JP5695974B2 - Mobile terminal, brightness control program, and brightness control method - Google Patents

Description

The present invention relates to a mobile terminal, a brightness control program, and a brightness control method, and more particularly to a mobile terminal, a brightness control program, and a brightness control method that control the brightness of a display unit, for example.

  An example of this type of portable terminal is disclosed in Patent Document 1. The control circuit of the mobile phone which is an example of the communication terminal of Patent Document 1 calculates the backlight control value according to the output of the ambient illuminance detection circuit, and determines whether the backlight is turned on / off and the brightness based on the calculation result. It has a function to control.

  Another example of the background art is disclosed in Patent Document 2. This environment-adaptive screen display system of Patent Document 2 includes, on a display device, an illuminance sensor that measures environmental illuminance in the vicinity of the display screen, and a distance sensor that measures the distance between an operator located in front and the display screen. Prepare. The computer controls the brightness and contrast of the display screen by the output of the illuminance sensor and the output of the distance sensor. For example, when the ambient illuminance is bright, it is easier to see when the brightness is high and the contrast is strong, and when the surroundings are dark, the brightness is low and the contrast is weak. Further, when the distance to the screen is short, the luminance may be low and the contrast may be weak. However, when the distance from the screen is increased, it is difficult to see unless the luminance is high and the contrast is strong.

Further, another example of the background art is disclosed in Patent Document 3. In the monitor device with dimming function of Patent Document 3, the controller adjusts the brightness of the LCD screen (automatic dimming rate control) according to the amount of external light detected by the external light sensor, and further operates the touch panel. During the period when the touch panel is operated, the luminance state at the time when the touch panel is operated (the dimming rate according to the amount of external light at the time of detecting the operation) is fixed and controlled to be constant.
JP 2004-96593 [H04M 1/00, G02F 1/133, G09G 3/20, G09G 3/30 G09G 3/34] JP 2000-98991 [G09G 5/00, G09G 5/10, H04N 5/57, H04N 5/66] JP 2007-79113 [G09G 5/00, G09G 3/36, H05B 37/02, G02F 1/1333, G02F 1/133]

  However, since the mobile phone of Patent Document 1 controls the lighting / non-lighting of the backlight and the luminance in accordance with the output of the environmental illuminance detection circuit, the portion for detecting the environmental illuminance is used as the face or finger of the user. When it is covered with, etc., environmental brightness cannot be detected accurately. In this case, the lighting / non-lighting of the backlight and the brightness controlled according to the output of the ambient illuminance detection circuit cannot be correctly controlled.

  In addition, in the environment adaptive screen display system of Patent Document 2, the brightness and contrast of the display screen are controlled based on the environmental illumination and the distance between the operator located in front and the display screen in order to make the screen easier to see. As with the mobile phone of Patent Document 1, when the portion for detecting the ambient illuminance is covered with the user's face or fingers, the ambient brightness cannot be detected accurately. Therefore, the brightness and contrast of the display screen may not be correctly controlled.

  Further, in the monitor device with dimming function of Patent Document 3, during the period when the touch panel operation is performed, the luminance state when the touch panel is operated and the luminance state when the disc ejection state is detected are fixed and fixed. Therefore, the brightness of the LCD screen may not be appropriate when light incident on the external light sensor is not blocked during the touch panel operation. In particular, when this monitor device with dimming function is employed in a portable electronic device, it is considered that it cannot cope with changes in the usage environment.

Therefore, a main object of the present invention is to provide a novel portable terminal, a brightness control program, and a brightness control method.

Another object of the present invention is to provide a portable terminal, a brightness control program, and a brightness control method that can detect ambient brightness with high accuracy.

  The present invention employs the following configuration in order to solve the above problems. The reference numerals in parentheses, supplementary explanations, and the like indicate correspondence relationships with embodiments described later to help understanding of the present invention, and do not limit the present invention in any way.

The first invention includes a display unit, a brightness detection unit that detects brightness around the portable terminal, a distance detection unit that detects a distance between the brightness detection unit and a shielding object that shields the brightness detection unit , According to the distance detected by the separation detection unit, the correction unit that corrects the brightness detected by the brightness detection unit , and the brightness corrected by the correction unit when the brightness detection unit is shielded The mobile terminal includes a luminance control unit that controls the luminance of the display unit .

