JP2007256480A - Photographing apparatus, control method therefor, and program therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more shorten a period of time needed from a photographing instruction to the start of photographing as compaired to an apparatus executing a range survey after a photographing instruction is given. <P>SOLUTION: A digital camera 10 includes: a range sensor 56 capable of measuring a distance from a subject to an imaging device 20 by using a triangulation method; and a shake sensor 58 composed of an angular velocity sensor capable of detecting vertical and lateral movements of the digital camera 10. In the digital camera 10, a blur of the imaging device 20 is detected by the shake sensor 58. If this detected output value has dropped to equal to or below a threshold value set so that the range sensor 56 is instructed to measure a distance prior to reception of a photographing instruction by the depression of a shutter button 32, the range survey is carried out. When the shutter button 32 is depressed thereafter, the process of imaging a subject is performed. Thus, the range survey is performed based on the shake state of the imaging device 20 reflecting the photographing intention of a user. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photographing apparatus, a control method thereof, and a program thereof.

Conventionally, as a photographing apparatus, a focus lens focusing process and a distance measuring process using a triangulation method are executed by pressing a shutter button, and the focus of the focus lens is obtained using the one obtained the detection result first. There has been proposed a technique that reduces the time lag from the pressing of the shutter button to the execution of the photographing process by adjusting (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2005-3693

  However, in the photographing apparatus described in Patent Document 1, it takes a long time to execute the focusing process and the distance measuring process after the shutter button is pressed. There was a time lag. In the photographing apparatus, since the subject may move, it is desired to shorten the time lag from the pressing of the shutter button to the start of photographing as much as possible.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide an imaging apparatus, a control method thereof, and a program thereof that can further shorten the time from the instruction of imaging to the start of imaging processing. To do.

  The present invention adopts the following means in order to achieve the above-mentioned object.

The photographing apparatus of the present invention
Imaging means capable of imaging a subject;
A shake detection means capable of detecting information relating to shake of the imaging means;
Ranging means capable of measuring the distance between the subject and the imaging means;
Control means for causing the distance measuring means to measure a distance based on the output value detected by the shake detecting means, and then causing the imaging means to image the subject;
It is equipped with.

  In this photographing apparatus, information relating to the shake of the image pickup means is detected, distance measurement is executed based on the detected output value, and then the subject is imaged. Here, since the user usually holds the photographing apparatus before inputting the photographing instruction, the blurring state of the imaging means reflects whether or not the user is willing to photograph. In this way, distance measurement is executed based on the blurring state of the imaging means reflecting the user's will to shoot. Therefore, it is possible to further reduce the time from the shooting instruction to the start of the shooting process, compared to the case where the distance measurement is performed after the shooting instruction is given.

  In the photographing apparatus of the present invention, when the control unit measures the distance based on the output value detected by the shake detection unit, the output value detected by the shake detection unit is within a predetermined stable range. The distance measuring means may measure the distance when it becomes inside. At this time, the photographing apparatus of the present invention includes instruction obtaining means capable of obtaining a photographing instruction from a user, and the control means outputs an output value detected by the shake detecting means to the photographing instruction by the instruction obtaining means. Prior to the acquisition, the range may be set within the stable range so that the distance measuring unit measures the distance. In this way, it is possible to more reliably reduce the time from the shooting instruction to the start of the shooting process.

  In the imaging apparatus of the present invention, the imaging unit may read the image signal by sequentially transferring the charge accumulated in the photoelectric conversion element to the charge transfer element, and image the subject. In this way, the subject can be imaged using the photoelectric conversion element and the charge transfer element.

  In the photographing apparatus of the present invention, the shake detection unit may be used for camera shake correction of the imaging unit. In this way, since the means for detecting the camera shake correction also serves as the means for detecting the start of the distance measurement, it is not necessary to provide a new detection means.

  In the photographing apparatus of the present invention, the distance measuring means may measure the distance between the subject and the imaging means using a triangulation method. In general, for example, since the distance measurement using the contrast involves driving the lens during the distance measurement and the power consumption is large, the distance measurement is executed with a lower power consumption than the distance measurement using the contrast. Can do.

The photographing apparatus control method of the present invention includes:
An imaging apparatus control method comprising: imaging means capable of imaging a subject; and distance measuring means capable of measuring a distance between the subject and the imaging means,
(A) detecting information relating to shaking of the imaging means;
(B) causing the distance measuring means to measure a distance based on the output value detected in the step (a), and then causing the imaging means to image the subject;
Is included.

