JP2003289368A - Mobile terminal and lighting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile terminal capable of quickly lighting with appropriate brightness even in the case of using a camera to detect ambient brightness and automatically adjusting a backlight. <P>SOLUTION: This mobile terminal is provided with first and second filters for transmitting light of wavelength bands different from each other, a light receiving part 104 having a first photodetector for receiving transmitted light filtered by the first filter in light coming from an object and a second photodetector for receiving transmitted light filtered by the second filter in the light coming from the object, an image processing part 105 for generating image data while reflecting the intensity of incident light received by the first and second photodetectors, a display part 101 for displaying an image on the basis of the image data, and a lighting part 111 for lighting a lighting place with brightness reflecting the intensity of only the incident light received by the first photodetector. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile terminal equipped with a camera and lighting, and more particularly to a technique for controlling the brightness of lighting.

[0002]

2. Description of the Related Art In recent years, CCD (Charge Coupled Devic
e) or CMOS (Complementary Metal Oxide Semicond)
Equipped with so-called camera such as uctor) sensor, PHS (Personal Handyphone Sy)
Stem) and mobile terminals such as PDAs (Personal Digital Assistance) (hereinafter referred to as “camera-equipped mobile terminals”) are becoming popular.

In this mobile terminal with a camera, an image of a subject such as a person or a landscape is photographed by a camera, and data of the photographed image is wirelessly communicated. FIG. 9 is an external view of a mobile terminal 800 which is an example of such a mobile terminal with a camera. The mobile terminal 800 includes a display unit 8 that displays an image.
01, an operation key unit 802 for turning on / off the power and making a call, and a ten-key unit 8 for inputting a telephone number and characters for composing an electronic mail.
03 and a light receiving unit 805 composed of the above-described CCD or the like.

[0006] Such a mobile terminal with a camera consumes more electric power for photographing than an ordinary mobile terminal having no photographing function. Therefore, from the viewpoint of extending the continuous use time, each mobile terminal in the mobile terminal Power saving is particularly desired in the functional unit. Therefore, like the mobile terminal 800, the numeric keypad 803, the operation keys 802, and the LCD (Liquid)
Display unit 80 such as a Crystal Display)
There are not a few mobile terminals equipped with a so-called automatic backlight adjustment function that determines the brightness of the backlight that illuminates 1 according to the ambient brightness, or that controls the backlight to be turned on and off.

More specifically, the mobile terminal 800 is
The intensity of the light received by the optical sensor 804 is detected,
When the intensity of the detected light is low, the backlight is turned on with high brightness. When the intensity of the detected light is high, the mobile terminal 800 turns on the backlight with low brightness or turns off the backlight to suppress the power consumption required for illumination.

As described above, the mobile terminal with the automatic backlight adjustment function can realize power saving in lighting, but on the other hand, since the above-mentioned optical sensor is required, the mobile terminal without the automatic backlight adjustment function is required. There is no choice but to increase the cost compared to terminals. Japanese Patent Laid-Open No. 2000-1840 discloses a mobile terminal with a camera that solves such a problem.
As disclosed in Japanese Laid-Open Patent Publication No. 13, a method is proposed in which ambient brightness is detected using image data obtained by a camera such as a CCD and the ringing volume is reduced by recognizing that the image is taken out from a pocket or the like. Has been done.

As a result, the mobile terminal with camera is
As a means for detecting ambient brightness, it is not necessary to provide a dedicated optical sensor, and the number of parts and cost are reduced. As described above, Japanese Patent Laid-Open No. 2000-18
It is also conceivable to apply the detection of the ambient brightness by the camera, which is implemented in the mobile terminal with camera No. 4013, to the backlight automatic adjustment function.

[0008]

However, in a mobile terminal with a backlight automatic adjustment function, the brightness of the illumination is changed stepwise according to the brightness of the surroundings, so it is simple to determine whether or not it is in a pocketed state. It is necessary to detect the ambient brightness with higher accuracy than in the case of using it for a simple determination.

Therefore, it is conceivable to use all of the image data to detect the ambient brightness, but the amount of information in the image data is much larger than the amount of information obtained from the optical sensor, and the ambient brightness is It takes a calculation time to obtain, and it is difficult to quickly start illumination with an appropriate brightness according to the ambient brightness. In particular, when lighting is performed, the operation input by the user is often used as a trigger, and when such an operation input is performed in a dark place, it is necessary to immediately illuminate the operation keys and the display unit. Even if the time from the input of an operation input to the start of lighting is one or two seconds, the user may feel frustrated.

