JP2743465B2 - Camera shake detection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera shake detection device, and more particularly to a camera shake warning or camera shake correction when a low-luminance subject is photographed at a low shutter speed without a tripod. It is suitable for the intended use.

[Prior art] Conventionally, incorporating an angular velocity sensor into a video camera,
It has been proposed to detect the attitude of a camera (Japanese Patent Application Laid-Open
No. 61-289769). As the angular velocity sensor, there is a sensor using a high-speed rotating body like an auto gyro, and a sensor using Coriolis force generated by a vibrating tuning fork.

[Problem to be Solved by the Invention] By incorporating the angular velocity sensor as described above into a camera,
It is considered that it is possible to perform control to detect a camera shake of the camera and issue a warning, and to more positively correct camera shake. However, since the angular velocity sensor has a high-speed rotating body or a vibrating body,
The detection output is not stable for a fixed time. For this reason, there has been a problem that an erroneous or unreported error occurs in the camera shake warning and an error occurs in the camera shake correction.

The present invention has been made in view of such a point,
An object of the present invention is to prevent a camera shake detection device having an angular velocity sensor from malfunctioning during a period when a detection output of the angular velocity sensor does not reach a steady state.

[Means for Solving the Problems] In a camera shake detection apparatus according to the present invention, as shown in FIG. 1, a camera shake detection sensor 1 and a camera shake detection sensor 1 , A time-measuring means 3 for measuring a certain time from the start of driving of the angular velocity sensor 1, and a release lock means 4 for performing a release lock while the time-measuring means 3 is measuring a certain time. It is characterized by the following.

A determination means 5 for determining whether the angular velocity sensor 1 needs to be driven is provided. When the determination means 5 determines that the driving of the angular velocity sensor 1 is unnecessary, the release lock release means 6 releases the release lock. Alternatively, it is preferable that the driving of the angular velocity sensor 1 be stopped by the sensor driving stopping means 7.

[Operation] Hereinafter, the operation of the present invention will be described with reference to FIG. The angular velocity sensor 1 includes a high-speed rotating body or a vibrating body, and detects camera shake. The sensor driving means 2 drives the angular velocity sensor 1 so that a detection output can be obtained from the angular velocity sensor 1. As described above, the detection output from the angular velocity sensor 1 is not stable for a certain time after the start of driving. Therefore, a predetermined time is measured from the start of the driving of the angular velocity sensor 1 by the timer means 3, and the release lock is performed by the release lock means 4 during the time measurement. Thereby, photographing is prohibited for a certain period of time after the start of driving of the angular velocity sensor 1, and malfunctions caused by unstable detection output of the angular velocity sensor 1 can be prevented.

When a tripod is attached or when it is detected that the shutter speed does not cause camera shake, camera shake need not be detected. Therefore, in such a case, the determination means 5 determines that the driving of the angular velocity sensor 1 is unnecessary, and the release lock release means 6 may release the release lock. Thus, the risk of missing a photo opportunity can be reduced. When it is determined by the determining means 5 that the driving of the angular velocity sensor 1 is unnecessary, the driving of the angular velocity sensor 1 is preferably stopped by the sensor driving stopping means 7. This allows
Power consumption for driving the angular velocity sensor 1 can be saved.

Embodiment FIG. 2 is a perspective view conceptually showing a configuration of a camera as one embodiment of the present invention. The camera body 11 has an angular velocity sensor for detecting angular velocities in a pitching direction and a rolling direction in a plane (xy plane in the figure) perpendicular to an optical axis (z axis in the figure) of the photographing lens 12. Sx and Sy are built-in.

