JPH02263656A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To improve the response characteristics of a rotor and to enhance recording quality by providing a means detecting ink volume remaining in a carriage and a means varying the output torque of a motor according to the detected result. CONSTITUTION:The serial ink jet recording device is so designed that an interchangeable head cartridge 31 that integrally forms a head 5 and an ink tank is mounted on a carriage 6 moving along a platen and the head 5 scans a sheet and records with a carriage motor 23 as a driving source. In this recording device, ink remaining in the head cartridge 31 is detected and conditions for driving the carriage motor 23 are changed according to the ink residual. Consequently, vibrational noise arising in a motor driving system or motor itself, which results from load fluctuation due to a change in the ink residual, and the inversion noise of the carriage 6 arising when the motor is accelerated or decelerated can be prevented. since ink quantity in the head cartridge can be made greater, a noisefree device requiring low running costs can be accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an output torque control device for a motor as a driving means for driving a carriage on which a recording head is mounted in an inkjet recording apparatus.

In recent years, so-called OA devices such as personal computers and word processors have become widespread, and there are various recording devices that use wire tod methods, thermal transfer methods, inkjet methods, etc. to output information input by these devices. being developed. These recording methods perform recording on a conveyed recording medium, such as a recording paper or a synthetic resin sheet, using a recording head formed by each method.

In response to the miniaturization of overall systems, portable computers began to appear, and recording devices also became smaller. For example, for convenient portability, a recording device that can be powered by a battery or a tank that stores ink as a recording liquid can be removably mounted on a carriage integrally with the recording head, so that the space can accommodate the ink tank. Recording devices have appeared that have been devised such as by omitting the .

In particular, in the above-mentioned printing devices, the printing head is replaced at the same time as the tank is replaced as the ink is consumed.
This is an extremely effective structure for small-sized recording devices, as maintenance is extremely easy.

[Problem that the invention is trying to solve]

However, mounting an ink tank on a carriage for scanning increases load fluctuations on the motor due to the weight of the stored ink.

In a recording apparatus in which the carriage scans in the vertical direction (direction with a gravitational component), the above fact is a particularly important problem, and the load fluctuation further increases due to the inertial force of the carriage.

The inventor of the present invention repeatedly conducted numerous experiments and found that this motor load fluctuation causes the following problems.

If the motor torque is determined based on the load when the amount of ink stored is small, there is a high risk that the motor will step out when the ink is full. If the torque is determined, problems such as deterioration of the response characteristics of the roller rotation angle and heat generation of the motor will occur when the ink is low and the load is low.

Specifically, when the response characteristics of the rotor deteriorate, the following problems occur.

Due to its own inertia, the stepping motor rotor rotates while overshooting and pulling back from a predetermined position as shown in Figure 7, and the width of the overshoot increases in proportion to the excess torque. . Overshoot causes the motor pinion to vibrate in the forward and reverse directions.
The vibration of the binion causes the vibration of the carriage, reducing the positional accuracy of the carriage, deteriorating the recording quality, and the vibration of the carriage may become one of the causes of noise generation. Furthermore, the battery capacity may be wasted due to the excess torque, that is, the extra current flowing to the motor. This becomes a problem especially when the device is driven by a battery or the like that cannot have a large capacity.

〔the purpose〕

The present invention solves the above-mentioned conventional technical problems, improves the response characteristics of the rotor, enables high-quality recording, reduces noise caused by carriage vibration, avoids temperature rise inside the machine due to motor heat generation, An object of the present invention is to provide an inkjet recording device that enables efficient use of power consumption.

[Means for solving problems]

An object of the present invention is to reduce the amount of ink in an inkjet recording apparatus that performs recording by mounting an inkjet recording head on a carriage that has an ink tank for storing ink and ejects ink supplied from the ink tank. The present invention is characterized by comprising: an ink quantity detecting means for detecting the amount of ink, a driving means for driving the carriage, and a means for changing the driving output torque of the driving means based on an output signal from the ink amount detecting means. This can be achieved by an inkjet recording device.

