Background technology
Code keypad is the computer peripheral that is widely used in the input of finance, securities industry customer transaction password.Its essence is a computer peripheral equipment that connects by interface circuit (RS232, TTL or keyboard interface etc.) and host computer (PC or network-termination device).During user's operator password keyboard, keyboard according to certain rule, converts user's enter action to corresponding key assignments (binary message of button representative), sends host computer to.
The code keypad employing laser-induced thermal etching method of current use is printed character or is engraved on the plastics keycap.The key of each character (being the character on the key) and key position (position of button) are all fixed.The user keys in own predefined password according to fixing key when the operator password keyboard.If in closely, there is the people to peep, can see the content of institute's key feeding cipher easily, even distance is far away, also can be when peeping the user and input password the action and the position of hand, know user cipher by inference.What is more, microcam can also in the dark be installed reach above illegal purpose.
For addressing this problem, the anti-means of peeping of passive-types such as protective cover, one-meter line have appearred.But effect is unsatisfactory all the time.
Relevant technologies also can realize realizing by electric approach the random alignment function of keyboard key-position.But it has adopted a small-scale integrated circuit and the more weak processor cooperation charactron realization of function ratio surplus in the of ten, the code keypad of manufacturing out is bulky, complex structure, power consumption big, poor reliability, can not online programming, function singleness can not substitute the product that uses now fully.
Summary of the invention
The present invention is exactly in order to address the above problem, a kind of principle by circuit hardware and software and optics is provided, when the user operates, unauthorized person can't be by closely directly peeping, or, prevent the LCD dynamically sorted code keypad of the generation of divulging a secret at the password of knowing at a distance the user by inference according to user's operational motion.
For achieving the above object, the present invention has adopted following technical scheme: a kind of LCD dynamically sorted code keypad, it is by showing that input module and two parts such as control corresponding and treatment circuit constitute, described demonstration input module is by liquid crystal key display and key assignments input media correspondingly and correct key, clear key is formed, and wherein liquid crystal key display connects with control and treatment circuit by flexible cable; Control and processing circuit controls liquid crystal key display show 0-9 10 numeric keys sign indicating number in addition at random, also control corrigendum, clear key, and the key assignments input media then will be selected the pairing key assignments of key and send into control and treatment circuit, transfer to host computer after treatment; Described liquid crystal key display is an independently LCD panel of ten of 0-9, and the key assignments input media is the independent switch device, and each LCD panel matches with a corresponding independent switch device; Described independent switch device is mechanical button, capacitance switch or conductive rubber switch; The Internal Spherical Surface body concavees lens containment vessel that the outside setting-in transparent material of described each LCD panel is made, containment vessel engages with connector on being movably arranged on corresponding independent switch, and LCD panel and independent switch are linked together.
Described control and treatment circuit comprise random number generation circuit, it divides into groups the section line and the common port of ten LCD panel respectively, be connected with S0-S20 and the COM0-COM3 of single-chip microcomputer IC1, show the data that single-chip microcomputer IC1 sends in real time, external three substitutional resistances of R03, R13, R23, R33 port of while single-chip microcomputer IC1, produce the necessary ac voltage signal of liquid crystal drive, the liquid crystal display drive circuit of single-chip microcomputer IC1 is worked according to the 4MUX mode; Key assignments input and computing circuit comprise 3 * 4 matrix circuits that connected to form by button, the line of matrix circuit connects with the input pin of single-chip microcomputer IC1, and have corresponding pull down resistor R8-R11 respectively, the alignment of matrix circuit connects with the input pin of single-chip microcomputer IC1, and single-chip microcomputer IC1 scans keyboard matrix and handles accordingly when button is pressed; Signal Processing and level shifting circuit, it has interface circuit, connects with the serial port of Transistor-Transistor Logic level, and also having model is the TTL RS 232 change-over circuit of integrated circuit (IC) 3 formations of MAX3221; Accessory circuit, it comprises power circuit, voice warning circuit, lighting display circuit, wherein power circuit is made of integrated circuit (IC) 2, and the 5V direct current is converted to 3.3V voltage; Voice warning circuit is made of sound circuit IC4, and it connects with single-chip microcomputer IC1, can send voice suggestion on demand; Lighting display circuit is made up of the LED of different colours, and they connect with single-chip microcomputer IC1.
The model of described single-chip microcomputer IC1 is MSP430F413, and it has the liquid crystal drive function; Integrated circuit (IC) 2 models are LT1086; Integrated circuit (IC) 3 models are MAX3221; In described key assignments input and the computing circuit, the line of matrix circuit connects with the P6.4-P6.7 pin of single-chip microcomputer IC1, and alignment connects with P1.7, P2.0, the P2.1 pin of single-chip microcomputer IC1; The reset circuit of single-chip microcomputer IC1 comprises resistance R 2, capacitor C 4; The P1.0 of single-chip microcomputer IC1, P1.1 pin are for sending and receiving port; P1.4 pin output signal is amplified the rear drive hummer through triode and is sent prompt tone with at button the time; In the described voice warning circuit, the P6.2 of single-chip microcomputer IC1, P6.3 pin connect with sound circuit IC4; The P6.0 of single-chip microcomputer IC1, P6.1 pin connect with LED in the lighting display circuit; Single-chip microcomputer IC1 also connects with the BSL interface, can carry out online programming to IC1 by this interface.
