JP2003289473A - Mobile terminal equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide mobile terminal equipment which can be much more improved in image quality obtained by flash photographing, without the use of a large scale circuit. <P>SOLUTION: A camera light receiving amount detection function 17d detects a luminous quantity received by a camera, an electronic shutter timing control function 17c compares detection data of the received luminous quantity with preset reference data and sets a timing of an electronic shutter so as to bring the difference to zero, and operating the electronic shutter in the set timing can open the shutter on the way when a flush is lighted. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile phone, a personal digital assistant (PDA), a PH.
The present invention relates to a mobile terminal device such as an S (Personal Handyphone System) terminal, and particularly to a mobile terminal device having a camera function and a flash function.

[0002]

2. Description of the Related Art In recent years, mobile phones, personal digital assistants, PH
Mobile terminal devices represented by S terminals and the like are rapidly spreading, and as one of them, mobile terminal devices having a camera function and a flash function have been developed. This type of mobile terminal device has, for example, a CCD (Cha
rge Coupled Device) and CMOS (Complementary MetalO)
xide Semiconductor) is attached to a camera, and still images captured by this camera are recorded or transmitted. For example, the user's face and surrounding scenery, pamphlets, photographs, catalogs, etc. Can be sent to the communication partner as image information, which is very convenient. However, in general, the number of elements and sensitivity of a camera are limited due to the size and price of the mobile terminal device,
It is difficult for the camera alone to obtain an image of satisfactory quality at night or in a dark room. Therefore, in order to improve this point,
Recently, a mobile terminal device equipped with a flash function has been developed. When this type of terminal device is used, an image having a certain quality can be taken by using the flash function at the time of shooting at night or in a dark room.

Generally, in order to make a flash emit light,
Electric charges are accumulated in a capacitor provided inside the flash unit, and in this state, for example, a switch of a transistor is turned on in response to a shutter operation, so that the electric charge accumulated in the capacitor is flashed with high brightness such as a xenon lamp. It is designed to be discharged by a lamp.

[0004]

The amount of light emitted during flash emission depends on the capacity of a capacitor provided in the flash unit. Therefore, the flash light amount is necessarily constant. If the amount of light is constant, the distance between the camera and the subject when the flash fires will be limited.
As a method of changing the flash light amount according to the distance to the subject, a high-speed and large-capacity switching element such as an IGBT (Insulated Gate) is used instead of the transistor.
It is possible to use a bipolar transistor. However, since a flash unit using an IGBT generally has a large circuit scale, it is not suitable for a portable terminal device that requires further miniaturization.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a portable terminal device capable of further improving the image quality by flash photography without using a large-scale circuit. To do.

[0006]

In order to achieve the above object, a first invention is a portable terminal device having a built-in camera and a flash, which generates an electronic shutter signal for driving a shutter of the camera. A shutter signal generation means, a light emission signal generation means for generating a flash light emission signal for causing the flash to emit light, and a timing control means for adjusting the amount of light received by the camera are provided. Then, by this control means, at least one of the generation timing of the electronic shutter signal by the shutter signal generation means and the generation timing of the flash light emission signal by the light emission signal generation means is varied to adjust the amount of light received by the camera. It was done.

The following various configurations are conceivable as a specific configuration of the control means.

In the first configuration, the light emission timing of the flash light emission signal is fixed, and the generation timing of the electronic shutter signal is variably controlled to adjust the amount of light captured by the camera.

Therefore, according to the first configuration, if the timing of the electronic shutter is controlled so that the shutter operates during the light emission period of the flash, the light emitted from the flash after the shutter is opened is displayed on the camera. Only the light will be received. That is, it is possible to adjust the amount of light received by the flash in the camera without adjusting the amount of light emitted by the flash itself. For this reason, it is possible to adjust the amount of light received by the camera without using a large and expensive switching element such as an IGBT in the flash unit, which makes the mobile terminal device compact and capable of high-quality flash photography. Can be provided.
This effect is extremely effective in a portable terminal device in which miniaturization and weight reduction are one of the important issues.

