JP2012010016A - Backlight control apparatus, electronic device, and control method of backlight - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a backlight by using a function equipped as a standard feature even in a cheap mobile terminal device without mounting any expensive sensor such as a illuminance sensor, thereby saving electric power.SOLUTION: A backlight control apparatus includes a display, a key input part to detect the presence of key input, at least one of a key backlight to light the key input part from back of the key input part and a display backlight to light the display from back of the display, and a control part. The control part maintains a state where the key backlight and/or the display backlight are/is not being lit for a prescribed time immediately after when the key input of the key input part became possible, and turns on the key backlight and/or the display backlight to be lit after a lapse of predetermined time immediately after when the key input of the key input part became possible.

Description

  The present invention relates to a backlight control device, an electronic device, and a backlight control method.

  In the foldable portable terminal device disclosed in Patent Document 1, when the state transition is made from the first state in which the display housing is closed to the opened second state, this transition operation (opening operation) is detected. Is detected, and the position of the power key is notified to the user by turning on the backlight (for example, LED) of the power key.

Japanese Patent No. 4430026

  However, for example, when the user opens the display housing only to check the time or the incoming mail status, the key backlight is used to notify the position of the power key immediately after the display housing transitions to the open state. If is turned on, the power of the mobile terminal device is wasted in a place different from the user's purpose. As an example of a technology that addresses this issue, there is a technology that uses an expensive sensor such as an illuminance sensor to reduce power consumption by turning off the backlight or turning it dark when the surroundings are bright. If an expensive sensor such as a sensor is used, the portable terminal device cannot be manufactured at a low cost.

  An object of the present invention is to provide a backlight control device that can save power by controlling a backlight using a function that is not provided with an expensive sensor such as an illuminance sensor and is also provided as a standard even in an inexpensive portable terminal device, and an electronic device It is to provide a device and a backlight control method.

  According to the first aspect of the present invention, a display unit, a key input unit that detects the presence or absence of key input, a key backlight that illuminates the key input unit from the back side of the key input unit, and a back side of the display unit A state in which the key backlight and / or the display backlight is not turned on for a predetermined time immediately after the key input of the key input unit is enabled and at least one of the display backlights that illuminate the display unit from And a control unit that turns on the key backlight and / or the display unit backlight after a predetermined time has passed since the key input unit is ready for key input. Providing equipment.

  According to the second aspect of the present invention, when there is a key input within the predetermined time period, the control unit performs the key backlight and / or the display unit backlight even before the predetermined time period elapses. Turn on the light.

  According to a third aspect of the present invention, in the backlight control device, the control unit performs key input to the key input unit after the key backlight and / or the display unit backlight is turned on. As the operation is continued, the illuminance of the key backlight and / or the display unit backlight is decreased stepwise so that the illuminance of the key backlight and / or the display unit backlight decreases.

  According to the fourth aspect of the present invention, in the backlight control device, the number of times the key input operation has been performed on the key input unit is measured, and the key backlight and / or the display unit backlight is turned on. Thereafter, control is performed so that the illuminance of the key backlight and / or the display unit backlight decreases as the number of key input operations per unit time increases.

  According to a fifth aspect of the present invention, in the backlight control device, the control unit further includes the key backlight and / or a predetermined time immediately after the key input unit is ready for key input. Alternatively, while maintaining a state in which the display unit backlight is not turned on, notification is made to prompt the user to turn on the key backlight and / or the display unit backlight.

  According to the sixth aspect of the present invention, the display unit, the key input unit for detecting presence / absence of key input, the key backlight for illuminating the key input unit from the back side of the key input unit, and the back side of the display unit A state in which the key backlight and / or the display backlight is not turned on for a predetermined time immediately after the key input of the key input unit is enabled and at least one of the display backlights that illuminate the display unit from And a control unit for notifying a user to turn on the key backlight and / or the display unit backlight after a predetermined time has passed since the key input unit is ready for key input. Provided is a backlight control device.

  According to a seventh aspect of the present invention, in the backlight control device, when there is a key input, the control unit performs the key backlight and / or the display unit backlight regardless of before and after the display. When the key backlight and / or the display unit backlight is turned on after the display, the key backlight and / or the display unit backlight is turned on before the display. The key backlight and / or the display unit backlight are turned on by lowering the illuminance than when the light is broken.

