JPH0828836B2 - Digital electronic still camera and external storage device for storing video signals thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electronic still camera, and more particularly to a digital electronic still camera which stores a video signal representing a still image in the form of digital data in a storage device, and digital data of the digital electronic still camera. The present invention relates to an external storage device for storing.

BACKGROUND ART For example, an electronic still camera described in Japanese Patent Laid-Open No. 59-183592 has a memory (memory card) detachably connected to a camera body having an imaging optical system and a fixed imaging device, and a still image captured by the imaging device is displayed. The video signal to be represented is stored in this memory in the form of a digital signal. The memory in which the video signal is stored is removed from the electronic still camera and loaded into the reproducing device, and the video signal read from the memory by the reproducing device is reproduced as a visible image on the screen of the video monitor.

The memory currently in practical use is a rewritable digital storage device in which, for example, an SRAM semiconductor memory is mounted in the form of “module” such as an integrated circuit (IC) card or a cartridge. The data storage capacity is about 1 Mbit, and only about 4 Mbit is expected to be put into practical use. Therefore, for example, when sufficient image quality is required, one frame of image is 1 Mbit or 1.5 M
Expressed in bit data, one card can store only about 2 or 3 frames of images.

For this reason, if a large number of subjects are to be captured with high image quality by the electronic still camera, the cards will be replaced frequently. In addition, it is possible to miss the photo opportunity because you cannot take an image while you swap the cards. This will also hinder the important feature of electronic still cameras, the high speed continuous shooting capability.

An object of the present invention is to provide a digital electronic still camera capable of continuously capturing a large number of subjects and an external storage device capable of effectively storing digital video signal data of the electronic still camera by solving the above drawbacks of the conventional technology. The purpose is to

DISCLOSURE OF THE INVENTION According to the present invention, there is provided an image pickup device having an image pickup device, the image pickup device picking up an image of a scene and outputting a video signal representing a still image of the scene in the form of digital data. A digital electronic still camera having a first connecting means for circuit-connecting a semiconductor memory which is stored in the form of digital data, and a second electronic device which connects an external storage device in which a video signal is stored in the form of digital data. Control for connecting the connection means, switching means for selectively connecting the image pickup means to either of the first and second connection means, and controlling the image pickup means to cause the image pickup means to pick up an image and control the connection of the switching means. The control means stores the video signal in the form of digital data in the external storage device from the imaging means when the imaging means is connected to the second connection means side by the switching means.

According to another aspect of the present invention, the first semiconductor memory is detachably connected to the first semiconductor memory so that a video signal representing a still image of the scene is captured in the first semiconductor memory in the form of digital data. An external storage device used in an electronic still camera is a memory means for storing a video signal in the form of digital data, and a control signal connected to the memory means for storing the video signal and the video signal in the memory means. And receiving means for receiving the image signal according to the control signal received by the receiving means.

Description of Embodiments Next, an embodiment in which the digital electronic still camera according to the present invention is connected to an external storage device will be described in detail with reference to the accompanying drawings.

Referring to FIG. 3, there is shown a system configuration example in which the digital electronic still camera according to the present invention is connected to an external storage device, and the electronic still camera 1 is connected to the external storage device 2 via a connection cable 8, for example.

FIG. 1 shows a block diagram of each embodiment of the electronic still camera 1 and the external storage device 2. The electronic still camera 1 includes an image capturing unit 30 that captures an image of a subject and a signal processing device that processes an image signal output from the image capturing unit 30.
12, a switch circuit 18 controlled by the signal processing device 12,
Interface circuit for interface matching with the external storage device 2 that stores the image signal output from the imaging unit 30
It has 16 and a memory 14 for storing the same image signal. In the figure, the memory 14 is detachably connected to the electronic still camera 1 by a connector 17, and the other element parts are mounted as the electronic still camera 1 in a single housing.

The imaging unit 30 is necessary for capturing still images of the imaging lens 40, the diaphragm 41, the shutter 46, the imaging device 44, the side light / distance measuring mechanism, the viewfinder (not shown), and their driving mechanism as shown in the figure. Focusing of the imaging lens 40, control of the diaphragm 41, opening and closing of the shutter 46, etc. are controlled from the signal processing device 12 via the control line 11. Imaging device 44
Is a solid-state imaging device such as CCD or MOS,
Alternatively, a picture tube is advantageously applied. In the case of a fixed image pickup device, a color filter is attached to the image pickup cell array 42 of the device 44, and a color-modulated video signal is generated in response to a sampling pulse having a frequency received from the pulse generator 124 (FIG. 2) through the drive line 48. The points (pixels) are sequentially output to the output 13. As the imaging device 44, an array of photosensitive cells of the imaging cell array 42, that is, an array having an appropriate number of pixels in the photosensitive area is used, and the color segment array of the color filter thereof may be of any type.

