JP5180042B2 - Imaging apparatus and imaging method - Google Patents

Description

  The present invention relates to an imaging apparatus and an imaging method.

  In an electronic imaging apparatus that includes an imaging device such as a CCD (Charge Coupled Devices) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor, such as a digital still camera, and that electronically captures a subject, the imaging device is connected. The imaged image can be displayed on the imaging device in real time (live view display).

  When auto focus processing is performed to automatically focus on the subject while live view is displayed, processing to move the focus lens before and after the focused position (focus position) is performed. . Therefore, when autofocus processing is executed, an image that is in focus and an image that is out of focus and blurred are displayed in succession, making it difficult to view an image displayed in live view. .

  For example, Patent Documents 1 to 3 are disclosed as techniques for solving such a problem. Patent Document 1 discloses a technique for starting live view display after performing focus adjustment. Japanese Patent Application Laid-Open No. 2004-228688 discloses a technique for continuously displaying a still image at the time when the shutter is half-pressed during execution of the autofocus process, and displaying an in-focus image after completion of the autofocus process. ing. Further, Patent Document 3 discloses a technique for appropriately displaying a subject image while combining a frame rate for image display and a frame rate for autofocus processing.

JP 2008-185611 A JP 2008-51938 A JP 2003-289469 A

  However, these techniques have a problem that an image to be displayed becomes unnatural when auto focus processing and live view display are combined. In particular, when the method of Patent Document 2 is used, the display image is not updated during execution of the autofocus process, so that the change in the focus state is reduced and the live view display is easy to see. In such a case, there is a problem that the image is stopped and displayed during the autofocus process.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to update the display when moving the position of the focus lens in the case of continuously displaying or recording images. It is an object of the present invention to provide a new and improved imaging apparatus and imaging method capable of reducing a change in focus state while increasing the frequency.

  In order to solve the above-described problems, according to an aspect of the present invention, a focus lens that can change a focal position, a focus lens moving unit that moves the focus lens in the optical axis direction, and a position of the focus lens are periodically set. And a display control means for controlling the update of the image to be displayed according to the position of the focus lens as a result of the movement of the focus lens by the focus lens moving means.

  According to this configuration, the focus lens can change the focal position, and the focus lens moving means moves the focus lens in the optical axis direction. Then, the display control means periodically detects the position of the focus lens, and controls the update of the image to be displayed according to the position of the focus lens as a result of the movement of the focus lens by the focus lens moving means. As a result, when moving the position of the focus lens, it is determined whether to display an image according to the position of the focus lens, thereby reducing the change in focus state while increasing the display update frequency. It becomes possible.

  Further, a focus state detection unit that periodically detects the focus state of the subject is provided, and the display control unit detects the focus state by the focus state detection unit, and as a result, the focus lens is positioned within a predetermined range. For example, an image at the time of the detection may be displayed, and if the focus lens is not in a predetermined range, an image when the focus lens has been previously positioned in the predetermined range may be displayed. Further, the predetermined range may be a range including a reference position serving as a reference for determining the in-focus state of the subject.

  The display control means may generate an image to be displayed using a plurality of images captured in the vicinity of the in-focus position when displaying the image.

  Then, the display control unit may generate an image to be displayed using a plurality of images continuously captured in the vicinity of the in-focus position when displaying the image.

  Further, the display control means acquires a difference between a plurality of images, and if the difference is larger than a predetermined amount, generates an image to be displayed with higher weighting as the image acquired later in time. Also good.

  In order to solve the above-described problem, according to another aspect of the present invention, a focus lens moving step for moving a focus lens capable of changing a focus position, a position of the focus lens is periodically detected, and a focus lens is moved. As a result of the movement of the focus lens by the lens movement step, a display control step for controlling update of an image to be displayed according to the position of the focus lens is provided.

