JP2002072059A - Camera with function of detecting object moving velocity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera capable of accurately detecting the moving velocity of an object, especially, the moving velocity of the object in a direction orthogonal to an optical axis direction. SOLUTION: The camera is provided with a distance detecting means (focusing sensor part 2) for measuring an object distance L-between the camera 100 and the object, a camera motion detecting means (camera posture detector 3) for detecting the motion of the camera related with the direction and the inclination, and a time counting means (timer 4) for measuring the time. The object distance and the rotation angle (Δθ) of the moving camera 100 are measured by a controller 1 at least two times or more while the user is pursuing the object through the finder, then, the camera is controlled by the controller 1 so that the measured time interval may be counted by the time counting means. Besides, the camera is controlled so that the object moving velocity may be obtained by an object velocity calculating means (calculation part 5) which is installed so as to calculate in accordance with a prescribed calculation expression based on respective variables obtained in such a way.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera having a function of detecting a moving speed of a subject, which calculates a moving speed of the subject from information on the movement of the camera and information on a distance to the subject and notifies the user of the calculated speed.

[0002]

2. Description of the Related Art Some of the cameras in the above technical field use, for example, focus information of a photographing lens or distance detecting means for detecting a distance to a subject, and calculate speed information of the subject as an object moving speed by calculation. Has been proposed, which is characterized in that the image is displayed on the image or is imprinted in a photograph. The details of this technology are disclosed in Japanese Patent Application Laid-Open No. Hei 5-27321.

[0003] Such a well-known technique is an example of a technique that can obtain information on a subject by using an existing function of a camera, and the obtained information can be used in various forms as needed. .

Conventionally, the moving speed of a subject has been detected by the method shown in FIG. For example, the direction of movement of the camera and its subject is detected, and the velocity component in the direction orthogonal to the optical axis of the taking lens can be geometrically calculated by simple trigonometry.

[0005]

However, although it is possible to calculate the subject moving speed as described above,
The accuracy obtained may be inaccurate depending on the situation to be detected. For example, in the above-described known technique, there is no problem in detecting the speed of a subject moving in the optical axis direction, but there is a problem that the speed of a moving subject in a direction orthogonal to the optical axis direction cannot be detected by actual measurement.

In this method, in the relationship between the subject and the camera, the equation relating to the detection speed in FIG.
In the case of cos α, the speed v ′ different from the actual speed v of the subject is detected as the angle α increases, and this value is displayed or imprinted, and the user may feel uncomfortable.

The obtained information on the moving speed of the subject is
Accuracy may be required depending on the intended use,
Failure to do so may cause some inconvenience.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a camera which can more accurately detect the speed of a moving subject, particularly the speed of movement of the subject in a direction orthogonal to the optical axis direction.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and in order to solve the above-mentioned problems and attain the object, the present invention employs the following means. That is, according to the present invention, there are provided distance detecting means for measuring a subject distance between a camera and a subject, camera motion detecting means for detecting a motion related to the direction and tilt of the camera, and timing means for measuring time. By measuring the subject distance and the angle at which the camera has moved at least twice while the user is looking at and chasing the subject through the viewfinder, the measured time interval is measured by the timing means, so that the subject is measured. A camera with a subject moving speed detection function that further includes a subject speed calculating means for calculating the moving speed of the subject is proposed.

The camera is further provided with a notifying means for notifying the user of the detected speed. In addition, the present invention proposes the camera further including a calculation unit that automatically sets an exposure time based on the calculated moving speed. In addition, the present invention proposes the camera further including a correction unit that corrects a displacement between the moving subject and the moving camera based on a positional displacement on a screen or the distance detection unit.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The gist of the present invention will be described below in detail with reference to specific embodiments. First of all,
Based on FIG. 1A, the principle for obtaining the subject distance between the subject and the camera and detecting a more accurate subject moving speed will be outlined.

Distance measuring means for optically measuring a subject distance
(Ranging section), camera movement detecting means (sensor) for detecting the direction and tilt of the camera, and time measuring means (timer) for measuring time
By using, for example, during a period in which the user is chasing the moving subject so that it falls within the viewfinder visual field,
Subject distance at least twice (multiple measurements)
And the angle at which the camera has rotated to track the subject,
The time required for this (measurement time) is detected or measured. Then, the following arithmetic processing is performed using the obtained information.

