JP3950873B2 - Mobile communication terminal with camera - Google Patents

Description

  The present invention relates to a camera-equipped mobile communication terminal such as a mobile phone having a camera and an incoming lamp for imaging a subject.

  Usually, when carrying a mobile phone, it is often stored in a closed space such as a bag or a pocket of clothes, and in such a storage state, it is required to perform control according to the situation.

  In recent years, since mobile phones with cameras have become widespread, Patent Document 1 (Japanese Patent Laid-Open No. 2000-184013) determines ambient brightness based on an imaging signal from a camera unit, and uses this determination signal as the determination signal. Based on this, a technique is disclosed in which the ringing tone level is controlled, the ringing tone level is reduced when the surroundings are bright, and the ringing tone level is increased when the surroundings are dark, for example, in a bag or a pocket of clothes.

  That is, in this prior art, when an incoming call by a sounder is selected at the time of an incoming call, the image pickup signal obtained by the solid-state image pickup device of the camera unit is input to the luminance detection unit under the control of the control unit. Based on, the ambient brightness level is detected. Next, the level detected by the luminance detection unit is compared with a reference level preset in the control unit by a comparator. If the comparator determines that the ambient brightness is above the reference, the control unit controls the incoming signal output to the sounder to be small. If the ambient brightness is determined to be less than the reference, the control is performed. The incoming signal output from the unit to the sounder is controlled so as to be transmitted at the initially set level.

However, according to this, since the camera unit simply picks up the image and determines the brightness of the surroundings based on whether the luminance of the image pickup signal is above or below the reference, the mobile phone can Whether it is stored in an enclosed space or in an open space in the dark cannot be identified, and even in an open space in the dark, the ringer level may increase unintentionally and disturb the surroundings .
JP 2000-184013 A

  An object of the present invention is to identify whether a mobile communication terminal such as a mobile phone is stored in a closed space such as a bag or a pocket of clothes, or in an open space in the dark, and a dedicated part is added. Without being able to determine the surrounding environment using a camera and an incoming lamp.

The present invention provides a camera-equipped mobile communication terminal having a camera and an incoming lamp for imaging a subject, a threshold value table for storing threshold values in a plurality of steps, and luminance information when the incoming lamp is turned on from image data of the camera. Luminance information extracting means for extracting, and ambient environment determining means for determining the surrounding environment by comparing the extracted brightness information with a threshold value stored in a threshold value table .

The preferable form is as follows.
The luminance information extracting means activates the camera after receiving the incoming signal, and extracts luminance information when the incoming lamp is turned on.

  The luminance information extracting means extracts a difference value between the luminance information at the time of lighting and the luminance information at the time of extinction in the blinking operation of the incoming lamp, and the surrounding environment determining means compares the difference value with a preset threshold value. To determine the surrounding environment.

  The luminance information extracting means synchronizes the extraction timing of the luminance information when the incoming lamp is turned on and the timing of extracting the luminance information when the incoming lamp is turned off with the timing of the image acquisition cycle of the camera.

  The luminance information extracting means extracts the luminance information when the incoming lamp is turned on and the luminance information when the incoming lamp is turned off at a time delayed from the lighting start time and the turn-off start time, respectively.

It has a threshold value table for storing the threshold value corresponding to the emission color of the incoming lamp, the environment determination means, for selecting a threshold value corresponding to the emission color of the incoming lamp from among the threshold table.

The luminance information extraction unit stops the camera after acquiring the image data from the camera .

In the present invention, the brightness information when the incoming lamp is turned on is extracted from the image data of the camera, and the ambient information is determined by comparing the extracted brightness information with a preset threshold value. Therefore, it is possible to identify whether the mobile communication terminal is housed in a closed space such as a bag or a pocket of clothes or in an open space in the dark. By using the determination result, it is possible to realize operation control at the time of incoming call suitable for the environment, such as ringtone control and backlight control. In addition, since a plurality of levels of threshold values are stored in the threshold value table and the luminance information is compared with the threshold values of a plurality of levels to determine the surrounding environment, the surrounding environment can be determined in multiple steps.

