JP2007264355A - Semiconductor integrated circuit for display control and mobile electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display system capable of improving security against loss or steal of electronic data such as personal information in mobile electronic equipment such as a mobile phone without depending upon only software, and a semiconductor integrated circuit used therefor. <P>SOLUTION: The mobile electronic equipment equipped with a display device (130) and an authentication system (260) does not issue a specific instruction code from the authentication system to the semiconductor integrated circuit (200) for display control when authentication is not performed by the authentication system, and the semiconductor integrated circuit for display control does not perform normal display and enters a display lock state where specific display is performed when the specific instruction code is not issued. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technology for improving security of a portable electronic device, and more particularly to a technology effective when used for a display control semiconductor integrated circuit such as a mobile phone or a liquid crystal controller constituting a PDA (Personal Digital Assistants).

  In recent years, mobile phones having an electronic money function have been put into practical use, and important data relating to personal property is stored in an internal memory. In addition, due to the enforcement of the Personal Information Protection Law, attention must be paid to the leakage of personal information such as names and phone numbers stored in mobile phones.

Therefore, security measures for mobile phones have become an important issue. In the early stages of mobile phone security, password authentication was generally used, but in recent years, an invention has been proposed in which human characteristics such as fingerprints and voiceprints are used as personal authentication to improve security. (Patent Document 1).
JP 2003-274006 A Japanese Patent Laid-Open No. 2004-080080

  Security measures against loss or theft of electronic data such as personal information in conventional mobile phones depend exclusively on software for collation functions such as passwords, fingerprints, and voiceprints. However, security by software has a risk that a program is analyzed by an unauthorized person called a hacker or a cracker and the confidentiality is broken, and it cannot be said that it is a sufficient safety measure.

  Also, if a conventional mobile phone is lost or left away from other people's eyes, the internal data can be easily seen by others even if it is a short time. The protective function was also relatively low.

  An object of the present invention is to provide a portable electronic device having a display device capable of improving security against loss or theft of electronic data such as personal information in a portable electronic device such as a mobile phone, and a display control semiconductor used therefor It is to provide an integrated circuit.

  Another object of the present invention is to provide a portable electronic device having a display device that does not misidentify as a failure by performing a predetermined display even when authentication is denied, and a display control semiconductor integrated circuit used therefor It is to provide.

  Still another object of the present invention is to provide a portable electronic device having a display device capable of improving the privacy protection function and a display control semiconductor integrated circuit used therefor.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Outlines of representative ones of the inventions disclosed in the present application will be described as follows.

  That is, in a portable electronic device equipped with a display device and an authentication system, a specific instruction code is not issued to the display control semiconductor integrated circuit when authentication by the authentication system is not performed at the time of activation. At the same time, the display control semiconductor integrated circuit is configured such that when a specific instruction code is not issued, a normal display is not performed and a display lock state in which a specific display is performed is set. Here, the instruction code includes a so-called command code and a control code set in a so-called control register. The startup time includes not only when the power is turned on but also when the device shifts from the standby state to the operating state.

  According to the above means, if the authentication system does not authenticate, the normal display is not made. Therefore, the hackers cheat on the software inside the main body and read the internal data, or if it is lost or stolen. It is possible to prevent an unauthorized person of a device suitable for the use of electronic money held in the device. In addition, if a specific instruction code is not issued, it may be possible not to display it at all. However, if this is done, it cannot be distinguished from a failure. Is avoided.

  Preferably, a specific instruction code is issued directly from the authentication system to the display control semiconductor integrated circuit, and the specific instruction code is not issued when the authentication system does not authenticate. Thereby, since security by hardware is applied, it is possible to make it difficult to obtain illegal data by a hacker as compared to security by conventional software.

  Furthermore, it is desirable that the user can freely set the security level. As a result, in the state where the highest security level is set, even if the device is left untouched, such as when the device is left behind, the data is not stolen and the privacy protection function is enhanced and the security level is low. If set to level, the device can be used without authentication, which improves usability.

  The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.

