JP2870773B2 - Electronic still camera - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic still camera provided with an image memory for temporarily storing a plurality of captured images.

[Related Art and Problems to be Solved] In recent years, electronic still cameras have been put to practical use. This electronic still camera is very convenient because it can be immediately reproduced and displayed on a monitor or a TV screen or the like without developing even immediately after shooting.

Therefore, in general, the camera has a full auto function,
Exposure and shutter speeds are now properly determined, but it's hard to tell if they're really the best unless you take a picture. For example, the reflected light, the background, or the like may result in poor image quality than expected.

In recent years, film cameras have been proposed in which a single shutter changes the shutter speed, exposure, and the like to shoot a plurality of images. However, this is because all the shot images are printed on a film. Yes, waste of film increases.

The present invention has been made in view of the above-described circumstances, and provides an electronic still camera that can shoot under various shooting conditions with a single shutter operation and that can select and record the best one among them. Aim.

Means for Solving the Problems The present invention comprises an image memory capable of storing a plurality of photographed images, and continuously performs photographing while changing photographing conditions when a shutter is pressed, and stores the photographed images in the image memory. After the photographing of a certain number of images is completed, the image stored in the image memory is displayed on a monitor, and as a result, the selected photographed image is recorded on a recording medium.

[Operation] With the above-described configuration, a plurality of photographs are photographed under different photographing conditions by one shutter operation and stored in the image memory. The plurality of captured images stored in the image memory are read in response to key operations and displayed on a monitor. Therefore, the image content is confirmed on the monitor display, and an arbitrary image is selected and designated from the image content, and the selected image is recorded on the recording medium.

For this reason, the photographer can select the best image from a plurality of images photographed under different photographing conditions and record it on the recording medium.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the overall circuit configuration. In FIG. 1, reference numeral 10 denotes an optical system, which includes a lens 11, a shutter 12, an image pickup device 13 such as a CCD, and the like, and focus, exposure, and the like are automatically adjusted by an autofocus mechanism and an EE mechanism. Reference numeral 14 denotes a shutter control circuit. The shutter control circuit 14 controls the shutter 12 according to the operation of the shutter button 15. The above shutter button
15 is a shutter control circuit 14 by signal lines 16a and 16b.
When the shutter button 15 is touched by a finger (lightly pressed), a touch signal is sent to the shutter control circuit 14 via the signal line 16a, and when the shutter button 15 is pressed, the signal is sent via the signal line 16b. ON signal to shutter control circuit 1
Output to 4. The shutter control circuit 14 enters a standby mode when a touch signal is transmitted from the shutter button 15, and determines focus and exposure by an auto focus and EE mechanism.
Make 12 work.

Then, with the operation of the shutter 12, an image of the subject is projected on the surface of the image sensor 13 via the lens 11 and the shutter 12, and a signal for the projected image from the image sensor 13, that is, a photographing signal is sent to the signal processing circuit 17. Sent. The signal processing circuit 17 processes the photographing signal to create a luminance signal Y and color difference signals RY and BY, and outputs them to the display control circuit 18 via the signal line a. The signal output from the signal processing circuit 17 is sent to the modulation circuit 19 via the switch SW1, and is sent to the A / D conversion circuit 21 via the switch SW2. The switches SW1 and SW2 are on / off controlled by switch signals S1 and S2 from the control circuit 24. A / D above
The conversion circuit 21 converts the luminance signal Y and the color difference signals RY and BY sent from the signal processing circuit 17 into digital data, respectively, and outputs the digital data to an image memory, for example, a semiconductor memory 22. The semiconductor memory 22 has a capacity capable of storing a plurality of images, for example, nine images. The image data sent from the A / D conversion circuit 21 is sequentially stored in the semiconductor memory 22 under the control of the memory control circuit 23. The memory control circuit 23 is supplied with a control signal from the control circuit 24 and a shutter signal from the shutter control circuit 14. The memory control circuit 23
Controls writing of image data to the semiconductor memory 22 when an ON signal of the shutter button 15 is given from the shutter control circuit 14 in the photographing mode.

On the other hand, the memory control circuit 23 reads an image stored in the semiconductor memory 22 in response to a control command from the control circuit 24, and inputs the read image to the D / A conversion circuit 25. The image read from the semiconductor memory 22 is converted into an analog signal by the D / A conversion circuit 25, sent to the display control circuit 18 via the signal line b, and controlled on / off by the switch signal S3 of the control circuit 24. Is input to the modulation circuit 19 through the switch SW3.
The modulation circuit 19 modulates a signal supplied from the signal processing circuit 17 via the switch SW1 or a signal supplied from the D / A conversion circuit 25 via the switch SW3, and
Output to The recording circuit 26 records a signal sent from the modulation circuit 19 on an image recording medium, for example, a floppy disk 28 via a recording head 27a. The floppy disk 28 can store, for example, about 50 images.

