JP2016038504A - Portable terminal device and control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable terminal device capable of adjusting brightness of a screen according to ambient lightness during use by a user.SOLUTION: Processing that a CPU of a portable terminal device performs includes: a step of adjusting brightness of a screen of a monitor based upon the quantity of light detected by an optical sensor; a step (S20) of detecting the optical sensor being covered with fingers or a hand of a user of the portable terminal device based upon the position of the fingers in an image captured by a camera and the positional relation of the camera and the optical sensor; and a step (S24) of correcting the brightness to be adjusted in the adjusting step when the covering of the optical sensor with the fingers or hand of the user is detected in the detecting step.SELECTED DRAWING: Figure 7

Description

  The present disclosure relates to control of a mobile terminal device, and particularly relates to brightness control of a screen of the mobile terminal device.

  In recent years, mobile terminal devices such as smartphones that can appropriately control the brightness of a screen in accordance with ambient brightness have become widespread. Such a portable terminal device has an optical sensor for detecting the amount of light received by itself, and brightens the screen as the detected amount of light increases. Thereby, the screen becomes bright in a bright environment, and the screen becomes dark in a dark environment. However, when the optical sensor is covered with a shield such as a hand or a finger, the optical sensor cannot accurately detect the amount of ambient light, and thus the brightness of the screen is not adjusted as intended. As a technique for solving such a problem, for example, Patent Document 1 discloses a portable terminal for making up for the brightness of a display that is reduced due to an illuminance sensor being blocked by a shield.

JP 2012-248974 A

  The portable terminal disclosed in Patent Document 1 uses a proximity sensor to determine whether there is a shield near the illuminance sensor, and when it is determined that there is a shield near the illuminance sensor, Increase brightness. However, when brightness control is realized in this way, even when the mobile terminal is placed in a bag or the like, a proximity object is detected by the proximity sensor, and the screen brightness increases even when the mobile terminal is not used. It will be. As a result, the power of the mobile terminal is wasted. For this reason, in the situation where the user is using the portable terminal device, a portable terminal device capable of appropriately controlling the brightness of the screen is desired.

  The present disclosure has been made to solve the above-described problems, and an object thereof is a portable terminal device capable of adjusting the luminance of the screen according to the ambient brightness during use by the user. Is to provide. An object in another aspect is to provide a method for controlling a mobile terminal device so that the brightness of a screen can be adjusted according to ambient brightness during use by a user.

  According to one embodiment, the mobile terminal device is detected by a monitor, an optical sensor for detecting the amount of light received by the mobile terminal device, a camera provided within a certain range from the optical sensor, and the optical sensor. Based on the received light amount, an adjustment unit for adjusting the brightness of the screen of the monitor and image information of the image obtained from the camera are used to specify the position in the image of the object included in the image Detection for detecting that the optical sensor is covered with the object based on the specific part, a predetermined positional relationship between the camera and the optical sensor, and the position of the object in the image specified by the specific part And a correction unit for correcting the luminance adjusted by the adjustment unit when the detection unit detects that the optical sensor is covered with the object.

  In one aspect, the brightness of the screen can be adjusted according to the ambient brightness during use by the user.

  The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the present invention taken in conjunction with the accompanying drawings.

It is a figure which shows an example of the external appearance of the smart phone according to 1st Embodiment. It is a figure which shows the picked-up image obtained when the user is operating the smart phone according to 1st Embodiment. It is a block diagram which shows the main hardware constitutions of the smart phone according to 1st Embodiment. It is a block diagram which shows an example of the function structure of the smart phone according to 1st Embodiment. It is the conceptual diagram which showed the outline of the correction process of screen brightness | luminance. It is the conceptual diagram which showed schematically the difference in the correction amount of the screen brightness | luminance by the difference in how to cover an optical sensor. It is a flowchart showing a part of process which the smart phone according to 1st Embodiment performs. It is a figure which shows the data structure of a correction table.

  Hereinafter, the present embodiment will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  In addition, below, although the detail of the smart phone which is an example of a portable terminal device is demonstrated, a portable terminal device is not limited to a smart phone. For example, the mobile terminal device may include a tablet terminal, a digital camera, an electronic dictionary, a PDA (Personal Digital Assistant), a game machine, and other portable electronic devices.

