JP2008118263A - Photography apparatus and heat generation suppressing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photography apparatus which prevents deterioration in picture quality and a heat generation suppressing method for the photography apparatus. <P>SOLUTION: The photography apparatus includes a photography section 1010 which captures subject light, and generates and processes an image signal, a temperature sensor 1004 which measures the temperature of an imaging device 1041 provided in the photography section 1010, and an imaging circuit clock section 1103 which changes a clock for operating the imaging device 1041 according to the temperature measured by the temperature sensor 1004. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photographing apparatus such as a digital camera and a method for suppressing heat generation in the photographing apparatus.

  In recent years, in the field of digital cameras, solid-state imaging devices such as CCD (Charge Coupled Device) image sensors and CMOS (Commentary Metal Oxide Semiconductor) image sensors have been rapidly increasing in resolution, and from such high-resolution solid-state imaging devices. How to deal with the large amount of generated heat is becoming a big problem. In recent years, digital cameras have become more intelligent, and an increasing number of digital cameras have incorporated signal processing circuits equipped with a large number of large-scale integrated circuits that perform advanced processing at high speed. Large amounts of heat are also a problem. Furthermore, the number of pixels of image display panels such as LCD (Liquid Crystal Display) for image display and EVF (Electronic View Finder) for composition confirmation is also increasing. From the backlight that illuminates these image display panels from the back side. The fever is also a big problem. As described above, when a large amount of heat is generated inside the camera, there is a problem that the temperature of the image sensor rises and the dark current increases, so that a large amount of noise is generated and the image quality is deteriorated. There is also a problem that the power consumption of the digital camera increases due to an increase in the number of devices having a large amount of heat generation as described above.

  As a technology to reduce power consumption, the voltage of the power supply for driving the digital camera is detected, and the internal temperature and external temperature of the digital camera are detected, and based on these power supply voltage, internal temperature, and external temperature A technique is disclosed in which the autofocus interval of the autofocus function is changed (see, for example, Patent Document 1).

  However, since the technique disclosed in Patent Document 1 controls only the automatic focusing interval of the autofocus function, which is a part of many operating parts in the digital camera, a sufficient effect is obtained. It is not possible.

  Further, Patent Document 2 proposes to reduce power consumption by lowering the clock frequency for driving the image sensor at low temperatures, paying attention to the fact that dark current is reduced at low temperatures and therefore image quality is less likely to deteriorate. ing.

However, this is true at low temperatures and cannot be applied when the temperature rises due to heat generation.
JP 2002-202453 A JP 2005-223588 A

  SUMMARY OF THE INVENTION In view of the circumstances described above, an object of the present invention is to provide a photographing apparatus that balances the prevention of image quality deterioration by suppressing heat generation in the photographing apparatus and the maintenance of the operation performance of the photographing apparatus, and a method for suppressing heat generation in the photographing apparatus. And

The first imaging device of the present invention that achieves the above object provides:
An imaging unit that captures subject light and generates and processes image signals;
A temperature sensor for measuring the temperature of the imaging unit;
A clock generation unit that generates a clock for operating the imaging unit,
The clock generator generates a clock having a frequency corresponding to the temperature measured by the temperature sensor.

  According to the first imaging device of the present invention, it is possible to reduce the dark current output from the imaging device by reducing the temperature of the imaging unit by generating a clock having a frequency corresponding to the temperature increase of the imaging unit. Therefore, it is possible to realize a photographing apparatus that balances the prevention of image quality degradation of the photographing apparatus and the maintenance of the operation performance of the photographing apparatus.

Here, the imaging unit includes an image sensor that operates with the clock generated by the clock generation unit, receives subject light, and generates an image signal by photoelectric conversion,
The clock generation unit may change a clock for operating the imaging device according to the temperature measured by the temperature sensor.

  When the first imaging apparatus of the present invention is configured as described above, the temperature of the imaging unit is lowered by lowering the clock frequency for operating the imaging device in response to the temperature rise of the imaging unit, thereby imaging. Since the dark current output from the element is reduced, it is possible to effectively prevent image quality deterioration of the photographing apparatus.

