JPH0665495B2 - Liquid jet recording device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a liquid jet recording apparatus, and more particularly to an on-demand type liquid jet recording apparatus that ejects ink droplets only when necessary.

[Prior art]

The on-demand type liquid jet recording apparatus has a feature that its recording speed is high, it is quiet, and its configuration is relatively simple. However, if it is left for a long time without recording, the nozzle will be clogged. . Therefore, a test jet that ejects ink droplets outside the recording area is used to eliminate the clogging, but it is inexpensive, and it is possible to automatically obtain confirmation of whether or not the ink droplets have been accurately ejected. Since there is no container, printing is started on the assumption that clogging has been eliminated by executing discharge a predetermined number of times with a general-purpose device, and for this reason clogging is sufficiently eliminated. If it is not printed, there is a problem that printing cannot be obtained.

〔Purpose〕

An object of the present invention is to eliminate the uncertainties of unclogging by open-loop control, which is found in the above-mentioned general-purpose example, and to realize closed-loop control so that nozzle clogging can be simplified and It is an object of the present invention to provide a liquid jet recording apparatus which detects with a low-priced structure and stops test jetting as soon as it is detected, thereby eliminating wasteful discharge of ink and improving printing efficiency accordingly.

[Means for Solving the Problem] In order to achieve such an object, the present invention provides a liquid jet recording apparatus having a carriage for moving a recording head provided with a nozzle for ejecting a liquid as a liquid droplet. A swelling member, which is disposed at a position facing the nozzle when the carriage moves out of the recording area, absorbs the liquid ejected from the nozzle and swells to expand its volume, and the swelling member expands the volume to expand the volume. A liquid drop receiving device that houses a movable member that is displaced by displacement in a case; and a detection unit that detects the displacement of the movable member. The liquid is discharged from the nozzle by detecting the displacement of the movable member by the detection unit. It is characterized in that it is possible to detect that the ink has been discharged.

[Operation] According to the present invention, when liquid is ejected as droplets from the nozzle to the droplet receiving device arranged at a position facing the nozzle, the ejected liquid is stored in the case of the droplet receiving device. The swelling member is absorbed to swell the volume, and the swelling causes displacement of the movable member to be detected by the detection means, which detects that ink droplets have been ejected. It is possible to inform the user that the clogging has been cleared.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. Here, 1 is a base of a recording apparatus formed of plastic or metal or the like, and 2 is a paper feed roller in which a drive shaft 3 of the base 1 is pivotally supported.
The paper feed roller 2 is rotated by the paper feed pulse motor 4, and the recording paper 5 held by the roller 2 can be fed in the rotational direction. Gears 6 and 7 transmit the rotation of the pulse motor 4 to the roller shaft 3.

On the other hand, a guide 9 is slidably held by guide rods 8A and 8B provided in parallel with the roller shaft 3, and an endless wire 10 is attached to the carriage 9. 11A and 11B are pulleys, 12 is a pulse motor for driving a carriage provided coaxially with the pulley 11A, and by driving this pulse motor, a wire 10 stretched between the pulleys 11A and 11B is used. The carriage 9 can be moved along the surface of the roller 2.

Further, a recording head unit 13 is detachably mounted on the carriage 9 via a holding spring 14, and a nozzle plate 15 provided with a nozzle 15A for ejecting liquid as a liquid droplet on the front surface thereof, that is, the side facing the recording paper 5. Are mounted as shown in FIGS. 2 (A) and 2 (B).

It should be noted that FIG. 1 shows a state in which the carriage 9 is guided to the outside of the recording area. When the carriage 9 is in this position, the ink droplets to be ejected can be converted to a position facing the nozzle plate 15. Drop receiver 16 and this drop receiver
A device described later, which can detect the presence or absence of clogging through 16 is provided.

Reference numeral 17 denotes a flexible cable provided between the connector 18 and the carriage 9. The flexible cable 17 can respond to the movement of the carriage 9 while maintaining electrical contact with the head unit 13.

Next, details of the recording head unit 13 are shown in FIG.
It will be explained by (B). Since the head unit 13 is detachable, it can be easily removed from the carriage 9 when the built-in ink tank 19 runs out of ink.
It can be replaced with a new head unit filled with ink.

The front panel 20 is formed of a material such as glass, and a nozzle plate 15 having nozzles 15A is mounted on the front surface of the panel 20. Reference numeral 21 is a wiring pattern for supplying electrical symbols for droplet ejection to the ejection portion of the nozzle plate 15 via the above-mentioned flexible cable 17.

