JP2001194701A - Digital camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital camera capable of correcting camera shake even when the remaining capacity of a battery is small. SOLUTION: In this digital camera, a CPU 121 calculates camera shake shutter time, based on a shake amount detected by a shake detecting device 136, judges whether or not set shutter time is equal to or under the calculated camera shake shutter time, and increases the gain of an AGC amplifier 105 to a specified value when it judges that the set shutter time is equal to or under the calculated camera shake shutter time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a digital camera, and more particularly, to a digital camera having a camera shake correction function.

[0002]

2. Description of the Related Art When a digital camera is reduced in size and weight and a zoom lens is increased in magnification, camera shake is likely to occur. As a method of correcting this, a mechanical method, an optical method, and an electronic method are known. The mechanical method is a method in which a camera shake is detected by an angular velocity sensor or the like, and correction is performed by mechanically moving the imaging unit in a direction opposite to the shake. The optical system is a system in which a change in an optical axis due to camera shake is canceled out by changing a part of the optical system. Further, the electronic method is a method in which a read address of a field memory is controlled in accordance with a motion vector obtained by a motion detection unit, and an output screen is translated in a direction opposite to the movement to correct the screen shake. As described above, there are various camera shake correction methods. Digital camera shake correction methods that have recently been proposed will be described below.

For example, in a camera equipped with a shake correction device disclosed in Japanese Patent Application Laid-Open No. 07-281239, a photographing auxiliary light emitting device, a shake amount detection device, and a shake correction based on a shake signal of the shake amount detection device. In a camera equipped with a correction device, when performing flash photography while driving the shake amount detection device, the longest shutter time during flash synchro photography, which emits light in synchronization with the shutter, and no flash emission, which does not emit the auxiliary light emission device for photography A technique is disclosed in which the relationship with the longest shutter time of the flash is such that the longest shutter time during flash synchro photography is shorter than or equal to the longest shutter time of the flashless flash.

Further, according to the camera disclosed in Japanese Patent Application Laid-Open No. 07-281240, a control device for performing exposure photographing sets a focal length, which is a reference of a shutter speed, to a longest focal length, and performs photographing regardless of zooming driving of a photographing optical system. There is disclosed a technique in which the time of the end of time is controlled to be constant, and the focal length as a reference for the shutter speed is set to the shortest focal length.

Further, according to the camera disclosed in Japanese Patent Application Laid-Open No. 08-313955, a camera shake detecting means for detecting camera shake, a correcting means for correcting, and a selection for selecting whether or not to operate the camera shake correcting means during exposure. Means, photometric means for measuring subject brightness, and storage means for storing a first shutter speed used when the blur correction means is not operating and a second shutter speed used when the blur correction means is slower than the first shutter speed. And the subject brightness and the first or second
And a shutter speed determining means for determining a shutter speed at the time of exposure based on the shutter speed.

According to Japanese Patent Application Laid-Open No. 08-313958, light is emitted when the blur is corrected, when the brightness is equal to or lower than the first brightness, and when the blur is not corrected, when the brightness is equal to or less than the second brightness, which is higher than the first brightness. There is disclosed a technology including a flash necessity determination unit that determines whether or not to perform flash emission at the time of shooting based on subject brightness so as to emit light.

According to the digital camera disclosed in Japanese Patent Application Laid-Open No. H11-215432, when the set shutter time is equal to or less than the camera shake shutter time in the camera shake reduction shooting mode, the AGC amplifier is turned to a specified value. Techniques for increasing the gain have been disclosed.

[0008]

However, in the prior art, there is a problem that the method of mechanically performing camera shake correction cannot perform camera shake correction when the remaining battery capacity is small. Also, in the method of increasing the gain of the AGC amplifier, if the gain is increased too much, S / S
There is a problem that N deteriorates.

The present invention has been made in view of the above, and has as its object to provide a digital camera capable of performing camera shake correction even when the remaining battery capacity is small.

Another object of the present invention is to provide a digital camera capable of performing camera shake correction while preventing deterioration of the S / N ratio as much as possible. I do.

[0011]

According to a first aspect of the present invention, there is provided a digital camera, comprising: a lens system for forming an image of a subject; Image-capturing means for converting, blur detecting means for detecting a blur amount, hand-shutter shutter time calculating means for calculating a hand-shutter shutter time based on the blur amount detected by the blur detecting means, and a signal level of the image signal Gain amplifying means for correcting the camera shake time, determining means for determining whether or not the set shutter time is equal to or less than the camera shake shutter time calculated by the camera shake shutter time calculating means, and setting by the determining means. When it is determined that the shutter time is equal to or less than the camera shake shutter time calculated by the camera shake shutter time calculation means, in order to perform camera shake correction,
Control means for increasing the gain of the variable gain amplifying means to a prescribed value.

According to the above invention, the shake detecting means detects the shake amount, the shutter time setting means calculates the camera shake shutter time based on the detected shake amount, and the gain amplifying means calculates the signal level of the image signal. The determination means determines whether or not the set shutter time is equal to or less than the camera shake shutter time, and the control means determines by the determination means that the set shutter time is equal to or less than the camera shake shutter time. When it is determined, the gain of the variable gain amplifying means is increased to a specified value.

[0013] The invention according to claim 2 is based on claim 1.
In the digital camera according to the first aspect, the control unit prohibits a shake detection operation of the shake detection unit, and when the shake detection operation of the shake detection unit is prohibited, the determination unit determines a set shutter time. The control means determines whether or not the shutter speed is equal to or less than the camera shake shutter time. If the determination means determines that the set shutter time is equal to or less than the specified camera shake shutter time, the control means corrects the camera shake. Is performed, the gain of the variable gain amplifying means is increased to a specified value.