In order to reduce the above calculation time, the CCD
It is possible to use the image data by limiting the position of the image data, such as using only the image data for one horizontal or vertical line above, but the brightness detected by this method is the brightness of the entire image of the subject. Therefore, it cannot be said that the ambient brightness is accurately detected. For example, in reality, even if the surroundings are dark and most of the subject is dark, if only the portion of the subject corresponding to one line described above is accidentally bright, it is detected that the surroundings are bright, It will light up at low brightness, or will not light up,
Lighting is not done properly.

Therefore, the present invention has been made in view of the above problems, and even when the ambient brightness is detected using a camera and the brightness of the backlight is automatically adjusted, the ambient brightness is also adjusted. It is an object of the present invention to provide a mobile terminal and an illumination method capable of rapidly illuminating with appropriate brightness according to the above.

[0012]

In order to achieve the above object, a mobile terminal according to the present invention comprises a first filter and a second filter which transmit lights in different wavelength bands, and a light which comes from a subject. A first light receiving element for receiving the transmitted light filtered by the first filter; a second light receiving element for receiving the transmitted light filtered by the second filter among the light coming from the subject; Image data generating means for generating image data reflecting the intensity of transmitted light received by the first and second light receiving elements, display means for displaying an image based on the image data, first light receiving element and second light receiving element One of the elements is provided with an illumination unit that illuminates the display unit or the operation unit as a backlight with a brightness that reflects the intensity of transmitted light received by one of the elements. The first to receive the incident light
A light receiving portion, a second light receiving portion that receives light incident from a direction different from the light incident direction, and a first image that acquires the intensity of light incident on the first light receiving portion to generate first image data. A data generation unit, a second image data generation unit that acquires the intensity of light incident on the second light receiving unit to generate second image data, and an illumination target of the first light receiving unit and the second light receiving unit. It is characterized by further comprising: illumination means for illuminating the above-mentioned portion with a brightness that reflects the value of the intensity of the light received by the one that is more likely to receive the light incident on the above-mentioned portion.

Further, according to the illumination method of the present invention, the first filter and the second filter which transmit lights of different wavelength bands and the transmitted light of the light coming from the subject which is filtered by the first filter are transmitted. A first light receiving element that receives light, a second light receiving element that receives transmitted light that has been filtered by a second filter among the light coming from the subject, and the intensity of transmitted light that is received by the first and second light receiving elements. A method for illuminating a mobile terminal, the method including: an image data generation unit that generates image data that reflects the information; a display unit that displays information; and an operation unit that receives an operation input from an operator. And an illumination that illuminates the display unit or the operation unit as a backlight with a brightness that reflects the intensity of transmitted light received by one of the second light receiving element and the second light receiving element. It characterized by having a step.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail with reference to the drawings. <Structure> FIG. 1 is an external view of a mobile phone 100 according to an embodiment of the present invention. The mobile phone 100 is a mobile phone having a photographing function, and includes a display unit 101, an operation key unit 102, a ten-key unit 103, and a light receiving unit 104.

FIG. 2 is a functional block diagram of the mobile phone 100. The mobile phone 100 includes, in addition to the functional units described above,
The image processing unit 105, the brightness calculation unit 106, and the control unit 10
7, a power saving control unit 108, a transmission / reception unit 109, a voice input unit 110, a lighting unit 111, a timer unit 112, a voice output unit 113, and a battery 114.

Of these, the control unit 107 and the power saving control unit 10
Reference numeral 8 has a recording medium such as a CPU, a ROM, and a RAM. The display unit 101 is a so-called transmissive LCD (Liquid C
It is a rystal display) and has a function of displaying a character such as a telephone number and an electronic mail and a photographed image based on a signal received from the control unit 107.

The operation key section 102 is used for the portable telephone 100.
Buttons for accepting instructions to turn the power on and off, a button for accepting instructions for starting and ending a call, and a button for accepting instructions for accessing the Internet. When these instructions are accepted, it is possible to confirm that these instructions have been accepted. The indicated signal is output to the control unit 107 and the power saving control unit 108.

The buttons are made of a material having a property of transmitting light, such as acrylic resin. Numeric keypad 103
Is a button that accepts input of numbers and characters such as telephone numbers and e-mails, and sends a signal indicating the accepted numbers and characters to the control unit 107 and the power saving control unit 10.
Output to 8.

Like the buttons of the operation key section 102, these buttons are also made of a material having a property of transmitting light, such as acrylic resin. The illumination unit 111 includes an LED (Light E).
Mitting Diode), operation key unit 1
02 is a backlight for illuminating the buttons of the numeric keypad unit 103 and the screen of the display unit 101 and the screen of the display unit 101 from behind, and emits light with two levels of brightness, low brightness and high brightness based on an instruction output from the power saving control unit 108. Have a function.

