JP2008048322A - Image photographing apparatus, and display method for the image photographing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain power saving while maintaining quality by reducing power consumption and varying image quality, according to human memory characteristics, on the assumption that attention will not be paid to a monitoring image. <P>SOLUTION: An initial value for monitoring is set to a clock generator (S11) and processing of monitoring display is carried out, on the basis of the initial value for monitoring (S12). Presence/absence of specific conditions of digital camera control is confirmed (S13) and out of the specific conditions (No), a clock with a high motion followup capability is set to the clock generator (S14). Furthermore, with the specific conditions (Yes) in the processing S13, a clock that becomes low in power consumption is selected and set to the clock generator (S15). Monitoring processing is repeated from the processing S12, thereafter. As the specific conditions, for example, for the case of display on a predetermined on-screen display, the processing S15 is performed; and when the display on the predetermined on-screen display is finished, the processing (S14) is performed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus for photographing a subject such as a digital still camera, and relates to an image photographing apparatus for saving power of the apparatus and maintaining the quality of an image to be displayed and a display method for the image photographing apparatus.

  In a conventional mobile device such as a digital still camera, a liquid crystal monitor provided in the device is a major factor of power consumption. For example, in a model case for measuring power consumption in a liquid crystal monitor provided in a digital video camera or digital still camera, the monitoring operation time is the longest. Therefore, reducing power consumption during monitoring contributes to the lowest power consumption.

  For this reason, there are many products on the market that allow the user to select whether the brightness of the liquid crystal monitor is suppressed or the liquid crystal monitor is turned off, and furthermore, the power of the liquid crystal monitor is turned on / off. Many products with power-saving settings are also available on the market, and many products turn off the LCD monitor or turn off the device itself when the idling state continues for several minutes. It is also conceivable to reduce the frame rate during the monitoring operation in order to reduce the power consumption during monitoring.

  In Patent Document 1, when 3 to 4 oscillators or oscillators are required to obtain a plurality of frame rates, the clock generator has a timing generator oscillation source, and a clock having a frequency of the oscillation source is provided. A configuration is disclosed in which the frequency of the clock output to the timing generator and the clock output to the timing generator can be changed.

  Further, Patent Document 2 stores a backlight control value as energy-saving data for lowering the backlight brightness when the camera is turned off, and whether or not the backlight brightness setting mode of the operator is turned on when the power is turned on. In the setting mode, the operator memorizes the brightness setting data, and the brightness control is performed based on this, and when not in the setting mode, the previously set energy saving data is read to reduce the brightness. Control is disclosed.

Patent Document 3 discloses a CCD that images a subject and outputs color image data, and detects the color components of external light and adjusts the signal levels of at least two colors of the color image data. It is disclosed that a controller that controls the gain of an amplifier based on a color component of light and color image data whose signal level is adjusted by the amplifier are displayed.
JP 2003-92698 A JP-A-11-341316 JP 2001-268405 A

  However, when the frame rate during the monitoring operation of the liquid crystal monitor is lowered, the power consumption is lowered but the followability is deteriorated, so that the image quality is lowered as generally 15 frames / second is set as the lower limit. In addition, power saving has been attempted with alternative methods such as turning the LCD monitor darker, turning off the power, and increasing the brightness to make it appear brighter while still saving power. There is a problem that the display is whitish and the image quality is deteriorated due to loss or brightness.

  Also, in audio compression technology and image compression technology represented by MPEG, the amount of data is reduced while suppressing deterioration of quality by reducing data along human auditory characteristics and visual characteristics. Furthermore, in human memory characteristics, it is widely known and scientifically proved that there are characteristics that leave memories of first impressions and emotions strong until later.

  The present invention is directed to solving the above-described problems of the prior art, and since power saving and the maintenance of display image quality are generally in a trade-off relationship, the brightness is simply adjusted by user settings. Instead of detecting the idling and turning off the power, the frame rate is automatically set when it is assumed that the user is not paying attention to the monitoring image, such as when the user is calling the setting screen during the monitoring operation. Reduces power consumption by reducing the power consumption, and also achieves power saving while maintaining quality by performing image quality fluctuations according to human memory characteristics, and an image capturing device and image capturing that improve the above-mentioned trade-off effect An object of the present invention is to provide a display method of an apparatus.

  In order to achieve the above object, an image photographing apparatus according to claim 1 of the present invention includes an image pickup unit that converts an optical image representing a subject into an electric signal, and information recording that records image data representing the electric signal. A display control unit that performs processing for displaying the image data converted into an electrical signal by the imaging unit on the display unit, and a specific condition relating to the control of the image capturing device And an changing means for changing a cycle of converting the imaging means into an electric signal in accordance with the extracted condition.

  The image photographing device according to any one of claims 2 to 7 is the image photographing device according to claim 1, wherein the on-screen display according to a predetermined control is selected from among the on-screen displays in which the specific condition is displayed on the display means. Of the on-screen display overlaid on the display means, and within the threshold time since the on-screen display related to the predetermined control is displayed. It is within a predetermined time since the operation was performed, the self-timer is being counted down, the photographing process is possible from a remote location, and the power of the display means for displaying image data is turned on / off It is characterized by that.

