JP3387779B2 - Printing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus that prints by ejecting ink onto a recording medium.

[0002]

2. Description of the Related Art Generally, in an ink jet printer for ejecting ink droplets to record on a recording medium, an ink jet type print head and an ink cartridge containing ink to be supplied to the print head are exchanged inside a main body case. The recording device is mounted as much as possible, a conveying device that conveys the recording medium, and a carriage device that reciprocates the recording device according to the size of the recording medium conveyed by the conveying device.

In such an ink jet printer, in order to ensure good printing performance regardless of the thickness of the recording medium, a gap indicating means for indicating a head gap which is a distance between the print head and the recording medium is provided. Are known. In such a case, when the user instructs the head gap by the gap instruction means, the gap adjusting mechanism changes the position of the print head according to the head gap and adjusts the head gap.

It is also known to provide a recovery device that covers the print head with a suction cap and sucks and removes the ink in the print head in order to maintain a good ink discharge state from the print head.

[0005]

However, when the position of the print head is changed in order to adjust the head gap according to the thickness of the recording medium by the gap adjusting mechanism, the gap between the suction cap and the print head is accordingly changed. Will also change. In particular, when the print head is moved in a direction away from the recording medium in order to adjust the head gap, the distance between the suction cap and the print head increases. Then, airtightness when the suction cap covers the nozzle surface of the print head is impaired, effective suction cannot be performed, and sufficient recovery operation cannot be performed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a printing apparatus capable of adjusting the head gap without affecting the recovery operation.

[0007]

According to the present invention, there is provided a print head for jetting ink onto a recording medium for printing, and a cap for airtightly covering a nozzle surface of the print head. A gap adjusting mechanism for adjusting a head gap to an amount instructed by a capping mechanism for contacting a surface so as to be able to move back and forth, and a gap instructing means for instructing a head gap which is a distance between the print head and the recording medium. Based on the premise of a printing device including: a head gap detecting means for detecting a head gap indicated by the gap indicating means, and a signal from the head gap detecting means, and controlling the capping mechanism, Cap position adjusting means for adjusting the amount of advance / retreat of the cap during the capping operation by the capping mechanism Equipped with a.

Therefore, by the cap position adjusting means,
By controlling the capping mechanism, the advancing / retreating amount of the cap during the capping operation by the capping mechanism is adjusted according to the head gap detected by the head gap detecting means, and the capping operation is performed effectively regardless of the head gap. Be seen.

Further, the cap is a suction cap for performing a recovery operation of the print head, and a recovery device for contacting the suction cap with a nozzle surface of the print head to suck and remove ink in the print head from the nozzle is provided. Prepare

The gap instructing means is an adjusting lever, and determines the head gap by the amount of rotation of the adjusting lever. The gap adjusting mechanism is an eccentricity in which the adjusting lever rotates integrally with the adjusting lever. Through the collar, the center of the adjusting lever and the center of the guide rod are fitted to the guide rod so as to be displaced from each other, and the print head is moved forward and backward with respect to the recording medium by the rotation of the adjusting lever. Therefore, when the head gap is determined by the rotation of the adjustment lever, the print head is moved back and forth with respect to the recording medium in association with the rotation of the adjustment lever, and the predetermined head gap is obtained.

The head gap detecting means detects the amount of rotation of the adjusting lever as electric resistance and detects the head gap based on the electric resistance.

Further, the cap position adjusting means has a cam member that is linked to the cap and controls the amount of advance and retreat of the cap by rotating, and adjusts the amount of rotation of the cam member. Therefore, the amount of advance / retreat of the cap is controlled by rotating the cam member linked to the cap.

Further, the gap instructing means sets a gap amount according to the recording medium, and determines the head gap by selecting the recording medium, and the head gap detecting means, the head gap detecting means. It is also possible to detect the corresponding head gap depending on the type of recording medium selected by the means.

