JP4196466B2 - Digital camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital camera that stores a subject as electronically compressed image data.
[0002]
[Prior art]
Conventionally, a focus detection / adjustment device that drives a photographic lens to detect a focus, an imaging device such as a CCD that captures a subject image passing through the photographic lens and outputs image data, and an output from the imaging device An image processing circuit that performs image processing such as white balance and γ correction on the image data, a compression circuit that compresses the data after image processing using a method such as JPEG, and stores it in a storage medium such as a flash memory, and image processing There has been known a digital camera including a monitor for displaying later data and a switch control circuit for checking whether or not each operation switch is operated.
[0003]
[Problems to be solved by the invention]
In such a conventional digital camera, when the storage capacity of a storage medium such as a flash memory that compresses and records data after image processing is large, or when an LCD monitor that displays data after image processing becomes large, Due to the increase in power consumption inside the digital camera, there is a problem that the continuous use time by the battery is shortened. In particular, when the recording capacity of a recording medium such as a flash memory is several tens of megabytes or more, a problem easily occurs.
[0004]
An object of the present invention is to provide a digital camera with reduced power consumption in the digital camera.
[0005]
[Means for Solving the Problems]
(1) The invention described in claim 1 is applied to a digital camera that captures a subject image with an imaging element through a photographing lens and records image data on a recording medium, and has at least a first CPU, and includes focus detection, Camera control means for controlling at least one of exposure adjustment and lens driving; discrimination means for discriminating conditions for not using the camera control means; standby control means for setting the camera control means to a standby state when the discrimination means discriminates the conditions; , Having at least a second CPU, regardless of whether the camera control means is in a standby state, always accepting an input signal by a user's operation, and transmitting control information to the standby control means based on the input signal And an operation control means.
(2) The invention described in claim 2 is applied to a digital camera that captures a subject image with an image sensor through a photographing lens and records image data on a recording medium, and has at least a first CPU, and includes focus detection, Camera control means for controlling at least one of exposure adjustment and lens drive, a display for displaying a setting menu for setting the operation of the digital camera in the menu setting mode, and at least a second CPU. An image processing control means for displaying an image on the screen, a standby control means for setting the camera control means in a standby state when the menu setting mode is set, and at least a third CPU, wherein the camera control means is in the standby state. Regardless of whether or not there is, an input signal by a user's operation is always accepted, and control information is transmitted to the standby control means based on the input signal. Characterized in that it comprises a work control unit.
(3) The invention according to claim 3 is the digital camera according to claim 1 or 2, wherein the standby control means transmits the control information from the operation control means when the camera control means is in the standby state. In response, the camera control unit can be controlled to cancel the standby state.
[0006]
In the section of the means for solving the above-described problem to explain the configuration of the present invention, the drawings of the embodiments are used for easy understanding of the present invention, but the present invention is thereby limited to the embodiments. It is not something.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B show the external appearance of a digital still camera according to an embodiment of the present invention when stored and carried, where FIG. 1A is a view from above and FIG. 1B is a view from behind. Fig. 2 shows the appearance of the camera shown in Fig. 1 during normal shooting. (A) is a view from the front, (b) is a view from above, and (c) is a view from behind. is there. The digital still camera 1 according to this embodiment is divided into a lens unit 1a including a photographing zoom lens 2 and a monitor unit 1b including an LCD monitor 3, and both the units 1a and 1b are connected to be relatively rotatable. .
[0008]
When stored or carried, the lens unit 1a is rotated so that the lens unit 1a and the monitor unit 1b are flat as shown in FIG. Further, during normal photographing, as shown in FIG. 2, the lens unit 1a is rotated so that the photographing zoom lens 2 faces the subject. At this time, since the monitor unit 1b is held so that the LCD monitor 3 faces the photographer, the photographer can take a picture while looking at the LCD monitor 3.
[0009]
In addition to the photographing zoom lens 2, the lens unit 1a includes an electronic flash device 4, a finder window 5, a red-eye reduction / self-timer display lamp 6, a finder eyepiece window 7, and the like. On the other hand, in addition to the LCD monitor 3, the monitor unit 1b includes a main switch 8, a release button 9, a display panel 10, a flash photography mode button 11, an AF mode button 12, an image quality mode button 13, a zoom switching button 14, a monitor button 15, A menu button 16 and a selection dial 17 are provided.
[0010]
FIG. 3 is a diagram showing a circuit block of the digital still camera 1 according to this embodiment. The digital still camera 1 includes a main CPU 21 that controls focus detection / adjustment processing, photometry processing, and the like, an image processing CPU 29 that controls image processing and image display processing, and a switch control CPU 41 that controls input signals from each switch. It is controlled by. The switch control CPU 41 sends the information to the main CPU 21 when each switch of the digital still camera 1 is operated, and controls the zoom lens driving device 37 to operate the photographing zoom lens 2 when the zoom switching button 14 is operated. It is configured to drive.