The image recorded on the floppy disk 28 is reproduced by a reproducing head 27b (generally, a recording head 27a) in a reproducing mode.
Read out by the demodulation circuit via the reproduction circuit 31
Sent to 32. The demodulation circuit 32 demodulates the reproduced signal and inputs the demodulated signal to the encoder 33, where the original luminance signal Y and color difference signal R
It returns to -Y and BY and outputs it to the display control circuit 18. The display control circuit 18 is connected to signal lines a, b, and c.
An image signal of the system is selected in accordance with an instruction from the control circuit 24, output to a monitor 34 such as a CRT, and displayed. This monitor 3
4 is located at the finder site.

The control circuit 24 is supplied with a shutter ON signal from the shutter control circuit 14 and a key input unit 35.
Is connected. The key input unit 35 includes a photographing mode switching key for switching between a normal photographing mode and a correction photographing mode for photographing a plurality of images by changing photographing conditions by one shutter operation, and operations such as a photographing mode and a reproduction mode. There are provided an operation mode designating key for designating a mode, and various operation keys such as a forward key and a back key for moving the read address of the semiconductor memory 22 or the floppy disk 28 forward and backward according to the operation mode. The control circuit 24 includes a key input signal from a key input unit 35, a shutter control circuit 14,
The switches SW1, SW2, and SW3 are controlled to be turned on / off in response to a shutter signal from the CPU, and control commands are given to the memory control circuit 23, the display control circuit 18, and other circuits.

Next, the operation of the above embodiment will be described. When taking a picture, the photographing mode is designated by operating the key of the key input unit 35, and the normal photographing mode or the corrected photographing mode is arbitrarily switched and designated. Hereinafter, the operation when the corrected shooting mode is designated will be described with reference to the flowchart of FIG. When the correction shooting mode is designated, the control circuit 24 outputs a correction shooting mode signal to the shutter control circuit 14 and the memory control circuit 23, and switches SW1 and SW
2. Turn off SW3 and instruct the display control circuit 18 to select the signal line a. In this state, when the photographer lightly presses the finger on the shutter button 15 (step A1), a touch signal is sent to the shutter control circuit 14 via the signal line 16a. When the touch signal is sent, the shutter control circuit 14 enters the standby mode, determines focus and exposure by the autofocus mechanism and the EE mechanism, and operates the shutter 12 every 1/60 second (step A2). As a result, an image of the subject is projected on the surface of the image sensor 13 via the lens 11 and the shutter 12, and a luminance signal Y and color difference signals RY and BY corresponding to the projected image are output from the image sensor 13, and the signal It is sent to the display control circuit 18 via the line a. The display control circuit 18 selects a signal transmitted through the signal line a in accordance with an instruction from the control circuit 24, and displays the selected signal on the monitor 34.
With this monitor display, the photographer can check the state of the subject and can operate the shutter.

Then, when the photographer presses the shutter button 15 (step
A3), an ON signal is sent to the shutter control circuit 14 via the signal line 16b. When an ON signal is given, the shutter control circuit 14 outputs the ON signal to the memory control circuit 23 and the control circuit 24, and first, as shown in FIG. Photographing is performed, and then a plurality of images are photographed by changing the shutter speed and the exposure back and forth around the set values, respectively (step A4). The above FIG.
This shows the relationship between the shutter speed and exposure during shooting.
The speed is changed to three steps of "speed" and "+1 speed", and the exposure is changed to "set exposure", "-1 step", and "+1 step" at each shutter speed. By changing the shutter speed and the exposure as described above, nine photographs under different photographing conditions are photographed.

On the other hand, the control circuit 24 keeps the switch SW2 in the ON state while the above-described photographing processing is being performed. Therefore, the luminance signal Y and the chrominance signals RY and BY output from the signal processing circuit 17 by the above photographing process are switched by the switch SW2
And is input to the A / D conversion circuit 21 via the. And converted into digital data. The nine image data output from the A / D conversion circuit 21 are sequentially written into the semiconductor memory 22 under the control of the memory control circuit 23.

