JP2006243167A - Photographing apparatus and hand shake warning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photographing apparatus capable of appropriately issuing a hand shake warning and to provide a hand shake warning method. <P>SOLUTION: A shutter speed is determined in accordance with the brightness of a subject. When the shutter speed is not higher than a preset specific speed, a CPU 40 detects the holding state of a digital camera 10 by a photographer by using a grip sensor 60. The specific speed is set so that the holding state is better when the shutter speed is slower. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photographing apparatus and a camera shake warning method, and in particular, determines a shutter speed according to the brightness of a subject and warns the occurrence of camera shake when the shutter speed is equal to or lower than a predetermined speed. The present invention relates to a photographing apparatus and a camera shake warning method for the photographing apparatus.

  In recent years, with the increase in resolution of solid-state imaging devices such as CCD (Charge Coupled Device) area sensors and CMOS (Complementary Metal Oxide Semiconductor) image sensors, digital cameras, cellular phones, PDAs (Personal Digital Assistants, personal digital assistants), etc. Demand for information equipment (hereinafter, also referred to as “photographing device”) having a photographing function is rapidly increasing, and this type of photographing device may cause camera shake during photographing such as when the shutter speed is extremely slow. Some cameras are equipped with a camera-shake warning function that issues a warning when the value is high.

  By the way, it is said that camera shake is highly likely to occur when the photographer holds the photographing apparatus in an unstable state. In particular, beginners often do not know how to hold the photographing apparatus, and in this case, the effects of camera shake are likely to occur.

  In order to solve this problem, conventionally, a contrivance has been made to clarify the holding area by providing a grip portion or the like in the right hand holding portion of the photographing apparatus. Therefore, the photographer holds the right hand relatively correctly. However, with this technology, a stable holding state can be secured by the grip portion for the right hand, but a stable holding state cannot be secured for the left hand side, and photography is likely to occur due to camera shake. There was still much to be done.

  Therefore, in order to solve this problem, Patent Document 1 includes a holding state determination unit that determines the holding state of the lens barrel, and issues a warning according to the output of the holding state determination unit. Is disclosed (hereinafter referred to as “first prior art”).

Further, in Patent Document 1, it is determined whether or not there is a high possibility that camera shake will occur by determining whether or not the shutter speed is slower than the reciprocal of the focal length, and there is a high possibility that camera shake will occur. A technique for issuing a warning when the holding state with respect to the photographing apparatus is not correct (hereinafter referred to as “second prior art”) is also disclosed.
JP 2000-338588 A

  However, in the first prior art, since a warning is always issued when the holding state with respect to the lens barrel is not correct, the photographer is forced to have a certain holding state with respect to the lens barrel. There is a problem that it may be bothersome and uncomfortable.

  In the second prior art, if it is determined that the shutter speed is faster than the reciprocal of the focal length and the possibility of camera shake is low, a warning is issued regardless of the state of the photographing device held by the photographer. Therefore, there is a problem that camera shake may occur when the holding state is not correct.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an imaging apparatus and a camera shake warning method capable of appropriately issuing a camera shake warning.

  In order to achieve the above object, a photographing apparatus according to claim 1 is a photographing apparatus for photographing a subject, the detecting means for detecting a holding state with respect to the photographing device, and a shutter speed according to the brightness of the subject. Determining means for determining the amount of movement, warning means for warning the occurrence of camera shake when the shutter speed is equal to or lower than a predetermined speed, and slowing as the holding state detected by the detecting means becomes better Setting means for setting the predetermined speed.

  In the photographing apparatus according to claim 1, the shutter speed is determined according to the brightness of the subject by the determining means, and the occurrence of camera shake occurs when the shutter speed is equal to or lower than a predetermined speed set by the warning means. Be warned. Note that the warning by the warning means includes a warning due to display by a display device or the like, a warning due to lighting or blinking of a lamp, a warning due to sound or buzzer sounding through a speaker, or the like.

  Here, in the present invention, the predetermined speed is set by the setting means so as to be slower as the holding state detected by the detecting unit that detects the holding state with respect to the photographing apparatus is better.

  As described above, according to the photographing apparatus of the first aspect, the shutter speed is determined according to the brightness of the subject, and the occurrence of camera shake is warned when the shutter speed is equal to or lower than the predetermined speed set in advance. In this case, since the holding state with respect to the photographing apparatus is detected and the predetermined speed is set so as to be slower as the holding state becomes better, only one of the shutter speed and the holding state with respect to the photographing apparatus is shaken. Even in a state where there is a high possibility of occurrence of a camera shake, a camera shake warning can be issued, and a camera shake warning can be appropriately issued.