In the first invention, the mobile terminal (10) is provided with a display unit (30), detector (24,44,48) detects the brightness around the mobile terminal end. The distance detection unit (24, 42, S1) detects the distance between the brightness detection unit and the shielding object that blocks the brightness detection unit. The correction unit (24, S3, S5) corrects the brightness detected by the brightness detection unit in accordance with the distance detected by the distance detection unit. In other words, when the brightness detected by the brightness detection unit is reduced by shielding the brightness detection unit by the shielding object, the brightness is compensated by the correction unit according to the degree of shielding. Is called. The luminance control unit (24, 40) controls the luminance of the display unit according to the brightness corrected by the correction unit when the brightness detection unit is shielded.

  According to the first aspect, since the brightness reduced by the shielding object is compensated, the brightness can be detected with high accuracy.

  A second invention is dependent on the first invention and further includes an amplifying unit that amplifies a value based on the brightness detected by the brightness detecting unit, and the correcting unit corresponds to the distance detected by the distance detecting unit. Then, the amplification factor of the amplification unit is changed.

  In the second invention, the portable terminal further includes an amplification unit (46). The amplifying unit amplifies a value (in the embodiment, a voltage value) based on the brightness detected by the brightness detecting unit. The correction unit changes the amplification factor of the amplification unit according to the distance detected by the distance detection unit. The longer the distance, the smaller the amplification factor, and the shorter the distance, the larger the amplification factor.

  According to the second invention, since the amplification factor of the value based on the brightness is changed according to the distance between the brightness detection unit and the shielding object that shields the brightness detection unit, the brightness reduced by the shielding object Can be supplemented.

  A third invention is dependent on the first invention, and the correction unit adds a correction value to a value based on the brightness detected by the brightness detection unit according to the distance detected by the distance detection unit.

  In the third invention, the correction unit adds the correction value to the value based on the brightness detected by the brightness detection unit according to the distance detected by the distance detection unit. For example, the correction value is determined in advance and is variably set according to the distance. This correction value is also increased as the distance is shorter, and is decreased as the distance is longer.

  In the third invention as well, as with the second invention, the brightness reduced by the shielding object can be compensated.

  A fourth invention is dependent on the first invention, and the correction unit multiplies a value based on the brightness detected by the brightness detection unit by a predetermined magnification according to the distance detected by the distance detection unit. .

  In a fourth invention, according to the first invention, the correction unit multiplies a value based on the brightness detected by the brightness detection unit by a predetermined magnification according to the distance detected by the distance detection unit. . For example, the predetermined magnification is determined in advance and is variably set according to the distance. The predetermined magnification is also increased as the distance is shorter, and is decreased as the distance is longer.

In the fourth invention as well, as with the second invention, the brightness reduced by the shielding object can be compensated.
A fifth invention is dependent on any one of the first to fourth inventions, and invalidates the brightness detected by the brightness detection unit when the distance detected by the distance detection unit is zero. The unit is further provided.
In the fifth invention, the invalid portion (24) invalidates the brightness detected by the brightness detector when the distance detected by the distance detector is zero.

Sixth invention, the display unit and comprising a brightness detector for detecting ambient brightness of the portable terminal, the processor of the portable terminal, the brightness thus detected in Brightness Is detector and the brightness detecting unit is distance detection step of detecting the distance between the shield to reduce, in accordance with the distance detected by the distance detecting step, the correction step of correcting the brightness is thus detected in brightness detector, and brightness detector This is a brightness control program that executes a brightness control step for controlling the brightness of the display unit in accordance with the brightness corrected by the correction step .

A seventh invention is a luminance control method in a mobile terminal , comprising a display unit and a brightness detection unit for detecting the brightness around the mobile terminal , wherein (a ) the brightness detection unit and the brightness detection unit Detecting the distance to the shield that reduces the detected brightness, correcting the brightness detected by the brightness detection unit according to the distance detected by (b ) step ( a ) , and (c ) A brightness control method for controlling the brightness of the display unit according to the brightness corrected in step (b) when the brightness detection unit is shielded .

In the sixth and seventh inventions, as in the first invention, ambient brightness can be detected with high accuracy.

  According to this invention, when the brightness detected by the brightness detecting unit is reduced by the brightness detecting unit being shielded by the shielding object, the brightness is corrected according to the degree of shielding. Therefore, ambient brightness can be detected with high accuracy.

