Abstract: A second printing unit includes a mark detection means for detecting a positioning mark that a first printing unit has formed on a front surface of a web. A control means controls web-transport speed in the second printing unit so that a time difference between a generation timing of a CPF-N signal and a detection timing of the positioning mark becomes constant, and also stores the web-transport speed into a memory. During a subsequent printing operation, a web-transport speed is controlled to be the same as the web-transport speed stored in the memory for a period until a positioning mark is first detected after the printing is started.

Abstract: An inkjet head is formed with a nozzle, a pressure chamber, a plurality of restrictors, and a common ink chamber. Because the plurality of restrictors are formed in the inkjet head, it is possible to increase a fluid resistance of the restrictors without decreasing the Helmholtz resonant frequency. Accordingly, the inkjet head can be driven at a high frequency while preventing residual pressure wave affecting a subsequent ink ejection.

Abstract: An electrophotographic cluster printing system for performing printing by using a plurality of electrophotographic recording apparatuses such as printers, facsimile machines or copying machines each capable of manifesting an image by using colored particles such as toner. The electrophotographic cluster printing system includes a plurality of electrophotograhic recording apparatuses each including a photoconductor, a charger, an exposure device, a developing device, and an image quality controller for detecting a factor concerning image quality and controlling image quality of an output image on the basis of information of the detected factor. In the system, at least two of the electrophotograhic recording apparatuses is used for printing one job and image quality of any one of the electrophotograhic recording apparatuses is controlled on the basis of detected information of the other electrophotograhic recording apparatuses.

Abstract: An optical recording apparatus includes an optical system, a photosensitive drum and a rotational mechanism. Multibeam laser light is focused through the optical system to form an image as a column of image-forming beam spots on the photosensitive drum. The column of image-forming beam spots is arranged obliquely on the photosensitive drum and scanned to perform optical recording. The optical system includes a resolution converting lens system which is detachably attached into the optical system. The rotating mechanism adjusts rotation of the resolution converting lens system around an optical axis thereof. The resolution converting lens system is rotated by the rotating mechanism to change of resolution of the recording image. The resolution converting lens system is attached into and detached from the optical system to change of resolution of the recording image.

Abstract: An inkjet head selectively ejects recording ink droplets and refresh ink droplets. The recording ink droplets are deflected so as to impinge on target locations on a recording medium, thereby forming recording dots thereon. On the other hand, the refresh ink droplets are deflected so as to impinge on an ink absorbing member. The ink clinging on the ink absorbing member is collected into an ink tank and reused. The ink absorbing member functions as a filter for preventing impurities being collected into the ink tank along with the ink.

Abstract: When a pixel-dividing number is increased to a predetermined number or more, then nozzles in each nozzle group become in one-to-one correspondence with the sub-pixel number, so that only one of the nozzles performs ink ejection at one time. Accordingly an analog driving signal drives only a single nozzle in the corresponding group at one time. Therefore, by trimming the analog driving signal in accordance with a subject nozzle each time, the all-amount trimming is possible without providing a large number of analog-driving-signal generating devices for all of the nozzles.

Abstract: An inkjet recording head includes: a nozzle plate having nozzles arranged in a row; a plurality of pressure generating chambers communicating to the nozzles, the plurality of pressure generating chambers including a first pressure generating chamber and a second pressure generating chamber; a diaphragm formed on one face of the pressure generating chamber; a common ink chamber for supplying the ink to the plurality of pressure generating chambers; and a piezoelectric element for displacing the diaphragm. The first pressure generating chamber is disposed on one side of the nozzles and a second pressure generating chamber is disposed on the other side. The first and second pressure generating chambers are opposed to each other across the nozzles so that the central lines of the first and second pressure generating chambers are almost coincident.

Abstract: A fixing apparatus employs a dimethylsilicone oil as a base oil. Two kinds of the oils including amino group as a functional group are mixed to use as a lubricant, thereby enabling the surface of a heating roller to exhibit the most excellent releasing property with respect to a toner as well as realize low running cost.

Abstract: When ink droplets are ejected, angled or splashed where a plurality of minute ink droplets are generated, angled or splashed ink clings on an electrode 401, 402 and increases the amount of electric current conducted therethrough. Hence, the defectiveness of ink ejection can be detected by monitoring the amount of the electric current. When the defectiveness of ink ejection is detected, ejection data D is retrieved and updates the ejection data D based on a condition register S, and set to a defect register E. When the defect register E has only one element that takes a condition value of 1 indicating defectiveness, the corresponding nozzle is identified as defective. The restoring means reallocates dots, which have been originally allocated to the defective nozzle, to neighboring nozzle.

Abstract: A print control method of an electrophotograph in an image formation apparatus including at least a photoconductor, a charger, a light exposure unit, and a developing device for forming a background area and an image area on the photoconductor using the charger and the light exposure unit and detecting a potential of the image area after transfer and controlling a developing electric field, thereby printing an electrophotograph, includes lowering the percentage of toner covering the image area on the photoconductor when the potential is detected.

Abstract: A paper ejection unit included in a print apparatus for stacking printed paper to provide a print apparatus for making it possible to provide compatibility between large-capacity stacking of short-size paper frequently used and easiness of handling printed paper of large size. Attention is focused on the fact that the weight of paper that can be handled safely is determined by the paper stack height for each paper size, and it is made possible to change the paper stackable amount for each paper size by a paper stack table moved down gradually with an increase in the stack amount of printed paper and a paper stack table height detector for detecting the position of the paper stack table.