FIG. 3 shows the internal structure of the camera. The taking lens 12 is a zoom lens composed of first to fourth groups of lenses L1 to L4, and includes a lens Lc for camera shake correction between the third and fourth groups of lenses L3 and L4. This shooting lens 12
Is reflected by the main mirror 13, forms an image on the focusing screen 14, and is observed through the pentaprism 15 and the eyepiece 16. The subject light transmitted through the central portion of the main mirror 13 is reflected by the sub-mirror 17 and guided to a focus detection circuit FD disposed below the mirror box. FP is a film surface, and a focal plane shutter (not shown) is disposed immediately before the FP. The focus detection circuit FD is disposed near a predetermined imaging plane equivalent to the film plane FP, and detects a focus state of the photographing lens 12 based on subject light. During exposure control, the main mirror 13 is retracted upward so as to be substantially parallel to the reticle 14, and the film surface FP
, A focal plane shutter disposed in the vicinity of the shutter travels, and exposure is performed. During exposure, the angular velocity sensor S
The lens Lc for camera shake correction is driven in the vertical and horizontal directions by the drive circuits Cx and Cy in accordance with the detection outputs of x and Sy to correct the camera shake.

FIG. 4 is a block circuit diagram of the camera. In the figure,
μC is a microcomputer that performs the entire camera sequence, exposure calculation, and exposure control (hereinafter referred to as “microcomputer”).
It is. LM is a photometric circuit that measures the brightness of the subject,
It is converted into a digital signal and transmitted to the microcomputer μC. FD is
This is a TTL phase difference detection type focus detection circuit having a CCD image sensor, converts an analog signal output from the CCD image sensor into a digital signal, and outputs the digital signal to the microcomputer μC. LD is a lens drive circuit that drives a focus adjustment lens based on the defocus amount obtained based on the data of the focus detection circuit FD. AE is the above photometric circuit
This is an exposure control circuit that controls the aperture and the shutter based on the aperture value and the shutter speed determined based on the output of the LM. ISO is a film sensitivity reading circuit which reads the film sensitivity SV recorded on the film cartridge and transmits it to the microcomputer μC. Sx and Sy are angular velocity sensors for detecting angular velocities in the pitching direction and the rolling direction, respectively. C
x and Cy are camera shake correction lens driving circuits that receive outputs from the angular velocity sensors Sx and Sy and drive a lens Lc for correcting camera shake in a plane perpendicular to the optical axis. DISP is a display circuit for displaying whether or not the subject is in focus. ZEN is a zoom encoder that transmits the focal length of the zoom lens to the microcomputer μC.

 Next, switches will be described.

_SM is a main switch. When ON, the camera is in a drivable state, and when OFF, the camera is in a driving stop state. S1 is ON with the first stroke of the release button (not shown)
When the switch is turned on, a shooting preparation operation such as a photometry operation and a focus detection operation is performed. S2 is a release switch that is turned on with the second stroke of the release button, and when it is turned on, exposure control is performed. _ST is a tripod switch, which is provided at a tripod screw hole provided at the bottom of the camera body, and is turned on when the tripod is fitted into the screw hole.

 Next, the power supply will be described.

E is a power supply battery, and its direct output voltage Vo is 1st to 1st.
Peripheral circuit CT1 via third power supply transistors Tr1 to Tr3
To CT3. C1 is a backup capacitor, which is charged by the power supply battery E via a backflow prevention diode D1, and its charging voltage V _DD is supplied to the microcomputer μC, the display circuit DISP, and the zoom encoder ZEN. The above-described peripheral circuits CT1 to CT3 include circuits with large power consumption, and when driven, the voltage of the power supply battery E may temporarily decrease. Even when the voltage decreases, power is supplied from the backup capacitor C1. The microcomputer μC and the like can operate normally.

This concludes the description of the hardware configuration of the present embodiment. Next, the software configuration of the present embodiment will be described.

