Abstract:
An ink jet recording apparatus has a recording head for recording by ejecting ink onto a recording medium, a head recovery device that recovers a function of the recording head, a suction switch for operating the head recovery device, and a print instruction switch, and an inhibition device that inhibits operation of the head recovery device under a predetermined condition. When operation of the head recovery device is inhibited under a certain condition, the head recovery device cannot be operated if the suction switch is operated. The inhibition of head recovery operation is canceled when the suction switch and a print instruction switch are operated. The recording apparatus thereby prevents unintentional head recovery operation and prevents unnecessary ink consumption, without degrading the operability of the head recovery device.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The invention relates to an ink jet recording apparatus having an ink jet recording head for recording by ejecting ink onto a recording medium, and a recovery device for recovering the function of the recording head. 
     2. Description of Related Art 
     In conventional ink jet recording apparatuses for recording by ejecting ink from nozzles, it is necessary to place a cap on an ink jet head when not in use because ink on a nozzle surface is likely to dry and solidify causing an ink ejection failure. In order to recover from an ink ejection failure or prevent an ink ejection failure, there is a need to perform maintenance of an ink jet head. There are several maintenance methods for ink jet heads, for example, a purging method in which nozzle clogging is eliminated by, for example, drawing dry ink from an ink jet head nozzle, or a wiping method in which an ink-wet nozzle surface is wiped. As a device for facilitating such an ink jet head maintenance operation, U.S. Pat. No. 4,543,591 discloses a maintenance device for an ink jet recording apparatus, which immediately performs the capping of a nozzle and the subsequent ink drawing at freely selectable timings by operation of a lever in one direction. 
     However, if the aforementioned maintenance device is incorporated into a head recovery device, the operability improves, but unnecessary ink consumption may result through improper operation. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the invention to provide an ink jet recording apparatus that prevents improper operation of a head recovery device and, thereby, eliminates unnecessary ink consumption, without degrading operability. 
     To achieve the aforementioned object, the invention provides an ink jet recording apparatus including a recording head for recording by ejecting ink onto a recording medium, a head recovery device that recovers a function of the recording head, a first switch for operating the head recovery device, and an inhibition device that inhibits operation of the head recovery device under a predetermined condition. 
     Because the inhibition device inhibits operation of the head recovery device under a predetermined condition, unintentional or accidental operation of the head recovery device can be prevented even if the switch for operating the head recovery device is operated in such an occasion. Therefore, unnecessary ink consumption is prevented. 
     The inhibition device may have a second switch provided aside from the first switch, and the inhibition device cancels the inhibition of operation of the head recovery device when the first switch and the second switch are operated. 
     The inhibition device may cancel the inhibition of operation of the head recovery device when the first switch is continually operated. 
     The inhibition device may have a timer for measuring time elapsed after a previous operation of the head recovery device, and the inhibition device cancels the inhibition of operation of the head recovery device when the time measured by the timer reaches a predetermined length of time. 
     The inhibition device may have a timer for measuring time elapsed after a previous operation of the recording head, and the inhibition device cancels the inhibition of operation of the head recovery device when the time measured by the timer reaches a predetermined length of time. 
     The inhibition device may have a timer for measuring time elapsed after a main switch of the ink jet recording apparatus is turned on, and the inhibition device cancels the inhibition of operation of the head recovery device when the time measured by the timer reaches a predetermined length of time. 
     The inhibition device may have a counter for counting an amount of printed characters that are printed by the recording head after a previous operation of the head recovery device, and the inhibition device cancels the inhibition of operation of the head recovery device when the count by the counter reaches a predetermined value. 
     The inhibition device may have a sensor for counting an amount of ink that is used by the recording head after a previous operation of the head recovery device, and the inhibition device cancels the inhibition of operation of the head recovery device when the count provided by the sensor reaches a predetermined amount. 
     The inhibition device may have a counter for counting a number of times that the recording head prints after a previous operation of the head recovery device, and wherein the inhibition device cancels the inhibition of operation of the head recovery device when the count by the counter reaches a predetermined value. 
     The inhibition device may have a counter for counting an amount of printed characters that are printed by the recording head after a main switch of the ink jet recording apparatus is turned on, and the inhibition device cancels the inhibition of operation of the head recovery device when the count by the counter reaches a predetermined amount. 
     The inhibition device may have a counter for counting an amount of ink that is used by the recording head after a main switch of the ink jet recording apparatus is turned on, and the inhibition device cancels the inhibition of operation of the head recovery device when the count by the counter reaches a predetermined amount. 
     The inhibition device may have a counter for counting a number of times that the recording head prints after a main switch of the ink jet recording apparatus is turned on, and the inhibition device cancels the inhibition of operation of the head recovery device when the count by the counter reaches a predetermined value. 
     The inhibition device may have a sensor for measuring an amount of ink remaining in the recording apparatus, and the inhibition device prevents cancellation of the inhibition of operation of the head recovery device when the amount measured by the sensor has become equal to or lower than a predetermined amount. With this structure, when the ink remaining in the recording apparatus has become equal to or less than the predetermined amount, it becomes impossible to operate the recovery device. This structure eliminates an inconvenient incident wherein the recovery device is operated when there is only a small amount of ink remaining, so that the remaining ink is completely consumed. That is, even when there is only a little ink left, it is possible to continue recording while preventing the recovery device from operating, even though minor problems occur in recording quality. 
