KR100786464B1 - A mobile communication termial for visual communication and method for saving power thereof - Google Patents

Abstract

A mobile terminal for picture calls and a power-saving method thereof are provided to minimize the current consumption of a camera module and increase picture call time by supplying a power-saving clock, created by lowering the frequency of a main clock for the driving of a camera, to the camera module in power-saving mode. A mobile terminal which executes a picture call using a camera module(100) comprises a main control part(210) and a clock supply part(213). The main control part(210) instructs the clock supply part(213) to drive the camera module(100) with a power-saving clock, created by lowering the frequency of a main clock for the driving of the camera module(100), when a power-saving mode is enabled. The clock supply part(213) creates the power-saving clock according to the control of the main control part(210) and drives the camera module(100).

Description

 Mobile communication terminal for video call and its power saving method {A MOBILE COMMUNICATION TERMIAL FOR VISUAL COMMUNICATION AND METHOD FOR SAVING POWER THEREOF}

1 is an internal block diagram of a mobile communication terminal for a video call according to an embodiment of the present invention.

2 is a block diagram illustrating an internal configuration of an image sensor according to an embodiment of the present invention.

3 is an internal block diagram of a mobile communication terminal for a video call according to another embodiment of the present invention.

4 is a flowchart illustrating a power saving method of a mobile communication terminal for a video call according to an embodiment of the present invention.

5 is a waveform diagram of a main clock and a power saving clock for driving a camera unit according to an exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: camera unit 120: image sensor

130: image processing unit 140: camera control unit

210: main control unit 212: mode setting unit

213: clock provider

The present invention relates to a mobile communication terminal capable of a video call, and more particularly, to a video communication mobile communication terminal and a power saving method for reducing current consumption by changing a main clock for driving a camera.

Nowadays, mobile communication terminals such as mobile phones and PDAs (Personal Digital Assistants) include various additional service functions such as digital cameras, video communications, TV broadcast programs, multimedia data playback, and Internet access in addition to wireless communication functions.

In particular, a mobile communication terminal provided with a digital camera can not only make a video call using a digital camera but also transmit multimedia data such as a video and an image to a counterpart.

As a mobile communication terminal capable of a video call enables not only a voice call but also a video playback, the battery consumes quickly due to a large amount of power consumption due to excessive power consumption due to the display or excessive operation of an internal control device, and battery use. There is a problem that the time becomes much shorter in the video call method than in the voice call method. In addition, because the battery is quickly consumed, the call time during the video call is also significantly reduced, causing inconvenience to the user.

In the video call power saving method, the conventional mobile communication terminal in the video communication power saving method is a video communication when there is no change in the input image to a predetermined time elapsed during the video communication disclosed in Korean Patent Laid-Open No. 2001-0058556 There is a method of switching to the power saving mode by controlling the power supply of the corresponding blocks for.

In the above method, since the change of the video signal input from the controller occurs, the user inputs the key, and the operation of canceling the power saving mode according to the key input, the operation amount of the controller may increase, and the video call may be performed even in the power saving mode. Since the driving of the camera is still ongoing since the is not terminated, there is a problem that the current consumption due to the driving of the camera, which consumes the most current during a video call, cannot be substantially reduced.

In addition, the power saving method of the mobile communication terminal of the prior art detects the total amount of the battery when the image coding disclosed in Korean Patent Laid-Open Publication No. 2004-0053999 to selectively limit the coding of the color difference signal to reduce the amount of computation for the image coding of the mobile communication terminal There is a way to reduce power consumption.

The above method is applied when a video call is made with a color image using a terminal in which the automatic power saving mode is set. In the power saving mode, the coding of the color difference signal is omitted and only the coding by the luminance signal is performed. Since the video call is performed, the current consumption due to the camera driving, which consumes the most current during the video call, has a substantially low reduction rate, and the black and white video may cause an image effect and may cause inconvenience to the user.

Accordingly, it is a first object of the present invention to provide a power saving method of a mobile communication terminal for video telephony to increase the video call time by reducing the current consumed by driving the camera.

In addition, a second object of the present invention is to provide a mobile communication terminal for a video call implementing the above power saving method.

According to an aspect of the present invention for achieving the above-described first object of the present invention, a power saving method of a mobile communication terminal for video call is a power saving mode of a video communication mobile communication terminal having a camera. In this case, generating a power saving clock that reduces the main clock frequency for driving the camera by a predetermined frequency, and driving the camera with the power saving clock when a video call is started.

The power saving method of the mobile communication terminal for a video call may include detecting the remaining battery level of the mobile communication terminal, and setting the power saving mode when the detected remaining battery level is less than or equal to a threshold value. The method may further include maintaining the normal mode when the threshold value is exceeded.