<First Embodiment>
[Overview]
With reference to FIG. 1 and FIG. 2, the outline | summary of the smart phone 100 according to 1st Embodiment is demonstrated. FIG. 1 is a diagram illustrating an example of the appearance of the smartphone 100. FIG. 2 is a diagram illustrating a captured image obtained when the user is operating the smartphone 100.

  As shown in FIG. 1, the smartphone 100 includes a camera 4, a monitor 5, and an optical sensor 7. The camera 4 is provided within a certain range (for example, within several centimeters) from the optical sensor 7. That is, the camera 4 is provided in the vicinity of the optical sensor 7. Such a positional relationship between the camera 4 and the optical sensor 7 is known information because it is determined when the smartphone 100 is manufactured.

  The optical sensor 7 detects the amount of light received by the smartphone 100. The smartphone 100 increases the brightness of the screen of the monitor 5 as the amount of light detected from the optical sensor 7 increases. Thereby, the screen of the monitor 5 becomes bright in a bright environment and dark in a dark environment. As described above, the smartphone 100 can adjust the brightness of the screen according to the surrounding brightness, so that the user can easily see the screen.

  However, when the optical sensor 7 is covered with an object such as a user's finger (hereinafter also referred to as “shielding object”), the screen is adjusted to be dark even in a bright environment. That is, in such a case, the screen is adjusted to be darker than intended. In particular, in recent years, the screen of a mobile terminal device such as a smartphone has become larger, and an optical sensor is often provided around the screen. For this reason, it frequently occurs that the optical sensor is unintentionally covered during the operation of the mobile terminal device.

  Therefore, smartphone 100 according to the present embodiment corrects the screen brightness so as to be higher than the currently set brightness when optical sensor 7 is covered with a shield. As a result, the smartphone 100 can display a screen with a luminance that matches the ambient brightness even when the optical sensor 7 is covered with a shield.

  Below, with reference to FIG. 2, the method to determine whether the optical sensor 7 is covered with the obstruction (for example, user's finger 50) is demonstrated.

  As shown in FIG. 2A, when the finger 50 covers the left side of the camera 4, the finger is displayed on the left side of the captured image 30 obtained from the camera 4 (see range 30A). The fact that a finger is displayed on the left side in the captured image 30 means that the actual finger 50 is on the left side of the camera 4. In the example of FIG. 2A, since the optical sensor 7 is disposed near the left side of the camera 4, the smartphone 100 can determine that the optical sensor 7 is covered with the finger 50 on the left side of the camera 4.

  On the other hand, as shown in FIG. 2B, when the finger 50 covers the right side of the camera 4, the finger is displayed on the right side of the captured image 32 obtained from the camera 4 (see range 32A). The fact that a finger is displayed on the right side in the captured image 30 means that the actual finger 50 is on the right side of the camera 4. In the example of FIG. 2B, since the optical sensor 7 is arranged in the vicinity of the left side of the camera 4, the smartphone 100 can determine that the optical sensor 7 is not covered with the finger 50 on the right side of the camera 4.

  Thus, the smartphone 100 determines whether or not the optical sensor 7 is covered with the finger 50 based on the position of the finger 50 in the captured image obtained from the camera 4 and the positional relationship between the camera 4 and the optical sensor 7. Judging. When the smartphone 100 detects that the optical sensor 7 is covered with the finger 50, the smartphone 100 corrects the screen brightness so as to be higher than the current brightness. Thereby, even if the optical sensor 7 is covered with a shielding object such as the finger 50, the smartphone 100 can display a screen with a luminance that matches the brightness of the surrounding area.

  In the following description, the finger of the user of the smartphone 100 will be described as an example of the shielding object detected by the smartphone 100. However, the shielding object detected by the smartphone 100 is not limited to the finger. For example, the smartphone 100 may detect a user's hand, a user's arm, a clothes sleeve, and the like of the smartphone 100 as a shield.

  FIG. 2 shows an example in which the camera 4 and the optical sensor 7 are arranged in the left-right direction of the housing of the smartphone 100. However, if the camera 4 and the optical sensor 7 are arranged in the vicinity of each other, FIG. It can be placed at any location on the housing of the smartphone 100.

