WO2007063835A1 - Portable electronic device and its control method, and portable terminal and its display method - Google Patents

Abstract

A portable electronic device having low power consumption realized reliable and easily and its control method, and a portable terminal realizing legibility most suitable for use by users and its display method are provided. The portable electronic device comprises a display section in which numerous pixels having self-emitting elements are arrayed, a display information storage section for storing data on the whole region or a partial region of the display image to be displayed on the display section, a luminance information computing section for computing luminance information on all the pixels in the region from the stored data on the region, and a control unit for controlling the luminance of the pixels according to comparison of the computed luminance information and a threshold. The portable electronic device has display means, storage means for storing the luminance value of the display means according to an application, and control means for controlling the luminance of the display means according to the luminance value corresponding to the application and stored in the storage means when the application is displayed.

Description

 Portable electronic device and control method thereof, and portable terminal and display method thereof

 Technical field

 The present invention relates to a portable electronic device including a self-luminous element type display such as an organic EL display and a control method thereof.

 The present invention also relates to a battery-driven portable terminal such as a cellular phone device, a PDA (Personal Digital Assistant), a digital camera, and a portable television, and a display method thereof. This application claims priority to Japanese Patent Application 2005-343375 filed on November 29, 2005 and Japanese Patent Application 2005-343843 filed on November 29, 2005, the contents of which are hereby incorporated by reference. Incorporate.

 Background art

 [0002] In recent years, organic EL displays have been attracting attention in mobile phone devices. This organic EL display is a display using an organic EL element which is a self-luminous element, and has features such as high brightness, wide viewing angle, ultra-thinness and power saving. Some organic EL elements emit light in a single color, such as green, blue, and red. By combining these, a multi-color display can be created. In addition, since a knocklight is not required, it is highly demanded in the factory!

 [0003] However, an organic EL display consumes power as the light emission luminance of a pixel to be displayed increases! The higher the proportion of pixels with high luminance values in all pixels, the higher the power consumption. Becomes larger. In addition, in the case of devices based on text information such as e-mail and Web browsing, such as portable electronic devices, the character color and background color are distinguished and one of them is bright. In many cases, the other is low-luminance color information.

[0004] When an organic EL display is used in a mobile phone device or the like, the power consumption is reduced by correcting the display so that the background is black and the characters are white to reduce power consumption. There is a technique for reducing the above (see JP 2002-199078 A). In other words, the OLED display cuts off the supply of current to the OLED element when displaying black. In order to stop the light emission, no current is consumed in the pixels that display black, so the power consumption is reduced by making the background black and displaying most of the pixels black.

 [0005] Further, in the prior art, as a method of changing the luminance value of the display liquid crystal screen, there is a method of changing the luminance value from the menu of the screen. A technology for a power saving function that turns off the backlight when no operation is performed for a certain period of time is already known. In addition, as a technique for changing the luminance value, there is a technique for reducing power consumption by changing the screen of characters and the like from a white tone to a black tone (see, for example, JP 2002-199078 A). ). Disclosure of the invention

 Problems to be solved by the invention

[0006] However, in the above-described prior art, it is necessary to distinguish between character information and background information, and a natural image taken by a camera such as that used in current mobile phone devices is displayed by a user as a background image. If it is set to, or if the background is filled with characters, it is not possible to achieve an appropriate reduction in power consumption. Furthermore, since it is necessary to control the brightness information by distinguishing between character information and background information, complicated control is required.

 [0007] In the conventional technique, the luminance value of the display unit is changed to a specific value, but the setting value cannot be changed for each application. For this reason, the display screen was difficult to see for some applications. Also, it is inconvenient for the user to change the brightness value every time the application is changed. Also, since the screen is corrected regardless of the application, depending on the application, it may be necessary to correct more than necessary, or there may be almost no correction. As a result, the atmosphere (appearance, image, etc.) of the application may be impaired.

 [0008] In view of such a problem, an object of the present invention is to provide a portable electronic device and a control method thereof that can reduce power consumption more reliably and easily.

[0009] Further, the present invention provides a portable terminal and a display method that achieve optimal visibility for use by a user and reduce power consumption by changing a luminance value for each displayed application. The purpose is to provide. Means for solving the problem

 [0010] In order to achieve the above object, according to a first aspect of the present invention, there is provided a display unit in which a plurality of pixels each having a plurality of self-luminous elements are arranged, and all or part of a display image displayed on the display unit. A display information storage unit that stores data of the area, a data power of the area stored in the display information storage unit, a luminance information calculation unit that calculates luminance information for all the pixels in the area, And a control unit that controls the luminance of the pixels in the region based on a comparison between the luminance information calculated by the luminance information calculation unit and a threshold value.

 [0011] In the portable electronic device, the luminance information calculation unit may calculate average luminance per pixel as the luminance information! /.

 In the present invention, the power required for displaying a predetermined image can be estimated by calculating the average luminance per pixel as luminance information. For example, when the average luminance exceeds a threshold value, power consumption can be reduced by controlling the luminance of each pixel to be low.

 [0012] In the portable electronic device, the control unit has a plurality of threshold values, and the pixel of the region is based on the calculation result of the luminance information calculation unit and the plurality of threshold values. You can control the brightness of the stage step by step.

 In the present invention, a plurality of threshold values are provided, and the luminance of the pixels in the area stored in the display information storage unit is controlled stepwise based on the calculation result of the luminance information calculation unit and the plurality of threshold values. Thus, it is possible to provide a display image without giving a sense of incongruity to the user at the time of luminance switching while reducing power consumption.

 [0013] In the portable electronic device, the control unit, which may further include a battery remaining amount detection unit, may control the luminance of the pixels in the region according to the battery remaining amount.

In the present invention, when the remaining battery level is low by controlling the data of the area stored in the display information storage unit according to the remaining battery level so as to change the luminance of the pixels in this area, The luminance of the pixels in the display portion can be greatly reduced. Therefore, when the remaining battery level is low, the time when the battery runs out can be extended by reducing power consumption. [0014] The portable electronic device may further include an optical sensor, and the control unit may control the luminance of the pixels in the region in accordance with the brightness of ambient light.

 In the present invention, the control unit controls the data of the region stored in the display information storage unit so as to change the luminance of the pixels in this region according to the brightness of the ambient light. Can be reduced while reducing power consumption. If the surroundings are bright, leave the pixels emitting light with high brightness, while if the surroundings are dark, the user can see them even if the brightness of the pixels is low. The time when the battery runs out can be extended by lowering the power consumption.

