JP2003302690A - Camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera capable of performing warning display to intelligibly inform a photographer of the occurrence of camera shake by accurately detecting the camera shake even when a subject to be measured is dark. <P>SOLUTION: The camera shake state of the camera is detected in accordance with the time change of a subject image signal based on the brightness of the subject to be photographed by a vibration detection means. In the case of the camera shake exerting influence on a photograph, the warning display is performed for the photographer by a display means. When a decision means decides that the subject is dark, sure range-finding with the emission of electronic flash light is performed, the warning on the camera shake is inhibited, and exposure with the emission of the electronic flash light is performed to prevent the camera shake according to the instructions of a control means. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention improves a display mode in a photographing mode set by a user according to his / her preference, such as a camera shake prevention mode in which a camera shake generated during photographing is detected and a vibration warning is given to a photographer. Regarding the camera that did.

[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, that is, 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 a user recognize a shaking condition and a technology for preventing image deterioration due to camera shake by driving and controlling a photographing lens. 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. Usually, these warnings are made to be recognized by the photographer by lighting or blinking a display section provided in the camera.

[0005]

However, in the vibration detection system utilizing the image signal output from the distance measuring sensor as described above, a sufficient level of the image signal cannot be obtained in a scene where the object is dark. I couldn't put it out. On the other hand, when a flash light such as a strobe light is emitted to take an image, the exposure is performed only during the flash light emission time, and thus it is known that hand shake is less likely to occur.

Therefore, an object of the present invention is to provide a camera capable of accurately detecting camera shake even when the subject to be measured is dark and providing a warning display for notifying the photographer of the occurrence of camera shake.

[0007]

In order to achieve the above object, the present invention provides an image signal detecting means for capturing a subject image and detecting a subject image signal, and a camera of the camera according to the change of the subject image signal with the passage of time. Vibration detection means for detecting a vibration state, display means for displaying a warning by the output from the vibration detection means, strobe means for irradiating the subject with strobe light, and strobe based on the brightness of the subject image. Strobe light emission determination means for determining whether or not the light emission of the means is necessary, and prohibition means for prohibiting the warning display regardless of the output of the vibration detection means when the strobe light emission determination means determines that strobe light emission is necessary. There is provided a camera including.

Further, the camera utilizes the output of the image signal detecting means to indicate the timing of starting the object distance measurement, and the object image when the switch means makes the above-mentioned suggestion. If sufficient contrast cannot be obtained for the signal, the electronic device further includes control means for causing the strobe means to emit light and performing display control of the warning display according to a change in the subject image signal during the emission of the strobe means.

Further, according to the time change of the subject image signal,
A camera that performs a vibration warning display has a determination unit that determines the brightness of a subject, and when the determination unit determines that the brightness of the subject is low brightness, the vibration warning display is stopped and the strobe light is emitted. And a control means for controlling the exposure with light.

In the camera having the above-mentioned structure, the camera shake state of the camera is detected in accordance with the change over time of the subject image signal based on the brightness of the subject to be photographed, and a warning is displayed to the photographer regarding the camera shake affecting the photograph. Is done. Also, when the subject is dark, it is possible to perform reliable distance measurement with flash light emission, and to prohibit the camera shake warning,
Shaking is prevented by exposing with flash light.

[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 for displaying a photographing range (finder field of view) according to a photographing mode provided in a viewfinder of a camera by a change in light transmittance, and a hand-shake determination, in addition to an existing distance measuring sensor, a monolithic acceleration sensor. In combination with a meter, it is equipped with vibration detection means that detects camera shake and indicates the occurrence of camera shake.If camera shake occurs, the transmittance of the display area of the liquid crystal display means can be changed in a pattern. This technology makes it easy for the user 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. FIG. 2 is a diagram showing an electrical block configuration of the camera of this 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. 2B, the acceleration sensor 3 is arranged in a direction in which the shake is detected in the Y direction rather than the X direction so that the detection in both the XY directions is complemented by another sensor. .