[0011]
In the digital still camera 1, the photographing mode (REC) and the reproduction mode (PLAY) are selected by the switching operation of the main switch 8. The main switch 8 is switched to at least three positions: OFF, REC, and PLAY. The shooting mode is an operation mode in which the captured subject image is recorded as image data, and the reproduction mode is an operation mode in which the recorded image data is read and displayed on the LCD monitor 3. In both operation modes, a menu setting mode for selecting / setting the camera operation is provided.
[0012]
-Shooting mode-
When the main switch 8 is switched to the shooting mode position, the digital still camera 1 is switched to the shooting mode when the power is turned on. When the photographing mode is switched, the subject light incident on the photographing zoom lens 2 is imaged on the CCD 26 which is an image pickup device, and the image signal is sent to the A / D conversion circuit 28 via the analog processing circuit 27 and converted into a digital signal. Converted. The digitally converted signal is guided to an image processing CPU 29 configured as an ASIC, for example, and image preprocessing such as contour compensation and gamma correction is performed and temporarily stored in the buffer memory 30. The image data stored in the buffer memory 30 is processed into display image data by a display image creation circuit 31 controlled by the image processing CPU 29, and a photographing monitor screen called a through screen is displayed on the LCD monitor 3. The through screen is updated at predetermined intervals based on the subject light incident on the photographing zoom lens 2 by repeating the above operation.
[0013]
The switch control CPU 41 receives a half-press signal and a full-press signal from a half-press switch 22 and a full-press switch 23 (hereinafter referred to as the release switch 23) that are linked to the release button 9. When the half-push switch 22 is operated and a half-push signal is input, the switch control CPU 41 transmits the information to the main CPU 21, and the focus detection / adjustment device 36 receives the focus detection state of the photographic zoom lens 2 according to a command from the main CPU 21. Is detected. Then, the photographic zoom lens 2 is driven to the in-focus position so that the subject light incident on the photographic zoom lens 2 forms an image on the CCD 26 that is the imaging device. The CCD 26 is driven and controlled via the timing generator 24 and the driver 25, and the timing generator 24 controls the operation timing of the analog processing circuit 27 and the A / D conversion circuit 28.
[0014]
The digital still camera 1 is provided with two AF operation modes of “single AF mode” and “continuous AF mode”. When the “single AF mode” is set, the focus detection operation by the focus detection / adjustment device 36 is performed by operating the half-press switch 22 as described above, and the “continuous AF mode” is set. When the main switch 8 is switched to the photographing mode position, the focus detection operation by the focus detection / adjustment device 36 is always performed.
[0015]
When the zoom switching button 14 is operated, the zoom lens driving device 37 drives the photographing zoom lens 2 according to a command from the switch control CPU 41 to change the focal length. The zoom button 14 is a seesaw type switch, and the focal length is moved to either the telephoto side (T) or the wide angle side (W). The photometry device 38 measures the luminance of the subject, and performs photometry when a half-press signal from the half-press switch 22 interlocked with the release button 9 is input to the main CPU 21 via the switch control CPU 41.
[0016]
When the release switch 23 is turned on after the half-push switch 22 is turned on, the flash device 4 emits light according to the photometry result by the photometry device 38 and the mode setting preset by the flash photography mode button 11. As the subject light from the photographing zoom lens 2 forms an image on the light receiving surface of the CCD 26, signal charges corresponding to the brightness of the subject image are accumulated in the CCD 26. The signal charges accumulated in the CCD 26 are discharged by the driver 25 and input to an analog signal processing circuit 27 including an AGC circuit and a CDS circuit. The analog signal processing circuit 27 performs analog processing such as gain control and noise removal on the analog image signal, and then the digital signal is converted by the A / D conversion circuit 28.
[0017]
The digitally converted signal is guided to the image processing CPU 29 described above, where image preprocessing such as contour compensation and gamma correction is performed and temporarily stored in the buffer memory 30. Then, image data is exchanged between the main CPU 21 and the buffer memory 30, a white balance adjustment value is obtained from the stored image data, and the white balance adjustment is performed by the image processing CPU 29 based on the adjustment value. The image data after the white balance adjustment is stored in the buffer memory 30 again.
[0018]
The image data stored in the buffer memory 30 is processed into display image data by a display image creation circuit 31 controlled by the image processing CPU 29, and this image data is displayed on the LCD monitor 3 as a photographing screen called a freeze screen. The
[0019]
The image data subjected to the image pre-processing as described above is further subjected to format processing (image post-processing) for JPEG compression by the image processing CPU 29, and is performed by the compression circuit 32 controlled by the image processing CPU 29. The data is compressed at a predetermined ratio by the JPEG method, given a predetermined data name by the main CPU 21, and recorded on a recording medium (PC card, CF card, etc.) 34 such as a flash memory together with time information from the real time clock 35. The When recording on the recording medium 34 is completed and the next shooting is possible, the freeze screen display displayed on the LCD monitor 3 is stopped and switched to the above-described through screen display. Also, as will be described later, it is possible to extend the freeze screen display.