[For production]

According to the above means, the carriage weight is calculated according to the remaining amount of ink in the ink tank and the output torque of the carriage driving means is controlled, so that accurate carriage driving is possible regardless of the remaining amount of ink.

〔Example〕

The inkjet recording apparatus according to the present invention will be specifically explained with reference to the drawings.

(First Embodiment) FIG. 1 is a schematic perspective view of an inkjet recording apparatus to which the present invention is applicable.

l is a sheet-like recording medium made of paper, plastic, etc., and a plurality of sheets 1 are stacked in a paper feed cassette, etc.
are fed one by one by a feed roller (not shown) having a partial cutout, and a first pair of transport rollers 3 and a second pair are spaced apart and each driven by an individual stepping motor (not shown). It is configured to be transported in the direction of arrow A by two transport roller pairs 4.

Reference numeral 5 denotes an inkjet type recording head for recording on the recording sheet 1. The recording head 5 is a head that has an ejection port, uses thermal energy to form droplets of recording liquid, and performs recording by a method of forming an image using the recording liquid. Such a recording head is provided with an electrothermal converter corresponding to the ejection port as a means for generating thermal energy, and in this embodiment, a configuration in which the recording head and the ink tank are separate is used. A recording head with an integrated ink tank is preferably used because it can be made smaller.

Ink is supplied from the ink tank 31 to the recording head 5 via a supply path, and is ejected from the ejection ports in accordance with an image signal. The recording head 5 and the ink chamber 31 are mounted on a carriage 6, and the carriage 6 includes a belt 7 and a pulley 8a.
, 8b, a carriage drive motor (hereinafter referred to as CR motor) 23 is connected. Therefore, the carriage 6 is moved to the guide shaft 9 by the drive of the CR motor 23.
It is configured to scan reciprocatingly or vertically along the

With the above configuration, the recording head 5 records an image using the ink by ejecting ink onto the recording sheet 1 according to the image signal while moving in the direction of the arrow B. When recording for one line is completed, the recording head 5 Ink recovery device 19 that returns to the home position and sucks ink from, for example, an ink discharge port.
This eliminates clogging of the nozzles, and at the same time, the transport roller pair 3.degree. 4 is driven to transport the recording sheet 1 by one line in the direction of the arrow. By repeating this process, predetermined recording is performed on the recording sheet 1.

Note that lO in the figure is a heat plate serving as a fixing means for heating, drying, and fixing the ink ejected from the recording head 5 onto the recording sheet 1.

Here, a control system for driving each mechanism of the recording apparatus will be explained.

As shown in FIG. 3, this control system includes a CPU 20a such as a microprocessor, a ROM 20b storing control programs and various data for the CPU 20a, and a CPU 20a such as a microprocessor.
RAM 20c is used as a work area for the PU 20a and temporarily stores various data, and EE stores data on the total number of ejected dots after replacing the ink tank.
Control system 20 equipped with PROM 20d, etc. Counter 32 that counts the number of ink ejected in one recording operation, interface 21, operation panel 22, each motor (carriage drive motor 23, paper feed motor drive motor 24, a driver 27° for driving a motor 25 for driving the first conveying roller pair, a motor 26 for driving the second conveying roller pair, and a driver 28 for driving the recording head.

The control section 20 inputs various information (for example, character pitch, character type, etc.) from the operation panel 22 via the interface 21 and inputs an image signal from the external device 29.

The control unit 20 also outputs ON and OFF signals for driving each motor 23 to 26, ON and OFF signals for the heat plate heater 30, and an image signal via the interface 21, and drives each member using the signals. let Further, after the recording operation is completed, the data of the counter 32 is input to the control unit 20 via the interface 21, and the data of the counter 32 is input to the control unit 20 via the
Add it to the data of M20d and temporarily save it to RAM20c, apply a high voltage to EEPROM20d to reset the old data, receive the updated data from RAM20c, and re-store the data of the total number of ejected dots. controlled like this.

In the device described above, the load applied to the CR motor varies greatly depending on the amount of ink remaining in the ink cartridge mounted on the carriage. It is possible to control the voltage applied to the CR motor.