  The image photographing device according to any one of claims 8 to 10 includes a sensor that detects a movement associated with handling of the image photographing device in the image photographing device according to claim 1, and the specific condition is that the detection value of the sensor is It is characterized by being larger than a predetermined threshold, and further, a sensor detecting a velocity or an acceleration, and a sensor detecting an angular velocity or an angular acceleration.

  In addition, an image photographing apparatus according to claims 11 and 12 is an image photographing apparatus having an imaging means for converting an optical image representing a subject into an electric signal and an information recording medium for recording image data representing the electric signal. A display control unit that performs processing for displaying the image data converted into an electrical signal by the imaging unit on the display unit, an extraction unit that extracts a specific condition related to the control of the image capturing apparatus, and It is provided with a changing means for changing the luminance of the display means for displaying the image data according to the conditions, or a changing means for changing the driving power of the display means for displaying the image data according to the extracted conditions. .

  Further, in the image photographing device according to claims 13 and 14, in the image photographing device according to claims 12 and 13, the specific condition is display of a photographing confirmation image for displaying the photographing image data only for a predetermined time immediately after photographing. In other words, it is a display of a recording confirmation image that is read from an information recording medium in which captured image data is recorded immediately after imaging.

  According to another aspect of the display method of the image photographing apparatus of the present invention, the optical image representing the subject is converted into an electric signal by the imaging means, and the image data representing the electric signal is recorded on the information recording medium. A method for performing processing for displaying image data converted into an electrical signal by an imaging unit on a display unit, a step of extracting a specific condition related to control of the image capturing apparatus, and an extracted condition And a step of changing a period for the imaging means to convert to an electrical signal.

  Moreover, the display method of the imaging device described in claims 16 to 21 is the display method according to claim 15, wherein the specific condition relates to a predetermined control among the on-screen displays displayed on the display means. The on-screen display is displayed, the on-screen display superimposed on the display means is within the threshold time after the on-screen display related to the predetermined control is displayed, and the user finally performs It is within a predetermined time since the predetermined operation was performed, the self-timer countdown process is in progress, the photographing process is possible from a remote location, and the display means for displaying image data is turned on / off. It is off.

  The display method of the image photographing device according to any one of claims 22 to 24 is the display method according to claim 15, further comprising a sensor for detecting a movement accompanying the handling of the image photographing device, wherein the specific condition is a detection value of the sensor. Is greater than a predetermined threshold, the sensor detects velocity or acceleration, and the sensor detects angular velocity or angular acceleration.

  According to a 25th and 26th aspect of the present invention, there is provided a display method for an image capturing apparatus that converts an optical image representing a subject into an electrical signal by an imaging means and records image data representing the electrical signal on an information recording medium. A method of performing a process for displaying image data converted into an electrical signal by an imaging unit on the display unit, a step of extracting a specific condition related to control of the image capturing device, and an extraction method And changing the luminance of the display means for displaying the image data according to the extracted conditions, or changing the driving power of the display means for displaying the image data according to the extracted conditions.

  The display method of the image photographing device described in claims 27 and 28 is the display method of claims 25 and 26, wherein the specific condition is that the photographing confirmation image is displayed for displaying the photographed image data only for a certain time immediately after photographing. It is a display of a recording confirmation image that is read from an information recording medium in which captured image data is recorded immediately after imaging.

  According to the image capturing apparatus having the above-described configuration and the display method of the image capturing apparatus, when it is assumed that the user does not pay attention to the monitoring image that moves the image capturing apparatus beyond a predetermined threshold, the frame rate is automatically set. The power consumption can be reduced while maintaining the image quality by reducing the power consumption and reducing the power consumption, and by changing the quality of the confirmation image immediately after shooting according to human memory characteristics. .

  According to the present invention, when it is assumed that attention is not paid to the monitoring image, the frame rate is automatically reduced to reduce power consumption, and the image quality is changed in accordance with human memory characteristics. Thus, there is an effect that the power consumption can be reduced while maintaining the image quality.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1A and 1B are external views of a digital still camera (hereinafter referred to as a digital camera) according to an embodiment of the present invention. FIG. 1B is a top view, FIG. 1B is a front view, and FIG. FIG. 2 is a block circuit diagram showing an outline of the system configuration inside the digital camera.

  As shown in FIG. 1, a release switch (shutter button) SW1, a mode dial switch SW2, and a sub LCD (liquid crystal display) 1 are disposed on the top surface of the digital camera body.

  Further, a lens barrel unit 7 including a photographic lens, an optical viewfinder 4, a strobe light emitting unit 3, a distance measuring unit 5, and a remote control light receiving unit 6 are provided on the front surface of the digital camera body.

