A recovery mechanism and an ink jet recording apparatus with said recovery mechanism

Abstract: A recovery mechanism for recovering the ink discharge performance of ink discharge orifices for an ink jet recording head (4). The recovery mechanism comprises a recovery member (5a) for use in performing a recovery operation of the ink discharge orifices for said recording head (4), a head moving member (3) for moving said ink jet recording head in a predetermined direction, said head moving member (3) having an elastic member (9) displacing said recording head (4) to a recovery processing position closer to and facing said recovery member (5a), a first guide member (3a) for guiding said head moving member in said predetermined direction, and a second guide member (3b,8a) for guiding said head moving (3) member in said predetermined direction, said second guide member (3b,8a) guiding said head moving member to said recovery processing position due to a biasing force of said elastic member (9).

Description: The present invention relates to an ink jet recording apparatus which performs the recording by discharging the ink onto the recording medium, and more particularly to a recovery mechanism for enclosing the ink discharge face of recording head and an ink jet recording apparatus having the recovery mechanism according to the preamble of claim 1. In recent years, along with the spread of personal computers, word processors, or facsimile apparatuses into offices, various types of recording apparatuses have been developed as output means. Among them, an ink jet recording apparatus has been widely used because of its small size and the low recording noise. In the ink jet recording apparatus, paper powder or dust may attach onto or around ink discharge orifices of recording head, or the ink may be thickened because ink water contents vaporize, causing the clogging of nozzles which yields an ink discharge failure. Thus, recovery means is provided for effecting the recovery operation for sucking the ink through ink discharge orifices via a cap member which is mounted on to the ink discharge orifices of the recording head to enclose them during the non-recording time, thereby maintaining the normal ink discharge operation. An example of ink jet recording apparatus equipped with such recovery means will be described below with reference to Figs. 11 to 13. Fig. 11 is a perspective view of ink jet recording apparatus, Fig. 12 is a cross-sectional view of recovery means, and Fig. 13 is a front view of recovery means. In Fig. 11, 50 is a recording head mounted on a carriage 51. The carriage 51 is slidably attached on the carriage shafts 53a, 53b disposed in parallel to the recording medium 52 so that it can be reciprocated on the carriage shafts 53a, 53b when driven by a carriage motor, not shown. 54 is a cap for use with recovery means which is brought into close contact with the ink discharge face when the recording head 50 is moved to a position opposed to the cap, and separated away from the ink discharge face when the recovery operation is ended. The cap 54 is caused to advance or retract when its back face side is forced by power transmission means, partially not shown, in accordance with the rotation of a cam 55 disposed rearward thereof, for example. The cap 54 is held within a cap holder 56, which is held within a holder 57, as shown in Fig. 12. On the back face side (right side in Fig. 12) of the cap holder 56, a pin-like projection 58 is attached to extend through a partition wall of the holder 57. A coil spring 59 is fitted around the projection 58 between the cap holder 56 and the holder 57. This coil spring 59 has one end thereof on the partition wall of the holder 57, and the other end urging the cap holder 56 to place the surface of the cap 54 into contact with the ink discharge face of the recording head 50 at an appropriate pressure. Also, at the trailing end of the projection 58, an E ring 60 for regulating the forward movement of the cap 54 is attached. On the upper surface of the holder 57 is provided a dowel portion 57a, and a coil spring 62 is extended between the dowel portion 57a and a dowel portion 61a of a flat cam 61, so that a cam face 61b of the flat cam 61 may abut on the dowel portion 57a. The holder 57 is mounted on a slider 63, which is moved in a left direction as shown in Fig. 11 along with the carriage 51 if a part of the recording head 50 comes into contact with an arm portion 63a of the slider 63. Then, since the dowel portion 57a of the holder 57 is moved upon abutting on the cam face 61b of the flat cam 61, the holder 57 is moved forward or toward the recording head 50, resulting in the cap 54 enclosing and protecting the ink discharge face of the recording head 50 to effect the suction recovery operation. However, the ink jet recording apparatus is required to have a slide mechanism for moving the cap 54 on to the ink discharge face of the recording head 50, which is provided for cap pressing means on recovery means, and pressing means for pressing the cap 50 onto the ink discharge face. This applies not only to the ink jet recording apparatus of the serial type as described above, but also to the ink jet recording apparatus of the full-line type. As a result, it