     The inhibition device may have a second counter for counting a number of operations of the recovery device, and the inhibition device prevents cancellation of the inhibition of operation of the head recovery device when the count by the second counter has reached a predetermined value. With this structure, when the number of operations of the recovery device has reached the predetermined number, it becomes impossible to operate the recovery device. This structure prevents an unnecessarily great number of recovery operations and, therefore, prevents unnecessary ink consumption. 
     The ink jet recording apparatus may further include a recovery permission device that forcibly cancels a condition setting for the inhibition by the inhibition device. This structure allows the head recovery device to be driven even under the inhibition condition, if a recovery operation is needed. 
     The ink jet recording apparatus may further have an inhibition condition setting device that enables selection of whether to set a condition for the inhibition by the inhibition device. This structure makes it possible for a user to select a condition for the inhibition in accordance with the working conditions, thereby improving usability and reducing unnecessary ink consumption. 
     The ink jet recording apparatus may be a small-size manually-driven printing apparatus that records by ejecting ink onto a recording medium when the apparatus is manually moved over the recording medium. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments of the invention will be described in detail with reference to the following figures wherein: 
     FIG. 1 is an exterior view of a manually-driven printing apparatus according to an embodiment of the invention; 
     FIG. 2 is a sectional view of the manually-driven printing apparatus shown in FIG. 1; 
     FIG. 3 is a bottom view of the manually-driven printing apparatus shown in FIG. 1; 
     FIG. 4 is a fragmental sectional view of the manually-driven printing apparatus, with a cap member being at a capping position; 
     FIG. 5 is a fragmental sectional view of the manually-driven printing apparatus, with the cap member being at a withdrawn position; 
     FIG. 6 is a block diagram of a control system of a recording apparatus according to a first embodiment; 
     FIG. 7 is a flowchart of a printing control of the recording apparatus; 
     FIG. 8 is a flowchart of a subroutine for suction operation by a suction mechanism according to the first embodiment; 
     FIG. 9 is a flowchart of a subroutine for suction operation by a suction mechanism according to a second embodiment; 
     FIG. 10 is a block diagram of a control system of a recording apparatus according to a third embodiment; 
     FIG. 11 is a flowchart of a printing control according to the third embodiment; 
     FIG. 12 is a flowchart of a printing control according to a fourth embodiment; 
     FIG. 13 schematically illustrates recording areas in a RAM; 
     FIG. 14 is a flowchart of a printing control according to a fifth embodiment; 
     FIG. 15 is a block diagram of a control system of a recording apparatus according to a sixth embodiment; 
     FIG. 16 is a flowchart of a printing control according to the sixth embodiment; 
     FIG. 17 is a flowchart of a printing control according to a seventh embodiment; 
     FIG. 18 is a flowchart of a printing control according to an eighth embodiment; 
     FIG. 19 is a flowchart of a printing control according to a ninth embodiment; 
     FIG. 20 is a flowchart of a printing control according to a tenth embodiment; 
     FIG. 21 is a flowchart of a printing control according to an eleventh embodiment; 
     FIG. 22 is a flowchart of a printing control according to a twelfth embodiment; 
     FIG. 23 is an exterior view of a manually-driven printing apparatus according to a further embodiment of the invention; and 
     FIG. 24 is an exterior view of a manually-driven printing apparatus according to a still further embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Preferred embodiments of the invention will be described in detail hereinafter with reference to the accompanying drawings. 
     A manually-driven printing apparatus according to a preferred embodiment of the invention will first be described. FIG. 1 is an exterior view, FIG. 2 is a sectional view, and FIG. 3 is a bottom view of a manually-driven printing apparatus  1 . The manually-driven recording apparatus  1  includes a recording mechanism  3  having an ink jet recording head  2 , a displacement detecting mechanism  4  for detecting the amount of movement of the recording apparatus  1 , an infrared photo-diode  5  and an infrared-emitting diode  6  for infrared communications with an external device, a control circuit board  7  carrying a control portion  7   a  for controlling the recording mechanism  3 , and a battery  8  which is a secondary battery, i.e., a rechargeable power source, and the like. The control portion  7   a  controls the transmission and reception of the diodes  5 ,  6 , and controls the driving of the recording mechanism  3  on the basis of an encoder signal from the displacement detecting mechanism  4 . The aforementioned components are electrically connected and compactly housed in a body case  10 . The manually-driven recording apparatus  1  is capable of recording characters and graphic images on a recording sheet (recording medium)  11  by manually moving the recording apparatus  1  on the recording sheet  11  in a printing direction. 
     The body case  10  is a synthetic resin-made case having the shape of a hollow prism with a bottom opening. When viewed two-dimensionally, the body case  10  has a generally rectangular shape. The infrared photo-diode  5  and the infrared-emitting diode  6  are disposed in an upper end wall of the body case  10 . Disposed in a front wall, i.e., the wall on the rear of the body case  10  relative to the printing direction, of the body case  10  are a power switch  12 , a print instruction switch  13  for instructing permission and inhibition of a recording operation, and a suction switch  14  for operating a suction mechanism (described later) which is a head recovery device. The suction switch  14  constitutes a first switch for operating the head recovery device. The print instruction switch  13  constitutes a second switch for canceling the inhibition of operation of the head recovery device. 
