Abstract: An image forming apparatus has an upper print head unit and a lower print head unit that print plural printing areas in order on a printing medium. The image forming apparatus defers printing, as long as the image data corresponding to the areas to be printed are not transferred from a host apparatus, and begins printing when the image data are transferred from the host apparatus. The image forming apparatus can thus print an unfixed length of continuous image without monopolizing the host apparatus.

Abstract: An ink-jet printing apparatus, having a first printing head at an upper position with respect to a cloth-conveying direction and a second printing head at a lower position with respect to the cloth-conveying direction, scans the printing heads in a direction orthogonal to the cloth-conveying direction. An image printed by the first printing head is complemented by the second printing head. If a stop of printing is instructed during the printing by the first printing head, the printing by the first printing head is stopped, and printing by the second printing head is continued until the position of the image printed by the first printing head is printed by the second printing head. In this manner, a printed image completed to the end of the image can be obtained.

Abstract: A test image is formed by performing overlap printing using a plurality of printing heads provided for a printing agent of one color. Density data attained by reading this test image is averaged. On the basis of this average value, a common correction is performed for drive signals for the printing heads. This makes it possible to perform head density unevenness correction at a high efficiency in performing overlap printing by using the plurality of printing heads.

Abstract: A recording apparatus employs a control unit to compensate for any variations in the feed speed of a recording medium. The recording apparatus includes a recording unit for recording an image on a recording medium in accordance with the image data; a speed detection unit for detecting the actual feed speed of the recording medium or of a feed unit for feeding the recording medium; and a control unit for controlling the record timing of the recording unit in accordance with a difference between a reference feed speed and the actual feed speed of the recording medium or feed unit detected by the speed detection unit.

Abstract: When an magnified and synthesized image is finally printed on a printing medium based on an original image and a character font data, linear magnifying processing is executed with the aid of a software on the host computer side for the original image optically read by a scanner. In addition, vector magnifying processing is executed for font data likewise with the aid of a software, and moreover, synthesizing processing is executed for the font data. At this time, forming processing such as edge emphasizing or the like can be executed after completion of the vector magnifying processing. Synthesizing data are additionally magnified in a printer with the aid of a hardware, and subsequently, the magnified and synthesized image is outputted to the printer for performing a printing operation by the latter. An magnifying rate applicable to the host computer and the printer can be determined such that productivity of the image forming system is maximized.

Abstract: A recovery method of an ink jet apparatus includes the steps of discharging ink for recovery from a plurality of discharge openings prior to recording, detecting a discharge condition for each discharge opening, and selectively discharging ink for recovery from the discharge openings detected to be unsatisfactory.

Abstract: An ink jet apparatus has an ink jet head with a heat generating resistance element, which head discharges ink droplets by causing a state change in ink using heat generated by the resistance element, conveying means for conveying a recording medium to be recorded upon in a conveyance direction so that a predetermined recording image is formed on the recording medium by ink droplets from the head, heat exchanging means for exchanging heat with the head, this exchanging means being attached to the side of the head where the element is provided, and heating means for heating the exchanging means, the heating means being part of the heat exchanging means. It also includes a cooling means for cooling the heat exchanging means, temperature detecting means for detecting the temperature of the heat exchanging means, and control means for controlling driving of the heating means and cooling means according to the temperature detected by the temperature detecting means.

Abstract: An ink jet recording apparatus records by discharging ink from plural recording heads toward a recording medium. Each of the recording heads has a heat pipe mounted thereon, and protruding therefrom so as to have a length which is greater than the recording width of the corresponding recording head. The protruding portions of each heat pipe extending from the recording heads have a heat discharging member attached thereto. That member constitutes a single blower fan for applying an air stream to the heat discharging members corresponding to the recording head, and plural air stream control means for applying the air stream produced by the blower fan to the heat discharging members individually or independently.

Abstract: An ink jet recording apparatus with plural full-line type recording heads has a heat pipe associated with each recording head. The heat pipes are connected together at a common portion in various ways, such as by a heat-conductive block, one or more additional heat pipes or a container with a heat transferring liquid medium. Such an arrangement enables more efficient and compact temperature control of the recording heads.

Abstract: This invention relates to a sheet feeding device having an endless belt for feeding a sheet; multiple rotation members bodies supporting the endless belt and including at least one crown roller, a cylindrical rotational member located between the crown roller and a first body member among the multiple rotation members from the crown roller in the endless belt moving direction.

Abstract: The present invention relates to a liquid jet recording apparatus in which a liquid discharge for recovery of a recording head is directly carried out by the conveying belt. A collecting effect of an ink mist generated at a recording area of the recording head is carried out by a charged conveying belt, a rotary member conveying the recording medium, preferably an electrostatically absorbing conveying belt.

Abstract: An ink jet recording apparatus for effecting recording with ink that adheres to a recording medium has an ink jet recording head unit having a recording head in which a plurality of electrothermal conversion elements available to discharge the ink are arranged, a heat exchange device having a first heat exchange portion contacting with the whole area of one side of the recording head in the lengthwise direction thereof and effecting heat exchange and a second heat exchange portion provided in continuation to the first heat exchange portion and extending on the outside far from the recording head, a heater provided near the second heat exchange portion for heating the heat exchange device, and a temperature detector provided on a portion of the first heat exchange portion; the second heat exchange portion being inclined upwardly relative to the recording head; a cooling device for acting on the second heat exchange portion of the heat exchange device and assisting the heat radiation of the second heat exchange

Abstract: A Doppler velocity meter has a radiation source for emitting a radiation beam the wavelength of which fluctuates, such as a laser; an optical system for directing the radiation beam to an object at an incident angle .theta. and a detector for detecting scattered beam generated from the object by directing the radiation beam. The optical system has a diffraction grating which serves to change the incident angle .theta. in accordance with a change in the wavelength .lambda. of the radiation beam in such a manner as to maintain the value of sin .theta./.lambda. substantially constant. The velocity meter can accurately detect the velocity of movement of the object regardless of any change in the wavelength .lambda., because the diffraction grating serves to substantially compensate for any change in the frequency of the scattered beam caused by the change in the wavelength.