In addition, the photographing unit includes a signal processing circuit that operates on the clock generated by the clock generation unit to process an image signal,
The clock generation unit may change a clock for operating the signal processing circuit in accordance with the temperature measured by the temperature sensor.

  When the first imaging device of the present invention is configured as described above, the temperature of the imaging unit is lowered by lowering the clock frequency for operating the signal processing circuit in accordance with the temperature increase of the imaging unit, and the imaging device. Therefore, it is possible to reduce the dark current output from the image pickup apparatus, and thus it is possible to realize an image pickup apparatus that balances the prevention of image quality degradation of the image pickup apparatus and the maintenance of the operation performance of the image pickup apparatus.

In addition, the second imaging device of the present invention that achieves the above-described object provides:
An imaging unit that captures subject light and generates and processes image signals;
A temperature sensor for measuring the temperature of the imaging unit;
An image display panel for displaying an image based on an image signal obtained by the photographing unit, and an image display unit having a backlight for illuminating the image display panel from the back surface;
The image display unit is configured to change the amount of light of the backlight according to the temperature measured by the temperature sensor.

  According to the second imaging apparatus of the present invention, the dark current output from the imaging device can be reduced by lowering the temperature of the imaging unit by changing the amount of light of the backlight according to the temperature increase of the imaging unit. As a result, it is possible to realize a photographing apparatus that balances the prevention of image quality degradation of the photographing apparatus and the maintenance of the operation performance of the photographing apparatus.

  Here, the image display unit may be an electronic view finder (EVF) for visually observing an image, or may be a liquid crystal display unit (LCD) provided on the back of the body.

  When the second photographing apparatus of the present invention is configured as described above, the temperature of the photographing unit is lowered by changing the light amount of the backlight of the electronic viewfinder or the liquid crystal display unit according to the temperature rise of the photographing unit. As a result, the dark current output from the image sensor can be reduced, so that it is possible to realize an image capturing apparatus that balances the prevention of image quality degradation of the image capturing apparatus and the maintenance of the operation performance of the image capturing apparatus.

  The temperature sensor may be a temperature measuring element.

  When the photographing apparatus of the present invention is configured as described above, a highly reliable temperature sensor can be easily obtained.

Furthermore, the imaging device of the present invention includes an imaging device made of CCD or CMOS,
The temperature sensor may detect a temperature based on a potential difference generated before and after a junction provided on the CCD or CMOS.

  When the photographing apparatus of the present invention is configured as described above, a highly reliable temperature sensor can be easily obtained.

In addition, the first method of suppressing heat generation according to the present invention that achieves the above object is as follows.
A method of suppressing heat generation in an imaging apparatus comprising: an imaging unit that captures subject light to generate and process an image signal; and a clock generation unit that generates a clock for operating the imaging unit,
The temperature of the imaging unit is measured, and heat generation is suppressed by changing the frequency of the clock generated by the clock generation unit according to the measured temperature.

  According to the first heat generation suppressing method of the present invention, it is possible to reduce the dark current output from the imaging device by lowering the temperature of the photographing unit by lowering the clock frequency according to the temperature rise of the photographing unit. Therefore, it is possible to realize a photographing apparatus that balances the prevention of image quality degradation of the photographing apparatus and the maintenance of the operation performance of the photographing apparatus.

In addition, the second method of suppressing heat generation according to the present invention that achieves the above object is as follows.
An imaging unit that captures subject light and generates and processes an image signal, an image display panel that displays an image based on the image signal obtained by the imaging unit, and an image that has a backlight that illuminates the image display panel from the back side A method for suppressing heat generation in an imaging device including a display unit,
The temperature of the photographing unit is measured, and heat generation is suppressed by changing the amount of light of the backlight according to the measured temperature.

