JP2006332954A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus which performs an efficient countermeasure for energy saving, and can display an image which maintains high quality without causing the deterioration of image quality in the imaging apparatus which has an LCD display device with back light illumination. <P>SOLUTION: The imaging apparatus is provided with a display means which has an image display unit to display an image signal, and a back light illuminator to illuminate the image display unit; a brightness control means which controls the brightness of the back light illuminator; a color property detection means which detects a color property of illumination irradiating a photographing object; and a timing means measuring a time. The brightness control means controls the brightness of the back light illuminator based on the detection result of the color property detection means when there is no operation input in a predetermined time measured by the timing means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an imaging device, and more particularly to an imaging device having an LCD display device with backlight illumination.

  In recent years, as imaging devices such as electronic cameras and digital video cameras have improved in performance, display devices represented by LCD (Liquid Crystal Display) used for visual recognition of captured standby images and reproduced images are also backlights. Large-sized ones with lighting have been adopted, and high-resolution and high-definition image display can be performed. In particular, recently, there is a need to perform operations such as image viewing and focus adjustment on a display device in the same way as an optical finder, so a high pixel graphic such as VGA or SVGA (Super Video Graphics Array: 800 × 600 pixels). Subsystems are expected to be used for display devices.

  Usually, an LCD display device is composed of an LCD panel and a backlight light source that provides illumination light from the back of the LCD panel. The LCD panel is a matrix of micro liquid crystal cells that can vary the transmission density for each pixel together with a micro color filter. In this configuration, the transmission density of the liquid crystal cell is controlled in accordance with an image signal, and a color image can be displayed by irradiating a backlight from the back side.

  By the way, since this type of large LCD display device consumes a large amount of power for backlight illumination, there is a concern about battery consumption. That is, the increase in power consumption due to the increase in the size of the backlight illumination device of the LCD display device has a great influence on the number of shots, and energy saving measures are required. Various imaging devices that consider energy saving measures have been studied.

For example, as a typical conventional technique, when the camera is not operated for a predetermined time, a well-known technique for reducing battery consumption to save energy by dimming the backlight illumination, A technology is disclosed that adjusts the brightness of the backlight illumination accordingly, that is, when the subject image is dark during metering, it is judged that the ambient brightness is also dark, and the backlight illumination is darkened to save energy (For example, refer to Patent Document 1). As described above, various techniques for an image pickup apparatus in which energy saving measures have been taken by reducing the power consumption of the backlight in accordance with the operation state of the camera and the use environment have been studied.
JP-A-8-242398 (see paragraph 0008, etc.)

  By the way, this type of LCD display device has a smaller amount of normal light emission and lower luminance than a conventional CRT (Cathode Ray Tube) display device, so that the visibility of the image is large due to the brightness of the surrounding use environment. It depends on you. In other words, it is possible to view images when used in a relatively dark environment such as indoors, but when used in a bright environment such as outdoors, the contrast decreases. It becomes difficult to view the image.

  The above-mentioned well-known technology is designed to save energy by suppressing battery consumption by dimming the backlight illumination regardless of the surrounding brightness when the camera is not operated for a predetermined time. As described above, when used in an environment where the surroundings are bright, such as outdoors, the backlight illumination becomes dark, so that the contrast is lowered and it is difficult to visually recognize the image. In addition, the technique disclosed in the above-mentioned Patent Document 1 determines that the surrounding brightness is dark when the subject image is dark at the time of photometry, and takes energy saving measures by darkening the backlight illumination. In the same way, when used in a relatively dark environment such as indoors, it is possible to visually recognize an image even if the backlight illumination is darkened. However, dimming the backlight illumination greatly reduces the image quality. In particular, a character display on a GUI (Graphical User Interface) screen that displays a menu screen or various statuses is an image with reduced sharpness and reduced visibility. Furthermore, the ambient brightness is replaced with the brightness of the subject image, and the brightness of the backlight illumination is adjusted based on the brightness of the subject image. The surrounding brightness may vary greatly. For example, in outdoor shooting, when the subject is backlit, the subject is covered with shadows and darkens, but the LCD display device of the camera may be illuminated brightly by external light. Under such circumstances, the backlight image is darkened due to the dark subject image, but the LCD display illuminated brightly by the external light becomes more difficult to see. That is, there is a concern about the accuracy of determination with respect to the brightness around the camera.

