JP2001169227A - Data recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data recorder that can attain consecutive shots (moving picture clip) of an object for a required and sufficient time and that allows a user to be able to recognize how much time the user can make consecutive shots depending on display of a display device. SOLUTION: A memory card 34 actually records compressed image data and the data recorder calculates a consecutive shot recording available time on the basis of the time required for the recording and the recorded data amount. The memory card 34 records the calculated consecutive shot recording available time. At a succeeding shot, the consecutive shot recording available time recorded in the memory card 34 is detected, a timer 36b sets the time data and a display device 48 displays the time data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording apparatus, which is applied to, for example, a digital camera or an audio recorder, and records data captured by capturing means on a removable recording medium via an internal memory. Related to the device.

[0002]

2. Description of the Related Art As a conventional digital camera, there has been a digital camera in which moving image data of a photographed subject is temporarily stored in an internal memory and then recorded on a recording medium such as a memory card. However, since the recording speed (recording rate) of the recording medium is lower than the photographing speed (photographing frame rate) of the image sensor, the photographing process has been stopped when a predetermined continuous recordable time has elapsed.

[0003]

However, the photographing frame rate is predetermined for an image sensor that cannot be removed, whereas the recording rate is not fixed for a removable recording medium. That is, since the recording rate differs for each medium, it is impossible to know the recording rate of the recording medium when designing the camera. For this reason, in the related art, the continuous recordable time cannot be accurately obtained, and as a result, it is necessary to stop shooting when a time shorter than the actual continuous recordable time has elapsed.

[0004] Therefore, a main object of the present invention is to provide a data recording device capable of capturing data for as long a time as possible.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a data recording apparatus for recording desired data continuously captured by a capturing means on a removable recording medium via an internal memory, the recording speed of the recording medium. Detecting means for detecting
A data recording apparatus comprising: a calculating unit that calculates a continuous recordable time based on a recording speed; and a disabling unit that disables a capturing unit based on the continuous recordable time.

[0006]

When the desired data continuously captured by the capturing means is recorded on the removable recording medium via the internal memory, first, the recording speed of the recording medium is detected by the detecting means. The calculating means calculates a continuous recordable time based on the detected recording speed, and the disabling means disables the capturing means based on the calculated continuous recordable time.

In one embodiment of the present invention, a predetermined data recording means records predetermined data on a recording medium before recording desired data. The measuring means measures the time required for recording the predetermined data, and the recording speed detecting means calculates the recording speed based on the data amount of the recorded predetermined data and the time measured by the measuring means. The calculated recording speed is recorded on the recording medium by the recording speed recording means. The predetermined data is preferably desired data previously captured by the capturing means.

In another embodiment of the present invention, the calculating means comprises:
The continuous recordable time is calculated based on the capacity of the internal memory, the capture speed of the capture means, and the recording speed. The capturing means preferably includes a photographing means for photographing a subject at predetermined time intervals, and a compressing means for compressing photographed image data by the photographing means. Expressed by the amount of data.

[0009] In another embodiment of the present invention, the continuous recordable time is displayed by the display means.

[0010] In still another embodiment of the present invention, the desired data has a size larger than the capacity of the internal memory.

In another embodiment of the present invention, the desired data is written to the internal memory cyclically by the writing means, and is read from the internal memory cyclically by the reading means. The read desired data is recorded on a recording medium by the recording means.

[0012]

According to the present invention, the continuous recordable time is calculated based on the recording speed of the recording medium, and the taking-in means is disabled based on the calculated continuous recordable time. Time data can be captured.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0014]

Referring to FIG. 1, a digital camera 10 of this embodiment includes a CCD imager 12. A color filter (not shown) is mounted on the front surface of the CCD imager 12, and the light image of the subject is irradiated on the light receiving surface through the color filter.

When the power is turned on, the system controller 38 instructs the CPU 36 to perform a through image display process. The CPU 36 instructs the timing generator (TG) 14 to perform thinning-out reading in response to the live view image display instruction, and the TG 14 drives the CCD imager 12 in a thinning-out reading method. Thus, a low-resolution camera signal (pixel signal) corresponding to the subject image irradiated on the light receiving surface is output from the CCD imager 12. The output camera signal is subjected to well-known noise removal and level adjustment by the CDS / AGC circuit 16, and then is converted into a digital signal (camera data) by the A / D converter 18.

When a through image display process is instructed, C
The PU 36 also gives a processing instruction to the signal processing circuit 20. The signal processing circuit 20 performs processing such as color separation and YUV conversion on the camera data output from the A / D converter 18, and requests the memory control circuit 22 to write the generated YUV data. Memory control circuit 22
Responds to such a write request with YUV
The data is temporarily stored in the SDRAM 24. CPU3
6 also gives processing instructions to the video encoder 26. At this time, the video encoder 26
Request to read YUV data to SD
The encoding process is performed on the YUV data read from the RAM 24. The YUV data is converted to an NTSC composite image signal, and the converted composite image signal is output to the monitor 28. The monitor 28 displays a real-time moving image (through image) of the subject.

