JPH02301732A - Shake detector for camera - Google Patents

Abstract

PURPOSE:To reduce the unnecessary power consumption of a sensor which detects the vibration of the camera by stopping power supply to the sensor when the camera is mounted on a tripod. CONSTITUTION:This camera is equipped with the sensor 1 which detects the vibration of the camera, a power feeding means 2 which supplies electric power to the sensor 1 from a battery power source E, a tripod mounting detecting means 3 which detects the camera being mounted on the tripod, and a power supply control means 4 which stops the power supply to the sensor 1 by the power feeding means 2 when the camera is mounted on the tripod. Therefore, when the tripod mounting detecting means 3 detects the camera being mounted on the tripod, shake detection is not necessary, so the power supply to the sensor 1 by the power feeding means 2 is stopped under the control of the power feeding control means 4. Consequently, when the camera is mounted on the tripod, the power is not fed to the sensor 1, so the power consumption is reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a camera shake detection device, and is used to issue a camera shake warning or shake correction when, for example, a low-brightness subject is photographed at a slow shutter speed without a tripod. It is suitable for the intended use.

[Prior Art] Conventionally, it has been proposed to incorporate an angular velocity sensor into a video camera to detect the attitude of the camera (Japanese Patent Laid-Open No. 6
1-289769). As an angular velocity sensor,
Some use a high-speed rotating body, such as an autogyro, and others use the Coriolis force generated by a vibrating tuning fork.

[Problems to be Solved by the Invention] It is believed that if an angular velocity sensor such as the one described above is incorporated into a camera, it will be possible to detect camera shake and issue a warning, as well as to actively correct camera shake. It will be done. However, since the angular velocity sensor is equipped with a high-speed rotating body or a vibrating body, there is a problem in that it consumes a large amount of power and accelerates the battery consumption of the camera.

The present invention has been made in view of the above, and an object thereof is to reduce power consumption by a sensor for detecting camera shake in a camera shake detection device powered by battery power. .

[Means for Solving the Problems] □In order to solve the above problems, the present invention provides a camera shake detection device driven by a battery power source E, as shown in FIG. A sensor 1 that detects camera vibration, a power supply means 2 that supplies power to the sensor 1 from a battery power source E, a tripod mounting detection means 3 that detects that the camera is mounted on a tripod, and a power supply means when detecting that the camera is mounted on a tripod. The present invention is characterized in that it includes a power supply control means 4 for stopping power supply to the sensor 1 by the sensor 2 .

In addition, an image stabilization means 5 that drives a part of the photographing lens according to the detection output of the sensor], and a second power supply means 6 that supplies power to the image stabilization means 5 from the battery power source E only during shooting.
It is more preferable to further include the following.

[Effect] Hereinafter, the operation of the present invention will be explained with reference to FIG.

The sensor 1 is, for example, an angular velocity sensor equipped with a high-speed rotating body or a vibrating body, and detects camera shake.

The sensor 1 starts being supplied with power from the battery power source E via the power supply means 2 when a main switch is turned on, for example. Since no power is supplied to the sensor 1 when the main switch is off, power consumption is reduced. Furthermore, when the tripod attachment detection means 3 detects that the camera is attached to a tripod, there is no need to detect camera shake.
The power supply to the sensor 1 by the power supply means 2 is stopped under the control of the power supply control means 4. As a result, power is not supplied to the sensor 1 when the camera is mounted on a tripod, so power consumption is reduced.

Note that when camera shake is detected by the detection output of the sensor 1, it is possible to prompt the photographer to attach a tripod or to illuminate the subject by, for example, locking the release or issuing a camera shake warning.

Furthermore, if an image stabilization means 5 is provided which drives a part of the photographic lens according to the detection output of the sensor 1, it will be possible to correct camera shake during photography and shoot low-brightness subjects at low speeds even without a tripod. It becomes possible to take pictures at a certain shutter speed. In this case, it is advantageous to provide a second power supply means 6 that supplies power to the image stabilization means 5 from the battery power source E only during shooting, since the power consumption by the image stabilization means 5 can be reduced.

[Embodiment] FIG. 2 is a perspective view conceptually showing the configuration of a camera as an embodiment of the present invention. The camera body 11 has a plane (xy, y, and
Angular velocity sensors Sx and Sy for detecting the angular velocity in the pitching direction and the rolling direction, respectively, are built in the plane.

FIG. 3 shows the internal configuration of the camera.

The photographic lens 12 includes first to fourth groups of lenses L1 to L.

