JP2870772B2 - 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.

However, when taking a picture with a camera, if you are not an amateur, you are not used to it, so the camera may shake when you operate the shutter or the subject may move due to the movement of the subject, so if you can always take good pictures Not necessarily. If you notice that the camera has shaken or the subject has moved during shooting, you can take it again, but usually you will notice it after seeing the picture, so it is impossible to take it again. It is also conceivable to physically detect the shaking of the camera body and issue a blur warning, but in that case, it is not possible to detect when the model has moved.

The present invention has been made in view of the above-described circumstances, and an electronic still camera which detects a state of a blur when a photographed image is taken when a photograph is taken, and warns the photographer of the occurrence of the blur with a buzzer or the like. The purpose is to provide.

Means for Solving the Problems The present invention relates to an electronic still camera, comprising: an imaging unit that captures an image of a subject and outputs a captured image; a storage unit that stores the captured image when a shutter is operated; Acquisition means for acquiring the photographed image and the photographed image before and after the shutter operation, and comparison means for comparing the photographed image at the time of the shutter operation and the photographed image before and after the shutter operation acquired by the acquisition means, It is characterized by comprising detecting means for detecting camera shake based on the result of comparison by the comparing means, and warning means for issuing a warning when camera shake is detected by the detecting means.

[Operation] With the above configuration, when a photograph is taken by pressing the shutter, it is automatically determined whether or not the captured image is blurred, and a warning is immediately issued if blurred. For this reason, the photographer can immediately know whether or not blurring has occurred when a picture is taken, and can take measures such as taking a picture again as necessary.

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 a human finger touches the shutter button 15 (when 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. To output an ON signal to the shutter control circuit 14. The shutter control circuit 14 enters a standby mode when a touch signal is sent from the shutter button 15, adjusts focus and exposure by an auto focus and EE mechanism, and starts shooting according to the shooting mode at that time, for example, 1 / Activate shutter 12 at 60 second intervals.

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, an image signal is sent to the signal processing circuit 17. Sent. The signal processing circuit 17 processes the image pickup signal to generate 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, 21 images, and is provided with a flag area 22b corresponding to the image storage area 22a as shown in FIG. The A / D is stored in the semiconductor memory 22.
The image data sent from the conversion circuit 21 is sequentially stored under the control of the memory control circuit 23. When the image data for 21 sheets is stored, the first stored image data is sequentially rewritten with new image data. 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 starts image data writing control to the semiconductor memory 22 when a touch signal of the shutter button 15 is given from the shutter control circuit 14 in the shooting mode, and thereafter, when an ON signal of the shutter button 15 is given. Then, the shutter flag F is set in the flag area 22b corresponding to the image stored in the semiconductor memory 22 at that time, and thereafter, the writing control of the image in the semiconductor memory 22 is continued for one second. Then, the semiconductor memory 22
Are read out to the CPU 20 by the memory control circuit 23. The CPU 20 compares the image for which the shutter flag F is set with an image in the vicinity of the shutter flag F to determine the “motion degree” between the images. Based on the value of the “motion degree”, whether the captured image is blurred It is determined whether or not. Then, when detecting the occurrence of the blur, the CPU 20 drives the buzzer BZ for a predetermined time to warn the photographer of the occurrence of the blur.

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 turned on / off by the switch signal S3 from the control circuit 24. The signal is input to the modulation circuit 19 via the controlled switch SW3. The modulation circuit 19 is provided with a switch SW from the signal processing circuit 17.
The modulation circuit 2 modulates a signal supplied through the switch 1 or a signal supplied from the D / A conversion circuit 25 through the switch SW3.
Output to 6. 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 read by the reproducing head 27b in the reproducing mode, and sent to the demodulating circuit 32 via the reproducing circuit 31. This demodulation circuit 32
Demodulates the reproduced signal, inputs the demodulated signal to the encoder 33, returns the original luminance signal Y and color difference signals RY and BY to the display control circuit 18. The display control circuit 18 includes a signal line a,
The three image signals input by b and c are selected in accordance with an instruction from the control circuit 24, and output to a monitor 34 such as a CRT for display. This monitor 34 is arranged 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 an operation mode designation key for designating an operation mode such as a photographing mode and a reproduction mode, a forward key and a back key for moving a read address of the semiconductor memory 22 or the floppy disk 28 forward and backward according to the operation mode. Various operation keys are provided. The control circuit 24 controls on / off of the switches SW1, SW2, and SW3 according to a key input signal from the key input unit 35 and a shutter signal from the shutter control circuit 14,
A control command is 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 with reference to the flowchart of FIG. When taking a picture, the photographing mode is designated by the operation mode designation key provided on the key input unit 35. When this shooting mode is designated, the control circuit 24 outputs a shooting mode signal to the memory control circuit 23, turns off the switches SW1 and SW3, turns on the switch SW2, and further connects the signal line a to the display control circuit 18. Instruct the user to make a selection. In this state, if the photographer touches the shutter button 15 lightly with his finger (step A1), a touch signal is sent to the shutter control circuit 14 via the signal line 16a. When a touch signal is sent, the shutter control circuit 14 enters a standby mode, focuses and exposures by the auto focus mechanism and the EE mechanism, and operates the shutter 12 every 1/60 second to start a shooting operation ( 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. Further, the image signal output from the signal processing circuit 17 is
The signal is input to the A / D conversion circuit 21 via the SW2, converted into a digital signal, and input to the semiconductor memory 22. At this time, the shutter control circuit 14 sends the shutter button to the memory control circuit 23.
Fifteen touch signals are given to the memory control circuit 23. The memory control circuit 23, while the touch signal is given,
The image data output from the A / D conversion circuit 21 is sequentially written into the semiconductor memory 22. When the writing of the 21 images is completed, the image data written first is rewritten to new image data in order.

