JP2014140186A - Imaging apparatus and control method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus having a pre-REC function capable of acquiring an image signal that gives no sense of discomfort even when a user changes the setting involving the alteration of view angle and image quality.SOLUTION: An imaging apparatus includes: a signal storage section 105 for storing a video signal; a recording instruction section 110 for instructing the signal storage section 105 to start recording the video signal; and a setting change section 109 for changing settings for the video signals. The signal storage section 105 includes a buffer memory 106 that buffers video signals for a prescribed time period before receiving an instruction from the recording instruction section 110 to start recording, and when a user uses the setting change section 109 to change the setting for the video signal while the buffering is working, the signal storage section 105 deletes video signals buffered in the buffer memory 106 under the previous setting.

Description

  The present invention relates to an imaging apparatus having a pre-REC function and a control method thereof.

  2. Description of the Related Art In recent years, there has been known an imaging apparatus such as a digital video camera having a pre-REC function (pre-frame function) for buffering a video signal for a predetermined time before a recording start instruction so as not to miss a sudden photo opportunity. (For example, refer to Patent Document 1).

  In an imaging apparatus having a pre-REC function, video data is generally stored by the following process. When the user turns on the power of the image pickup apparatus, the optical image received by the image pickup device through the lens optical system is converted into an electric signal by the image pickup device, and is sequentially stored in a primary storage medium such as a semiconductor memory as image data (digital data). It will be done. When the storage capacity of the primary storage medium becomes full (full), the old video data is overwritten with the old video data, so that the old video data is sequentially erased while the new video data is sequentially stored.

  When the user of the imaging apparatus is instructed to start video recording, video data stored in the primary storage medium from a certain time before the recording start instruction time and video data after the recording start instruction time are stored in a hard disk (HDD) It is stored in a secondary storage medium such as a DVD-RAM. When a video recording end instruction is given, the storage processing of the video data in the secondary storage medium is ended and the storage processing of the video data in the primary storage medium is resumed.

JP 2002-118822 A

  However, the conventional imaging device having the pre-REC function has the following problems. For example, when the user changes the imaging conditions, the angle of view or the image quality of the video signal changes significantly, or the lens unit is removed or attached (disturbance or discontinuity in the video, etc.) There is a problem that a certain video is stored. In addition, if the user gives an instruction to start video recording before a certain time has elapsed since the imaging condition was changed, the video signal with the uncomfortable feeling stored in the primary storage device is stored as it is in the secondary storage device, There is a problem that the video quality is low.

  The present invention relates to an image pickup apparatus having a pre-REC function and a control method therefor, which can obtain a video signal without a sense of incongruity even when a user changes a setting with a change in an angle of view or an image quality. And it aims at providing the control method.

  In order to achieve the above object, an imaging apparatus according to claim 1 includes a signal storage unit for storing a captured video signal, and a recording instruction unit for instructing the recording start of the video signal to the signal storage unit. A setting change means for changing a setting relating to a video signal stored in the signal storage means, wherein the signal storage means is a constant before receiving a recording start instruction from the recording instruction means. Buffering means for buffering a video signal for a time, and when the setting change means is operated and the setting relating to the video signal is changed during the buffering, the setting before the setting relating to the video signal is changed The video signal buffered in the buffering means is deleted by setting.

  According to a third aspect of the present invention, there is provided an image pickup apparatus having a pre-REC function for storing a video signal for a predetermined time before a recording instruction by a recording instruction means, in order to change a setting relating to the video signal. And when the setting change means changes the setting related to the video signal during the pre-REC period, the stored video signal is deleted by the setting before the setting change related to the video signal is performed. It has the control means to do.

  According to the present invention, even when a large change occurs in the setting of the video signal due to the user's operation in the imaging device provided with the pre-REC function, the video signal that feels uncomfortable is not stored. Video can be stored and played back. In addition, according to the present invention, in photographing with an imaging apparatus having a lens exchange mechanism and a pre-REC function, even when the user removes the lens, normal photographing is not performed because the lens is not attached. It is possible not to store the video signal.

