JP2009170956A - Photographing apparatus and method for controlling display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To extend the life of a light source by preventing or suppressing the use of the light source over an absolute maximum rated current or in a state close to that. <P>SOLUTION: A photographing apparatus provided with a display device 23 including a light source 27 of which the luminance can be adjusted by current control is also provided with: setting means 22, 35 for selectively setting a normal mode for allowing the light source 27 to emit light at normal luminance and a high luminance mode for allowing the light source 27 to emit light at luminance higher than the normal luminance; a temperature detection means 29 for detecting the temperature of the light source 27, a storage means 37 which has stored control data including a threshold concerned with the temperature of the light source 27 which is preset with respect to the life of the light source 27; and a control means 31 for controlling so as to issue an alert to a user when the light source 27 emits light at the high luminance mode and the detection temperature of the temperature detection means 29 exceeds the threshold. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photographing apparatus such as a digital camera provided with a display device having a light source whose luminance can be adjusted by current control, and a control method for the display device.

  An imaging device such as a digital camera includes a liquid crystal display (LCD) for displaying an image formed on an image sensor, reproducing a recorded still image or moving image, and displaying other information. In a liquid crystal display, since the liquid crystal panel does not emit light, a backlight including a light source such as an LED (Light Emitting Diode) is disposed on the back side of the liquid crystal panel so that the liquid crystal panel is illuminated from the back side. Yes.

  In such a photographing device, when the surroundings are bright, such as when used outdoors on a sunny day, it may be difficult to visually recognize the display image. Therefore, the brightness of the liquid crystal display is increased from the luminance in the normal mode to improve visibility. There is known a high-luminance mode (also referred to as a backlight boost mode or the like) that improves the image quality so that a user can switch modes as necessary. Such a high luminance mode is realized by setting the current value supplied to the LEDs constituting the backlight to a higher value than in the normal mode.

  However, the LED has an absolute maximum rated current in relation to the temperature due to its specifications, and generally cannot be used beyond this, and if used beyond this, the deterioration of the element is accelerated. Therefore, there is a possibility that the maximum luminance decreases with time and the life is shortened. Therefore, it is necessary to avoid performing high-intensity light emission for a long time particularly in a high temperature environment.

  The present invention has been made in view of the above points, and prevents or suppresses the use of the light source in a state exceeding or close to the absolute maximum rated current, thereby extending its life. Objective.

As a technique for controlling the current supplied to the light source, the temperature of the light source is measured by a temperature sensor, and the current value supplied to the light source in accordance with the temperature change of the backlight light source is controlled. (See Patent Document 1 below), a color temperature change accompanying a change in current value (see Patent Document 2 below), and a color tone change accompanying a temperature change. (Refer to Patent Document 3 below)) is known, but none relates to the lifetime of the light source.
JP 2003-319291 A JP 2006-229548 A JP 2007-87720 A

  According to a first aspect of the present invention, there is provided a photographing apparatus (CM) including a display device (23) having a light source (27) whose luminance can be adjusted by current control, wherein the light source emits light at normal luminance. And a setting means (22, 35) for selectively setting a high brightness mode for emitting the light source at a brightness higher than the normal brightness, a temperature detection means (29) for detecting the temperature of the light source, Storage means (37) storing control data including a threshold value (41) relating to the temperature of the light source set in advance in relation to the lifetime, and a case where the light source emits light in the high luminance mode. In addition, there is provided an imaging device including control means (31) for controlling to generate a warning to the user when the temperature detected by the temperature detection means exceeds the threshold value.

  According to a second aspect of the present invention, there is provided a control method for a display device (23) having a light source (27) whose brightness can be adjusted by current control, wherein the light source emits light at normal brightness, and the light source includes the light source (27). A setting detection step (S11) for detecting which of the high luminance modes for emitting light with a luminance higher than the normal luminance is set, a temperature detection step (S12) for detecting the temperature of the light source, and the lifetime of the light source. A reading step (S16) for reading control data including a threshold value (41) relating to the temperature of the light source set in advance in relation to A control method for a display device, comprising: a warning step (S17) for generating a warning to a user when the temperature detected by the detection step exceeds the threshold (S16) It is provided.