Next, the configuration for calculating the remaining amount of ink will be explained in detail.

Normally, after installing an ink tank, it is rare to remove the ink cartridge before the ink runs out. Therefore, when an image signal is input from the external device 29, the total number of ejected dots is counted, the amount of ejected dots is stored, and the remaining amount of ink is estimated from this ejected amount.

The load applied to the CR motor is roughly divided into two types: one is a friction load, and the other is an inertial load. The total value of both loads when there is not enough ink on the carriage can be determined as one constant by allowing a slight margin, although it varies depending on the ambient temperature.

By mounting an ink tank on the carriage, both frictional load and inertial load increase and fluctuate, but this increase can be calculated from the calculated value of the remaining amount of ink, so CR
It becomes possible to know the required torque of the motor.

As an example, the required torque of the CR motor can be expressed as shown in the following equation.

Inertia load Friction load required torque cl: (□・J) + (μWR) cc (
--WR" + μwR) (support) W (□・R2+
μR) where ω: Angular acceleration, t: Acceleration time J: Moment of inertia of the carriage μ: Coefficient of friction between the carriage and φ guide shaft W: Weight of the carriage + head and ink tank R: Pulley radius and inertia of the pulley and motor Moment, viscous resistance, etc. are designed to be negligibly small.

Here, when W = 200 g, the required torque is -400 g
'cm system, 150g of ink is consumed and W=5
When the torque becomes 0g, the torque may be controlled to be 100g/am.

Here, the torque of the stepping motor as the CR motor has the following relationship.

Torque ccI water Φ (where ■ = current, Φ: magnetic flux density) Therefore, if the drive circuit of the CR motor is, for example, a constant voltage circuit, the surplus can be reduced by controlling the flowing current by changing the set value of the applied voltage. It becomes possible to prevent torque generation. Further, if the drive circuit is a constant current circuit, the same effect can be obtained by changing the set value of the control current.

Next, the operation of recording using the recording apparatus having the above-described configuration will be described with reference to the flowchart of FIG.

When the previously inserted ink tank is removed in step S1 and replaced with a new ink tank, the EEPR
The information on the total number of ejected dots stored in OM2Od is erased and EEPROM20d is reset.

When a recording command, that is, a command to scan the carriage, is entered in step S3, the data stored in the EEPROM 20d, that is, the total number of ejected dots, is checked and the current remaining amount of ink tank is calculated. From the load-torque table, calculate the required torque of the CR motor according to the remaining amount of ink.Step S5
), and controls the current value flowing to the CR motor according to the required torque (step S6).

In step S7, the CR motor is controlled based on the control described above, and the carriage starts scanning. During recording, the number of ejected dots is counted by the counter 32 (step S8).

When the carriage stops and one recording operation is completed (step S9), information on the number of ejected dots is input to the control section 20, and the value of the total number of ejected dots in the EEPROM 20d is updated (step S5IO).

After the update, the process returns to step Sl and there is no longer a need to wait while constantly checking to see if the cartridge has been replaced or if there is a command to perform carriage scanning.

Here, even if we assume that the EEPROM 20d can be erased 100,000 times and the lifespan of the recording device is 5 years (20 days/month),
It can be seen that it can be updated more than 80 times a day on average, and is sufficiently durable for actual use.

Furthermore, the counter does not count once for one dot (it may also be controlled so that it counts once for multiple dots).

As mentioned above, by controlling the current supplied to the cR motor to vary during carriage scanning, generation of excess torque is prevented, clear images are recorded, noise and heat generation are prevented, and power is efficiently used. It can be used.

(Second Embodiment) FIG. 5 is a schematic cross-sectional view of the remaining ink amount detection means.

In this embodiment, the sensor lever 11 and the photosensor 12 constitute a detection means. Said sensor lever 1
1 is attached to the lower part of the ink cartridge 31. The ink tank is installed on a spring 13, and moves upward as the ink is consumed. A plurality of light emitting diodes 12a (for example, three) are attached to the photosensor 12, and all the light emitting diodes 12a are shut off by the sensor lever 11 when the ink is full. As the ink is consumed, the ink tank 31 moves upward, and the light emitting diodes 12a are sequentially turned on from the bottom, and the light is received by a phototransistor (not shown).