If the normal mode is set, further comprising the step of driving the camera to the main clock, the power saving mode is to set the power saving mode or normal mode for the current consumption control of the mobile communication terminal according to the user's setting Can be.

When the power saving mode is released, the main clock may be provided to the camera instead of the power saving clock.

According to an aspect of the present invention, a mobile communication terminal for performing a video call using a camera unit includes a camera unit when a power saving mode is set. And a controller for instructing to drive the camera unit with a power saving clock in which a main clock frequency for driving is reduced by a predetermined frequency, and a clock providing unit for generating the power saving clock under the control of the controller and driving the camera unit.

The controller may be configured to continuously monitor a battery state of the mobile communication terminal to detect a remaining battery level at predetermined time intervals, and compare the detected battery remaining amount with a preset threshold value to determine whether the remaining battery level is equal to or less than a threshold value. In this case, the power saving mode may be set, and the battery may include a mode setting unit for setting to a normal mode when the battery level is greater than or equal to a threshold.

The control unit may include a mode setting unit for setting a power saving mode or a general mode for controlling current consumption of the mobile communication terminal according to a user's setting.

The clock providing unit may drive the camera unit with the power saving clock when the power saving mode is set, and drive the camera unit with the main clock when the normal mode is set.

The clock providing unit may be installed in the camera unit to generate the power saving clock according to the instruction of the controller to drive the camera unit, or the clock providing unit may drive the main clock according to the instruction of the power saving unit. It can be changed to a clock and provided to the camera unit.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

In describing the drawings, similar reference numerals are used for similar components.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention. Hereinafter, the same reference numerals are used for the same components in the drawings, and duplicate descriptions of the same components are omitted.

1 is an internal block diagram of a mobile communication terminal for video call according to an embodiment of the present invention, Figure 2 is an internal block diagram of a mobile communication terminal for video call according to an embodiment of the present invention.

1 and 2, a mobile communication terminal for a video call according to an embodiment of the present invention includes a camera unit 100 for capturing an image of a subject and a main control unit for performing overall control operations of the mobile communication terminal ( 210, an RF module unit 220, a key input unit 230, an audio unit 240, a display unit 250 for displaying images and characters, and an interface for displaying images and characters on the display unit 250. The unit 260 includes a main memory 270, but is not limited thereto.

The camera unit 100 includes a lens unit 110, an image sensor 120, an image processing unit 130, a camera controller 140, and a memory 150.

The lens unit 110 may include a zoom lens, a focus lens, an iris, and the like, which are typically provided in a digital camera.

The image sensor 120 converts the optical signal of the subject passing through the lens unit 110 into an image signal which is an electrical signal, and converts the converted image signal into a digital signal and outputs the converted digital signal.

The image sensor 120 includes a pixel array unit 121, a timing controller 122, a sensor register unit 123, a CDS 124, and an ADC 125.

The pixel array unit 121 includes a plurality of unit pixels arranged in a matrix form, and the plurality of unit pixels are formed of a photoelectric conversion element and a switching element to absorb light energy reflected from a subject and convert the light energy into an electrical signal. Perform.

The pixel array unit 121 includes a row decoder, a column decoder, a row driver, a column driving circuit, and the like for controlling the pixels connected to the row line and the column line and processing the output signals of the pixels.

The timing controller 122 generates a timing signal and a control signal and provides them to the row decoder and the column decoder of the pixel array unit 121.

The row driver provides a plurality of driving signals to the plurality of pixels for driving the plurality of pixels according to a result decoded in the row decoder.

The sensor register unit 123 has registers for adjusting exposure, gamma, gain adjustment, white correction, black level adjustment, and communication with the camera peripheral circuit. The sensor register unit 123 may be included in the image sensor 120 as shown in FIG. 2 or may be installed outside the image sensor 120.

That is, the sensor register unit 123 stores sensor register setting values necessary for driving the image sensor 120 and providing image modes for various image effects.

The sensor register unit 123 registers necessary for setting various image modes for performing functions such as exposure, gamma, gain adjustment, black level adjustment, white balance, and color matrix, and the image sensor 120 and the image sensor of the camera. Registers having a set value for performing communication function adjustment with the peripheral circuit of 120.

The CDS 124 includes a correlated double sampling circuit (CDS) for each column line, and samples the reference voltage and the data voltage, which are the output signals of the pixels, and converts the difference between the reference voltage and the data voltage into an analog signal. Output

The ADC 125 outputs an image signal obtained by converting an analog signal output from the CDS 124 into a digital signal. Although not shown in the drawing, the output of the ADC 125 may be latched through a latch unit (not shown), serialized in a mux (not shown), and then output in serialized form.

