JP2003140220A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera capable of taking a photograph hardly influenced by camera shake by giving a warning so that a user who does not pay attention to camera shake may call his (her) attention to holding even when such a user uses the camera in a situation that a user who does not know that the photograph out of focus is taken because of a camera shake in the case of photographing, exists. SOLUTION: This camera is equipped with a camera shake detection mode for judging camera shake by a holding check function utilizing an acceleration sensor and an image sensor for range-finding. When the camera shake detection mode is set, the shake of the camera in the XY direction is detected in a photographing mode other than a forcible strobe light emitting mode, and the moving amount of the camera is exactly calculated while dealing with a dark scene or a low-contrast scene according to output from the image sensor. In the case of judging that the shake state of the camera causes a camera shake phenomenon on the photograph to be taken, a photographer or the user is warned of it within or near the finder of the camera or on the front surface of the camera as necessary, and such setting is performed by using a self mode switch.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for preventing camera shake, which detects camera shake that occurs when shooting with a camera and gives a vibration warning to a photographer.

[0002]

2. Description of the Related Art Normally, when a photographer holds a camera by hand to take a picture, a camera shakes during exposure, resulting in a failure photograph, so-called camera shake may occur.
In order to prevent this camera shake, various anti-vibration techniques have been studied. This anti-vibration technique is divided into two techniques: detection of vibration and countermeasures against the detected vibration.

Further, the technology for preventing camera shake is classified into a warning technology for making the user recognize a camera shake state and a technology for controlling the taking lens to prevent image deterioration due to camera shake. Among them, as a warning technique, the present applicant has proposed, for example, in Japanese Patent Application No. 11-201845, a camera that suppresses a failure due to a camera shake by devising a display means.

An example in which a distance measuring sensor is applied is also disclosed in Japanese Patent Laid-Open No. 2001-165622, which was previously published in Japanese Patent Publication No. 62-62.
No. 27686.

[0005]

If a recent camera has been set to an automatic shooting mode or the like, the camera automatically performs distance measurement and photometry at the time of shooting, and is set to appropriate shooting conditions. For this reason, almost no failed photos have occurred.

However, some ordinary users do not know that if the camera shakes due to camera shake during shooting, a blurred image will be generated, and the shutter button is pushed deeply without being aware of camera shake prevention to shake the camera. There is a person who ends up. For example, when handing a camera to another person and requesting a release in order to get a picture of himself / herself while traveling, the person who is unfamiliar with the handed camera can use the camera shown in FIG. As shown in a)
In many cases, the camera was shaken so much that the image became out of focus.

Even in such a situation, it is desired to have a photograph taken without blurring. In other words, there is a demand for a camera that can be used by a user who does not pay attention to camera shake, for example, to warn the holding state by a warning displayed on the camera and take a photograph with little effect of camera shake.

In view of this, the present invention is provided with a camera shake detection mode that makes it easy to recognize in the viewfinder or in the vicinity by using an existing member when camera shake occurs at the time of shooting, and the setting is made by operating an existing switch. It is an object of the present invention to provide a camera that gives a handshake warning to a photographer or a user as needed to warn the user or the user of handshake prevention without increasing the cost with a simple configuration.

[0009]

In order to achieve the above object, the present invention provides a camera shake detecting means for detecting a camera shake state and a first flash light emission mode of the camera.
An operation member, a second operation member for setting and switching the self-timer function and the remote control function of the camera, and a shake detection mode for warning the user when a shake of a predetermined amount or more is detected by using the shake detection means, The camera shake detection mode provides a camera that is set by scrolling the mode by operating the second operation member. Further, in the case of the forced light emission mode in which the camera shake detection mode is set by operating the first operation member, the camera shake detection mode is not set.

The camera having the above-mentioned structure is highly reliable by effectively utilizing the image sensor mounted on the camera, which has been conventionally used only as a distance-measuring sensor, and used together with the acceleration sensor having a simple structure. The camera shake detection is possible, and the camera shake detection mode is set by scrolling by existing switch operation except when the forced light emission mode is set.

[0011]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. In this embodiment, a liquid crystal display means is provided in the viewfinder of the camera for displaying a photographing range (viewfinder field) according to a change in light transmittance, and as a camera shake determination, the distance measuring sensor described above and other monolithic accelerometers are used. When a camera shake occurs, the transmittance of the display area of the liquid crystal display means is changed in a pattern to provide the user with a vibration detection means for detecting the camera shake and suggesting the occurrence of camera shake. This technology makes it easy to recognize the occurrence of camera shake.

The monolithic accelerometer, which is formed on an IC chip, is a device for detecting vibration by utilizing a capacitance change generated between a movable pattern and an immovable pattern. Is, for example, JP-A-8-178.
It is possible to use those proposed in Japanese Patent Publication No. 954, etc.

