Abstract: A method and device for image processing free from full loss of an entire vector in a halftone image relatively low in density. An N*N mask matrix is generated for a given density, based on an N*N dither matrix used in an area gradation method which represents a halftone image with binary (bi-level) image data from multi-level image data. In a case of N*N mask matrix relatively low in density, rearrangements on a column and row basis are performed (N*N−1) times to generate (N*N−1) number of N*N mask matrices which are then combined with the original N*N mask matrix to form an (N*N)*(N*N) mask matrix. Thus, for a halftone image relatively low in density, a binary halftone image is generated via the (N*N)*(N*N) mask matrix from multi-level image data.

Abstract: This invention provides a printing system capable of minimizing the blurring of ink which would otherwise accompany color printing, and of reducing the time required for color printing. A first black printer head 12a1, and color printer heads 12b1 to 12b3 are arrayed in parallel along the direction in which a carriage moves. A second black printer head 12a2 is placed such that it is displaced by a certain distance in the medium advance direction with respect to the array comprising the first black printer head 12a1 and color printer heads 12b1 to 12b3, and prints dots such that the dots do not overlap with those printed by the first black printer head 12a1 or by the color printer heads 12b1 to 12b3 within any given band.

Abstract: A sensor configuration and signal processing, which are not affected by a paper rise when a print pattern for auto head shading and density correction is read, are provided. A predetermined print pattern is printed with a plurality of heads, and the predetermined pattern that is printed is scanned with a sensor (110) to detect a density unevenness for the print pattern in each color on a nozzle basis. The sensor (110) comprises a light emitting element which emits a light including all light regions, R, G, and B, and a plurality of light receiving elements each of which receives R, G, and B lights, respectively. The plurality of light receiving elements are arranged in a main scanning direction.

Abstract: When a roll paper unit 200 is incorporated into an image formation apparatus, a second outlet guide member 92 is turned around a pivot 92a in the direction of an arrow G, i.e., moved from a position of solid lines to a position of two-dot chain lines, a rear end portion 92b of this second outlet guide member 92 pressing down a front end portion 80c of a guide member 80 to cause the guide member 80 to be turned around a central shaft 80d in the direction of an arrow H, i.e., moved from a position of solid lines to a position of two-dot chain line. Consequently, a path extending in the direction of an arrow C is closed, while a path extending in the direction of an arrow F is opened, the roll paper 72 being transferred in the paper feed direction. When the roll paper unit 200 is drawn out, the second outlet guide member 92 and the guide member 80 are turned in the directions opposite to those mentioned above.

Abstract: A second passage 20 is arranged on a side opposite to a discharge port 16 relative to a first passage 18. Additionally, an intercepting member 24 is provided which intercepts the communication between the first passage 18 and the insertion port 14 and allows the insertion port 64 to communicate only with the second passage 20, at a portion of the first passage 18 near the insertion port 14, whereby the intercepting member 24 intercepts the communication between the first passage and the insertion port 14 at a prescribed timing.

Abstract: An image forming apparatus having a print member for forming an image on a recording sheet while reciprocating in a predetermined direction includes a pair of conveyance rollers and a separating member for separating the of conveyance rollers from one another. A control lever for controlling the separating member is provided as is a changeover element for permitting the control lever to rotate when said print member moves in a predetermined direction and is not located at an interference area in which the print member would collide with the conveyance rollers if they were separated, and for prohibiting the control lever from rotating when the print member is located at the interference area.

Abstract: To detach a cleaning roller 64 from a fixation unit 70, an assembly 80 is taken out from the fixation unit 70, and the cleaning roller 64 is detached from the assembly 80. Thereby, in the fixation unit 70, the operation of detaching and attaching the cleaning roller 64 for cleaning a pressure roller 46 is made easier.

Abstract: An ink supply pipe 70 is inserted into a sponge 44 to reach a central or lower portion thereof where ink density higher. Thereby, the ink can be fed stably to a nozzle 42 and to reduce influence of the air introduced through an ink supply tube 60 and an ink supply pipe 70. Lateral holes 72 for ink discharge are provided on a side wall of the ink supply pipe 70. Thereby, a sufficient amount of the ink can be supplied from the lateral holes 72 of the supply holes 70, even when the sponge 44 is crushed upon insertion of the ink supply pipe 70 to narrow the tip orifice of the ink supply pipe 70.

Abstract: An image-forming apparatus employs a manual sheet feeder tray that overlaps a part of a side wall of an upper main body portion to be in contact therewith in a non-working mode irrespective of an opener assembly being open or closed. A guide member can be provided to prevent contact of the manual sheet feeder tray with the upper main body portion. Further, an image-forming apparatus employs a discharged-sheet selectively positionable for a working mode or a non-working mode, where the discharged-sheet tray overlaps a part of a side wall of the upper main body when in the non-working mode, irrespective of an opener assembly being opened or closed. A guide member can be provided to prevent contact of the discharged-sheet tray with the upper main body portion.

Abstract: An ink supply pipe 70 is inserted into a sponge 44 to reach a central or lower portion thereof where ink density higher. Thereby, the ink can be fed stably to a nozzle 42 and to reduce influence of the air introduced through an ink supply tube 60 and an ink supply pipe 70. Lateral holes 72 for ink discharge are provided on a side wall of the ink supply pipe 70. Thereby, a sufficient amount of the ink can be supplied from the lateral holes 72 of the supply holes 70, even when the sponge 44 is crushed upon insertion of the ink supply pipe 70 to narrow the tip orifice of the ink supply pipe 70.