In the second configuration, the generation timing of the electronic shutter signal is fixed, and the light emission timing of the flash light emission signal is variably controlled to adjust the amount of light captured by the camera.

Therefore, according to the second configuration, if the flash light emission timing is controlled so that the camera frame ends in the middle of the flash light emission period, the camera emits light from the flash light after the camera frame. It will not be received. That is, it is possible to adjust the amount of light received by the flash in the camera without adjusting the amount of light emitted by the flash itself. Further, similarly to the first configuration, it is possible to prevent the mobile communication terminal from becoming large.

In the third configuration, both the light emission timing of the flash light emission signal and the generation timing of the electronic shutter signal are variably controlled to adjust the amount of light captured by the camera.

Therefore, according to the third structure, if the electronic shutter and the flash emission timing are controlled so that the shutter operates and the camera frame ends in the middle of the flash emission period, the camera emits the flash emission. Of these, light is received during the period from the time the shutter is opened to the time the camera frame ends. That is, it is possible to adjust the amount of light received by the flash in the camera without adjusting the amount of light emitted by the flash itself. Further, similarly to the first and second configurations, it is possible to prevent the mobile communication terminal from increasing in size.

On the other hand, a second aspect of the present invention provides the above portable terminal device,
The camera further comprises input means for the user to input the amount of light received by the camera, and controls the timing of at least one of the electronic shutter signal and the flash light emission signal in accordance with the amount of light received that is specified and input by the input means. is there.

According to the present invention, since the amount of light received by the camera is adjusted to a value corresponding to the amount of received light designated and input by the user, an image having the brightness designated by the user can be obtained.

According to a third aspect of the present invention, the portable terminal device further comprises detection means for detecting the amount of light received by the camera,
The timing of at least one of the electronic shutter signal and the flash light emission signal is controlled according to the amount of received light detected by the detection means.

According to the present invention, even if the brightness of the subject or its surroundings changes, the amount of light received by the camera is automatically controlled so as to always be an optimum value. For this reason, it is possible to always obtain a captured image with optimum brightness even if the user does not perform the adjusting operation by himself.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a front view showing the outer appearance of a mobile communication terminal according to the first embodiment of the present invention.

This mobile communication terminal is a foldable type terminal in which an upper casing A and a lower casing B are rotatably connected by a hinge portion C, and a liquid crystal display ( An LCD 22 and a speaker (not shown) for reception are arranged, and a key input section 21 and a microphone (not shown) for transmission are arranged on the front surface of the lower housing B.

Further, a camera unit D and an antenna 1 are arranged on the upper end of the upper housing A. Of these, the camera unit D accommodates the camera 23 and the light emitting unit 27, and is rotatable with respect to the upper housing A by a rotating mechanism. This rotation mechanism allows the orientations of the camera 23 and the light emitting unit 27 to be changed according to the position of the subject, so that the user can use the display unit 22 as a finder while viewing the surrounding scenery and people, It is possible to capture an image of a document and also the face of oneself.

On the other hand, FIG. 2 is a block diagram showing a circuit configuration of a mobile communication terminal according to the first embodiment of the present invention.

In FIG. 1, a radio carrier signal sent from a base station (not shown) via a radio channel is received by an antenna 1 and then input to a receiving circuit (RX) 3 via an antenna duplexer (DUP) 2. To be done. In the reception circuit 3, the received radio carrier signal is mixed with the reception local oscillation signal output from the frequency synthesizer (SYN) 4 and frequency-converted into a reception intermediate frequency signal. The received intermediate frequency signal is sampled by the A / D converter 6 including a low pass filter and then input to the digital demodulation circuit (DEM) 7.