The acceleration sensor 3 will now 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 by a resist mask on the oxide film 21, 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, as shown in 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. 4 (c), the processing circuit section 29 is formed on-chip on this chip together with the movable electrode capacitor constituted by the monolithic structure. 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 for explanation. 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 section 11 including an LED, a resistor 11a connected in series to the warning display section 11, switches 13a and 13b for starting a photographing sequence of the camera, and a camera shake. A mode switch 13c for setting the detection mode and a flash switch 13 for changing the flashing state of the flash of the camera.
d, a motor 18 that drives a drive mechanism such as a photographing lens, a shutter, and a film feeding mechanism, a rotary blade 16 that rotates in conjunction with the motor 18, and a rotary blade 16 that rotates for drive control of the motor 18. It is composed of a photo interrupter 17 that optically detects a hole.

Further, the motor 18 may switch the drive destination by the switching mechanism when driving each drive mechanism such as the shutter 19 and the zoom lens frame, or each drive mechanism may be provided with a separate motor. Good.

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. 7 shows an example of a warning pattern displayed on the in-viewfinder LCD 6a as a first display example. 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 a combination of the screen A and the screen C shown in FIG. 7, is a light-shielding pattern that is displayed when the panoramic photography is set, and this pattern 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 swaying, when the user re-holds the camera and the camera shake does not occur, the screen D of FIG. Returning to the screen E of 8 (b), the subject can be monitored.

Further, FIG. 9 shows a second display example of the camera shake warning displayed on the LCD 6a. This display example is
Similarly to the pattern described in FIG. 7, the light-shielding portion displayed when the panoramic shooting is set is used. In this pattern, the upper and lower light-shielding portions are alternately displayed as screen A and screen C. Unlike the pattern in FIG. 7, 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 it is blinking, unlike the normal display in FIGS. 8A and 8B, 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 displays the display as described above with reference to FIGS. 7 to 9, the user takes a photograph to take a measure to suppress the vibration, such as holding the left hand 100a in the camera. 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 enjoy taking pictures that effectively use the shake of this camera, such as panning, so this holding check function is one of the modes. For example, the camera shake detection mode is set, and the device can be set only when the user thinks it is necessary.

That is, the mode changeover switch 13c and the liquid crystal display section 6 as shown in FIG. 10A are provided, and in the normal state, only the function of the film counter or the like by the segment 6a is displayed. Then, as shown in FIG. 10B, if the user 100 operates the mode changeover switch 13c to set the camera shake detection mode, FIG.
Display segments 6b and 6c as shown in (b) and (c)
The shake detection mode setting display consisting of 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 forming a new segment in the liquid crystal display element 6, and the layout can be burdened. Absent. As shown in FIG. 11, these segments are obtained by dividing the segment for self-timer mode display into a plurality of segments.
Each part is wired so that each part can be independently display-controlled.

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 portion 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 which 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 setting this camera shake detection mode, if the camera is swaying due to unstable holding when holding the camera, the LCD in the viewfinder blinks as described above, or as shown in FIG. The LED 11 in the vicinity of the eyepiece unit 61 may blink to give a warning.

Further, when such shaking is occurring, 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.

Generally, in a compact camera, since the miniaturization of the camera body is pursued, the area of the display screen of the liquid crystal display element 6 usually arranged on the upper surface of the camera is not sufficient,
The size and number of segments displayed on this display screen are also limited. With the increasing number of functions of cameras, it is necessary to display many modes. On the other hand, if each segment is made smaller, it becomes difficult to recognize. Also, if one segment is used for several displays, the user will not know what. It is not possible to recognize whether or not it is indicated, and the display becomes meaningless.

Therefore, in this embodiment, in order to emphasize the meaning of preventing camera shake, a blinking instability is displayed in order to express a feeling of shaking and a feeling of holding it down, and a portion supporting from below is displayed. Then, let the user recognize the meaning of the mode in an easily understandable manner.