Code keypad of the present invention is by showing that input module and control processing circuit two parts constitute.Show that input module is divided into liquid crystal key display and key assignments input media, both are dismountable integral structure, and the concavees lens containment vessel that has transparent material to make on liquid crystal key display is watched key for the user.When the key assignments input block is independently when switching device such as mechanical button, capacitance switch or conductive rubber, show that liquid crystal is ten independent LCD panel, be contained in the concavees lens containment vessel, and be assembled into one with the key assignments input block.When the key assignments input block adopts touch pad, show that liquid crystal is the single chip liquid crystal of a slice with the same size of touch pad, be installed under the touch pad.
Using liquid crystal display device is to have utilized the little inherent characteristics in its visual angle.After the observer departs from observation axis certain angle, can't see content displayed on the liquid crystal clearly.This is one of shortcoming of liquid crystal display device originally, but when using on this code keypad, and the unauthorized person that can make the operator next door is because of exceeding effective visual angle of observation, and can't reach the purpose of peeping.
Concavees lens containment vessel outside surface be around protruding umbilicate Internal Spherical Surface body, form optic concavees lens, further reduced effective visual angle of display device.The user can differentiate the character of liquid crystal display clearly by transparent outer cover in effective visual angle.Even person of peeping's distance is very near,, also can't see content displayed clearly because of departing from effective observation visual angle.The effect that permeation-proof is closely peeped is more remarkable.Key shows usually demonstration 0-9 totally ten characters.Key display part and key assignments importation are installed in one by web member.When moving in the key assignments importation with its displacement.The key display part is connected with circuit board by flexible cable.The installation site of key assignments importation on code keypad fixed, but the displaying contents of the key display part of installing above is a random variation, by the control of software, the key assignments of corresponding key assignments of key assignments input and the key that display shows above it is united.
The key assignments importation also has " affirmation " and " corrigendum " two function keys except corresponding 0-9 tens symbol.Different is the top key display part of not installing of function key.
The ingredient of control processing circuit and the effect of each several part are as follows:
1, key produces and display driver circuit at random: produce ten characters of unduplicated 0-9 at random, and it is outputed on the liquid crystal device show.Because the generation of array is at random, also be uncertain so the user observes the ordering of key on liquid crystal at every turn.
2, key assignments input and computing circuit: this part has judged whether that by scan mode key pressed by the user.Press if any key, then the key with liquid crystal display on the key assignments of this key position and this position is mapped, and sends host computer to.
3, signal Processing and level shifting circuit: the information translation of code keypad is become and the host computer unified form, supporting in order to adapt to different host computers.As the serial signal that converts Transistor-Transistor Logic level to is supporting with the Chinese and western languages terminal of " Star ", and terminals such as the serial signal that converts the RS232 level to and IBM are supporting, or transfers to the keyboard interface etc. of PC after changing.
4, accessory circuit: power unit is the operating voltage that becomes code keypad to use the power source conversion that host computer provides; Sound circuit sends the prompt tone of various regulations as requested as " please input password " " please importing once " etc. again; Lighting display circuit makes the pilot lamp of different colours on the code keypad panel bright or go out, and operates accordingly with the prompting user.
Control and treatment circuit cooperate with corresponding software.Can increase various additional functions such as encryption easily by revising software.
All devices and the key assignments entering apparatus of control and treatment circuit are installed on the printed circuit board (PCB) of a 127 * 83mm.LCD is by flexible cable and the electric connection of this circuit board.When operation push-button (or key entering apparatus of other types), liquid crystal display device can be among a small circle with pressing bond shifting.
The core parts of control and treatment circuit are the microprocessor that includes the liquid crystal drive function.Use the high density paster technique to install.Therefore can make the code keypad volume little, low in energy consumption.
When the user accesses to your password keyboard, input predefined password according to this according to the actual key of liquid crystal display, input finishes by behind " affirmation " key, and code keypad sends and the corresponding key assignments of key to host computer.The key ordering randomly changing that shows on the while code keypad.Therefore avoided the not operation person to know the possibility of divulging a secret of password by inference according to operational motion.