According to the invention, the control means inhibits the shake detection operation of the shake detection means, and when the shake detection operation of the shake detection means is inhibited, the determination means sets the shutter time at the specified shutter time. The control means determines whether or not the shutter speed is equal to or less than the camera shake shutter time, and when the shutter time set by the determination means is determined to be equal to or less than the specified camera shake shutter time, the variable gain amplification to a specified value. Increase the gain of the means.

According to a third aspect of the present invention, there is provided a digital camera, comprising: a lens system for forming a subject image; an imaging unit for converting the formed subject image into an image signal; a blur detecting unit for detecting a blur amount; In accordance with the amount of shake detected by the shake detection means, a camera shake correction means for performing camera shake correction, and a camera shake shutter time calculation means for calculating the camera shake shutter time based on the shake amount detected by the shake detection means, Gain amplifying means for correcting the signal level of the image signal, and judging means for judging whether or not the set shutter time is equal to or less than a camera shake shutter time detected by the shake detecting means,
When the set shutter time is determined to be equal to or less than the camera shake shutter time calculated by the camera shake shutter time calculation means, the variable gain amplifying means up to a prescribed value to perform camera shake correction. And / or control means for causing the camera shake correction means to perform camera shake correction.

According to the above invention, the shake detecting means detects the amount of shake, the shake correcting means performs the shake correction in accordance with the amount of shake detected by the shake detecting means, and based on the detected shake amount, the camera shake shutter. The second time is calculated, the gain amplifying means corrects the signal level of the image signal, the judging means judges whether or not the set shutter time is equal to or less than the camera shake shutter time. When it is determined that the set shutter time is equal to or less than the camera shake shutter time, the gain of the variable gain amplifying means is increased to a specified value,
And / or causing camera shake correction means to perform camera shake correction.

According to a fourth aspect of the present invention, in the digital camera according to the third aspect, the control means increases the gain of the variable gain amplifying means up to the predetermined value and corrects the camera shake by the camera shake correcting means. Is prohibited.

According to the above-mentioned invention, the control means inhibits any one of an increase in the gain of the variable gain amplifying means up to the prescribed value and a camera shake correction by the camera shake correcting means.

In the digital camera according to a fifth aspect of the present invention, in the digital camera according to the third aspect, when the determination unit determines that the set shutter time is equal to or less than the camera shake shutter time, One of increasing the gain of the variable gain amplifying unit up to a prescribed value and correcting the camera shake by the camera shake correcting unit is preferentially executed.

According to the invention, when it is determined that the shutter time set by the determining means is equal to or less than the camera shake shutter time, the gain of the variable gain amplifying means is increased to a specified value and the camera shake by the camera shake correcting means is performed. One of the corrections is executed with priority.

According to a sixth aspect of the present invention, there is provided the digital camera according to any one of the first to fifth aspects, further comprising: display means for displaying information; Display control means for controlling to display the amount of blur detected by the means and / or the content of the executed camera shake correction.

According to the above-mentioned invention, the display control means displays, on the display means, the shake calibration amount detected by the shake detection means and / or the details of the executed camera shake correction.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a digital camera according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a configuration diagram of a digital camera according to the present embodiment. In FIG. 1, reference numeral 100 denotes a digital camera. The digital camera 100 includes a lens system 101, a mechanical mechanism 102 including an aperture / filter unit, and the like.
CCD 103, CDS circuit 104, variable gain amplifier (A
GC amplifier: VG (variable) amplifier 105, A / D converter 106, IPP 107, DCT 108, coder 10
9, MCC 110, DRAM 111, PC card interface 112, CPU 121, display unit 122, operation unit 123, SG (control signal generation) unit 126, strobe device 127, battery 128, DC-DC converter 12
9, EEPROM 130, focus driver 131,
Pulse motor 132, zoom driver 133, pulse motor 134, motor driver 135, blur detector 13
6 and a shake correction device 137. A detachable PC card 150 is connected via the PC card interface 112.

The lens unit includes a mechanical mechanism 102 including a lens 101 system, a diaphragm and a filter section, and the mechanical shutter of the mechanical mechanism 102 performs simultaneous exposure of two fields. The lens system 101 includes, for example, a variable focal lens, and
1a and a zoom lens system 101b.

The focus driver 131 is connected to the CPU 12
1 according to the control signal supplied from the
2 to move the focus lens system 101a in the optical axis direction. The zoom driver 133 includes a CPU 121
Pulse motor 132 according to the control signal supplied from
To move the zoom lens system 101b in the optical axis direction. In addition, the motor driver 135 includes the CPU 121
The mechanical mechanism 102 is driven in accordance with a control signal supplied from the controller, and for example, an aperture value of the aperture is set.

The CCD (Charge Coupled Device) 103 converts an image input through the lens unit into an electric signal (analog image data). The CDS (correlated double sampling) circuit 104 is a circuit for reducing noise in the CCD type image pickup device.

The AGC amplifier 105 corrects the level of the signal double correlated sampled by the CDS circuit 104. The gain of the AGC amplifier 105 is determined by the CPU 1
A CPU 21 uses data stored in the EEPROM 130 to determine the relationship between the control voltage and the output gain.
The setting is performed by setting the setting data (control voltage) to the AGC amplifier 105 via a D / A converter built in 121. Further, the A / D converter 106 is connected to the AG
The analog image data from the CCD 103 input via the C amplifier 105 is converted into digital image data. That is, the output signal of the CCD 103 is output to the CDS circuit 104.
And A / D converter 1 via AGC amplifier 105
06, the optimum sampling frequency (for example, NT
It is converted into a digital signal at an integer multiple of the subcarrier frequency of the SC signal.