  The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

FIG. 1 is a block diagram showing the electrical configuration of a mobile phone according to an embodiment of the present invention. FIG. 2 is a diagram showing an appearance of the mobile phone shown in FIG. FIG. 3 is a diagram illustrating an example of the correction table. FIG. 4 is a diagram showing an example of a memory map of the RAM shown in FIG. FIG. 5 is a flowchart showing gain adjustment processing of the processor shown in FIG. FIG. 6 is a diagram showing another example of the correction table. FIG. 7 is a diagram showing another example of the correction table.

  Referring to FIG. 1, a mobile phone 10 as an embodiment of a mobile terminal of the present invention includes a processor 24 called a CPU or a computer. The processor 24 includes a wireless communication circuit 14, an A / D converter 16, a D / A converter 20, a key input device 26, a display driver 28, a flash memory 32, a RAM 34, a touch panel control circuit 36, a backlight 40, a proximity A sensor 42, an A / D converter 44 and an amplifier 46 are connected.

  An antenna 12 is connected to the wireless communication circuit 14, a microphone 18 is connected to the A / D converter 16, and a speaker 22 is connected to the D / A converter 20 via an amplifier (not shown). The A display 30 is connected to the display driver 28. Further, a touch panel 38 is connected to the touch panel control circuit 36. An illuminance sensor 48 is connected to the A / D converter 44 via an amplifier 46.

  The processor 24 is an IC for control, and governs overall control of the mobile phone 10. The RAM 34 is used as a work area (including a drawing area) or a buffer area of the processor 24. The flash memory 32 stores contents such as characters, images, sounds, sounds and videos of the mobile phone 10, data such as an address book, electronic mail (transmitted mail, received mail), schedule, and memo pad.

  The A / D converter 16 converts an analog audio signal for audio or sound input through the microphone 18 into a digital audio signal and outputs the digital audio signal to the processor 24. The D / A converter 20 converts (decodes) the digital audio signal into an analog audio signal, and supplies the analog audio signal to the speaker 22 via the amplifier. Therefore, sound or sound corresponding to the analog sound signal is output from the speaker 22.

  As shown in FIG. 2A, the key input device 26 includes a call key 26 a, a menu key 26 b, and an end key 26 c, and key information (key data) operated by the user is input to the processor 24. . Although a detailed description is omitted, for example, when each key included in the key input device 26 is operated, a click sound is generated. Therefore, the user can obtain an operational feeling for the key operation by listening to the click sound.

  The display driver 28 controls display on the display 30 under the instruction of the processor 24. The display driver 28 includes a VRAM (Video RAM) that temporarily stores image data to be displayed, and the processor 24 stores the image data to be output to the display 30 in the VRAM.

  The touch panel 38 is a capacitive touch panel that detects a change in capacitance between electrodes that occurs when a finger approaches the surface. For example, the touch panel 38 detects that one or more fingers touch the touch panel 38. To do. The touch panel 38 functions as a pointing device for instructing an arbitrary position within the screen of the display 30. For example, when the touch panel 38 is operated by pressing, stroking (rubbing), or touching the surface with a finger, the touch panel 38 detects the operation. Then, when the touch panel 38 touches the touch panel 38, the touch panel control circuit 36 that functions as a contact detection unit specifies the position of the finger and outputs coordinate data (coordinate data) indicating the operated position to the processor 24.

  The touch operation is not limited to a finger, and may be performed using a touch pen with a conductor attached to the tip. Further, the touch panel 38 is not limited to the capacitive type, and other types such as a resistive film type, an ultrasonic type, an infrared type, and an electromagnetic induction type may be used.

  The backlight 40 illuminates the display 30 from the back, and for example, an edge light system is adopted. The brightness of the backlight 40 is variably set by the processor 24. For example, the brightness of the backlight 40 is linearly changed between a maximum value and a minimum value, or is changed stepwise.

  The proximity sensor 42 is a general-purpose proximity sensor using infrared rays, for example, and measures (detects) the presence / absence of the target object and the distance to the target object (for example, about several mm to several tens of centimeters). However, the proximity sensor 42 may employ one using light (laser light) other than infrared light, or may employ another proximity sensor using ultrasonic waves.