  According to the second heat generation suppressing method of the present invention, the dark current output from the image sensor can be reduced by lowering the light amount of the backlight in accordance with the temperature rise of the photographing unit to lower the temperature of the photographing unit. As a result, it is possible to realize a photographing apparatus that balances the prevention of image quality degradation of the photographing apparatus and the maintenance of the operation performance of the photographing apparatus.

  According to the present invention, it is possible to realize a photographing apparatus and a method for suppressing heat generation in the photographing apparatus, which are balanced between prevention of image quality deterioration due to suppression of heat generation in the photographing apparatus and maintenance of operation performance of the photographing apparatus.

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

  In each of the following embodiments, a so-called digital camera that mainly captures a still image will be described as an example of the imaging device of the present invention. However, the imaging device and the heat generation suppression method of the present invention are limited to only a digital camera. For example, the present invention can be applied to a so-called digital video camera or a mobile phone having a photographing function.

  FIG. 1 is an external perspective view of the digital camera according to the first embodiment of the present invention as viewed obliquely from the front top.

  Note that the digital camera of the first embodiment corresponds to an example of the first photographing apparatus of the present invention.

  A digital camera 100 shown in FIG. 1 captures subject light and generates image data. On the front surface of the digital camera 100, a zoom lens barrel 111 including an optical zoom lens is flashed in synchronization with photographing. A flash light emission window 112 for emitting light and an AF auxiliary light lamp 113 for improving autofocus (AF) accuracy at low contrast such as in a dark place are provided.

  On the top surface of the digital camera 100, a power switch 114, a release button 115, and a rotary mode dial 116 are provided around the release button 115. The mode dial 116 can be switched alternately between the still image mode and the moving image mode by turning the dial.

  FIG. 2 is an external view showing the back of the digital camera shown in FIG.

  On the back of the digital camera 100 shown in FIG. 2, there are an LCD 117, EVF 124, MENU / OK button 118, DISP / BACK button 119, photo mode button 120, play button 121, cross button 122, zoom button 123, and viewfinder switch button 125. Etc. are provided.

  The LCD 117 displays an image composed of image data generated by capturing subject light with a photographing lens, and information at various settings.

  The EVF 124 is a kind of finder that allows a user to view an image by looking through the eyes, and displays an image generated by capturing subject light with a photographing lens and information at various settings.

  The viewfinder switching button 125 is a button for switching between the display on the LCD 117 and the display on the EVF 124.

  The MENU / OK button 118 is a button for displaying various menus at the time of shooting or reproduction on the LCD 117 or selecting and determining a desired menu from the displayed menus.

  The DISP / BACK button 119 is a button for switching the state of the screen displayed on the LCD 117, returning the operation by the MENU / OK button 118 or the like to the previous state, or canceling the operation.

  The photo mode button 120 is a button for setting the number of pixels, sensitivity, color, number of prints, and the like.

  The reproduction button 121 is a button for reproducing and displaying a captured image recorded on a recording medium 1059 described later on the LCD 117.

  The role of the cross button 122 changes in various modes. For example, the cross button 122 is a macro button or a flash button in the still image mode, or a thumbnail selection button displayed on the LCD 117 in the playback mode. The macro button is a button for switching whether or not to perform macro shooting. When the macro button is pressed once, the macro shooting mode is set, and when pressed again, the macro shooting mode is canceled. The flash button is a button for sequentially switching the flash state, such as auto flash, red-eye reduction flash, forced flash, flash prohibition, slow shutter flash, and auto flash each time the button is pressed.

  The zoom button 123 is a button for zooming in on the telephoto side (tele side) by pressing down to the right and zooming down on the wide angle side (wide side) by pressing down on the left side.

  Next, the circuit configuration of the digital camera shown in FIGS. 1 and 2 will be described.

  FIG. 3 is a block diagram showing a circuit configuration of the digital camera shown in FIGS.

