JP2007101860A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a distinct picked-up image having little noise by decreasing the noise component contained in the picked-up image. <P>SOLUTION: The imaging apparatus where a subject image is formed on an imaging device and converted into an electrical signal and fetched is provided with a tripod detection means for detecting whether or not a camera is fixed on a tripod; and an ISO sensitivity changing means for changing ISO sensitivity, when photographing. When that the camera is fixed on the tripod is detected, the ISO sensitivity is automatically shifted by predetermined amount by the ISO sensitivity changing means. When a predetermined photographic mode is selected by a user, the setting of the ISO sensitivity changing means is released, even when detecting that the camera is fixed on the tripod. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an imaging apparatus having a function capable of automatically changing the ISO sensitivity of a camera by detecting whether or not shooting is performed with the camera fixed on a tripod.

  2. Description of the Related Art Conventionally, there is a camera configured to automatically detect whether or not the camera is fixed on a tripod and change exposure control according to the detection result.

For example, there is a camera disclosed in Patent Document 1. This publication detects whether or not the camera is fixed on a tripod. When the camera is in a tripod fixed state, the program exposure control is performed with the narrow-down priority method in the normal shooting mode and the slow sync in the flash shooting mode. The system is configured to perform program exposure control using the camera system, and is configured to perform exposure control using the shutter priority system in the normal shooting mode and the flashmatic system in the flash shooting mode when the camera is not in the fixed tripod state. is doing. In addition, there is a camera having a shake correction function for correcting shake of a captured image due to camera shake or the like. In Patent Document 2, it is configured to automatically detect whether or not the camera is fixed to a tripod, and to end the shake correction operation according to the detection result.
Japanese Utility Model Publication No. 5-25428 JP 2003-189164 A

  In the above prior art, there is no invention that detects the tripod fixed state, automatically changes the ISO sensitivity of the camera, and changes the shutter speed accordingly.

  Conventionally, when the subject is dark, shooting is performed for a long time, so taking a camera shake or the like into consideration, the camera is fixed on a tripod or the photographer himself sets the ISO sensitivity on the high sensitivity side. However, when the ISO sensitivity is increased (from 100 to 400, from 400 to 800, from 800 to 1600, etc.), there is a problem that noise tends to enter the captured image and the captured image becomes rough. Therefore, there is a camera equipped with a noise reduction mode. This is a mode for removing a noise component included in a photographed image when photographing with ISO on the high sensitivity side. However, when shooting in the noise reduction mode, there is a problem in that the processing time of the shot image is slowed, the capacity of the shot image per shot is increased, and the number of shots that can be shot is reduced.

  The present invention has been made paying attention to the above points, and an object thereof is to reduce a noise component included in a captured image and to provide a clear captured image with less noise.

  In order to solve the above problems and achieve the object, the present invention takes the following measures.

  The invention according to claim 1 detects whether or not the camera is fixed to a tripod in an imaging apparatus in which a subject image is formed on a light receiving surface of an imaging element by an imaging optical system, and converted into an electrical signal. And a ISO sensitivity changing means for changing the ISO sensitivity at the time of photographing. When it is detected that the camera is fixed to the tripod, the ISO sensitivity changing means automatically shifts the ISO sensitivity by a predetermined amount. It is configured.

  Further, the invention according to claim 2 cancels the setting of the ISO sensitivity changing means when the specific photographing mode is selected by the user even when it is detected that the camera is fixed on the tripod. An imaging apparatus configured as described above is proposed.

  As described above, since the possibility of camera shake is eliminated by fixing to a tripod, the ISO sensitivity can be automatically shifted to a low sensitivity side by a predetermined amount, and the shutter can be released by setting the ISO sensitivity to a low sensitivity side. Seconds can be set on the low speed side. Thereby, it is possible to provide a clear photographed image with less noise than an image photographed by ISO on the high sensitivity side.

  In addition, when the noise reduction mode is set, if it is detected that the camera is fixed on a tripod, the noise reduction mode is automatically canceled to prevent the possibility of camera shake as described above. The shutter speed can be set to the low speed side. In addition, it is possible to eliminate the above-described drawbacks that the processing time of the captured image is delayed, the captured image capacity per image is increased, and the number of images that can be captured is reduced. In addition, when the specific shooting mode is selected by user selection, it is possible to prevent the ISO unintentional automatic change by making the setting of the ISO sensitivity changing means cancelable.