This is a zoom lens consisting of four lenses, and includes an image stabilization lens Lc between the third and fourth lens groups L3 and L4. The object light that has passed through the photographic lens 12 is reflected by the main mirror 13, formed into an image on the focus plate 1-4, and observed through the pentaprism 15 and the eyepiece lens 16. Further, the subject light that has passed through the center of the main mirror 13 is reflected by the sub-mirror 17 and guided to the focus detection circuit FD arranged at the bottom of the mirror box. F.P.
is a film surface, and a focal plane shutter (not shown) is arranged just in front of it. The focus detection circuit FD is arranged near a planned imaging plane equivalent to the film plane FP, and detects the focus state of the photographic lens 12 based on the subject light. During exposure control, the main mirror 13 is retracted upward so that it is approximately parallel to the focus plate 14, and the film plane F
A focal plane shutter placed near P moves to perform exposure. During exposure, the drive circuits Cx and Cy drive the camera shake correction lens Lc in the vertical and horizontal directions in response to the detection outputs of the angular velocity sensors Sx and Sy, thereby correcting camera shake.

FIG. 4 is a block circuit diagram of the camera described in item 1.

In the figure, μC is a microcomputer (hereinafter referred to as "microcomputer") that performs sequence, exposure calculation, and exposure control for the entire camera. LM is a photometric circuit that measures the brightness of the subject, converts it into a digital signal, and transmits it to the microcomputer μC. FD 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 an exposure control circuit that controls the aperture and shutter based on the aperture value and shutter speed determined based on the output of the photometry circuit LM. ISO is a film sensitivity reading circuit that reads the film sensitivity SV recorded on the film cartridge and transmits it to the microcomputer μC. SX.

sy is an angular velocity sensor that detects angular velocity in the pitching direction and the rolling direction, respectively. Cx, Cy is a camera shake correction lens drive circuit that receives outputs from the angular velocity sensors Sx, Sy and drives a lens Tc for compensating camera shake in a plane perpendicular to the optical axis.

The D-block SP is a display circuit that displays whether or not focus is achieved.

ZEN is a zoom encoder that transmits the focal length of the zoom lens to the microcomputer μC.

Next, switches will be explained.

The SM has a main switch, and when it is turned on, the camera is ready to drive, and when it is turned off, the camera is stopped. Sl is a photographing preparation switch that is turned on by the first stroke of a release button (not shown), and when turned on, photographing preparation operations such as photometry and focus detection are performed. S
Reference numeral 2 denotes a release switch that is turned on by the second stroke of the release button, and when turned on, exposure control is performed. science fiction
is a tripod switch, which is installed in a screw hole for a tripod 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 explained.

E is a power supply battery, and its direct output voltage VO is the first to
The power is supplied to peripheral circuits CTI to CT3 via third power supply transistors T r 1 to T r 3, respectively. In addition, C1- is a backup capacitor, which is charged by the power supply battery E via the backflow prevention diode D1, and its charging voltage ■DD is the microcomputer μ01 display circuit DI.
Supplied to SP and zoom encoder ZEN. The above-mentioned peripheral circuits CTI to CT3 include circuits with large power consumption, and when they are driven, the voltage of the power supply battery E may drop temporarily, but even during this voltage drop, power is supplied from the backup capacitor C1. The microcomputer μC etc. can operate normally.

This concludes the explanation of the hardware configuration of this embodiment, and next, the software configuration of this embodiment will be explained.

FIG. 5 shows the contents of the interrupt SMIN which is executed when the main switch SM is operated and switched from OFF to ON or from ON to OFF. This interrupt SM
When INT occurs, first the main switch SM is turned on.
It is determined whether or not (#5).

If the main switch SM is OFF, it is determined that the main switch SM has been operated from ON to OFF, and the first
The power supply transistor Tr1 is turned off to stop the power supply to the first peripheral circuit CT including the photometric circuit LM, etc., and the second power supply transistor Tr2 is turned off to stop the power supply to the first peripheral circuit CT including the photometric circuit LM etc. The power supply to the peripheral circuit CT2 is stopped, the display is erased, and the microcomputer μC enters a halt state (#65 to #75). In #5, if the main switch SM is ON, all flags are reset, power supply 1 to transistor Tr2 are turned ON, and power supply to the second peripheral circuit including the angular velocity sensors Sx and Sy is started;
Timer T], reset T2 to 1, star 1- (
#10 to #20). Here, T1 is the entire circuit CTI~CT
A holding timer T2 is used to maintain the power supply to the angular velocity sensors Sx and Sy. Next, in step #25, it is determined whether or not the photographing preparation switch S1 is turned on, and the photographing preparation switch S1 is turned on.
If so, #30 and 31. Execute the ON subroutine and return to #25.

FIG. 6 shows the above S1. The ON subroutine is shown. When this subroutine is called, first, the power supply transistor T r 1 is turned ONL to start supplying power to the first peripheral circuit CTI including the photometry circuit LM, etc.
, execute each subroutine for camera shake detection (# ),
OO~#1-15).

