JP2016095365A - Portable terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable terminal device capable of displaying on a display device with easier-to-see luminance than usual according to ambient brightness.SOLUTION: A portable terminal device comprises: a display device 30; an illuminance sensor 32; a detection part 62 which detects information on current time and information associated with a current position of the portable terminal device; and a luminance control part 64. The luminance control part 64 controls a luminance level of the display device 30 based upon a current detection value of the illuminance sensor 32. The luminance control part 64 varies a luminance variation rate in controlling the luminance level of the display device 30 based upon the detected information associated with the current time and current position.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a mobile terminal device, and is suitably used for, for example, a smartphone.

  Since mobile terminal devices such as smartphones are used in various environments, it is necessary to adjust the luminance of a display device provided in the mobile terminal device in accordance with ambient brightness. Japanese Patent Laying-Open No. 2005-316322 (Patent Document 1) discloses a method of automatically adjusting the brightness of a display device in accordance with ambient brightness.

  Specifically, the portable terminal device of this document should be able to be adjusted to an optimal luminance level without imposing a burden on the user's eyes even under circumstances where ambient brightness changes rapidly in a short time. Aim. Therefore, when automatically adjusting the brightness level, this mobile terminal device gradually increases or decreases the brightness of the display device by a predetermined change amount.

JP 2005-316332 A

  Depending on the usage environment, it may be desirable to quickly change the brightness of the display device according to the ambient brightness. For example, when the brightness of the surroundings suddenly changes from a dark environment to a bright environment, such as when the user moves from indoors to outdoors during the day, the brightness of the display device is moderated as in the above-mentioned patent document. When the screen is raised, the screen becomes difficult to see until the brightness is sufficiently increased.

  The present invention has been made in consideration of the above-mentioned problems, and an object thereof is to provide a portable communication terminal capable of displaying on a display device with brightness that is easier to see than before according to ambient brightness. It is to be.

  The portable terminal device according to the present invention includes a display device, an illuminance sensor, a detection unit that detects current time information and information on the current position of the portable terminal device, and a luminance control unit. The luminance control unit controls the luminance level of the display device based on the current detection value of the illuminance sensor. The luminance control unit changes the luminance change rate when controlling the luminance level of the display device based on the detected information regarding the current time and the current position.

  According to the present invention, it is possible to display on a display device with brightness that is easier to see than in the past according to ambient brightness.

It is a block diagram which shows roughly the hardware constitutions of the portable terminal device by 1st Embodiment. It is a front view which shows the external appearance of the portable terminal device of FIG. It is a functional block diagram related to the brightness control of the display device in the mobile terminal device. It is a timing diagram which shows the specific example of the luminance control of a display apparatus. It is a flowchart which shows the procedure which controls the brightness | luminance of a portable terminal device. It is a flowchart which shows the procedure of step S120 of FIG. 5 in more detail. It is a flowchart which shows the modification of FIG. It is a flowchart which shows the procedure of step S130 of FIG. 5 in more detail. 6 is a flowchart showing in more detail the procedure of step S120 of FIG. 5 in the mobile terminal device according to the second embodiment. It is a flowchart which shows the modification of FIG.

  Hereinafter, each embodiment will be described in detail with reference to the drawings. Hereinafter, a smartphone will be described as an example of the mobile communication terminal, but the mobile communication terminal is not necessarily limited to the smartphone. In the following description, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

<First Embodiment>
[Overall configuration of portable terminal device]
FIG. 1 is a block diagram schematically illustrating a hardware configuration of the mobile terminal device according to the first embodiment.

  Referring to FIG. 1, a mobile terminal device 10 includes a CPU (Central Processing Unit) 12, a RAM (Random Access Memory) 14, a ROM (Read Only Memory) 16, a plurality of wireless communication modules 18, and a plurality of wireless communication modules. An antenna 20, a GPS (Global Positioning System) module 22, a GPS antenna 24, and a touch panel 26 are included.

  The CPU 12 controls the entire mobile terminal device 10 based on programs stored in the RAM 14 and the ROM 16. The RAM 14 is used as the main memory of the CPU 12. An EEPROM (Electrically Erasable Programmable Read-Only Memory) such as a flash memory may be used as the ROM 16.

  A plurality of wireless communication modules 18 are provided in accordance with the communication method, such as for mobile phones, wireless LAN (Local Area Network), and short-range wireless communication. The wireless communication module 18 performs transmission signal modulation and frequency conversion (up-conversion), reception signal frequency conversion (down-conversion), demodulation, and the like.