  When the camera is activated after receiving the incoming signal and the brightness information is extracted when the incoming lamp is lit, the camera is automatically activated when the incoming signal is received, and the brightness is obtained from the captured image data when the incoming lamp is lit. Information can be extracted automatically.

  By extracting the difference value between the brightness information at the time of lighting and the brightness information at the time of extinction in the blinking operation of the incoming call lamp, and comparing the difference value with a preset threshold value, the surrounding environment can be determined accurately and in detail. .

  If the extraction timing of the brightness information when the incoming lamp is turned on and off, and the timing of the image acquisition cycle of the camera are synchronized, the luminance information adapted to the operating characteristics of the incoming lamp and the camera Extraction is possible.

  If the luminance information when the incoming lamp is turned on and the luminance information when the light is turned off are extracted after the lighting start time and the light emission start time, respectively, luminance information corresponding to the exposure time of the camera can be extracted.

When image data is acquired from a camera to extract luminance information and then the camera is stopped, power consumption for ambient environment determination can be suppressed as much as possible .

  If the threshold value corresponding to the light emission color of the incoming lamp is stored in the threshold table, and the threshold value corresponding to the light emission color of the incoming lamp is selected from the threshold value, the judgment of the surrounding environment is the same even if the light emission color of the incoming lamp is different Can be done.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an outline of a first embodiment of the present invention applied to a mobile phone.
The cellular phone includes an antenna 102, a wireless unit 101, a control unit 110, a memory unit 111, an operation unit 112, a display unit 113, an operation unit backlight 114, a camera 115, an incoming call LED 116 which is an incoming call lamp, and an audio codec unit 117. The display unit backlight 118, the speaker 120, and the microphone unit 121 are included.

  This camera-equipped mobile phone communicates with a base station (not shown) via the wireless unit 101 and the antenna 102 under the control of the control unit 110. Radio section 101 selects a signal frequency to be received from a signal received by antenna 102, performs frequency conversion, amplifies, demodulates, and outputs received data to control section 110. The control unit 110 processes the received data and outputs an audio signal to the audio codec unit 117. The audio codec unit 117 changes the audio signal to an analog signal and outputs audio from the speaker 120. The audio input from the microphone unit 121 is A / D converted into a PCM signal by the audio codec unit 117, and the control unit 110 processes the signal into transmission data, modulates it by the radio unit 101, and defines it. And is transmitted from the antenna 102.

  The control unit 110 controls lighting of the operation unit backlight 114, the display unit backlight 118, and the incoming LED 116, registration of image data captured by the camera 115 in the memory unit 111, and extraction of luminance information from the image information, Information is written to and read from the memory 111, display control of the display unit 113, operation detection processing of the operation unit 112, and the like are performed. In addition, the control unit 110 performs image processing in normal camera shooting on the captured image data acquired from the camera 115, stores the image data in the memory 111, and extracts luminance information from the image data in the surrounding environment detection operation. The surrounding environment is determined by making a comparison with a detection luminance threshold table and a detection luminance difference determination threshold registered in advance in the memory 111.

The operation unit backlight 114 and the display unit backlight 118 are lit to improve the visibility of the operation unit 112 and the display unit 113 for the operator under the control of the control unit 110. The incoming LED 116 is controlled to be turned on and off by the control unit 110 in synchronization with camera imaging during the ambient environment detection operation as described below.
The camera 115 outputs an image obtained by imaging the subject to the control unit 110 as image data.

Next, the operation of this mobile phone will be described using the flowchart of FIG.
The control unit 110 monitors whether or not the wireless unit 101 has received an incoming signal from a base station (not shown) (step S200). When receiving the incoming signal, the control unit 110 activates the camera 115 (S201). The incoming LED 116 starts blinking (S202). Here, after confirming reception of the image data output from the camera 115, the control unit 110 performs blinking of the incoming LED 116 in synchronization with the acquisition timing of the camera. FIG. 5 shows an example of the blinking cycle of the incoming LED 116 and the camera image acquisition timing. The incoming LED 116 is turned on / off every 4 frames of the camera image acquisition cycle. This blinking cycle is generated from the image capture cycle of the camera 115. Alternatively, the image capturing period of the camera 115 is matched with the blinking period of the incoming LED 116.

