KR100675005B1 - Mobile communication terminal having dual-camera-function, dual camera apparatus and method for performing dual-camera-function - Google Patents

Abstract

A mobile communication terminal having a dual camera function, a dual camera apparatus, and a method for executing the dual camera function are provided to perform the dual camera function without using an analog multiplexer, thereby reducing hardware configuration costs necessary for realizing the dual camera function and making the dual camera apparatus and the mobile communication terminal having the same miniaturized. A mobile communication terminal comprises the followings: the first camera module(240) which generates the first image signal and outputs the generated signal to a transmission bus(245); the first bus(265) which transmits the first image signal; a series interface unit(250,260) which connects the transmission bus(245) with the first bus(240); the second camera module(270) which generates the second image signal; the second bus(275) which transmits the second image signal; and a share bus(285) which is connected to the first bus(265) and the second bus and transmits the first/second image signal to a central processing unit(280) performing signal processing.

Description

A mobile communication terminal having dual camera function, a dual camera device, and a method of performing the dual camera function

BRIEF DESCRIPTION OF THE DRAWINGS In order to understand the drawings referred to in the detailed description of the invention, a brief description of each drawing is provided.

1 is a diagram illustrating a mobile communication terminal providing a dual camera function.

2 is a diagram illustrating a mobile communication terminal having a dual camera function according to the present invention.

3 is a view illustrating in detail the lower portion 220 in FIG.

4 is a view showing another embodiment of a mobile communication terminal according to the present invention.

5 is a view for explaining an operation mode of the mobile communication terminal illustrated in FIGS. 2 and 3.

<Description of Reference Number in Drawing>

110: upper part 120: lower part

130: hinge 140: first camera module

145: transmission bus 150: upper serial interface unit

155: serial bus 160: lower serial interface unit

165: first bus 170: second camera module

175: second bus 180: central processing unit

181: multiplexer side bus

210: upper portion 220: lower portion

230: hinge 240: first camera module

245: transmission bus 250: upper serial interface portion

251: Transmission bus side pad 252: Transmission bus side buffer

256: upper transfer buffer portion 257: upper direction selection connecting portion

255: serial bus 260: lower serial interface

261: First Bus Side Pad 262: First Bus Side Buffer Section

263: connection portion 266: lower transfer buffer portion

267: lower direction selection connecting portion 265: first bus

270: second camera module 271: signal generator

272: second bus side buffer portion 273: second bus side pad

275: second bus 285: shared bus

280: central processing unit

The present invention relates to a mobile communication terminal having a dual camera function, a dual camera device, and a method of executing a dual camera function. In particular, when displaying an image corresponding to an image signal output from one camera, the other camera is used. The present invention relates to a technique for executing a dual camera function by floating a bus to which an image signal output from a video signal is transmitted.

At present, the mobile communication terminal has evolved into a multi-purpose device that provides a variety of new and various functions and applications in addition to the functions as the original voice call means. That is, current mobile communication terminals provide various functions such as wireless Internet access function, MP3 function, digital camera function, and the like. Meanwhile, in addition to a mobile communication terminal having a camera module to provide a digital camera function, there is a mobile communication terminal having two camera modules to provide a dual camera function.

1 is a diagram illustrating a mobile communication terminal providing a dual camera function.

FIG. 1 illustrates a mobile communication terminal having a folder type structure in which an upper clamshell 110 and a lower clamshell 120 are engaged by a hinge 130.

The upper end 110 includes a first camera module 140, a transmission bus 145, and an upper serial interface unit 150. The lower part 120 has an analog multiplexer which receives the lower serial interface unit 160, the first bus 165, the second camera module 170, the second bus 175, and the selection control signal Sc. ), A multiplexer side bus 181, a central processing unit 180, and the like.

