JPS59207258A - Liquid jet recorder - Google Patents

Abstract

PURPOSE:To obviate the need for piping from main ink tank to the head by a method in which a capping device is provided to the head in a separable and contactual manner and a mechanism to supply ink in a given amount to the subtank in the head is provided to the capping device. CONSTITUTION:Recording is made with ink in a subtank 31 in the head unit 2 on given numbers of papers, and the head unit 2 is restored to its initial position. A capping device 7 is contacted with the front face of the head in the position by advancing it by a motor 12, a gear 13 and a wheel 14. A pump 8 is actuated, the pressure in the upper part of the subtank 31 is reduced through a pipe 34, and ink is supplied through pipes 18 and 33 from the main tank 16 to the subtank 31. Ink to be injected to the portion higher than the level pointer 34a in the subtank 31 is sucked up by the pipe 34 and the amount of ink is kept at a given level. Afterwards, the motor 12 is inversly turned, the capping device 7 is separated from the head 2, and recording is restarted by the head 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a liquid jet recording device such as a quick jet recording device.1) A simple mechanism for supplying recording liquid to a jetting head and returning a jetting head to non-displacement. The object of the present invention is to develop a means that can improve carriage feeding accuracy.

Conventional inkjet recording apparatuses have advantages such as being able to perform direct recording, easily producing color, and producing negligible noise, and are attracting attention as a new recording technology. In particular, on-demand type inkjet recording devices are inexpensive and can be miniaturized, and are becoming central to the full-color printer technology that has been attracting attention recently.

However, conventionally, this type of recording device has a complicated ink supply system to the inkjet head, and the viscosity of the ink increases due to the evaporation of volatile substances in the ink at the tip of the head, making it difficult to maintain the stability of ink ejection. The disadvantage was that it became difficult.

First of all, regarding the ink supply system, various means have been proposed in the past, but one typical one is a configuration in which the ink tank and the head are connected with a highly flexible tube, and others are The ink tank is arranged on a head carriage and the ink tank and head are directly connected. However, in the former case, the tube is pulled as the head moves during recording, which causes problems with the durability of the tube itself, and also causes instability in carriage feeding due to load fluctuations caused by the movement of the tube 7', i.e. ( +)
(11) Instability of ink ejection due to incomplete ink supply due to variations in tube flow path resistance or air bubbles mixed into the tube; and (iii) Maintaining the relative position of the head and ink tank. Therefore, there are many design constraints, which makes it difficult to optimally design the equipment. On the other hand, the latter method increases the load on the carriage motor due to loading a sufficient amount of ink on the head carriage for recording, which increases the size and cost of the entire device, and also causes ink leakage when replacing the ink cartridge. This has the disadvantage of staining the user's hands and equipment. These drawbacks become even more noticeable in an apparatus configured to hold a plurality of types of ink having different ink densities in order to improve image quality.

Next, as clogging prevention means, capping means and ink discharging means from the head tip have been proposed to prevent the head tip from drying out, and these have been effective. However, the configuration in which these operations are performed manually has disadvantages such as poor operability and ink ejection instability due to forgetting to perform blurring. As the residual ink in the ink tank decreases accordingly, it is necessary to provide special means to detect the residual ink, and furthermore, these means must be installed separately from the ink supply system, which reduces the size of the equipment. There are drawbacks that lead to increased formalism and increased costs.

OBJECTS OF THE INVENTION The present invention therefore eliminates the above-mentioned drawbacks of conventional devices and uses a simple mechanism! An object of the present invention is to provide a liquid jet recording apparatus that can supply recording liquid to a jet head and return the meniscus of the jet head.

A further object of the present invention is to provide a liquid jet recording apparatus that does not place an extra load on the carriage motor during recording and has high accuracy in carriage feeding.

Furthermore, the present invention achieves the above-mentioned objects and has a large degree of freedom in arranging the main storage chamber for the recording liquid, thereby making it possible to downsize the device, reduce manufacturing costs, and improve reliability and operability. SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid jet recording device. a small-capacity second recording liquid storage chamber provided in the ejection head unit (also the sub-tank 31 in FIG. 2); a capping device for the liquid ejection head unit (the capping device 7 also shown in FIG. 2); The first recording liquid storage chamber is provided so as to be able to be connected to and separated from the liquid ejecting head unit via a capping device.
means for supplying the recording liquid to the recording liquid storage chamber in the recording liquid storage chamber and means for returning the meniscus of the jetting head (also shown in FIG.
8 and recovery tube 19); means for separating the capping device and the liquid ejecting head unit during recording (also means for retracting the capping device 7 by the output of the recording start signal output circuit 118 in FIG. 4); The present invention is characterized by a liquid jet recording device comprising:

In the above, the citation of the specific examples described later does not limit the scope of the present invention in any way, and the present invention can be modified as appropriate within the scope of the claims.

