JP6889566B2 - Recording device and its control method - Google Patents

Description

The present invention relates to a recording device and a control method thereof, and more particularly to a technique for recording data on a recording medium.

Recording devices such as digital cameras and digital video cameras that record moving images, still images, audio data, etc. on a recording medium are known. The recorded data is managed as a file by a file system such as a system such as FAT16, FAT32, exFAT.

Further, some recording media support a plurality of writing methods having different writing speeds. A technique has been proposed in which a recording device properly uses a writing method for such a recording medium according to the type of data to be recorded and the necessity of real-time recording (Patent Document 1).

JP-A-2007-49639

The writing speed to the recording medium is affected by a large change in the writing address, the location of the writing area, and the like, but a technique for suppressing a decrease in the writing speed due to such an influence is not known.

The present invention has been made in view of such problems of the prior art. An object of the present invention is to provide a recording device capable of suppressing a decrease in data recording speed on a recording medium and a control method thereof.

The above-mentioned purpose is to provide a first recording mode in which data is recorded in a recording medium having a plurality of recording areas having a first area of the first size in units of a second area of a second size smaller than the first size. In the first recording mode, the recording device has a determination means for determining whether or not the next write address candidate corresponds to a predetermined address that may reduce the write speed, and the next write. If it is determined that the address candidate corresponds to an address that may reduce the write speed, the resetting means for changing the next write address candidate and the next write address candidate may reduce the write speed. If it is not determined to correspond to, the recording device is achieved by having a writing means for writing data in a second area having the next writing address candidate as a starting address.

According to the present invention, it is possible to provide a recording device capable of suppressing a decrease in data recording speed on a recording medium and a control method thereof.

The figure regarding the camera system as an example of the recording apparatus which concerns on embodiment. Schematic diagram of the recording area of the recording medium according to the embodiment Flowchart of still image recording control operation according to the embodiment Flow chart related to low-speed address determination processing in FIG. Flow chart regarding the remaining capacity acquisition process in FIG.

● (First embodiment)
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Here, an embodiment in which the focus detection device according to the present invention is applied to an interchangeable lens type digital single-lens reflex camera (camera system) will be described. However, the focus detection device according to the present invention can be applied to any electronic device having an image pickup device capable of generating a signal used for focus detection of a phase difference detection method. Such electronic devices include not only cameras such as digital still cameras and digital video cameras in general, but also mobile phones having camera functions, computer devices, media players, robot devices, game devices, home appliances, and the like. Not limited to.

FIG. 1 is a diagram showing a configuration example of a camera system including a camera having an interchangeable shooting lens and a shooting lens as an example of an imaging device including the focus detection device according to the embodiment of the present invention. In FIG. 1, the camera system includes a camera body 100 and an interchangeable lens unit 300.

The lens unit 300 is mechanically and electrically coupled to the camera body 100 by engaging the lens mount 306 with the lens mount 106 of the camera body 100. The electrical coupling is realized by the connector 322 and the connector 122 provided on the lens mount 306 and the lens mount 106. The lens 310 includes a focus lens for adjusting the focusing distance of the lens unit 300. The focus control unit 342 adjusts the focus of the lens unit 300 by driving the focus lens along the optical axis. The operation of the focus control unit 342 is controlled by the system control unit 50 of the camera body 100 through the lens system control unit 350. The aperture 312 adjusts the amount and angle of the subject light incident on the camera body 100.

The connector 322 and the interface (I / F) 320 electrically connect the lens unit 300 to the connector 122 of the camera body 100. Then, the connector 322 transmits signals such as a control signal, a state signal, and a data signal between the camera body 100 and the lens unit 300, and transfers the drive voltage supplied from the camera body 100 to each part of the lens unit 300. Supply. The connector 322 may be capable of transmitting not only electrical signals but also other types of signals such as optical signals.

The zoom control unit 344 drives the variable magnification lens of the lens 310 and adjusts the focal length (angle of view) of the lens unit 300. If the lens unit 300 is a single focus lens, the zoom control unit 344 does not exist. The aperture control unit 340 controls the aperture 312 based on the photometric information from the photometric control unit 46 in cooperation with the exposure control unit 40 that controls the shutter 12.

The lens system control unit 350 has a programmable processor such as a CPU or MPU, and controls the operation of the entire lens unit 300 by executing a program stored in advance. Then, the non-volatile memory 348 stores constants, variables, programs, etc. for the operation of the lens unit 300. The non-volatile memory 348 also stores identification information such as a number unique to the lens unit 300, management information, functional information such as an open aperture value and a minimum aperture value, a focal length, and current and past setting values.