  In the present invention, the “warning” means notifying the user of information through some method, and not only is notified by an image or characters visible through a display device or the like, but also light emission of an indicator lamp or the like. It also includes aural notification by means of display, sound or voice.

  In the present invention, the light source emits light in the high luminance mode, and the temperature of the light source exceeds a preset threshold value related to the temperature of the light source in relation to the lifetime of the light source. Since the warning is issued to the user, the user can recognize that there is an adverse effect on the life of the light source if the high brightness mode is continued, and the mode is changed to the normal mode. It becomes possible to take measures such as switching, and as a result, the life of the light source can be extended.

  According to the present invention, it is possible to prevent or suppress the light source from being used in a state exceeding or close to the absolute maximum rated current, and it is possible to increase the life of the light source. is there.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The photographing apparatus of this embodiment is a single-lens reflex digital camera. However, it may be a compact digital camera equipped with a transparent viewfinder, a camera for shooting still images, a video camera for shooting movies, a camera or video capable of shooting both still images and movies. It may be a camera.

[Overall configuration of digital camera]
FIG. 1 is a diagram showing a schematic configuration of a digital camera according to an embodiment of the present invention. This camera is a single-lens reflex digital camera capable of capturing still images and moving images. In FIG. 1, the camera CM includes a camera body CB, a finder unit FD, and a photographing lens CL that is detachably or fixedly attached to the camera body CB.

  The photographing lens CL includes a lens system 11 including a plurality of lenses such as a main lens, a focal length adjustment lens, and a focus lens, a diaphragm 12 and the like inside the lens barrel. Inside the camera body CB, an image sensor 13 such as a CCD or CMOS that converts an image of a subject through an imaging lens CL into an image signal and outputs it, a mechanical shutter 14, a quick return mirror 15 for switching an optical path, and the like. The phase difference detection AF detection element 16 and the like are accommodated. The finder unit FD is an optical finder for visually observing an optical image of a subject formed through the photographing lens CL and the quick return mirror 15, and includes a focusing screen (focus plate) 17 and a penta (dach) prism 18. , A photometric element 19, a photometric optical system 20, an eyepiece (eyepiece lens) 21, and the like.

  Although not shown, an operation unit such as various buttons, a dial, and a cross key for manually inputting instruction contents is arranged on the upper or rear surface of the camera body CB. As the operation unit, a power dial for turning on / off the power, a release button, a shooting mode button, a command dial, and the like are provided. Reference numeral 22 denotes a luminance mode setting button as an operation unit for setting a luminance mode of the image display monitor 23 described later. In the figure, the brightness mode setting button 22 is depicted as being provided on the back surface of the camera body CB, but may be provided on the top surface of the camera body CB or at other positions.

  On the back surface of the camera body CB, an image display monitor 23 for reproducing and displaying an image of a subject (live view image) formed on the image sensor 13 or a captured still image or moving image is provided. In addition to the image, the image display monitor 23 also displays a menu screen, various mode selection screens, information regarding shooting, various warnings, and the like.

  2 and 3 are diagrams showing a schematic configuration of the image display monitor. The image display monitor 23 includes, for example, a TFT type liquid crystal panel 24 and a backlight that illuminates the same from the back side. The backlight includes a light source 27 having a plurality of LEDs 26 arranged linearly on an element substrate 25, a light guide plate 28 having a reflection sheet 28a, a diffusion sheet 28b, and the like. A temperature sensor 29 is provided on the element substrate 25 as temperature detecting means for detecting the temperature of the light source 27. A detection signal from the temperature sensor 29 is supplied to a control device 31 (see FIG. 4) described later. In the present invention, the temperature sensor is installed in the image display monitor 23, but the installation location of the temperature sensor is not limited to this, and may be installed inside the camera. In that case, it is preferable to measure the relationship between the output of the temperature sensor and the temperature of the monitor in advance, and apply correction based on the relationship.

  Further, the camera CM has a speaker (sounding member) 36 for reproducing sound recorded at the time of recording a moving image or outputting a pseudo shutter sound or a self-timer operating sound for perceiving a shutter operation. I have. The speaker 36 is also used for outputting a warning sound and sound described later. In the figure, the speaker 36 is depicted as being provided in the finder portion FD, but may be provided in the camera body CB.