As its constitution, both patterns are both formed of a polysilicon member on a silicon substrate,
A pair of capacitors is formed with one electrode movable and responsive to acceleration, while the other electrode is stationary with respect to acceleration. When acceleration is applied to such a silicon substrate, the capacitance of one capacitor increases and the capacitance of the other capacitor decreases. A signal processing circuit for converting these differential capacitances into voltage signals is required, and these movable electrodes, capacitors, and signal processing circuits are monolithically formed on the same substrate.

Further, Japanese Patent Application Laid-Open No. 8-178954 describes an application for actuating a safety device such as an automobile braking system and an air bag, and by making it monolithic, dimensional cost, required power, Although it has been described that the device is excellent in reliability, the present embodiment effectively arranges and controls such elements, keeps the above characteristics, adds a situation peculiar to the camera, and effects with high accuracy. Realizes an anti-vibration camera. This portion may be configured by a so-called shock sensor or the like that detects a shock or the like.

1 and 2 show an example of the structure of a camera according to an embodiment of the present invention. FIG. 1A shows the appearance of the camera and the internal structure of a part thereof, and FIG.
FIG. 1 is a diagram showing a positional relationship between a hard printed circuit board and a flexible printed circuit board (hereinafter, referred to as a flexible printed circuit), which is a feature of this embodiment, and FIG. 1C shows a distance measuring optical system of the present invention. 2 is a diagram showing an electrical block configuration of the camera of the present embodiment.

As shown in FIG. 1A, on the front surface of the camera 10, in addition to the taking lens 9 and the strobe 8, a finder objective lens 15, a distance measuring section for auto focus (AF) and photometry are used. The light receiving lens of the photometric distance measuring unit 5 and the like are arranged. Inside this camera, an electronic circuit for fully automatic operation of the camera is provided. This electronic circuit also includes the above-mentioned monolithic accelerometer (acceleration sensor) 3 mounted on the rigid printed circuit board 14. In order to show the positional relationship, a part of the internal structure is shown in FIG. It is cut so that it can be seen.

In addition to the acceleration sensor 3, a one-chip microcomputer (CPU) 1 for controlling the operation relating to photographing of the entire camera and an actuator such as a motor are operated on the hard printed circuit board 14 to operate the mechanical mechanism. An interface IC (IFIC) 2 for driving the unit is mounted. Further, in the vicinity of the CPU 1, for example, an EEPROM is provided as a memory 4 for storing adjustment data for component variations in the camera assembly process.

FIG. 1B is a view showing the relationship between the hard printed board 14 and the flexible board 7 when the camera is viewed from the lateral direction. This rigid printed circuit board 14
Since is not bent along the curved surface inside the camera, the flexible substrate 7 is used and is connected by the connector 12. The display element (LC
D) 6 is mounted, and a communication line with the autofocus (AF) sensor 5c and a switch pattern 13 are formed. The flexible board 7 wraps around to the back of the camera, and a notification element such as a sounding element PCV or an LED in the warning display section 11 as shown in FIG. 1B is mounted, and is output from the CPU 1 to the warning display section 11. In addition to transmitting the signal, the AF sensor 5c is also capable of transmitting and receiving the signal.

As shown in FIG. 1C, the AF sensor 5c uses the well-known principle of triangulation to measure the subject 101.
Of the image signal 10 of the subject 101.
2 can be detected by two sets of the light receiving lens 5d and the sensor array 5e, and the subject distance L can be detected from the relative position difference x.

Generally, the subject has a vertical shadow, and the two light receiving lenses 5d are arranged in the horizontal direction (X direction) as shown in FIG. 1 (a). The sensor array 5e is also divided in the horizontal direction. With such an arrangement, an image shift in the X direction caused by a camera shake in the lateral direction can be detected by the AF sensor. Therefore, as shown in FIG.
It is placed in the direction that detects blurring in the Y direction rather than the direction, and X
Detection in both Y directions is complemented by another sensor.

Here, the acceleration sensor 3 will be described with reference to an example of the manufacturing process shown in FIG. First, an oxide film 21 is formed on a silicon substrate (IC chip) 20 (FIGS. 3A and 3B), a pattern is formed on the oxide film 21 by a resist mask, and the exposed portion is etched. Then, the resist mask is removed and the opening can be formed in an arbitrary portion (FIG. 3C). Then, after depositing a polysilicon layer 22 (see FIG.
(D)) When the oxide film 21 is selectively removed by wet etching, a polysilicon layer 22 is formed on the silicon substrate 20 in a bridge structure (FIG. 3).
(E)). Impurities such as phosphorus are diffused into the polysilicon layer to make it conductive. With this type of bridge structure, the movable electrodes 22 having pillars at four corners as shown in FIG. 4B are formed on the silicon substrate 20.