22 has the ink tank 19 attached to its back side so that it can be detached
On the front side, a head base to which the front panel 20 is attached, 23 is a head cover that is attached to the head base 22 and protects the ink tank 19, and both the head base 22 and the head cover 23 are made of a material such as plastic.

Next, the ink droplet receiving device 16 and the clogging detection device will be described with reference to FIG. Reference numeral 26 denotes a droplet receiving case formed of a plastic or metal material, and an opening 26 through which droplets are introduced in a portion of the case 26 facing the nozzle plate 15.
Have an A.

Reference numeral 27 denotes a mover slidably supported by the case 16, and the space on one side accommodating the mover 27 is made of a water-absorbing rubber that swells in volume when it contains water like a water-absorbing polymer. The member 28 is fitted. By the way, the water-absorbent polymer is used as a water leakage preventive material in tunnels and the like, and its volume increases up to 5 times when it contains water. 29
Is a cover lid member that covers the upper surface of the swelling member 28, and is formed of a mesh or porous material that allows ink to penetrate.

On the other hand, the switch 3 is provided at a position corresponding to the tip of the actuating shaft 27A protruding from the case 26 of the mover 27 pivotally supported by the case 26.
0 is provided, and when the swelling member 28 is swollen by the ink liquid as described later, the actuating shaft 27A of the mover 27 is pushed toward the switch 30 as shown in the figure to turn on the switch 30. Can be in the state of.

Next, various operations in the liquid jet recording apparatus configured as described above will be described.

First, when the power source of the recording apparatus is turned on, the pulse motor 12 for driving the carriage is driven to move the carriage 9 in the direction of the arrow in FIG. 1, and the carriage 9 comes into contact with the side wall of the pedestal 1. Although stopped, the pulse motor 12 is rotated by a predetermined number of pulses more than the rotation number corresponding to the stroke when normal recording is performed.

Thus, when the drive phase of the motor 12 reaches the state where the driving phase of the motor 12 is advanced by the predetermined number of pulses, the pulse motor 12 is rotated in the reverse direction. At this time, the drive phase of the pulse motor 12 is advanced by a predetermined number of pulses, so that the carriage 9 abutting on the pedestal 1 and stopped is moved to the right in the figure simultaneously with the reverse rotation of the pulse motor 12. The recording medium is stopped when it reaches the position where the droplet receiving device 16 is disposed beyond the recording area.

That is, this position is the home position of the recording device, and the initial conditions of the mechanical position and the electrical storage position are matched here. On the other hand, in this state, in the droplet receiving device 16, since it is in an unused state, the swelling member 28 has not yet been infiltrated with ink, and therefore the switch
30 is kept off.

Therefore, an electric signal is supplied to the head 13 via the connector 18 and the flexible cable 17 so that ink droplets are ejected from all the nozzles 15A. In this case, ink is not ejected when recording is not performed for a long time and clogging occurs due to drying of the ink. However, even in such a case, the clogging can be recovered by continuing the ejection operation a certain number of times,
The ink droplets thus ejected are absorbed by the swelling member 28 from the opening 26A through the cover member 29, and the volume thereof is rapidly and significantly expanded.

Due to the expansion of the swelling member 28, the mover 27 is pushed to the left in FIG. 3, and the switch 30 is operated at the shaft end of its operating shaft 27A to turn it on. When the switch 30 is turned “on”, the electric pulse signal supplied to the head 13 is stopped, the ejection is stopped, and the carriage 9 can be put in a standby state for recording as it is.

The swelling member 28 swollen by the ink returns to its original volume in accordance with the evaporation of the ink, so that the switch 30 is returned to the off state and is prepared for the next clogging detection.
Furthermore, when the power of the recording device is turned on, the switch 30
If is on, there is no clogging due to drying, it is judged that the nozzle 15A is in a dischargeable state,
The injection test for blank discharge may not be performed.

As described above, when the switch 30 is in the ON state, the test ejection of ink is stopped, so that the recording amount can be increased by that much without wasting ink. Since the closed loop control is performed as described above, the clogging can be confirmed easily and surely.

In this way, the risk of clogging at the pre-recording stage is eliminated, and then the carriage drive pulse motor 12 is driven again by the recording start signal to move the carriage 9 from the home position to the left in FIG. Thus, when the head unit 16 reaches a predetermined position facing the recording paper 5, an electric signal can be supplied to the desired nozzle 15A to eject ink droplets.

