JP2006197205A - Portable terminal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable terminal, such as a portable telephone with a camera, which can be reduced in power consumption when the ambient brightness is detected by the camera. <P>SOLUTION: The portable telephone device with the camera is used not only as a camera with usual functions but also a device for detecting the ambient brightness. When it is judged by a brightness detection result that the surroundings are dark, an LCD backlight is reduced in brightness, and when it is judged by a brightness detection result that the surroundings are bright, the LCD backlight is increased in brightness. When the camera is used as a device for detecting the ambient brightness, the operating clock of the camera is set lower than that in a case wherein the camera is used as usual, and the camera is controlled so as to operate intermittently. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mobile terminal device, and more particularly to a mobile phone with a camera function.

  In order to display information to an operator, a mobile phone as an example of a mobile terminal device is provided with a display unit composed of, for example, an LCD so that display brightness can be selected according to the brightness of the backlight of the LCD. .

  The brightness of the LCD backlight in the conventional device is selected by the user's settings, and if set once, regardless of the ambient brightness of the usage environment, the brightness was strictly observed. LCD screen can be seen at night, but it becomes very dazzling and difficult to see at night.

  By the way, recently, there are many scenes in which a mobile phone is operated while walking at night or riding a bicycle, and e-mails are browsed or characters are input. When this operation was actually performed, the LCD backlight at night was quite dazzling, but there was a problem that it was difficult to see in the daytime when the surroundings were bright if the brightness was lowered. In order to make the brightness different between daytime and nighttime, the operator only has to redo the brightness setting each time, but there is a problem that it is troublesome to redo it at nighttime and daytime.

  On the other hand, in the invention described in Patent Document 1, ambient brightness is detected by the camera of the camera-equipped mobile phone, and the brightness of the display unit of the mobile phone is adjusted based on the detected brightness.

JP 2002-344598 A

  As described above, in the invention described in Patent Document 1, the ambient brightness is detected by the camera of the camera-equipped mobile phone, but no consideration is given to the power consumption for the camera operation for the ambient brightness detection. There wasn't.

  In mobile phones, reduction in power consumption is an important issue in order to enable downsizing and use for a long time, and the invention described in Patent Document 1 lacking correspondence to this point still has problems. there were.

  The present invention has been made in view of the above points, and enables a reduction in power consumption when detecting ambient brightness with a camera in a mobile terminal device such as a camera-equipped mobile phone. For the purpose.

  In order to achieve the above object, the present invention uses a camera for a mobile phone device with a camera function not only for a normal camera function but also for detecting ambient light and darkness. When the brightness of the backlight is lowered and the brightness is determined to be high, the brightness is increased. When the camera is used for light / dark detection, control is performed so that the camera operating clock is lowered than in normal camera operation and the camera operates intermittently.

  That is, the present invention provides a display unit that displays information to an operator, a backlight that adjusts the luminance of the display unit according to the brightness that it illuminates, a camera that captures surrounding images, and an image that is captured by the camera. A control unit that adjusts the brightness of the backlight based on data, and when the control unit operates the camera to adjust the brightness of the backlight, an operation to operate the camera Control is performed to reduce the frequency of the clock.

  The present invention also provides a display unit for displaying information to the operator, a backlight for adjusting the luminance in the display unit according to the brightness illuminated by the operator, a camera for capturing surrounding images, and an image captured by the camera. A control unit that adjusts the brightness of the backlight based on data, and the control unit intermittently performs the process of adjusting the brightness of the backlight based on the image data. To do.

  In the invention according to claim 1, the control unit intermittently performs the process of adjusting the brightness of the backlight based on the image data.

  According to the present invention, in the invention according to any one of claims 1 to 3, the control unit increases the brightness of the backlight when the surroundings are bright based on the image data. When the light is dark, the brightness of the backlight is reduced.

  In the invention according to claim 4, the display unit is an LCD.

  According to the present invention, in the invention described in any one of claims 1 to 5, the mobile terminal device is a mobile phone.

  According to the present invention, it is possible to reduce power consumption when detecting ambient brightness with a camera in a mobile terminal device such as a camera-equipped mobile phone.