  Embodiments of the present invention will be described below with reference to the drawings and flowcharts.

  FIG. 1 is a central sectional view of a single-lens reflex camera according to the present invention, and the configuration will be described below. The interchangeable lens 2 that can be attached to and detached from the camera 1 in FIG. 1 is fixed by a camera mount 5 and a lens mount (not shown), and is electrically connected by contact between a camera contact (not shown) and a lens contact. The connection is made, and the power supply from the camera 1 to the interchangeable lens 2 and the communication for controlling the lens are performed through this contact portion. The light beam that has passed through the photographing lens 3 of the interchangeable lens 2 enters the main mirror 6 of the camera. The main mirror 6 is a half mirror, and the reflected light beam is guided to the finder, and the transmitted light beam is reflected downward by the sub mirror 7 and guided to the focus detection device 8. The focus detection device 8 detects the defocus amount of the photographing lens 3, calculates the lens driving amount for driving the photographing lens 3 so that the photographing lens is in focus, and the lens driving amount is exchanged via the contact portion. When the lens 2 is sent out, the lens controls a motor (not shown) to drive the photographing lens 3 to adjust the focus. Reference numeral 4 denotes an aperture which controls the amount of light by changing the aperture diameter.

  The light beam guided to the finder by the main mirror 6 forms a subject image on the focus plate 9, and the photographer observes the subject image on the focus plate via the pentaprism 10 and the eyepiece 11. The The focus plate 9 is supported by a focus plate holder (not shown), and is configured so that it can be attached and detached as appropriate.

  The photometric lens 12 disposed above the rear part of the pentaprism 10 projects the image on the photometric sensor (light receiving element) 13 by using the subject image on the focusing plate 9 as a secondary light source. The photometric lens 12 and the photometric sensor (light receiving element) 13 are known light receiving means for exposure.

  A shutter 14 is disposed behind the sub-mirror 7, and an optical filter 15 in which an optical low-pass filter and an infrared cut filter are integrated is disposed behind the shutter 14, and a light beam that has passed through the optical filter 15 is further disposed rearward during photographing. The light enters the image pickup device 16. Reference numeral 17 denotes an image display monitor configured to display a captured image, a shooting menu, and the like. Also, there is a known tripod detection means at the bottom of the camera, and there are two terminals 20 and 21 facing each other with the insulator 19 in between. When the screw portion 24 of the tripod 23 is attached to the tripod seat 18, the terminal By pushing up one terminal 21 of the two terminals 20 and 21 facing each other when the pin 22 is pushed, the other terminal 20 is short-circuited and the attachment of the tripod is detected. Reference numeral 25 denotes a noise reduction mode button for setting the noise reduction mode. The above is the main configuration of the single-lens reflex camera of the present invention.

  FIG. 2 is a block diagram showing an internal configuration of the imaging apparatus according to the embodiment of the present invention.

  An imaging apparatus according to an embodiment of the present invention includes a lens driving device 122 that drives a photographing lens 150 mounted on a camera via a mount (not shown), a mechanical shutter device 121, a solid-state imaging device 100, an analog signal processing circuit 101, A / D converter 102, main signal processing circuit 103, memory 108, D / A converter 109, image display monitor 110, compression / decompression circuit 112, memory slot (1) 113 and memory card (1) 114, memory slot (2) 115, a memory card (2) 116, a control circuit 120, a CPU (central processing circuit) 117, and the like.

  Reference numeral 143 denotes a main SW that is turned on / off by an operation of a main switch of a camera (not shown), and sets operation / non-operation of all operations of the imaging apparatus. Reference numeral 126 denotes a release SW1 that is turned on by a first stroke of a release button (not shown). Reference numeral 127 denotes a release SW2 that is turned on by a second stroke of a release button (not shown). When the release SW1 is turned on, photometric control / focusing control is performed. When the release SW2 is turned on, the release operation is started.

  A main electronic dial SW 128 generates a signal in conjunction with the rotation of a main electronic dial (not shown). By rotating the main electronic dial, for example, a 2-bit signal having a phase difference of 90 ° is sent to the switch sense circuit, whereby the rotation direction and the number of clicks are detected. By detecting this rotation direction and the number of rotation clicks, it is possible to input numerical values to the camera and switch the shooting mode in combination with other operation buttons.