[Control system configuration]
FIG. 4 is a block diagram showing the main configuration of the control system of the digital camera according to the present embodiment. In the figure, reference numeral 31 denotes a control device (control means) constituted by a microcomputer or the like, and this control device 31 performs overall control of each part constituting the camera CM. The image sensor 13 receives the subject light transmitted through the photographing lens CL and outputs an image signal (analog signal as accumulated charge). The image signal from the image sensor 13 is A / D converted after gain adjustment, and is sent as a digital signal to an image processing circuit (not shown) as a part of the control device 31. The image processing circuit is configured by ASIC (Application Specific Integrated Circuit) or the like, performs image processing such as white balance (WB) adjustment, contour compensation, and gamma correction on the original image data which is a digital signal, and has a predetermined format. Performs compression processing, decompression processing, and the like.

  The captured image data is recorded on the recording medium 32. The recording medium 32 is a memory card composed of a flash memory or the like, and records image data (still image, moving image) after compression processing, and is configured to be detachable from the camera body CB. . The display drive circuit 33 outputs an image signal (a signal related to a live view image, a reproduction image of an image recorded on the recording medium 32, information related to photographing, etc.) sent from the control device 31 to the liquid crystal panel 24 of the image display monitor 23. In this case, the liquid crystal panel 24 of the image display monitor 23 is driven to display the image. The current control circuit 34 is a circuit that supplies a current to each LED 26 of the light source 27 of the backlight. The current control circuit 34 changes the current value supplied to the light source 27 based on the control signal from the control device 31 and controls the luminance. The control device 31 sends a corresponding control signal to the current control circuit 34 according to the setting content (normal mode / high luminance mode) of the luminance mode setting unit 35 described later, and the current control circuit 34 has the luminance mode in the normal mode. In some cases, the luminance of the backlight light source 27 is changed by supplying a low current corresponding thereto and a high current corresponding thereto in the high luminance mode.

  The temperature detected by the temperature sensor 29 that detects the temperature of the light source 27 of the backlight is input to the control device 31 for use in warning processing described later. Further, when the control device 31 generates a warning to be described later in the high luminance mode, as one mode, the control device 31 drives a speaker (sounding member) 36 to give a warning sound or sound to inform the user. generate. Examples of the warning sound or sound emitted from the speaker 36 include a buzzer sound (continuous sound, intermittent sound), speech of words, and the like.

  The luminance mode setting unit 35 is set to either a normal mode in which the backlight light source 27 emits light at normal luminance or a high luminance mode in which light is emitted at higher luminance than the normal luminance. The setting content of the luminance mode setting unit 35 is changed when the user operates (presses) the luminance mode setting button 22. Here, when the luminance mode setting button 22 is pressed in the normal mode, the mode setting is changed to the high luminance mode, and when the luminance mode setting button 22 is pressed in the high luminance mode, the mode setting is changed to the normal mode. It has been changed. The setting content of the luminance mode setting unit 35 can be changed by a change instruction from the control device 31.

  The data storage unit 37 stores control data used for warning processing described later. As shown in FIG. 5, the control data includes a threshold value 41, prediction data 42, forced change waiting time 43, correction data 44, cumulative number counter 45 and cumulative time counter 46.

  The threshold value 41 is a threshold value related to the temperature of the light source 27 determined in relation to the lifetime of the light source 27. This threshold value 41 includes a preset initial value and a value after correction appropriately corrected by a correction process described later. Hereinafter, when these are distinguished, the initial value of the threshold value is referred to as an initial threshold value, and the corrected threshold value is referred to as a corrected threshold value. When it is simply referred to as a threshold value, it refers to either or both of these. The initial threshold value is set in advance based on the specification (absolute maximum rated current) of the LED 26 constituting the light source 27.