  As shown in FIG. 3, the digital camera 100 includes an imaging unit 1010 that includes an imaging element 1041 that receives subject light and generates an image signal by photoelectric conversion, a temperature sensor 1004 that measures the temperature of the imaging unit 1010, and An image display unit including an EVF 124 (see FIG. 2) and an LCD 117 (see FIG. 2), and an imaging circuit clock unit that generates an imaging circuit clock for operating the imaging device 1041 in accordance with the temperature measured by the temperature sensor 1004 1103 and a signal processing circuit clock unit 1005 for generating a reference clock for operating a signal processing circuit (described later). The imaging circuit clock unit 1103 and the signal processing circuit clock unit 1005 can generate clocks having a plurality of clock frequencies.

  Note that the imaging circuit clock unit 1103 and the signal processing circuit clock unit 1005 are a combination of them and correspond to an example of a clock generation unit according to the present invention.

  As the temperature sensor 1004, for example, a temperature measuring element such as a thermistor or an IC temperature sensor, or a sensor that detects a temperature by a potential difference generated before and after a junction provided on a CCD or CMOS can be used.

  The digital camera 100 also includes an analog signal processing unit 1051 that processes an analog image signal from the image sensor 1041, an A / D conversion circuit 1052 that converts the processed analog signal into a digital signal, and a main memory necessary for data processing. A memory control unit 1053 for controlling 1054; a digital signal processing unit 1055 for processing an A / D converted digital image signal; a compression / decompression processing unit 1056 for performing processing for recording and reproducing the image signal; 1057, an external memory control unit 1058 that controls recording of a captured image signal on the recording medium 1059 and reproduction from the recording medium 1059, a system control circuit 110 that controls the entire circuit, and the like.

  Of the above-described units, the analog signal processing unit 1051, the A / D conversion circuit 1052, and the system control circuit 110 constitute a signal processing circuit 1050. This signal processing circuit 1050 corresponds to an example of a signal processing circuit according to the present invention.

  Further, the digital camera 100 includes a lens driving unit 1101 that drives an aperture mechanism, a shutter mechanism, a zoom mechanism, and the like of the photographing lens 1021, an image sensor driving unit 1102 that drives the image sensor 1041, and a user operating the digital camera. And a display control unit 1060 for performing control for displaying the camera through image and the reproduction image on the EVF 124 and the LCD 117. The EVF 124 and the LCD 117 are provided with an image display panel for displaying a camera through image and a reproduction image, and a backlight for illuminating the image display panel from the back surface.

  The display control unit 1060, the EVF 124, and the LCD 117 in the present embodiment correspond to an example of the image display unit referred to in the present invention.

  Here, the basic operation of the digital camera 100 will be described.

  In the digital camera 100, when the power is turned on, the subject light passes through the photographing lens 1021 and forms an image on the light receiving surface on the image sensor 1041 to generate an image signal. The generated image signal representing the through image (hereinafter referred to as a through image signal) is processed by an analog signal processing unit 1051 and converted from an analog signal to a digital signal by an A / D conversion circuit 1052, and the converted image signal is converted into a system signal. Under the control of the control circuit 110, the RGB through image signal is converted into a YC signal through image signal, compressed by the compression / decompression processing unit 1056, and then guided to the main memory 1054 under the control of the memory control unit 1053. It is memorized there. The through image signal for one frame stored in the main memory 1054 is read out by the memory control unit 1053, guided to the display control unit 1060, and under the control of the display control unit 1060, the EVF 124 (see FIG. 2) or the LCD 117. (See FIG. 2).

  Next, the operation of the digital camera in the first embodiment will be described.

  FIG. 4 is a flowchart showing the operation of the digital camera in the first embodiment.

  In the first embodiment, first, when the user presses the power switch 114 (see FIG. 1) to turn on the power (step S01), the temperature sensor 1004 (see FIG. 3) starts measuring the temperature of the photographing unit 1010. In step S02, it is determined whether or not the temperature measured by the temperature sensor 1004 has reached a specified temperature, that is, a temperature at which image quality deterioration of the image sensor 1041 occurs or not (step S03).

  As a result of the determination in step S03, when it is determined that the temperature has reached the specified temperature or more, the imaging circuit clock unit 1103 (see FIG. 3) decreases the imaging circuit clock frequency for driving the imaging element 1041 (step After step S04, the process returns to step S03.