  On the back of the digital camera are a power switch SW13, LCD monitor 1 ', AFLED 8, strobe LED 9, wide-angle zoom switch SW3, telephoto zoom switch SW4, self-timer switch SW5 for setting / deleting a self-timer, menu switch SW6 A movement / strobe set switch SW7, a right movement switch SW8, a display switch SW9, a downward movement / macro switch SW10, a left movement / image confirmation switch SW11, an OK switch SW12, and a power switch SW13 are provided. A memory card / battery loading chamber lid 2 is provided on the side of the camera body.

  Since the function and operation of each member of the digital camera are known, the description thereof will be omitted, and the internal system configuration of the camera will be described with reference to FIG. 1 based on FIG.

  As shown in FIG. 2, reference numeral 104 denotes a digital still camera processor (hereinafter referred to as a processor).

  The processor 104 includes a first CCD signal processing block 1041, a second CCD signal processing block 1042, a CPU block 1043, a local SRAM 1044, a USB block 1045, a serial block 1046, a JPEG / CODEC block (a block for performing JPEG compression / decompression) 1047, and a RESIZE block. (Block for enlarging / reducing the size of image data by interpolation processing) 1048, TV signal display block (block for converting image data to a video signal for display on an external display device such as a liquid crystal monitor / TV) 1049, memory card A controller block (block for controlling a memory card that records captured image data) 10410 is included. Each of these blocks is connected to each other via a bus line.

  Further, outside the processor 104, RAW-RGB image data (image data in a state where white balance setting and γ setting are performed), YUV image data (image data in which luminance data and color difference data are converted), An SDRAM 103 for storing JPEG image data (image data in a JPEG compressed state) is disposed, and the SDRAM 103 is connected to the processor 104 via a memory controller (not shown) and a bus line.

  Outside the processor 104, there are also a RAM 107, a built-in memory (a memory for recording captured image data even when no memory card is inserted in the memory card slot) 120, and a ROM 108 storing control programs, parameters, and the like. These are also connected to the processor 104 by a bus line.

  The control program stored in the ROM 108 is loaded into the main memory (not shown) of the processor 104 when the power switch SW13 of the digital camera is turned on. The processor 104 controls the operation of each unit according to the control program, Parameters and the like are temporarily stored in the RAM 107 or the like. Further, by using a rewritable flash ROM in the ROM 8, it is possible to change the control program and parameters for control, and the function can be easily upgraded.

  The lens barrel unit 7 includes a lens barrel including a zoom optical system 71 having a zoom lens 71a, a focus optical system 72 having a focus lens 72a, a diaphragm unit 73 having a diaphragm 73a, and a mechanical shutter unit 74 having a mechanical shutter 74a. ing. Note that the zoom lens 71a, the focus lens 72a, and the stop 73a constitute a photographing optical system.

  The zoom optical system 71, the focus optical system 72, the aperture unit 73, and the mechanical shutter unit 74 are driven by a zoom motor 71b, a focus motor 72b, an aperture motor 73b, and a mechanical shutter motor 74b, respectively.

  Each motor of the lens barrel unit 7 is driven by a motor driver 75, and the motor driver 75 is controlled by a CPU block 1043 of the processor 104.

  A subject image is formed on the CCD 101 by each lens system of the lens barrel unit 7. The CCD 101 converts the subject image into an image signal and outputs the image signal to an F / E (front end) -IC 102. The F / E-IC 102 includes a CDS 1021 that performs correlated double sampling for image noise removal, an AGC 1022 for gain adjustment, and an A / D conversion unit 1023 that performs analog-digital conversion. That is, the F / E-IC 102 performs predetermined processing on the image signal, converts the analog image signal into a digital signal, and outputs the digital signal to the first CCD signal processing block 1041 of the processor 104.

  These signal control processes are performed via the TG 1024 by a VD (vertical synchronization) -HD (horizontal synchronization) signal output from the first CCD signal processing block 1041 of the processor 104. The TG 1024 generates a drive timing signal based on the VD-HD signal. In the second CCD signal processing block 1042, conversion to luminance data / color difference data is performed by filtering processing.

  The CPU block 1043 of the processor 104 controls the sound recording operation by the sound recording circuit 1151. The voice recording circuit 1151 records an amplified signal of a voice recording signal converted by a microphone (hereinafter referred to as a microphone) 1153 by a microphone AMP (amplifier) 1152 according to a command. The CPU block 1043 also controls the operation of the audio reproduction circuit 1161. The audio reproduction circuit 1161 is configured to reproduce an audio signal recorded in the memory as appropriate according to an instruction, output the audio signal to the audio AMP 1162, and output audio from the speaker 1163.

  The CPU block 1043 further controls the strobe circuit 114 to emit illumination light from the strobe light emitting unit 3. In addition to this, the CPU block 1043 also controls the distance measuring unit 5.

