JP2984380B2 - Ink jet recording 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 heating type ink jet recording apparatus utilizing ink discharge amount control.

[0002]

2. Description of the Related Art Conventionally, in an ink jet recording apparatus using thermal energy generated by an ejection heater, in order to eliminate the occurrence of density fluctuation and density unevenness in the ink ejection performance, the ejection speed and directionality (landing accuracy) are required. ) And discharge rate VDROP
The aim was to stabilize the ejection characteristics related to [pl / dot]. In order to achieve this stabilization, the following method has been used.

[0003] 1. There is always head temperature control (external / internal) feedback.

[0004] 2. With sequential head temperature control (external / internal) feedback.

[0005] 3. High temperature head temperature control (higher than ambient temperature)
With feedback.

However, 1.2.3. In the method (1), density fluctuation and density unevenness could not be completely removed due to ink evaporation, head structure change, and insufficient control accuracy due to temperature control ripple.

Therefore, as a method of supplying a driving pulse to the discharge heater, a divided pulse width modulation driving method has been proposed. This is a driving method in which a preheat pulse having a variable pulse width is first applied, and then a main heat pulse is applied via an interval time. The preheat pulse is a pulse for mainly controlling the temperature of the ink in the nozzle, and the pulse width is varied by temperature detection using a temperature sensor of the head. At this time, pre-foaming phenomenon is prevented from occurring by applying too much heat energy to H and B. The interval time is provided with a fixed time interval so that the preheat pulse and the main heat pulse do not interfere with each other, and has a function of making the temperature distribution of the ink in the nozzle uniform. The main heat pulse causes a bubbling phenomenon on H · B to cause ink droplets to be ejected from the nozzle holes.

By using the divided pulse width modulation driving method, it is possible to eliminate the density fluctuation and the density unevenness due to the fluctuation of the discharge amount during printing.

However, printing is not always performed using all the nozzles. For example, printing may be performed using only one half of the nozzles. That is, the relationship between the print area and the print width of the head is not always a positive multiple of the print width, and printing must be performed with an odd nozzle in the last line of the print.

When an ink jet recording apparatus is used by a control signal from an external device such as a reading apparatus,
In some cases, the number of nozzles of the head must be changed from the normal printing state. For example, in the case of a serial printing type ink jet recording apparatus, the paper feeding accuracy is usually the normal feeding (head width).
Therefore, if the paper feed is changed at the time of reduction, the accuracy is reduced and a connecting streak is generated to disturb the image.
Therefore, two-pass printing in which printing is performed twice for one paper feed is effective. In such a case, it is necessary to change the number of ejection nozzles of the head for printing.

As described above, when the number of print nozzles of the head is changed, a temperature distribution is generated according to the use state of the discharge heater, and the discharge amount fluctuates due to this temperature distribution. In addition, in an ink jet recording apparatus in which the head drive is controlled by a temperature sensor, if the control in consideration of the temperature distribution is not performed, as a result, print density unevenness occurs.

In the above state, when color printing is performed in four colors of cyan, magenta, yellow, and black,
Since the formed full-color image loses its color balance, the color tone changes and the color reproducibility deteriorates (the color difference increases), so that the image quality deteriorates. In addition, black red blue
When a single color image such as green is formed, there is a problem that density unevenness occurs.

Accordingly, the present invention has been made to solve the above-described problem, and when performing a printing operation using only a specific discharge heater, the variation in the ink discharge amount caused by the temperature distribution occurs. Inkjet recording apparatus capable of reducing temperature, and inkjet capable of reducing the occurrence of temperature distribution by controlling the driving of a heater for temperature adjustment when performing a recording operation using only a specific ejection heater It is an object to provide a recording device.

[0014]

In order to achieve the above object, an ink jet recording apparatus according to the present invention comprises a plurality of ejection heaters arranged for ejecting ink, and a plurality of ejection heaters arranged along the arrangement direction of the plurality of heaters. An inkjet recording apparatus that performs recording by ejecting ink from the inkjet head by driving the plurality of ejection heaters, using an inkjet head including a plurality of temperature sensors for detecting a temperature to be arranged, Determining means for detecting a temperature by each of the plurality of temperature sensors and determining driving conditions of the plurality of discharge heaters based on the detected temperatures; and the plurality of discharge heaters based on the driving conditions determined by the determining means. And a printing control means for performing printing by driving the plurality of ejection heaters arranged in the array. The temperature detected by each of the plurality of temperature sensors is calculated in accordance with the position and the number of the discharge heaters used for recording on the array, and the driving condition of the discharge heater is determined based on the temperature obtained by the calculation. It is characterized in that it is determined. The ink jet recording apparatus of the present invention uses an ink jet head having a plurality of discharge heaters for discharging ink, a plurality of temperature control heaters for temperature control, and a plurality of temperature sensors for detecting the temperature. An ink jet recording apparatus that determines driving conditions for the discharge heater based on the detected temperatures of the plurality of temperature sensors, wherein the temperature is detected by each of the plurality of temperature sensors, and the plurality of temperature controls are performed based on the detected temperatures. Determining means for determining a driving condition of the heater; and temperature control controlling means for controlling the temperature of the inkjet head by driving the plurality of temperature controlling heaters based on the driving condition determined by the determining means. The determining means is configured to determine, based on the position and the number of the discharge heaters used for recording among the plurality of the arranged discharge heaters, on the arrangement. , Calculates the temperature detected by each of the plurality of temperature sensors, and determines the driving condition of the temperature control heater based on the temperature obtained by the calculation.

[0015]

According to the present invention, a head is calculated based on the temperature calculated from the outputs of a plurality of temperature sensors in accordance with the ejection ports used for recording (for example, in accordance with the number and position of the ejection ports). (E.g., temperature control / drive pulse control), it is possible to reduce variations in the ejection amount regardless of the temperature distribution of the head, and to reduce the occurrence of temperature distribution by controlling the temperature of the head. Therefore, it is possible to eliminate the occurrence of density unevenness and streaks, and to stabilize the density and color balance at the time of final line printing or reduced printing.

[0016]

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

FIGS. 1 to 3 are flowcharts showing the main control of the ink jet recording apparatus according to one embodiment of the present invention. The outline of the main control will be described with reference to FIGS.

When the power is turned on, the apparatus performs an initial check of the apparatus in step S1. This check is to check the ROM and RAM of the apparatus, that is, check programs and data to confirm whether the apparatus can operate normally. In step S2, a correction value of the temperature sensor circuit is read. In step S3, an initial jam check is performed. In this embodiment, even when the front door is closed, an initial jam check is performed in step S3. Step S4
Then, in the next step, a check on the device side necessary for reading the information of the recording head is performed. Step S5
Reads data from a ROM incorporated in the recording head. Next, initial data is set in step S6.

In step S7, the initial temperature control at 20 ° C. is started, and in step S8, a recovery operation determination [1] (determination of whether or not to perform a suction recovery operation when the power is turned on) is performed. The above is the description of the sequence flow up to the wait state.

Next, a sequence flow in the standby state will be described. In step S9, the temperature is controlled at 20 ° C., and in step S10, standby idle discharge is performed. In step S11, it is checked whether there is no paper feed. If there is no paper feed, the process proceeds to step S21. It is checked in step S12 whether the cleaning button has been pressed, and if so, the cleaning operation is performed in step S13. If the RHS button has been pressed in step S14, the RHS mode flag is set in step S15. Here, RHS refers to a head shading process for correcting the density unevenness of the recording head. The density unevenness of the printed pattern is read by a reading unit (reader) to correct the density unevenness.

If manual paper is fed in step S16, a manual feed flag is set in step S17, and the flow advances to step S22, which is a copy start sequence. If the OHP button is turned on in step S18, step S1
In step 9, the OHP mode flag is set, and if not turned on, the OHP mode flag is reset in step S20. If the copy button is pressed in step S21, the process proceeds to step S22, which is a copy start sequence. On the other hand, if it has not been pressed, the process returns to step S9. When the cleaning operation is completed in step S13, the process returns to step S9.