  The GPS module 22 is a receiving device used in a satellite positioning system. The satellite positioning system receives signals from at least three or four satellites in the line-of-sight range from about 30 GPS satellites, and detects the current position of the own device based on the received signals. .

  The touch panel 26 (also referred to as a touch screen) includes a display device 30 such as a liquid crystal display (LCD) and a touch pad 28 formed integrally with the display device 30. The touch pad 28 is a position input device that detects a contact position of a finger or a pen on the screen.

  The mobile terminal device 10 further includes various sensors such as an illuminance sensor 32, an acceleration sensor 34, an angular velocity sensor 36, a geomagnetic sensor 38, and a real time clock 40. The real time clock 40 is a clock that can operate even when the mobile terminal device 10 is powered off. In addition, the mobile terminal device 10 includes a microphone, a speaker, and the like (not shown) used for a mobile phone. Furthermore, the mobile terminal device 10 includes a plurality of hardware buttons such as a home button for returning the display of the display device 30 to the home screen. In the mobile terminal device 10, the above components are connected to each other via a bus 42.

  FIG. 2 is a front view showing the appearance of the mobile terminal device of FIG. With reference to FIG. 2, the mobile terminal device 10 includes a substantially rectangular plate-like casing 50, and the components described in FIG. 1 are mounted on the surface and inside of the casing 50. The touch panel 26 is attached to the front surface of the housing 50. A home button 52 is provided at the lower part of the touch panel 26, and an illuminance sensor 32 is attached to, for example, the upper part of the touch panel 26 (near the display surface of the touch panel 26). The CPU 12, RAM 14, ROM 16, wireless communication module 18, GPS module 22, acceleration sensor 34, angular velocity sensor 36, geomagnetic sensor 38, and the like in FIG. 1 are mounted on a printed circuit board provided inside the housing 50.

[Functional configuration of portable terminal device]
FIG. 3 is a functional block diagram related to luminance control of the display device in the mobile terminal device. With reference to FIG. 1 and FIG. 3, the CPU 12 functions as a usage state detection unit 62, a luminance control unit 64, and a display control unit 66 by executing a program for luminance control of the display device 30.

  The usage status detection unit 62 detects information (hereinafter collectively referred to as usage status) regarding the usage location and usage time at which the user uses the mobile terminal device. Specifically, the use time is detected by the real-time clock 40, and the information on the use place is detected by the GPS module 22, the wireless communication module 18, various sensors (particularly the acceleration sensor 34), and the like.

  The luminance control unit 64 controls the luminance of the display device 30 so that the luminance level according to the current illuminance is obtained when the illuminance on the display surface of the display device 30 (measured value of the illuminance sensor 32) changes.

  More specifically, the luminance control unit 64 sets the luminance control mode based on at least information on usage time and usage location (usage status). The manner in which the luminance of the display device 30 changes when the luminance control unit 64 controls the luminance level of the display device 30 (the manner in which the screen luminance follows the illuminance change, that is, the luminance change rate) varies depending on the luminance control mode.

  The display control unit 66 controls the screen display content of the display device 30. The display control unit 66 sets the luminance level of the display device 30 based on a command from the luminance control unit 64. The luminance level of the display device 30 can be set in multiple stages.

[Specific example of brightness control]
FIG. 4 is a timing chart showing a specific example of luminance control of the display device. In the example of FIG. 4, the case where the normal mode, the first mode, and the second mode are provided as the luminance control mode is shown.

  The normal mode is a luminance control mode in a general case other than the first mode and the second mode. Referring to FIGS. 4A and 4B, when the illuminance detected by illuminance sensor 32 increases at time t1, luminance control unit 64 in FIG. 3 causes time t4 when a predetermined delay time has elapsed from time t1. Until the time t5, the luminance of the display device 30 is increased to a luminance level corresponding to the current illuminance at a relatively moderate increase rate. Similarly, when the illuminance detected by the illuminance sensor 32 decreases at time t6, the luminance control unit 64 has a relatively gradual decrease rate from time t9 to time t10 when a predetermined delay time has elapsed from time t4. The brightness of the display device 30 is reduced to a brightness level corresponding to the current illuminance. As described above, in the normal mode, the load on the user's eyes due to the flickering of the screen can be reduced and the sense of incongruity can be eliminated by causing the luminance of the screen to follow the illuminance change relatively gently.