The image processor 130 performs color interpolation, color correction, gamma correction, image scaling, etc. on the digitally converted raw image signal, and YcbCr type image signal. Under the control of the main control unit 210, the video signal is subjected to MPEG compression encoding to be output as video data for video call, or transmitted to the interface unit 260 to display video data for video call on the screen.

The memory 150 stores digital image data output from the image sensor 120 and stores compressed image data output from the image processor 130. The memory 150 may be implemented as a line memory.

When a user command is transmitted through the main controller 210, the camera controller 140 performs an overall control operation of the camera unit 100 to perform an operation corresponding to the user command. Here, the user command may be directly transmitted to the camera controller 140 instead of being transmitted through the main controller 210.

The main control unit 210 of the mobile communication terminal performs overall control operations for voice call, video call, and message transmission and reception.

The main controller 210 includes a battery remaining amount detector 211 and a mode setting unit 212 to reduce the current consumed by the camera unit 100. At this time, the remaining battery level detection unit 211 and the mode setting unit 212 is divided into functional blocks for convenience of description, but to implement the software operation by integrating each function to control the driving clock provided to the camera unit 100 Can be.

In the above description, the clock providing unit 213 may be included in the main control unit 210 or may be installed outside the main control unit 210. The battery remaining amount detector 211 continuously monitors the battery state of the mobile communication terminal to detect the remaining battery level at predetermined time intervals.

The mode setting unit 212 sets the power state of the mobile communication terminal to the power saving mode when the remaining battery level is less than or equal to the preset threshold, and sets the normal mode when the remaining battery level is greater than or equal to the threshold value. do.

The clock providing unit 213 generates a power saving clock when the power saving mode is set and provides the driving clock for driving the camera unit 100 to the camera unit 100, and provides a main clock when the normal mode is set. Provided to the part 100. Here, the power saving clock has a frequency lower than that of the main clock. For example, the clock provider 213 may implement a divider that divides the main clock into 1 / N (N is a natural number of 2 or more).

On the other hand, as shown in Figure 3, as another embodiment of the present invention, the main control unit 210 is a mode setting unit for setting the power saving mode / normal mode for the current consumption control of the mobile communication terminal according to the user's setting 212. In this case, the mode setting unit 212 may be implemented to operate in software to control the driving clock provided to the camera unit 100.

When the user directly sets the power saving mode to limit the current consumption of the mobile communication terminal, the mode setting unit 212 receives a power saving mode setting command from the user through the key input unit 230 to set the power saving mode. .

Therefore, when the power saving mode is set, the controller 210 instructs the camera unit 100 to provide a power saving clock in which the main clock frequency for driving the camera unit 100 is reduced by a predetermined frequency.

At this time, the clock providing unit 213 is installed in the camera unit 100 as shown in FIG. 3 to generate a power saving clock of a predetermined frequency in response to the command of the main control unit 210 to generate an image in the camera unit 100. To the sensor 120.

Instructions of the main control unit 210 to provide the power saving clock to the camera unit 100 may be provided to the clock providing unit 213 directly from the main control unit 210, but from the control unit 210 to the camera control unit 140. It may be provided to the clock providing unit 213 through.

Meanwhile, the power saving clock may be provided to the image processor 130 and / or the camera controller 140 in addition to the image sensor 120.

The RF module unit 220 performs transmission and reception of wireless data and video data for a video call. The key input unit 230 includes a plurality of numeric keys, special keys, and the like, and a user command is input. The audio unit 240 converts digital sound data into analog voice and outputs the same through a speaker SP. The analog voice input through the MIC is converted into digital sound data and transmitted to the main control unit 210.

The display unit 250 displays an image or an image under the control of the main controller 210. The interface unit 260 interfaces with the display unit 250 under the control of the main controller 210 or the image processor 130.

The main memory 270 stores programs and data for performing operations of various mobile communication terminals such as voice calls, video calls, and cameras.

In the above, the mobile communication terminal can be applied to a mobile terminal such as a mobile phone, a PMP, and an MP3 having a camera function for a video call.

Hereinafter, a power saving method of a mobile communication terminal for video call according to an embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

4 is a flowchart illustrating a power saving method of a mobile communication terminal for a video call according to an embodiment of the present invention, and FIG. 5 is a waveform diagram of a main clock and a power saving clock for driving a camera unit according to an embodiment of the present invention. .

4 and 5, in a power saving method of a mobile communication terminal for a video call according to an embodiment of the present invention, the mobile communication terminal is set to a power saving mode according to the battery level of the mobile communication terminal or a user directly saves power. When the power saving mode is set (step S1) and the power saving mode is set, the mobile communication terminal sets the camera driving clock as the power saving clock and provides it to the camera unit 100. The power saving clock is the camera driving clock in the normal mode. The frequency of the main clock is set by decreasing the frequency by a predetermined frequency (step S2).