The digital signal processor IPP
(Image Pre-Processor) 107, DCT (Discrete Cos)
ine Transform) 108 and coder (Huffman Enco
A der / Decoder) 109 performs various processing, correction, and data processing for image compression / decompression on the digital image data input from the A / D converter 106 by dividing the digital image data into color difference (Cb, Cr) and luminance (Y). Apply. In particular, DCT (Discre
te Cosine Transform) 108 and coder (Huffma
n Encoder / Decoder) 109 is, for example, an orthogonal transform which is a process of JPEG-compliant image compression / decompression, and a JPE
Huffman encoding / decoding, which is one of the G-compliant image compression / decompression processes, is performed.

Further, an MCC (Memory Card Controlle)
An r) 110 temporarily stores the compressed image and records the image on the PC card 150 via the PC card interface 112 or reads the image from the PC card 150.

The CPU 121 uses the RAM of the CPU 121 as a work area in accordance with a program stored in the ROM of the CPU 121, and in accordance with an instruction from the operation unit 123 or an external operation instruction such as a remote controller (not shown). Control behavior. In particular,
The CPU 121 controls an imaging operation, an automatic exposure (AE) operation, an automatic white balance (AWB) adjustment operation, an AF operation, and the like.

The camera power is supplied from a battery 128, for example, NiCd, nickel metal hydride, lithium battery, or the like.
The signal is input to the C-DC converter 129 and supplied to the inside of the digital camera.

The display unit 122 is realized by an LCD, an LED, an EL, or the like, and displays photographed digital image data, decompressed recorded image data, and the like. Operation unit 1
Reference numeral 23 includes buttons for externally performing function selection, shooting instructions, and other various settings. EEPRO
In M130, adjustment data and the like used when the CPU 121 controls the operation of the digital camera are written.

The blur detecting device 136 includes, for example, an angular velocity sensor, and detects vertical and horizontal blurs on a plane perpendicular to the optical axis and outputs the detected blur to the CPU 121. CPU 12
Numeral 1 calculates a shake amount based on a shake detection result of the shake detection device 136. The camera shake correction device 137 is composed of a piezoelectric element that moves the CCD 103 in the vertical and horizontal directions, and performs camera shake correction by moving the CCD 103 under the control of the CPU 110.

FIG. 3 shows a control voltage (Control Voltage) and an output gain (Measured G) of the AGC amplifier 105.
ain). 3, the horizontal axis represents the control voltage (Control Voltage) of the AGC amplifier 105.
age), and the vertical axis represents the output gain (Mea) of the AGC amplifier 105.
sured Gain). The characteristic curve data shown in FIG. 3 is digitized and stored in the EEPROM 130.

FIG. 2 is a diagram showing an example of a specific configuration of the IPP 107. As shown in FIG. 2, the IPP 107 separates the digital image data input from the A / D converter 106 into R, G, and B color components.
A signal interpolating unit 1072 for interpolating the separated R, G, B image data, a pedestal adjusting unit 1073 for adjusting the black level of each of the R, G, B image data, and each of the R, B images A white balance adjustment unit 1074 for adjusting the white level of the data; a digital gain adjustment unit 1075 for correcting each of the R, G, and B image data with a gain set by the CPU 121; a gamma conversion unit 1076 for performing γ conversion, a matrix unit 1077 for separating RGB image data into color difference signals (Cb, Cr) and a luminance signal (Y), a color difference signal (Cb, Cr), and a luminance signal (Y) And generates a video signal based on the
And a video signal processing unit 1078 for outputting to the P.22.

Further, the IPP 107 includes a Y operation unit 1079 for detecting the luminance data (Y) of the image data after the pedestal adjustment by the pedestal adjustment unit 1073, and a Y operation unit 1
079, a BPF 1080 that passes only a predetermined frequency component of the luminance data (Y) detected, and an integrated value of the luminance data (Y) that has passed through the BPF 1080 is used as an AF evaluation value as C value.
An AF evaluation value circuit 1081 that outputs to the PU 121, an AE evaluation value circuit 1082 that outputs to the CPU 121 a digital count value corresponding to the luminance data (Y) detected by the Y operation unit 1079 as an AE evaluation value, and a white balance adjustment unit 1074 Calculation unit 1083 for detecting luminance data (Y) of each of R, G, and B image data after gain adjustment by
And an AWB evaluation value circuit 1084 that counts the luminance data (Y) of each color detected by the Y operation unit 1083 and outputs the result to the CPU 121 as an AWB evaluation value of each color.
And CPUI which is an interface with the CPU 121
/ F 1085 and a DCTI / F 1086 which is an interface with the DCT 108.

The above-described AE evaluation value circuit 1082 outputs an AE evaluation value obtained by weighting the luminance value of each area when the screen (the light receiving screen of the CCD 103) is divided into six AE areas. More specifically, the Y operation unit 1079 converts the luminance data of each pixel of the image data into an AE
Output to the evaluation value circuit 1082 and the AE evaluation value circuit 1082
The CPU 1 calculates a value obtained by integrating the luminance data in each of the AE areas as a luminance value, and calculates a weighted value of the calculated luminance value of each AE area as an AE evaluation value.
21.

The digital camera 100 (CPU 1
21) a monitoring function (monitoring mode) for continuously displaying captured images on the display unit 122, and an image recording function (image recording mode) for recording image data obtained by imaging a subject on the PC card 150. And a reproduction function (reproduction mode) for displaying image data recorded on the PC card 150.