Next, the copy sequence will be described. In step S22, the fan for suppressing the temperature rise in the apparatus is rotated, and in step S23, the temperature control at 25 ° C. is started. Step S
At 24, it is checked whether or not the paper is fed.
Performs idle discharge [1] (N = 100) in step S29.
Proceed to. Here, N indicates the number of times of idle discharge. Step S
At 26, a recovery operation determination [2] (determination of whether or not to perform a suction recovery operation before paper feeding) is performed, and paper feeding is performed at the next step S27. In step S28, a paper width and paper type detection operation is performed. In step S29, it is checked whether to move the image. If the image is to be moved, the sub-scanning movement (paper movement) is performed in step S30. If the image is not to be moved, the flow proceeds to step S31. In step S31, it is checked whether the temperature of the write head has reached 25 ° C. or higher. If the temperature is equal to or higher than 25 ° C., a recovery operation determination [3] (a determination as to whether or not to perform the recovery operation based on the amount of ink evaporation in the non-capping state) is made in step S32, and a one-line portion is determined in step S33. Perform the recording operation. Then, in step S34, the recovery operation is determined [6].
(Determining whether to perform a recovery operation based on the wiping timing) is performed, and the sheet is conveyed in step S35.

In step S36, it is checked whether the recording operation has been completed. If completed, data such as the number of prints is written into the ROM of the head, and then the process proceeds to step S37. If not, the process returns to step S31. In step S37, it is checked whether or not to shift to the standby state.

Step S38 and subsequent steps are a routine for performing a discharge operation and a recovery operation determination after printing one sheet [4] (removal of print bubbles, removal of bubbles in the liquid chamber, cooling and recovery at abnormally high temperatures). In step S38, it is checked whether or not there is a sheet discharging operation. If there is no sheet discharging operation, the process waits for the temperature to drop to 45 ° C. or less in steps S39, S40, and S41. If the temperature does not fall within two minutes, the abnormality is stopped in step S42. If the temperature falls below 45 ° C., a wiping operation is performed in step S50, and
The idle ejection operation (N = 50) is performed in 43, and the next step S4
8. Capping is performed. If there is a paper ejection operation, step S
At 44, a paper discharging operation is performed. In step S45, it is checked whether continuous printing is performed. If continuous printing is performed, the recovery operation is determined in step S47 [4].
After that, the process returns to step S24. If it is not continuous printing,
A recovery operation determination [4] is performed in step S46, and after the determination, capping is performed in step S48 as in the case where there is no paper ejection. Then, in step S49, the fan is stopped, the process returns to step S9, and the copy operation ends.

FIG. 4 is a flowchart showing details of the initial jam check routine in step S3. This routine is a jam detection immediately after the power is turned on. Step S
In steps S201 to S204, a paper feed sensor, a paper discharge sensor, a paper float detection sensor, and a paper width sensor are used to check whether a recording sheet or the like is in the transport path or near the carriage. If so, it is determined that a jam has occurred and a warning is issued; otherwise, the process returns to the main flow. FIG. 5 is a flowchart showing details of the head information reading routine in step S5. In step S301, a head-specific serial number of the write head is read, and it is checked whether the value of the serial number is FFFFH (step S302). If the serial number is FFFFH, it is determined in step S304 that there is no head and an error occurs. If the serial number is not FFFFH, the color information of the head is read in step S303. Step S
At 305, it is checked from the color information whether the head is mounted at a regular position designated for each color. If the head is mounted correctly, the process proceeds to step S306, and if the head is erroneously mounted, the process proceeds to step S307.

In step S306, the remaining head information (print pulse width, temperature sensor correction value, number of prints, wiping count, etc.) is read and stored. Step S308
Then, it is checked whether the attached write head is new by comparing the serial number of the head.
The serial number of the head is always stored in the backup RAM and can be compared with the data read from the head. If both values are different, a new head will be installed,
If the values are equal, it can be determined that the head has not been replaced. In this embodiment, each of the colors Bk, C, M, and Y is performed. If the head is not a new head, the head information reading routine ends. If the head is a new head, the new head information is stored in the memory of the apparatus in step S309, and a flag (or data) indicating that the new head is mounted is set in the memory. Next, in step S310, the HS data (shading information) of the write head is read, and in step S311, the time at which the new head starts to be used is written from the clock in the apparatus to the non-volatile memory in the head, and the head information read routine ends.

Here, a method of using the head ROM will be described in detail. (Drive setting) The apparatus used in this embodiment uses a replaceable head (cartridge type), and has an advantage that the user can replace the head at any time. For this reason, fine adjustment of the device by a service person or the like cannot be expected. In addition, since the replaceable heads are supplied by mass production, individual heads have different characteristics due to variations in the manufacturing process such as the area of the heater board (HB), the resistance value, and the film structure. have. Therefore, in order to more stably obtain high image quality, it is necessary to correct variations in the above characteristics.

As a method of correcting such a difference in the setting of driving conditions for each head, correction by reading ROM information and density unevenness due to variation in the discharge amount within one head due to the distribution of the discharge hole diameter of the head are corrected. The method (reading of HS data) is performed.

When such correction is not performed for each head, among the ejection characteristics, the ejection speed, direction (landing accuracy), ejection amount (density), ejection stability (refill frequency,
(Unevenness) is not optimized. For this reason, not only is a stable image not obtained, but also a significant image disturbance occurs due to non-ejection or distortion during printing.

In particular, a full-color image is formed by four heads of cyan, magenta, yellow, and black. Therefore, even if one color is printed by a head having a discharge amount and a control characteristic different from a standard state, an image is formed. Cause trouble. Above all, the variation in the discharge amount is caused by a change in color and a decrease in color reproducibility (increase in color difference) due to a collapse of the overall color balance,
Image quality is degraded. Black, red, blue,
In a monochromatic image such as green, a density fluctuation occurs. In addition, the variation in the control characteristics changes the halftone reproducibility. Therefore, in this embodiment, these variations in the ejection characteristics are corrected.

First, the printing method in this embodiment will be described in detail. (Printing Method) In this embodiment, the head driving method and the printing method are characterized. For the head driving, a divided pulse width modulation (PWM) driving method is used. Vop is, as shown in FIG. 6, electric energy for providing electric energy necessary for generating heat energy on H.B.
And is determined by the area, resistance value, film structure of H and B, and the nozzle structure of the head. P1 is the preheat pulse width, P
2 indicates an interval time, and P3 indicates a main heat pulse width. T1, T2, and T3 are times from the rise of the preheat pulse, and are P1, P2, and P, respectively.
Indicates the time to decide 3.

The divided pulse width modulation driving method includes P1, P2,
A pulse is given in the order of P3. P1 is a pulse width for mainly controlling the ink temperature in the nozzle by a preheat pulse, and the pulse width of P1 is controlled by temperature detection using a temperature sensor of the head. At this time, pre-foaming phenomenon is prevented from occurring by applying too much heat energy to H and B.

P2 has an interval time so as to provide a predetermined time interval so that the preheat pulse P1 and the main heat pulse P2 do not interfere with each other, and has a function of making the temperature distribution of the ink in the nozzles uniform. P3 is a main heat pulse which causes a bubbling phenomenon on H.B to eject ink droplets from the nozzle holes. These pulse widths are determined by the area of H and B, the resistance value, the film structure, the nozzle structure of the head, and the physical properties of the ink.

In this embodiment, a head having a head structure as shown in FIG. 7 is used. Head temperature TH = 25.
In an environment of 0 (° C.), when Vop = 18.0 (V), P1
= 1.867 (μsec) and P3 = 4.114 (μsec)
When the pulse of (2) is given, the optimal driving condition is obtained, and a stable ink ejection state is obtained. The discharge characteristics at this time are as follows: ink discharge amount Vd = 30.0 ng / dot, discharge speed V
= 12.0 m / sec. Incidentally, the maximum driving frequency of the head is fr = 4.0 KHz, and 400 dp.
With a resolution of i, 128 nozzles are divided into 16 blocks and driven sequentially from 1 block. The head according to the present embodiment has a ROM in which characteristics of each head are recorded, and by reading this information into a main body, variations in characteristics of individual heads are corrected.

A method for correcting the variation in the ejection characteristics of each head and forming an optimum image will be described below. When the power is turned on to the main unit equipped with the head, the R
Information (ROM information) stored in the OM at the time of manufacturing the head
Into the main unit. At this time, head ID number, color information, TA1 (header driving condition table pointer corresponding to print pulse width), TA3 (PWM table pointer),
It reads information such as the temperature sensor correction value, the number of prints, and the number of times of wiping. The table pointer TA1 read here
Accordingly, the main body determines the value of the main heat pulse width: P3 in the divided pulse width modulation drive control method described later.

