JP3416651B2 - Digital camera - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital camera, and more particularly to a digital camera for writing photographed image data in a storage memory in which MS-DOS (registered trademark) format is set.

[0002]

2. Description of the Related Art In the MS-DOS format, a root directory area and a FAT (File Allocation) are stored in a memory.
Table) area and data area are formed, and the data area is divided into a plurality of clusters. Data is stored discretely in units of clusters, and the link state of clusters related to each other is managed by FAT. Also, F
The AT entry number (FAT entry) is managed by the root directory. Therefore, even when data is discretely stored, desired data can be read out by using the FAT entry written in the root directory as a clue.

In a conventional digital camera, photographed image data is recorded in a memory according to such MS-DOS format.

[0004]

However, MS-DOS
In the format, it takes time to write data because it is necessary to search for a free cluster at the time of recording data and to form a link each time the writing of data to one cluster is completed. Therefore, the conventional digital camera has a problem in that it takes a long time from when the shutter button is pressed once until the next shutter button operation becomes possible.

Therefore, a main object of the present invention is to provide a digital camera capable of increasing the number of images that can be taken per unit time.

[0006]

A digitizer according to the invention.
Cameras has a shot images data in the buffer memory
Writing means for continuously writing and buffer memory
A recording means for discretely recorded image data stored in the record medium, the buffer memory image data of a plurality
Has a capacity to store.

[0007]

[Action] captured images data are written continuously into the buffer memory by the writing means. Recording means discretely recorded image data stored in the buffer memory to the record medium. Here, there are multiple buffer memories.
It has the capacity to store the image data of.

[0008]

Effects of the Invention According to the present invention, since the images data so as to store in the buffer memory, the formation of the search and the link free space is not required, it is possible to shorten the interval to the next shooting from shooting it can. That is, it is possible to increase the number of images taken per unit time.

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

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a digital camera 10 of this embodiment includes a lens 12, and an optical image incident from this lens 12 is converted into an electric signal by a CCD imager 14. The CCD imager 14 has, for example, a complementary color filter, and outputs an electric signal (progressive scan signal) for each pixel in accordance with progressive scan (pixel sequential scan).

The progressive scan signal from the CCD imager 14 is applied to the CDS / AGC circuit 16. The CDS / AGC circuit 16 includes the CCD imager 14
The well-known noise removal and level adjustment are applied to the progressive scan signal from the CDS / AGC circuit 16
The progressive scan signal processed by
It is converted into digital data (image data) by the / D converter 18. The signal processing circuit 20 performs well-known white balance adjustment and gamma correction on the image data output from the A / D converter 18.

When the operator presses the shutter button 38, the system controller 36 gives a control signal to the CPU 28 through the interrupt terminal 28a. Therefore, the CPU 28 disables the CCD imager 14 when the CCD imager 14 outputs the progressive scan signal for one frame after the shutter button 40 is pressed. As a result, the image data for one frame (captured image data) that has been captured is output from the signal processing circuit 20, and is provided to the DRAM 24 via the bus 22. Then, the captured image data is stored in the memory control circuit 2
6, that is, the data is written in the memory area 24a by DMA (Direct Memory Access).

The CPU 28 compresses the photographed image data in the memory area 24a in the JPEG format using the work area 24b. The CPU 28 sequentially stores the compressed data in the second buffer area 24c having a memory capacity of one cluster, and when the second buffer area 24c becomes full, the compressed data in the second buffer area 24c is stored in the memory card shown in FIG. 34 to the first buffer area 34d. As can be seen from FIG. 2, the first buffer area 34d is divided for each cluster, and the compressed data for one cluster read from the second buffer area 24c starts from the first cluster D0 of the first buffer area 34d. Written in order. Note that the maximum number of clusters required to store one piece of captured image data is 10, and 100 clusters are prepared in the first buffer area 34d.

When the operator finishes photographing the desired number of sheets, the CPU 28 writes the compressed data stored in the first buffer area into the data area 34c according to the MS-DOS format. That is, the CPU 28 uses the data area 3
A free cluster is searched from 4c, compressed data for one cluster is written in the found free cluster, and the link state is recorded in the FAT area 34a. The CPU 28 also writes the FAT entry in the root directory area 34b. Therefore, the compressed data is recorded in the data area 34c as shown in FIG.

When the continuous shooting mode is set by the mode switch button 40, the CPU 28 stores the compressed data for 10 shots, that is, 10 sheets of compressed data in the first buffer area 34d. At that time, the compressed data is converted into the data area 3 according to the MS-DOS format.
Write to 4c. What is continuous shooting mode? Shutter button 38
In this mode, the CCD imager 14 outputs a progressive scan signal for one frame every 0.5 seconds, for example, in a mode in which photographing is performed a predetermined number of times (10 times) according to one operation.