Therefore, when the ink tank 31 moves above a predetermined position due to ink consumption, the photo sensor 12 detects the remaining amount of ink.

The information that the light emitting phototransistor has received the light from the light emitting diode 12a is input to the control unit 20, and depending on how many light emitting diodes are in operation, the CR motor is Performs torque control.

Configurations other than the configuration of the remaining ink amount detection means, such as a control circuit,
The processing procedures and the like are the same as those in the above-described embodiment, so a description thereof will be omitted.

(Third Embodiment) Further, as another embodiment of the remaining ink amount detection means, it is also possible to configure it as shown in FIG. 6.

In FIG. 6, the ink tank is installed on the support 33 and the spring 13. Therefore, when the ink is consumed, the slide terminal 14a slides in the direction of the arrow in accordance with the remaining amount of ink, and the change in the remaining ink amount appears as a change in the resistance value of the variable resistor 14.

The resistance value change is input to the control unit 20, and the torque of the CR motor is controlled according to the input data as in the first embodiment.

Similar to the embodiment described above, explanation of the configuration other than the in/out remaining amount detection means will be omitted.

(Fourth Embodiment) FIG. 7 is a schematic cross-sectional view of the remaining ink amount detection means of the fourth embodiment.

In FIG. 7, an ink tank 31 is installed on a spring 13 similarly to the second embodiment, and moves up and down depending on the amount of ink remaining. Further, a touch member 17 that rotates around a shaft 17a depending on the remaining amount of ink is connected to a slider 18a of a variable resistor 18. Further, the slider 18a is configured to be rotatable about a shaft 18b, and the distance 11 from the shaft 18b to the connecting point of the touch member 17 and the distance 1. 'Relationship 1. Set <l.

With this configuration, a slight change in the remaining amount of ink can be detected as a large change in resistance value, and detection sensitivity can be improved.

In addition to the above-mentioned embodiments, remaining ink amount detection means include one that uses a resistance value that changes with the amount of ink using an electrode provided in an ink tank, one that uses a change in capacitance, or one that uses a change in capacitance. The present invention is not limited to the above-mentioned structure as long as it can achieve the object of the present invention, such as a pressure detection method using a flexible membrane.

Further, although the above-mentioned power control is preferable, a configuration may also be adopted in which mechanical means such as switching of a clutch is used to change the torque.

(Fifth Embodiment) Hereinafter, a fifth embodiment of the present invention will be described in detail based on the embodiment and with reference to the drawings.

FIG. 8 is a schematic perspective view showing an inkjet recording apparatus according to the present invention, and 601 is a head cartridge composed of a head for ejecting ink and an ink tank thereof;
602 is a carriage on which the head cartridge 1 is mounted and moves in the recording line direction (main scanning direction). Carriage 6
02 is slidably supported by guide shafts 603 and 604, and reciprocated in the recording line direction by a timing belt 608. A timing belt 608 engaged with pulleys 606 and 607 is driven by a carriage motor 605 via pulley 607.

The recording paper 609 is guided by a paper pan 610 and is conveyed while being pressed against a paper feed roller (not shown) by a pinch roller. This conveyance is performed using a paper feed motor 615 as a driving source. The conveyed recording paper 609 is ejected with tension applied by a paper ejection roller 612 and a spur 613.

614 is an ejection recovery means having three ink ejection ports and a suction pump. Foreign matter, highly viscous ink, air bubbles, etc. attached to the ejection port of the head are removed by the ejection recovery means 14.
It works to improve the ejection characteristics (.

FIG. 9 shows the structure of the head cartridge 1. In this example, thermal energy is used to form droplets of recording liquid (ink). A head that uses a method of forming an image using recording liquid is used. A print head 601b is disposed on an outer device a made of plastic or the like, and a flexible circuit 601c is attached to the bottom of the outer device a for supplying a drive current to a heater as a means for generating thermal energy in the head 601b. There is. This flexible circuit 6
01C is connected to a head drive circuit on the recording apparatus side by contacting a flexible circuit provided on the carriage.