[0015] In the second aspect of the present invention, the data power of all or a part of a region in a display image displayed on a display unit in which a large number of pixels having a plurality of self-luminous elements are arranged. This is a control method for a portable electronic device that calculates information and controls the luminance of the pixel in the region based on a comparison between the calculated luminance information and a threshold value. In the present invention, the data power of all or a part of a region in a display image displayed on a display unit in which a large number of pixels having a plurality of self-luminous elements are arranged is calculated and the luminance information is calculated for all the pixels in this region. By controlling the brightness of the pixels in the area based on the comparison between the brightness information and the threshold value, it is possible to display without any complicated control regardless of the image set by the user as the background. It is possible to reduce the power consumption of the part. In addition, the power consumption of the display unit can be reduced without degrading the image quality in any screen configuration. This makes it possible to reliably and easily reduce power consumption.

 [0016] In a third aspect of the present invention, a display unit, a storage unit that stores a luminance value in the display unit based on an application, and a luminance corresponding to the application in the storage unit when the application is displayed. And a control means for controlling the luminance of the display means based on the value.

[0017] Further, in the mobile terminal, the storage unit stores the luminance value in the display unit for each of a case where the application mainly displays text strings and a group mainly displays images. Then, the control means displays the application based on the luminance value corresponding to the group of the application. You may control the brightness value of the display means.

 [0018] Further, in the mobile terminal, the storage unit stores a luminance value in the display unit based on an area ratio on which a natural image is displayed with respect to a display screen, and the control unit displays the natural image on the display screen. When displaying the application, the area ratio of the natural image may be calculated, and the luminance of the display unit may be controlled based on the luminance value corresponding to the area ratio of the storage unit.

 [0019] In the portable terminal, the storage unit stores a luminance value in the display unit based on the remaining battery level, and the control unit acquires the remaining battery level and changes the remaining battery level. Further, the luminance of the display means may be controlled based on the remaining battery level of the storage means.

[0020] Further, in the portable terminal, the control unit may decrease the luminance value in accordance with an elapsed time after the operation unit is operated.

[0021] Further, in the portable terminal, the storage unit stores a luminance value in the display unit based on a display area of the application, and the control unit displays the application of the storage unit when displaying the application. The brightness value of the display means may be controlled based on the brightness value corresponding to the display area.

[0022] Further, in the portable terminal, the control means may decrease the luminance value according to the time that has passed since an event occurred!ヽ.

[0023] Further, in the portable terminal, the control means may decrease the luminance value according to the elapsed time after the screen update occurs.

[0024] Further, in the fourth aspect of the present invention, an application is specified, a luminance value corresponding to the specified result of the application is specified, and the brightness of the display screen is determined based on the specified luminance value. It is a display method that displays the application by controlling the degree.

 The invention's effect

 [0025] According to the present invention, it is possible to reduce the power consumption of the display unit without degrading the image quality in any screen configuration. This makes it possible to reduce power consumption reliably and easily.

[0026] Further, according to the present invention, by changing the luminance value for each application being displayed, it is possible to achieve optimal visibility for use by the user and to reduce power consumption. Can do.

Brief Description of Drawings

FIG. 1 is a block diagram schematically showing a configuration of a mobile phone according to an embodiment of the present invention.

 FIG. 2 is a flowchart showing a control method according to the first embodiment of the present invention.

 FIG. 3 is a diagram showing a display image based on data before control in the present invention.

 FIG. 4A is a diagram showing a display image based on data controlled by the control method of the first embodiment of the present invention.

 FIG. 4B is a diagram showing a display image based on data controlled by another control method of the first embodiment.

 FIG. 5 is a flowchart showing a control method for a mobile phone according to a second embodiment of the present invention.

 FIG. 6 is a table showing luminance levels used in the control method according to the second embodiment of the present invention.

 FIG. 7 is a flowchart showing a control method according to a third embodiment of the present invention.

 FIG. 8 is a diagram showing a remaining battery level table of a mobile phone according to the present invention.

 FIG. 9 is a flowchart showing a control method according to a fourth embodiment of the present invention.

 FIG. 10A is a diagram showing a brightness level table of the mobile phone according to the present invention when the ambient light is “喑 ヽ”.

 FIG. 10B is a diagram showing a luminance level table of the mobile phone according to the present invention when the ambient light power S is “normal”.

 FIG. 10C is a diagram showing a luminance level table of the mobile phone according to the present invention when the ambient light is “bright light”.

 FIG. 11 is a block diagram showing a configuration of a mobile terminal that is relevant to an embodiment of the present invention.

 FIG. 12 is a diagram showing an example of a reference table 56b used in a portable terminal that is effective in an embodiment of the present invention.

FIG. 13 is a diagram showing an example of a brightness value table 56a used in a mobile terminal according to an embodiment of the present invention. FIG. 14 is a diagram showing an example of a relative luminance value table 56d used by the display area determination unit 57 according to the embodiment of the present invention.

 FIG. 15 is a diagram showing an example of a relative luminance value table 56d used by the remaining battery level detector 58 according to the embodiment of the present invention.

 FIG. 16 is a diagram showing an example of an application group 56c used by the display type determination unit 55 that works according to the embodiment of the present invention.

 FIG. 17 is a flowchart showing the processing contents when the luminance value is changed for each application of the portable terminal that is relevant to the embodiment of the present invention.

 FIG. 18 is a flowchart showing the processing contents when the luminance value is changed for each application group of the portable terminal that is relevant to the embodiment of the present invention.

 FIG. 19 is a flowchart showing the processing contents when the luminance value is changed in accordance with the area ratio of the natural image in the display area of the mobile terminal according to the embodiment of the present invention.

FIG. 20 is a flowchart showing the processing contents when the luminance value is changed according to the remaining battery level of the mobile terminal, which is relevant to the embodiment of the present invention.

 FIG. 21 is a flowchart showing the contents of a process when a predetermined time of the mobile terminal that is relevant to the embodiment of the present invention has elapsed.

 FIG. 22 is a diagram showing an example of how to divide a screen image of a display screen that is relevant to an embodiment of the present invention into display areas.

 FIG. 23 is a diagram showing an example of a display area table showing a correspondence relationship when an area type is associated with a display area according to an embodiment of the present invention.

 FIG. 24 is a diagram showing an example of a region type table that associates a luminance value number to be referenced for each region type related to the embodiment of the present invention.

 FIG. 25 is a diagram showing an example of a screen image when the luminance value of the screen image of the display screen that is useful for the embodiment of the present invention is changed.

 FIG. 26 is a flowchart showing luminance change processing when the luminance value change magnification of the display screen according to the embodiment of the present invention is changed for each display region.