Also, on the silicon substrate 20, FIG.
As shown in (a), separate electrodes 24 and 25 are formed and arranged adjacent to the arm portions 23a and 23b of the movable electrode 22 described above, whereby the arm portion 23a, the electrode 24, and the arm portion 23 are formed.
A small capacitor capacitance is formed between b and the electrode 25.
Further, as shown in FIG. 4C, an IC chip having this movable electrode structure arranged on the silicon substrate 20 can be used as a monolithic IC with a processing circuit capable of determining acceleration in a predetermined direction.

That is, as shown in FIG. 4C, the processing circuit section 29 is formed on-chip on this chip together with the monolithic movable electrode capacitor. This is to detect a capacitance component changing by the movable electrode 22 and output a signal according to the acceleration. The movement of the bridge-shaped movable electrode 22 increases one of the capacitances formed in the two electrodes and decreases one of them, so that the acceleration in the arrow direction of FIG. 4B can be detected. Therefore, if this IC chip is mounted on a camera,
The acceleration in the Y direction can be determined as in (b).

FIG. 5A shows a configuration example of the processing circuit 29. As described above, a capacitance component is formed between the arm portions 23a and 23b included in the acceleration 3 for detecting the movement in the Y direction and the electrode 24, and between the arm portion 23b and the electrode 25, and the arm portion 23a, The movement of 23b changes these capacities. This capacitance change is converted into an electric signal by the processing circuit 29.

The processing circuit 29 includes a carrier wave generator (oscillation circuit) 31 that oscillates a carrier wave having a pulse waveform, and a demodulation circuit 32 that demodulates the respective oscillation waveforms changed by the capacitance change of the acceleration sensor 3 by full-wave switching rectification.
And a filter circuit 33 that outputs an acceleration-dependent analog signal, and a PWM signal generation circuit 34 that performs analog-PWM conversion. The output waveform is shown in FIG. In this way, the duty ratio of the pulse (ratio of T1 and T2) changes according to the acceleration.

Therefore, the acceleration sensor 3 outputs a voltage signal proportional to the acceleration or a pulse width modulation (PWM) signal proportional to the acceleration. The CPU 1 that can handle only digital signals can detect acceleration by demodulating a PWM signal using a built-in counter. For the voltage signal proportional to the acceleration, a regulator having an A / D converter may be used. If the PWM signal is used, the CPU
It is not necessary to mount the A / D converter in 1.

FIG. 2A shows a block circuit diagram of a camera in which such an acceleration sensor 3 is mounted, which will be described. In this configuration, the CPU that controls the entire camera
1, an IFIC 2, a monolithic accelerometer (acceleration sensor) 3, and a memory (EEPR) for storing adjustment data.
OM) 4, an autofocus (AF) unit 5a, a photometric unit 5b, an AF sensor 5c, and a liquid crystal display element (LCD) for displaying the setting state of the camera and information regarding shooting.
6, an in-viewfinder LCD 6a that is provided in the finder to display information related to shooting, a strobe unit 8 including an arc tube that emits auxiliary light, and a main capacitor 8a that charges the arc tube to emit light. , A photographing lens 9 having a zooming function, a warning display portion 11 including an LED, a resistor 11a connected in series to the warning display portion 11, switches 13a and 13b for starting a photographing sequence of the camera, and a remote controller. , A self-switch 13c set to execute a self-timer and a holding check function, and a flash switch 13d for changing the flashing state of the strobe of the camera,
A motor 18 that drives a driving mechanism such as a photographing lens, a shutter, and a film feeding device, a rotary blade 16 that rotates in conjunction with the motor 18, and a motor 18 that rotates for drive control of the motor 18. When driving each drive mechanism such as the zoom lens 19 and the zoom lens barrel, the drive destination may be switched by the switching mechanism, or a separate motor may be provided for each drive mechanism.

In this structure, the CPU 1 controls the photographing sequence of the camera according to the operating states of the switches 13a and 13b. In other words, according to the output of the monolithic accelerometer 3, in addition to the warning display by the in-view LCD 6a for the camera shake warning, the AF unit 5a at the time of shooting and the photometric circuit 5b for measuring the brightness of the subject for exposure control are driven to output the necessary signals. Then, the motor 18 is controlled via the IFIC 2 described above. At this time, the rotation of the motor 18 is transmitted to the rotary blade 16, the IFIC 2 waveform-matches the signal output by the photo interrupter 17 according to the position of the adjustment hole, and the CPU 1 monitors the rotation state of the motor 18. In addition, the strobe unit 8 emits auxiliary light as needed.

FIG. 16 shows an example of a warning pattern displayed on the LCD 6a in the finder.
As the in-finder LCD 6a, the one used for the screen display in the panorama mode, the blackout display indicating that the shutter is released, or the like is diverted.

