JPS60177330A - Hand-shake detector of camera - Google Patents

Abstract

PURPOSE:To detect a camera hand-shake and to warn it by sampling and processing the output signal of a CCD line sensor. CONSTITUTION:Pieces of information on the shutter speed and aperture value at the point I of time when a shutter button is pressed and set are sent from a terminal 7 to a driving circuit 2 to determine the optimum storage time of the CCD line sensor 1. The circuit 2 drives the sensor 1 to sends an output picture signal A to a signal processing circuit 3. A signal processing circuit 8 decides on a threshold value L by inputting the pieces of information on the shutter speed and aperture value from the terminal 7, and sends the threshold value to the circuit 3. The circuit 3 samples part of the signal A above the threshold value L to obtain a signal B. The output picture signal C of the sensor 1 at a point II of time determined after the point I of time is transmitted to the circuit 3 and sampled on the basis of the threshold value L stored in the circuit 3 to obtain a signal B. The shifting extent of the signal D when the correlation calculated from the signals B and D is maximum corresponds to the picture blur amount generated between the points I and II of time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a camera shake detection device for detecting camera shake during photographing of a camera, particularly a still camera.

Some conventional still cameras display a camera shake warning when shooting at a shutter speed slower than a certain shutter speed, but this is simply a mechanical warning. Therefore, it was not possible to determine whether or not there was actual camera shake. Also, when shooting at a relatively fast shutter speed, there is no camera shake warning, and even if there is actual camera shake, the I7! Since the person in the shadow did not notice this, they did not take the shot again, often resulting in failures due to camera shake.

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and provide a camera shake detection device that detects whether or not there is camera shake during shooting and notifies the photographer immediately after shooting. The gist is that the C is placed at a position Iζ that is optically equivalent to the film surface, and outputs image signals at different times set by I7 in response to the movement of pressing the shanks.
A CD line sensor, a circuit that determines a threshold value based on information on shutter speed and aperture value, and a circuit that samples the two image signals using the threshold value and calculates the correlation between the two sampling signals to determine the difference between the different points in time. The present invention is characterized in that it includes a circuit for calculating image blurring.

The present invention will be explained in detail below based on illustrated embodiments.

FIG. 1 shows an embodiment of a camera shake detection device according to the present invention, in which an optical system is used. A CCD line sensor 1 that receives a subject image, a CCD drive circuit 2, and a CCD line sensor 1.
A first signal processing circuit 3 that performs sampling processing on the output image signal and performs a correlation calculation, and determines the magnitude relationship between the image blurring based on the correlation calculated by the first signal processing circuit 3 and the set blurring E. and a drive circuit 5 which displays a warning to the photographer when the image blur is larger than the set blur tolerance E based on the output from the judgment circuit 4.
, a light emitting diode 6 operated by this drive circuit 5, a second signal processing circuit 8 which inputs information on the camera's shutter speed and aperture value from a terminal 7 and determines the threshold value, and an enlargement magnification when printing from negative film. The third signal processing circuit 10 inputs the information from the terminal 9 to determine the set blur amount E before photographing. The terminal 7 is also connected to the drive circuit 2, and information on the shutter speed and aperture is obtained from the terminal 7 to determine the optimum accumulation time for the CCD line sensor 1.

FIG. 2 shows the output image signal from the CCD line sensor 1 and its sampling signal, and the signals (A),
(C) is the output image signal at the first time point and the second time point, respectively, signal (s), and (D) are the signal (
Figure 3 shows the optical system of a single-lens reflex camera that performs this shake detection, and the photographic lens The light entering 11 passes through a quick return mirror 12, is reflected by a reflection mirror 13 provided on the back of the Fink return mirror 12, and is guided to a CCD line sensor 1 provided at the bottom of the camera box. It has become so.

The part of the quick return mirror 12 that passes light to the reflection mirror 13 is a half mirror with a transmittance of about 50%, and the remaining part is a complete reflection mirror. Further, 14 indicates a film, and 15 indicates a pentaprism.

Although a plurality of CCD line sensors 1 are used, FIG. 4 shows an example of the arrangement when two CCDCC line sensors 1b are used, and FIG. 5 shows three CCD line sensors 1a, 11], an example of the arrangement when using 1c is shown in 1. I'm here.

The operating principle of this embodiment will be explained below. When photographing a subject, press the camera f) shutter button to set the first time point, and information on the shutter speed and aperture value at this first time point is sent from the terminal 7 to the drive circuit 2, as described above. to CCD
The optimum storage time for the line sensor 1 is determined. Then, the CCD line sensor 1 is driven by the drive circuit 2, and its output image signal, that is, the signal (A) shown in FIG. 2 is sent to the first signal processing circuit 3. Second signal processing circuit 8
In this case, information on the shutter speed and the aperture ratio is inputted through the ☆Hjli element 7 to determine the threshold value. If the accumulation time of the CCD line sensor 1, that is, the time determined by the shutter speed and aperture value information, is long, the output signal of the CCD line sensor 1 will also become an averaged image signal, increasing the number of data required for calculation. It is necessary to set the threshold value to a small value. This threshold value is determined to be approximately 50 to 80% of the maximum level of the output signal of the CCD line sensor 1. The signal is sent to the first signal processing circuit 3, which samples the signal (A) above the threshold value and generates the sampling signal (B) shown in FIG.
is obtained.