  As described above, according to the present invention, when the position of the focus lens is moved in the case of continuously displaying or recording images, the change in focus state is reduced while the display update frequency is increased. It is possible to provide a new and improved image pickup apparatus and image pickup method capable of

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  First, the configuration of an imaging apparatus according to an embodiment of the present invention will be described. FIG. 1 is an explanatory diagram illustrating a configuration of an imaging apparatus 100 according to an embodiment of the present invention. Hereinafter, the configuration of the imaging apparatus 100 according to the embodiment of the present invention will be described with reference to FIG.

  The imaging device 100 is a device that can capture still images and moving images. As shown in FIG. 1, an imaging apparatus 100 according to an embodiment of the present invention includes a zoom lens 102, a diaphragm 104, a focus lens 106, a CCD (Charge Coupled Devices) element 108, and an amplifier-integrated CDS. (Correlated Double Sampling) circuit 110, A / D converter 112, image input controller 114, image signal processing unit 116, compression processing unit 120, LCD (Liquid Crystal Display) driver 122, LCD 124, timing Generator 126, motor drivers 142a, 142b, 142c, control unit 128, operation unit 132, memory 134, VRAM (Video Random Access Memory) 136, media A controller 138, and a recording medium 140.

  The zoom lens 102, the diaphragm 104, the focus lens 106, and the CCD element 108 constitute an exposure unit. In the present embodiment, the exposure unit is configured using the CCD element 108, but the present invention is not limited to this example, and a CMOS (Complementary Metal Oxide Semiconductor) element may be used instead of the CCD element. Since the CMOS element can convert the image light of the subject into an electric signal at a higher speed than the CCD element, it is possible to shorten the time from when the subject is photographed until the image is recorded.

  The zoom lens 102 is a lens whose focal length continuously changes by moving back and forth in the optical axis direction, and shoots while changing the size of the subject. The diaphragm 104 adjusts the amount of light entering the CCD element 108 when taking an image. The focus lens 106 adjusts the focus of the subject by moving back and forth in the optical axis direction.

  Motor drivers 142a, 142b, and 142c control motors that operate the zoom lens 102, the diaphragm 104, and the focus lens 106. By operating the zoom lens 102, the diaphragm 104, and the focus lens 106 via the motor drivers 142a, 142b, and 142c, the size of the subject, the amount of light, and the focus are adjusted.

  The CCD element 108 is an element for converting light incident from the zoom lens 102, the diaphragm 104, and the focus lens 106 into an electric signal. In this embodiment, the incident light is controlled by the electronic shutter to adjust the time for extracting the electric signal. However, the time for extracting the electric signal may be adjusted by controlling the incident light using the mechanical shutter.

  The CDS circuit 110 is a circuit in which a CDS circuit that is a kind of sampling circuit that removes noise from the electrical signal output from the CCD element 108 and an amplifier that amplifies the electrical signal after removing the noise are integrated. . In the present embodiment, the imaging apparatus 100 is configured using a circuit in which a CDS circuit and an amplifier are integrated. However, the CDS circuit and the amplifier may be configured as separate circuits.

  The A / D converter 112 converts the electrical signal generated by the CCD element 108 into a digital signal, and generates raw image data.

  The image signal processing unit 116 is a circuit that performs various signal processing on the raw image data generated by the A / D converter 112.

  The compression processing unit 120 executes a compression process for compressing the data subjected to the signal processing by the image signal processing unit 116 into image data of an appropriate format. The image compression format may be a reversible format or an irreversible format. As an example of a suitable format, you may convert into a JPEG (Joint Photographic Experts Group) format and a JPEG2000 format.

  The LCD 124 performs live view display before performing a shooting operation, various setting screens of the imaging apparatus 100, display of captured images, and the like. Display of image data and various information of the imaging apparatus 100 on the LCD 124 is performed via the LCD driver 122. In this embodiment, live view display before performing a shooting operation on the LCD, various setting screens of the imaging apparatus 100, display of a captured image, and the like are performed. However, the present invention is not limited to such an example. . Live view display before shooting operation, various setting screens of the imaging apparatus 100, display of captured images, and the like are performed on a display device other than the LCD, for example, a display device using an organic EL (Electro Luminescence). May be.