  The setting means of the present invention may set the predetermined speed stepwise as in the invention described in claim 2. This makes it possible to set the predetermined speed more easily than when the predetermined speed is set continuously.

  On the other hand, in order to achieve the above object, the camera shake warning method according to claim 3 determines the shutter speed according to the brightness of the subject, and the camera shake occurs when the shutter speed is equal to or lower than a predetermined speed set in advance. This is a camera shake warning method for an imaging apparatus that warns of the occurrence of the above-mentioned problem, wherein the holding state with respect to the imaging apparatus is detected, and the predetermined speed is set so as to become slower as the holding state becomes better.

  Therefore, according to the camera shake warning method according to the third aspect, since it operates in the same manner as the invention according to the first aspect, it is possible to appropriately issue the camera shake warning similarly to the invention according to the first aspect.

  According to the present invention, the shutter speed is determined according to the brightness of the subject, and when the shutter speed is equal to or lower than a predetermined speed set in advance, the warning state of the photographing apparatus is set when warning of occurrence of camera shake is issued. Since the predetermined speed is set so as to be detected and slower as the holding state is better, only one of the shutter speed and the holding state with respect to the photographing apparatus is highly likely to cause camera shake. Even if it is a case, the camera shake warning can be issued and the camera shake warning can be appropriately issued.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, a case where the present invention is applied to a digital electronic still camera (hereinafter referred to as “digital camera”) will be described.

  First, an external configuration of the digital camera 10 according to the present embodiment will be described with reference to FIG.

  In front of the digital camera 10, a lens 21 for forming a subject image, a strobe 44 that emits light to irradiate the subject when necessary, and a viewfinder used to determine the composition of the subject to be photographed. 20 is provided. Further, on the upper surface of the digital camera 10, a release switch (so-called shutter) 56A, a power switch 56B, and a mode changeover switch 56C that are pressed when performing shooting are provided.

  Note that the release switch 56A of the digital camera 10 according to the present embodiment is pressed down to an intermediate position (hereinafter referred to as “half-pressed state”) and to a final pressed position beyond the intermediate position. A two-stage pressing operation of a state (hereinafter referred to as a “fully pressed state”) can be detected.

  In the digital camera 10, the release switch 56 </ b> A is pressed halfway to activate the AE (Automatic Exposure) function to determine and set the exposure state (shutter speed, aperture state), and then perform AF. The (Auto Focus) function works to control the focus, and then exposure (photographing) is performed when the button is fully pressed.

  The mode changeover switch 56C is rotated when setting to any one of a shooting mode that is a mode for shooting and a playback mode that is a mode for playing back a subject image on the LCD 38 described later.

  On the other hand, on the back surface of the digital camera 10, an eyepiece of the finder 20, a liquid crystal display (hereinafter referred to as “LCD”) 38 for displaying a photographed subject image, a menu screen, and the like, and a cross cursor switch 56D. And are provided. The cross-cursor switch 56D includes four arrow keys that indicate four moving directions of up, down, left, and right in the display area of the LCD 38.

  Furthermore, on the back of the digital camera 10, a menu switch that is pressed when displaying the menu screen on the LCD 38, a determination switch that is pressed when confirming the operation content up to that point, and the previous operation content are displayed. A cancel switch that is pressed when canceling, a strobe switch that is pressed when setting the light emission state of the strobe 44, and a macro shooting switch that is pressed when performing macro shooting are provided. .

  Here, the digital camera 10 according to the present embodiment includes a plurality of grip sensors 60 (in the present embodiment, four grip sensors 60A, 60B, 60C, and 60D) that detect the holding state by the photographer for each arrangement position. ) Is provided.

  Each of the grip sensors is disposed at a position where a finger is placed when the photographer holds the digital camera 10 in an appropriate manner (a position at which the occurrence of camera shake can be prevented by being held by the photographer). As shown in FIG. 1, in the digital camera 10 according to the present embodiment, the grip sensor 60A and the grip sensor 60B are provided in the vicinity of the left and right end portions on the front side, opposite to the arrangement side of the release switch 56A on the upper surface. A grip sensor 60C is disposed in the vicinity of the end on the side, and a grip sensor 60D is disposed in the vicinity of the lower portion of the grip sensor 60C on the back surface.

  In this embodiment, a pressure-sensitive sensor is applied as the grip sensor. However, the present invention is not limited to this, and a sensor using a button rubber, a photo reflector disclosed in Patent Document 1, or a conductor is used. Any sensor can be used as long as it can detect that the photographer is holding it, such as a sensor using the.