  That is, according to the present invention, since the camera of the mobile phone with a camera function is used as a brightness / darkness detection circuit, it is not necessary to mount a dedicated brightness / darkness detection circuit. Furthermore, since the brightness of the LCD backlight can be controlled based on the detection result, it is possible to always display a good LCD screen regardless of whether the surroundings are bright or dark. In addition, by having multiple camera operation CLKs (operation clocks) and using a lower CLK for camera operation CLK during light / dark detection, it is possible to achieve lower power consumption than during normal camera operation, and furthermore, light / dark detection. Low power consumption can also be realized by controlling the operation to be performed intermittently.

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

  In this embodiment, the case where the present invention is applied to a mobile phone will be described. However, the present invention is not limited to a mobile phone and can be applied to any mobile terminal device such as a PDA.

  FIG. 1 is a block diagram showing a configuration of an embodiment of a mobile phone according to the present invention.

  As shown in FIG. 1, the cellular phone according to the present embodiment receives an electric wave from a base station, transmits an electric wave to the base station, and amplifies and demodulates the received electric wave. The radio section 2 that modulates and amplifies the data, the control section 3 that controls the operation of the entire apparatus, the LCD 4 that displays to the operator, and a light for the LCD 4 that is easy to see the display from behind the LCD 4 LCD backlight 5 that performs image capturing, camera 6 that captures an image, camera CLK supply selection unit 7 that supplies an operation clock for camera 6, and a light and dark detection unit that detects ambient light and darkness based on image data captured by camera 6 8, a key unit 9 on which an operator performs key input, a speaker 10 that emits a ring tone, and a battery 11 that is a power source.

  The configuration of the mobile phone shown in FIG. 1 will be described in more detail with reference to FIG.

  FIG. 2 is a block diagram showing in more detail a configuration related to control based on light / dark detection in the configuration of the mobile phone shown in FIG.

  As shown in FIG. 2, the camera CLK supply selection unit 7 includes a frequency divider, and generates an operation clock (first operation clock) when the camera 6 is used for normal camera photography. The second operation clock having a frequency lower than that of the first operation clock can be generated by passing through.

  That is, a first operation clock for camera operation is input from the control unit 2 to the camera CLK supply selection unit 7. The camera CLK supply selection unit 7 is controlled by the control unit 2, and performs normal camera shooting. The first operation clock is directly passed through and supplied to the camera 6, and when the surrounding light and darkness is detected, the first operation clock is divided by a predetermined frequency to be a second operation clock, This second operation clock is supplied to the camera 6 as a clock. The camera 6 operates with the supplied operation clock.

  Dividing is, for example, dividing a clock having a frequency of 10 MHz by 10 to obtain a frequency of 1 MHz, that is, 1/10. As described above, the first operation clock is used as an operation clock when the camera 6 is used as a normal camera, and the second operation clock is used as an operation clock when the camera 6 is used as a circuit for detecting light and dark. Is done.

  Since the camera 6 used in the cellular phone according to the present embodiment is made of CMOS, it operates at a high speed if the operating clock frequency is high, but the current consumption increases, and the operation is slow if the operating clock frequency is low. However, current consumption is reduced. Utilizing this principle, when the camera 6 is used as a light / dark detection function, the operation clock is lowered to suppress current consumption, and when used as a normal camera, the operation clock is increased. Note that high and low are only a relative comparison, and what is important is to provide an operation clock that meets the specifications of the camera. The power consumption is excessive for the light / dark detection because it is a measure for the mobile phone that can move the battery. In this embodiment, the operation clock is lowered to reduce the power consumption.

  The light / darkness detection unit 8 is configured to determine the lightness and darkness around the mobile phone, and image data captured by the camera 6 is sent to the lightness / darkness detection unit 8.

  The image data photographed by the camera 6 and sent to the light / darkness detection unit 8 is composed of, for example, two types of data of luminance and color. In the mobile phone of the present embodiment, the light / darkness detection unit 8 includes the image data. The device usage environment, that is, the brightness of the surroundings of the mobile phone is determined using the luminance data.