  The timing generator 126 inputs a timing signal to the CCD element 108. The shutter speed is determined by the timing signal from the timing generator 126. That is, the drive of the CCD element 108 is controlled by the timing signal from the timing generator 126, and the image signal from the subject is incident within the time that the CCD element 108 is driven, thereby generating an electrical signal that is the basis of the image data. The

  The control unit 128 issues a signal-related command to the CCD element 108, the CDS circuit 110, and the like, and issues an operation-related command to the operation of the operation unit 132. In the present embodiment, the control unit 128 may be a single CPU (Central Processing Unit), and a signal system command and an operation system command are performed by separate CPUs or DSPs (Digital Signal Processors). Also good.

  The operation unit 132 includes a function as a shooting mode selection unit, and members for operating the imaging apparatus 100 and various settings at the time of shooting are arranged. The members arranged on the operation unit 132 include a power button, a cross key and a selection button for selecting a shooting mode and a shooting drive mode and setting effect parameters, a shutter button for starting a shooting operation, and the like.

  The memory 134 temporarily stores captured images and images subjected to signal processing by the image signal processing unit 116. The memory 134 has a storage capacity sufficient to store a plurality of images. Reading and writing of images to and from the memory 134 is controlled by the image input controller 114.

  The VRAM 136 holds contents displayed on the LCD 124, and the resolution and the maximum number of colors of the LCD 124 depend on the capacity of the VRAM 136.

  The recording medium 140 records a photographed image. Input / output to / from the recording medium 140 is controlled by the media controller 138. As the recording medium 140, a memory card that is a card-type storage device that records data in a flash memory can be used.

  The configuration of the imaging device 100 according to the embodiment of the present invention has been described above. Next, the configuration of the control unit 128 included in the imaging apparatus 100 according to the embodiment of the present invention will be described.

  FIG. 2 is an explanatory diagram illustrating the configuration of the control unit 128 included in the imaging apparatus 100 according to the embodiment of the present invention. Hereinafter, the configuration of the control unit 128 included in the imaging apparatus 100 according to the embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 2, the control unit 128 included in the imaging apparatus 100 according to the embodiment of the present invention includes an autofocus control unit 152, a focus lens drive control unit 154, an aperture drive control unit 156, and a display. And a control unit 158.

  The autofocus control unit 152 executes autofocus processing according to the start operation of autofocus processing. The start operation of the autofocus process may be, for example, a half-press operation of a shutter button included in the operation unit 132 by the photographer, or other operations using the operation unit 132. Further, for example, when an image is displayed in live view, the autofocus process may be automatically started by the autofocus control unit 152 after a predetermined time has elapsed since the start of live view display. When the autofocus control unit 152 recognizes that there is some change in the image displayed in the live view, the autofocus process may be automatically started. When the autofocus process is started by the autofocus control unit 152, the position of the focus lens 106 focused on the subject is determined by controlling the position of the focus lens 106. The autofocus process may be executed by, for example, a contrast detection method in which the contrast of an image formed by the CCD element 108 is detected to determine a position at which the subject is focused, or is executed by another method. You may do it. In the following, a case where the autofocus process is executed by the contrast detection method will be described.

  The focus lens drive control unit 154 controls the drive of the focus lens 106 according to the autofocus process executed by the autofocus control unit 152. In the contrast detection method, the position of the focus lens 106 is periodically changed in the optical axis direction to detect the contrast of the image formed by the CCD element 108, and the focus having the highest contrast evaluation value (contrast evaluation value). The position of the lens 106 is determined as a position to focus on the subject. The position of the focus lens 106 is controlled by the focus lens drive control unit 154, and the contrast evaluation value is acquired by the autofocus control unit 152, so that the position of the focus lens 106 can be set to a position for focusing on the subject.