FIG. 8 shows the relationship between the table pointer: TA1 and the main heat pulse width: P3 obtained from TA1.

(1) Determination of TA1: When manufacturing the head,
The ejection characteristics of each head were measured in advance under standard driving conditions (head temperature: TH = 25.0 (° C.), driving voltage: Vop = 1).
At 8.0 (V), P1 = 1.87 (μsec) and P3 =
4.114 (μsec) pulse, the optimum driving conditions for each head are determined and stored as information in the ROM of the head.

(2) Drive condition setting: On the main body side, each pulse width at the time of divided pulse width drive Preheat pulse width: P 1,
Interval time width: P2, main heat pulse width:
In order to set P3, the times from the rise of the preheat pulse are set as T1, T2 and T3 as shown in FIG. 6, and the value of T3 (T3 = 8.602 μsec) is fixed from the beginning on the main body. Pulse width condition T2 given by the pointer read from the head: TA1 (for example, TA1 = 4.
488 .mu.sec), P3 (P3 = T3 -T2 = 4.
114 μsec).

As described above, the head driving condition setting table pointer TA1 stored in the ROM of the head is read as information, and the setting conditions (driving conditions) on the main body side are changed, so that the ejection characteristics of each head vary. Can be corrected, and color image quality can be easily stabilized even when a replaceable head is used.

(Correction Method by PWM) Here, in order to more effectively use the PWM control method which is a method for correcting an ejection amount variation for each head and performing an optimum image forming, which is used in the present embodiment. The method will be described.

The control conditions of the PWM are as follows. When the power is turned on, the main unit on which the head is mounted is stored in the ROM of the head.
The information is read together with the ID number, color, driving condition, and HS data. In this embodiment, a table pointer: TA3 is read as a PWM control condition. As described below,
The number TA3 is assigned a number corresponding to the head discharge amount (VDM), and the main body determines the upper limit value of the PWM preheat pulse width: P1 according to the read TA3.

Next, the correction method using PWM will be described in order.

(1) Determination of the table pointer TA3: The discharge amount of each head is measured in advance during the manufacturing process of the head during the manufacturing process under a standard driving condition (head temperature: TH = 25.0 (° C.). Voltage: P1 = 1 when Vop = 18.0 (V)
At 87 (μsec), a pulse of P3 = 4.114 (μsec) is applied. next,
The difference from the standard discharge amount: VD0 = 30.0 (ng / dot) is obtained as ΔV = VD0−VDM.

As shown in FIG. 9, the relationship between the value of ΔV and the table pointer: TA3 was determined from this ΔV. In this manner, the ranking is made according to the amount of the ejection amount, and the T
A3 is stored as information in each ROM.

When a table is created from .DELTA.V, it is necessary to make the change equal to .DELTA.VP for one table change of the preheat pulse width P1 which can be controlled by the divided pulse width modulation driving method described later. is there. That is, as described later, the ejection amount of the head is corrected by the preheat pulse width P1.

(2) Reading of a table pointer: A head having information stored in the ROM of the head is mounted on the main body of the ink jet recording apparatus as shown in (1) above, and is read when the power is turned on. The information stored in the head ROM is transferred to the SRA of the main unit in accordance with the sequence shown in FIG.
Store it in M.

(3) Determination of table for PWM control: In a head having a large discharge amount, the value of the preheat pulse width P1 at 25.0 DEG C. is set to the standard driving condition (P1 = 1.86).
7 .mu.sec) to reduce the ejection amount and approach the standard ejection amount VD0. 2. For a head having a small ejection amount, the value of the preheat pulse width P1 at 25.0 DEG C. is adjusted to the standard driving condition (P1 = 1.8).
67 [mu] sec) to increase the ejection amount to approach the standard ejection amount VD0. 3. In the above operation, as shown in FIG. 9, the relationship between the table pointer TA3 and the preheat pulse width P1 is determined in accordance with the ejection amount of each head, so that the standard ejection amount VD0 is always obtained. It has been set. 4. By such a method, the standard discharge amount VD0 (30.
0 ng / dot), it is possible to correct the variation in the discharge amount of ± 0.6 (ng / dot). As described above, by reading the PWM control table pointer TA3 as the ROM information of the head and changing the setting conditions (driving conditions) on the main body side, it becomes possible to absorb the variation in the discharge amount of each head, and replace the head. The color image quality can be easily stabilized even with a main unit using a possible head. Further, since the yield of the head can be improved, the cost of the cartridge head can be reduced.

Next, a discharge amount control method using the preheat pulse: P1 will be described in detail. Head temperature (TH
) Under certain conditions, preheat pulse width: P1 and discharge amount:
FIG. 10 shows the relationship with Vd. As shown in the figure, as the preheat pulse width P1 increases, it increases linearly up to P1LMT, after which the foaming of the main heat pulse P3 is disturbed by the prefoaming phenomenon, and the ejection amount becomes smaller than P1MAX. It shows a tendency to decrease.

Under a constant condition of the preheat pulse width: P1, the relationship between the head temperature TH (environmental temperature) and the discharge amount: VD increases linearly with the increase of the head temperature TH as shown in FIG. Show a tendency to. The coefficients of the regions exhibiting each linearity are the preheat pulse dependence coefficient of the ejection amount: KP = △ VDP / △ P1 (ng / μs · dot) The head temperature dependence coefficient of the ejection amount: KTH = △ VDT / △ TH ( ng / ° C. · dot).

In the head structure shown in FIG. 61, K P =
3.21 (ng / μsec · dot), KTH = 0.3 (n
g / μsec · dot). If these two relationships are effectively used as described below, the ink discharge amount of the head is always constant even if the head temperature changes due to various factors such as a change in environmental temperature or a change due to self-heating caused by printing. And a discharge amount control method that can maintain the discharge amount. FIG. 12 shows a state of the discharge amount control with respect to the head temperature in the relationship between the head temperature and the discharge amount. In FIG. 12, T
0 indicates a standard temperature, TL indicates a limit temperature of discharge amount control, and TC indicates a foaming limit temperature.

The discharge amount control is performed under the following three conditions. (1) TH.ltoreq.T0 The ejection amount compensation at low temperature is performed by controlling the temperature of the head. (2) T0 <TH≤TL Performed by controlling the discharge amount by the divided pulse width modulation method (PWM). (3) TL <TH (<TC) P1 = constant and non-controlled.

The state (1) is for securing a discharge amount mainly in a low temperature environment in the temperature control region of FIG. When the head temperature TH is 25.0 ° C. or less, the head temperature TH is kept constant at the controlled temperature T0 = 25.0 (° C.), so that T
The discharge amount VD0 when H = T0 = 30.0 (ng / dot)
Have gained. The reason for setting T0 to 25.0 ° C. is to minimize adverse effects due to ink viscosity increase due to temperature control, ink fixation, and temperature control ripple. The pulse width of P1 at this time is P1 = 1.867 .mu.sec.

The state (2) is the PWM area shown in FIG. 12, and the head temperature TH is set between 26.0 ° C. and 44.0 ° C. The sensor detects the temperature rise of the self-heating and the change of the environmental temperature by printing. Preheat pulse width P1
Is to change the value of P1 for each suitable range of the head temperature TH as shown in FIG.
Just follow Kens.

FIG. 13 (A) shows a case where the reference value of P1 is P1 = 0A, and the preheat pulse width P1 is changed by one step (1H) every 2.0 ° C. FIGS. 3B and 3C show that the reference value of P1 is P1 =
The case where 0B or P1 = 09 is shown.

In the case of following the sequence shown in FIG. 14, the operation is performed as follows. In this sequence, in order to prevent erroneous detection of the head temperature and perform more accurate temperature detection, the temperature (Tn-3, Tn-2, Tn-1) in the past three times and the newly detected temperature T
The average head temperature Tm with respect to n is determined as Tm = (Tn-3 + Tn-2 + Tn-1 + Tn) / 4, and the average value of the left and right sensors is determined.