1 is a block diagram showing a general hardware configuration of an imaging apparatus according to a first embodiment of the present invention. In the imaging device concerning a 1st embodiment of the present invention, when a user changes an aspect ratio of a video signal, it is a mimetic diagram of a video signal written in a storage medium. FIG. 6 is a schematic diagram of a video signal written to a storage medium when a user switches the aspect ratio of the video signal in an imaging apparatus having a conventional pre-REC function. It is a control flowchart with the imaging device concerning a 1st embodiment of the present invention.

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

<First Embodiment>
[Hardware configuration of imaging device]
FIG. 1 is a block diagram showing a general hardware configuration of an imaging apparatus according to the present invention.

  The imaging apparatus includes a lens unit 101, a lens mount 102 for exchanging lenses, a photographing unit 103, a signal processing unit 104, a signal storage unit 105 including a buffer memory 106 and a storage medium 107, a setting change unit 109, and a recording instruction unit. 110. In addition, the imaging apparatus includes a control microcomputer 108 for performing overall control related to the operation of the imaging apparatus and image processing.

  The lens unit 101 that constitutes the optical system of the imaging apparatus includes a zoom lens group, a diaphragm, an ND filter, and the like. The lens mount 102 includes a mechanism that allows the lens unit 101 to be attached to and detached from the imaging apparatus main body, and an imaging element such as a CMOS or a CCD. The imaging unit 103 includes a sample / hold circuit (S / H circuit), a preprocess circuit, and the like. The signal processing unit 104 performs processing and correction on the video signal to generate a video signal (hereinafter referred to as “recording video signal”) to be stored in the signal storage unit 105.

  The signal storage unit 105 stores the recording video signal generated by the signal processing unit 104. As will be described in detail later, the buffer memory 106 buffers a video signal for a certain period of time before receiving a recording start instruction from the recording instruction unit 110, and the storage medium 107 stores the video signal stored in the buffer memory 106 and the recording The video signal after the start instruction is stored. Each of the buffer memory 106 and the storage medium 107 is built in or externally connected to the signal storage unit 105. For example, a semiconductor memory such as a volatile memory (RAM), a hard disk drive (HDD), a DVD-RAM, a tape, or the like is used. be able to. Note that each of the buffer memory 106 and the storage medium 107 can be configured to be replaceable according to the specifications and usage status of the imaging apparatus.

  The control microcomputer 108 controls the operation and signal processing of the entire imaging apparatus. The setting change unit 109 includes a panel and operation buttons for setting various conditions for storing video, and transmits information set by the user by operating the operation buttons and the like to the control microcomputer 108. The recording instruction unit 110 includes buttons for the user to instruct the start and end of recording of the recording video signal, and the button operation instruction is transmitted to the control microcomputer 108. “Recording start of recording video signal” is synonymous with “recording start by user operation”, and “recording video signal recording end” is “recording end by user operation”. It is synonymous.

[Buffering of recording video signal to buffer memory 106]
The process up to buffering (temporary storage) of recording video signals in the buffer memory 106 in the imaging apparatus is generally performed as follows. The amount of light from the subject received from the lens via the lens unit 101 is adjusted by the diaphragm and the ND filter. The light whose light amount is adjusted from the subject is imaged on the image sensor surface in the lens mount 102, photoelectrically converted, and converted into a video signal. The video signal output from the image sensor is sampled and held by the S / H circuit of the imaging unit 103 and then supplied to the preprocess circuit, where AGC processing, black balance processing, and the like are performed. Supplied. In the signal processing unit 104, processing and correction such as white balance processing and gamma correction processing are performed on the supplied video signal based on an instruction from the control microcomputer 108, and thus a recording video signal is generated. .