  The CPU block 1043 is connected to the sub CPU 109 of the processor 104, and the sub CPU 109 performs display control of the sub LCD 1 for displaying the number of shootable images and the like via the LCD driver 111. The sub CPU 109 further includes an AF LED 8 that displays a focusing state at the time of shooting, a strobe LED 9 that indicates a strobe charging state, a remote control light receiving unit 6 that receives a signal from a remote control transmitter, and operation switches SW1 to SW14 that are operated by a user. The operation key unit is connected to the buzzer 113. Note that the AFLED 8 and the strobe LED 9 may be used for another display application such as when a memory card is being accessed.

  In order to communicate with an external device such as a personal computer, the USB block 1045 is connected to the USB connector 122, and the serial block 1046 is connected to the RS-232C connector 1232 via the serial driver circuit 1231. The TV signal display block 1049 is connected to the LCD monitor 1 ′ via the LCD driver 117, and is also connected to a video AMP (AMP (amplifier) for converting the video signal output from the TV signal display block 1049 into 75Ω impedance). ) 118 is connected to a video jack 119 (jack for connecting the camera to an external display device such as a TV) 119. The memory card controller block 10410 is connected to the card contact of the memory card slot 121.

  The LCD driver 117 serves to drive the LCD monitor 1 ′ and convert the video signal output from the TV signal display block 1049 into a signal to be displayed on the LCD monitor 1 ′. The LCD monitor 1 ′ is used to monitor the state of the subject before photographing, to check the photographed image, and to display image data recorded on the memory card or the built-in memory 120.

  FIG. 3 is a block diagram showing a main part of a digital camera as an image photographing apparatus in the embodiment of the present invention. Light received by the CCD 101 of the solid-state imaging device from the subject via the photographing lens is photoelectrically converted by the CCD 101 and sent to the F / E-IC 102. The F / E-IC 102 samples the output signal of the CCD 101 while removing noise components by correlated double sampling, sequentially A / D converts it into 10-bit data, and sends it to the DSP 104a in the processor 104.

  The DSP 104a performs processing such as interpolation, aperture enhancement, and white balance processing of the signal sent from the F / E-IC 102, and further converts it into a luminance signal Y and color difference signals Cb and Cr and temporarily stores them in the frame buffer of the SDRAM 103. Save to. This operation is repeated during monitoring, and data stored in the SDRAM 103 is sequentially read out to the video encoder of the TV signal display block 1049 in the DSP 104a and converted into a video signal, and then displayed on an external television receiver or the like. Output to the device.

  The CCD 101 is driven by a horizontal drive pulse output from the TG (timing generator) 1024 to the CCD 101, a vertical drive pulse output from the vertical driver (VDr) 1026 to the CCD 101, and an electronic shutter pulse. The CPU block 1043 as a control means controls the TG 1024, the F / E-IC 102, and the clock generator 20 by electronic shutter pulses. The TG 1024 outputs a vertical drive pulse of the CCD 101 to the vertical driver 1026 and sends a clock to the F / E-IC 102. Output.

  The source signal of the TG 1024 is a CCD driving pulse output from the clock generator 20, and this CCD driving pulse is frequency-divided by a frequency divider 1025 in the TG 1024 and sent to the DSP 104a. On the other hand, the DSP 104a has a built-in counter that counts the CCD driving pulses from the TG 1024. When the count of the counter reaches a predetermined count, a horizontal reset signal, a vertical reset signal, etc. are sent to the TG 1024. Is output.

  Here, the CCD driving pulse is output from the clock generator 20, and this is a circuit that divides the clock of the oscillation frequency of the CCD driving crystal oscillator 21 attached to the clock generator 20 inside the clock generator 20. This is because it can be built in relatively easily. Thus, by dividing the CCD driving pulse, it becomes possible to reduce the power consumption of monitoring.

  In the present embodiment, the source signal from the clock generator 20 (clock generated by the crystal oscillation circuit using the CCD driving crystal oscillator 21) and the clock obtained by dividing the source signal by two by the frequency divider 1025 are used for CCD driving. 1 and 2 are selectively output as the second clock. Of course, a plurality of frequency dividers that divide the clock generated by the crystal oscillation circuit using the CCD drive crystal oscillator 21 may be prepared. The slower the frame is (the lower the frequency is), the slower the monitoring frame update speed is. Therefore, a frequency divider that divides the clock by two is used in consideration of practicality.

  The remarkable effects of low power consumption obtained by actually dividing the CCD drive pulse are the low power consumption of the logic system inside the TG 1024 and the low power consumption of the horizontal and vertical drive output buffers of the CCD 101. This is power consumption and is proportional to the frequency division ratio of the frequency divider that divides the CCD driving pulse so that the power consumption is halved if the CCD driving pulse is divided by two. In addition, although not as effective as the above-described block (logic system, horizontal and vertical drive output buffers of the CCD 101), the power consumption of the F / E-IC 102 is also reduced.

  In the present embodiment, the monitoring frame update speed is arbitrarily set, and the CPU block 1043 controls the clock generator 20 to generate a clock (CCD driving pulse) from the clock generator 20 to the TG 1024. Change the frequency. For this reason, when the update speed of the monitoring frame is slow and the followability deteriorates, an arbitrary update speed of the monitoring frame can be determined.