In another aspect of the present invention, a mobile phone including the backlight control device is provided.
In another aspect of the present invention, there is provided a backlight control method for performing the same control as that of the backlight control device.

  According to the first aspect of the present invention, the key backlight and / or the display unit backlight is not turned on immediately after the key input is enabled, and the key backlight and / or the display is displayed after a predetermined time has elapsed. Turn on the backlight. Therefore, when the user can confirm desired information such as confirmation of time in a bright place without turning on the key backlight and / or the display unit backlight, the key backlight and / or the display unit Since processing is completed before the backlight is turned on, power consumption can be suppressed. Moreover, since it is sufficient to have a function of measuring a predetermined time for realizing this aspect, an expensive sensor such as an illuminance sensor is not necessary.

  According to the second aspect of the present invention, when there is a key input within a predetermined time, the key backlight and / or the display backlight is turned on even before the predetermined time has elapsed. Therefore, user convenience can be improved when the key backlight and / or the display unit backlight are needed immediately, such as when checking the time in a dark place.

  According to the third aspect of the present invention, the backlight becomes dark as the key input continues. This makes it possible to save power in such a way that it is difficult for the user to notice by utilizing the characteristic that it is difficult to notice a subtle change when looking at the same thing for a long time.

  According to the fourth aspect of the present invention, the backlight becomes darker as the number of key input operations per unit time is larger. Thereby, it is possible to adjust the backlight to a brightness suitable for the surrounding illuminance without using the illuminance sensor. That is, if it can be determined that the surroundings are bright enough that the user can perform key input at high speed, it can be estimated that the surroundings are sufficiently bright, so there is no problem even if the backlight is darkened.

  According to the fifth aspect of the present invention, a display that prompts the user to turn on the key backlight and / or the display unit backlight is performed. Accordingly, it is possible to notify the user that the key backlight and / or the display unit backlight can be turned on.

  According to the sixth aspect of the present invention, the key backlight and / or the display unit backlight is not turned on immediately after key input is enabled, and the key backlight and / or A display that prompts the user to turn on the display unit backlight is performed. Accordingly, when the user can confirm desired information such as confirmation of time in a bright place without turning on the key backlight and / or the display unit backlight, the key backlight and / or the display is displayed. Since the process is completed before the backlight is turned on, power consumption can be reduced. Moreover, since it is sufficient to have a function of measuring a predetermined time for realizing this aspect, an expensive sensor such as an illuminance sensor is not necessary.

  According to the seventh aspect of the present invention, if the timing at which the key backlight and / or the display unit backlight is turned on is after notification, the key backlight and / or the display unit backlight are darkened. Light. This is because when the key backlight and / or the display unit backlight is turned on through notification, it can be estimated that the place where the user is is a dark place where input is difficult. In such a dark place, if the key backlight and / or the display unit backlight is suddenly brightened, the user is likely to feel dazzled due to a difference from ambient light. Therefore, the user's discomfort can be reduced by turning on the key backlight and / or the display unit backlight darkly.

(A) The figure which shows the cellular phone 100 of a closed state, (b) The figure which shows the cellular phone 100 of an open state The block diagram which shows the structure of the mobile telephone 100 (A)-(c) is a figure for demonstrating control (1) of the key backlight 103. FIG. (A)-(d) is a figure for demonstrating control (2) of the key backlight 103. FIG. (A)-(d) is a figure for demonstrating control (3) of the key backlight 103. FIG. (A)-(c) is a figure for demonstrating control of the 2nd backlight 107. FIG. Control flow of key backlight 103 Control flow of second backlight 107 (A), (b) is a figure which shows the modification of the key backlight 103. FIG.

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

  As an embodiment of the mobile terminal device of the present invention, a foldable mobile phone 100 (hereinafter simply referred to as a mobile phone 100) will be described.

  The configuration of the mobile phone 100 will be described with reference to FIGS. 1 (a), 1 (b), and 2. FIG. FIG. 1A is a diagram showing the cellular phone 100 in the closed state, and FIG. 1B is a diagram showing the cellular phone 100 in the opened state.

  The cellular phone 100 includes a first casing 121 and a second casing 123, and a connecting portion 125 that rotatably connects the first casing 121 and the second casing 123.