In the digital demodulation circuit 7, the frame demodulation and the bit synchronization for the digital received intermediate frequency signal are established, and then the digital demodulation processing is performed. The baseband digital demodulated signal obtained by this demodulation processing is input to a time division multiple access circuit (TDMA) 8, where the time slot destined for itself is separated and extracted for each transmission frame. The frame synchronization and bit synchronization information obtained in the digital demodulation circuit 7 is notified to the control circuit 17.

The digital demodulated signal output from the TDMA circuit 8 is subsequently subjected to an error correction code decoding circuit (CH-
COD) 9 and undergoes error correction decoding processing. In this error-correction-decoded digital demodulated signal,
Depending on the communication mode at that time, there are information data such as mail and call voice data. Of these, the call voice data is input to the voice code decoding circuit (SP-COD) 10 and subjected to voice decoding processing, whereby a digital received signal is reproduced. This digital reception signal is converted into an analog reception signal by the D / A converter 11 and then output from the speaker 12 via a reception amplifier (not shown). Information data such as received mail and received download data is stored in the control circuit 1.
7 and the control circuit 17 controls the memory (ME
M) 20 is stored, decrypted and displayed on the display unit 22.

On the other hand, the voice transmitted by the speaker is the microphone 1
The sound is collected by 3 and converted into a transmission signal, further amplified by a transmission amplifier (not shown) to a predetermined level, and then A
It is input to the / D converter 14. Then, the A / D converter 14 samples the signal at a predetermined sampling period, thereby converting it into a digital transmission signal composed of a sample pulse train. After the acoustic echo is canceled by an echo canceller (not shown), the digital transmission signal is input to the voice code decoding circuit (SP-COD) 10 and is voice coded here.

This voice-encoded digital transmission signal is input to an error correction code decoding circuit (CH-COD) 9 where it is error correction coded. In addition, the control circuit 17
Information data such as image data and a transmission mail output from is also input to the error correction code decoding circuit 9 and is error correction coded. The digital transmission signal output from the error correction code decoding circuit 9 is input to the TDMA circuit 8. In the TDMA circuit 8, time division multiple access (TDM
A transmission frame corresponding to the A) method is generated, and a process for inserting the digital transmission signal in the time slot assigned to the own device in the transmission frame is performed.

The digital transmission signal output from the TDMA circuit 8 is subsequently supplied to a digital modulation circuit (MOD).
15 is input. In the digital modulation circuit 15, a transmission intermediate frequency signal digitally modulated by the digital transmission signal is generated, and the transmission intermediate frequency signal is D / A.
After being converted into an analog signal by the converter 16, it is input to the transmission circuit (TX) 5. As a digital modulation method, for example, π / 4 shift DQPSK (π / 4 shif
ted, differentially encoded quadrature phase shift
keying) method is used.

In the transmission circuit 5, the modulated transmission intermediate frequency signal is mixed with the transmission local oscillation signal output from the frequency synthesizer 4, and thereby converted into a radio carrier frequency corresponding to a radio communication channel. Then, this transmission radio carrier signal is controlled to a predetermined transmission power level by a transmission power amplifier (not shown), and then transmitted from the antenna 1 to the base station (not shown) via the antenna duplexer 2.

The key input unit 21 is provided with various keys necessary for communication such as a transmission key, an end key, a plurality of function keys and a dial key, and further charges a shutter key and a flash for operating the camera 23. Equipped with a charging key for. The shutter key and charge key are
It is also possible to use each key required for the above communication by controlling software.

The display 22 is, for example, a liquid crystal display (LC
D: Liquid Crystal Display) is used to display the display data output from the control circuit 17. The display data includes not only management data such as a telephone directory and transmission / reception history, data representing the operating state of the apparatus, but also transmission / reception mail and image data.

The camera 23 is, for example, a CMOS (Compleme).
ntary Metal Oxide Semiconductor) or CCD (Charg
It uses a solid-state imaging device such as an e-coupled device) and is controlled by the control circuit 17.