The digital camera 100 (CPU 12
1) has a camera shake function (camera shake correction mode) for performing camera shake correction. There are six first to sixth modes in the camera shake correction mode, and one of the modes is operated by operating the operation unit 123 or the like. You can choose. This camera shake correction mode is executed when an image is recorded (when the image recording mode is executed) or when monitoring (when the monitoring mode is executed). Next,
The AE control in the camera shake correction mode will be described. CPU
121 calculates Ev (ExposureValue) based on the AE evaluation value in the AE control, and
D103 shutter speed (shutter time Tv) and AGC
The gain and the like of the amplifier 105 are calculated, and the shutter speed (shutter time Tv) of the CCD 103 and the AGC amplifier 105 are calculated.
And perform proper exposure. In this operation example,
The description will be made assuming that the aperture is fixed (F4; Av (Aperture Value) 4). Table 1 below shows the contents of the first to sixth modes of the camera shake correction mode.

[0041]

[Table 1]

In the first mode, no camera shake correction is performed. In the second mode, when it is determined that the set shutter time is equal to or less than the specified camera shake shutter time without performing the shake detection by the shake detection device 136, the gain of the variable gain amplifier is increased to the specified value. increase. In the third mode, the camera shake shutter time is calculated based on the shake amount detected by the camera shake detection device 136, and when it is determined that the set shutter time is equal to or less than the calculated camera shake shutter time. , The gain of the AGC amplifier 105 is increased to a specified value. In the fourth mode, the shake detection device 1
The camera shake shutter time is calculated based on the camera shake amount detected at 36, and if it is determined that the set shutter time is equal to or less than the calculated camera shake shutter time, the camera shake correction is performed by the camera shake correction device 137. Do. In the fifth mode, the camera shake shutter time is calculated based on the camera shake amount detected by the camera shake detection device 136, and when it is determined that the set shutter time is equal to or less than the calculated camera shake shutter time. , First, the AGC amplifier 10 up to the specified value.
5 and, if necessary, the camera shake correction by the camera shake correction device 137 is also performed. In the sixth mode, the camera shake shutter time is calculated based on the camera shake amount detected by the camera shake detection device 136, and when it is determined that the set shutter time is equal to or less than the calculated camera shake shutter time. First, the camera shake correction is performed by the camera shake correction device 137 first, and if necessary, the gain of the AGC amplifier 105 is increased to a specified value. In addition, CPU
A display unit 122 displays the contents of the camera shake correction being performed.
To be displayed.

In each of the above modes, the fourth and sixth modes are selected when priority is given to image quality. On the other hand, when priority is given to power consumption (such as when the remaining battery capacity is small), the fourth mode is selected. The second, third or fifth mode may be selected.

As described above, the CPU 121 determines the shake amount based on the detection result of the shake detection device 136, and calculates the camera shake shutter time based on the shake amount. Table 2 below
Shows the relationship between the blur amount and the camera shake shutter time.

[0045]

[Table 2]

The CPU 121 sets the camera shake shutter time to one half (（times the focal length) when the camera shake amount is small, and sets the camera shake shutter time to (focal length) when the camera shake amount is medium. If the blur amount is large, the camera shake shutter time is determined to be 1 (two times the focal length). Also,
When the shake detection by the shake detection device 136 is not performed,
The CPU 121 sets the specified value as the camera shake shutter time.
(Focal length) is determined to be one-seventh. In general, it is said that the camera shake shutter time is 1 / (focal length). Therefore, when the camera shake detection device 136 does not perform shake detection, the normal camera shake shutter time is determined. The time is used, and the CPU 121 displays the detected blur amount on the display unit 122. Fig. 4 shows a display example of the blur amount, and the example shown in the figure shows a case where the blur amount is large. .

Hereinafter, the second to sixth modes of the camera shake correction will be described in detail. [Second Mode] In the second mode, the CPU 121
The shake detection by the shake detection device 136 is prohibited, and the set shutter time is set to the specified camera shake shutter time (see Table 2 above).
When the shutter speed is determined to be equal to or less than the shutter speed when the camera shake is not detected, the AGC amplifier 10 reaches the specified value.
Increase the gain of 5. Table 3 below shows the blur detection device 13.
In the case where the shake detection is not performed by the
The point of Ev at the time of shifting control from v or Sv to Tv is shown.

[0048]

[Table 3]

When there is no blur detection, the wide (Ev10
(1/60 sec), Tele (Ev12 (1/250 sec) or less, AGC up (CCD ISO sensitivity up)
By doing so, the shutter time is kept up to a maximum of 2 Ev minutes to avoid camera shake. Hereinafter, the case of wide, tele, and the case where the focal length is between wide and tele will be described.

(Wide) Ev10 to Ev17 are set for the shutter time (Tv6; 1/60 second to Tv6).
13; 1/8000 second) is changed (Ev = Av + Tv; Av = 4 fixed). Also,
From Ev8 to Ev10, the shutter time is set to Tv6; 1 /
AE control is performed by changing the gain (ISO100; Sv5 to ISO400; Sv7) set in the AGC amplifier 105 as 60 seconds. Also, Ev6 to Ev8
Until the gain setting of the AGC amplifier 105 is
As 0, the shutter time setting is changed in a range later than 1/60 second.

(Tele) In the case of Ev12 to Ev17, setting of shutter time (Tv8; 1/250 second to T
v13; 1/8000 sec.)
Control is performed (Ev = Av + Tv; Av = 4 fixed). For Ev10 to Ev12, the shutter time is set to Tv.
8; 1/250 second, gain set in AGC amplifier 105 (ISO100; Sv5 to ISO400; Sv
AE control is performed by changing 7). Ev6
From Ev10 to Ev10, the gain setting of the AGC amplifier 105 is set to ISO400 and the setting for the shutter time is 1/250.
Change within seconds.

