KR100613567B1 - Wireless communication terminal and method with appropriate exposure of built-in flash - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a wireless communication terminal having a flash proper exposure function and a method thereof.

2. The technical problem to be solved by the invention

According to the present invention, when photographing an image using a camera provided in a wireless communication terminal including a flash, the illumination information of an environment in which a subject exists is detected to control on / off of a flash (light emitting unit), and the illumination information And inputting exposure information corresponding to the light emission environment of the flash unit into the illuminance information detection unit to capture an image in a situation in which the exposure environment of the illuminance information detection unit is reset, thereby reducing noise and depending on the brightness around the subject when the flash is driven. An object of the present invention is to provide a wireless communication terminal having a flash proper exposure function and a method for obtaining an appropriately exposed image.

3. Summary of Solution to Invention

According to the present invention, in a wireless communication terminal having a flash proper exposure function, in the state in which the automatic exposure control function is set by the control of the central processing means, the illumination information of the surrounding environment of the subject for the subject image acquired through the preview mode is detected. Illuminance information detecting means; Input means for receiving an image capturing instruction signal; Light emitting means for generating light under control of the central processing means; And analyzing the illumination information detected by the illumination information detecting means when receiving the image photographing instruction signal from the input means, and determining that the light emitting means is driven when the illumination information satisfies a preset light emission driving condition. And the central processing means for photographing a subject image while driving the light emitting means in a state where the illumination information detecting means is set to exposure information corresponding to a corresponding threshold value range when belonging to a preset specific threshold range. .

4. Important uses of the invention

The present invention is used for a wireless communication terminal equipped with a camera.

Illuminance Information, Proper Exposure, Exposure Environment, Exposure Information

Description

Wireless communication terminal having flash proper exposure function and its method {Wireless communication terminal and method with appropriate exposure of built-in flash}             

1 is a block diagram of an embodiment of a wireless communication terminal having a flash proper exposure function according to the present invention.

Figure 2 is an embodiment of a flash implementation circuit with a proper exposure function in accordance with the present invention.

3 is a flow chart of an embodiment of a flash proper exposure method in a wireless communication terminal according to the present invention.

4 is a diagram illustrating an embodiment of updating exposure information of FIG. 3;

* Explanation of symbols for the main parts of the drawings

100: wireless transmission and reception unit 110: codec

120: storage unit 130: voice input unit

140: audio output unit 150: display unit

160: input unit 170: illumination information detection unit

180: flash charge pump 190: flash

200: main processor 210: back-end chipset unit

220: MSM

The present invention relates to a wireless communication terminal having a flash proper exposure function and a method thereof, and more particularly, to control on / off of a flash (light emitting unit) by analyzing illuminance information of a surrounding environment of a subject detected by an illuminance information detecting unit. The exposure information may be input to the illumination information detection unit so as to correspond to the illumination information of the illumination information and the flash (light emitting unit) to capture an image while resetting the exposure environment of the illumination information detection unit to obtain an appropriately exposed image. A wireless communication terminal having a flash proper exposure function and a method thereof are provided.

In the present invention, a wireless communication terminal is a mobile communication terminal, a personal portable terminal (PCS), a personal digital terminal (PDA), a smart phone, a next generation mobile communication terminal (IMT-2000), wireless communication such as a wireless terminal while carrying the individual Say possible terminal.

Advantages of the wireless communication terminal may be various, but above all, it is said that the greatest advantage is in the mobility provided to the user who is calling. Due to this mobility, the number of wireless communication subscribers has increased exponentially, and in recent years, wireless communication terminals are widely used by the general public.

As the number of users of wireless communication terminals increases, users of wireless communication terminals hope that the wireless communication terminals provide more additional functions. In response to these demands, camera phones have recently been released and are becoming explosive among users. In particular, wireless communication terminals equipped with ultra-compact digital cameras have enjoyed a lot of popularity due to the convenience of taking pictures and sending them immediately to the desired party. Because of the development of camera technology, image quality is approaching the level of general digital cameras. In the future, digital cameras along with color liquid crystal displays (LCDs) are expected to become essential items for wireless communication terminals.

However, most of the wireless communication terminals equipped with such cameras do not include a flash function, so it is not only possible to take pictures at night or in dark places, but also to take pictures in a place where the amount of light is low even in a lighted room. There was a problem that the image quality is poor.

In addition, even if a flash is mounted, the flash control is performed using an illuminance sensor or exposure information obtained as a result of automatic exposure control of an image sensor.

However, the method of using the illuminance sensor is not an effective method in the wireless communication terminal which is miniaturized due to the increase in the cost and the increase of the occupied area due to the addition of parts.