Further, in order to realize optimum paper feeding and printing conditions, a signal is received from the head gap detecting means, the signal applied to the print head is controlled, and the ejection condition of ink droplets is adjusted. A paper feed unit for feeding a recording medium appropriately according to the printing situation and a signal from the head gap detection unit to control the paper feed unit to feed the paper per time. It is also possible to provide a drive amount adjusting means for adjusting the drive amount of the means.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1 showing a schematic configuration of an ink jet printer which is a printing apparatus according to the first embodiment,
The inkjet printer 1 has a printer frame 2, and a cylindrical platen roller 4 for conveying a recording sheet 3 (recording medium) is rotatably provided on the printer frame 2 about a shaft 4A as a rotation center. A guide rod 5 is provided in parallel with the platen roller 4.
A carriage 7 is inserted into the guide rod 5 so as to be capable of reciprocating in a direction parallel to the axis of the platen roller 4, and the carriage 7 is rotatably supported around the guide rod 5.

The carriage 7 is driven by a carriage motor 8 provided under the printer frame 2 through a belt 9 and pulleys 10 and 11. The carriage 7 is provided with a print head 12 that ejects ink onto the recording paper 3 for printing, and an ink cartridge 13 that supplies ink to the print head 12. Further, by engaging the engaging portion 7A (see FIG. 2) provided on the lower rear surface of the carriage 7 with the guide plate 6 fixed to the printer frame 2, the postures of the carriage 7 and the print head 12 are A fixed positional relationship is maintained with respect to the printer frame 2.

Further, as shown in FIGS. 3 and 4, the print head 12 and the ink cartridge 13 are provided on the carriage 7 while being mounted on the head unit 33, and a flexible printed board 34 (so-called dimple FPC) is provided. ), The print data is sent to the print head 12. In addition, the head unit 33 and the printed circuit board 34
Between the printed circuit board 3 and the carriage 7
A backup rubber 35 is provided to absorb the impact on the sheet 4.

Further, the printer frame 2 is provided with a suction cap 14 that hermetically covers the nozzle surface of the print head 12 as a recovery device for recovering the ink discharge state of the print head 12 when it deteriorates. Suction cap 14
And a suction pump 15 for bringing the suction cap 14 into contact with the nozzle surface of the print head 12 to suck and remove the deteriorated ink in the print head 12 from the nozzle.

Further, the printer frame 2 is provided with a paper feed motor 16 for rotationally driving the platen roller 4 for feeding the recording paper 3. This paper feed motor 16
Is also used to drive the recovery device, and by switching the drive transmission mechanism (not shown), the cam member 41 that drives the recovery device while controlling the drive timing.
Is designed to rotate.

A gap adjusting mechanism for adjusting the head gap, which is the distance between the print head 12 and the recording paper 3, will be described with reference to FIGS.

As shown in FIGS. 2-5, the print head 12
An adjusting lever 21, which is a gap instructing means for instructing a head gap that is the distance between the recording sheet 3 and the recording sheet 3, is eccentrically fitted to the guide rod 5 via an eccentric collar 21A. The eccentric collar 21A is slidably and rotatably fitted to the outer peripheral surface of the guide rod 5 so as to operate integrally with the adjusting lever 21, and holds the carriage 7 rotatably with a certain amount of eccentricity. There is. The adjusting lever 21 and the eccentric collar 21A are configured such that a certain amount of eccentricity is generated between the rotation center of the adjusting lever 21 and the rotation center of the eccentric collar 21A with respect to the carriage 7.

When the adjusting lever 21 is eccentrically rotated via the eccentric collar 21A by such an eccentric rotation mechanism, the carriage 7 (the print head 1 is linked with the rotation).
2) moves back and forth in the direction perpendicular to the paper surface (print surface) of the recording paper 3. Further, a scale corresponding to the thickness, type, etc. of the recording paper 3 is provided on the side surface of the carriage 7 on the outer periphery of the adjustment lever 21, and the adjustment lever 21 is rotated to any one of the scales. The carriage 7 can be moved so that the head gap corresponding to the thickness, type, etc. of the recording paper 3 is set by aligning the reference points provided at predetermined positions on the outer circumference of 21.
That is, the head gap is adjusted by the amount of rotation of the adjusting lever 21.