When the writing of the image data to the semiconductor memory 22 is completed, the control circuit 24 turns off the switch SW2 and instructs the memory control circuit 23 to read the image data stored in the semiconductor memory 22. 18 is instructed to select the signal line b. The above memory control circuit
23 reads out the image of the head address from the semiconductor memory 22 according to the instruction of the control circuit 24, that is, the image captured at the reference shutter speed and exposure, outputs it to the display control circuit 18 via the signal line b, indicate. By operating the forward key of the key input unit 35 in this state, the captured images stored in the semiconductor memory 22 are sequentially read under the control of the memory control circuit 23, and the display control circuit 18
Is displayed on the monitor 34 via the. The photographer is
The best image is selected by operating the forward key or the back key from among the nine images stored in the semiconductor memory 22, that is, the best image is displayed on the monitor 34. Operate the record key in the state. When the recording key is operated, the control circuit 24 turns on the switch SW3 for a certain period of time, and outputs an image read from the semiconductor memory 22 via the D / A conversion circuit 25 to the modulation circuit 19.
The modulation circuit 19 modulates the image signal sent from the D / A conversion circuit 25 and outputs the modulated image signal to the recording circuit 26, and the recording head 27a
On the floppy disk 28. Photographing in the corrected photographing mode is performed as described above. In this corrected photographing mode, a plurality of images are photographed by one shutter operation, so that photographing using a tripod is preferable.

When the normal shooting mode is designated, every time the shutter button 15 is operated, the switch SW1 is turned on for a certain period of time, and the image signal output from the signal processing circuit 17 is modulated by the modulation circuit.
It is sent to 19 and is recorded on the floppy disk 28 by the recording circuit 26 via the recording head 27a.

If the user wants to reproduce the image recorded on the floppy disk 28, the user designates the reproduction mode. Control circuit
When the playback mode is specified, the playback control circuit 18 instructs the display control circuit 18 to select the signal line c, and plays the first image recorded on the floppy disk 28 by the playback head.
After being read by 27b and amplified by the reproduction circuit 31, it is input to the demodulation circuit 32 to perform a demodulation operation. This demodulation circuit
The signal demodulated by 32 is input to the encoder 33 and returned to the original luminance signal Y and color difference signals RY and BY, and is sent to the display control circuit 18 via the signal line c. The display control circuit 18 selects an image signal sent from the encoder 33 in accordance with an instruction from the control circuit 24 and displays the image signal on the monitor 34. By operating the forward key in this state, the recorded images on the floppy disk 28 are sequentially read out and displayed on the monitor 34.

In the above embodiment, the shutter 12 is controlled every 1/60 second, but it is a matter of course that the shutter 12 may be set to another value.

Further, in the above-described embodiment, the case where the semiconductor memory 22 is used as the image memory has been described. Alternatively, for example, a magnetic tape, a floppy disk, or the like may be used.

Further, in the above-described embodiment, the captured image signal is recorded on the floppy disk 28. However, instead of the floppy disk, the image signal may be converted into an analog signal by the D / A conversion circuit 25 and then printed on a film. .

[Effects of the Invention] As described in detail above, according to the present invention, when the shutter is pressed once, a plurality of pictures are taken under different shooting conditions and stored in the image memory. The stored image can be checked on the monitor, and the best image can be selected and recorded on the recording medium. Therefore, even when a photograph is taken using the fully automatic mechanism, the best photograph can always be taken, and the recording medium such as a film is not wasted.

[Brief description of the drawings]

1 shows an embodiment of the present invention, FIG. 1 is a block diagram showing the overall circuit configuration, FIG. 2 is a flowchart for explaining a photographing operation, and FIG. 3 is a shutter speed and exposure during photographing. FIG. 10 ... Optical system, 11 ... Lens, 12 ... Shutter, 13 ...
... Imaging element, 14 ... Shutter control circuit, 15 ... Shutter button, 16a, 16b ... Signal line, 17 ... Signal processing circuit, 18 ... Display control circuit, 19 ... Modulation circuit, 21 ... A / D
Conversion circuit, 22 semiconductor memory, 23 memory control circuit, 24 control circuit, 25 D / A conversion circuit, 26 recording circuit, 27a recording head, 27b reproduction head, 28 ......
Floppy disk, 31 playback circuit, 32 demodulation circuit, 33 encoder, 34 monitor, 35 key input unit, SW1 to SW3 switches.

Claims (1)

(57) [Claims] 1. An electronic still camera, comprising: an image memory for temporarily storing a plurality of images; a photographing control means for photographing a plurality of images by changing photographing conditions when a shutter is operated; Storage means for sequentially storing photographed images in the image memory; display means for reading out the images stored in the image memory and displaying them on a monitor; recording an image selected and designated from the images displayed on the monitor An electronic still camera comprising: an image recording medium;