Abstract: 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.

Abstract: A test pattern P3 longer than a length Ld corresponding to a circumferential length of a developing roller is formed along a moving direction of a photosensitive member (or developing roller). The developing roller transports a great quantity of toner on its surface in a first revolution thereof and hence, the test pattern has a high density. When the residual toner runs low, the toner transport quantity is decreased in the subsequent revolution, so that the test pattern P3 is decreased in the density at its portion beyond the length Ld from its head. If a density difference is observed at place corresponding to a boundary between image portions formed in the first revolution and the second revolution, it is concluded that image quality is degraded due to the shortage of residual toner.

Abstract: A process for producing a hollow blow-molded product with high productivity is provided by improving heating efficiency of a parison without significant changes to a molding machine for producing the product. The invention relates to the following production process. A process for producing a resin hollow molded product, which comprises the step of heating a parison formed of a thermoplastic resin material, and the step of blow-molding the heated parison, the heating step involving a near-infrared heater with a maximum energy wavelength in the range of 900 nm to 1500 nm and a wavelength converter disposed outside the parison, which absorbs the radiation from the near-infrared heater and emits the radiation as an infrared radiation longer than the maximum radiation energy. The wavelength converter emits radiation preferably with a maximum energy wavelength in the range of 3000 nm to 5000 nm.

Abstract: When the remaining toner amount within a developer is relatively large, a control target value of a toner amount is set to Ttgt1, and a lower limit value of a toner amount which can regarded proper is set to TL1. 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 Ttgt2 and the lower limit value is set to TL2 in light of this. In this fashion, regardless of whether the toner characteristic has changed, abnormality in the apparatus is detected without fail.

Abstract: In a density control technique wherein a density of a toner image formed as a patch image is detected for performing density control based on the detected result, detection errors are decreased so as to properly set a density control factor. The density control factor is optimized based on a variation rate of the patch image densities against a varied density control factor. The detected results of the patch image densities are corrected based on information on an image carrier acquired before the formation of the patch images.

Abstract: It is an object of the present invention to provide a hollow bottle made of polyester, which has excellent heat resistance and is not likely to undergo deformation or change in capacity even if a liquid of high temperature is filled therein. The present invention relates to a hollow bottle formed by blow molding polyester, which has a thickness in the range of 200 to 400 ?m, and satisfies that ?d=d1?d2 is not less than ?7 kg/m3 and not more than 7 kg/m3, with d1 [kg/m3] being a density of a part ranging from an outer surface up to 50 ?m inward, and d2 [kg/m3] being a density of a part ranging from an inner surface up to 50 ?m inward. The polyester is preferably polyethylene terephthalate, and it is preferable that d1=1370 to 1375 kg/m3, while d2=1373 to 1378 kg/m3.

Abstract: Optimization of a density control factor accompanying formation of a patch image is executed every time a predetermined period of time elapses since the end of a preceding image forming operation. Since an image is formed at regular intervals in this manner, it is possible to suppress a density variation which is created as toner carried on a developer roller is left unused for long. This effect further improves when the developer roller is rotated idle prior to formation of a patch image or regularly at predetermined timing.

Abstract: It is an object of the invention to provide a polyester resin from which a bottle superior in transparency and mechanical characteristics can be provided even though it has a large wall thickness. A hollow bottle comprising a polyester resin containing a dicarboxylic acid unit and a diol unit, and having a vent plug portion, a shoulder portion, a body portion and a bottom portion, wherein; (1) the wall thickness of the bottle body is 500 ?m; and (2) the content of a titanium atom is 1 ppm or more to 30 ppm or less. It is preferable that the cooling-down crystallization temperature (Thc) of the bottle body portion be 170° C. or less, and 97 mol % or more of all dicarboxylic acid units be terephthalic acid and 97 mol % or more of all diol units be ethylene glycol.