  On the other hand, if it is determined in step S03 that the temperature has not reached the specified temperature, the imaging circuit clock unit 1103 (see FIG. 3) uses the imaging circuit clock frequency for driving the imaging element 1041 as it is. The state is maintained (step S05). Then, after the specified time has elapsed (step S06), the process returns to step S02.

  FIG. 5 is a graph showing a correspondence relationship between the imaging circuit clock frequency and the temperature measured by the temperature sensor in the first embodiment.

  In the present embodiment, as shown in FIG. 5, when the temperature T measured by the temperature sensor 1004 is lower than the specified temperature t1 at which image quality degradation may occur, the imaging circuit clock frequency F is at the f1 level. However, when the temperature T exceeds the specified temperature t1, the imaging circuit clock frequency F is lowered to the f2 level. If the temperature rise stops by lowering the imaging circuit clock frequency F to the f2 level, the imaging circuit clock frequency F is maintained at the f2 level. However, even if the imaging circuit clock frequency F is lowered to the f2 level, the temperature T still rises and the specified temperature t2 Is exceeded, the imaging circuit clock frequency F is lowered to the f3 level. If the temperature rise stops due to the reduction to the f3 level, the imaging circuit clock frequency F is maintained at the f3 level.

  Thus, in the present embodiment, when the temperature sensor detects that the temperature of the image pickup device has exceeded the temperature at which image quality deterioration occurs, the image pickup circuit clock frequency for driving the image pickup device is lowered to suppress heat generation. This makes it possible to reduce the dark current output from the image sensor by lowering the temperature of the photographing unit, so that a photographing device that balances the prevention of image quality deterioration of the photographing device and the maintenance of the operation performance of the photographing device is provided. Can be realized.

  Next, a digital camera according to the second embodiment of the present invention will be described.

  The digital camera of the second embodiment has the same appearance as the appearance of the digital camera of the first embodiment shown in FIG. 1 and the appearance of the digital camera of the first embodiment shown in FIG. . In order to avoid duplication, description of the appearance of the digital camera in the second embodiment is omitted.

  The second embodiment also corresponds to the first photographing apparatus of the present invention as in the first embodiment.

  The digital camera according to the second embodiment has a circuit configuration similar to that of the digital camera 100 according to the first embodiment shown in FIG. The difference between the second embodiment and the first embodiment is that, in the first embodiment, the imaging circuit clock unit 1103 operates the imaging element 1041 according to the temperature measured by the temperature sensor 1004. However, in the second embodiment, the signal processing circuit clock unit 1005 operates the signal processing circuit 1052 in accordance with the temperature measured by the temperature sensor 1004. The configuration is such that the signal processing circuit clock to be changed is changed.

  Next, the operation of the digital camera in the second embodiment of the present invention will be described.

  FIG. 6 is a flowchart showing the operation of the digital camera according to the second embodiment of the present invention.

  In the second embodiment, first, when the user depresses the power switch 114 (see FIG. 1) to turn on the power (step S11), the temperature sensor 1004 (see FIG. 3) measures the temperature of the photographing unit 1010. The process is started (step S12), and it is determined whether or not the temperature sensor 1004 detects that the temperature has reached a specified temperature or higher, that is, a temperature at which image quality degradation of the image sensor 1041 occurs or not (step S13).

  As a result of the determination in step S13, when it is determined that the temperature has reached the specified temperature or more, the signal processing circuit clock unit 1005 (see FIG. 3) decreases the signal processing circuit clock frequency for driving the signal processing circuit 1050. After (Step S14), the process returns to Step S03.

  On the other hand, as a result of the determination in step S13, if it is determined that the temperature has not reached the specified temperature, the imaging circuit clock unit 1103 (see FIG. 3) maintains the signal processing circuit clock frequency as it is (step S15). After the specified time has elapsed (step S16), the process returns to step S12.