The light-shielding pattern which is obtained by combining the screen A and the screen C shown in FIG. 16 is a light-shielding pattern which is displayed when the panoramic photography is set, and is used. First, as shown in screen A, only the upper area is shielded from light, then, as shown in screen B, only the central area showing the shooting range at the time of panoramic shooting is shielded, and finally, as shown in screen C, the panorama light shield unit This is a pattern in which the light shielding of only the lower region of the above is sequentially and repeatedly performed. By repeating this display form, the user looking into the finder can recognize that the hand shake is occurring (if the patterns A, B, and C are shielded at the same time, the blackout display can be performed). .

Since such a display makes it possible to express the feeling that the viewfinder screen is shaking, when the user re-holds the camera and the camera shake does not occur, the screen D of FIG. 17 (b)
The screen E is displayed again, and the subject can be monitored.

FIG. 18 shows a display example of the camera shake warning displayed on the LCD 6a. This display example is shown in FIG.
Similarly, the light shielding part displayed when the panoramic shooting is set is used in the pattern described in the above. In this pattern, the upper and lower light-shielding portions are alternately displayed as screen A and screen C. Unlike the pattern in FIG. 16, this pattern does not obscure the panoramic shooting mode and the facial expression of the subject because the central portion of the screen is always visible. Further, since the blinking is performed, unlike the normal display in FIGS. 17A and 17B, the user does not misunderstand.

Next, the vibration detection principle of the camera thus constructed will be described with reference to FIG. Figure 6
As shown in (a), when the user 100 holds the camera with one hand and holds it, the camera tends to be slightly shaken in an oblique direction.
It can be decomposed into the movement in the Y direction. In general, most users are unconscious about such minute vibrations causing the effect of “camera shake” during shooting.
Since the camera detects this minute vibration and performs the display as described with reference to FIGS. 16 to 18 above, the user takes a measure to suppress the vibration, such as holding the left hand 100a in the camera, for photographing. Therefore, it is possible to take a picture without failure due to camera shake.

However, if a warning is given at all times, it will be troublesome for the photographer. Experienced users who are careful about camera shake may rather enjoy taking pictures that make effective use of this camera shake.
The holding check function is set to one of the modes, for example, the camera shake detection mode, and devised so that it can be set only when the user thinks it is necessary. That is, FIG.
A mode changeover switch 13c and a liquid crystal display unit 6 as shown in FIG. 7A are provided, and in the normal state, only the functions of the film counter and the like shown in 6a are displayed. And
If the user 100 operates the mode changeover switch 13c to set the camera shake detection mode as shown in FIG. 8B, the display segments 6b and 6c as shown in FIGS. The camera shake detection mode setting display is displayed. In this camera shake detection mode setting display, only the display segment 6b blinks, and the user can recognize that the mode is set.

This camera shake detection mode setting display is shown in FIG.
Since a part of the segment of the self-timer mode display 6d as shown in (d) is also used, it is not necessary to secure a space for creating a new segment in the LCD, and the layout is not burdened. As shown in FIG. 9, these segments are formed by dividing a segment for self-timer mode display into a plurality of segments, which are wired to each other and are configured so that respective parts can be independently display-controlled. ing.

There are various light emission modes in the strobe mode of the camera depending on the photographing conditions. For example, the strobe automatically emits light when a subject is in a dark state, a backlit state, or under artificial light such as a fluorescent lamp. Auto mode, red-eye reduction mode to prevent red-eye photography by shrinking the pupil of the subject by strobe pre-flashes or self LED lighting before starting exposure when strobe flash is required in the auto mode,
When shooting in places where flash photography is prohibited, or when you want to take pictures that take advantage of the mood there, strobe off mode that forcibly stops the flash firing, or when the subject is shaded, unnatural shadows If you want to turn off the flash, or in a backlit scene, the flash will always fire to prevent the subject's face from becoming underexposed when taking pictures. There are a night-view mode in which a subject is illuminated with appropriate brightness and a night-view red-eye reduction mode in which a red-eye reduction effect is added to the night-view mode.

The flash mode is the flash SW1.
Press 3d to change sequentially. The holding check mode is switched to the normal state, the self-timer use mode, the remote control mode, and the holding check mode by pressing the self SW 13C. In the self-timer mode and the remote control mode, the user usually fixes the camera on a tripod or the like and therefore does not need to activate the holding check function when the mode is set. Further, in the forced light emission mode, the background is often bright, and the strobe emits light, which makes it difficult for a camera shake photograph to occur. Therefore, similarly, it is not necessary to operate the holding check function.

Referring to the flow chart shown in FIG.
The change to the camera shake detection mode that operates the holding check function will be described. First, the change to the camera shake detection mode is started by the user operating the self SW 13c. It is determined whether or not the currently set mode is the self-timer mode (step S1). If the self-timer mode is set in this determination (YES), the mode is changed to the remote control mode (step S
2). On the other hand, if the self-timer mode is not set (NO), it is determined whether the remote control mode is set (step S3).

