Image forming apparatus, image forming system, image processing method, and computer-readable recording medium

Patent metadata

Field	Value
Publication number	US-2016335035-A1
Application number	US-201615133971-A
Country	US
Kind code	A1
Filing date	Apr 20, 2016
Priority date	May 15, 2015
Publication date	Nov 17, 2016
Grant date	—

Abstract

An image forming apparatus according to the present invention performs image processing on image data in units of pages stored in a page memory on the basis of parameter setting, transferring the image data to a buffer at a first speed, transmitting the image data, which is read out from the buffer at a second speed, to an image forming unit, and executing parameter setting for image processing performed when image data for a subsequent page is transferred after the image data for a single page has been transferred but before image data for the subsequent page is started to be transferred, wherein the first speed is faster than a second speed.

First claim

What is claimed is:

1 . An image forming apparatus for forming an image on a sheet on the basis of image data in units of pages, the image forming apparatus comprising:
a page memory storing the image data in units of pages; a buffer temporarily storing the image data transferred from the page memory at a first speed; an image forming unit forming an image on the basis of the image data read out from the buffer at a second speed; and an image control circuit controlling operation of the transfer and the read out, performing parameter setting for each page, and performing image processing on the image data on the basis of the parameter setting, wherein the first speed is faster than the second speed, and after the image data for a single page has been transferred from the page memory to the buffer but before image data for a subsequent page is started to be transferred, the image control circuit executes the parameter setting for the image data for the subsequent page.

2 . The image forming apparatus according to claim 1 , wherein the transfer and the read out are performed on image data for a single main scanning line,
the image control circuit uses first and second index signals to control operation timing of the transfer and the read out, respectively, for each main scanning line, the second index signal is commonly used for control of operation timing of writing of the main scanning line with a writing unit of the image forming unit, and a cycle of the first index signal is set to be shorter than a cycle of the second index signal, so that the first speed is configured to be faster than the second speed.

3 . The image forming apparatus according to claim 1 , wherein the first speed is set to such a speed that a time for executing the parameter setting can be ensured after image data for a single page has been transferred from the page memory to the buffer but before image data for a subsequent page is started to be transferred.

4 . The image forming apparatus according to claim 1 , wherein the image forming unit includes a plurality of writing units corresponding to a plurality of colors,
a plurality of the buffers are provided so as to correspond to the plurality of writing units, respectively, the image control circuit executes image processing on image data constituted by signals of a plurality of color components stored in the page memory on the basis of the parameter setting when the image data of all the colors are transferred, at a time, to the buffers respectively corresponding to the colors.

5 . The image forming apparatus according to claim 4 , wherein the image control circuit performs read out of image data of pages from the plurality of buffers at operation timing which differs according to the color components.

6 . The image forming apparatus according to claim 4 , comprising a control unit calculating an upper limit value of the first speed for each color on the basis of an image size of image data in units of pages in a sub-scanning direction, a capacity of each of the plurality of the buffers, a relative distance between exposure positions of the plurality of writing units, the second speed, and a maximum transfer speed in design with the image control circuit,
wherein the control unit compares the calculated upper limit value of the first speed for each color, and the control unit commonly applies the lowest first speed to all the colors, and the control unit causes the image control circuit to execute transfer of the image data of the colors from the page memory to the plurality of the buffers, respectively.

7 . The image forming apparatus according to claim 6 , wherein the control unit executes calculation and application of the first speed for each page.

8 . The image forming apparatus according to claim 6 , wherein the control unit calculates the first speed on the basis of a maximum image size in design that can be processed.

9 . The image forming apparatus according to claim 4 , wherein the first speed is equal to or more than a lower limit value of the first speed with which it is possible to ensure a time to execute the parameter setting after the image data for a single page has been transferred from the page memory to the buffer but before image data for a subsequent page is started to be transferred, and
the first speed is equal to or less than an upper limit value of the first speed which is the lowest one of upper limit values of the first speed of the colors, which are calculated on the basis of a maximum image size in design that can be processed in a sub-scanning direction of the image data in units of pages, a capacity of each of the plurality of the buffers, a relative distance between exposure positions of the plurality of writing units, the second speed, and a maximum transfer speed in design with the image control circuit.

10 . An image forming system comprising:
the image forming apparatus according to claim 1 ; and a sheet feeding apparatus conveying a continuous sheet to the image forming apparatus, wherein the image forming unit continuously forms images in units of pages on a continuous sheet on the basis of a plurality of image data in units of pages.

11 . An image processing method comprising:
a step of storing image data in units of pages to a page memory; a step of performing image processing on the image data stored in the page memory on the basis of parameter setting, and transferring the image data to a buffer at a first speed; a step of transmitting the image data, which is read out from the buffer at a second speed, to an image forming unit; and a step of executing parameter setting on the image data for a subsequent page after the image data for a single page has been transferred to the buffer but before image data for the subsequent page is started to be transferred, wherein the first speed is faster than the second speed.

12 . The image processing method according to claim 11 , wherein in the step of transfer the image data and the step of reading out and transmitting the image data, first and second index signals are used to control operation timing of the transfer and the read out, respectively, for the image data in a single main scanning line,
the second index signal is commonly used for control of operation timing of writing of the main scanning line with a writing unit of the image forming unit, and a cycle of the first index signal is set to be shorter than a cycle of the second index signal, so that the first speed is configured to be faster than the second speed.

13 . The image processing method according to claim 11 , wherein the first speed is set to a speed with which it is possible to ensure a time to execute the parameter setting after the image data for a single page has been transferred from the page memory to the buffer but before image data for a subsequent page is started to be transferred.

14 . The image processing method according to claim 11 , wherein the image forming unit includes a plurality of writing units corresponding to a plurality of colors,
a plurality of the buffers are provided so as to correspond to the plurality of writing units, respectively, in the step of transferring the image data, the image data of all the colors constituted by signals of a plurality of color components stored in the page memory on the basis of the parameter setting are transferred, at a time, to the buffers respectively corresponding to the colors, and image processing is executed on the image data on the basis of the parameter setting.

15 . The image processing method according to claim 14 ,

Assignees

• Konica Minolta Inc

Inventors

• Uchida Yuji

Classifications

• G06F3/1244

  Job translation or job parsing, e.g. page banding · CPC title

• G06F3/1282

  High volume printer device · CPC title

• G06F3/1295

  Buffering means · CPC title

• G06F3/1254

  Automatic configuration, e.g. by driver · CPC title

• G06F3/1211 Primary

  Improving printing performance · CPC title