  Reference numeral 25 denotes a triaxial acceleration sensor, which detects the movement of the digital camera accompanying the handling of the user such as photographing. Since this structure is known, its description is omitted.

  FIG. 4 is a diagram showing an example of a specific configuration of the DSP in the digital camera. As shown in FIG. 4, the DSP 104 a includes a color separation unit 41 that separates digital image data input from the A / D conversion unit 1023 (see FIG. 3) into R, G, and B color components; A signal interpolation unit 42 that interpolates each of the G, B image data, a pedestal adjustment unit 43 that adjusts the black level of each of the R, G, B image data, and a white level of each of the R, B image data. The white balance adjustment unit 44, the digital gain adjustment unit 45 that corrects the R, G, and B image data with the gain set by the CPU block 1043, and the γ that performs γ conversion of the R, G, and B image data Based on the conversion unit 46, the matrix unit 47 that separates RGB image data into color difference signals (Cb, Cr) and luminance signals (Y), and video based on the color difference signals (Cb, Cr) and luminance signals (Y). Create signal outside And a video signal processing unit 48 for outputting to a partial display device.

  Further, the DSP 104a passes only a predetermined frequency component of the luminance data (Y) detected by the Y calculation unit 49 and the Y calculation unit 49 that detects the luminance data (Y) of the image data after the pedestal adjustment by the pedestal adjustment unit 43. The BPF 50 to be performed, the AF evaluation value circuit 51 that outputs the integrated value of the luminance data (Y) that has passed through the BPF 50 to the CPU block 1043 as an AF evaluation value, and the digital corresponding to the luminance data (Y) detected by the Y calculation unit 49 An AE evaluation value circuit 52 that outputs the count value to the CPU block 1043 as an AE evaluation value, and a Y calculation unit that detects luminance data (Y) of each of the R, G, and B image data after adjustment by the white balance adjustment unit 44 53 and the luminance data (Y) of each color detected by the Y calculation unit 53 are counted, and the CPU block is used as the AWB evaluation value for each color. And AWB evaluation value circuit 54 to be output to the click 1043, and a DCTI / F 56 or the like as an interface to the CPU I / F55, and DCT is an interface between the CPU block 1043.

  The case where the in-focus position is detected using the CCD 101 is called CCD-AF (internal AF). In the CCD-AF, the focus lens system is moved, the AF evaluation value indicating the contrast of the subject corresponding to the image signal output from the CCD 101 is sampled, and the hill-climbing servo system with the AF evaluation value peak position as the in-focus position Is used.

  FIG. 5 is a flowchart showing an outline of the operation of the digital camera of this embodiment. When the digital camera is activated by turning on the power, the shooting mode is confirmed as a mode set by the mode dial switch SW2 or the like shown in FIG. 1 (S1). When the photographing mode is set in this process S1 (Yes in process S1), a monitoring process for displaying a subject image on the LCD monitor 1 'is started (S2). Thereafter, whether or not there is any further mode setting change is confirmed (S3). If there is a mode change (Yes in process S3), the process returns to process S1, and if there is no mode change (No in process S3), the process proceeds to the shooting process ( S4). After the photographing process is completed, the process proceeds to the monitoring process of process S2.

  Further, in the process S1, when the shooting mode is not set (No in S1), the reproduction process of the imaged image data stored in the information recording medium or the like is performed (S5). Further, whether or not the mode setting has been changed is confirmed (S6). If there is no change in the mode setting (No in step S6), the process returns to step S5 to perform the reproduction process. If there is a mode setting change in process S6 (Yes in process S6), the process returns to process S1 to change the setting mode. FIG. 6 is a diagram showing a display example of the on-screen display.

  FIG. 7 is a flowchart showing the monitoring operation of the digital camera in Embodiment 1 of the present invention. The operation of the first embodiment will be described based on FIG. 7 with reference to FIG. An initial value for monitoring is set in the clock generator 20 (S11). Based on this setting, monitoring display processing is executed (S12). The presence or absence of a specific condition related to the control of the digital camera is confirmed (S13), and if the specific condition is not met (No in process S13), a high clock is set in the clock generator 20 to improve the tracking of movement. (S14).

  Further, in the process S13, when a specific condition is met (Yes in the process S13), a low clock with a not very good tracking ability is selected and set in the clock generator 20 (S15). Thereafter, the monitoring process is repeated from the process S12.

  Further, as a specific condition, when a predetermined on-screen display is displayed among the on-screen displays displayed on the monitoring screen, the process S15 is set, but the predetermined on-screen display is set. When the display on the display is turned off, the clock generator 20 is set to a high clock in the process S14.

  As a specific condition, if the elapsed time for which the predetermined on-screen display is displayed is within the predetermined time, it is extracted how much time has elapsed since the predetermined on-screen display was displayed. If the extracted time is smaller than the predetermined time, the process S15 is performed. If the extracted time is larger than the predetermined time, the process S14 is performed. Thereafter, the monitoring process is repeated from the process S12.

