KR20030005539A - Lcd backlight controlling method for mobile communication device - Google Patents

Abstract

PURPOSE: A method for controlling an LCD backlight in a mobile communication terminal is provided to control the brightness of the LCD backlight according to the illuminance of an object using the LCD backlight as an optical source for photographing the object. CONSTITUTION: The illuminance(brightness) of an object or the circumference of the object is detected from an image photographed through a camera without using a specific illuminance(brightness) detecting sensor(S11,S12). It is compared whether the illuminance is greater than an illuminant reference value for backlight(S13). If the illuminance is less than the illuminant reference value, the LCD backlight is turned on(S14).

Description

LCD backlight control method of mobile communication terminal {LCD BACKLIGHT CONTROLLING METHOD FOR MOBILE COMMUNICATION DEVICE}

The present invention relates to a method for controlling LCD backlighting of a mobile communication terminal. In particular, a next-generation mobile communication terminal including a camera uses LCD backlighting as a light source for photographing a subject, and according to the illumination of the subject. The present invention relates to an LCD background lighting control method of a mobile communication terminal for controlling the brightness of the background lighting.

Recently, the rapid development of mobile communication technology has enabled video communication, and thus various mobile communication terminals and related technologies have been introduced.

In most cases, a camera is attached to perform video communication using a mobile communication terminal. At this time, a charge couple device (hereinafter, referred to as a “CD”) is mainly used as an image sensor used as a camera. LCD is mainly used.

The LCD has a low power and free expression of characters, pictures, animations, and the like.

On the other hand, there is a problem that can not recognize the display content at night because it can not self-luminescing, but this problem was solved by providing a backlight on the back of the LCD.

However, since the backlight consumes a lot of power, there is a need to adjust the backlight appropriately to the situation in order to increase battery life.

In other words, the night time zone, which is usually dark, is set in advance so that the LCD backlight is automatically turned on only when a call is received or a call is made during the time zone.

On the other hand, a camera (not shown) provided in the mobile communication terminal mainly photographs an image of a subject in front of the user, that is, a user's face, and transmits the image to a counterpart. You will not be able to get it.

Accordingly, in order to capture a clear image, an optical sensor or the like for recognizing ambient illumination (brightness) is additionally provided, and a light source for brightly illuminating the subject when the surroundings are dark must be provided separately.

However, due to the addition of the device (optical sensor, light source), the current consumption of the battery increases, and there is a problem in miniaturization and weight reduction of the terminal.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and uses LCD Backlight as a light source for photographing a subject in a next-generation mobile communication terminal equipped with a camera. Accordingly, an object of the present invention is to provide a method of controlling an LCD background light of a mobile communication terminal that can control the brightness of the LCD background light.

1 is a block diagram schematically illustrating an internal configuration of a general mobile communication terminal.

Figure 2 is an exemplary view shown for explaining an indicator for use as an auxiliary light source in the present invention.

Figure 3 is a flow chart for explaining the LCD background lighting control method according to the present invention.

In order to achieve the above object, the present invention provides a mobile communication terminal including a camera, wherein the illuminance around the subject or the subject from the image photographed through the camera without using a separate illuminance (brightness) detection sensor is used. A first step of detecting (brightness); A second step of comparing the detected illuminance with a lighting reference value for LCD background lighting; As a result of the comparison, if the detected illuminance is greater than or equal to the reference value, the LCD background light is not turned on. If the detected illuminance is less than or equal to the reference value, the LCD backlight is turned on.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

First, the present invention does not use a separate brightness detection sensor, detects the illumination (brightness) around the subject from the image taken through the camera, and controls the brightness of the LCD background light to be used as a light source for subject shooting It can be characterized by.

FIG. 1 is a block diagram schematically illustrating an internal configuration of a general mobile communication terminal. As shown in FIG. 1, an image is captured and displayed in a brightness and color information (Y, U, V) format that can be used in the video codec (2). An image detection / image processing unit 1 for converting; A video codec (2) for generating an actual video image from the signal output from the image detection / image processing unit (1); An LCD controller (3) for displaying the video image on the LCD (4); A main processor 5 for controlling communication and the operation of the entire terminal smoothly; It is composed of a background light control unit 6 for controlling the LCD background light (9) by the control of the main processor (5).