  Reference numeral 129 denotes a sub electronic dial SW that generates a signal in conjunction with rotation of a sub electronic dial (not shown). By rotating the sub electronic dial, for example, a 2-bit signal having a phase difference of 90 ° is sent to the switch sense circuit, whereby the rotation direction and the number of clicks are detected. By detecting this rotation direction and the number of rotation clicks, it is possible to input numerical values to the camera and switch the shooting mode in combination with other operation buttons.

  Reference numeral 147 denotes an AE (automatic exposure) lock SW which is turned on by pushing an unillustrated AE lock button. Reference numeral 148 denotes an AF (autofocus) distance measurement point selection SW which is turned on by pressing a distance measurement point selection button (not shown). Reference numeral 149 denotes an external display device serving as display means including an image display monitor 17 having an external display function for displaying photographing conditions and the like. Reference numeral 110 denotes an image display monitor as a display unit including an LCD monitor device for displaying a photographed image or the like. Since the image display monitor 110 is a transmissive type, the image cannot be visually recognized only by driving the external video display device, and a backlight illumination device (not shown) is always required on the back surface. In addition to displaying video, the image display monitor 110 displays menus, setting items, selection items, and the like corresponding to operations of menu buttons (not shown), selection buttons, and display buttons.

  Reference numeral 150 denotes a photographic lens that forms a subject image on an imaging plane, and is configured to be detachable from the camera body 1. Although simplified in this figure, the lens may be composed of one or a plurality of lenses and may be a single focal length (fixed focal length) lens, or a variable focal length lens such as a zoom lens or a step zoom lens. But you can. Reference numeral 122 denotes a lens driving device for driving the photographing lens 150 to form a subject image on the imaging surface. Reference numeral 151 denotes a diaphragm blade group for performing exposure control. A diaphragm driving device 123 drives the diaphragm blade group 151.

  145 is a shooting mode selection SW that is turned on by pressing a shooting mode selection button (not shown), 144 is an AF mode selection SW that is turned on by pressing an AF mode selection button (not shown), and 146 is a metering mode selection button (not shown). This is a photometry mode selection SW that is turned on when pressed, and also serves as a dimming correction button / SW.

  For example, if the main electronic dial is rotated while pressing the shooting mode selection button, Tv priority → Av priority → manual → program → multiple exposure shooting → Tv priority → Av priority → manual → program → multiple exposure shooting ... Can be set to the mode intended by the user. Further, when the main electronic dial is rotated in the reverse direction, the mode is changed as follows: multiple exposure shooting → program → manual → Av priority → Tv priority → multiple exposure shooting → program →. When Tv priority is set as a mode by the shooting mode selection button and the main electronic dial, the Tv value desired by the photographer can be set by rotating the main electronic dial. When Av priority is set as a mode by the shooting mode selection button and the main electronic dial, the Av value desired by the photographer can be set by rotating the main electronic dial. If the main electronic dial is operated while the metering mode selection button and the AF selection mode button are pressed at the same time, the imaging sensitivity at the time of imaging can be changed. If the main electronic dial is operated while the metering mode selection button and the shooting mode selection button are pressed at the same time, the drive mode can be selected from single shooting, continuous shooting, and self-timer. When the main electronic dial is operated while the shooting mode selection button and the AF mode selection button are pressed at the same time, the number of brackets in the AEB shooting mode can be set.

  A display panel illumination SW 139 is turned on when a display panel illumination button (not shown) is pressed. An exposure correction SW 138 is turned on when an exposure correction button (not shown) is pressed. When the main electronic dial is operated with the exposure correction SW 138 turned on, the exposure correction value can be set. Reference numeral 135 denotes a slot cover opening / closing detection SW that is turned on / off in response to opening / closing of a card slot cover (not shown). A memory card (1) 114 is detachably attached to the memory slot (1) 113. A card detection SW 136 in the slot (1) 113 is turned on when the memory card (1) 114 is inserted into the memory slot (1) 113. A slot (2) card detection SW 137 is turned on when the memory card (2) 116 is inserted into the memory slot (2) 115. The protect SW 130 is a switch that is turned on when a display (DISPLAY) button (not shown) is pressed. Press the display (DISPLAY) button, turn on the protect SW 130, play back the recorded image, rotate the sub-dial while pressing the select button (not shown), select the image you want to protect, select (SELECT) ) Protection is completed by releasing the button.