  The recording video signal generated by the signal processing unit 104 is supplied to the signal storage unit 105. In the signal storage unit 105, the supplied recording video signal is processed into a data format suitable for the buffer memory 106 and the storage medium 107, converted, data compressed, and buffered in the buffer memory 106. As described above, by performing processing, conversion, data compression, and the like on the recording video signal and buffering in the buffer memory 106, it is possible to secure a bufferable time for the recording video signal for a long time. On the other hand, the recording video signal is buffered in the buffer memory 106 without being processed, converted, or compressed, so that the buffered recording video signal can be processed, converted, compressed, etc. It is good also as a structure which raises a freedom degree. The signal storage unit 105 buffers the recording video signal for a predetermined time in the buffer memory 106, and when the buffer becomes full, the newest recording video signal is stored in the storage area where the oldest recording video signal is buffered. , Overwrite sequentially.

[Write (store) video signal to storage medium 107]
The writing (storage) of the recording video signal to the storage medium 107 when the setting changing unit 109 is not operated will be described below. When a recording start instruction is transmitted to the control microcomputer 108 by the operation of the recording instruction unit 110 by the user, the control microcomputer 108 stores an instruction to start writing a video signal to the storage medium 107 (writing start instruction). Send to part 105. Receiving the write start instruction, the signal storage unit 105 writes the recording video signal for a predetermined time buffered in the buffer memory 106 to the storage medium 107. Subsequently, the signal storage unit 105 processes, converts, and compresses the recording video signal supplied from the signal processing unit 104 after the writing start instruction, and writes it in the storage medium 107. It should be noted that how long the recording video signal is written from the buffer memory 106 to the storage medium 107 (that is, the recording video signal for a predetermined time) is set by default setting or user setting. It is predetermined.

  When a recording end instruction is transmitted to the control microcomputer 108 by a re-operation of the recording instruction unit 110 by the user, the control microcomputer 108 terminates the writing of the recording video signal to the storage medium 107 (writing end instruction). ) To the signal storage unit 105. Receiving the write end instruction, the signal storage unit 105 stops writing the recording video signal supplied from the signal processing unit 104 to the storage medium 107.

  By performing such a series of controls, the recording medium 107 stores a recording video signal from a point in time preceding the writing start instruction to a writing end instruction. When receiving a write end instruction, the signal storage unit 105 stops writing the recording video signal to the storage medium 107 as described above, and restarts buffering of the recording video signal to the buffer memory 106.

[Change of setting of imaging apparatus by operation of setting change unit 109]
When the user operates the setting change unit 109 to change the setting content related to the recording video signal such as the shooting condition, the setting change content is transmitted to the control microcomputer 108, and the control microcomputer 108 reflects the setting change content. Deriving control parameters. The derived control parameters are transmitted to the related units constituting the imaging apparatus. Here, the related units are the lens unit 101 connected via the lens mount 102, the image sensor incorporated in the lens mount 102, the imaging unit 103, the signal processing unit 104, and the signal storage unit 105. Each of these units performs lens driving, recording video signal processing, conversion, data compression, and the like based on the received control parameters.

  In parallel with the above-described control parameter derivation, the control microcomputer 108 also determines the degree of influence of the setting change contents on the angle of view and the image quality of the recording video signal, and if the degree of influence is greater than a predetermined reference. When the determination is made, a control switching instruction is issued to the signal storage unit 105. Listed below are examples of changes in the setting contents related to the recording video signal for which this control switching instruction is issued.

  First, when the electronic zoom magnification is changed by the user, the control microcomputer 108 compares the electronic zoom magnification before the change with the electronic zoom magnification after the change. Then, the control microcomputer 108 determines that the degree of influence on the angle of view is large when a change of a predetermined magnification or more is performed, and issues a control switching instruction to the signal storage unit 105.

  Second, when the aspect ratio of the recording video signal is changed by the user, the control microcomputer 108 determines that the influence on the angle of view is large and issues a control switching instruction to the signal storage unit 105. .

