Seiko Epson Corporation

Hidenori Kin

Yoichi Yamada

Tomoe Aruga

Tahei Ishiwatari

Kazuhiro Ichikawa

Yoshihiro Nakashima

Yukio Takayama

Hidetsugu Shimura

Isao Inaba

Takehiko Okamura

Shinsuke Yokote

Keiichi Taguchi

Takashi Hama

Hiroshi Nakazato

Takatoshi Sugita

Ken Ikuma

Toshiki Shiroki

Toru Fujita

Yoshiro Koga

Masanao Kunugi

Fumio Takagi

Kuniaki Tanaka

Tsuneo Handa

An image forming apparatus which forms an image using toner includes: a data processor which performs data processing of input image data corresponding to a toner color and accordingly generates output image data needed to obtain a predetermined tone reproduction characteristic; an image forming unit which forms an image corresponding to the output image data; and a toner consumption amount calculator which executes data selection for selecting one of the input image data and the output image data in accordance with a scheme of the data processing, sums up values of the selected image data, and calculates amount of toner consumed as an image is formed based on resulting integration value.

Image forming apparatus and toner consumption amount calculating method

An image It is formed as a patch image which includes a header image portion Ih of a solid image having a length of a circumferential length of a developing roller or more, and a gradation image portion Ig progressively varied in the tone level thereof from the maximum level to the minimum level. The densities of the patch image on an intermediate transfer belt are sampled. However, the sampling results contain errors resulting from noises or variations and hence, are subjected to a noise removal process, a periodical variation correction process and a reverse correction process. The results detected on the intermediate transfer belt do not always coincide with image densities (OD values) on a recording material. Therefore, the detection results are converted into the OD values, based on which tone characteristics of an apparatus is estimated. Then a tone correction table is updated in a manner to compensate for the tone characteristics. This approach is taken to improve image quality on the recording material.

Image forming apparatus and method for controlling tone characteristics based on tone-control patch image

An image forming apparatus for forming an image corresponding to an image signal on a recording material, comprising: a signal processor which generates an image-formation control signal by subjecting the image signal to a signal processing process including a screening process selectively using one of plural types of different processing screens; an image forming unit which includes an intermediate transfer medium, and which forms the image by forming a toner image on the intermediate transfer medium corresponding to the image-formation control signal and transferring and fixing the toner image to a recording material; and a detector which detects a quantity of the toner carried on the intermediate transfer medium as the toner image, wherein the signal processing process performed by the signal processor includes a tone correction process for compensating for a gamma characteristics of the apparatus based on a detection result given by the detector detecting a toner image formed as a patch image by using the processing screen and a transferring/fixing characteristics, which represents a relation between a quantity of toner constituting a toner image carried on the intermediate transfer medium and a density of an image formed on the recording material as a result of transferring and fixing the toner image to the recording material, previously determined in correspondence to the processing screen.

Image forming apparatus and control method thereof

An image forming apparatus, includes: a developer which is attachable to and detachable from an apparatus main body and which holds toner; an image forming section which forms a toner image using the toner held inside the developer; and a controller which executes a density control operation of forming a patch image using the toner held inside the developer and controlling an image forming condition for the image forming section based on a density detection result of the patch image, wherein the developer includes a memory which stores specific information regarding an attribute which is specific to the developer, and the controller determines a mode of the density control operation based on the specific information read out from the memory.

Image forming apparatus and a method of controlling the image forming apparatus

Based on a video signal, a toner dot counter and an off dot counter detect a size of a toner dot portion to carry an adherent toner thereto and a size of an off dot portion not to carry an adherent toner, respectively. Reference is made to a look-up table based on the detection results, so as to retrieve a coefficient Kv corresponding to a combination of the sizes of the toner dot portion and the off dot portion. A count value Cdot given by the toner dot counter is multiplied by the coefficient Kv, while the resultant product is integrated by an accumulator. An integration value for an image of one page is multiplied by a coefficient Kequivalent to a toner adhesion percentage of solid image. Thus is determined a toner consumption TC on the page image.

Image forming apparatus, a toner counter and a calculation method of toner consumption

An image forming apparatus of forming an image corresponding to image data is formed on a recording medium comprises a data processor which performs data processing of input image data so that a first correlation will be established between a target image density expressed by the input image data and the actual image density of an image formed on the recording medium, thereby generating output image data, an image forming unit which forms an image corresponding to the output image data on the recording medium, and a toner consumption amount calculator which calculates a toner consumption amount which is consumed for image formation based on the input image data and based on a second correlation between the input image data and an adhering toner amount on the recording medium.

Image forming apparatus, image forming method, toner counter and calculation method of toner consumption

Based on a video signal, a toner dot counter and an off dot counter detect a size of a toner dot portion to carry an adherent toner thereto and a size of an off dot portion not to carry an adherent toner, respectively. Reference is made to a look-up table based on the detection results, so as to retrieve a coefficient Kv corresponding to a combination of the sizes of the toner dot portion and the off dot portion. A count value Cdot given by the toner dot counter is multiplied by the coefficient Kv, while the resultant product is integrated by an accumulator. An integration value for an image of one page is multiplied by a coefficient K0 equivalent to a toner adhesion percentage of solid image. Thus is determined a toner consumption TC on the page image.