     The recording mechanism  3  will now be described in detail. An ink tank  15  containing an ink absorbent impregnated with a recording ink is detachably disposed in a lower end portion of the body case  10 . The ink tank  15  is connected to the recording head  2 . The recording head  2  has, for example, two rows of downward-directed ejection nozzles (not shown) that extend in a transverse direction perpendicular to the recording direction. Each row includes, for example, thirty-two ejection nozzles. Ink is supplied from the ink tank  15  to each ejection nozzle of the recording head  2 , and ink droplets are ejected selectively from ejection nozzles to the recording sheet  11  placed below. 
     The displacement detecting mechanism  4  is designed to detect the amount of movement of the manually-driven recording apparatus  1  relative to the recording sheet  11 . A timing roller  21  made of rubber, extending close to the recording head  2  in the transverse direction is rotatably supported by a journal shaft  22  to a lower end portion of the body case  10 . A gear  23 , in contact with a portion of the timing roller  21 , is rotatably journaled to the body case  10 . A circular encoder plate  24  rotatable by the gear  23  is rotatably journaled to the body case  10 . A plurality of slits are formed in an outer peripheral portion of the encoder plate  24 . A photo-sensor  25  having a light-emitting portion and a light-receiving portion is disposed so that the light-emitting portion and the light-receiving portion respectively face opposite surfaces of the outer peripheral portion of the encoder plate  24 . A pair of auxiliary rollers  26  are rotatably journaled to a lower end portion of the body case  10 . Lower end portions of the timing roller  21  and the auxiliary rollers  26  protrude from the lower end of the body case  10 . As the body case  10  is manually moved in the recording direction while the timing roller  21  is in contact with the recording sheet  11 , the timing roller  21  rotates in a predetermined direction (clockwise in FIG. 2) and, simultaneously, the encoder plate  24  is rotated by the gear  23 , so that the photo-sensor  25  outputs an encoder signal composed of a pulse train (that is, a signal indicating the amount of movement). Based on the encoder signal and recording data, ink is selectively ejected from ejection nozzles at each recording timing at intervals corresponding to a movement of the body case  10  of a predetermined number of recording pitches, thereby recording characters and graphic images on the recording sheet  11 . 
     A cap member  31  capable of tightly contacting a head surface  2   a  of the recording head  2 , and a cap drive mechanism  30  for driving the cap member  31 , will be described with reference to FIGS. 4 and 5 as well. In FIG. 4, the cap member  31  is at a capping position. In FIG. 5, the cap member  31  is at a withdrawn position. The cap member  31  is formed of an elastic rubber, and has a block shape that is slightly larger than the head surface  2   a  (lower end surface) of the recording head  2 . The cap member  31  has a transversely long suction recess  31   a  corresponding to the ejection nozzle array disposed in the recording head  2 . A wiper blade  32 , extending in the transverse direction and having a predetermined height, is provided integrally with an end portion of the cap member  31 , the end being in the printing direction. The wiper blade  32  is formed of the same elastic rubber as the cap member  31 . The wiper blade  32  has a certain elasticity and is deformable. 
     A position switching solenoid  33  for driving the cap member  31  is disposed on a lower end portion of the body case  10 . A distal end of a plunger  33   a  of the position switching solenoid  33  is connected to the cap member  31 . When recording is not performed, the position switching solenoid  33  remains undriven so that the plunger  33   a  is in a projected position. Therefore, the cap member  31  remains in tight contact with the downward-facing head surface  2   a  of the recording head  2 , as shown in FIG.  4 . When recording is to be performed, the position switching solenoid  33  is driven so that the plunger  33   a  is withdrawn as shown in FIG.  5 . Therefore, the cap member  31  is horizontally moved, sliding on the head surface  2   a,  in a direction opposite to the recording direction. The cap member  31  is thus switched to the withdrawn position. While the cap member  31  is being moved to the withdrawn position, the wiper blade  32  thoroughly wipes unnecessary ink from the head surface  2   a,  that is, the ejection nozzle surface. When the driving of the position switching solenoid  33  is discontinued, the plunger  33   a  is projected or thrust out so that the cap member  31  is moved back to the capping position sliding on the head surface  2   a.    
     A suction mechanism (a head recovery device)  40  for sucking the ejection nozzles of the recording head  2  will now be described in detail. An end of a suction tube  41  is connected to a side surface of the suction recess  31   a  of the cap member  31 . The other end of the suction tube  41  is connected to a suction pump  42  disposed on the body case  10 . The suction pump  42  is designed to produce a negative pressure for suction by using a cam body that is rotated by a small-size motor driven by the battery  8 . Due to the negative pressure, the ejection nozzles are sucked via the suction recess  31   a  and the suction tube  41 . 
     A control system provided in the control portion  7   a  for controlling the manually-driven recording apparatus  1  is structured as schematically shown in the block diagram of FIG. 6. A control device  50  includes a microprocessor that has a CPU  51 , a ROM  52 , a RAM  53  and an input/output interface  54 . The control device  50  further includes an optical communication interface  55 , an infrared-receiving circuit  56  and an infrared-transmitting circuit  57  for communication by infrared light with an external electronic device (not shown), such as a personal computer, and further includes drive circuits  58 - 60 , and the like. The input/output interface  54  is connected to the power switch  12 , the print instruction switch  13 , the suction switch  14 , the photo-sensor  25 , a drive circuit  58  for the position switching solenoid  33 , a drive circuit  59  for the suction pump  42 , and a drive circuit  60  for the recording head  2 . The infrared-receiving circuit  56  is connected to the infrared photo-diode  5 , and the infrared-transmitting circuit  57  is connected to the infrared-emitting diode  6 . The infrared-receiving circuit  56  receives optical data transmitted from an external electronic device by infrared, via the infrared photo-diode  5 . The infrared-transmitting circuit  57  transmits, to the external electronic device, recording format data regarding character sizes or fonts and various data regarding data transfer, in the form of optical data, via the infrared-emitting diode  6 . 