Inside the exterior 601a is a sponge 60 that absorbs ink.
It is an ink tank based on 1d.

This sponge applies negative pressure to the ink against the ejection port,
This is to prevent ink from leaking from the ejection port. Note 6
01e is a cover for sealing the exterior 601a.

FIG. 10 is a block diagram of a control system in the apparatus shown in FIG. 8. In the figure, 621 is a central processing unit (CPU) comprised of a microprocessor element and the like that controls the operation of the entire inkjet recording apparatus. Data to be recorded and commands to control the operation of the recording device are transferred from a host device 620 such as a computer system to the CPU 621 via a recording data receiving section 22 that is configured of a known interface circuit such as a parallel interface or a serial interface. be done. Based on the transferred data, the CPU 621 controls the head in the head cartridge l via the head control section 623 and head drive 624. The drive timing of the head is controlled to a predetermined value by using a timer 625.

If the recording data transferred from the host device 620 is characters or symbols, the data is transferred in the form of a character code, so the recording device converts it into bit image data so that it can be recorded with a dot matrix recording head. be done. For this conversion, the character generator ROM
(CGROM) 626 is provided. Also CPU6
The control program to be processed by 21 is control RO
It is stored in M627. Further, a RAM 628 is provided for use as a buffer area for transferred recording data or a work area for the CPU 621.

An input port 29 is provided for detecting other various switches and sensors 30, and an output port 31 is provided for outputting control signals for mechanical mechanisms such as the carriage motor 605. A carriage motor drive circuit 632, which will be described later, is connected to this output capo/toro 31.

A rotary encoder 6 is attached to the shaft of the carriage motor 605.
33 is attached. rotary encoder 633
As shown in FIG. 11, there is an optical sensor module consisting of a photodiode, a phototransistor, etc. on a circular thin plate 633a having slits cut at equal intervals around the periphery (there are parts that pass light and parts that block light alternately). 633b, and by directly connecting it to the motor shaft 633C, the rotation of the carriage motor 605, that is, the carriage 602. , a two-phase output signal (with a phase difference of 90 degrees) as shown in FIG. 12 is generated. By using these two-phase signals, accurate positioning is possible. Note that the purpose of generating signals having a phase difference of 90 degrees is to specify the rotational direction of the motor.

In the present invention, the output signal of the echoer 633 is used to detect the amount of ink in the ink cartridge 601, that is, the weight (load) of the entire carriage 602. The detection method will be described in detail below.

Usually, the carriage drive system includes a carriage motor 605.
However, inertia exists regardless of the type of motor, such as a stepping motor or a DC motor. Therefore, when the motor accelerates from a stopped state to a certain constant rotation in the recording state, the motor always follows the command speed curve with a delay. The amount of this delay increases in proportion to the total weight of the carriage.When the carriage motor 605 is a step motor, if the delay exceeds the limit, the carriage motor 605 will step out.
Since the output signal of the encoder 633 (output A or output B in Fig. 11) directly connected to the shaft of the encoder 633 corresponds precisely to the amount of rotation of the motor, ) or pulse width (
By measuring the rotational speed of the motor, that is, the moving speed of the carriage 2, it is possible to know the rotational speed of the motor, that is, the moving speed of the carriage 2. Therefore, the period of the output signal of the encoder 633 at a certain point in time when the motor is accelerating, or By measuring the pulse width, it is possible to relatively detect the total weight of the carriage 602 including the head cartridge 1.

To measure the period of the output signal of the encoder 633, as shown in the block diagram, the period of the output signal of the encoder 633 is measured between the rising edge and the rising edge (the same applies from falling edge to falling edge).
The counter 634 is enabled to count the reference clock whose period is sufficiently shorter than the encoder output signal. - When the cycle count ends, load the count value into the register 635 and generate an interrupt to the CPU 621 as necessary. The CPU 621 can relatively know the total weight of the carriage 2 by reading the count value of the register 635.