is apprehended that recovery means becomes complex in structure, raising production costs with increased number of components and reducing the easiness of assembly because of small recovery means. In the US 4 571 601 a recovery mechanism is disclosed for recovering the ink discharge performance of ink discharge orifices of an ink jet recording head. The recovery mechanism comprises a recovery member for a recovery process of the ink discharge orifices of the ink jet recording head and a head moving member for moving the ink jet recording head in a predetermined direction orthogonal to the conveying direction of a recording medium. The head moving member has a guide member for guiding the head moving member in the aforementioned predetermined direction. In particular, this is achieved in that the ink jet recoding head is brought into close contact to a nozzle cleaning device by means of an eccentric guide shaft. SUMMARY OF THE INVENTION The present invention has been achieved to solve the aforementioned conventional problems, and its object is to provide an ink jet recording apparatus wherein a recovery mechanism is simplified with lower costs and the improved ease of assembly. This is achieved by a recovery mechanism according to claim 1. Further improvements are the subject matter of the appended dependent claims. It an aspect of the present invention to provide a recovery mechanism and an ink jet recovery apparatus having said recovery mechanism wherein a recording head movement mechanism for moving a recording head in a predetermined direction is provided with pressing means for pressing the ink discharge orifices of the recording head onto the recovery mechanism, so that the constitution of the recovery mechanism is simplified with the number of components reduced. It is a further aspect of the present invention to provide a recovery mechanism and an ink jet recording apparatus having the recovery mechanism, wherein the recovery mechanism is capable of regulating the interval between the recording head and the recording medium, as well as preventing the vibration produced by pressing means for pressing the ink discharge orifices of recording head onto the recovery mechanism during the movement of the recording head. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional explanation view showing the constitution of pressing means provided on a carriage according to the first embodiment of the invention. Fig. 2 is a schematic perspective explanation view of an ink jet recording apparatus according to the first embodiment of the invention. Fig. 3 is a schematic cross-sectional explanation view of the ink jet recording apparatus. Fig. 4 is a schematic cross-sectional explanation view showing the constitution of pressing means provided on a carriage according to the second embodiment of the invention. Fig. 5 is a schematic perspective explanation view of an ink jet recording apparatus according to the second embodiment of the invention. Fig. 6 is a schematic cross-sectional explanation view showing the constitution of pressing means provided on a carriage according to the third embodiment of the invention. Fig. 7 is a schematic plan view from the above of the carriage as shown in Fig. 6. Fig. 8 is a schematic cross-sectional explanation view showing the constitution of pressing means provided on a carriage according to the fourth embodiment of the invention. Fig. 9 is a schematic plan view showing the operation of pressing means. Fig. 10 is a schematic plan view showing the operation of pressing means. Fig. 11 is a schematic perspective explanation view of a conventional ink jet recording apparatus. Fig. 12 is a schematic cross-sectional explanation view of conventional recovery means. Fig. 13 is a schematic front explanation view of conventional recovery means. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First embodiment] An ink jet recording apparatus according to the first embodiment of the present invention will be now described with reference to Figs. 1 and 2. Note that Fig. 1 is a cross-sectional explanation view showing the constitution of pressing means provided on a carriage, Fig. 2 is a perspective explanation view of the ink jet recording apparatus, and Fig. 3 is a cross-sectional explanation view of the ink jet recording apparatus. (Overall constitution) First, the overall constitution of the apparatus will be described below. This apparatus performs the recording by discharging the ink in response to an image signal in such a manner as to reciprocate a recording head 4 mounted on a carriage 3 with respect to the recording medium 1, while conveying a recording medium 1 (e.g., paper, cloth, OHP sheet, etc.) with conveying means 2. And the recording medium 1 after the recording is exhausted into a predetermined exhaust portion, and the recording head 4 is caused to be recovered by a recovery system 5. In the following, the constitution of each component will be described in sequence with reference to Figs. 1 to 3. (Conveying means) In Fig. 3, conveying means 2 conveys the recording medium 1 to a recording position IP, and exhausts the recording medium 1 into the exhaust portion after the recording. This apparatus allows for both the automatic sheet feeding with