Sometimes it's called ink.

With reference to the drawings, a specific example of the liquid jet recording apparatus according to the present invention will be described below, with the overall configuration, the capping device, and the configuration of the liquid jet head unit.

The configuration of the pump, the configuration of the control system, and the order of their actions will be explained in detail.

Overall Configuration of Liquid Jet Recording Apparatus (FIG. 1) In FIG. 1, a platen that is linked to a paper feeding mechanism (not shown) is shown.

2 is a liquid ejecting head unit, the details of which will be described later. It is a three-seater carriage and is driven by a carriage motor 4 along a screw 5 and a guide 6 in the direction of the arrow. These control mechanisms are well known and are not related to the gist of the invention of this application, so detailed descriptions will not be provided. The explanation will be omitted.

7 is a capping device, and 8 is a pump, the details of which will be described later in connection with FIGS. 2 and 3, respectively. 9 is a pulse motor for driving the pump, 10 is a worm gear, and 11 is an electromagnetic clutch. The worm gear lo is interlocked with the motor 9 through the electromagnetic clutch 11 and drives the cam 15. 12 is a motor for driving the capping device, 13 is a worm gear, and 14 is a wheel fixed to the capping device 7. The worm gear 13 is interlocked with the motor 12 and meshes with the wheel 14 to drive the capping device 7. 16 is a large capacity recording liquid tank (
Hereinafter referred to as an ink tank. ), 17 is a suction tube that connects the pump 8 and the capping device 7, 18 is a supply tube that connects the ink tank 16 and the capping device 7, and 19 is the tip of the ejection head (32 in FIG. 2) (same (32a) ); 20 is a waste liquid tube that connects the pump 8 and the waste liquid tank 21;
SWl is a detection switch for detecting the initial position of the carriage 3, and FA is a recording paper.

Configuration of capping device and liquid jet head unit (
Fig. 2) Fig. 2 shows a sub-tank storing the capping device 7 and a liquid ejection head, 32 is a known ejection head, 32a is the tip thereof, 33 is an ink supply port, 34 is a suction port, and the pressure inside the sub-tank 31 is ftjlJ. In addition to controlling and discharging ink, it also has a level pointer 34a and functions to keep the initial softness of ink supplied to the sub tank 31 constant. Reference numeral 35 indicates ink stored in the sub-tank 31. Reference numeral 36 indicates the main body of the capping device 7, which is fixed to the main body to a recording device (not shown). 37 is a cap made of a material such as rubber; 38 is a movable member to which the cap 37 is fixed; the movable member 38 is fitted with the main body 36 by a guide (not shown), and the wheel 14 is fixedly mounted. , motor 12
is driven in the direction of the arrow. 39 is a spring and movable member 3
8 toward the head unit 2. Note that 17, 18, and 19 in the figure indicate a suction tube, a supply tube, and a recovery tube, respectively, as in FIG. 1.

Pump configuration (Figure 3) FIG. 3 is a sectional view showing details of the pump 8.

In the figure, 41 is a piston that fits into a cylinder 42-,
It is closed and closed by O-rings 41a, 41b, 41C and 41d, and is urged upward by a spring 43. 44 and 45 are located below the piston 41. A valve 46 is made of an elastic member, and a portion thereof is fixed to the piston 41.

47 is a waste liquid discharge port.

Configuration of control system (Fig. 4) Fig. 4 shows a block diagram of the control system, in which 100 is a recording device control circuit, in addition to the usual digital control section, CNT
Kaunota 1ooa, n, counter 100 b l
n2 counter 100c, W v raster 100 (1
゜Includes timer 1ooe. The function 1C of the CNT counter 100a to timer 100e will be described later.

101 is a recording device control circuit which transfers an end signal to the control circuit 100 in response to recording end γ;
A recording start signal is given from. J, O2U, a signal output circuit 10 that transfers a high level signal to the control circuit 100 when the initial position detection switch SWI of the carriage 3 is activated;
3 is a monthly output circuit which transfers a high level signal to the n2 counter 100c in OO when the recovery switch SW2 is activated.