     The ROM  52  stores a recording control program for drive-controlling an actuator provided for each ejection nozzle of the recording head  2 , a control program for optical data transmission and reception, a control program for recording control (described below), dot pattern data regarding individual characters and symbols, and the like. The RAM  53  includes a data memory for storing optical data received, and various memories needed for recording control or optical communication control and the like. 
     A print control routine executed by the control device  50  of the manually-driven recording apparatus  1  will be described with reference to the flowchart of FIG. 7, in which Si (i=10, 11, 12, . . . ) indicates individual steps. When the power switch  12  of the recording apparatus  1  is turned on, this control routine is started. The control device  50  waits until recording data is received via the infrared photo-diode  5  (No in step S 10 ). If recording data has been received (Yes in step S 10 ), the control device  50  performs data development into dot pattern data (step S 11 ). If recording data composed of a plurality of code data is received, a plurality of code data for recording individual lines are separately developed into dot pattern data. Until the print instruction switch  13  is turned on, the control device  50  remains in a recording standby state (No in step S 12 ) 
     The body case  10  is manually held in a substantially vertical upstanding position so that the timing roller  21  is in contact with the recording sheet  11 . Then, the print instruction switch  13  is turned on for recording (Yes in step S 12 ). The body case  10  is then manually moved linearly in the printing direction while the print instruction switch  13  is held in the on-position. As the encoder plate  24  is rotated by rotation of the timing roller  21 , the encoder signal outputted from the photo-sensor  25  is inputted to the control device  10  (Yes in S 13 ). The position switching solenoid  33  is then driven so that the cap member  31  is moved from the capping position (FIG. 4) to the withdrawn position (FIG.  5 ), sliding on the head surface  2   a  (S 15 ). While the cap member  31  is being moved to the withdrawn position, the wiper blade  32  thoroughly wipes unnecessary ink from the head surface  2   a,  that is, the ejection nozzle surface. Based on the recording data for one row of dots, the control device  50  performs recording of the dot row (S 16 ), by driving the corresponding ejection nozzles to eject ink. Subsequently, if the print instruction switch  13  is on (Yes in step S 17 ) and the encoder signal is inputted, that is, the manually-driven movement of the body case  10  continues (Yes in step S 18 ), it is then determined in step S 19  whether the recording is completed. If recording is not completed (No in step S 19 ), the operation of steps S 16 -S 19  is repeated to performing recording of one dot row at a time. 
     When recording of a line is completed (Yes in step S 19 ), the operation of steps S 17 -S 19  is repeated. When the body case  10  is stopped, input of the encoder signal discontinues (No in step S 18 ). If the non-recording state continues for a predetermined length of time (for example, 2 to 3 seconds) (Yes in step S 20 ), the driving of the position switching solenoid  33  is stopped so that the cap member  31  is moved from the withdrawn position to the capping position (FIG.  4 ), sliding on the head surface  2   a  (S 21 ). Since the cap member  31  is thus switched between the capping position and the withdrawn position in cooperation with the recording operation so that the cap member  31  is at the capping position when recording is not performed, ink on the head surface  2   a  is protected from drying. If recording of a line is completed (Yes in S 19 ) and then the print instruction switch  13  is turned off so that recording inhibition is instructed (No in step S 17 ), it is determined in step S 20  whether the recording inhibited state has continued for a predetermined length of time. If the recording inhibited state has continued for the predetermined length of time (Yes in step  20 ), the cap member  31  is moved to the capping position (S 21 ). If the body case  10  is temporarily stopped during a recording operation, the determination in step S 18  is NO, and the operation proceeds to step S 20 . If the print instruction switch  13  is temporarily turned off, the determination in step S 17  is NO, and the operation proceeds to step S 20 . If it is subsequently determined in step S 20  that the recording inhibited state has not continued for the predetermined length of time, the operation starting at step S 16  is repeated to continue recording. 
     If it is determined in step S 10  that recording data is not received, the control device  50  checks whether the suction switch  14  is turned on (S 10 - 1 ). If the suction switch  14  is turned on (Yes in step S 10 - 1 ), the control device  50  starts a suction operation by the suction mechanism  40  (S 10 - 2 ). After that, the operation returns to step S 10 . 
     FIG. 8 illustrates the suction operation subroutine. When this routine is started, it is determined in step S 50  whether the cap member  31  is at the capping position relative to the recording head  2 . If the cap member  31  is at the capping position (Yes in step S 50 ), it is determined in step S 52  whether the print instruction switch  13  has been turned on within a predetermined time, for example, 10 sec., after the suction switch  14  is turned on. If the print instruction switch  13  is on (Yes in step S 52 ), the suction pump  42  is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member  31  in step S 53 . That is, only when both the suction switch  14  and the print instruction switch  13  are on, operation of the suction mechanism  40  is manually instructed, thereby preventing unintentional or accidental suction operation. Thus, the print instruction switch  13 , and the control device  50  constitute an inhibition device for inhibiting operation of the head recovery device under a predetermined condition. The number of such switches may be more than two. The switches are not limited to electrical switches but may be mechanical switches. 
