Invention Grant
- Patent Title: Pixel clock generator and image forming apparatus
- Patent Title (中): 像素时钟发生器和图像形成装置
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Application No.: US12998063Application Date: 2009-09-15
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Publication No.: US08493578B2Publication Date: 2013-07-23
- Inventor: Naruhiro Masui
- Applicant: Naruhiro Masui
- Applicant Address: JP Tokyo
- Assignee: Ricoh Company, Limited
- Current Assignee: Ricoh Company, Limited
- Current Assignee Address: JP Tokyo
- Agency: Harness, Dickey & Pierce, P.L.C.
- Priority: JP2008-236561 20080916
- International Application: PCT/JP2009/066572 WO 20090915
- International Announcement: WO2010/032862 WO 20100325
- Main IPC: B41J2/435
- IPC: B41J2/435 ; H04N1/40

Abstract:
A pixel clock generator includes a frequency divider 4 that generates a pixel clock PCLK based on a high frequency clock VCLK, a comparator 5 that calculates an error Lerr in the time obtained by integrating a cycle of the pixel clock PCLK for a target number RefN from a time when synchronization signals SPSYNC and EPSYNC are detected, a filter 6, and a frequency calculating unit 7 that sets a frequency dividing value M of the frequency divider 4. The filter 6 and the frequency calculating unit 7 calculate an average of a frequency of the pixel clock PCLK based on the error Lerr, determine a reference error value from the error Lerr in N-cycles, calculate offset values of the frequencies of N pieces of pixel clocks PCLK based on a difference between the reference error value and the error Lerr, and calculate the frequency dividing value M based on a result obtained by adding the circularly selected offset values and the average of the frequency of the pixel clock PCLK.
Public/Granted literature
- US20110164273A1 PIXEL CLOCK GENERATOR AND IMAGE FORMING APPARATUS Public/Granted day:2011-07-07
Information query
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