  In this photographing apparatus control method, information relating to the shake of the imaging means is detected, distance measurement is executed based on the detected output value, and then the subject is imaged. Here, since the user usually holds the photographing apparatus before inputting the photographing instruction, the blurring state of the imaging means reflects whether or not the user is willing to photograph. In this way, distance measurement is executed based on the blurring state of the imaging means reflecting the user's will to shoot. Therefore, it is possible to further reduce the time from the shooting instruction to the start of the shooting process, compared to the case where the distance measurement is performed after the shooting instruction is given. In this photographing apparatus control method, various aspects of the photographing apparatus described above may be adopted, and steps for realizing each function of the photographing apparatus described above may be added.

  The program of the present invention is a program for causing one or more computers to execute one of the above-described imaging device control methods. This program may be recorded on a computer-readable recording medium (for example, hard disk, ROM, FD, CD, DVD, etc.), or from a computer via a transmission medium (communication network such as the Internet or LAN). It may be distributed to another computer, or may be exchanged in any other form. If this program is executed by one computer or if each computer is caused to execute each program in a shared manner, the above-described photographing apparatus control method is executed, so that the same effect as the above-described control method can be obtained. it can.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing an outline of a configuration of a digital camera 10 according to an embodiment of the present invention.

  The digital camera 10 according to the present embodiment includes a lens 12, an image sensor 20 that converts light into an electrical signal by photoelectric conversion, a mechanical shutter 14 disposed between the lens 12 and the image sensor 20, and an image sensor 20. A timing generator (TG) 16 that outputs the start timing of various operations to the image sensor 20 via the driver circuit 28, and an analog front end (AFE) 18 that converts an electrical signal output from the image sensor 20 into a digital signal; The shutter button 32 that can be half-pressed or fully pressed by the user, the battery 34 that can be charged and discharged, the distance measuring sensor 56 that can measure the distance from the subject, and the camera shake sensor that can detect the shake of the digital camera 10 58 and a controller 40 that executes various controls.

  The lens 12 is configured by combining a convex lens and a concave lens in order to suppress aberrations. The lens 12 includes an autofocus mechanism (not shown).

  The imaging device 20 includes a plurality of photodiodes 22 arranged in a matrix, a vertical transfer CCD 24 formed for each photodiode 22 and capable of transferring charges received from the photodiodes 22 in the vertical direction, and a vertical termination. And a horizontal transfer CCD 26 that can transfer charges received from the vertical transfer CCD 24 in the horizontal direction. The image sensor 20 is held by an actuator 21 and can move in the vertical and horizontal directions on the substrate. The photodiode 22 is a photoelectric conversion element corresponding to a pixel, and converts light when exposed to electric charge and accumulates it. The photodiode 22 has an electronic shutter function, and charges can be released to a substrate (not shown) by the electronic shutter function. The vertical transfer CCD 24 and the horizontal transfer CCD 26 are charge transfer elements and do not operate during exposure, but noise accumulated in the CCDs 24 and 26 at a timing immediately before exposure or a timing before receiving charge from the photodiode 22 after exposure. Unnecessary charges are swept out, and the image signals are read out by receiving the charges after exposure from the photodiode 22 and sequentially transferring them. The photodiode 22, the vertical transfer CCD 24, and the horizontal transfer CCD 26 included in the image sensor 20 are driven by a driver circuit 28.

  The mechanical shutter 14 physically blocks light irradiation to the image sensor 20 and is provided in the immediate vicinity of the image sensor 20 away from the lens 12 in this embodiment.

  The TG 16 outputs a synchronization signal for synchronizing the operation of various devices in addition to the output timing of the vertical line shift pulse for determining the drive speed of the vertical transfer CCD 24 and the horizontal line shift pulse for determining the drive speed of the horizontal transfer CCD 26. The VD output timing or the like is output to the driver circuit 28. Here, the output timing is set by the value set in the register.

  The AFE 18 converts the electrical signal read from the photodiode 22 in the image sensor 20 from an analog signal to a digital signal and outputs the signal. The digital signal output from the AFE 18 is stored in the memory card 30 as a JPEG file after being subjected to known image processing such as pixel interpolation processing, white balance processing, and gamma correction processing.

  The shutter button 32 can be half-pressed or fully pressed by a user's operation. When the shutter button 32 is pressed halfway, the shutter button 32 outputs to the controller 40 a timing for capturing an image formed on the image sensor 20 through the lens.

