IP Library Granted Patent US 11,347,172
Granted Patent B2
US 11,347,172 · App. 17/188,003 · Granted May 31, 2022

System and methods for detecting non-authentic slave components using clock frequency changes

Inventors: Zachary Nathan Fister (Lexington, KY); Timothy John Rademacher (Lexington, KY)
Assignee: Lexmark International, Inc.
G03G15/55G03G15/0863G06F13/4291G06F21/44G03G2215/0697
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Quick Facts
Patent No.
US 11,347,172
App. No.
17/188,003
Granted
May 31, 2022
Kind
B2
Abstract

A method for detecting a non-authentic slave component in an electronic printer device which includes receiving a command from a master component in the device, identifying a response to the command based upon a frequency of a plurality of clock pulses used by the master component while sending the command, and sending the response to the master component for use as a basis in determining whether the slave component is one of an authentic slave component and a non-authentic slave component. The disclosed method may be performed by a replaceable slave component in an imaging device including a slave circuit communicating with a master circuit of the master component along a serial communications interface. The master circuit includes an instruction to change a clock frequency when sending a command to the slave circuit to trigger a unique response from slave circuits of authentic slave components.

Claims (9)

1. A method for detecting a non-authentic slave component in an electronic printer device, the method comprising:

receiving, by a slave component communicatively connected to a master component in the device, a command from the master component;

identifying a response to the command based upon a frequency of a plurality of clock pulses used by the master component while sending the command;

performing an enforcement action in the device following the identification that the slave component is not an authentic slave component; and

sending the response to the master component,

wherein the master component determines, using a plurality of clock pulses of a same rate, whether the response received from the slave component is an expected slave component response when the command is sent by the master component to the slave component, thus identifying the slave component as an authentic slave component.

2. The method of claim 1 , further comprising determining whether the frequency of the plurality of clock pulses matches a predetermined frequency used by the master component in communicating with the slave component prior to the identifying the response.

3. The method of claim 1 , wherein the receiving the command from the master component is performed upon every power on reset of the device.

4. The method of claim 1 , wherein the slave component is a replaceable component having a circuit communicatively coupled to the master component along a serial communications interface in the device.

Assignments (5)
SECURITY INTEREST Recorded Jan 5, 2026
From: LEXMARK INTERNATIONAL, INC.
To: BANK TRUST COMPANY, NATIONAL ASSOCIATION
Reel/Frame 074202/0192 →
SECURITY INTEREST Recorded Jan 5, 2026
From: LEXMARK INTERNATIONAL, INC.
To: BANK TRUST COMPANY, NATIONAL ASSOCIATION
Reel/Frame 074202/0293 →
SECURITY INTEREST Recorded Sep 23, 2025
From: LEXMARK INTERNATIONAL, INC.
To: CITIBANK, N.A.
Reel/Frame 073007/0118 →
SECURITY INTEREST Recorded Sep 23, 2025
From: LEXMARK INTERNATIONAL, INC.
To: JEFFERIES FINANCE LLC
Reel/Frame 073007/0346 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 1, 2021
From: FISTER, ZACHARY NATHAN; RADEMACHER, TIMOTHY JOHN
To: LEXMARK INTERNATIONAL, INC.
Reel/Frame 055441/0417 →