  For the determination of light and dark, a predetermined threshold is set, and if the luminance is higher than the threshold, it is determined as “bright”, and if the luminance is lower than the threshold, it is determined as “dark”.

  In the case of “bright”, the luminance of the LCD backlight 5 is increased, and in the case of “dark”, the luminance of the backlight 5 is decreased. That is, if the environment is bright, the LCD backlight 5 is brightened. If the environment is dark, the LCD backlight 5 is darkened. This control seems to be the opposite, but the brighter the surroundings, the brighter the LCD backlight 5 is, the brighter the LCD 4 display cannot be seen. Can be seen. If the LCD backlight 5 is too bright even though the surroundings are dark, the surroundings cannot be seen well at the moment when the eyes are removed from the LCD 4, which is very dangerous.

  In the above description, only one threshold value is used for determining the distinction between light and dark. However, controlling the LCD backlight 5 with a plurality of threshold values and a plurality of luminances is included in the present invention.

  Of course, since the LCD backlight 5 is lit while the LCD 4 is displayed, the light / dark detection operation is performed only when some kind of display is performed on the LCD 4.

  FIG. 3 is a time chart showing the operation timing of light / dark detection by the camera 6 in the mobile phone according to the present embodiment shown in FIG.

  In the mobile phone according to the present embodiment, intermittent control for intermittently performing the light / dark detection operation is realized. This point will be described with reference to FIG.

  First, at the same time when the display on the LCD 4 is turned on, the operation of the camera 6 as a light / dark detection circuit is turned on. Although the operation clock of the camera 6 at the time of light / dark detection is lowered as the second operation clock as described above, it is a fact that power is consumed for the light / dark detection, so it is desired to further reduce the power consumption. Therefore, the brightness / darkness detection camera operation is intermittently controlled as shown in FIG.

  In FIG. 3, the horizontal axis is time, X is the on time, that is, the time for operating the camera 6 as a light / dark detection circuit, and Y is the off time, that is, the time for not operating the camera 6. In order to reduce power consumption, it is natural that X should be shortened and Y should be lengthened as much as possible. However, since the detection capability varies depending on the performance of the camera 6, the ratio of X and Y is the cellular phone of the present invention. It is desirable to be able to set a variable.

  FIG. 4 is a diagram showing a control flowchart in the mobile phone according to the present embodiment shown in FIG.

  First, in step (A-1), the LCD 4 is not displayed and is left unattended. Since recent color LCDs consume a large amount of power, the LCD display is turned off when left for a certain period of time. Step (A-1) is, for example, this state. Subsequently, in step (A-2), for example, by pressing an SW (switch) such as a key of the key unit 9 of the mobile phone or opening the mobile phone if it is a foldable mobile phone, the operator's will is carried by the mobile phone. The process proceeds with the message transmitted to the telephone.

  When the will of the operator is transmitted to the mobile phone in step (A-2), the control unit 3 turns on the display of the LCD 4, turns on the LCD backlight 5, and detects the brightness / darkness by the camera 6. The operation is turned on (A-3).

  The light / dark detection unit 8 determines whether the light / dark detection result by the light / dark detection operation of the camera 6 is equal to or greater than a predetermined threshold (A-4). Is increased (A-5), and if it is determined that it is below the threshold value, that is, dark, the luminance of the LCD backlight 5 is decreased (A-6).

  Finally, in step (A-7), if the LCD 4 is still displaying, the process returns to step (A-4), the luminance detection result is compared with the threshold value, and the process is continued. Since this operation is intermittent, it is repeated any number of times while the LCD 4 is being displayed. On the other hand, if the display on the LCD 4 is OFF in step (A-7), it is not necessary to perform light / dark detection by the camera 6, so the light / dark detection is stopped and the LCD 4 in step (A-1) is not displayed. Return.

  In the above description, the brightness / darkness detection result by the camera 6 is used for luminance control of the LCD backlight 5, but the brightness / darkness detection result by the camera 6 can also be used for opening / closing detection of the folding cellular phone. A mobile phone according to an embodiment different from that shown in FIG. 1 will be described with reference to FIG.