Abstract: In a density control technique wherein a density of a toner image formed as a patch image is detected for performing density control based on the detected result, detection errors are decreased so as to properly set a density control factor. The density control factor is optimized based on a variation rate of the patch image densities against a varied density control factor. The detected results of the patch image densities are corrected based on information on an image carrier acquired before the formation of the patch images.

Abstract: Optimization of a density control factor accompanying formation of a patch image is executed every time a predetermined period of time elapses since the end of a preceding image forming operation. Since an image is formed at regular intervals in this manner, it is possible to suppress a density variation which is created as toner carried on a developer roller is left unused for long. This effect further improves when the developer roller is rotated idle prior to formation of a patch image or regularly at predetermined timing.

Abstract: In a density control technique wherein a density of a toner image formed as a patch image is detected for performing density control based on the detected result, detection errors are decreased so as to properly set a density control factor. The density control factor is optimized based on a variation rate of the patch image densities against a varied density control factor. The detected results of the patch image densities are corrected based on information on an image carrier acquired before the formation of the patch images.

Abstract: Optimization of a density control factor accompanying formation of a patch image is executed every time a predetermined period of time elapses since the end of a preceding image forming operation. Since an image is formed at regular intervals in this manner, it is possible to suppress a density variation which is created as toner carried on a developer roller is left unused for long. This effect further improves when the developer roller is rotated idle prior to formation of a patch image or regularly at predetermined timing.

Abstract: A test pattern P3 longer than a length Ld corresponding to a circumferential length of a developing roller is formed along a moving direction of a photosensitive member (or developing roller). The developing roller transports a great quantity of toner on its surface in a first revolution thereof and hence, the test pattern has a high density. When the residual toner runs low, the toner transport quantity is decreased in the subsequent revolution, so that the test pattern P3 is decreased in the density at its portion beyond the length Ld from its head. If a density difference is observed at place corresponding to a boundary between image portions formed in the first revolution and the second revolution, it is concluded that image quality is degraded due to the shortage of residual toner.

Abstract: When the remaining toner amount within a developer is relatively large, a control target value of a toner amount is set to Ttgt1 and a lower limit value of a toner amount which can regarded proper is set to TL1. 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 Ttgt2 and the lower limit value is set to TL2 in light of this. In this fashion, regardless of whether the toner characteristic has changed, abnormality in the apparatus is detected without fail.

Abstract: A gradation patch image Ip used for determination of tone characteristics of an apparatus is progressively varied in the tone level thereof from the maximum tone level (level 255) to the minimum tone level (level 0). The gradation patch image is either a toner image continuously and consistently varied in the tone level thereof or a toner image having the tone levels varied stepwise at a smaller pitch than a width of a detection region of a patch sensor. In density detection of such a gradation patch image Ip, toner image densities at portions on either sides in the detection region of the patch sensor are canceled each other out by averaging and hence, only a toner image density substantially at the center of the detection region can be obtained.

Abstract: Output signals Vp from a density sensor are sampled for plural positions on an intermediate transfer belt and an amount of toner adhesion is determined based on the results of sampling. Since these sample data pieces may contain noises, each predetermined number of data pieces of higher order and of lower order are removed from the resultant sample data string. The removed data pieces are each replaced by an average value Vpavg of the other sample data pieces. The amount of toner adhesion is calculated based on the data string thus replaced.

Abstract: 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.

Abstract: 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.

Abstract: In a density control technique wherein a density of a toner image formed as a patch image is detected for performing density control based on the detected result, detection errors are decreased so as to properly set a density control factor. The density control factor is optimized based on a variation rate of the patch image densities against a varied density control factor. The detected results of the patch image densities are corrected based on information on an image carrier acquired before the formation of the patch images.

Abstract: Output signals Vp from a density sensor are sampled for plural positions on an intermediate transfer belt and an amount of toner adhesion is determined based on the results of sampling. Since these sample data pieces may contain noises, each predetermined number of data pieces of higher order and of lower order are removed from the resultant sample data string. The removed data pieces are each replaced by an average value Vpavg of the other sample data pieces. The amount of toner adhesion is calculated based on the data string thus replaced.