With reference to FIGS. 14A and 14B, the output (image signal) of the AF sensor 5c described above and the acceleration sensor 3 will be described.
The relationship of the outputs 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, when the swing width of the camera is large, that is, when the moving distance is long, as shown in FIG. 14A, the acceleration sensor 3 starts moving at the timing t = t1 when the camera moves. To output the signal. However, after that, if the camera moves at a constant speed, the acceleration sensor 3 does not output the detection signal because there is no acceleration even though the camera shakes. Again, when the camera stops, at the timing of t = t7, this time, the output result in the direction in which the previous constant velocity motion is stopped is output. That is, it is difficult to detect the camera shake.
However, the image sensor (AF sensor 5c) of the camera outputs an image signal that keeps changing even during constant-speed movement. Therefore, if the output result is judged, the output of the acceleration sensor 3 is 0, the camera The CPU 1 can determine that the camera is shaking, and can supplement the output of the acceleration sensor 3.

Further, when the swing width of the camera is small, that is, when the moving distance is short, as shown in FIG.
The image signal detected by the sensor 5c is output every time the acceleration sensor 3 repeatedly shakes, even if the image signal hardly changes. Such small shaking is that when the photographer holds the camera, the shaking of the hand is transmitted to the camera while trying to fix and hold the camera, which is different from FIG. 14A. 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 in which the main subject has no contrast compared to the background, or in a scene in which the subject image cannot be detected because it is dark, the change in the subject image is not sensed and determination cannot be performed. Further, as in the present embodiment, the sensor having only one direction of detection does not recognize the movement of the camera or the image change in a direction different from that, and when the camera shakes too much, the AF sensor 5c monitors it. The position where it is displaced will change, and the image will change completely, making it impossible to accurately determine the amount of shaking. Therefore,
It is necessary to properly use these two sensors to judge vibrations, and it is necessary to use other means in combination to ensure the reliability of the warning display.

With reference to the flow charts shown in FIGS. 15 and 16, the output (image signal) of such an AF sensor 5c is obtained.
The warning display operation of the camera which realizes the warning display corresponding to the scene in which the main subject is dark, and further includes the camera shake detection by 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, the image capturing is enabled, and the display sequence starts to move depending on the setting of the camera shake warning mode.

First, the user carries out framing by holding 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 AF sensor 5c
Even if the judgment is made by the detection result by, it 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 S21). 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 issued for a predetermined time after the start of the shaking, and the shaking is continuously detected while the display of the shaking warning is prohibited (step S22). However, if the output of the acceleration sensor 3 is smaller than the predetermined value (NO), it is determined that the composition of the photograph is determined and the holding state is entered, and the image detection using the AF sensor 5c is performed (step S23). ).

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 signal (subject image signal) is in a photographing state in which camera shake detection can be performed (step S24). ). If it is determined that the luminance is low (YES), the image signal from the AF sensor 5c is not used for the hand-shake warning, and the mode shifts to the strobe light emission mode (step S25) to turn on the strobe light (flash). The exposure is caused by the exposure, and the camera shake can be prevented. Therefore, the warning prohibition flag is set so that the warning of the camera shake is not issued (step S26).

Then, the sequence shifts to the next sequence of shake determination by 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 S27). If the acceleration sensor 3 outputs a detection signal in this determination (YES), it is determined whether a detection signal in the opposite direction has been output (step S2).
8). If the detection signal in the reverse direction is not output (NO), the time until detection is counted to determine whether or not the predetermined time has been reached (step S29). If the predetermined time has been reached, If (YES), it is determined whether or not the warning is prohibited here (step S30), and if the warning is not prohibited (NO), the photographer is warned (step S31).