If it is determined in step S3 that the remote control mode is set (YES), it is determined whether or not the current strobe mode is the forced flash mode when the camera shake detection mode is switched to next. Yes (step S4). On the other hand, if the remote control mode is not set (NO), it is determined whether or not the currently set mode is the camera shake detection mode (step S5).

If it is determined in step S4 that the strobe forced light emission mode is not set (NO), the camera shake detection mode is set. However, if the strobe forced light emission mode is set (YES), the camera shake detection by the holding check function has little effect, and therefore the camera shake detection function is not switched to the normal mode (step S7). If it is determined in step S5 that the camera shake detection mode is set (YES), the process proceeds to step S7 to switch to the normal mode. If the camera shake detection mode is not set (NO), the normal mode is set. Therefore, the mode is switched to the self mode (step S8).

Next, the change to the strobe mode will be described with reference to the flowchart shown in FIG. First, the change to the flash emission mode is started by the operation of the self SW 13d by the user.

It is determined whether or not the currently set strobe mode is the auto mode (step S11). If the auto mode is set in this judgment (YE
S) and switch to the red-eye reduction mode (step S1)
2). On the other hand, if the auto mode is not set (N
O), and it is determined whether the red-eye reduction mode is set (step S13). If the red-eye reduction mode is set in this determination (YES), the flash-off mode is switched to (step S14). However, if the red-eye reduction mode is not set (NO), it is determined whether or not the strobe off mode is set (step S1).
5).

If it is determined in step S15 that the strobe off mode is set (YES), it is determined whether the camera shake detection mode is currently set (step S16). If the camera shake detection mode has been set (YES), the holding check function is unnecessary in the forced light emission mode to be set later, so the setting of the camera shake detection mode is cleared (step S17). However, when the flash SW 13d is pressed again to release the forced light emission mode, the backup flag of the camera shake detection mode is set to 1 in order to reset the camera shake detection mode.
Is set (step S18). After that, the forced light emission mode is set (step S19). On the other hand, if the camera shake detection mode is not set in step S16 (NO), the backup flag of the camera shake detection mode is cleared (step S20).

If it is determined in step S15 that the strobe off mode is not set (NO), it is determined whether the forced light emission mode is set (step S21). Here, if the forced light emission mode is set (YES), it is determined whether or not the backup flag of the camera shake detection mode is set to 1 (step S
22) If the flag is set (YES), the camera shake detection mode has been canceled when the forced light emission mode was previously set, and therefore the camera shake detection mode is set again (step S23). Then, the backup flag of the camera shake detection mode used is cleared (step S
24), the strobe mode is set to the night view mode (step S25). On the other hand, the flag is set to 1 in step S22.
If is not set (NO), the process proceeds to step S24.

If it is determined in step S21 that the forced light emission mode is not set (NO), it is determined whether the night view mode is set (step S2).
6) If the night view mode has been set (YES),
The night-view red-eye reduction mode is set (step S27). If the night-view red-eye mode is not set (NO), the night-view red-eye mode is set, and thus the mode is returned to the automatic mode (step S28).

FIG. 12 and FIG. 13 show the appearance of an example of the configuration of a camera having such a camera shake detection mode. Here, FIG. 12 shows the configuration viewed from the rear side of the camera,
FIG. 13 shows the configuration seen from the front oblique direction. With reference to these drawings, the function of warning the occurrence of camera shake due to the holding check will be described.

As shown in FIG. 12, a finder eyepiece portion 61 is provided on the back surface of the camera 10, and a light emitting diode (LED) 11 is provided beside it. The LED 11 is displayed in a blinking manner when the camera shake occurs, and the user can recognize the warning even when the camera is held. When such a warning is recognized, for example, as shown in FIG. 6A, the left hand 100a is attached to the camera held by the photographer with one hand (right hand) to hold the camera more firmly. You can take measures to prevent shaking. On the top surface of the camera 10, a mode display LCD 6 and a mode setting switch 1
3c, a release button 51, etc. are provided.

As shown in FIG. 13, a photographing lens 63 is provided on the front surface of the camera 10, a finder objective lens 64 and a light receiving lens of the photometric distance measuring unit 5 are provided above the photographing lens 63, and a strobe light emitting section 62 and LE for self-timer
D65 is arranged. If the LED 65 is also displayed in a blinking manner when a camera shake occurs, it is possible to know whether or not the camera shake has occurred to the photographer who requested when the user was in front of the camera.

As shown in FIG. 13, the front surface of the camera 10 is provided with a barrier 10a that is slidable and covers the taking lens 63, the finder objective lens 64, and the light receiving lens of the photometric distance measuring unit 5 when being carried. There is. The barrier 10a also serves as a power switch, and when opened, the power is turned on so that the retracted photographing lens 63 is extended to a predetermined position to enable photographing, and when closing the photographing lens 63, photographing is performed. The lens 63 may be retracted in the camera to have a function of turning off the power.