[Hardware configuration]
With reference to FIG. 3, an example of a hardware configuration of smartphone 100 according to the first embodiment will be described. FIG. 3 is a block diagram illustrating a main hardware configuration of the smartphone 100. As shown in FIG. 3, the smartphone 100 includes a ROM (Read Only Memory) 1, a CPU (Central Processing Unit) 2, a RAM (Random Access Memory) 3, a camera 4, a monitor 5, and a backlight 6. And an optical sensor 7, a network interface (I / F) 8, and a storage device 20. The storage device 20 stores a positional relationship 22 and a correction table 24.

  The ROM 1 stores an operating system (OS), a control program executed by the smartphone 100, and the like. The CPU 2 controls the operation of the smartphone 100 by executing various programs such as an operating system and a control program for the smartphone 100. The RAM 3 functions as a working memory and temporarily stores various data necessary for program execution.

  The camera 4 includes a lens and an image sensor such as a CMOS (Complementary Metal-Oxide Semiconductor). The camera 4 continues to capture the subject while the screen is lit, and sequentially outputs the generated captured images to the CPU 2.

  The monitor 5 includes, for example, a liquid crystal display, an organic EL (Electro Luminescence) display, or other display devices. The backlight 6 is a light source for illuminating the monitor 5. The brightness of the backlight 6 is adjusted based on the control of the CPU 2. Thereby, the brightness of the monitor 5 is adjusted. The optical sensor 7 is provided within a certain range from the camera 4. The optical sensor 7 detects the amount of light received by the smartphone 100.

  The network I / F 8 transmits / receives data to / from other communication devices via the antenna 8A. Other communication devices include, for example, smartphones, personal computers, server devices, and other electronic devices having communication functions. Smartphone 100 may be configured to download a program for realizing various processes according to the present embodiment via antenna 8A.

  The storage device 20 includes, for example, a storage medium such as eMMC (Embedded MultiMediaCard). The eMMC includes a NAND flash memory and a control circuit. The storage device 20 stores a program for realizing various processes according to the present embodiment, a positional relationship 22 between the camera 4 and the optical sensor 7, a correction table 24, and the like. The positional relationship 22 is indicated, for example, as a two-dimensional or three-dimensional coordinate value of the optical sensor 7 with the camera 4 as a reference (origin). The correction table 24 will be described in the following “second embodiment”. The positional relationship 22 and the correction table 24 may be stored not in the storage device 20 but in the ROM 1, RAM 3, or a storage device of an external device.

  Note that a program for realizing various processes according to the present embodiment may be provided by being incorporated in a part of an arbitrary program, not as a single program. In this case, processing according to the present embodiment is realized in cooperation with an arbitrary program. Even such a program that does not include some modules does not depart from the spirit of the smartphone 100 according to the present embodiment. Furthermore, part or all of the functions provided by the program according to the present embodiment may be realized by dedicated hardware. Furthermore, it is not necessary for the server device side to execute all functions, and the smartphone 100 and the server device may cooperate to implement the processing according to the present embodiment. Furthermore, the smartphone 100 may be configured in a form such as a so-called cloud service in which at least one server device realizes processing according to the present embodiment.

[Function configuration]
The function of the smartphone 100 will be described with reference to FIGS. 4 and 5. FIG. 4 is a block diagram illustrating an example of a functional configuration of the smartphone 100. FIG. 5 is a conceptual diagram showing an outline of a screen brightness correction process. As illustrated in FIG. 4, the CPU 2 of the smartphone 100 includes an adjustment unit 40, a specification unit 42, a detection unit 44, and a correction unit 46.

  The adjustment unit 40 adjusts the brightness of the screen of the monitor 5 based on the light amount detected by the optical sensor 7. In one aspect, the adjustment unit 40 increases the brightness of the screen of the monitor 5 as the amount of light detected by the optical sensor 7 increases. As a result, the adjustment unit 40 brightens the screen of the monitor 5 in a bright environment, and darkens the screen of the monitor 5 in a dark environment.

  The specifying unit 42 uses the image information of the captured image obtained from the camera 4 to specify the position in the image of the user's finger included in the captured image. As an example, the specifying unit 42 specifies the position in the image of the user's finger using the color information of the captured image. When the smartphone 100 is placed in a dark place or covered with paper or the like, the captured image becomes black. However, when the user's finger is reflected in the captured image, the finger portion of the captured image It turns red. For this reason, the specific | specification part 42 detects the skin color and red part of a picked-up image as a finger. The identifying unit 42 outputs the detected finger position to the detecting unit 44. The position of the finger in the captured image is indicated as a coordinate value in the captured image, for example. In a certain aspect, the position of the finger in the captured image is indicated as the center coordinate or the barycentric coordinate of the finger captured in the captured image. In another aspect, the position of the finger in the captured image is indicated as a coordinate group of the finger portion in the captured image. As an example, the coordinate group is shown as coordinates of four corners of a rectangle surrounding the finger of the captured image.