  In this way, when the temperature sensor detects that the temperature has exceeded the temperature at which image quality degradation of the image sensor occurs, the signal processing circuit clock frequency for driving the signal processing circuit is lowered to suppress heat generation, thereby Since it is possible to reduce the dark current output from the imaging device by lowering the temperature, it is possible to realize an imaging device that is balanced between prevention of image quality degradation of the imaging device and maintenance of the operation performance of the imaging device. it can.

  Next, a digital camera according to the third embodiment of the present invention will be described.

  The digital camera of the third embodiment has the same appearance as the appearance of the digital camera of the first embodiment shown in FIG. 1 and the appearance of the digital camera of the first embodiment shown in FIG. . In order to avoid duplication, description of the appearance of the digital camera in the third embodiment is omitted.

  This third embodiment corresponds to the second photographing apparatus of the present invention.

  The digital camera according to the third embodiment has a circuit configuration similar to that of the digital camera 100 according to the first embodiment shown in FIG. The difference of the third embodiment from the first embodiment is that, in the first embodiment, the imaging circuit clock unit 1103 operates the imaging device 1041 according to the temperature measured by the temperature sensor 1004. However, in the third embodiment, the image display unit 1070 (the display control unit 1060, the EVF 124, and the LCD 117) has a temperature measured by the temperature sensor 1004. Accordingly, the light amount of the backlight that illuminates the image display panel of the EVF 124 from the back surface is changed.

  Next, the operation of the digital camera in the third embodiment of the present invention will be described.

  FIG. 7 is a flowchart showing the operation of the digital camera according to the third embodiment of the present invention.

  In the third embodiment, first, when the user depresses the power switch 114 (see FIG. 1) to turn on the power (step S21), the temperature sensor 1004 (see FIG. 3) measures the temperature of the photographing unit 1010. It is started (step S22), and it is determined whether or not it has been detected that the temperature sensor 1004 has reached a specified temperature or higher, that is, a temperature at which image quality deterioration of the image sensor 1041 occurs (step S23).

  As a result of the determination in step S23, when it is determined that the temperature has reached the specified temperature or more, the display control unit 1060 (see FIG. 3) reduces the current to the backlight of the EVF 124 (see FIG. 3), thereby the EVF 124. Is reduced to a level that does not hinder the user's visual recognition (step S24), and then the process returns to step S23.

  On the other hand, as a result of the determination in step S23, if it is determined that the temperature has not reached the specified temperature, the brightness of the EVF 124 is maintained as it is (step S25). Then, after the specified time has elapsed (step S26), the process returns to step S22.

  In this way, when the temperature sensor detects that the temperature of the image pickup device has exceeded the temperature at which image quality deterioration occurs, the current to the backlight of the EVF is reduced to suppress heat generation, thereby lowering the temperature of the photographing unit. Since it is possible to reduce the dark current output from the element, it is possible to realize a photographing apparatus that balances the prevention of image quality deterioration of the photographing apparatus and the maintenance of the operation performance of the photographing apparatus.

  Next, a digital camera according to the fourth embodiment of the present invention will be described.

  The digital camera of the fourth embodiment has the same appearance as the appearance of the digital camera of the first embodiment shown in FIG. 1 and the appearance of the digital camera of the first embodiment shown in FIG. . In order to avoid duplication, description of the appearance of the digital camera in the fourth embodiment is omitted.

  The fourth embodiment corresponds to the second photographing apparatus of the present invention, as in the third embodiment described above.

  The digital camera according to the fourth embodiment has a circuit configuration similar to that of the digital camera 100 according to the first embodiment shown in FIG. The difference of the fourth embodiment from the first embodiment is that, in the first embodiment, the imaging circuit clock unit 1103 operates the imaging element 1041 in accordance with the temperature measured by the temperature sensor 1004. However, in the fourth embodiment, the image display unit 1070 (the display control unit 1060, the EVF 124, and the LCD 117) has a temperature measured by the temperature sensor 1004. Accordingly, the light amount of the backlight that illuminates the image display panel of the EVF 124 from the back surface is changed.