Also, at this time, if necessary, the reference clock count is started again based on the output of the encoder.

Note that when position control is not performed using the output signal of the rotary encoder 633, that is, when open-loop control of the step motor is performed, the spacing between the slits in the circular thin plate 633a can be made rough, so that the overall device There is almost no impact from the cost increase. Furthermore, when performing position control, the rotary encoder for performing the position control can be used as is, so there is almost no increase in cost.

Next, a description will be given of switching the voltage or current applied to the carriage motor 605 based on the detection result of the weight of the carriage. Here, a four-phase stepping motor is used as the carriage motor 605.

FIG. 13 shows an example of a circuit that generates the applied voltage (2) when driving the carriage motor 605 at a constant voltage. When the voltage switching signal output from the output port 31 is set to "H" level, the transistor Q1 is turned on and the base current of the transistor Q2 flows. As a result, Q2 turns ON, and a high voltage V n (assuming V u > V t) appears at 1. Next, when the voltage switching signal is set to the "L" level, the transistor Q1 becomes 0FFL, and the base current of the transistor Q2 stops flowing. As a result, Q2 turns OFF and a low voltage vL appears at VIl.

FIG. 14 shows a self-excited chopper circuit that drives the carriage motor 5 at a constant current. Although only the A and λ phases are shown in the figure, the B and U phases are also the same circuit. Now, when excitation signal A or excitation signal λ is activated (“H” level), the winding current increases according to the time constant determined by the motor winding resistance and inductance, and the force of comparator A1 becomes (1+r)Vref−VL (However, r=R2/R1, Vt: :7 "L" level output of comparator A1, Vref: comparator A1
(one input terminal), transistor Q3 turns off and the winding current decreases. After that, when the ten inputs of the comparator become (1+r)Vref -Vn (however, V,: "H" level output of comparator A1), transistor Q3 is turned on and the winding current increases again, and the above Constant current driving is performed by repetition. As described above, the winding current, that is, the motor current, is determined by one input terminal Vref of the comparator A1, so the motor current can be changed by changing Vref.

Now, change the current switching signal output from the output boat 31 to “
When the level is L'', the transistor Q4 becomes 0FFL, and V
ref is the divided voltage of resistor R3 and resistor R4 in ■2,
In other words, the motor current 11 determined by Vref flows. Next, when the current switching signal is set to 'H' level, transistor Q4 is turned on and resistor R5 is inserted in parallel with R4, resulting in a decrease in Vref (Vsat: saturation voltage of transistor Q4), which becomes 11
Less motor current I2 will flow. Therefore, by switching the output level of the current switching signal output from the output port 31, the motor current can be changed.

FIG. 15 is a flowchart showing the control procedure according to this embodiment, and best illustrates the features of the present invention.

First, after powering on the device, initial settings of the device are performed in step 5101. At this time, in step 5102, the RAM 28
Clears the motor power flag X provided in , and sets it to high power mode. When a recording start command is input in step 5103, the motor power flag X is checked in step 5104, and if X=0, the ink cartridge 60 is
It is determined that there is a large amount of remaining ink in the cartridge 1 and the total weight of the carriage is greater than a certain specified value, and the voltage switching signal output from the output port 31 is set to H" level (when driving with constant voltage).
, current switching signal to “L” level (when driving with constant current)
is set to enable the motor to be driven at high torque (step 5105). Next, in step 8106, the speed counter 34 in FIG. 10 is put into a countable state, and in step 8106, the carriage motor is accelerated from a stopped state to a constant speed, which is a recording state. When the carriage motor rotates, the rotary encoder 633 outputs a waveform as shown in FIG. 12, so the period or pulse width of this rectangular wave at a specific point in time is counted using the reference clock (step 5107). When the count is finished in step 8108, the counter value loaded into the register 635 is read (step 5109), and in step 5ILO it is determined whether the count value and the determined value N are larger or smaller. If the count value≦N, it is determined that the ink has been consumed and the carriage weight has become less than the specified value, and the motor power flag X is set to "1" (step 5ill). Count value>
In the case of N, it is determined that ink remains and the weight of the carriage is greater than the specified value, and the flag X is left unchanged and 8112 henges. After the ramp-up of the motor is completed, a recording operation is performed in step 5112, and after the recording of that row is completed, the motor is decelerated and stopped in step 5113. If there is a special feed command, the paper is fed and then jumps to step 5103 to wait for the start of recording.