  In the detection unit 44, the optical sensor 7 is covered with the finger based on the position of the finger in the captured image specified by the specifying unit 42 and the predetermined positional relationship 22 between the camera 4 and the optical sensor 7. Detect that. More specifically, the smartphone 100 estimates the actual position of the finger with respect to the camera 4 from the position of the finger in the captured image. The detection unit 44 refers to the positional relationship 22 (see FIG. 3) of the optical sensor 7 with respect to the camera 4 and detects that the optical sensor 7 is covered with fingers.

  The correction unit 46 corrects the luminance adjusted by the adjustment unit 40 when the detection unit 44 detects that the optical sensor 7 is covered with a finger. In one aspect, the brightness of the screen is corrected to be higher than the brightness adjusted by the adjustment unit 40. For example, it is assumed that the brightness of the screen is adjusted to the luminance 60 by the adjustment unit 40 as shown in FIG. In this case, the correction unit 46 corrects the screen brightness from the brightness 60 to the brightness 66 brighter than the brightness 60.

  Thereby, the correction | amendment part 46 can display a screen with the brightness | luminance according to the surrounding brightness, even when the optical sensor 7 is covered with a finger. In addition, the correction unit 46 performs luminance correction when a finger is captured in the photographed image from the camera 4, so that the screen luminance is corrected only when the user is using the smartphone 100. Thereby, the smart phone 100 can prevent that a screen is adjusted brightly in the condition which is not used, and can reduce power consumption.

[Screen brightness correction method]
With reference to FIG. 6, the detail of the correction method of the screen brightness | luminance of the monitor 5 is demonstrated. FIG. 6 is a conceptual diagram schematically showing the difference in the correction amount of the screen luminance due to the difference in how the optical sensor is covered. In the following description, the description will be made on the assumption that the optical sensor 7 is provided on the left side of the camera 4 as shown in FIG.

  The amount of light detected by the optical sensor 7 varies depending on how the finger is covered. That is, the amount of light detected by the optical sensor 7 decreases as the degree to which the optical sensor 7 is covered with fingers (hereinafter also referred to as “covered degree”) increases. As a result, as the degree of coverage increases, the screen becomes darker than intended by the brightness adjustment by the adjustment unit 40 (see FIG. 4). In order to solve this, the correction unit 46 (see FIG. 4) increases the correction amount for increasing the screen brightness as the degree of coverage increases.

  The degree of coverage of the optical sensor 7 can be estimated from the position of fingers in the captured image, the range of fingers in the captured image, and the like. For example, as shown in FIG. 6A, when all of the optical sensor 7 is covered with the finger 50, the finger 50 is displayed on the left side of the captured image 34 (see a range 34A). As shown in FIG. 6B, when a part of the optical sensor 7 is covered with the finger 50, the finger 50 is displayed at the lower left of the captured image 35 (see a range 35A). As shown in FIG. 6C, when the degree of coverage of the optical sensor 7 is further reduced, the range of the finger 50 in the captured image 36 is further narrowed (see the range 36A). As shown in FIG. 6D, when a finger is displayed on the right side (see range 37A) in the captured image 36, the optical sensor 7 is not covered with the finger 50 at all.

  Thus, since the degree of coverage of the optical sensor 7 is determined by the position of the finger 50 in the captured image, the detection unit 44 (see FIG. 4) of the smartphone 100 detects the finger in the captured image obtained from the camera 4. The degree of coverage is detected based on the position and the positional relationship 22 (see FIG. 3) of the camera 4 and the optical sensor 7. The correction | amendment part 46 (refer FIG. 4) of the smart phone 100 increases the correction amount of the brightness | luminance of a screen, and correct | amends so that a screen may become bright, so that the cover degree detected by the detection part 44 is high.

  In one aspect, the correction unit 46 increases the correction amount of the screen brightness as the range of the finger in the captured image is wider. The range of the finger in the captured image is indicated, for example, as the ratio of the number of pixels detected as a finger to the number of pixels in the captured image.