  Next, the operation of the digital camera according to the fourth embodiment of the present invention will be described.

  FIG. 8 is a flowchart showing the operation of the digital camera according to the fourth embodiment of the present invention.

  In the fourth embodiment, first, when the user depresses the power switch 114 (see FIG. 1) to turn on the power (step S31), the temperature sensor 1004 (see FIG. 3) measures the temperature of the photographing unit 1010. The process is started (step S32), and it is determined whether or not the temperature sensor 1004 detects that the temperature has reached a specified temperature or higher, that is, a temperature at which image quality deterioration of the image sensor 1041 occurs or not (step S33).

  As a result of the determination in step S33, if it is determined that the temperature has reached the specified temperature or higher, the display control unit 1060 (see FIG. 3) reduces the current to the backlight of the LCD 117 (see FIG. 3), thereby reducing the LCD 117. Is reduced to a level that does not hinder the user's visual recognition (step S34), and then the process returns to step S33.

  On the other hand, if it is determined in step S33 that the temperature has not reached the specified temperature, the brightness of the LCD 117 is maintained as it is (step S35). Then, after the specified time has elapsed (step S36), the process returns to step S32.

  In this way, when the temperature sensor detects that the temperature has exceeded the temperature at which image quality degradation of the image sensor occurs, the current to the LCD backlight is reduced to suppress heat generation, thereby lowering the temperature of the imaging unit. Since it is possible to reduce the dark current output from the element, it is possible to realize a photographing apparatus that balances the prevention of image quality deterioration of the photographing apparatus and the maintenance of the operation performance of the photographing apparatus.

  Next, the heat generation suppressing method according to the fifth embodiment of the present invention will be described.

  This fifth embodiment corresponds to the first heat generation suppressing method of the present invention.

  The fifth embodiment is a method for suppressing heat generation in an imaging apparatus including an imaging unit that captures subject light to generate and process an image signal, and a clock generation unit that generates a clock for operating the imaging unit. The method includes a step of measuring the temperature of the photographing unit and a step of suppressing heat generation by changing a frequency of a clock generated by the clock generation unit according to the measured temperature. . These two steps are steps S02 and S04 in the flowchart showing the operation of the digital camera of the first embodiment described above (see FIG. 4), or the flowchart showing the operation of the digital camera of the second embodiment (see FIG. 4). The operations are substantially the same as those in steps S12 and S14 in FIG. 6), and detailed description thereof is omitted here to avoid duplication.

  In the heat generation suppressing method of the present embodiment, the temperature of the imaging unit is measured, and the image pickup device is configured by suppressing heat generation by changing the frequency of the clock generated by the clock generation unit according to the measured temperature. As a result, image quality deterioration due to an increase in dark current generated from the image sensor is prevented.

  Next, a heat generation suppressing method according to the sixth embodiment of the present invention will be described.

  The sixth embodiment corresponds to the second heat generation suppressing method of the present invention.

  The sixth embodiment includes a photographing unit that captures subject light and generates and processes an image signal, an image display panel that displays an image based on the image signal obtained by the photographing unit, and the image display panel on the back surface. A method of suppressing heat generation in an imaging apparatus including an image display unit having a backlight that illuminates from the step, measuring the temperature of the imaging unit, and changing the amount of light of the backlight according to the measured temperature To suppress heat generation. These two steps are steps S22 and S24 in the flowchart showing the operation of the digital camera of the third embodiment described above (see FIG. 7), or the flowchart showing the operation of the digital camera of the fourth embodiment (see FIG. 7). The operations are substantially the same as those in step S32 and step S34 in FIG. 8), and detailed description thereof is omitted here to avoid duplication.

  In the heat generation suppression method of the present embodiment, the temperature of the imaging unit is measured, and the temperature rise of the image sensor is prevented by suppressing the heat generation by changing the amount of light of the backlight according to the measured temperature. As a result, image quality deterioration due to an increase in dark current generated from the image sensor is prevented.