FIG. 2 is a block diagram showing a configuration example of the signal processing device 12, and the signal processing device 12 will be described with reference to FIG. The signal processing device 12 includes an analog / digital converter (ADC) 122, a pulse generator 124, a timing circuit 126, an operation display unit 128, and a system control circuit 120. It should be noted that, in the figure, those not directly related to the present invention are not described.

The video output 13 of the imaging device 44 is connected to the input of the analog-to-digital converter 122, and the converter 122 inputs its input 13.
Is a signal conversion circuit for converting the analog type video signal of to the corresponding digital data of 8 bits and outputting it to the output 202 thereof. Output 202 is connected to signal line 3 as shown in the figure.
It is connected to the changeover switch circuit 18 as 6 and finally outputted to the memory 14 or the external storage device 2 which will be described later in detail via the interface circuit 16.

The pulse generation circuit 124 is controlled by the system control circuit 120 via a control line 206, and outputs a drive signal such as a clock or an address required to drive the imaging device 44 and output a video signal from its output 48. Is a synchronizing signal generating circuit for outputting to. This produces, for example, sampling pulses at frequency f _s at outputs 48 and 204. Output 204
Are connected to analog-to-digital converter 122 and timing circuit 126 as shown.

The timing circuit 126 is a control circuit that generates at its output 210 various timing signals mainly required for write control of the memory 14 or the external storage device 2, for example, write enable, chip select, and clock. It is connected to the switch circuit 18.

The operation display unit 128 has a shutter release button and various manual operation buttons such as automatic / manual setting, exposure setting, and white balance adjustment, and inputs an operator's instruction to the apparatus.
It has a function of giving this to the system control circuit 120 through the signal line 208, and has a display function of receiving a signal from the system control circuit 120 from the signal line 208 and displaying it to the operator. The display function includes, for example, the number of frames capable of capturing a subject.

The system control circuit 120 is a signal line from the operation display unit 128.
It is a control function unit that controls the operation of the entire apparatus in response to an instruction signal from 208, and is advantageously configured in a processing system. The control signal is connected to the pulse generator 124 via the control line 206 and to the imaging unit 30 via the control line 11. The system control circuit 120 also monitors the state of each part of the apparatus by these control lines 206 and 11.
The system control circuit 120 also has a function of mainly controlling writing of the external storage device 2 via the memory 14 or the interface circuit 16, and an address bus 212 for giving the write address is connected to the switch circuit 18.

The system control circuit 120 also controls the switch circuit 18, as conceptually indicated by the dotted line 34, to selectively take the connection state shown and the connection state opposite thereto. That is, the switch circuit 18 is connected to the state shown in the drawing when the digital video signal data can be stored in the memory 14. For example, when the memory 14 is full and the external storage device 2 can store the digital video signal data, the switch circuit 18 is in the opposite state to that shown in the drawing. Connected to. As a result, the digital video signal data bus 202, various control lines 210 and address bus 21
0 is connected to either the memory 14 via the signal line 38 or to the interface circuit 16 via the signal line 32. The system control circuit 120 further receives a storage capacity capable of accumulating a video signal, calculates the number of sheets from this signal, and sends a display signal of the number of frames to the operation display unit 128.

1 and 2, the switch 18 to the memory
14 inputs 31 and switch 18 to memory 22
Although the line leading to the input 50 of FIG. 2 is shown as a single line, they have a plurality of signal lines corresponding to the data bus 202, the control line 210 and the address bus 210 as shown by the signal line 36 in FIG. It includes.

The memory 14 is, for example, an SRAM semiconductor memory and is a "module" such as an integrated circuit (IC) card or a cartridge.
Is a rewritable digital storage device mounted in the form of, and a signal line 31 such as a data input / output line and a control line including an address, a read / write enable, a chip select, a strobe, a clock, etc., via a connector 17. It is connected to the signal line 38. The connector 17 may have a power supply line for the memory 14.