  Both the first casing 121 and the second casing 123 are substantially rectangular flat plate-shaped casings. The first housing 121 is configured to be rotatable with respect to the second housing 123 via the connecting portion 125. Similarly, the second housing 123 is configured to be rotatable with respect to the first housing 121 via the connecting portion 125.

On the main surface 121A of the first housing 121, a display unit 111 and a call receiver 135 are arranged.
The call receiver 135 outputs the call partner's voice processed by the voice processing unit 131.

  In the present embodiment, display unit 111 is configured by a liquid crystal display (LCD), and is controlled by a second backlight control unit described later. The display unit 111 is illuminated by a backlight (second backlight) of the liquid crystal display.

  On the main surface 123 </ b> A of the second housing 123, the key input unit 101 and the call microphone 133 are arranged. The main surface 123A of the second housing 123 is an operation surface on which a user performs a key input operation.

  The key input unit 101 accepts user input operations. The key input unit 101 is provided with various operation keys such as a numeric key 161, a power key 162, a backlight lighting key 163 of the display unit 111, and a multi-function key 164.

  A voice of the user is input to the microphone 133 for a call. The input user's voice is processed by the voice processing unit 131 and transmitted to the mobile phone of the other party via a wireless unit (not shown).

  A key backlight 103 is arranged over the entire back surface of the key input unit 101. The key backlight 103 is controlled by a first backlight control unit 105 described later. When the user performs a key input operation, the entire key input unit 101 is illuminated under a predetermined condition.

  The connecting portion 125 rotatably connects the first housing 121 and the second housing 123, and can relatively rotate both housings around the rotation axis X. In other words, when the first casing 121 is rotated with respect to the second casing 123 about the rotation axis X, the main surfaces of both casings can be opposed to each other and folded (see FIG. 1A). Status). Further, when the first casing 121 is rotated about the rotation axis X with respect to the second casing 123, both casings can be deployed by opening the main surfaces of both casings in the same direction (FIG. 1). (B) Open state).

  The open / closed state of the mobile phone 100 is detected by a magnet 171 provided in the first housing 121 and a magnetic sensor 173 provided in a position facing the magnet 171 in the closed state in the second housing. Is done. When the magnetic sensor 173 detects a change in the magnetic force of the magnet 171, the open / close state of the mobile phone 100 is detected.

  FIG. 2 is a block diagram showing a configuration of the mobile phone 100 according to the first embodiment. A mobile phone 100 shown in FIG. 2 includes a key input unit 101, a key backlight 103, a first backlight control unit 105, a second backlight 107, a second backlight control unit 109, and a display unit 111. A display control unit 113, an audio processing unit 131, a microphone 133, a receiver 135, a terminal state determination unit 141, and a key input processing unit 151.

  The key input unit 101 receives a user key input operation. A user's key press operation is detected. The detection result of the key input operation is output to the key input processing unit 151.

  The key input processing unit 151 sends an operation signal corresponding to the key input operation to the first backlight control unit 105, the second backlight control unit 109, and the display control unit 113 based on the detection result of the input key input operation. Output.

  Based on the detection result of the magnetic sensor 173 described above, the terminal state determination unit 141 determines whether the mobile phone 100 is in an open state (see FIG. 1B) or a closed state (see FIG. 1A). The determination result is output to the first backlight control unit 105, the second backlight control unit 109, and the display control unit 113.

  The first backlight control unit 105 controls turning on / off of the key backlight 103 based on the operation signal corresponding to the input key input operation or the determination result of the terminal state determination unit 141.

  Specifically, the first backlight control unit 105 performs control to keep the key backlight 103 off for a predetermined time when the mobile phone 100 transitions from the closed state to the open state (FIG. 3A, ( b)). In addition, since it is assumed that the mobile phone 100 of the present embodiment does not include an illuminance sensor, this control is performed regardless of the ambient light level.

  Further, the first backlight control unit 105 performs control to turn on the key backlight 103 when a key pressing operation is started by the user after the mobile phone 100 transitions from the closed state to the open state. Note that the first backlight control unit 105 performs control to turn on the key backlight 103 until a predetermined time has elapsed since the key backlight 103 has been turned off after the mobile phone 100 has transitioned from the closed state to the opened state. Not performed.