Next, in step 5104, if flag X is 1,
When the ink in the ink cartridge 601 is consumed and the total weight of the carriage is determined to be less than a certain specified value, a constant voltage is applied to lower the voltage applied to the motor in order to prevent motor vibration and carriage reversal noise due to excessive motor torque. Constant current drive control that lowers the drive or motor current setting value is performed. This is done in step 5114 by output port 31.
This can be achieved by setting the voltage switching signal outputted from the circuit to the "L" level (when driving at constant voltage) and the current switching signal to the "H" level (when driving at constant current). Thereafter, the carriage motor is accelerated in the set low power mode (step 3115), and recording is performed (step 5112).
, After recording is completed, the motor is decelerated and stopped in step 5113, jumps to step 5103 again, and this process is repeated thereafter.

In the embodiment described above, both the voltage and current are switched by two
However, by using a DA converter,
It is clear that it can be changed to multiple stages depending on the number of bits. In addition, a rotary encoder attached to the carriage motor was used as a means for detecting the remaining amount of ink, that is, the weight of the carriage, but a linear encoder placed parallel to the scanning direction of the carriage was used, and an electrode or The object of the present invention can also be achieved by direct detection using a pressure detection sensor.

(Sixth Embodiment) FIG. 16 is a flowchart showing another example of the operation of the inkjet recording apparatus according to the present invention.

The control operation shown in FIG. 16 is based on the ramp-up curve (speed curve accelerating from a stopped state to a constant speed state) and ramp-down curve ( By changing the deceleration curve (from a constant speed state to a stop), it is possible to prevent the carriage from producing reversal noise due to excessive torque of the motor. In this embodiment, the most common step motor is used as the carriage motor, a constant is read from a data table stored in the control ROM 27, and the constant is set in the timer 25. When the timer times out, the excitation phase of the motor is A method is adopted in which the motor is accelerated or decelerated by switching the motors one after another.

Two sets of ramp-up and ramp-down constant tables are stored in different areas in the control ROM 627, and depending on the amount of ink remaining, there are tables with gentle rise and fall curves (if there is a lot of ink remaining), and tables with steep curves. Select one of the tables (when the ink level is low).

In FIG. 16, after powering on the device, step 5201
Perform the initial settings of the device. At this time, flag Y provided in the RAM 28 is cleared (step 202). When a recording start command is input in step 5203, step 5
Check flag Y in step 204, and if Y is "0", the in"
It is determined that the amount of ink remaining in the cartridge 601 is large, that is, the total weight of the carriage 602 is large, and in order to accelerate this large load, the carriage motor is accelerated from a stopped state to a recording state at a gentle speed curve A. (Step 5205). During this acceleration, the remaining amount of ink is detected in step 8206 by the same means as the detection method of the first embodiment, and when the remaining ink amount is less than a certain specified value in step 5207, flag Y is set to "1". Step 520
After the ramp-up is completed in step 9, recording is performed at a constant speed in step 5208, and after the recording is completed, the speed is decelerated to a gentle speed curve and then stopped. Thereafter, the process jumps to step 5203 again, and this routine is repeated until the remaining amount of ink falls below the specified value.

If flag Y is set to 1' in step 5204, it is determined that the remaining amount of ink in the ink cartridge 601 is below the specified value and the load driving the carriage 602 has become lighter, and the speed curve Ramp-up is performed at a steep speed curve B (S210). After the ramp-up is completed, recording is performed at a constant speed in step 5211, and after the recording is completed, in step 8212, the speed is decelerated along a curve B' with a steeper fall than the speed curve A', and then stopped.

After that, 5203 hesitation again and speed curves B and B
At ', the carriage motor 605 repeats acceleration and deceleration.