It is the external appearance perspective view which looked at the digital camera which is 1st Embodiment of this invention from diagonally upward front. It is an external view which shows the back surface of the digital camera shown in FIG. FIG. 3 is a block diagram illustrating a circuit configuration of the digital camera illustrated in FIGS. 1 and 2. It is a flowchart which shows operation | movement of the digital camera in 1st Embodiment. It is a graph which shows the correspondence of the image pick-up circuit clock frequency in 1st Embodiment, and the measured temperature of a temperature sensor. It is a flowchart which shows operation | movement of the digital camera in the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the digital camera in the 3rd Embodiment of this invention. It is a flowchart which shows operation | movement of the digital camera in the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Digital camera 110 System control circuit 111 Zoom lens barrel 112 Flash light emission window 113 AF auxiliary light lamp 114 Power switch 115 Release button 116 Mode dial 117 LCD
118 MENU / OK button 119 DISP / BACK button 120 Photo mode button 121 Playback button 122 Cross button 123 Zoom button 124 EVF
125 finder switch button 1004 temperature sensor 1005 signal processing circuit clock unit 1010 imaging unit 1021 imaging lens 1041 imaging element 1050 signal processing circuit 1051 analog signal processing unit 1052 A / D conversion circuit 1053 memory control unit 1054 main memory 1055 digital signal processing unit 1056 Compression / decompression processing unit 1058 External memory control unit 1059 Recording medium 1060 Display control unit 1061 Operation unit 1101 Lens driving unit 1102 Imaging element driving unit 1103 Imaging circuit clock unit

Claims (10)

An imaging unit that captures subject light and generates and processes image signals;
A temperature sensor for measuring the temperature of the imaging unit;
A clock generation unit that generates a clock for operating the imaging unit,
The imaging apparatus according to claim 1, wherein the clock generation unit generates a clock having a frequency corresponding to a temperature measured by the temperature sensor. The imaging unit includes an imaging element that operates with the clock generated by the clock generation unit, receives subject light, and generates an image signal by photoelectric conversion;
The imaging apparatus according to claim 1, wherein the clock generation unit changes a clock for operating the imaging device in accordance with a temperature measured by the temperature sensor. The imaging unit includes a signal processing circuit that operates with a clock generated by the clock generation unit to process an image signal;
The imaging apparatus according to claim 1, wherein the clock generation unit changes a clock for operating the signal processing circuit in accordance with a temperature measured by the temperature sensor. An imaging unit that captures subject light and generates and processes image signals;
A temperature sensor for measuring the temperature of the imaging unit;
An image display panel for displaying an image based on an image signal obtained by the photographing unit, and an image display unit having a backlight for illuminating the image display panel from the back surface;
The imaging apparatus, wherein the image display unit changes a light amount of the backlight according to a temperature measured by the temperature sensor.   The imaging apparatus according to claim 4, wherein the image display unit is an electronic viewfinder that allows an image to be viewed through eyes.   The photographing apparatus according to claim 4, wherein the image display unit is a liquid crystal display unit provided on a back surface of the body.   The photographing apparatus according to claim 2, wherein the temperature sensor includes a temperature measuring element. It has an image sensor consisting of CCD or CMOS,
2. The photographing apparatus according to claim 1, wherein the temperature sensor detects a temperature based on a potential difference generated before and after a junction provided on the CCD or CMOS. A method of suppressing heat generation in an imaging apparatus comprising: an imaging unit that captures subject light to generate and process an image signal; and a clock generation unit that generates a clock for operating the imaging unit,
A method for suppressing heat generation, wherein the temperature of the photographing unit is measured, and heat generation is suppressed by changing a frequency of a clock generated by the clock generation unit according to the measured temperature. An image capturing unit that captures subject light to generate and process an image signal, an image display panel that displays an image based on the image signal obtained by the image capturing unit, and a backlight that illuminates the image display panel from the back surface A method for suppressing heat generation in an imaging device including a display unit,
A method of suppressing heat generation, wherein the temperature of the photographing unit is measured, and heat generation is suppressed by changing the amount of light of the backlight according to the measured temperature.

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