Further, as shown in FIG. 3, a spring member 30 is provided between the carriage 7 and the eccentric collar 21A, and the adjustment lever 21 integrally formed with the eccentric collar 21A is provided by the spring member 30. Biased against 7. Therefore, the adjusting lever 21 can be held at any rotated position. Further, in the present embodiment, the operator determines the amount of headgear by rotating the adjustment lever 21, but the adjustment lever 21 is not provided, and the type of the recording paper 3 to be used may be changed. Accordingly, the eccentric collar 21A may be rotated by a predetermined amount by driving the motor, and the rotated position may be held.

Next, the movement of the carriage 7 due to the rotation of the adjusting lever 21 will be described with reference to FIGS. 4 and 5.

As described above, the eccentric collar 21A of the adjusting lever 21 causes the guide rod 5 so that the center of rotation of the adjusting lever 21 and the center of rotation of the guide rod 5 are displaced from each other.
Is fitted to. Therefore, from the state shown in FIG.
When the adjusting lever 21 is rotated clockwise in the state shown in (4), the adjusting lever 21 rotates with the eccentric collar 21A about the guide rod 5 as the center of rotation. Then, the carriage 7 horizontally moves toward the platen roller 4,
The head gap decreases from the head gap D1 shown in FIG. 4 to the head gap D2 shown in FIG. For the adjustment of the head gap, see Japanese Patent Laid-Open No. 2073/1996.
No. 8 publication.

Next, the head gap detecting means for detecting the head cap indicated by the adjusting lever 21 (gap indicating means) will be described with reference to FIGS. 4 and 5.

Further, as shown in FIGS. 4 and 5, the contact member 3 is provided on the surface of the adjusting lever 21 facing the carriage 7.
1 is provided, and the surface of the carriage 7 facing the adjustment lever 21 has a substantially arcuate resistance corresponding to the trajectory of the contact member 31 generated by the rotation of the adjustment lever 21 and the movement of the carriage 7 accompanying it. A member 32 is provided. The contact member 31 and the resistance member 32 are provided so as to be in contact with each other, and the relative positions of the contact member 31 and the resistance member 32 change as the adjustment lever 21 rotates. Then, based on the relationship between the contact member 31 and the resistance member 32, the voltage obtained based on the electric resistance generated by the rotation of the adjusting lever 21 can be detected as the rotation amount of the adjusting lever 21. In this way, the contact member 31 and the resistance member 32 are used to detect the amount of rotation of the adjusting lever 21 as electric resistance, and the head gap is detected based on the electric resistance.

Next, the contact member 31 and the resistance member 32 will be described with reference to FIG.

An end portion 32A of the resistance member 32, which is separated from the printing head 12, is connected to a power source that outputs a voltage of 5V, and the other end portion 32B is grounded. The resistance value is determined by the position of the resistance member 32 in contact with the contact member 31, and the voltage obtained by the resistance value is output from the output unit 66 to the CPU 53 (see FIG. 9). For example, when the contact member 31 is in contact with the end portion 32B side of the resistance member 32, the resistance value is high, so that the voltage output from the output unit 66 is low, and the contact member is the resistance member 32. When it is in contact with the end portion 32A side, the resistance value is low, and the voltage output from the output unit 66 is high.

As described above, when the adjusting lever 21 is rotated on the basis of the thickness of the recording paper 3, the contact member 31 provided on the back surface of the adjusting lever 21 also moves as the adjusting lever 21 rotates, Further, the carriage 7 also moves.
At that time, since the contact member 31 moves while being in contact with the resistance member 32, the relative positional relationship between the contact member 31 and the resistance member 32 changes, and the electrical resistance also changes accordingly. The rotational position of the adjusting lever 21, the contact member 31, and the resistance member 32
The relationship with the output voltage output from the output section 66 changes as shown in FIG.