  The aperture drive control unit 156 controls the driving of the aperture 104 according to the autofocus process executed by the autofocus control unit 152. By controlling the driving of the diaphragm 104 according to the autofocus process and adjusting the amount of light incident on the CCD element 108, the subject can be properly focused.

  The display control unit 158 controls live view display on the LCD 124 according to the autofocus process executed by the autofocus control unit 152. By controlling the live view display on the LCD 124 by the display control unit 158, it is possible to reduce the change in the in-focus state while increasing the display update frequency as compared with the conventional imaging device. The control of live view display on the LCD 124 according to the autofocus process will be described in detail later.

  The configuration of the control unit 128 included in the imaging device 100 according to the embodiment of the present invention has been described above. Next, the operation of the imaging apparatus 100 according to an embodiment of the present invention will be described.

  FIG. 3 is a flowchart for explaining the operation when the autofocus process is executed in the imaging apparatus 100 according to the embodiment of the present invention. Hereinafter, the operation of the imaging apparatus 100 according to the embodiment of the present invention will be described with reference to FIG.

  In the imaging apparatus 100 according to the embodiment of the present invention, when the autofocus process is executed, the autofocus control unit 152 first acquires a reference value (focus position vicinity reference value) immediately before the autofocus process is executed. (Step S102). The reference value near the focus position acquired in step S102 may be the position of the focus lens 106 immediately before the execution of the autofocus process, and the contrast evaluation of the image formed by the CCD element 108 immediately before the execution of the autofocus process. It may be a value.

  When the focus position vicinity reference value is acquired in step S102, an image formed by the CCD element 108 immediately before execution of the autofocus process is displayed on the LCD 124 by the display control unit 158 (step S104). When the image is displayed on the LCD 124, the autofocus control unit 152 starts autofocus processing (step S106). When the autofocus process is started by the autofocus control unit 152, the position of the focus lens 106 is moved by the focus lens drive control unit 154 to detect the position of the focus lens 106 focused on the subject.

  When the autofocus process is started, movement of the focus lens 106 and acquisition of an image formed by the CCD element 108 are periodically executed (step S108). Then, the autofocus control unit 152 acquires a determination amount (focus position vicinity determination amount) when an image is acquired during execution of the autofocus process (step S110). The focus position vicinity determination amount may be the position of the focus lens 106 or a contrast evaluation value of an image formed by the CCD element 108. Then, based on the focus position vicinity reference value acquired in step S102 and the focus position vicinity determination amount acquired in step S110, whether the position of the focus lens 106 when the image is acquired is close to the position where the subject is focused. Whether or not it is determined by the autofocus control unit 152 (step S112).

  As a result of the determination in step S112, when the autofocus control unit 152 determines that the position of the focus lens 106 is close to the position at which the subject is in focus, the image acquired in step S108 is displayed on the LCD 124 by the display control unit 158. (Step S114). Then, the focus position vicinity reference value is updated with the focus position vicinity determination amount acquired in step S110 (step S116).

  On the other hand, as a result of the determination in step S112, when the autofocus control unit 152 determines that the position of the focus lens 106 is not close to the position at which the subject is in focus, the display of the image displayed on the LCD 124 is continued. (Step S118).

  Then, it is determined whether or not the autofocus control unit 152 has received a command to stop autofocus processing (autofocus processing stop command) (step S120). The autofocus process stop command may be sent to the autofocus control unit 152 when, for example, the position of the focus lens 106 focused on the subject is determined, and when the photographer stops executing the autofocus process (for example, It may be sent to the autofocus control unit 152 (when the half-press of the shutter button is released). If it is determined in step S120 that the autofocus control unit 152 has not received an autofocus process stop command, the process returns to step S108 and the focus lens 106 is moved and an image is formed by the CCD element 108. Execute acquisition of the selected image. On the other hand, if the autofocus control unit 152 determines that an autofocus process stop command has been received, the process ends.