The voice input unit 110 is a voice input device such as a microphone and converts the input voice into a voice signal and outputs it to the control unit 107. The voice output unit 113 is a speaker including a piezoelectric element or the like, and outputs voice according to the voice signal received from the control unit 107. The transmission / reception unit 109 is a wireless circuit including a filter, an amplifier, and the like that transmits / receives a wireless signal, and according to an instruction from the control unit 107, wirelessly transmits communication data such as voice, images, and characters, and also comes from outside. The communication data to the mobile phone 100 is received and output to the control unit 107.

As shown in FIG. 3, the light receiving unit 104 is composed of a light receiving element such as a CCD covered with a lens and a color filter and arranged in a matrix, and an image is formed on the matrix by the lens. At this time, the intensity of light detected by each light receiving element is converted into an analog electric signal to generate an image signal, and the generated image signal is output to the image processing unit 105.

This CCD is a so-called single-plate color CCD in which any one of the color filters 301 to 304 is attached to each light receiving element. The above-mentioned color filter 301 has a property of transmitting only light in the red wavelength band, the color filters 302 and 304 have a property of transmitting only light in the green wavelength band, and the color filter 303 is , Has the property of transmitting only light in the blue wavelength band.

Each of the color filters 301 to 304 constitutes one filter pattern, and such filter patterns are arranged vertically and horizontally. Each light receiving element produces an amount of electric charge according to the intensity of the received light. The light receiving unit 104 sequentially applies the charges to the image processing unit 105.
The output of the above-mentioned image signal is executed by transferring the image signal.

Since such processing based on the original function of the CCD is a conventional technique, detailed description thereof will be omitted. The image processing unit 105 includes a memory for temporarily storing data, an A / D conversion circuit, and the like, and the light receiving unit 104.
An image signal which is an analog signal is received from the device, the image signal is converted into a digital signal, color and brightness in each pixel of the image are calculated to generate image data, and the image data is used in the mobile phone 100. The data is converted into a data format and stored in the above memory, and the operation key unit 102
When an instruction to display an image is received from the control unit 10
7 has the function of outputting.

Further, the image processing section 105 includes a power saving control section 1
When the sampling signal is received from the color filter 08, the color filters 302 and 30 are located in a rectangular area (n × n light receiving element area) in the center of the CCD as shown in FIG.
A / D is applied only to the image signals obtained from all the light receiving elements to which filters (hereinafter, referred to as “green filters”) that transmit only light in the green wavelength band such as 4 are attached.
The converted value, that is, the light intensity value L _{i, j} is calculated by the luminance calculation unit 1.
It outputs to 06.

Here, L _{i, j} indicates the intensity value of light obtained from the light receiving element located at the coordinates (i, j) in the above-mentioned rectangular range and to which the green filter is attached. It should be noted that this light intensity value L _{i, j} will be used as a value for calculating the ambient brightness of the mobile phone 100. As described above, only the intensity value of light obtained from the light receiving element to which the green filter is attached is used as the value for calculating the above-mentioned brightness because the sensitivity to human light (hereinafter, "ratio It is said that humans mainly use green light to capture brightness and red and blue light to determine the shade because green light has higher luminosity than red and blue light. This is because there is a property and there is almost no problem even if the intensity value of green light is substituted for the total intensity value of natural light.

Further, as shown in FIG. 3, since the above-mentioned filter patterns are regularly arranged, when attention is paid only to the filters of respective colors, these positions are almost evenly distributed, and the green filters are attached. Even if the ambient brightness is calculated using only the intensity value of the light obtained from the light receiving element, the intensity of the light in the entire rectangular range, that is, the brightness of the entire rectangular range is calculated as the ambient brightness. It can be said that it is reflected in the calculation.

As described above, the amount of data to be processed is reduced by using the intensity of green light in the above-mentioned rectangular range as the intensity of the entire natural light, and the time required for the later-described calculation for calculating the ambient brightness is reduced. By shortening, the response is as good as that of an optical sensor. The brightness calculation unit 106
Intensity value of the light from the image processing unit 105 L _i, receives the _j, received light intensity values L _i, a function of calculating an average value L _m of the intensity of light using Equation 1 below and _j Have.

[0029]

[Equation 1]

Further, the brightness calculation unit 106 judges which of the following three conditions the calculated average value of the light intensity corresponds to, and outputs a signal corresponding to each condition to the power saving control unit 10.
8 has the function of outputting. Condition 1: 0 ≤ L _m <L1 Condition 2: L1 ≤ L _m <L2 Condition 3: L2 ≤ L _m However, L1 and L2 are threshold values, and 0 <L1 <L2.