Therefore, most image sensor companies use the method of controlling the flash by using the illumination information available from the image sensor instead of the illumination sensor, which reduces the area of occupancy and the cost, but the illumination in the existing exposure environment. Since only the information is used to drive the flash to shoot an image, a large amount of light is instantaneously input to the image sensor, resulting in an excessively bright image and an increase in noise.

Korean Patent Laid-Open Publication No. 10-2003-0056113 discloses a contrast detecting unit for detecting contrast around an object in which a photographing object is located, a light emitting unit for instantaneously generating a constant intensity of light, and according to a user's instruction. The present invention relates to a mobile communication terminal including a control unit for controlling the light emission of the light emitting means and a photographing unit for capturing an image of an object according to control.

However, the above-described prior art also suggests only a method of controlling ON / OFF of the flash according to ambient illumination, but does not suggest a method of obtaining a properly exposed image in a light emitting environment in which the flash is driven.

The present invention has been proposed to solve the above problems, and when photographing an image using a camera provided in a wireless communication terminal including a flash, the illumination information of the environment in which the subject is present is detected to turn on the flash (light emitting unit). By controlling the on / off and inputting the exposure information set to correspond to the illumination information and the light emitting environment of the flash, the image is taken in a situation in which the exposure environment of the illumination information detection unit is reset, thereby reducing the noise and It is an object of the present invention to provide a wireless communication terminal having a flash proper exposure function and a method thereof to obtain an image properly exposed according to the brightness around a subject when driven.

The apparatus of the present invention for achieving the above object is, in a wireless communication terminal having a flash appropriate exposure function, the automatic exposure control function is set by the control of the central processing means, the subject image obtained through the preview mode Illuminance information detecting means for detecting illuminance information of an environment surrounding a subject; Input means for receiving an image capturing instruction signal; Light emitting means for generating light under control of the central processing means; And analyzing the illumination information detected by the illumination information detecting means when receiving the image photographing instruction signal from the input means, and determining that the light emitting means is driven when the illumination information satisfies a preset light emission driving condition. And the central processing means for photographing a subject image while driving the light emitting means in a state where the illumination information detecting means is set to exposure information corresponding to a corresponding threshold value range when belonging to a preset specific threshold range. .

On the other hand, the method of the present invention, in the flash appropriate exposure method in a wireless communication terminal, detecting the illumination information of the surrounding environment of the subject to the subject image obtained through the preview mode, with the automatic exposure control function is set; Determining that the light emitting means is to be driven when the detected illuminance information satisfies a predetermined light emission driving condition when the image photographing instruction signal is input in the state of detecting the illuminance information; Setting the exposure information corresponding to a corresponding threshold range when the detected illuminance information belongs to a predetermined threshold range while determining driving of the light emitting means; And photographing a subject image while driving the light emitting means while the exposure information is set.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing an embodiment of a wireless communication terminal having a flash proper exposure function according to the present invention.

As shown in FIG. 1, a wireless communication terminal having a flash proper exposure function according to the present invention includes a wireless transmitter / receiver 100, a codec 110, a storage unit 120, a voice input unit 130, and a voice output unit ( 140, a display unit 150, an input unit 160, an illuminance information detector 170, a flash charge pump 180, a light emitting unit 190, and a main processor 200.

The wireless transmitter / receiver 100 plays a role of transmitting and receiving a signal wirelessly through an antenna.

The codec 110 converts a signal received from the wireless transmitter / receiver 100 into voice and outputs it to the voice output unit 140 under the control of the main processor 200, and outputs the voice input unit 130. It converts the voice received from the signal into a signal and delivers it to the main processor 200 to be transmitted through the wireless transmitter and receiver 100.

The storage unit 120 stores a program for driving the wireless communication terminal, a file system (image, character, icon), photographed image data, and the like.

The voice input unit 130 receives a voice and delivers it to the codec 110, and the voice output unit 140 outputs the voice received from the codec 110.

In addition, the display unit 150 serves to display a screen (preview screen, etc.) that can be recognized by the user of the wireless communication terminal under the control of the main processor 200.

The input unit 160 activates an image capturing instruction signal for capturing an image of a subject by a user's selection, and outputs the activated image capturing instruction signal to the main processor 200.

The illuminance information detector 170 acquires an image of an environment in which a subject exists in real time by exposure information or an automatic exposure control function in a camera preview mode, and detects illuminance information of the image acquisition environment.

At this time, the illumination information detection unit 170 may use an image sensor built in a camera device of a conventional wireless communication terminal as an embodiment, but is not limited thereto.

