Abstract: An ink jet recording device including a head unit and a support member. The head unit includes a head member that ejects ink in a predetermined direction and a head-unit-side connection member formed with a first channel in fluid connection with the head member for supplying ink to the head member. The support member detachably supports the head unit. The support member includes a support-member-side connection member formed with a second channel. While the support member supports the head unit, the support-member-side connection member and the head-unit-side connection member are connected to each other with the second channel and the first channel in fluid communication. Also, the connection members extend in a substantial linear relationship at an angle.

Abstract: The invention includes a suction cap that does not retain ink therein. The suction cap includes a cap member having a recess and a suction opening formed therein and a capillary force generating member disposed in the recess. When a recovery operation is performed for ink ejection using the suction cap, ink sucked from a nozzle flows downwardly from a tilt surface of the recess due to gravity and a suction force applied through the suction opening. The ink impinges a side face of a projection of the capillary force generating member, flowing into defined narrow spaces, due to the action of capillary force of the ink, and flowing toward the suction opening. The ink in the defined narrow spaces is discharged by the suction force applied through the suction opening to outside the suction cap.

Abstract: To eliminate influence of air bubbles introduced into an ink jet head along with ink, an ink circulation pathway is provided which includes first to third ink channels. The first ink channel is connected between the sub-tank and a buffer tank to supply ink in the sub-tank to the buffer tank. The buffer tank is provided in a head unit to be mounted on an ink jet printer body. The second ink channel is connected between the buffer tank and the sub-tank. Any air or bubbles that have accumulated at the upper portion of the buffer tank can be discharged to the sub-tank by the pumping operation of a buffer purge pump disposed in the second ink channel. The third ink channel is connected between an ink cartridge and the sub-tank, and ink stored in the ink cartridge is supplied to the sub-tank through the third ink channel by the pumping operation of a ink supply pump disposed in the third ink channel when the ink stored in the sub-tank has gone below a certain fixed amount.

Abstract: To eliminate influence of air bubbles introduced into an ink jet head along with ink, an ink circulation pathway is provided which includes first to third ink channels. The first ink channel is connected between the sub-tank and a buffer tank to supply ink in the sub-tank to the buffer tank. The buffer tank is provided in a head unit to be mounted on an ink jet printer body. The second ink channel is connected between the buffer tank and the sub-tank. Any air or bubbles that have accumulated at the upper portion of the buffer tank can be discharged to the sub-tank by the pumping operation of a buffer purge pump disposed in the second ink channel. The third ink channel is connected between an ink cartridge and the sub-tank, and ink stored in the ink cartridge is supplied to the sub-tank through the third ink channel by the pumping operation of a ink supply pump disposed in the third ink channel when the ink stored in the sub-tank has gone below a certain fixed amount.

Abstract: An ink jet recording device including a head unit and a support member. The head unit includes a head member that ejects ink in a predetermined direction and a head-unit-side connection member formed with a first channel in fluid connection with the head member for supplying ink to the head member. The support member detachably supports the head unit. The support member includes a support-member-side connection member formed with a second channel. While the support member supports the head unit, the support-member-side connection member and the head-unit-side connection member are connected to each other with the second channel and the first channel in fluid communication. Also, the connection members extend in a substantial linear relationship at an angle.

Abstract: The invention includes a suction cap that does not retain ink therein. The suction cap includes a cap member having a recess and a suction opening formed therein and a capillary force generating member disposed in the recess. When a recovery operation is performed for ink ejection using the suction cap, ink sucked from a nozzle flows downwardly from a tilt surface of the recess due to gravity and a suction force applied through the suction opening. The ink impinges a side face of a projection of the capillary force generating member, flowing into defined narrow spaces, due to the action of capillary force of the ink, and flowing toward the suction opening. The ink in the defined narrow spaces is discharged by the suction force applied through the suction opening to outside the suction cap.

Abstract: A recorder like an ink jet printer includes a head unit, which includes recording head and a head holder. Intermediate members are screwed to the holder. Each of the recording heads is bonded to one of the members and has a number of ink ejection nozzles. After the unit is assembled, one of the heads may be found to be defective. Even in this case, it is possible to remove only the defective head and the associated member, fit a new intermediate member to the holder, and bond a new recording head to the new member with the nozzles of this head aligned with the nozzles of the other heads. The intermediate member has a hole engaging with part of the head with play for positioning the head relative to the holder.