  FIG. 4 is an explanatory diagram illustrating, as a graph, an example of the relationship between the position of the focus lens 106 and the contrast evaluation value when the autofocus process is executed in the imaging apparatus 100 according to the embodiment of the present invention. . In the graph shown in FIG. 4, the horizontal axis indicates the position of the focus lens 106, and the vertical axis indicates the contrast evaluation value. In the following description, in the graph shown in FIG. 4, the position of the focus lens 106 is moved from c → a → b → c → d → e, and finally moved to p, which is the position where the subject is focused. Will be described as an example.

  FIG. 5 illustrates an image displayed on the LCD 124 when the autofocus process is performed and the focus lens 106 is moved in the imaging apparatus 100 according to the embodiment of the present invention, as compared with the related art. It is explanatory drawing. FIGS. 5A and 5B show changes in the image displayed in the imaging apparatus according to the conventional technique, and FIGS. 5C and 5D show an embodiment of the present invention. 6 shows changes in the image displayed on the LCD 124 of the imaging apparatus 100 according to FIG. Note that the numbers shown in the lower right part of each image in FIG. 5 indicate the time at which the images were acquired, and correspond to the numbers in the leftmost column. Further, the alphabet shown at the lower left indicates the position of the focus lens in FIG.

  As shown in FIG. 5A, in the past, when the focus lens 106 was moved, the image formed by the image sensor was displayed as it was, so the image with a clear outline and the outline were blurred. Since the image is displayed instead of the image, there is a problem that it is difficult to see the image displayed in the live view. Further, as shown in FIG. 5B, in the technique described in Patent Document 2, since the image acquired at the start of the autofocus process is continuously displayed until the autofocus process ends, the live view is displayed. When viewing a moving object on the display, there was a problem that the image stopped and displayed during autofocus processing.

  Compared with these, the image displayed on the LCD 124 of the imaging apparatus 100 according to the embodiment of the present invention is the focus position vicinity reference value acquired in step S102 of FIG. 3 or updated in step S116, and step S110. Since the image to be displayed is determined by comparing with the focus position vicinity determination amount acquired in step 1, it is possible to reduce the change in the focus state while increasing the display update frequency.

  In the example shown in FIG. 5C, first, an image at the position c where the focus lens 106 is positioned is displayed, and the contrast evaluation value at the position c is held as a reference value near the focus position. Subsequently, when the focus lens 106 moves to the position a, the contrast evaluation value at the position a is acquired as a focus position vicinity determination amount. When the focus position vicinity reference value is compared with the acquired focus position vicinity determination amount, the position a is farther from the in-focus position than the position c, so that the image formed at the position a is not displayed on the LCD 124.

  Subsequently, when the focus lens 106 moves to the position b, the evaluation value of the contrast at the position b is acquired as the focus position vicinity determination amount. When the focus position vicinity reference value is compared with the acquired focus position vicinity determination amount, the position b is farther from the in-focus position than the position c. Therefore, the image formed at the position b is not displayed on the LCD 124.

  Subsequently, when the focus lens 106 moves to the position c, the contrast evaluation value at the position c is acquired as the focus position vicinity determination amount. When the focus position vicinity reference value is compared with the acquired focus position vicinity determination amount, since the position of c is the position where the focus position vicinity reference value is first acquired, the image acquired at the position of c at time 4 is displayed on the LCD 124. The focus position vicinity reference value is updated with the focus position vicinity determination amount at time 4.

  Subsequently, when the focus lens 106 moves to the position d, the contrast evaluation value at the position d is acquired as the focus position vicinity determination amount. When the focus position vicinity reference value is compared with the acquired focus position vicinity determination amount, the position of d is farther from the in-focus position than the position of c, so that the image formed at the position of d is not displayed on the LCD 124.

  Subsequently, when the focus lens 106 moves to the position e, the contrast evaluation value at the position e is acquired as a focus position vicinity determination amount. When the focus position vicinity reference value is compared with the acquired focus position vicinity determination amount, the position e is farther from the in-focus position than the position c. Therefore, the image formed at the position e is not displayed on the LCD 124.