  The first mode corresponds to, for example, when the user is out during the daytime. When the user carrying the mobile terminal device 10 moves from the building under the sun, the illuminance detected by the illuminance sensor 32 increases (time t1 in FIG. 4). In this case, if the followability of the luminance change of the display device 30 is poor, the screen is dark and difficult to see. Therefore, as shown in the first mode of FIG. 4C, the luminance control unit 64 increases the rate of increase between time t2 and time t3, which is earlier than in the normal mode, compared with that in the normal mode. Thus, the luminance of the display device 30 is quickly increased to the luminance level corresponding to the current illuminance.

  On the other hand, when the user carrying the mobile terminal device 10 moves from under the sun into the building, the illuminance detected by the illuminance sensor 32 decreases (time t6 in FIG. 4). In this case, even if the follow-up property of the luminance change of the display device 30 is bad, the user does not care about the glare of the screen. Therefore, in this case, as shown from the time t6 to the time t10 in the first mode in FIG. 4C, the luminance control unit 64 has the following capability similar to that in the normal mode. Reduce brightness.

  The second mode corresponds to, for example, when the user is in a predetermined building such as home at night. When the user turns off the lighting in the room at home, the illuminance detected by the illuminance sensor 32 decreases (time t6 in FIG. 4). In this case, if the followability of the luminance change of the display device 30 is poor, the screen becomes too bright and dazzling. Therefore, as shown in FIG. 4D, the second mode, the luminance control unit 64 has a larger reduction rate than that in the normal mode between time t7 and time t8, which is a timing earlier than that in the normal mode. The brightness of the display device 30 is quickly reduced to a brightness level corresponding to the current illuminance.

  On the other hand, when the user turns on the lighting of the room at home at night, the illuminance detected by the illuminance sensor 32 increases (time t1 in FIG. 4). In this case, even if the follow-up of the luminance change of the display device 30 is poor, the user does not have difficulty in seeing because the screen is darker than when going out during the day. Therefore, in this case, as shown between the time t1 and the time t5 in the second mode in FIG. 4D, the brightness control unit 64 follows the brightness of the display device 30 with the same followability as in the normal mode. Increase.

[Brightness control procedure]
Hereinafter, the procedure for controlling the luminance of the display device 30 will be described in detail with reference mainly to the flowcharts of FIGS.

  FIG. 5 is a flowchart illustrating a procedure for controlling the luminance of the mobile terminal device. Referring to FIGS. 1, 3, and 5, luminance control unit 64 sets the luminance level of display device 30 to the initial level when the power of display device 30 is turned on (YES in step S <b> 100). Further, the luminance control mode determination unit 68 of the luminance control unit 64 initially sets the luminance control mode to the normal mode (step S110).

  Subsequently, the usage status detection unit 62 detects the usage time by the real-time clock 40, and information on the usage location based on outputs of the GPS module 22, the wireless communication module 18, and various sensors (34, 36, 38) and the like. Is detected. The luminance control mode determination unit 68 of the luminance control unit 64 sets the luminance control mode based on the detected usage time and information about the usage location (step S120). In the present embodiment, the brightness control mode includes a normal mode, a first mode, and a second mode. A method for detecting information regarding a specific place of use and a method for setting the luminance control mode will be described later with reference to the flowcharts of FIGS.

  Subsequently, the luminance control unit 64 controls the luminance of the display device 30 based on the set luminance control mode and the detection value of the illuminance sensor 32 (step S130). A specific luminance control method will be described later with reference to the flowchart of FIG. The above steps S120 and S130 are repeated at a predetermined control period until the power of the display device 30 is turned off (YES in step S140).

  FIG. 6 is a flowchart showing in more detail the procedure of step S120 of FIG. In the example of FIG. 6, detection of information related to the current position and the current time is executed only when the movement of the user carrying the mobile terminal device 10 is detected (in the case of YES in step S200). Whether or not the user is moving can be determined based on, for example, movements in the up-down direction and the front-rear direction (or left-right direction) detected by the acceleration sensor 34. In order to prevent erroneous detection, it is desirable to determine that the user is moving when a continuous movement for a predetermined time or longer (for example, several seconds or longer) is detected. On the other hand, when no movement is detected (NO in step S200), that is, when it is detected that the mobile terminal device 10 is in a stationary state, the currently set luminance detection mode is maintained.

