Abstract: A liquid discharge head is arranged in a manner that in the cross section of a discharge port in a liquid discharge direction, the discharge port includes: at least one projection that is convex inside the discharge port; a first area, for holding a liquid surface connecting a pillar-shaped liquid that is elongated outside the discharge port; and second areas where a fluid resistance is lower than that in the first area so as to pull the liquid in the discharge port in a direction opposite to the liquid discharge direction; and the first area is formed in the direction in which the projection is convex, and the second areas are formed on both sides of the projection.

Abstract: A liquid discharge head is arranged in a manner that in the cross-section of a discharge port in a liquid discharge direction, the discharge port includes at least one projection that is convex inside the discharge port; a first area, for holding a liquid surface connecting a pillar-shaped liquid that is elongated outside the discharge port; and second areas where a fluid resistance is lower than that in the first area so as to pull the liquid in the discharge port in a direction opposite to the liquid discharge direction. The first area is formed in the direction in which the projection is convex, and the second areas are formed on both sides of the projection.

Abstract: An object of this invention is to provide a printhead tolerant of switching noise occurred when concurrently driving plural printing elements, a head cartridge using the printhead, and a printing apparatus. To achieve this object, a printhead includes plural printing elements and plural driving elements for driving the plural printing elements, and prints by these printing elements. The printhead includes the following arrangement. More specifically, the printhead includes a shift register which receives print data in synchronism with a clock signal, and a latch circuit which latches the print data input to the shift register in synchronism with a latch signal. The printhead further includes a restriction circuit which restricts input of the print data and clock signal to the shift register and input of the latch signal to the latch circuit in synchronism with input of an enable signal for driving the plural driving elements.

Abstract: The present invention provides a liquid ejecting head which inhibits the possible generation of satellites and possible inappropriate ejection during liquid ejection, enabling printing with improved image quality and reliability. Thus, ejection openings in the liquid ejecting head each selectively have projections or a circular shape depending on the characteristics of a liquid to be ejected.

Abstract: A liquid ejection method is provided which ejects small-volume droplets from ejection openings and causes them to reliably combine together on the fly into a large droplet that is less susceptible to influences of air flows, thus realizing a printing with reduced droplet landing position deviations. To that end, each of the ejection openings is constructed of two openings spaced apart and a slit-like constricted connection portion that connects the two openings together.

Abstract: A liquid ejection head capable of achieving satisfactory printing without nozzle misfiring in an area close to an end of a nozzle row and droplet misdirection is provided. The ejection orifices, except for dummy orifices, are provided with protrusions. Four operative ejection orifices located close to each of the ends of each ejection orifice row are defined as end-located ejection orifices. Each of the protrusions provided in the end-located ejection orifices has a shorter length than that of the protrusion provided in the ejection orifice located in the central portion of the nozzle row.

Abstract: A print head, which ejects ink by using a method whereby a bubble generated by a heat generating element communicates with the air, and for which the occurrence of cavitation is deterred and the durability is improved, is provided. According to the print head, a bubble grows until the maximum volume is attained, and then, at a volume reduction step, communicates with the air. As a result, a liquid in a bubble generation chamber is ejected. An ejection port and the heat generating element are arranged so that the center of the ejection port is shifted away from the center of the heat generating element in a direction leading from an ink supply port to the ejection port.

Abstract: A chip device having a ground electrode and a plurality of top-surface electrodes on a plate-like dielectric substrate. Two of the top-surface electrodes are connected to the ground electrode via respective short-circuit side-surface electrodes to form quarter wavelength resonant lines. A third top-surface electrode is provided between the two top-surface electrodes and both ends thereof are opened to form a half wavelength resonant line. The two top-surface electrodes each have a parallel portion arranged near and in parallel to the third top-surface electrode and a flexion that curves from the parallel portion, extends toward the remaining of the two top-surface electrodes, and is jump-coupled to the remaining of the two top-surface electrodes. The short-circuit side-surface electrodes are jump-coupled to each other, like the flexions.

Abstract: A recording head circuit is configured to drive a plurality of recording elements by dividing the plurality of recording elements into a plurality of blocks. The circuit delays not only heat signals, which are used to drive the recording elements in each of the blocks, but also block signals. Consequently, noises are prevented from appearing due to overlapping of signals.

Abstract: A liquid discharge head is arranged in a manner that in the cross section of a discharge port in a liquid discharge direction, the discharge port includes: at least one projection that is convex inside the discharge port; a first area, for holding a liquid surface connecting a pillar-shaped liquid that is elongated outside the discharge port; and second areas where a fluid resistance is lower than that in the first area so as to pull the liquid in the discharge port in a direction opposite to the liquid discharge direction; and the first area is formed in the direction in which the projection is convex, and the second areas are formed on both sides of the projection.

Abstract: The invention provides a portable gas detector which is equipped with filters for removal of interfering gases, high in convenience for use, easy to exchange the filters, and easy to confirm the time the filters are exchanged. The portable gas detector has a housing in the form of a slim and flat box holdable by grasping with a hand, and a foreside half portion in the interior of the housing is provided as functional part region, in which a plurality of gas sensors are arranged in a state fixed by a holder and a cap, in the interior of which a gas flowing path has been formed. At a position corresponding to at least one gas sensor in the sensor cap exposed to the back surface of the housing, a filter assembly for removal of an interfering gas component related to the gas sensor is detachably provided.

