JPH0731352B2 - Image blur detection device on camera screen - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image blur detection device on a screen of a camera for detecting image blur on the screen of the camera.

(Prior Art) When a subject with low brightness is shot with a camera, the shutter speed slows down, causing camera shake. Therefore, if the shutter speed is below a certain level, camera shake is detected. It is detected and displayed by the device to alert the user of the camera.

A conventional camera shake detection device has been designed to detect the camera shake based on the brightness information of a subject using an automatic exposure control device. However, even with a shutter speed that does not cause camera shake for a normal subject, a subject image may flow on the camera screen for a fast-moving subject, and a situation substantially similar to camera shake may occur, The conventional camera shake detection device cannot detect such a case. Here, camera shake is referred to as image blur on the screen of the camera, and this image blur on the screen of the camera means that the subject image flows on the fast-moving subject on the screen of the camera, and the camera shake is substantially This includes cases where similar situations occur.

Further, the limit of the shutter speed that causes the image blur on the screen of the camera varies depending on the skill level of the user of the camera, but in the conventional camera shake detection device, the image blur on the screen of the camera according to the skill level of the user. Cannot be detected.

(Purpose) The present invention solves the above problems, and as an image blur on the screen of the camera, not only camera shake of the camera but also a subject image flowing on a fast-moving subject substantially flows on the camera screen. (EN) An image blur detection device on a screen of a camera capable of detecting a situation similar to camera shake and capable of detecting image blur on the screen of a camera according to the skill of a camera user. With the goal.

(Structure) In order to achieve the above object, the present invention uses a first light receiving unit group 11 for photoelectrically converting a subject image by one optical system as shown in FIG. 1, and a subject image by another optical system by photoelectric conversion. The second light receiving unit group 12 that performs the second light receiving unit group 12 and the first light receiving unit group 12.
Monitor light receiving unit 13 provided near the light receiving unit group 11 for photoelectrically converting the average luminance of the subject image, and a first light receiving unit 13 for clearing the monitor light receiving unit 13 and the first light receiving unit group 11 to a constant level. The first clear pulse generating means 14 for generating the first clear pulse, and the second light receiving unit group 12 after a predetermined time from the first clear pulse generating means 14 issuing the first clear pulse. A second clear pulse generating means 15 for generating a second clear pulse for clearing to a constant level, a judging means 16 for judging whether or not the output of the monitor light receiving section 13 has become a reference voltage or less, Judgment means 16
When the output of the monitor light receiving section 13 is determined to be equal to or lower than the reference voltage by the above, a first shift pulse is generated to output a first shift pulse to shift the accumulated charge of the first light receiving section group 11 to the transfer section. Means 17 and a second shift pulse for outputting a second shift pulse to shift the charge accumulated in the second light receiving section group 12 to the transfer section after the lapse of the predetermined time from the generation of the first shift pulse. Generating means 19 and pulse delay means 18 for controlling the delay from the first clear pulse to the second clear pulse and the delay from the first shift pulse to the second shift pulse to an equal amount.
At least from the generation of the first shift pulse to the generation of the second shift pulse, the transfer of the stored home appliances of the light receiving unit groups 11 and 12 is prohibited, and the accumulated charge of the light receiving unit groups 11 and 12 after the second shift pulse is generated. Transfer pulse generating means 20 for generating a pulse for transferring the first light receiving unit group 11 and each output of the first light receiving unit group 11 and each output of the second light receiving unit group 12. And a comparison calculation unit 21 for calculating the presence or absence of image blur on the screen of the camera by calculating whether or not the amount of change in the image distance on the second light receiving unit group 12 is equal to or greater than a predetermined limit value. It is a thing.

Embodiments of the image blur detection device on the screen of the camera according to the present invention shown in the drawings will be described in detail below.

First, the principle of the present invention will be described.