  That is, according to the present invention, it is possible to improve security against loss or theft of electronic data such as personal information in a portable electronic device such as a mobile phone without depending on software alone. Further, even when authentication is rejected, a portable electronic device including a display device that does not misidentify as a failure by performing a predetermined display, and a display control semiconductor integrated circuit used therefor can be realized.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows the external appearance of a foldable mobile phone equipped with a display control semiconductor integrated circuit (liquid crystal controller driver) to which the present invention is applied, that is, in a closed state.

  As shown in FIG. 1, the surface of the main body of the cellular phone 100 according to the present embodiment includes an input unit 110 for inputting authentication information and a liquid crystal panel. A sub-display unit 120 used for displaying is provided. The authentication input unit 110 uses an image sensor such as a CCD (charge coupled device) in the case of an authentication system using an image such as a fingerprint or a retina, and uses a microphone in the case of a voice authentication system using a voice print. Composed.

  In the case of the fingerprint authentication system, a pressure sensor is provided in the vicinity of the input unit 110 in addition to the CCD image sensor, and when a pressure higher than a certain level is applied, an activation signal is issued to start the authentication operation. It can be constituted as follows. In the case of a retina authentication system or a voice authentication system, an activation switch for starting an authentication operation can be provided on the side surface of the main body.

  FIGS. 2A and 2B show the appearance of the foldable mobile phone to which the present invention is applied, that is, the opened state. Reference numeral 130 denotes a main display unit including a liquid crystal panel, and 140 denotes an input operation unit including a numeric keypad including push-type input buttons. Of these, the main display unit 130 in FIG. 2A shows a display example when authentication is performed. This display screen is the same as the display screen of a conventional mobile phone.

  FIG. 2B shows a display example when authentication is not performed. Here, as an example, there is shown a case in which a message prompting a call to the service center of a mobile manufacturer and a telephone number of the center are displayed assuming that it is not authenticated and lost. Preventing theft of important data such as phone numbers stored in the internal memory by displaying such a specific display when authentication is not performed and preventing normal display Can do.

  Next, an example of a specific mechanism for preventing normal display as shown in FIG. 2A when authentication is not performed will be described.

  In this embodiment, an authentication process for authenticating a user is executed at the time of activation such as when the power switch of the cellular phone is turned on or when the phone body is opened. When authentication is performed, a specific instruction code or command code is issued from the authentication system provided in the cellular phone or the processor that controls the entire system to the liquid crystal controller driver that controls the display of the liquid crystal panel. . On the other hand, if the authentication is not performed, the specific instruction code or command code is not issued, and if it is not issued, the liquid crystal controller driver does not perform the normal display, and the specific code as shown in FIG. The display is locked to perform display.

  FIG. 3 is a block diagram showing the overall configuration of a cellular phone provided with a display control semiconductor integrated circuit (liquid crystal controller driver) according to the present invention. In FIG. 3, the ICs and components in a portion surrounded by a dashed line A are mounted on a single board such as a printed wiring board.

  The cellular phone according to this embodiment includes an image sensor 110 including a CCD or MOS sensor as an authentication input unit, a liquid crystal panel 120 as a sub display unit, a liquid crystal panel 130 as a main display unit, an antenna 150 for transmission / reception, an audio output. Speaker 160, voice input microphone 170, and the like. In addition, the liquid crystal control driver 200 according to the present invention, an authentication processing circuit 260 such as a DSP that performs authentication processing based on an image signal from the image sensor 110, and an audio interface 261 that inputs and outputs signals from the speaker 160 and the microphone 170. A high frequency interface 262 for inputting / outputting signals to / from the antenna 150 is provided. The image sensor 110 and the authentication processing circuit 260 constitute an authentication system.

  In this embodiment, when authentication is performed, a specific instruction code is issued from the authentication processing circuit 260 to the liquid crystal controller driver 200. When authentication is not performed, the authentication processing circuit 260 transmits to the liquid crystal controller driver 200. A specific instruction code is not issued. The system that performs authentication by the application processor 280 is configured such that a specific instruction code is issued to the liquid crystal controller driver 200 by the application processor 280.