More specifically, when the condition 1 is satisfied, the brightness calculation section 106 gives a signal for notifying that the illumination section 111 emits light with high brightness (hereinafter referred to as "high brightness light emission signal"). Is output to the power saving control unit 108. Also, condition 2
If the above applies, the brightness calculation unit 106 outputs a signal (hereinafter, referred to as a signal for notifying that the illumination unit 111 emits light with low brightness).
It is called "low-brightness emission signal". ) Is output to the power saving control unit 108.

Further, when the condition 3 is satisfied, the brightness calculation unit 106 outputs a signal (hereinafter, referred to as “non-light emission signal”) for notifying that the illumination unit 111 does not emit light to the power saving control unit 108. . The control unit 107 controls the input / output of voice data, character data, image data, and the like D
When the numeric keypad 103 has an SP or the like and accepts a telephone number, a call is made to the telephone having this telephone number to perform the connection process, and also when the call is received, the connection process is performed.

With the execution of this connection processing, the control unit 107
Inputs and outputs an audio signal to and from the transmitting / receiving unit 109, receives the audio signal from the transmitting / receiving unit 109, and outputs the audio signal to the audio output unit 113. In addition, the control unit 107
A process of receiving character data such as an electronic mail from the ten-key unit 103 and transmitting / receiving the character data is executed.

Further, the control section 107 carries out a process for taking an image by using a camera mounted therein. More specifically, when receiving an instruction to activate the camera from the operation key unit 102, the control unit 107 instructs the battery 114 to start supplying power to the light receiving unit 104 and the image processing unit 105.

The control unit 107 also includes an image processing unit 105.
The image data is received from and the signal for displaying the received image data as an image is output to the display unit 101. Upon receiving the instruction to stop the camera from the operation key unit 102, the control unit 107 instructs the battery 114 to stop the supply of power to the light receiving unit 104 and the image processing unit 105.

The control unit 107 also transmits the image data generated in the mobile phone 100,
Also, control is performed to receive image data sent from the outside. Since this control is a process that has been conventionally performed, detailed description thereof will be omitted.

The power saving control unit 108 receives signals output from the operation key unit 102 and the ten key unit 103, and uses the received signals as a trigger to cause the battery 114 to receive the light receiving unit 104,
The image processing unit 105 and the brightness calculation unit 106 are instructed to supply power, a sampling signal is output to the image processing unit 105, and the brightness calculation unit 106 further outputs a high brightness light emission signal, a low brightness light emission signal, and a non-light emission. It has a function of receiving any one of the signals and performing processing (hereinafter, referred to as “illumination adjustment processing”) according to the signal received from the brightness calculation unit 106.

The illumination adjusting process will be described below. When the power saving control unit 108 receives the high brightness light emission signal from the brightness calculation unit 106, the power saving control unit 108 gives an instruction to emit light with high brightness.
In addition to the output to 1, the timer unit 112 outputs a signal instructing to start counting up. Also, the brightness calculation unit 10
When the low-luminance light emission signal is received from 6, the power saving control unit 10
Reference numeral 8 outputs an instruction to emit light with low luminance to the illumination unit 111, and also outputs a signal to the timer unit 112 to instruct start of counting up.

When the non-emission signal is received from the brightness calculation section 106 and the count-up completion signal described later is received from the timer section 112, the power saving control section 108 outputs an instruction to end the emission to the illumination section 111. Here, for convenience, the above-described high-luminance light emission signal, low-luminance light emission signal, and non-light emission signal are collectively referred to as a response signal.

Further, upon receipt of the response signal from the brightness calculation section 106, the power saving control section 108 determines whether or not the power supply to the light receiving section 104 and the image processing section 105 can be stopped by the control section 107. When the response is incapable of being stopped, the battery 114 is instructed to stop the supply of power to the light receiving unit 104, the image processing unit 105, and the brightness calculation unit 106.

On the other hand, when the response from the control unit 107 cannot be stopped, that is, when the camera is activated for taking a picture, the power saving control unit 108 stops only the power supply to the brightness calculation unit 106. To the battery 114. In this way, control is performed so that power is supplied to the light receiving unit 104, the image processing unit 105, and the brightness calculation unit 106 from the time the operation key unit 102 or the numeric keypad unit 103 is pressed until the response signal is received. The reason is as follows.

That is, the CCD consumes more electric power than the optical sensor, and consumes electric power rather than operating continuously like the optical sensor, which defeats the original purpose of power saving. Therefore, when the ambient brightness is calculated, the light receiving unit 104 including the CCD, the image processing unit 105, and the brightness calculation unit 106 are temporarily activated to suppress power consumption as much as possible.

