JPH04212581A - Electronic still camera - Google Patents

Abstract

PURPOSE:To increase the number of sheets of still images which can be recorded by effectively utilizing a memory card for recording image data to be used by being attached and detached to and from the electronic still camera. CONSTITUTION:The image data of the upper plural bits of the image data obtd. by the electronic still camera are written into the memory 15 in the attachable and detachable memory card 13 by a memory control IC 8. The image data of the lower plural bits are written into the internal memory 11 built in the electronic still camera. The greater part of the still images can be observed even if the image data is reproduced with the memory card 13 alone and, therefore, many number of sheets of the still images are reproduced simply by sending the memory card 13 to a remote place. The reproduction of the fine still images is possible as well if the image data are read out of the internal memory 11 of the electronic still camera and are reproduced together with the image data from the memory card 13.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic still camera in which image data obtained is written separately into a memory card that can be attached to and removed from the camera body and to an internal memory built into the camera body.

0002

[Prior Art] Some recent electronic still cameras include IC
There are devices that write image data to a memory card such as a card or an LSI card. Like conventional still video floppies, such a memory card can be removed from the camera body after image data has been written to it, so it has the advantage that it can be easily sent to remote locations by mail or the like.

0003

However, since the S-RAM built into the memory card as a storage element is still expensive, the cost required to store each still image is also high. Furthermore, when considering the size and unit price of a memory card, the capacity of memory that can be built into a single memory card is naturally limited, so the number of still images that can be recorded as image data on a single memory card is also limited. It's coming.

The present invention has been made in consideration of the above background, and makes it possible to efficiently utilize the memory element built into a memory card and increase the number of still images that can be recorded on one memory card. The purpose is to provide electronic still cameras.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention has a configuration in which image data is written to both a memory card that is attached to and removed from the camera body of an electronic still camera and an internal memory built into the camera body. In addition, image data of a plurality of upper bits of image data consisting of a plurality of bits is written to the memory card, and image data of a plurality of lower bits is written to the internal memory.

[0006]

[Effect] When a still image is played back using the upper multiple bits written to the memory card, it is possible to reproduce most of the main part of the still image, although it is inferior to the reproduced image that includes the image data of the lower multiple bits. can. Therefore, the number of still images that can be stored on one expensive memory card can be easily increased, although the details of the still images may be sacrificed to some extent. Of course, if image data is simultaneously read from both the memory card and the internal memory and played back, it is possible to play back the image based on all the image data. Hereinafter, the present invention will be explained according to the illustrated embodiments.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, which schematically shows the configuration of an electronic still camera to which the present invention is applied, an optical image obtained by a lens 2 is focused on a photocathode of an image sensor 3. When a release operation is performed, the image sensor 3 converts an optical image into a photoelectric signal for each pixel and supplies it to the print amplifier 4 in time series. The photoelectric signal amplified by the preamplifier 4 is
It is converted into a digital signal by the A/D converter 5, and 1
The image data is input to the shift register 6 as 8-bit image data per pixel. The shift register 6 includes a memory control IC controlled by the system controller 7.
8 is connected, and shift register 6 is connected in recording mode.
When 8-bit image data is input to , these image data are read in parallel.

A mode setting section 10 is connected to the system controller 7, and a mode signal from the mode setting section 10 sets the operating mode of the electronic still camera to either recording mode or playback mode. That is, the knob 10a provided in the mode setting section 10 is set to the index "record".
When set to , the memory control IC 8 operates in a recording mode, and the memory control IC 8 writes 8-bit image data from the shift register 6 to the internal memory 11 or to the memory card 13 via the connector 12.

The other knob 10b provided in the mode setting section 10 selects an object to be accessed by the memory control IC 8 in the recording mode and the playback mode. knob 1
When 0b is set to the index “Normal”,
Of the 8-bit image data per pixel, the upper 4 bits are accessed to the memory 15 in the memory card 13, and the lower 4 bits are accessed to the internal memory 11. When the knob 10b is set to the index "Fine", the memory control IC 8 accesses only the memory 15 built into the memory card 13, and 8-bit image data is recorded in or read out from the memory 15. become.

