JP2005148249A - Camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera in which a photographing operation can be sped up by shortening a processing period needed for photographing. <P>SOLUTION: The camera includes an optical unit 13A and an optical unit 13B which can be AF controlled independently and fetch image information showing a subject image from different positions. A first detection circuit 34A and a second detection circuit 34B corresponding to the optical unit 13A and an optical unit 13B, respectively, detect contrast values indicating degrees to which the optical units are focused based upon the image information fetched via the corresponding optical units. When the AF control is exerted, the AF operations of the optical units are independently controlled at the same time. At this time, the final focused states of the respective optical units are determined based on the contrast values detected by the first detection circuit 34A and the second detection circuit 34B. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a camera that is configured to be capable of focusing control and includes a plurality of imaging optical systems for acquiring image information indicating a subject image from different positions.

  In recent years, interest in stereoscopic images has increased, and a camera that can capture stereoscopic images by acquiring right-eye images and left-eye images using two camera units provided at two different positions has been put into practical use. Has been.

  In this type of camera, due to the parallax between the camera units, there may be a shift in the in-focus state between the images obtained by the camera units. A stereoscopic image generated based on these images There is a possibility that the information becomes inappropriate and it is difficult to stereoscopically view the image indicated by the stereoscopic image information.

In view of this point, Patent Document 1 includes two lens systems for obtaining left-eye and right-eye imaging information, and each lens based on information such as a focus position and a line-of-sight direction angle related to each lens system. A technique is disclosed in which a focus detection range including a common subject is calculated for the system, and focus control is performed in the calculated focus detection range.
JP-A-8-194274

  By the way, in a camera having a function for performing focus control, it is desired to reduce the time required for the focus control. This is because if the time required for focusing control is long, not only the operational feeling during photographing is bad, but also a photo opportunity may be missed.

  However, the technique of Patent Document 1 has a problem in that the focus control operation cannot always be performed at high speed because no consideration is given to the reduction of the time required for the focus control.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a camera that can reduce the time required for focusing control.

  In order to achieve the above object, each of the cameras according to claim 1 is configured to be capable of focusing control, and has a plurality of imaging optical systems for acquiring image information indicating subject images from different positions, and A plurality of detection units that correspond to the plurality of imaging optical systems on a one-to-one basis and detect a physical quantity indicating a degree of focusing in the imaging optical system based on image information acquired through the corresponding imaging optical system. And controlling the focusing operations of the plurality of imaging optical systems simultaneously and independently when performing focusing control, and the plurality of imaging optics based on the physical quantities detected by the plurality of detection means at this time Control means for determining the final focusing state of the system.

  The camera according to claim 1 is provided with a plurality of imaging optical systems configured to be capable of focusing control and acquiring image information indicating subject images from different positions. Stereo imaging can be performed using a plurality of pieces of image information acquired via.

  In the camera according to the present invention, each of the plurality of imaging optical systems has a one-to-one correspondence with the plurality of imaging optical systems based on image information acquired via the corresponding imaging optical system. A physical quantity indicating the degree of focusing is detected.

  Here, in the present invention, when the focusing control is performed by the control means, the focusing operations of the plurality of imaging optical systems are simultaneously and independently controlled, and at this time, detected by the plurality of detection means. Based on the physical quantity, final focusing states of the plurality of imaging optical systems are determined.

  That is, in the camera according to the present invention, the physical quantity used to determine the final in-focus state is obtained simultaneously from each detection unit by performing the focusing operation of the plurality of imaging optical systems, and as a result, The time required for focusing control can be shortened.

  As described above, the camera according to claim 1 is configured so as to be capable of focusing control, and includes a plurality of imaging optical systems for acquiring image information indicating subject images from different positions, and each of the plurality of imaging optical systems. A physical quantity indicating the degree of focusing in the imaging optical system is detected on the basis of image information acquired via the corresponding imaging optical system by a plurality of detection means corresponding to the imaging optical system on a one-to-one basis. When performing the focus control, the focusing operations of the plurality of imaging optical systems are controlled simultaneously and independently, and at the same time, the final operation of the plurality of imaging optical systems is performed based on the physical quantities detected by the plurality of detection units. Since the in-focus state is determined, the time required for focusing control can be shortened.

