Image forming apparatus
AssigneeFuji Photo Film Co., Ltd.
InventorKenichi Kodama
Life of this patent
Estimating the term…
Abstract
On a basis of a frequency analysis of the irregularities in density caused by a subscanning direction feed amount error of an exposure head, subscanning direction intervals between LEDs of the exposure head within the image forming apparatus are unequal such that the irregularities in density generated in an image is generated in high frequency area with a spatial frequency of at least 1 lp/mm. By using such image forming apparatus, an image is formed in which the irregularities in density is sufficiently suppressed in low frequency area with the spatial frequency of less than 1 lp/mm. Even if the irregularities in density is relatively large in high spatial frequency area, human eyes are difficult to view the irregularities in density thus the image quality can be improved.
Claims12
An image forming apparatus, wherein each interval of plurality of recording elements provided at a recording head in an intermittent relative feed direction is set such that irregularities in density, generated in an image, due to a feed amount error between a recorded material and the recording head in the intermittent relative feed direction, is generated in an area with a spatial frequency of 1 lp/mm or more.
An image forming apparatus, wherein:
- each interval of plurality of pixels in an intermittent relative feed direction, recorded substantially simultaneously by a plurality of recording elements which are provided at a recording head, is a natural number multiplied by d, wherein a minimum interval of the pixel in the intermittent relative feed direction is d;
- a feed amount of the intermittent relative feed direction between a recorded material and the recording head is set to be (n×2×d/k), wherein a number of the recording elements is n, k is a natural number of 2 or more;
- and
- assuming that a pixel recorded by i th recording element is recorded on a position of the recorded material, which position is apart from a pixel recorded by a first recording element by a distance Li in the intermittent relative feed direction, each interval of plurality of the recording elements in the intermittent relative feed direction is set such that a pixel is not recorded on a position of the recorded material, which position is apart from the pixel recorded by the first recording element by a distance {Li+j×(n×2×d/k)} in the intermittent relative feed direction, wherein j is a natural number.
An image forming apparatus which forms an image by repeating for a plurality of times a relative movement of a recorded material and a recording portion for recording an image in a subscanning direction at a predetermined amount and a relative movement of the recorded material and the recording portion in the main scanning direction, the image forming apparatus comprising:
- a plurality of recording elements which are provided at the recording portion and which are arranged in at least one row in the subscanning direction;
- wherein the plurality of recording elements are arranged with non-uniform interval thereof in the subscanning direction.
An image forming method for forming an image on a recorded material by a comb-teeth type printing by using an image forming apparatus, in which each interval of plurality of recording elements provided at a recording head in an intermittent relative feed direction is set such that irregularities in density, generated in an image, due to a feed amount error between the recorded material and the recording head in the intermittent relative feed direction, is generated in an area with a spatial frequency of 1 lp/mm or more.
Dependencies are inferred from the claim text.