  Next, with reference to FIG. 2, the configuration of the main part of the electrical system of the digital camera 10 according to the present embodiment will be described.

  The digital camera 10 includes an optical unit 22 including the lens 21 described above, a charge coupled device (hereinafter referred to as “CCD”) 24 disposed behind the optical axis of the lens 21, and an input analog. And an analog signal processing unit 26 that performs various analog signal processing on the signal.

  The digital camera 10 also performs an analog / digital converter (hereinafter referred to as “ADC”) 28 that converts an input analog signal into digital data, and performs various digital signal processing on the input digital data. And a digital signal processing unit 30.

  The digital signal processing unit 30 has a built-in line buffer having a predetermined capacity, and also performs control to directly store the input digital data in a predetermined area of the memory 48 described later.

  The output terminal of the CCD 24 is connected to the input terminal of the analog signal processing unit 26, the output terminal of the analog signal processing unit 26 is connected to the input terminal of the ADC 28, and the output terminal of the ADC 28 is connected to the input terminal of the digital signal processing unit 30. . Accordingly, the analog signal indicating the subject image output from the CCD 24 is subjected to predetermined analog signal processing by the analog signal processing unit 26, converted into digital image data by the ADC 28, and then input to the digital signal processing unit 30.

  On the other hand, the digital camera 10 generates a signal for displaying a subject image, a menu screen or the like on the LCD 38 and supplies the signal to the LCD 38, and a CPU (Central Processing Unit) 40 that controls the operation of the entire digital camera 10. A memory 48 that temporarily stores digital image data obtained by photographing, and a memory interface 46 that controls access to the memory 48 are included.

  Further, the digital camera 10 includes an external memory interface 50 for enabling the portable memory card 52 to be accessed by the digital camera 10, and a compression / decompression processing circuit 54 for performing compression processing and decompression processing on the digital image data. It is configured to include.

  In the digital camera 10 of the present embodiment, a flash memory is used as the memory 48, and a smart media (Smart Media (registered trademark)) is used as the memory card 52.

  The digital signal processing unit 30, the LCD interface 36, the CPU 40, the memory interface 46, the external memory interface 50, and the compression / decompression processing circuit 54 are connected to each other via a system bus BUS. Therefore, the CPU 40 controls the operation of the digital signal processing unit 30 and the compression / decompression processing circuit 54, displays various information via the LCD interface 36 to the LCD 38, and the memory interface 46 or the external memory interface to the memory 48 and the memory card 52. 50 can be accessed each.

  On the other hand, the digital camera 10 includes a timing generator 32 that mainly generates a timing signal for driving the CCD 24 and supplies the timing signal to the CCD 24, and the driving of the CCD 24 is controlled by the CPU 40 via the timing generator 32.

  Further, the digital camera 10 is provided with a motor drive unit 34, and driving of a focus adjustment motor, a zoom motor, and an aperture drive motor (not shown) provided in the optical unit 22 is also controlled by the CPU 40 via the motor drive unit 34. The

  In other words, the lens 21 according to the present embodiment has a plurality of lenses, is configured as a zoom lens that can change (magnify) the focal length, and includes a lens driving mechanism (not shown). The lens drive mechanism includes the focus adjustment motor, the zoom motor, and the aperture drive motor, and these motors are each driven by a drive signal supplied from the motor drive unit 34 under the control of the CPU 40.

  Further, various switches such as the release switch 56A, the power switch 56B, the mode switch 56C, the cross cursor switch 56D, and the menu switch (generically referred to as “operation unit 56” in the figure) are connected to the CPU 40. The CPU 40 can always grasp the operation state with respect to the operation unit 56.

  The above-described grip sensors 60A to 60D (generally referred to as “grip sensor 60” in the figure) are also connected to the CPU 40, and the CPU 40 constantly detects the detection result of the holding state by the photographer for these grip sensors 60. I can grasp.

  In addition, the digital camera 10 includes a charging unit 42 that is interposed between the strobe 44 and the CPU 40 and charges power for causing the strobe 44 to emit light under the control of the CPU 40. Further, the strobe 44 is also connected to the CPU 40, and the light emission of the strobe 44 is controlled by the CPU 40.

  Next, an overall operation at the time of shooting of the digital camera 10 according to the present embodiment will be briefly described.

  First, the CCD 24 performs imaging through the optical unit 22 and sequentially outputs analog signals for R (red), G (green), and B (blue) indicating the subject image to the analog signal processing unit 26. The analog signal processing unit 26 performs analog signal processing such as correlated double sampling processing on the analog signal input from the CCD 24 and sequentially outputs the analog signal to the ADC 28.