  The control means according to claim 1 controls the plurality of imaging optical systems to change the focal positions in different ranges as the focusing operation, as in the invention according to claim 2. Accordingly, it is preferable to determine the same final in-focus state for the plurality of imaging optical systems based on the physical quantities detected by the plurality of detection units. As a result, it is possible to share the range in which the focal position is changed by a plurality of imaging optical systems capable of focusing at the same time and independently, so that the focal position can be changed in all ranges by each imaging optical system as in the past. Compared with the case of making it, the time required for focusing control can be further shortened.

  Further, as in the invention described in claim 3, the control means described in claim 2 is obtained by equally dividing the different ranges from each other and the range in which the focal position can be changed by the number of the imaging optical systems. A plurality of ranges may be used. As a result, the range in which the focus position is changed can be equally shared by the plurality of imaging optical systems, and the focusing operation period of each imaging optical system can be equalized, so that the time required for focusing control varies. Can be suppressed.

  The control means according to claim 2 or claim 3 reaches an amount indicating that any of the physical quantities detected by the plurality of detection means is in focus as in the invention according to claim 4. At that time, the focal position where the physical quantity is detected may be determined as the final focused state. As a result, the final focus state can be determined without waiting for the detection of the physical quantity for all ranges in which the focus position can be changed, so that the time required for focus control can be further shortened. .

  On the other hand, as in the invention described in claim 5, the control means described in claim 2 or claim 3 changes the focal position of the plurality of imaging optical systems over the entire corresponding range. Accordingly, the focal position where the physical quantity with the highest degree of focus among the physical quantities detected by the plurality of detection means may be determined as the final focused state. Accordingly, it is possible to prevent the in-focus state from being erroneously determined, for example, when a plurality of subjects having different distances from the camera are included, and focus control can be performed with higher accuracy.

  As described above, the camera according to the present invention is configured to be capable of focusing control, and includes a plurality of imaging optical systems for acquiring image information indicating subject images from different positions, and each of the plurality of imaging optical systems. A physical quantity indicating the degree of focusing in the imaging optical system is detected on the basis of image information acquired via the corresponding imaging optical system by a plurality of detection means corresponding to the imaging optical system on a one-to-one basis. When performing the focus control, the focusing operations of the plurality of imaging optical systems are controlled simultaneously and independently, and at the same time, the final operation of the plurality of imaging optical systems is performed based on the physical quantities detected by the plurality of detection units. Since the in-focus state is determined, it has an excellent effect that the time required for in-focus control can be shortened.

The best mode for carrying out the invention will be described below in detail with reference to the drawings. Here, a case where the present invention is applied to a digital electronic still camera (hereinafter simply referred to as “digital camera”) having a function of capturing a stereoscopic still image and a normal (two-dimensional) still image will be described.
(First embodiment)
First, an external configuration of the digital camera 10 according to the present embodiment will be described with reference to FIG. As shown in the figure, on the front of the digital camera 10, there are a pair of lenses 12A and 12B for forming a subject image, and a viewfinder 70 used for determining the composition of the subject to be photographed. Is provided.

  On the top surface of the digital camera 10, a release button (so-called shutter) 52A that is pressed by a photographer when performing shooting and a power switch 52E are provided.

  Note that the release button 52A according to the present embodiment is in a state where it is pressed down to an intermediate position (hereinafter referred to as “half-pressed state”) and a state where it is pressed down to a final pressed position that exceeds the intermediate position (hereinafter referred to as “herein”) It is configured to be able to detect a two-stage pressing operation of “fully pressed state”.

  In the digital camera 10 according to the present embodiment, when the shooting mode to be described later is set, the release button 52A is pressed halfway to activate the AE (Automatic Exposure) function to expose the exposure state ( After the shutter speed and aperture state are set, the AF (Auto Focus) function is activated to control the focus, and then exposure (shooting) is performed when the shutter button is fully pressed.

  On the other hand, on the back of the digital camera 10, a liquid crystal display (hereinafter referred to as “the eyepiece” of the finder 70 and a subject image, various menu screens, messages, etc. indicated by the digital image data obtained by photographing). “LCD”) 30, a stereoscopic shooting mode that is a mode for shooting a three-dimensional still image, a normal shooting mode that is a mode for shooting a two-dimensional still image, and digital image data obtained by shooting. The subject image to be displayed (reproduced) on the LCD 30, a mode changeover switch 52 </ b> B that is operated to set any one of the playback modes, a cross-cursor button 52 </ b> C, and zooming of the subject image during shooting. Zoom switch 52D that is operated when performing (reduction).