  Referring to FIG. 1, FIG. 3, and FIG. 6, when detecting the movement of the user (YES in step S200), usage status detector 62 determines the current position of mobile terminal device 10 (own device) (ie, usage location). And information on the current time are detected (step S205). The detection of the information related to the current position of the own device may use, for example, a GPS signal, detection of a wireless LAN access point, or detection of a counterpart device of short-range wireless communication. May be. Alternatively, information regarding the current position may be detected by combining a plurality of these. Whether the current location of the mobile terminal device 10 corresponds to the registered location by registering the address of the access point of the wireless LAN and the address of the counterpart device for short-range wireless communication in advance in the ROM 16 of the device itself. Can be determined.

  Next, the luminance control mode determination unit 68 of the luminance control unit 64 determines that the own device is in the predetermined first building based on the detection result of the information related to the current position of the own device (YES in step S210). In this case, the brightness control mode is set to “in-building mode” (step S215). In the example of FIG. 6, the in-building mode corresponds to the normal mode (step S235). Here, the first building is a home, a workplace, a station premises, or the like.

  On the other hand, when the brightness control mode determination unit 68 determines that the current position of the device itself is not within the first building (NO in step S210), the brightness control mode determination unit 68 determines that the current time is daytime (YES in step S220). In step S240, the luminance control mode is set to the first mode. Here, daytime refers to the time period from sunrise to sunset. A limited time period from sunrise to sunset (for example, excluding early morning and evening) may be defined as daytime. If the brightness control mode determination unit 68 determines that the current position of the own device is not in the first building (NO in step S210) and the current time is not daytime (NO in step S220), the brightness control mode is determined. The normal mode is set (step S235).

  The setting of the luminance control mode described above is repeatedly executed every control cycle. When the movement of the own device is not detected, the currently set brightness control mode is maintained as it is.

  FIG. 7 is a flowchart showing a modification of FIG. In the flowchart of FIG. 7, the procedure after the brightness control mode is set to the in-building mode (step S215) is different from the case of FIG. Specifically, in the modification of FIG. 7, the in-building mode is further divided into a normal mode and a second mode. Since the other control procedures in FIG. 7 are the same as those in FIG. 6, the same or corresponding steps are denoted by the same reference numerals, and description thereof will not be repeated.

  Referring to FIGS. 1, 3, and 7, luminance control mode determination unit 68 determines that the current time is night when the luminance control mode is set to the in-building mode (step S215). (YES in step S225), it is determined whether or not the current position of the own device is in the second building (step S230). Here, night refers to the time period from sunset to sunrise. A limited time zone (for example, a sleeping time zone) in the time zone from sunset to sunrise may be defined as nighttime. The second building is included in the first building and refers to, for example, a home.

  When the brightness control mode is set to the in-building mode (step S215), the brightness control mode determination unit 68 is at night (YES in step S225), and the current position of the own device is within the second building. If it is determined that there is (YES in step S230), the luminance control mode is set to the second mode (step S245). On the other hand, when the brightness control mode is set to the in-building mode (step S215), the brightness control mode determination unit 68 determines that the current time is not night (NO in step S225), or the current position of the own device is If it is determined that it is not in the second building (NO in step S230), the luminance control mode is set to the normal mode (step S235).

  The setting of the luminance control mode described above is repeatedly executed every control cycle. When the movement of the own device is not detected, the currently set brightness control mode is maintained as it is.

  FIG. 8 is a flowchart showing in more detail the procedure of step S130 of FIG. With reference to FIG. 1, FIG. 3, and FIG. 8, first, the luminance control unit 64 detects the illuminance by the illuminance sensor 32 (S300).

  First, when the detected luminance level corresponding to the current illuminance (hereinafter referred to as “target luminance level”) is larger than the currently set luminance level (YES in step S310), the luminance control unit 64 Determines whether the luminance control mode is the first mode (step S330). As a result, when the luminance control mode is the first mode (YES in step S330), the luminance control unit 64 sets the delay time to be shorter than in the normal mode (sets the delay time to 0). The display device 30 is controlled so that the luminance increases to the target luminance level at a steep increase rate than in the normal mode (step S350). On the other hand, when the luminance control mode is not the first mode (NO in step S330), the luminance control unit 64 causes the luminance to increase relatively slowly to the target luminance level according to the delay time and the luminance increase rate in the normal mode. The display device 30 is controlled (step S360).