On the other hand, when the normal shooting mode is set by the mode switch button 40, the CPU 28 shoots once each time the shutter button 38 is pressed, and the DRAM
The compressed data for one sheet obtained at 24 is stored in the first buffer area 34d. If the shutter button 38 is not pressed for 3 seconds or more after the previous shutter button 38 was pressed, it is determined that the desired number of images have been captured, and the compressed data in the first buffer area 34d is converted into data according to the MS-DOS format. Write to area 34c.

As described above, the compressed data is held in the first buffer area 34d until the desired number of times of photographing is completed, and when writing to the first buffer area, it is not necessary to search for a free cluster or to form a link. Therefore, it is possible to shorten the writing time of the compressed data for one sheet. That is, the time interval from the previous shooting to the current shooting can be shortened, and the number of images that can be shot per unit time can be increased.

The CPU 28 specifically processes the flowcharts shown in FIGS. That is, the CPU 28 first determines in step S1 whether or not the shutter button 38 is turned on. Then, if the shutter button 38 is pressed,
The CPU 28 initializes the storage cluster number in step S3, and sets the number of storage clusters to "1" in step S5. The storage cluster means a cluster in which compressed data will be stored or in which compressed data has already been stored, and the storage cluster numbers are D0, D1, and
It is represented by D2 ....

Next, the CPU 28 makes a predetermined value 6 in step S7.
The captured image data of 4 pixels (8 pixels in the vertical direction and 8 pixels in the horizontal direction) is compressed, and the compressed data is stored in the second buffer area 24c in step S9. The CPU 28 subsequently determines in step S11 whether or not uncompressed data still remains, that is, whether or not there is still captured image data that has not been compressed. When the photographed image data in the memory area 24a is completely compressed, the CPU 28 sets the flag 28b in step S15, and proceeds to step S17. On the other hand, if there is still uncompressed captured image data in the memory area 24a, the CPU 28
Determines in step S13 whether the second buffer area 24c is full. Then, if "NO", the process returns to step S7 to repeat the above-described operation, but if "YES", the process proceeds to step S17.

In step S17, the CPU 28 writes the compressed data of the second buffer area 24c in the cluster provided in the first buffer area 34d and indicated by the storage cluster number, and then in step S19, the flag 28b is set. to decide. If the flag 28b is not set, it is determined that the photographed image data to be compressed still remains, the storage cluster number and the storage cluster number are incremented in steps S21 and S23, respectively, and the process returns to step S7. On the other hand, flag 2
If 8b is set, the compression of one shot image data is completed, and all the compressed data are stored in the first buffer area 34.
Since it is stored in d, the flag 28 is set in step S25.
b is reset, and in step S27, the current captured image number and the number of stored clusters are associated with each other, and the table 28c
Write in. As shown in FIG. 4, the captured image numbers are “1”, “2”, “3” ...
The number of clusters required to store the compressed data of each captured image is associated with each captured image number. Note that in the example of FIG. 4, 4 clusters are required to store the compressed data of the captured image number “1”, 7 clusters are required to store the compressed data of the captured image number “2”, and Five clusters are required to store the compressed data of image number “3”.

When the processing of step S27 is completed, the CPU
In step S29, 28 refers to the number of stored clusters and sets 1
It is determined whether or not 0 images have been taken. The maximum number of clusters that can store the compressed data of one image is 10, and the number of clusters secured in the first buffer area 34d of the memory card 34 is 100. Data in the first buffer area 34
There is a risk that it cannot be stored in d. Also, in continuous shooting mode,
The number of images taken by one shutter operation is 10. Therefore, in step S29, it is determined whether or not 10 images have been captured, and if "YES", the operation of the shutter button 38 is invalidated, and in step S37 and subsequent steps, the compressed data in the first buffer area is saved. The data area 34c is written according to the MS-DOS format.

On the other hand, if "NO" in the step S29, the CPU 28 determines in a step S31 whether or not the current mode is the continuous shooting mode. If "YES", the process returns to step S5 to process the image to be captured next time. While the number of storage clusters returns to "1", the storage cluster number is not initialized, so the next step S
In 17, the next compressed data is written subsequent to the compressed data obtained by this photographing. That is, in FIG. 2, when the compressed data is written in the clusters D0 to D3 according to the current shooting, the compressed data obtained next time is written in the cluster D4 and the subsequent clusters.

If "NO" is determined in the step S31, since the current mode is the normal photographing mode, the CPU
Step 28 determines whether or not 3 seconds have elapsed since the shutter button 38 was operated last time in step S33. Here "Y
If "ES", the process proceeds to step S37 assuming that the desired number of images have been captured, but if "NO", step S3
In step 5, it is determined whether the shutter button 38 has been pressed.
Then, unless the shutter button 38 is pressed, the processing of steps S33 and S35 is repeated for 3 seconds.
If the shutter button 38 is pressed within 3 seconds, the CPU 2
8 returns to step S5 and repeats the above-mentioned processing.