The flash charging pump 180 receives the light emitting unit driving signal generated by the main processor 200 to charge the light emitting unit.

On the other hand, the light emitting unit 190 serves to instantaneously generate the light of the intensity corresponding to the charging current applied from the flash charging pump 180.

The main processor 200 drives and controls the wireless communication terminal, and controls the on / off of the light emitting unit 190 by analyzing the illumination information as the image photographing instruction signal is received from the input unit 160, The illuminance information and exposure information set to correspond to the light emitting environment of the light emitting unit 190 are transmitted to the illuminance information detecting unit 170 to reset the exposure environment of the illuminance information detecting unit 170.

Here, when it is determined that the illuminance information received from the illuminance information detecting unit 170 is below a threshold condition for driving the light emitting unit 190, the main processor 200 outputs a light emitting unit driving signal, and the illuminance information detecting unit ( When the exposure environment of 170 is reset, the illumination information detection unit 170 captures the captured image data and stores the captured image data in the storage unit 120.

However, the main processor 200 does not drive the light emitting unit 190 when the illuminance information received from the illuminance information detecting unit 170 exceeds a threshold condition for driving the light emitting unit 190, and the illuminance information detecting unit ( The image data captured by the illuminance information detector 170 in the current exposure environment of 170 is captured and stored in the storage 120.

The operation of the wireless communication terminal having the flash proper exposure function of the present invention will be described in detail with reference to FIG.

First, when the illuminance information detector 170 receives illuminance information of an environment in which an object to be photographed exists in real time and transmits the illuminance information to the mobile station modem 220 via the back end chipset unit 210, the MSM ( In order to control the on / off of the flash, 220 determines whether the illuminance information is below a threshold condition for popping the light emitting unit 190.

As a result of the determination, if the illuminance information is less than or equal to the threshold condition, the MSM 220 applies the light emitting unit driving signal to the flash charge pump 180, and if the illuminance information exceeds the threshold condition, emits the light emitting unit driving signal. It is not applied to the flash charge pump 180.

Subsequently, when the light emitting unit driving signal is applied to the flash charging pump 180, the MSM 220 receives illuminance through the back end chipset unit 210 and sets exposure information corresponding to the light intensity information and the light emitting environment. The information detector 170 transmits the information.

At this time, the back end chipset unit 210 applies an enable signal to a flash (light emitting unit) driving switch located at the output terminal of the light emitting unit 190 to instantaneously emit light corresponding to the charging current output from the flash charging pump 180. To generate the flash 190.

As described above, the flash 190 emits light after the illumination information detecting unit 170 sets a new exposure environment. At this time, the image of the subject is photographed to capture an image in the exposure environment suitable for the illumination information and the light emission environment. Can be captured.

3 is a flowchart illustrating a flash proper exposure method in a wireless communication terminal according to an embodiment of the present invention, wherein the illumination information detecting unit 170 acquires an image of an environment in which an object exists in a camera preview mode in real time. The operation process until the new exposure environment of the illuminance information detection unit 170 is set is shown.

First, in the camera preview mode, the illumination information detection unit 170 acquires an image of an environment in which an object exists in real time according to an exposure environment setting by an automatic exposure control function (310).

Thereafter, the illuminance information detector 170 detects illuminance information on the environment (image acquisition environment) in which the subject exists and transmits the illuminance information to the main processor 200 (320).

In this case, the illuminance information refers to a clock rate (vertical synchronization, horizontal synchronization) that determines the frame rate of the image or the frame rate that can be obtained by the automatic exposure control function of the illumination information detection unit 170.

Thereafter, when the image capturing instruction signal for capturing the image of the subject is activated through the button of the input unit 160, the activated image capturing instruction signal is transmitted to the main processor 200 (330).

Thereafter, the main processor 200 determines whether the illuminance information received from the illuminance information detector 170 is less than or equal to a threshold condition for driving the light emitter 190 (340).

As a result of the determination, if the illuminance information exceeds the threshold condition for driving the light emitting unit 190, the light emitting unit 190 is not driven. Thus, the process ends with maintaining the exposure environment setting by the automatic exposure control function. Proceeds to 350.

However, as a result of the determination, if the illuminance information is less than or equal to a threshold condition for driving the light emitting unit 190, the illuminant information is analyzed and transmitted to the flash charging pump 180 by transmitting the light emitting unit driving signal (360). The exposure information set to correspond to the information and the light emitting environment is transmitted to the illumination information detecting unit 170 (361).

Here, the exposure information update step 352 of FIG. 3 will be described in detail with reference to FIG. 4.