Explanation of symbols

1… Mobile phone 10 '… Control section

 11 '… Display information storage

 12 '… Luminance information calculator

 13 '… Brightness controller

 20 '··· EL display (display)

 21 '... EL display drive circuit

 30 '… Operation part

 31 '... ROM

 32 '... RAM

 33-Battery level detector

 34 '... microphone

 35 '·· Speaker

 36 '… Antenna

 37 '… Transmitter / receiver

 38 '··· Optical sensor (optical sensor)

 51 '… Transmitter / receiver

 52 '… Display

 53 '… Control part

 54 '··· Application judgment section

 55 '… Display type judgment part

 56 '' · · pL IM P¾

 57 '… Display area judgment part

 58 '-Battery level detector

 59 '··· Timer section

BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

Here, a mobile phone will be described as an example of the portable electronic device of the present embodiment. FIG. 1 is a block diagram showing the configuration of this embodiment. In FIG. 1, reference numeral 10 denotes a control unit that performs overall control of processing operations of the mobile phone 1, and includes a display information storage unit 11, a luminance information calculation unit 12, and a luminance control unit 13. Symbol 20 is an EL display unit that displays a battery level mark, a radio wave reception state indicator, a time display, an arbitrary image, and the like according to a signal output from the control unit 10, and is configured by an organic EL display. An image can be displayed. Reference numeral 21 denotes an EL display driving circuit for driving the EL display unit 20.

 [0030] The control unit 10 includes all or a predetermined part of a display image displayed on the EL display unit 20 in which a large number of pixels that also have organic EL element power, which is a self-luminous element, are arranged vertically and horizontally. The area data is stored in the display information storage unit 11, while the luminance information calculation unit 12 adds the luminance value Y of all the pixels that display the area data stored in the display information storage unit 11. Average to calculate the average luminance value per pixel. Then, the luminance control unit 13 controls the luminance value Y of all pixels that display the data of the area stored in the display information storage unit 11 based on the calculated average luminance value. The data converted by the luminance control unit 13 is displayed on the EL display unit 20 via the EL display drive circuit 21.

Reference numeral 30 denotes an operation unit that outputs a signal corresponding to the operation content by the user to the control unit 10. Reference numeral 31 denotes a ROM in which a program for operating the mobile phone 1 is stored in advance. Reference numeral 32 denotes a RAM that stores a program for displaying an image or the like on the EL display unit 20 as needed. Reference numeral 33 denotes a remaining battery level detection unit that detects the remaining battery level (power supply amount) of the mobile phone 1, and outputs the measured value detected here to the control unit 10. In addition, a display corresponding to the remaining battery level is displayed on the EL display unit 20 as a remaining battery level mark, and the user uses the mobile phone 1 while checking the remaining battery level by displaying the remaining battery level mark. And charge when the battery level is low. Reference numeral 34 denotes a microphone that collects the voice of the speaker, which converts the voice uttered by the user into a voice signal and outputs the voice signal. Reference numeral 35 is a speaker that emits the voice of the other party, and is produced by converting the voice signal into voice. Reference numeral 36 denotes an antenna that receives radio waves from the base station and transmits radio waves toward the base station. Reference numeral 37 denotes a transmission / reception unit that establishes wireless communication between the antenna 36 and the base station and realizes a telephone function and information communication. Reference numeral 38 denotes an optical sensor unit that measures the brightness around the mobile phone 1 during use. The measured value is output to the control unit 10. The control unit 10 controls the luminance of the EL display unit 20 according to the measurement value of the optical sensor unit 38.

 [0032] The electric circuit provided in the mobile phone 1 includes these control unit 10, EL display unit 20, EL display drive circuit 21, operation unit 30, ROM31, RAM32, battery remaining amount detection unit 33, microphone 34, A speaker 35, an antenna 36, a transmission / reception unit 37, and an optical sensor unit 38 are included.

 Next, the EL display unit 20 will be described. The EL display unit 20 has a number of pixels composed of organic EL elements, which are self-luminous elements, arranged vertically and horizontally, in this case, 240 × 320 pixels. Each of these pixels emits light, and a large number of pixels emit light continuously to form an arbitrary image. One pixel is composed of three organic EL elements of red, green, and blue (i.e., RGB), and the emission color of the entire pixel is formed by adjusting the emission intensity of each of these organic EL elements. Yes.

 As described above, the pixel can produce various colors depending on the emission intensity of each of the red, green, and blue organic EL elements. Each RGB value (light intensity) of each organic EL element is defined to vary between 0 and 255. For example, according to the law of the three primary colors of light, not only can yellow and purple be produced, but all three organic EL elements emit strong light, and if the RGB values are all “255”, “white”, conversely If all RGB values are “0” without emitting light, the background color of the display, that is, “black” can be expressed. In this way, the light emission color of the pixel can be indicated by a combination (pattern) of the signal indicating the light emission intensity for each of the three organic EL elements for each pixel, and the image is displayed on the EL display unit 20. A little In other words, by performing pattern instructions for the RGB values of the pixels for multiple pixels, the color display for each pixel in the EL display unit 20 is changed, and the display object such as characters, symbols, icons, etc., and its background The color can be displayed. There is no special backlight because the organic EL element itself emits light.

 [0035] However, white display, that is, high-luminance light emission is directly reflected in power consumption, and a display image based on white is more power-consuming than a display image based on black. Will increase. Therefore, in order to reduce power consumption, it is necessary to reduce the luminance without changing the hue of the pixel.

[0036] Depending on the three primary colors RGB, the luminance value Y (luminance information) and the color difference (difference from the reference color) U, V and Can be requested.

 These Y, U, and V are obtained, for example, by the following formula.

 Y = 0. 299R + 0. 587G + 0. 114Β (1)

 U = — 0. 169R-0. 331G + 0. 500B (2)

 V = 0. 500R-0. 419G-0. 081B (3)

[0037] U is the difference from blue, V is the difference from red, and sometimes U = Cb, V = Cr. For example, when the value of U is small, it becomes green, and when the value of U becomes large, blue is displayed. When the value of V is small, the color is green, and as the value of V is large, the color is red. Thus, Y represents the luminance per pixel, that is, the brightness, and U and V represent the color. From the above, it is possible to control only the luminance value Y without changing the pixel color. Therefore, the power consumption can be reduced by controlling the luminance of the pixels to be displayed without changing the display image.

Note that the RGB value of the pixel after changing the luminance value Y can be obtained, for example, by the following equation.

 R = 1. OOOY + 1. 402V (4)

 G = 1. OOOY-O. 344U-0. 714V (5)

 Β = 1. OOOY + 1. 772U (6)

 Here, since the display color remains as it is, only the brightness of the pixel is controlled, and U and V do not need to be changed, and the value when the brightness value Y is obtained is used as it is.

Next, the operation of the mobile phone 1 having the above configuration, that is, the method for controlling the mobile electronic device according to the present embodiment will be described.

 FIG. 2 is a flowchart showing a first embodiment of the control method of the mobile phone 1. This flowchart shows a process from acquiring an image to be displayed to controlling the luminance of a pixel indicating data of a predetermined area in the image and displaying it on the EL display unit 20. When the power is turned on, when a predetermined operation is performed by the user, or when the operation is on standby, it is performed as needed until the power is turned off.