If the second time point is set after the first time point, the image blurring between the first and second time points will be measured. The processing of the signal at the second time point is similar to that at the first time point, but
The output image signal (C) shown in FIG. 2 of the CCD line sensor l at this second time point is transmitted to the first signal processing circuit 3, and the signal processing circuit 3 stores the 1! When sampling is performed by ξ1 value, the sampling signal (,0) shown in FIG. 2 is leaked.

The sampling signal (B) obtained in this way,
According to (D), the amount of correlation is calculated using the correlation function shown in the following equation. That is, the correlation amount is S(,x), k is the pixel number of the CCD line sensor, B(k), D(k) are the sampling signals (B), The shift amount is expressed as follows.

5(X)=Σ-[3(k)-D(k,x)where x
=0, ±1, ±2,...φHere, D(k,0) is D
(k), and D(k,l) has D(k) overall 1
It represents a signal shifted by a pixel. Further, the sign of X indicates the shift direction, and minus indicates the opposite direction to plus.

The shift amount X of the signal (D) when the correlation amount 5(X) becomes the maximum corresponds to the amount of image blur that occurs between the first time point and the second time point. The determination circuit 4 compares the magnitude relationship between the image blur amount calculated in the first signal processing circuit 3 and the set blur amount E, and the image blur amount is determined by the set blur amount (i:
If the value exceeds E, the drive circuit 5 turns on the light emitting diode 6 to warn the photographer.

The set amount of blur E corresponds to the allowable blur when the negative film is flat, and this allowable amount of blur changes depending on the enlargement magnification from the negative film to the print. for example,
If the allowable amount of blur on the negative film surface for a service version print is 75 gm, then the allowable amount of blur on the negative film surface F for a cabinet version print, which is about twice that amount, is 37 gm, and the allowable amount of blur is 75 gm. It varies depending on the enlargement magnification for printing. Therefore, the setting blur E is determined by inputting information on the enlargement magnification when printing from a negative film to the third signal processing circuit 10 via the terminal 9 before shooting, and inputting the information to the determination circuit 4 in advance. being sent. Note that this information on the enlargement magnification can be obtained by the photographer operating a switch provided on the outside of the camera, for example, before photographing.

For example, the amount of image blur obtained by the first processing circuit 3
It will be seen in each direction of the CCD line sensors 1a and 1b in the figure. Of course, if one CCD line sensor l is used,
If it is known in advance that the amount of image blurring is particularly large in the direction in which the shank is pushed, for example, it may be arranged only in that direction. Furthermore, if three CCD line sensors 1 are used as shown in FIG. 5, 7111 amounts of image blur can be determined in three directions.

Furthermore, although the above embodiment is an example in which the amount of image blur between the first and second time points is measured, image signals from the CCD line sensor 1 at the third and fourth time points in addition to the second time point are measured. By reading the image and calculating the amount of image blur between the first and third and the first and fourth time points, it is possible to measure the amount of image blur as a function of time. Further, although the set blur amount E is determined by the enlargement magnification, it may be set to a constant value in consideration of the enlargement of the normal service version print.

The CCD line sensor 1 is not limited to the position shown in FIG. 3, but can form an image using a lens at any other position as long as the distance is optically equal to the film surface. Furthermore, the CCD line sensor 1 can be placed outside together with other lenses without using the photographing lens 11. In addition, although a light emitting diode was used in the embodiment as a warning display means for camera shake, in addition to this lighting warning,
It is also possible to give a warning by sound, text, etc.

As explained above, the camera shake detection device according to the present invention
According to No. 6, by sampling and processing the output signal of the CCD line sensor, it is possible to detect camera shake through quick calculation and warn the photographer.
■If there is camera movement, the person in the darkest position can use the warning to accurately target the shooting and recover from failures caused by camera shake. Furthermore, it is also possible to store the direction and components of camera shake in a memory and effectively utilize the information, for example, when performing blur correction after detecting image blur.

[Brief explanation of drawings]

The drawings show an embodiment of the camera shake detection device according to the present invention, and FIG. 1 is a block circuit diagram thereof, and FIG.
The figure is a waveform diagram of the output signal from the CCD line sensor and its sampling gain stage number, Figure 3 is an optical system diagram of an example of the arrangement of CCD line sensors in a camera, and Figures 4 and 5 are the arrangement of multiple CCD line sensors. It is an explanatory diagram of an example. Symbols 1.1a, ■b, and 1c are CCD line sensors, 2 is a drive circuit, 3.8.10 is a signal processing circuit, 4 is a determination circuit, 5 is a drive circuit, 6 is a light emitting diode, 11 is a photographing lens, 12 is a quick return mirror, and 13 is a reflection mirror. Patent applicant: Canon Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. A CCD line sensor that is arranged at a position optically equivalent to the film surface and outputs image signals at different times set in response to the action of pressing the shirt button, and a shutter button. A circuit that determines a threshold value based on information on speed and aperture value, and samples the two image signals using the threshold value, and calculates the amount of image blur between the different time points by calculating the amount of correlation between these sampling signals. A camera shake detection device comprising a circuit. 2. The camera shake detection device according to claim 1, wherein the image blur amount is the shift height of the image signals when the correlation amount is maximum. 3. The camera shake detection device according to claim 1, wherein the integration time of the CCD line sensor is determined based on information on shutter speed and aperture value. 4. The camera shake detection device according to claim 1, further comprising means for displaying a warning to the photographer when the calculated image blur amount exceeds a set shake amount. 5. The camera shake detection device according to claim 4, wherein the set shake amount is determined based on information on an enlargement magnification when printing from a negative film. 6. The camera shake detection device according to claim 1, wherein the CCD line sensor is arranged in a plurality of directions, and the amount of image blur in the plurality of directions is detected.