  Conversely, when the target luminance level is smaller than the currently set luminance level (YES in step S320), the luminance control unit 64 determines whether or not the luminance control mode is the second mode (step S320). S340). As a result, when the luminance control mode is the second mode (YES in step S340), after the delay time set shorter than in the normal mode has elapsed (the delay time may be set to 0), the normal mode is set. In step S370, the display device 30 is controlled so that the luminance decreases to the target luminance level at a steep decrease rate than in the above case. On the other hand, when the luminance control mode is not the second mode (NO in step S340), display device 30 is controlled so that the luminance decreases relatively slowly to the target luminance level according to the delay time and the luminance increase rate in the normal mode. (Step S380).

  The luminance control of the display device 30 described above is repeatedly executed every control cycle. The control cycle is set shorter than the time (delay time + increase or decrease time) required for the luminance change of the display device 30 in the normal mode. Therefore, when the detection value of the illuminance sensor 32 changes before the luminance of the display device 30 reaches the target luminance level, the target luminance level is reset, and the delay time and the luminance are set according to the reset luminance. The increase rate (or decrease rate) is reset.

[Effect of the first embodiment]
As described above, according to the mobile terminal device of the first embodiment, the usage status of the mobile terminal device by the user (information on usage time and usage location, etc.) is detected. When automatically adjusting the luminance of the display device based on the detection value of the illuminance sensor, the manner in which the screen luminance follows the change in illuminance is adjusted according to the detected usage situation. As a result, it is possible to achieve both a case where a steep luminance change is required according to the usage situation and a case where the luminance is gradually changed in order to suppress the user's uncomfortable feeling due to flickering.

<Second Embodiment>
In the mobile terminal device according to the second embodiment, the device configuration and the basic operation described with reference to FIGS. 1 to 5 are the same as those in the first embodiment. Further, the detailed operation of step S130 in FIG. 5 is the same as that in FIG. On the other hand, in the case of the second embodiment, the detailed operation in step S120 of FIG. 5 is different from the case of FIGS. 6 and 7 described in the first embodiment. The detailed operation of step S120 will be described below with reference to the flowcharts of FIGS.

  FIG. 9 is a flowchart showing in more detail the procedure of step S120 of FIG. 5 in the mobile terminal device according to the second embodiment. In the example of FIG. 9, as in the case of the first embodiment, detection of information related to the current time and the current position of the own device is limited to the case where the movement of the user carrying the mobile terminal device 10 is detected. (In the case of YES in step S400). As described in the sixth example, the detection of the movement of the user is performed using the acceleration sensor 34, for example.

  Referring to FIG. 1, FIG. 3, and FIG. 9, when detecting the movement of the user (YES in step S400), usage status detector 62 detects information on the current position and information on the current time (step S405).

  Next, the luminance control mode determination unit 68 of the luminance control unit 64 sets the luminance control mode to the daytime mode when it is determined that the current time is daytime (YES in step S410) based on the detection result of the current time. Setting is made (step S415). In the example of FIG. 9, the daytime mode corresponds to the normal mode (step S435). Here, daytime refers to the time zone from sunrise to sunset as described in FIG. A limited time period from sunrise to sunset (for example, excluding early morning and evening) may be defined as daytime.

  When the brightness control mode determination unit 68 determines that the current time is not daytime (NO in step S410), the own device is in the predetermined second building based on the detection result of the information related to the current position of the own device. Is determined (step S420). Here, the second building refers to a home or the like as described in FIG.

  As a result, the brightness control mode determination unit 68 determines that the device is in the second building (YES in step S420) and further determines that the current time is night (YES in step S425). Set the mode to the second mode. Here, night refers to the time period from sunset to sunrise as described in FIG. A limited time zone (for example, a sleeping time zone) in the time zone from sunset to sunrise may be defined as nighttime.

  On the other hand, when the brightness control mode determination unit 68 determines that the current time is not daytime (NO in step S410), the position of the own device is not in the second building (NO in step S420), or the current time Is not nighttime (NO in step S425), the luminance control mode is set to the normal mode (step S435).

  The setting of the luminance control mode described above is repeatedly executed every control cycle. When the movement of the own device is not detected, the currently set brightness control mode is maintained as it is.