First, in operation 410, a range within which a periodic time of a vertical synchronous clock signal V _sync determines a frame length of an image acquired by the illumination information detection unit 170, which is one of the illumination information, belongs. Here, the cycle time of the vertical synchronization clock, which is one of the illumination information, may be divided into three arbitrary ranges, but is not limited thereto.

At this time, V _sync means the period of the vertical synchronization clock, T_ _flash means the period of the shortest clock at which the flash starts to operate, and T_ ₁ , T_ ₂ , and T_ ₃ indicate the period of the clock that is arbitrarily designated for setting exposure information. do.

In addition, the range of the vertical synchronization clock can be more finely divided than in three cases, it can be reduced more simply.

Afterwards, the exposure information (exposure information_) of the camera register (not shown) of the illumination information detection unit 170 corresponds to the determined range (T_ _flash to T_ ₁ , T_ ₁ to T_ ₂ or T_ ₂ to T_ ₃ ). 1, either exposure information_2 or exposure information_3) is set (421 to 423), and the set exposure information is transmitted to the illumination information detecting unit 170 (430), and the illumination information detecting unit 170 performs the illumination. The exposure environment is reset to correspond to the information and light emission environment.

Meanwhile, in the operation process of FIG. 3, the illuminance information detecting unit 170 detects illuminance information on the environment in which the subject exists and transmits the illuminance information to the main processor 200 and the input unit 160 via a button. The process 330 of receiving an image capturing instruction signal for capturing an image of a subject and transmitting the image capturing instruction signal to the main processor 200 may be changed according to the image capturing process preset in the wireless communication terminal.

In addition, if the illuminance information is less than or equal to a threshold condition for driving the light emitting unit 190 during the operation of FIG. 3, the main processing unit 200 analyzes the illuminance information and outputs a light emitting unit driving signal to the flash charge pump 180. In step 360 of transmitting the illumination information and exposure information set to correspond to the illumination information and the light emitting environment to the illumination information detecting unit 170, the order 361 is performed according to a control process preset in the wireless communication terminal. May change.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

According to the present invention, when photographing an image using a camera provided in a wireless communication terminal including a flash, the illuminance information detecting unit analyzes the illuminance information of the environment in which the subject is detected and turns on the flash (light emitting unit). Controlling on / off has the effect of reducing the footprint and cost.

In addition, the present invention as described above, by inputting the exposure information set to correspond to the illuminance information and the light emitting environment of the flash unit to the illumination information detection unit to shoot the image in the situation of resetting the exposure environment of the illumination information detection unit, to reduce the noise during shooting There is an effect that can be obtained, and an appropriately exposed image can be obtained according to the brightness around the subject when the flash is driven.

Claims (5)

In a wireless communication terminal having a flash proper exposure function, Illuminance information detecting means for detecting illuminance information of the surrounding environment of the subject with respect to the subject image acquired through the preview mode while the automatic exposure control function is set by the control of the central processing means; Input means for receiving an image capturing instruction signal; Light emitting means for generating light under control of the central processing means; And When the image photographing instruction signal is input from the input means, the illuminance information detected by the illuminance information detecting means is analyzed, and when the illuminance information satisfies a predetermined light emission driving condition, it is determined to drive the light emitting means. The central processing means for photographing a subject image while driving the light emitting means while the illuminance information detecting means is set to exposure information corresponding to the corresponding threshold value range when the value falls within a specific threshold range; Wireless communication terminal having a flash appropriate exposure function comprising a. The method of claim 1, The illumination information is a wireless communication terminal having a flash appropriate exposure function, characterized in that the period of the vertical synchronization clock signal (V _sync ) that determines the frame length of the subject image. In the flash appropriate exposure method in a wireless communication terminal, Detecting illuminance information of the surrounding environment of the subject with respect to the subject image acquired through the preview mode while the automatic exposure control function is set; Determining that the light emitting means is to be driven when the detected illuminance information satisfies a predetermined light emission driving condition when the image photographing instruction signal is input in the state of detecting the illuminance information; Setting the exposure information corresponding to a corresponding threshold range when the detected illuminance information belongs to a predetermined threshold range while determining driving of the light emitting means; And Photographing a subject image while driving the light emitting means in a state where the exposure information is set; Flash appropriate exposure method in a wireless communication terminal comprising a. The method of claim 3, wherein The illuminance information is a flash exposure method of a wireless communication terminal, characterized in that the period of the vertical synchronization clock signal (V _sync ) for determining the frame length of the subject image. The method according to claim 3 or 4, And the exposure information includes different exposure values according to the length of the period of the vertical synchronization clock signal (V _sync ), which determines the frame length of the subject image.

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