  In addition, when the user's key pressing operation is continuously detected, the first backlight control unit 105 sets the lighting level of the key backlight 103 within a range that does not hinder the user's key pressing operation. (See FIGS. 4A to 4D). Specifically, the amount of current flowing through the key backlight 103 is reduced by a predetermined amount every unit time.

  The first backlight control unit 105 controls the lighting level of the key backlight based on the number of key pressing operations per unit time when a user's key pressing operation is continuously detected (FIG. 5). (See (a) to FIG. 5 (d)).

  The key backlight 103 is turned on or off under the control of the first backlight control unit 105. In the present embodiment, a key backlight composed of a plurality of LED elements is provided on the entire key input unit 101 over the entire back surface of the key input unit 101, and the entire back surface of the key input unit 101 shines.

  The second backlight control unit 109 controls turning on / off of the second backlight 107 based on the operation signal corresponding to the input key input operation or the determination result of the terminal state determination unit 141. The second backlight 107 is a backlight of the display unit 111. Specifically, when the second backlight control unit 109 continues to press the key for operating the browser screen of the display unit 111, the lighting level of the second backlight 107 is decreased stepwise (see FIG. 6 (a) to FIG. 6 (c)). For example, this is realized by increasing or decreasing the amount of current flowing through the second backlight 107 by a predetermined amount per unit time.

  The second backlight 107 that functions as the backlight of the display unit 111 is turned on or off under the control of the second backlight control unit 109. In the present embodiment, display unit 111 is a liquid crystal display (LCD), and second backlight 107 is an LCD backlight.

  The display control unit 113 controls the display of the display unit 111 based on the operation signal corresponding to the input key input operation and the determination result of the terminal state determination unit 141. Specifically, the display control unit 113, when the cellular phone 100 is in an open state with the key backlight 103 turned off and a predetermined time elapses without detection of a key pressing operation (see FIG. 3C). ), The display unit 111 is controlled so as to perform a display prompting the key backlight to be turned on. At this time, a button used to turn on the backlight may be emitted together with the display on the display unit or instead of the display. In FIG. 3 (c), turning on the backlight lighting key 163 corresponds to this. That is, any means can be used as long as it is possible to notify that the backlight is turned on.

  The display of the display unit 111 is controlled by the control of the display control unit 113. Note that the backlight of the display unit 111 is turned on or off under the control of the second backlight control unit 109 as described above.

  The voice processing unit 131 receives the user's voice via the telephone microphone 133. Various voice processes are performed on the user's voice for wireless transmission to the mobile phone of the other party. In addition, the voice processing unit 131 performs various kinds of voice processing in order to output the voice of the other party of the call via the call receiver 135.

[Control of key backlight 103 (1)]
The control (1) of the key backlight 103 will be described with reference to FIGS. FIG. 3A to FIG. 3C are diagrams for explaining the control (1) of the key backlight 103.

  As shown in FIG. 3A, when the cellular phone 100 is changed from the closed state to the open state shown in FIG. 3B, the key backlight 103 is kept off. Even when the key backlight 103 is turned off, the cellular phone 100 can save power by not turning on the key backlight 103.

  In particular, as shown in FIG. 3B, the key backlight 103 does not have to be turned on only to confirm the time display “12:34”, the antenna reception state, the mail reception state, and the like. In other words, if only the time display “12:34”, the antenna reception state, the mail reception state, etc. are confirmed, the key operation is not necessary, so that the operation input can be performed even when the key backlight 103 is turned off. It won't be difficult to do. In the present embodiment, second backlight 107 (LCD backlight) is turned on when mobile phone 100 transitions to the open state. This is so that the time display can be confirmed even in a dark place. However, in order to further reduce power consumption, it is possible to keep the light off until a predetermined time elapses, as with the key backlight 103.

  In the state shown in FIG. 3B, when a predetermined time elapses without detection of a key pressing operation, a key backlight lighting function is assigned to the display unit 111 as shown in FIG. 3C. A display prompting the user to press the backlight lighting key 163 is made.