104. 109, 111 and 112 are carriage motor 4, pump drive pulse motor 9%'...: magnetic clutch 11 and capping device drive motor], 2
, and is controlled by control circuit 1.00. 113 is a large capacity ink tank 16 (Fig. 1)
114 is a driver for the remaining ink level, 0115 is a button meter for detecting the position of the piston 4.1- (Fig. 3), and 116 is a level detector. 41 is located at bottom dead center, intermediate center, or top dead center, and when it is at bottom dead center, it outputs signal SI, when it is at intermediate point, it outputs signal S2, and when it is at top dead center, it outputs signal S. These signals are set to high level and input to the control circuit 1.00.

11-7 is a detector that detects the position of the capping device 7 (FIGS. 1 and 2), and 118 is a signal output circuit that outputs a high level signal when the recording start switch SW3 is pressed. is transferred to the timer 1006 or the like. Note that in place of the remaining ink level warning display 113 in the above, a display device that displays the remaining amount ψ itself may be provided.

Operation of a specific example of the liquid jet recording device according to the present invention (C) (FIGS. 1 to 5) Next, the operation of the apparatus shown in FIGS. 1 to 4 will be explained with reference to the flowchart in FIG. 5. do.

(1) Recording liquid supply and meniscus return operation When the recording of a predetermined number of sheets is completed, the CNT counter 100a outputs a signal indicating this and is reset itself (see step 212 in Fig. 5). (Hereinafter, the drawing number will be omitted and only the step number will be displayed.) This signal causes the n1 counter 100b'l'' to count up, and the carriage morph driver 104 drives the gear carriage motor 4 to move the carriage 3. is returned to the initial position (steps 221 to 222).The return of the carriage 3 is confirmed by the initial position detection switch 5WIK, and the capping motor driver 112 drives the capping device drive motor 12 by the high level output of the signal output circuit 02. As a result, the movable member 38 of the capping device 7 moves to the tip of the head unit 2 due to the engagement between the worm gear 13 and the wheel 14. Due to the movement of the movable member 38, the suction tube 17 and the suction port 34
, the supply tube 18 and the ink supply port 33 are engaged with each other, and the recovery tube 19 and the tip 32a of the liquid ejecting head are engaged with each other. In this state, the capping position detector 117 operates to confirm that the motor is in the capping position, and the capping motor driver 112 is turned off. Even if the capping motor driver 11.2 is turned off, the cap 37 is pressed toward the tip of the head unit 2 by the spring 39, and the above-mentioned engagement is not released (step 22: 226).

Next, the pump motor driver 109 and clutch driver 111 are operated to drive the pump driving pulse motor 9 and anal magnetic clutch 11, thereby rotating the gear 10 and therefore the cam 15 (step 227). After 50 rotations of the cam, the piston 4I of the pump 8 begins to descend, and the upper chamber of the pump 8 becomes negative pressure.

The negative pressure becomes maximum when the piston 41 reaches the bottom dead center.

In this process, the sub tank 31
The internal pressure becomes negative, and accordingly, ink is supplied from the ink tank 16 to the sub-tank 31 via the supply port 33 and the supply tube 18. At the same time, ink is sucked from the tip 32a of the ejecting head via the recovery tube 9 to restore the meniscus of the head.

The pressure in the upper chamber of the pump 8 is restored by the sucked air and ink, and the pressure in the sub-tank 3 is also restored by the supply of ink.

Here, the level pointer 34a is set so that a predetermined pressure is restored when the ink level reaches the pointer. Note that even if excess ink remains in the sub-tank 31 depending on the recording state and exceeds the level pointer 34a, it is discharged as excess ink to the pump 8 via the discharge port 34 and the suction tube 17. This useless sub tank 31
If the level pointer 34a is set lower than the head tip 32a, pressure printing will not occur due to the movement of the head unit 2. Pressure fluctuations can be suppressed by the damper effect of air, and since the meniscus at the head tip 32a has also recovered, good recording can be performed.

On the other hand, air and discharged ink from the head unit 2 are sent to the upper chamber of the pump 8 via the suction tube 7 and the second connecting hole 45. When the piston 410F is descending, the pressure in the lower chamber increases and the valve 46 is closed, so the previously discharged ink, etc. that has accumulated in the lower chamber is removed from the discharge port 47 and the waste liquid tube 20.
The liquid is discharged through the waste liquid tank 21. When the piston 4J reaches the bottom dead center, the signal S1 becomes high level, and upon confirming this, the pump motor driver 109 and the clutch driver 11 are turned off, and the motor 9 is stopped.