The LED 11 provided in the vicinity of the viewfinder eyepiece lens 61 on the rear surface side of the camera described above may also be used as an existing LED for displaying the charging status of the strobe or the AF focusing display.

After the camera shake detection mode is set, if the camera is shaken due to unstable holding when holding the camera, the LCD in the viewfinder blinks as described above, or as shown in FIG. Alternatively, the LED 11 in the vicinity of the camera finder eyepiece 61 may be blinked to give a warning.

Further, when such shaking occurs, the self-timer display LED 6 provided on the front surface of the camera.
By providing the function of making 5 blink, for example, the user of the camera can recognize the shaking state of the camera of the photographer who has requested for photographing himself.

Referring to FIG. 7, the AF sensor 5c described above is used.
The relationship between the output (image signal) and the output of the acceleration sensor 3 will be described. In this explanation, it is assumed that the camera held by the user is causing a camera shake having movements of both components in the X and Y directions as shown in FIGS. 6A and 6B.

First, the camera swing is large, that is,
If the moving distance is long, as shown in FIG.
The moment t moves t = t1 Acceleration sensor 3 at the timing of
Outputs a signal when the camera starts moving. Only
Then, if it is moving at a constant speed, the camera is shaking.
However, the acceleration sensor 3 has no acceleration.
Therefore, the detection signal is not output. The camera stopped again
When t = t7 At the timing of this time, this time the constant speed exercise
The output result is output in such a direction as to stop. Tsuma
This means that camera shake is difficult to detect.
However, the image sensor (AF sensor 5c) of the camera moves at a constant speed.
Outputs a continuously changing image signal even when it is in motion.
Therefore, if this output result is judged, the output of the acceleration sensor 3
Even if is 0, the camera CPU1 is
And the output of the acceleration sensor 3 can be supplemented.
It

Further, when the swing width of the camera is small, that is, when the moving distance is short, as shown in FIG. 7B, the image signal detected by the AF sensor 5c hardly changes, but the acceleration sensor 3 Is output each time the shaking repeats. Such small shaking is a tremor of the hand transmitted to the camera when the photographer holds the camera in an attempt to fix and hold the camera, which is different from FIG. 7A. However, depending on the focal length, it is often possible to take a picture with no problem even if the picture is taken in a state in which the shaking is actually occurring. That is, even if the acceleration sensor 3 outputs a large output, the camera may only make a slight movement, and even if the output interval of the acceleration sensor 3 is open, the camera position may change significantly.

Further, there are some limits to the blur determination by the AF sensor 5c. For example, in a scene where the main subject has no contrast compared to the background, or in a dark scene where the main subject cannot be identified, changes in the subject image are not detected,
I can't judge. In addition, as in this embodiment,
A sensor that has only one direction cannot detect movement of the camera or image change in a direction different from that, and when the camera shakes too much, the position monitored by the AF sensor 5c deviates and the image is completely removed. Therefore, it becomes impossible to accurately judge the amount of shaking. Therefore, it is necessary to properly use these two sensors to determine vibration.

With reference to the flow charts shown in FIGS. 14 and 15, the output (image signal) of such an AF sensor 5c is obtained.
Then, the warning display operation of the camera with a camera shake detection mode function equipped with a sensor based on the output of the acceleration sensor 3 will be described. The sequence of this warning display is performed according to the program built in the CPU mounted in the camera. For example, in the camera shown in FIG. 13, when the barrier 10a for protecting the taking lens 63 on the front surface of the camera is opened, it becomes possible to take a picture, and this display sequence starts to move.

First, the user carries out framing with the camera ready to take a picture, and the approximate composition is determined. At this time, since the holding operation has not been started yet and the camera is largely moved, the determination based on the detection result by the AF sensor 5c is not effective. That is, since the AF sensor 5c monitors only a narrow portion within the shooting screen, it is not possible to quantitatively evaluate a large camera shake.

Therefore, it is first determined whether or not the output of the acceleration sensor 3 is larger than a predetermined value (step S1). In this determination, when the output of the acceleration sensor 3 is larger than a predetermined value (YES), it is determined that a shake occurs when the barrier 10a is opened and a shake occurs until the user determines the composition of the photograph with the camera. Then, the warning is not displayed for a predetermined time after the start of the shaking, the display of the shaking warning is prohibited (step S2), and the shaking is continuously detected. However, when the output of the acceleration sensor 3 is smaller than the predetermined value (N
O), the composition of the photograph is determined, it is determined that the state of holding has been entered, and the process proceeds to image detection using the AF sensor 5c (step S3).