More specifically, when the recording paper 3 is thick, as shown in FIG. 4, the adjusting lever 21 is not rotated and a wide headgap amount is set. In this case, since the contact member 31 is in contact with the end portion 32B of the resistance member 32, the resistance value is high and the voltage output from the output unit 66 is low. On the other hand, when the recording paper 3 is thin,
As shown in FIG. 5, the adjustment lever 21 is rotated in the clockwise direction, and the amount of headgear decreases. In this case,
Since the contact member 31 is in contact with the end portion 32A side of the resistance member 32, the resistance value is low and the voltage output from the output unit 66 is high.

As described above, the thicker the recording paper 3 is, the larger the electric resistance is, the lower the output voltage from the output unit 66 is, and the thinner the recording paper 3 is, the smaller the electric resistance is, and the output voltage from the output unit 66 is decreased. Is getting higher. The output voltage to the A / D port of the CPU 53 changes in the range of 0 to 5V according to the thickness of the recording paper 3.

Next, the recovery device will be described with reference to FIGS. 7 and 8.

The suction cap 14 is connected via a spring 44 to the tip of a rod member 43 that is fitted in the support member 42 so as to be able to move forward and backward. An engaging portion 43A provided at the rear end of the rod member 43 is movably engaged with the cam groove 41A of the cam member 41. As a result, a capping mechanism for contacting the suction cap 14 with the nozzle surface of the print head 12 so as to be able to move back and forth is configured.

The cam groove 41A is provided at a position eccentric with respect to the cam member 41, and when the cam member 41 rotates, the distance between the suction cap 14 and the print head 12 is increased via the rod member 43 and the spring 44. Change. In this way, the suction cap 14 is adjusted by adjusting the rotation angle (rotation amount) of the cam member 41 linked to the suction cap 14 via the rod member 43.
The advancing / retreating amount of the print head 12 with respect to the nozzle surface is controlled, and a cap position adjusting means is configured. Cam member 41
Is driven by the paper feed motor 16, and the rotation angle of the cam member 41 is the paper feed motor 16 (step motor).
It is adjusted by counting the number of driving pulses.

Next, the control mechanism of the ink jet printer 1 will be described with reference to FIG.

This control mechanism includes a head driver 51,
The head driver 51 is a circuit that includes a gate array 52 and a CPU 53, and applies a drive signal to each channel of the print head 12. The gate array 52 receives print data (code data) from a host computer 54 such as a personal computer via an interface 55,
This is a circuit for expanding the print data into image data and transferring it to the head driver 51. An image memory 56 for storing the expanded image data is attached to the gate array 52.

The CPU 53 is the ink jet printer 1.
Is a one-chip microcomputer that controls the entire operation of the. The CPU 53 and the gate array 52 are connected by a bus 57 so that data, timing signals, etc. can be exchanged. Further, the CPU 53 uses the bus 57
It is also connected to the ROM 58 and the RAM 59 via.
The CPU 53 is also connected to a switch panel 60 (SW panel) for setting and displaying print parameters and the like, and a drive system 61 of the machine part. Here, the drive system 61 includes a contact member 31 and a resistance member 32 that detect the amount of rotation of the adjusting lever 21, the carriage motor 8 and the paper feed motor 16, and position sensors for them.

Next, C corresponding to the amount of rotation of the adjusting lever 21
The control of the rotation amount of the cam member 41 by the PU 53 will be described.