The subject distance is obtained according to the following processing procedure shown in FIG. The distance (L1) to the subject is detected. Wait until the time (T) elapses by the timing means. The distance (L2) to the subject is measured. The rotation angle (Δθ) moved during the period of time (T) is detected by the camera motion detection means.

The subject moving speed v is calculated by applying each data obtained in the above to the following formula.

(Equation 1)

By calculating in this way, FIG.
The speed component in the direction orthogonal to the optical axis of the photographing lens, which cannot be detected by the conventional method shown in FIG. This principle employed by the present invention results in speeds that are close to reality, thus improving accuracy. As a result, the user does not feel uncomfortable with the moving speed of the subject as obtained by the conventional method.

Hereinafter, a camera with a subject moving speed detecting function according to the present invention will be sequentially described with reference to specific first to third embodiments. (Embodiment 1-1) FIGS. 2 (a) and 2 (b) show the front and back appearances of a camera according to a first embodiment of the present invention.
Shows a system configuration diagram of this camera. Camera 100
As shown in FIGS. 2A and 2B, a release switch (button) 7a using a two-stage switch protruding from the top of the camera as an operation unit, and a mode changeover switch (button) on the left side of the back. 7b is provided so as to be able to be pressed.

A window of a finder 14 for observing a subject is provided obliquely above the lens 15 at the center of the front surface.
The window of the flash light emitting device 8 is arranged. Further, a liquid crystal panel of the display device 13 for electrically displaying and outputting is provided at the center of the rear surface.

A target mark 16 as shown in FIG. 2C is displayed in the finder 14 so that a moving subject can be easily tracked. The button 7a of the release switch employing the two-stage switch is shown in FIG.
In this case, the function of detecting the speed of the moving subject is started when the button is half-pressed, that is, in the half-pressed state (1st release state). It is set as follows.

The camera with the moving speed detecting function is shown in FIG.
Are configured as shown in FIG. That is, the camera has a control device 1 for controlling the camera in general, a distance measuring sensor unit 2 for measuring the distance of the subject from the camera, and a camera posture including an acceleration sensor for detecting the direction of the camera. A detection device 3, a timekeeping unit 4 as timekeeping means for measuring time, an operation unit 5 for performing various predetermined calculations,
A photometric sensor unit 6 for measuring the brightness of the subject, a switch operation unit 7 for the user to operate the camera, and a flash light emitting unit for supplementing when the amount of light irradiating the subject is too small to be suitable for shooting 8, a lens driving device 9 for moving the taking lens to focus the image on the film surface, a shutter driving device 10 for moving the shutter for adjusting the exposure amount, a film winding device 11, and, for example, the film An imprinting device 12 for imprinting characters on 150 and a display device 1 for displaying various status information of the camera.
3 is provided.

In the camera system configured as described above, control and calculation relating to detection of the moving speed of the subject are performed under program control of the control device 1 as follows. The operation will be described according to the processing sequence shown in the flowchart of FIG. 4. First, during a period in which the user half-presses the release switch button 7a (hereinafter, this first release state is abbreviated as "1R"). When the target to be measured (that is, the subject) is continuously captured by the target mark 16 in the viewfinder 14, it is detected in step S10 that the release switch button 7a is half-pressed (S10). However, here, it waits until it is half-pressed.

In step S20, the distance to the subject is detected by the distance measuring sensor unit 2 which is a distance measuring means of the camera (for example, as a simple example, autofocus is performed on one center of the field of view). Then, the object at the position of the target mark 16 is measured by the distance measuring sensor unit 2. Thereafter, the measured distance data is stored in the variable area L1 of the memory (S20).

In step S30, a variable range θ of the memory relating to the rotation angle θ is initialized to 0 (S30). In step S40, wait for a predetermined time T (for example,
(S40).
If a time T is required between step S30 and the next step S50, a predetermined photometric process, a calculation process, or the like may be performed within this time.

Subsequently, in step S50, the distance to the subject is detected by the distance measuring means 2 (S50). Then, the measured distance data is stored in the variable area L2 of the memory. In step S60, the camera rotation angle θ is detected by the camera posture detecting means 3 (for example, an angular acceleration sensor). Then, the measurement data is stored in the variable area θ of the memory (S60).

Here, in step S70, if the state of the release switch 7a is half-pressed, the process returns to step S20. Otherwise, the process proceeds to step S80.
Go to (S70).

In step S80, a speed calculation for obtaining the moving speed of the subject is performed by the calculating section 5 which also functions as the subject speed calculating means (S80). Note that the speed calculation here complies with the following equation similar to that described above.