The upper serial interface unit 150 and the lower serial interface unit 160 are connected by a serial bus 155. That is, the upper serial interface unit 150 and the lower serial interface unit 160 exchange image signals through the serial bus 155. In the past, image signals were exchanged through a parallel bus, but recently, image signals are transmitted and received through the serial bus 155 as described above. In the mobile communication terminal having a folder type structure, since a hinge part such as 130 exists and the size of the cable is limited, the serial communication is more effective than the case of sending and receiving image signals through a parallel bus. Transmitting and receiving image signals via the bus 155 is advantageous in terms of the size of the cable.

The first image signal generated by the first camera module 140 is connected to the transmission bus 145, the upper serial interface unit 150, the serial bus 155, the lower serial interface unit 160, and the first bus 165. Via the analog multiplexer (MUX). The second image signal generated by the second camera module 170 is input to the analog multiplexer MUX via the second bus 175. The analog multiplexer MUX receives the first image signal and the second image signal, and outputs any one of the first image signal and the second image signal in response to the selection control signal Sc. That is, the analog multiplexer MUX outputs the first image signal to the central processing unit 180 through the multiplexer side bus 181 when the image corresponding to the first image signal is displayed on the screen, and the second image signal. When the image corresponding to the screen is displayed on the screen, the second image signal is output to the central processing unit 180 through the multiplexer side bus 181.

  By the way, as described above, the technique of implementing the dual camera function using the analog multiplexer (MUX) has the advantage that the implementation is simple, but there is a disadvantage that the manufacturing cost to implement a functional block, such as analog multiplexer (MUX). In addition, since the hardware for implementing the analog multiplexer (MUX) occupies a large volume, there is a disadvantage that goes against the miniaturization trend of the mobile communication terminal.

The present invention provides a dual camera device that does not require an analog multiplexer in executing the dual camera function, a mobile communication terminal having the same, and a method of executing the dual camera function.

The mobile communication terminal according to the present invention includes a first camera module, a first bus, a serial interface unit, a second camera module, a second bus, and a shared bus. The first camera module generates a first image signal and outputs the first image signal to a transmission bus. The first bus transmits the first image signal. The serial interface unit connects the transmission bus and the first bus. The second camera module generates a second image signal. The second bus transmits the second image signal. The shared bus is connected to the first bus and the second bus, and transmits the first image signal or the second image signal to a central processing unit that performs signal processing. When the first image signal is transmitted to the central processing unit via the first bus and the shared bus, the second bus is in a floating state. When the second image signal is transmitted to the central processing unit via the second bus and the shared bus, the first bus is in a floating state.

In one embodiment of the present invention, the mobile communication terminal, a folder type structure or a slide type that can be divided into an upper end portion in which the first camera module is disposed and a lower end portion in which the second camera module is disposed. (Slide type) has a structure.

In one embodiment of the present invention, the serial interface unit, the upper serial interface unit for receiving the first image signal from the transmission bus; A lower serial interface unit outputting the first image signal to the first bus; And a serial bus connecting the upper serial interface unit and the lower serial interface unit.

In one embodiment of the present invention, the lower serial interface unit may include: a first bus side pad connected to the first bus; And a first bus side buffer for transmitting the first image signal to the first bus side pad in response to a first bus side control signal.

In one embodiment of the present invention, the lower serial interface unit, the transmission buffer unit for receiving a signal output from the first bus-side pad for the bi-directional transmission of the signal between the serial bus and the first bus ; And a direction selection connecting unit for selectively transmitting the first image signal transmitted from the serial bus to the first bus side buffer unit and transmitting the signal output from the transmission buffer unit to the serial bus. It is provided.

In one embodiment of the present invention, the second camera module, Signal generation unit for generating the second image signal to correspond to the incident light; A second bus side pad connected to the second bus; And a second bus side buffer for transmitting the second image signal to the second bus side pad in response to a second bus side control signal.

In one embodiment of the present invention, when the second image signal is not transmitted to the shared bus, the second bus side pad and the second bus are in a floating state, whereby the second camera module has a power saving function. Can have

According to another aspect of the present invention, a dual camera device includes a first camera module for generating a first image signal; A first bus for transmitting the first image signal; A second camera module for generating a second image signal; A second bus for transmitting the second image signal; And a shared bus connected to the first bus and the second bus and transmitting the first image signal or the second image signal to a central processing unit. When the first image signal is transmitted to the first bus, the second bus is in a floating state. When the second image signal is transmitted to the second bus, the first bus is in a floating state.