The memory 20 is composed of, for example, a RAM or a flash memory, and stores a mail or download data received from a telephone directory, a terminal of a communication partner, or an information site, and at the same time, image data picked up by the camera 23 and a transmission mail. And so on.

The power supply circuit 19 charges the power supply voltage Vcc necessary for the operation of each circuit of the mobile communication terminal and the capacitor 26 of the flash circuit 24 on the basis of the output voltage of the battery 18 which is a secondary battery. Generate the required power supply voltage Vss.

By the way, this mobile communication terminal has a built-in flash circuit 24. This flash circuit 24
For example, it has a light emitting section 27 using a high voltage light emission drive type flash lamp such as a xenon lamp, and further has a transistor 25, a capacitor 26 and a power supply circuit 28 for driving the light emitting section 27 to emit light.

The power supply circuit 28 supplies the power supply voltage Vss output from the power supply circuit 19 to the capacitor 26 according to the power supply control signal supplied from the control circuit 17.

The control circuit 17 includes, for example, a microcomputer as a main control unit, and has an electronic shutter signal generation function 17a and a flash light emission signal generation function in addition to normal control functions such as a wireless access control function and a call control function. It has a function 17b, a timing control function 17c, and a camera received light amount detection function 17d.

The electronic shutter signal generating function 17a is a function for giving an electronic shutter signal to the camera 23 when the shutter for photographing the camera is pressed, and normally gives a signal at a constant timing in synchronization with the camera frame. When a timing is designated by the electronic shutter timing control function 17c described later, the electronic shutter signal is generated at the designated timing.

The flash light emission signal generation function 17b is a circuit which gives a light emission signal to the flash circuit 24 at the time of photographing by the camera when the flash mode is set, and gives a signal at a constant timing in synchronization with the camera frame.

Electronic shutter timing control function 17c
Controls the timing of the electronic shutter signal at the time of shooting when the flash mode is set. For example, the received light amount data detected by the camera received light amount detecting function 17d, which will be described later, is compared with the reference data of the optimum received light amount, which is stored in the control circuit 17 in advance, to obtain the difference. Then, the electronic shutter signal generation timing for making this difference close to zero is determined, and this timing is given to the electronic shutter signal generation function 17a.

The camera light receiving amount detection function 17d detects the light amount taken into the camera 23 for each camera frame when the flash mode is set. The received light amount data detected by this function is used for the determination process of the electronic shutter signal generation timing by the electronic shutter timing control function 17c.

Next, the camera photographing operation of the mobile communication terminal configured as described above will be described.

In the standby state, the control circuit 17 monitors the occurrence of incoming / outgoing calls and the selection operation of other functions. If an incoming or outgoing call occurs in this state, the call mode is entered.

On the other hand, if the user selects the camera mode, the control circuit 17 sets the camera mode and then starts the control. FIG. 3 is a flowchart showing the control procedure and contents of the control circuit 17 in the camera mode.

When the camera mode is set, the control circuit 1
In step 3a, 7 operates the display unit 22 as a finder to display the image data captured by the camera 23 on the display unit 22. When the user presses the shutter key without selecting the flash mode in step 3b, the process proceeds from step 3c to step 3d, and the captured image data at this point is stored in the memory 20.
When the erase operation is performed, the image data stored in the memory 20 is selectively discarded.

When the photographing control operation corresponding to one photograph is completed, the control circuit 17 determines in step 3e whether the photographing is completed. Then, in this state, when the user performs a camera mode end operation on the key input unit 21, the process proceeds to step 4f, where the camera 23 and the display unit 22 are
Stop the operation and cancel the camera mode setting. On the other hand, if the end operation of the camera mode is not performed, the process returns to step 3a to repeatedly execute the control of the camera mode described above.

On the other hand, it is assumed that the user depresses the charge key to perform flash photography while the camera mode is set. Then, the control circuit 17 detects this operation in step 3b, and thereafter starts the control of the flash mode. FIG. 4 shows the control circuit 1 in the flash mode.
7 is a flowchart showing the control procedure and contents of No. 7.