The LED 26 used for the light source 27 is regulated in temperature and current by a current reduction curve as indicated by a symbol A in FIG. This generally defines the range guaranteed by the LED or light source manufacturer in relation to the lifetime of the LED. In the figure, the vertical axis represents the forward current I _F (mA), and the horizontal axis represents the temperature T (° C.). For example, if the current value supplied to the LED in the normal mode is Ia and the current value supplied to the LED in the high brightness mode is Ib, the current value Ia can be used up to the temperature Ta, and the current value Ib can be used up to the temperature Tb. Indicates that it is possible to use. That is, in the high luminance mode, since the supplied current value is larger than the current value in the normal mode, the maximum temperature that can be used (hereinafter referred to as the maximum usable temperature) is lower than that in the normal mode. On the other hand, the LED generates heat to some extent when energized, and the amount of heat generated increases as the supplied current value increases. Therefore, if the high brightness mode is continued for a long time, the temperature may be higher than the maximum usable temperature depending on the ambient temperature of the camera and the ambient temperature of the LED due to heat generated by the heat generating parts such as the image sensor inside. If this is left unattended, even if it is unlikely to fail immediately, it will adversely affect the life of the LED.

  The initial threshold value 41 is set to prevent the maximum usable temperature Tb from being exceeded. Therefore, this initial threshold value is set to a value lower than the maximum usable temperature Tb corresponding to the current value Ib supplied in the high luminance mode. However, if the value is set to a value that is much lower than the maximum usable temperature Tb, a warning described later is frequently performed even though the life of the light source 27 is not so much affected, and this may be troublesome. A value close to the maximum temperature Tb is set. For example, the temperature can be lower than the maximum usable temperature Tb by a predetermined temperature. The predetermined temperature in this case is preferably a value having a certain margin in consideration of the relationship between the light emission time of the light source 27 in the high luminance mode and the temperature increase due to the self-heating of the light source 27. Specifically, For example, it can be 5 ° C. (therefore, the initial threshold value is Tb−5 ° C.).

  The prediction data 42 is data indicating the relationship between the light emission time of the light source and the temperature, and is obtained in advance and stored in the data storage unit 37. The prediction data 42 is data for predicting a temperature rise due to heat generation of the light source itself due to light emission of the light source 27. For example, the prediction data 42 is detected by the temperature sensor 29 by actually causing the light source 27 to emit light in the high luminance mode. The temperature can be obtained by monitoring the temperature and collecting the temperature at every predetermined elapsed time. You may decide based on the specification of the light source 27 or LED26. The prediction data 42 may be stored as a data table in which the temperature at that time is set for each predetermined elapsed time, or may be stored as a function obtained based on the data table.

  The forced change waiting time 43 is a predetermined time until a forced return to the normal mode after a warning described later is performed, and is determined in advance and stored in the data storage unit 37. The forcible change waiting time 43 is a value with a margin that does not exceed the maximum usable temperature Tb in consideration of the relationship between the light emission time of the light source 27 in the high luminance mode and the temperature rise due to self-heating of the light source 27. Specifically, for example, it may be 5 minutes.

  The correction data 44 is data indicating the relationship between the cumulative number of times the temperature of the light source 27 has exceeded the threshold value 41 and the cumulative time and the correction value for decreasing the threshold value 41 in accordance with this in the high luminance mode. , Determined in advance and stored in the data storage unit 37. As described above, the initial threshold value 41 is set to a value close to the maximum usable temperature Tb because it is not preferable to set the value to an excessively low value with a certain degree of margin in view of frequent warnings. The Therefore, repeated use at a temperature exceeding the threshold value 41, that is, a temperature close to the maximum usable temperature Tb, or prolonged use should be avoided as much as possible from the viewpoint of the life of the light source 27. For this reason, in this embodiment, the threshold value 41 is corrected to a low value in accordance with the number of accumulations or the accumulation time, thereby suppressing use at a temperature close to the maximum usable temperature Tb. Data 44 is data used to correct this threshold value 41. Specifically, for example, the threshold value is corrected by a predetermined temperature (for example, 0.1 ° C.) for a predetermined number of times (for example, 5 times) or for a predetermined time (for example, 5 minutes). It is like doing.

  The cumulative number counter 45 and the cumulative time counter 46 are counters that cumulatively hold the number of times or time when the temperature detected by the temperature sensor 29 exceeds the threshold value 41. The default values of these counters 45 and 46 are “0”, and the cumulative number of times and the cumulative time set in these counters 45 and 46 are not replaced with new ones for the image display monitor 23 or the backlight or light source 27. As long as there is no special circumstances, it will not be reset.