The interface circuit 16 is connected to the interface circuit 20 of the external storage device 2 via the connector 19 and the connection cable 8. The interface circuit 16 allows the interface circuit 20 on the external device side to handle the digital video signal received from the signal processing device 12 at the input 32 and the control signal including address, read / write enable, chip select, strobe, clock and the like. , A driver for performing signal matching and transmitting the signal from the output 60 to the latter interface circuit 20. The connection cable 8 is composed of a multi-core metallic cable suitable for transmitting a large amount of information, and may have a shield, for example.

The external storage device 2 has an interface circuit 20, and a plurality of memories 22 are detachably connected by a connector 25 of this device so that a large amount of digital video signals can be stored. The external storage device 2 functions as a memory expansion unit for the memory 14 of the main body of the camera 1, and its housing has, for example, a rectangular parallelepiped shape, and may be provided with a handle or a shoulder bag for easy carrying. Further, the structure may be such that it can be easily attached to clothes such as a belt.

The interface circuit 20 has a receiver for receiving the signal output from the camera side interface circuit 16.
When the interface circuit 20 receives a digital video signal and a control signal including an address, a read / write enable, a chip select, a strobe and a clock via the connection cable 8, the external storage device 2
It also has a circuit for selecting the memory 22 corresponding to the received address from the plurality of memories 22 mounted in the memory 22 and writing the digital video signal in the memory 22. The interface circuit 20 further informs the system control circuit 120 of the signal processing device 12 of the storage capacity of the connected memory 22.

The memory 22 may be the same as the memory 14. That is, it is a rewritable digital storage device in which an SRAM semiconductor memory is mounted in the form of a module, and is used for input / output lines of video data and signals such as control lines including address, read / write enable, chip select, strobe and clock. Line 50 is signal line through connector 25
Connected to 52. The connector 25 may have a power supply line for the memory 14.

The operation will be described. The memory 14 is attached to the camera 1 by the connector 17, the external storage device 2 is connected to the camera 1 by the connection cable 8, and the operation display unit 128 is operated to perform the photographing operation of the subject. The system control circuit 120 checks the storable capacities of the memory 14 and the external storage device 2 prior to the shooting operation, determines the number of frames that can be shot, and displays the number on the operation display unit 128. Then, for example, when nothing is stored in the memory 14, the switch circuit 18 is in the connection state shown in the figure under the control of the system control circuit 120.

When the shutter release button of the operation display unit 128 is operated, the system control circuit 120 controls the control line 11 to perform a shooting operation including opening the shutter 46 and the like. As a result, one frame of the subject image captured by the image pickup device 44 is output in the form of a dot-sequential video signal from the image pickup device 44 to the output 13 in accordance with the clock of the frequency fs given from the pulse generator 124 through the clock line 48.

The analog-to-digital converter 122 is a pulse generator 124
Is activated in accordance with the synchronizing signal generated by. That is, the analog-to-digital converter 122 is driven by the sampling pulse of the frequency fs obtained from the output 204 of the pulse generator 124. Therefore, the dot-sequential video signal is
The digital data is converted into corresponding digital data by the digital converter 122 and output from the output 202 to the switch circuit 18.

At the same time, the system control circuit 120 outputs the write address from the output 212 to the switch circuit 18. The timing circuit 126 also sends an output 210, which is a control signal such as write enable, chip select, and clock, to the switch circuit 18. At this time, since the switch circuit 18 is connected to the memory 14 side, the digital data of the output 210, the write address of the output 212 and the control signal of the output 210 are sent to the memory 14, and the sequential storage positions of the memory 14 are stored. , Video signals are written one after another. In this way, the video signal data of the pixels of one frame, that is, all the pixels of the image pickup cell array 42 is accumulated in the storage area of the memory 14.

For example, assuming that the memory 14 can store the video signal data of the image of 3 frames, the control circuit 12 switches the switch circuit 18 to the interface circuit 16 side when the storage of the image of 3 frames is completed in the memory 14. Therefore, in the image pickup for the fourth and subsequent frames, the respective signals of the outputs 202, 210 and 212 which have been sent to the memory 14 until then are sent to the interface circuit 16. Upon receiving these signals, the interface circuit 16 performs interface matching and outputs the signal 60 to the connection cable 8.

When the interface circuit 20 on the external device side receives the signal 60 via the connection cable 8, it selects one of the memories 22 connected to the connector 25 from the write address of the received signal. Then, the video signals are sequentially written to the selected storage locations of the memory 22. Thus, like the memory 14, one frame of pixels, that is, the image pickup cell array
The video signal data of all pixels of 42 are accumulated in the storage area of the memory 22. Interface circuit for shooting subsequent frames
When the memory 22 designated by the write address changes, the memory 20 selects the memory 22 corresponding thereto and writes the video signal data in the memory 22 in the same manner.