This warning judgment is made as shown in FIG. 14A when the acceleration sensor 3 outputs the detection signal, and when the detection signal indicating the reverse acceleration is not detected for a predetermined time.
This is for allowing the photographer (user) to recognize that the camera shake may occur by determining that the camera continues to move at a constant speed. It should be noted that the determination of this state may be performed by the user with the intention of performing follow shots, and therefore, for example, the LCD in the finder is not blinked (FIGS. 7 and 9) but is shown in FIG. As described above, as the warning only for blinking the LED 11 near the finder eyepiece 61, a warning display different from the warning using the AF sensor 5c may be displayed.

On the other hand, if the reverse detection signal is output in step S28 (YES), or if the warning prohibition is set in step S30 (YE).
S), it is determined whether or not the release is performed (step S32). Here, if the release is performed (YE
S), and shifts to distance measurement in step S44 described later. On the other hand, if the release has not been performed (NO), the process returns to step S23.

If it is not determined that the luminance is low in the determination in step S24 (NO), it is determined whether the contrast of the subject is lower than a predetermined value (step S3).
3) If it is determined that the low contrast is lower than the predetermined value (YES), the sequence proceeds to the step S27 and subsequent steps, and if it is not the low contrast (NO), the image signal is suitable for the shake determination. It is judged that there is. Therefore, the prohibition of camera shake warning is released (step S34).

If it is determined in step S40 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 or not the release button has been operated (step S4).
3). Here, if the release button is not operated (N
O), and returns to step S37. However, if it is operated (YES), the process proceeds to the exposure sequence after step S44 described below.

First, photometry for exposure control is performed (step S44), and calculation is performed according to the image detection result obtained in step S23. Based on the result of this calculation, it is determined whether strobe light emission is necessary (step S45). If it is determined in this determination that the subject is dark (YE
S), the strobe light emission mode is set, that is, the strobe light emission flag is set (step S46). After this flag is set, or if it is determined that strobe light emission is not necessary (NO), distance measurement is performed (step S4).
7). It is determined whether or not the distance measurement has failed, that is, whether or not the obtained distance measurement result can be used for focusing (step S48). If it can be used (YES),
Focusing is performed based on the distance measurement result (step S49).

On the other hand, if the distance measurement result cannot be used for focusing (NO), the distance measurement is performed by emitting auxiliary light by strobe light twice in succession (steps S50 and S5).
1). Then, it is determined whether or not there is a change in the obtained image signal (step S52), and if there is a change (YES),
It is judged that the photographer has a hand shake, and a warning is given (step S53). On the other hand, in step S52,
If there is no change in the image signal (NO), it is determined whether or not the subject has low contrast (step S54), and if it is low contrast (YES), a warning indicating that accurate distance measurement is not performed is issued. . This warning may be performed by a method other than the camera shake warning. If reliable distance measurement cannot be performed in this way, some warning is issued before focusing is performed based on the obtained distance measurement result.

Next, after focusing is performed in step S49, it is determined whether or not strobe light emission is performed during exposure (step S56). If the flag is set to strobe light emission in step S46 (YES), exposure is performed with strobe light emission (step S57), and the process returns. In the exposure accompanied by the stroboscopic light emission, the subject image is exposed by a momentary strobe light emission. Therefore, it is assumed that the camera shake is not affected and the photographer is not warned.

However, if stroboscopic light emission is not set (NO), the exposure time is determined based on the brightness information obtained by the image detection in step S23, the exposure is started, and the time measurement by the counter is started. Yes (step S58). 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 S59). If the acceleration g is large, the photograph will be blurred even if the exposure time is short, and if the acceleration g is small, the photograph will be blurred if the exposure time is long. To determine this, if the exposure time tEND is reached (step S
60), count up and end exposure (step S
61).