[0020]
In addition, a display panel driver 33 is connected to the main CPU 21 to display the flash mode setting by the flash photography mode button 11, the distance range setting by the AF mode button 12, and the compression rate setting by the image quality mode button 13. Displayed on the panel 10.
[0021]
FIG. 4 is a block diagram showing details of the image processing CPU 29 in the digital camera operating as described above. FIG. 4 shows a line processing circuit 100 that processes the image data from the CCD 26 for each line, and performs the above-described image processing. The line processing circuit 100 shown in FIG. 4 performs various signal processing to be described later on the R, G, and B signals output from the A / D conversion circuit 28, and includes a defect correction circuit 101 and a digital clamp circuit 102. A black level circuit 103, a γ correction circuit 104, an average value calculation circuit 105, a gain circuit 106, and a white balance adjustment circuit 107.
[0022]
The defect correction circuit 101 corrects data from a defective pixel (specified in advance and its address is set in a register) dot-sequentially for each line with respect to the output of the CCD 26. The digital clamp circuit 102 subtracts a weighted average of a plurality of pixel data used as so-called optical black from each pixel data of the line in a dot sequential manner for each line with respect to the output of the CCD 26.
[0023]
The black level circuit 103 adds the values determined in advance and stored in the register of the main CPU 21 to the R, G, and B signals in a dot-sequential manner for each line of the output of the CCD 26. The γ correction circuit 104 performs γ correction on the output of the CCD 26 in a dot-sequential manner for each line using a gradation lookup table.
[0024]
Next, white balance adjustment will be described. The average value calculation circuit 105 extracts, for example, image data of a 512 × 512 area centered on the area used as the focus detection area from the image data of all areas once stored in the buffer memory 30 after γ correction. Then, the white signal adjusting gain Rgain for the R signal and the white signal adjusting gain Bgain for the B signal are calculated by the following equations (1) and (2), for example. The gains Rgain and Bgain are stored in a register of the main CPU 21. For example, when a color filter is arranged on a 512 × 512 pixel region, the average values of R, G, and B signals are calculated by equations (3) to (5), and equations (1) and (2) are obtained. As shown, white balance adjustment gains Rgain and Bgain are calculated from the ratio between the average value Gave of the G signal and the average value Rave of the R signal and the ratio of the average value Gave of the G signal and the average value Bave of the B signal.
[0025]
[Expression 1]
Rgain = Gave / Rave (1)
Bgain = Gave / Bave (2)
However, Rave = Rsum / Rpixel number (3)
Gave = Gsum / Gpixel number (4)
Bave = Bsum / Bpixel number (5)
According to such an average value method, the average value of the gradations of the RGB signals of the image data is obtained, and the white balance adjustment result (overall white balance) is empirically improved. That is, adjustment values such as R gain and B gain for white balance adjustment are determined so that the average color temperature of the screen approaches white, and white balance adjustment is performed based on the white balance adjustment value.
[0026]
The gain circuit 106 is used for white balance adjustment so that the white balance adjustment described above is performed point-sequentially for each line corresponding to the output of the CCD 26 for each of the R, G, and B signals stored in the buffer memory 30. The gain is set in the white balance adjustment circuit 107. At the time of these settings, the correction of sensitivity variation of the CCD 26 performed on the G signal and the variation correction of sensitivity ratio of the CCD 26 performed on the R and B signals are performed.
[0027]
The white balance adjustment circuit 107 multiplies the R and B signals by the R gain and B gain, which are white balance adjustment coefficients set by the gain circuit 106. In this embodiment, the white balance adjustment value used for correction by the white balance adjustment circuit 107, that is, the R gain and B gain, which are white balance adjustment coefficients, can be set manually.
[0028]
The configuration of the focus detection / adjustment device 36 and the principle of the focus detection operation by the focus detection / adjustment device 36 will be described with reference to FIG. The focus detection / adjustment device 36 is controlled by the main CPU 21, and includes an infrared light cut filter 700, a field mask 900, a field lens 300, an aperture mask 400, re-imaging lenses 501 and 502, an image sensor 310, and the like. A region 800 is an exit pupil of the photographing zoom lens 2 (FIG. 1). Regions 801 and 802 are regions where images obtained by back projecting the openings 401 and 402 formed in the opening mask 400 onto the region 800 by the field lens 300 exist. The position of the infrared light cut filter 700 may be on the right side or the left side of the field mask 900. The light beam incident through the regions 801 and 802 is focused on the CCD equivalent surface 600, and then the infrared light cut filter 700, the field mask 900, the field lens 300, the apertures 401 and 402, and the re-imaging lens 501. , 502 and images on the image sensor arrays 310a and 310b.