  In another aspect, the correction unit 46 may correct the brightness of the screen using not only the position of the finger in the captured image but also the direction of the finger. The direction of the finger is indicated as, for example, the longitudinal direction of the finger in the captured image. The correction unit 46 determines the degree of coverage of the optical sensor 7 based on the direction of the finger relative to the camera 4 and the direction of the optical sensor 7 relative to the camera. At this time, the correction unit 46 increases the degree of coverage as the direction of the finger relative to the camera 4 and the direction of the optical sensor 7 relative to the camera are closer. The correction unit 46 corrects the brightness of the screen according to the determined degree of coverage.

[Control structure]
The control structure of the smartphone 100 will be described with reference to FIG. FIG. 7 is a flowchart showing a part of the process executed by smartphone 100. The processing in FIG. 7 is realized by the CPU 12 (processor) of the smartphone 100 executing the program. In another aspect, part or all of the processing may be performed by a circuit element or other hardware.

  In step S10, the CPU 2 determines whether or not the screen is lit. For example, the CPU 2 determines that the screen is turned on when the operation mode of the smartphone 100 is not in a dormant state, and determines that the screen is turned off when the operation mode of the smartphone 100 is in a dormant state. When CPU 2 determines that the screen is lit (YES in step S10), CPU 2 switches control to step S12. If not (NO in step S10), CPU 2 executes the process of step S10 again.

  In step S12, the CPU 2 activates the camera 4 (see FIG. 3) and starts photographing the subject. The camera 4 continues to capture the subject while the screen is lit, and the CPU 2 sequentially acquires the captured images generated by the camera 4.

  In step S20, the CPU 2 determines whether or not a finger is displayed in the captured image as the specifying unit 42 (see FIG. 4). Since the finger detection method is as described above, the description will not be repeated. When CPU 2 determines that a finger is displayed in the captured image (YES in step S20), CPU 2 switches control to step S22. If not (NO in step S20), CPU 2 returns control to step S10.

  In step S <b> 22, the CPU 2 detects, as the detection unit 44, the degree of coverage of the optical sensor 7 from the display content of the captured image. Since the method of detecting the degree of coverage is as described above, description thereof will not be repeated.

  In step S <b> 24, the CPU 2, as the correction unit 46, corrects the luminance so that the screen becomes brighter as the degree of coverage of the optical sensor 7 is higher. Since the screen brightness correction method is as described above, description thereof will not be repeated.

[Brief Summary]
As described above, smartphone 100 according to the present embodiment corrects luminance so that the screen is brightened when the optical sensor is covered with a shielding object such as a user's finger. Thereby, even when the optical sensor is covered, the smartphone 100 can display the screen with a luminance suitable for the ambient brightness, and the ease of the screen for the user is improved. Moreover, since the smart phone 100 changes the correction amount of screen brightness according to the degree to which the optical sensor is covered, the screen brightness can be corrected more accurately.

<Second Embodiment>
With reference to FIG. 8, the outline | summary of 100 A of smart phones according to 2nd Embodiment is demonstrated. FIG. 8 is a diagram illustrating the data structure of the correction table 24. The smartphone 100 according to the first embodiment determines the correction amount of the screen brightness according to the degree of coverage of the optical sensor 7. In contrast, the smartphone 100A according to the second embodiment determines the correction amount of the screen luminance with reference to the correction table 24 as described below. Since other points such as the hardware configuration of smartphone 100A are the same as those of smartphone 100 according to the first embodiment, description thereof will not be repeated.

  The correction table 24 is stored in advance in the storage device 20 (see FIG. 3). In the correction table 24, a finger position 24A, a finger direction 24B, and a screen luminance correction amount 24C are associated with each other. The finger position 24A is indicated as a coordinate value in the corrected image, for example. The coordinate value of the finger is indicated, for example, as the center value or the centroid value of the finger in the captured image. For example, the finger direction 24B is indicated by the angle of the finger relative to the horizontal direction in the corrected image. In the correction amount 24C, the correction amount of the screen brightness by the correction unit 46 is shown. This correction amount may be indicated as an increase amount of the screen brightness, or may be indicated as a coefficient to be multiplied with the currently set screen brightness.