ASF (Automatic Sheet Feeder) and the manual insertion sheet feeding. ASF sheet feeding is operable by setting recording sheets 1 on an ASF 2a mounted on an apparatus main body 6 as shown in Fig. 2 to have a recording sheet 1 at the nip between a conveying roller 2b and a pinch roller 2c driven for rotation by making contact therewith and apply a conveying force by driving for rotation the conveying roller 2b. Note that a driving force of the conveying motor 2d is transmitted via a gear train 2e to the conveying roller 2b. Also, the recording medium 1 after the recording is exhausted into the exhaust portion by means of an exhausting roller 2f and a spur 2g driven for rotation by making contact therewith. On the other hand, the manual insertion sheet feeding is operable by manually setting one sheet at a manual insertion opening 2h and convey it linearly by the driving of the conveying roller 2b and the exhausting roller 2f. Downstream of the recording position of the recording head 4 in a conveying direction of the recording medium is provided a platen 2i which is a supporting member for supporting the back surface of the recording medium 2. (Carriage) In Fig. 2, the carriage 3 is recording head moving means for reciprocating the recording head mounted thereon, and is slidably attached on two guide shafts 3a, 3b extending along a direction orthogonal to the conveying direction of the recording medium 1. A driving pulley 3c1 and a driven pulley 3c2 are attached near both ends of the guide shaft 3a, and a timing belt 3d engaged with the carriage 3 is looped between both pulleys 3c1, 3c2, and tensioned by a tension spring 3e. Also, a carriage motor 3f is connected to the driving pulley 3c1, and the carriage 3 is reciprocated along the guide shafts 3a, 3b by the forward or reverse rotations of the motor 3f. (Recording head) The recording head 4 records an image onto the recording medium 1 conveyed by the conveying means 2 by discharging the ink thereto, wherein the recording head in this apparatus relies on an ink jet recording method for recording by discharging ink droplets. That is, this recording head 4 comprises minute liquid discharging openings (orifices), liquid channels having an energy acting portion provided on a part of this liquid channel, and energy generating means for generating liquid droplet forming energy which is applied to the liquid in the energy acting portion. Energy generating means for generating such energy relies on a recording method of utilizing an electromechanical converter such as a piezoelectric element, a recording method of utilizing energy generating means for discharging liquid droplets by applying radiation of an electromagnetic wave such as a laser to heat liquid, or a recording method of utilizing energy generating means for discharging liquid droplets by heating liquid with electricity-heat converters such as heat generating elements having heat generating resistors. Among them, an recording head relying on the ink jet recording method for discharging liquid droplets by the use of heat energy can perform the recording at high resolutions because of its high density arrangement of liquid discharge openings (orifices) for discharging liquid droplets formed to make the discharge by discharging liquid droplets for the recording. In particular, the recording head which uses electricity-heat converters as energy generating means is easily made compact, and is favorable because of making the effective use of the advancement of technologies in the recent semiconductor fields as well as the merits of the IC technology or micro process technology which has been remarkably improved in the respect of reliability, with the ease of high density packaging and the low manufacturing costs. (Recovery means) Recovery means 5 prevents the clogging of the recording head 4 which may occur after the recording operation, comprising a capping mechanism for preventing an ink discharge failure with the recording head 4 as well as preventing the evaporation of water through the discharge orifices by placing a cap 5a made of an elastic material such as a rubber into contact with the ink discharge orifices of the recording head 4. Further, the recovery means 5 includes a feature of making the discharging excellent by sucking the thickened ink through the ink discharge orifices by means of a pump so that the inside of the cap may be at the negative pressure. The recovery means 5 prevents the recording head 4 from having increased viscosity of the ink therein to lower the ink discharge rate or yield the clogging of the nozzles. (Pressing means) As shown in Fig. 1, a sliding member 7 is inserted through a hole provided near the guide shaft 3b of the carriage 3 to be slidable in left and right directions as shown in the figure. This sliding member 7 comprises a pin-like slide portion 7b and a semi-spherical sliding portion 7a for sliding with its spherical face abutting on a chassis 8. A spring is fitted around the slide portion 7b between the carriage 3 and the sliding portion 7a to force the sliding portion 7a to the chassis 8. Note that the sliding portion 7a may be of a roll shape rolling on the chassis 8, but is not limited to them, as long as the sliding portion always makes