By this image detection, it is determined whether or not the luminance is lower than a predetermined value in order to determine whether or not the image state is a photographing state in which camera shake detection can be performed (step S).
4). If it is determined that the brightness is low in this determination (YE
S), it is assumed that the image signal from the AF sensor 5c is not used for the hand-shake warning, and the process shifts to the next shake determination sequence based on the output of the acceleration sensor 3. In this shake determination, it is determined whether or not the acceleration sensor 3 outputs a detection signal (step S5). If the acceleration sensor 3 outputs a detection signal in this determination (YES), a detection signal in the opposite direction is output. It is determined whether it has been done (step S6). Here, if the reverse detection signal is not output (NO),
The time until detection is counted to determine whether or not the predetermined time has been reached (step S7). If the predetermined time has been reached (YES), the occurrence of camera shake is warned (step S8).

This warning judgment is made when the acceleration sensor 3 outputs a detection signal and when the detection signal indicating the reverse acceleration is not detected for a predetermined time, as shown in FIG. This is for discriminating an object that is still moving in, and for allowing a photographer (user) to recognize that camera shake may occur. It should be noted that in the determination of this state, the user may be intentionally performing follow shots, and therefore, for example,
Without blinking the LCD in the viewfinder (FIGS. 16 and 18), as shown in FIG. 12, a warning using the AF sensor 5c is used as a warning only for blinking the LED 11 near the viewfinder eyepiece 61. May have different warning displays.

On the other hand, if the reverse direction detection signal is output in step S6 (YES), it is determined whether relays have been performed (step S9). If the release is performed (YES), step S20 described later.
Shift to range finding. On the other hand, if the release has not been performed (NO), the process returns to step S3.

If it is not determined that the luminance is low in step S4 (NO), it is determined whether the contrast of the subject is lower than a predetermined value (step S10), and the brightness is lower than the predetermined value. If it is determined that the contrast is low (YES), the sequence proceeds to step S5 and subsequent steps, and if it is not low contrast (NO), it is determined that the image signal is suitable for the shake determination.

Next, when the image signal is suitable for camera shake determination, the number of detections n = 0 is set (step S11), and the image is detected by the AF sensor 5c as described with reference to FIG. The image detection result is set to X0 (step S
12). Then, after a predetermined time has elapsed (step S13), n is incremented (step S1).
4), image detection is performed (step S15). The image signal obtained here is the previously detected image signal (step S only for the first time).
It is determined whether or not the difference from the image signal obtained in 3) is larger than a predetermined level Xc (step S16). If the difference is larger than the predetermined level Xc in this determination (YE
S), it is determined that the photographer's holding state is insufficient and the camera is shaking, and a camera shake warning is issued (step S17). With this camera shake warning, the photographer can recognize that camera shake has occurred, and can take various measures such as holding with both hands or placing it on something.

After the warning, it is judged whether or not the difference between the image signals is larger than a predetermined level Xcc which is larger than the predetermined level Xc (step S18). If the difference is larger than the predetermined level Xcc in this determination (YES), it is determined that the photographer has taken a completely different angle or changed the composition, and the process returns to step S1. However, if the difference is not larger than the predetermined level Xcc (NO), the process returns to step S13 and the image signal is detected.

If it is determined in step S16 that the difference between the image signals is not larger than the predetermined level Xc (NO),
It is judged that the holding state is stable and the release is possible. After this determination, it is determined whether the release button has been operated (step S1).
9). Here, if the release button is not operated (N
O), and returns to step S13. However, if it is operated (YES), the process moves to the following exposure sequence.

First, distance measurement is performed (step S20),
Focusing is performed based on the distance measurement result (step S21). Next, the exposure time is determined by the brightness information obtained by the image detection in step S3, the exposure is started, and the time measurement by the counter is started (step S22). If the camera shakes during this exposure, camera shake occurs, so the acceleration is detected again, and the acceleration g due to a shock or the like when the release button is pressed is obtained (step S23). If this acceleration g is large,
If the exposure time is short, the photograph will be blurred, and if the acceleration g is small, the photograph will be blurred if the exposure time is long. In order to determine this, if the exposure time tEND is reached (step S24), the count-up is performed and the exposure ends (step S25).

Then, the obtained acceleration g and exposure time t
The speed is calculated from END, and the movement speed (1/2 gt END ² ) is calculated from the fact that the speed has changed for the time t END depending on the speed obtained. It is determined whether or not this movement amount exceeds the allowable amount ΔY of the photographing lens (step S26). If the amount of movement exceeds the allowable amount ΔY (YES), a camera shake warning is given (step S27). However, if it does not exceed (NO), the process returns.

As described above, only the acceleration change due to camera shake can be used as the criterion for determining the occurrence of camera shake, and only the change in speed can be known. However, in the present embodiment, first, the AF sensor 5c indicates that the camera is stopped at a predetermined position. Since the determination is made by not changing the output (image signal) of, the reference can be used to accurately determine how much the camera has moved during exposure.