(When the focal length is between wide and tele) The point of Ev at which the AE control for wide and tele is shifted from the control performed by changing Tv to the control for changing Sv is described above. As shown in Table 3, AE control is performed by changing according to the ratio between the set focal length and the focal lengths of wide and tele.

From Ev11 to Ev17, the shutter time setting (Tv7; 1/125 second to Tv13; 1/80)
AE control is performed by changing only (00 seconds) (Ev
= Av + Tv; Av = 4 fixed). Also, Ev9 to Ev1
Until 1, the shutter time is set to Tv7; 1/125 second, and the gain (ISO10
0; Sv5 to ISO400; Sv7) to perform AE control. Also, from Ev6 to Ev0, AG
The gain setting of the C amplifier 105 is set to ISO400, and the setting of the shutter time is changed in a range later than 1/125 second.

According to the second mode described above, the shake detection by the shake detecting device 136 is prohibited, and when it is determined that the set shutter time is equal to or less than the specified camera shake shutter time, the image is reduced to the specified value. Since the gain of the AGC amplifier 105 is increased, camera shake can be reduced even when power consumption is a problem, such as when the remaining battery capacity is small.

[Third Mode] In the third mode, the CP
U <b> 121 prohibits the camera shake correction by the camera shake correction device 137, calculates the camera shake shutter time (in the case of performing the camera shake detection in Table 2 above) based on the camera shake amount detected by the camera shake detection device 136, and sets the set shutter. When it is determined that the second time is equal to or less than the calculated camera shake shutter time, the gain of the AGC amplifier 105 is increased to a specified value. Table 4 below
When the blur amount is small, Tv to Sv or Sv
Shows the point of Ev when the control is shifted from Tv to Tv.

[0056]

[Table 4]

In the case of the blur amount (small), the wide (Ev9)
(1/30)), tele (Ev11 (1/125 second) or less, AGC is raised (CCD ISO sensitivity is increased), shutter time is kept up to 2Ev minutes to avoid camera shake. For wide, tele,
A case where the focal length is between wide and tele will be described.

(In the case of wide) From Ev9 to Ev17, the shutter time setting (Tv5; 1/30 second to Tv5)
13; 1/8000 second) is changed (Ev = Av + Tv; Av = 4 fixed). Also,
From Ev7 to Ev9, the shutter time is Tv5;
0 second, the gain (I
AE control is performed by changing SO100; Sv5 to ISO400; Sv7). From Ev6 to Ev7, the gain setting of the AGC amplifier 105 is set to ISO400, and the setting for the shutter time is changed in a range later than 1/30 second.

(Tele) In the case of Ev11 to Ev17, setting of shutter time (Tv7; 1/125 second to Tv7)
v13; 1/8000 sec.)
Control is performed (Ev = Av + Tv; Av = 4 fixed). From Ev9 to Ev11, the shutter time is set to Tv7;
AE control is performed by changing the gain (ISO100; Sv5 to ISO400; Sv7) set in the AGC amplifier 105 as 1/125. Also, Ev6 to Ev
Up to 9, the gain setting of the AGC amplifier 105 is
As 00, the shutter time setting is changed in a range later than 1/125 second.

(When the focal length is between wide and tele) The point of Ev at which the AE control for wide and tele is shifted from the control performed by changing Tv to the control for changing Sv is described above. As shown in Table 4, AE control is performed by changing according to the ratio between the set focal length and the focal length between wide and tele.

From Ev10 to Ev17, the shutter time setting (Tv6; 1/60 seconds to Tv13; 1/800)
AE control is performed by changing only (0 second) (Ev =
Av + Tv; Av = 4 fixed). In addition, Ev8 to Ev10
Until the shutter time is Tv6; 1/60 second, A
Gain (ISO100; S) set for the GC amplifier 105
AE by changing v5 to ISO400; Sv7)
Perform control. Ev6 to Ev8, AGC amplifier 10
The gain setting of 5 is set to ISO 400, and the setting of the shutter time is changed in a range later than 1/60 second.

Table 5 below shows that when the blur amount is medium, T
E when transferring control from v to Sv or from Sv to Tv
Indicates the point of v.

[0063]

[Table 5]

In the case of the blur amount (medium), the wide (Ev10
(1/60 sec), Tele (Ev12 (1/250 sec) or less, AGC up (CCD ISO sensitivity up)
By doing so, the shutter time is kept up to a maximum of 2 Ev minutes to avoid camera shake. Hereinafter, the case of wide, tele, and the case where the focal length is between wide and tele will be described.

(Wide) Setting of shutter time (Ev10 to Ev17) (Tv6; 1/60 sec to Tv6)
13; 1/8000) is changed (Ev = Av + Tv; Av = 4 fixed). Also, E
From v8 to Ev10, the shutter time is Tv6; 1/6
0 second, the gain (I
AE control is performed by changing SO100; Sv5 to ISO400; Sv7). From Ev6 to Ev8, the gain setting of the AGC amplifier 105 is set to ISO400, and the setting of the shutter time is changed in a range later than 1/60 second.

(Tele) In the case of Ev12 to Ev17, setting of shutter time (Tv8; 250 seconds to Tv1)
3; 1/8000) is changed (Ev = Av + Tv; Av = 4 fixed). Also, Ev
From 10 to Ev12, the shutter time is Tv8; 1/2.
AE control is performed by changing the gain (ISO100; Sv5 to ISO400; Sv7) set in the AGC amplifier 105 as 50 seconds. From Ev6 to Ev10, the gain setting of the AGC amplifier 105 is set to ISO400, and the setting of the shutter time is changed in a range later than 1/250 second.