In the image detection device, an image of the object to be measured at a certain time point and a predetermined time from that time point (hereinafter referred to as “Tα”).
It is possible to detect the relative movement of the measured object image within the screen of the detection device by comparing the measured object image after the elapse. Therefore, if the object to be measured is a subject and the detection device is an autofocus device of a camera, it should be possible to detect the relative movement amount of the subject image within a predetermined time Tα. It should be possible to detect the image blur on the screen of the camera by determining that the image blur occurs on the screen of the camera when the amount is more than a certain amount.

In such an apparatus for detecting the relative movement amount of the image of the object to be measured, it is ideal to detect the same object to be measured with the same optical system and the same element, but an element for photoelectrically converting the image of the object to be measured. When using an integration type device such as a charge coupled device (hereinafter referred to as “CCD”), Tα cannot be freely set. For example, if the object to be measured is a general subject of the camera and the purpose of detection is image blur on the screen of the camera, the situation in which this purpose is sufficiently exhibited is when the shutter speed is slow, that is, when the subject brightness is low. However, in such a case, the integration time of the element becomes long.
In order to detect the amount of movement of the image of the object to be measured with the same optical system and the same element, it is necessary to set Tα longer than the integration time. On the other hand, the image blur on the screen of the camera depends on the shutter speed. Therefore, it is preferable that Tα corresponds to the shutter speed.

From the above, it is sufficient if there is some relationship between the integration time and the shutter speed.
The shutter speed is determined in combination with parameters such as the lens aperture value, and there is no uniform relationship between the integration time of the detection element such as CCD and the shutter speed. That is, there are many situations in which Tα is not always long even if the integration time is long. In that case, the same optical system and the same element cannot cope with the situation.

From the above, it can be seen that two optical systems and two detection elements are necessary to detect the image blur on the screen of the camera.

Therefore, next, a method of forming an image of the same subject on two elements, as shown in FIG. 3, an image of the subject is formed on the diffusion plate 23 by an imaging lens L1 such as a photographing lens. It can be realized by forming an image on the diffuser plate 23 by the image forming lenses L3 and L4 via the condenser lens L2 on the right side sensor array unit A and the left side sensor array unit B of the CCD 25, respectively. . The optical system itself can be replaced by an optical system of an autofocus device of a camera currently used. The optical system shown in FIG. 2 is an example of an optical system of an autofocus device by the correlation method, and the same subject is formed on each of the imaging lens L1, the condenser lens L2, and the left and right sensor arrays A and B of the CCD 25. It has lenses L3 and L4 for forming an image. The optical system shown in FIG. 5 is an example of an optical system of an autofocus device by the contrast method, and the imaging lens L1 and the optical path from this lens L1 are divided to form a sensor array A on the left and right of the CCD 25. , B, and a beam splitter 26 for forming an image on B respectively. The optical system of FIG. 2 can be applied to the light receiving element arrangement as shown in FIG. 4, and the optical system of FIG. 5 can be applied to the light receiving element arrangement as shown in FIG. .

Also, with auto focus, the CCD reset pulse φ
Although r and the shift pulse φt are set to constant timing, if the timings of these pulses are variable, the autofocus device can be used for detecting image blur on the screen of the camera.

When the autofocus device is to be used as a device for detecting image blur on the screen of the camera, the following is more effective. First, the distance is measured with Tα = 0 and an autofocus operation is performed to drive the photographing lens to the in-focus position. Then, after confirming that the lens has stopped at the in-focus position, Tα is replaced with a value proportional to the shutter speed to detect image blur on the screen of the camera. The reason for this is that in the case of the correlation autofocus as shown in FIG. 4, an image shift occurs on the A and B columns of the CCD when out of focus, and this is detected to calculate the defocus amount of the lens. However, if an attempt is made to detect the image blur on the screen of the camera at this time, the lens defocus amount and the information on the image blur on the screen of the camera are mixed. Sixth
This is because in the case of the contrast method as shown in the figure, information is mixed for almost the same reason.

An embodiment of the image blur detection device on the screen of the camera according to the present invention will be described below.