When the operation of the charge key is detected, the control circuit 1
7 is a function 17d for detecting the amount of light received by the camera
The amount of light received by the camera is detected by. The detection of the amount of light received by the camera is performed, for example, by obtaining the average of the received light levels from the received light image obtained for each frame by the camera 23. The detection data of the received light amount is temporarily stored in the memory in the control circuit 17. The received light amount may be detected by using a light receiving element dedicated to the received light amount detection instead of using the output of the camera 23.

Further, the control circuit 17 causes the display unit 22 to display a message indicating that power is being supplied in step 4b, and also generates a power supply signal in step 4c to give this signal to the power supply circuit 28. Then, the power supply circuit 28 supplies the power supply voltage Vss to the capacitor 26 to charge the capacitor 26.

When the capacitor 26 is fully charged, the feeding circuit 28 gives a charging completion signal to the control circuit 17. When this charge completion signal is detected, the control circuit 17 proceeds to step 4
The process proceeds from step d to step 4e, and a message indicating that charging is completed is displayed in place of the message indicating that the display unit 22 is supplying power.
This allows the user to know from the display unit 22 that charging has been completed.

In this state, the user presses the shutter key. Then, the control circuit 17 shifts from step 4f to step 4g and executes electronic shutter timing control. FIG. 5 is a flowchart showing the control procedure of the electronic shutter timing and its contents, and FIG. 6 is a timing chart for explaining the control operation of the electronic shutter timing.

When the control circuit 17 detects the operation of the shutter key, first, the electronic shutter timing control function 17c first detects the amount of light received by the camera one frame before detected by the function 17d for detecting the amount of received light of the camera, and the control circuit 17. In step 5a, the reference data of the optimum light amount for the image stored in advance in the memory is compared, and the difference is obtained in step 5b. Then, in step 5c, the generation timing of the electronic shutter signal for making this difference close to zero is determined.

Next, the control circuit 17 returns to the control procedure of FIG. 4, and first, at step 4h, at the timing fixed in synchronization with the camera frame, the flash light emission signal generated by the flash light emission signal generation function 17b is used in the flash circuit. Give to 24. As a result, in the flash circuit 24, the transistor 25 is turned on, the electric charge accumulated in the capacitor 26 is discharged through the light emitting section 27, and flash light is emitted. At this time, the amount of flash light is always constant because it is determined by the capacity of the condenser 26.

At the same time, the control circuit 17 first performs the electronic shutter timing control function 17 in step 4i.
The electronic shutter signal is generated from the electronic shutter signal generation function 17a at the timing determined by c, and the camera 2
Give to 3. Therefore, as shown in FIG. 6, the shutter operates during the period during which the flash is emitting light.

The camera 23 receives the optical image of the subject during the light receiving period from the time when the electronic shutter signal is given to the time when the camera frame ends. Then, the control circuit 17 captures the captured image data corresponding to the received optical image of the subject, displays the captured image data on the display unit 22, and stores the captured image data in the memory 20.

Therefore, according to the first embodiment, the electronic shutter timing is controlled so that the shutter operates in the middle of the flash emission period. Therefore, the shaded portion in FIG. The captured image data in which only the flash light amount of is reflected is obtained. Accordingly, since it is not necessary to variably control the flash emission amount itself, it is possible to obtain a captured image of appropriate brightness without using a large and expensive switching element such as an IGBT.

(Second Embodiment) FIG. 7 shows a second embodiment of the present invention.
2 is a block diagram showing a circuit configuration of a mobile communication terminal according to the embodiment of FIG. In the figure, the same parts as those in FIG. 2 are designated by the same reference numerals and detailed description thereof will be omitted.

The electronic shutter signal generating function 17e is a function of giving an electronic shutter signal to the camera 23 when the shutter for photographing the camera is pressed, and gives a signal at a constant timing in synchronization with the camera frame.