  The cross-cursor button 52C has a total of five arrow keys indicating four movement directions of up, down, left, and right in the display area of the LCD 30, and a determination key positioned at the center of the four arrow keys. Consists of two keys. The zoom switch 52D corresponds to the position of “T” in the figure and is operated when enlarging the subject image, corresponds to the position of “W” in the figure, and corresponds to the subject image. And a wide switch that is operated when the image is reduced.

  On the other hand, on the side of the digital camera 10, a slot in which a recording medium capable of recording digital image data obtained by photographing (here, a recording medium on which the digital image data is recorded as an image file) can be mounted. SL is provided.

  Next, the configuration of the electrical system of the digital camera 10 according to the present embodiment will be described with reference to FIG.

  As shown in the figure, the digital camera 10 includes an optical unit 13A configured to include the lens 12A described above, a CCD (charge coupled device) 14A disposed behind the optical axis of the lens 12A, and a correlated double. A first circuit configured to include a sampling circuit (hereinafter referred to as “CDS”) 16A and an analog / digital converter (hereinafter referred to as “ADC”) 18A that converts an input analog signal into digital data. An imaging system 88A is provided. The digital camera 10 includes a second optical unit 13B configured to include the lens 12B described above, a CCD 14B disposed behind the optical axis of the lens 12B, a CDS 16B, and an ADC 18B. An imaging system 88B is provided.

  That is, the digital camera 10 according to the present embodiment includes two imaging systems, the first imaging system 88A and the second imaging system 88B, which have the same configuration as each other, and can be used for stereoscopic shooting by using them. It is said. Note that the normal shooting mode is set, and when performing normal two-dimensional shooting, one of the first imaging system 88A and the second imaging system 88B is selectively used.

  In the first imaging system 88A, the output end of the CCD 14A is connected to the input end of the CDS 16A, and the output end of the CDS 16A is connected to the input end of the ADC 18A. Similarly, in the second imaging system 88B, the output end of the CCD 14B is connected to the input end of the CDS 16B, and the output end of the CDS 16B is connected to the input end of the ADC 18B.

  Here, the correlated double sampling processing by the CDS 16A and the CDS 16B is included in the output signal for each pixel of the solid-state image sensor for the purpose of reducing noise (particularly thermal noise) included in the output signal of the solid-state image sensor. This process is to obtain accurate pixel data by taking the difference between the feedthrough component level and the pixel signal component level.

  On the other hand, the digital camera 10 has input terminals connected to the output terminals of the ADC 18A and ADC 18C and has a built-in line buffer of a predetermined capacity, and the input digital image data is stored in a predetermined area of the second memory 40 described later. Digital image data acquired by one of the first imaging system 88A and the second imaging system 88B applied when the image input controller 20 that performs direct storage control and the normal imaging mode is set. The image signal processing circuit 22 that performs various image processing on the two digital image data acquired by both the first imaging system 88A and the second imaging system 88B when the stereoscopic imaging mode is set. Stereoscopic image signal processing circuit 23 that performs various image processing and synthesis, and compression processing for digital image data in a predetermined compression format Subjecting one, and a compression and decompression circuit 24 for performing expansion processing in the format specified by the compression format for compressed digital image data.

  In addition, the digital camera 10 generates a signal for displaying an image, a menu screen, or the like indicated by the digital image data on the LCD 30 and supplies the signal to the LCD 30, while a video signal indicating the image to be displayed on the LCD 30 (the present embodiment). The video / LCD encoder 28 generates an NTSC signal and outputs it to the video output terminal OUT.

  The digital camera 10 includes a CPU (Central Processing Unit) 32 that controls the operation of the entire digital camera 10 and an AF detection circuit 34 that detects a physical quantity required to operate the AF function. . The AF detection circuit 34 detects a contrast value of an image obtained by imaging with the CCD 14A as the physical quantity, and detects a contrast value of an image obtained by imaging with the CCD 14B as the physical quantity. And a detection circuit 43B, which are configured to be capable of simultaneously detecting the contrast values of the respective images obtained by imaging by the CCD 14A and the CCD 14B.

  Further, the digital camera 10 is obtained by imaging with at least one of the CCD 14A and the CCD 14B used for photographing in the present embodiment (physical quantities required for operating the AE function and the AWB (Automatic White Balance) function). An AE / AWB detection circuit 36 that detects an amount indicating the brightness of the image (hereinafter referred to as “photometric data”), and an SDRAM (Synchronous Dynamic Random Access) used as a work area when the CPU 32 executes various processes. The first memory 38 is configured by a memory, and the second memory 40 is configured by a VRAM (Video RAM) that mainly stores digital image data obtained by photographing.

