Keyless entry system for an automotive vehicle

• US 4,492,959 A
• Filed: 06/23/1982
• Issued: 01/08/1985
• Est. Priority Date: 06/24/1981
• Status: Expired due to Term

• Current Assignee: Kokusan Kinzoku Kogyo Company Limited 8-2 Kamata 2-Chome Ota-Tokyo
• Original Assignee: Kokusan Kinzoku Kogyo Company Limited, Nissan Motor Co., Ltd.
• Inventors: Mochida, Haruo, Namazue, Hirotoshi, Nakakooji, Hiroshi
• Primary Examiner(s): Yusko, Donald J.
• Application Number:
  US06/391,343
• Time in Patent Office: 930 Days
• Field of Search: 340/825.31, 340/825.56, 340/63, 361/172, 235/382, 307/10 AT
• US Class Current: 340/5.72
• CPC Class Codes: G07C 9/0069 actuated in a predetermined sequence

Abstract

There is provided a keyless entry system in which a permanent code, or first code, and a user'"'"'s code, or second code are used. The second code is presettable in conjunction with use of the first code. When the first code is inputted, the system gets ready for presetting a desired number of code elements consituting the second code. According to the invention, the system is provided with a circuit for variably presetting the number of the code elements, which circuit is responsive to the first code to vary the presetted number of the second code elements to that inputted following to the input of the first code. Preferably, the keyless entry system further includes a theft prevention circuit which inhibits input of a code for a given period of time when wrong codes are inputted more than a predetermined number of times.

Claims

1. A keyless entry system for unlocking an automotive door lock in use with a code inputted thereto, which comprises:

an input unit for inputting an input code;

a first memory means for storing a first code;

a second memory means for storing a second code having a given number of code elements, the number being variable in a range limited by a predetermined maximum number; and

a third means, responsive to an inputted first code through said input unit, for enabling variation of said second code and for varying said number of code elements, said third means being adapted to record the varied second code in said second memory means.

6. The keyless entry system as set forth in any one of claims 1 to 5, wherein said third means produces a third signal representative of the recorded number of code elements of the second code stored in said second memory means, and said second memory means is responsive to said third signal under a read out mode for permitting reading out of the second code.

7. The keyless entry system as set forth in anyone of claims 1 to 4, which further includes an address signal generator responsive to signals fed from said input unit and producing address signals to access said first and second memory means for reading out stored first and second code.

8. The keyless entry system as set forth in claim 7, wherein said address signal generator includes a counter for counting up the number of signals inputted from said input unit and an address signal produced therein represents the order of access in said first and second memory means.

9. The keyless entry system as set forth in claim 8, which further comprises a reset signal generator for producing a counter reset signal for resetting said counter in said address signal generator, which reset signal generator is responsive to said first signal to produce said counter reset signal with a given delay time.

10. The keyless entry system as set forth in claim 9, wherein said third means is responsive to said counter reset signal for starting the counting up of the inputted code elements after said counter reset signal.

11. The keyless entry system as set forth in claim 10, wherein said second memory means is placed in a write mode for writing therein the second code in response to said counter reset signal, said new second code inputted following said counter reset signal.

12. The keyles entry system as set forth in claim 11, which further comprises a theft preventing circuit which inhibits input of said input code when the time between occurrence of said input code elements exceeds a predetermined time.

13. The keyless entry system as set forth in claim 12, wherein said theft preventing system comprises fourth means incorporated with said second means for producing a fourth signal indicating said input code being different from said second code, a counter for counting up said fourth signal and producing a fifth signal when the counter value exceeds a given value, a timer responsive to said fifth signal for producing a timer signal having a given duration and a gate associated with said input unit and responsive to said timer signal to close the gate for inhibiting input of said input code as long as said timer signal is present.