  When the focus lens 106 moves to the position p where the subject is focused, the evaluation value of the contrast at the position p is acquired as the focus position vicinity determination amount. When the focus position vicinity reference value is compared with the acquired focus position vicinity determination amount, since the position of p is the position where the focus position vicinity reference value is first acquired, the image acquired at the position of p at time 7 is displayed on the LCD 124. The focus position vicinity reference value is updated with the focus position vicinity determination amount at time 7. Since the position p is a position at which the subject is focused, the autofocus control unit 152 receives an autofocus process stop command and ends the autofocus process.

  In this way, the display position is determined by comparing the focus position vicinity reference value acquired in advance or updated as needed with the focus position vicinity determination amount acquired sequentially, so the display update frequency is increased. However, the change in focus can be suppressed.

  In the flowchart shown in FIG. 3, in step S112, the autofocus control unit 152 determines whether or not the position of the focus lens 106 is close to the position at which the subject is in focus. The image displayed on the LCD 124 is updated only when it is close to the position where the subject is in focus as compared with the position where the image is acquired, but the present invention is not limited to such an example. When it is desired to increase the update frequency of the image displayed on the LCD 124, the process for determining whether the position of the focus lens 106 is close to the position at which the subject is in focus may be changed.

  FIG. 5D shows a case where the determination process of the position of the focus lens 106 is changed to increase the update frequency of the image displayed on the LCD 124 as compared with the case of FIG. It is. FIG. 5D shows that when the focus lens 106 is moved as shown in FIG. 4, even when the focus lens 106 is in the position b or d, it is determined that it is close to the position where the subject is in focus. An image when the focus lens 106 is at these positions is displayed on the LCD 124. In this case, when the position of the focus lens 106 moves to a or e, the determination process can be changed by updating the focus position vicinity reference value at these positions. In this way, by changing the process for determining whether the position of the focus lens 106 is close to the position at which the subject is in focus, the update frequency of the image displayed on the LCD 124 can be increased, and the image display on the LCD 124 can be increased. The frame rate can be improved.

  The operation of the imaging device 100 according to the embodiment of the present invention has been described above. In the above description, in FIG. 4, the display of the image on the LCD 124 in step S114 displays the acquired image as it is, but the present invention is not limited to such an example. For example, instead of using the acquired image as it is as the image displayed in step S112, an image to be displayed using a plurality of images may be generated and the generated image may be displayed. For example, in the case shown in FIG. 4C, when displaying an image when the focus lens 106 is at the position c at time 4, the image at time 4 and the time 1 are displayed. An image to be displayed on the LCD 124 may be generated using the image.

  For example, when generating from a plurality of images including past images, for example, the display control unit 158 may weight and add a plurality of temporally continuous images, and the temporally discontinuous images. Alternatively, a plurality of images close to the position of the focus lens 106 may be weighted and added. For example, the same weight may be used for weighting and adding together, or for example, a weight for a past frame may be decreased and a weight may be increased as a new frame is obtained. Further, for example, the display control unit 158 obtains a movement amount by taking a difference between frames, determines whether or not there is a moving subject based on the movement amount, and there is no moving subject or is determined in advance. If the amount of movement is less than the predetermined amount, all the images are given a uniform weight, and if there is a moving subject or if the amount of movement is larger than the predetermined amount, the weight for the past frame is reduced. Also good.

  As described above, according to the imaging apparatus 100 according to the embodiment of the present invention, the reference position is specified in advance at the start of the autofocus process, and the position of the focus lens 106 is determined in advance during the autofocus process. The positional relationship with the designated reference position is determined. Whether or not the image formed on the CCD 108 is displayed on the LCD 124 is determined based on whether or not the position of the focus lens 106 is closer to the in-focus position than the reference position designated in advance. By controlling the image display on the LCD 124 in this way, it is possible to suppress blurring of an image displayed in a live view on the LCD 124 during autofocus processing.