contact with the chassis 8. The slide portion 7b is urged in a direction of the arrow B due to a biasing force of the spring 9 because it is fitted loosely through the hole formed in the carriage 3. Also, when the cap 5a and the ink discharge face of the recording head 4 are placed at opposed position to each other, it is necessary to place the ink discharge face into close contact with the cap 5a by rotating the carriage 3 around the guide shaft 3a in a direction of the arrow A to press the ink discharge face onto the cap 5a. Thus, the guide shaft 3b has a shaft diameter narrowed toward the right hand in Fig. 2 (3b0). The carriage 3 is brought to a site of the guide shaft 3b0 and the ink discharge face is brought to a position opposed to the cap 5a and closer to the cap 5a to make contact therewith. (Carriage moving operation) The moving operation of the carriage 3 will be described below. The carriage 3 is connected to the timing belt 3d extended between the driving pulley 3c1 and the driven pulley 3c2, and reciprocated along the guide shafts 3a, 3b by driving the carriage motor 3f. And the recording head 4 records an image on the recording medium 1 by discharging the ink through the ink discharge orifices thereof in accordance with image information. After the completion of the recording, the carriage 3 is moved toward the recovery means side as shown in Fig. 2, and stopped at a position at which the ink discharge orifices of the recording head 4 and the cap 5a face each other (hereinafter referred to as a "capping position"). In this state, the ink discharge face are completely enclosed with the cap 5a, with no small interstice left therein, wherein it is necessary to make a complete enclosed state by applying a pressure to the cap 5a. Thus, the carriage 3 is urged in a direction of the arrow B owing to the spring 9 fitted between the carriage 3 and the sliding member 7, as shown in Fig. 1, and is rotated around the guide shaft 3a in a direction of the arrow A by virtue of having a shaft diameter of the guide shaft 3b narrowing at a capping position, as shown in Fig. 2, so that the ink discharge face is placed into close contact with the cap 5a. Thereby, the ink discharge face is enclosed with the cap 5a. With the above constitution, it is unnecessary for the recovery means 5 to have pressing means for pressing the cap 5 on to the ink discharge face, so that the recovery means 5 is simplified in construction with the improved easiness of assembly, and the apparatus can be reduced in whole size with the lower costs because of the reduced number of components. [Second embodiment] A second embodiment other than the ink jet recording apparatus as shown in the first embodiment will be described below with reference to Figs. 4 and 5. A schematic constitution of the ink jet recording apparatus is the same as that of the first embodiment, and the like numerals are attached to the like parts, the explanation of which is omitted. This embodiment is configured such that a carriage 3 is recirpocated along a plate-like guide rail 8a formed by bending a part of a chassis 8 like an U-shaped character in cross section. In Fig. 4, on the upper face of the carriage 3 is attached a guide member 3g shaped as an U-shaped character in cross section, and a carriage sliding portion 3h is formed on a wall surface opposed to the guide rail 8a of the guide member 3g to be slidable therewith while abutting on the guide rails 8a. Also, the guide member 3g has a sliding member 7 inserted therethrough slidable in left and right directions in the figure. This sliding member 7 has a pin-like slide portion 7b and a semi-spherical sliding portion 7a for sliding with its spherical face abutting on the guide rail 8a. A spring 9 is fitted around the slide portion 7b between the guide member 3a and the sliding portion 7a to force the sliding portion 7a into contact with the guide rail 8a. Hence, the carriage 3 can be moved leftward or rightward with the guide rail 8a carried between the sliding portion 7a and the carriage sliding portion 3h. Also, as shown in Fig. 5, the guide rail 8a is bent forth at a capping position located on the right side. Hence, when the carriage 3 is moved to the capping position, the carriage sliding portion 3h loses contact with the guide rail 8a, and the carriage 3 is forced toward a direction of the arrow B by the spring 9 fitted between the guide member 3g and the sliding member 7, and rotated around the guide shaft 3a in a direction of the arrow A on the guide rail 8a bent protruding forth (8a0) at a capping position as shown in Fig. 5, so that the ink discharge face is caused to approach to a position facing the cap 5a to establish contact therewith. With the above constitution, the guide for the carriage 3 is made from a plate member such as a sheet metal, but there is a risk that the carriage 3 may fluctuate leftward or rightward in Fig. 4 during the reciprocative movement because of the tolerance or longitudinal dispersion of plate thickness for the guide rail 8a. However, the sliding portion 7a is brought into contact with the guide rail 8a by the spring 9 fitted between the guide member 3g and the sliding member 7 to always press the carriage 3 on the guide rail 8a and absorb the