  The battery 34 is a secondary battery represented by a chargeable / dischargeable lithium ion battery, a nickel metal hydride battery, or the like, and has a property of increasing the rate of voltage drop from a fully charged state as the cumulative usage time becomes longer. It is. A power supply unit 36 is connected to the battery 34. The power supply unit 36 supplies a voltage converted into a necessary voltage level according to a command from the controller 40 to various circuits and devices. Further, a voltage sensor 38 is attached to the battery 34. This voltage sensor 38 detects the voltage across the terminals of the battery 34 and outputs it to the controller 40.

  The distance measuring sensor 56 includes a light emitting diode capable of emitting infrared light, and a photodiode array provided at a position away from the light emitting diode and capable of detecting light irradiated from the light emitting diode and reflected by a subject. This is a sensor that can measure the distance from the subject to the image sensor 20 using a triangulation method. The distance measuring sensor 56 detects the distance from the subject to the image sensor 20 and outputs it to the controller 40.

  The camera shake sensor 58 includes two sensors, an angular velocity sensor that can detect the vertical movement of the digital camera 10 and an angular velocity sensor that can detect the horizontal movement of the digital camera 10, and each has an angular velocity in the vertical direction or the horizontal direction. Output a signal according to. In the digital camera 10, camera shake correction is executed by driving the actuator 21 provided in the image sensor 20 using the signal relating to the camera shake output from the camera shake sensor 58. Note that the camera shake correction may be performed by arranging a camera shake correction optical system between the lens 12 and the image sensor 20 and driving the camera shake correction optical system.

  The controller 40 is configured as a microprocessor centered on the CPU 42, and includes a ROM 44 for storing a processing program, a RAM 46 for temporarily storing data, an input / output port and a communication port (not shown), in addition to the CPU 42. ing. The controller 40 includes a half-press signal and a full-press signal of the shutter button 32, a detection signal from the voltage sensor 38, a digital signal from the AFE 18, various data read from the memory card 30, a signal from the distance measuring sensor 56, and a camera shake sensor. A signal from 58 is input. The controller 40 outputs a shutter drive signal to the mechanical shutter 14, a signal to the TG 16, a control signal to the power supply unit 36, various data request signals to the memory card 30, and the like.

  Next, the operation of the digital camera 10 of the present embodiment configured as described above, particularly the operation when shooting a subject will be described. FIG. 2 is a flowchart showing an example of the photographing processing routine. This routine is stored in the ROM 44 and is repeatedly executed by the CPU 42 after the digital camera 10 is turned on. When this routine is started, the CPU 42 of the controller 40 first inputs a detection signal from the camera shake sensor 58 and analyzes the input signal (step S100). In the analysis of the input signal, for example, the input signal is extracted as a frequency component by Fourier transform or the like, and a frequency indicating the maximum intensity among the extracted frequencies is calculated as an output value. Next, the CPU 42 determines whether or not the analyzed output value is less than a threshold value (step S110). This threshold value is obtained by empirically obtaining a frequency value that can determine a state in which the shake of the digital camera 10 stops and the user is highly likely to take a picture, such as when the user holds the digital camera 10, and the obtained frequency value It is stipulated in. When it is determined that the analyzed output value is equal to or greater than the threshold value, it is estimated that the user does not hold the digital camera 10, and the process of step S100 is executed.

  On the other hand, when it is determined in step S110 that the output value is less than the threshold value, it is estimated that the user is likely to give a shooting instruction, and ranging processing is executed (step S120), and shooting setting processing is executed. (Step S130). In the distance measurement process, the distance measurement sensor 56 irradiates the subject with infrared rays, detects reflected light reflected by the subject, and inputs the obtained signal. In the shooting setting process, automatic exposure is performed, a shutter speed and an aperture value are set based on the automatic exposure, and an automatic focusing mechanism (not shown) is operated based on the distance measurement result to automatically perform focusing. As described above, it is presumed that the user has held the digital camera 10 by using the shake of the digital camera 10, and the user and the image sensor 20 are informed before the user indicates the intention of shooting by pressing the shutter button 32. In addition to measuring the distance, a setting process necessary for shooting is performed. For this reason, after the user presses the shutter button 32, no time is required for executing the distance measurement process or the shooting setting process.