  The menu SW 131 is a switch that is turned on when a menu button (not shown) is pressed. A setting item can be selected by pressing the menu button, turning on the menu SW 131, and operating the sub-electronic dial. The setting items are displayed on the image display monitor 110 at this time. The SELECT (selection) SW 132 is a switch that is turned on when a selection button (not shown) is depressed. The setting value of the setting item selected by the menu button can be changed by pushing the selection button and turning on the SELECT (selection) SW 132 and operating the sub-electronic dial. At this time, the setting item setting value is displayed on the image display monitor 110.

  The display SW 133 is a switch that is turned on when a display button (not shown) is pressed. When the display button is pressed and the display SW 133 is turned on, the images stored in the memory card (1) 114 and the memory card (2) 116 are displayed on the image display monitor 110.

  The erase SW 134 is a switch that is turned on when an unillustrated erase button is pressed. By pressing the delete button when the image is displayed on the image display monitor 110 and turning on the delete SW 134, the displayed image data can be deleted from the memory card. If the erase SW 134 is kept on, a menu for inquiring whether to erase the image data stored in the memory card (1) 114 and the memory card (2) 116 at once is displayed on the image display monitor 110. By operating the sub electronic dial to select batch erase, releasing the erase button and turning off the erase SW 134, the image data in the memory card can be erased at once.

  Reference numeral 140 denotes an FE lock SW that is turned on when an unillustrated FE lock button is depressed. When the SW is turned on while an external strobe (not shown) is attached, pre-flash is emitted, and the flash emission amount, Tv value, and Av value at the time of flash emission are determined and stored. Reference numeral 141 denotes a narrowing SW that is turned on when a narrowing button (not shown) is depressed. When SW is turned on, the aperture blade 151 is driven to the aperture value selected at that time so that the depth of field can be confirmed.

  A photometric device 124 measures the luminance of a subject image formed on a focusing screen (not shown) through an optical member (not shown), and the exposure at the time of exposure based on an output signal of the photometric device 124. Control is to be performed. A focus detection device 125 controls the lens driving device 122 of the photographing lens 150 based on an output signal of the focus detection device 125 and performs focus adjustment by the imaging lens 150. Reference numeral 121 denotes a mechanical shutter device that mechanically controls the incident time of the subject light flux on the imaging surface. This mechanical shutter device 121 shields the subject luminous flux during finder observation and retracts from the optical path of the subject luminous flux according to the release signal during photographing, and retracts from the optical path of the subject luminous flux during finder observation. In addition, it is a focal plane shutter having a rear blade group that blocks a subject light beam at a predetermined timing after the start (driving) of the front blade group at the time of photographing.

  Reference numeral 100 denotes a solid-state image sensor that captures a subject image formed by the photographing lens 150 and converts it into an electrical signal. As the solid-state imaging device 100, a known two-dimensional imaging device is used. There are various types of imaging devices such as a CCD type, a MOS type, and a CID type, and any type of imaging device may be employed. In this embodiment, a photoelectric conversion element (photosensor) is used. Are two-dimensionally arranged, and an image sensor of an interline CCD (charge coupled device) is employed in which signal charges accumulated in each photosensor are output via a vertical transfer path and a horizontal transfer path. Further, the solid-state imaging device 100 has a so-called electronic shutter function (electronic shutter means) that controls the accumulation time (in shutter seconds) of charges accumulated in each photosensor. The amount of light of the subject luminous flux that has passed through the photographing lens 150 is regulated by the diaphragm blade group 151 and the mechanical shutter device 121 that are driven by the diaphragm driving device 123, and is projected and imaged on the solid-state imaging device 100. At this time, the charge accumulation time of the solid-state imaging device 100 is controlled via the control circuit 120. The subject image formed on the light receiving surface of the solid-state imaging device 100 is converted into a signal charge of an amount corresponding to the amount of incident light by each photosensor and sequentially read out as an imaging output signal, and then an analog signal processing circuit 101.

  The analog signal processing circuit 101 includes a CDS clamp circuit, a gain adjustment circuit, and the like, and appropriately processes an imaging output signal (analog electric signal) input from the solid-state imaging device 100 based on control of the control circuit 120. The signal output from the analog signal processing circuit 101 is converted into a digital signal by the A / D converter 102 and then sent to the main signal processing circuit 103.

  The main signal processing circuit 103 includes a gain adjustment circuit 104, an offset circuit 105, a histogram generation circuit 107, a digital signal processing circuit 106, and the like. The data output from the A / D converter 102 is sent to the histogram generation circuit 107 and the digital signal processing circuit 106 via the gain adjustment circuit 104 and the offset circuit 105.