[0029]
A pair of subject images formed on the image sensor arrays 310a and 310b approach each other in a so-called front pin state in which the photographing zoom lens 2 forms a sharp image of the subject in front of the CCD equivalent surface 600 (subject side), and vice versa. Further, they move away from each other in a so-called rear pin state in which a sharp image of the subject is connected after the CCD equivalent surface 600. The sharp image of the subject is located on the CCD equivalent plane 600 when the subject images formed on the image sensor arrays 310a and 310b have a predetermined interval. Therefore, the pair of subject images are photoelectrically converted by the image sensor arrays 310a and 310b to be converted into electric signals, and these signals are subjected to arithmetic processing to obtain the relative distance between the pair of subject images, thereby adjusting the focus adjustment state of the photographic zoom lens 2. That is, how far the position at which a sharp image is formed by the photographing zoom lens 2 is located in what direction with respect to the CCD equivalent plane 600, that is, the amount of deviation is obtained. In FIG. 5, the focus detection area corresponds to a portion where the image sensor arrays 310 a and 310 b are back-projected by the re-imaging lenses 501 and 502 and overlap in the vicinity of the CCD equivalent surface 600. In this way, the focus is detected in the focus detection area in the photographing screen.
[0030]
-Shooting mode menu settings-
FIG. 6 is a diagram illustrating a menu setting screen for the shooting mode displayed on the LCD monitor 3 of the digital still camera 1. When the menu button 16 in FIG. 1 is pressed in the shooting mode, a menu setting screen as shown in FIG. 6A is displayed on the LCD monitor 3 of the digital still camera 1. By operating the selection dial 17 or the zoom switching button 14 (functioning as a selection switch during the menu setting mode), for example, the item “AF operation” is selected from the menu, and the release button 9 (menu setting mode When “AF operation” is pressed and “AF operation” is selected and determined, a menu setting screen relating to the AF operation mode as shown in FIG. 6B is displayed on the LCD monitor 3. As described above, the AF operation mode is the “continuous AF mode” in which the focus detection operation is always performed when the camera is set to the shooting mode by the main switch 8 and the half-press switch 22 is turned on. This is a “single AF mode” that is performed only in
[0031]
By operating the selection dial 17 or the zoom switching button 14, for example, an item of “single AF mode” is selected from the menu. When the release button 9 is pressed and the “single AF mode” item is selected and determined, an operation mode in which focus detection is performed only when the half-press switch 22 is turned on is selected. This setting content becomes effective when the menu button 16 is pressed again to return from the menu setting mode to the shooting mode.
[0032]
The shooting mode menu settings as described above are used to set camera operations relating to shooting functions such as exposure correction, metering method, and white balance adjustment value in addition to the AF mode described above. is there. In addition, the power saving mode on / off setting for suppressing the power consumption of the camera, which will be described later, and the time until the freeze screen display displayed on the LCD monitor 3 during shooting is switched to the through screen display are extended longer than a predetermined time. Settings are also made in the shooting mode menu settings. During this menu setting mode, the menu screen as shown in FIG. 6 is displayed on the LCD monitor 3, and the screen of the subject image captured through the photographing zoom lens 2 is not displayed. Further, neither exposure adjustment (AE) based on the photometry result by the photometry device 38 nor focus detection (AF) by the focus detection / adjustment device 36 is performed.
[0033]
-Playback mode-
When the main switch 8 is switched to the playback mode position, the digital still camera 1 is switched to the playback mode when the power is turned on. When image data has already been recorded on the recording medium 34, the recorded image data is read into the main CPU 21. The read data is sent to the buffer memory 30 and then processed into display image data by the display image creation circuit 31 controlled by the image processing CPU 29, and is displayed on the LCD monitor 3 as a reproduced image 70 as shown in FIG. Is displayed. In FIG. 7, 71 is a compression rate setting state set by the image quality mode button 13, 72 is a frame number of the display image, 73 is a file name of the display image data, and 74 is time information of a photographed image.
[0034]
When a plurality of image data are recorded on the recording medium 34, the zoom switching button 14 (functioning as a frame advance switch in the playback mode) is operated, so that one frame before the currently displayed display image is displayed. Image data and image data after one frame are read out and displayed on the LCD monitor 3. During this playback mode, a playback image as shown in FIG. 7 is displayed on the LCD monitor 3, but the screen of the subject image captured through the shooting zoom lens 2 is not displayed. Further, neither exposure adjustment (AE) based on the photometry result by the photometry device 38 nor focus detection (AF) by the focus detection / adjustment device 36 is performed.
[0035]
-Playback mode menu settings-
FIG. 8 is a view for explaining a menu setting screen for the playback mode displayed on the LCD monitor 3 of the digital still camera 1. When the menu button 16 in FIG. 1 is pressed in the playback mode, a menu setting screen as shown in FIG. 8A is displayed on the LCD monitor 3 of the digital still camera 1. By operating the selection dial 17 or the zoom switching button 14 (functioning as a selection switch in the menu setting mode), for example, the item “delete” is selected from the menu, and the release button 9 (in the menu setting mode). When “Delete” is pressed and “Delete” is selected and determined, a menu setting screen regarding deletion as shown in FIG. 8B is displayed on the LCD monitor 3. Deletion in this case is processing for deleting image data recorded on the recording medium 34.
