JP2003112445A - Electrophotographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic apparatus which can share a host apparatus irrespective of the number of beams by solving the problem that signal lines increase depending on the number of beams when binary image data is transmitted by a serial transfer system in an electrophotographic apparatus having multi beams. SOLUTION: In the electrophotographic apparatus having N (N=1, 2,..., N) multi beams for printing images on the basis of binary image data, an interface part of the electrophotographic apparatus which receives data parallel transferred from an interface part of the host apparatus is provided with a data distribution part for distributing data to each beam.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus that prints an image based on binary image data.

[0002]

2. Description of the Related Art In the electrophotographic apparatus described in Japanese Patent Laid-Open No. 10-305612, binary image data sequentially transmitted from a host apparatus is serially transferred by bit-by-bit data transfer using one signal line. Sent by the method. As the speed and image quality of an electrophotographic apparatus advance, the one-dot time of binary image data becomes shorter and the transfer speed becomes faster in the serial transfer method. For example, if 600dpi is set to 1200dpi, 1 dot time becomes 1/4 and transfer speed is 4
Double. Therefore, signal processing of the interface between the host device and the electrophotographic device, such as data setup / hold time, becomes difficult.

[0003]

As a solution to this problem, a method of making the electrophotographic apparatus into multiple beams is conceivable. Multi-beam is a single-beam 60 serial transfer method
When 0 dpi is set to 2 beams and 4 beams, 1 dot time is doubled by 2 beams and 4 times by 4 beams. Also, the transfer speeds are 1/2 and 1/4, respectively, which facilitates signal processing in the interface section.

However, since the transfer is serial, the number of signal lines increases depending on the number of beams. Japanese Patent Laid-Open No. 10-30561
In the case of the electrophotographic apparatus described in Japanese Patent Laid-Open No. 2-2, a signal beam which is twice as many as a single beam and four times as much as a four beam is required for a single beam. It is useless.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an electrophotographic apparatus in which the interface section configuration is unchanged regardless of the number of beams and the host apparatus can be shared.

[0006]

In the electrophotographic apparatus having N beams for printing an image based on binary image data, an X-bit binary value transferred in parallel from an interface section of a host apparatus is provided. This is achieved by providing an interface unit for receiving image data with a data distribution unit for distributing data to each of the N beams.

[0007]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows the configuration of the interface unit.

A host device 101, a driver / receiver unit 102 for receiving and transmitting parallel data and interface signals, a sampling and data distribution unit 103 for sampling parallel data and distributing the data to each beam, and serial conversion of parallel data for each beam The parallel-serial conversion unit 104 is used.

Pixel synchronization signal N (depending on the number of beams: N =
, 1, ..., N) are signals used when converting parallel data to serial data, and are generated inside the electrophotographic apparatus. From the host device 101, X-bit (X = 8 in this case) parallel data that is binary image data and a data transfer signal synchronized with the parallel data are transmitted.

FIG. 2 shows an example of serial transfer and an example of parallel transfer. With parallel transfer, the transfer speed is 1 / X of serial transfer with a single beam and N / X with multi-beam (X = 8, N = 1, 2, ..., N). At this time, the setup time T _SET and the hold time T _HOLD have an increased margin as compared with the serial time, and the sampling and signal processing in the data distribution unit 103 are facilitated.

FIG. 3 shows the driver / receiver unit 102 and the sampling / data distribution unit 103. The parallel data transmitted continuously is the driver / receiver unit 102.
To receive. The sampling and data distribution unit 103
It consists of FIFO (Fast In Fast Out) 301-304,
The parallel data received by the driver / receiver unit 102 is written in the FIFOs 301 to 304 by the data transfer signal. The FIFO is prepared for each beam, and the FIFO enable / disable of the FIFO control unit 305 enables / disables the FIFO.
While disabling, write parallel data for each beam.

In the figure, a FIFO 301 is shown in FIG.
Beam 2 for 302, beam (N-1) for FIFO 303
And the data for the beam N is written in the FIFO 304. When a beam number signal from the electrophotographic apparatus is received, the FIFO enable signal of the FIFO control unit 305 disables the unused FIFO, and the FIFO corresponding to the number of beams is used. For example, in the case of 2 beams, FIFO 30
3 and FIFO 304 disabled, FIFO 301 and FIFO
By operating 302, two-beam printing is performed.

The parallel data of each beam written in each FIFO is read out by an X-divided pixel synchronization signal N (X = 8, N = 1, 2, ..., N) obtained by dividing the pixel synchronization signal by X. .

The beam N parallel data (N = 1, 2, ..., N) read from the FIFO is processed by the parallel-serial conversion unit 103 in the pixel synchronization signal N (N = 1, 1).
2, ..., N) is converted into serial data and input to the laser drive circuit (not shown). The processing speed at this time is 1 / N (N = 1, 2, ..., N) for all the beams as compared with the single beam.

[0015]

As described above, according to the present invention, the number of signal lines of binary image data (X bit parallel) and other number of interface signal lines can be fixed regardless of the number of beams. The configuration is unchanged and the host device can be shared. Also setup /
There is a margin in the hold time, which facilitates signal processing.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of an interface unit.

FIG. 2 is an explanatory diagram of serial transfer and parallel transfer.

FIG. 3 is a detailed configuration diagram of a data distribution unit.

[Explanation of symbols]

101 host device 102 driver / receiver section 103 Sampling and data distribution unit 104 parallel-serial converter 301-304 FIFO

Claims (2)

[Claims] 1. An N for printing an image based on binary image data.
In an electrophotographic apparatus having two beams, an interface section for receiving X-bit binary image data transferred in parallel from an interface section of a host apparatus is provided with a data distributing section for distributing data to each of the N beams. An electrophotographic device characterized in that 2. The electrophotographic apparatus according to claim 1, wherein the interface unit can be fixed by the data distribution unit without depending on the number of beams.