  Also, the digital camera 10 performs processing for outputting audio information to the outside by the media controller 42 for making the recording medium 43 mounted in the slot SL accessible by the digital camera 10, the speaker 72, and the speaker 72. An analog signal indicating audio information input via an audio output processing unit 46 to be performed, a microphone (stereo microphone) provided in two systems, and an amplifier 84 is converted into digital audio data that can be handled by the digital camera 10. And a voice input processing unit 82 that performs processing.

  The image input controller 20, image signal processing circuit 22, stereoscopic image signal processing circuit 23, compression / decompression processing circuit 24, video / LCD encoder 28, CPU 32, AF detection circuit 34, AE / AWB detection circuit 36, first memory 38, the second memory 40, the media controller 42, the audio output processing unit 46, and the audio input processing unit 82 are connected to each other via the system bus BUS.

  Therefore, the CPU 32 controls the operations of the image input controller 20, the image signal processing circuit 22, the stereoscopic image signal processing circuit 23, the compression / decompression processing circuit 24, and the video / LCD encoder 28, and the AF detection circuit 34 and the AE. Acquisition of the physical quantity detected by the AWB detection circuit 36, access to the first memory 38, the second memory 40, and the recording medium 43, output of audio information by the speaker 72 via the audio output processing unit 46, Audio information can be input via the microphone, the amplifier 84, and the audio input processing unit 82, respectively.

  On the other hand, the first imaging system 88A is provided with a timing generator 48A that mainly generates a timing signal for driving the CCD 14A and supplies the timing signal to the CCD 14A. The input end of the timing generator 48A is connected to the CPU 32, and the output end is Each is connected to the CCD 14A, and the drive of the CCD 14A is controlled by the CPU 32 via the timing generator 48A.

  Further, the CPU 32 is connected to an input end of a motor drive unit 50A provided in the first imaging system 88A, and an output end of the motor drive unit 50A is connected to a focus adjustment motor, a zoom motor, and an aperture drive motor provided in the optical unit 13A. It is connected.

  That is, the lens 12A included in the optical unit 13A according to the present embodiment has a plurality of lenses and is configured as a zoom lens that can change (magnify) the focal length. I have. The lens drive mechanism includes the focus adjustment motor, the zoom motor, and the aperture drive motor. The focus adjustment motor, the zoom motor, and the aperture drive motor are each supplied with a drive signal supplied from the motor drive unit 50A under the control of the CPU 32. Driven by.

  When changing the optical zoom magnification, the CPU 32 drives and controls the zoom motor to change the focal length of the lens 12A included in the optical unit 13A.

  Further, the CPU 32 performs focusing control by driving and controlling the focus adjustment motor so that the contrast of an image obtained by imaging by the CCD 14A is maximized. In other words, the digital camera 10 according to the present embodiment employs a so-called TTL (Through The Lens) method in which the lens position is set so that the contrast of the read image is maximized as the focus control. .

  Note that the second imaging system 88B is also provided with a timing generator 48B and a motor drive unit 50B having the same configuration as that of the first imaging system 88A. The CPU 32 controls driving of the CCD 14B and driving of a focus adjustment motor, a zoom motor, and an aperture driving motor included in a lens driving mechanism (not shown) provided in the optical unit 13B. In the present embodiment, the range in which the focal positions of the optical unit 13A and the optical unit 13B can be changed is shared.

  Further, the release button 52A, the mode switch 52B, the cross cursor button 52C, the zoom switch 52D, and the various buttons and switches (generally referred to as “operation unit 52” in FIG. 2) of the power switch 52E are stored in the CPU 32. Connected, the CPU 32 can always grasp the operation state of these buttons and switches.

  In addition, the digital camera 10 according to the present embodiment includes a power supply circuit 54 and a battery 56, and the power supply circuit 54 is appropriate based on the power input from the battery 56 under the control of the CPU 32. Electric power for operation is generated and supplied to each part. In order to avoid complications, connection lines to the respective parts to which power is supplied from the power supply circuit 54 are not shown in the figure.

  Furthermore, the digital camera 10 according to the present embodiment is provided with a clock generator 80. The clock generator 80 generates an appropriate clock signal under the control of the CPU 32 and supplies it to each unit. In order to avoid complications, connection lines to the respective parts to which the clock signal is supplied from the clock generator 80 are omitted in FIG.