An operator sets a moving image photographing mode by a mode setting switch 42 and a shutter button 4
When 0 is pressed once, the system controller 38
36 is instructed to perform a recording process. Then, the CPU 36
The compression processing instruction is given to the EG codec 30, and the JPEG codec 30 requests the memory control circuit 22 to read the YUV data in response to the compression instruction. The memory control circuit 22 reads YUV data of a continuous frame, that is, moving image data of a subject, from the SDRAM 24 in response to a read request from the JPEG codec 30 and supplies the read data to the JPEG codec 30. The moving image data is compressed frame by frame according to the JPEG format. When the compressed image data (JPEG data) is generated, the JPEG codec 30 supplies the compressed image data to the memory control circuit 22 together with a write request. Therefore, the compressed image data is also stored in SDRAM2.
4 is stored.

However, the compressed image data is stored in the compressed image area 24a. FIG. 2 shows the compressed image area 24a.
As shown in FIG. 5, a plurality of memory areas are formed, and each memory area has a capacity enough to store one frame of compressed image data. The memory control circuit 22 sequentially stores the compressed image data generated by the JPEG codec 30 from the memory area 1, and when the compressed image data is written to the memory area M, stores the compressed image data of the next frame in the memory area 1. Write. That is, the writing of the compressed image data is cyclically written to the memory areas 1 to M.

The CPU 36 requests the memory control circuit 22 to read out compressed image data from the compressed image area 24a before the compressed image area 24a becomes full. The memory control circuit 22 reads the compressed image data sequentially from the memory area 1, and when the reading from the memory area M is completed, returns the next read destination to the memory area 1. That is, the reading of the compressed image data from the compressed image area 24a is also performed cyclically. in this way,
The compressed image area 24a operates as a ring buffer.

The CPU 36 records the read compressed image data together with the associated header data in the memory card 34, and as a result, an image file is created in the memory card 34. The memory card 34 is a detachable recording medium, and the I / F circuit 3
2 is connected. Therefore, the header data and the compressed image data are transferred to the memory card 34 through the I / F circuit 32.
Will be recorded.

The generation speed when the compressed image data is generated by the JPEG codec 30 is faster than the recording speed when the same compressed image data is recorded on the memory card 34. For this reason, if the generated compressed image data is output to the memory card 34 as it is, the processing is broken. In order to prevent processing failure due to such a difference in speed, a compressed image area 24a is formed in the SDRAM 24, and the compressed image data generated by the JPEG codec 30 is temporarily saved in the compressed image area 24a.

When the operator operates the shutter button 40 again, the system controller 38 instructs the CPU 36 to stop the recording process. Then, the CPU 36 becomes the JPE
The output of the compression processing instruction to the G codec 30 is stopped.
As a result, after the shutter button 40 is operated, no compressed image data is generated, and writing of the compressed image data to the compressed image area 24a is not performed. However, while the compressed image data remains in the compressed image area 24a, a read request is output from the CPU 36 to read the compressed image data and
Will continue to be recorded. Then, the output of the read request is stopped when all the compressed image data has been read, and the recording operation is also stopped when all the compressed image data has been recorded on the memory card 34. The through image is displayed on the monitor 28 while the recording process is being performed, and this through image display is continuously performed even after the recording is completed.

The processing of the CPU 36 will be described in detail with reference to FIGS. When a through image display processing command is given from the system controller 38 in response to power-on, the CPU 36 determines YES in step S1 and performs through image display processing in step S3. That is, TG
14 instructs a thinning process, and instructs the signal processing circuit 20 and the video encoder 26 to perform predetermined signal processing. As a result, a through image is displayed on the monitor 28. CP
U36 then determines whether a predetermined recording speed measurement file has been recorded in the memory card 34 in step S5.
To judge.

When a plurality of image files and recording speed measurement files are recorded on the memory card 34, the directory in the memory card 34 has a structure as shown in FIG. That is, “SANY00N.JPG” (N is an integer)
A plurality of image files represented by "\ DCIM \ SA"
NDS \ ”is located under the directory“ WS
PEED. A recording speed measurement file represented by “TXT” is arranged in a lower layer of the directory “{SYSTEM}.” In the recording speed measurement file, the model name and the recording speed are written as shown in FIG. According to FIG. 4, the recording speed measurement file is created by the model “SX112”, and the recording speed when the memory card 34 is inserted in this model is 700 Kbytes / sec.