(Equation 2)

In step S90, the moving speed v of the subject calculated in step S80 is displayed on the display device 13.
(For example, a liquid crystal display: see the example of the object speed notification in FIG. 5D) and output (S90).

Here, in step S100, it is checked whether or not the release switch has been fully pressed. If fully pressed, the process proceeds to the next step S110,
If it remains OFF, the process branches to step S130.

In step S110, an exposure operation is performed as a normal photographing operation of the camera (S110).
The photograph is printed on the photograph by the reference 2 (refer to the example of notification of the object speed by the photograph in FIG. 5C). In step S130,
The operation shifts to a normal camera operation (S130).

(Embodiment 1-2) Embodiment 1-2, which is exemplified next, has the same appearance of the camera and the configuration of the camera system as the above-described embodiment 1-1, except that FIG.
Have the following operational differences in the arithmetic processing sequence shown in the flowchart of FIG. For example,
In the above sequence, the speed is displayed by half-pressing (1R) and then OFF or full-press. However, steps S80 and S90 surrounded by broken lines are performed between step S60 and step S70 in FIG. By moving
It can be changed to display the detected subject moving speed during the 1R.

(Embodiment 1-3) The embodiment 1-3 shown below has the same appearance of the camera and the configuration of the camera system as those of the first and second embodiments. However, step S9 in the processing sequence shown in the flowchart of FIG.
As a means for displaying the moving speed of the object to be performed at 0, a function for switching the operation of the following notification means is provided. For example, FIG.
The present invention is implemented in such a manner that a desired notification means can be selected so that it can be operated in various forms as described in (a) to (d).

As shown in FIG.
When a photograph is taken by tracking at 00, a number indicating the moving speed is displayed in the viewfinder 14 as in Example 1 of FIG. 5B. Alternatively, the level can be displayed by a bar graph or the like as in Example 2. It should be noted that this level display may be used for other displays (for example, display of a camera shake level).

In the case of a photograph, it can be imprinted in the photograph of the film 150 as shown in FIG. In the case of the liquid crystal display, the moving speed of the subject can be displayed in a predetermined format on a date display section in the liquid crystal panel as shown in FIG. A mark 1 indicating that the moving speed of the subject is being displayed.
3a may be displayed as in Example 1. In addition, if a speaker or the like is used, the notification may be made by a voice message.

(Embodiment 1-4) Embodiment 1-4, which is exemplified next, has the same appearance of the camera and the configuration of the camera system as those of the above-described Embodiments 1-1 to 1-3, but FIG.
Has the following operational differences in the processing sequence shown in the flowchart of FIG. That is, in the above-described step S120, as a method of imprinting the moving speed of the object on the photograph, the speed is imprinted on the lower right by a number as shown in FIG. 5C, and the moving direction of the object is displayed by an arrow.

Also, in the present invention, since both the optical axis direction component and the orthogonal component are measured, an arrow is displayed three-dimensionally so as to indicate that the object moves from the right back to the left front. You may do so. Further, in the case of a camera using a film or a recording device capable of magnetic recording, it is easily conceivable to implement the method so that velocity data can be magnetically recorded.

(Embodiment 1-5) The appearance and system configuration of the camera in the next embodiment 1-5 are the same as those in the above-mentioned embodiments 1-1 to 1-4, but are shown in the flowchart of FIG. There is the following operational difference in the processing sequence. That is, the above-described steps S20 and S50
In the distance measurement, it is also possible to measure the moving speed distance from one point to a plurality of points with respect to the subject, and to store the closest distance among them in the data. In such a case, there is an advantage that the distance measuring means can easily catch the subject.

(Embodiment 1-6) In the following embodiment 1-6, the appearance of the camera and the configuration of the camera system are the same as those of the above-mentioned embodiments 1-1 to 1-5, but the flowchart of FIG. Are different from each other in the following processing sequence. That is, although the determinations made in steps S10, S70, and S100 described above are made based on the state of the release switch, a dedicated speed measurement switch may be separately provided on the camera, Alternatively, the speed measurement and the speed display may be continuously performed in conjunction with the ON operation of the power switch of the camera.

(Embodiment 2-1) Next, one embodiment 2-1 as a second embodiment according to the present invention will be described. It has the following features of a prediction function. A method of predicting a moving object and calculating a distance between a camera and a subject at the time of exposure using the present invention will be described with reference to FIG.