As described above, the carriage motor 605 for each tine
The remaining amount of ink is detected during acceleration of the motor, and the acceleration/deceleration curve of the motor can be changed based on the result.

In this embodiment, it is possible to prevent the occurrence of carriage reversal noise due to excessive driving force of the carriage motor without adding hardware or increasing the burden on software. Further, if there is enough space in the control ROM 27, it is possible to prepare many types of speed tables, and even smoother carriage motor driving can be realized.

As described above, a replaceable head cartridge that integrates a head and an ink tank is mounted on a carriage that moves along a platen, and the head scans and records while using the carriage motor as its drive source. In a serial inkjet recording device, by detecting the amount of ink remaining in the head cartridge and changing the driving conditions of the carriage motor according to the amount of ink remaining, It has become possible to prevent 1) vibration noise generated by the motor drive system or the motor itself; and 2) reversal noise of the carriage generated when the motor accelerates or decelerates.

Therefore, since it is possible to increase the ink capacity in the head cartridge, it is possible to provide an extremely quiet inkjet recording apparatus with low running costs.

〔Effect of the invention〕

As explained in detail above, the present invention provides a means for detecting the amount of ink remaining on the carriage and a means for changing the output torque of the motor according to the detection result. This makes it possible to improve the response characteristics of the rotor, improve the recording quality, reduce noise caused by carriage vibration, and prevent the motor from generating heat due to excess torque, extending its life.

In addition, particularly in a battery-powered recording device, it is possible to suppress wasteful power consumption and efficiently perform recording using limited battery capacity.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of a recording apparatus to which the present invention can be applied; FIG. 2 is a block diagram of a control system according to the present invention; FIG. 3 is a flowchart for detecting the amount of remaining ink according to the present invention; FIGS. 5 and 6 are schematic diagrams of other embodiments of the remaining ink amount detecting means according to the present invention. FIG. 7 is a schematic diagram of another embodiment of the remaining ink amount detecting means according to the present invention. Response characteristic diagram, FIG. 8 is a perspective view of an inkjet recording apparatus embodying the present invention, FIG. 9 is a configuration diagram of a head cartridge, and FIG. 10 is a diagram of a head cartridge.
Figure 11 is a block diagram of the control system of the recording device shown in Figure 1. Figure 11 is a configuration diagram of the rotary encoder attached to the carriage motor. Figure 12 is the signal waveform output from the rotary encoder in Figure 1. Figure 13 is the step motor. FIG. 14 shows an example of a motor applied voltage generation circuit when driving a step motor with a constant current. FIG. 15 shows the operation of an inkjet recording apparatus according to a fifth embodiment of the present invention. Flowchart FIG. 16 is a flowchart showing the operation of an inkjet recording apparatus according to a sixth embodiment of the present invention. 1 is a recording sheet, 3 is a first conveyance roller, 4 is a second conveyance roller, 5 is a head, 6 is a carriage, 7 is a belt, 8a
, 8b is a pulley, 9 is a guide shaft, 10 is a heat plate, 12 is a photosensor, 12a is a light emitting diode,
13 is a spring, 14 is a variable resistor, 14a is a slide terminal, 17 is a touch member, 17a is a shaft, 18 is a variable resistor, 18a is a slider, 18b is a shaft, 2o is a control unit,
20a is a CPU, and 20b is a ROM. 20c is a RAM, 20d is an EEPROM, 21 is an interface, 22 is an operation panel, 23 to 26 are motors,
27 and 28 are drivers, 29 is an external device, 31 is an ink cartridge, and 33 is a support. Genealogy 6θid drawing/4 diagram

Claims (1)

[Scope of Claims] In an inkjet recording apparatus that performs recording by mounting an inkjet recording head on a carriage, which has an ink tank containing ink and discharges ink supplied from the ink tank, the amount of ink can be controlled. The apparatus is characterized by comprising: an ink amount detecting means for detecting the amount of ink, a driving means for driving the carriage, and a means for changing the driving output torque of the driving means based on an output signal from the ink amount detecting means. Inkjet recording device.