  The ADC 28 converts the R, G, and B analog signals input from the analog signal processing unit 26 into 12-bit R, G, and B signals (digital image data) and sequentially outputs them to the digital signal processing unit 30. To do. The digital signal processing unit 30 accumulates digital image data sequentially input from the ADC 28 in a built-in line buffer and temporarily stores the digital image data directly in a predetermined area of the memory 48.

  The digital image data stored in a predetermined area of the memory 48 is read out by the digital signal processing unit 30 according to the control by the CPU 40, and is subjected to white gain by applying a digital gain for each of R, G, and B according to a predetermined physical quantity. In addition to performing balance adjustment, gamma processing and sharpness processing are performed to generate 8-bit digital image data.

  The digital signal processing unit 30 performs YC signal processing on the generated 8-bit digital image data to generate a luminance signal Y and chroma signals Cr and Cb (hereinafter referred to as “YC signal”), and the YC signal. Are stored in an area different from the predetermined area of the memory 48.

  The LCD 38 is configured to display a moving image (through image) obtained by continuous imaging by the CCD 24 and can be used as a finder. When the LCD 38 is used as a finder, the LCD 38 is generated. The YC signals thus output are sequentially output to the LCD 38 via the LCD interface 36. As a result, a through image is displayed on the LCD 38.

  Here, at the timing when the release switch 56A is half-pressed by the user, the exposure state is set by operating the AE function as described above, and the camera shake warning process to be described later is executed after performing the focusing control by the AF function. Thereafter, at the timing when the release switch 56A is continuously shifted from the half-pressed state to the fully-pressed state, the YC signal stored in the memory 48 at that time is converted into a predetermined compression format (this embodiment). In this form, after compression in the JPEG format), it is recorded as an electronic file (image file) on the memory card 52 via the external memory interface 50.

  Next, the operation of the digital camera 10 when the camera shake warning process is executed will be described with reference to FIG. FIG. 3 is a flowchart showing a flow of processing of the camera shake warning processing program executed by the CPU 40 of the digital camera 10 at this time, and the program is stored in a predetermined area of the memory 48 in advance.

  In step 100 of the figure, based on the detection result of the holding state by the photographer with respect to the grip sensors 60A to 60D, it is determined whether or not the holding state of the digital camera 10 by the photographer is good. If so, go to Step 102. In the camera shake warning processing program according to the present embodiment, it is determined that the holding state is good when the photographer holds the grip sensor 60A and holds at least one of the grip sensors 60B to 60D. However, the present invention is not limited to this. For example, when more than half of the grip sensors 60A to 60D are held, it is determined that the holding state is good, or all the grip sensors 60A to 60D are held. In this case, it can be determined that the holding state is good.

  In step 102, a predetermined low value (in this embodiment, 1/15 second (1/15 second)) is set as a threshold for the shutter speed applied in step 106 described later, and then step 106. Migrate to On the other hand, if a negative determination is made in step 100, the process proceeds to step 104, where the threshold value is set to a predetermined high value (at least a value greater than the low value. In the present embodiment, 1/30 sec. (1/30 second)) is set, and then the process proceeds to step 106.

  In step 106, it is determined whether or not the shutter speed determined by the AE function performed immediately before executing the camera shake warning processing program is equal to or less than the threshold set in step 102 or step 104. If YES in step 108, the flow advances to step 108 to control to display a predetermined warning screen on the LCD 38, and then the camera shake warning processing program ends.

  FIG. 4 shows an example of the display state of the warning screen displayed on the LCD 38 by the processing of step 108 described above. As shown in the figure, on this warning screen, a message indicating that there is a possibility of camera shake and a message prompting to hold the digital camera 10 correctly are displayed. The warning screen as shown in the figure is displayed on the LCD 38, so that the photographer is more likely to hold the digital camera 10 correctly. As a result, the possibility of the occurrence of camera shake may be avoided. Get higher.

  On the other hand, if a negative determination is made in step 106, the camera shake warning processing program is terminated without executing the processing of step 108.

  As described above in detail, in the present embodiment, the shutter speed is determined according to the brightness of the subject, and the occurrence of camera shake occurs when the shutter speed is equal to or lower than a predetermined speed (threshold) set in advance. In warning, the holding state with respect to the photographing apparatus (digital camera 10) is detected, and the predetermined speed is set so as to be slower as the holding state is better. Even if only one of them is in a state where there is a high possibility that camera shake will occur, a camera shake warning can be issued, and a camera shake warning can be appropriately issued.