Then, the obtained acceleration g and exposure time t
The speed is calculated from END, and the movement speed (1/2 gt END2) is calculated because the speed has changed for the time t END.
To calculate. This moving amount is defined as the allowable amount ΔY of the photographing lens.
It is determined whether or not it exceeds (step S62). If the amount of movement exceeds the allowable amount ΔY (YES), a camera shake warning is given (step S63). However, if it does not exceed (NO), the process returns.

As described above, in the case where the subject is dark, the accuracy of the determination is deteriorated only by the image change caused by the shaking of the camera as the criterion for the occurrence of camera shake. However, according to the present embodiment, the darkness of the subject Depending on the
Since the determination is made based on whether or not the output (image signal) of the AF sensor 5c changes, the camera shake can be accurately determined even in a dark scene.

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. Further, in a scene where the subject is dark, since the reliability of the subject image signal is reduced, it is prohibited to perform camera shake detection, and stroboscopic light emission is accompanied to reduce the effect of camera shake. As a result, it is possible to enhance the reliability of the hand-shake warning display by distinguishing between the time of deciding the composition and the time of the hand-shake, and to give the photographer an easy-to-understand instruction. In the present embodiment, the acceleration sensor is also used, but a camera that performs camera shake determination only with the AF sensor is
The effective use of such a strobe mode is even more effective.

[0067]

As described above in detail, according to the present invention, the present invention performs accurate camera shake detection even when the subject to be measured is dark, and provides a warning display informing the photographer of the occurrence of camera shake. It is possible to provide a camera that can.

[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 showing a first display example of a warning pattern displayed on an LCD in a viewfinder of a camera.

FIG. 8 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. 9 is a diagram showing a second display example of the warning pattern displayed on the LCD in the viewfinder of the camera.

FIG. 10 is a diagram for explaining setting of a camera shake detection mode and setting display.

FIG. 11 is a diagram showing an example of a segment for self-timer mode display.

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 diagram for explaining the relationship between the output of the AF sensor and the output of the acceleration sensor.

FIG. 15 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. 16 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.

[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 section 11a ... resistance 12 ... Connector 13a, 13b ... switch 14 ... Rigid printed circuit board 15 ... Finder objective lens 16 ... Rotary blade 17 ... Photointerrupter 18 ... Motor

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03B 7/28 G03B 15/05 5C024 15/05 H04N 5/225 A H04N 5/225 5/232 Z 5 / 232 5/335 Z 5/335 G02B 7/11 ZF term (reference) 2H002 AB04 BB06 BB10 GA44 2H051 AA01 BB01 EA28 EB10 2H053 AB03 AC13 AD11 2H102 AB08 5C022 AA13 AB15 AB28 AB55 AC12 AC18 AC31 5C024 AX04 CY01 BX01

Claims (3)

[Claims] 1. An image signal detecting means for optically capturing a subject image and detecting a subject image signal, a vibration detecting means for detecting a vibration state of a camera according to a change in the subject image signal with the passage of time, and the vibration. A display unit that gives a warning display by an output from the detection unit, a strobe unit that irradiates the subject with strobe light, and a strobe emission that determines whether or not the strobe unit emits light based on the brightness of the subject image. A camera comprising: a determination unit; and a prohibition unit that prohibits the warning display regardless of the output of the vibration detection unit when the strobe light emission determination unit determines that strobe light emission is necessary. 2. A camera for displaying a vibration warning according to a temporal change of a subject image signal, having a determination means for determining the brightness of the subject, wherein the determination means determines that the brightness of the subject is low luminance. And a control means for controlling the exposure to be accompanied by strobe light when the vibration warning display is stopped. 3. The camera according to claim 1, further comprising a switch means for suggesting a timing to start subject distance measurement using the output of the image signal detecting means, and the switch means for suggesting the timing when the switch means makes the suggestion. When sufficient contrast cannot be obtained for the subject image signal, the strobe means is caused to emit light, and a control means for performing display control of the warning display according to a change in the subject image signal while the strobe means is emitting light. The camera according to claim 1, wherein the camera is provided.