  The illuminance sensor 48 is a sensor (photosensor) that senses light, and generates a current having a magnitude corresponding to the brightness of the sensed light. The current generated by the illuminance sensor 48 is supplied to the amplifier 46, and the amplifier 46 converts the current from the illuminance sensor 48 into a voltage by the amplifier 46, amplifies it, and provides it to the A / D converter 44. The A / D converter 44 converts the analog voltage value supplied from the amplifier 46 into a digital voltage value and supplies the digital voltage value to the processor 24. The processor 24 adjusts the brightness (luminance) of the backlight 40 that illuminates the display 30 according to the brightness of the surroundings (environment) of the mobile phone 10 detected by the illuminance sensor 48. For example, when the outside is bright, the backlight 40 is turned on brightly, and when the outside is dark, the brightness is reduced and the backlight 40 is turned on. However, as described above, the processor 24 is connected to the amplifier 46, and the processor 24 adjusts the gain G of the amplifier 46. As shown in FIG. 1, the processor 24 outputs a gain adjustment signal to the amplifier 46. Therefore, the amplification factor of the amplifier 46 is changed, and the value (voltage value) based on the brightness detected by the illuminance sensor 48 is adjusted.

  The wireless communication circuit 14 is a circuit for performing wireless communication by the CDMA method. For example, when the user instructs a telephone call using the key input device 26, the wireless communication circuit 14 executes a telephone call process under the instruction of the processor 24 and outputs a telephone call signal through the antenna 12. The telephone call signal is transmitted to the other party's telephone through a base station and a communication network (not shown). Then, when an incoming call process is performed at the other party's telephone, a communicable state is established, and the processor 24 executes a call process.

  The normal call processing will be described in detail. The modulated audio signal transmitted from the other party's telephone is received by the antenna 12. The received modulated audio signal is demodulated and decoded by the wireless communication circuit 14. The received voice signal obtained by these processes is converted into an analog voice signal by the D / A converter 20 and then output from the speaker 22. On the other hand, the transmission voice signal captured through the microphone 18 is converted into a digital voice signal by the A / D converter 16 and then given to the processor 24. The transmission signal converted into the digital audio signal is subjected to encoding processing and modulation processing by the wireless communication circuit 14 under the instruction of the processor 24, and is output via the antenna 12. Therefore, the modulated voice signal is transmitted to the other party's telephone through the base station and the communication network.

  When a call signal from the other party's telephone is received by the antenna 12, the wireless communication circuit 14 notifies the processor 24 of an incoming call (sometimes called an incoming call). In response to this, the processor 24 controls the display driver 28 to display the caller information (phone number) described in the incoming call notification on the display 30. At substantially the same time, the processor 24 outputs a ring tone (sometimes called a ringing melody or a ringing voice) from a speaker (not shown). Further, the processor 24 vibrates the mobile phone 10 or emits an LED (not shown) to notify the user of an incoming call.

  When the user performs a response operation using the call key 26a, the wireless communication circuit 14 executes the incoming call process under the instruction of the processor 24, and a communicable state is established. Perform normal call processing.

  In addition, when a call end operation is performed by the call end key 26c after the transition to the call ready state, the processor 24 controls the wireless communication circuit 14 to transmit a call end signal to the call partner. After transmitting the call end signal, the processor 24 ends the call process. The processor 24 also ends the call process when a call end signal is received from the other party first. Furthermore, the processor 24 also ends the call process when a call end signal is received from the mobile communication network regardless of the call partner.

  2A and 2B are views showing the appearance of the mobile phone 10. However, FIG. 2A is a diagram showing the appearance of the front side (front side) of the mobile phone 10, and FIG. 2B is a diagram showing the appearance of the back side (back side) of the mobile phone 10. Referring to FIG. 2A, the mobile phone 10 has a housing C formed in a planar rectangular plate shape. A display 30 is disposed in the approximate center of the surface of the housing C with its monitor screen exposed. A touch panel 38 is provided on the upper surface of the display 30.

  An opening OP1, a proximity sensor 42, and an illuminance sensor 48 are provided at the upper end of the surface of the housing C. Corresponding to the position where the opening OP1 is provided, the above-described speaker 22 is provided inside the housing C. The proximity sensor 42 and the illuminance sensor 48 are at the upper right end of the surface of the housing C, and are provided close to (adjacent to) each other so that at least each detection unit is exposed from the housing C. However, the proximity sensor 42 and the illuminance sensor 48 may be provided at the upper left end of the surface of the housing C.