  In the example of FIG. 5, taking the exposure time of the camera 115 into consideration, the image capture when the incoming LED 116 is turned on is delayed from the lighting start time, so the camera image acquisition cycle is, for example, the fourth frame, and the incoming LED 116 is turned off. Since the image capture is delayed from the start time of turning off, the fourth frame is also set as the camera image acquisition cycle. The blinking cycle of the incoming LED 116 is arbitrary after image data acquisition.

  The control unit 110 confirms the lighting timing of the incoming LED 116, acquires image data when the incoming LED 116 is extinguished (S203), extracts luminance information from the acquired image, and stores it (S204). As a method for extracting luminance information, a method using an average value of one image or a maximum luminance value in all pixels can be considered, and an optimum method is adopted in consideration of conditions such as camera / incoming LED arrangement.

  Next, in order to determine the luminance value of the extracted luminance information, the extracted luminance information is compared with each threshold value in the incoming LED extinction detection luminance threshold value table (hereinafter simply referred to as a threshold value table) stored in the memory 111 in advance.

  FIG. 3 shows an example of the threshold table. As shown in the figure, threshold values are set in several stages, and among them, for example, a luminance value that is the upper limit of ambient environment detection is set as the threshold value with the highest luminance.

  The extracted luminance information is first compared with the threshold A having the highest luminance value set in the threshold table (S205). If the extracted luminance value is greater than A, the determination of the luminance value is stopped, the camera 115 is stopped (S213), the surrounding environment is determined not to be an enclosed space, and the surrounding environment detection process is completed (S214). .

  If the extracted luminance value is A or less, the determination of the luminance value is continued, the comparison with each threshold value in the threshold value table is sequentially performed, and the luminance range is obtained (S206). A luminance difference determination threshold is determined based on the luminance range obtained here (S207).

  The luminance difference determination threshold value is a determination threshold value that is stored in advance in the memory 111 and used to determine the surrounding environment. The luminance information in the previously acquired incoming LED extinguishing condition and the incoming LED lighting condition to be acquired from now on. It is a threshold value for comparing and determining the difference value with the luminance information.

  FIG. 4 is an example of a luminance difference determination threshold value. In the closed space, the amount of difference with the luminance information of the reflected light under the incoming LED lighting condition changes greatly depending on the luminance information under the incoming LED lighting condition, that is, the ambient illuminance, and the difference amount decreases as the ambient illuminance increases. Is self-explanatory. Therefore, it is desirable that the luminance difference determination threshold has several levels as shown in FIG. 4, and which value is used for the determination of the surrounding environment is the magnitude of the luminance information acquired under the incoming LED extinction condition. It is determined by the size.

  Next, in order to acquire luminance information when the incoming LED 116 is lit, the control unit 110 checks the lighting timing of the incoming LED 116, acquires image data (S208), and stops the camera 115 (S209). Luminance information is extracted from the image data (S210). The extraction method is as described above. The camera 115 is unnecessary and is stopped (S209), but the stop timing is arbitrary.

  Subsequently, the control unit 110 analyzes the surrounding environment from the acquired luminance information. The surrounding environment is determined using the acquired luminance information and the luminance difference determination threshold. The difference between the luminance value acquired under the incoming LED turn-off condition and the luminance value acquired under the incoming LED lighting condition is calculated and compared with a predetermined luminance difference determination threshold (S211). If the calculated luminance difference is smaller than the threshold value, it is determined that the surrounding environment is not an enclosed space and the surrounding environment detection process is completed (S214). The detection process is completed (S212).

  Cameras used in mobile phones generally have automatic gain control and automatic exposure control to keep the brightness value constant according to the amount of received light, and these functions are used effectively during normal camera shooting. However, in the case of the use in the present invention, since expected information cannot be obtained by these functions, it is desirable to make adjustments such as disabling the functions.

