 11 Focus lens 12, 13 Zoom lens 14 Aperture 16 Beam splitter 17 Mirror 18 Condensing lens 19 Separator lens 20 First image sensor 21 AF unit 31 Second image sensor

Claims (25)

1. A first imaging device that outputs a pair of image signals shifted in one direction with respect to one subject light image;
   A part of subject light incident on the imaging optical system is incident on a second imaging element that captures a subject light image through an imaging optical system including a focus lens, and the remainder excluding the part of the subject light is An optical element that is incident on the first imaging element;
   A focus control unit that performs focus control of the focus lens based on a phase difference between the pair of image signals output from the first image sensor;
   And a read rate control unit that controls a read rate of the image signal from the first image sensor.
2. The focus control device according to claim 1,
   The read rate control unit is a focus control device that controls the read rate according to a condition related to a subject light image formed by the imaging optical system.
3. The focusing control device according to claim 2,
   The condition relating to the subject optical image includes the brightness of the subject optical image,
   The read rate control unit is a focus control device that lowers the read rate as the subject light image is darker.
4. It is a focusing control apparatus of Claim 2 or 3,
   The condition relating to the subject optical image includes a phase difference between the pair of image signals output for the subject optical image,
   The focusing control device, wherein the reading rate control unit increases the reading rate as the variation in the phase difference increases.
5. The in-focus control device according to any one of claims 2 to 4,
   The condition relating to the subject light image includes the speed of a moving object included in the subject light image,
   The read rate control unit is a focusing control device that increases the read rate as the speed of the moving object increases.
6. The focusing control device according to any one of claims 1 to 5,
   The read rate control unit is a focus control device that controls the read rate according to a state of the imaging optical system.
7. The focusing control device according to claim 6,
   In the state where the readout rate control unit controls the readout rate to a first value lower than a maximum value that can be set, a change has occurred in the operating state of the movable optical element included in the imaging optical system In this case, a focus control device that controls the reading rate to a value larger than the first value.
8. The focusing control device according to claim 6 or 7,
   In the state where the readout rate control unit is controlling the readout rate to a first value lower than a maximum value that can be set, when a change occurs in the direction of the optical axis of the imaging optical system, A focus control device that controls the read rate to a value larger than the first value.
9. The focusing control device according to any one of claims 1 to 8,
   When the manual focus mode in which the position of the focus lens is manually changed is set, the readout rate control unit controls the readout rate to a value lower than a maximum value that can be set.
10. The focusing control device according to any one of claims 1 to 9,
    The first image sensor is an area sensor in which a plurality of pixels are two-dimensionally arranged on a light receiving surface,
    An in-focus control device further comprising a pair of separator lenses arranged in the one direction so as to face the light receiving surface.
11. The focusing control device according to any one of claims 1 to 9,
    The focus control device, wherein the first image sensor is an area sensor in which a pair of phase difference detection pixels that are pupil-divided in the one direction are arranged two-dimensionally on a light receiving surface.
12. A focusing control device according to any one of claims 1 to 11,
    A lens apparatus comprising the imaging optical system.
13. A focusing control device according to any one of claims 1 to 11,
    An imaging device comprising the second imaging device.
14. The first imaging element that outputs a pair of image signals shifted in one direction with respect to one subject optical image, and the second imaging element that captures the subject optical image through an imaging optical system including a focus lens. An in-focus control method using an in-focus control device comprising: an optical element that causes a part of subject light incident on an optical system to enter, and an optical element that causes the remaining part of the subject light to be incident on the first image sensor Because
    A focus control step for performing focus control of the focus lens based on a phase difference between the pair of image signals output from the first image sensor;
    A read rate control step of controlling a read rate of the image signal from the first image sensor.
15. The focus control method according to claim 14,
    In the read rate control step, a focus control method for controlling the read rate according to a condition relating to a subject light image formed by the imaging optical system.
16. The focus control method according to claim 15, comprising:
    The condition relating to the subject optical image includes the brightness of the subject optical image,
    The focus control method in which, in the readout rate control step, the readout rate is lowered as the subject light image is darker.
17. The focus control method according to claim 15 or 16,
    The condition relating to the subject optical image includes a phase difference between the pair of image signals output for the subject optical image,
    In the read rate control step, a focus control method in which the read rate is increased as the variation in the phase difference increases.
18. The focus control method according to any one of claims 15 to 17,
    The condition relating to the subject light image includes the speed of a moving object included in the subject light image,
    In the readout rate control step, a focus control method in which the readout rate is increased as the speed of the moving body is increased.
19. The focus control method according to any one of claims 14 to 18, comprising:
    A focus control method for controlling the readout rate in accordance with a state of the imaging optical system in the readout rate control step.
20. The focus control method according to claim 19, comprising:
    In the readout rate control step, a change has occurred in the operating state of the movable optical element included in the imaging optical system in a state where the readout rate is controlled to a first value lower than a maximum value that can be set. In this case, a focus control method for controlling the reading rate to a value larger than the first value.
21. The focus control method according to claim 19 or 20,
    In the read rate control step, in the state where the read rate is controlled to a first value lower than a settable maximum value, when a change occurs in the direction of the optical axis of the imaging optical system, A focus control method for controlling the reading rate to a value larger than the first value.
22. The focus control method according to any one of claims 14 to 21,
    A focus control method for controlling the readout rate to a value lower than a maximum value that can be set in the readout rate control step when a manual focus mode in which a position of the focus lens is manually changed is set.
23. The focusing control method according to any one of claims 14 to 22,
    The first image sensor is an area sensor in which a plurality of pixels are two-dimensionally arranged on a light receiving surface,
    The focus control apparatus further includes a pair of separator lenses arranged in the one direction and arranged to face the light receiving surface.
24. The focusing control method according to any one of claims 14 to 22,
    The focus control method, wherein the first image sensor is an area sensor in which a pair of phase difference detection pixels that are pupil-divided in the one direction are arranged in a two-dimensional manner on a light receiving surface.
25. The first imaging element that outputs a pair of image signals shifted in one direction with respect to one subject optical image, and the second imaging element that captures the subject optical image through an imaging optical system including a focus lens. An in-focus control device having an optical element that makes a part of subject light incident on an optical system incident and makes the remaining part of the subject light except the part incident on the first image sensor;
    A focus control step for performing focus control of the focus lens based on a phase difference between the pair of image signals output from the first image sensor;
    And a read rate control step for controlling a read rate of the image signal from the first image sensor.

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