  The histogram generation circuit 107 creates a histogram indicating the distribution of the integrated value of the image sensor signal with respect to the signal level from the data for one screen sent from the A / D converter 102. A gain value and an offset value are determined based on this histogram calculation, and the gain and offset are controlled from the CPU 117 via the control circuit 120. In this way, the signal that has passed through the gain and offset control is sent to the digital signal processing circuit 106.

  The digital signal processing circuit 106 includes a luminance (Y) signal generation circuit and a color difference (C) signal generation circuit, and performs Y / C signal processing on the signal input from the offset circuit 105. The image data that has been subjected to Y / C signal processing by the digital signal processing circuit 106 is temporarily stored in the memory 108. The image data stored in the memory 108 is decoded, converted to an analog signal by a D / A converter 109, and supplied to an image display monitor 110 such as a liquid crystal monitor as image display means.

  In this way, the image captured by the solid-state imaging device 100 is displayed on the image display monitor 110. On this image display monitor 110, a still image shot based on a shooting start signal issued by a release SW2 (127) which is turned on by operating a release button is displayed. The signal converted into an analog signal by the D / A converter 109 can be taken out as an external video output 111 from a video output terminal (not shown) or the like.

  Also, the actual image data acquired in response to the input of the shooting start signal is guided from the memory 108 to the compression / decompression circuit 112, where it is compressed according to a predetermined format (for example, JPEG) and then recorded. It is recorded on the memory card (1) (114) or the memory card (2) (116) as a medium. The recording medium can be in various forms such as smart media and IC card. The image data recorded in the memory card (1) (114) or the memory card (2) (116) can be called up via the CPU 117, and the called image data is decompressed by the compression / decompression circuit 112. After the reproduction processing, it is output to the image display monitor 110 via the memory 108 and the D / A converter 109, or supplied to a video signal output terminal (not shown) and the like, and can be output to other external devices.

  The CPU 117 includes a photometry device 124, a focus detection device 125, a control circuit 120, a histogram generation circuit 107, a digital signal processing circuit 106, a memory 108, a memory card (1) (114), a memory card (2) (116), and each SW. And performs various calculations such as the exposure value and the focal position of the taking lens 150 in accordance with a predetermined algorithm, and comprehensively manages controls such as automatic exposure control, autofocus, auto strobe, and auto white balance. The CPU 117 controls a corresponding circuit based on various signals input from operation units such as a release button, a main electronic dial, a sub electronic dial, a shooting mode selection button, an AF mode selection button, and a photometry mode selection button. The output signal of the photometry device 124 is sent to the CPU 117, and the CPU 117 calculates an exposure control value indicating the exposure time. The obtained exposure control value is sent from the CPU 117 to the control circuit 120, and control such as automatic exposure control, auto strobe, and auto white balance is performed via the control circuit 120.

  The temperature sensor 119 is a sensor that measures the temperature of the camera. The buzzer 118 is a sound generating means mainly used for a warning at the time of shooting. Reference numeral 152 denotes LEDs 152a and 152b for displaying an access state to the memory card (1) (114) or the memory card (2) (116), which is a two-color light emission type. The control circuit 120 controls the drive circuit of the solid-state image sensor 100 based on the exposure control value sent from the CPU 117. In the electronic shutter control mode, the charge accumulation time of the solid-state image sensor 100 is detected, and in the mechanical shutter control mode. In addition to controlling the opening and closing timing of the mechanical shutter device 121, the aperture driving device 123 is controlled during exposure.

  Reference numeral 153 denotes a tripod detection switch which detects whether or not the camera is fixed to the tripod. Reference numeral 154 denotes a noise reduction mode SW, which is turned ON / OFF when the noise reduction mode button 25 is pressed, and when the high sensitivity side ISO is set, noise is likely to enter the captured image and the captured image becomes rough. This is a switch to prevent the

  This is the description of the main configuration and internal configuration of the single-lens reflex camera according to the present invention.

  Next, the camera according to the present invention will be described in detail with reference to FIGS.

  FIG. 3 is a flowchart showing an outline of the photographing operation by the imaging apparatus of the present invention. FIG. 4 is a flowchart showing an outline of an imaging operation when a specific shooting mode (for example, a noise reduction mode) is set. FIG. 5 shows the relationship between the ISO sensitivity set by the ISO sensitivity changing means and the shutter speed.