The luminous flux that has passed through the lens unit 300 passes through the lens mount 106, is incident on the camera body 100, is reflected upward by the mirror 130, and is incident on the optical viewfinder 104. The mirror 130 may be a movable type (click return mirror) or a fixed type (half mirror). Here, it is assumed that the mirror 130 is a half mirror for the sake of simplicity. The optical finder 104 allows the photographer to take a picture while observing the optical image of the subject. In the optical finder 104, some functions of the display unit 54, for example, a focus display, a camera shake warning display, an aperture value display, an exposure compensation display, and the like are installed.

Of the luminous flux that has passed through the lens unit 300 and is incident on the camera body 100, the luminous flux that has passed through the mirror 130 forms a subject image on the image pickup surface of the image pickup device 14 via the shutter 12 for controlling the exposure amount. ..

The image pickup device 14 is a CCD or CMOS image sensor, and has a configuration in which a plurality of pixels having a photoelectric conversion region (or photodiode) are arranged two-dimensionally. The image sensor 14 outputs an electric signal corresponding to the optical image of the subject. The electrical signal photoelectrically converted by the image sensor 14 is sent to the A / D converter 16, and the analog signal output is converted into a digital signal (image data). The A / D converter 16 may be incorporated in the image sensor 14. At least a part of the pixels of the image pickup device 14 may be configured as focus detection pixels. In this case, the image sensor 14 can output a signal used for focus detection in the phase difference detection method.

The timing generator 18 supplies a clock signal and a control signal to the image sensor 14, the A / D converter 16, and the D / A converter 26. The timing generation unit 18 is controlled by the memory control unit 22 and the system control unit 50. The system control unit 50 controls the timing generation unit 18 to supply the control signal for reading the signal from the image sensor 14 to the image sensor 14.

The image processing unit 20 applies predetermined processing such as pixel interpolation processing, white balance adjustment processing, and color conversion processing to the image data from the A / D converter 16 or the image data from the memory control unit 22. Further, the image processing unit 20 detects a subject area such as a face area, calculates subject luminance information for automatic exposure control, and outputs the result to the system control unit 50.

The image processing unit 20 also calculates a contrast evaluation value for the image data in the focus detection region among the image data (output signal of the image sensor 14) from the A / D converter 16, and the system control unit 50 supplies the image data to. To do. When the image sensor 14 has the focus detection pixel, a signal pair for phase difference detection is generated from the signal of the focus detection pixel in the focus detection region and supplied to the system control unit 50.

When the system control unit 50 receives the signal pair for phase difference detection from the image processing unit 20, the system control unit 50 supplies the signal pair to the AF control unit 42. The AF control unit 42 detects the phase difference (shift amount) between the signals by the correlation calculation of the signal pair, and converts the phase difference into the defocus amount and the defocus direction of the lens unit 300. The AF control unit 42 outputs the converted amount and direction of defocus to the system control unit 50. The system control unit 50 drives the focus lens through the focus control unit 342 of the lens unit 300 and adjusts the focusing distance of the lens unit 300.

When the system control unit 50 receives the contrast evaluation value from the image processing unit 20, the system control unit 50 takes an image with the image sensor 14 while changing the focus lens position through the focus control unit 342 of the lens unit 300. Then, the system control unit 50 examines the change in the contrast evaluation value received from the image processing unit 20, and drives the focus lens to the position where the contrast evaluation value is maximized.

The memory control unit 22 controls the A / D converter 16, the timing generation unit 18, the image processing unit 20, the image display memory 24, the D / A converter 26, the memory 30, and the compression / expansion unit 32. Then, the data of the A / D converter 16 is written to the image display memory 24 or the memory 30 via the image processing unit 20 and the memory control unit 22, or only through the memory control unit 22. The image data for display written in the image display memory 24 is displayed on the image display unit 28 composed of a liquid crystal monitor or the like via the D / A converter 26. The electronic finder function (live view display) can be realized by sequentially displaying the moving images captured by the image sensor 14 on the image display unit 28. The image display unit 28 can turn on / off the display according to the instruction of the system control unit 50, and when the display is turned off, the power consumption of the camera body 100 can be significantly reduced.

Further, the memory 30 is used for temporary storage of captured still images and moving images, and has a sufficient storage capacity for storing a predetermined number of still images and moving images for a predetermined time. As a result, even in the case of continuous shooting or panoramic shooting, it is possible to write a large amount of images at high speed to the memory 30. The memory 30 can also be used as a work area for the system control unit 50. The image synthesizing unit 31 synthesizes a plurality of images stored in the memory 30 to generate a composite image. The image composition unit 31 can generate a composite image in which a plurality of images are joined together, such as a panoramic image, or a composite image in which the same scene is shot with different exposures, such as an HDR image. The image synthesizing unit 31 saves the generated composite image in the memory 30. The compression / decompression unit 32 has a function of compressing / decompressing image data by adaptive discrete cosine transform (ADCT) or the like, reads the image stored in the memory 30 and performs compression processing or decompression processing, and the processed image data. Is written back to the memory 30.