Then, the piston 4 holds its position by the holding force of a worm gear (not shown) (steps 228 to 229) During this holding period, the above operations are completed and the royal pressure is restored. The predetermined time required for these steps is After confirming that it is the current position, the motor 9 is reversed and the piston 41 is raised (steps 230 to 231). At this time, since the valve 46 opens, the air and waste ink in the upper chamber are sent to the royal chamber and stopped, but because the fluid resistance of the ≠m 45 is high, there is no backflow to the head unit 2. Piston 4J is held by the barbs 43 when it reaches the top dead center.Next, the capping motor drivers 11 and 2 operate again, the capping device drive motor 12 reverses, and the movable member 38 is returned to its initial position. , the capping of the head unit 2 is released, the recording becomes possible, and the lucky operation is completed (step 232, ■, ......, ■, ......
, steps 204-208).

The above liquid jet recording device has a large capacity ink tank】6
and a small-capacity sub-tank 31 in the head unit 2, and the pump 8, which is a single pressure generating means, supplies ink from the ink tank 16 to the sub-tank 31. Since the discharge is performed and the meniscus is restored, i′f
1) Ink supply can be performed accurately with a compact configuration, and meniscus recovery can be performed at the same time to ensure stable recording.Furthermore, ink supply and meniscus recovery can be performed simultaneously with a single pressure generating means. Because of this configuration, it is possible to downsize the device and reduce manufacturing costs.

Furthermore, in the above recording apparatus, the single capping device 7 is provided with an ink supply system (supply tube 18) and an ink suction system (recovery tube 19) for meniscus recovery.
Since the structure 11'4 is configured to engage with and disengage from the ink supply port 33 and the ejection head 32 in the 741, the simple mechanism 741 can supply the ink and return the meniscus. The above-mentioned operations can be performed reliably, and reliability can be improved. Furthermore, since there is no extra load on the carriage motor 4, such as an ink supply tube, during the recording operation, the inertia can be reduced, the flexibility of the carriage feed can be improved, and the motor can be made smaller. This greatly contributes to miniaturization and reduction of production costs. Furthermore, the degree of freedom in arranging the ink tank 16 is increased, and operability can be further improved.

Furthermore, since the above recording device is configured to dynamically supply ink to the sub-tank 31 after recording a predetermined number of sheets, the ink tank is divided into the large-capacity main tank 16 and the small-capacity sub-tank 31. Even with this configuration, ink can be supplied accurately, and thereby the above-mentioned effects such as miniaturization of the device and improvement of operability can be achieved.

(2) When operating the operation recovery switch SW2 that only restores the meniscus, the signal output circuit 103 transfers the high level signal to the 02 counter 1ooc and %n2
The counter 100c counts up 1". Subsequently, the pump motor driver 109 operates to drive the pump driving pulse motor 9 and move the piston 41 to the third
Move from the person's position in the figure to position B. Movement of the piston 41 is confirmed by the signal S2 becoming high level, and then the carriage motor driver 104 operates to drive the carriage motor 4 and return the carriage 3. Confirm the return of the carriage 3 by operating the switch SWl and try the capping motor/<1121r' operation L s
The capping device driving motor x2 is rotated in the forward direction to engage the capping device f7 with the head unit 2 (steps 241 to 246). After confirming that the capping position has been reached (step 247), the operations from step 226 in FIG. , Ai
Unlike the case of ink supply described above, since the negative pressure in the upper chamber of the pump 8 is small, the ink supply to the subtank 31 is restricted to perform the meniscus return operation.

The liquid jet recording apparatus described above generates two levels of pressure by adjusting the position of the piston 41 in the bonder 8, which is a pressure generating means, and thereby generates pressure from the ink tank 16 to the sub tank 31.
Since it is configured to supply ink to the eyelid, it is easy to switch the generated pressure between the ink supply operation and the operation that only restores the meniscus, and the mechanism for both operations is equivalent. Since the parts can be shared and both operations can be performed reliably, it is possible to avoid complication of mechanisms for ink supply and meniscus recovery and deterioration of operability in conventional recording apparatuses.

(3) Automatic capping operation When recording of one sheet is completed, the capping timer 1QOe starts operating in response to an end signal from the recording device drive circuit 101. The timer 100e is reset by a signal output from the signal output circuit 118 by operating the recording start switch SW3. Therefore, h is recorded within the time set by the timer 100e.
If recording of the desired information is started, the cat-watching/regulating operation is not performed, and when normal recording is performed, the aforementioned meniscus return operation is performed (steps 201 to 2o5.■). /
Although the pump 8 after the start of the meniscus returns to normal (step 231L), the capping device 7 is not retracted, and will be retracted only when the recording start switch SW3 is operated (steps 204 to 208). Therefore, the tip 32a of the ejecting head 32 becomes Pj L at the start of recording.
: Since the cap is released only once, dryness is prevented. This point also applies to the other operations described above.