  Subsequently, the CPU 42 determines whether or not the shutter button 32 is in a half-pressed state based on a half-press signal from the shutter button 32 (step S140), and when it is determined that the shutter button 32 is not in a half-pressed state. Therefore, it is assumed that the user does not intend to shoot, and the processing after step S100 is executed. On the other hand, when it is determined that the shutter button 32 is half-pressed, the CPU 42 determines whether or not the shutter button 32 is fully pressed based on the full-press signal from the shutter button 32 (step S150). When it is determined that the shutter button 32 is not fully pressed, the processing after step S140 is executed, and when it is determined that the shutter button 32 is fully pressed, the CPU 42 executes imaging processing (step S160). ). Here, the imaging process will be described. In the imaging process, a high-speed discharge process for removing noise accumulated in the vertical transfer CCD 24 and the horizontal transfer CCD 26 is executed, the mechanical shutter 14 is operated, and an exposure process for storing charges in the photodiode 22 is executed. A discharge process is executed to remove noise accumulated in the vertical transfer CCD 24 and the horizontal transfer CCD 26, and a read process for sequentially transferring the charges exposed to the photodiode 22 to the vertical transfer CCD 24 and the horizontal transfer CCD 26 is executed. To do. Note that the image blur of the subject is corrected by driving the actuator 21 based on the output value from the camera shake sensor 58 during the exposure process. In this way, imaging is performed by outputting the charge as an image signal from the image sensor 20 to the AFE 18 while suppressing the mixing of noise. After executing the imaging process in step S160, the CPU 42 stores the obtained image signal in the memory card 30 (step S170), and ends this routine.

  Here, the correspondence between the components of the present embodiment and the components of the present invention will be clarified. The imaging device 20 of the present embodiment corresponds to the imaging means of the present invention, among which the photodiode 22 corresponds to a photoelectric conversion device, and the vertical transfer CCD 24 and the horizontal transfer CCD 26 correspond to charge transfer devices. The distance measuring sensor 56 corresponds to a distance measuring unit, the camera shake sensor 58 corresponds to a camera shake detecting unit, and the controller 40 corresponds to an instruction acquiring unit and a control unit. In this embodiment, the configuration, operation, and effect of the digital camera 10 are described to describe the imaging apparatus of the present invention, and at the same time, the control method of the imaging apparatus and the imaging processing program are also described.

  According to the digital camera 10 of the present embodiment described in detail above, the shake of the image sensor 20 is detected by the camera shake sensor 58, and the distance is measured by the distance measuring sensor 56 when the detected output value becomes less than the threshold value. After that, when the shutter button 32 is pressed, the subject is imaged. Here, since the user normally holds the digital camera 10 before inputting the shooting instruction, the shaking of the image sensor 20 reflects whether or not the user is willing to shoot. In this way, distance measurement is executed based on the shake state of the image sensor 20 reflecting the user's will to shoot. Therefore, it is possible to further reduce the time from the shooting instruction to the start of the shooting process, compared to the case where the distance measurement is performed after the shooting instruction is given. Further, since the shooting setting process is also executed based on the shake state of the image sensor 20, the time from the shooting instruction to the start of the shooting process can be further reduced.

  In addition, since the threshold value for determining the output value detected by the camera shake sensor 58 is set so that the distance measuring sensor 56 measures the distance before the photographing instruction is acquired by pressing the shutter button 32, it is more reliable. It is possible to shorten the time from the shooting instruction to the start of the shooting process. Further, the image pickup device 20 can read the image signal by sequentially transferring the charges accumulated in the photodiode 22 to the vertical transfer CCD 24 and the horizontal transfer CCD 26 to pick up an image of the subject. Furthermore, the camera shake sensor 58 also serves as a camera shake correction sensor for the image sensor 20 that also determines whether or not the distance measurement sensor 56 can perform distance measurement, and thus it is not necessary to provide a new sensor. Since the distance measuring sensor 56 measures the distance between the subject and the image sensor 20 using the triangulation method, the distance measuring device 56 uses the contrast method to drive the lens and consumes a large amount of power during distance measurement. Ranging can be executed with lower power consumption.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  For example, in the above-described embodiment, the distance measurement process and the shooting setting process are performed after the output value falls below the threshold value in step S110, that is, after the shaking of the digital camera 10 is settled. The shooting setting process may be executed after the shutter button 32 is half-pressed in step S140. In this way, the shooting setting process can be executed only when an instruction for shooting is input and shooting is surely performed.