[0040] In the control method of the first embodiment, the display information storage unit 11 stores the data of the entire display image to be displayed on the EL display unit 20 or a predetermined partial region (step S1). The luminance value Y and color difference U, V for all the pixels that display the data in the stored area are described above. The luminance value Y of each pixel calculated by the equations (1) to (3) is added and averaged by the luminance information calculation unit 12 to obtain an average luminance value per pixel (step S2). Then, the average luminance value obtained in step S2 is compared with a preset threshold value (a predetermined value between 0 and 255) to determine whether the average luminance value exceeds the threshold value (step S3 ), If this determination result is `` Yes '', the luminance control unit 13 sets the luminance value Y of each pixel without changing the hue of all the pixels that display the data of the area stored in step S1. For example, control is performed so that it is reduced to about 50% from the default value, and using the brightness value Y after control and the values of the color differences U and V similar to those before control, the above equations (4) to (6) To calculate the RGB value after control and display the processed data on the EL display unit 20 (steps S4 and S5). On the other hand, if the determination result in step S3 is “No”, the process is terminated without controlling the luminance value Y, and the data is displayed on the EL display unit 20 as it is (step S5).

Thus, in the flowchart shown in FIG. 2, when the average luminance value of all the pixels belonging to the designated screen area is compared with the threshold value, the average luminance value exceeds the threshold value, that is, the high luminance value. In the case of an image containing a large number of pixels, the display image that should have been displayed as shown in Fig. 3 on the EL display unit 20 is controlled by controlling the luminance to be lowered without changing the hue of the display image. As shown in Fig. 4A, the brightness of the entire display screen is controlled to be low. In Fig. 4A, the power of the battery remaining mark, the mail reception mark, the time, and the operation display mark is controlled to decrease. As shown in Fig. 4B, only the brightness of the background image is controlled. The brightness of the mark, mail reception mark, time, and operation display mark may be controlled so as not to change.

 Regardless of the V deviation, it is possible to effectively reduce the power consumption by reducing the luminance of the pixels of the whole or part of the display image.

It should be noted that the setting of the image area stored in the display information storage unit 11 may be appropriately changed by the user. Further, the calculation of the average luminance value in step S2 may be performed every time for all the pixels in the data stored in the display information storage unit 11, or the luminance value of each pixel in the previously stored data is calculated. It is also possible to save and control only the changed pixels. In the above description, the calculation result of the display information storage unit 11 is used as the average luminance value. However, other values such as the total luminance value of all pixels are used. May be. Further, the threshold value and the luminance level may be appropriately changed by the user. The same applies to the following embodiments (second embodiment to fourth embodiment).

FIG. 5 is a flowchart showing a second embodiment of the control method of the mobile phone 1.

 In this flowchart, the luminance levels of all the pixels that display the data in the area stored in the display information storage unit 11 are selected based on the luminance level table shown in FIG. This pattern table is used to determine the luminance level according to the average luminance value per pixel calculated by the luminance information calculation unit 12, and a plurality of specific values set between 0 and 255, specifically three The brightness level is set stepwise in association with the threshold value.

[0044] In the control method of the second embodiment, for example, the data of the entire display image displayed on the EL display unit 20 or a predetermined part of the data is stored in the display information storage unit 11 (step S1). Then, the luminance information calculation unit 12 adds and averages the luminance value Y for all the pixels displaying the data in the stored area to obtain the average luminance value per pixel (step S2). The luminance level corresponding to the average luminance value obtained in step S2 is obtained from the table shown in FIG. 6 and stored in step S1 so that the luminance control unit 13 emits light according to the corresponding luminance level. The luminance value Y is controlled without changing the hue of all the pixels displaying the data in the area (step Sal), and the processed data is displayed on the EL display unit 20 (step S5).

 As described above, in the luminance level table shown in FIG. 6, the luminance level of each pixel is set in a stepwise manner according to the average luminance value of all the pixels belonging to the designated screen area as the calculation result. For example, when the average luminance value is in the range of 0 to less than 63, the luminance level of each pixel is set to 90%, and the luminance value based on the data stored in step S1 is controlled to be 10% lower. When the average luminance value is within the range of 63 to less than 127, the luminance level is 80%, and when the average luminance value is within the range of 127 to less than 191, the luminance level is 70% and the average luminance value is between 191 and 255 or less. If it is within the range, the luminance level is lowered so that the luminance level becomes 60%, and the light emission of each pixel is suppressed. In this way, it is possible to reduce the power consumption more effectively by reducing the luminance level significantly for an image with many pixels having a high luminance value.

FIG. 7 is a flowchart showing a third embodiment of the control method of the mobile phone 1. In this flowchart, the luminance levels of all the pixels displaying the data of the area stored in the display information storage unit 11 are selected based on the luminance table for each remaining battery level shown in FIG. This pattern table is used to determine the luminance level according to the average luminance value per pixel calculated by the luminance information calculation unit 12 and the remaining battery level detected by the remaining battery level detection unit 33. The brightness level is set in steps in association with the three threshold values set between 255 and the remaining battery level set in three steps.

 [0047] In the control method of the third embodiment, the display information storage unit 11 stores the data of the entire display image to be displayed on the EL display unit 20 or a predetermined partial region (step S1). Then, the luminance information calculation unit 12 adds and averages the luminance information for all the pixels displaying the data in the stored area to obtain an average luminance value per pixel (step S2). Further, the remaining battery level of the mobile phone 1 is obtained from the remaining battery level detection unit 33 (step Sbl), and the brightness corresponding to the average brightness value obtained in step S2 and the remaining battery level obtained in step Sb1. The brightness table power for each remaining battery level is also obtained (step Sb2), and the brightness control unit 13 displays the data of the area stored in step S1 so that light emission is performed according to the corresponding brightness level. The luminance value is controlled without changing the hue of all the pixels to be displayed, and the processed data is displayed on the EL display unit 20 (step S5). In some cases, display is performed on the EL display unit 20 without control (step S5).

That is, in the luminance table for each remaining battery level shown in FIG. 8, the luminance level of each pixel is set according to the average luminance value per pixel and the remaining battery level in all pixels belonging to the designated screen area. As for the remaining battery level, a threshold is set to normally divide it into three levels until the full force is empty. Set full to “3” and set the remaining battery level to “1” to “1”. In addition, although three threshold values are provided and the luminance level is set to four levels, the present invention is not limited to this and may be set to any number of levels. Here, for example, if the average brightness value is a low brightness value in the range of 0 to less than 63 and the battery level is “3”, the brightness value is not changed and the data stored in step S1 is not changed. The display image is displayed with the luminance value based on the. On the other hand, if the average brightness value is a high brightness value in the range of 191 to 255 and the remaining battery level is low, the status is `` 1 '', which is half the brightness value based on the data stored in step S1. Controlled to decrease. Also, even if the average brightness is the same, the remaining battery power is low. If the battery level is low (1), the power level is reduced by lowering the brightness level of each pixel than when the battery level is high (3). Can be further extended. As described above, the power consumption can be effectively reduced by changing the decrease rate of the luminance value of each pixel in accordance with the remaining battery level.