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. Upon receiving the ON signal, the shutter control circuit 14 outputs the ON signal to the memory control circuit 23 and the control circuit 24, and continues the shutter control operation for one second thereafter. The memory control circuit 23
When the shutter ON signal is sent from the shutter control circuit 14, the 1/60 second captured image recorded in the semiconductor memory 22 at that time is stored in the corresponding flag area 22b as shown in FIG. The shutter flag F is set (step A4), and thereafter, the semiconductor memory 22 is set for one second.
The writing of the captured image with respect to is continued at predetermined intervals (step A5). Then, for example, when the shutter button 15 is pressed, ten images are stored in the semiconductor memory 22 after ten shutter operations before the shutter operation.

On the other hand, when the shutter ON signal is given from the shutter control circuit 14, the control circuit 24
Is held in the ON state for 1/60 second, and the luminance signal Y and the color difference signals RY and BY for the captured image when the shutter is ON, which are output from the signal processing circuit 17, are transferred to the modulation circuit 19.
The modulation circuit 19 modulates the image signal sent from the signal processing circuit 17 and outputs the modulated image signal to the recording circuit 26.
To record on the floppy disk 28 (step A
6).

Thus, the memory control circuit 23
When the writing of the photographed image into the CPU is completed, the image with the shutter flag F set and several images before and after the image are read from the semiconductor memory 22 and output to the CPU 20. This CPU20
As shown in FIG. 4, the image in which the shutter flag F is set is compared with the images before and after the shutter flag F, and a "motion degree" between the images is obtained by detecting a motion vector (step A7). The degree of motion is compared with a preset value to determine whether or not the captured image is blurred (step A8). Various methods of detecting the “motion degree” are known, and a program for that may be incorporated in the CPU 20. For example, “NEC Corporation C & C System Research Laboratories”
Are well known, such as "Toukata Kenshi CS81-87" and "Motion Compensation Inter-Frame Coding of Conference Television Signals", issued in July 1981. For example, a moving image research method described in the specification of Japanese Patent Application No. 63-43497 by the present applicant may be used. Numerical values such as “2” and “3” in FIG. 4 indicate the relative magnitude of “motion degree”. Then, for example, if the degree of movement is “3” or more, it is considered that there is blurring.

Therefore, the CPU 20 determines whether or not the captured image when the shutter is turned on is blurred based on the principle described above, and if blurred, drives the buzzer BZ for a fixed time to warn the photographer. I do.

By giving the above warning, the photographer can immediately retake the photograph.

Alternatively, for example, the images stored in the semiconductor memory 22 may be sequentially read out by operating the forward key or the back key, displayed on the monitor 34, and an arbitrary image may be selected and recorded on the floppy disk 28. Alternatively, the CPU 20 may select the best image with the least blur from the images stored in the semiconductor memory 22 and record the selected image on the floppy disk 28.

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 of 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, the present invention can be applied to a normal film camera by incorporating a circuit similar to that of the present embodiment into a finder system, for example. Therefore, the “electronic still camera” in the present invention includes an electronically controlled film camera.

According to the present invention, a warning is issued when a moving object such as a car is photographed. In this case, the warning may be ignored or an on / off mode of a blur detection function may be provided.

[Effects of the Invention] As described in detail above, according to the present invention, it is determined whether or not blur has occurred when a picture is taken by pressing a shutter, and a warning is issued when blur has occurred. So
Immediately on the spot, appropriate measures such as re-examination of photos can be taken. Therefore, a photograph can be taken with confidence without worrying about blurring.

[Brief description of the drawings]

1 shows an embodiment of the present invention. FIG. 1 is a block diagram showing an entire circuit configuration, FIG. 2 is a diagram showing a storage configuration of a semiconductor memory in FIG. 1, and FIG. FIG. 4 is a flow chart for explaining the operation, and FIG. 4 is a diagram for explaining the operation when the image with the least blur is selected from the images stored in the semiconductor memory. 10 ... Optical system, 11 ... Lens, 12 ... Shutter, 13 ...
... Imaging device, 14 ... Shutter control circuit, 15 ... Shutter button, 16a, 16b ... Signal line, 17 ... Signal processing circuit, 18 ... Display control circuit, 19 ... Modulation circuit, 20 ... CP
U, 21 A / D conversion circuit, 22 Semiconductor memory, 23 Memory control circuit, 24 Control circuit, 25 D / A conversion circuit, 2
6 Recording circuit 27a Recording head 27b Reproduction head 28 Floppy disk 31 Reproduction circuit 32
... demodulation circuit, 33 ... encoder, 34 ... monitor, 35 ...
Key input section, SW1 to SW3 ... switch, BZ ... buzzer.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04N 5/225

Claims (1)

(57) [Claims] 1. An imaging means for photographing a subject and outputting a photographed image, a storage means for storing the photographed image when a shutter is operated, the photographed image when the shutter is operated, and the photographed image before and after the shutter operation. Acquiring means for acquiring the image, a comparing means for comparing the photographed image at the time of the shutter operation acquired by the acquiring means with the photographed images before and after the shutter operation, and a detecting means for detecting camera shake based on the comparison result by the comparing means An electronic still camera, comprising: warning means for issuing a warning when a camera shake is detected by the detection means.