  As a specific condition, when the elapsed time since the last predetermined operation performed by the user is smaller than the predetermined time, the time elapsed since the user performed the specific operation is extracted and a predetermined threshold value is extracted. If it is smaller, the process S15 is performed. If it is larger than the predetermined threshold, the process S14 is performed. Thereafter, the monitoring process is repeated from the process S12.

  As a specific condition, when the self-timer countdown process is being performed, the process S15 is performed when the self-timer countdown process is confirmed, and when the self-timer countdown process is not being performed, the process S14 is performed. Thereafter, the monitoring process is repeated from the process S12.

  As a specific condition, when it is in a state where the photographing process can be performed remotely, a process S15 is performed when the state where the photographing process can be performed remotely is confirmed, and a process S14 is performed when the photographing process is not possible from a remote place. Thereafter, the monitoring process is repeated from the process S12.

  As a specific condition, when the power of the display means for displaying image data is turned on / off, the process S15 is performed when the power of the display means is on, and the process S14 is performed when the power of the display means is off. Thereafter, the monitoring process is repeated from the process S12.

  Further, as shown in FIG. 3, when an acceleration sensor 25 or the like is provided as a sensor for detecting a movement associated with the handling of the digital camera, a specific condition is that the detected value of the sensor is larger than a predetermined threshold value. .

  For example, when considering a three-axis acceleration sensor 25 as this sensor, the detected accelerations x, y, and z are data in different acceleration directions. Here, x⊥y, y⊥z, and z⊥x are the three axes. However, it is not limited to three axes. The x axis is matched with the horizontal direction of the display means, the y axis is matched with the vertical direction of the display means, and the z axis is matched with the perspective direction of the display means. Further, the threshold value of acceleration z is Tx, the threshold value of acceleration y is Ty, the threshold value of acceleration z is Tz, and each threshold value is Tx> Ty> Tz.

  FIG. 8 is a flowchart showing processing for obtaining a predetermined condition using a triaxial acceleration sensor. As shown in the flowchart of FIG. 8, it is determined whether or not a specific condition is met by comparing each of the accelerations x, y, and z with a predetermined threshold value.

  In the flowchart shown in FIG. 7, when the specific condition is greater than a predetermined threshold value, the process S15 is performed. When the specific condition is smaller than the predetermined threshold value, the process S14 is performed. Thereafter, the monitoring process is repeated from the process S12.

  In addition, although the acceleration sensor which extracts a speed or an acceleration was demonstrated to the example as a sensor, it is not limited to this, What is necessary is just to be able to extract a speed or an acceleration.

  With the above configuration, when it is assumed that the user does not pay attention to the monitoring image, the frame rate can be automatically lowered to reduce the power consumption.

  FIG. 9 is a flowchart showing the monitoring operation of the digital camera according to Embodiment 2 of the present invention. The operation of the second embodiment will be described based on FIG. 9 with reference to FIG. Here, since the flowchart of FIG. 9 is substantially the same as the flowchart of FIG. 7 described in the first embodiment, the same reference numerals are given to those performing the same processing.

  The difference between the flowcharts of FIG. 9 and FIG. 7 is that, in the process S13 for confirming the presence or absence of a specific condition, if the specific condition is not met (No in the process S13), whether or not the display image being monitored is changed. Confirmation is made (S17), and if the display image does not change (No in process S17), the process proceeds to process S15. If the display image is changed in the process S17 (Yes in the process S17), the process proceeds to the process S14. Thereafter, the monitoring process is repeated from the process S12.

  In addition, as a method for determining an image having no change and no motion determined in the process S17, the output of the AE evaluation value circuit 52 extracted in the previous monitoring process and the output of the AE evaluation value circuit 52 extracted in the current monitoring process are used. In comparison, if the evaluation value exceeds a certain level, it is assumed that the image has changed.

  Alternatively, the output of the AWB evaluation value circuit 54 extracted in the previous monitoring process is compared with the output of the AWB evaluation value circuit 54 extracted in the current monitoring process, and if the evaluation value exceeds a certain level, the image is changed.

  Alternatively, the output of the AF evaluation value circuit 51 extracted in the previous monitoring process is compared with the output of the AF evaluation value circuit 51 extracted in the current monitoring process. If the evaluation value exceeds a certain level, it is determined that the image has changed. .

  Alternatively, by combining the above three processes, when each evaluation value exceeds a certain level, it is assumed that there is a change in the image.

  In the second embodiment, each process performed based on specific conditions is the same as that in the first embodiment, and a description thereof will be omitted.

  As in the first embodiment, when it is assumed that the user does not pay attention to the monitoring image, the frame rate can be automatically lowered to reduce the power consumption.

  FIG. 10 is a flowchart showing the operation of the digital camera according to Embodiment 3 of the present invention. In the photographing process S4 in the flowchart describing the operation of the digital camera shown in FIG. 5 described above, the digital camera has a function of displaying a confirmation image for confirming image data taken immediately after photographing.