As described above, the output voltage output from the output unit 66 is 0 to 5 V depending on the rotation amount of the adjusting lever 21.
Changes in the range of. The CPU 53 changes the rotation amount of the cam member 41 in the range of θ2 to θ1 shown in FIG. 8 according to the change of the output voltage, and adjusts the amount of advance / retreat of the suction cap 14 with respect to the print head 12. In this way, the amount of advance / retreat of the suction cap 14 with respect to the print head 12 is adjusted according to the thickness, type, etc. of the recording paper 3. The relationship between the output voltage output from the output unit 66 according to the rotation of the adjusting lever 21 and the rotation amount of the cam member 41 is as shown in FIG. That is, when the output voltage is 0V, the cam member 4
The rotation angle of 1 is θ2, the rotation angle of the cam member 41 is θ1 when the output voltage is 5V, and the output voltage and the rotation angle of the cam member 41 are in a proportional relationship. Figure 10 (a)
The relationship between the output voltage output from the output unit 66 and the rotation amount of the cam member 41 according to the rotation of the adjusting lever 21 as shown in (b) is stored in the ROM 58 in advance.

Next, the adjustment of the headgear and the capping operation of the suction cap 14 in the ink jet printer 1 having the above-mentioned structure will be described.

After determining the type of recording paper 3 to be used, the operator rotates the adjusting lever 21 up to the scale on the carriage 7 according to the type of recording paper 3 to adjust the headgear amount. For example, when plain paper is used, the adjusting lever 21 is rotated to the scale of the plain paper. Then, the output voltage of 3.4 V obtained based on the resistance value determined by the rotational position of the adjusting lever 21 is output from the output unit 66. Then, the CPU 53 detects the output from the output unit 66 through the A / D port, and based on Table 1 shown below, from the reference position (rotation angle 0 °) of the cam member 41 when the output voltage is 3.4V. Rotation angle of
2+ (θ1-θ2) × 2/3} is calculated.

[Table 1] Then, the cam member 41 is rotated based on the obtained rotation angle. As a result, the head gap is adjusted and the distance between the suction cap 14 and the nozzle surface of the print head 12 is adjusted according to the thickness and type of the recording paper 3 used. Therefore, even if the head gap is changed according to the recording paper 3, the recovery operation by the suction cap 14 can be effectively performed. Further, regardless of the thickness, type, etc. of the recording paper 3, the suction cap 1 is always kept under substantially the same conditions.
4 can cover the nozzle surface of the print head 12, and an effective recovery operation can be performed.

Subsequently, the second embodiment will be described with reference to FIG.
This will be described with reference to FIGS. In the following description, the same members as those in the first embodiment will be designated by the same reference numerals, and detailed description thereof will be omitted.

In the second embodiment, as shown in FIGS. 11 and 12, one of the resistance members 32 corresponds to the type of the recording paper 3, for example, envelope, OHP paper, general paper, trace paper. Is located on the side surface of the carriage 7 and has four contact points 7
1A, 71B, 71C and 71D are provided so as to be able to contact the contact member 31. Four contact points 71A, 71
B, 71C, 71D are provided in a substantially arcuate shape corresponding to the movement locus of the contact member 31 caused by the rotation of the adjusting lever 21 and the movement of the carriage 7 accompanying it. The contact member 31 is formed in a protruding shape, and has four contact portions 71A, 71
B, 71C, 71D are formed in a concave shape, and the concave contact portions 71A, 71B, 71C, 71D and the protruding contact member 31 engage with each other in a detachable manner. Contact parts 71A, 71B, 71C, 71
The adjusting lever 21 is held at that position with the contact member 31 engaged with D. Here, for example, the contact portion 71A is a position corresponding to an envelope, the contact portion 71B is a position corresponding to OHP paper, the contact portion 71C is a position corresponding to plain paper, and the contact portion 71D is a trace paper. Corresponding position. In the second embodiment, the contact point member 31 has contact points 71A and 71A with respect to the resistance member 32.
Since the contact is made only at any one of B, 71C, and 71D, the rotational position of the adjusting lever 21 and the output voltage output to the output unit 66 due to the change in the relative positional relationship between the contact member 31 and the resistance member 32. The relationship changes as shown in FIG.

The resistance member 32 of the second embodiment will be described with reference to FIG.