In FIG. 4, the CCD 25 includes a first light receiving section group 11 composed of a photodiode array in the A row, and a second light receiving section group 12 composed of a photodiode array in the B row on the same line as the light receiving group 11. , And a shift register 28 for transferring the charge accumulated in each pixel forming the light receiving unit group in each column, and receives light from the subject that has passed through the taking lens L1 of the camera. In the vicinity of the first light receiving unit group 11,
A monitor light receiving unit 13 including a photodiode for monitoring the charge accumulation state in the CCD 25 is arranged. The first light receiving unit group 11 photoelectrically converts a subject image by one optical system L1, L2, L3, and the second light receiving unit group 12 photoelectrically converts a subject image by another optical system L1, L2, L4. To do. The monitor light receiving unit 13 photoelectrically converts the average luminance of the subject image.

In FIG. 7, reference numeral 30 is a central processing unit for focus (hereinafter referred to as “AFCPU”), and CCD 25 is AFCPU30.
Is driven via the CCD driver 27. The CPU 30 is the first clear pulse generating means 1
When the clear pulse .phi.r1 is issued from the clear pulse generating means 14, the transistor 31 in FIG. 4 is turned on and the capacitor 32 is charged by the power source + V, and the first light receiving unit group 11 and the monitor light receiving unit 13 are provided. Is cleared to a certain level. When the clear pulse φr1 becomes low level, a photocurrent corresponding to the brightness distribution of the subject image flows to the first light receiving unit group 11 and electric charges are accumulated in the accumulation electrode. At the same time monitor light receiver
A photocurrent also flows through 13 through the transistor 33 in accordance with the brightness of the subject, and the photocurrent reduces the potential of the capacitor 32. The potential of the capacitor 32 is output to the CCD driver 27 as a monitor output Vagc via a buffer amplifier including transistors 34 and 35.

The second clear pallet generating means 15 is adapted to generate the clear pulse φr2 after a certain time Tα from the generation of the clear pulse φr1 from the first clear pulse generating means 14. When the clear pulse φr2 is emitted, the second light receiving unit group 12 is cleared by a certain lens, and when the clear pulse φr2 becomes a low level, a photocurrent according to the brightness distribution of the subject image flows to the light receiving unit group 12 and its accumulation. Electric charges are accumulated on the electrodes.

The CCD driver 27 has the judging means 16 and the first shift pulse generating means 17. The judging means 16 judges whether or not the output Vagc of the monitor light receiving unit 13 becomes equal to or lower than the reference voltage Vo (see FIG. 9). The first shift pulse generating means 17 shifts the accumulated charges of the first light receiving section group 11 to the transfer section when the judging section 16 judges that the output of the monitor light receiving section 13 becomes equal to or lower than the reference voltage. Outputs pulse φt1.
When the shift pulse φt1 is input from the driver 27 to the CCD 25, the shift gate is opened and the charge accumulated in the accumulation electrode of the first light receiving unit group 11 is transferred to the shift register 28.

The second shift pulse generating means 19 generates a pulse .phi.t2 for shifting the charges of the second light receiving section group 12 to the transfer section after T.alpha. Has elapsed since the generation of the first shift pulse .phi.t1. When the shift pulse φt2 is input from the driver 27 to the CCD 25, the shift gate is opened and the charges accumulated in the accumulated charge pole of the second light receiving unit group 12 are transferred to the shift register 28.

The CCD driver 27 has at least the first shift pulse φt1.
From the occurrence of the second shift pulse φt2 to the second shift pulse φt2
After the generation of t2, a pulse φ1, for transferring the accumulated charge
The transfer pulse generating means 20 for generating φ2 is provided. When transfer pulses φ1 and φ2 are output from the driver 27, CCD2
5 shift register 28 to transistor 36, capacitor 3
It is sequentially output as a video signal Vout via 7 and a buffer amplifier composed of transistors 38 and 39.