The exposure control unit 40 controls the shutter 12 based on the photometric information from the photometric control unit 46 in cooperation with the aperture control unit 340 that controls the aperture 312 of the lens unit 300. The interface unit (I / F) 120 and the connector 122 electrically connect the camera body 100 and the lens unit 300, and transmit an electric signal and a power source from the camera body 100 to the lens unit 300. The interface unit 120 may be capable of transmitting signals other than electrical signals, such as optical signals.

The metering control unit 46 performs automatic exposure control (AE) processing. The brightness of the subject optical image can be measured by causing the luminous flux that has passed through the lens unit 300 to enter the photometric control unit 46 via the lens mount 106, the mirror 130, and a photometric lens (not shown). The photometric control unit 46 can determine the exposure condition by using a program diagram or the like in which the subject brightness and the exposure condition are associated with each other. The photometric control unit 46 also has a dimming processing function in cooperation with the flash 48. It is also possible for the system control unit 50 to perform AE control on the exposure control unit 40 and the aperture control unit 340 of the lens unit 300 based on the calculation result obtained by calculating the image data of the image sensor 14 by the image processing unit 20. Is. The flash 48 also has an AF auxiliary light projection function and a flash dimming function.

The system control unit 50 has a programmable processor such as a CPU or MPU, and controls the operation of the entire camera system by executing a program stored in advance. The non-volatile memory 52 stores constants, variables, programs, and the like for the operation of the system control unit 50. The display unit 54 is, for example, a liquid crystal display device that displays an operating state, a message, or the like using characters, images, voices, or the like according to the execution of a program by the system control unit 50. A single or a plurality of display units 54 are installed at positions near the operation unit of the camera body 100 so that they can be easily seen, and are composed of, for example, a combination of LCDs, LEDs, and the like. Among the display contents of the display unit 54, the ones to be displayed on the LCD or the like include information on the number of shots such as the number of recorded shots and the number of remaining shots, information on shooting conditions such as shutter speed, aperture value, exposure compensation, and flash. There is. In addition, the battery level, date, time, etc. are also displayed. Further, as described above, some of the functions of the display unit 54 are installed in the optical finder 104.

The non-volatile memory 56 is a memory that can be electrically erased and recorded, and for example, EEPROM or the like is used. Reference numerals 60, 62, 64, 66, 68 and 70 are operation units for inputting various operation instructions of the system control unit 50, such as a switch, a dial, a touch panel, pointing by line-of-sight detection, a voice recognition device, or the like. It consists of multiple combinations.

The mode dial 60 can switch and set each function mode such as power off, auto shooting mode, manual shooting mode, playback mode, and PC connection mode. The shutter switch SW1 62 turns on when the shutter button (not shown) is pressed halfway, and instructs the start of operations such as AF processing, AE processing, AWB processing, and EF processing. The shutter switch SW2 64 turns on when the shutter button is fully pressed, and instructs the start of a series of processing related to shooting. The series of processing related to photography includes exposure processing, development processing, recording processing, and the like. In the exposure process, the signal read from the image sensor 14 is written as image data in the memory 30 via the A / D converter 16 and the memory control unit 22. In the development process, development is performed using calculations in the image processing unit 20 and the memory control unit 22. In the recording process, image data is read from the memory 30, compressed by the compression / decompression unit 32, and written as an image data file on the recording medium 200 according to the file system of the recording medium 200. These processes are realized by the system control unit 50 controlling each unit.

The operation unit 70 includes various buttons, a touch panel, and the like. Various buttons include a menu button, a flash setting button, a single shooting / continuous shooting / self-timer switching button, and an exposure compensation button.

The power supply control unit 80 includes a battery detection circuit, a DC / DC converter, a switch circuit for switching a block to be energized, and the like. It detects whether or not a battery is installed, the type of battery, and the remaining battery level, controls the DC / DC converter based on the detection result and the instruction of the system control unit 50, and applies the required voltage for the required period, including the recording medium. Supply to each part. The connectors 82 and 84 connect a power supply unit 86 including a primary battery such as an alkaline battery or a lithium battery, a NiCd battery, a NiMH battery, a secondary battery such as a lithium ion battery, an AC adapter, or the like to the camera body 100.