In the next step, the value Tm is compared with the previously obtained head temperature Tm-1 by the following equation, and correction is performed as follows.

(1) In the case of | Tm−Tm−1 | ≦ ΔT (ΔT = 1 ° C. in this embodiment) The temperature change is within ± 1 ° C. and is shown in one table of FIG. The pulse width of P1 is not changed because the temperature is within the temperature range. (2) In the case of Tm-Tm-1> ΔT Since the temperature change is shifted to the high temperature side, the preheat pulse width P1 is reduced by 1H to narrow the pulse width. (3) In the case of Tm-Tm-1 <-ΔT Since the temperature change is shifted to the lower temperature side, the preheat pulse width P1 is increased by 1H to increase the pulse width.

FIG. 14 shows a flowchart of the above-described sequence. This flowchart is a part of the timer interrupt and enters this routine once every 20 ms. In step S401, the temperature of the head is read from the two left and right temperature sensors on the four-color head, and the average of the temperature data from the past three times is read by each sensor in step S401.
The calculation is performed at 402. Next, the average of left and right temperature data is obtained for each head. Then, at step S403, Tm and T
According to the relationship between m-1 and ΔT, in the above condition (3), P1 is increased by 1H in step S404, in the case of condition (1), P1 is kept in step S405, and in the case of condition (2), P1 is increased in step S406. By 1H. In the case of using the table as shown in FIG. 13 and the case of using the sequence as shown in FIG. 14, if the amount of change of P1 is increased by one correction, there is a possibility that density unevenness may occur. Therefore, even if the temperature change exceeds the correction range of one pointer, control is performed so that the amount of change of P1 becomes one pointer (1H in this embodiment) at one time.

When the sequence is used, the time required for changing one pointer during printing (feedback time) is TF = 20 msec. Therefore, it is possible to change the pointer about 40 times in one line (about 800 msec). Therefore, at most △ Tup =
It is possible to cope with a temperature rise of 19.0 ° C., and the occurrence of shading change is reduced in a wide temperature range. The four-time averaging is used for temperature detection to prevent erroneous detection due to sensor noise, etc., perform smooth feedback, minimize density fluctuations by control and minimize density fluctuations by serial printing. This is to make the (connection streaks) blind.

With this discharge amount control method, it is possible to control the target discharge amount within a range of ± 0.3 (ng / dot) from the target discharge amount VD0 = 30.0 (ng / dot) in the above temperature range. Become. By suppressing the discharge amount fluctuation within such a range, the density fluctuation occurring during printing of one sheet is about ±
This is suppressed to about 0.2, so that the occurrence of remarkable density unevenness and connecting streaks in the serial printing method does not cause a problem.

When the average number of temperature detections is increased, noise and the like become stronger, resulting in a smoother change. However, in real-time control, detection accuracy is impaired and accurate control cannot be performed. In addition, when the average number of temperature detections is reduced, the temperature is weakened to noise and the like, and a rapid change occurs. However, in real-time control, the detection accuracy is increased and accurate control is possible.

The state (3) is a non-control region and assumes a case where the head temperature TH is equal to or higher than 44.0 ° C. In the printing state, for example, when printing is continuously performed at 100% duty (printing at the highest ejection frequency), the head temperature may instantaneously reach this region. And the head drive conditions are set. In the event that this state occurs continuously, it is determined that a high temperature abnormal state has occurred and a recovery operation is performed to cope with the situation. Also, the pulse width of P1 is P1
= 0.187 μsec, the heating by the preheat pulse is suppressed, and the self-heating by printing is reduced as much as possible.

(Temperature Control) Next, the temperature control sequence will be described in detail. In the present embodiment, control is performed on the main body side using left and right sub-heaters located on the head side and left and right temperature sensors located near the ejection heater.
FIG. 15 shows the H.V. of the head used in this embodiment. 2 shows a schematic diagram of FIG. Temperature sensor 8e, sub heater 8
d, a discharge section row 8g in which discharge (main) heaters 8c are arranged, and drive elements 8h are formed on the same substrate in a positional relationship as shown in FIG. By arranging each element on the same substrate in this manner, the head temperature can be detected and controlled efficiently, and the head can be made compact and the manufacturing process can be simplified. FIG. The positional relationship of the outer peripheral wall section 8f of the top plate that separates B into a region filled with ink and a region not filled with ink is shown. As shown in the figure, the temperature sensor 8e is located closer to the ejection port than the outer peripheral wall 8f of the top plate, that is, a region filled with ink, and is located at a position close to the ejection port. This makes it possible to efficiently detect the head temperature near the ejection port.

The temperature is detected in the same manner as in the discharge amount control method.
The average value of the times is used. At this time, the head temperature TH is an average value of the temperature TR detected from the right sensor and the temperature TL detected from the left sensor (TH = (TR + T
L) / 2) is used. The temperature is controlled by supplying a current to the sub-heater on the head side based on the detected temperature. The temperature control method is basically an ON / OFF method. That is, the maximum power (1.2 W each on the left and right sides) is applied until the target temperature T0 = 25.0 ° C. is reached, the current is cut off when the target temperature is reached, and the current is passed when the temperature falls.
The ON / OFF timing is performed every 40 msec. Increasing this timing increases the width of the ripple and extends the cycle. Further, when this timing is shortened, the width of the ripple is reduced and the cycle is shortened. According to this method, the temperature control ripple width at the target temperature is about 2 ° C., but since temperature detection by averaging four times is used, there is almost no influence on the discharge amount control by the temperature control ripple. If necessary, an expensive control method such as PID control may be used.

FIG. 16 is a flowchart of the initial 20 ° C. temperature control routine. In step S2001, set the timer counter to 3
After setting for 0 seconds, if the temperature is higher than 20 ° C., the routine ends (step S2002). If the temperature is lower than 20 ° C., the heater of the head is turned on in step S2003. In step S2004, it is checked whether the timer has expired for 30 seconds. If 30 seconds have elapsed, the operation is abnormally stopped in step S2005. If not, the process returns to step S2002.

FIG. 17 is a flowchart of the 20 ° C. temperature control and the 25 ° C. temperature control routine. In step S2101, it is checked whether the head temperature is higher or lower than 20 ° C. If the temperature is higher than 20 ° C., the heater of the head is turned on in step S2102.
If FF is performed and the temperature is lower than 20 ° C., the heater of the head is turned on in step S2103, and the 20 ° C. temperature control routine ends. Step S2 in the 25 ° C. temperature control routine
Steps S104 to S2106 are the same as steps S2101 to S2103 in the 20 ° C. temperature control routine, and thus description thereof is omitted.

(HS Table) Here, a method for effectively utilizing the HS control method used in this embodiment will be described. In this embodiment, since a replaceable head (cartridge type) is used, the head can be replaced at any time by the user, so that fine adjustment by a service person or the like cannot be expected. In addition, since the cartridge head is manufactured by mass production, it has characteristics peculiar to each head, and the ejection within one head due to variations in the manufacturing process such as the H / B area, the resistance value, the film structure, and the nozzle formation. Since a characteristic distribution and a distribution of the discharge hole diameter occur, a method for correcting the density unevenness due to the discharge amount variation is required.

A method for correcting the variation in the ejection amount in one head and performing the optimum image formation without unevenness will be described below. When the power is turned on, the R
The table THS is read as HS data together with the ID number, color, and driving conditions as OM information. This table THS
Is copied on the main unit side.

The determination of THS is performed as follows. The HS data is calculated in advance by measuring the diameter distribution of each head under standard driving conditions in the head manufacturing process, and a table of the calculation results is stored as ROM information of the head.

As described above, the HS data table THS
Is read as the ROM information of the heads, so that the unevenness of each head can be corrected on the main body side, thereby making it possible to absorb the density unevenness due to the variation in the discharge amount of each head. Therefore, it is possible to easily stabilize color image quality even in a main body using a replaceable head. (One-Line Printing Operation) FIG. 18 is a flowchart showing details of the one-line printing routine in step S24.
First, print control is performed in step S2501. In step S2502, the moving amount of the carriage is set. In step S2503, the carriage is advanced, and in step S25
At 04, the timer is set. In step S2505, a paper floating check is performed, and if paper floating is detected, step S25 is performed.
It becomes jam at 06.