  Thus, the cellular phone 100 can save power by not turning on the key backlight 103. Furthermore, when a predetermined time elapses, a display for prompting the key backlight to appear appears on the display unit 111, so that the key backlight can be lit according to the user's application. If only the time display “12:34”, the antenna reception state, the mail reception state, etc. are confirmed, the ambient light level is sufficient even when the key backlight 103 is turned off.

[Control of key backlight 103 (2)]
The control (2) of the key backlight 103 will be described with reference to FIGS. FIG. 4A to FIG. 4D are diagrams for explaining the control (2) of the key backlight 103.

  When the cellular phone 100 transitions from the closed state to the open state shown in FIG. 4B as shown in FIG. 4A, when the user starts a key press operation, the backlight is turned on for key input. It is determined that it is necessary, and the key backlight 103 is turned on. Here, for example, when a key pressing operation is continuously detected from the open state shown in FIG. 4B, for example, during mail creation, as shown in FIG. 4C, the key backlight 103 is turned on. The state transitions from the brightest lighting level shown in FIG. 4B to the lighting level one level lowers. Further, when the key pressing operation is continuously detected in the state of FIG. 4C, as shown in FIG. 4D, the lighting state of the key backlight 103 is the lighting shown in FIG. Transition from the level to the lighting level where the brightness level has decreased by one. Note that a method for gradually lowering the lighting level of the key backlight 103 is realized by reducing the amount of current flowing through the key backlight 103 by a predetermined amount per unit time.

  As described with reference to FIGS. 4A to 4D, the mobile phone 100 allows the current flowing through the key backlight 103 to be constant per unit time when the user has been operating for a long time. The amount can be reduced and the lighting level of the key backlight 103 can be lowered. This uses a characteristic that makes it difficult to notice subtle changes when the user looks at the same item (for example, the key input unit 101) for a long time. Thereby, the mobile phone 100 can realize power saving of the key backlight 103 without hindering the user's key pressing operation. In other words, when the user looks at the same thing (for example, the key input unit 101) for a long time, the cellular phone 100 uses a key backlight without using an illuminance sensor, using characteristics that make it difficult to notice subtle changes. The lighting level of 103 is lowered stepwise by a predetermined amount, and the ambient light level is obtained to such an extent that the user's key pressing operation is not hindered. This is a power saving method that is particularly effective when key pressing operations such as e-mail creation and browsing are performed continuously for a long time.

[Control of key backlight 103 (3)]
With reference to FIGS. 5A to 5D, the control (3) of the key backlight 103 will be described. FIG. 5A to FIG. 5D are diagrams for explaining the control (3) of the key backlight 103. In the control of the key backlight 103 (3), the first backlight control unit 105 controls the lighting level of the key backlight based on the number of key pressing operations per unit time. A method for controlling the lighting level of the key backlight 103 stepwise is realized by increasing or decreasing the amount of current flowing through the key backlight 103 by a predetermined amount per unit time.

  In the open state shown in FIG. 5A, the key backlight 103 is turned off. In this case, the key pressing operation of the key input unit 101 is 50 times or more per 10 seconds. That is, since there are more than a predetermined number of key pressing operations per unit time, it is determined that there is no problem with the key pressing operation even if the key backlight 103 is not lit. The key backlight 103 is turned off.

  In the open state shown in FIG. 5B, the key backlight 103 is lit at the brightest lighting level. In this case, the key pressing operation of the key input unit 101 is less than a predetermined amount of 20 times per unit time of 10 seconds. That is, since the key pressing operation is less than the predetermined number of times per unit time, if the key backlight 103 is not lit at the brightest lighting level, it is determined that there is an obstacle to the key pressing operation, and the first backlight control unit Under the control of 105, the key backlight 103 is fully lit.

  In the open state shown in FIG. 5C, the key backlight 103 is lit at a lighting level one lower than the brightest lighting level. In this case, the key pressing operation of the key input unit 101 is a predetermined amount 20 times or more per unit time 10 seconds.

  In the open state shown in FIG. 5D, the key backlight 103 is turned on at a lighting level one level higher than the state in which the key backlight 103 is turned off. In this case, the key pressing operation of the key input unit 101 is a predetermined amount 30 times or more per unit time of 10 seconds.