In conjunction with above-mentioned analysis; the invention has the beneficial effects as follows; adopt little liquid crystal display of visible angle and concavees lens formula containment vessel, can prevent other people illegally peeping, adopted the digital display mode of random variation; got rid of the possibility of knowing password according to user action by inference; adopted 16 super low power consuming single chip processors, effectively simplified the formation of circuit, improved the stability of system with liquid crystal drive function; dwindled the volume of product, can be widely used in bank, the financial institution.
Embodiment
The present invention as shown in Figures 1 to 4.Code keypad reaches " affirmation ", " corrigendum " two function keys, control and treatment circuit formation by ten liquid crystal keys of 0-9 display, ten corresponding with it key assignments input buttons 4.The LCD panel 2 of liquid crystal key be inlaid in that transparent material makes concavees lens containment vessel 1 in, and constitute a display module, and be connected with control and treatment circuit by flexible cable by the connector 3 that is movably arranged on the button 4.Display module forms a whole with digital keys 4, and display module can be with button 4 displacement freely.There is not display module on " affirmation " and " corrigendum " key.When the key assignments input block adopts touch pad, show that liquid crystal is the single chip liquid crystal of a slice with the same size of touch pad, be installed under the touch pad.Concavees lens containment vessel 1 outside surface be around protruding umbilicate Internal Spherical Surface body, form optic concavees lens, further reduced effective visual angle of display device.
The core component single-chip microcomputer IC1 of control and treatment circuit uses 16 super low power consuming single chip processor MSP430F413 that are integrated with the liquid crystal drive function.12 buttons 4 connect to form 3 * 4 matrix circuit.The line of matrix circuit is connected with the P6.4-P6.7 of IC1.And be connected to pull down resistor R8-R11.The alignment of matrix circuit is connected with the P1.7 of IC1, P2.0, P2.1.Single-chip microcomputer IC1 constantly scans keyboard matrix under the control of software, as has scanned and make corresponding processing when key is pressed.The section line and the common port of ten LCD panel 2 divide into groups respectively.Be connected with S0-S20 and the COM0-COM3 of single-chip microcomputer IC1.Show the data that single-chip microcomputer IC1 sends in real time.External three substitutional resistances of R03, R13, R23, R33 port of while single-chip microcomputer IC1.Produce the necessary ac voltage signal of liquid crystal drive.The liquid crystal display drive circuit of single-chip microcomputer IC1 is worked according to the 4MUX mode.Constitute the reset circuit of IC1 by elements such as R2, C4.The P1.0 of single-chip microcomputer IC1 and P1.1 are the transmission and the receiving ports of data.For cooperating different host computers, the transmission of data and acceptance will be through necessary conversions.Wherein R12-R14 constitutes interface circuit, can be connected with the serial port of Transistor-Transistor Logic level, and integrated circuit (IC) 3 (model is MAX3221) and peripheral circuit constitute TTL and convert the RS232 level signal to.The P1.4 port output signal of single-chip microcomputer IC1 amplifies the rear drive hummer through triode, sends the buzz that is used to point out when the user pushes button.The P6.2 of single-chip microcomputer IC1 and P6.3 port controlling sound circuit IC4 can send the voice suggestion of " please input password ", " please importing once again " as required.The P6.0 of single-chip microcomputer IC1 and P6.1 port are controlled two LEDs of different colours respectively.Different luminance prompting user operation by LED.The BSL interface links to each other with single-chip microcomputer IC1, can be at any time the software program of single-chip microcomputer IC1 be carried out online programming and revises, and realizes that relevant function (as encrypting etc.) changes and adds.Therefore this code keypad can change function under the prerequisite that does not change circuit connection and structure.The power supply of this code keypad is directly taken from host computer.The integrated circuit (IC) 2 that by model is LT1086 changes into the needed 3.3V voltage of internal circuit with the DC voltage of 5V.
Use of the present invention is: when code keypad powers up for the first time, send interrupted buzz three, glittering three times of two light emitting diodes illustrate that the code keypad self check is correct.Arrange one group of key position of ten display device demonstrations at random simultaneously.When host computer when code keypad sends out the signal that requires input operation, code keypad sends the voice suggestion of " please input password ", simultaneously green LED is lighted, the user can input predefined password according to the array of liquid crystal reality.Password input finishing back is by " affirmation " key, and code keypad transmits data to host computer and handles for host computer.The array order randomly changing of Xian Shiing simultaneously.
Import as the user and to occur misoperation in the cryptographic processes, can be by re-entering proper password behind " corrigendum " key.Also change simultaneously by the ordering that shows behind " corrigendum " key.
Need code keypad to re-enter password as host computer, code keypad receives and sends voice suggestion " please defeated more once " after the instruction of host computer, and red LED is lighted simultaneously.
The continuous time by " corrigendum " key, the array order that this code keypad shows was changed to the ordering of conventional code keypad automatically when surpassing 3 seconds.The method of operating of this moment is in full accord with conventional code keypad.Show ordering up to the user by changing once more behind " affirmation " or " corrigendum " key.