  Next, the operation of the digital camera 10 according to the present embodiment will be described. First, the overall operation of the digital camera 10 when the stereoscopic shooting mode is set will be described.

  First, in the first imaging system 88A, the subject image is picked up by the CCD 14A via the optical unit 13A, and a signal indicating the subject image is sequentially output from the CCD 14A to the CDS 16A.

  The CDS 16A performs correlated double sampling processing on the signal input from the CCD 14A and sequentially outputs analog image signals of R (red), G (green), and B (blue) obtained thereby to the ADC 18A.

  The ADC 18A converts the R, G, and B analog image signals input from the CDS 16A into 12-bit R, G, and B signals (digital image data) and outputs the converted signals to the image input controller 20.

  In parallel with the operation of the first image pickup system 88A, the second image pickup system 88B also picks up the subject image by the CCD 14B via the optical unit 13B, and sequentially outputs a signal indicating the subject image from the CCD 14B to the CDS 16B. The CDS 16B performs correlated double sampling processing on the signal input from the CCD 14B and sequentially outputs the R, G, B analog image signals to the ADC 18B. The ADC 18B is input from the CDS 16B. The R, G, B analog image signals are converted into 12-bit R, G, B signals (digital image data), respectively, and output to the image input controller 20.

  The image input controller 20 accumulates digital image data for two images sequentially input from the ADC 18 </ b> A and ADC 18 </ b> B in a built-in line buffer and temporarily stores them in a predetermined area of the second memory 40.

  Digital image data for two images stored in a predetermined area of the second memory 40 is read out by the stereoscopic image signal processing circuit 23 under the control of the CPU 32, and the physical quantity (detected by the AE / AWB detection circuit 36 ( The white balance is adjusted by applying a digital gain corresponding to the photometric data), gamma processing and sharpness processing are performed to generate 8-bit digital image data, and further YC signal processing is performed to obtain the luminance signal Y and chroma signal. Cr and Cb (hereinafter referred to as “YC signal”) are generated, YC signals for these two images are combined by the stereoscopic image signal processing circuit 23 to generate a YC signal indicating a stereoscopic image, and the YC signal is 2 Stored in an area different from the predetermined area of the memory 40.

  Here, the stereoscopic image signal processing circuit 23 recognizes the YC signals obtained by the first imaging system 88A and the second imaging system 88B as YC signals indicating the images for the right eye and the left eye, respectively. A YC signal indicating a stereoscopic image is generated based on the YC signal.

  The LCD 30 is configured to display a moving image (through image) obtained by continuous imaging by each imaging system and can be used as a finder. In this way, the LCD 30 is used as a finder. In this case, the YC signal indicating the stereoscopic image stored in the predetermined area of the second memory is sequentially output to the LCD 30 via the video / LCD encoder 28. As a result, a through image is displayed on the LCD 30.

  Here, at the timing when the release button 52A is half-pressed by the user, after the AE function is activated and the exposure state is set in each imaging system as described above, the AF function is activated and focus control is performed. The YC signal stored in the second memory 40 at that time is then fully pressed, and is compressed in a predetermined compression format (in this embodiment, JPEG format) by the compression / decompression processing circuit 24. After that, recording is performed on the recording medium 43 via the media controller 42.

  Note that the operation of the digital camera 10 when the normal shooting mode is set is such that only the digital image data obtained by the imaging system previously selected by the image signal processing circuit 22 instead of the stereoscopic image signal processing circuit 23 is used. Is substantially the same as the above-described operation in the case where the stereoscopic shooting mode is set, except that a YC signal is generated by performing various image signal processing on the image and the YC signal is stored in the second memory 40. Therefore, explanation here is omitted.

  By the way, in the digital camera 10 according to the present embodiment, the AF control when the stereoscopic shooting mode is set is different from the control when the normal shooting mode is set.

  That is, when the normal shooting mode is set, only the optical unit (the optical unit 13A or the optical unit 13B) provided in the imaging system used for shooting is subject to AF control. The range in which the focal position can be changed by the lens system provided is the target range for AF control.