The interface units (I / F) 90 and 204 have a function of connecting to a recording medium such as a memory card or a hard disk, and the connectors 92 and 206 make a physical connection to a recording medium such as a memory card or a hard disk. The recording medium attachment / detachment detection unit 98 detects whether or not the recording medium 200 is attached to the connector 92 or 206. In the present embodiment, the interface and the connector to which the recording medium is attached are described as having one system, but the interface and the connector may be configured to include a plurality of systems. Further, the configuration may include a combination of interfaces and connectors of different standards. Further, by connecting various communication cards such as a LAN card to the interface and the connector, the image data and the management information attached to the image data can be transferred to each other with other peripheral devices such as a computer and a printer.

The recording medium 200 is a memory card in the present embodiment, and includes a recording unit 202 composed of a semiconductor memory, an interface unit 204 with the camera body 100, and a connector 206 for connecting to the camera body 100.
The above is the configuration of the camera system of the present embodiment including the camera body 100 and the lens unit 300.

In the present embodiment, a memory card (SD card) conforming to the SD standard by the SD Card Association is used as the recording medium 200. Then, the moving image is recorded by a writing method (speed class writing) according to the speed class specification in the SD standard. The speed class specification is a specification that guarantees the minimum speed when continuously recording data on a recording medium.

In the speed class writing (second recording mode) only, the recording area (User Area) is managed in units of AU (Allocation Unit) which is the first area having a fixed size (first size). One AU is composed of a plurality of RUs (Recording Units). The size of the RU (second area) (second size) varies depending on the type of card (SDSC, SDHC, SDXC) and the type of speed class, but is a multiple of 16KB and a maximum of 512KB in the current standard. The RU has an integer multiple size of a cluster of recording media (minimum management unit). Speed class writing is performed only on empty AUs (AUs that do not have a RU on which data is recorded). On the other hand, the AU having the RU in which the data is recorded is called a fragmented AU (fragmented AU).

Still images are recorded by writing (normal writing or first recording mode) that does not comply with the speed class specifications. In normal writing, the recording area is managed in cluster units. Note that management in AU units (RU units) means managing whether or not there is a free area in that unit. Therefore, a fragmented AU is considered free space in normal writing, but not free space in speed class writing.

The present embodiment can also be applied to a recording device using a recording medium of another standard that supports a writing method in which the management unit of the recording area is different. Examples of such recording media include CF cards and Cfast cards. For CF cards and Cfast cards, VPG (Video Performance Guarantee) is defined as a writing method that guarantees the minimum recording speed.

FIG. 2A schematically shows a logical address map immediately after the execution of the initialization process of the recording area (recording unit 202) of the recording medium 200. The address space of the recording area is divided into AU units from the beginning. The address area B at the end corresponds to the remainder obtained by dividing the recording area by the AU size. The AU size is equal to or less than the maximum AU size determined by the capacity of the recording medium 200, and is set to 16 * 2 ^ i (an integer of i = 0 or more) [KB].

System information is recorded in the AU 0 located at the head of the recording area when the initialization process of the recording medium 200 is executed. Here, MBR (Master Boot Record), BPB (BIOS Parameter Block), FAT (File Allocation Table), Allocation Bitmap, and RDE (Root Directory Entry) are shown as examples of system information, but the system information is not limited thereto. Since the system information exemplified here is publicly known, the detailed description thereof will be omitted.

In FIG. 2, the user areas that can be used for writing data are the area A of AU0, the entire AU1 to AUMAX, and the area B. Here, in order to facilitate the explanation described later, the area C is the AU1 next to the AU0 on which the system information is recorded, and the area D is the next AU2.

When data is recorded on the recording medium 200 whose address space is managed in this way, the write address is controlled so that the data is recorded only in an empty AU in speed class writing. On the other hand, in normal writing (non-speed class writing), the writing address is controlled so that the data is preferentially recorded from the free area of the AU in which the data is recorded in some clusters. Access control to the recording medium 200, including address control, may be realized by the system control unit 50 controlling, for example, the host controller of the interface unit 90, or the system control unit 50 functions as a host controller. You may. In the following, for ease of explanation and understanding, the system control unit 50 controls access to the recording medium 200.

Before explaining the recording control operation of this embodiment, an example of the recording control operation will be described. When writing the speed class in the state of FIG. 2 (when recording the moving image data), the system control unit 50 continuously starts the moving image data from the beginning of the free area (area C) existing at the beginning of the recording area in AU units. To record. When the data has been recorded in the entire AU1, the moving image data is continuously recorded from the beginning of the next empty AU2 (area D). After that, the system control unit 50 sequentially records the moving image data in the empty AU until the moving image shooting is completed.

On the other hand, in the case of normal writing (when recording still image data), conventionally, the system control unit 50 records still image data from a free area (area A) of AU0, which exists at the beginning of a recording area in cluster units. .. However, in the recording medium 200, the head region where system information is assumed to be recorded has a circuit configuration suitable for random access of small data such as system information, and is similar to recording image data. Not suitable for sequential access. Therefore, for example, it takes about 3 to 10 times longer than the sequential access to the normal data recording area.

