摘要:
An image density discrimination chart is used to discriminate a density of a test image printed by an image forming apparatus. The chart includes an exposing portion for exposing the test image when the chart is overlaid relative to a printed recording material, a first comparison image having an upper limit level of a latitude, permitted by the image forming apparatus, for image density of the test image, and a second comparison image having a lower limit level of a latitude, permitted by the image forming apparatus, for image density of the test image.
摘要:
An image forming apparatus that increases the relative resolution of a small image to be output for recording. When the image forming apparatus is used for copying an image of an original document, when the size of an image to be output is not greater than a predetermined size, a CPU controls a resolution switching unit for increasing the resolution to form an image with increased resolution.
摘要:
An image can be outputted with a high sharpness without deteriorating a resolution. In order to output an image of a high picture quality while suppressing the occurrence of a moire, an exposure amount is modulated in accordance with pixel density information of the image divided into pixels of a predetermined size by an exposure amount modulating unit in a light scanning unit, thereby expressing an image dark/light state. In this case, in a highlight density region in which a pixel density is equal to or less than ⅓ of the maximum image density, the density data of two adjoining pixels is modulated by one pixel and the other pixel is not recorded. In a density region in which the image density lies within a range from ⅓ to ½ of the maximum image density, a part of the density data of one of the two adjoining pixels is transposed to the other pixel. In a density region in which the image density is equal to or larger than ½ of the maximum density, the pixel transposition is not performed.
摘要:
This invention provides an image reading device capable of precise detection of the optical signal over a wide wavelength range, by forming a photoelectric converting unit for converting the visible light into an electrical signal and a photoelectric converting unit for converting the invisible light into an electrical signal, in monolithic manner on a single semiconductor chip.
摘要:
When a gradation test pattern is read a predetermined period of time after the gradation test pattern was fixed, the correction amount can be controlled based on a stable image density, and an image with good gradation characteristics can be formed. A gradation test pattern including all color patterns is output in accordance with a gradation test pattern registered in a test pattern memory area, and at the same time, a timer is started. After an elapse of a predetermined period of time stored in a RAM, the output gradation test pattern is read by an original reader. On the basis of the read image density, a .gamma.-LUT is set.
摘要:
An image reading apparatus includes, as an arrangement for discriminating a specific image with high precision, first illumination means for illuminating an object image so as to perform a normal reading operation, second illumination means for illuminating the object image with light having characteristics different from those of the light from the first illumination means so as to discriminate whether or not the object image is a specific image, and means for adjusting the quantity of light emitted from the first and second illumination means.
摘要:
An image forming system includes a generator for generating an image signal representing a predetermined test image having a plurality of tone levels, an image forming device for forming the predetermined test image on a recording medium based on the signal, a first measuring device for measuring density levels of the formed predetermined test image, corresponding to each of the plurality of tone levels of the image signal, a controller for determining characteristics of a change of density levels in the predetermined test image to a change of tone levels in the image signal based on a plurality of density levels measured by the first measuring device, and for making a conversion data table for converting tone levels of an input image signal in accordance with the characteristics, a designator for generating instructions for designation a correction of the conversion data table, a transferring device for transferring the image formed on the recording medium to a recording sheet, a second measuring device for measuring density levels of the image on the recording sheet, wherein the controller controls the generator, the image forming device, and the transferring devices to correct the conversion data table based on the density levels measured by the second measuring device.
摘要:
An object of the present invention is the forming over a long period of time of images that have a desirable density and gradation.According to the present invention, an image pattern, at the maximum image density, is formed on a photosensitive drum and read by a detection unit that incorporates an LED and a photosensor. Based on the read-out data, an image forming condition is corrected so that a maximum density is slightly higher than a target maximum density. Further, an image pattern that shows density gradations is formed on the photosensitive drum, and is read by the detection unit. Based on the read-out data, the image forming condition is corrected so that the gradation characteristic is stable. With these corrections, even if the density characteristic and the gradation characteristic of the photosensitive drum are changed, the initial preferable state of the output density range can be maintained, and stable gradation characteristics for print effects that range from highlighting to shadowing is constantly ensured.
摘要:
An image forming apparatus forms a predetermined test image, detects a spatial frequency characteristic of the test image, and determines an optimum image forming condition on the basis of the detected spatial frequency characteristic.
摘要:
The present invention provides an electrophotographing apparatus for forming a color image of an improved image quality. For the provision of such an apparatus, a plurality of color developing means are arranged in the traveling direction of the electrophotographing member. The length of the traveling direction of the photosensitive member becomes longer, and the dark attenuation characteristics are created. The resultant problems which tend to lower the image quality are solved.In consideration of the dark attenuation characteristics of an electrophotographing photosensitive member, the present invention performs fine color adjustments according to each color of an developing image. In this adjustment, the gradation is corrected, or the color is corrected, per color in accordance with the dark attenuation characteristic.