Abstract: An ink supply pipe 70 is inserted into a sponge 44 to reach a central or lower portion thereof where ink density higher. Thereby, the ink can be fed stably to a nozzle 42 and to reduce influence of the air introduced through an ink supply tube 60 and an ink supply pipe 70. Lateral holes 72 for ink discharge are provided on a side wall of the ink supply pipe 70. Thereby, a sufficient amount of the ink can be supplied from the lateral holes 72 of the supply holes 70, even when the sponge 44 is crushed upon insertion of the ink supply pipe 70 to narrow the tip orifice of the ink supply pipe 70.

Abstract: An ink-jet image forming device such that the test pattern detecting accuracy is improved with a single photodetector. A binarizing circuit (16) which binarizes the output of a sensor for a test pattern includes a peak hold circuit (82) which follows slow change in the sensor output, a voltage dividing circuit (83) which divides the held output, and a comparator (84) which converts the sensor output into a bi-level signal by using the output of the circuit (83) as a threshold.

Abstract: In order to reduce the number of signal lines of the cable between the controller and the carriage and to allow the print timing of each head to be adjusted in increments smaller than one pixel, the signal lines include a line for carrying serial print data to be supplied to a plurality of print heads in a predetermined order, a line for carrying a clock signal corresponding to individual bits of the data, lines for carrying signal HDSEL[1 . . . 0] indicating which print head corresponds to which print data included in the serial print data, and lines for driving the heads. When data is transferred over this cable, one slice section is divided into a plurality of sections, the slice section corresponding to a time slot required to transfer a unit of print data corresponding to a plurality of dot printing elements of the plurality of heads, each divided section is further divided into a number of subsections the number of which is equal to the number of the print heads.

Abstract: A media detection method and device which can detect media precisely in spite of individual variations and mechanical assembly errors of optical sensors and contamination of light emitting and receiving parts of the optical sensors, and which, even when the medium is not yet provided, can make setting for medium detection and precisely detect the medium in a short time; wherein first, a comparison reference voltage of the differential amplifier (10) is set at 0 volts and the output of the differential amplifier (10) corresponding to the output of the optical sensor (11) is determined when or where a medium is absent; by applying the output of the differential amplifier (10) to a predetermined formula, a comparison reference voltage to be given to the differential amplifier (10) during the medium detection operation is determined; next, during the actual medium detection operation, this comparison reference voltage is applied to the differential amplifier (10) and the amplifier output is compared with a predet

Abstract: When a carriage 16 is positioned in an end portion in the direction indicated by arrow B in a scanning area thereof, an attachment 46 is in contact with a main frame side wall 1a of a plotter 1, and turns in the direction indicated by arrow D against the enabling force in the direction indicated by arrow C of a helical torsion coil spring 50, so that an image position detector 40 is stored in a storage unit 16c of the carriage 16.

Abstract: The relative positions of cutter blade 42, platen 28, pressing member 44, and bending guide 46 are adjusted to obtain the acute angle &THgr; between side face 42a of cutter blade 42 facing to the delivery direction and recording medium 29 in the range from 25° to 65°.

Abstract: There are provided three periods of time immediately after an AC power-supply voltage is started to be applied to fixing heaters when the heater temperature falls below a target temperature: a first period for driving only a first heater; a second period for driving only a second heater following the first period; and a third period for driving the first and second heaters following the second period. During the first and second periods, the first and second heaters are thinning-controlled, respectively. At this time, at a cycle of 3 half-waves of the AC voltage applied to each fixing heater, a thinning frequency is changed from a large value to a smaller one. The third period includes first and second sub periods which are alternately repeated. In at least one of the first and second sub periods, the first and second heaters are thinning-controlled and the relation of the thinning controls of the two heaters is such that they are complementary to each other on the time axis.

Abstract: A cam 37 is rotated in an arrow F direction. This causes sheet conveyance rollers 10a, 10b and guide elements 33, 34 to rotate on a lower conveyance shaft 27 and an upper conveyance shaft 30, respectively, so that they are separated from a drive roller 12. Thus, a spur plate 21 faces the upward stream end with respect to the recording sheet conveyance direction and opens in synchronism with the sheet conveyance rollers 10a and 10b, etc. Accordingly, it is possible to readily remove a recording sheet subjected to the jam.

Abstract: A data communication unit (1) receives input image data of a first data format which comprises coordinate data of the end points of vectors forming an image and various modifying information of the vectors, and stores them in an input buffer (2). A data analyzer unit (3) converts the input image data into image data of a second data format and stores the data in a storage unit (6). The second data format holds the various modifying information independently of the coordinate data of the end points, decreasing the amount of data compared with the first data format. Based on the image data of the second data format, the data analyzer unit (3) generates, in a band-by-band manner, intermediate codes comprising coordinate data that constitute the contours of the vectors reflecting the various modifying information. The intermediate codes are converted into corresponding raster data in a band-by-band manner, and are printed as an image by a printer unit (10).

Abstract: An extension guide unit 30 is provided on a side portion of a recording medium conveying passage. An extension guide 36 is held in a wound state in an extension guide holder 31 of the extension guide unit 30. In order to convey a recording medium, the extension guide 36 is drawn out, by which the recording medium is guided. This enables the recording medium to be smoothly conveyed.