Note that the set position data of the knob 10b in the recording mode is written to the memory 15 as flag data, and the knob 10b is set to "Fine" when reproducing from the memory card 13 recorded in "Normal". or when playing back from the memory card 13 recorded in "Fine", the knob 10b is set to "No.
rmal", reproduction is performed according to the set position of the knob 10b at the time of recording.

The signal processing circuit 16 operates in response to a command from the system controller 7 during the playback mode, and operates by commands from the system controller 7 to process the internal memory 11 and the memory 15 built into the memory card 13.
The image data read out from the converter converts the image data into a video signal compliant with the NTSC system and outputs the video signal to the output terminal 17. Note that the memory card 13 has a built-in backup battery 18, but the memory card 13 is connected to the connector 12 through the connector pin 12a.
When connected to the camera, power is supplied from the camera body.

The operation of the electronic still camera described above will be explained. The knob 10a is the index "record", and the knob 10b is the index "record".
When used in the "Normal" mode, the image data D8 of 8 bits per pixel obtained by the release operation as shown in FIG.
H4 is written to the memory 15 in the memory card 13,
The remaining lower 4 bits of image data DL4 are written into the internal memory 11. Since the 8-bit image data D8 has a larger influence on the reproduced image as the image data has higher bits, the image data DH4 is written into the memory card 13 so that the still image can be roughly determined during reproduction. , image data DL4 is written into the internal memory 11 so that the still image can be reproduced more precisely.

When recording is performed under such a mode, only 4 bits are used per still image in the memory 15, so all of the 8-bit image data D8 is stored in the memory 15.
5, the number of recorded still images is twice as large. Therefore, as shown in FIG. 3, the memory card 13 recorded by one electronic still camera 20 is sent to a distant place, and the
When playing back a still image, if it is sufficient to roughly play the still image, it is possible to obtain twice the recording capacity compared to the conventional usage mode of a memory card.

[0014] Also, an electronic still camera 20 used for recording
The lower 4 bits of image data DL are stored in the internal memory 11 of
4 is written. Therefore, when playing back images with the same electronic still camera 20, the memory card 13
In addition to the upper 4 bits of image data DH4 read from the internal memory 11, a fine still image can be reproduced by reading out the lower 4 bits of image data DL4 written in the internal memory 11. Of course, these 8 bits It is also possible to record a video signal based on image data on another medium such as an optical disk. If you want to play back fine still images with the other electronic still camera 22, set the knob 10b to the "Fine" index and record, and store the 8-bit image on the memory card 13 as before. It is sufficient to write the image data D8 in advance.

Although the present invention has been described above in accordance with the illustrated embodiments, the number of bits of image data for each pixel is not limited to 8 bits, but may be 16 bits or some other number of bits. Further, regarding the number of upper bits to be written to the memory card, not only the upper bits when the total number of bits is divided into two, but also arbitrary plural bits from the upper digit position may be written.

[0016]

[Effects of the Invention] As described above, according to the electronic still camera of the present invention, only the upper part of the image data represented by multiple bits is written to the memory card. Since it is possible to reproduce a general still image just by reading the image data, it is possible to increase the number of still images stored on one memory card and use the expensive memory elements used in memory cards at a low cost. be able to.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an electronic still camera of the present invention.

FIG. 2 is a conceptual diagram of image data consisting of multiple bits.

FIG. 3 is an explanatory diagram showing an example of how a memory card is used.

[Explanation of symbols]

3 Image sensor 8 Memory control IC 10 Mode setting section 11 Internal memory 13 Memory card D8 Image data

Claims (1)

[Claims] 1. An electronic still camera having a recording function for converting an optical image into image data consisting of a plurality of bits for each pixel and writing it to a storage medium, and a playback function for reading out the image data written to the storage medium, An electronic device characterized in that the image data of a plurality of upper bits of the image data are written to a memory card that can be attached to and removed from the camera body, and the image data of a plurality of lower bits of the image data are written to an internal memory built into the camera body. still camera.