  As described above, the mobile phone 100 can be controlled by controlling the first backlight control unit 105 step by step based on the number of key pressing operations per unit time. Thus, it is possible to realize power saving of the key backlight 103 without hindering the key pressing operation. In other words, the mobile phone 100 adjusts the lighting level of the key backlight 103 based on the number of key pressing operations per unit time, even if it does not include an illuminance sensor (or without using an illuminance sensor). Thereby, the ambient light level is obtained to such an extent that the user's key pressing operation is not hindered.

[Control of Second Backlight 107 (1)]
With reference to FIG. 6A to FIG. 6C, control of the second backlight 107 serving as the backlight of the display unit 111 will be described. FIG. 6A to FIG. 6C are diagrams for explaining the control of the second backlight 107. In the control of the second backlight 107 (1), the second backlight control unit 109 controls the lighting level of the second backlight 107 while the key pressing operation for operating the browser screen of the display unit 111 is continued, for example. To do. As a method for controlling the lighting level of the second backlight 107 in a stepwise manner, for example, the amount of current flowing through the second backlight 107 is increased or decreased by a predetermined amount per unit time.

  In the open state shown in FIG. 6A, the second backlight 107 which is the backlight of the display unit 111 is lit at the brightest lighting level. Here, when the key pressing operation is continued for a long time to operate the browser screen, as shown in FIG. 6B, the lighting level of the second backlight 107 is 1 from the brightest lighting level. It is lowered to the next lighting level. Further, when the key press operation is continued for a long time to operate the browser screen, the lighting level of the second backlight 107 is changed to the lighting level one lower than the lighting level shown in FIG. Be lowered. This change in the lighting level is a subtle change for the user viewing the display unit 111 and is difficult to notice. Therefore, the lighting level of the second backlight 107 can be lowered and power saving of the second backlight 107 can be achieved without hindering the key pressing operation for operating the browser screen.

  As described with reference to FIG. 6A to FIG. 6C, the mobile phone 100 determines the current flowing through the second backlight 107 for each unit time when the user has operated for a long time. A certain amount can be reduced, and the lighting level of the second backlight 107 can be lowered. This utilizes a characteristic that makes it difficult to notice subtle changes when the user looks at the same item (for example, the display unit 111) for a long time. Thereby, the mobile phone 100 can realize power saving of the second backlight 107 without hindering the user's key pressing operation. In other words, when the user looks at the same item (for example, the display unit 111) for a long time, the mobile phone 100 uses the second backlight without using the illuminance sensor, using a characteristic that makes it difficult to notice subtle changes. The lighting level 107 is lowered step by step by a predetermined amount, and the ambient light level is obtained to such an extent that the user's key pressing operation is not hindered. This is a power saving method that is particularly effective when key pressing operations are continuously performed for a long time, such as in mail creation or browsing.

Next, the control flow of the key backlight 103 will be described with reference to FIG.
In step ST701, the mobile phone 100 transitions from the closed state to the open state. And it changes to branch ST703.

  In branch ST703, it is determined whether or not a predetermined time has passed in a state where key input operation is possible. And when predetermined time passes (YES), it changes to step ST705, and when that is not right (NO), it changes to step ST801 of the control flow of the 2nd backlight 107 of FIG.

  In step ST705, a display prompting the user to turn on the key backlight 103 is displayed on the display unit 111. And it changes to branch ST707.

  In branch ST707, it is determined whether or not the key backlight 103 is turned on. If the key backlight 103 is lit (YES), the process proceeds to branch ST709. If the key backlight 103 is not lit (NO), the process proceeds to step ST713.

  In branch ST709, it is determined whether key input operation is continuing. If the key input operation is continued (YES), the process proceeds to step ST711. If the key input operation is not continued (NO), the process proceeds to step ST713.

  In step ST711, the lighting level of the key backlight is decreased stepwise. And it changes to step ST715.

  In step ST713, the key backlight 103 is turned off. Then, the control flow (1) of the key backlight 103 ends.

  Next, a control flow of the second backlight 107 serving as the backlight of the display unit 111 will be described with reference to FIG.

  In step ST801, the backlight (second backlight 107) of the display unit 111 is turned on. And it changes to branch ST803.

  In branch ST803, it is determined whether key input operation is continuing. When key input operation is continuing (YES), it changes to step ST805, and when key input operation is not continuing (NO), it changes to step ST807.