  The smartphone 100A detects the position and direction of the finger in the captured image. The method for detecting the finger position is as described above. The direction of the finger is determined by, for example, the shape of the finger in the captured image. As an example, the smartphone 100A determines the longitudinal direction of the finger in the captured image as the direction of the finger. The smartphone 100A selects the combination closest to the finger position and direction in the detected captured image from the combinations of the finger position 24A and the finger direction 24B defined in the correction table 24. The smartphone 100A corrects the screen brightness using the correction amount 24C associated with the selected combination.

  As described above, smartphone 100A according to the present embodiment refers to stored correction table 24 to determine a screen luminance correction amount. Thereby, since the smart phone 100A can omit detection processing such as the degree of coverage of the optical sensor, the processing can be speeded up.

<Third Embodiment>
Hereinafter, smartphone 100B according to the third embodiment will be described. Smartphone 100 according to the first embodiment detects a finger by image processing using color information of a captured image. On the other hand, the smartphone 100B according to the third embodiment detects the position of the finger in the captured image using another image processing technique. Since other points such as the hardware configuration of smartphone 100B are the same as smartphone 100 according to the first embodiment, description thereof will not be repeated.

  The smartphone 100B according to the third embodiment detects the user's finger using an image processing technique such as template matching without using the color information of the captured image. More specifically, the smartphone 100B searches for a finger image from the photographed image on the basis of a finger image (not shown) registered in advance in the storage device 20 (see FIG. 3) or the like, thereby detecting the finger in the photographed image. Detect position. In another aspect, the smartphone 100B may detect a moving object from sequentially obtained captured images, and may detect the detected moving object as a finger.

  In another aspect, the smartphone 100B may detect the user's hand, arm, or the like using an image processing technique such as template matching in addition to the user's finger. In this case, the smartphone 100B detects the position of the finger in the captured image by searching for the image from the captured image with reference to an image of a hand or arm registered in advance in the storage device 20 or the like.

  As described above, since smartphone 100B according to the present embodiment can detect a finger without using color information, it can detect a finger even in a situation where it is difficult to acquire color information such as at night. become.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. 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.

  1 ROM, 2 CPU, 3 RAM, 4 camera, 5 monitor, 6 backlight, 7 optical sensor, 8 network I / F, 8A antenna, 20 storage device, 22 positional relationship, 24 correction table, 24A position, 24B direction, 24C Correction amount, 30, 32, 34 to 37 Captured image, 30A, 32A, 34A to 37A Range, 40 adjustment unit, 42 identification unit, 44 detection unit, 46 correction unit, 50 fingers, 60, 66 brightness, 100 smartphone.

Claims (5)

A portable terminal device,
A monitor,
An optical sensor for detecting the amount of light received by the mobile terminal device;
A camera provided within a certain range from the optical sensor;
An adjustment unit for adjusting the luminance of the screen of the monitor based on the amount of light detected by the optical sensor;
Using the image information of the image obtained from the camera, a specifying unit for specifying the position in the image of the object included in the image,
In order to detect that the optical sensor is covered with the object based on a predetermined positional relationship between the camera and the optical sensor and a position of the object in the image specified by the specifying unit. A detector of
A portable terminal device comprising: a correction unit for correcting luminance adjusted by the adjustment unit when the detection unit detects that the optical sensor is covered with the object.   The mobile terminal device according to claim 1, wherein the specifying unit specifies a position in an image of a user's finger included in the image using color information of the image obtained from the camera. The detection unit further detects the degree to which the light sensor is covered by the object based on the display position of the object in the image obtained from the camera and the predetermined positional relationship,
The portable terminal device according to claim 1, wherein the correction unit increases the correction amount of the luminance of the screen as the degree to which the optical sensor is covered with the object is higher.   The portable terminal device according to claim 1, wherein the correction unit increases the correction amount of the luminance of the screen as the range of the object occupying in the image is wider. A method for controlling a portable terminal device, comprising:
The portable terminal device
A monitor,
An optical sensor for detecting the amount of light received by the mobile terminal device;
A camera provided on the same plane as the photosensor and provided within a certain range from the photosensor;
The control method is:
Adjusting the brightness of the screen of the monitor based on the amount of light detected by the photosensor;
Identifying the position in the image of the object included in the image using image information of the image obtained from the camera;
The optical sensor is covered with the object based on a predetermined positional relationship between the camera and the optical sensor and a display position of the object included in the image specified in the specifying step. Detecting step;
And a step of correcting the brightness adjusted in the adjusting step when the optical sensor is detected to be covered with the object in the detecting step.

Images