  Thirdly, there is a case where the user has changed the image acquisition method from the image sensor, such as switching between addition readout and non-addition readout, or switching the position where the recording video signal is cut out from the effective pixels of the image sensor. It is done. In this case, the control microcomputer 108 determines that the influence on the angle of view is large, and issues a control switching instruction to the signal storage unit 105.

  Fourth, when the storage format of the recording video signal is changed by the user, such as switching between SD / HD, the control microcomputer 108 determines that the influence on the angle of view and the image quality is large, and the signal storage unit A control switching instruction is issued to 105.

  Fifth, if the user changes the frame rate of the recording video signal, such as switching between 60 frames per second and 24 frames per second, the control microcomputer 108 determines that the influence on the angle of view and image quality is large. Then, a control switching instruction is issued to the signal storage unit 105.

  Sixth, the image processing parameters for the recording video signal such as the shooting mode such as the sunset mode and the night mode, the AWB preset corresponding to the light source such as halogen light and sunlight, the shutter speed and the aperture value are changed by the user. The case is broken. In addition, when a predetermined determination criterion set in advance according to each of these operations is changed, for example, when switching the shutter speed, the shutter speed higher than 1/60 is changed to the shutter speed lower than 1/30. The case where it switches is mentioned. When these changes are made, the control microcomputer 108 determines that the degree of influence on the image quality is large, and issues a control switching instruction to the signal storage unit 105.

  Seventh, when the user changes the compression rate of the recording video signal (for example, from 6 Mbps to 10 Mbps), the control microcomputer 108 compares the compression rate before and after the change. The control microcomputer 108 determines that the degree of influence on the image quality is large when a change of a predetermined compression rate or higher is performed, and issues a control switching instruction to the signal storage unit 105.

  When a control switching instruction is transmitted from the control microcomputer 108 to the signal storage unit 105 due to the setting change, the signal storage unit 105 temporarily deletes (deletes) the recording video signal buffered in the buffer memory 106. At this time, a flag indicating that the data is to be stored is provided for each control unit (GOP or the like) of the recording video signal in the buffer memory 106, and the flag is cleared according to a control switching instruction from the control microcomputer 108. It may be configured as follows.

  When the angle of view and image quality are changed as the setting is changed, and the fluctuations in exposure, focus, white balance, etc. converge to a predetermined target value, the control microcomputer 108 transmits a buffering restart instruction to the signal storage unit 105. . When receiving a buffering restart instruction from the control microcomputer 108, the signal storage unit 105 restarts buffering of the recording video signal. As described above, in the imaging apparatus according to the first embodiment, once the buffered recording video signal is discarded, the buffering is automatically restarted when an appropriate recording video signal can be obtained. Is done. Thereby, since the user does not need to perform the operation for enabling the buffering again, high operability can be realized.

  As a specific example, FIG. 2 shows a schematic diagram of a video signal written in the storage medium 107 when the user switches the aspect ratio of the video signal for recording using the imaging apparatus according to the first embodiment. Here, it is assumed that the pre-REC time in which the buffer memory 106 buffers the video signal, that is, the predetermined time for storing the video signal before receiving the recording start instruction from the recording instruction unit 110 is 3 seconds.

  In the example of FIG. 2, the user operates the setting change unit 109 0.5 seconds after the recording video signal buffering is started to change the aspect ratio of the recording video signal from 4: 3 to 16: 9. The recording instruction unit 110 issues a recording start instruction 2.5 seconds later. The recording video signal shown in FIG. 2 is recorded in the storage medium 107 by the signal storage unit 105 that has received the imaging start instruction.

  For comparison, FIG. 3 shows a schematic diagram of a recording video signal written in the storage medium of the imaging apparatus when the same setting change as that of FIG. 2 is performed using a conventional imaging apparatus. In the imaging apparatus according to the first embodiment, as shown in FIG. 2, when the recording video signal stored in the storage medium 107 is reproduced, the aspect ratio is 16: 9 from the beginning until the end of shooting. It can be seen that only a video is reproduced and a good video with no change in the angle of view can be obtained. On the other hand, in the conventional imaging device, as shown in FIG. 3, since a large angle of view change from 4: 3 to 16: 9 occurs 0.5 seconds after the start of reproduction, Will feel uncomfortable.