FIG. 5 shows that the main switch S _M is operated and turned from OFF to ON.
SMI executed when switching from ON to OFF
Shows the contents of NT. When this interrupt SMINT occurs,
First, it is determined whether or not the main switch _SM is ON (♯
5). If the main switch S _M is OFF, it is determined that the main switch S _M has been operated from ON to OFF, the first power supply transistor Tr1 is turned OFF, and the first power supply transistor Tr1 including the photometric circuit LM and the like is turned off.
Of the peripheral circuit CT2, turning off the second power supply transistor Tr2, stopping the power supply to the second peripheral circuit CT2 including the angular velocity sensors Sx and Sy, erasing the display, and resetting the microcomputer μC Is in a halt state ($ 65- $ 75). In # 5, if the main switch S _M is ON, it resets all flags, and ON the power supply transistor Tr2, and starts to supply power to the second peripheral circuit including the angular velocity sensor Sx, the Sy, timer T1 , T2 reset and start (♯10 ～ ♯2
0). Here, T1 is a holding timer for holding power supply to all the circuits CT1 to CT3, and T2 is a timer for measuring the time from when power supply to the angular velocity sensors Sx and Sy is started. Next, it is determined in step # 25 whether or not the shooting preparation switch S1 is ON. If it is ON, the subroutine S1ON is executed in step # 30, and the process returns to step # 25.

FIG. 6 shows the subroutine of S1ON. When this subroutine is called, first, the power supply transistor
The Tr1 is turned on to start supplying power to the first peripheral circuit CT1 including the photometric circuit LM and the like, and execute the subroutines of photometry, AF, and camera shake determination (# 100 to # 115).

 Hereinafter, each subroutine will be described.

First, FIG. 7 shows the photometry subroutine. When this subroutine is called, it is determined whether or not the flag AFEF indicating focusing is set at $ 200, and if it is set, the routine returns without updating the photometric value. If the flag AFEF is not set in # 200, the luminance value BV is input from the photometric circuit LM and the film sensitivity value SV is input from the film sensitivity reading circuit ISO (# 205, # 210). Then, the exposure value EV is obtained by EV = BV + SV, and a predetermined value is obtained from the obtained exposure value EV.
The aperture value AV and the shutter speed TV are determined based on the AE program diagram, and the process returns (# 215, # 220).

Next, the AF subroutine is shown in FIG. When this subroutine is called, first, it is determined whether or not the shooting preparation switch S1 is turned on at # 250, and if not, the flag AFEF indicating focus is reset at # 252, and the routine returns. . If the shooting preparation switch S1 is ON at # 250, it is determined at # 255 whether or not the focusing flag AFEF is set, and if it is set, it is determined that there is no need to perform AF (focus detection). To return. ♯ If the flag AFEF is not set at 255, the focus detection circuit FD
Let CCD image sensor integrate (charge accumulation)
After the integration, a data dump is performed, and a defocus amount DF is calculated based on the dumped data (♯260 to ♯27
0). Then, based on the obtained defocus amount DF, it is determined whether or not the subject is in focus. If the subject is in focus, the in-focus flag AFEF is set, the in-focus display is performed, and the routine returns (# 275 to # 28)
Five). If the lens is not in focus at 275, the lens drive amount _NL up to the in-focus position is obtained from the defocus amount, and the obtained lens drive amount
The focus adjusting lens is driven by the lens driving circuit LD according to N _L and the process returns (# 290, # 295).