Abstract: An ink jet recording head that enables a reduction in the amount of piezoelectric plate consumed, so that costs can be lowered, without lowering efficiency of piezoelectric actuators, even if the piezoelectric actuators are only roughly fixed to the housing, and that also enables accurately and easily positioning the piezoelectric actuators with respect to a diaphragm that defines an ink channel. Assuming that mB is the mass (kg) of the base 3 to which the piezoelectric actuator 5 is fixed and Tfall is the rising edge time (s) of the drive signal that drives the piezoelectric actuator 5, the spring modulus determined from mB and Tfall is 2×mB/Tfall2≧5.0 e6 (N/m). Therefore, the displacement of the piezoelectric actuator can be efficiently transmitted to the ink chamber regardless of the spring modulus of the adhesive agent used to fix the base to the housing.

Abstract: A second print device prints images on a rear surface of a web with no sprockets after a first print device prints images on a front surface of the web. A CPF-OFF signal is generated at a time of when an irradiating unit of the second print device completes irradiating for a last page. The second print device calculates, based on a web transport speed at the generation timing of the CPF-OFF signal, a time duration required for the web to reach a predetermined waiting position after the CPF-OFF signal was generated, and starts counting a clock when the time duration elapses from when the CPF-OFF signal was generated. After a last-page image is completely transferred from a photosensitive drum onto the web, the web is transported in a reverse direction by a distance corresponding to the count value, thereby positioning the web at a predetermined waiting position.

Abstract: In an electrostatic charge image developing toner containing at least a fixing resin and a wax, assume that the wax is used as one type wax or a mixed system of K types (K is an integer in excess of 2) waxes, Tn (°C.) is an onset temperature of an absorbed heat quantity curve of a wax constitutive component N in a differential scanning calorimeter (DSC), and Wn (wt %) is a compound rate occupied in an overall wax, the toner that satisfies predetermined relationships among them is obtained.

Abstract: In an electrostatic charge image developing toner that contains a hydrocarbon wax whose crystallinity is less than 93%, an amount of maximum change in a quantity of charge of the toner is smaller than 20 &mgr;C/g and an amount of contamination of a carrier by the toner is less than 0.4 wt % when a developer which is formed by mixing the toner into the carrier is stirred for 24 hours at an atmospheric temperature that is lower than a glass transition point of the toner and is higher than 45 ° C.

Abstract: An electrophotographic toner for visualizing an electrostatic latent image formed by an electrophotographic process, an electrostatic printing process, an electrostatic recording process, etc., which is produced in consideration of the environment and safety. The electrophotographic toner includes a fixing resin and a colorant. The electrophotographic toner is a black toner using a titanium compound containing no carbon black as the colorant. The electrophotographic toner may be an electrophotographic two-component black toner using magnetic iron oxide containing no carbon black as the colorant.

Abstract: A transfer member transporting section is disposed so as to bring a tip end of a transfer member into contact with a peripheral face of a transfer rotary member before the tip end of the transfer member enters a nip area. A bias power supply has a polarity inverting function of, during a period from a timing when the tip end of the transfer member is brought into contact with the transfer rotary member by the transfer member transporting section, to that when the tip end of the transfer member enters the nip area, applying a voltage of a polarity which is identical with that of a toner, to the transfer rotary member, and after the tip end of the transfer member enters the nip area, applying a voltage of a polarity which is opposite to that of the toner, to the transfer rotary member.

Abstract: When positively charged ink droplets 608 from a defective nozzle impact a negatively charged deflector electrode 320, the positive charge on condenser 609 flows to the ground via a FET 618 of a photo-coupler 610. As a result, the electric discharge occurs by an amount equivalent to the charging amount of the ink droplets 608 clinging on the electrode 320. Because a switching signal 606 is “1”, the ON resistance of the photo-coupler 610 is large, and the ON resistance of the FET 620 of the photo-coupler 612 is small. Accordingly, the discharge due to the charged ink droplets 608 is detected as a large detection voltage and amplified by an operational amplifier 613 . Because the charger voltage of the condenser 609 is static and has no noise, even when the detection output 615 is highly amplified, noise during the detection is suppressed.

Abstract: To stably transport an elongated web-like print paper so as not to move in the widthwise direction of the print paper, a first sensor is disposed at a first position in a paper conveying path and a second sensor at a second position downstream of the first position with respect to the paper conveying direction. Both the first and second sensors detect a position of a side edge or the print paper. A difference between the outputs from the first and second sensors is computed while taking a travel time of the edge detected by the first sensor to reach the second sensor into account. A main controller generates a drive signal based on the difference computed and controls a mechanism for moving the print paper in the widthwise direction in accordance with the drive signal.

Abstract: An inkjet head 100 includes a pair of support plates 17A, 17B and a diaphragm plate 9 interposed between the support plates 17A, 17B. In this configuration, even when adhesion between the diaphragm plate 9 and the support plate 17B is insecure, and when a piezoelectric element 12 deforms a diaphragm 7 toward a pressure chamber 3, that is, in a direction away from the support plate 17B, the support plate 17A prevents the diaphragm plate 9 from peeling off the support plate 17B. Accordingly, the dimension and thus a deforming amount of the diaphragm 7 is maintained uniform, whereby a uniform ink ejection performance is maintained.