  5A and 5B are views showing an external appearance of a general foldable mobile phone, wherein FIG. 5A is a diagram showing a front view when the mobile phone is opened, and FIG. 5B is a diagram showing a rear view when the mobile phone is opened. (C) is a figure which shows the side surface of the state which closed the mobile telephone.

  As shown in FIG. 5A, the cellular phone 20 has a key surface camera 21 and a display unit 23 on a surface having a key unit 22 on which an operator performs key operations in an opened state. Further, as shown in FIG. 5B, the mobile phone 20 has a rear camera 25 on the back in the opened state. Further, as shown in FIG. 5C, the cellular phone 20 can be folded by a hinge 24 so that the key surface camera 21 is inside.

  The key plane camera 21 is mainly used when taking an image of an operator, and is the most effective camera for a videophone together with the display unit 23. On the other hand, the rear camera 25 can be used as a so-called ordinary camera.

  As can be seen with reference to FIG. 5C, the key surface camera 21 faces the key portion 22 and is dark when the cellular phone 20 is folded. In the present embodiment, the open / closed state of the mobile phone 20 is detected by using this property and using the key surface camera 21 for light / dark detection. That is, if the detection result by the key surface camera 21 is bright, the mobile phone 20 is in the open state, and if the detection result by the key surface camera 21 is dark, the mobile phone 20 is required to be in the closed state.

  In the conventional mobile phone, the open / closed state of the folding mobile phone is detected mainly by magnetic force detection by a magnet or detection by a small button. In this conventional method, both require a circuit for detection, a magnet, and a structural SW, and there is a drawback that the hardware scale becomes large. According to the mobile phone 20 of the embodiment of the present invention described with reference to FIGS. 5A to 5C, open / close detection can be performed without increasing the number of circuits.

It is a block diagram which shows the structure of one Embodiment of the mobile telephone by this invention. FIG. 2 is a block diagram showing in more detail a configuration related to control based on light / dark detection in the configuration of the mobile phone shown in FIG. 1. 3 is a time chart showing the operation timing of light / dark detection by a camera in the mobile phone of the present embodiment shown in FIG. 1; It is a figure which shows the flowchart of control in the mobile telephone of this Embodiment shown in FIG. It is a figure which shows the external appearance of a common folding type | mold mobile phone, (a) is a figure which shows the front in the state which opened the mobile phone, (b) is a figure which shows the back surface in the state which opened the mobile phone. (C) is a figure which shows the side surface of the state which closed the mobile telephone.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antenna 2 Radio | wireless part 3 Control part 4 LCD
5 LCD backlight 6 Camera 7 Camera CLK supply selection unit 8 Light / darkness detection unit 9 Key unit 10 Speaker 11 Battery 20 Mobile phone 21 Key surface camera 22 Key unit 23 LCD
24 Hinge 25 Rear camera

Claims (6)

A display unit that displays information to the operator, a backlight that adjusts the luminance of the display unit according to the brightness that it illuminates, a camera that captures surrounding images, and the image data that is captured by the camera And a controller for adjusting the brightness of the backlight,
The mobile terminal device, wherein when the camera is operated to adjust the brightness of the backlight, the control unit controls the frequency of an operation clock for operating the camera to be lowered. A display unit that displays information to the operator, a backlight that adjusts the luminance of the display unit according to the brightness that it illuminates, a camera that captures surrounding images, and the image data that is captured by the camera And a controller for adjusting the brightness of the backlight,
The mobile terminal device, wherein the control unit intermittently performs a process of adjusting the brightness of the backlight based on the image data.   The mobile terminal device according to claim 1, wherein the control unit intermittently performs a process of adjusting the brightness of the backlight based on the image data.   The control unit, based on the image data, brightens the backlight when the surroundings are bright, and darkens the backlight when the surroundings are dark. 4. The mobile terminal device according to any one of items 3 to 3.   The portable terminal device according to claim 4, wherein the display unit is an LCD.   The mobile terminal device according to claim 1, wherein the mobile terminal device is a mobile phone.

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