Further, it is not specified in particular how much capacity the area having a circuit configuration suitable for system information (referred to as a system information area for convenience) is adopted from the beginning. Therefore, the free area of AU0 may include a system information area. Although it is assumed here that the system information area is smaller than the AU size, the essence of the invention is to avoid the use of the free area in the system information area, so that the system information area is limited to the free area of AU0. is not it.

Further, when the area A becomes full, the system control unit 50 sets the next write address to the start address of the area B instead of the start address of the AU1. In normal writing, fragmentation is performed by preferentially using the free area of the fragmented AU or the free area of the area (area B) not included in the AU over the free AU used for speed class writing. This is to suppress the occurrence of AU. After that, when there is no space in the area B, the system control unit 50 continues recording from the beginning of the AU1 (area C). In normal writing after the areas A and B are full, data is written to the free area if there is a fragmented AU, or from the beginning of the free AU if there is no fragmented AU.

When there is no space in area A and recording is continued in area B, or when there is no space in area B and recording is continued in area C, data is continuously recorded at a large distance (jumped) address. There is a need to. Then, writing with a large address jump causes a decrease in writing speed. After the end of writing to the area A, when writing continuously from the start address of AU1 without an address jump, when there are two large address jumps of area A → area B → area C, for example, about three times as much writing is performed. Become slow.

Therefore, especially when a normal write recording instruction is given immediately after the initialization process shown in FIG. 2, the speed decrease due to writing to the area A and the speed decrease due to the jump of the write address overlap, resulting in a large write speed. May occur. Then, for example, the nominal continuous shooting speed may not be realized.

In the present embodiment, the writing order at the time of normal writing is made different from the writing order in the above-mentioned recording operation control, thereby suppressing the decrease in writing speed. Hereinafter, the recording control operation of the present embodiment will be described with reference to FIGS. 3 and later. As for the speed class writing at the time of moving image recording, since the same writing control as the above-mentioned recording control operation is performed, the description thereof will be omitted. Further, the system control unit 50 can distinguish between the moving image recording and the still image recording by the member used in the operation unit 70 for inputting the shooting start instruction.

FIG. 3 is a flowchart relating to the recording control operation of the still image in the camera body 100 of the present embodiment.
First, the overall flow will be described with reference to the flowchart of FIG. Here, it is assumed that the system control unit 50 as the initialization means executes the initialization process of the recording medium 200 in S201, but it is not essential to execute the initialization process of the recording medium 200 in the recording control operation. If the recording medium 200 has been initialized, S201 may be skipped. The initialization process may be in either a physical format or a logical format. By the initialization process, the system control unit 50 writes the system information to the AU0.

In S202, the system control unit 50 acquires the final write logical address (the logical address where the write was performed immediately before). A logical address is used to access the recording medium 200. By designating a logical address and instructing writing or reading, data can be written to or read from a specific place in the recording area of the recording medium 200. Hereinafter, a logical address may be simply referred to as an address.

For example, when data is not recorded after the initialization process of the recording medium 200, such as when the initialization process is executed in S201, the final write address is the address where the system information was last written. If the still image or moving image is recorded even once after the initialization process, the final writing address is the writing address of the last recorded still image or moving image data. The final write address can be obtained from, for example, system information.

In S203, the system control unit 50 starts still image shooting in response to a user instruction through the operation unit 70. Since the operations during still image and moving image shooting are as described above and may be known operations, the details thereof will be omitted. Note that S202 and S203 may be executed in the reverse order. That is, the final writing address may be acquired after the shooting start instruction is detected and the still image shooting process is started.

In S204, the system control unit 50 acquires the next write address candidate. Normally, the system control unit 50 acquires the address next to the final write address acquired in S202 as the next write address candidate. However, it does not always become the next address due to AU fragmentation or the like.

The following S205 to S207 correspond to the determination process of whether or not the next write address candidate corresponds to an address that may reduce the write speed.

In S205, the system control unit 50 compares the final write address acquired in S202 with the next write address candidate acquired in S204, and acquires the jump amount of the write address.

In S206, the system control unit 50 determines whether or not the jump amount of the address obtained in S205 is equal to or greater than the threshold value, and if the jump amount is determined to be equal to or greater than the threshold value, the process proceeds to S209, and if it is determined to be less than the threshold value, the process proceeds to S207. To proceed. For example, a jump amount at which the decrease in writing speed is less than the threshold value can be prepared in advance as a threshold value according to the combination of the capacity of the recording medium 200, the AU size, and the like.