The power saving control unit 108 precedes outputting to the lighting unit 111 an instruction to emit light with high brightness, an instruction to emit light with low brightness, and an instruction to end light emission.
In the case where the present light emission state in is detected and these instructions are output, the above instruction is output to the illumination unit 111 only when the light emission state changes. This is because, for example, the illumination unit 1 does not emit light, but the illumination unit 1
This is to prevent a meaningless instruction such as outputting an instruction to end the light emission to 11.

The timer unit 112 is a timer composed of a clock and a memory, and when it receives a signal instructing to start counting up from the power saving control unit 108, the reception of this signal is used as a trigger to set this value to 0 as an initial value. The value is incremented by 1 every 1 second, and when this value becomes equal to or greater than the default value “10” stored in the above-mentioned memory, the count-up is ended, and the power-saving control unit 108 is indicated that the count-up is ended. It has a function of outputting a count-up completion signal.

The battery 114 has a lithium-ion battery, a relay, and the like, and has a light receiving section 104 and an image processing section 105.
A luminance calculation unit 106, a control unit 107, a power saving control unit 108, a transmission / reception unit 109, a voice input unit 110, a voice output unit 113, an illumination unit 111, a display unit 101,
Power is supplied to the timer unit 112. It should be noted that when the above-described illumination adjustment processing is being performed, the battery 114 turns on the power supply to the light receiving unit 104, the image processing unit 105, and the brightness calculation unit 106 according to an instruction from the power saving control unit 108.
/ OFF is executed. <Operation> In the following, an operation of the mobile phone 100 for saving power consumption in lighting will be described.

FIG. 5 is a flowchart showing a process for controlling the illumination brightness in the illumination section 111. The power saving control unit 108 waits until it receives a signal output from the operation key unit 102 or the numeric keypad unit 103 (step S401). Then, when the signal output from the operation key unit 102 or the numeric keypad unit 103 is received, the power saving control unit 108 instructs the battery 114 to supply power to the light receiving unit 104, the image processing unit 105, and the brightness calculation unit 106. By doing so, a so-called camera is activated (step S402), and a signal for instructing the timer unit 112 to start counting up is output.

At this time, the timer unit 112 sets 0 as an initial value (step S403), and starts counting up by 1 increment every 1 second to this initial value (step S404). When the camera is activated, the image processing unit 1
Reference numeral 05 outputs only the intensity value of the light detected by the light receiving element to which the green filter is attached among the plurality of light receiving elements included in the light receiving section 104, to the brightness calculating section 106.

As a result, the brightness calculation section 106 acquires the intensity value of green light from the image processing section 105 (step S4).
05), using these values as parameters, the average value of the light intensity is calculated using the formula of Equation 1 (step S406), the calculated average value and the threshold values L1 and L1 are compared, and the signal corresponding to this average value is calculated. That is, the brightness is determined by outputting one of the high-luminance light emission signal, the low-luminance light emission signal, and the non-light emission signal to the power saving control unit 108, and the illumination unit 111 is caused to emit light (step S407).

Then, the power saving control unit 108 has the timer unit 1
It is determined whether or not the count-up completion signal output from 12 is input (step S408). When the count-up completion signal is input, the power saving control unit 108 outputs an instruction to stop the illumination to the illumination unit 111 (step S4).
09), the processing ends. On the other hand, in the determination in step S408, if the count-up completion signal is not input, the power saving control unit 108 determines whether a signal is input from the operation key unit 102 or the numeric keypad unit 103 (step S410), When a signal is input from the operation key unit 102 or the numeric keypad unit 103, the timer unit 112
A signal for instructing to start counting up is output to.

As a result, the timer unit 112 resets this count value to 0 while continuing the count-up currently being performed (step S411), and the brightness calculation unit 106 outputs the intensity value of the green light from the image processing unit 105. The process returns to step S405 of acquiring. Further, when the determination is made in step S410, the operation key unit 102 or the ten-key unit 103
If no signal is input from, the power saving control unit 108 returns to step S408 to determine whether or not a count-up completion signal is input.

As described above, according to the present embodiment, the mobile phone 100 is based on the intensity of light in the wavelength band showing green, which is a part of the image data obtained by using the camera. Since the brightness of the ambient natural light is calculated and the brightness of the illumination is determined, the calculation time can be shortened and the illumination can be started more quickly by reducing the data processing amount in the above calculation. It is possible to improve the calculation accuracy of the ambient brightness by reflecting the almost average brightness in the shooting range in the calculation.

In this embodiment, the light receiving section 104
Is a CCD, but may be another light receiving element such as a CMOS sensor. Further, in the present embodiment, the light receiving section 104 is a single-plate color CCD, but the incident light is refracted and divided into three different directions by a prism, and the respective divided lights are red and green. , Each of which is led to each of the blue filters, and received by the dedicated CCD for each color component 3
It may be a CCD.