[Warning processing]
Next, processing related to a warning executed by the control device 31 of FIG. 4 will be described with reference to a flowchart shown in FIG. The processing related to the warning is realized by the control device 31 reading and executing a high brightness warning program from a program storage unit (not shown).

  First, it is determined whether the mode setting of the brightness mode setting unit 35 is the high brightness mode or the normal mode (step S11). If it is determined that the mode is the normal mode (N), this process is performed. finish. If it is determined in step S11 that the mode is the high luminance mode (in the case of Y), the temperature of the light source 27 is detected by the temperature sensor 29 (step S12), and the remaining time until reaching the threshold value 41 is predicted. (Step S13). In step S13, a difference between the detected temperature detected in step S12 and the temperature related to the threshold value 41 is obtained, and the temperature until the temperature of the light source 27 rises to the temperature related to the difference based on the prediction data. Find time (remaining time). The threshold value 41 used in this case is an initial threshold value when the threshold value is not corrected in step S22 described later, and the threshold value correction is performed in step S22 described later. When it is performed once or more, it is a correction threshold value.

  Next, the predicted remaining time is displayed on the image display monitor 23 (step S14). In this display, for example, as shown by the symbol D1 in FIG. 9, the remaining time is displayed in characters. However, in addition to the display with such character information, a graph (bar) display such as a bar graph may be used as indicated by reference numeral D2 in FIG. By using such a graph display, it is possible to intuitively recognize the time until the temperature of the light source 27 reaches the threshold value 41 and the progress state, and it is possible to easily grasp the rough state. Note that such a graph display may be displayed not only horizontally long as indicated by reference numeral D2 in FIG. 9 but also vertically long. Further, instead of such a bar graph, a pie graph or a graph of another shape may be used. The character information as described above and such a graph display may be used in combination (combined).

  Thereafter, it is determined again whether the mode setting of the luminance mode setting unit 35 is the high luminance mode or the normal mode (step S15). If it is determined that the mode is the normal mode (N), that is, the user If the brightness mode setting button 22 is operated to change the mode from the high brightness mode to the normal mode, this process ends.

  If it is determined in step S15 that the mode is the high brightness mode (in the case of Y), that is, if the user continues the high brightness mode without operating the brightness mode setting button 22, the detection detected in S12. It is determined whether or not the temperature has reached the temperature related to the threshold value 41 (step S16). Note that the threshold value used in step S16 is the initial threshold value when the threshold value is not corrected in step S22, which will be described later, as in step S13, and in step S22, which will be described later. When the threshold value is corrected once or more, it is a correction threshold value. If it is determined in step S16 that the temperature detected in step S12 has not reached the temperature related to the threshold value 41 (in the case of N), the process returns to step S12 and steps S12 to S16 are repeated. If it is determined in step S16 that the detected temperature in step S12 has reached the temperature related to the threshold value 41 (in the case of Y), the process proceeds to step S17 to give a warning.

  The warning performed in step S17 is, for example, a character string (sentence) such as “Please terminate the high-intensity mode because the temperature of the light source has increased” as indicated by reference numeral D3 in FIG. Is displayed on the image display monitor 23. This warning is performed by uttering a word similar to the above or generating a warning sound such as a buzzer through the speaker 36 instead of or in addition to the display on the image display monitor 23. May be. A warning LED lamp or the like may be provided on the camera body, and the lamp may be lit continuously or intermittently to notify the user. Moreover, it is good also as a mark display etc. which made the content the figure instead of such a character display.

  Thereafter, it is determined again whether the mode setting of the brightness mode setting unit 35 is the high brightness mode or the normal mode (step S18). If it is determined that the mode is the normal mode (N), that is, the user When the brightness mode setting button 22 is operated to change from the high brightness mode to the normal mode, the process proceeds to step S21. When it is determined in step S18 that the mode is the high luminance mode (in the case of Y), that is, when the user continues the high luminance mode without operating the luminance mode setting button 22 at all, the control of the data storage unit 37 is performed. The forced change waiting time 43 is read from the data, and it is determined whether or not the time has elapsed (step S19). If it is determined that the time has not elapsed (in the case of N), the process returns to step S17 to continue the warning. If it is determined that the time has elapsed (in the case of Y), the process proceeds to step S20. In step S20, the control device 31 forcibly changes the mode setting of the luminance mode setting unit 35 from the high luminance mode to the normal mode.