(When the focal length is between wide and tele) The AE control in the case of wide and tele is shifted from the control performed by changing Tv to the control of changing Sv. As shown in Table 5, A is changed according to the set focal length and the ratio of the focal length of wide and tele.
Perform E control. From Ev11 to Ev17, setting of shutter time (Tv7; 1/125 second to Tv13; 1/8)
AE control is performed by changing only
v = Av + Tv; Av = 4 fixed).

From Ev9 to Ev11, the shutter time is set to Tv7; 1/125 second, and the gain (ISO100; Sv5 to ISO400;
AE control is performed by changing Sv7). Ev6 ~
Until Ev9, the gain setting of the AGC amplifier 105
As O400, the shutter time setting is changed in a range later than 1/125 second.

Table 6 below shows that when the blur amount is medium, T
E when transferring control from v to Sv or from Sv to Tv
Indicates the point of v.

[0070]

[Table 6]

In the case of the blur amount (large), the wide (Ev11)
(1/125 second)), Tele (Ev13 (1/500 second)
By increasing the AGC (increasing the CCD ISO sensitivity) below, the shutter time is maintained up to 2 Ev minutes to avoid camera shake. Hereinafter, the case of wide, tele, and the case where the focal length is between wide and tele will be described.

(Wide) In the case of Ev11 to Ev17, the shutter time is set (Tv7; 1/125 second to Tv7).
v13; 1/8000 sec.)
Control is performed (Ev = Av + Tv; Av = 4 fixed). From Ev9 to Ev11, the shutter time is set to Tv7;
Gain set to AGC amplifier 105 as 1/125 second (ISO100; Sv5 to ISO400; Sv7)
AE control is performed by changing. From Ev6 to Ev9, the gain setting of the AGC amplifier 105 is
The setting of the shutter time is changed in a range later than 1/125 second.

(Tele) In the case of Ev13 to Ev17, the shutter time is set (Tv9; 1/500 second to Tv9).
v13; 1/8000 sec.)
Control is performed (Ev = Av + Tv; Av = 4 fixed). For Ev11 to Ev13, the shutter time is set to Tv.
9; gain set to AGC amplifier 105 as 1/500 second (ISO100; Sv5 to ISO400; Sv
AE control is performed by changing 7). Ev6-Ev
Up to 11, the gain setting of the AGC amplifier 105 is set to ISO
As 400, the shutter time setting is changed in a range slower than 1/500 second.

(When the focal length is between wide and tele) The point of Ev at which the AE control in the case of wide and tele is shifted from the control performed by changing Tv to the control of changing Sv is described above. As shown in the table, the AE is changed by changing the set focal length and the ratio between the wide and tele focal lengths.
Perform control. From Ev12 to Ev17, the shutter time setting (Tv7; 250 seconds to Tv13; 1/800)
AE control is performed by changing only (0) (Ev = A
v + Tv; Av = 4 fixed). Ev10 to Ev12
Until the shutter time is Tv8; 1/250 second,
Gain (ISO 100; set to AGC amplifier 105)
Sv5 to ISO400; Av by changing Sv7)
Perform E control. From Ev6 to Ev10, the gain setting of the AGC amplifier 105 is set to ISO400, and the setting of the shutter time is changed in a range later than 1/250 second.

According to the third mode, the camera shake correction by the camera shake correction device 137 is prohibited, and the camera shake detection device 1
The camera shake shutter time is determined based on the camera shake amount detected at 36, and when it is determined that the set shutter time is equal to or less than the determined camera shake shutter time, the gain of the AGC amplifier 105 is increased to a specified value. Is increased, the shutter time at which camera shake occurs can be determined more accurately, and the camera shake can be reduced by raising the AGC only when necessary. In addition, if the AGC rises, the noise component is also amplified and the SN deteriorates. Therefore, by accurately determining the camera shake shutter time, unnecessary A
GC up can be prevented.

[Fourth Mode] In the fourth mode, the CP
U <b> 121 prohibits the gain of the AGC amplifier 105 from increasing to the specified value, and calculates the handshake shutter time (in the case of performing the shake detection in Table 2 above) based on the shake amount detected by the shake detection device 136. When it is determined that the set shutter time is equal to or shorter than the calculated camera shake shutter time, the camera shake correction is performed by the camera shake correction device 137.

[Fifth Mode] In the fifth mode, the CP
U121 calculates the camera shake shutter time (in the case of performing the shake detection in Table 2 above) based on the camera shake amount detected by the camera shake detection device 136, and the set shutter time is equal to or less than the calculated camera shake shutter time. If it is determined that the above is true, the gain of the AGC amplifier 105 is first preferentially increased to the specified value, and if necessary, the camera shake correction by the shake correction device 137 is also performed. Table 7 below shows the relationship between the amount of blur and the details of camera shake correction in the fifth mode.

[0078]

[Table 7]

As shown in Table 7, the CPU 121
If the shake amount is small and the set shutter time is equal to or longer than the camera shake shutter time, no correction is performed. Also, CPU
Reference numeral 121 denotes only increasing the gain of the AGC amplifier 105 to a specified value when the amount of shake is small and the set shutter time is equal to or less than the camera shake shutter time. The CPU 12
When the set shutter time is equal to or less than the camera shake shutter time, the shake correction is performed by the shake correction device 137 and the gain of the AGC amplifier 105 is increased to a specified value. When the amount of shake is large and the set shutter time is equal to or longer than the camera shake shutter time, the CPU 121 only increases the gain of the AGC amplifier 105 to a specified value. If the amount of shake is large and the set shutter time is equal to or less than the camera shake shutter time, the CPU 121 performs shake correction by the shake correction device 137 and increases the gain of the AGC amplifier 105 to a specified value. When the CPU 121 determines that the camera shake cannot be reduced even if the camera shake reduction is performed (for example, when the camera shake amount is large and the AGCUP is equal to or shorter than the shutter shutter time), the CPU 121 displays the image on the display unit 122. “Blur compensation + AGCUP + slow shutter” is displayed. FIG.
The display example of "UP + slow shutter" is shown.