As described above, according to the present embodiment, the image sensor for AF is not only used for distance measurement, but also effectively used as a holding check for camera shake determination, thus adding value to the camera. Can be increased. Also used in combination with the signal from the acceleration sensor,
Detects sway in the direction and supports dark scenes and low-contrast scenes. Also, by using it as a stillness detection sensor, it is possible to accurately calculate the camera movement amount from the output of the acceleration sensor. As a result, it is possible to realize accurate camera shake determination after shooting according to the focal length and aperture of the shooting lens and the shutter speed during shooting. Further, it is needless to mention again that if the photographing lens position is corrected based on this calculation result, it can be applied to a camera with an anti-vibration function.

[0071]

As described above, according to the present invention,
Especially in situations where camera shake is a concern, if the camera shake detection mode is set by the holding check function, when a camera shake occurs, the existing light-shielding pattern provided in the viewfinder and the display member provided on the exterior of the camera allow the photographer and the user to see it. Since the camera shake warning is issued to the camera to recognize the camera shake, it is possible to take a photograph without camera shake failure even if the user is the photographer or the user himself becomes the main subject. Furthermore, for camera shake detection,
In addition to the acceleration sensor having a simple structure, the image signal output from the existing distance-measuring sensor is effectively used, so that the cost increase can be suppressed slightly and highly reliable determination can be performed. In addition, the camera shake detection mode that operates the holding check function is switched by operating the existing self-switch.In addition, in the flash forced flash mode, which does not easily result in camera shake photography, the camera shake detection mode is not set, and It can be used easily without increasing.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration example of a camera and a ranging theory according to an embodiment of the present invention.

FIG. 2 is a diagram showing an electrical block configuration of the camera of the embodiment.

FIG. 3 is a diagram showing an example of a manufacturing process of an acceleration sensor.

FIG. 4 is a diagram for explaining a configuration and an operation of an acceleration sensor used in the camera of the embodiment.

FIG. 5 is a diagram showing a configuration example of a processing circuit used in the camera of the embodiment.

FIG. 6 is a diagram for explaining the principle of camera vibration detection.

FIG. 7 is a diagram for explaining the relationship between the output of the AF sensor and the output of the acceleration sensor.

FIG. 8 is a diagram for explaining setting of a camera shake detection mode and setting display.

FIG. 9 is a diagram showing an example of a segment for self-timer mode display.

FIG. 10 is a flow chart for explaining a change to a camera shake detection mode.

FIG. 11 is a flowchart for explaining a change to a strobe mode.

FIG. 12 is a diagram showing an example of an external appearance of a camera having a camera shake detection mode according to an embodiment, as viewed from a rear oblique direction.

FIG. 13 is a diagram showing an example of an external appearance of a camera having a camera shake detection mode according to an embodiment as viewed from a front oblique direction.

FIG. 14 is a first half portion of a flowchart for explaining a warning display operation of the camera with a shake detection mode function of the embodiment.

FIG. 15 is a second half of a flowchart for explaining a warning display operation of the camera with a shake detection mode function of the embodiment.

FIG. 16 is a diagram showing a first example of a warning pattern displayed on the LCD in the viewfinder of the camera.

FIG. 17 is a diagram showing an example of a normal shooting pattern and a panoramic shooting pattern displayed on the LCD in the viewfinder of the camera.

FIG. 18 is a diagram showing a second example of a warning pattern displayed on the LCD in the viewfinder of the camera.

[Explanation of symbols]

1 ... CPU 2 ... IFIC 3 ... Monolithic accelerometer (acceleration sensor) 4 ... Memory (EEPROM) 5a ... Auto focus (AF) section 5b ... Photometer 5c ... AF sensor 6 ... Liquid crystal display element (LCD) 6a ... LCD in viewfinder 7 ... Flexible substrate 8 ... Strobe part 8a ... Main capacitor 9 ... Shooting lens 10 ... Camera 11 ... Warning display part Resistor 11a 12 ... Connector 13a, 13b ... switch 14 ... Rigid printed circuit board 15 ... rotary blade of rotary blade 16 17 ... Photointerrupter 18 ... Motor

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03B 17/40 G03B 17/40 A

Claims (2)

[Claims] 1. A camera shake detection means for detecting a camera shake state, a first operation member for switching a flash emission mode of the camera, and a second operation member for setting and switching a self-timer function and a remote control function of the camera. The camera shake detection mode that warns the user when the camera shake detection means detects a shake of a predetermined amount or more, and the camera shake detection mode is set by scrolling the mode by operating the second operation member. A camera characterized by. 2. The camera according to claim 1, wherein the camera shake detection mode is not set when the forced light emission mode is set by operating the first operation member. .