According to another aspect of the present invention, a method of executing a dual camera function includes a first camera module generating a first image signal, a first bus transmitting the first image signal to a shared bus, and a second image signal generating method. A second camera module, a second bus that transmits the second image signal to the shared bus, a central processor that receives the first image signal or the second image signal through the shared bus, and a signal processing by the central processor A method of executing a dual camera function for a dual camera device having a display unit for displaying an image corresponding to a first image signal or a second image signal on a screen, the method comprising: (a) displaying an image corresponding to the first image signal; Whether to display or display an image corresponding to the second image signal. The step; (b) when displaying an image corresponding to the first image signal, floating the second bus such that the first image signal is transmitted to the central processing unit via the first bus and the shared bus. ) State; And (c) when displaying an image corresponding to the second image signal, floating the first bus such that the second image signal is transmitted to the central processing unit via the second bus and the shared bus. Characterized in that it comprises a step of making.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that the detailed description of the related well-known configuration or function may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

2 is a diagram illustrating a mobile communication terminal having a dual camera function according to the present invention.

2 illustrates a mobile communication terminal having a folder type structure in which an upper clamshell 210 and a lower clamshell 220 are engaged by a hinge 230. However, the present invention is not limited to the mobile communication terminal having such a folding structure. For example, the present invention can be applied to mobile communication terminals having various structures to support dual camera functions, such as slide type mobile communication terminals.

The upper end 210 includes a first camera module 240, a transmission bus 245, and an upper serial interface unit 250. The lower end 220 includes a lower serial interface 260, a first bus 265, a second camera module 270, a second bus 275, a shared bus 285, and a central processing unit 280. Other components such as a display unit are omitted in the illustration of FIG.

The upper serial interface unit 250 and the lower serial interface unit 260 are connected by a serial bus 255. That is, the upper serial interface unit 250 and the lower serial interface unit 260 exchange image signals through the serial bus 255. The upper serial interface unit 250, the serial bus 255, and the lower serial interface unit 260 constitute the serial interface units 250, 255, and 260.

The first image signal generated by the first camera module 240 is connected to the transmission bus 245, the upper serial interface unit 250, the serial bus 255, the lower serial interface unit 260, and the first bus 265. Via shared bus 285 via. The second image signal generated by the second camera module 270 is transmitted to the shared bus 285 via the second bus 275.

As shown in FIG. 2, the shared bus 285 is directly connected to the first bus 265 and the second bus 275. The shared bus 285 transmits the first image signal transmitted from the first bus 265 or the second image signal transmitted from the second bus 275 to the central processing unit 280. The central processing unit 280 may signal-process the first image signal or the second image signal received from the shared bus 285, and transmit the signal-processed first image signal or the second image signal to a display unit (not shown). The image corresponding to the signal-processed first image signal or second image signal is displayed on the screen.

As can be seen by comparing FIG. 2 with FIG. 1, the present invention does not employ a method of executing a dual camera function using an analog multiplexer (MUX in FIG. 1), and the first bus 265 and the second bus 275. ) Is directly connected to the shared bus 285 to execute the dual camera function. In the scheme of executing the dual camera function according to the present invention, when the first image signal is transmitted to the central processing unit 280 via the first bus 265 and the shared bus 285, the second bus 275 It is in a floating state. On the contrary, when the second image signal is transmitted to the central processing unit 280 via the second bus 275 and the shared bus 285, the first bus 265 is in a floating state.