  In this embodiment, the proximity sensor 42 and the illuminance sensor 48 are provided adjacent to each other in order to measure the distance between the illuminance sensor 48 and the shielding object that shields it as accurately as possible. However, as will be described later, since the gain G of the amplifier 46 is adjusted according to a certain range of distance, the distance may be measured with a certain degree of accuracy. Therefore, the proximity sensor 42 and the illuminance sensor 48 may be arranged with a certain distance therebetween. However, it is necessary to be able to detect that the detection unit of the illuminance sensor 48 is closed with fingers.

  Further, as described above, the key input device 26 (the call key 26a, the menu key 26b, and the call end key 26c) is provided at the lower end of the surface of the housing C. An opening OP2 is provided below the key input device 26 (menu key 26b). Corresponding to the position where the opening OP2 is provided, the above-described microphone 18 is provided inside the housing C.

  1, the antenna 12, the wireless communication circuit 14, the A / D converter 16, the D / A converter 20, the processor 24, the display driver 28, the flash memory 32, the RAM 34, the touch panel control circuit 36, and the backlight 40. The A / D converter 44 and the amplifier 46 are not shown in FIGS. 2A and 2B because they are built in the housing C.

  For example, the mobile phone 10 performs incoming and outgoing calls, creates, sends, receives, and confirms e-mails, edits and confirms an address book, and inputs and confirms schedules. Or run other applications.

  At this time, a screen corresponding to the operation (process) of each application is displayed on the display 30. At that time, the brightness (luminance) of the backlight 40 is controlled according to the brightness detected by the illuminance sensor 48. The user holds the mobile phone 10 with one hand and operates the key input device 26 and the touch panel 38 with the other hand, for example.

  However, when the user's finger or face covers or closes the detection unit of the illuminance sensor 48 and there is a shield in front of the illuminance sensor 48 (the detection unit), the illuminance sensor 48d. Since the brightness detected by the shutter is reduced by the shielding object, the ambient brightness cannot be detected correctly.

  Therefore, in this embodiment, the proximity sensor 42 measures the distance to the shielding object in front of the illuminance sensor 48, and changes the gain G of the amplifier 46 according to the measured distance to the shielding object (adjustment). The ambient brightness can be detected with high accuracy according to the situation. In other words, the reduced brightness is compensated by blocking the light that the shielding object irradiates the illuminance sensor 48 with.

  For example, a correction table as shown in FIG. 3 is prepared, and the gain G of the amplifier 46 is adjusted with reference to this correction table. As shown in FIG. 3, the gain G of the amplifier 46 is described in the correction table corresponding to the range of the distance D to the shielding object in front of the illuminance sensor 48. However, in the correction table, the relationship between the distances d1, d2, d3, and d4 is d1> d2> d3> d4, and the relationship between the gains G1, G2, G3, G4, and G5 is G5> G4> G3>. G2> G1. That is, as the measured distance D becomes longer, the gain G becomes smaller, and as the measured distance D becomes shorter, the gain G becomes larger. That is, the measured distance D and gain G are inversely proportional. This is because the shorter the distance D, the higher the degree that the shielding object shields the detection unit of the illuminance sensor 48. In such a case, the gain G of the amplifier 46 is increased.

  The distances D, d1-d4, and the gains G1-G5 are values (numerical values) that are variably set depending on the performance of the proximity sensor 42 and the illuminance sensor 48 to be used, and are obtained empirically through experiments and the like. Therefore, specific numerical values are not shown.

  Here, it is described that the gain G is adjusted using a correction table as shown in FIG. 3, but in practice, the volume of the variable resistor of the amplifier 46 is controlled in order to adjust the gain G. . That is, the above-described gain adjustment signal is strictly a volume control signal.

  In this embodiment, according to the correction table, the gain G is set to G5 when the distance D is smaller than d4. However, when the distance D is 0, all or part of the detection unit of the illuminance sensor 48 is blocked, and thus the brightness cannot be detected correctly. In such a case, the brightness detected by the illuminance sensor 48 may be invalidated, and for example, a sound indicating that the brightness has not been correctly detected or a sound to that effect (synthesized sound) may be output.

  In this embodiment, the gain G is set in five steps according to the detected distance D. However, the gain G may be set in six steps or more as long as it is two or more steps. Further, the gain G may be calculated based on the distance D regardless of the correction table. In such a case, the gain G can be adjusted linearly.