fluctuation therein, resulting in the stable reciprocative movement of the carriage 3. Note that the guide rail 8a may not be integrally formed with the chassis 8. [Third embodiment] A third embodiment other than the ink jet recording apparatus as shown in the first embodiment will be described below with reference to Figs. 6 and 7. A schematic constitution of the ink jet recording apparatus is the same as that of the first embodiment, and the like numerals are attached to the like parts, the explanation of which is omitted. Note that Fig. 7 is a plan view from the above of the carriage as shown in Fig. 6. This embodiment is configured such that a carriage 3 is reciprocated along a plate-like guide rail 8a formed by bending a part of a chassis 8 like an U-shaped character in cross section, as in the second embodiment, and the gap between the ink discharge face of a recording head 4 and the recording medium 1 (hereinafter referred to as a "paper gap") can be changed. In Figs. 6 and 7, on the upper face of the carriage 3 is attached a guide member 3i on which a shaft 10a is provided, the shaft 10a having a gap adjusting cam 10 mounted rotatably. The gap adjusting cam 10 is mounted eccentrically to the shaft 10a, and a cam gear 10b is integrally mounted under the gap adjusting cam 10. Further, on the guide member 3i, an adjusting lever 11 is rotatably mounted around a shaft 11a, and a lever gear 11b formed on the circular surface of the adjusting lever 11 is mated with the cam gear 10b. The adjusting lever 11 has a concave portion formed on the back side thereof, which secures the position of the adjusting lever 11 upon engagement with a click 12 formed on the upper surface of the guide member 3i. Through an upstanding surface 3j of the guide member 3i, a sliding member 7 is inserted to be slidable in left and right directions in Fig. 6. This sliding member 7 has a pin-like slide portion 7b and a semi-spherical sliding portion 7a for sliding with its spherical face abutting on the guide rail 8a. A spring 9 is fitted around the slide portion 7b between the upstanding surface 3j and the sliding portion 7a to force the sliding portion 7a into contact with the guide rail 8a. With the above constitution, if the adjusting lever 11 is rotated in a direction of the arrow in Fig. 7, the gap adjusting cam 10 is rotated clockwise around the shaft 10a, because the lever gear 11b is mated with the cam gear 10b. Since the gap adjusting cam 10 is eccentric, the gap adjusting cam 10 has a variable radius around the shaft 10a, and urges the guide rail 8a toward a direction of the arrow B at the maximum radius thereof to cause the carriage 3 to be rotated via the sliding member 7 around the guide shaft 3a in a direction of the arrow A, as shown in Fig. 6. As a result, the ink discharge face of the recording head 4 is directed downward to permit a narrower paper gap. Also, if the adjusting lever 11 is rotated in a direction opposite to the direction of the arrow in Fig. 7, the ink discharge face is directed upward to permit a wider gap between the recording head 4 and the recording medium 1. This makes it possible to convey and record on a variety of kinds of recording medium 1 having different thicknesses, resulting in the improved generality. If the diameter 10W of the gap adjusting cam 10 is equal to the interval 8W between the chassis 8 and the guide rail 8a, the carriage 3 can be reciprocated stably (without fluctuation) along the guide shaft 3a. However, since the gap adjusting cam 10 must be slidable on the guide rail 8a of the chassis 8, there is necessarily a minute gap between the gap adjusting cam 10 and the guide rail 8a or the chassis 8. Also, there is a risk that the carriage 3 may fluctuate leftward or rightward in Fig. 6 during the reciprocative movement due to the tolerance or longitudinal dispersion of plate thickness for the guide rail 8a. However, the sliding portion 7a is brought into contact with the guide rail 8a by the spring 9 fitted between the upstanding surface 3j and the sliding member 7 to always press the carriage 3 on to the guide rail 8a, and absorb the fluctuation, so that the carriage 3 can be reciprocated stably though the adjustment of paper gap may be made. [Fourth embodiment] A fourth embodiment other than the ink jet recording apparatus as shown in the first embodiment will be described below with reference to Figs. 8 to 10. A schematic constitution of the ink jet recording apparatus is the same as that of the first embodiment, and the like numerals are attached to the like parts, the explanation of which is omitted. Note that Figs. 9 and 10 are plan views from the above of the carriage as shown in Fig. 8. This embodiment is different from the third embodiment but is configured like the third embodiment in that the gap between the ink discharge face of the recording head 4 and the recording medium 1 (hereinafter referred to as a "paper gap") can be adjusted. Its constitution will be described in the following. In Figs. 8 and 9, on the upper face of a carriage 3 is attached an adjusting lever 13 mounted rotatably around a shaft 13a in a direction of the arrow C. An adjusting lever cam 13b of a triangular prism shape is attached coaxially with the adjusting lever 13, and rotated along with the movement of the adjusting lever 13 while being always in direct contact with a guide rail 8a. Depending on the stop position of the adjusting lever 13, the distance from the shaft 13a to the peripheral surface of the adjusting lever cam 13b is changed, so that the carriage 3 is moved in a direction of the arrow D in Fig. 9. 