     The invention is not limited to the foregoing embodiment, but may be modified in various ways. For example, although the embodiment employs two switches as a device for inhibiting operation of the head recovery device and canceling the inhibition, devices other than two switches may be employed as in an embodiment described below. 
     A second embodiment will be described with reference to FIGS. 7 and 9. Referring first to the flowchart of FIG. 7, when print control is started, it is determined in step S 10  whether recording data is received. If recording data is not received, it is checked in step S 10 - 1  whether the suction switch  14  is on. If it is determined that the suction switch  14  is on (Yes in step S 10 - 1 ), the control device  50  starts suction operation by the suction mechanism  40  in step S 10 - 2 . 
     A modification of the suction operation subroutine is illustrated in FIG.  9 . It is first determined in step S 60  whether the cap member  31  is at the capping position relative to the recording head  2 . If the cap member  31  is at the capping position (Yes in step S 60 ), it is determined in step S 62  whether the suction switch  14  has been turned on within a predetermined time, for example, 10 sec. If the suction switch  14  is turned on (Yes in step S 62 ), the suction pump  42  is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member  31  in step S 63 . That is, when a single switch (the suction switch  14  in this modification) is continually operated, i.e., double clicked, i.e., turned on a second time for this embodiment the inhibition of operation of the suction mechanism  40  is canceled so that the suction operation is performed. Therefore, an unnecessary suction operation caused by a single misoperation of the suction switch  14  is prevented. Thus the first operation of the suction switch  14  and the control device  50  constitute an inhibition device. 
     A third embodiment will be described with reference to FIGS. 10 and 11. In the third embodiment, a timer  61  is connected to the CPU  51  of the control device  50  as shown in FIG.  10 . The timer  61  measures the time elapsed from a previous operation of the head recovery device (suction mechanism  40 ). When the time measured by timer  61  reaches a predetermined length of time, the inhibition of operation of the head recovery device (suction mechanism  40 ) is canceled. 
     Referring to the flowchart of print control of FIG. 11, if recording data is not received (No in step S 10 ), it is determined in step S 10 - 11  whether a predetermined length of time has elapsed following a previous operation of the head recovery device (suction mechanism  40 ) on the basis of the time measured by the timer  61 . The timer  61  is reset in response to an operation of the suction mechanism  40 , and measures the time elapsed from the operation of the suction mechanism  40 . When the predetermined length of time has elapsed following the previous operation of the suction mechanism  40  (Yes in step S 10 ), the control device  50  starts suction operation by the suction mechanism  40  in step S 10 - 2 . 
     The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG.  9 . It is first determined in step S 60  whether the cap member  31  is at the capping position relative to the recording head  2 . If the cap member  31  is at the capping position (Yes in step S 60 ), it is determined in step S 62  whether the suction switch  14  is turned on. If the suction switch  14  is on (Yes in step S 62 ), the suction pump  42  is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member  31  in step S 63 . That is, only when the predetermined length of time has elapsed following the previous operation of the suction mechanism  40 , the operation of the suction switch  14  becomes valid. The inhibition of operation of the suction mechanism  40  is thereby canceled so that the suction operation is performed. Therefore, the unnecessary performance of a great number of suction operations by the misoperation of the suction switch  14  in a short time is prevented and, therefore, unnecessary ink consumption is prevented. In this embodiment, the timer  61  and the control device  50  constitute the inhibition device. 
     A fourth embodiment will be described with reference to FIGS. 10 and 12. In the fourth embodiment, the timer  61  is connected to the CPU  51  of the control device  50 . The timer  61  measures the time elapsed from the turning on of the power switch  12 . When the time measured by timer  61  reaches a predetermined length of time, the inhibition of operation of the head recovery device (suction mechanism  40 ) is canceled. 
     Referring to the flowchart of print control of FIG. 12, if recording data is not received (No in step S 10 ), it is determined in step S 10 - 12  whether a predetermined length of time has elapsed following the turning on of the power switch  12 , on the basis of the time measured by the timer  61 . The timer  61  measures the time elapsed from the turning on of the power switch  12 . When the predetermined length of time has elapsed following the turning on of the power switch  12  (Yes in Step  10 - 12 ), the control device  50  starts suction operation by the suction mechanism  40  in step S 10 - 2 . 
     The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG.  9 . It is first determined in step S 60  whether the cap member  31  is at the capping position relative to the recording head  2 . If the cap member  31  is at the capping position (Yes in step S 60 ), it is determined in step S 62  whether the suction switch  14  is turned on. If the suction switch  14  is on (Yes in step S 62 ), the suction pump  42  is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member  31  in step S 63 . That is, only when the predetermined length of time has elapsed following the turning on of the power switch  12 , the operation of the suction switch  14  becomes valid. The inhibition of operation of the suction mechanism  40  is thereby canceled so that the suction operation is performed. Therefore, unnecessary performance of a great number of suction operations by misoperation of the suction switch  14  in a short time is prevented and, therefore, unnecessary ink consumption is prevented. The power switch  12 , the timer  61 , and the control device  50  constitute the inhibition device. 