The flash light emission signal generation function 17f is a function for giving a light emission signal to the flash circuit 24 at the time of photographing when the flash mode is set, and normally gives a signal at a constant timing in synchronization with the camera frame, but will be described later. When the light emission timing by the flash light emission timing control function 17g is designated, the flash light emission signal is generated at the designated timing.

Flash emission timing control function 17g
Controls the timing of the flash light emission signal at the time of shooting when the flash mode is set. For example, the received light amount data detected by the camera received light amount detection function 17d is compared with the reference data of the optimum received light amount for the captured image stored in advance in the control circuit 17, and the difference is obtained. Then, the flash emission signal generation timing for making this difference close to zero is determined, and this timing is given to the flash emission signal generation function 17f.

With this configuration, when the user operates the shutter key while the flash mode is set, the control circuit 17 causes the step 4f as shown in FIG.
To step 4j, the flash emission timing control is executed. FIG. 9 is a flowchart showing the control procedure of the flash emission timing and its contents, and FIG. 10 is a timing chart showing the control operation of the flash emission timing.

First, the control circuit 17 causes the flash light emission timing control function 17g to store in advance in the memory in the control circuit 17 the camera light reception amount one frame before detected by the camera light reception amount detection function 17d in step 5a. The stored image is compared with the reference data of the optimum light amount, and the difference is obtained in step 5b. And
In step 5d, the generation timing of the flash light emission signal for making this difference close to zero is determined.

Next, the control circuit 17 returns to the control procedure of FIG. 8, and at the timing fixed in synchronization with the camera frame in step 4k, the electronic shutter signal generation function 17 is executed.
The electronic shutter signal generated from e is given to the camera 23. As a result, the camera 23 starts the light receiving operation of the subject image from the time when the electronic shutter signal is given. And
In this state, the control circuit 17 causes the flash light emission signal generation function 17f to generate a flash light emission signal at step 4l at the timing previously determined by the flash light emission timing control function 17g.
Give to. Therefore, the flash circuit 24 emits flash light so as to extend over two frame periods as shown in FIG.

Therefore, according to the second embodiment, since the light emission timing of the flash circuit 24 is controlled so that only the first half of the flash light emission period corresponds to the camera light receiving period, the flash light amount in the shaded portion in FIG. 10 is reflected. The captured image data thus obtained is obtained. Accordingly, since it is not necessary to variably control the flash emission amount itself, it is possible to obtain a captured image of appropriate brightness without using a large and expensive switching element such as an IGBT.

(Third Embodiment) FIG. 11 is a block diagram showing a circuit configuration of a mobile communication terminal according to the third embodiment. In the figure, the same parts as those in FIG. 2 are designated by the same reference numerals and detailed description thereof will be omitted.

The electronic shutter signal generation function 17h is a function for giving an electronic shutter signal to the camera 23 when the shutter for photographing the camera is depressed, and normally gives a signal at a constant timing in synchronization with the camera frame. Electronic shutter / flash emission timing control function 1 described later
When the timing is designated by 7j, the electronic shutter signal is generated at the designated timing.

The flash light emission signal generation function 17i is a function for giving a light emission signal to the flash circuit 24 at the time of photographing by the camera when the flash mode is set, and normally gives a signal at a constant timing in synchronization with the camera frame. When the light emission timing by the electronic shutter / flash light emission timing control function 17j described later is designated, the flash light emission signal is generated at the designated timing.

The electronic shutter / flash emission timing control function 17j variably controls each timing of the electronic shutter signal and the flash emission signal at the time of photographing when the flash mode is set.
For example, the received light amount data detected by the camera received light amount detection function 17d is compared with the reference data of the optimum received light amount for the captured image stored in advance in the control circuit 17, and the difference is obtained. Then, the generation timings of the electronic shutter signal and the flash light emission signal for making the difference close to zero are respectively determined, and the respective timings are determined by the electronic shutter signal generation function 17h and the flash light emission signal generation function 1
Give to 7i.