Each subroutine will be explained below.

First, the photometry subroutine described above is shown in FIG.

When the same subroutine is called, it is determined in #200 whether or not focus is indicated and the flag AFEF is set.
If set, returns without updating the photometric value. If the flag AFEF is not set in #200, input the brightness value BV from the photometry circuit LM and the film sensitivity value S from the film sensitivity reading circuit ISO (#
205. #210〉. Then, the exposure value EV is EV =
Determine the aperture value AV and shutter speed TV from the determined exposure value EV based on a predetermined AE program diagram, and return (#2), 5
．． #220).

Next, the AF subroutine described above is shown in FIG.

When the same subroutine is called, first, it is determined in #250 whether or not the shooting preparation switch S1 is turned on.
If it is not turned on, #252 indicates the focus flag A.
Reset FEF and return. If the shooting preparation switch S] is turned on in #250, it is determined in #255 whether the focus flag AFEF is set, and if it is set, it is necessary to perform AP (focus detection). If not, I will return it. #255 If the flag AFEF is not set, the CCD of the focus detection circuit FD
The image sensor performs integration (charge accumulation), and after the integration is completed, data dump is performed, and defocus iDF is calculated based on the dumped data (#260 to #2
70). Then, based on the obtained defocus amount DF, it is determined whether or not it is in focus, and if it is in focus, the focus flag AF is set.
Set the EF to 1~, display the focus, and return (#
275~#285). If the focus is not in focus in #275, the lens driving amount NL to the in-focus position is determined from the defocus amount, the focusing lens is driven by the lens driving circuit LD according to the determined lens driving amount Nl-, and the process returns (
#290. #295>.

Next, FIG. 9 shows a subroutine for determining the camera shake.

When this subroutine is called, first, in #300, data on the focal length f is read from the zoom encoder ZEN, and a fixed camera shake limit speed is determined according to the current focal length 1r. As a guide, the shutter speed that limits camera shake according to the focal length [mm] is 5s = 1/fc seconds],
The APEX value is set as TVf (#305). Let this camera shake limit speed TVf be TVf=TVf+1 (#3)
-0). The reason why the camera shake limit speed TVf is set to be +1 higher than the APEX value is to provide some margin for the determination in #320, which will be described later. Next, in step #312, it is determined whether the tripod switch ST'hL-ON is turned on. When the tripod switch ST is ON, it is assumed that almost no camera shake occurs, and the power supply 1 to
The transistor T r 2 is turned OFF, and the flags FE and LK F are reset to 1 to indicate release lock, and the process returns (#335.#340). 3: Leg switch ST
is not ON, the focus flag AF is set in #315.
It is determined whether or not EF has been set, and if it has not been set, the process advances to #345. When the focus flag AFEF is set in #315, the shutter speed TV calculated in #320 is the camera shake limit speed T.
It is determined whether the shutter speed TV is equal to or higher than Vr, and the shutter speed TV is set to TVf.
If it is less than 1, 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
Then, it is determined whether N≧10 (#325.
#330). If N≧10, power supply I/transistor T
r2 is 0FFL, release lock is not indicated, flag RL
Reset KF and return (#335.
#340). In other words, when the shutter speed TV calculated by the calculation continues to be less than or equal to the camera shake limit speed TVf multiple times (10 times in the example), it is determined that camera shake will not occur, and the angular velocity sensors Sx and Sy are The power supply is cut off. This is the angular velocity sensor Sx,
This is to reduce the power consumption as much as possible since the power consumption of Sy is large. Further, the reason why this determination is made only after focusing is because the photometric value will change unless it is after focusing.

If #330 is N・ku10, proceed to #350.

Further, in #345, N=O is set, and the process proceeds to #350.

In #350, the timer T2 determines whether 15 seconds have elapsed since the start of power supply to the angular velocity sensors Sx and Sy. This is the angular velocity sensor Sx.

This is the time required for Sy to reach a steady state.

If the timer T2 is counting 15 seconds at #350, it can be determined that the detection outputs from the angular velocity sensors S x and S y are steady and accurate. In this case, even if camera shake occurs, camera shake correction can be performed according to the detection output from the angular velocity sensors Sx and Sy, so flags R and I-KF are reset without indicating release lock in #340.
Return. On the other hand, if the timer T2 has not counted 15 seconds in #350, the above flag RI-K is determined in #355.
Set F and return.