In order to display an image corresponding to the first image signal, when the first image signal is transmitted to the central processing unit 280 via the first bus 265 and the shared bus 285, the second bus 275 may be used. Is made into a floating state with high-impedance so that the first image signal is not disturbed from being transmitted. Similarly, in order to display the image corresponding to the second image signal, the second image signal is transmitted to the central processing unit 280 via the second bus 275 and the shared bus 285. 265 is made into a floating state with high impedance, so as not to interfere with the transmission of the second image signal. In the present invention, as described above, the first bus 265 and the second bus 275 are directly connected to the shared bus 285, the second bus 275 is floated, and the first bus 265 has a first bus. The image signal is transmitted, or the first bus 265 is floated and the second bus 275 is transmitted with the second image signal, so that the dual camera function is executed without mutual interference of signal transmission.

Next, a technical configuration for making the first bus 265 or the second bus 275 in a floating state will be described.

3 is a view illustrating in detail the lower portion 220 in FIG.

The lower serial interface unit 260 in FIG. 3 has a first bus side pad (PAD1.22), a first bus side buffer unit 262 and a connection unit 263 in response to the first bus side control signal Sc1. Equipped. The second camera module 270 in FIG. 3 includes a signal generator 271, a second bus side buffer unit 272 and a second bus side pad (PAD2. 273) in response to the second bus side control signal Sc2. ).

The first bus side pads PAD1.21 are provided for connection between the lower serial interface unit 260 and the first bus 265.

The first bus side buffer unit 262 transmits the first image signal to the first bus side pad PAD1.22 in response to the first bus side control signal Sc1. According to the case of FIG. 3, the first bus-side buffer unit 262 receives the first image signal when the logic level of the first bus-side control signal Sc1 is at the low level. To send). That is, when the logic level of the first bus-side control signal Sc1 is at a low level, the first image signal passes through the first bus-side buffer unit 262 and the first bus-side pad PAD1.226. Is sent to 265. In addition, according to the case of FIG. 3, the first bus-side buffer unit 262 blocks transmission of the first image signal when the logic level of the first bus-side control signal Sc1 is at a high level so that the first bus is blocked. The side pads PAD1.21 and the first bus 265 are made floating.

3 illustrates only an embodiment of the present invention, and unlike FIG. 3, the first bus-side buffer unit 262 may have a logic level of the first bus-side control signal Sc1. In case of the high level, the first image signal is transmitted to the first bus-side pad PAD1.22, and the transmission of the first image signal is blocked when the logic level of the first bus-side control signal Sc1 is low level. Thus, the first bus side pads PAD1.21 and the first bus 265 may be in a floating state.

The connection part 263 shows the other components provided for the connection of the upper serial interface part 250 and the lower serial interface part 260 as one functional block.

In the signal generator 271, a second image signal is generated to correspond to incident light. In order to generate the second image signal, the signal generator 271 may include a CMOS image sensor (CIS), an amplifier circuit, a driver circuit, a filter circuit, and the like.

The second bus side pads PAD2. 273 are provided for connection between the second camera module 270 and the second bus 275.

The second bus side buffer unit 272 transmits the second image signal to the second bus side pad PAD2. 273 in response to the second bus side control signal Sc2. According to the case of FIG. 3, the second bus side buffer unit 272 receives the second image signal when the logic level of the second bus side control signal Sc2 is at a high level. To send). That is, when the logic level of the second bus-side control signal Sc2 is at a high level, the second image signal passes through the second bus-side buffer unit 272 and the second bus-side pad PAD2. 273 to the second bus. Is sent to 275. In addition, according to the case of FIG. 3, the second bus side buffer unit 272 interrupts the transmission of the second image signal when the logic level of the second bus side control signal Sc2 is at a low level, thereby preventing the second bus. The side pads PAD273 and the second bus 275 are made floating.

Similarly to the case of the first bus side buffer section 262 described above, the second bus side buffer section 272 transmits the second image signal to the second bus side pad PAD2.73 or the second bus side. The logic level of the second bus side control signal Sc2, which determines whether the pads PAD273 and the second bus 275 are to be floated, can be changed.

In terms of power consumption, when the second image signal is not transmitted to the shared bus 285, the second bus-side pads PAD273 and the second bus 275 are in a floating state, and thus the second The camera module 270 may have a power saving function.