     A fifth embodiment will be described with reference to FIGS. 13 and 14. In the fifth embodiment, the RAM  53  has, in addition to a data memory  53 A, an amount of printed characters storage area  53 B, a number-of-prints storage area  53 C for storing the number of print operations, and an ink consumption storage area  53 D for storing the amount of ink used, as shown in FIG. 13. A count value of an amount of printed characters after a previous head recovery operation by the suction mechanism  40  is stored in the amount of printed characters storage area  53 B. 
     Referring to the flowchart of print control according to this embodiment illustrated in FIG. 14, the count value stored in the amount of printed characters storage area  53 B is incremented every print of one character in the one dot row print operation of step S 16 . If recording data is not received (No in step S 10 ), it is determined in step S 10 - 13  whether the amount of print performed after a previous head recovery operation has reached or exceeded a predetermined amount of print, on the basis of the count value stored in the amount of printed characters storage area  53 B. If the value stored in the amount of printed characters storage area  53 B is equal to or greater than the predetermined amount of print (Yes in Step S 10 - 13 ), the control device  50  starts a suction operation by the suction mechanism  40  in step S 10 - 2 . 
     The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG.  9 . It is first determined in step S 60  whether the cap member  31  is at the capping position relative to the recording head  2 . If the cap member  31  is at the capping position (Yes in step S 60 ), it is determined in step S 62  whether the suction switch  14  is turned on. If the suction switch  14  is on (Yes in step S 62 ), the suction pump  42  is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member  31  in step S 63 . That is, when the amount of print performed after a previous head recovery operation has reached or exceeded the predetermined amount of print, the operation of the suction switch  14  becomes valid. The inhibition of operation of the suction mechanism  40  is thereby canceled so that the suction operation is performed. Therefore, unnecessary performance of a great number of suction operations by misoperation of the suction switch  14  before the amount of print performed after a previous head recovery operation has reached or exceeded the predetermined amount is prevented and, therefore, unnecessary ink consumption is prevented. Thus, the inhibition device is the control device  50 , a counter therein, and its RAM  53 . 
     A sixth embodiment will be described with reference to FIGS. 13,  15  and  16 . In the sixth embodiment, the input-output interface  54  is further connected to an ink flow sensor  63  for detecting the flow of ink from the ink tank  15  to the recording head  2 , as shown in FIG.  15 . The accumulated count value of ink consumed which is output by the ink flow sensor  63  after a previous head recovery operation of the head recovery device (suction mechanism  40 ) is stored in the ink consumption storage area  53 D of the RAM  53  shown in FIG.  13 . 
     Referring to the flowchart of print control according to this embodiment illustrated in FIG. 16, if recording data is not received (No in step S 10 ), it is determined in step S 10 - 14  whether the amount of ink consumed after a previous operation of the head recovery device (suction mechanism  40 ) has reached or exceeded a predetermined amount, on the basis of the accumulated value stored in the consumption storage area  53 D. If the value stored in the consumption storage area  53 D is equal to or greater than the predetermined amount of ink consumption (Yes in Step S 10 - 14 ), the control device  50  starts the suction operation by the suction mechanism  40  in step S 10 - 2 . 
     The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG.  9 . It is first determined in step S 60  whether the cap member  31  is at the capping position relative to the recording head  2 . If the cap member  31  is at the capping position (Yes in step S 60 ), it is determined in step S 62  whether the suction switch  14  is turned on. If the suction switch  14  is on (Yes in step S 62 ), the suction pump  42  is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member  31  in step S 63 . That is, when the amount of ink consumed after a previous head recovery operation has reached or exceeded the predetermined amount, the operation of the suction switch  14  becomes valid. The inhibition of the operation of the suction mechanism  40  is thereby canceled so that the suction operation is performed. Therefore, the unnecessary performance of a great number of suction operations by misoperation of the suction switch  14  before the amount of ink consumed after a previous head recovery operation has reached or exceeded the predetermined amount is prevented and, therefore, unnecessary ink consumption is prevented. Thus, the ink flow sensor and the control device  50 , with its RAM  53 , constitute the inhibition device. 
     A seventh embodiment will be described with reference to FIGS. 13 and 17. In the seventh embodiment, the number of print operations following a previous operation of the head recovery device (suction mechanism  40 ) is stored in the number-of-prints storage area  53 C of the RAM  53 . The number of print operations herein means the number of times that printing is instructed. 
     Referring to the flowchart of print control according to this embodiment shown in FIG. 17, every time the print instruction switch  13  is turned on, a number-of-prints counter is incremented in step S 12 - 1 . The incremented count of the number-of-prints counter is stored in the number-of-prints storage area  53 C of the RAM  53 . 
     If recording data is not received (No in step S 10 ), it is determined in step S 10 - 15  whether the number of print operations following a previous operation of the head recovery device (suction mechanism  40 ) has reached or exceeded a predetermined number, on the basis of the count value stored in the number-of-prints storage area  53 C. If the value stored in the number-of-prints storage area  53 C is equal to or greater than the predetermined number (Yes in Step S 10 - 15 ), the control device  50  starts the suction operation by the suction mechanism  40  in step S 10 - 2 . 
     The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG.  9 . It is first determined in step S 60  whether the cap member  31  is at the capping position relative to the recording head  2 . If the cap member  31  is at the capping position (Yes in step S 60 ), it is determined in step S 62  whether the suction switch  14  is turned on. If the suction switch  14  is on (Yes in step S 62 ), the suction pump  42  is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member  31  in step S 63 . That is, when the number of print operations following a previous head recovery operation has reached or exceeded the predetermined number, the operation of the suction switch  14  becomes valid. The inhibition of the operation of the suction mechanism  40  is thereby canceled so that the suction operation is performed. Therefore, the unnecessary performance of a great number of suction operations by the misoperation of the suction switch  14  before the number of print operations following a previous head recovery operation has reached or exceeded the predetermined number is prevented and, therefore, unnecessary ink consumption is prevented. Thus, the print switch  13 , the control device  50 , and its RAM  53 , constitute the inhibition device for the embodiment. 