In S207, the system control unit 50 determines whether or not the next write address candidate corresponds to the low-speed address, and determines whether or not the next write address candidate can be used based on the determination result. Details of S207 will be described later.

In S208, the system control unit 50 determines in S207 whether or not the next write address candidate is determined to be available, and if it is determined to be available, it goes to S210, and if it is determined that it is not available, it goes to S209. , Proceed with processing.

In S209, the system control unit 50 as the resetting means changes the next write address candidate. Here, the system control unit 50 changes to the address next to the address acquired in S204 and proceeds with the process in S204. Alternatively, the system control unit 50 may make the address to be reset different depending on the cause of the reset. For example, when it is determined in S206 that the address jump amount is equal to or greater than the threshold value, the system control unit 50 can change the address jump amount from the final write address to the start address of the free area having the minimum address jump amount and less than the threshold value. If it is determined in S206 that it cannot be used, the system control unit 50 can change the address from the last write address to the start address of the nearest free AU.

In S210, the system control unit 50 writes the image data in cluster units using the next write address candidate as the write address, and proceeds to the process in S211.
In S211 the system control unit 50 determines whether or not the recording of image data for one screen has been completed, and if it is determined that the recording has been completed, the process proceeds to S213. The write address is acquired and the process is returned to S204.

In S213, the system control unit 50 determines whether or not the still image shooting is completed, and if it is determined that the still image shooting is completed, the processing is terminated, and if it is determined that the still image shooting is not completed, the processing is returned to S204. For example, the system control unit 50 determines that shooting is continuing (still image shooting is not completed) if unrecorded still image data remains in the memory 30 when recording for one screen is completed. If there is no remaining image, it can be determined that the shooting is completed.

Next, the details of the low-speed address determination process in S207 will be described with reference to the flowchart of FIG.
In S301, the system control unit 50 acquires the AU size from the system information of the recording medium 200. The AU size is a value unique to the recording medium selected from predetermined values. The system control unit 50 can know the start address of each AU and the start address of the area B in FIG. 2 from the AU size.

In S302, the system control unit 50 acquires the start address of the second AU (AU1 in FIG. 2) using the AU size. Since it is assumed here that the system information is contained in the first AU (the same AU0), the start address of the second AU is acquired. However, for example, when the final write address immediately after the execution of the initialization process is a larger (later) address than the start address of the second AU, S302 acquires the start address of the first free AU.

The system control unit 50 compares the next write address candidate with the start address of the second AU in S303, and determines in S304 whether the next write candidate address is before the start address of the second AU. .. If the system control unit 50 determines that the next write candidate address is before the start address of the second AU, the system control unit 50 advances the process to S305, determines the next write address candidate as a low-speed address, and proceeds to the process to S306. ..

Further, if the system control unit 50 determines that the next write address candidate is after the start address of the second AU, the process proceeds to S309, and the system control unit 50 determines that the next write address candidate is not a low-speed address. Then, the system control unit 50 advances the process to S310, determines that the next write address candidate can be used, and ends the process.

On the other hand, in S306, the system control unit 50 executes the remaining capacity acquisition process of the recording medium 200 in S306, and advances the process to S307. Details of the processing of S306 will be described later.
In S307, the system control unit 50 determines whether or not the remaining capacity of the recording medium 200 is equal to or less than the threshold value, and if it is determined to be equal to or less than the threshold value, the process proceeds to S310, and if it is determined to be equal to or more than the threshold value, the process proceeds to S308. The threshold value used here can be predetermined according to the unit of the remaining capacity acquired in S306.

In S308, the system control unit 50 determines that the next write address candidate cannot be used and ends the process.

Next, the remaining capacity acquisition process in S306 will be described with reference to the flowchart of FIG.
In S401, the system control unit 50 determines whether to acquire the remaining capacity based on the number of remaining clusters (or whether to acquire the number of possible shots), and if it is determined that the remaining capacity is acquired based on the number of remaining clusters, the process is set to S403 and the number of remaining clusters. If it is not determined to be acquired in, the process proceeds to S405.
In S403, the system control unit 50 acquires the total number of clusters from the system information.
In S404, the system control unit 50 acquires the number of remaining clusters from the system information, calculates the ratio of the remaining clusters to the total number of clusters as the remaining capacity, and ends the process.

In S405, the system control unit 50 acquires the current standard data size for still image shooting. The standard data size can be prepared in advance for each settable image size and stored in the non-volatile memory 56, for example.
In S406, the system control unit 50 acquires the number of remaining clusters of the recording medium 200 from the system information, converts it into a data size, divides it by the standard data size, calculates the number of shootable sheets as the remaining capacity, and ends the process.