(4) Remaining ink - sewing + extraction operation The above-mentioned Mli recording device ~: Now, jl! 2I ink 1
The ink supply amount W1 at the time of 1 and the meniscus return operation 1, the ink supply amount W2 of J is always constant, and the ink tank 1
Since the initial capacity W in 6 is also constant, when nl and n2 are the 18J number of ink supplies and the number of meniscus return operations, respectively, L and W' are the remaining ink capacity, W = W - (n + W, +nt W2 )−・−(
The iJ relationship is established. Therefore n, counter 1oo
From the count values of b and n2 counter 100c, formula (11
The remaining amount of ink can be calculated based on the result.

Specifically, n for the previous count value ■.

Every time the counter 100b or n2 counter 100C counts up, the contents of the W register 100d are changed to vV = W, -(n, W, +n2 W2)
(First, compare this with the reference value V, and if W<V,
The driver lid is operated to display a warning on the M warning display 113 when the remaining amount is left. As described above, instead of the warning indicator 113, a display device that displays the residual ore itself may be used. If a warning is displayed, the ink tank 16 is replenished with ink and the W register 1ood is reset (steps 251 to 255).

With the above configuration, it is possible to easily know whether or not the ink tank 16 needs to be refilled, and not only can incomplete recording due to running out of ink be prevented, but also a special device is installed to detect the remaining amount of ink. Since this method does not require any ink, it is possible to easily detect remaining ink even in devices that use multiple types of ink, such as multi-color recording devices, which can reduce device size and improve operability. can be measured.

Effects of the Invention As described in detail above, according to the present invention, a large-capacity first recording liquid storage chamber, a small-capacity second recording liquid storage chamber provided in a liquid jetting unit, and a capping device for the liquid ejecting head unit, through which the liquid is discharged from the first recording liquid storage chamber to the second recording liquid storage chamber.
The means for supplying the recording liquid to the recording liquid storage chamber and the meniscus return means for the ejecting head are provided so that they can be combined with and separated from the liquid ejecting head unit, so that the capping device and the liquid ejecting head unit can be separated during recording. A simple mechanism can supply the recording liquid to the ejecting head and return the ejecting head to the meniscus, and since there is no extra load on the carriage motor during recording, the carriage feeding accuracy can be increased. At the same time, the degree of freedom in the arrangement of the large-capacity first recording liquid storage chamber is increased.
This contributes to the miniaturization of equipment, reduction in manufacturing costs, and improvement in reliability and operability.

[Brief explanation of drawings]

The drawings show a specific example of the liquid jet recording apparatus according to the present invention, and FIG. 2 is a perspective view showing the overall structure of the liquid jet recording apparatus, and FIG. Figure 3 is a sectional view showing the details of the pump, Figure 4 is a block diagram of the control system, Figures 5 (5) and 5 (1) are sectional views showing the details of the pump, Figure 4 is a block diagram of the control system, Figure 6 is a diagram showing the arrangement of Figure 5 (8) and Figure 5 (equipment). 2 in the figure is a set of flowcharts explaining the operation of the device shown in Figure 6. unit, 3 is carriage, 4 is carriage motor, 7 is capping-Jk
+'ffi, 8' I:i pump, 9 is a pump drive pulse motor, 10 is a worm gear, 12 is a gear rubbing device drive motor, 15 is a cam, 16 (11 is a large capacity ink tank, 17 is a suction tube,] 8 is a supply tube, 19 is a recovery tube, 31 is a sub tank, 32 is a jetting head, 32a is its tip, 33 is an ink supply port:
34?1. Suction port, 37 is a gap, 38 is a movable member,
3 is a spring, 41 is a piston, 43 is a spring, 46 is a valve,
113 is a remaining amount warning indicator, 118 is a recording start signal output circuit, and SWl is a detection switch for detecting the initial position of the carriage 3.

Claims (1)

[Scope of Claims] A first recording liquid storage chamber with a large capacity; a second recording liquid storage chamber with a small capacity provided in a liquid ejecting head unit; a capping device for the liquid ejecting head unit; and the capping device. n11 means for supplying recording liquid from the first recording liquid storage chamber to the second recording liquid storage chamber, which are provided so as to be connectable to and separable from the liquid ejection head unit via a device, and return of the meniscus of the ejection head; A liquid jet recording apparatus comprising: means for separating the capping device and the liquid jet head unit during recording; and a metal fitting.