  The present invention has been made in view of the above problems, and in an imaging apparatus having an LCD display device with backlight illumination, if there is no operation input for a predetermined time, the surroundings are not degraded without causing a decrease in image quality. An imaging device that can efficiently save energy by adjusting the brightness of the backlight illumination according to the brightness of the image, and can display images with high quality even when energy saving measures are taken The purpose is to provide.

  The object is achieved by the invention according to any one of claims 1 to 3.

(Claim 1)
Display means comprising: an image display unit for displaying an image signal; and a backlight illumination unit for illuminating the image display unit;
Brightness control means for controlling the brightness of the backlight illumination section;
Color characteristic detection means for detecting the color characteristic of illumination for illuminating the subject;
A time measuring means for measuring time,
The brightness control means includes
When there is no operation input within a predetermined time counted by the timing means,
An image pickup apparatus that controls brightness of the backlight illumination unit based on a detection result of the color characteristic detection means.

(Claim 2)
Image correction means for correcting the contrast, color, or size of the image displayed on the image display unit;
The image correcting means includes
The contrast, color, or size of an image displayed on the image display unit is corrected based on a brightness control result of the backlight illumination unit performed by the brightness control unit. Item 2. The imaging device according to Item 1.

(Claim 3)
The image correcting means includes
When the brightness control means darkens the brightness of the backlight illumination unit,
The imaging apparatus according to claim 2, wherein the contrast of an image displayed on the image display unit is increased, the color of a displayed character is changed, or the size of the character is enlarged. .

  According to the first aspect of the present invention, the color characteristic detecting means detects the color characteristic of the illumination that irradiates the subject. Accordingly, it is possible to determine whether the environment where the imaging device is placed is outdoors under sunlight or indoors such as under a fluorescent lamp or an electric lamp. That is, it is possible to determine with high accuracy whether the imaging device is used outdoors or in a dark room. In addition, the brightness control unit is configured to display a backlight when the color characteristic detection unit determines that the imaging device is used indoors when there is no operation input within a predetermined time counted by the timing unit. Since the illumination of the battery is made dark, it is possible to suppress battery consumption. On the other hand, when it is determined by the color characteristic detection means that the imaging device is being used outdoors, the backlight illumination is kept bright so that the display image can be sufficiently visually recognized. It becomes like. In this way, the brightness of the surroundings is determined with high accuracy, and the brightness of the backlight illumination is adjusted based on the determined results. Therefore, efficient energy saving is achieved without impairing the visibility of the displayed image. It will be possible to take measures.

  According to the second aspect of the present invention, the image correction means appropriately corrects the contrast, color, or size of the display image when the brightness of the backlight illumination is changed by the brightness control means. By doing so, even when energy saving measures are taken, it becomes possible to display without reducing the visibility.

  According to the third aspect of the present invention, when the backlight illumination is dark, the image quality is deteriorated. Particularly in the character display on the GUI screen such as the menu screen and various status displays, the image quality is sharp. However, the image correction means increases the contrast of the displayed image, and the character color is changed to a conspicuous color in character display, etc. By increasing the size, it is possible to display a high-quality image without reducing visibility.

  As a specific embodiment of the imaging apparatus according to the present invention, a digital camera is typical, but a mobile phone with a camera, a digital video camera, and the like are also included.

  The appearance of a digital camera that is one of the representative embodiments of the imaging apparatus according to the present invention will be described with reference to FIG. 1A is a side view of the digital camera 1 according to the present invention, and FIG. 1B is a rear view. As shown in FIG. 1A, the digital camera 1 includes a camera body 2 and a lens unit 3.

  The lens unit 3 includes a photographing lens having a macro zoom (not shown), a diaphragm, a shutter, and the like.

  The camera body 2 includes an LCD monitor 211 formed of an LCD (Liquid Crystal Display), an EVF (Electronic View Finder) 210, and external connection terminals for connecting the digital camera 1 to a personal computer (not shown). The image signal captured by the CCD area sensor 241 described later is subjected to predetermined signal processing, image display on the LCD monitor 211 and EVF 210, and image recording on a recording medium such as a memory card 277 described later, Alternatively, processing such as image transfer to a personal computer is performed.