[Control flow in imaging device]
FIG. 4 shows a control flowchart of the imaging apparatus according to the first embodiment. The control microcomputer 108 determines whether the setting change content has been transmitted by the operation of the setting change unit 109 by the user (step S1). When the setting change content is not transmitted (“NO” in S1), the determination is repeated until the setting change content is transmitted. On the other hand, when the setting change content is transmitted ("YES" in S1), the control microcomputer 108 advances the process to step S2.

  In step S2, although not shown, the control microcomputer 108 derives a control parameter corresponding to the setting change content and transmits it to each unit constituting the imaging apparatus as described above. Each unit to which the control parameter is transmitted performs lens driving, processing, conversion, data compression, and the like for the recording video signal based on the control parameter. In parallel with this, in step S2, the control microcomputer 108 determines whether the influence of the setting change on the angle of view and the image quality is large. When the influence degree is small (“NO” in S2), the control microcomputer 108 returns the process to step S1. On the other hand, when the degree of influence is large (“YES” in S2), the control microcomputer 108 advances the process to step S3.

  In step S3, the control microcomputer 108 issues a control switching instruction to the signal storage unit 105, and the signal storage unit 105 that has received the control switching instruction erases the recording video signal buffered from the buffer memory 106 and performs processing. Advances to step S4.

  In step S4, the control microcomputer 108 determines whether an appropriate recording video signal can be obtained. Specifically, as described above, the control microcomputer 108 determines whether changes in exposure, focus, white balance, and the like due to the change in the angle of view and the image quality in accordance with the setting change have converged to a predetermined target value. . When an appropriate video signal for recording is obtained (when it converges to a predetermined target value; “YES” in S4), the control microcomputer 108 advances the process to step S5. On the other hand, when a proper video signal for recording cannot be obtained (when it has not converged to a predetermined target value; “NO” in S4), it converges to a predetermined target value until a proper video signal for recording is obtained. Repeat the determination.

  In step S5, the control microcomputer 108 transmits a buffering resumption instruction to the signal storage unit 105, and the signal storage unit 105 that has received the buffering resumption instruction resumes buffering of the recording video signal.

  As described above, in the image pickup apparatus according to the first embodiment having the pre-REC function, when the setting change is performed on the recording video signal, the recording with the uncomfortable feeling that the angle of view and the image quality greatly change is performed. No video signal is stored. Therefore, even if the user changes the setting with a large change in the angle of view and the image quality, it is possible to obtain a recording video signal with no sense of incongruity.

Second Embodiment
[Hardware configuration of imaging device]
Since the hardware configuration of the imaging apparatus according to the second embodiment of the present invention is the same as the hardware configuration of the imaging apparatus according to the first embodiment of the present invention, the hardware of the imaging apparatus according to the second embodiment is here. Description of the hardware configuration is omitted.

[Control with imaging device]
When the user removes the lens unit 101, a signal indicating a lens non-mounted state is transmitted from the lens mount 102 to the control microcomputer 108. The control microcomputer 108 that has received this signal issues a control switching instruction to the signal storage unit 105, and the signal storage unit 105 that has received the control switching instruction temporarily stores the recording video signal buffered in the buffer memory 106. ,to erase. At this time, a flag indicating that the data is to be stored is provided for each control unit (GOP or the like) of the recording video signal in the buffer memory 106, and the flag is cleared according to a control switching instruction from the control microcomputer 108. It may be configured as follows.

  When the user remounts the lens unit 101, a signal indicating the lens mounting state is transmitted from the lens mount 102 to the control microcomputer 108. Upon receiving this signal, the control microcomputer 108 communicates with the lens unit 101 via the lens mount 102 to acquire information on the configuration, performance, and function of the lens.