  FIG. 4 shows an example of the memory map 500 of the RAM 34 shown in FIG. As shown in FIG. 4, the RAM 34 includes a program storage area 502 and a data storage area 504. An operation program for operating the mobile phone 10 is stored in the program storage area 502. The operation program includes a call program 502a, a communication program 502b, a distance detection program 502c, a gain adjustment program 502d, a brightness detection program 502e, and the like. Consists of.

  The call program 502a is a program for executing a call process with another telephone. The communication program 502b is a program for communicating with other computers such as sending and receiving electronic mail. The distance detection program 502c is a program for detecting the distance between the illuminance sensor 48 and a shield in front of the illuminance sensor 48. The gain adjustment program 502d is a program for adjusting the gain G of the amplifier 46 according to the distance detected according to the distance detection program 502c with reference to the correction table. Therefore, the value (voltage value) based on the brightness detected by the illuminance sensor 48 is adjusted. The brightness detection program 502 e is a program for detecting the brightness around the mobile phone 10 by the illuminance sensor 48.

  Although illustration is omitted, the program storage area 502 also stores other programs for operating the mobile phone 10 and programs for various applications.

  The data storage area 504 stores distance data 504a, brightness data 504b, and correction table data 504c. The distance data 504a is data on the distance between the illuminance sensor 48 and the shielding object detected according to the distance detection program 502c. The brightness data 504b is data of a voltage value corresponding to the brightness detected according to the brightness detection program 502e. The correction table data 504c is data regarding the correction table shown in FIG.

  Although illustration is omitted, the data storage area 504 stores other data necessary for the execution of the operation program and the application program, and is provided with a flag and a counter (timer) necessary for the execution of these programs. .

  FIG. 5 is a flowchart showing the gain adjustment processing of the processor 24 shown in FIG. As shown in FIG. 5, when starting the gain adjustment process, the processor 24 detects the distance in step S1. That is, the processor 24 acquires the distance D detected by the proximity sensor 42 and stores the distance data 504 a corresponding to the distance D in the data storage area 504. In the next step S3, the gain is determined according to the distance. That is, the processor 24 refers to the correction table for the correction table data 504c and acquires the gain G corresponding to the distance D detected in step S1.

  Subsequently, in step S5, the gain is adjusted. Here, the processor 24 adjusts the volume of the variable resistor of the amplifier 46 so that the gain G determined in step S3 is obtained. Therefore, the amplification factor of the amplifier 46 is changed. Therefore, the current corresponding to the brightness output from the illuminance sensor 48 is converted into a voltage and amplified, converted into a digital voltage signal by the A / D converter 44, and supplied to the processor 24. That is, even if the detected brightness is reduced by the shielding object, the brightness is corrected by increasing the gain G of the amplifier 46. Specifically, the voltage value based on the brightness is corrected.

  In step S7, it is determined whether or not the process is finished. Here, the processor 24 determines whether or not to end the display on the display 30, for example. If “NO” in the step S7, that is, if not finished, the process returns to the step S1 as it is. On the other hand, if “YES” in the step S7, that is, if it is finished, the gain adjustment processing is finished.

  Although illustration is omitted, when the call, communication, and application processes are executed by a task different from the task that executes the gain adjustment process shown in FIG. The brightness is detected by the sensor 48, and the luminance of the backlight 40 is controlled.

  According to this embodiment, since the gain of the amplifier that amplifies the output of the illuminance sensor is adjusted according to the distance between the illuminance sensor and the shielding object that shields the illuminance sensor, ambient brightness can be detected with high accuracy. Can do. Therefore, it is possible to appropriately control parameters such as the brightness of the backlight that is controlled based on the brightness.

  In this embodiment, the gain of the amplifier (analog amplifier) that amplifies the voltage value based on the brightness detected by the illuminance sensor is adjusted. However, the present invention is not limited to this. A digital amplifier may be used as the amplifier. In such a case, for example, a current value corresponding to the brightness output from the illuminance sensor 48 is converted into a voltage value, further A / D converted, and then amplified by a digital amplifier. The digital amplifier may be provided between the processor 24 and the A / D converter 44 or may be built in the processor 24. The gain of this digital amplifier is adjusted according to the distance D detected by the proximity sensor 42.