  On the other hand, when the stereoscopic shooting mode is set, in order to shorten the time required for AF control, both the first imaging system 88A and the second imaging system 88B are used for shooting. By using the two optical units of the optical unit 13A and the optical unit 13B provided in each imaging system, an AF operation is performed in different AF control ranges, and the first detection circuit 34A and the second detection circuit 34A are controlled accordingly. Based on the physical quantity (here, the contrast value) detected by the detection circuit 34B, the same (common) final in-focus state is determined for the optical unit 13A and the optical unit 13B.

  Specifically, as shown in FIG. 3 as an example, the range in which the focal position that can be changed common to the optical unit 13A and the optical unit 13B is equally divided into two, and one of the ranges is AF of the optical unit 13A. The control range and the other range are allotted to the AF control range of the optical unit 13B, respectively, and control is performed so that AF operations are performed simultaneously and independently in each range, and the AF detection circuit 34 sequentially in response thereto. Based on the detected contrast value for each imaging system, the same final in-focus state is determined for the optical unit 13A and the optical unit 13B.

  Hereinafter, the AF control process executed when the stereoscopic shooting mode is set will be described more specifically with reference to FIG. FIG. 4 is a flowchart showing the flow of processing of the AF control processing program executed by the CPU 32 at this time.

  First, in step 100, each of the motor driving units 50A and 50B is controlled simultaneously and independently to start changing the focal position within a predetermined AF control range by the optical unit 13A and the optical unit 13B. The AF operation by the optical unit is started, and in the next step 102, the acquisition of the contrast value according to the focus position sequentially detected by the first detection circuit 34A and the second detection circuit 34B according to the AF operation and the contrast value Recording to the first memory 38 associated with the corresponding focal position is started.

  In this embodiment, as shown in FIG. 3 as an example, the focal position of each optical unit is set at a predetermined speed from one end side to the other end side of the corresponding AF control range (in the direction indicated by the arrow in FIG. 3). Thus, the AF operation is performed by changing the above.

  At this time, the contrast value detected by the AF detection circuit 34 generally tends to change so as to draw an upwardly convex curve in accordance with the change of the focal position, and the maximum value in a focused state. Will be shown.

  Therefore, in the next step 104, it is determined whether or not the peak of the recorded contrast value has been detected, and the AF operation by each optical unit is continued until the determination is affirmative. After that, when a peak is detected, the process proceeds to step 106, the AF operation and physical quantity recording by each optical unit is finished, and then the process proceeds to step 108.

  In step 108, the focal position where the peak of the contrast value is detected is determined as the final in-focus state, and the focal position of one optical unit in the vicinity of the focal position corresponding to the peak of the contrast value is determined. Is controlled so as to be finely adjusted so that the focus position corresponds to the peak.

  In the next step 110, control is performed so that the focal position of the other optical unit becomes one focal position via the motor drive unit, and then the AF control processing program is terminated.

  As described above in detail, according to the first embodiment, each of the optical unit 13A and the optical unit is configured to be able to perform AF control and to acquire image information indicating a subject image from different positions. 13B, and the optical unit 13A and the optical unit 13B respectively corresponding to the optical unit 13A on a one-to-one basis by the first detection circuit 34A and the second detection circuit 34B based on the image information acquired via the corresponding optical unit. When the contrast value indicating the degree of in-focus is detected and AF control is performed, the AF operation of each optical unit is controlled simultaneously and independently. At this time, the first detection circuit 34A and the second detection circuit 34B Since the final focus state of each optical unit is determined based on the detected contrast value, when AF control is required It is possible to shorten the.

  Further, according to the first embodiment, as the focusing operation, the optical unit 13A and the optical unit 13B are controlled to change the focal position in different ranges, and the first detection circuit is correspondingly controlled. Since the same final in-focus position is determined for the optical unit 13A and the optical unit 13B based on the contrast values detected by the 34A and the second detection circuit 34B, the optical unit capable of AF operation simultaneously and independently Since the range in which the focal position is changed by the optical unit 13A and the optical unit 13B can be shared, the time required for focusing control can be compared with the conventional case where the focal position is changed in the entire range by each optical unit. , Can be shortened more.

  Furthermore, according to the first embodiment, the different ranges are a plurality of ranges obtained by equally dividing the number of optical units using a range in which the focus position can be changed. The range to be changed can be equally shared by a plurality of imaging optical systems, and the AF operation period of each optical unit can be equalized, so that occurrence of variations in time required for AF control can be suppressed.