     An eighth embodiment will be described with reference to FIGS. 13 and 18. The eighth embodiment is a modification of the fifth embodiment. In the eighth embodiment, the count value of amount of printed characters after the power switch  12  has been turned on is stored in the amount of printed characters storage area  53 B. 
     Referring to the flowchart of print control according to this embodiment illustrated in FIG. 18, the count value stored in the amount of printed characters storage area  53 B corresponding to the amount of printed characters after the power switch  12  has been turned on is incremented every print of one character in the one dot row print operation of step S 16 . If recording data is not received (No in step S 10 ), it is determined in step S 10 - 16  whether the amount of print performed after the turning on of the power switch  12  has reached or exceeded a predetermined amount of print, on the basis of the count value stored in the amount of printed characters storage area  53 B. If the value stored in the amount of printed characters storage area  53 B is equal to or greater than the predetermined amount of print (Yes in Step S 10 - 16 ), the control device  50  starts the suction operation by the suction mechanism  40  in step S 10 - 2 . 
     The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG.  9 . It is first determined in step S 60  whether the cap member  31  is at the capping position relative to the recording head  2 . If the cap member  31  is at the capping position (Yes in step S 60 ), it is determined in step S 62  whether the suction switch  14  is turned on. If the suction switch  14  is on (Yes in step S 62 ), the suction pump  42  is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member  31  in step S 63 . That is, when the amount of print performed after the turning on of the power switch  12  has reached or exceeded the predetermined amount of print, the operation of the suction switch  14  becomes valid. The inhibition of the operation of the suction mechanism  40  is thereby canceled so that the suction operation is performed. Therefore, the unnecessary performance of a great number of suction operations by misoperation of the suction switch  14  before the amount of print performed after the turning on of the power switch  12  has reached or exceeded the predetermined amount is prevented and, therefore, unnecessary ink consumption is prevented. Thus, the control device  50  and its RAM  53  constitute the inhibition device of the embodiment. 
     A ninth embodiment will be described with reference to FIGS. 13,  15  and  19 . In the ninth embodiment, the input-output interface  54  is further connected to the remaining ink amount sensor  62  for detecting the amount of ink remaining in the ink tank  15 , and the ink flow sensor  63  for detecting the flow of ink from the ink tank  15  to the recording head  2 , as shown in FIG.  15 . The accumulated count value of ink consumed which is output by the ink flow sensor  63  after the power switch  12  has been turned on is stored in the consumption storage area  53 D of the RAM  53  shown in FIG.  13 . 
     Referring to the flowchart of print control according to this embodiment illustrated in FIG. 19, if recording data is not received (No in step S 10 ), it is determined in step S 10 - 17  whether the amount of ink consumed after the turning on of the power switch  12  has reached or exceeded a predetermined amount, on the basis of the accumulated value stored in the consumption storage area  53 D. If the value stored in the consumption storage area  53 D is equal to or greater than the predetermined amount of ink consumption (Yes in Step S 10 - 17 ), the control device  50  starts the suction operation by the suction mechanism  40  in step S 10 - 2 . 
     The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG.  9 . It is first determined in step S 60  whether the cap member  31  is at the capping position relative to the recording head  2 . If the cap member  31  is at the capping position (Yes in step S 60 ), it is determined in step S 62  whether the suction switch  14  is turned on. If the suction switch  14  is on (Yes in step S 62 ), the suction pump  42  is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member  31  in step S 63 . That is, when the amount of ink consumed after the turning on of the power switch  12  has reached or exceeded the predetermined amount, the operation of the suction switch  14  becomes valid. The inhibition of the operation of the suction mechanism  40  is thereby canceled so that the suction operation is performed. Therefore, the unnecessary performance of a great number of suction operations by misoperation of the suction switch  14  before the amount of ink consumed after the turning on of the power switch  12  has reached or exceeded the predetermined amount is prevented and, therefore, unnecessary ink consumption is prevented. The inhibition device is constituted of the remaining ink amount sensor  62 , the ink flow sensor  63 , and the control device  50  with its RAM  53 . 
     A tenth embodiment will be described with reference to FIGS. 13 and 20. In the tenth embodiment, the number of print operations performed after the power switch  12  has been turned on is stored in the number-of-prints storage area  53 C of the RAM  53 . The number of print operations herein means the number of times that printing is instructed. 
     Referring to the flowchart of print control according to this embodiment shown in FIG. 20, every time the print instruction switch  13  is turned on, a number-of-prints counter is incremented in step S 12 - 2 . The incremented count of the number-of-prints counter is stored in the number-of-prints storage area  53 C of the RAM  53 . This stored value is reset every time the power switch  12  is turned on, and the value is incremented every time the print instruction switch  13  is turned on. 
     If recording data is not received (No in step S 10 ), it is determined in step S 10 - 18  whether the number of print operations following the turning on of the power switch  12  has reached or exceeded a predetermined number, on the basis of the count value stored in the number-of-prints storage area  53 C. If the value stored in the number-of-prints storage area  53 C is equal to or greater than the predetermined number (Yes in Step  10 - 18 ), the control device  50  starts suction operation by the suction mechanism  40  in step S 10 - 2 . 
