JP4880203B2 - Mobile terminal with camera and backlight adjustment method - Google Patents

Description

  The present invention relates to a portable terminal having a camera function, and more particularly to a configuration and method of backlight automatic adjustment technology.

  In a portable terminal such as a cellular phone, when the luminance of the backlight that irradiates the liquid crystal display of the display unit is constant, there is a problem that characters are difficult to see depending on the surrounding brightness.

  Therefore, in a conventional portable terminal, for example, by mounting a dedicated light receiving element / light receiving circuit, the ambient brightness is measured, and the luminance of the backlight is controlled.

  For example, the following publications are known as publications relating to the backlight automatic adjustment function.

  Patent Document 1 described later describes a configuration in which the luminance of the backlight is controlled by changing the power supplied to the backlight according to the ambient brightness by an optical sensor that detects the brightness of the periphery of the mobile phone. ing. However, in the case of a configuration in which ambient brightness is measured using an optical sensor, a dedicated circuit must be mounted, resulting in waste in terms of cost. Also, in the automatic brightness adjustment by the light receiving element / light receiving circuit, the control method has been adjusted to a uniquely determined brightness.

  Further, as a technique for using a camera instead of an optical sensor, for example, in Patent Document 2 described later, in a mobile phone with a camera, an illumination level at which a backlight LED illuminates a liquid crystal display is stored according to exposure in the camera. A configuration is disclosed in which the illumination level at which the backlight illuminates the liquid crystal display can be automatically adjusted according to the brightness of the cycle by adjusting based on time without providing a dedicated component. However, the brightness adjustment data is programmed, and the user of the mobile phone cannot arbitrarily store the setting.

  Further, in Patent Document 3 described later, in a mobile terminal with a camera, when detecting ambient brightness using a camera and performing automatic backlight adjustment, a configuration capable of quickly illuminating to an appropriate brightness is as follows: First and second filters having different transmitted light wavelength bands, and a light receiving unit having first and second light receiving elements that receive light transmitted through the first and second filters out of light coming from the subject An image processing unit that creates image data reflecting the incident intensity of light received by the first and second light receiving elements, a display unit that displays an image based on the image data, and a first light receiving element The structure provided with the illumination part which illuminates an illumination location with the brightness | luminance reflecting the intensity | strength of the received incident light is disclosed.

  Further, Patent Document 4 described below discloses a configuration for controlling the brightness of a backlight based on a shutter speed, a gain value, and a photometric evaluation value in a camera-equipped mobile terminal. In this camera-equipped mobile terminal, by estimating the ambient brightness based on a signal for controlling the exposure signal of the camera, the backlight of the display unit is controlled without providing a detector, thereby saving power. Yes.

JP 2000-324239 A JP 2002-344598 A JP 2003-289368 A JP 2002-300447 A

  Although the technology for detecting ambient brightness using a camera is disclosed in the above-described conventional technology, for example, consideration is given to handling of a plurality of cameras or handling of user usage conditions such as backlighting. Lacks.

  Accordingly, an object of the present invention is to provide an apparatus and method that can cope with the use situation of the user and can variably adjust the luminance of the backlight of the display unit without mounting a dedicated light receiving element / light receiving circuit. There is.

  In order to achieve the above object, the invention disclosed in the present application is generally configured as follows.

  An apparatus according to an aspect of the present invention includes a light amount calculation unit that derives brightness data based on data input from an imaging unit, and a luminance setting storage that stores correspondence between the brightness data and the luminance setting data. A luminance search means for searching the luminance setting storage unit to obtain luminance setting data based on the derived brightness data, and adjusting the luminance of the backlight by the luminance setting data, Adjust the brightness of the display device.

  An apparatus according to another aspect of the present invention includes a first imaging unit and a second imaging unit, and the first and second imaging units are based on data input from the first and second imaging units, respectively. Light intensity calculation means for deriving the brightness data of 2 respectively, a brightness setting storage unit storing correspondence between brightness data and brightness setting data, and valid data among the first and second brightness data are determined. Brightness search means for searching the brightness setting storage unit to obtain brightness setting data based on the selected brightness data, and adjusting the brightness of the backlight based on the brightness setting data Adjust the brightness of the display.