[0036]
By operating the selection dial 17 or the zoom switching button 14, for example, an item “delete selection screen” is selected from the menu. When the release button 9 is pressed and “selection screen deletion” is selected and determined, an image to be deleted is selected on a selection screen (not shown), and processing for deleting the selected image data is performed.
[0037]
The menu settings for the playback mode as described above include camera operations related to playback functions such as a thumbnail for displaying a plurality of reduced images in addition to the above-described image deletion, and a slide show for displaying image data frame by frame at a predetermined time interval. It is used for setting in detail. During this menu setting mode, a menu screen as shown in FIG. 8 is displayed on the LCD monitor 3, and the screen of the subject image captured through the photographing zoom lens 2 is not displayed. Further, neither exposure adjustment (AE) based on the photometry result by the photometry device 38 nor focus detection (AF) by the focus detection / adjustment device 36 is performed.
[0038]
Next, the power saving operation of the digital still camera 1 that operates as described above will be described. The power saving operation is performed by putting the main CPU 21 in a standby state (sleep state) under a predetermined condition. That is, when the screen of the subject image captured through the photographing zoom lens 2 is not displayed on the LCD monitor 3 due to the operation mode of the digital still camera 1, the photometry device 38, the focus detection / adjustment device controlled by the main CPU 21. 36, the real-time clock 35, the recording medium 34, the flash device 4, and the consumption of the commands and data sent and received between the main CPU 21 and the main CPU 21 itself and the above-described devices. Suppress power. Further, when the above apparatus can be set in a standby state, it is set in a standby state together with the main CPU 21.
[0039]
The main CPU 21 is used in the shooting mode and is not used when setting the shooting mode menu. The main CPU 21 is used when the image data recorded in the reproduction mode is read from the recording medium 34, and is not used when setting other operations and the menu of the reproduction mode. Therefore, the main CPU 21 determines whether or not to enter the standby state based on the operation mode of the digital still camera 1 described above, and enters the standby state based on the determination result.
[0040]
FIG. 9 is a flowchart for explaining processing for determining whether or not to put the main CPU 21 in a standby state. This program is executed in the main CPU 21. At the beginning of the determination process, the standby flag is turned off (step S1), and it is checked in step S2 whether or not the playback mode is set. When it is determined in step S2 that the playback mode is set, it is checked whether or not a predetermined time has elapsed since the predetermined operation button of the digital still camera 1 was last operated (step S3). ). When it is determined that the predetermined time has not elapsed, it is determined that the main CPU 21 does not need to be in a standby state, and the determination process is terminated.
[0041]
On the other hand, when it is determined that the predetermined time has elapsed, the process proceeds to step S10 to turn on the standby flag. If it is determined in step S2 that the shooting mode is set instead of the playback mode, the process proceeds to step S4. In step S4, it is determined whether or not the display of the freeze screen is displayed by extending a predetermined display time. The extended display of the freeze screen is a function set in the shooting mode setting menu screen of FIG. 6 as described above.
[0042]
In the setting menu, the freeze screen is set to be extended and displayed longer than the predetermined time, and when it is determined in step S4 that the freeze screen is extended and displayed longer than the predetermined time based on this setting, shooting is performed. Since the operation of recording the processed image data on the recording medium 34 has been completed, the process proceeds to step S10 to turn on the standby flag. On the other hand, when it is determined that the freeze screen has not been extended and displayed longer than the predetermined time, the operation of recording the captured image data on the recording medium 34 has not been completed, and thus the standby flag is not turned on. The determination that the freeze screen has not been extended and displayed for a longer time than the predetermined time includes when the freeze screen is displayed within the predetermined time and when the through screen is displayed. In step S5, it is checked whether or not the flash device is being charged. When it is determined in step S5 that the flash device is being charged, the process proceeds to step S10 in order to turn on the standby flag, and when it is not determined that it is being charged, the process proceeds to step S6.
[0043]
In step S6, it is checked whether or not the power saving mode is set in advance on the shooting mode setting menu screen of FIG. The power saving mode is provided to give a condition for the main CPU 21 to enter a standby state, and when the power saving mode is set, the main CPU 21 is put into a standby state under a predetermined condition. If it is determined in step S6 that the power saving mode is not set, it is determined that the main CPU 21 does not need to be in a standby state, and the determination process is terminated. On the other hand, when it is determined that the power saving mode is set, the process proceeds to step S7, and it is checked whether or not the shooting mode setting menu as shown in FIG. 6 is activated.
[0044]
If it is determined in step S7 that the shooting mode setting menu is activated, the process proceeds to step S10 to turn on the standby flag. If it is determined that the shooting mode setting menu is not activated, step S8 is performed. Proceed to In step S8, it is checked in advance whether or not the AF operation mode for performing focus detection is set to “single AF mode” on the above-described shooting mode setting menu screen of FIG. When it is determined that the “single AF mode” is not set, that is, it is determined that the “continuous AF mode” is set, it is necessary to always perform the focus detection operation, so the main CPU 21 is set in a standby state. It is determined that it is not necessary, and this determination process ends. On the other hand, when it is determined that the “single AF mode” is set, the process proceeds to step S9 to check whether or not the through screen is displayed.