FIG. 9 is a flowchart showing a fourth embodiment of the control method of mobile phone 1.

 In this flowchart, the luminance levels of all the pixels displaying the data of the area stored in the display information storage unit 11 are selected based on the luminance table for each ambient light shown in FIG. This pattern table determines the luminance level according to the average luminance value per pixel calculated by the luminance information calculation unit 12, the remaining battery level, and the intensity of ambient light of the mobile phone 1. The ambient light detected by the light sensor unit is “dark” (Fig. 10A), “normal” (Fig. 1 OB), “ Brightness (Fig. 10C) is a stepwise setting of the luminance level that is judged in three levels of light conditions.

 [0050] Here, as for the intensity of ambient light, for example, the situation where the mobile phone 1 is used in a "bright" situation is assumed to be "ordinary" assuming that it is used outdoors under strong sunlight. The situation is assumed to be used under indoor lighting such as fluorescent lamps, and the situation that is “dark” is assumed to be used at night, when there is no light such as lighting. And

[0051] In the control method of the fourth embodiment, the display information storage unit 11 stores the data of the entire display image to be displayed on the EL display unit 20 or a predetermined partial region (step S1). Then, the luminance information calculation unit 12 adds and averages the luminance information for all the pixels displaying the data in the stored area to obtain an average luminance value per pixel (step S2). Further, the optical sensor unit 38 acquires the ambient light intensity of the cellular phone 1 and the battery level detection unit 33 to acquire the remaining battery level (step Scl). The ambient light of the cellular phone 1 obtained in step Scl is obtained. A pattern table corresponding to the intensity of the battery and the remaining battery level is selected, and the brightness level corresponding to the average brightness value obtained in step S2 is obtained from the selected pattern table (step Sc2). The luminance value is controlled without changing the hue of all the pixels that display the data of the area stored in step S1 so that the light emission according to the corresponding luminance level is performed. Display is performed (step S5). Also In some cases, display is performed on the EL display unit 20 without control (step S5).

That is, in the brightness table for each ambient light shown in FIG. 10, the pattern table is selected according to the ambient light in addition to the remaining battery level when the mobile phone 1 is used, and stored in the display information storage unit 11. The luminance level of each pixel is set according to the average luminance value per pixel and the remaining battery level in all pixels displaying the data. As described above, the threshold for judging the remaining battery level is set in three levels until the full force is empty, full is set to “3”, and empty is set to “1”. The threshold of average luminance value is set in 4 levels. For example, as shown in FIG. 10C, when the ambient light is detected as “bright”, the average luminance value is in the range of 0 to less than 63, and the remaining battery level is “3”, the luminance value is changed. The display image is displayed with the brightness value based on the data stored in step S1. On the other hand, as shown in FIG. 10A, when the ambient light is detected as “dark” and the average luminance value is in the range of 191 to 255 and the remaining battery level is “1”, step S1 The brightness is controlled to drop to less than half of the brightness value based on the data stored in (a brightness level of 40%). Also, referring to FIG. 10A and FIG. 10C, when the ambient light is determined to be “残 量 ヽ” even with the same average luminance value and battery level, the ambient light is “bright ヽ”. ”Lower the brightness level of each pixel than in the case.

 [0053] This means that when the mobile phone 1 is used in a dark environment, it can be visually recognized even if the luminance level of the EL display unit 20 is low. By reducing the brightness level compared to using the mobile phone 1 below, it is possible to extend the battery exhaustion period.

 [0054] Note that, in the above, the force in which three threshold values are provided and the luminance level is set at four levels is not limited to this, and may be set at any level. By setting more thresholds and changing the luminance level to be changed in stages, the luminance change of the display image viewed from the user can be reduced. Further, the threshold setting may be freely changed.

From the above, according to the present embodiment, all or part of the data in the display image to be displayed on the EL display unit 20 is stored in the display information storage unit 11, and this region data power is also stored. Luminance information for all pixels in this area is calculated by the luminance information calculation unit 12, and based on the comparison between the luminance information and the threshold value, the luminance control unit 13 stores the information in the display information storage unit 11. By controlling the stored area data so as to change the brightness of the pixels in this area, the power consumption of the EL display unit 20 is reduced regardless of the image set by the user as the background. This is possible without requiring complicated control. In addition, the power consumption of the EL display unit 20 can be reduced without degrading the image quality in any screen configuration. This makes it possible to reduce power consumption reliably and easily.

 [0056] Further, by calculating the average luminance per pixel as the luminance information, it is possible to estimate the power required for displaying a predetermined image. That is, when this average luminance exceeds a preset threshold value, power consumption can be reduced by controlling the luminance of each pixel to be low.

 [0057] In addition, by having a plurality of threshold values and controlling the data in the area stored in the display information storage unit 11 stepwise based on the calculation result of the luminance information calculation unit 12, power consumption can be reduced. As a result, a good display image can be provided without causing the user to feel uncomfortable when switching the luminance.

 [0058] Furthermore, by controlling the area data stored in the display information storage unit 11 according to the remaining battery level so as to change the brightness of the pixels in the area, The brightness of the display unit 20 can be significantly reduced. Therefore, when the remaining battery level is low, the time when the battery runs out can be extended by reducing power consumption.

 [0059] Further, since the mobile phone 1 includes the light sensor unit 38, the area data stored in the display information storage unit 11 is converted to the brightness of the pixels in this area according to the brightness of the ambient light. By controlling to change, it is possible to reduce the power consumption while displaying the image of the EL display unit 20 satisfactorily. In other words, when the surroundings of the mobile phone 1 are bright, the pixels are allowed to emit light with high luminance. On the other hand, when the surroundings are dark, the user can see even if the luminance of the pixels is low. Decreasing the brightness can reduce the power consumption and extend the time when the battery runs out.

In this embodiment, the luminance value to be changed is shown as a reduction rate with respect to the default luminance. The display data is processed based on this reduction rate. In addition to this process, the current, voltage, and light emission time (duty on the display unit) are displayed. The ratio may be realized by controlling the luminance based on the luminance value to change the luminance of the screen.

 While the present invention has been described with reference to the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit and intention of the present invention.

 Hereinafter, another embodiment of the present invention will be described with reference to the drawings. FIG. 11 is a block diagram showing the configuration of the mobile terminal (mobile device) according to this embodiment. The mobile terminal in FIG. 11 includes a transmission / reception unit 51 that performs transmission / reception with a base station, a display unit 52 that includes a display device and a display control unit, a control unit 53 that controls the entire device, and an application that is currently displayed. An application determination unit 54 for determining whether the content displayed on the screen is text data or a natural image, a luminance value table 56a, a reference table 56b, Storage group 56 storing each table of application group 56c and relative luminance value table 56d, and display area determination that identifies the area of a natural image such as a photographic image displayed on the screen and performs processing according to the determination result Unit 57, battery level detection unit 58 that detects the battery level (not shown) of the battery (not shown) of the terminal (apparatus), and performs processing according to the detection result. Receive Etc.) and a timer unit 59 for setting the force and the timer.