  As shown in FIG. 1A, a built-in flash 212 that is hopped up when necessary is provided on the upper surface of the camera body 2. A colorimetric sensor 213 that measures color characteristics of external light is provided below the built-in flash 212. Based on the data obtained by the colorimetric sensor 213, white balance adjustment and brightness adjustment of the backlight illumination unit 284 described later are performed.

  Further, as shown in FIG. 1B, an LCD for displaying a photographed image, reproducing a recorded image, or displaying a GUI such as a menu screen or various statuses is displayed at a substantially central portion on the back of the camera body 2. A monitor 211 and an EVF 210 are provided. The LCD monitor 211 includes an image display unit 283 (to be described later) and a backlight illumination unit 274 that illuminates the image display unit and displays an image signal captured by the CCD area sensor 241 and GUI display.

  As shown in FIG. 1B, a shutter setting button 203 for setting the operation mode of the digital camera 1 is provided near the shutter button 201 on the upper surface of the camera body 2. . The operation mode of the digital camera 1 set by the mode setting dial 203 includes “still image shooting mode”, “moving image shooting mode”, “playback mode”, and the like.

  For example, the still image shooting mode is a mode for taking a picture from the standby state to the shooting through the exposure control process, and the playback mode is for playing back the shot image recorded on the memory card 277 on the LCD monitor 211 or the EVF 210. This is the display mode.

  Further, as shown in FIG. 1B, an electronic zoom button 209 for setting the zoom magnification of the electronic zoom is provided near the main switch 202 and the main switch 202 as shown in FIG. Is provided.

  Further, as shown in FIG. 1B, a menu button 207 for displaying a menu on the LCD monitor 211 and an image on the LCD monitor 211 near the menu button 207 are displayed at the lower back of the camera body 2. Is provided with a quick view button 208.

  Further, a selection / determination button 206 for performing various settings is provided at a substantially central portion on the back surface of the camera body 2. The selection / determination button 206 includes a jog dial (cross key) 204 for selecting various settings and a determination button 205 for confirming the setting selected by the jog dial (cross key) 204.

  Next, the control system of the digital camera 1 will be described with reference to FIG. FIG. 2 is a block diagram of a control system of the digital camera 1 according to the present invention. In FIG. 2, the same members as those shown in FIG.

  The CCD area sensor 241 (hereinafter abbreviated as CCD 241) arranges each color transmission filter of R (red) light, G (green) light, and B (blue) light in a checkered pattern in pixel units (pixel units). The object light image formed by the lens unit 3 with the color area imaging sensor is received as an image signal of each color component of R (red) light, G (green) light, and B (blue) light (each pixel unit). Photoelectric conversion into a signal composed of a signal string of pixel signals).

  The timing generator 246 generates a drive control signal for the CCD 241 based on a reference clock transmitted from a reference clock generator 271 described later. The drive control signal generated by the timing generator 246 includes, for example, an integration start / end timing signal for controlling the exposure start and end timings in the CCD 241, and a readout control signal (horizontal synchronization signal, vertical synchronization) of the light reception signal of each pixel. Clock signals such as signals, transfer signals, and the like. When these clock signals are supplied to the CCD 241, the CCD 241 performs drive control corresponding to each clock signal.

  The signal processing circuit 242 includes a CDS circuit 243 and an AGC circuit 244, and a predetermined process is performed on the image signal via these components. Hereinafter, a predetermined process for the image signal performed by the signal processing circuit 242 will be described.

  A CDS (Correlated Double Sampling) circuit 243 reduces noise generated at the time of reading from the image signal read from the CCD 241 and corrects dark noise by OB clamping operation.

  An AGC (automatic gain control) circuit 244 adjusts the gain of the image signal processed by the CDS circuit 243.

  The A / D converter 245 converts each pixel signal constituting the image signal input from the AGC circuit 244 into a digital signal. The A / D converter 245 converts each pixel signal of an analog signal into, for example, a 14-bit digital signal based on the A / D conversion clock input from the reference clock generation unit 271.

  In this manner, the image signal read by the CCD 241 is subjected to predetermined processing by the signal processing circuit 242 and the A / D converter 245, and is converted into a digital image signal. The digitized image signal is captured by the image processing CPU 261 and subjected to predetermined processing.

  The image processing CPU 261 is composed of a microcomputer, and comprehensively controls image signal processing operations performed by the digital camera 1. In the following, processing for a digital image signal performed by the image processing CPU 261 will be described.