A method according to another aspect (side surface) of the present invention is a backlight adjustment method for a portable terminal including an imaging unit, a display unit, and a backlight for illuminating the display unit,
(A1) The correspondence between the brightness data and the brightness setting data is stored in the brightness setting storage unit,
(A2) deriving brightness data based on the data input from the imaging means;
(A3) searching the brightness setting storage unit based on the derived brightness data to obtain brightness setting data;
(A4) adjusting the brightness of the backlight according to the brightness setting data and adjusting the brightness of the display unit;
including.

A method according to still another aspect (side surface) of the present invention is a backlight adjustment method for a portable terminal comprising a plurality of imaging means, a display unit, and a backlight for illuminating the display unit,
(B1) The correspondence between the brightness data and the brightness setting data is stored in the brightness setting storage unit,
(B2) deriving a plurality of brightness data based on the data respectively input from the plurality of imaging means;
(B3) determining and selecting valid data among the plurality of brightness data;
(B4) searching the brightness setting storage unit based on the selected brightness data to obtain brightness setting data;
(B5) adjusting the brightness of the backlight according to the brightness setting data and adjusting the brightness of the display unit;
including.

  According to the present invention, since the ambient brightness is measured using the camera as the imaging means, it is not necessary to mount a dedicated light receiving element / light receiving circuit, and the brightness of the backlight is set. It can be changed arbitrarily.

  In addition, according to the present invention, it is possible to cope with backlight or the like by performing backlight adjustment based on data from a plurality of imaging means.

  The best mode for carrying out the present invention will be described with reference to the accompanying drawings. An apparatus according to an embodiment of the present invention includes a light amount calculation unit (21) for deriving ambient brightness data based on data input from an imaging unit (1) such as a camera, brightness data, and luminance. A luminance setting storage unit (31) that stores the correspondence of the setting data; and a luminance search unit (22) that searches the luminance setting storage unit to obtain the luminance setting data based on the derived brightness data. And adjusting the brightness of the backlight (42) and the brightness of the display unit (41) according to the brightness setting data.

  An apparatus according to another embodiment of the present invention includes a first imaging unit (1) and a second imaging unit (5), and is based on data input from the first and second imaging units, respectively. , A light amount calculation means (21) for deriving the first and second brightness data, a brightness setting storage section (31) storing the correspondence between the brightness data and the brightness setting data, and the first and second brightness data. Brightness search means (22) for determining and selecting valid data from the brightness data, and searching the brightness setting storage unit based on the selected brightness data to obtain the brightness setting data; And adjusting the brightness of the backlight (42) and the brightness of the display unit (41) according to the brightness setting data.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of the first exemplary embodiment of the present invention. Referring to FIG. 1, in this embodiment, a camera 1 (CCD camera) as an image pickup means, a data processing device 2 operated by program control, a storage device 3 for storing information, and a liquid crystal display device as a display device are shown. 4 is included. Imaging data from the camera 1 is input to the data processing device 2 as digital data.

  The liquid crystal display device 4 includes a display unit (display panel) 41 that constitutes a display, and a backlight 42 that adjusts the brightness with which the display unit 41 is irradiated.

  The storage device 3 includes a brightness setting storage unit 31 that stores brightness setting data of the backlight 42.

  The data processing device 2 includes a light amount calculation unit 21 and a luminance search unit 22. The light quantity calculation unit 21 extracts brightness data from the input signal of the camera 1.

  The luminance search means 22 searches the luminance setting data stored in the luminance setting storage unit 31 using the brightness data extracted by the light quantity calculation unit 21 as a key.

  FIG. 2 is a flowchart for explaining the operation of the first embodiment of the present invention. With reference to FIG. 1 and FIG. 2, the operation of this embodiment will be described in detail.