A recording speed measurement file represented by "WSPEED.TXT" exists under the directory of "{SYSTEM}", and the model name written in the recording speed measurement file is the digital name of this embodiment. If the same as the camera 10, the CPU 36 determines in step S5 that YE
Judge as S. On the other hand, "{SYSTEM}"
If the recording speed measurement file does not exist in the lower hierarchy of the directory or if the model name written in the file is different from that of the digital camera 10 of this embodiment, the CPU 36 determines NO in step S5. I do.

If YES is determined in the step S5, C
The PU 36 reads out the recording speed data from the recording speed measurement file in step S7, and calculates the continuous recordable time according to Equation 1 in step S9. Then, the calculated continuous recordable time is set in the timer 36b.

[0027]

## EQU1 ## Continuous recordable time = compressed image area / (writing speed to compressed image area−recording speed to memory card) 15 frames of compressed image data are generated per second,
When the compressed image data amount of each frame is 50K bytes, the writing speed to the compressed image area 24a is 750K bytes.
Bytes / second. On the other hand, the recording speed on the memory card 34 is 700 Kbytes / sec as described above. Therefore, if the capacity of the compressed image area 24a is 7.5 Mbytes, the continuous recordable time is 150 seconds.

On the other hand, if NO is determined in the step S5, the CPU 36 proceeds to a step S11 to initialize a recordable time. That is, the initial value is set in the timer 36b. The initial value is, for example, 10 seconds, and this value corresponds to the time required until the compressed image area 24a becomes full when the recording process is not performed.

Thereafter, the CPU 36 calculates the continuous recordable time determined in step S9 or S11 in step S13.
Is displayed on the display 48. Therefore, the operator can easily confirm how many seconds the subject can be continuously photographed by the display on the display 48.

In step S15, it is determined whether or not the shutter button 40 has been operated. If YES, the register 36a is initialized in step S17. Register 36
a is a register for ascertaining how much data has been recorded on the memory card 34 by the recording processing in step S23, and in step S19, the data amount = 0 is written to the register 36a. The CPU 36 continues to
In step S19, a compression process is instructed to the JPEG codec 30, and a clock 37 is set in step S21. CP
When a compression command is issued from U36, the JPEG codec 30 starts compressing moving image data. That is, it requests the memory control circuit 22 to read the moving image data, and compresses the moving image data read from the SDRM 24 for each frame. Then, the generated compressed image data is output to the memory control circuit 22 together with the write request. The compressed image data is accumulated in the compressed image area 24a by the memory control circuit 22. At this time, the compressed image data is cyclically written to the memory areas 1 to M.

In step S23, the compressed image area 24
The recording process of the compressed image data stored in a is performed. First, a request is made to the memory control circuit 22 to read a predetermined byte of compressed image data, and the predetermined byte of compressed image data read from the compressed image area 24a is input to the I /
2 to the memory card 34. When the recording for the predetermined byte is completed, the CPU 36 updates the value of the register 36a and the continuous recordable time in steps S25 and S27. In step S25, a predetermined bit is added to the current value of the register 36a, and in step S27,
A predetermined time is subtracted from the continuous recordable time set in the timer 36b and the continuous recordable time displayed on the display 48.

Thereafter, the CPU 36 determines whether or not the continuous recordable time has reached "0" in step S29, and determines in step S31 whether or not the shutter button 40 has been pressed again. If both are NO, the processes of steps S23 to S31 are repeated. Therefore, unless the continuous recordable time becomes “0” or the shutter button 40 is pressed, the operation of reading the compressed image data from the compressed image area 24 a and the recording of the read compressed image data to the memory card 34 are performed. Operation continues. In addition,
The read destination of the compressed image data changes cyclically among the memory areas 1 to M.

If YES is determined in any one of steps S29 and S31, the CPU 36 instructs the JPEG codec 30 to stop the compression processing in step S33. In response to the stop instruction, the JPEG codec 30 stops all read requests to the memory control circuit 22, JPEG compression, and write requests to the memory control circuit 22. Therefore, even if the operator does not press the shutter button 40, the compression process is forcibly stopped when the continuous recordable time elapses.

In step S35, it is determined whether the recording of the compressed image data has been completed. Compressed image area 24a
If the compressed image data still remains in step S35, the CPU 36 determines NO in step S35, and proceeds to steps S37 and S37.
In step 39, the same processing as in steps S23 and S25 described above is performed. Then, the process returns to step S35. By repeating such processing, when all the compressed image data in the compressed image area 24a is recorded on the memory card 34, the CP
U36 proceeds from step S35 to step S41. In step S45, clock data is fetched from the clock 37,
In step S47, the recording speed is calculated according to equation (2).