  First, the image signal captured by the image processing CPU 261 is written into the image memory 275 in synchronization with the reading of the image signal output from the CCD 241. That is, the digital image signal used for the processing performed by the image processing CPU 261 is once recorded in the image memory 275, taken out from the image memory 275, and used for processing in each block.

  As shown in FIG. 2, the image processing CPU 261 includes, for example, a black level correction unit 263, a pixel interpolation unit 264, a resolution conversion unit 265, a white balance control unit 266, a gamma correction unit 267, a matrix calculation unit 268, a shading correction unit 269, The image processing unit 262 includes an image compression unit 270 and the like, and a reference clock generation unit 271, and the image processing unit 262 performs known image signal processing on the digital image signal extracted from the image memory 275. Then, the digital image signal that has been subjected to the predetermined processing in these parts is stored in the image memory 275 again.

  The reference clock generation unit 271 is a circuit that generates a reference clock used for driving control of the digital camera 1 and supplies the reference clock to each circuit. Specific examples of the reference clock in the present invention include a reference clock used for the timing generator 246, an A / D conversion clock used for the A / D converter 245, and the like. Generate a clock.

  Next, the LCD monitor 211 includes an image display unit 283 and a backlight illumination unit 284 that displays the image signal captured by the CCD 241 and performs GUI display, and illuminates the image display unit 283.

  In the contrast of the image displayed on the image display unit 283, and in the GUI display, the color, size, etc. of the characters are adjusted by an LCD drive circuit 279 described later.

  Moreover, the light source which comprises the backlight illumination part 284 consists of LED which is not illustrated, for example, and the brightness of the backlight illumination part 284 is adjusted by changing the electric current value applied to LED. The current applied to the LED is generated by a backlight drive circuit 285 described later. As described above, the LCD monitor 211 functions as a display unit in the imaging apparatus according to the present invention.

  The LCD drive circuit 279 includes a buffer memory (VRAM) that temporarily stores an image signal read from the image memory 275 by the image processing CPU 261, and displays the image signal on the LCD monitor 211 as a field image. The LCD driver 279 includes a gamma conversion unit 280, a size conversion unit 281 and a color conversion unit 282. The gamma conversion unit 280 adjusts the gradation characteristics of the image displayed on the image display unit 283 in the LCD monitor 211 to correct the contrast. The size conversion unit 281 and the color conversion unit 282 convert the size and color of characters on the GUI screen displayed on the image display unit 283. Operations performed by the gamma conversion unit 280, the size conversion unit 281 and the color conversion unit 282 are controlled by a camera control CPU 291 described later.

  Specifically, when the brightness of the backlight illumination unit 284 is dark, the image quality displayed on the image display unit 283 is deteriorated. In particular, in the character display on the GUI screen, the sharpness is impaired and the visibility is reduced. Reduced image. In such a case, the gamma conversion unit 280, the size conversion unit 281 and the color conversion unit 282 increase the contrast of the image under the control of the camera control CPU 291, and the character color is conspicuous when displaying characters. By changing the color to an easy color or increasing the size of the characters, the visibility is prevented from being lowered.

  The backlight drive circuit 285 generates a current that flows to the LED of the backlight illumination unit 284 in the LCD monitor 211, and the backlight drive circuit 285 flows to the LED under the control of a camera control CPU 291 described later. The current is adjusted.

  For the colorimetric sensor 213, R (red) light, G (green) light, and B (blue) light transmission filters are arranged in units of sensors in a plurality of light receiving sensors made of, for example, SPD (Silicon Photo Diode). A colorimetric sensor that illuminates a subject, photoelectrically converts illumination light that illuminates the subject into electrical signals of each color component of R (red) light, G (green) light, and B (blue) light, and the converted electrical signal is a camera described later. It transmits to control CPU291.

  The camera control CPU 291 is composed of a microcomputer, and based on switch signals generated by switch operations of a switch group 295 described later, the camera body CPU 2 and the lens unit 3 are sequentially controlled to drive the digital camera 1. Centrally control the operation.

  The program built in the camera control CPU 291 is provided with a time measuring unit that measures the time corresponding to the time measuring means in the present invention.