  In the above-described embodiment, the state of the shutter button 32 is not determined when the output value is greater than or equal to the threshold value in step S110, that is, when the shake of the digital camera 10 is not settled. Even in the above case, it is determined whether or not the shutter button 32 has been pressed, and when it is determined that the shutter button 32 has been pressed, a ranging process, a shooting setting process, and an imaging process may be executed. In this way, it is possible to satisfy the user's request to take a picture even when the digital camera 10 is blurred.

  In the embodiment described above, the state in which the shake of the digital camera 10 is reduced and the user is highly likely to shoot is determined based on the output value of the frequency obtained based on the signal from the camera shake sensor 58 and the predetermined threshold value. However, in addition to or instead of this, it is also possible to determine a state in which the shake of the digital camera 10 is reduced and the user is highly likely to perform shooting based on the peak intensity of the frequency.

  In the embodiment described above, the distance between the subject and the image sensor 20 is measured by the distance measuring sensor 56 using the triangulation method. However, the contrast method is used to measure the distance between the subject and the image sensor 20. The distance may be measured. By doing so, the image sensor 20 and the controller 40 can be used for distance measurement instead of the distance measurement sensor 56, so that the configuration can be simplified.

  In the embodiment described above, the camera shake sensor 58 serves as both a camera shake correction of the image sensor 20 and a sensor that determines whether or not the distance measurement sensor 56 can perform distance measurement. However, the camera shake correction sensor and the start of distance measurement are used. The determination sensor may be provided separately.

  In the above-described embodiment, the digital camera 10 that captures a subject with the image sensor 20 has been described. However, a film camera that captures a subject on a film may be used. Even in this case, it is possible to further shorten the time from the imaging instruction to the start of the imaging process.

  In the above-described embodiment, the digital camera 10 is taken up as an example of the photographing apparatus. However, the present invention can be applied to any photographing apparatus that measures the distance to the subject. Examples of such a photographing device include a digital video, a mobile phone with a camera, etc. in addition to a digital camera.

It is a block diagram which shows the outline of a structure of the digital camera 10 of this embodiment. It is a flowchart showing an example of an imaging process routine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Digital camera, 12 ... Lens, 14 ... Mechanical shutter, 16 ... Timing generator (TG), 18 ... Analog front end (AFE), 20 ... Image sensor, 21 ... Actuator, 22 ... Photodiode, 24 ... For vertical transfer CCD, 26 ... CCD for horizontal transfer, 28 ... Driver circuit, 30 ... Memory card, 32 ... Shutter button, 34 ... Battery, 36 ... Power supply unit, 38 ... Voltage sensor, 40 ... Controller, 42 ... CPU, 44 ... ROM, 46: RAM, 56: Ranging sensor, 58: Camera shake sensor.

Claims (8)

Imaging means capable of imaging a subject;
A shake detection means capable of detecting information relating to shake of the imaging means;
Ranging means capable of measuring the distance between the subject and the imaging means;
Control means for causing the distance measuring means to measure a distance based on the output value detected by the shake detecting means, and then causing the imaging means to image the subject;
An imaging device with   The control means, when causing the distance measuring means to measure the distance based on the output value detected by the shake detecting means, when the output value detected by the shake detecting means falls within a predetermined stable range. The photographing apparatus according to claim 1, wherein the distance measuring unit measures the distance. The imaging device according to claim 2,
Instruction acquisition means capable of acquiring a shooting instruction from a user,
The control means is set within the stable range so that the output value detected by the shake detection means causes the distance measurement means to measure the distance before the instruction acquisition means acquires a photographing instruction.
Shooting device.   The imaging apparatus according to claim 1, wherein the imaging unit reads the image signal by sequentially transferring the charge accumulated in the photoelectric conversion element to the charge transfer element and images the subject.   The imaging apparatus according to claim 1, wherein the shake detection unit is used for camera shake correction of the imaging unit.   The imaging apparatus according to claim 1, wherein the distance measuring unit measures a distance between the subject and the imaging unit using a triangulation method. An imaging apparatus control method comprising: imaging means capable of imaging a subject; and distance measuring means capable of measuring a distance between the subject and the imaging means,
(A) detecting information relating to shaking of the imaging means;
(B) causing the distance measuring means to measure a distance based on the output value detected in the step (a), and then causing the imaging means to image the subject;
An imaging apparatus control method including:   A program for causing one or more computers to realize each step of the imaging device control method according to claim 7.

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