Next, a second embodiment of the present invention will be described.
Example 2 shows the case where the incoming LED 116 has a plurality of emission colors.
About a structure, it is equivalent to Example 1. FIG. In the case of having a plurality of emission colors, the threshold table and the detected luminance difference determination threshold table shown in FIGS. 3 and 4 of the first embodiment are replaced with the threshold table and the detected luminance difference determination threshold table of FIGS. 6 and 7 are a threshold value table and a detected luminance difference determination threshold value table when there are three emission colors, which are stored in the memory 111 in advance as tables corresponding to the three emission colors. A table corresponding to the case of having four or more colors is assumed.

The operation is basically the same as that of the first embodiment. However, the difference from the first embodiment is that the threshold value table and the detected luminance difference determination threshold table shown in FIGS. The threshold value table to be referred to and the detected luminance difference determination threshold value table are switched in accordance with the lighting color of the incoming LED that is stored in the memory 111 in advance according to the light emission luminance and is turned on during the incoming call operation.
Thereby, even in a mobile phone having a plurality of incoming LEDs that can emit light, the same effect as in the first embodiment can be obtained.

  The embodiment in which the present invention is applied to a camera-equipped mobile phone has been described above, but the present invention is also applicable to other portable communication terminals such as a camera-equipped portable information terminal having a communication function.

It is a block diagram of a mobile phone to which the present invention is applied. 3 is a flowchart showing the operation of the first embodiment. It is a table | surface figure of an example of the threshold value table in Example 1. FIG. It is a table | surface figure of an example of a brightness | luminance difference determination threshold similarly. It is a timing chart which shows the relationship between the blinking period of incoming LED and the acquisition period of a camera image. FIG. 10 is a table of an example of a threshold value table in the second embodiment. It is a table | surface figure of an example of a brightness | luminance difference determination threshold similarly.

Explanation of symbols

101 Wireless unit 102 Antenna 110 Control unit 111 Memory unit 112 Operation unit 113 Display unit 114 Operation unit backlight 115 Camera 116 Incoming LED
117 Audio codec unit 118 Display unit backlight 120 Speaker 121 Microphone unit

Claims (7)

In a camera-equipped mobile communication terminal having a camera and an incoming lamp for imaging a subject,
A threshold value table for storing a plurality of threshold values; luminance information extracting means for extracting luminance information when the incoming lamp is turned on from the image data of the camera; and the extracted luminance information stored in the threshold table. A mobile communication terminal with a camera, comprising: an ambient environment determination unit that determines an ambient environment by comparing with a plurality of threshold levels .   The camera-equipped mobile communication terminal according to claim 1, wherein the luminance information extracting means activates the camera after receiving the incoming signal and extracts the luminance information when the incoming lamp is turned on. The luminance information extraction unit extracts a difference value between the luminance information at the time of lighting and the luminance information at the time of extinction in the blinking operation of the incoming lamp, and the surrounding environment determination unit calculates the difference value as a threshold value for luminance difference determination. The camera-equipped mobile communication terminal according to claim 1, wherein the surrounding environment is determined by comparing the threshold value with a threshold value stored in the detected luminance difference determination threshold value table .   4. The camera-equipped mobile phone according to claim 3, wherein the luminance information extracting means synchronizes the extraction timing of the luminance information when the incoming lamp is turned on and the timing of extracting the luminance information when the incoming lamp is turned off and the timing of the image acquisition cycle of the camera. Communication terminal.   4. The luminance information extracting unit performs extraction of luminance information when the incoming lamp is turned on and luminance information when the incoming lamp is turned off at a time delayed from a lighting start time and a light turning off time, respectively. Mobile communication terminal with camera. A threshold table is provided for storing a threshold value corresponding to the light emission color of the incoming lamp, and the ambient environment determining means selects a threshold value corresponding to the light emission color of the incoming lamp from the threshold table. Item 6. A mobile communication terminal with a camera according to Item 1, 2, 3, 4 or 5 . 6. The camera-equipped mobile communication terminal according to claim 1, wherein the luminance information extraction unit stops the camera after acquiring image data from the camera.

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