  In addition, the camera control CPU 291 determines the brightness of the backlight illumination unit 284 based on data sent from the colorimetric sensor 295 when there is no operation input by the switch group 295 within a predetermined time counted by the timing unit. It adjusts the height and controls the operations of the gamma conversion unit 280, size conversion unit 281 and color conversion unit 282 in the LCD drive circuit 279.

  Specifically, the camera control CPU 291 sends the intensity of each color component of illumination light R (red) light, G (green) light, and B (blue) light that is sent from the colorimetric sensor 213 and illuminates the subject. That is, it is determined whether the illumination light is sunlight, a fluorescent lamp, an electric lamp, or the like based on an electrical signal representing the spectral characteristics of the illumination light. That is, it is determined whether the environment in which the digital camera 1 is placed is outdoors under bright sunlight or indoors such as under a dark fluorescent light or electric light.

  Next, when it is determined that the use environment of the digital camera 1 is indoor, the camera control CPU 291 reduces the current that flows to the LED of the backlight illumination unit 284 generated by the backlight drive circuit 285 to reduce the backlight illumination unit 284. Decrease the brightness.

  Further, when the use environment of the digital camera 1 is determined to be indoors, the camera control CPU 291 controls the operations of the gamma conversion unit 280, the size conversion unit 281 and the color conversion unit 282 in the LCD drive circuit 279, and the image display unit The contrast of the image displayed by H.283 is increased, and in character display or the like, the size of the character is increased or the color of the character is changed to a conspicuous color.

  As described above, the colorimetric sensor 213 and the camera control CPU 291 are used as color characteristic detection means in the imaging apparatus according to the present invention, and the backlight drive circuit 285 and the camera control CPU 291 are brightness control means in the imaging apparatus according to the present invention. Further, the LCD drive circuit 279 and the camera control CPU 291 function as image correction means in the image pickup apparatus according to the present invention. Details of the brightness control of the backlight illumination unit 284 and the image correction of the LCD drive circuit 279 performed by the camera control CPU 291 will be described later.

  As described above, in the digital camera 1, the image processing CPU 261 performs the signal processing as described above on the image signal captured from the CCD 241, and records the image signal subjected to these processing in the image memory 275. .

  The digital camera 1 according to the present invention records the image signal captured from the CCD 241 under the mode set by the mode setting dial 203 in the image memory 275 or displays it on the LCD monitor 211 or EVF 210.

  In the shooting standby state (for example, the state set to “still image shooting mode” by the mode setting dial 203), the image signal is sent from the CCD 241 to the signal processing circuit 242 and the A / D converter at a predetermined interval such as every 1/30 seconds. The image processing CPU 261 is loaded via H.245. As described above, the captured image signal is subjected to predetermined signal processing at a portion from the black level correction unit 263 to the shading correction unit 269 of the image processing unit 262 in the image processing CPU 261, and then as a digital image signal. It is recorded in the image memory 275. The image signal recorded in the image memory 275 is read, and the read image signal is displayed on the LCD monitor 211 or EVF 210 as a field image via the LCD drive circuit 279 or the EVF drive circuit 286.

  Further, at the time of image recording, the image signal is compressed by the image compression unit 270 of the image processing unit 262 in the image processing CPU 261 to obtain an image of the set recording resolution, and the obtained compressed image is a memory card driver 276. To the memory card 277.

In the reproduction mode (the state in which “reproduction mode” is set by the mode setting dial 203), the image signal read from the memory card 277 is subjected to predetermined signal processing by the image processing CPU 261, and is driven by the LCD drive circuit 279 or EVF drive. 2 is displayed on the LCD monitor 211 and the EVF 210 via the circuit 286. The switch group 295 in FIG. 2 includes the shutter button 201, the main switch 202, the mode setting dial 203, the selection / decision button 206, the menu button 207, Switches corresponding to the quick view button 208, the electronic zoom button 209, and the like.

  Here, the LCD monitor display control performed by the digital camera 1 according to the present invention will be described in detail with reference to the flowchart of FIG. 4 and FIG. FIG. 3A shows an example of the display screen of the LCD monitor 211 in the normal state. (B) shows an example of a display screen of the LCD monitor 211 when the backlight illumination is darkened. (C) shows a display screen example of the LCD monitor 211 when image correction is performed.

  The LCD monitor 211 performs live view display of a captured image, playback display of a recorded image, or GUI display such as a menu screen and various status displays. Here, control of the status display screen will be described.