Abstract: The invention provides a portable gas detector of a novel structure that is easy to be fabricated as a small-sized one handy to carry and high in convenience for use. The portable gas detector has a housing in the form of a slim and flat box holdable by grasping with a hand, and a foreside half portion in the interior of he housing is provided as a functional part region, and a rear half portion in the interior of the housing is provided as a battery part region. In the functional part region, one of 5 gas sensors is arranged at a curved portion in a gas sensor-arranging region of an L shape as a whole, and 2 gas sensors are arranged in a row in both lateral and vertical directions of the above gas sensor, respectively. A gas sucking means is arranged in a region, the 2 directions of which is sectioned by the gas sensor-arranging region.

Abstract: The invention provides a portable gas detector of a novel structure that is easy to be fabricated as a small-sized one handy to carry and high in convenience for use. The portable gas detector has a housing in the form of a slim and flat box holdable by grasping with a hand, and a foreside half portion in the interior of he housing is provided as a functional part region, and a rear half portion in the interior of the housing is provided as a battery part region. In the functional part region, one of 5 gas sensors is arranged at a curved portion in a gas sensor-arranging region of an L shape as a whole, and 2 gas sensors are arranged in a row in both lateral and vertical directions of the above gas sensor, respectively. A gas sucking means is arranged in a region, the 2 directions of which is sectioned by the gas sensor-arranging region.

Abstract: The invention provides a portable gas detector of a novel structure that is easy to be fabricated as a small-sized one handy to carry and high in convenience for use. The portable gas detector has a housing in the form of a slim and flat box holdable by grasping with a hand, and on the front side in the interior of the housing a circuit board for control is arranged so as to extend along a flat plane direction of the housing. A foreside half portion in the interior of the housing is provided as a functional part region, in which functional members related to a gas detecting operation are arranged, and a rear half portion is provided as a battery part region, in which either one of 3 rod-like dry cells or a chargeable battery pack formed by holding 3 chargeable batteries having the same external shape as the dry cell by a holding frame member in a state arranged in parallel is installed exchangeably with the other.

Abstract: The invention provides a portable gas detector which is equipped with filters for removal of interfering gases, high in convenience for use, easy to exchange the filters, and easy to confirm the time the filters are exchanged. The portable gas detector has a housing in the form of a slim and flat box holdable by grasping with a hand, and a foreside half portion in the interior of the housing is provided as functional part region, in which a plurality of gas sensors are arranged in a state fixed by a holder and a cap, in the interior of which a gas flowing path has been formed. At a position corresponding to at least one gas sensor in the sensor cap exposed to the back surface of the housing, a filter assembly for removal of an interfering gas component related to the gas sensor is detachably provided.

Abstract: A plurality of cylindrical inner conductor portions having different diameters are connected with each other to form an inner conductor. The inner conductor portions include high-impedance portions and low-impedance portions. The inner conductor is formed within an outer conductor with a nonuniform inner diameter. The inner conductor is formed so that the axial length of some of the inner conductor portions forming the high-impedance portions is smaller than the axial length of the other inner conductor portions forming the high-impedance portions, and the diameter of the inner conductor portions forming the high-impedance portions is greater than a predetermined minimum diameter.

Abstract: An inner conductor comprising high impedance portions and low impedance portions alternately connected to each other is disposed in the center of an outer conductor having a substantially square cross-section. Two holes are formed in one side of the outer conductor so as to extend through the wall of the outer conductor. A substantially &pgr;-shaped coupling line comprising a main line portion and probe-connecting portions is formed on the surface of a dielectric substrate. Probes made of conductor rods are connected at the ends, respectively. A resistor is provided at one end of the main line of the coupling line. The other end of the main line functions as an output terminal, and can be connected to an external circuit. The probes are inserted through the holes. The dielectric substrate is disposed inside of the outer conductor at predetermined positions.

Abstract: The invention provides a gas suction pump device equipped with a casing having a substantially rectangular frame-like sectional shape and formed slenderly in a gas flowing direction and into a size holdable by grasping with a hand, a control circuit board provided in the casing so as to extend in a longitudinal direction along the upper wall of the casing, a pump unit arranged in a region on the side of one side wall on the lower side of the control circuit board in a state that one end and the other end of a gas flow path defined by the pump unit have been connected to a gas inlet port and a gas outlet port, respectively, and a battery fitting chamber provided in a region on the side of the other side wall. The invention also provides a gas alarm unit constructed by connecting the above pump device to a portable gas alarm device provided with a specific gas feed adapter through a connecting tube.

Abstract: An inner conductor comprising high impedance portions and low impedance portions alternately connected to each other is disposed in the center of an outer conductor having a substantially square cross-section. Two holes are formed in one side of the outer conductor so as to extend through the wall of the outer conductor. A substantially &pgr;-shaped coupling line comprising a main line portion and probe-connecting portions is formed on the surface of a dielectric substrate. Probes made of conductor rods are connected at the ends, respectively. A resistor is provided at one end of the main line of the coupling line. The other end of the main line functions as an output terminal, and can be connected to an external circuit. The probes are inserted through the holes. The dielectric substrate is disposed inside of the outer conductor at predetermined positions.

Abstract: The invention provides a gas suction pump device equipped with a casing having a substantially rectangular frame-like sectional shape and formed slenderly in a gas flowing direction and into a size holdable by grasping with a hand, a control circuit board provided in the casing so as to extend in a longitudinal direction along the upper wall of the casing, a pump unit arranged in a region on the side of one side wall on the lower side of the control circuit board in a state that one end and the other end of a gas flow path defined by the pump unit have been connected to a gas inlet port and a gas outlet port, respectively, and a battery fitting chamber provided in a region on the side of the other side wall. The invention also provides a gas alarm unit constructed by connecting the above pump device to a portable gas alarm device provided with a specific gas feed adapter through a connecting tube.