In step S2509, it is checked whether the motor has stopped. If the motor is stopped, step S251
If the motor is running, the timer is checked in step S2511. If the time has elapsed, an error occurs in step S2512. If the time has not elapsed, the process returns to step S2505.

In step S2513, a timer is set, and in step S2514, the start position movement of the carriage is started. In step S2515, one line is printed and a counter is added. In step S2516, it is checked whether the motor has stopped. If the motor has stopped, the one-line printing routine ends. If the motor is running, the timer is checked in step S2517.
If the time has elapsed, an error occurs in step S2518. If the time has not elapsed, step S2516 occurs.
Return to

FIG. 19 shows the flow of the print control routine of step S2501 in FIG. In step S2601, it is checked whether the mode is the RHS mode. If the mode is the RHS mode, the process proceeds to the print control [1] in step S2602. If the mode is not the RHS mode, the process proceeds to step S2605. Step S2605
To check if it is in OHP mode. If the mode is the OHP mode, the process proceeds to step S2607; otherwise, the process proceeds to step S2608.

In step S2607, it is checked whether the mode is the reduction mode. If the mode is the reduction mode, the process proceeds to print control [4] in step S2609; otherwise, the process proceeds to print control [5] in step S2610. In step S2608, it is checked whether the mode is the reduction mode. If the mode is the reduction mode, the process proceeds to print control [6] in step S2611, and if not, the process proceeds to print control [7] in step S2612.

FIG. 20 shows print control in reduced print mode [6].
The flow of is shown. As print control, head digit control, ink ejection force control, and head timing control are performed. Here, the head digit control will be described in detail.

The number of nozzles of the recording head is 128. The head digit control controls ON / OFF of the nozzles of the head in units of eight nozzles. These eight nozzle units are digitized. FIG. 22 is an explanatory diagram thereof. For example, digit 1 is composed of nozzles 1 to 8, and digit 16 is composed of nozzles 121 to 128. There are 16 digits to be controlled by one head.

FIG. 21 shows the flow of the head digit control [6] routine, and FIG. 22 is an explanatory diagram. In this routine, when the carriage performs A4 size recording at the time of reduced printing, 65 lines of one-line printing are performed, and therefore, each digit is controlled 65 times. At the time of odd-numbered one-line printing (steps S2801 and S2802),
In step S2805, ink is ejected from the nozzle 1 to the nozzle 64, and ink is not ejected from the nozzle 65 to the nozzle 128.

When the even-numbered one-line printing is performed (step S2801), the nozzle 6 is printed in step S2803.
No. 5 to the nozzle 128 are ejected, and no ink is ejected from the nozzle 1 to the nozzle 64. In the 65th one-line printing of the final printing, the ink from the nozzles 81 to 128 is ejected in step S2804.

FIG. 23 shows the flow of the print control [1] routine in the RHS print mode. As print control, head digit control, ink ejection force control, and head timing control are performed. Here, head digit control and head timing control will be described. The description of the ink ejection force control is omitted.

FIG. 24 is a flowchart of the head digit control [1] routine in the RHS print mode, and FIG. 25 is an explanatory diagram thereof. In this routine, the carriage performs 12-line 1-line printing at the time of RHS printing, and therefore controls each digit. 3n + 1 times (n = 0, 1, 2,
3) In the case of one-line printing (step S3101),
In step S3102, digits 13 to 16 (nozzle 9
7 to the nozzle 128).

In the case of 3n + 2nd one-line printing (step S3103), digit 1 to digit 16 (nozzle 1 to nozzle 128) are set in step S3104.
Up to discharge. For other (3n + 3rd) one-line printing, digit 1 to digit 4 (nozzle 1 to nozzle 39) are ejected in step S3105.

FIG. 26 is a flowchart of the head timing control [1] routine in the RHS print mode.

The printing pattern of Bk, C, M, Y is
It is set so that printing is performed in an area as shown in FIG.
Although a specific description of the timing control is omitted, FIG. 27 shows a comparison diagram with the normal print timing. FIG.
FIG. 27A shows the print timing in a print mode other than the RHS print mode, and FIG. 27B shows the RHS print timing.

The print control at the time of OHP printing is the print control [5].
It is. The flow of this print control [5] routine is shown in FIG.
It is. FIG. 30 shows the head digit control [5] and FIG. 31 shows the head nozzle control [5], and the head digit control [5] and the head nozzle control [5] will be described. In this routine, the carriage scans the same area twice to thin out and prints out the same area for recording on OHP paper. For this reason, since the carriage performs one-line printing 66 times when printing on the A4 size, the digit control is performed 66 times.

In FIGS. 30 and 31, in the odd-numbered one-line printing, only the odd nozzles from nozzle 1 to nozzle 128 (step S3703) are driven (step S3802) to eject ink. In the case of even-numbered one-line printing, only the even-numbered nozzles from nozzle 1 to nozzle 128 (step S3703) are driven (step S3803) to eject ink. In the 65th one-line printing, only the odd nozzles from the nozzle 81 to the nozzle 128 (step S3702) are driven (step S3802) to discharge ink. In the 66th one-line printing, only the even-numbered nozzles from the nozzle 81 to the nozzle 128 (step S3702) are driven (step S3803) to eject ink. 32 and 33
FIG.

The printing control at the time of OHP reduced printing is printing control [4]. FIG. 34 shows the flow of this print control [4] routine. FIG. 35 shows the head digit control [4].
FIG. 36 shows the head nozzle control [4], and the head digit control [4] and the head nozzle control [4] will be described. In this routine, the carriage scans the same area four times to record on an OHP sheet and thins out and prints. For this reason, when the A4 size recording is performed, the carriage performs one-line printing 130 times, so that each digit control is performed 130 times.

4n + 1 times (n = 0, 1,...) 1
At the time of line printing, nozzles 1 to 64, that is, from digit 1 to digit 8 (step S42)
05) Only the odd-numbered nozzles are driven (step S4302)
Then, the ink is ejected. 4n + 2nd time (n = 0, 1,
..), Only the even-numbered nozzles from nozzle 1 to nozzle 64 are driven (step S430).
3) Then, the ink is ejected. 4n + 3rd time (n = 0,
1, 1), the nozzles 65 to 128, that is, from the digit 9 to the digit 16 are printed.
Only the odd nozzles up to (Step S4202) are driven (Step S4302) to eject ink. 4n
In the + 4th (n = 0, 1,...) One-line printing, only the even-numbered nozzles from the nozzle 65 to the nozzle 128 are driven (step S4303) to eject ink. 37 and 38 are explanatory diagrams thereof.

In the 129th one-line printing, only the odd nozzles from nozzle 81 to nozzle 128, that is, from digit 11 to digit 16 (step S4204) are driven (step S4302) to discharge ink. In the 130th one-line printing, only the even-numbered nozzles from nozzle 81 to nozzle 128 are driven (step S
4303) and eject ink. FIG. 39 is an explanatory diagram thereof.

(Control Configuration) Next, a control configuration for executing the above-described recording control flow will be described with reference to FIG. In the figure, 60 is a CPU, 61 is a CP.
A program ROM for storing a control program to be executed by the U60, and a backup RAM 62 for storing various data. 63 is a main scanning motor for transporting the recording head, and 64 is a sub-scanning motor for transporting the recording paper, which is also used for a suction operation by a pump. 65 is a wiping solenoid, 66 is a paper feed solenoid used for paper feed control, 67 is a cooling fan, and 68 is a paper width detection LED that is turned on during the paper width detection operation. 69 is a paper width sensor, 70 is a paper floating sensor, 71 is a paper feed sensor, 72 is a paper discharge sensor, and 73 is a suction pump position sensor for detecting the position of the suction pump. 74 is a carriage HP sensor that detects the home position of the carriage, 75 is a door open sensor that detects opening and closing of a door, 76 is a manual feed button sensor that detects pressing of a manual feed button, and 77 is an OHP button sensor that detects pressing of an OHP button It is.

Reference numeral 78 denotes a gate array for controlling the supply of print data to the four color heads, 79 denotes a head driver for driving the head, 8a denotes an ink cartridge for four colors,
Reference numeral 8b denotes a recording head for four colors, and here, 8a and 8b
As a representative of black (Bk). The ink cartridge 8a has an ink remaining amount sensor 8f for detecting the remaining amount of ink. The head 8b includes a main heater 8c for discharging ink, a sub-heater 8d for controlling the temperature of the head, and a head temperature sensor 8 for detecting the head temperature.
e, a ROM 854 for storing head characteristic information.