4 is a view showing another embodiment of a mobile communication terminal according to the present invention.

The upper serial interface 250 and the lower serial interface 260 in FIG. 4 have the same components. In the production of the product, if the upper serial interface unit 250 and the lower serial interface unit 260 are not produced differently in separate processes, but are produced identically by the same process, the manufacturing cost of the product can be lowered. . 4 illustrates the upper serial interface unit 250 and the lower serial interface unit 260 produced in the same process in consideration of the manufacturing cost of the product.

In FIG. 4, the upper serial interface unit 250 and the lower serial interface unit 260 both include pads 261 and 251, buffer units 262 and 252 corresponding to control signals Sc1 and Sc3, and transmission buffer units ( 266 and 256 and direction select connecting portions 267 and 257. Named and described, the lower serial interface unit 260 may include a first bus side pad PAD1.22, a first bus side buffer unit 262 in response to the first bus side control signal Sc1, and a bottom transfer. A buffer portion 266 and a lower direction selection connecting portion 267 are provided. The upper serial interface unit 250 includes a transmission bus side pad PAD3.251, a transmission bus side buffer unit 252 corresponding to the transmission bus side control signal Sc3, an upper transmission buffer unit 256, and an upper direction selection connector. 257 is provided.

The roles of the first bus side pads PAD1.22 and the first bus side buffer unit 262 in the lower serial interface unit 260 have been described with reference to FIGS. 2 to 3.

The lower transmission buffer unit 266 receives a signal output from the first bus side pad PAD1.22.

The lower direction selection connecting unit 267 transmits a first image signal transmitted from the serial bus 255 to the first bus side buffer unit 262 and outputs a signal output from the lower transfer buffer unit 266 to the serial bus. Alternatively, an operation of transmitting to 255 may be performed.

In the lower serial interface portion 260, as described above, the lower transfer buffer portion 266 and the lower direction selection connecting portion 267, in addition to the first bus side pad PAD1.21 and the first bus side buffer portion 262, are provided. The bidirectional transmission of signals is possible between the serial bus 255 and the first bus 265.

In the upper serial interface unit 250, the roles of the transmission bus side pads PAD3. 251, the transmission bus side buffer unit 252, the upper transmission buffer unit 256, and the upper direction selection connecting unit 257 serve as the lower serial interface unit ( 260, similar to the role of the first bus-side pad (PAD1.22), the first bus-side buffer unit 262, the lower transfer buffer unit 266 and the lower direction selection connector 267. Accordingly, the bidirectional transmission of signals is also possible between the serial bus 255 and the transmission bus 245 through the upper serial interface unit 250.

As a result, the bidirectional transmission of signals between the first camera module 240 and the first bus 265 is possible through the upper serial interface 250, the serial bus 255, and the lower serial interface 260. The first image signal is transmitted from the first camera module 240 to the first bus 265, and the first camera module 240 is controlled from the first bus 265 to the first camera module 240. The control signal is sent.

The first image signal generated by the first camera module 240 includes a transmission bus 245, a transmission bus side pad (PAD3.251), an upper transmission buffer unit 256, an upper direction selection connector 257, and a serial bus ( 255, the central direction selection unit 267, the first bus-side buffer unit 262, the first bus-side pad PAD1.22, the first bus 265, and the shared bus 285. 280). The various control signals output from the central processing unit 280 are shared bus 285, first bus 265, first bus side pads PAD1.22, lower transfer buffer unit 266, and lower direction selection connecting unit 267. ), The first camera module 240 via the serial bus 255, the upper direction select connector 257, the transmission bus side buffer unit 252, the transmission bus side pads (PAD3.251) and the transmission bus 245. Is entered.

5 is a view for explaining an operation mode of the mobile communication terminal illustrated in FIGS. 2 and 3.