As in the first embodiment, the end portion 32A of the resistance member 32 is connected to the power source that outputs a voltage of 5V, and the other end portion 32B is grounded. Contact part 71 of resistance member 32 with which contact member 31 contacts
A, 71B, 71C, 71D determines the resistance value,
The output voltage obtained by the resistance value is C from the output section 66.
It is output to the PU 53. As can be seen from FIG. 13, when the contact member 31 is in contact with the contact portion 71A, the output voltage is 0V, and when the contact member 31 is in contact with the contact portion 71B, the output power is 1.7V. When the member 31 is in contact with the contact portion 71C, the output power is 3.4V, when the contact member 31 is in contact with the contact portion 71D, the output power is 5V, and the output voltage is as shown in FIG. Changes stepwise.

Next, the operation of the ink jet printer according to the second embodiment will be described.

When the operator selects the type of the recording sheet 3 to be used, the contact portion 71 corresponding to the type of the recording sheet 3 is used.
The head gap is determined by rotating the adjusting lever 21 to A, 71B, 71C, 71D. For example, when the trace paper is used, the adjusting lever 21 is rotated to the contact portion 71D, and the contact member 31 of the adjusting lever 21 is rotated.
The adjusting lever 21 is fixed by engaging the protruding part of the contact part with the recessed part of the contact part 71D. Regarding the capping operation of the suction cap 14 based on the adjustment of the head gap,
This is the same as in the first embodiment. In addition, the same effect as that of the first embodiment can be obtained in the second embodiment.

Further, characteristics such as the degree of ink bleeding, the degree of ink fixing, and the drying speed differ depending on the type of the recording paper 3.
Therefore, it is desirable to eject the ink droplets under ejection conditions that match the characteristics of the recording paper 3. If the characteristics of the recording paper 3 are ignored and printing is always performed with the same amount of ink droplets, the ink may bleed or the ink may slip on the recording paper 3 and the print head 12 This is because the ink may adhere to the paper, the paper feed roller, or the like.

Therefore, in the third embodiment, the signal applied to the print head 12 is controlled by the output voltage value input from the contact member 31 to the CPU 53 (ejection condition adjusting means) via the output section 66. Then, the ejection condition (ejection amount) of the ink droplet is adjusted. Since the output voltage corresponds to the type of recording paper 3, use it to
The amount of ink droplets can be adjusted according to the type of recording paper 3. With reference to Table 1 described above, a specific example will be described based on the case of general paper. First, in the case of an envelope, the amount of ink droplets is usually larger than that in the case of general paper because it is normally black monochromatic and is often printed with relatively large characters. In the case of OHP paper or trace paper, ink is not absorbed, so the amount of ink droplets is made smaller than in the case of ordinary paper. In such a configuration, the amount of ink droplets to be ejected is adjusted to an appropriate amount according to the type of recording paper 3 used, so that no matter what type of recording paper is used, the ink may bleed, Good fixing results can be obtained without the ink fixing ability being bad and the ink not dripping on the recording paper.

Further, since the characteristics such as the degree of friction and the rigidity of the surface are different depending on the type of the recording paper 3, when the different papers are fed under the same conditions, the feed amount changes. Therefore, it is desirable that the recording sheet 3 is conveyed under conditions suitable for its characteristics so that the recording sheet 3 is not displaced.

Therefore, in the fourth embodiment, based on the output voltage value input from the contact member 31 to the CPU 53 (driving amount adjusting means) via the output unit 66 according to the recording paper 3 used. , The paper feed motor 16 that appropriately feeds the recording paper 3 in accordance with the printing condition, and the paper feed motor 1
6 (platen roller 4) is adapted to adjust the driving amount per time. As a result, no matter what kind of recording paper 3 is used, the actual feeding amount of the recording paper 3 can be made constant without causing a paper conveyance deviation.

With reference to Table 1, a specific example will be described with reference to the case of general paper.