  First, the menu button 207 is operated to display a menu screen on the LCD monitor 211 (step S1). On the displayed menu screen, when the state setting mode is selected by up / down the jog dial (cross key) 204 and the setting selected by the jog dial (cross key) 204 is confirmed by operating the decision button 205, For example, as shown in FIG. 3A, the LCD monitor 211 displays a screen showing various states of the digital camera 1 such as an exposure control value, an autofocus mode, and a white balance mode (step S2).

  Thereafter, the process proceeds to the time measuring routine of step S3. The timing routine is a routine for automatically controlling the brightness of the LCD monitor 211 when no operation is performed on the digital camera 1 within a predetermined time, and will be described in detail later.

  Next, the camera control CPU 291 resets the timing unit. When the reset is performed, the time measuring unit starts measuring the subsequent time (step S3).

  The camera control CPU 291 determines whether or not various operation switches of the switch group 295 are turned on (step S4). If it is ON (step S4; Yes), the process returns to step S3, the camera control CPU 291 resets the timekeeping section, and the timekeeping section starts counting again.

  If it is not ON (step S4; No), the camera control CPU 291 inputs the timer time (1) set in advance and the time measured by the time measuring unit reset in step S3 (inputs a signal from the switch group 295). (The delay time from the input of the next switch group 295 to the input of the signal) (step S5). Then, the camera control CPU 291 determines whether or not the time measured by the time measuring unit exceeds the timer time (1), that is, whether or not the time is up (step S6).

  If the time is not up (step S6; No), the process returns to S4, and the camera control CPU 291 continuously monitors the operation status of the switch group 295.

  If the time is up (step S6; Yes), the process proceeds to a routine for controlling the display screen of the LCD monitor 211 after step S7.

  First, the camera control CPU 291 determines the intensity of each color component of illumination light R (red) light, G (green) light, and B (blue) light that illuminates the subject measured by the colorimetric sensor 213, that is, the illumination light. Electrical signal data representing spectral characteristics is acquired (step S7).

  Next, the camera control CPU 291 performs a known process based on the electrical signal data representing the spectral characteristics of the illumination light acquired from the colorimetric sensor 213, and determines whether the illumination light is sunlight, fluorescent light, electric light, or the like. Determination is made (step S8). That is, it is determined whether the environment in which the digital camera 1 is placed is outdoors under bright sunlight or indoors such as under a dark fluorescent light or electric light.

  If it is determined that the digital camera 1 is used indoors (step S8; Yes), since the surrounding environment is relatively dark, even if the brightness of the backlight illumination unit 284 is reduced, the LCD monitor 211 is displayed. It is possible to visually recognize the displayed image. Therefore, the camera control CPU 291 decreases the current of the backlight illumination unit 284 generated by the backlight drive circuit 285 and decreases the brightness of the backlight illumination unit 284 (step S9). At this time, the image displayed on the LCD monitor 211 can be visually recognized as shown in FIG. 3B because the brightness of the backlight illumination unit 284 becomes dark, but the sharpness is impaired. The image is hard to see. Therefore, image correction is performed in step 10 so as to improve the lowered image quality and make it easier to see.

  In other words, the camera control CPU 291 adjusts the gamma conversion characteristic performed by the gamma conversion unit 280 in the LCD drive circuit 279 to increase the contrast of the image displayed on the LCD monitor 211, thereby clarifying the outline of the character. Improves sharpness. Further, the camera control CPU 291 controls the operation of the size conversion unit 281 and the color conversion unit 282 in the LCD drive circuit 279 to increase the size of the character or change the character color to a conspicuous color (step). S10).

  For example, before changing the brightness of the backlight illumination, when the background color is blue and the character color is white, when the brightness is darkened, the background color is black, the character color is yellow, or In addition to changing to orange, the characters are enlarged and displayed.

  In this way, when the brightness of the backlight illumination unit 284 becomes dark, by performing image correction, as shown in FIG. 3C, an image display with high sharpness and easy visual recognition can be performed. It becomes like.

  On the other hand, when it is determined in step S8 that the digital camera 1 is being used outdoors (step S8; No), the camera control CPU 291 displays the LED of the backlight illumination unit 284 generated by the backlight drive circuit 285. Does not decrease the current flow. That is, since the backlight illumination unit 284 maintains normal brightness (step S11), the display image can be sufficiently viewed even when used in a bright environment such as outdoors. It becomes like.