In step S37, the CPU 28 advances the current address to "002" in the FAT area 34a and sets the address to be moved next time to "001".
FATC is the current address and FATS is the destination address. Subsequently, the CPU 28 initializes the address and the storage cluster number of the table 28c in steps S38 and S39, sets the storage cluster number to "1" in step S41, and increments FATS in step S43. In step S45, F
It is determined whether the ATS data is “000H”, that is, whether the cluster corresponding to the destination table is an empty cluster, and if “NO”, step S43.
Return to and increment FATS again, but "YE
If "S", it is determined in step S47 whether the current number of stored clusters is "1". If "YES" here, the CPU 28 sets the current FATS as a directory entry in step S51, and proceeds to step S53. .

In the example of FIG. 5, the address of the FAT corresponding to the first cluster storing the compressed data is "00".
2 "," 042 "," 04E "," 04F "," 05 "
Since they are 0 ”,“ 06A ”,“ 068 ”and“ 066 ”, the respective data are written in the root directory.

On the other hand, if "NO" is determined in step S47, the CPU 28 writes the destination address FATS in association with the current address FATC in step S49, and advances the current address to FATS in step S53.
Then, in step S55, the compressed data corresponding to the currently stored cluster number is written in the cluster corresponding to the current address. Referring to FIG. 5, the current address is, for example, "04".
If it is "0", the compressed data is written in the cluster of address "049".

In step S57, it is determined whether the number of currently stored clusters exceeds the number of stored clusters written in the current address of the table 28c. If “NO” here, it is determined that the processing of the currently captured image is not completed, and the number of stored clusters and the stored cluster number are incremented in steps S59 and S61, respectively, and step S4
Return to 3. Therefore, the F corresponding to the empty cluster is again used.
The address of the AT is searched, and the remaining compressed data is written. On the other hand, if "YES" is determined in the step S57, the CPU 28 writes "FFFH" indicating the end marker in the current address of the FAT in a step S63,
After that, in step S65, it is determined whether or not writing of all the captured compressed data to the data area 34c is completed. If "YES", the process ends, but "N"
If it is O ″, the storage cluster number and the address of the table 28c are incremented in steps S67 and S69, respectively, and the process returns to step S41.

The digital camera of the present invention includes:
Besides a so-called digital still camera that records only still images, a video movie having a function of recording still images is also included. In addition, as a memory card, CompactFlash (registered trademark), smart media (SS
FDC), miniature card, PC card, small P
Any memory card such as a C card can be used. Further, as the external memory, a floppy (registered trademark) disk may be used in addition to the memory card. Furthermore, in this embodiment, the first buffer area is formed in the memory card and the second buffer area is formed in the DRAM provided in the camera body. However, both buffer areas are formed in either the memory card or the DRAM. May be collected in one. Further, as the memory for recording the image data according to the MS-DOS format, in addition to an external memory card, a non-volatile RAM installed in advance in the camera body may be used.

In this embodiment, the compressed data is recorded in the data area when the shutter button has not been operated for 3 seconds or more since the previous shutter operation in the normal photographing mode. The compressed data may be recorded in the data area in response to the write command. In this case, a write command button is added to FIG. 1, and a step of determining whether or not the write command button is pressed is provided between steps S33 and S35. If “NO”, the process proceeds to step S35. ,
If "YES", it is necessary to proceed to step S37. Further, if an indicator showing the storage state of the first buffer area is provided in the camera body, it will be a guide for the operator's operation.

[Brief description of drawings]

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

FIG. 2 is an illustrative view showing an internal structure of a memory card.

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

FIG. 4 is an illustrative view showing a table formed in a CPU.

FIG. 5 is an illustrative view showing a data structure of an MS-DOS format.

FIG. 6 is a flowchart showing a part of the operation of FIG. 1 embodiment.

FIG. 7 is a flowchart showing another portion of the operation of the embodiment in FIG. 1;

FIG. 8 is a flowchart showing another portion of the operation of the embodiment in FIG. 1;

FIG. 9 is a flowchart showing yet another portion of the operation of the embodiment in FIG. 1;

[Explanation of symbols]

10 ... Digital camera 24 ... DRAM 28 ... CPU 34 ... Memory card

Claims (2)

(57) [Claims] [Claim 1] The photographed images data in the buffer memory
Continuously write writing means, and a recording means for discretely recorded image data stored in the buffer memory to the record medium, the buffer memory can store image data of a plurality
A digital camera having a capacity . 2. The recording means is a free area searching means for searching a plurality of free areas discretely formed on the recording medium, and an image for writing the image data in the plurality of free areas found by the searching means. data writing means, and a linking means for the image data to form a link in a region that has been written, according to claim 1 Symbol mounting digital camera.