  Further, the cellular phone of this embodiment has a baseband unit 270 that performs signal processing related to audio signals and transmission / reception signals, a function of controlling the entire system and processing moving image data received via the high-frequency interface 262. And an application processor 280, a power supply IC 281 and a data storage memory 282. In a system in which the authentication processing circuit 260 is not provided, the application processor 280 can be configured to execute authentication processing based on the image signal from the image sensor 150.

  The authentication processing circuit 260, the liquid crystal control driver 200, the baseband unit 270, the application processor 280, and the memory 282 are connected via a system bus 291, and the liquid crystal control driver 200, the application processor 280, and the memory 282 are further connected to a display data bus 292. Has been. Although not particularly limited, the two main and sub liquid crystal panels 120 and 130 are coupled by a flexible printed wiring cable 180 called FPC, and are configured to be driven by one liquid crystal controller driver 200. An invention relating to a liquid crystal controller driver having such a function is disclosed in Japanese Patent Application Laid-Open No. 2004-233742.

  The baseband unit 270 is composed of, for example, a DSP and performs an audio signal processing circuit 271 that performs audio signal processing, an ASIC 272 that provides a custom function (user logic), baseband signal generation and display control, overall system control, and the like. It is constituted by a microprocessor or a microcomputer 273 as a data processing device.

  A flash memory 283 capable of batch erasure in predetermined block units is provided, and the flash memory 283 stores control programs and control data for the entire mobile phone system including display control. The fingerprint data for authentication obtained by the authentication processing circuit 260 can also be stored in the flash memory 283. The memory 282 is used as a frame buffer or the like in which image data subjected to various image processing is stored, and usually an SRAM or SDRAM is used.

  The liquid crystal controller driver 200 is provided with an EEPROM interface for enabling connection of an EEPROM as a non-volatile memory. The EEPROM connected to the liquid crystal controller driver 200 has a gamma characteristic and a frame frequency of the liquid crystal panel to be used. Such specifications are stored. When the authentication is not performed or when a mismatch is detected by the authentication, display data for performing a specific display as shown in FIG. 2B can also be stored in the EEPROM.

  The cellular phone of this embodiment is not particularly limited, but is configured so that the user can freely set the security level. For example, when the security level is set in three stages, in the state where the highest security level is set, normal display is not performed unless confirmation is made by the authentication system. As a result, even if the device is simply left behind and left unattended, the data protection function is enhanced without data being stolen.

  Also, when the security level is set to an intermediate level, input from the input section is performed when the phone book data stored in the internal memory is displayed or when an operation for making a payment with electronic money is performed. It can be configured to request and execute an authentication operation according to. Thereby, the theft of the data stored in the internal memory can be prevented.

  On the other hand, if the security level is set to the lowest level, if the crisis can be used without authentication, the user can use the device without performing authentication, which frees up the trouble of the authentication procedure. This improves the usability of the equipment. When using the device for the first time, it is necessary to register human features such as fingerprints for authentication. If the initial state is set to the lowest security level, the identification as shown in FIG. Since it does not shift to the display, registration operation is possible. However, it can be configured so that registration for authentication can only be performed by a dedicated device located in the store, not by the mobile phone itself, in which case the user will use it for the first time. It is possible to activate security by authentication.

  FIG. 4 shows an embodiment of a liquid crystal controller driver 200 having a function of causing the liquid crystal panel 130 to perform a specific display when the specific instruction is not issued.

  The liquid crystal controller driver 200 of this embodiment incorporates a RAM (hereinafter referred to as a display memory) 206 as a memory for storing data to be graphically displayed on a dot matrix type liquid crystal display panel, its writing circuit, reading circuit, and liquid crystal. A semiconductor integrated circuit is formed on one semiconductor substrate together with a driver for outputting a display panel drive signal.

  The liquid crystal controller driver 200 of this embodiment includes a control unit 201 that controls the entire inside of the chip based on a command from an external microprocessor or microcomputer (hereinafter abbreviated as a microcomputer). Further, a pulse generator 202 that generates a reference clock pulse inside the chip based on an oscillation signal from the outside or an oscillation signal from a vibrator connected to an external terminal, and the operation of various circuits inside the chip based on this clock pulse A timing control circuit 203 that generates a timing signal for providing timing is provided.