Abstract: An ink jet recorder includes a sub ink tank and a recording head which includes a manifold. The tank and the manifold are connected to an upstream supply tube and a downstream supply tube, respectively. The supply tubes can be connected by a first joint. The manifold and an upstream return tube can be connected by a second joint. The joints are fitted with filters, respectively, for removing foreign substances etc. from ink. The filters are so positioned that ink can flow upward through them. This makes it easy for the air in the ink flowing through the filters to pass buoyantly through them. Because no air stays at the filters, it is possible to increase their effective areas, and therefore secure the quantity of ink flow necessary for printing.

Abstract: A recording head of a printer and its driving circuit are electrically connected via a flexible printed circuit that is provided with electrodes in pitch corresponding to the nozzles of the recording head and a general purpose flexible printed circuit. Thus, the manufacturing cost is reduced. In addition, the connection of both flexible printed circuits is prevented from being dirtied, and the handling during manufacturing is facilitated.

Abstract: An information recording head of an information recording apparatus for recording information on a record medium by a dot matrix method is provided with: a holding member movable in a scanning direction relative to the record medium in the information recording apparatus; and a plurality of recording elements arranged in two rows in parallel to each other for recording the information by the dot matrix method, and held by the holding member such that each of the two rows is inclined by an inclination angle .theta. with respect to the scanning direction. The recording elements are arranged such that the inclination angle .theta., a distance DL between the two rows and a distance DN between the adjacent recording elements in each of the two rows are expressed by predetermined expressions respectively.

Abstract: A lever is rotatably mounted on a carriage on which a print head in a printer is mounted. The lever is integrally formed with an eccentric cam and a projection. Either a first position where a guide plate in the printer is sandwiched on its both surfaces by a first cam surface of the eccentric cam and the projection or a second position where the guide plate is sandwiched on its both surfaces by a second cam surface of the eccentric cam and the projection is selected by rotating the lever, thereby adjusting a head gap.

Abstract: An optical surface roughness measuring apparatus for measuring roughness of a surface of a subject, by irradiating the surface with two linearly polarized beams of light which have orthogonal planes of polarization and different frequencies, and detecting a change in a beat frequency of the two beams reflected by the surface. The optical surface measuring apparatus includes a laser device for producing two linearly polarized laser beams as the two linearly polarized beams, and an optical device having a single optical path between the laser device and the surface of the subject, so that the two linearly polarized laser beams are propagated from the laser device toward the surface along the single optical path.

Abstract: An optical surface roughness measuring device for measuring roughness of a surface of a subject in a non-contacting manner. The apparatus includes a laser device for producing two linearly polarized laser beams which has mutually perpendicular polarization planes and different frequencies, and an optical device adapted to receive the two linearly polarized beams, converge one of the two laser beams so as to irradiate a first reading spot on the surface of the subject, convert the other of the two laser beams into parallel rays of light, and irradiate a second reading spot on the surface with the parallel rays of light of the other laser beam such that the second reading spot is aligned with the first reading spot and has a diameter sufficiently larger than that of the first reading spot. The surface roughness is measured based on a detected change in a beat frequency of the two laser beams reflected by the first and second reading spots.

Abstract: A rotary encoder includes a laser device which emits a laser beam having beats caused by superposition of a parallel wave and a vertical wave, which have mutually different frequencies and whose oscillating surfaces are normal to each other. A part of the beating laser beam is led to a first detector where the beat frequency of the original laser beam is detected. The remaining laser beam is split into the parallel and vertical waves by a splitting/irradiating device, and the parallel wave is irradiated onto a predetermined position of the rotational member and is scattered or reflected upon Doppler shifting attendant to the rotation of the rotational member. The scattered or reflected parallel and vertical waves are led to a synthesizer where both waves are synthesized to provide a laser beam with beats. The synthesized laser beam is led to a second detector where the beat frequency of the laser beam after being Doppler shifted is detected.

Abstract: An optical system for producing an optical output having a beat frequency. The shifter has a beam splitter for splitting a laser radiation generated by a laser source, into a first and a second laser beam, and includes an acoustooptical modulator for deflecting the first laser beam and thereby changing the frequency of the first laser beam. The shifter further has an optical-path changing device such as a convex lens or parabolic reflector for changing an optical path of the first laser beam deflected by the acoustooptical modulator, into parallelism with the optical axis of the changing device. The focal point of the optical-path changing device is located at a point of emission of the deflected first laser beam. A mixer is provided for mixing the deflected first laser beam with the second laser beam, thereby causing an interference between the first and second laser beams, to produce a beat frequency equal to a difference between the frequencies of the first and second laser beams.