[0045]
In step S9, it is checked whether or not a through screen is displayed. When it is determined that the through screen is not displayed, it is determined that it is not necessary to put the main CPU 21 in the standby state, and this determination process ends. On the other hand, when it is determined that the through screen is displayed, the process proceeds to step S10, the standby flag is turned on, and this determination process is terminated. The process of setting the main CPU 21 to the standby state is performed in the main process of the digital camera 1 described later. That is, the main determination process prepared as a subroutine is performed at regular intervals from the main process or whenever a switch operation is detected, and the standby state is set based on the on / off state of the standby flag set by the main process. Perform migration and release. That is, when the standby flag is turned on, the standby state is set, and when the standby flag is turned off, the standby state is canceled and the normal operation state is restored.
[0046]
-Main processing-
The main process performed by the main CPU 21 in the shooting mode of the digital camera 1 will be described with reference to the flowchart of FIG. FIG. 10 is a flowchart for explaining the main processing in the shooting mode of the digital still camera 1 according to the present embodiment. When the main switch 8 (FIG. 1) of the digital camera 1 is operated to the photographing mode side, the power is turned on and the main processing program of FIG. 10 is started. First, in step S201, it is checked whether or not the menu button 16 has been operated. If it is determined that the menu button 16 has been operated, the menu processing 250 in step S202 is performed. When the menu process 250 is completed, the process returns to step S201. On the other hand, when it is determined in step S201 that the menu button 16 has not been operated, the process proceeds to step S203.
[0047]
In step S203, it is checked whether or not the zoom switching button 14 is operated. If it is determined that the zoom switching button 14 is operated, the zoom lens driving device 37 is controlled based on the operation of the zoom switching button 14. Thus, the focal length of the photographic zoom lens 2 is adjusted (step S204). When the adjustment of the focal length is completed, the process returns to step S201. On the other hand, when it is determined that the zoom switching button 14 is not operated, an AE / AF lock flag described later is checked in step S205. If it is determined that the AE / AF lock flag is off, the power saving flag is checked in step S206. The power saving flag is a flag indicating whether or not the power saving mode is turned on. On the other hand, when it is determined in step S205 that the AE / AF lock flag is turned on, the process proceeds to step S214 described later.
[0048]
When it is determined in step S206 that the power saving flag is turned on, the process proceeds to step S207, and the single AF mode flag indicating the setting state of the AF operation mode for performing focus detection is checked. If it is determined in step S207 that the single AF mode flag is turned on, image preprocessing 270 described later is performed in step S208. On the other hand, when it is determined in step S206 that the power saving flag is turned off and in step S207, it is determined that the single AF mode flag is turned off, in step S213, the photometry device 38 (FIG. Exposure adjustment (AE) based on the photometric result of 3) and focus detection (AF) by the focus detection / adjustment device 36 are performed. When the AE operation and the AF operation are completed, the image preprocessing 270 in step S208 is performed.
[0049]
When the image preprocessing in step S208 is completed, a through screen is displayed on the LCD monitor 3 (step S209). In step S210, it is determined whether or not the half-push switch 22 has been operated. If it is determined that the switch has been operated, an AE operation for shooting and an AF operation are performed. When the AE operation and the AF operation are completed, the results of both operations are held in the main CPU 21, the lock flag is turned on (step S212), and the process returns to step S201. The lock flag is a flag indicating that both the AE operation result and the AF operation result are held in the main CPU 21.
[0050]
In step S214, it is checked whether or not the full push switch 23 is operated. When it is determined that the full-press switch 23 is operated, the image preprocessing 270 in step S215 is performed. The image preprocessing 270 is the same as the processing performed in step S208.
[0051]
When the image preprocessing 270 in step S215 is completed, a freeze screen is displayed on the LCD monitor 3 (step S216). Subsequently, image post-processing 280, which will be described later, is performed (step S217), and it is checked whether or not an extended display flag indicating whether or not the freeze screen is extended is turned on (step S218). When it is determined that the extended display flag is turned off, the lock flag is turned off (step S219), and the process returns to step S201.
[0052]
On the other hand, when it is determined in step S218 that the extended display flag is turned on, time-up determination processing is performed in step S220. If time-up is determined, the lock flag is turned off in step S219. That is, the time-up determination processing time in step S220 corresponds to the time for which the freeze image display is extended after the image post-processing 280.
[0053]
A case where it is determined in step S214 that the full push switch 23 has not been operated will be described. In step S221, the lock flag is turned off, and it is checked whether or not auto power-off processing is in progress (step S222). When it is determined that the auto power-off process is not being performed, the process returns to step S201. When it is determined that the auto power-off process is being performed, a predetermined auto power-off process is performed at step S223. The auto power off process is a process in which the power is automatically turned off under a predetermined condition.