  Claim 1 will be described with reference to FIG. Step 1 is a state in which the main switch 143 of the camera 1 is turned on and the power of the camera 1 is turned on, and the operation starts from Step 2. First, in step 2, it is detected whether the camera 1 is attached to the tripod 23 or not. When the screw portion 24 of the tripod 23 is attached to the tripod seat 18 of the camera 1, one terminal 21 of the two terminals 20, 21 that contacts the terminal pin 22 that is the tripod detection SW 153 and faces the insulator 19 is sandwiched. By pushing up, the other terminal 20 is short-circuited, and the attachment of the tripod is detected. If it is detected that the tripod is in a fixed state (tripod detection SW 153 is ON), the process proceeds to step 3, and if it is detected that the tripod is not fixed (tripod detection SW 153 is OFF), the process proceeds to step 4.

  In step 3, the fact that the tripod is fixed is transmitted to the CPU (central processing circuit) 117 of the camera 1, and the ISO sensitivity is changed by the ISO sensitivity changing means based on this information in the CPU (central processing circuit) 117. Is automatically shifted to the low sensitivity side by a predetermined number of steps.

  Here, the ISO sensitivity changing means will be described with reference to FIG. FIGS. 5A and 5B are diagrams showing the relationship between ISO sensitivity and shutter speed. As shown in FIG. 5A, when it is detected that the camera 1 is attached to a tripod, the ISO sensitivity is changed. By means, the ISO sensitivity is automatically shifted to the low sensitivity side by a predetermined number of steps (for example, one step 800 => 400). As a result, the shutter speed is also automatically shifted to the lower speed side by a predetermined number of steps (one step, for example, 125 → 60). In FIG. 5B, when it is detected that the camera 1 is attached to a tripod, the ISO sensitivity is automatically shifted to a low sensitivity side by a predetermined number of steps (for example, two steps 800 → 200) by the ISO sensitivity changing means. . As a result, the shutter speed is also automatically shifted to the low speed side by a predetermined number of steps (2 steps, for example, 125 → 30). The number of stages to be shifted is one or two in this proposal, but the shift amount is changed to ISO that reduces noise entering the captured image.

  In step 4 of FIG. 3, when the first stroke of a release button (not shown) is pushed down and the release switch SW1 (126) is turned on, in step 5, the photometric device 124 is operated to capture the reflected light from the subject, and A / Photometric information is obtained by D conversion. Here, the exposure conditions (aperture, shutter speed) after the ISO sensitivity is shifted by a predetermined number of steps are calculated. In step 6, it is determined whether the focus detection mode is an autofocus mode (AF) or a manual focus mode (MF), and focus information for each focus detection region is calculated using the focus detection device 125. Based on these focus detection results, a defocus amount calculation calculation is performed using an existing algorithm. After calculating a lens drive amount based on a focus detection result in a predetermined area, the lens drive device 122 is driven to focus so as to focus. Communicate the amount, drive and focus the lens.

  In step 7, when the release switch SW2 (127) is turned on, the process proceeds to step 8 in order to perform the photographing operation. In step 8, the solid-state imaging device 100 is exposed under the exposure conditions (aperture and shutter speed) calculated in step 5 and the in-focus state of the lens driven in step 6. Then, the process proceeds to step 9 where the image captured by the solid-state image sensor 100 is automatically reproduced and displayed as a still image on the image display monitor 110.

  In step 10, the captured image data acquired in response to the input of the shooting start signal is guided from the memory 108 to the compression / decompression circuit 112, where the captured image is compressed according to a predetermined format (for example, JPEG). After the processing, the data is recorded on the memory card 1 (114) as the first recording medium or the memory card 2 (116) as the second recording medium. In step 11, shooting is finished.

  Next, the case where the specific photographing mode of Claim 2 (here, the noise reduction mode) is set will be described with reference to FIG.

  Step 21 is a state in which the main switch 143 of the camera 1 is turned on and the power of the camera 1 is turned on, and the operation starts from Step 22. First, in step 22, the noise reduction mode button 25 of the camera 1 (a button for preventing the captured image from easily becoming noise when the high-sensitivity ISO is set and preventing the captured image from becoming rough). ) Is pressed, and if it is detected that the noise reduction mode SW154 is ON, the process proceeds to step 23, and if it is detected that the noise reduction mode SW154 is OFF, the process proceeds to step 34.