  When the user manually changes the luminance mode of the luminance mode setting unit 35 from the high luminance mode to the normal mode in step S18, or when the control device 31 forcibly changes from the high luminance mode to the normal mode in step S20. In step S21, the number of times or time when the temperature detected by the temperature sensor 29 exceeds the threshold value 41 is measured, and the cumulative number or cumulative number set in the cumulative number counter 45 or cumulative time counter 46 of the data storage unit 37 is measured. The measured number or time is added to the time, and the accumulated number counter 45 or the accumulated time counter 46 is overwritten. The cumulative number is a cumulative addition of the number of times from when the warning is issued in step S17 until the luminance mode is returned from the high luminance mode to the normal mode. The accumulated time is a cumulative addition of the time from when the warning is issued in step S17 until the luminance mode is returned from the high luminance mode to the normal mode.

  Next, in step S 22, the data storage unit 37 is used by using the correction value obtained based on the value of the cumulative number counter 45 or the cumulative time counter 46 (cumulative number or cumulative time) of the data storage unit 37 and the correction data 44. The initial threshold value is corrected and stored in the data storage unit 37 as a corrected threshold value in distinction from the initial threshold value.

  As described above, in the present embodiment, when the user changes the luminance mode from the normal mode to the high luminance mode using the luminance mode setting button 22, the temperature of the light source 27 is related to the specification of the light source 27. Since the time predicted to reach the threshold value 41 determined in (1) is displayed while being sequentially changed as the remaining time, the user can determine whether to continue the high brightness mode or return to the normal mode while visually recognizing this. It can be determined, and it can be expected to perform an operation to return to the normal mode before reaching the threshold value.

  Further, when the temperature of the light source 27 reaches the threshold value 41, a warning is given by a warning display or the like. Therefore, if the user continues the high luminance mode any more, the life of the light source 27 is adversely affected. It is possible to recognize that there is a possibility of giving, and to expect to perform an operation to return to the normal mode as soon as possible. Furthermore, when the user continues the high brightness mode even after the warning, the camera CM side forcibly returns to the normal mode when the predetermined time (forced change waiting time 43) arrives. It is possible to reliably prevent the temperature of the light source 27 from reaching the maximum usable temperature Tb. Therefore, deterioration of the light source 27 can be suppressed, the life of the light source 27 can be extended, and as a result, the life of the digital camera CM can be extended.

  FIG. 7 is a flowchart showing a modification of the warning process described above with reference to FIG. Steps substantially the same as those in FIG. 6 are denoted by the same reference numerals, and description thereof is omitted. The processing shown in FIG. 7 differs from FIG. 6 in that steps S13-1 and S13-2 are used instead of step S13 in FIG. That is, in step S13-1, the remaining time until reaching the threshold value 41 is the same as in step S13 of FIG. 6, but the threshold value 41 used in this case is the step S22. The initial threshold value is used regardless of whether the threshold value is corrected or not.

  In addition, after step S13-1 is executed, in step S13-2, it is obtained based on the value of the cumulative number counter 45 or cumulative time counter 46 (cumulative number or cumulative time) of the data storage unit 37 and the correction data 44. The remaining time obtained in step S13-1 is corrected to be reduced using a correction value (time) obtained by converting the correction value (temperature) to be converted into time. Accordingly, in step S14, the remaining time corrected in step S13-2 is displayed. Others are the same as those shown in FIG. Note that the threshold value 41 used in step S16 of FIG. 7 is the initial threshold value for the first time and the correction threshold value for the second time and thereafter, as in the case of FIG.

  As another modified example of the warning process shown in FIG. 7, although not shown, whether or not the detected temperature detected in step S12 has reached the temperature related to the threshold value 41 in step S16. Instead of determining whether or not the remaining time corrected in step S13-2 has elapsed, if the remaining time has not elapsed (in the case of N), the process returns to step S12, and the remaining time When the time elapses (in the case of Y), it is possible to proceed to S17 and issue a warning. In this case, when it is determined in step S16 that the remaining time has not elapsed (in the case of N), the return destination can be changed to step S14.