  In step ST805, the lighting level of the backlight (second backlight 107) of the display unit 111 is decreased stepwise.

  In Step ST807, the backlight (second backlight 107) of the display unit 111 is turned off.

(Modification: Key backlight 103A)
In this embodiment, the current reduction method for controlling the key backlight 103 is expressed to reduce the current flowing per lamp, but the present invention is not limited to this. 9A and 9B show a modification of the key backlight 103. FIG. In this case, the lighting level of the key backlight 103A is controlled by the number of LED elements that emit light. For example, as shown in FIG. 9A, when 16 LEDs are lit (all lit), the brightest lighting level is set, and as shown in FIG. 9B, 4 LEDs are lit. The case is set to the minimum lighting level that does not prevent the user from pressing the key.

  In this embodiment, an LED is used as the key backlight 103, but the present invention is not limited to this. For example, a light emitting element (for example, an organic EL element) may be provided on the entire back surface of the key input unit 101. However, since the organic EL element is more expensive than the LED element, it is preferable to use an LED for a low-priced terminal that omits an expensive sensor or the like as assumed in the present embodiment. .

  In the present embodiment, mobile phone 100 is not provided with an illuminance sensor, but the present invention is not limited to this. A cellular phone including an illuminance sensor may have the function of this embodiment. Even in this case, power to be supplied to the illuminance sensor and each backlight can be reduced, so that power consumption can be suppressed.

  In the present embodiment, the control of each of the key backlight 103 and the second backlight 107 has been described. However, the present invention is not limited to this. The control described for the key backlight may be applied to the second backlight 107, or the control described for the second backlight may be applied to the key backlight 103.

  Further, in the present embodiment, in the case of FIG. 5B, the key backlight 103 is fully turned on, but the present invention is not limited to this. For example, the user may be able to specify the maximum brightness in advance.

  In the present embodiment, the browser operation is assumed as an example of the case where the brightness of the key backlight 103 or the second backlight 107 is gradually reduced. However, the present invention is not limited to this. The browser operation is just one example of the user's operation for a long time, in other cases where there is a high possibility of a long-time operation such as creating an email or operating an app, or when the user does not perform a long-time operation. Even if it exists, you may reduce the brightness of each backlight in steps.

  In the present embodiment, the range of brightness variation of each backlight is not limited. However, the present invention is not limited to this. In recent mobile phones, the brightness of the backlight can be set at any one of a plurality of levels such as five levels. However, in terms of the function of the mobile phone, the backlight is more detailed than each level that can be set by the user. It is often possible to fine-tune the brightness of the. In such a case, the brightness may be controlled within a range that does not exceed the level range set by the user.

  Further, in the present embodiment, the notification that prompts lighting of each backlight is performed after a predetermined time has elapsed, but the present invention is not limited to this. You may perform the notification which urges lighting of each backlight, before predetermined time passes.

  In this embodiment, lighting of the key backlight 103 is instructed by the backlight lighting key 163, but the present invention is not limited to this. For example, the backlight may be turned on by pressing an arbitrary key.

  In this embodiment, no distinction is made between the case where the backlight is turned on after the notification and the case where the backlight is turned on before the notification. However, the present invention is not limited to this. When the backlight is turned on after the notification, the backlight may be turned on darker than when the backlight is turned on before the notification. This is because if the backlight cannot be turned on until notified, it is highly likely that the user is operating the mobile phone 100 in a very dark place. In such a dark place, the user's eyes are accustomed to the dark place, and suddenly turning on the backlight suddenly makes the backlight feel very dazzling and may cause discomfort. Therefore, in such a case, the user's discomfort is reduced by lighting the backlight darker.

  In the present embodiment, a foldable mobile phone has been described as an example, but the present invention is not limited to this. As long as the electronic device uses a backlight for a key or display, such as a PDA, a game machine, or a PC, the above-described embodiment can be applied to other electronic devices. Further, the shape is not limited to the folding type, and the present embodiment can be applied to a slide type or a straight type. In the case of the slide type, as an example of a state in which key input is possible, it is conceivable that the key covered with the display housing is slid to expose. In the case of the straight type, an example of a state where key input is possible is cancellation of the sleep state. Note that the release of the sleep state or the like can occur not only in the straight type but also in the folding type and the sliding type, and thus corresponds to one example of a state in which key input is possible even in the case of these shapes.