In FIG. 5, Sc1 represents the first bus side control signal Sc1 in FIG. 3, and Sc2 represents the second bus side control signal Sc2 in FIG. 3. As shown in FIG. 3, when the logic level of the first bus-side control signal Sc1 is low, the first image signal passes through the first bus-side buffer unit 262 and the second bus-side control signal. When the logic level of Sc2 is a high level, the second image signal passes through the second bus side buffer portion 272.

In section A of FIG. 5, since the logic level of the first bus-side control signal Sc1 is at a high level and the logic level of the second bus-side control signal Sc2 is at a low level, the first image signal and the second image signal. Not all of them are sent to the central processing unit 280. As a result, both the first camera module 240 and the second camera module 270 may be in an OFF state.

In the section B of FIG. 5, since the logic level of the first bus-side control signal Sc1 is at a high level and the logic level of the second bus-side control signal Sc2 is at a high level, only the second image signal is the central processing unit ( 280). As a result, only the second camera module 270 is in the ON state.

In the section C of FIG. 5, since the logic level of the first bus-side control signal Sc1 is low level and the logic level of the second bus-side control signal Sc2 is low level, only the first image signal is the central processing unit ( 280). As a result, only the first camera module 240 appears to be in an ON state.

In the above, the description has been focused on the mobile communication terminal having a dual camera function. However, the present invention is not limited thereto and may be implemented as a dual camera device as follows.

The dual camera apparatus according to the present invention includes a first camera module for generating a first image signal, a first bus for transmitting a first image signal, a second camera module for generating a second image signal, and a second image signal for transmitting a second image signal. A shared bus is connected to the second bus, the first bus, and the second bus and transmits the first image signal or the second image signal to the central processing unit.

In the dual camera apparatus according to the present invention, when the first image signal is transmitted to the first bus, the second bus is in a floating state, and when the second image signal is transmitted to the second bus, the first bus is It becomes a floating state. In the dual camera device according to the present invention, the first bus and the second bus are directly connected to the shared bus, the second bus is floated, and the first image signal is transmitted to the first bus or the first bus. Is floated and a second image signal is transmitted on the second bus, so that the dual camera function is executed without interfering with the signal transmission.

Meanwhile, the present invention can also be understood as a method of executing the dual camera function as follows.

A method of executing a dual camera function according to the present invention includes a first camera module for generating a first image signal, a first bus for transmitting a first image signal to a shared bus, a second camera module for generating a second image signal, A second bus that transmits the second image signal to the shared bus, a central processor that receives the first image signal or the second image signal through the shared bus, and a first image signal or the second image signal processed by the central processor; A dual camera function is executed for a dual camera device having a display unit for displaying a corresponding image on a screen.

First, a step of receiving an input of displaying an image corresponding to the first image signal or an image corresponding to the second image signal is provided. Whether to display an image corresponding to the first image signal or to display an image corresponding to the second image signal may be selected by a user of the dual camera apparatus through an input means or determined by control of an external control device.

Next, when displaying an image corresponding to the first image signal, the step of floating the second bus so that the first image signal is transmitted to the central processing unit via the first bus and the shared bus may include: It is provided. The second bus is in a floating state so it does not interfere with signal transmission over the first bus.

Next, when displaying an image corresponding to the second image signal, a step of floating the first bus is provided such that the second image signal is transmitted to the central processing unit via the second bus and the shared bus. Likewise, the floating first bus does not interfere with signal transmission over the second bus.

In the above described the present invention with reference to the specific embodiment shown in the drawings, but this is only an example, those of ordinary skill in the art to which the present invention pertains various modifications and variations therefrom. Therefore, the protection scope of the present invention should be interpreted by the claims to be described later, and all the technical ideas within the equivalent and equivalent ranges should be construed as being included in the protection scope of the present invention.

As described above, the present invention has the following effects.

The ability to run dual camera functions without the use of an analog multiplexer reduces the hardware configuration cost of implementing dual camera functions.

In addition, since the analog multiplexer is not used, the dual camera device or the mobile communication terminal having the same can be made smaller.