FIG. 41A is a view showing the appearance of the ink jet cartridge of this embodiment. FIG. 2B is a diagram showing details of the printed board 85 of FIG. 1A. In FIG. 41B, reference numeral 851 denotes a printed circuit board;
Reference numeral 852 denotes an aluminum heat radiating plate, 853 denotes a heater board including a heating element and a diode matrix, 854 denotes an EEPROM (non-volatile memory) storing density unevenness information and the like in advance, and 855 denotes a contact electrode serving as a joint portion with the main body. is there. Here, the line-shaped discharge port group is not shown.

As described above, the ink jet recording head 8
An EEPROM 854 for storing density unevenness information and the like unique to each recording head is mounted on a printed circuit board 851 including a heating element b and a drive control unit b. In this way, when the recording head 8b is mounted on the main unit, the main unit reads information on recording head characteristics such as density unevenness from the recording head 8b, and performs predetermined control for improving recording characteristics based on this information. I do. This makes it possible to ensure high quality image quality.

FIGS. 42A and 42B are diagrams showing a circuit configuration of a main part on the printed board 851 of FIG. here,
The circuit configuration inside the heater board 853 is indicated by a dashed-dotted frame, and the heater board 853 includes an N-series circuit of a heating element 857 and a diode 856 for preventing current from flowing around.
It has a matrix structure of × M (here, 16 × 8). That is, these heating elements 857 are driven in a time-division manner for each block as shown in FIG. 43, and the control of the supply amount of the driving energy is performed by changing the pulse width (T) applied to the segment (seg) side. This is achieved by controlling

FIG. 42 (B) shows the EEPROM of FIG. 41 (B).
FIG. 8 is a diagram illustrating an example of M854, in which information on density unevenness and the like according to the present embodiment is stored. These pieces of information are output to the main unit by serial communication in response to a request signal (address signal) D1 from the main unit. An overall description of an apparatus to which the present invention can be applied will be given.

FIG. 44 is an explanatory perspective view of the structure of this embodiment, and FIG.
5 is a cross-sectional explanatory view thereof. First, the overall configuration will be described. This apparatus includes a reading device R and a recording device P.

In the configuration of the reading device R, the reading means 1 is provided on the reading carriage 2, and the carriage 2 is configured to be able to reciprocate in the main scanning direction (the direction of arrow a). The carriage 2 is attached to a reading unit 3 so that the unit 3 can reciprocate in the sub-scanning direction (the direction of arrow b).

Accordingly, when the original 5 is placed on the original platen glass 4 attached to the upper surface of the apparatus, with the original side down, the original 5 is fixed and set with the cover 6 and the copy switch (not shown) is pressed. Moves in the main scanning direction, reads one line of the original, and transmits the information to a control system (not shown) via the signal cable 7. When reading of one line is completed as described above, the carriage 2 is returned to the home position, and the reading unit 3 is moved by one line in the sub-scanning direction, and reads the next line and below in the same manner as described above. .

Further, the configuration of the recording apparatus P is such that the recording means 8 is mounted on the recording carriage 9 and the recording sheet 11 is conveyed to the position of the recording means 8 by the sheet conveying means 10.

Therefore, when the read signal from the reader R is transmitted via the signal cable 7, the recording sheet 11
Is conveyed in the direction of arrow c by the conveying means 10, and the sheet 11
Is transported to the recording position, the recording carriage 9
3, the recording means 8 is driven in accordance with the image signal in synchronism with the movement, and the recording sheet 1 is moved.
1 to record an image. When the recording for one line is completed, the recording sheet 11 is conveyed by one line in the direction of arrow c to perform the recording similarly, and the recorded sheet 11 is discharged to the discharge tray 12.

Here, the bottom of a part of the reading unit 3 is configured to protrude so as to be lower than the highest part of the recording device P,
One end of the signal cable 7 is connected and fixed to this portion.

FIG. 46 is a schematic perspective view of the ink jet recording apparatus. In the figure, a recording sheet 11 is transported by a transport roller 10c, 1 driven by a stepping motor.
0d. Reference numeral 8a denotes black, cyan, magenta, and yellow ink cartridges.
b (not shown) is attached. Recording head 8b
Is mounted on the carriage 9, and driven by the carriage motor, the main scanning rail 9a via the belt 9c and the pulley.
Is configured to scan reciprocally along. With the above configuration, ink is ejected onto the recording sheet 11 while the recording head 8b moves to form an image. If necessary, the ink recovery system unit (cap unit 30)
0, pump unit 500, etc.) to eliminate nozzle clogging.

(Head Temperature Correction) Next, the characteristic portion of this embodiment will be described in detail. In this embodiment, as described above, at the time of normal printing, the average value of the left and right (TH = [THL + THR] / 2) is used as the head temperature TH for head drive control. Further, at the time of the last line printing or reduced printing, the corrected temperature TH ′ = (XTHL + YTHR) / (X + Y) calculated by weighting the temperatures detected by the left and right temperature sensors according to the position and number of nozzles to be used. Based on this configuration, the drive of the head is controlled.

When only the left half of the head nozzle is used, the head temperature shows a temperature distribution as shown in FIG.
This tendency becomes more remarkable as the print duty becomes higher. During printing, the left temperature sensor always indicates a high temperature, and the right temperature sensor always indicates a low temperature. When the head is driven using the head temperature TH measured in this state, the temperature THL (THL> THL) of the actually ejecting nozzle portion is obtained.
In order to perform control at a temperature lower than H), control for increasing the discharge amount, that is, control for increasing the pulse width of the preheat pulse P1 is performed. Normally, the control must work so as to reduce the discharge amount, so that the control diverges. Further, as the pulse width of the preheat pulse P1 becomes longer, the temperature rise due to ejection becomes larger, so that the temperature difference between the left and right becomes even greater.

Therefore, in this embodiment, in order to eliminate the vicious circle described above, the corrected temperature TH '= calculated by weighting the temperatures detected by the left and right temperature sensors as described above.
It is controlled by (XTHL + YTHR) / (X + Y). Here, when discharging by the above left half nozzle, X =
4, the main unit is set in advance so that Y = 1. For example, when printing at a print duty of 50%, the temperature detected in the first line is THLMAX = 40 ° C., THRMAX =
In the case of 30 ° C., (1) In the normal control, the pulse width control of the preheat pulse P1 is controlled based on TH = (40 + 30) / 2 = 35 ° C., so the difference from THLMAX is 5 ° C. Become. (2) In the control of this embodiment, since the pulse width control of the preheat pulse P1 is controlled based on TH '= (160 + 30) / 5 = 38 ° C., the difference from THLMAX is 2 ° C. The difference is reduced. Therefore, more accurate head drive control can be performed.

(Second Embodiment) Next, a second embodiment of the present invention will be described. In this embodiment, a head temperature correction is performed for temperature control during head driving, and a case where the present invention is applied to a monochrome printer will be described.

In this apparatus, when printing the head temperature TH, the average value of three times each of the left sensor and the right sensor (THL =
[THLN-2 + THLN-1 + THLN] / 3) is used for drive control of the right and left temperature control sub-hitters of the head.
At this time, the temperature difference detected by the left and right temperature sensors is detected according to the position and number of nozzles to be used, and the power given to the sub-heater is weighted to control the power so as to eliminate the temperature distribution. is there.

When using only the left half of the head nozzle,
The head temperature has a temperature distribution as shown in FIG. 47 described above. This tendency becomes more remarkable as the print duty becomes higher. During printing, the left temperature sensor always indicates a high temperature, and the right temperature sensor always indicates a low temperature. By driving the sub-heater in consideration of the head temperature difference ΔTH measured in this state, that is, the head temperature THL on the side of the discharging nozzle portion (left half) is low considering the head temperature difference ΔTH. Set the temperature control temperature to lower the power of the sub-heater, and the nozzle part not discharging (right half)
The head temperature THR is set to a high temperature in consideration of the head temperature difference ΔTH, and the power is increased to eliminate the left and right temperature distribution.