  Each functional block used in the description of each of the above embodiments is typically realized as an LSI that is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them. The name used here is LSI, but it may also be called IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.

  Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

  Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. Biotechnology can be applied.

  The backlight control device and the mobile phone according to the present invention have an effect that power can be saved by controlling the backlight without using the illuminance sensor, and are useful as a mobile phone or the like.

DESCRIPTION OF SYMBOLS 100 Mobile telephone 101 Key input part 103, 103A Key backlight 105 1st backlight control part 107 2nd backlight 109 2nd backlight control part 111 Display part 113 Display control part 141 Terminal state determination part 151 Key input process part

Claims (10)

A display unit;
A key input unit for detecting presence or absence of key input;
At least one of a key backlight that illuminates the key input unit from the back of the key input unit, and a display unit backlight that illuminates the display unit from the back of the display unit;
Maintaining a state in which the key backlight and / or the display unit backlight is not turned on for a predetermined time immediately after the key input of the key input unit is enabled.
A control unit that turns on the key backlight and / or the display unit backlight after a predetermined time has passed since the key input unit is ready for key input; and
A backlight control device comprising: The backlight control device according to claim 1,
The control unit turns on the key backlight and / or the display unit backlight even when the key input is performed within the predetermined time, even before the predetermined time has elapsed.
Backlight control device. The backlight control device according to any one of claims 1 to 2,
After the key backlight and / or the display unit backlight is turned on, the control unit performs the key backlight and / or the display unit backlight as the key input operation to the key input unit is continued. The illuminance of the key backlight and / or the display unit backlight is gradually reduced so that the illuminance of
Backlight control device. The backlight control device according to any one of claims 1 to 2,
The control unit measures the number of times that the key input operation has been performed on the key input unit, and after the key backlight and / or the display unit backlight is turned on, the key input operation is performed every unit time. The higher the number of times, the lower the illuminance of the key backlight and / or the display unit backlight is controlled.
Backlight control device. 2. The backlight control device according to claim 1, wherein the control unit controls the key backlight and / or the display unit backlight for a predetermined time immediately after the key input of the key input unit is enabled. While maintaining the state of not turning on, the display unit is notified to prompt the user to turn on the key backlight and / or the display unit backlight,
Backlight control device. A display unit;
A key input unit for detecting presence or absence of key input;
At least one of a key backlight that illuminates the key input unit from the back of the key input unit, and a display unit backlight that illuminates the display unit from the back of the display unit;
Maintaining a state in which the key backlight and / or the display unit backlight is not turned on for a predetermined time immediately after the key input of the key input unit is enabled.
A control unit for notifying a user to turn on the key backlight and / or the display unit backlight after a predetermined time has passed since the key input unit is ready for key input; and
A backlight control device comprising: When there is a key input, the control unit turns on the key backlight and / or the display unit backlight regardless of before and after the display,
When the key backlight and / or the display unit backlight is turned on after the display, the key backlight and / or the display unit backlight is turned on before the display. Reduce the illuminance and turn on the key backlight and / or the display backlight.
Backlight control device.   An electronic device comprising the backlight control device according to any one of claims 1 to 7. A display unit, a key input unit for detecting presence or absence of key input,
A backlight control method used in a device including at least one of a key backlight that illuminates the key input unit from the back of the key input unit and a display unit backlight that illuminates the display unit from the back of the display unit. And
Maintaining a state in which the key backlight and / or the display unit backlight is not turned on for a predetermined time immediately after the key input of the key input unit is enabled.
The key backlight and / or the display backlight are turned on after a predetermined time has passed since the key input unit is ready for key input.
Backlight control method. A display unit, a key input unit for detecting presence or absence of key input,
A backlight control method used in a device including at least one of a key backlight that illuminates the key input unit from the back of the key input unit and a display unit backlight that illuminates the display unit from the back of the display unit. And
Maintaining a state in which the key backlight and / or the display unit backlight is not turned on for a predetermined time immediately after the key input of the key input unit is enabled.
Immediately after the key input unit is ready for key input, after a predetermined time has elapsed, the display unit displays a display prompting the user to turn on the key backlight and / or the display unit backlight.
Backlight control method.

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