According to the fifth mode described above, the camera shake shutter time is calculated based on the camera shake amount detected by the camera shake detection device 136, and the set shutter time is calculated to be less than or equal to the calculated camera shake shutter time. If it is determined that there is, firstly, the gain of the AGC amplifier 105 is preferentially increased to a specified value, and if necessary, the camera shake correction is also performed by the camera shake correction device 137. Even when power consumption is a problem, such as when the remaining battery capacity is small, camera shake can be reduced.

[Sixth Mode] In the sixth mode, the CP
U121 calculates the camera shake shutter time (in the case of performing the shake detection in Table 2 above) based on the camera shake amount detected by the camera shake detection device 136, and the set shutter time is equal to or less than the calculated camera shake shutter time. If it is determined that the AGC amplifier 10 has a higher priority, the camera shake correction is performed by the shake correction device 137 first, and if necessary, the AGC amplifier 10
Increase the gain of 5. Table 8 below shows the relationship between the amount of shake and the contents of camera shake correction in the sixth mode.

[0082]

[Table 8]

As shown in the above table, the CPU 121 does not perform the correction when the shake amount is small and the set shutter time is longer than the camera shake shutter time. CPU1
Reference numeral 21 denotes a shake correction device 137 when the shake amount is small and the set shutter time is equal to or less than the camera shake shutter time.
Is performed only by the camera shake correction. If the set shutter time is equal to or shorter than the camera shake shutter time, the CPU 121 performs the shake correction by the shake correction device 137 and increases the gain of the AGC amplifier 105 to a specified value. When the amount of blur is large and the set shutter time is equal to or longer than the camera shake shutter time, the CPU 121 performs only the blur correction by the blur correction device 137. If the amount of shake is large and the set shutter time is equal to or less than the camera shake shutter time, the CPU 121 performs shake correction by the shake correction device 137 and increases the gain of the AGC amplifier 105 to a specified value.

If the CPU 121 determines that the camera shake cannot be reduced even if the camera shake is reduced (for example, when the camera shake amount is large and the AGCUP is less than or equal to the camera shutter time), the display is performed. In the section 122, “blur correction + AG
CUP + slow shutter "is displayed.

According to the sixth mode described above, the camera shake shutter time is calculated based on the camera shake amount detected by the camera shake detection device 136, and the set shutter time is set to be equal to or less than the calculated camera shake shutter time. If it is determined that there is, firstly, the camera shake correction is performed by the camera shake correction device 137, and if necessary, the AGC amplifier 10
Since the gain of No. 5 is increased, camera shake can be reduced, and a decrease in S / N due to an increase in AGC can be prevented as much as possible.

The present invention is not limited to the above-described embodiment, and can be carried out with appropriate modifications without changing the gist of the invention. Methods other than the above-described camera shake reduction modes are also conceivable. For example, if the camera shake is not detected by the camera shake detector 136 and the specified camera shake shutter time can be maintained with the specified value of AGCUP with AGCUP priority, the camera shake detection is not performed. May be performed to perform shake correction. Also,
In the present embodiment, the CCD 1
Although the camera shake correction is performed by moving the lens 03, the camera shake correction may be performed by moving the lens system.

[0087]

According to the digital camera of the first aspect, the shake detecting means detects the shake amount, and the shutter time setting means calculates the camera shake shutter time based on the detected shake amount, and gain amplification is performed. The means corrects the signal level of the image signal, the judging means judges whether or not the set shutter time is equal to or less than the camera shake shutter time, and the control means uses the judgment means to judge whether the set shutter time is camera shake. When it is determined that the shutter time is equal to or less than the shutter time, the gain of the variable gain amplifying means is increased to a specified value, so that the shutter time at which camera shake occurs can be more accurately determined, and only when necessary. AGC can be raised to reduce camera shake. In addition, when the AGC rises, the noise component is also amplified and the S / N deteriorates. Therefore, by accurately determining the camera shake shutter time, unnecessary AGC up can be prevented.

According to the digital camera of the second aspect, in the digital camera of the first aspect, the control means prohibits the motion detection operation of the motion detection means, and prohibits the motion detection operation of the motion detection means. In this case, the determining means determines whether or not the set shutter time is equal to or less than a specified camera shake shutter time, and the control means determines that the shutter time set by the determining means is the specified camera shake shutter time. When it is determined that the following conditions are satisfied, the gain of the variable gain amplifying means is increased to a specified value. The power can be reduced, and even when no shake detection is performed by the shake detection means, the camera shake light can be reduced by increasing the AGC by setting the camera shake shutter time to a specified value. It is possible to perform.

Further, according to the digital camera of the present invention, the blur detecting means detects the blur amount, and the camera shake correcting means performs the camera shake correction in accordance with the blur amount detected by the blur detecting means, and detects the detected amount. The camera shake shutter time is calculated based on the shake amount, the gain amplifying means corrects the signal level of the image signal, and the judging means judges whether or not the set shutter time is equal to or less than the camera shake shutter time, When it is determined that the shutter time set by the determination means is equal to or less than the camera shake shutter time, the control means increases the gain of the variable gain amplifying means to a prescribed value and / or shakes the camera shake correction means. Since the correction is performed, it is possible to reduce the camera shake even when a large camera shake occurs.