In this case, of the three CCDs, only the CCD that receives the light transmitted through the green filter is activated,
By detecting the intensity value of light, the power consumption in the light receiving unit can be suppressed to about one-third as compared with the normal case where three CCDs are activated, and power saving can be achieved. The effect is obtained. Further, the CCD of the light receiving unit 104 in the present embodiment is a so-called primary color CCD using a color filter that transmits light for each of the RGB three components, but not the RGB components, but cyan (C),
It may be a so-called complementary color CCD using color filters of so-called complementary colors of magenta (M) and yellow (Y).

The relationship between the complementary color and the primary color is yellow =
Red + green, cyan = green + blue, magenta = blue + red, and complementary colors including green, which is easily perceived by human eyes as brightness, are yellow and cyan. Therefore, if the ambient brightness is calculated based on the brightness value detected by the light receiving element to which one of the yellow and cyan color filters is attached, the function as a highly sensitive optical sensor can be exerted. it can.

In the present embodiment, light in the wavelength band showing green, which has a high relative luminous efficiency, is used as the intensity of natural light. However, the intensity is not limited to this, and light other than this wavelength band, for example, red or blue. The intensity of natural light may be obtained by detecting the intensity of light that indicates. Further, although the default value “10” is stored in the memory of the timer unit 112, an instruction to change this value may be accepted by the operation key unit 102 or the ten key unit 103.

By reducing this value, the illumination unit 1
In 11, the continuous light emission time is shortened, and the power consumption is further reduced. When the image processing unit 105 receives the sampling signal from the power saving control unit 108,
As shown in FIG. 4, the values obtained by A / D conversion of only the image signals obtained from the respective light receiving elements, which are located in the rectangular area of the central portion of the CCD and to which the green filters are attached, that is, The brightness value L _{i, j}
However, the value obtained by A / D conversion of only the image signal obtained from each of the light receiving elements on one horizontal or vertical line on the CCD matrix instead of the rectangular range, that is, the light intensity value Each of the L _{i, j} is calculated by the brightness calculation unit 106.
It may be output to.

Further, as shown in FIG. 6, a mobile terminal such as a mobile phone 500 equipped with two cameras has recently appeared, and the present invention may be applied to one of the two cameras. This mobile phone 500 has a light receiving unit 502 arranged on the same surface as a surface (hereinafter, referred to as “front surface”) on which a numeric keypad, operation keys, a display unit and the like are arranged, and a surface opposite to the front surface (hereinafter referred to as “the front surface”). It is referred to as a “rear surface”).

In this case, as the light receiving section used for calculating the ambient brightness, the light receiving section 501 arranged on the same surface as the surface on which the ten keys and operation keys are arranged. For example, as shown in FIG. 7, when the user detects the above-mentioned display unit under a night light and detects the light intensity at the light receiving unit 501 arranged on the back surface of the mobile phone 500. , The intensity of the light in the direction A in the figure where the light of the electric light does not reach is detected, which is not suitable for the calculation of the ambient brightness, but the light receiving unit 502 arranged in the front direction in the direction B in the figure. This is because it is convenient to detect the intensity of the light, because the intensity of the light reflected by the light of the electric lamp can be detected.

Therefore, in a mobile terminal equipped with two cameras in this way, it is necessary to detect the intensity of the light received by the light receiving portion at a position where it is easier to receive the light incident on the place to be illuminated. Will adjust the brightness of the illumination. Further, as shown in FIG. 8, the display unit 701 and the light receiving unit 70 are provided on the front surface of the foldable housing 700.
4 is arranged, and the display unit 7 is provided on the rear surface of the housing 700.
03 and the light receiving unit 702 are expected to appear in the future, but in such a case, in the light receiving unit arranged on the same plane as the surface on which the display unit being confirmed by the user is arranged. The brightness of the illumination is adjusted by detecting the intensity of the received light.

[0060]

As is apparent from the above description, the mobile terminal according to the present invention has a first filter and a second filter that transmit light in different wavelength bands, and a first filter that receives light from a subject. A first light receiving element for receiving the transmitted light filtered by the filter, a second light receiving element for receiving the transmitted light filtered by the second filter among the light coming from the subject, and the first and second The image data generating means for generating image data reflecting the intensity of the transmitted light received by the light receiving element, the display means for displaying an image based on the image data, and the first light receiving element or the second light receiving element. And a lighting unit that illuminates the display unit or the operation unit as a backlight with a brightness that reflects the intensity of transmitted light received by one side. Lighting method according to includes a first filter and a second filter that transmits light in different wavelength bands from each other,
Of the light coming from the subject, a first light receiving element that receives the transmitted light that has been filtered by the first filter, and the second light receiving element that receives the transmitted light that has been filtered by the second filter from the light that comes from the subject. A light receiving element, an image data generating unit that generates image data that reflects the intensity of transmitted light received by the first and second light receiving elements, a display unit that displays information, and an operation that receives an operation input from an operator. An illumination method for illuminating a mobile terminal including a display section or the operation as a backlight with a brightness that reflects the intensity of transmitted light received by one of the first light receiving element and the second light receiving element. It has a lighting step for illuminating a section.