[0035]

## EQU2 ## Recording speed = register value / clock data value As described above, the clock 37 is set immediately before the start of recording.
Indicates the time required for recording. On the other hand, the value of the register 36a indicates the amount of recorded compressed image data. For this reason, the recording speed is obtained from Equation 2.

Subsequently, the CPU 36 creates a recording speed measurement file in step S43. Specifically, if the recording speed measurement file in which the same model name is written does not exist in the memory card 34, the recording speed data calculated in step S43 and the digital camera 10 of this embodiment are stored.
Create a new recording speed measurement file with the model name written. On the other hand, if there is a recording speed measurement file in which the same model name is written in the memory card 34, the recording speed data in this file is stored in step S47.
It is updated with the recording speed data calculated in. After finishing such processing, the CPU 36 returns to step S17.

As can be seen from the above description, in this embodiment, the compressed image data is actually recorded on the memory card 34, and the continuous recordable time is determined based on the time required for the recording and the amount of data recorded. Is calculated. Then, the calculated continuous recordable time is recorded on the memory card 34. At the time of the next shooting, the continuous recordable time recorded on the memory card 34 is detected, and the time data is set in the timer 36b. The operator can perform shooting only for the time set in the timer 36b. That is, continuous shooting (moving image clip) of the subject can be performed for a necessary and sufficient time.

The continuous recordable time detected from the memory card 34 is also displayed on the display 48. For this reason, the operator can know from the display on the display 48 how long a continuous shooting can be performed.

In this embodiment, the continuous recordable time is calculated by actually recording the compressed image data. However, the continuous recordable time is calculated by recording a predetermined amount of dummy data. You may. Further, in this embodiment, the continuous recordable time calculated at the time of the previous photographing is used for the current photographing. However, when the compressed image data generated by the current photographing is recorded, the current continuous recording is possible. The time may be obtained, and the photographing may be stopped when the obtained continuous recordable time has elapsed. In this case, the compressed image data generated by the current shooting is
It is conceivable to calculate the continuous recordable time at the time of recording for seconds, and to set a time obtained by subtracting 5 seconds from the calculated continuous recordable time in the timer.

Although this embodiment is described using a digital camera, the present invention is also applicable to an audio recorder that records music data downloaded by wireless communication to a memory card via an internal memory. The data to be downloaded may be image data or character data in addition to music data.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is an illustrative view showing a compressed image area of the SDRAM;

FIG. 3 is an illustrative view showing a directory structure of a memory card;

FIG. 4 is an illustrative view showing a recording speed measurement file;

FIG. 5 is a flowchart showing a part of the operation of the embodiment in FIG. 1;

FIG. 6 is a flowchart showing another portion of the operation of the embodiment in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Digital camera 12 ... CCD imager 22 ... Memory control circuit 24 ... SDRAM 30 ... JPEG codec 34 ... Memory card 36 ... CPU 38 ... System controller

Claims (8)

[Claims] 1. A data recording apparatus for recording desired data continuously captured by a capturing means on a removable recording medium via an internal memory, wherein the detecting means detects a recording speed of the recording medium; A data recording apparatus comprising: a calculating unit that calculates a continuous recordable time based on a recording speed; and a disabling unit that disables the capturing unit based on the continuous recordable time. A predetermined data recording means for recording predetermined data on the recording medium prior to the recording of the desired data; a measuring means for measuring a time required for recording the predetermined data; a data amount of the predetermined data; 2. The data recording apparatus according to claim 1, further comprising: a recording speed calculating unit that calculates the recording speed based on the time measured by the measuring unit; and a recording speed recording unit that records the recording speed on the recording medium. 3. The data processing apparatus according to claim 3, wherein said predetermined data is said desired data previously captured by said capturing means.
The data recording device according to the above. 4. The computer according to claim 1, wherein said calculating means includes: a capacity of said internal memory;
2. The continuous recording possible time is calculated based on a capturing speed of the capturing unit and the recording speed.
4. The data recording device according to any one of claims 3 to 3. 5. The capturing means includes photographing means for photographing a subject at predetermined time intervals, and compression means for compressing image data taken by the photographing means, wherein the capturing speed is generated by the compression means in a unit time. 5. The data recording device according to claim 4, wherein the data amount is represented by a data amount of the compressed image data. 6. The data recording apparatus according to claim 1, further comprising display means for displaying the continuous recordable time. 7. The data recording apparatus according to claim 1, wherein said desired data has a size larger than a capacity of said internal memory. 8. A writing means for cyclically writing the desired data to the internal memory; a reading means for cyclically reading the desired data from the internal memory; and the recording of the desired data read by the reading means. The data recording apparatus according to claim 1, further comprising a recording unit that records on a medium.