  Note that the application of the present invention is not limited to the autofocus process in which the subject is automatically focused. For example, the position of the focus lens 106 moved by the focus lens drive control unit 154 is periodically detected by the display control unit 158, and the LCD 124 determines whether or not the detected position of the focus lens 106 has changed beyond a predetermined range. The image to be displayed may be controlled. For example, when it is desired to continue displaying an image in which the subject is blurred, even when the position of the focus lens 106 changes beyond a predetermined range and is positioned near the position where the subject is focused. The display control unit 158 may perform control so that an image at the time when the subject is blurred is displayed on the LCD 124.

  In addition, even when a moving image is shot using the imaging apparatus 100 according to the embodiment of the present invention, for example, when it is desired to continue focusing on a specific subject, the subject is in a relatively good focus state. Can be kept.

  The above-described operation of the imaging apparatus 100 is performed by storing a computer program inside the imaging apparatus 100 (for example, in the memory 134), and reading out the stored computer program and sequentially executing the stored computer program. It may be.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention can be applied to an imaging apparatus and an imaging method, and in particular, can be applied to an imaging apparatus and an imaging method including a process for automatically focusing on a subject.

It is explanatory drawing shown about the structure of the imaging device 100 concerning one Embodiment of this invention. It is explanatory drawing explaining the structure of the control part 128 contained in the imaging device 100 concerning one Embodiment of this invention. 5 is a flowchart illustrating an operation when an autofocus process is executed in the imaging apparatus 100 according to the embodiment of the present invention. It is explanatory drawing which shows an example of the relationship between the position of the focus lens 106, and the evaluation value of contrast with a graph. It is explanatory drawing explaining the image displayed on LCD124 compared with a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Imaging device 102 Zoom lens 104 Aperture 106 Focus lens 108 CCD element 110 CDS circuit 112 A / D converter 114 Image input controller 116 Image signal processing part 120 Compression processing part 122 LCD driver 124 LCD
126 Timing generator 128 Control unit 132 Operation unit 134 Memory 138 Media controller 140 Recording medium 142a, 142b, 142c Motor driver 152 Autofocus control unit 154 Focus lens drive control unit 156 Aperture drive control unit 158 Display control unit

Claims (6)

A focus lens that can change the focal position;
Focus lens moving means for moving the focus lens in the optical axis direction;
Display control means for periodically detecting the position of the focus lens, and as a result of movement of the focus lens by the focus lens moving means, controlling update of an image to be displayed according to the position of the focus lens;
In-focus state detecting means for periodically detecting the in-focus state of the subject;
Equipped with a,
The display control means displays an image at the time of detection if the focus lens is located within a predetermined range as a result of detecting the focus state by the focus state detection means, and the focus lens is previously the focus lens if situated in the range Ru display the image when was located in the predetermined range, the image pickup device. The imaging apparatus according to claim 1 , wherein the predetermined range is a range including a reference position serving as a reference for determining an in-focus state of the subject.   The imaging apparatus according to claim 1, wherein the display control unit generates an image to be displayed using a plurality of images captured in the vicinity of the in-focus position when displaying the image.   The imaging apparatus according to claim 3, wherein the display control unit generates an image to be displayed using a plurality of images continuously captured in the vicinity of the in-focus position when the image is displayed.   The display control means acquires a difference between a plurality of images, and generates an image to be displayed with a greater weight as the image acquired later in time when the difference is larger than a predetermined amount. Item 5. The imaging device according to Item 4. A focus lens moving step for moving a focus lens capable of changing a focal position;
A focus state detection step for periodically detecting the focus state of the subject;
A display control step of periodically detecting the position of the focus lens, and controlling updating of an image to be displayed according to the position of the focus lens as a result of the movement of the focus lens by the focus lens movement step;
With
In the display control step, as a result of detecting the in-focus state in the in-focus state detecting step, if the focus lens is located in a predetermined range, an image at the time of detection is displayed, and the focus lens is previously the focus lens if situated in the range Ru display the image when was located in the predetermined range, the imaging method.

Images