  In step 23, it is detected whether or not the noise reduction mode SW154 is ON and the camera 1 is attached to the tripod 23. When the screw portion 24 of the tripod 23 is attached to the tripod seat 18 of the camera 1, one terminal 21 of the two terminals 20, 21 that contacts the terminal pin 22 that is the tripod detection SW 153 and faces the insulator 19 is sandwiched. By pushing up, the other terminal 20 is short-circuited, and the attachment of the tripod is detected. If it is detected that the tripod is fixed (tripod detection SW153 is ON), the process proceeds to step 24, and if it is detected that the tripod is not fixed to the tripod (tripod detection SW153 is OFF), the process proceeds to step 26.

  In step 24, if it is detected that the camera is fixed to the tripod (tripod detection SW 153 is ON), the CPU (central processing circuit) 117 of the camera 1 is notified that the camera is fixed to the tripod, and then the noise reduction mode. Even when SW154 is in an ON state, it is forcibly switched to OFF. In step 25, when the noise reduction mode SW154 is switched to OFF, the fact that the noise reduction mode SW154 is OFF is transmitted to the CPU (central processing circuit) 117 of the camera 1, and the CPU (central processing circuit) 117 internal. Then, based on this information, the ISO sensitivity changing means automatically shifts the ISO sensitivity to the low sensitivity side by a predetermined number of steps.

  Here, as described above, when it is detected that the camera 1 is attached to a tripod, as shown in FIG. 5A, the ISO sensitivity is changed by a predetermined number of steps (for example, one step 800) by the ISO sensitivity changing means. ⇒400) Automatically shifted to the low sensitivity side. As a result, the shutter speed is also automatically shifted to the lower speed side by a predetermined number of steps (one step, for example, 125 → 60). In FIG. 5B, when it is detected that the camera 1 is attached to a tripod, the ISO sensitivity is automatically shifted to a low sensitivity side by a predetermined number of steps (for example, two steps 800 → 200) by the ISO sensitivity changing means. . As a result, the shutter speed is also automatically shifted to the low speed side by a predetermined number of steps (2 steps, for example, 125 → 30).

  In step 26 of FIG. 4, when the first stroke of a release button (not shown) is pushed down and the release switch SW1 (126) is turned on, in step 27, the photometric device 124 is operated to capture the reflected light from the subject, and A / Photometric information is obtained by D conversion. Here, the exposure conditions (aperture, shutter speed) after the ISO sensitivity is shifted by a predetermined number of steps are calculated.

  In step 28, it is determined whether the focus detection mode is an autofocus mode (AF) or a manual focus mode (MF), and focus information for each focus detection region is calculated using the focus detection device 125. Based on these focus detection results, a defocus amount calculation calculation is performed using an existing algorithm. After calculating a lens drive amount based on a focus detection result in a predetermined area, the lens drive device 122 is driven to focus so as to focus. Communicate the amount, drive and focus the lens.

  In step 29, when the release switch SW2 (127) is turned on, the process proceeds to step 30 in order to perform a photographing operation. In step 30, the solid-state imaging device 100 is exposed with the exposure conditions (aperture and shutter speed) calculated in step 27 and the in-focus state of the lens driven in step 28. Then, the process proceeds to step 31, and the image captured by the solid-state image sensor 100 is automatically reproduced and displayed as a still image on the image display monitor 110. In step 32, the captured image data obtained in response to the input of the shooting start signal is guided from the memory 108 to the compression / decompression circuit 112, where the captured image is compressed according to a predetermined format (for example, JPEG). After the processing, the data is recorded on the memory card (1) (114) as the first recording medium or the memory card (2) (116) as the second recording medium. In step 33, shooting is terminated.

  Next, the case where it is detected in step 22 that the noise reduction mode SW154 is OFF will be described. If it is detected in step 34 that the noise reduction mode SW154 is in the OFF state, it is detected whether or not the camera 1 is attached to the tripod 23. When the screw portion 24 of the tripod 23 is attached to the tripod seat 18 of the camera 1, one terminal 21 of the two terminals 20, 21 that contacts the terminal pin 22 that is the tripod detection SW 153 and faces the insulator 19 is sandwiched. By pushing up, the other terminal 20 is short-circuited, and the attachment of the tripod is detected. If it is detected that the camera is fixed to a tripod (tripod detection SW153 is ON), the process proceeds to step 25. If it is detected that the camera is not fixed to a tripod (tripod detection SW153 is OFF), the process proceeds to step 26.