Here, the RF unit 7 and the illumination unit 8, which are not described, are lighting blocks used as light sources for wireless transmission / reception and camera photographing for phone calls.

In this case, the general matters not directly related to the present invention may obscure the gist of the present invention. Thus, the description thereof will be omitted, and the method of detecting illuminance of the subject by the main processor 5 and the method of controlling the LCD backlight accordingly will be omitted. This will be described.

First, since the subject's illuminance is mostly located in the center of the subject, the specific gravity of the center is the highest and the specific gravity is lowered as the deviation from the center is reduced, and the illuminance is measured by the average of the values.

Accordingly, the measured illuminance is compared with the 'background lighting lighting reference value', and the background lighting is turned on when the reference value is lower than the reference value, and the background lighting is not turned on when the reference value is higher than the reference value.

In addition, it improves reliability by applying different lighting reference values for day and night by using time information, and when not talking with the other party (data communication etc.), the weight is processed equally so that the user is placed in front of the camera. Be prepared in case you haven't.

On the other hand, if it is determined that the reliability is low, such as when the average illuminance is too high, it is changed to the conventional lighting method so that the light is only turned on for a predetermined time after opening the folder, or turned on only at night.

In this case, the control of the background light may be simple on / off control or multi-step control.

That is, the brightness of the background light is made to be as high as possible to use as a light source for photographing the subject, and when there is a limit in photographing the subject by only the background light, as shown in FIG. In this case, the illuminance of the surroundings can be increased by turning on.

In other words, even if a separate light for photographing a subject is not turned on, all the light sources added to the mobile communication terminal such as an indicator and LCD backlight may be turned on to increase the illuminance of the subject.

3 is a flowchart illustrating a method for controlling LCD backlighting according to an embodiment of the present invention. As shown in FIG. 3, a subject or a subject is obtained from an image photographed through a camera without using a separate illuminance (brightness) detection sensor (S11). The ambient illuminance (brightness) is detected (S12), and it is compared whether or not the illuminance is equal to or greater than a lighting reference value for the background light (S13).

As a result, if the measured illuminance is above the reference value, the background light is not turned on (S17), and it is determined whether there is no abnormality in the reliability of the previously measured illuminance (S15). If there is no abnormality, the background light is not turned on as described above. If there is an abnormality in the reliability, the background lighting is controlled by the existing method (such as lighting the backlight only for a certain time after opening the folder or lighting at night).

On the contrary, when the illuminance is below the reference value, the LCD background light is turned on (S14).

At this time, even after the background lighting is turned on, if the measured illuminance is below the reference value, the auxiliary light source (a white indicator that can be used as a light source) can be further turned on.

Of course, when a dedicated light source for increasing illuminance is provided, it is obvious to turn on the light source.

However, in the present invention, in order to reduce the consumption of the battery as much as possible, the light source with high current consumption is turned on last.

As described above, the LCD background lighting control method of the mobile communication terminal of the present invention measures the illuminance of the subject with an image photographed through a camera provided for video communication, and does not add an additional device according to the measured illuminance. By using the LCD background light as a light source, it is possible to reduce the size and weight of the mobile communication terminal and to reduce the battery consumption as much as possible.

Claims (5)

A mobile communication terminal including a camera, comprising: a first step of detecting an illuminance (brightness) around a subject or an image from an image photographed through a camera without using a separate illuminance (brightness) detecting sensor; A second step of comparing the detected illuminance with a lighting reference value for LCD background lighting; And a third step of turning on the LCD background light when the detected illuminance is equal to or greater than the reference value, and lighting the LCD background light when the detected illuminance is equal to or greater than the reference value. The method of claim 1, wherein when the detection illuminance of the third step is too large compared to the reference value, it is determined whether or not the reliability of the detection illuminance is abnormal. An LCD background lighting control method of a mobile communication terminal, characterized in that to control the LCD backlight by a conventional method, such as lighting or lighting at night. The method of claim 1, wherein the brightness of the LCD background light is controlled in multiple stages. The method of claim 1, wherein the auxiliary light source is further turned on when the detected illuminance is lower than the reference value even after the backlight is turned on in the third step. [5] The method of claim 4, wherein the auxiliary light source uses a white light to indicate an incoming call.