Immediately after measuring the object speed at the positions Pn-2 and Pn-1, a straight line passing through the two points is calculated from the position information of the two points, and the angle θn at which the distance L to the object becomes the minimum is calculated. By predicting and calculating the distance L and controlling the shutter so that the release switch is automatically turned off when the camera moves by the angle θn, panning can be easily performed. The release switch may be turned off at the moment when the subject has reached the predicted minimum distance L, or the time T to reach the release switch may be predicted and calculated.

At this time, an appropriate exposure time can be obtained from the speed of the subject at that time, so that the panning can be automatically and easily performed. Further, in order to prevent the exposure from being performed unexpectedly by the user, the panning mode and the normal mode may be switched by the mode switch 7b.

(Embodiment 2-2) The above-described embodiment 2-1 can be implemented as follows. That is, the object moving speed at the positions Pn-2 and Pn-1 is measured, and
It is also possible to predict the subject distance at the timing when the shutter is released after a predetermined release time lag and calculate the focus at the time of in-focus exposure.

(Embodiment 3) Next, a third embodiment of the present invention will be described. This feature is as follows. When the user is chasing the subject to be measured through the finder, the position of the subject in the finder of the camera 100 may be shifted each time the measurement is performed, as shown in FIG.

Therefore, a camera provided with a function of correcting this displacement is implemented as follows. FIGS. 7A to 7C illustrate the principle of correcting the displacement in the viewfinder.
In particular, FIGS. 7B and 7C show the auto focus (AF).
FIG. 4 is an explanatory diagram of a method of correcting with a line sensor used in a “passive method”.

When the user moves from the position A to the position B and the user moves at a speed higher than the speed of the camera object, the object image is moved from the optical axis of the lens as shown in FIG. Is shifted. At this time, when the data of the image detected by the AF sensor is shown in the histograms in FIGS. 8A and 8B, it is assumed that the reflected waveform from the subject is a mountain (peak) portion, but the background is far away. In this case, it can be seen that the subject is relatively shifted to the left as compared with the data when the subject is in front of the camera.

If the difference at this time is ΔX (however, ΔXL or ΔXr of one of the two sensors,
Alternatively, these two average values ΔX may be used. ), This Δ
X is the horizontal axis ΔX in FIG. 7C, and the distance f (focal length) between the sensor lens and the line sensor forming the distance measuring sensor unit 2 of the camera is known from the sensor specifications. The angle detected by the posture detecting means 3 (for example, an angular velocity sensor, an acceleration sensor, a shake sensor, etc.) is represented by θ.
F, assuming that the true angle (that is, the angle after correction) is θT, the corrected angle θT is obtained according to the following equation.

(Equation 3)

This blur correction function makes it easier for the user to measure the moving speed of the subject.

By implementing according to the first to third embodiments, the camera according to the present invention has the following operational effects. That is, while the user presses the release button halfway, the moving object is tracked at the center position of the target mark in the viewfinder, whereby a plurality of distance measurement operations are automatically performed, and the obtained plurality of object distances are obtained. A calculation based on a predetermined calculation formula is automatically performed from the measurement information of the measurement time interval and the rotation angle of the camera itself detected by the acceleration sensor or the like.

As a result, it is possible to realize a camera having a subject moving speed detection function capable of notifying the user of a more accurate subject moving speed than the conventional technology. The notification can be made in any desired form from among voice, display, imprinting a photograph, magnetic recording, and the like.
Also, various processing operations using the accurate subject speed can be performed with higher accuracy than in the past.

(Modification) The above embodiment may be modified as follows. For example, in the illustrated example, the movement form of the subject is based on linear approximation movement for the sake of simplicity of description. It may be applied as appropriate depending on the form of the trajectory of the moving object to maintain the accuracy.

The obtained value of the moving speed of the subject may be appropriately used for controlling a predetermined portion of the camera which is deeply related to the speed of the subject and other matters, in addition to printing and displaying. . According to these modified embodiments, effects equivalent to or greater than those of the illustrated embodiment can be expected.

In addition, various modifications can be made without departing from the spirit of the present invention.