As shown in FIG. 7, the video signal V from the CCD 25
The variable-magnification amplifier 41 is amplified via the multiplexer 40, converted into a digital signal by the analog-to-digital converter 42, and input to the CPU 30 via the interface 43.
The monitor output signal Vagc in the driver 27 is converted into a digital signal by the analog / digital converter 42 via the multiplexer 40 and input to the CPU 30 via the interface 43. The monitor output signal Vagc in the driver 27 is converted into a digital signal by the analog-to-digital converter 42 via the multiplexer 40, and the CP signal via the interface 43.
Input to U30. CPU30 is video signal Vout from CCD25
The gain of the variable-magnification amplifier 41 before monitoring
Adjust via multiplexer 44 according to Vagc CCD25
The defocus amount is calculated with high accuracy by taking in a signal obtained by amplifying the video signal Vout from the video signal Vout at a magnification corresponding to the brightness and contrast of the subject image.

The focal length signal and the distance set position signal of the taking lens 50 (L1) are input to the CPU 30 from the detection circuits 45 and 46 via the multiplexer 40, the analog / digital converter 42, and the interface 43, and the encoder 47. And the signal from the manual switch 51 are input. The encoder 47 constitutes a rotation detector that detects the rotation of the photographing lens 50 driving motor 53. The switcher 51 is a power switch which is a release switch that is turned on when the release button is pressed to perform automatic focus adjustment.

The CPU 30 outputs the output of the first light receiving unit group 11 and the second light receiving unit group 12
It has a comparison calculation unit 21 for calculating the presence or absence of image blur on the screen of the camera by comparing the output of the above. This comparison calculation unit 21
It can be shared with the distance measurement calculation unit of the automatic focus adjustment device. Further, the CPU 30 delays from the first clear pulse to the second clear pulse and from the first shift pulse to the second clear pulse.
It has pulse delay means 18 for controlling the delay up to the shift pulse of 1 to the same amount.

Next, the operation of the above embodiment will be described with reference to FIGS. 8 and 9. However, as the automatic focus adjusting device, a device known in the prior art or the Japanese Patent Application No.
The same operation as described in the specification of 60-241168 may be performed. That is, Tα = 0 by the distance measurement start signal and CCD2
The outputs of the first and second light receiving unit groups 11 and 12 of 5 are used for the calculation of the automatic focus detection, and the photographing lens L1 is driven to the in-focus position based on the calculation result. When it is confirmed by this automatic focusing flow that focusing has been completed, it is then checked whether the presence or absence of image blur on the camera screen is detected, and image blur on the camera screen is detected. In that case, the process proceeds to the flow of FIG.

In FIG. 8, in step S1, Tα is set to a constant To which is proportional to the shutter speed obtained by photometry, and in step S2 the CCD 25 is initialized. next,
In step S3, the clear pulse φr1 is output from the first clear pulse generating means 14 to output the monitor light receiving unit 13 and the first light receiving unit group.
11 is cleared to a certain level, and integration of the first light receiving unit group 11 of the CCD and the monitor light receiving unit 13 of the CCD is started in step S4. In step S5, the determination unit 16 checks whether the output voltage of the monitor light receiving unit 13 has become equal to or lower than the reference voltage, that is, whether the above integration is completed. If the integration is completed, the first shift pulse is generated in Step S6. The generating means 17 outputs the shift pulse φt1.

On the other hand, in step S7, the second clear pulse generating means 15
From the above, clearing pulse φr1 with a delay of To
Clear the light receiving unit group 12 to a certain level, and
At S8, the integration of the second light receiving unit group 12 of the CCD is started, and further,
In step S9, the shift pulse φt1 is delayed by To and the second shift pulse generation means 19 delays the silt pulse φ.
Output t2. The output of these shift pulses φt1 and φt2 causes the charges accumulated in the respective light receiving section groups 11 and 12 to be silted to the transfer section.