14 is a pressure contact roller which rolls on the rail along with the movement of the carriage 3, while pressing on the guide rail 8a. 15 is a pressure contact lever, which is rotatably mounted around a pressure contact lever shaft 15a provided on the upper surface of the carriage 3. The pressure contact lever 15 has the pressure contact roller 14 rotatably held at one end thereof. At the other end of the pressure contact lever 15 is provided a projection 15b, and between the projection 15b and a projection 3k on the upper surface of the carriage 3 is stretched a pressure contact spring 16, which urges the pressure contact lever 15 to cause the pressure contact roller 14 to always press on the guide rail 8a. Note that a click spring 17 is provided between a projection 13c provided on the adjusting lever 13 and the pressure contact lever shaft 15a to hold the adjusting lever 13 at a position as shown in Fig. 9 or Fig. 10. Also, the adjusting lever 13 has a circular longitudinal hole 13d formed, as shown in Fig. 9, whereby the adjusting lever 13 can be rotated in a range where the end portion of the longitudinal hole 13d is not engaged by the pressure contact lever shaft 15a. With the above constitution, if the adjusting lever 13 is rotated counterclockwise until the longitudinal hole 13d is engaged by the pressure contact lever shaft 15a, as shown in Fig. 9, the distance between the shaft 13a and the peripheral surface of the adjusting lever cam 13b becomes maximum, so that the carriage 3 is moved in a direction of the arrow X as shown in Fig. 8, and slightly rotated clockwise around the guide shaft 3a, resulting in a wider paper gap. Next, if the adjusting lever 13 is rotated clockwise to a position at which the pressure contact lever shaft 15a engages the longitudinal hole 13d, as shown in Fig. 10, the distance between the shaft 13a and the peripheral surface of the adjusting lever cam 13b becomes minimum, so that the carriage 3 is moved in a direction of the arrow Y as shown in Fig. 8, and slightly rotated counterclockwise around the guide shaft 3a, resulting in a narrower paper interval. With the above constitution, it is possible to provide the same effects as with the third embodiment. [Fifth embodiment] While in the above-described embodiments, recording means used the ink jet recording system, it is more preferable that the recording means is constituted in such a manner as to energize electricity-heat converters in accordance with a recording signal, and discharge the ink through discharge orifices by growth and shrinkage of bubbles occurring in the ink due to film boiling produced by heat energy applied by the electricity-heat converters. As to its representative constitution and principle, for example, one practiced by use of the basic principle disclosed in, for example, U.S. Patents 4,723,129 and 4,740,796 is preferred. This system is applicable to either of the so-called on-demand type and the continuous type. Particularly, the case of the on-demand type is effective because, by applying at least one driving signal which gives rapid temperature elevation exceeding nucleus boiling corresponding to the recording information on electricity-heat converters arranged corresponding to the sheets or liquid channels holding a liquid (ink), heat energy is generated at the electricity-heat converters to effect film boiling at the heat acting surface of the recording head, and consequently the bubbles within the liquid (ink) can be formed corresponding one by one to the driving signals. By discharging the liquid (ink) through an opening for discharging by growth and shrinkage of the bubble, at least one droplet is formed. By making the driving signals into the pulse shapes, growth and shrinkage of the bubbles can be effected instantly and adequately to accomplish more preferably discharging of the liquid (ink) particularly excellent in response characteristic. As the driving signals of such pulse shape, those as disclosed in U.S. Patents 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employment of the conditions described in U.S. Patent 4,313,124 of the invention concerning the temperature elevation rate of the above-mentioned heat acting surface. As the constitution of the recording head, in addition to the combination of the discharging orifice, liquid channel, and electricity-heat converter (linear liquid channel or right-angled liquid channel) as disclosed in the above-mentioned respective specifications, the constitution by use of U.S. Patent 4,558,333 or 4,459,600 disclosing the constitution having the heat acting portion arranged in the flexed region is also included in the present invention. In addition, the present invention can be also effectively made the constitution as disclosed in Japanese Patent Application Laid-Open No. 59-123670 which discloses the constitution using a slit common to a plurality of electricity-heat converters