[0054]
Next, the menu processing 250 will be described with reference to the flowchart of FIG. In step S251, the menu display as shown in FIG. 6 is performed, and it is determined whether or not the setting for the extended display of the freeze screen has been made (step S252). When it is determined that the extended display of the freeze screen is set, the extended display flag is turned on (step S253). On the other hand, when it is determined in step S252 that the extended display of the freeze screen is not set, the extended display flag is turned off (step S254).
[0055]
In step S255, it is determined whether or not the AF operation is set to the single AF mode. If it is determined that the single AF mode is set, the single AF mode flag is turned on (step S256). On the other hand, when it is determined in step S255 that the continuous AF mode is set, the single AF mode flag is turned off (step S257). In a succeeding step S258, it is determined whether or not the power saving mode is set. When it is determined that the power saving mode is set, the power saving flag is turned on (step S259). On the other hand, when it is determined in step S258 that the power saving mode is not set, the power saving flag is turned off (step S260).
[0056]
In step S261, it is determined whether another shooting menu item has been set. When it is determined that another shooting menu item has been set, a predetermined setting based on the setting content is performed (step S262), and when it is determined that no other shooting menu item has been set, the menu process is terminated. .
[0057]
Next, the image preprocessing 270 will be described with reference to the flowchart of FIG. In step S271, charges corresponding to the brightness of the subject image are accumulated in the CCD 26 (FIG. 3), and the charges accumulated in step S272 are discharged and input to the analog signal processing circuit 27. The analog signal processing circuit 27 performs analog signal processing (step S273), and the A / D conversion circuit 28 converts the analog signal into a digital signal (step S274). The digitized image signal is subjected to image processing such as contour compensation, gamma correction, and white balance adjustment in the image processing CPU 29 (step S275), and the image preprocessing 270 ends.
[0058]
Next, the image post-processing 280 will be described with reference to the flowchart of FIG. The image data that has undergone image preprocessing is sent to the compression circuit 32 (FIG. 3), and is compressed to a predetermined ratio by the JPEG method (step S281). The compressed image data is given a predetermined image data name by the main CPU 21 and recorded on the recording medium 34 (step S282), and the image post-processing 280 is completed.
[0059]
The effect of this embodiment will be described.
(1) Since the digital still camera 1 is divided into a plurality of internal blocks and each is provided with a CPU 21, 29, 41 to be controlled, one CPU and a block related to the CPU are set in a standby state. The operation of the entire camera is not stopped. As a result, since the CPU and related blocks can be set in a standby state according to the operation state of the camera, it is possible to suppress power consumption without stopping the camera.
(2) In the reproduction mode (step S2 is affirmative determination), when a predetermined time has elapsed since a predetermined operation button for reading or deleting image data was last operated (step S3 is affirmative determination). Based on this determination, the main CPU 21 and related blocks are put into a standby state. As a result, focus detection, photometry operation, and accompanying internal processing of the main CPU 21 are not performed when the subject image is not required to be displayed on the screen, so that power consumption can be suppressed and the camera is continuously operated. It is prevented from being put into a standby state when it is in
(3) Since the switch control CPU 41 for controlling the input signal from each switch is not set to the standby state, when it is determined that the switch is operated by the CPU 41 during the standby state according to the above (2), the switch control CPU 41 enters the standby state. A certain CPU 21 can be restored. As a result, when the switch is operated, an operation corresponding to the operated switch can be performed immediately.
(4) While the freeze screen is being extended (step S4 is affirmative), the main CPU 21 is set in a standby state. Therefore, when a through screen is unnecessary, focus detection and photometric operation, and the accompanying main CPU 21 internal Therefore, the power consumption can be suppressed.
(5) While the flash device is being charged (Yes in step S5), the main CPU 21 is set in a standby state. Therefore, when power is required for the flash device light-emitting charging operation, focus detection, photometry operation, and Accordingly, the internal processing of the main CPU 21 is not performed, so that power is saved and the flash device charging time can be shortened. This is particularly effective when the battery capacity is reduced.
(6) When the power saving mode is on (Yes in Step S6) When the menu of the shooting mode is set (Yes in Step S7), the main CPU 21 is set in the standby state. Detection, photometry operation, and accompanying internal processing of the main CPU 21 are not performed, and power consumption can be suppressed.
(7) When the power saving mode is on (step S6 is affirmative determination) and the single AF mode is being operated (step S8 is affirmative determination), the main CPU 21 is set to the standby state while the through screen is being displayed (step S9 is affirmative determination). did. As a result, before the half-push switch 22 is operated, the main CPU 21 is placed in a standby state, so that focus detection and photometric operation are not performed, and power consumption can be suppressed.
(8) Since the power saving mode is provided and the operations (6) and (7) are performed when the power saving mode is on, the above operations are performed against the photographer's will. The effect which prevents is also show | played.
[0060]
In the above-described camera, the setting for switching between the continuous AF mode and the single AF mode of the AF operation, the on / off switching setting of the power saving mode, and the extended display of the freeze screen are performed in the setting menu screen. However, a changeover switch for switching these setting contents may be provided in the camera.