Returning to FIG. 6, after executing the photometry, A, F, and camera shake determination subroutines, the program proceeds to #125 and determines whether or not the release switch S2 is turned on. If release switch S2 is OFF, proceed to #155,
It is determined whether or not the photographing preparation switch S1 is turned on, and if it is not turned on, the process immediately returns. On the other hand, when the shooting preparation switch S] is turned on, #1
Reset the power hold timer T1 at 60 1~, star 1
Let me go and return. When the release switch S2 is turned on in #125, it is determined in #130 whether the control shutter speed TV is higher than the camera shake limit speed TVfl. If TV≧TVf, it is assumed that no camera shake occurs, and the power supply transistor T r 2 is turned off in #1-35 to stop the power supply to the second peripheral circuit CT2 including the angular velocity sensors Sx and Sy, and then, Exposure control is performed in #145. As a result, the angular velocity sensors Sx, Sy
This reduces wasteful power consumption. #130 TV<
If TVf is present, the process proceeds to #165, and it is determined whether or not the flag RLKF indicating release lock is set. If it is set, the process proceeds to #155, and exposure control is prohibited. On the other hand, when the flag RLKF is not set to 1~, the power supply transistor T r
3, turn on the image stabilization lens drive circuit CX, Cy.
Power is supplied to the third peripheral circuit CT3 including the third peripheral circuit CT3. As a result, the image stabilization lens drive circuits Cx and Cy are driven based on the detection outputs from the angular velocity sensors Sx and Sy.
Even if camera shake occurs, it can be corrected. Then, the process advances to #145 and an exposure control routine is executed. Regarding the exposure control routine, it is not related to the present invention, so
Illustrations and explanations are omitted. Then, since image stabilization is not necessary after the exposure is completed, the power supply transistor Tr3 is turned off.
and an image stabilization lens drive circuit Cx.

Stops power supply to the third peripheral circuit CT3 including Cy, and #
Proceed to 155.

Returning to FIG. 5, in #25, the photographing preparation switch S1
If it is OFF, the flag AFEF will not indicate focus in #35.
Reset #40 and set the power hold timer T1 to 10.
Determine whether the second has been counted. If the timer T1 is not counting 10 seconds, the process moves to #30 and the subroutine 81ON is executed. #40 If the timer T1 is 10 seconds at 31 o'clock, the power supply transistor Trl is set in #45.
OFF, and the first peripheral circuit C including the photometric circuit LM etc.
Stop power supply to T1, and use #50 to connect power supply 1 to transistor T.
r2 is turned off to stop power supply to the second peripheral circuit CT2 including the angular velocity sensors Sx and Sy, and in step #55, all the display by the display circuit DISP is erased. and,#
Wait until the shooting preparation switch S1 is turned ON at 60, and then press O.
If N, execute the flow from #]0.

[Effects of the Invention] According to the present invention, in a camera shake detection device driven by battery power, when the camera is mounted on a tripod, the power supply to the sensor for detecting vibration of the camera is stopped. This also has the effect of reducing wasteful power consumption by sensors.

Note that if the present invention is applied when the sensor that detects the vibration of the camera is an angular velocity sensor equipped with a high-speed rotating body or a vibrating body, the power consumption of the angular velocity sensor is large.
The effect of reducing power consumption becomes noticeable.

Furthermore, if power supply to the sensor is started when the main switch of the camera is turned on, power consumption when the main switch is turned off can be reduced, and the detection output of the sensor can be stabilized at an early stage.

Furthermore, by providing an image stabilization device that drives a part of the photographic lens according to the detection output of the sensor, it is possible to correct camera shake during photography and to photograph low-brightness subjects at low shutter speeds even without a tripod. In this case, if power is supplied to the image stabilization means from the battery power supply only during shooting, the power consumption by the image stabilization means during non-photography can be reduced, which is advantageous.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the basic configuration of the present invention, Figure 2 is a perspective view conceptually showing the configuration of a camera as an embodiment of the present invention, and Figure 3 is the same optical system and camera shake detection. FIG. 4 is a block circuit diagram of the system, and FIGS. 5 to 9 are flowcharts for explaining the operation of the system. E is a battery power supply, 1 is a sensor, 2 is a power supply means, 3 is a tripod attachment detection means, 4 is a power supply control means, 5 is an image stabilization means, and 6 is a second power supply means.

Claims (4)

[Claims] (1) A camera shake detection device powered by battery power, which includes a sensor that detects camera vibration, a power supply means that supplies power to this sensor from battery power, and detects when the camera is mounted on a tripod. A camera shake detection device comprising: a tripod attachment detection means; and a power supply control means for stopping power supply to a sensor by a power supply means when tripod attachment is detected. (2) The camera shake detection device according to claim 1, wherein the sensor is an angular velocity sensor. (3) The camera shake detection device according to claim 1 or 2, wherein the power supply means starts supplying power to the sensor when a main switch of the camera is turned on. (4) It is characterized by further comprising an image stabilizing means that drives a part of the photographing lens in accordance with the detection output of the sensor, and a second power supply means that supplies power to the image stabilizing means from a battery power source only during shooting. The camera shake detection device according to claim 1.