Further, according to the first embodiment, when one of the contrast values detected by the first detection circuit 34A and the second detection circuit 34B reaches an amount indicating the in-focus state, the contrast Since the focus position where the value is detected is determined as the final focus state, the final focus state is not waited until the detection of the contrast value for all the ranges where the focus position can be changed is completed. Since it can be determined, the time required for AF control can be further shortened.
(Second Embodiment)
In the first embodiment, the contrast values detected by either the first detection circuit 34A or the second detection circuit 34B according to the simultaneous AF operations in the different AF control ranges by the optical units are performed. In the embodiment, the focus position where the peak is detected is determined to be determined to be in the final focused state at the time when becomes the peak. In the case where a plurality of subject images having different distances from the digital camera 10 are included in a region for which a contrast value is to be detected, focusing control may not be performed properly.

  That is, the contrast value may have a local peak corresponding to the plurality of subject images. In this case, the focal position where the contrast value first peaks after the AF operation starts is determined as the final focused state. It is not always appropriate to determine as

  Therefore, in the second embodiment, in order to perform appropriate focusing control at high speed even in such a case, a final determination is made based on the contrast values for the entire range of the focus position changeable range. An example of a mode for determining the in-focus state will be described.

  The configuration of the digital camera according to the second embodiment is the same as the configuration of the digital camera 10 according to the first embodiment described above (see FIGS. 1 and 2). Hereinafter, the AF control process executed when the stereoscopic shooting mode is set will be described more specifically with reference to FIG.

  FIG. 5 is a flowchart showing the flow of processing of the AF control processing program executed by the CPU 32 at this time. Also, in the figure, the same step numbers are assigned to steps that perform the same processing as in the flowchart shown in FIG.

  In step 105, the completion of the AF operation by all the optical units is waited, and in the next step 107, the contrast value detected and recorded from the AF detection circuit 34 corresponds to the maximum contrast value. The focal position is determined as the final in-focus state, and then the process proceeds to step 111.

  In step 111, control is performed so that the focal position of each optical unit becomes the focal position determined in step 107 via the motor driving unit 50A and the motor driving unit 50B, and then the present AF control processing program is terminated.

  As described above in detail, according to the second embodiment, each of the optical unit 13A and the optical unit is configured to be able to perform AF control and acquire image information indicating a subject image from different positions. 13B, and the optical unit 13A and the optical unit 13B respectively corresponding to the optical unit 13A on a one-to-one basis by the first detection circuit 34A and the second detection circuit 34B based on the image information acquired via the corresponding optical unit. When the contrast value indicating the degree of in-focus is detected and AF control is performed, the AF operation of each optical unit is controlled simultaneously and independently. At this time, the first detection circuit 34A and the second detection circuit 34B Since the final focus state of each optical unit is determined based on the detected contrast value, when AF control is required It is possible to shorten the.

  Further, according to the second embodiment, as the focusing operation, the optical unit 13A and the optical unit 13B are controlled to change the focal position in different ranges, and the first detection circuit is accordingly changed. Since the same final in-focus position is determined for the optical unit 13A and the optical unit 13B based on the contrast values detected by the 34A and the second detection circuit 34B, the optical unit capable of AF operation simultaneously and independently Since the range in which the focal position is changed by the optical unit 13A and the optical unit 13B can be shared, the time required for focusing control can be compared with the conventional case where the focal position is changed in the entire range by each optical unit. , Can be shortened more.

  Furthermore, according to the second embodiment, the different ranges are a plurality of ranges obtained by equally dividing the number of optical units using a range in which the focus position can be changed. The range to be changed can be equally shared by a plurality of imaging optical systems, and the AF operation period of each optical unit can be equalized, so that occurrence of variations in time required for AF control can be suppressed.

  Further, according to the second embodiment, the optical unit 13A and the optical unit 13B change the focal position for the entire corresponding range, and the first detection circuit 34A and the second detection circuit 34B are changed accordingly. The focus position where the contrast value with the highest degree of focusing is detected is determined as the final focusing state among the detected contrast values, and thus a plurality of subjects with different distances from the camera are included. In such a case, it is possible to prevent the in-focus state from being erroneously determined, and it is possible to perform AF control with higher accuracy.

  In each of the above-described embodiments, it has been described that the AF control is performed using the two optical units only when the stereoscopic shooting mode is set. However, the present invention is not limited to this, and is usually Even when the shooting mode is set, AF control can be performed using two optical units. Thereby, even when the normal shooting mode is set, the time required for AF control can be shortened. If the normal shooting mode is set, only the optical unit that actually acquires the image information needs to be adjusted to the focal position where the final in-focus state is obtained (step 110 in FIG. 4, step in FIG. 5). 111).