[0061]
In the above-described camera, three CPUs for controlling each circuit block for operating the camera are provided, and one of the CPUs is set in a standby state. However, more CPUs are provided for each circuit block. A plurality of CPUs may be placed in a standby state according to the operation of the camera. Alternatively, all the circuit blocks of the camera are controlled by one CPU, and each circuit block can be set to a standby state, and one or a plurality of circuit blocks are set to a standby state according to the operation of the camera. You may do it.
[0062]
In the above description, a camera having a freeze screen display extension function in which the freeze screen is displayed longer than a predetermined time has been described. However, even a camera that does not have such a freeze screen display extension function has been described. When the freeze screen display time switching function is provided so that the display time of the freeze screen can be switched, the main CPU 21 waits when the freeze screen is still displayed after the recording operation of the captured image data is completed. It should be in a state.
[0063]
Furthermore, in the above description, the main CPU 21 is set in the standby state while the flash device is being charged, but the display on the LCD monitor 3 may be turned off. Further, if the image processing CPU 29 is also set in a standby state, the flash device charging time can be shortened when the remaining battery capacity decreases.
[0064]
In addition, although the power saving mode can be set arbitrarily, the same processing as when the power saving mode is set is performed by setting the focus detection (AF) operation mode to “single AF mode”. You may do it.
[0065]
In the above description, a digital still camera in which lenses cannot be exchanged has been described. However, the present invention can also be applied to a single-lens reflex digital still camera and a digital video camera capable of capturing moving images.
[0067]
【The invention's effect】
  In the digital camera according to the present invention, Power consumption can be suppressed while constantly accepting operation input signals.
[Brief description of the drawings]
FIGS. 1A and 1B are views showing an external appearance of a digital still camera according to an embodiment when the digital still camera is housed and carried, and FIG. 1B is a view seen from above, and FIG.
2 is a diagram showing an external appearance of the camera of FIG. 1 during normal shooting, where (a) is a view from the front, (b) is a view from above, and (c) is a view from behind. It is.
FIG. 3 is a diagram illustrating a circuit block of a digital still camera according to an embodiment.
4 is a block diagram illustrating a circuit that performs line processing in the signal processing system illustrated in FIG. 3;
FIG. 5 is a diagram illustrating a focus detection / adjustment apparatus.
FIGS. 6A and 6B are diagrams illustrating a shooting mode menu setting screen; FIG. 6A is a shooting menu screen; and FIG. 6B is an AF operation setting screen.
FIG. 7 is a diagram for explaining a reproduction mode, and is a monitor screen after image data is read.
FIGS. 8A and 8B are diagrams for explaining a menu setting screen in a playback mode; FIG. 8A is a playback menu screen; and FIG. 8B is a deletion setting screen.
FIG. 9 is a flowchart illustrating a process for determining whether or not to set the main CPU to a standby state.
FIG. 10 is a flowchart illustrating main processing in a shooting mode.
FIG. 11 is a flowchart illustrating menu processing.
FIG. 12 is a flowchart illustrating image preprocessing.
FIG. 13 is a flowchart illustrating image post-processing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Digital still camera, 2 ... Shooting zoom lens, 3 ... LCD monitor, 4 ... Flash device, 8 ... Main switch, 9 ... Release button, 11 ... Flash shooting mode button, 14 ... Zoom change button, 16 ... Menu button, DESCRIPTION OF SYMBOLS 17 ... Selection dial, 21 ... Main CPU, 22 ... Half press switch, 23 ... Full press switch, 26 ... CCD, 29 ... Image processing CPU, 31 ... Display image creation circuit, 32 ... Compression circuit, 34 ... Recording medium, 35 Real time clock 36 Focus detection / adjustment device 37 Zoom lens driving device 38 Photometry device 41 Switch control CPU

Claims (3)

In a digital camera that captures a subject image with an image sensor through a photographing lens and records image data on a recording medium
Camera control means having at least a first CPU and controlling at least one of focus detection, exposure adjustment and lens driving ;
Discriminating means for discriminating a condition of not using the camera control means;
Standby control means for placing the camera control means in a standby state when the determination means determines the condition ;
Regardless of whether or not the camera control means is in the standby state, it always accepts an input signal by a user's operation and sends control information based on the input signal to the standby control means. An operation control means for transmitting to the digital camera. In a digital camera that captures a subject image with an image sensor through a photographing lens and records image data on a recording medium
Camera control means having at least a first CPU and controlling at least one of focus detection, exposure adjustment and lens driving ;
A display for displaying a setting menu for setting the operation of the digital camera in the menu setting mode;
Image processing control means having at least a second CPU and displaying an image on the display;
Standby control means for placing the camera control means in a standby state when the menu setting mode is set ;
Regardless of whether or not the camera control means is in the standby state, it always accepts an input signal by a user's operation and sends control information based on the input signal to the standby control means. An operation control means for transmitting to the digital camera. The digital camera according to claim 1 or 2,
  The standby control unit controls the camera control unit to release the standby state in response to transmission of the control information from the operation control unit when the camera control unit is in the standby state. A digital camera characterized by

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