  Further, in the present embodiment, the predetermined speed is set stepwise (here, two stages of a predetermined low value and a predetermined high value), so compared to the case where the predetermined speed is set continuously, The predetermined speed can be easily set.

  In the present embodiment, as shown in FIG. 1, the case where a total of four grip sensors are provided on the front, top, and back of the digital camera 10 has been described, but the present invention is not limited to this. For example, it is possible to adopt a form in which any one of these is deleted or a form provided on the bottom in addition to these. In this case, the holding state of the digital camera 10 by the photographer can be detected with higher accuracy as the number of grip sensors increases, and the cost of the digital camera 10 can be reduced as the number of grip sensors decreases.

  Further, in the present embodiment, the case where a camera shake warning is given by display on the LCD 38 has been described. However, the present invention is not limited to this, and for example, the finder 20 is an EVF (electric view finder). Warning by display by the finder 20 in the case, warning by sound by the speaker when the digital camera 10 is provided with a speaker, warning by sounding the buzzer when the buzzer is provided in the digital camera 10, viewfinder 20 An LED (light emitting diode) may be provided in the vicinity of the eyepiece, and a warning or the like caused by lighting, blinking, or the like of the LED may be used. Also in this case, the same effects as in the present embodiment can be obtained.

  In the present embodiment, no particular mention is made of tripod shooting, but a camera shake warning may be prohibited during tripod shooting. In this case, an unnecessary camera shake warning can be avoided.

  Further, in the present embodiment, a case has been described in which the shutter speed threshold value used when determining whether or not to perform a camera shake warning is set in two stages depending on whether or not the holding state is good. However, the threshold value is not limited to this. For example, the threshold value may be set continuously in a stepless manner so as to be smaller as the holding state is better. In this case, it is possible to determine whether or not a camera shake warning is necessary with higher accuracy than in the present embodiment.

  Further, in the present embodiment, a grip sensor that detects whether or not the photographer holds the image sensor is used as the detection unit of the present invention, and the digital camera 10 is held by the photographer according to the detection result of the sensor. However, the present invention is not limited to this. For example, as a detection unit of the present invention, a holding force (gripping force) by a photographer can be detected. A sensor such as a pressure sensor may be applied to determine whether or not the digital camera 10 is held well by the photographer according to the strength of the holding force detected by the sensor. In this case, it is possible to determine whether or not a camera shake warning is necessary with higher accuracy than in the present embodiment.

  In addition, the configuration of the digital camera 10 according to the present embodiment (see FIGS. 1 and 2) is an example, and it is needless to say that the configuration can be appropriately changed without departing from the gist of the present invention.

  Further, the flow of processing of the camera shake warning processing program described in the present embodiment (see FIG. 3) is also an example, and it goes without saying that the flow can be appropriately changed without departing from the gist of the present invention.

  Further, the display state of the warning screen (see FIG. 4) shown in this embodiment is also an example, and it is needless to say that it can be changed as appropriate without departing from the gist of the present invention.

  Furthermore, although the case where the present invention is applied to a digital camera has been described in this embodiment, it is needless to say that the present invention can be applied to any information device having a photographing function such as a PDA or a mobile phone. .

It is an external view which shows the external appearance of the digital camera which concerns on embodiment. It is a block diagram which shows the principal part structure of the electric system of the digital camera which concerns on embodiment. It is a flowchart which shows the flow of a process of the camera shake warning processing program which concerns on embodiment. It is the schematic which shows the example of a display state of the warning screen which concerns on embodiment.

Explanation of symbols

10 digital camera 40 CPU (determination means, warning means, setting means)
60A-60D Grip sensor (detection means)

Claims (3)

An imaging device for imaging a subject,
Detecting means for detecting a holding state with respect to the photographing apparatus;
Determining means for determining a shutter speed according to the brightness of the subject;
Warning means for warning the occurrence of camera shake when the shutter speed is equal to or lower than a predetermined speed set in advance;
Setting means for setting the predetermined speed so as to be slower as the holding state detected by the detection means is better;
An imaging device with The photographing apparatus according to claim 1, wherein the setting unit sets the predetermined speed stepwise. A camera shake warning method for a photographing apparatus that determines a shutter speed according to the brightness of a subject and warns the occurrence of camera shake when the shutter speed is equal to or lower than a predetermined speed,
Detecting the holding state with respect to the photographing apparatus, and setting the predetermined speed so as to be slower as the holding state is better;
Camera shake warning method.

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