2. A keyless entry system for an automotive vehicle comprising:

a door unlocking actuator for unlocking a door lock of a vehicle door;

an input unit for inputting an input code;

a first memory means for storing a first code;

a first means for comparing said input code with said first code for producing a first signal when said input code matches said first code;

a second memory means for storing a second input code of variable length, said second code stored in said second memory means, said second memory means operable in response to said first signal for storing, as an updated second code, further input code inputted subsequently to said first signal, said second memory being operable for storing second codes updated both with respect to specific digits forming code elements thereof and with respect to the number of said digits;

second means for comparing said input code with said second code stored in said second memory means and producing an actuation signal for activating said door unlocking actuator for unlocking said door lock when said input code matches said second code; and

third means, associated with said second memory means, for counting the number of digits of said second code for controlling writing and reading of said second code in said second memory.

3. A keyless entry system for an automotive vehicle comprising:

a door unlocking actuator for unlocking a door lock of a vehicle door;

an input unit for inputting an input code;

a first memory means for storing a first code comprising a first number of code elements;

first means for comparing said input code with said first code and producing a first signal when said input code matches said first code;

a second memory means for storing a second code comprising a second number of code elements, said second code stored being variable in response to said first signal to vary a combination of code elements forming said second code and to vary said second number;

second means for comparing said input code with said second code and for producing a second signal for activating said door unlocking actuator for unlocking said door lock when said input code matches said second code; and

third means, associated with said second memory means for counting the number of code elements of said second code for controlling reading of said second code in said second memory means.

4. A keyless entry system for an automotive vehicle comprising:

a door unlocking actuator for unlocking a door lock of a vehicle door;

an input unit positioned on the exterior of a vehicle for external operation for inputting an input code;

a first memory means for storing a first code;

first means for comparing said input code with said first code and producing a first signal when said input code matches said first code;

a second memory means for storing a second code including a given number of code elements, said second memory means having a read and write mode wherein said second code stored therein is readable and writable as a replacement of the previously stored second code, said second memory means being responsive to said first signal to change the mode thereof from said read mode to said write mode for inputting a new second code having a different number of code elements;

second means for comparing said input code with said second code and producing a second signal for activating said door unlocking actuator for unlocking said door lock when said input code matches said second code; and

third means, associated with said second memory means, for counting the number of code elements of said second code and recording the number of code elements of said second code stored in said second memory means, said third means being responsive to said first signal for resetting the recorded value therein for controlling the reading of said second code in said second memory means.

5. A keyless entry system for an automotive vehicle comprising:

a door unlocking actuator associated with a door lock provided in a vehicle door for unlocking said door lock;

an input unit including a plurality of push buttons respectively adapted to produce different values of input signals respectively indicative of values of inputted code elements of an input code;

an address signal generator, associated with said input unit and responsive to said input signals for producing address signals;

a first memory means for storing a first code comprised of a plurality of code elements, each of said code elements being stored in a corresponding address in said first memory means and read out upon access by said address signals;

first means for comparing each of the inputted code elements with a corresponding code element of said first code stored in the corresponding address in said first memory means and producing a first signal when all of said inputted code elements match the corresponding code elements of said first code;

a second memory means for storing a second code comprised of a given number of code elements stored in respective addresses therein, said second memory means being accessed by said address signals for reading out the code elements stored therein, said second memory means being responsive to said first signal for varying the combination of code elements of said second code and for varying said given number of code elements;

second means for comparing the inputted code elements with the corresponding code elements of said second code and producing a second signal for activating said door unlocking actuator for unlocking said door lock when said input code matches with said second code, and a reset signal for resetting and initializing the system otherwise; and

third means, associated with said second memory means and responsive to said first signal, for counting the number of digits forming said second code and recording the same for controlling the writing of said second code in said second memory means.

14. A keyless entry system for unlocking an automotive door lock in use with a code inputted thereto, which comprises:

an input unit for inputting an input code comprised of a plurality of code elements;

a first memory for storing a first code;

a second memory for storing a second code comprised of a variable number of code elements;

varying means, responsive to an inputted first code, for varying said second code to be stored in said second memory and for varying said number of code elements comprising said second code, said varying means being adapted to record said number of code elements of said second code stored in said second memory.