As described above, according to this embodiment, since the external storage device 2 having a large storage capacity is connected in addition to the memory 14, the memory area for writing the video signal becomes large. Therefore, the camera 1
It is possible to take many pictures in succession without having to replace the main body side memory 14 frequently.

In the present embodiment, the memory 14 is attachable / detachable to / from the camera 1, but the present invention is not limited to this.
14 may be built-in.

Further, although the connection cable 8 is a multi-core metallic cable in this embodiment, the present invention is not limited to this, and the interface circuit 16 and the interface circuit 20 may be provided with an optical signal conversion circuit to be an optical cable. Further, the electronic still camera 1 and the external storage device 2 may be connected to each other by a radio wave transmission / reception circuit in the interface circuit 16 and the interface circuit 20 without connecting them by a cable, and may transmit signals by radio waves.

Further, the memory 22 is a rewritable digital storage device in which, for example, an SRAM semiconductor memory is mounted in the form of a module, but the present invention is not limited to this. For example, a magnetic material such as a magnetic disk or a magnetic tape, or an optical reading device. It may be a storage medium that is reproducible by the device, for example, an optical disk.

Further, since a plurality of equivalent memories 22 are attached to the external storage device 2, even if the memory 22 in which the image data is written by mistake is attached, the image data is written by the system control circuit 120. It is also possible to identify that it is present and not to overwrite it.

Effect According to the present invention, the digital electronic still camera body is thus provided with the interface circuit for sending the digital video signal and the signal such as the address to the outside. Therefore, even if the storage area of the storage device mounted on the camera body is full, by transmitting the video data to the external storage device and storing the video data therein, it is possible to continuously capture many subjects.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a digital electronic still camera and an external storage device connected thereto according to the present invention, and FIG. 2 is a block showing an example of a signal processing device of the digital electronic still camera of FIG. 3 and 4 are external perspective views showing an embodiment of the present invention shown in FIG. Description of main part symbols 1 ... Digital electronic still camera 2 ... External storage device 8 ... Connection cable 12 ... Signal processing device 14, 22 ... Memory 16, 20 ... Interface circuit 18 ... Switch circuit 30 ... ... Imaging unit

Claims (5)

[Claims] 1. An image pickup device having an image pickup device, the image pickup device picking up an image of a scene and outputting a video signal representing a still image of the scene in the form of digital data, and a plurality of the image signals. A digital electronic still camera having a first connecting means for circuit-connecting a semiconductor memory in which the frames of the digital data are stored in the form of digital data, the external storage device being housed in a casing separate from the camera device. The camera has interface means for receiving digital data of a plurality of frames of the video signal, converting the received digital data into a signal format that can be handled by the external storage device, and outputting the interface means; and an output of the interface means. A second connecting means for connecting the external storage device, and a disconnecting means for selectively connecting the image pickup means to either the first connecting means or the interface means. And an image capturing unit that controls the image capturing unit to capture an image,
Control means for controlling connection of the switching means, the control means connecting the imaging means to the interface means side by the switching means when the semiconductor memory becomes full, and the external storage from the imaging means. A digital electronic still camera, characterized in that the video signal is stored in a device in the form of digital data. 2. The camera according to claim 1, wherein the interface means further includes means for receiving information indicating a storage capacity of the external storage device from the external storage device, and the control means further includes A digital electronic still camera, characterized in that it receives information indicating a storage capacity of an external storage device from the interface means and controls accumulation of digital data of the video signal in the external storage device based on the information. 3. The digital electronic still camera according to claim 1, wherein the second connecting means connects the external storage device with a cable. 4. A first semiconductor memory is detachably connected to the first semiconductor memory, and a plurality of predetermined frames of a video signal representing a still image of the object scene are captured in the form of digital data in the first semiconductor. In an external storage device used in a digital electronic still camera for storing in a memory, the device includes second semiconductor memory means for storing a plurality of predetermined frames of the video signal in the form of digital data, and the second semiconductor memory means. Is connected to the semiconductor memory means, receives the video signal and a control signal for storing the video signal in the second semiconductor memory means from the camera,
A receiving means for notifying the camera of a storage capacity that can be stored in the second semiconductor memory means, and the received video signal is stored in the second semiconductor memory means according to a control signal received by the receiving means. An external storage device characterized by the above. 5. The external storage device according to claim 4, wherein the second semiconductor memory means is detachably attached to the second semiconductor memory.