When the remaining toner amount within a developer is relatively large, a control target value of a toner amount is set to Ttgtand a lower limit value of a toner amount which can regarded proper is set to TL. When the density of a patch image formed under a predetermined condition is smaller than a minimum guaranteed density Dma, it is determined abnormality has occurred in the apparatus. Since the characteristic of toner within the developer changes as the remaining toner amount decreases, the control target value is changed to Ttgtand the lower limit value is set to TLin light of this. In this fashion, regardless of whether the toner characteristic has changed, abnormality in the apparatus is detected without fail.

Image forming apparatus, control method and toner consumption calculating apparatus and method

The content of processing of an input image signal varies depending upon the conditions of an apparatus. In view of the fact that this results in the variations of correlation between tone data and toner consumption, a coefficient by which an integration value of the tone data is defined according to the content of the signal processing. In an image forming apparatus which performs tone correction as the signal processing and which has a characteristic () of forming images of higher densities relative to tone levels, for example, a larger amount of toner is consumed. Therefore, the coefficient of the apparatus is defined to be a higher value than that of an apparatus having a substantially linear characteristic (). Conversely, in the case of an apparatus having a characteristic () of forming images of lower densities, thus consuming less toner, the coefficient is defined to be a lower value.

In a device for calculating a total amount of toner consumed from a toner cartridge, a first amount of the toner, which is consumed in a first region of a recording medium at which a toner image is formed, is obtained. A time period of which the toner cartridge is in operation is clocked. A second amount of the toner, which is consumed in a second region of the recording medium at which the toner image is not formed, is stored in advance. The second amount is associated with the time period. The second amount is added to the first amount in accordance with the clocked time period, in order to obtain the total amount.

Device and method of calculating toner consumption, and image forming apparatus using the same

A condition controlling process is executed when parameters expressing a state of toner within a developer reaches predetermined threshold values. On each one of two parameters, namely, a dot count value which is indicative of a toner consumption amount (an integrated value of the number of dots formed using an exposure beam) and a developer roller rotating time which is indicative of the degree of toner fatigue, a threshold value (denoted at the dotted lines) which triggers execution of the condition controlling process is set. At the time that the path d of dots which are expressed as combinations of these parameters intersects each dotted line (the intersections (1) through (6)), the condition controlling process is executed.

Apparatus for and method of forming image under controlled image forming condition

An image forming apparatus has a latent image carrier on which a latent image is formed. A developer carrier conveys a one-component non-magnetic developer and develops the latent image either in close proximity to or in contact with the latent image carrier. A voltage application unit applies an AC-superimposed bias voltage to the developer carrier. A regulating member abuts against the developer carrier to regulate the thickness of the developer layer on the developer carrier. The regulating member has a semiconductive member provided at the distal end thereof to produce an electric potential difference between the semiconductive member and the developer carrier, to which the AC-superimposed bias voltage is applied, when regulating the thickness of the developer layer on the developer carrier, thereby forming a line-shaped uneven conveying surface. Thus, the occurrence of banding and longitudinal unevenness and stripes is prevented, and fogging and scattering are also prevented. Further, the occurrence of filming is prevented, thereby allowing formation of a uniform image free from density unevenness.

Image forming apparatus with reduced image defects

A developing device includes a supply member disposed to rotate in contact with a developer carrier to supply developer layer having a predetermined thickness to the developer carrier surface. A layer forming member is disposed to abut against the developer carrier to regulate the layer thickness of the developer so as to form a thin developer layer on the developer carrier. A bias application unit applies an AC-superimposed bias voltage to the developer carrier. A latent image on a latent image carrier is developed with the thin developer layer formed on the developer carrier by the layer forming member. The minimum value of the AC-superimposed bias voltage may be lower than the exposure potential of the latent image carrier, and a maximum value of the bias voltage is to be lower then the charge potential. However, the polarities of the two voltages may be identical.

Developing device

A developing device according to the present invention comprises an image developing roll having a roll surface treated with sand blast treatment to form a rough surface morphology in which aluminum anodizing is also applied to the surface of the image developing roll where the rough surface morphology is formed. To the image developing roll is applied a development bias consisting of a direct current voltage overlapped with an alternate current voltage. In this arrangement, the image developing roll can perform the functions of conveying developer, charging developer, and preventing of discharge of the developing bias, while the image developing roll can be manufactured from a metallic roll such as aluminum roll at a low cost. Moreover, a gradual scraping of the image developing roll surface by external additives of toner suppresses adhering of toner onto the surface of the image developing roll , preventing the occurrence of filming.

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Nagano-ken, Japan

Hidenori Kin