First, in the case of envelopes, there is unevenness due to paper folding compared to the case of plain paper, and line breaks are more likely to occur, so the amount of line breaks per time is smaller than in the case of plain paper.
It is 0.5 mm. In the case of OHP paper, the surface is slippery and it is very difficult to feed paper, so the line feed amount per time is much smaller than in the case of ordinary paper, and it is 0.25
mm. Also, in the case of trace paper, it is difficult to feed because it is thinner and less rigid than regular paper,
The line feed amount per time is smaller than that of ordinary paper, and
It is 5 mm. In such a configuration, the amount of paper conveyance is adjusted according to the type of recording paper 3 used, so no matter what kind of recording paper 3 is used, there will be no deviation in paper conveyance. Absent.

As described above, in the above embodiment,
Based on the output voltage value obtained by adjusting the headgap according to the type of recording paper 3 used, the amount of advancing / retreating of the suction cap 14 to / from the print head 12 is adjusted, and the jetting liquid is adjusted to the droplet amount. Or adjust the paper feed amount. As a result, no matter what kind of recording paper 3 is used, an effective recovery operation can be performed, the recording paper is not misaligned, the ink does not bleed, and the ink does not come off. The result can be obtained.
Of course, when the first embodiment or the second embodiment is combined with the third embodiment and / or the fourth embodiment, a further excellent effect can be obtained.

[0057]

As described above, according to the present invention, the cap position adjusting means controls the capping mechanism to adjust the amount of advance / retreat of the cap during the capping operation by the capping mechanism. Regardless of this, the capping operation can always be performed in substantially the same state.

The cap is a suction cap for performing the recovery operation of the print head, and a recovery device for bringing the suction cap into contact with the nozzle surface of the print head to suck and remove the ink in the print head from the nozzle. Because I'm prepared
The recovery operation can always be performed in a good state.

The gap instructing means is an adjusting lever, and the head gap is determined by the amount of rotation of the adjusting lever, and the gap adjusting mechanism interlocks with the rotation of the adjusting lever so that the print head advances and retreats with respect to the recording medium. The head gap can be easily adjusted by rotating the adjustment lever because the head gap is moved to a predetermined head gap.

Since the head gap detecting means detects the amount of rotation of the adjusting lever as an electric resistance and detects the head gap based on the electric resistance, the head gap can be easily detected.

Further, the cap position adjusting means has a cam member that is linked to the cap and controls the amount of advance and retreat of the cap by rotation, and adjusts the amount of rotation of the cam member. By adjusting the amount of rotation, the amount of advance / retreat of the cap can be easily adjusted.

The gap instructing means sets a gap amount according to the recording medium, and determines the head gap by selecting the recording medium. The head gap detecting means uses the gap instructing means. Since the head gap corresponding to the selected type of recording medium is detected, the head gap can be easily detected only by selecting the recording medium.

Further, an ejecting condition adjusting device is provided which receives the signal from the head gap detecting device and controls the signal applied to the print head to adjust the ejecting condition of the ink droplet. It is possible to adjust the droplet ejection conditions and ensure good printability.

Further, by receiving a signal from the paper feeding means for appropriately feeding the recording medium according to the printing condition and the head gap detecting means, the paper feeding means is controlled and the driving amount of the paper feeding means per time is controlled. By adjusting the driving amount of the paper feeding unit according to the type of the recording medium, the actual feeding amount of the recording medium itself becomes constant regardless of the type of the recording medium. Since the adjustment is performed as described above, optimum feeding of the recording medium (so-called sheet feeding) can be realized, and high-quality recording with no image distortion can be maintained regardless of the type of recording medium.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a printing apparatus according to the present invention.

FIG. 2 is a perspective view of a part of the carriage.

FIG. 3 is a partial cross-sectional view of a carriage.

FIG. 4 is an explanatory diagram of a head gap adjusting operation.

FIG. 5 is an explanatory diagram of a head gap adjusting operation.

FIG. 6 is an explanatory diagram of a resistance member and a contact member.