  FIG. 10 is a flowchart showing a modification of FIG. In the flowchart of FIG. 10, the procedure after the luminance control mode is set to the daytime mode (step S415) is different from that in FIG. Specifically, in the modification of FIG. 10, the daytime mode is further divided into a normal mode and a first mode. Since other control procedures in FIG. 10 are the same as those in FIG. 9, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

  Referring to FIG. 1, FIG. 3, and FIG. 10, luminance control mode determination unit 68 determines that the current position of its own device is within a predetermined first building when the luminance control mode is set to daytime mode (step S415). If it is determined that the brightness control mode is present (YES in step S430), the luminance control mode is set to the normal mode (step S435). The first building in this case includes the second building as described with reference to FIGS. 6 and 7, and refers to, for example, a home, a workplace, a station premises, or the like.

  On the other hand, when the luminance control mode is set to the daytime mode (step S415), the luminance control mode determination unit 68 determines that the current position of the own device is not within the predetermined first building (step S430). NO), the brightness control mode is set to the first mode (step S445).

  Also in the second embodiment, as in the case of the first embodiment, the brightness of the display device is changed abruptly according to the usage status of the mobile terminal device, and the user feels uncomfortable due to flickering or the like. Therefore, both the case where the luminance is gradually changed can be achieved.

<Third Embodiment>
The mobile terminal device of the third embodiment differs from the first and second embodiments in the control operation of the usage status detection unit 62 in FIG. Specifically, the third embodiment is different from the first and second embodiments in that step S200 is not executed in the flowcharts of FIGS. 6 and 7 and that step S400 is not executed in the flowcharts of FIGS. And different. Other points of the third embodiment are the same as those of the first and second embodiments.

  In the case of the first and second embodiments, it is not until the user's movement is detected using the acceleration sensor 34 that the current position of the own apparatus is related using the communication means such as the GPS module 22 or the wireless communication module 18. It was supposed to detect information. Therefore, when the user is neither communicating nor moving, it is not necessary to start the communication means again, so that the power consumption can be reduced.

  On the other hand, in the case of the third embodiment, it is not necessary to mount the acceleration sensor 34, but it is necessary to always use communication means in order to detect information related to the current position of the own device. Therefore, the power consumption is increased as compared with the first and second embodiments.

<Other variations>
Unlike the above embodiments, the total number of luminance control modes can be four or more.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 10 Portable terminal device, 12 CPU, 18 Wireless communication module, 22 GPS module, 26 Touch panel, 28 Touch pad, 30 Display device, 32 Illuminance sensor, 34 Acceleration sensor, 40 Real time clock, 50 Case, 62 Usage condition detection part, 64 luminance control units, 66 display control units, 68 luminance control mode determination units.

Claims (5)

A portable terminal device,
A display device;
An illuminance sensor;
A detection unit for detecting information on a current time and information on a current position of the mobile terminal device;
A luminance control unit that controls a luminance level of the display device based on a current detection value of the illuminance sensor;
The said brightness | luminance control part is a portable terminal device which changes the brightness | luminance change rate at the time of controlling the brightness | luminance level of the said display apparatus based on the information regarding the detected said present | current time and present position. The luminance control unit includes a luminance control mode determination unit that determines which luminance control mode corresponds to a predetermined one among a plurality of predetermined luminance control modes based on information on the detected current time and current position,
The brightness control unit controls a brightness level of the display device based on a currently set brightness control mode among the plurality of brightness control modes and a current detection value of the illuminance sensor. The portable terminal device described. The brightness control mode determination unit
When the current position of the mobile terminal device is in a predetermined building, the brightness control mode is set to the building mode,
In the case where the current position of the mobile terminal device is not within the predetermined building, and the current time is daytime, the brightness control mode is configured to be set to the first mode,
When increasing the luminance of the display device, the luminance control unit controls the luminance of the display device so that the increase rate of the luminance in the first mode is larger than the increase rate of the luminance in the in-building mode. The portable terminal device according to claim 2. The brightness control mode determination unit
When the current time detected by the detection unit is daytime, the brightness control mode is set to daytime mode,
In the case where the current position of the mobile terminal device is within a predetermined building, when the current time is night, the brightness control mode is set to the second mode,
When the luminance control unit decreases the luminance of the display device, the absolute value of the luminance reduction rate in the second mode is larger than the absolute value of the luminance reduction rate in the daytime mode. The mobile terminal device according to claim 2, wherein the luminance of the mobile terminal device is controlled. The portable terminal device further includes:
An acceleration sensor;
With GPS (Global Positioning System) module or wireless LAN (Local Area Network) module,
The detection unit is configured to detect information related to the current position of the mobile terminal device based on a GPS module or a wireless LAN module only when movement of the mobile terminal device is detected by the acceleration sensor. The mobile terminal device according to any one of claims 1 to 4.

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