The control unit 53 notifies the display unit 52 of the contents to be drawn at the time of screen drawing. After being set when the application is started, the timer unit 59 resets the timer every time there is a key operation, and notifies the control unit 53 when the timer expires. Note that the timer unit 59 is not necessarily limited to every key operation, and an event may occur to reset the force timer. The brightness value table 56a in the storage unit 56 is also referred to by the application determination unit 54 and the like, and the application group 56c stores a group of applications. Note that the luminance value table 56a in the storage unit 56 may be prepared individually by the application determination unit 54, the display type determination unit 55, the display area determination unit 57, and the remaining battery level detection unit 58. The luminance value table 56a may be shared and used by the application determination unit 54 and the like. Of the tables stored in the storage unit 56, the luminance value table 56a and the application group 56c may be combined into one force. FIG. 12 is an example of a reference table 56b used by the application determination unit 54. The reference table 56b in FIG. 12 includes an application column and a reference luminance value number column, and designates a reference luminance value number for each application. Note that a luminance value number may be provided for each application, or a plurality of applications may refer to the same luminance value number.

 FIG. 13 is an example of the brightness value table 56a. The luminance value table 56a in FIG. 13 includes a luminance value No. column and a luminance value column. Here, the luminance value in FIG. 13 is a parameter for changing the luminance value, and the luminance value increases as the value increases. The luminance value after the change can be obtained by the following formula, for example.

 Luminance value after change = (Original luminance value) X (Luminance value) (7) The display unit 52 obtains the color to be displayed on the screen and draws it on the screen.

 Since the luminance value No. referenced by the telephone in Fig. 12 is "1", the luminance value is 0.6 from Fig. 13, so the luminance value of the pixel after the change is 60% of the original luminance value. It will be. Although only one brightness value table 56a is described in FIG. 13, a plurality of brightness value tables 56a may be prepared and used according to the application.

 FIG. 14 is an example of a relative luminance value table 56d used by the display area determination unit 57 when the area ratio of the natural image changes. The relative luminance value table 56d in FIG. 14 is composed of a display area and a natural image area ratio column and a luminance value No. relative level column, and the natural image of the area ratio divided into four levels. When “” is displayed, it indicates which luminance value number is to be changed relatively from each luminance value number used.

 [0066] For example, if the area ratio of the natural image to be displayed is 70% at the current luminance value No. power, the relative level of the luminance value No. to which 70% belongs from the relative luminance value table 56d. Is -1, so lower the brightness value number by one step and change the brightness value number to 3. If the area ratio of the natural image to be displayed is 50% at the current luminance value No. ¾, the relative level is 2, but neither can be lowered. It shall be changed to 1.

FIG. 15 is an example of a relative luminance value table 56d used when the remaining battery level changes. The relative luminance value table 56d in Figure 15 shows the relative levels of the remaining battery level and the luminance value number. This indicates the brightness value number that should be changed from the currently used brightness value number when the remaining battery level is divided into 5 levels. .

 [0068] For example, if the remaining battery level changes to 3 at the current brightness value No. power, the relative stage of the brightness value No. is 1 from the relative brightness value table, so the brightness value No. Change the brightness value No. to 3 by lowering. If the display is charging, do not change the brightness value number.

 FIG. 16 is an example of an application group 56c stored in the storage unit 56. The application group 56c shown in Fig. 16 includes an application gnole field, an application field, a reference brightness value number field, and a force. The application group 56c includes an application currently displayed by the display type determination unit 55. Used to determine the group to which it belongs. The application registered in the application group may be registered so that the user can change the registered Z change Z. It is also possible to allow the user to register application Z change Z deletion Z.

 Next, the operation of the present embodiment will be described with reference to the drawings. Figure 17 shows the processing flow for changing the brightness for each application. The following operations are performed at the timing when the control unit 53 draws the screen. In this example, application B is assumed to be email.

 In step S101, the control unit 53 checks whether or not another application B is displayed with respect to the application A that is currently drawing the screen, and determines whether or not the screen drawing is started. If started, the process proceeds to step S102. If not started, step S101 is repeated.

 In step S102, the application determination unit 54 determines and identifies application B.

 In step S103, the control unit 53 refers to the mail from the brightness value reference table 56b in the storage unit 6 based on the identified application B, and acquires the brightness value No. 3 corresponding to the application B (mail). .

In step S104, the control unit 53 stores the luminance value No. obtained in step S103. Find the brightness value of 0.8 in club 6.

In step S105, the control unit 53 notifies the display unit 52 of the luminance value.

 In step S106, the display unit 52 obtains the luminance value of the screen image.

 In step S107, the display unit 52 obtains the changed luminance value using the equation (7)).

 In step S108, the display unit 52 creates a screen image based on the changed luminance value. In step S109, the display unit 52 screen-draws the screen image created in step S108.

 [0072] Here, in the above embodiment, as an embodiment, the force described in the process (S106 to S109) for obtaining and drawing the luminance value of the screen image is controlled in step S105 instead of steps S106 to S109. The unit 53 notifies the corresponding luminance value to the display unit, and the display unit controls the current, voltage, light emission time (duty ratio), etc., and the screen luminance is based on the notified luminance value. This can be achieved by lowering the control.

 FIG. 18 is a processing flow when changing the brightness for each application group.

 The following operation is performed at the timing when the control unit 53 performs screen drawing. In this example, it is assumed that mail is selected by the application.

 In step S201, the control unit 53 checks whether or not an application B that is different from the application A that is currently drawing the screen is displayed, and determines whether or not the screen drawing is started. If started, the process proceeds to step S202. If not started, step S201 is repeated.

 In step S202, the application determination unit 54 determines and identifies application B.

 In step S203, the control unit 53 obtains the “text character string” that is the application group to which the application B of the identified mail belongs from the application group in the storage unit 56.

In step S204, the luminance value No. 3 corresponding to the application group is acquired from the application group in the storage unit 56. In step S205, the control unit 53 obtains the luminance value 0.8 in the storage unit 56 based on the luminance value No. acquired in step S204.

In step S206, the control unit 53 notifies the display unit 52 of the luminance value.

 In step S207, the display unit 52 obtains the luminance value of the screen image.

 In step S208, the display unit 52 obtains the changed luminance value using the equation (7)).

 In step S209, the display unit 52 creates a screen image based on the changed luminance value. In step S210, the display unit 52 screen-draws the screen image created in step S209.