  The present invention is suitable for use in the digital camera as described above, but can be applied to any device provided with a display device having a light source whose luminance can be adjusted by current control. The present invention can be widely applied to terminals (cell phones, PDAs, etc.), electronic computers, in-vehicle electronic devices, and other electronic devices in general.

  The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment includes all design changes and equivalents belonging to the technical scope of the present invention.

It is sectional drawing which shows schematic structure of the digital camera which concerns on embodiment of this invention. It is the side view in which one part which showed schematic structure of the image display monitor with which the digital camera which concerns on embodiment of this invention is equipped was made into the cross section. It is the top view in which one part which showed schematic structure of the image display monitor with which the digital camera which concerns on embodiment of this invention is equipped was made into a cross section. It is a block diagram which shows the structure of the principal part of the control system of the digital camera which concerns on embodiment of this invention. It is a block diagram which shows the structure of the control data of embodiment of this invention. It is a flowchart which shows the process (warning process) of the control system of embodiment of this invention. It is a flowchart which shows the modification of the process (warning process) of the control system of embodiment of this invention. It is a figure which shows the electric current reduction curve of LED of embodiment of this invention. It is a figure which shows the example of a display of the remaining time until the threshold value reach | attainment of embodiment of this invention. It is a figure which shows the example of a warning display of embodiment of this invention.

Explanation of symbols

  CM: Digital camera, 22: Brightness mode setting button, 23: Image display monitor, 24: Liquid crystal panel, 26 ... LED, 27 ... Light source, 29 ... Temperature sensor, 31 ... Control device, 34 ... Current control circuit, 35 ... Luminance Mode setting unit 36 ... Speaker 37 ... Data storage unit 41 ... Threshold value 42 ... Prediction data 43 ... Forced change waiting time 44 ... Correction data 45 ... Cumulative number counter 46 ... Cumulative time counter

Claims (6)

An imaging device including a display device having a light source whose brightness can be adjusted by current control,
Setting means for selectively setting a normal mode in which the light source emits light at a normal brightness and a high brightness mode in which the light source emits light at a brightness higher than the normal brightness;
Temperature detecting means for detecting the temperature of the light source;
Storage means for storing control data including a threshold value relating to the temperature of the light source set in advance in relation to the lifetime of the light source;
Control means for controlling the user to issue a warning when the light source is emitting in the high brightness mode and the temperature detected by the temperature detection means exceeds the threshold value; ,
An imaging apparatus comprising:   In the case where the warning is given, the control means does not change the normal mode by the setting means even if a predetermined time has elapsed since the warning was given. The imaging apparatus according to claim 1, wherein the mode setting of the setting unit is forcibly changed to the normal mode in the event of a failure.   The control means measures the cumulative number or accumulated time when the temperature detected by the temperature detection means exceeds the threshold value, and corrects the threshold value used for the control for generating the warning based on the measurement result. The photographing apparatus according to claim 1 or 2, characterized in that The control data includes prediction data indicating a relationship between a light emission time and a temperature of the light source,
When the setting unit changes the setting from the normal mode to the high luminance mode, the control unit is configured to output the light source based on the temperature detected by the temperature detection unit and the prediction data at the time of the setting change. The remaining time required until the temperature reaches the threshold value is predicted, and the remaining time is controlled to be displayed on the display device while being sequentially updated as time elapses. The imaging device described in 1.   5. The control unit according to claim 4, wherein the control unit measures a cumulative number or a cumulative time when the temperature detected by the temperature detection unit exceeds the threshold value, and corrects the remaining time based on the measurement result. The imaging device described in 1. A control method of a display device having a light source whose brightness can be adjusted by current control,
A setting detection step for detecting which mode is set to a normal mode in which the light source emits light at a normal brightness and a high brightness mode in which the light source emits light at a brightness higher than the normal brightness;
A temperature detecting step for detecting a temperature of the light source;
A step of reading out control data including a threshold value relating to the temperature of the light source set in advance in relation to the lifetime of the light source;
A warning step for generating a warning to a user when the light source is emitting light in the high-luminance mode and the temperature detected by the temperature detection step exceeds the threshold;
A control method for a display device, comprising:

Images