According to the still image recording control operation using FIGS. 3 to 5, the free area (area A) of the AU on which the system information is recorded is not used until the remaining capacity of the recording medium 200 becomes equal to or less than the threshold value. Further, the last address area (area B) not included in the AU is not used until the final write address approaches the start address of the area B. Therefore, when recording a still image immediately after executing the initialization process, an address other than the area where the writing speed may decrease, specifically, a writing address similar to that at the time of moving image recording is set (FIG. 2 (FIG. 2). b)). Therefore, it is possible to avoid the occurrence of a large address jump and the decrease in recording speed due to the use of an area that takes a long time to write. In the above-described embodiment, when the remaining capacity of the recording medium 200 becomes equal to or less than the threshold value, the region A is used for still image recording. Therefore, although the current remaining capacity is larger than the threshold value, if it is expected that the remaining capacity will be equal to or less than the threshold value in the next still image shooting, the image display unit 28 indicates that the recording speed may decrease for the next shooting. The user may be notified through such as.

In the above-described embodiment, the recording control operation of the embodiment is always executed when the still image is recorded, on the premise that it cannot be determined whether the still image is a single shot or a continuous shot at the start of the still image shooting. However, when it can be determined from the shooting mode setting or the like that it is single shooting or continuous shooting at the start of still image shooting, the recording control operation of the embodiment is executed only when it is determined that continuous shooting is performed. It may be configured.

Further, although an example of determining an address in the free area of the AU in which system information is recorded as a low-speed address has been described, other addresses may also be determined as low-speed addresses. For example, writing to a fragmented AU takes longer than writing to a free AU, so if continuous shooting speed is particularly required, the address in the free area of the fragmented AU should also be determined as a low-speed address. May be good. In this case, the still image data is recorded only in the empty AU like the moving image data.

In the above-described embodiment, for example, in the case of normal writing immediately after the initialization process is executed, the start address of the free area (area A) of AU0 is first selected as the next write address candidate. Then, until the start address of the AU1 finally becomes the next write address candidate, the reset of the write address candidate, the address jump, and the determination of the low-speed address are repeated.

Therefore, when performing normal writing, it is first determined whether or not the free area of the recording medium 200 is equal to or greater than the threshold value, and if it is equal to or greater than the threshold value, the next write address candidate is set so as not to use the area A. May be good. Alternatively, for the first recording after the initialization process, the start address of the second AU (AU1) may be used as a write address candidate for both the still image and the moving image. When the next write address candidate is determined to be unusable, the last of the start address of the free AU and the start address of the free area of the fragmented AU is not the address next to the address determined to be unusable in S209. An address close to the write address may be reset.

Since there is a risk that the writing speed will decrease when the area A is used, the user may be able to set whether or not the area A is used for recording. When the area A is set not to be used for recording, the system control unit 50 skips the processes of S306 and S307.

Further, the above-described embodiment is based on the assumption that the range of the system information area is unknown. However, when the range of the system information area is known, it may be disabled if the next write address candidate is an address in the system information area in the low-speed address determination process.

Further, in the above-described embodiment, the configuration in which the address jump is recorded so as not to use both the address above the threshold value and the address in the specific area has been described, but the writing speed can be increased by avoiding only one of them. The effect of the invention of suppressing the decrease can be obtained.

As described above, according to the present embodiment, when recording data on a recording medium, control is performed so as to avoid addresses that may reduce the writing speed. Therefore, it is possible to suppress a decrease in speed due to factors that cannot be dealt with by the conventional technology, such as the circuit configuration of the recording medium and the address jump.

100 ... Camera body, 300 ... Lens unit, 14 ... Image sensor, 20 ... Image processing circuit, 22 ... Memory control circuit, 50 ... System control unit, 28 ... Image display unit, 30 ... Memory

Claims (15)