As described above, the difference between the temperatures detected by the left and right temperature sensors is detected, and the power is controlled by weighting the left and right sub-heaters. In the case of performing the discharge by the left half nozzle described above, the temperature control before printing is started at TH = 35 ° C., and when the printing duty 50% is printed, if the temperature detected in the first line is THLMAX = 45 ° C. and THRMAX = 35 ° C.
ΔTH = (THLMAX−THRMAX) = 10 ° C. (1) In normal control, the left target temperature control temperature THL = 35 ° C. The right target temperature control temperature THR = 35 ° C. Do not change. (2) In the control of the present embodiment, the target temperature regulation temperature THL on the left side is TH-TH- △ TH / 2 = 30 ° C. The target temperature regulation temperature THR on the right side is TH + TH + △ TH / 2 = 40 ° C. Is changed according to the difference from the true temperature, so that the temperature difference between right and left printing is controlled to be small. In this method as well, a table corresponding to the position and the number of nozzles used for printing is made to correspond to ΔTH in advance in the main body, and is controlled.

(Third Embodiment) Next, a third embodiment of the present invention will be described. In this embodiment, of the head driving, P
A description will be given of a case in which head temperature correction is performed for WM control and is applied to a color copying machine. The configuration of this embodiment is basically the same as that of the first embodiment.

Since the color copier drives the printer unit in accordance with the image signal sent from the reader, the relationship between the print area and the print width of the head is not always a positive multiple of the print width. Printing must be done with an odd nozzle. Also, the serial printing type ink jet recording apparatus is designed so that the paper feeding accuracy is stable at the normal feeding (head width). For this reason, if the paper feed is changed, especially at the time of reduction, the feed accuracy is reduced, and a connecting streak is generated to disturb the image. Therefore, printing is performed twice for each paper feed.
Pass printing is enabled. In such a case, it is necessary to change the number of ejection nozzles of the head for printing. For example,
At the time of 50% reduction, 2-pass printing is performed by using the left and right 64 nozzles alternately.

Therefore, in the third embodiment, a control method for changing the drive pulse (for example, for each block) is performed based on the left-right temperature difference ΔTH detected by the right and left temperature sensors.
In this device, the head temperature: TH is averaged three times for each of the left and right sensors during printing (THL = [THLN-
2 + THLN-1 + THLN] / 3) is used for head drive control. At this time, a temperature difference detected from the left and right temperature sensors is detected according to the position and the number of nozzles to be used, and drive control is performed so as to weight the drive pulse given to the head and eliminate the temperature distribution. .

When only the left half of the head nozzle is used, the head temperature shows a temperature distribution as shown in FIG. This tendency becomes more remarkable as the print duty becomes higher. During printing, the left temperature sensor always indicates a high temperature, and the right temperature sensor always indicates a low temperature.
By driving the head in consideration of the head temperature difference ΔTH measured in this state, that is, a short pulse is set as the head driving pulse P1L on the side of the nozzle section (left half) which is discharging, and the discharge amount is reduced. By setting a long pulse for the head drive pulse P1R on the nozzle portion side (right half) that is not discharging and discharging, and raising the discharge amount (raising the temperature),
The left and right discharge amount (temperature) distribution is eliminated. The same applies when only the right half of the head nozzle is used. FIG. 48 shows a pulse waveform during PWM control.

As described above, the difference between the temperatures detected by the right and left temperature sensors is detected, and the left and right drive blocks are weighted to perform power control. In the case of performing the ejection by the left half nozzle, the driving pulse P1 is 1.87 μsec, the temperature control before printing TH is 25 ° C., and the printing duty is 50%.
The temperature detected on the first line when
If X = 45 ° C. and THRMA = 35 ° C., ΔTH = (THLMAX−THRMAX) = 10 ° C. (1) Under normal control, the left preheat pulse width P1L = P1 μsec The right preheat pulse width P1R = P1 μsec and the control before printing is not changed. That is, control is performed by P1. (2) In the control of this embodiment, ΔP1 = P1 · ΔTH / 20 ° C., and the preheat pulse width P1L on the left side = (P1−ΔP1) μs
ec Right preheat pulse width P1R = (P1 + △ P1
) As μsec, the driving conditions are changed depending on the temperature difference between the left and right sides, and control is performed so as to reduce the difference in the ejection amount due to the left and right printing. That is, control is performed by (P1 ± △ P1).

When ΔTH = 20 ° C. or more, control is impossible and an error occurs. Further, in the third embodiment, the preheat pulse is supplied to the non-ejection nozzle to increase the temperature. However, the control may be such that the preheat pulse is not supplied to the non-ejection nozzle.

(Others) It should be noted that the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for performing ink ejection, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical structure and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, liquid (ink)
By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding nucleate boiling, to the electrothermal transducer disposed corresponding to the sheet or the liquid path in which is held, This is effective because thermal energy is generated in the electrothermal transducer, and the film is boiled on the heat-acting surface of the recording head. As a result, bubbles in the liquid (ink) can be formed in one-to-one correspondence with the drive signal. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. Examples of the drive signal in the form of a pulse include those described in U.S. Pat.
Suitable are those described in US Pat. No. 45,262. If the conditions described in U.S. Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,558,333 which disclose a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of Japanese Patent No. 459600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication (Kokai) No. 123670/1984 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing pressure waves of thermal energy. The present invention is also effective as a configuration based on JP-A-59-138461 which discloses a configuration corresponding to a discharge unit.

Further, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, a combination of a plurality of recording heads as disclosed in the above specification is used. Either a configuration that satisfies the length or a configuration as one integrally formed recording head may be used, but the present invention can more effectively exert the above-described effects.

In addition, the print head is replaceable with a print head of a replaceable chip type, which can be electrically connected to the main body of the apparatus or supplied with ink from the main body of the apparatus, or is integrated with the print head itself. The present invention is also effective when a cartridge-type recording head provided in a fixed manner is used.

It is preferable to add recovery means for the recording head, preliminary auxiliary means, and the like provided as components of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. To be more specific, a capping unit, a cleaning unit, a pressure or suction unit, a preheating unit using an electrothermal converter, another heating element, or a combination thereof, for the recording head. ,
Performing a preliminary ejection mode in which ejection is performed separately from printing is also effective for performing stable printing.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but may be a single recording head or a combination of plural recording heads. The present invention is also very effective for an apparatus provided with at least one of full colors by color mixture.

In the embodiments of the present invention described above, the description is made using the liquid ink. However, in the present invention, the ink which is solid at room temperature or the ink which becomes soft at room temperature is used. Can be used. In the above-described ink jet apparatus, the temperature of the ink itself is generally controlled within a range of 30 ° C. or more and 70 ° C. or less so that the viscosity of the ink is controlled to be in a stable ejection range. It is sufficient if the ink is in a liquid state.
In addition, positively prevent the temperature rise due to thermal energy by using the energy of the state change of the ink from the solid state to the liquid state, or use ink that solidifies in a standing state to prevent evaporation of the ink. In any case, heat energy is applied by heat energy, such as one in which ink is liquefied and ejected as an ink liquid by application of heat energy according to a recording signal, or one which already starts to solidify when reaching a recording medium. The use of an ink that liquefies for the first time is also applicable to the present invention. In such a case, as described in JP-A-54-56847 or JP-A-60-71260, the ink is held as a liquid or solid substance in the concave portion or through hole of the porous sheet, It is good also as a form which opposes an electrothermal transducer. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

[0123]

According to the present invention, in an ink jet recording apparatus utilizing thermal energy, a head is driven based on a temperature obtained by calculating from outputs of a plurality of temperature sensors in accordance with the number of nozzles used in the head. By changing the control (temperature control method, drive pulse, etc.), it is possible to eliminate the temperature distribution of the head and reduce the variation in the ejection amount. As a result, it is possible to eliminate the occurrence of density unevenness and connecting streaks, and to stabilize the density and color balance at the time of final line printing or reduced printing.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating main control of an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart showing main control of the ink jet recording apparatus according to one embodiment of the present invention.

FIG. 3 is a flowchart showing main control of the ink jet recording apparatus according to one embodiment of the present invention.

FIG. 4 is a flowchart showing details of an initial jam check routine of step S3.

FIG. 5 is a flowchart showing details of a head information reading routine in step S5.