Next, FIG. 9 shows a subroutine for the above-mentioned camera shake determination. When this subroutine is called, first, data of the focal length f is read from the zoom encoder ZEN at # 300, and a camera shake limit speed determined according to the current focal length f is obtained. As a guide, the shutter speed at the camera shake limit corresponding to the focal length f [mm] is set to SS = 1 / f [second].
The PEX value is set to TVf (# 305). This shake limit speed TVf
TVf = TVf + 1 (# 310). Here, the reason why the camera shake limit speed TVf is set to be larger by +1 in the APEX value is to allow a margin for the determination at # 320 described later. Then, ♯3
At 12, it is determined whether or not the tripod switch _ST is ON. When the tripod switch _ST is ON, almost no camera shake occurs, and the power supply transistor Tr2 is used to stop power supply to the second peripheral circuit CT2 including the angular velocity sensors Sx and Sy.
Is turned off, the flag RLKF indicating the release lock is reset, and the routine returns (# 335, # 340). Tripod switch S _T
If is not ON, it is determined at # 315 whether or not the focusing flag AFEF is set, and if not, the process proceeds to # 345. If the focusing flag AFEF is set in # 315, it is determined whether the calculated shutter speed TV is equal to or greater than the camera shake limit speed TVf in # 320, and if the shutter speed TV is less than TVf, the process proceeds to # 345. . When the shutter speed TV is equal to or higher than the camera shake limit speed TVf, N = N + 1, and it is determined whether or not N ≧ 10 (# 325, # 330). If N ≧ 10, the power supply transistor T
r2 is turned off, the flag RLKF indicating the release lock is reset, and the routine returns (# 335, # 340). That is, when the shutter speed TV obtained by the calculation is equal to or higher than the camera shake limit speed TVf a plurality of times (10 times in the embodiment), it is determined that camera shake will not occur, and the power supply to the angular velocity sensors Sx and Sy is determined. Supply is shut off. This is because the power consumption of the angular velocity sensors Sx and Sy is large, so that the power consumption is reduced even a little. The reason why the determination is made only after focusing is that the photometric value changes unless focusing is performed.

If N <10 at $ 330, proceed to $ 350. Also, ♯345
Then, N = 0 is set, and the process proceeds to $ 350. In # 350, the timer T2 determines whether or not 15 seconds have elapsed since the power supply to the angular velocity sensors Sx and Sy was started. This is an angular velocity sensor
This is the time required for Sx and Sy to reach a steady state. ♯350
If the timer T2 measures 15 seconds, the angular velocity sensor
The detection outputs from Sx and Sy are steady and can be determined to be accurate. In this case, even if a camera shake occurs, the camera shake can be corrected according to the detection output from the angular velocity sensors Sx and Sy. Therefore, the flag RLKF indicating the release lock is reset at # 340 and the process returns. On the other hand, timer T2 is 1 at 1350
If 5 seconds have not been counted, the flag RLKF is set at $ 355 and the routine returns.

Referring back to FIG. 6, after executing the above-described subroutines of the photometry, AF, and camera shake determination, the process proceeds to # 125, and the release switch S
It is determined whether or not 2 is ON. Release switch S
If 2 is OFF, proceed to # 155 and set the shooting preparation switch S1 to O
It is determined whether or not N is set, and if it is not turned on,
Return immediately. On the other hand, when the shooting preparation switch S1 is ON, the power holding timer T1 is reset and started at # 160, and the process returns. If the release switch S2 is ON in # 125, it is determined in # 130 whether the control shutter speed TV is equal to or higher than the camera shake limit speed TVf. If TV ≧ TVf, it is determined that camera shake does not occur, and the power supply transistor Tr2 is turned off at # 135, and the power supply to the second peripheral circuit CT2 including the angular velocity sensors Sx and Sy is stopped. Perform control. Thereby, useless power consumption by the angular velocity sensors Sx and Sy can be reduced. If TV <TVf at # 130, the process proceeds to # 165 to determine whether or not the flag RLKF indicating the release lock is set. If it is set, the process proceeds to # 155 to prohibit the exposure control. On the other hand, when the flag RLKF is not set, the power supply transistor Tr3 is turned on at # 170 to supply power to the third peripheral circuit CT3 including the camera shake correction lens driving circuits Cx and Cy. Thereby, based on the detection output from the angular velocity sensors Sx, Sy, the camera shake correction lens driving circuits Cx, Cy
Is driven, and even if camera shake occurs, it can be corrected. Then, the flow advances to # 145 to execute an exposure control routine. Since the exposure control routine is not related to the present invention, illustration and description are omitted. After exposure is completed, camera shake correction is not required, so the power supply transistor Tr3
Is turned off, and the third including the camera shake correction lens driving circuits Cx and Cy
The power supply to the peripheral circuit CT3 is stopped, and the process proceeds to # 155.

