Abstract: According to an image forming apparatus of the present invention, when a user with the intention of having a processing completed in a short time inputs execution of an image forming job involving the intention, this operation information is acquired by an operation information acquisition section. In response to that, an invalidation determining section determines to invalidate processing for maintenance, based on the operation information. Responding to that, an invalidation control section invalidates the processing for maintenance on image forming during execution of the image forming job regardless of predetermined rules. By this means, the processing for maintenance on image forming cannot be executed during the image forming job in the case of a user with the intention of having a processing completed in a short time.

Abstract: A multi-color image-forming apparatus having image-forming sections for a plurality of different colors can include an optical sensor having a light-casting section that casts single polarized light and a light-receiving section that receives polarized light different from the cast light. A pattern for detecting toner positions can be used in which toner having high reflectance to a particular light emission wavelength is independently formed. In addition, other patterns in which toner having low reflectance to the particular light emission wavelength are partially formed on a central portion of the pattern of high reflection toner by using the high reflection toner as a foundation. The apparatus can detect each toner pattern by the optical sensor to correct the color shift of each color.

Abstract: A media information distribution and recording system for distributing media information from a central apparatus to terminal apparatus through a network and for recording the media information on a detachable recording medium in the terminal apparatus, wherein the terminal apparatus serves not only as a transmitting terminal apparatus, but also as a receiving terminal apparatus, is proposed, together with the terminal apparatus, a media information recording apparatus for use in this system, and a recording medium which stores a program that controls the operation of a computer for use in this system as well as in the media information recording apparatus.

Abstract: According to an image forming apparatus of the present invention, when a user with the intention of having a processing completed in a short time inputs execution of an image forming job involving the intention, this operation information is acquired by an operation information acquisition section. In response to that, an invalidation determining section determines to invalidate processing for maintenance, based on the operation information. Responding to that, an invalidation control section invalidates the processing for maintenance on image forming during execution of the image forming job regardless of predetermined rules. By this means, the processing for maintenance on image forming cannot be executed during the image forming job in the case of a user with the intention of having a processing completed in a short time.

Abstract: A multi-color image-forming apparatus having image-forming sections for a plurality of different colors can include an optical sensor having a light-casting section that casts single polarized light and a light-receiving section that receives polarized light different from the cast light. A pattern for detecting toner positions can be used in which toner having high reflectance to a particular light emission wavelength is independently formed. In addition, other patterns in which toner having low reflectance to the particular light emission wavelength are partially formed on a central portion of the pattern of high reflection toner by using the high reflection toner as a foundation. The apparatus can detect each toner pattern by the optical sensor to correct the color shift of each color.

Abstract: When a card reader detects that a magnetic card is inserted (YES in S1), an operative program stored in the magnetic card is installed in a storage unit by an installing unit (S3), while when the card reader detects that the magnetic card is removed (YES in S4), the operative control program installed hitherto is uninstalled from the storage unit by an uninstalling unit (S5).

Abstract: An image processing apparatus for quantizing image data indicative of a density gradation level of a constituent pixel of an image into a discrete value on the basis of quantization levels of a number smaller than the maximum density gradation level and not smaller than two.

Abstract: A media information distribution and recording system for distributing media information from a central apparatus to terminal apparatus through a network and for recording the media information on a detachable recording medium in the terminal apparatus, wherein the terminal apparatus serves not only as a transmitting terminal apparatus, but also as a receiving terminal apparatus, is proposed, together with the terminal apparatus, a media information recording apparatus for use in this system, and a recording medium which stores a program that controls the operation of a computer for use in this system as well as in the media information recording apparatus.

Abstract: A media information distribution and recording system for distributing media information from a central apparatus to terminal apparatus through a network and for recording the media information on a detachable recording medium in the terminal apparatus, wherein the terminal apparatus serves not only as a transmitting terminal apparatus, but also as a receiving terminal apparatus, is proposed, together with the terminal apparatus, a media information recording apparatus for use in this system, and a recording medium which stores a program that controls the operation of a computer for use in this system as well as in the media information recording apparatus.

Abstract: An image processing apparatus for quantizing image data indicative of a density gradation level of a constituent pixel of an image into a discrete value on the basis of quantization levels of a number smaller than the maximum density gradation level and not smaller than two.

Abstract: A sheet transportation device for use in an image forming apparatus is provided which has self-diagnosis and self-repair functions. The sheet transportation device has a sheet transportation system including a plurality of units (8). A control sequence for a sheet transportation operation is applied from a system body (10) to the respective units (8). The units (8) each execute the control sequence to perform the sheet transportation operation. The units (8) are each constructed so as to perform an autonomous operation. This construction allows the respective units to autonomously perform self-diagnosis and repair operations. The fault diagnosis and repair operations are performed in parallel to the sheet transportation control. Therefore, the sheet transportation device can flexibly adapt itself to an external influence such as a change in the use environment and a malfunction due to a time-related change such as the aging of components thereof.

Abstract: A simulation system is provided which is capable of simulating the behavior of a sheet transported by a transportation system. In response to application of a control sequence formulated for the sheet transportation system, a simulation is performed to check how the sheet is to be transported in the sheet transportation system on the basis of the applied control sequence. Necessary data are extracted from hardware systems constituting the real sheet transportation system. On the basis of the extracted data, a virtual sheet transportation system is constructed in a computer, and the sheet is represented by information indicative of the locations of opposite ends of the sheet and the distance therebetween. The sheet thus represented is moved by a predetermined unit distance in the virtual sheet transportation system on the basis of the control sequence, and data is computed for every movement of the sheet.

Abstract: A method and an apparatus for selecting an amount of light to be irradiated for fog detection onto a photoreceptor from a density detecting device out of amounts of light for low density or for high density. A real original is illuminated by a predetermined amount of illuminating light, whereby a toner image corresponding to the real original is formed on the photoreceptor. Light of an amount for low density from the density detecting device is irradiated onto the toner image to acquire a first density data. Thereafter, a pseudo original is illuminated by the predetermined amount of illuminating light, whereby a toner image corresponding to the pseudo original is formed. Light of the amount for low density from the density detecting device is irradiated onto the toner image to acquire a second density data. The difference between the first and the second density data is compared with a predetermined threshold value.

Abstract: A device and method for detecting a toner image density accurately while using a characteristic curve found at the time of initialization. In the initialization, light of a first amount for low density is irradiated onto a photoreceptor from a density sensor, to acquire a first low-density light amount characteristic curve. In the characteristic curve, a toner image density corresponding to first density data is taken as a first reference density. A first amount of light for high density is then set to acquire a high-density light amount characteristic curve. In the characteristic curve, density data corresponding to the first reference density is taken as first correcting reference data. In density detection, a second amount of light for low density and a second amount of light for high density are found. A second low-density light amount characteristic curve corresponding to the second amount for low density is acquired.

Abstract: A method and an apparatus for setting an amount of light to be irradiated onto a photoreceptor from a density detecting device precisely in a short time in detecting the density of a toner image on the photoreceptor. Light of amounts in a plurality of steps is successively irradiated onto one point of the photoreceptor on which no toner adheres. Density data outputted by the density detecting device which correspond to the amounts of light in the respective steps are acquired. One density data is selected on a predetermined basis out of a plurality of density data acquired. Light of the amount in the step corresponding to the selected one density data (a reference amount of light) is irradiated onto a plurality of points of the photoreceptor. The density data outputted by the density detecting device at each of the points is acquired. The average value of the acquired density data corresponding to the plurality of points is found as average density data.