     The suction operation subroutine is performed in the same manner as in the second embodiment, following the flowchart of FIG.  9 . It is first determined in step S 60  whether the cap member  31  is at the capping position relative to the recording head  2 . If the cap member  31  is at the capping position (Yes in step S 60 ), it is determined in step S 62  whether the suction switch  14  is turned on. If the suction switch  14  is on (Yes in step S 62 ), the suction pump  42  is driven for a predetermined length of time (for example, 1 to 2 seconds) to perform suction of the ejection nozzles via the cap member  31  in step S 63 . That is, when the number of print operations following the turning on of the power switch  12  has reached or exceeded the predetermined number, the operation of the suction switch  14  becomes valid. The inhibition of the operation of the suction mechanism  40  is thereby canceled so that the suction operation is performed. Therefore, the unnecessary performance of a great number of suction operations by misoperation of the suction switch  14  before the number of print operations following the turning on of the power switch  12  has reached or exceeded the predetermined number is prevented and, therefore, unnecessary ink consumption is prevented. The control device  50 , and its RAM  53 A, constitute the inhibition device. 
     An eleventh embodiment will be described with reference to FIGS. 15 and 21. In the eleventh embodiment, the input-output interface  54  of the control device  50  is further connected to the remaining ink amount sensor  62  for detecting the amount of ink remaining in the ink tank  15 . Referring to the flowchart of print control according to this embodiment illustrated in FIG. 21, if recording data is not received (No in step S 10 ), it is determined in step S 10 - 19  whether the amount of ink remaining detected by the remaining ink amount sensor  62  is equal to or less than a predetermined amount. If the remaining ink amount is equal to or less than the predetermined amount (Yes in step S 10 - 19 ), the operation returns to step S 10 , thereby avoiding cancellation of the inhibition of operation of the head recovery device (suction mechanism  40 ). With this structure, when the amount of remaining ink has become small, cancellation of the inhibition of recovery operation is prevented, thereby avoiding an inconvenient incident wherein a small amount of ink left is completely consumed by recovery operation so that printing becomes impossible. Thus, the remaining ink amount sensor  62  and the control device  50  constitute the inhibition device. 
     A twelfth embodiment will be described with reference to the flowchart of FIG.  22 . The twelfth embodiment employs a second counter for counting the number of operations of the head recovery device (suction mechanism  40 ). When the count of the second counter reaches a predetermined number, cancellation of the inhibition of operation of the head recovery device is prevented. 
     As illustrated in the flowchart of print control of the twelfth embodiment, when an ink cartridge is replaced, the count of the second counter is cleared to n=0. If recording data is not received (No in step S 10 ), it is determined in step S 10 - 20  whether the value n of the second counter is equal to or less than a predetermined number k. If the counter value n is equal to or less than the predetermined number k (Yes in step S 10 - 21 ), it is determined in step S 10 - 21  whether the suction switch  14  is turned on. If the suction switch  14  is on (Yes in step S 10 - 22 ), the control device  50  performs suction operation in step S 10 - 2 , and increments the value n of the second counter in step S 10 - 3 , and returns to step S 10 . When the value n of the second counter becomes has become greater than the predetermined number k (No in step S 10 - 21 ), the operation returns to step S 10 , thereby avoiding cancellation of the inhibition of operation of the head recovery device. The value n of the second counter is stored in a number-of-recoveries storage area  53 E of the RAM  53  shown in FIG.  13 . 
     In the twelfth embodiment, the number of operations of the head recovery device (suction mechanism  40 ) is counted, and recovery operation is prevented if the count exceeds the predetermined number. Therefore, unnecessary performance of a great number of recovery operations by misoperation of the suction switch  14  is prevented and, therefore, unnecessary ink consumption is prevented. Thus, the control device  50  and its RAM  53  constitute the inhibition device. In all embodiments, the control device  50  can be considered the inhibition override mechanism as it checks for a condition precedent before allowing an activated manual switch commanding recovery to be executed. 
     A slide switch  80  may be provided for selecting whether to set a condition for inhibition by an inhibiting device, as in a modification shown in FIG. 23, thereby enabling selection of whether to set a condition for inhibition by the inhibiting device. Furthermore, it is also possible to provide a device for setting a plurality of conditions for inhibition or to allow the head recovery device to be driven without any inhibition conditions for the inhibiting device. 
     Furthermore, it is possible to provide a reset switch  81  as shown in FIG.  24 . If the head recovery operation is really needed under a condition for inhibition by the inhibiting device, a recovery operation is allowed by pressing the reset switch  81 . The reset switch may be designed so that the reset switch is not easily pressed by a finger during normal operation. For example, the reset switch may be disposed inside a small recess so that the reset switch is pressed only by a pen tip or the like. Such a reset device is not limited to the reset switch, but may be a device that cancels the inhibition condition upon receiving a permitting instruction from an external device. 
     The above-described embodiments are for small-size portable recording apparatuses, such as manually-driven printing apparatus, and particularly useful for apparatuses equipped with small-capacity ink tanks. 
     It is to be understood that the invention is not restricted to the particular forms shown in the foregoing embodiments. Various modifications and alterations can be made thereto without departing from the scope of the invention encompassed by the appended claims.