 [0075] Here, in the above embodiment, as an embodiment, a process (S207 to S210) for obtaining and drawing the luminance value of the screen image is described! /, A force to be used instead of steps S207 to S210. In S206, the control unit 53 notifies the corresponding luminance value to the display unit, and the display unit controls the current, voltage, light emission time (duty ratio), etc., and the screen luminance is set to the notified luminance value. Based on this, it can be realized by lowering control.

 FIG. 19 is a processing flow when changing the luminance in accordance with the area ratio of the natural image in the display area. The following operation is performed at the timing when the control unit 53 performs screen drawing. In this example, the area ratio of natural images is 70%.

 Here, a natural image (natural image) is an image obtained by a camera or video, such as photo data.

 In step S301, the control unit 53 checks whether or not an application B that is different from the application A that is currently drawing the screen is displayed, and determines whether or not the screen drawing is started. If started, the process proceeds to step S302. If not started, the process proceeds to step S307.

 In step S302, the application determination unit 54 determines and identifies application B.

In step S303, the control unit 53 obtains the “natural image” of the application group to which the identified application B belongs from the application group in the storage unit 56. In step S304, the luminance value No. 4 corresponding to the application group is acquired from the application group in the storage unit 56.

 In step S305, the control unit 53 determines whether the screen (scene) to be displayed is a screen that handles natural images. If the screen handles a natural image, the process proceeds to step S306. If it is not a screen that handles natural images, the process proceeds to step S310.

 In step S306, the control unit 53 obtains the area ratio between the display area displayed by the application and the natural image.

 In step S307, the control unit 53 is a relative stage of the corresponding luminance value No. based on the relative luminance value table stored in the storage unit 56 based on 70% of the area ratio obtained in step S306. Ask for one.

 In step S308, the control unit 53 obtains a new luminance value No. 3 from the relative stage 1 obtained in step S307 and the luminance value No. 4 obtained in step S304.

 (New luminance value No. = luminance value No. obtained in step S304 + relative stage obtained in step S307)

 [0078] In step S309, the control unit 53 obtains 0.8 of the luminance value in the storage unit 56 based on the luminance value No. obtained in step S308.

 In step S310, the control unit 53 notifies the display unit 52 of the luminance value.

 In step S311, the display unit 52 obtains the luminance value of the screen image.

 In step S312, the display unit 52 obtains the changed luminance value using the equation (7)). In step S313, the display unit 52 creates a screen image based on the changed luminance value. In step S314, the display unit 52 screen-draws the screen image created in step S313.

[0079] Here, in the above-described embodiment, as an embodiment, the force describing the process (S311 to S314) for obtaining and drawing the luminance value of the screen image is described. The control is performed in step S310 instead of steps S311 to S314. Section 53 notifies the corresponding brightness value to the display section, and the display section controls the current, voltage, duration of light emission (duty ratio), etc., and is notified of the screen brightness. Depending on the brightness value, it may be realized by lowering control.

 [0080] In Fig. 19, the force when using the application group type is also applicable when using the application type of Fig. 17. In this case, after obtaining the luminance value No. in step S103, it is determined whether or not the screen is a screen that handles natural images in step S305.

 FIG. 20 is a processing flow when changing the luminance according to the remaining battery level. Here, the control unit 53 periodically acquires the remaining battery level, and the following operations are performed at the timing when the control unit 53 acquires the remaining battery level from the remaining battery level detection unit 58. The process of FIG. 20 operates independently of the processes of FIGS. 17 to 19 and can be performed simultaneously with FIGS. In this example, the case where the remaining battery level is 3 is taken as an example.

 In step S 401, control unit 53 acquires the remaining battery level from remaining battery level detection unit 58.

 In step S402, the control unit 53 compares the remaining battery level acquired in step S401 with the previously acquired battery level.

 In step S403, based on the remaining battery level 3 obtained in step S402 by the control unit 53, the relative luminance value No. 1 of the corresponding luminance value No. is stored in the relative luminance value table 56d in the storage unit 56. Ask for.

 In step S404, the control unit 53 obtains the relative level —1 obtained in step S403, the luminance value No. 3 and the force possessed by the control unit 53, and the new luminance value No. 2.

(New luminance value No. = luminance value No. held by control unit 53 + relative stage obtained in step S403)

 [0083] In step S405, the control unit 53 obtains 0.7 of the luminance value from the luminance value table 56a in the storage unit 56 based on the luminance value No. obtained in step S404.

 In step S406, the control unit 53 notifies the display unit 52 of the luminance value.

 In step S407, the display unit 52 obtains the luminance value of the screen image.

 In step S408, the display unit 52 obtains the changed luminance value using the equation (7)).

In step S409, the display unit 52 creates a screen image based on the changed luminance value. In step S410, the display unit 52 creates the screen image created in step S409. Draw.

 [0084] Here, in the above embodiment, as one embodiment, a process (S407 to S410) for obtaining and drawing the luminance value of the screen image is described! /, The power to be used instead of steps S407 to S410. In S406, the control unit 53 notifies the corresponding luminance value to the display unit, and the display unit

It can be realized by controlling the voltage, the light emission time (duty ratio), etc., and lowering the screen brightness based on the notified brightness value.

FIG. 21 is a processing flow when a predetermined time has elapsed (when there is no user operation). The process of FIG. 21 operates independently of the processes of FIGS.

It can be done at the same time as 20.

 In step S501, the control unit 53 instructs the timer unit 59 to set the timer when a user operation, a screen update, an event occurs, or the like. The timer unit 59 sets the timer with the instruction.

 In step S502, when the timer time expires, the timer unit 59 notifies the control unit 53 and proceeds to step S503. If it has not expired, proceed to step S502. In step S503, the control unit 53 acquires the current luminance value number.

 In step S504, based on the notification sent from the timer unit 59, the control unit 53 decreases the luminance value number held by the control unit 53 by one.

[0086] In step S505, the control unit 53 obtains the luminance value from the luminance value table inside the storage unit 56 based on the luminance value No. obtained in step S504.

 In step S506, the control unit 53 notifies the display unit 52 of the luminance value.

 In step S507, the display unit 52 obtains the luminance value of the screen image.

 In step S508, the display unit 52 obtains the changed luminance value using the equation (7)).

 In step S509, the display unit 52 creates a screen image based on the changed brightness value. In step S510, the display unit 52 screen-draws the screen image created in step S509.

Here, in the above embodiment, as one embodiment, the process of obtaining and drawing the luminance value of the screen image (S507 to S510) is described! /, The power to be output instead of steps S507 to S510. In step S506, the control unit 53 notifies the corresponding luminance value to the display unit, and the display unit controls the current, voltage, duration of light emission (duty ratio), etc., and the luminance value notified of the screen luminance. Based on the above, it can be realized by lowering control.