With such a configuration, when the user operates the shutter key in the state where the flash mode is set, the control circuit 17 causes the step 4 as shown in FIG.
The process proceeds from step f to step 4m to execute electronic shutter / flash light emission timing control. FIG. 13 is a flow chart showing the control procedure of the electronic shutter and flash light emission and its contents, and FIG. 14 is a timing chart showing the control operation of the electronic shutter and flash light emission timing.

The control circuit 17 first uses the electronic shutter / flash light emission timing control function 17j to detect the amount of camera light received one frame before detected by the camera light reception amount detection function 17d in step 5a and the control circuit 17
The reference data of the optimum light amount for the image stored in the inside is compared, and the difference is obtained in step 5b. Then, in step 5e, each generation timing of the electronic shutter signal and the flash light emission signal for making this difference close to zero is determined.

Next, the control circuit 17 returns to the control procedure of FIG. 12, and outputs the flash emission signal from the flash emission signal generation function 17i at the timing previously determined by the electronic shutter / flash emission timing control function 17j in step 4n. It is generated and given to the flash circuit 24. At the same time, the control circuit 17 generates an electronic shutter signal from the electronic shutter signal generation function 17h at the timing determined by the electronic shutter / flash emission timing control function 17j in step 4o, and gives it to the camera 23. Therefore, as shown in FIG. 14, the flash circuit 24 emits the flash so as to extend over two frame periods, and the shutter operates in the middle of the period during which the flash emits light.

The camera 23 receives the optical image of the object during the light receiving period from the time when the electronic shutter signal is given to the time when the camera frame ends. Then, the control circuit 17 displays the picked-up image data corresponding to the received optical image of the subject on the display unit 22 and the memory 2
Save to 0.

Therefore, according to the third embodiment, the timing of the electronic shutter is controlled so that the shutter operates in the middle of the flash emission period, and only the first half of the flash emission period takes the camera light receiving period. Since the light emission timing of the flash circuit 24 is controlled, the captured image data in which only the flash light amount of the shaded portion in FIG.
Accordingly, since it is not necessary to variably control the flash emission amount itself, it is possible to obtain a captured image of appropriate brightness without using a large and expensive switching element such as an IGBT.

(Other Embodiments) By providing a function for the user to specify and input a desired camera light-receiving amount from the key input unit 21, the electronic shutter timing or flash is set so that the camera light-receiving amount becomes the value specified and input by the user. The light emission timing may be controlled. In this way, it is possible to obtain a captured image with the brightness desired by the user. That is, it is possible to set the amount of received light in the manual mode.

Further, the camera is provided with a function of designating and inputting the reference data of the received light amount and a function of performing timing control based on the received light amount of the camera described in each of the first to third embodiments. The detection data of the received light amount may be compared with the reference data designated and input by the user, and the timing control may be performed based on the comparison result.

In addition, types of mobile communication terminals and their configurations,
The procedures and contents of the photographing control and the timing control can be modified in various ways without departing from the scope of the present invention.

[0076]

As described above in detail, according to the present invention, in a portable terminal device incorporating a camera and a flash, at least one of the generation timing of the electronic shutter signal and the flash emission signal is variably controlled. By doing so, it is possible to provide a mobile terminal device capable of further improving the image quality by flash photography without using a large-scale circuit.

[Brief description of drawings]

FIG. 1 is a front view showing an external configuration of a mobile communication terminal according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of a mobile communication terminal according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing a control procedure and contents of a camera mode in the mobile communication terminal shown in FIG.

4 is a flowchart showing a flash mode control procedure and its contents in the mobile communication terminal shown in FIG.

5 is a flowchart showing a control procedure of electronic shutter timing and its contents in the mobile communication terminal shown in FIG.

6 is a timing chart showing a control operation of electronic shutter timing in the mobile communication terminal shown in FIG.