Further, according to the digital camera of the fourth aspect, in the digital camera of the third aspect, the control unit is configured to perform any one of an increase in the gain of the variable gain amplifying unit up to a specified value and a camera shake correction by the camera shake correcting unit. Since either of them is prohibited, it is possible to give priority to image quality or reduction of power consumption in addition to the effect of the invention according to claim 3.

According to the digital camera of the fifth aspect, in the digital camera of the third aspect, when the determining unit determines that the set shutter time is equal to or less than the camera shake shutter time, Since either one of the gain increase of the variable gain amplifying means up to the specified value and the camera shake correction by the camera shake correcting means is preferentially executed, the image quality priority or consumption is achieved in addition to the effect of the invention according to claim 3. It is possible to give priority to the reduction of power.

According to the digital camera of the present invention, in the digital camera of any one of the first to fifth aspects, the display control means includes: a display unit that detects the amount of blur detected by the blur detection means; And / or to display the contents of the image stabilization being performed,
In addition to the effects of the invention according to any one of the first to fifth aspects, the user can recognize the amount of blur and / or the details of the executed camera shake correction.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a digital camera according to an embodiment.

FIG. 2 is a diagram illustrating an example of a specific configuration of the IPP of FIG. 1;

FIG. 3 shows a control voltage (Control Vo) of an AGC amplifier.
FIG. 7 is a diagram illustrating a relationship between an output gain (Ltage) and an output gain (Measured Gain).

FIG. 4 is a diagram showing a display example of a blur amount.

FIG. 5 is a diagram showing a display example of camera shake correction contents.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 Digital camera 101 Lens system 101 a Focus lens system 101 b Zoom lens system 102 Mechanical mechanism including autofocus 103 CCD (charge coupled device) 104 CDS (correlated double sampling) circuit 105 Variable gain amplifier (AGC amplifier) 106 A / D Converter 107 IPP (Image Pre-Processor) 108 DCT (Discrete Cosine Transform) 109 Coder (Huffman Encoder / Decoder) 110 MCC (Memory Card Controller) 111 RAM (Internal Memory) 112 PC Card Interface 121 CPU 122 Display Unit 123 Operation Unit 125 motor driver 126 SG unit 127 strobe 128 battery 129 DC-DC converter 130 EEPROM 131 focus driver 132 pulse motor 133 zoom driver 134 Sumomotor 135 Motor driver 136 Shake detection device 137 Shake correction device 150 PC card 1071 Color separation unit 1072 Signal interpolation unit 1073 Pedestal adjustment unit 1074 White balance adjustment unit 1075 Digital gain adjustment unit 1076 γ conversion unit 1077 Matrix unit 1078 Video signal processing unit 1079 Y operation unit 1080 BPF 1081 AF evaluation value circuit 1082 AE evaluation value circuit 1083 Y operation unit 1084 AWB evaluation value circuit 1085 CPU I / F 1086 DCTI / F 1075r, 1075g, 1075b Multiplier

Claims (6)

[Claims] A lens system for forming a subject image; an imaging unit for converting the formed subject image into an image signal; a blur detection unit for detecting a blur amount; A camera shake shutter time calculating means for calculating a camera shake shutter time based on a camera shake amount; a gain amplifying means for correcting the signal level of the image signal; and a set shutter time calculated by the camera shake shutter time calculating means. Determining means for determining whether the shutter speed is equal to or less than the determined camera shake shutter time, and determining that the shutter time set by the determining means is equal to or less than the camera shake shutter time calculated by the camera shake shutter time calculating means. Control means for increasing the gain of the variable gain amplifying means to a prescribed value in order to perform camera shake correction in the event that the camera shake has been performed. . 2. The method according to claim 1, wherein the control unit prohibits a shake detection operation of the shake detection unit, and when the shake detection operation of the shake detection unit is prohibited, the determination unit determines that the set shutter time is a predetermined time. The control unit determines whether or not the shutter speed is equal to or shorter than a camera shake shutter time.If the determination unit determines that the set shutter time is equal to or less than a specified camera shake shutter time, the control unit performs a camera shake correction. 2. The digital camera according to claim 1, wherein the gain of the variable gain amplifying unit is increased to a specified value to perform the operation. 3. A lens system for forming an image of a subject, an imaging unit for converting the formed subject image into an image signal, a blur detecting unit for detecting a blur amount, and a blur detected by the blur detecting unit. A camera shake correction unit that performs a camera shake correction according to a camera shake amount, a camera shake shutter time calculation unit that calculates a camera shake shutter time based on the camera shake amount detected by the camera shake detection unit, and a signal level of the image signal. Gain amplifying means for compensating; determining means for determining whether or not the set shutter time is equal to or less than a camera shake shutter time detected by the shake detecting means; and a shutter time set by the determining means. Is determined to be equal to or less than the camera shake shutter time calculated by the camera shake shutter time calculator, the gain of the variable gain amplifier is increased to a specified value to perform camera shake correction. Allowed, and / or a digital camera, characterized in that it and a control means for causing the image stabilization in the camera shake correction means. 4. The digital device according to claim 3, wherein the control unit prohibits any one of an increase in the gain of the variable gain amplifying unit up to the prescribed value and a camera shake correction by the camera shake correction unit. camera. 5. When the set shutter time is determined to be equal to or less than the camera shake shutter time by the determining means, the gain of the variable gain amplifying means is increased to the specified value and the camera shake correction means performs the operation. 4. The digital camera according to claim 3, wherein one of camera shake correction is preferentially executed. 6. A display unit for displaying information, and a display unit for displaying a blur amount detected by the blur detection unit and / or a content of the executed camera shake correction. The digital camera according to any one of claims 1 to 5, further comprising: display control means for controlling.