FIG. 6 is an explanatory diagram of a divided pulse width modulation driving method.

FIG. 7 is an explanatory diagram of a head structure used in the present embodiment.

FIG. 8 is a diagram showing a relationship between table pointers TA1 and a main heat pulse width P3 obtained from TA1.

FIG. 9 shows a table pointer TA3 and a preheat pulse width P.
FIG. 2 is a diagram illustrating a relationship of FIG.

FIG. 10 is a diagram showing a relationship between a preheat pulse width P1 and a discharge amount VD.

FIG. 11 is a diagram showing a relationship between a head temperature TH and a discharge amount VD.

FIG. 12 is a diagram illustrating a state of discharge amount control with respect to a head temperature in a relationship between a head temperature and a discharge amount.

FIG. 13 is a diagram showing a relationship between a head temperature TH and a preheat pulse width P1.

FIG. 14 is a diagram showing a sequence for setting a preheat pulse width P1.

FIG. 15 is a diagram showing a positional relationship among a temperature sensor, a sub heater, and a discharge (main) heater of a head used in this embodiment.

FIG. 16 is a flowchart of an initial 20 ° C. temperature control routine.

FIG. 17 is a flowchart of a 20-degree temperature control and a 25-degree temperature control routine.

FIG. 18 is a flowchart showing details of a one-line printing routine in step S24.

FIG. 19 is a flowchart of a print control routine of step S2501 in FIG. 18;

FIG. 20 is a flowchart of a print control [6] routine in a reduced print mode.

FIG. 21 is a flowchart of a head digit control [6] routine.

FIG. 22 is an explanatory diagram of head digit control [6].

FIG. 23 is a flowchart of a print control [1] routine in the RHS print mode.

FIG. 24 is a flowchart of a head digit control [1] routine in the RHS print mode.

FIG. 25 is an explanatory diagram of head digit control [1] in the RHS print mode.

FIG. 26 is a flowchart of a head timing control [1] routine in the RHS print mode.

FIG. 27 is a diagram showing print timing.

FIG. 28 is a diagram showing an area where a print pattern of Bk, C, M, and Y is printed.

FIG. 29 is a flowchart of a print control [5] routine during OHP printing.

FIG. 30 is a flowchart of a head digit control [5] routine.

FIG. 31 is a flowchart of a head nozzle control [5] routine.

32 is an explanatory diagram of nozzle driving performed by head digit control [5] in FIG. 30 and head nozzle control [5] in FIG. 31.

33 is an explanatory diagram of nozzle driving performed by head digit control [5] in FIG. 30 and head nozzle control [5] in FIG. 31.

FIG. 34 is a flowchart of a print control [4] routine during OHP reduced printing.

FIG. 35 is a flowchart of a head digit control [4] routine.

FIG. 36 is a flowchart of a head nozzle control [4] routine.

FIG. 37 is an explanatory diagram of nozzle driving performed by head digit control [4] of FIG. 35 and head nozzle control [4] of FIG. 36;

38 is an explanatory diagram of nozzle driving performed by head digit control [4] of FIG. 35 and head nozzle control [4] of FIG. 36.

39 is an explanatory diagram of nozzle driving performed by head digit control [4] in FIG. 35 and head nozzle control [4] in FIG. 36.

FIG. 40 is a block diagram showing a control configuration for executing a recording control flow.

FIG. 41 is a diagram illustrating an ink jet cartridge according to the present embodiment.

FIG. 42 is a diagram illustrating a circuit configuration of a main part on a printed board 851.

FIG. 43 is a timing chart for driving the heating element 857 in a time-division manner for each block.

FIG. 44 is a configuration perspective explanatory view of the present embodiment.

FIG. 45 is an explanatory sectional view of the present embodiment.

FIG. 46 is a schematic perspective view of an ink jet recording apparatus.

FIG. 47 is an explanatory diagram showing a temperature distribution of a head temperature.

FIG. 48 is a waveform diagram showing a pulse waveform during PWM control.

[Explanation of symbols]

 P recording device R reading device HP home position SP start position 1 reading means 2 reading carriage 3 reading unit 8 recording means 8a ink cartridge 8b print head 8c ejection (main) heater 8d sub heater 8e Temperature Sensor 9 Recording Carriage 9a Main Scan Rail 9b Driving Pulley 9c Timing Belt 9d Recording Carriage Motor 10 Sheet Conveying Means 60 CPU 853 Heater Board 854 EEPROM

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoshiaki Takayanagi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A 1-290437 (JP, A) JP-A Hei 1 JP-A-299045 (JP, A) JP-A-62-5856 (JP, A) JP-A-60-125675 (JP, A) JP-A-62-41047 (JP, A) JP-A-3-272854 (JP, A) (58) Fields surveyed (Int. Cl. ⁶ , DB name) B41J 2/05 B41J 2/125 B41J 2/175

Claims (10)

(57) [Claims] 1. An ink jet head comprising: a plurality of ejection heaters arranged for ejecting ink; and a plurality of temperature sensors for detecting temperatures arranged along an arrangement direction of the plurality of heaters. In an ink jet recording apparatus for performing recording by discharging ink from the ink jet head by driving the plurality of discharge heaters, a temperature is detected by each of the plurality of temperature sensors, and the plurality of temperature sensors are detected based on the detected temperatures. Determining means for determining the driving conditions of the discharge heaters, and recording control means for performing printing by driving the plurality of discharge heaters based on the driving conditions determined by the determining means. The plurality of ejection heaters used for printing among the plurality of ejection heaters arranged in accordance with the position and the number of the ejection heaters on the arrangement. An ink jet recording apparatus which calculates a temperature detected by each of the temperature sensors and determines a driving condition of the discharge heater based on the temperature obtained by the calculation. 2. The ink jet recording apparatus according to claim 1, wherein said determining means determines a width of a driving signal supplied to said discharge heater as said driving condition. 3. The driving signal according to claim 2, wherein the driving signal is composed of a plurality of divided pulses, and a width of at least one of the plurality of pulses is determined based on a temperature detected by the temperature sensor. 3. The ink jet recording apparatus according to 2. 4. The method according to claim 1, wherein the determining unit weights the temperature detected by the plurality of temperature sensors according to a position and a number of the ejection ports used for recording on the array. 2. The ink jet recording apparatus according to claim 1, wherein a driving condition of the discharge heater is determined. 5. The ink jet recording apparatus according to claim 1, wherein said plurality of discharge heaters and said plurality of temperature sensors are formed on a same chip. 6. An ink jet head comprising a plurality of ejection heaters for ejecting ink, a plurality of temperature control heaters for temperature adjustment, and a plurality of temperature sensors for detecting temperature, wherein said plurality of temperatures are used. An ink jet recording apparatus that determines a driving condition for the discharge heater based on a temperature detected by a sensor, wherein a temperature is detected by each of the plurality of temperature sensors, and a driving condition of the plurality of temperature control heaters is determined based on the detected temperature. Determining means for determining; and temperature control control means for adjusting the temperature of the inkjet head by driving the plurality of temperature control heaters based on the driving conditions determined by the determining means. The plurality of temperature sensors and the plurality of discharge heaters used for printing based on the position and the number of the discharge heaters used for recording among the plurality of discharge heaters. An ink jet recording apparatus, wherein the temperature detected by each operation is calculated, and the driving condition of the temperature control heater is determined based on the temperature obtained by the calculation. 7. The method according to claim 6, wherein the determining unit changes a condition of a drive pulse supplied to the plurality of temperature control heaters based on a temperature detected by the plurality of temperature sensors.
The inkjet recording apparatus according to any one of the preceding claims. 8. The ink jet recording apparatus according to claim 6, wherein said determining means further determines a pulse width of a driving pulse to be supplied to said discharge heater, based on a temperature detected by said plurality of temperature sensors. apparatus. 9. The ink jet recording apparatus according to claim 6, wherein the plurality of discharge heaters, the plurality of temperature control heaters, and the plurality of temperature sensors are formed on a same chip. 10. The ink-jet head according to claim 1, wherein bubbles are generated in the ink by driving the discharge heater, and the ink is discharged from a discharge port provided in the ink-jet by the generation of the bubbles. 10. The ink jet recording apparatus according to any one of items 9.