  If it is detected in step 34 that the tripod is fixed (tripod detection SW 153 is ON), in step 25, the CPU (central processing circuit) 117 of the camera 1 is informed that the tripod is fixed, and the CPU ( In the central processing circuit (117), the ISO sensitivity is automatically shifted to the low sensitivity side by a predetermined number of steps by the ISO sensitivity changing means based on this information.

  Since the ISO sensitivity changing means is the same as described above, description thereof is omitted. In step 26, when the first stroke of a release button (not shown) is pressed down and the release switch SW1 (126) is turned on, in step 27, the photometric device 124 is operated to capture the reflected light from the subject and perform A / D conversion. To obtain photometric information. Here, the exposure conditions (aperture, shutter speed) after the ISO sensitivity is shifted by a predetermined number of steps are calculated.

  In step 28, it is determined whether the focus detection mode is an autofocus mode (AF) or a manual focus mode (MF), and focus information for each focus detection region is calculated using the focus detection device 125. Based on these focus detection results, a defocus amount calculation calculation is performed using an existing algorithm. After calculating a lens drive amount based on a focus detection result in a predetermined area, the lens drive device 122 is driven to focus so as to focus. Communicate the amount, drive and focus the lens.

  In step 29, when the release switch SW2 (127) is turned on, the process proceeds to step 30 in order to perform a photographing operation. In step 30, the solid-state imaging device 100 is exposed with the exposure conditions (aperture and shutter speed) calculated in step 27 and the in-focus state of the lens driven in step 28. Then, the process proceeds to step 31, and the image captured by the solid-state image sensor 100 is automatically reproduced and displayed as a still image on the image display monitor 110. In step 32, the captured image data obtained in response to the input of the shooting start signal is guided from the memory 108 to the compression / decompression circuit 112, where the captured image is compressed according to a predetermined format (for example, JPEG). After the processing, the data is recorded on the memory card (1) (114) as the first recording medium or the memory card (2) (116) as the second recording medium. In step 33, shooting is terminated.

  Here, the case where the specific shooting mode (noise reduction mode) is set has been described. However, for example, when the simple shooting mode ⇒ portrait, sports, landscape, or the like is set, the camera 1 is fixed to a tripod. Based on this information, the ISO sensitivity changing means automatically shifts the ISO sensitivity by a predetermined number of steps to the low sensitivity side, and the application shooting mode ⇒ P (program) , Tv (shutter priority), Av (aperture priority), etc. are set, it is detected whether or not the camera 1 is fixed to a tripod. Based on this information, the ISO sensitivity is changed by the ISO sensitivity changing means. You may comprise so that it may shift to the low sensitivity side by a predetermined number of steps automatically.

It is sectional drawing which shows the structure of the camera which concerns on the form of a present Example. It is a block diagram which shows the internal structure of the camera which concerns on the form of a present Example. It is a flowchart which shows operation | movement of the camera which concerns on the form of a present Example. It is a flowchart which shows operation | movement of the camera of the specific imaging | photography mode which concerns on the form of a present Example. It is a figure which shows the ISO sensitivity of the camera which concerns on the form of a present Example, and the relationship between shutter time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera 2 Interchangeable lens 4 Aperture 5 Camera mount part 6 Main mirror 7 Sub mirror 8 Focus detection apparatus 9 Focus plate 10 Pentaprism 11 Eyepiece lens 12 Photometric lens 13 Photometric sensor 14 Shutter 15 Optical filter 16 Image sensor 17 Image display monitor 18 Tripod mount 19 Insulator 20 Terminal A
21 Terminal B
22 Terminal pin 23 Tripod screw 24 Screw part 117 CPU (Central processing circuit)
153 Tripod detection SW
154 Noise reduction mode SW

Claims (2)

  In an imaging device that forms a subject image on a light receiving surface of an image sensor by an imaging optical system, converts it into an electrical signal, and captures the tripod detection means for detecting whether the camera is fixed to a tripod; An imaging apparatus comprising: an ISO sensitivity changing means for changing sensitivity, wherein the ISO sensitivity changing means shifts a predetermined amount of ISO sensitivity when it is detected that the camera is fixed to a tripod.   The ISO sensitivity changing means is canceled when the specific photographing mode is selected by the user even when it is detected that the camera is fixed to a tripod. The imaging device described.

Images