  A signal from the camera 1 is input to the data processing device 2 (step A1). Depending on the configuration of the camera 1, several methods such as YUV and RGB can be considered as the signal input from the camera 1, but in this embodiment, it is RGB data.

  The light quantity calculation unit 21 calculates brightness data from data input from the camera 1. (Step A2). Various methods are used for calculating the brightness data. In this embodiment, for example, the brightness data of green (G) at the center position of the captured image range is used.

  The luminance search means 22 searches the luminance setting data from the luminance setting storage unit 31 using the brightness data calculated by the light quantity calculation unit 21 as a key (step A3).

  The luminance setting storage unit 31 stores luminance setting data that can be arbitrarily set. For example, brightness setting data is stored such that the backlight 42 is brightened when the surroundings are bright, and the backlight 42 is darkened when the surroundings are dark. . The fact that the brightness setting storage unit 31 is variably settable is one of the features of the present invention.

  The data processing device 2 sets the luminance of the liquid crystal display device 4 from the retrieved luminance setting data (step A4). For example, brightness adjustment is realized by using a constant current source for the backlight 42 and adjusting the current value.

  Next, the operation of this embodiment will be described using a specific example. FIG. 3 is an explanatory diagram for explaining the operation of the present embodiment.

  Camera data B1 from the camera 1 is input as 16-bit RGB information (step A1). RGB = (1Fh, 2Fh, 1Fh) (where h represents hexadecimal display). From the camera data B1, the light quantity calculation unit 21 extracts green (G) data (3Fh) at the center of the screen as brightness data B2 (step A2).

  The luminance search means 22 searches the luminance setting storage unit 31 using the brightness data B2 as a key (step A3).

  As a result of the search, a result in which brightness data “3Fh” is registered as brightness setting data “18 [mA]” in the brightness setting storage unit 31 is obtained.

  The data processing device 2 sets the constant current source of the backlight 42 to “18 [mA]” and realizes brightness adjustment (step A4).

  The operational effects of the present embodiment will be described.

  According to the present embodiment, since the ambient brightness is measured using the camera as the imaging means, it is not necessary to mount a dedicated light receiving element / light receiving circuit.

  In addition, according to the present embodiment, the storage device for storing the luminance setting data of an arbitrary backlight is provided, so that the setting of the luminance of the backlight can be changed by the operation of the mobile terminal.

  Next, a second embodiment of the present invention will be described in detail with reference to the drawings. FIG. 4 is a diagram showing the configuration of the second exemplary embodiment of the present invention.

  Referring to FIG. 4, in the second embodiment of the present invention, the camera as the image pickup means has a camera 5 in addition to the configuration of the camera 1 in the first embodiment shown in FIG. For example, it is assumed that the camera 1 is mounted in the direction of the display surface of the liquid crystal display device 4 and the camera 5 is mounted in the direction opposite to the display of the liquid crystal display device 4.

  FIG. 5 is a flowchart for explaining the operation of the second embodiment of the present invention. The operation of the second embodiment of the present invention will be described with reference to FIGS.

  Input signals from the camera 1 and the camera 5 in the second embodiment of the present invention are the same as those in the first embodiment shown in FIG. 1 (steps A1 and A3).

  The light quantity calculation unit 21 receives data from both the camera 1 and the camera 5. The method for converting the input camera data into luminance data is the same as that in the first embodiment shown in FIG. 1 (steps A2 and A4).

  In the second embodiment of the present invention, a determination process is performed as to which of the data from the camera 1 and the data from the camera 5 is used as valid data (step A5).

  For example, the brightness data extracted from the camera 1 facing the display surface of the liquid crystal display device 4 is substantially the same as the brightness data extracted from the camera 5 facing away from the display of the liquid crystal display device 4. If it is present or brighter, the brightness data of the camera 1 is used as valid data for the key of the brightness search means 22.