Although the embodiments have been described above, the present invention includes the following inventions. (1) a control device for controlling the camera as a whole, a distance measuring sensor unit for measuring a subject distance of the subject from the camera, and a camera posture detecting device including an acceleration sensor for detecting the orientation of the camera; A timekeeping unit as timekeeping means for measuring time, an arithmetic unit for performing various calculations, a photometric sensor unit for measuring the brightness of the subject, a switch operation unit for the user to operate the camera, and a light source for irradiating the subject. When the amount of light is too small to be suitable for shooting, etc., a flash light emitting unit that compensates for this, a lens driving device that moves the shooting lens to focus the image on the film surface, and a shutter for adjusting the exposure amount are moved A subject moving speed including a shutter driving device, a film winding device, a printing device for printing characters on the film, and a display device for displaying camera status information. A camera with a detection function can be provided.

(2) The distance measuring sensor unit operates so as to calculate a plurality of object distances by performing a distance measuring operation at least twice within a predetermined time measured by the time measuring unit. The camera described in (1) can be provided. (3) The camera according to (1), wherein the acceleration sensor measures an angle of rotation of the optical axis of the taking lens within a predetermined time on a plane including the camera and the subject. .

(4) The arithmetic section calculates the subject moving speed by substituting the plurality of subject distances and the angles into a predetermined formula.
The camera described in (3) can be provided.

[0054]

As described above, according to the present invention,
It is possible to provide a camera that can more accurately detect the speed of a moving subject, particularly the subject moving speed in a direction orthogonal to the optical axis direction.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) show the functional principle of a camera according to the present invention. FIG. 1 (a) is a principle diagram for obtaining a moving speed of a subject, and FIG. FIG.

2 (a) to 2 (d) show a camera of the present invention, and FIG. 2 (a) is an external view from the back of the camera, FIG.
FIG. 2B is an external view of the camera from the front, FIG. 2C is an explanatory view showing a finder visual field, and FIG. 2D is an explanatory view showing a two-stage operation release.

FIG. 3 is a system configuration diagram of a camera according to the present invention.

FIG. 4 is a flowchart showing a processing procedure for obtaining a subject moving speed in the camera of the present invention.

5 (a) to 5 (d) show examples of notification of a moving speed of a subject by a camera, FIG. 5 (a) is an explanatory diagram showing a measurement situation of the moving speed of a subject, and FIG. FIG. 5C is an explanatory diagram showing an example of a finder display, FIG. 5C is an explanatory diagram showing an example of imprinting the moving speed on a photograph, and FIG. 5D is an explanatory diagram showing an example of a liquid crystal display.

FIG. 6 is a principle diagram illustrating prediction of a subject position by linear approximation.

7 (a) to 7 (c) show a method of correcting a position shift in a viewfinder of a camera according to the present invention, and FIG.
FIG. 7B is an explanatory view showing a positional shift in the viewfinder, and FIG.
FIG. 7C is an explanatory diagram showing a method of correcting a positional shift, and FIG.
FIG. 4 is an explanatory diagram showing a method of correcting a positional shift.

FIGS. 8A and 8B show a method of obtaining a shift in a passive type, and are histograms of data corresponding to a moving subject.

FIG. 9 is an explanatory view schematically showing a conventional moving speed detection method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Control device, 2 ... Distance measuring sensor part (distance measuring means), 3 ... Camera attitude detecting device (camera movement detecting means: acceleration sensor etc.), 4 ... Time measuring means (timer), 5 ... Calculation part (subject moving speed) 7) Switch operation unit, 7a Release switch (button), 7b Mode switch (button), 8 Flash light-emitting device, 9 Lens drive device, 10 ... Shutter driving device, 11 ... Film winding device, 12 ... Printing device (notifying means), 13 ... Display device (notifying means), 14 ... Finder, 15 ... Film, 16 ... Target mark, 100 ... Camera, 150 ... Film .

Claims (4)

[Claims] 1. A camera comprising: a distance detecting means for measuring a subject distance between a camera and a subject; a camera motion detecting means for detecting a motion related to a direction and an inclination of the camera; and a time measuring means for measuring time. The user measures the subject distance and the angle at which the camera has moved at least twice while the user is looking at and chasing the subject through the viewfinder, and measures the measured time interval by the timing means. A subject speed calculating means for calculating a moving speed of the subject. 2. The camera according to claim 1, further comprising notification means for notifying the user of the detected speed. 3. The camera according to claim 1, further comprising a calculating means for automatically setting an exposure time based on the calculated moving speed. 4. The camera according to claim 1, further comprising a correction unit that corrects a shift between the moving subject and the moving camera due to a position shift on a screen or the distance detection unit.