When the shift pulses φt1 and φt2 are output, the next step
At S10, transfer pulses φ1 and φ2 are transferred from the transfer pulse generating means 20 to C
The data is output to the CD25, the random access memory (RAM) is cleared in step S11, and the analog / digital converter 42 is caused to start digital conversion of the video signal from the CCD25 in step S12. In this way, the amount of change in the image interval in the first and second light receiving unit groups 11 and 12 is calculated from the digitally converted video signal in step S13. This calculation method is the same as the distance measurement calculation method in the automatic focus adjustment device. In step S14, the comparison calculation unit 21 compares the absolute value of the calculation result Cooo with the limit value Ct of whether or not the image blur on the camera screen occurs, and a value that causes the image blur on the camera screen. If so, the image blurring display on the camera screen is performed in step S15. If the value does not cause the image blurring on the camera screen, the release is allowed in step S16 to detect the image blurring on the camera screen. To complete the flow.

In the above-described embodiment, in short, the automatic focusing device is used, and in the automatic focusing, the video signals from the first light receiving unit group and the second light receiving unit group are simultaneously output to detect the focus. Then, in detecting the image blur on the screen of the camera, the video signals from the first light receiving unit group and the second light receiving unit group are output after being shifted by the time Tα, and output from the first and second light receiving unit groups. By calculating whether or not the amount of change in the interval between the images obtained by is equal to or greater than a predetermined limit value, the relative shift between the images on the first light receiving unit group and the second light receiving unit is calculated. It enables the detection of image blur on the camera screen. Therefore, according to the above-described embodiment, when a subject image flows on a fast-moving subject on the screen of the camera and a situation substantially similar to camera shake occurs, and when camera shake occurs as image blur on the camera screen. It is possible to detect, and using the hardware of the automatic focusing device as it is, the subject image will flow on the camera screen for a fast-moving subject by simply modifying the software part, and it will be practically possible. Since it is possible to detect a situation similar to camera shake and camera shake, it is possible to provide an inexpensive apparatus for detecting image blur on the screen of the camera.

Further, if the time lag Tα between the output from the first light receiving unit group and the output from the second light receiving unit group can be set according to the skill level of the camera user, the skill of the camera user can be improved. It is possible to detect the image blur on the screen of the camera according to the degree.

The hand-shake detecting device as described above can be similarly applied to the automatic focusing device based on the contrast method as shown in FIG.