As a result, the illumination is performed with the brightness that reflects the intensity of the light in the wavelength band limited by either the first filter or the second filter in the image data.
In other words, the ambient brightness is calculated by diverting part of the image data generated in the process of shooting by the camera, but some of the above image data is not obtained by limiting the range of the image. However, since it can be obtained by limiting the wavelength band of light, the brightness of all captured image ranges is reflected, and the amount of data used for calculating ambient brightness is also reduced. Calculation time is reduced.

Further, the light of the first wavelength band has a characteristic that the relative luminous efficiency in human is higher than that of the light of the second wavelength band, and the illuminating means transmits the light received by the first light receiving element. The illumination may be performed with a brightness that reflects the intensity of light. As a result, the light intensity used as the basis for determining the illumination brightness is set to the light intensity in the wavelength band with high relative luminous efficiency.

In other words, natural light is a state in which lights of various wavelengths are mixed, but the wavelength of light that can be sensed by a person is within the limited range, and further, it can be sensed by a person. Even if the light has a wavelength that can be generated, the sensitivity is different for each wavelength, so when the intensity of only the light in a certain wavelength band is detected and used as the intensity of the total natural light, the wavelength of the substitute light is Due to the wavelength of high visibility,
The correlation between the intensity of the detected light and the intensity of natural light perceived by a person is enhanced.

Further, the first wavelength band may include light having a wavelength showing green. As a result, the intensity of green light having high relative visibility is used as the intensity of natural light. Further, the mobile terminal further includes a reception unit that receives an operation input from a user, and the illumination unit starts the illumination when the reception unit receives the operation input, and a predetermined period from the start of the illumination. The illumination may be terminated when the reception unit does not receive a new operation input before the time elapses.

As a result, a predetermined time is required for the operation input,
The illuminated area is illuminated. That is, by limiting the illumination time, useless power consumption required for illumination can be suppressed.
Further, the first light receiving element generates intensity information indicating the intensity of the received light, the illuminating unit grasps the intensity of the transmitted light based on the intensity information, and the mobile terminal further includes: A power supply that starts supplying power to the first light receiving element when the operation input is received by the receiving means, and stops the power supply to the first light receiving element when the intensity information is generated by the lighting means. Means may be provided.

As a result, electric power is supplied to the first light receiving element from the time when the operation input from the user is received until the intensity information is generated. That is,
Useless power consumption is suppressed. In addition, the power supply unit further supplies power to the second light receiving element, and from the start to the stop of power supply to the first light receiving element accompanying reception of the operation input and acquisition of the first information, The power supply to the second light receiving element may be stopped.

As a result, power is not consumed in the light receiving element that does not contribute to the illumination, and power saving is further achieved. In other words, for the one having a dedicated CCD for each of red, green, and blue components, such as 3CCD, C for the green component is used.
Power consumption can be reduced by driving only the CD.

Further, the illuminating means determines whether or not the value of the intensity of the light indicated by the intensity information is equal to or less than a predetermined value, and illuminates only when the value is equal to or less than the predetermined value. You may. Thereby, when the intensity value exceeds a predetermined value, that is, when the surroundings are bright, unnecessary illumination is not performed, and power saving is further achieved.

Further, the mobile terminal according to the present invention has a first light receiving section for receiving incident light, a second light receiving section for receiving light incident from a direction different from the incident direction of the light, and a first light receiving section. Image data generating means for acquiring the intensity of the light incident on the part to generate the first image data, and the second image for acquiring the intensity of the light incident on the second light receiving part to generate the second image data. The value of the intensity of the light received by the data generation means and the one of the first light receiving portion and the second light receiving portion, which is located at a position where it is easier to receive the light incident on the site to be illuminated, is reflected. An illumination means for illuminating the location with brightness may be provided.

As a result, the brightness of the illumination is adjusted based on the value of the intensity of the light received by the light receiving portion located at the position where it is easier to receive the light incident on the illuminated portion.
That is, by using one of the two cameras that is more likely to receive the light incident on the site to be illuminated, the intensity value of the light that reflects the brightness of the surroundings is detected.