FIG. 7 is an explanatory diagram of the operation of the suction cap.

FIG. 8 is an explanatory diagram of the operation of the suction cap.

FIG. 9 is an explanatory diagram of a control mechanism of the printing apparatus according to the present invention.

FIG. 10A is a diagram showing a relationship between a lever position and an output voltage from a contact member depending on the type of recording paper, and FIG. 10B is a diagram showing a relationship between an output voltage from the contact member and a rotation angle of a cam member. Is.

FIG. 11 is an explanatory diagram of a head gap adjusting operation according to the second embodiment.

FIG. 12 is an explanatory diagram of a head gap adjusting operation according to the second embodiment.

FIG. 13 is an explanatory diagram of a resistance member and a contact member according to the second embodiment.

FIG. 14 is an explanatory diagram showing a relationship between a recording sheet and an output voltage from a contact member according to the second embodiment.

[Explanation of symbols]

1 inkjet printer 3 recording paper 7 carriage 12 print head 14 Suction cap 21 Adjustment lever 21A eccentric collar 31 Contact member 32 Resistance member 41 Cam member 53 CPU 71A-71D contact part

─────────────────────────────────────────────────── --Continued front page (56) Reference JP-A-7-117296 (JP, A) JP-A-6-8459 (JP, A) JP-A-6-297721 (JP, A) JP-A-5- 246105 (JP, A) JP 8-25715 (JP, A) JP 64-58576 (JP, A) JP 4-238067 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41J 25/308 B41J 2/165 B41J 2/18 B41J 2/185 B41J 11/42

Claims (8)

(57) [Claims] 1. A cap having a print head for ejecting ink onto a recording medium for printing, and a cap that hermetically covers a nozzle surface of the print head, the cap being in contact with the nozzle surface of the print head so as to be able to move back and forth. A printing apparatus comprising: a mechanism; and a gap adjusting mechanism for adjusting a head gap to an amount instructed by a gap instructing means for instructing a head gap, which is a distance between the print head and a recording medium, A head gap detecting means for detecting the head gap indicated by the gap indicating means, and a signal from the head gap detecting means are received to control the capping mechanism to control the amount of advance / retreat of the cap during the capping operation by the capping mechanism. A printing device comprising a cap position adjusting means for adjusting. 2. The printing apparatus according to claim 1, wherein the cap is a suction cap, and a recovery device is provided to bring the suction cap into contact with a nozzle surface of the print head to suck and remove ink in the print head from the nozzle. . 3. The gap instructing means is an adjusting lever, and determines the head gap by the amount of rotation of the adjusting lever. In the gap adjusting mechanism, the adjusting lever rotates integrally with the adjusting lever. The center of the adjusting lever and the center of the guide rod are fitted to the guide rod via the eccentric collar, and the print head is moved back and forth with respect to the recording medium by the rotation of the adjusting lever. The printing device according to claim 1 or 2. 4. The printer according to claim 3, wherein the head gap detecting means detects the amount of rotation of the adjusting lever as electric resistance and detects the head gap based on the electric resistance. 5. The cap position adjusting means has a cam member that is linked to the cap and controls the amount of advance and retreat of the cap by rotating, and adjusts the amount of rotation of the cam member. The printing device according to any one of 1 to 4. 6. The gap instructing means sets a gap amount according to a recording medium, and determines a head gap by selecting a recording medium. The head gap detecting means comprises the gap instructing means. The head gap corresponding to the type of recording medium selected by the means is detected.
The printing device according to any one of 5. 7. A jetting condition adjusting device for adjusting a jetting condition of an ink droplet by receiving a signal from the head gap detecting device and controlling a signal applied to the print head. The printer according to any one of 1 to 6. 8. A paper feeding means for appropriately feeding a recording medium according to a printing condition and a signal from the head gap detecting means to control the paper feeding means to control the paper feeding means for each time. The printing apparatus according to any one of claims 1 to 7, further comprising drive amount adjusting means for adjusting a drive amount.