  Here, the LCD monitor of the display means for displaying the confirmation image will be described in detail. The LCD monitor is composed of a liquid crystal panel and a backlight, and there are two methods for making the LCD monitor appear bright. As a first method, the backlight is brightened to change the luminance. Extra power is consumed for changing the brightness of the backlight. As a second method, there is a method of increasing the brightness by changing the driving power of the liquid crystal panel. In this case, since the brightness of the backlight may be constant, it can be brightened with the power consumption almost constant, but the image becomes whitish and the image quality deteriorates.

  The third embodiment will be described based on the flowchart shown in FIG. As shown in FIG. 10, (S2) mode change is confirmed from the state of the monitoring process (S3), and when there is no change (No in process S3), the photographing process is performed. Here, shooting is performed by pressing the shutter button (S31). At this time, it is confirmed whether or not the confirmation image display function of the digital camera is set (S32). If the confirmation image display is set (Yes in step S32), the image data captured immediately after the capturing is captured. Is displayed for a certain period of time, and automatically returns to the monitoring process state without any operation by the user (S33). The image displayed at this time is called a shooting confirmation image.

  Since the first impression of humans has a residual effect, power is consumed but displayed in high quality only when this shooting confirmation image is displayed. In this way, by performing image quality fluctuations in accordance with human memory characteristics, a low power consumption effect can be obtained while maintaining image quality.

  FIG. 11 is a flowchart showing the operation of another digital camera according to the third embodiment. As shown in FIG. 11, (S2) mode change is confirmed from the state of the monitoring process (S3), and when there is no change (No in process S3), the photographing process is performed. Here, when the quick view button (left shift / image confirmation switch SW11 shown in FIG. 1) is pressed (S35), the presence or absence of image data captured immediately before is confirmed (S36), and a confirmation image is recorded. In the case (Yes in process S36), a confirmation image is displayed (S37).

  When the same quick view button is pressed again, the monitoring process is resumed (S38). In the process S36, when the image data captured immediately before is not recorded (No in the process S36), a warning sound is emitted (S39), and the process returns to the monitoring process. A recording confirmation image that can be confirmed by this operation is called a quick view.

  As described above, since the first impression of a human has a residual effect, when a recording confirmation image for confirming image data recorded immediately after shooting by the user is displayed, power is consumed but the display is performed with high quality. In this way, by performing image quality fluctuations in accordance with human memory characteristics, a low power consumption effect can be obtained while maintaining image quality.

  In addition, when the playback mode is selected by the mode dial switch SW2 shown in FIG. 1, it is possible to perform playback by reading out all the image data shot by the digital camera and recorded on the information recording medium. An image displayed on the display means in this mode is called a reproduced image.

  As described above, the reproduced image is used for confirming the contents when the captured image data is processed. Therefore, there is no problem even if the image display provides the power consumption effect.

  The image capturing device and the display method of the image capturing device according to the present invention automatically reduce the frame rate to reduce power consumption and reduce the image quality fluctuation when it is assumed that attention is not paid to the monitoring image. By performing according to human memory characteristics, it is possible to reduce power consumption while maintaining image quality, and it is useful as an apparatus for photographing a subject such as a digital still camera.

1A is a top view, FIG. 1B is a front view, and FIG. 1C is a rear view showing the appearance of a digital camera in an embodiment of the present invention. Block circuit diagram showing the outline of the system configuration inside the digital camera Block diagram showing the main parts of a digital camera The figure which shows an example of the concrete structure of DSP in a digital camera Flow chart showing the outline of the operation of the digital camera Diagram showing an example of on-screen display The flowchart which shows the monitoring operation | movement of the digital camera in Embodiment 1 of this invention. A flowchart showing processing for obtaining a predetermined condition using a triaxial acceleration sensor The flowchart which shows the monitoring operation | movement of the digital camera in Embodiment 2 of this invention. The flowchart which shows operation | movement of the digital camera in Embodiment 3 of this invention. The flowchart which shows the operation | movement of another digital camera in this Embodiment 3.

Explanation of symbols

1 'LCD monitor 20 clock generator 25 acceleration sensor 51 AF evaluation value circuit 52 AE evaluation value circuit 54 AWB evaluation value circuit 101 CCD
103 SDRAM
104a DSP
1024 TG
1025 frequency divider 1043 CPU block

Claims (28)