[Brief description of drawings]

FIG. 1 is an external view of a mobile phone according to an embodiment of the present invention.

FIG. 2 is a functional block diagram of a mobile phone.

FIG. 3 is a diagram showing a structure of a light receiving portion.

FIG. 4 is a diagram illustrating values used for calculation in a brightness calculation unit.

FIG. 5 is a flowchart showing a process for controlling illumination brightness in an illumination unit.

FIG. 6 is an external view of a mobile phone equipped with two cameras.

FIG. 7 is a diagram illustrating detection of ambient brightness in a mobile phone equipped with two cameras.

FIG. 8 is an external view of a mobile phone having a foldable housing and having two cameras and two display units.

FIG. 9 is an external view of a conventional mobile phone.

[Explanation of symbols]

100 mobile phones 101 display 102 Operation key section 103 Numeric keypad 104 Light receiving part 105 image processing unit 106 brightness calculation unit 107 control unit 108 Power saving control unit 109 transmitter / receiver 110 Voice input section 111 Lighting unit 112 Timer part 113 voice output section 114 batteries 500 mobile phones 501, 502 Light receiving part

Continued front page    F term (reference) 5C065 AA03 AA07 BB48 CC01 CC08                       DD02 EE06 FF02 GG17 GG18                 5K023 AA07 HH06                 5K027 AA11 FF22 HH30

Claims (9)

[Claims] 1. A first device that transmits light in different wavelength bands from each other.
A filter and a second filter; a first light receiving element that receives the transmitted light that has been filtered by the first filter among the light that has come from the subject; and the light that has come from the subject that has been filtered by the second filter. Second light receiving element for receiving the transmitted light, image data generating means for generating image data reflecting the intensity of the transmitted light received by the first and second light receiving elements, and an image is displayed based on the image data. And a lighting unit that illuminates the display unit or the operation unit as a backlight with a brightness that reflects the intensity of the transmitted light received by one of the first light receiving element and the second light receiving element. And a mobile terminal. 2. The light in the first wavelength band has a property of having higher relative luminous efficiency in humans than the light in the second wavelength band, and the illuminating means transmits the light received by the first light receiving element. The mobile terminal according to claim 1, wherein the illumination is performed with a brightness that reflects the intensity of light. 3. The mobile terminal according to claim 2, wherein the first wavelength band includes light having a wavelength showing green. 4. The mobile terminal further comprises reception means for receiving an operation input from a user, and the lighting means starts the lighting when the reception means receives the operation input, and starts the lighting. The mobile terminal according to claim 1, wherein when the receiving unit does not receive a new operation input before a predetermined time elapses, the lighting is terminated. 5. The first light receiving element generates intensity information indicating the intensity of the received light, the illumination means grasps the intensity of the transmitted light based on the intensity information, and the mobile terminal, Furthermore, when the operation input is accepted by the acceptance means,
The power supply means for starting the power supply to the first light receiving element and stopping the power supply to the first light receiving element when the intensity information is generated in the illumination means is provided. The described mobile terminal. 6. The power supply means further supplies power to the second light-receiving element, and stops from the start of power supply to the first light-receiving element upon reception of the operation input and acquisition of the first information. The mobile terminal according to claim 5, wherein the power supply to the second light receiving element is stopped until the end. 7. The illuminating means determines whether or not the value of the intensity of the light indicated by the intensity information is below a predetermined value, and illuminates only when the value is below the predetermined value. The mobile terminal according to claim 1, wherein: 8. A first light receiving portion for receiving incident light, a second light receiving portion for receiving light incident from a direction different from the incident direction of the light, and an intensity of light incident on the first light receiving portion. First image data generating means for acquiring and generating first image data; second image data generating means for acquiring the intensity of light incident on the second light receiving part to generate second image data; and first light receiving That illuminates the location with a brightness that reflects the value of the intensity of the light received by the one that is more likely to receive the light that is incident on the site that is the target of illumination, of the first section and the second light receiving section And a mobile terminal. 9. A first device that transmits light in different wavelength bands from each other.
Of the light coming from the subject, the filter and the second filter, the first light receiving element that receives the transmitted light that is filtered by the first filter, and the light that comes from the subject is filtered by the second filter. A second light receiving element that receives transmitted light, an image data generation unit that generates image data that reflects the intensity of the transmitted light received by the first and second light receiving elements, a display unit that displays information, and an operator. An illumination method for illuminating a mobile terminal, comprising: an operation unit that receives an operation input from the backlight, the backlight having a brightness that reflects the intensity of transmitted light received by one of the first light receiving element and the second light receiving element. And a lighting step of illuminating the display unit or the operation unit.