  Thereafter, the processing proceeds to step S12 and subsequent steps. The processing performed here is usually called a sleep timer, and when no camera is operated within a predetermined time, the backlight illumination is turned off and the LCD monitor display is turned off. Energy conservation measures are taken by setting the state.

  That is, if the various operation switches of the switch group 295 are not turned on within the preset timer time (2) following step 10 or step 11, the camera control CPU 291 determines that the backlight drive circuit 285 The operation is stopped, the illumination of the backlight illumination unit 284 is turned off (step S15), the operation of the LCD drive circuit 279 is stopped, and the display on the LCD monitor is turned off (step S15). The details are omitted.

  As described above, in the imaging apparatus according to the present invention, if there is no operation input for a predetermined time, the colorimetric sensor determines whether the imaging apparatus is used outdoors in a bright environment or indoors relatively dark. Since the brightness of the backlight illumination is adjusted based on the determination result, efficient energy saving is achieved without impairing the visibility of the displayed image regardless of the surrounding brightness. It will be possible to take measures. In addition, the image quality decreases when the brightness of the backlight illumination is reduced, and the sharpness is impaired and the visibility is reduced particularly in the character display on the GUI screen such as the menu screen and various status displays. In such a case, increase the contrast of the displayed image, and change the character color to a conspicuous color or increase the size of the character when displaying characters. Therefore, it is possible to prevent a decrease in visibility and display a high-quality image.

1 is a schematic external view of a digital camera according to the present invention. It is a circuit block block diagram in the digital camera which concerns on this invention. It is a figure which shows the example of a display screen of the correction | amendment image displayed on the LCD monitor. It is a flowchart which shows the flow of LCD monitor display control in the digital camera which concerns on this invention.

Explanation of symbols

1 Digital Camera 2 Camera Body 201 Shutter Button 202 Main Switch 203 Mode Setting Dial 204 Jog Dial (Cross Key)
205 OK button 206 Select / OK button 207 Menu button 208 Quick view button 209 Electronic zoom button 210 Electronic viewfinder (EVF)
211 LCD monitor 212 Built-in flash 213 Colorimetric sensor 241 CCD area sensor 242 Signal processing circuit 243 CDS circuit 244 AGC circuit 245 A / D converter 246 Timing generator 247 Aperture / shutter drive circuit 248 Focus / zoom motor drive circuit 261 Image processing CPU
262 Image processing unit 263 Black level correction unit 264 Pixel complementation unit 265 Resolution conversion unit 266 White balance control unit 267 Gamma correction unit 268 Matrix calculation unit 269 Shading correction unit 270 Image compression unit 271 Reference clock generation unit 275 Image memory 276 Memory card driver 277 Memory card 278 External communication I / F
279 LCD drive circuit 280 Gamma conversion unit 281 Size conversion unit 282 Color conversion unit 283 Image display unit 284 Backlight illumination unit 285 Backlight drive circuit 286 EVF drive circuit 291 Camera control CPU
292 Flash control circuit 293 Buzzer 295 Switch group (shutter button, etc.)
3 Lens unit 351 Focus / zoom motor 352 Aperture

Claims (3)

Display means comprising: an image display unit for displaying an image signal; and a backlight illumination unit for illuminating the image display unit;
Brightness control means for controlling the brightness of the backlight illumination section;
Color characteristic detection means for detecting the color characteristic of illumination for illuminating the subject;
A time measuring means for measuring time,
The brightness control means includes
When there is no operation input within a predetermined time counted by the timing means,
An image pickup apparatus that controls brightness of the backlight illumination unit based on a detection result of the color characteristic detection means. Image correction means for correcting the contrast, color, or size of the image displayed on the image display unit;
The image correcting means includes
The contrast, color, or size of an image displayed on the image display unit is corrected based on a brightness control result of the backlight illumination unit performed by the brightness control unit. Item 2. The imaging device according to Item 1. The image correcting means includes
When the brightness control means darkens the brightness of the backlight illumination unit,
The imaging apparatus according to claim 2, wherein the contrast of an image displayed on the image display unit is increased, the color of a displayed character is changed, or the size of the character is enlarged. .

Images