  In this embodiment, the gain of the amplifier is adjusted. However, the correction value may be added to the voltage value corresponding to the brightness according to the distance D. Alternatively, a voltage value corresponding to the brightness may be multiplied by a predetermined magnification (greater than 1) according to the distance D. For example, in the former case, as shown in FIG. 6, a correction table describing the correction value α according to the range of the distance D is prepared in advance. In the latter case, as shown in FIG. 7, a correction table describing the magnification φ in accordance with the range of the distance D is prepared in advance. However, in the correction table, the correction value α and the magnification φ are reduced as the distance becomes longer, and the correction value α and the magnification φ are increased as the distance becomes shorter. That is, in FIG. 6, d1> d2> d3> d4 and α5> α4> α3> α2> α1. In FIG. 7, d1> d2> d3> d4, and φ5> φ4> φ3> φ2> φ1. However, the correction values α1-α5 and the magnifications φ1-φ5 are also values (numerical values) that are variably set according to the performance of the proximity sensor 42 and the illuminance sensor 48 to be used, similarly to the gains G1-G5 shown in FIG. It can be obtained empirically through experiments and the like. As described above, when the correction value α is added or multiplied by the magnification φ, the processor 46 only executes the arithmetic processing, and thus the amplifier 46 is unnecessary.

  Furthermore, in this embodiment, a mobile phone is shown as an example of a mobile terminal, but the present invention is not limited to this. For example, the present invention can also be applied to PDAs, tablet computers (including iPad, iPod, Walkman (registered trademark), etc.) and portable game machines.

  Furthermore, in this embodiment, the touch panel is provided on the display, but the touch panel may not be provided.

  In addition, the specific numerical values given in the above description are merely examples, and can be appropriately changed according to the needs of product specifications and the like.

DESCRIPTION OF SYMBOLS 10 ... Mobile phone 14 ... Wireless communication circuit 18 ... Microphone 22 ... Speaker 24 ... Processor 26 ... Key input device 28 ... Display driver 30 ... Display 32 ... Flash memory 34 ... RAM
38 ... Touch panel 40 ... Backlight 42 ... Proximity sensor 46 ... Amplifier 48 ... Illuminance sensor

Claims (7)

Display,
A brightness detector that detects the brightness around the mobile device,
A distance detection unit that detects a distance between the brightness detection unit and a shield that shields the brightness detection unit ;
A correction unit that corrects the brightness detected by the brightness detection unit according to the distance detected by the distance detection unit ; and
A portable terminal comprising: a luminance control unit that controls the luminance of the display unit according to the brightness corrected by the correction unit when the brightness detection unit is shielded . An amplifying unit for amplifying a value based on the brightness detected by the brightness detecting unit;
The mobile terminal according to claim 1, wherein the correction unit changes an amplification factor of the amplification unit according to the distance detected by the distance detection unit.   The mobile terminal according to claim 1, wherein the correction unit adds a correction value to a value based on the brightness detected by the brightness detection unit according to the distance detected by the distance detection unit.   The mobile terminal according to claim 1, wherein the correction unit multiplies a value based on the brightness detected by the brightness detection unit by a predetermined magnification according to the distance detected by the distance detection unit. 5. The mobile terminal according to claim 1, further comprising: an invalid unit that invalidates the brightness detected by the brightness detection unit when the distance detected by the distance detection unit is zero. . A processor of a mobile terminal including a brightness detection unit that detects brightness around the display unit and the mobile terminal ,
Distance detection step of detecting the distance between the shield to reduce the pre-Symbol brightness detector and the brightness detection portion thus brightness to be detected,
Depending on the distance detected by the prior Symbol distance detection step, the correction step of correcting a result detected by the brightness in the brightness detection unit, and
A brightness control program for executing a brightness control step for controlling the brightness of the display unit according to the brightness corrected by the correction step when the brightness detection unit is shielded . A brightness control method for a mobile terminal, comprising a brightness detector for detecting brightness around the display unit and the mobile terminal,
(A ) detecting a distance between the brightness detection unit and a shield that reduces the brightness detected by the brightness detection unit ;
(B) in response to said distance detected by the step (a), to correct the brightness detected by the brightness detection unit, and
(C) A brightness control method for controlling the brightness of the display unit according to the brightness corrected in the step (b) when the brightness detection unit is shielded .

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