  The control microcomputer 108 derives a control parameter based on the information acquired from the lens unit 101 and transmits it to each related part constituting the imaging apparatus. Here, the related units are the lens unit 101, the image sensor incorporated in the lens mount 102, the imaging unit 103, the signal processing unit 104, and the signal storage unit 105. Each of these related parts performs lens driving, processing and conversion of recording video signals, data compression, and the like based on the transmitted control parameters.

  When the control of each related part is changed based on the changed control parameter, and the accompanying fluctuations in exposure, focus, white balance, etc. converge to a predetermined target value, the control microcomputer 108 issues a buffering restart instruction to the signal storage part 105. To communicate. When receiving a buffering restart instruction from the control microcomputer 108, the signal storage unit 105 restarts buffering of the recording video signal.

  As described above, in the imaging apparatus according to the second embodiment, when the user attaches / detaches the lens, the buffer is automatically buffered when the lens is reattached and a suitable recording video signal is obtained. The ring is resumed. Therefore, the user does not need to perform the operation for enabling the buffering of the recording video signal again. That is, the operability of the imaging device is improved. In addition, it is possible to obtain a recording video signal without a sense of incongruity.

<Other embodiments>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention, changes, modifications, and the like.

  For example, in the above embodiment, the recording video signal is buffered in the buffer memory 106 in order to realize the pre-REC function. However, the present invention is not limited to this, and the recording video signal is directly written on the storage medium 107 without going through the buffer memory 106, and the recording video signal on the storage medium 107 is received in response to a control switching instruction from the control microcomputer 108. You may comprise so that may be erase | eliminated.

DESCRIPTION OF SYMBOLS 101 Lens unit 102 Lens mount 103 Image pick-up part 104 Signal processing part 105 Signal storage part 106 Buffer memory 107 Storage medium 108 Control microcomputer 109 Setting change part 110 Recording instruction | indication part

Claims (5)

Signal storage means for storing the imaged video signal, recording instruction means for instructing recording start of the video signal to the signal storage means, and setting for the video signal stored in the signal storage means An image pickup apparatus comprising:
The signal storage means includes buffering means for buffering a video signal for a predetermined time before receiving a recording start instruction from the recording instruction means, and the setting change means is operated to relate to the video signal during the buffering. When the setting is changed, the imaging apparatus is configured to delete the video signal buffered in the buffering unit according to the setting before the setting related to the video signal is changed.   Changes in the settings relating to the video signal include changing the electronic zoom magnification, changing the aspect ratio of the video signal, changing the acquisition method of the video signal from the image sensor that captures the video signal, and changing the storage format of the video signal. The imaging apparatus according to claim 1, wherein any one of a change in a frame rate of the video signal, a change in an image processing parameter for the video signal, and a change in a compression rate of the video signal. An imaging apparatus having a pre-REC function for storing a video signal for a predetermined time before a recording instruction by a recording instruction unit,
Setting changing means for changing the setting relating to the video signal;
In the pre-REC period, when the setting related to the video signal is changed by the setting changing unit, the control unit deletes the video signal stored by the setting before the setting related to the video signal is changed. An imaging apparatus characterized by the above.   Changes in the settings relating to the video signal include changing the electronic zoom magnification, changing the aspect ratio of the video signal, changing the acquisition method of the video signal from the image sensor that captures the video signal, and changing the storage format of the video signal. 4. The imaging apparatus according to claim 3, wherein the imaging apparatus is any one of a change in a frame rate of the video signal, a change in an image processing parameter for the video signal, and a change in a compression rate of the video signal. A method for controlling an imaging apparatus having a pre-REC function for storing a video signal for a predetermined time before a recording instruction by a recording instruction means,
When the setting relating to the video signal is changed during the pre-REC period, the video signal stored according to the setting before the setting relating to the video signal is changed is deleted. .

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