as the discharting portion of the electricity-heat converter or Japanese Patent Application Laid-Open No. 59-138461 which discloses the constitution having the opening for absorbing pressure wave of heat energy correspondent to the discharging portion. That is, the present invention makes it possible to realize the secure and efficient recording, in whatever form the recording head may be configured. Further, the present invention can be effectively applied to the recording head of the full line type having a length corresponding to the maximum width of a recording medium which can be recorded by the recording device. As such a recording head, either the constitution which satisfies its length by a combination of a plurality of recording heads or the constitution as one recording head integrally formed may be used. In addition, among the serial-type recording heads as above described, the present invention is effective for a recording head fixed to the carriage, a recording head of the freely exchangeable chip type which enables electrical connection to the main device or supply of ink from the main device by being mounted on the carriage, or a recording head of the cartridge type having an ink tank integrally provided on the recording head itself. Also, addition of a restoration means for the recording head, a preliminary auxiliary means, etc., provided as the constitution of the recording device of the present invention is preferable, because the effect of the present invention can be further stabilized. Specific examples of these may include, for the recording head, capping means, cleaning means, pressurization or suction means, electricity-heat converters or another type of heating elements, or preliminary heating means according to a combination of these, and it is also effective for performing stable recording to perform preliminary mode which performs discharging separate from recording. As for the types or number of recording heads to be mounted on the carriage, the present invention is effective to a single recording head provided corresponding to the monocolor ink or a plurality of recording heads corresponding to a plurality of inks having different recording colors or densities, for example. That is, as the recording mode of the recording device, the present invention is extremely effective for not only the recording mode only of a primary color such as black, etc., but also a device equipped with at least one of plural different colors or full color by color mixing, whether the recording head may be either integrally constituted or combined in plural number. In addition, though the ink is considered as the liquid in the embodiments as above described, another ink may be also usable which is solid below room temperature and will soften or liquefy at or above room temperature, or liquefy when a recording signal is issued during use as it is common with the ink jet device to control the viscosity of ink to be maintained within a certain range of the stable discharge by adjusting the temperature of ink in a range from 30°C to 70°C. In addition, in order to avoid the temperature elevation due to heat energy by positively utilizing the heat energy as the energy for the change of state from solid to liquid, or to prevent the evaporation of ink by using the ink which will stiffen in the shelf state, the use of the ink having a property of liquefying only with the application of heat energy, such as liquefying with the application of heat energy in accordance with a recording signal so that liquid ink is discharged, or may be solidified prior to reaching a recording medium, is also applicable in the present invention. In such a case, the ink may be held as liquid or solid in recesses or through holes of a porous sheet, which is placed opposed to electricity-heat converters, as described in Japanese Patent Application Laid-Open No. 54-56847 or No. 60-71260. The most effective method for the ink as above described in the present invention is based on the film boiling. Further, the ink jet recording apparatus as described above may be used as an image output terminal in an information processing equipment such as a computer, a copying machine in combination with a reader, or a facsimile terminal equipment having the transmission and reception feature. As previously described, in this embodiment, recording head moving means for moving the recording head in a predetermined direction is provided with pressing means for pressing the ink discharge orifices of the recording head against the recovery means, and therefore the recovery means does not require pressing means for urging the ink discharge face of recording means, whereby the recovery means is simplified in construction with the easiness of assembly improved, and the apparatus is reduced in whole size with the lower costs because of the reduced number of components. The pressing means provided on the recording head moving means can absorb the fluctuation occurring during the reciprocative movement of the recording head moving means to assure stable moving operation, and accordingly a mechanism for adjusting the interval between the recording means and the recording medium is provided to enhance the generality of the apparatus.