 Next, a case will be described in which the screen image of the display screen is divided into display areas and the luminance value is associated with each display area of the display screen. Fig. 22 shows an example of how to divide the screen image of the display screen into display areas. FIG. 23 is an example of an area type table showing luminance value numbers to be referenced for each area type. FIG. 24 is an example of a display area table showing the correspondence when the area type is associated with the display area. In setting the brightness value of each display area, set the brightness value number for each “area type” as shown in FIG. The screen image is divided by the application, and the display area coordinates and area type are notified to the display unit 52 every time the display area changes. The display unit 52 specifies the luminance value table 56a based on the region type notified of the application power, and changes the luminance value based on the luminance value table 56a that specifies the luminance value in the display region.

 FIG. 25 shows an example of a screen image when the luminance value is changed for the entire screen. For the screen image before the change, if the brightness values are 0.9 and 0.6, it can be seen that the brightness decreases in order. FIG. 25 shows an example in which the brightness value change for each display area is performed on the screen image before the change when the display area is set as shown in FIG. In addition, the display type of each display area at this time is as shown in FIG. Display area 1 has a luminance value No. 1 (luminance value 0.6), so the brightness is almost halved. Display area 2 has a luminance value No. 5 (brightness value 1.0), so the brightness is low. Has not changed.

 [0090] It should be noted that the number of display areas into which the screen image is divided and the shape of the display areas are not limited. However, if the display area to be divided increases or the shape of the display area is complicated, it takes time for processing to change the screen image in the display unit 52. Therefore, a restriction may be provided for each abrasion. Further, the area type item may be a functional distinction such as a menu, a pitato, an image display area, etc., as shown in FIG.

FIG. 26 is a flowchart showing the process of changing the brightness when the brightness value change magnification of the display screen is changed for each display area. The following operations are the timing when the control unit 53 draws the screen. It shall be done in

 In step S601, the control unit 53 checks whether or not another application B different from the application A that is currently drawing the screen is displayed, and determines whether or not the screen drawing is started. If started, the process proceeds to step S602. If not started, the process proceeds to step S603.

 In step S602, the application determination unit 54 determines and identifies application B.

 In step S603, the control unit 53 acquires the area type table in the storage unit 56, and acquires the display area table from the application.

In step S604, the control unit 53 checks whether the display area table has changed from the previous time. If it has changed, the process proceeds to step S605. If not, the process returns to step S601.

 In step S605, the control unit 53 acquires a brightness value number corresponding to the region type from the region type table.

 In step S606, the control unit 53 also acquires the luminance value of the luminance value table force.

 In step S607, the control unit 53 notifies the display unit 52 of the coordinates of the display area notified from the application and the luminance value obtained in step S606.

[0093] In step S608, the display unit 52 obtains the luminance value of the display area.

 In step S609, the display unit 52 obtains the changed luminance value using the equation (7)). In step S610, the display unit 52 creates a screen image based on the changed luminance value. In step S611, the display unit 52 draws the screen image created in step S610.

 The processing from step S605, step S606, and step S608 to step S611 is performed for the entire display area.

[0094] Here, in the above-described embodiment, as one embodiment, a process (S608 to S611) for obtaining and drawing the luminance value of the screen image is described! /, The power to be used instead of steps S608 to S611. In S607, the control unit 53 notifies the corresponding luminance value to the display unit, and the display unit It can be realized by controlling the voltage, the light emission time (duty ratio), etc., and lowering the screen brightness based on the notified brightness value.

 The present invention is suitable for use in a portable terminal and a display method by battery driving, such as a cellular phone device, a PDA (Personal Digital Assistant), a digital camera, and a portable television. In addition, the luminance value to be changed according to the present invention indicates a reduction rate with respect to the default luminance, and the reduction method is not limited to the present embodiment, and various methods can be used without departing from the spirit and intention of the present invention. Deformation is possible.

Claims

The scope of the claims

 [1] a display unit in which a large number of pixels having a plurality of self-luminous elements are arranged;

 A display information storage unit for storing data of all or a part of a region of a display image to be displayed on the display unit;

 A luminance information calculation unit that calculates luminance information for all the pixels in the region from the data in the region stored in the display information storage unit;

 A portable electronic device comprising: a control unit that controls the luminance of the pixel in the region based on a comparison between the luminance information calculated by the luminance information calculation unit and a threshold value.

 2. The portable electronic device according to claim 1, wherein the luminance information calculation unit calculates an average luminance per pixel as the luminance information.

[3] The control unit has a plurality of the threshold values, and controls the luminance of the pixels in the region stepwise based on the calculation result of the luminance information calculation unit and the plurality of threshold values. Claim

The portable electronic device according to 1.

[4] The portable electronic device according to [1], further comprising a battery remaining amount detecting unit, wherein the control unit controls the luminance of the pixels in the region according to the remaining amount of the battery.

5. The portable electronic device according to claim 1, further comprising an optical sensor, wherein the control unit controls the luminance of the pixel in the region according to the brightness of ambient light.

[6] Data power of all or part of a region in a display image displayed on a display unit in which a large number of pixels having a plurality of self-light-emitting elements are arranged.

 A method for controlling a portable electronic device, which controls the luminance of the pixel in the area based on a comparison between the calculated luminance information and a threshold value.

[7] display means;

 Storage means for storing a luminance value in the display means based on an application; control means for controlling the luminance of the display means based on a luminance value corresponding to the application in the storage means when displaying an application;

 Mobile terminal having.

[8] The storage means includes a group in which the application mainly displays text strings. In each case with the group that mainly displays images, store the brightness value in the display means,

 8. The portable terminal according to claim 7, wherein when the application is displayed, the control unit controls a luminance value of the display unit based on a luminance value corresponding to the group of the application.

 [9] The storage means stores a luminance value in a display means based on an area ratio in which a natural image is displayed on a display screen.

 The control unit calculates an area ratio of the natural image when displaying an application for displaying a natural image on the display screen, and based on a luminance value corresponding to the area ratio of the storage unit, the luminance of the display unit The mobile terminal according to claim 7, wherein the mobile terminal is controlled.

[10] The storage means stores the luminance value in the display means based on the remaining battery level,

 8. The mobile terminal according to claim 7, wherein the control unit acquires a remaining battery level, and controls the luminance of the display unit based on the remaining battery level of the storage unit when the remaining battery level changes.

11. The mobile terminal according to claim 7, wherein the control means decreases the luminance value according to the elapsed time of the force when the operation means is operated.

[12] The storage means stores a luminance value in the display means based on a display area of the application,

 8. The portable terminal according to claim 7, wherein the control unit controls the luminance value of the display unit based on a luminance value corresponding to the display area of the storage unit when displaying an application.

 13. The mobile terminal according to claim 7, wherein the control means lowers the luminance value according to an elapsed time of force after an event occurs.

14. The mobile terminal according to claim 7, wherein the control unit decreases the luminance value according to an elapsed time after the screen update occurs.

[15] Identify the application,

 Identify the brightness value corresponding to the identification result of the application,

 A display method that displays the application by controlling the brightness of the display screen based on the specified brightness value.