(Effect) According to the present invention, a first light receiving unit group for photoelectrically converting a subject image by one optical system, a second light receiving unit group for photoelectrically converting a subject image by another optical system, and the second light receiving unit group Monitor light receiving unit provided near the first light receiving unit group and the first light receiving unit group and photoelectrically converting the average luminance of the subject image, and the monitor light receiving unit and the first light receiving unit group are cleared to a certain level. And a first clear pulse generating means for generating a first clear pulse for
Second clear pulse generating means for generating a second clear pulse for clearing the second light receiving unit group to a constant level after a predetermined time has elapsed from the generation of the clear pulse of the above, and the output of the monitor light receiving unit. Of the first light receiving portion group to the transfer portion when the output of the monitor light receiving portion is determined to be equal to or lower than the reference voltage by the determining means. A first shift pulse generating means for outputting a first shift pulse to shift, and a stored charge of the second light receiving section group is shifted to a transfer section after a lapse of the predetermined time from the generation of the first shift pulse. To output the second shift pulse
Shift pulse generating means, and pulse delay means for controlling the delay from the first clear pulse to the second clear pulse and the delay from the first shift pulse to the second shift pulse to an equal amount. For inhibiting the transfer of the accumulated charges of the light receiving unit group at least from the generation of the first shift pulse to the generation of the second shift pulse, and transferring the accumulated charges of the light receiving unit group after the generation of the second shift pulse. On the first light receiving unit group and the second light receiving unit group, the transfer pulse generating means for generating a pulse, the respective outputs of the first light receiving unit group and the respective outputs of the second light receiving unit group are used. Since it has a comparison calculation unit that calculates the presence or absence of image blur on the camera screen by calculating whether or not the amount of change in the image interval has become equal to or greater than a predetermined limit value, Camera Not only can detect the deflection, it is possible to subject image with respect to fast-moving object is detected a case where the same situation substantially camera shake flows on the camera screen occurs. Further, by setting the predetermined time arbitrarily and setting the predetermined time according to the skill level of the camera user, image blur detection on the screen of the camera according to the skill level of the camera user can be detected. Is possible. Further, it is possible to detect the image blur on the screen of the camera by using the automatic focusing device of the camera.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing the basic configuration of the present invention, and FIG.
FIG. 3 is an optical arrangement diagram showing an example of an image forming optical system applicable to the present invention, FIG. 3 is an optical arrangement diagram showing another example of an image forming optical system applicable to the present invention, and FIG. FIG. 5 is a circuit diagram showing an example of the configuration of a light receiving section applicable to the present invention, FIG. 5 is an optical layout diagram showing another example of the imaging optical system applicable to the present invention, and FIG. 6 is a light receiving section applicable to the present invention. FIG. 7 is a circuit diagram showing another example of the configuration of the parts, FIG. 7 is a block diagram showing an embodiment of the image blur detection device on the screen of the camera according to the present invention, and FIG. 8 shows the operation of the embodiment of the present invention. Flowchart for explaining the ninth
The figure is also a timing chart. 11 …… First light receiving section group, 12 …… Second light receiving section group, 13 ……
Monitor light receiving part, 14 ... First clear pulse generating means, 15
...... Second clear pulse generating means, 16 …… Decision means, 17
...... First shift pulse generating means, 18 ...... Pulse delay means, 19 ...... Second shift pulse generating means, 20 ...... Transfer pulse generating means, 21 ...... Comparison unit.

Front Page Continuation (72) Inventor Takayuki Hatase 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Kazumasa Aoki 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (56) References JP-A-55-106442 (JP, A) JP-A-57-105709 (JP, A) JP-A-58-174929 (JP, A)

Claims (1)

[Claims] 1. A first light receiving section group for photoelectrically converting a subject image by one optical system, a second light receiving section group for photoelectrically converting a subject image by another optical system, and this second light receiving section group. And a monitor light-receiving unit which is provided in the vicinity of the first light-receiving unit group and photoelectrically converts the average luminance of the subject image, and a first light-receiving unit for clearing the monitor light-receiving unit and the first light-receiving unit group to a certain level. A first clear pulse generating means for generating a first clear pulse, and a predetermined level after the first clear pulse is emitted from the first clear pulse generating means for a predetermined level. Second clear pulse generating means for generating a second clear pulse for clearing, a judging means for judging whether or not the output of the monitor light receiving section becomes equal to or lower than a reference voltage, and the monitor light receiving means by this judging means. Based on the output of First shift pulse generating means for outputting a first shift pulse to shift the charge accumulated in the first light receiving portion group to the transfer portion when it is determined that the voltage has become equal to or lower than the voltage; and when the first shift pulse is generated. From the first clear pulse to second shift pulse generating means for outputting a second shift pulse to shift the charge accumulated in the second light receiving section group to the transfer section after the lapse of the predetermined time. Pulse delay means for controlling the delay up to the second clear pulse and the delay from the first shift pulse to the second shift pulse to an equal amount, and at least the first shift pulse generation to the second shift. Transfer pulse generation means for inhibiting transfer of the accumulated charges of the light receiving unit group until a pulse is generated and generating a pulse for transferring the accumulated charges of the light receiving unit group after the generation of the second shift pulse; From each output of the first light receiving unit group and each output of the second light receiving unit group, the change amount of the image interval on the first light receiving unit group and the second light receiving unit group is a predetermined limit value. An image blur detection device on a screen of a camera, comprising: a comparison calculation unit that calculates presence or absence of image blur on the screen of the camera by calculating whether or not the above.