Claims: Recovery mechanism for recovering the ink discharge performance of ink discharge orifices of an ink jet recording head (4), said recovery mechanism comprising: a recovery member (5) for a recovery process of the ink discharge orifices of said ink jet recording head (4), a head moving mechanism (3, 7) for moving said ink jet recording head (4) in a predetermined direction different from the conveying direction of a recording medium, said head moving mechanism (3, 7) having a first guide member (3a) for guiding said head (4) in said predetermined direction, and characterized in that said head moving mechanism (3, 7) has a second guide member (3b, 8a, 10) for guiding said head (4) to a recovery processing position closer to and facing said recovery member (5) owing to a biasing force of an elastic member (9, 16) displacing said recording head (4) to said recovery processing position. A recovery mechanism according to claim 1, wherein said head moving mechanism (3, 7) displaces said recording head (4) to said recovery processing position by the rotation of said head moving mechanism (3, 7) with respect to said first guide member (3a). A recovery mechanism according to claim 1, wherein said second guide member (3b) is an axial member having a portion of smaller axial diameter (3b0) than in other portions to guide said head moving mechanism (3, 7) to said recovery processing position. A recovery mechanism according to claim 1, wherein said second guide member (8a) has a flexed portion (8a0) for guiding said head moving mechanism (3, 7) to said recovery processing position. A recovery mechanism according to claim 1, wherein said head moving mechanism (3, 7) has an adjusting mechanism (11, 13) for adjusting the interval between the recording medium and said ink discharge orifices in the recording area. A recovery mechanism according to claim 1, wherein said head moving mechanism (3, 7) comprises a carriage (3). A recovery mechanism according to claim 1, wherein said recovery member (5) comprises a cap member (5a). A recovery mechanism according to any one of claims 1 to 7, wherein said ink jet recording unit is an ink jet recording head having electricity-heat converters for generating heat energy for use in discharging the ink. A recovery mechanism according to claim 8, wherein said ink jet recording head discharges the ink through said ink discharge orifices due to film boiling produced in the ink by heat energy generated by said electricity-heat converters. Ink jet recording apparatus, characterizied by a recovery mechanism according to the preceding claims. Ink jet recording apparatus according to claim 10, further comprising a conveying mechanism (2) for conveying the recording medium to a recording area on which said ink jet recording head (4) performs the recording.

Inventors: HIRAMATSU SOICHI, KAWAKAMI HIDEAKI, KINOSHITA HIROYUKI, NOJIMA TAKASHI, SAIKAWA SATOSHI, SAITO HIROYUKI, SUZUKI TETSUO, TANIGURO MASAHIRO, YANAGI HARUYUKI, HIRAMATSU, SOICHI, KAWAKAMI, HIDEAKI, KINOSHITA, HIROYUKI, NOJIMA, TAKASHI, SAIKAWA, SATOSHI, SAITO, HIROYUKI, SUZUKI, TETSUO, TANIGURO, MASAHIRO, YANAGI, HARUYUKI, HIRAMATSU, SOICHI, C/O CANON KABUSHIKI KAISHA, KAWAKAMI, HIDEAKI, C/O CANON KABUSHIKI KAISHA, KINOSHITA, HIROYUKI, C/O CANON KABUSHIKI KAISHA, NOJIMA, TAKASHI, C/O CANON KABUSHIKI KAISHA, SAIKAWA, SATOSHI, C/O CANON KABUSHIKI KAISHA, SAITO, HIROYUKI, C/O CANON KABUSHIKI KAISHA, SUZUKI, TETSUO, C/O CANON KABUSHIKI KAISHA, TANIGURO, MASAHIRO, C/O CANON KABUSHIKI KAISHA, YANAGI, HARUYUKI, C/O CANON KABUSHIKI KAISHA
Applicants: CANON KK, CANON KABUSHIKI KAISHA
Application year: 1993
Main classification: B41J2
IPC codes: B41J2, B41J25