  Furthermore, a system interface 204 that mainly transmits / receives data such as instructions and still display data to / from a microcomputer or the like via a system bus (not shown), video data from an application processor or the like mainly via a display data bus (not shown) An external display interface 205 for receiving horizontal / vertical synchronization signals HSYNC and VSYNC is provided. Also, an EEPROM interface 240 for enabling connection of an EEPROM as a nonvolatile memory is provided.

  The liquid crystal controller driver 200 further includes a display memory 206 that stores display data in a bitmap format, and a bit conversion circuit 207 that performs bit processing such as rearrangement of bits of RGB write data from the microcomputer. In addition, the display data converted by the bit conversion circuit 207 or the display data input via the external display interface 205 is read and held, and the read that holds the display data read from the display memory 206 is held. A data latch circuit 209 and an address generation circuit 210 for generating a selection address for the display memory 206 are provided.

  The display memory 206 selects a word line and a bit line in the memory array by decoding a memory array including a plurality of memory cells, word lines, and bit lines (data lines), and an address supplied from the address generation circuit 210. The read / write RAM has an address decoder for generating signals. Further, the display memory 206 includes a sense amplifier that amplifies a signal read from the memory cell, a write driver that applies a predetermined voltage to a bit line in the memory array in accordance with write data, and the like.

  Further, first and second latch circuits 211 and 212 that sequentially latch display data read from the display memory 206, and AC that converts the latched display data into data for AC driving that prevents liquid crystal deterioration. And a latch circuit 214 for holding data converted by the circuit. Further, a liquid crystal drive level generation circuit 216 that generates a plurality of levels of voltages necessary for driving the liquid crystal panel, and a waveform signal suitable for color display and gradation display based on the voltage generated by the liquid crystal drive level generation circuit 216. A gradation voltage generation circuit 217 that generates a gradation voltage necessary for generation and a γ adjustment circuit 218 that sets a gradation voltage for correcting the γ characteristic of the liquid crystal panel are provided.

  At the subsequent stage of the latch circuit 214, a voltage corresponding to the display data latched in the latch circuit 214 is selected from the grayscale voltages supplied from the grayscale voltage generation circuit 217 and used as a signal line of the liquid crystal panel. A source line driving circuit 215 for outputting voltages (source line driving signals) S1 to S720 applied to the source lines is provided. On the other hand, a gate line driving circuit 219 that outputs voltages (gate line driving signals) G1 to G320 applied to gate lines (also referred to as common lines) as selection lines of the liquid crystal panel, and gate lines of the liquid crystal panel one by one in order. A scan data generation circuit 220 including a shift register for generating scan data for driving to a selection level is provided.

  Further, an internal reference voltage generation circuit 221 for generating an internal reference voltage, a voltage Vcc such as 3.3 V or 2.5 V supplied from the outside is stepped down, and the power supply voltage Vdd of the internal logic circuit such as 1.5 V is reduced. A voltage regulator 222 is provided for generation. In FIG. 4, SEL1 and SEL2 are data selectors, which are controlled by a switching signal output from the timing control circuit 203, respectively, and selectively pass any one of a plurality of input signals.

  The control unit 201 stores a control register CTR for controlling the operation state of the entire chip, such as an operation mode of the liquid crystal controller driver 200, and an index IXR for storing index information for referring to the control register CTR and the display memory 206. Etc. are provided. When an instruction to be executed is designated by an external microcomputer or the like by writing to the index register IXR, the control unit 201 generates and outputs a control signal corresponding to the designated instruction.

  Under the control of the control unit 201 configured as described above, the liquid crystal controller driver 200 sequentially writes display data to the display memory 206 when performing display on a liquid crystal panel (not shown) based on commands and data from a microcomputer or the like. The drawing process going on is performed. In addition, a read process for periodically reading display data from the display memory 206 is performed to generate and output a signal to be applied to the source line of the liquid crystal panel, and a signal to be sequentially applied to the gate line is generated and output.