Since the nozzles 15A are arranged in one vertical line, if one character is composed of 12 dots horizontally and 12 dots vertically, for example, while moving the carriage 9 in the row direction,
One character is formed by ejecting the ink droplets once. When the recording for the required number of digits is completed in this way, the pulse motor 12 is rotated in the reverse direction so that the carriage 9 is removed. It is returned to the original home position again.

On the other hand, with respect to the roller 2, by driving the paper feed pulse motor 4 while the carriage 9 is returned to the home position, the roller 2 is rotated via the gears 6 and 7, and the recording paper 5 is loaded. Paper can be fed at a predetermined pitch. The drive timing of the pulse motor 4 is not limited to when the carriage 9 is returned, and may be any timing as long as printing is not performed.
Paper can be fed as desired, which is also an advantage of the non-contact inkjet method.

As described above, the carriage 9 which has been returned to the home position waits for the next recording signal. However, the carriage 9 may be kept waiting for a long time while the power is on. May be done. Therefore, in the present invention, if such a situation is dealt with, and if the standby time is short, the above-described switch 30 is kept in the ON state, so that the idle discharge is not performed and the recording is executed as it is, and the standby is performed. If the time is long, the blank discharge is performed before the recording, and the switch 30 is turned on to confirm that the clogging is eliminated.

If the switch 30 is not turned on even after the ink is ejected, it is determined that the ink in the tank 19 of the head unit 13 is exhausted, and the head unit 13 is removed from the carriage 9, You can replace it with a new one. The attachment and detachment of the unit 13 can be easily performed by compressing the spring 14 that holds the head unit 13.

By mounting and mounting the head unit 13 on the carriage 9 as shown in FIG. 3, a pattern portion (not shown) provided at the end of the flexible cable 17 is provided on the front panel 20 provided on the head unit 13. By electrically connecting to the wiring pattern 21, a recording state in which ink droplets can be ejected can be obtained.

Also, the ink droplet receiving device 16 can be freely attached and detached together with the case 26, and the internal member can be easily replaced.

〔effect〕

As described above, according to the present invention, when the carriage moves to the outside of the recording area, it is arranged at a position facing the nozzle, absorbs the liquid ejected from the nozzle, swells, and the volume expands. A droplet receiving device that accommodates a swelling member and a movable member that is displaced by being expanded by the expansion of the volume of the swelling member in a case; and a detection unit that detects the displacement of the movable member. Since it is possible to detect that the liquid has been ejected from the nozzle by detecting the displacement of the movable member, it is possible to reliably detect the clogging of the ink in the nozzle with a simple and inexpensive device, and it is possible to detect the ink droplet. It is possible to save the use of ink and to increase the recording amount accordingly.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of the configuration of the liquid jet recording apparatus of the present invention, and FIGS. 2 (A) and 2 (B) are front views and sectional views showing the outline of the configuration of the recording head unit, respectively, and FIG. FIG. 3 is a side view showing a partial cross-section of the relative relationship between the ink droplet receiver, the switch member, and the recording head unit mounted on the carriage according to the present invention when clogging is detected. 1 ... Pedestal, 2 ... Paper feed roller, 3 ... Drive shaft, 4 ... Pulse motor, 5 ... Recording paper, 6,7 ... Gear, 8A, 8B ... Guide rod, 9 ... Carriage, 10 ... Endless wire, 11A, 11B ... Pulley, 12 ... Pulse motor, 13 ... Recording head unit, 14 ... Holding spring, 15 ... Nozzle plate, 15A ... Nozzle, 16 ... Droplet receiver , 17 ... Flexible cable, 18 ... Connector, 19 ... Ink tank, 20 ... Front panel, 21 ... Wiring pattern, 22 ... Head base, 23 ... Head cover, 26 ... Case, 26A ... Opening , 27 ... mover, 27A ... operating shaft, 28 ... swelling member, 29 ... cover member, 30 ... switch.

Claims (1)

[Claims] 1. A liquid jet recording apparatus having a carriage for moving a recording head provided with a nozzle for ejecting a liquid as a liquid droplet, the position facing the nozzle when the carriage moves out of a recording area. And a movable member disposed in the case, the swelling member absorbing the liquid discharged from the nozzle and swelling to expand the volume, and the movable member pushed and displaced by the expansion of the volume of the swelling member in a case. And a detection means for detecting the displacement of the movable member, wherein it is possible to detect the discharge of the liquid from the nozzle by detecting the displacement of the movable member by the detection means. Jet recording device.