An image photographing apparatus comprising: an imaging unit that converts an optical image representing a subject into an electrical signal; and an information recording medium that records image data representing the electrical signal,
Display control means for performing processing for displaying the image data converted into an electrical signal by the imaging means on the display means, extraction means for extracting a specific condition related to control of the image photographing apparatus, and the extracted An image photographing apparatus comprising: a changing unit that changes a cycle of converting the imaging unit into an electric signal according to a condition.   The image capturing apparatus according to claim 1, wherein the specific condition is display of an on-screen display according to a predetermined control among on-screen displays displayed on the display unit.   The said specific condition is within the time which becomes a threshold value, after the display of the on-screen display which concerns on predetermined | prescribed control among the on-screen displays displayed on a display means is made. Image shooting device.   The image capturing apparatus according to claim 1, wherein the specific condition is within a predetermined time after a predetermined operation last performed by the user.   The image capturing apparatus according to claim 1, wherein the specific condition is a countdown process of a self-timer.   2. The image photographing apparatus according to claim 1, wherein the specific condition is a state in which photographing processing can be performed remotely.   2. The image photographing apparatus according to claim 1, wherein the specific condition is power on / off of a display means for displaying image data.   The image capturing apparatus according to claim 1, further comprising a sensor that detects a movement associated with the handling of the image capturing apparatus, wherein the specific condition is that a detection value of the sensor is larger than a predetermined threshold value.   The image capturing apparatus according to claim 8, wherein the sensor detects speed or acceleration.   The image capturing apparatus according to claim 8, wherein the sensor detects an angular velocity or an angular acceleration. An image photographing apparatus comprising: an imaging unit that converts an optical image representing a subject into an electrical signal; and an information recording medium that records image data representing the electrical signal,
Display control means for performing processing for displaying the image data converted into an electrical signal by the imaging means on the display means, extraction means for extracting a specific condition related to control of the image photographing apparatus, and the extracted An image photographing apparatus comprising: a changing unit that changes a luminance of a display unit that displays the image data according to a condition. An image photographing apparatus comprising: an imaging unit that converts an optical image representing a subject into an electrical signal; and an information recording medium that records image data representing the electrical signal,
Display control means for performing processing for displaying the image data converted into an electrical signal by the imaging means on the display means, extraction means for extracting a specific condition related to control of the image photographing apparatus, and the extracted An image photographing apparatus comprising: changing means for changing drive power of a display means for displaying the image data according to a condition.   14. The image photographing apparatus according to claim 12, wherein the specific condition is display of a photographing confirmation image in which the photographed image data is displayed only for a predetermined time immediately after photographing.   14. The image photographing apparatus according to claim 12, wherein the specific condition is display of a recording confirmation image read from an information recording medium in which photographed image data is recorded immediately after photographing. A display method of an image capturing apparatus that converts an optical image representing a subject into an electrical signal by an imaging means and records image data representing the electrical signal on an information recording medium,
Performing a process for displaying on the display means the image data converted into an electrical signal by the imaging means, extracting a specific condition relating to the control of the image capturing apparatus, and according to the extracted condition And a step of changing a cycle in which the imaging means converts to an electrical signal.   16. The display method of an image capturing apparatus according to claim 15, wherein the specific condition is display of an on-screen display according to a predetermined control among on-screen displays displayed on the display unit.   16. The specific condition according to claim 15, wherein the specific condition is within a threshold time after the on-screen display related to the predetermined control is displayed among the on-screen displays displayed on the display means. Display method of image capturing apparatus.   16. The display method for an image capturing apparatus according to claim 15, wherein the specific condition is within a predetermined time after a predetermined operation last performed by the user.   The display method of the image capturing apparatus according to claim 15, wherein the specific condition is a countdown process of a self-timer.   16. The display method for an image photographing apparatus according to claim 15, wherein the specific condition is a state in which photographing processing can be performed remotely.   16. The display method of an image capturing apparatus according to claim 15, wherein the specific condition is power on / off of display means for displaying image data.   16. The display method for an image photographing device according to claim 15, further comprising a sensor for detecting a movement accompanying handling of the image photographing device, wherein the specific condition is that a detection value of the sensor is larger than a predetermined threshold value.   The display method of the image capturing apparatus according to claim 22, wherein the sensor detects speed or acceleration.   The display method of the image photographing apparatus according to claim 22, wherein the sensor detects angular velocity or angular acceleration. A display method of an image capturing apparatus that converts an optical image representing a subject into an electrical signal by an imaging means and records image data representing the electrical signal on an information recording medium,
Performing a process for displaying on the display means the image data converted into an electrical signal by the imaging means, extracting a specific condition relating to the control of the image capturing apparatus, and according to the extracted condition And a step of changing luminance of display means for displaying image data. A display method of an image capturing apparatus that converts an optical image representing a subject into an electrical signal by an imaging means and records image data representing the electrical signal on an information recording medium,
Performing a process for displaying on the display means the image data converted into an electrical signal by the imaging means, extracting a specific condition relating to the control of the image capturing apparatus, and according to the extracted condition And a step of changing the drive power of the display means for displaying the image data.   27. The display method of an image photographing apparatus according to claim 25 or 26, wherein the specific condition is display of a photographing confirmation image in which the photographed image data is displayed for a predetermined time immediately after photographing.   27. The display method of an image capturing apparatus according to claim 25 or 26, wherein the specific condition is display of a recording confirmation image read from an information recording medium in which captured image data is recorded immediately after capturing.

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