A recording device having a first recording mode for recording data in a unit of a second area of a second size smaller than the first size on a recording medium having a plurality of recording areas having a first area of the first size. There,
In the first recording mode, a determination means for determining whether or not the next write address candidate corresponds to a predetermined address that may reduce the write speed.
When it is determined that the next write address candidate corresponds to an address that may reduce the write speed, the resetting means for changing the next write address candidate and the resetting means.
When it is not determined that the next write address candidate corresponds to an address that may reduce the write speed, a write means for writing data to a second area having the next write address candidate as a start address, and a write means.
A recording device characterized by having. When the remaining capacity of the recording area is equal to or less than the threshold value, the writing means designates an address determined by the determining means to correspond to an address that may reduce the writing speed as a writing start address and writes data. The recording device according to claim 1. In the determination means, when the next write address candidate is an address in the first area in which the system information is written among the plurality of first areas, the next write address candidate reduces the write speed. The recording device according to claim 1 or 2, wherein it is determined that the address corresponds to an address that may cause the information to be generated. When the next write address candidate is an address in the system information area of the recording medium, the determination means determines that the next write address candidate corresponds to an address that may reduce the write speed. The recording device according to any one of claims 1 to 3, wherein the recording device is characterized. In the determination means, when the next write address candidate is an address in the first region in which data has already been recorded among the plurality of first regions, the next write address candidate reduces the write speed. The recording device according to any one of claims 1 to 4, wherein it is determined that the address corresponds to an address that may cause the data to be generated. When the difference between the next write address candidate and the final write address is equal to or greater than the threshold value, the determination means determines that the next write address candidate corresponds to an address that may reduce the write speed. The recording device according to any one of claims 1 to 5, which is characterized. When the difference between the next write address candidate and the final write address is equal to or greater than the threshold value, the determination means may reduce the write speed of the next write address candidate regardless of the remaining capacity of the recording area. The recording device according to claim 5, wherein it is determined that the address corresponds to a certain address. The recording device according to any one of claims 1 to 7, further comprising a second recording mode for recording data in units of the first area. The recording device according to claim 8, wherein the first recording mode is used for still image recording, and the second recording mode is used for moving image recording. The resetting means according to any one of claims 1 to 9, wherein the next write address candidate is changed to a start address of a vacant first area among the plurality of first areas. The recording device described. The resetting means changes the next write address candidate to the start address of a vacant second area included in the first area in which the system information is not recorded among the plurality of first areas. The recording device according to any one of claims 1 to 9, wherein the recording device is characterized. A first recording mode in which image data is recorded in a recording medium having a plurality of recording areas having a first area of the first size in units of a second area of a second size smaller than the first size, and the first recording mode. A recording device having a second recording mode for recording image data in units of one area, and managing image data recorded on the recording medium according to a predetermined file system.
Initialization that performs initialization processing by writing system information according to the predetermined file system to a predetermined first area among the plurality of first areas in response to an instruction for initializing the recording medium. Means and
In the first recording mode, the writing means for writing the image data by designating the address of the second area, and in the second recording mode, writing the image data by designating the address of the first area.
When there is a recording instruction by the first recording mode as the first recording instruction of the image data after the initialization process by the initialization means, the first of the plurality of first regions other than the predetermined first region. A control means for controlling the writing means so as to write image data to the second area included in one area in the first recording mode.
Have,
When the remaining capacity of the recording medium is equal to or less than the threshold value, the control means records the first recording with respect to the second region included in the predetermined first region in response to the recording instruction in the first recording mode. to write image data in the mode, record device shall be the controls said writing means. A first recording mode in which image data is recorded in a recording medium having a plurality of recording areas having a first area of the first size in units of a second area of a second size smaller than the first size, and the first recording mode. A recording device having a second recording mode for recording image data in units of one area, and managing image data recorded on the recording medium according to a predetermined file system.
Initialization that performs initialization processing by writing system information according to the predetermined file system to a predetermined first area among the plurality of first areas in response to an instruction for initializing the recording medium. Means and
In the first recording mode, the writing means for writing the image data by designating the address of the second area, and in the second recording mode, writing the image data by designating the address of the first area.
When there is a recording instruction by the first recording mode as the first recording instruction of the image data after the initialization process by the initialization means, the first of the plurality of first regions other than the predetermined first region. A control means for controlling the writing means so as to write image data to the second area included in one area in the first recording mode.
Have,
The control means at the end corresponds to the remainder obtained by dividing the recording area by the first size when a recording instruction is given by the first recording mode until the remaining capacity of the recording medium becomes equal to or less than the threshold value. The writing means is controlled so that the image data is not written in the third region including the address and having one or more of the second regions.
When the remaining capacity of the recording medium is equal to or less than the threshold value, image data is generated in the first recording mode with respect to the second region included in the predetermined third region in response to the recording instruction in the first recording mode. writing manner, records system shall be the controls said writing means. A recording apparatus having a first recording mode for recording data in a unit of a second area of a second size smaller than the first size on a recording medium having a plurality of recording areas having a first area of the first size. It ’s a control method,
A determination step in which the determination means determines whether or not the next write address candidate corresponds to a predetermined address that may reduce the write speed in the first recording mode.
When the resetting means determines that the next write address candidate corresponds to an address that may reduce the write speed, the resetting step of changing the next write address candidate and the resetting step.
When the writing means does not determine that the next writing address candidate corresponds to an address that may reduce the writing speed, a writing step of writing data to a second area having the next writing address candidate as a starting address. ,
A method of controlling a recording device, which comprises. A program for causing a computer to function as each means of the recording device according to any one of claims 1 to 13.

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