  When a specific instruction code is set in the index register IXD from an external microcomputer or the above-described authentication system via the system interface 204, the liquid crystal controller driver 200 of this embodiment displays the display data stored in the display memory 206. To display on the liquid crystal panel. On the other hand, when a specific instruction code is not set in the index register IXD, a display for performing a specific display as shown in FIG. 2A stored in the EPROM of the corresponding section via the EPROM interface 240. It is configured to read and display data.

  In a liquid crystal controller driver (including a liquid crystal controller), the storage capacity of the built-in display memory for storing display data is generally determined according to the size of the display screen of the liquid crystal panel to be driven, and the address of the display memory An unused address area exists in the effective address space defined by the number of bits.

  Therefore, the storage capacity of the display memory is set to be larger than the data of the display screen of the liquid crystal panel, and display data for performing a specific display from an external EPROM is read into this storage area in advance when the power is turned on. It can be configured to be stored. Further, instead of using an external EPROM, a built-in ROM may be provided, and display data for performing a specific display may be stored in the built-in ROM.

  The invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Nor. For example, in the above-described embodiment, a case has been described in which security is improved by preventing normal display on the display unit when authentication is not performed.

  The present invention is not limited to such an embodiment. When authentication is not performed, a wired communication port generally provided at the bottom of a mobile phone or an infrared type provided at the top of the phone is used. It is also possible to configure so that data extraction using the communication port is not permitted. In that case, a function that prevents communication from being executed unless a specific instruction code or command code is issued from the authentication system may be provided in the IC or interface that performs communication.

  When a voice authentication system using voiceprints is used, a telephone microphone can be used also as an input unit of the authentication system. Although the foldable mobile phone is shown in the embodiment, it is needless to say that the embodiment is not limited thereto.

  In the above description, the invention made mainly by the present inventor has been described as applied to the mobile phone which is the field of use behind it. However, the present invention is not limited thereto. For example, it can be used for a PDA or a notebook personal computer.

It is a front view which shows the external appearance of the closed state of the mobile telephone provided with the semiconductor integrated circuit for display control (liquid crystal controller driver) to which this invention is applied. The external appearance of the open state of the mobile telephone provided with the semiconductor integrated circuit for display control to which the present invention is applied is shown. (A) is a display example when authentication is made, and (B) is not authenticated. It is a front view which respectively shows the example of a display when a mismatch is detected by the case or authentication. 1 is a block diagram showing an overall configuration of a cellular phone provided with a display control semiconductor integrated circuit (liquid crystal controller driver) according to the present invention. It is a block diagram which shows one Example of the liquid crystal controller driver which has a function to perform a specific display on a liquid crystal panel when the specific instruction is not issued.

Explanation of symbols

100 Mobile phone body 110 Authentication input unit (image sensor)
120 Sub-display unit 130 Main display unit 140 Input operation unit 200 Liquid crystal controller driver 201 Control unit 206 Display memory (RAM)
215 Source line driver circuit (output circuit)
260 Authentication processing circuit (authentication system)

Claims (5)

Read / write display memory for storing display data for display on an external display device, an output circuit for generating and outputting a signal corresponding to the display data in the display memory, and instructions supplied from the outside A display-control semiconductor integrated circuit comprising a control unit that decodes and generates a control signal for an internal circuit,
The control unit is configured to output a signal for causing the display device to display a content indicating that it is not authenticated when a specific instruction is not supplied from the outside at the time of activation. Semiconductor integrated circuit for display control.   A portable electronic device including a display device, a display-controlling semiconductor integrated circuit that performs processing for display on the display device, and an authentication system, and when the authentication system is not authenticated at the time of activation, A portable electronic device configured to prevent a specific instruction from being supplied to the display control semiconductor integrated circuit.   The display control semiconductor integrated circuit outputs a signal for causing the display device to display a content indicating that the display control semiconductor integrated circuit is not authenticated when a specific instruction is not supplied from the outside at the time of startup. 2. The portable electronic device according to 2.   The portable electronic device according to claim 2, wherein the authentication system determines whether human characteristics match or do not match. The portable electronic device according to any one of claims 2 to 4, wherein the security level can be set in a plurality of stages.

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