  Further, in each of the above-described embodiments, the AF operation of each optical unit is performed toward the same end portion in the range (in the direction indicated by the arrow in FIG. 3) as shown in FIG. The present invention is not limited to this, but as shown in FIG. 6A, the first imaging system 88A changes its focal position from one end, and the second imaging system 88B changes its focal position from the other end. You may make it carry out toward the center of the possible range. In this case, since the focal positions of the optical units are close to each other, the operation of adjusting the focal position of the optical unit to the final focal position can be quickly performed. As a result, the time required for AF control can be further reduced.

  Moreover, it is needless to say that the processing flow of the flowcharts (see FIGS. 4 and 5) described in the present embodiment is an example, and can be appropriately changed without departing from the gist of the present invention.

  Further, the above-described configuration of the digital camera 10 (see FIGS. 1 and 2) is an example, and it goes without saying that the configuration can be appropriately changed without departing from the gist of the present invention.

  For example, in this embodiment, the case where two optical units are provided has been described. However, the present invention is not limited to this, and the present invention is also applicable to a camera including three or more optical system units. be able to. When three optical system units are provided, as shown in FIG. 6B, the range in which the focal length can be changed when performing focusing control is divided into three equal parts, and the respective ranges are assigned to the respective optical units. (Optical unit A, optical unit B, optical unit C) may be shared.

  In each of the above embodiments, the mode of the digital camera has been described as being set to any one of the 3D shooting mode, the normal shooting mode, and the playback mode by operating the mode switch 52B. The digital camera may be set to either the shooting mode or the playback mode, and a switch for setting either a stereoscopic image mode for handling a stereoscopic image or a normal image mode for handling a normal image may be separately provided. In such a configuration, the digital camera operates in any one of the three-dimensional image shooting mode, the normal image shooting mode, the three-dimensional image reproduction mode, and the normal image reproduction mode according to the operation state of these switches. Become.

  Further, in each of the above embodiments, the case where the present invention is applied to a digital camera has been described. However, the present invention is not limited to a digital camera, and can also be applied to a camera using a silver-lead photographic film. .

It is an external view which shows the external appearance of the digital camera which concerns on embodiment. It is a block diagram which shows the structure of the electric system of the digital camera which concerns on embodiment. It is a schematic diagram which shows the AF control range of each optical unit as an example. It is a flowchart which shows the flow of a process of AF control processing program performed by CPU which concerns on 1st Embodiment. It is a flowchart which shows the flow of a process of AF process control program performed by CPU which concerns on 2nd Embodiment. It is a schematic diagram which shows the AF control range and AF operation | movement of each optical unit as an example.

Explanation of symbols

10 Digital camera 13A, 13B Optical unit (imaging optical system)
32 CPU (control means)
34A First detection circuit (detection means)
34B Second detection circuit (detection means)

Claims (5)

A plurality of imaging optical systems configured to be capable of focusing control and acquiring image information indicating subject images from different positions;
A plurality of detections that respectively correspond to the plurality of imaging optical systems on a one-to-one basis and detect physical quantities indicating the degree of focusing in the imaging optical system based on image information acquired through the corresponding imaging optical system Means,
When performing focusing control, the focusing operations of the plurality of imaging optical systems are controlled simultaneously and independently, and at the same time, based on the physical quantities detected by the plurality of detecting means, the plurality of imaging optical systems Control means for determining the final in-focus state;
With a camera. The control unit controls the plurality of imaging optical systems to change the focal position in different ranges as the focusing operation, and based on the physical quantity detected by the plurality of detection units according to the control. The camera according to claim 1, wherein the same final in-focus state is determined for the plurality of imaging optical systems. The camera according to claim 2, wherein the different ranges are a plurality of ranges obtained by equally dividing a range in which a focal position can be changed by the number of the imaging optical systems. The control means determines the focal position at which the physical quantity is detected as the final in-focus state when reaching a quantity indicating that any physical quantity detected by the plurality of detection means is in focus. The camera according to claim 2 or 3. The control unit changes the focal position of the plurality of imaging optical systems for the entire range of the corresponding range, and according to this, the degree of focusing is the highest among the physical quantities detected by the plurality of detection units. The camera according to claim 2, wherein a focal position where a physical quantity is detected is determined as the final focused state.

Images