  On the other hand, when the brightness data of the camera 5 is sufficiently larger than the brightness data of the camera 1, the display surface of the mobile phone is treated as being backlit, and the brightness data of the camera 5 is used as effective data. Treat as (search key).

  Subsequent processing is the same as in the first embodiment, and a description thereof will be omitted.

  As described above, in the second embodiment of the present invention, when the brightness data of two cameras (camera 1 and camera 5) mounted as imaging means are compared, the display surface is dark under backlight. However, it is possible to realize more diverse backlight control such as setting the brightness of the backlight brighter.

  Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the configuration of the above embodiment, and various modifications that can be made by those skilled in the art within the scope of the present invention. Of course, modifications are included.

It is a figure which shows the structure of the 1st Example of this invention. It is a flowchart for demonstrating operation | movement of the 1st Example of this invention. It is a figure for demonstrating operation | movement of the 1st Example of this invention. It is a figure which shows the structure of the 2nd Example of this invention. It is a flowchart for demonstrating operation | movement of the 2nd Example of this invention.

Explanation of symbols

1 Camera (imaging means)
2 Data processing device 3 Storage device 4 Liquid crystal display device 5 Camera (imaging means)
DESCRIPTION OF SYMBOLS 21 Light quantity calculation part 22 Luminance search means 31 Brightness setting memory | storage part 41 Display part 42 Backlight

Claims (4)

A portable terminal having a camera function,
Ri Do from the camera phone, the first imaging means is disposed in the same direction as the display section front, and a second imaging means which is disposed opposite direction to the display section the front,
A display unit;
A backlight that illuminates the display unit and has a variable brightness;
A brightness setting storage unit storing correspondence between brightness data and brightness setting data;
Based on the data input from each of said first, second imaging means, and the first, the first corresponding to each of the second imaging means, the light amount calculating means for deriving a second brightness data,
A brightness search that determines and selects valid data from the first and second brightness data, and searches the brightness setting storage unit based on the selected brightness data to obtain brightness setting data. Means,
With
The luminance search means is such that the first brightness data extracted from the first imaging means is substantially the same as the second brightness data extracted from the second imaging means, or If the brightness is brighter, the first brightness data of the first imaging means is treated as the effective data, and used as a search key of the brightness setting storage unit to obtain the brightness setting data,
If the second brightness data of the second imaging means is sufficiently larger than the first brightness data of the first imaging means, the second imaging means of the second imaging means. 2 brightness data is treated as the effective data, used as a search key of the brightness setting storage unit to obtain brightness setting data,
The mobile terminal, wherein the brightness of the backlight is adjusted by adjusting the brightness of the backlight based on the acquired brightness setting data.   The portable terminal according to claim 1, wherein the content stored in the luminance setting storage unit is variably settable. The display unit is composed of a camera of a portable terminal, and includes a first imaging unit disposed in the same direction as the front of the display unit and a second imaging unit disposed in the direction opposite to the front of the display unit. A backlight adjustment method for adjusting the luminance of the backlight to be irradiated,
The correspondence between the brightness data and the brightness setting data is stored in the brightness setting storage unit,
The first, a step based on data respectively input from the second imaging means, for deriving the first, second brightness data corresponding to each of said first, second imaging means,
Determining and selecting valid data from the first and second brightness data;
Searching the brightness setting storage unit based on the selected valid data to obtain brightness setting data;
Adjusting the brightness of the backlight according to the brightness setting data and adjusting the brightness of the display unit;
Only including,
In the step of determining and selecting the effective data, the first brightness data extracted from the first imaging unit is compared with the second brightness data extracted from the second imaging unit. If they are substantially the same or brighter, the first brightness data of the first imaging means is treated as the effective data,
If the second brightness data of the second imaging means is sufficiently larger than the first brightness data of the first imaging means, the second imaging means of the second imaging means. 2. A method of adjusting a backlight of a portable terminal, wherein the brightness data of 2 is treated as the effective data .   The backlight adjustment method according to claim 3, wherein the content stored in the luminance setting storage unit is variably settable.

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