Claims (12)

In the mobile communication terminal having a dual camera function, A first camera module generating a first image signal and outputting the first image signal to a transmission bus; A first bus for transmitting the first image signal; A serial interface unit connecting the transmission bus and the first bus; A second camera module for generating a second image signal; A second bus for transmitting the second image signal; And A shared bus connected to the first bus and the second bus and transmitting the first image signal or the second image signal to a central processing unit that performs signal processing; When the first image signal is transmitted to the central processing unit via the first bus and the shared bus, the second bus is in a floating state, and the second image signal is connected to the second bus and the shared bus. And the first bus is in a floating state when it is transmitted to the central processing unit via a shared bus. The method of claim 1, A mobile communication terminal can be divided into an upper end in which the first camera module is disposed and a lower end in which the second camera module is disposed. The method of claim 2, A mobile communication terminal comprising a folder type structure having the upper end and the lower end, or a slide type structure having the upper end and the lower end. The method of claim 2, wherein the serial interface unit, An upper serial interface unit receiving the first image signal from the transmission bus; A lower serial interface unit outputting the first image signal to the first bus; And And a serial bus connecting the upper serial interface unit and the lower serial interface unit. The method of claim 4, wherein the lower serial interface unit, A first bus side pad connected to the first bus; And And a first bus side buffer for transmitting the first image signal to the first bus side pad in response to a first bus side control signal. The method of claim 5, wherein the first bus side buffer unit, If the logic level of the first bus-side control signal is at a low level, transfer the first image signal to the first bus-side pad, When the logic level of the first bus-side control signal is a high level, the transmission of the first image signal is interrupted, and the first bus-side pad and the first bus are brought into a floating state. terminal. The method of claim 5, wherein the lower serial interface unit, for bidirectional transmission of signals between the serial bus and the first bus, A transmission buffer unit receiving a signal output from the first bus side pad; And A direction selection connection unit for selectively transmitting the first image signal transmitted from the serial bus to the first bus side buffer unit and transmitting the signal output from the transmission buffer unit to the serial bus; Mobile communication terminal, characterized in that. The method of claim 2, wherein the second camera module, A signal generator which generates the second image signal to correspond to incident light; A second bus side pad connected to the second bus; And And a second bus side buffer for transmitting the second image signal to the second bus side pad in response to a second bus side control signal. The method of claim 8, wherein the second bus side buffer unit, If the logic level of the second bus-side control signal is a high level, transfer the second image signal to the second bus-side pad, And when the logic level of the second bus-side control signal is at a low level, the transmission of the second image signal is interrupted and makes the second bus-side pad and the second bus floating. terminal. The second camera module of claim 9, wherein when the second image signal is not transmitted to the shared bus, the second bus side pad and the second bus are in a floating state. A mobile communication terminal having a power saving function. A first camera module for generating a first image signal; A first bus for transmitting the first image signal; A second camera module for generating a second image signal; A second bus for transmitting the second image signal; And A shared bus connected to the first bus and the second bus and transmitting the first image signal or the second image signal to a central processing unit; When the first image signal is transmitted to the first bus, the second bus is in a floating state. When the second image signal is transmitted to the second bus, the first bus is in a floating state. Dual camera device characterized in that the. A first camera module for generating a first image signal, a first bus for transmitting the first image signal to a shared bus, a second camera module for generating a second image signal, and transmitting the second image signal to the shared bus A second bus, a central processing unit receiving the first image signal or the second image signal through the shared bus, and an image corresponding to the first image signal or the second image signal processed by the central processing unit; In the method for executing a dual camera function for a dual camera device having a display unit to display in, (a) receiving input whether to display an image corresponding to the first image signal or to display an image corresponding to the second image signal; (b) when displaying an image corresponding to the first image signal, floating the second bus such that the first image signal is transmitted to the central processing unit via the first bus and the shared bus. ) State; And (c) when displaying an image corresponding to the second image signal, the first bus in a floating state such that the second image signal is transmitted to the central processing unit via the second bus and the shared bus. And a step of making the dual camera function.

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