Returning to FIG. 5, at # 25, the shooting preparation switch S1 is
If OFF, the in-focus flag AFEF is reset at # 35, and it is determined at # 40 whether the power holding timer T1 has counted 10 seconds. If the timer T1 has not counted 10 seconds, the process proceeds to # 30, and the subroutine of S1ON is executed. ♯
If the timer T1 measures 10 seconds at 40, the power supply transistor Tr1 is turned off at # 45, and the power supply to the first peripheral circuit CT1 including the photometric circuit LM and the like is stopped.
By turning off r2, the power supply to the second peripheral circuit CT2 including the angular velocity sensors Sx and Sy is stopped, and all the display by the display circuit DISP is erased at # 55. And at $ 60, the shooting preparation switch S1
Is turned on, and if it is turned on, the flow from # 10 is executed.

[Effects of the Invention] According to the present invention, as described above, in a camera touch detection device including a camera shake detection sensor, for example, an angular velocity sensor, the release lock is performed for a fixed time from the start of driving of the angular velocity sensor. In addition, there is an effect that malfunction can be prevented during a period when the detection output of the angular velocity sensor does not reach a steady state.

When it is determined that the driving of the angular velocity sensor is unnecessary, the release lock is released, so that there is an effect that the risk of missing a photo opportunity can be reduced.

Further, when it is determined that the driving of the angular velocity sensor is unnecessary, the driving of the angular velocity sensor is stopped, so that the power consumption by the angular velocity sensor can be saved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the basic configuration of the present invention, FIG. 2 is a perspective view conceptually showing the configuration of a camera as one embodiment of the present invention, and FIG. FIG. 4 is a schematic block diagram of the above, FIG.
The figure is a flowchart for explaining the operation of the above. 1 is an angular velocity sensor, 2 is a sensor driving means, 3 is a timing means, 4 is a release lock means, 5 is a judgment means, 6 is a release lock release means, and 7 is a sensor drive stop means.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masatoshi Kamiya 2-3-113 Azuchicho, Chuo-ku, Osaka-shi, Osaka Osaka International Building Minolta Camera Co., Ltd. (72) Inventor Naoshi Okada Azuchi, Chuo-ku, Osaka-shi, Osaka 2-3-13 Machi, Osaka International Building Minolta Camera Co., Ltd. (72) Inventor Katsumi Kosakai 2-3-13, Azuchicho, Chuo-ku, Osaka-shi, Osaka Osaka International Building Minolta Camera Co., Ltd. (72) Inventor Otsuka Hiroshi 2-13-13 Azuchicho, Chuo-ku, Osaka City, Osaka Pref. Osaka International Building Minolta Camera Co., Ltd. (56) References JP-A-62-215873 (JP, A) JP-A-62-221216 (JP, A)

Claims (6)

(57) [Claims] 1. A camera shake detection sensor for detecting camera shake, a sensor driving means for driving the camera shake detection sensor, a clock means for clocking a predetermined time from the start of driving of the camera shake detection sensor, and the clock means measures the predetermined time. A camera shake detection device, comprising: a release lock unit that prohibits a release operation of the camera while time is being measured. 2. The camera shake detection device according to claim 1, further comprising a release lock release unit that releases the release lock when the drive of the camera shake detection sensor is unnecessary. 3. The control system according to claim 2, further comprising a determination unit for determining whether or not the drive of the camera shake detection sensor is required, and outputting a signal indicating the determination result to the release lock release unit when it is determined to be unnecessary. The camera shake detection device according to claim 2, wherein 4. The apparatus according to claim 1, further comprising a sensor drive stopping means for stopping the drive of the camera shake detection sensor when the drive of the camera shake detection sensor is unnecessary.
A camera shake detection device according to the above. 5. The apparatus according to claim 1, further comprising a determination unit configured to determine whether or not it is necessary to drive the camera shake detection sensor, and to output a signal indicating the result of the determination to the sensor drive stop unit if the determination is not necessary. The camera shake detection device according to claim 4, wherein 6. A camera shake detecting device according to claim 1, wherein said camera shake detecting sensor is an angular velocity sensor.