FIG. 7 is a block diagram showing a circuit configuration of a mobile communication terminal according to a second embodiment of the present invention.

FIG. 8 is a flowchart showing a flash mode control procedure and its contents in the mobile communication terminal shown in FIG. 7.

9 is a flowchart showing a control procedure of flash emission timing and its contents in the mobile communication terminal shown in FIG.

10 is a timing chart showing a flash light emission timing control operation in the mobile communication terminal shown in FIG.

FIG. 11 is a block diagram showing a circuit configuration of a mobile communication terminal according to a third embodiment of the present invention.

12 is a flowchart showing a flash mode control procedure and its contents in the mobile communication terminal shown in FIG.

13 is a flowchart showing a control procedure of electronic shutter and flash emission timing in the mobile communication terminal shown in FIG. 11 and its contents.

14 is a timing chart showing a control operation of electronic shutter and flash emission timing in the mobile communication terminal shown in FIG.

[Explanation of symbols]

A ... Upper housing B ... Lower housing C ... Hinge portion D ... Camera unit 1 ... Antenna 2 ... Antenna duplexer (DUP) 3 ... Reception circuit (RX) 4 ... Frequency synthesizer (SYN) 5 ... Transmission circuit (TX) 6, 14 ... A / D converter 7 ... Digital demodulation circuit (DEM) 8 ... Time division multiple access circuit (TDMA) 9 ... Error correction code decoding circuit (CH-COD) 10 ... Speech code decoding circuit (SP-COD) 11, 16 ... D / A converter 12 ... Speaker 13 ... Microphone 15 ... Digital modulation circuit (MOD) 17 ... Control circuits 17a, 17e, 17h ... Electronic shutter signal generation function 17b, 17f, 17i ... Flash light emission signal generation function 17c ... electronic shutter timing control function 17d ... camera light receiving amount detection function 17g ... flash light emission timing control function 17j ... electronic shutter Flash light emission timing control function 18 ... Battery 19 ... Power supply circuit (POW) 20 ... Memory (MEM) 21 ... Key input section 22 ... Display section 23 ... Camera 24 ... Flash circuit 25 ... Transistor 26 ... Capacitor 27 ... Light emitting section 28 ... Power supply circuit

Continued front page    F-term (reference) 2H002 CD03 JA07                 2H053 AD03 BA78 DA03                 5C022 AA12 AB15 AB17 AC31 AC42                       AC52 AC69                 5C024 AX04 BX07 CX54 CX67 CY17                       DX04 EX11 HX15 JX46                 5K027 AA11 GG08 HH29

Claims (5)

[Claims] 1. A portable terminal device having a camera and a flash built-in, comprising: a shutter signal generating means for generating an electronic shutter signal for driving a shutter of the camera; and a flash light emission signal for causing the flash to emit light. At least one of the light emission signal generation means for generating the light emission signal, the electronic shutter signal generation timing by the shutter signal generation means, and the flash light emission signal generation timing by the light emission signal generation means. A mobile terminal device, comprising: 2. The portable terminal device according to claim 1, wherein the timing control unit fixes the light emission timing of the flash light emission signal and variably controls the generation timing of the electronic shutter signal. 3. The portable terminal device according to claim 1, wherein the timing control unit fixes the generation timing of the electronic shutter signal and variably controls the generation timing of the flash light emission signal. 4. The input means for allowing the user to specify and input the amount of light received by the camera, wherein the timing control means generates the timing of generating the electronic shutter signal in accordance with the amount of received light specified and input by the input means. 2. The mobile terminal device according to claim 1, wherein at least one of the generation timing of the flash emission signal and the generation timing of the flash emission signal is variably controlled. 5. The detection means for detecting the amount of light received by the camera is further provided, and the timing control means is responsive to the amount of light received by the detector to generate the electronic shutter signal and the timing of generation of the electronic shutter signal. 2. At least one of the flash emission signal generation timings is variably controlled.
The portable terminal device described.