For example, when the frame rate of the camera unit 100 is '15' when the frequency of the main clock is 60 MHz, as shown in FIG. 4, the power saving clock is generated after lowering the frequency of the main clock by 30 MHz. When the power saving clock is provided to the camera unit 100, the frame rate of the camera unit 100 is reduced to '7' to '8', and the operation of the camera unit is also slower than when driven by the main clock.

When the video call is initiated, the power saving clock is provided to the camera unit 100, and the camera unit 100 generates the video data for the video call using the power saving clock. In this case, the operation clock frequency of the timing controller 122 and the CDS 124 is reduced in the camera unit 100 driven by the power saving clock, and thus the amount of calculation per unit time is reduced, thereby reducing the camera unit 100 itself. The consumption current of can be reduced.

Table 1 below shows the results of testing the current state consumed by the camera unit 100 by changing the frequency of the camera driving clock provided to the camera unit 100.

Camera driven clock Mode (Preview) FPS Current consumption (mA) 12 MHz VGA 7 fps 17.2 40 MHz VGA 24 fps 44.0

As shown in Table 1, it can be seen that as the frequency of the camera driving clock decreases, the current consumed by the camera unit 100 decreases. Accordingly, the camera driving clock is dualized into the power saving mode and the normal mode according to the remaining battery state, and provided to the camera unit 100. In particular, in the power saving mode, the minimum driving clock capable of driving the camera is set as the power saving clock. Provided at 100.

When the power saving mode is released, the camera driving clock is provided as the main clock to the camera unit 100, and when the power saving mode is maintained, the power saving clock is continuously provided to the camera unit 100. (S3 to S5 step)

The above method may be switched from the normal mode to the power saving mode according to the remaining battery state even before the start of the video call or during the video call, and the main clock provided to the camera unit 100 at the time of switching to the power saving mode. Provided by changing to the clock for power saving.

In this case, since the power saving clock is provided to the camera unit 100 instead of the main clock provided to the camera unit 100 in the power saving mode, the current consumed due to the camera driving may be reduced. Battery drains slowly and can increase video call time.

According to the mobile communication terminal for a video call and the power saving method as described above, by providing a power saving clock generated by reducing the frequency of the main clock for driving the camera in the power saving mode, the camera unit reduces the amount of calculation per unit time The current consumption of the part itself can be reduced, and as a result, the battery consumption slows down, thereby increasing the video call time.

Although described with reference to the embodiments above, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

Claims (11)

In the power saving method of a mobile communication terminal for a video call having a camera possible, Generating a power saving clock in which a main clock frequency for driving the camera is reduced by a predetermined frequency when the power saving mode is set; And Driving the camera with the power saving clock when a video call is initiated Power saving method of a mobile communication terminal for a video call comprising a. The method of claim 1, Detecting a battery level of the mobile communication terminal; And And setting the power saving mode when the detected battery level is less than or equal to a threshold, and maintaining a normal mode when the battery level exceeds the threshold. . The method of claim 2, And when the general mode is set, driving the camera with the main clock. The method of claim 1 The power saving mode, A power saving method of a video communication mobile communication terminal, characterized in that the power saving mode or the normal mode is set to control the current consumption of the mobile communication terminal according to the user's setting. The method of claim 1, And if the power saving mode is released, providing the main clock to the camera instead of the power saving clock. In the mobile communication terminal for performing a video call using the camera unit, A control unit instructing to drive the camera unit with a power saving clock in which a main clock frequency for driving the camera unit is reduced by a predetermined frequency when a power saving mode is set; And And a clock providing unit which generates the power saving clock and drives the camera unit under the control of the controller. The method of claim 6, The control unit, A battery level detector for continuously monitoring a battery state of the mobile communication terminal to detect a battery level at predetermined time intervals; And a mode setting unit configured to set the power saving mode when the remaining battery level is less than or equal to a threshold value by comparing the detected remaining battery level with a preset threshold value and to set a normal mode when the remaining battery level is greater than or equal to a threshold value. Mobile communication terminal. The method of claim 6, The control unit includes a mode setting unit for setting a power saving mode or a normal mode for controlling the current consumption of the mobile communication terminal according to the user's settings. The method of claim 6, And the clock providing unit drives the camera unit with the power saving clock when the power saving mode is set, and drives the camera unit with the main clock when the general mode is set. The method of claim 6, The clock providing unit is installed in the camera unit to generate the power saving clock according to the instructions of the controller to drive the camera unit, characterized in that for driving the camera unit. The method of claim 6, And the clock providing unit changes the main clock into the power saving clock and provides it to the camera unit according to an instruction of the controller.

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