JP2000280467A - INK JET RECORDING APPARATUS AND ITS MANUFACTURING METHOD - Google Patents

Abstract

(57) [Object] To provide an ink jet recording apparatus in which the weight of ink droplets does not vary between products even when the ON resistance of a switching element or the wiring resistance of a substrate varies, and a method of manufacturing the same. SOLUTION: In an ink jet recording apparatus 100, on-resistance levels of switching elements 16A to 16N are inspected by using inspection wirings 105, 106, 107 via an on-resistance inspection element 16X, and based on the inspection result. Automatically adjust the waveform of the drive signal COM. Therefore, even if the on-resistance levels of the switching elements 16A to 16N vary for each head driving IC 101 or for each lot of the head driving IC 101, the piezoelectric vibrator 17A
To 17N can be made constant in the waveform (potential) of the drive signal COM actually applied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus using a pressure generating element such as a piezoelectric vibrator as a recording head. More specifically, the present invention relates to a technique for optimizing driving conditions for a pressure generating element.

[0002]

2. Description of the Related Art An ink jet recording apparatus used as a printer or a copying machine generally comprises a print controller 1 and a print engine 2, as shown in FIG. The unit 6 serially transfers the dot pattern data corresponding to one scan of the recording head 10 to the recording head 10. In the recording head 10, print data SI developed into dot pattern data
After the (print data) is serially transferred to the shift register 13, the print data SI is latched by the latch circuit 14, and the latched print data SI is applied to the switch circuit 16 via the level shifter 15. The drive signal COM from the drive signal generation circuit 8 is applied to the input side of the switch circuit 16, and the piezoelectric vibrator 1 is connected to the output side of the switch circuit 16.
7 and the like are connected. Here, the print data SI controls the operation of the switch circuit 16.

For example, while the print data SI applied to the switch circuit 16 is "1", a drive signal COM is applied to the piezoelectric vibrator 17, and the piezoelectric vibrator 17 expands and contracts according to this signal. On the other hand, while the print data SI applied to the switch circuit 16 is “0”, the piezoelectric vibrator 1
7 is cut off.

In the recording head 10 configured as described above, the shift register circuit 13 and the latch circuit 1 shown in FIG.
4, the level shifter 15, the switch circuit 16, and the piezoelectric vibrator 17 are elements 13A to 13N and 14A to 1 corresponding to each nozzle opening of the recording head 10, as shown in FIG.
4N, 15A-15N, 16A-16N, 17A-17
N. Among these elements, the shift register circuit 13, the latch circuit 14, the level shifter 15,
Elements 13A to 13N, 14 Constituting Switch Circuit 16
A to 14N, 15A to 15N and 16A to 16N are built in the head driving IC 101, and the head driving IC 101
101 is mounted on the recording head 10 after being mounted on the flexible wiring board 202.

Here, the switching elements 16A to 16N
And the piezoelectric vibrators 17A to 17N are connected in series. Therefore, when the bit data applied to each of the switching elements 16A to 16N is "1", the switching elements 16A to 16N are turned on, and the drive signal COM is applied to the piezoelectric vibrator 1 via the switching elements 16A to 16N.
7A to 17N.

The driving signal COM is, for example, as shown in FIG.
As shown in (B), after the voltage value starts from the intermediate potential Vm (hold pulse 311), it rises with a constant gradient from time T1 to time T2 to the maximum potential VPS (charge pulse 312), and from time T2. The maximum potential VPS is maintained for a predetermined time until time T3 (hold pulse 3
13). Next, after falling from the time T3 to the time T4 with a constant slope to the lowest potential VLS (discharge pulse 31).
4) From time T4 to time T5, the lowest potential VLS is maintained for a predetermined time (hold pulse 315). And
From time T5 to time T6, the voltage value rises at a constant gradient to the intermediate potential Vm (charging pulse 316). in the meantime,
The piezoelectric vibrator 17 is displaced according to the waveform of the drive signal COM, and contracts the pressure generating chamber communicating with the nozzle opening.

[0007] Since ink droplets are ejected from the pressure generating chamber by such an operation, the maximum potential VPS and the intermediate potential Vm of the drive signal COM are set to a predetermined potential so that a predetermined weight of ink droplets are ejected from the nozzle opening. Is set to

[0008]

However, in the head driving IC 101, since the switching elements 16A to 16N vary in on-resistance for each lot or each product, the driving signal COM is supplied via the switching elements 16A to 16N. Is applied to the piezoelectric vibrators 17A to 17N, the voltage actually applied to the piezoelectric vibrators 17A to 17N fluctuates depending on the degree of the voltage drop in the switching elements 16A to 16N, and the weight of the ink droplets varies for each inkjet recording apparatus. (Dot size) varies. In addition, the wiring resistance of the flexible wiring board 102 on which the head driving IC 101 is mounted and the wiring resistance of the flexible wiring board 102 may vary from lot to lot.
This causes the voltage actually applied to A to 17N to vary.

An object of the present invention is to provide an ink jet recording apparatus in which the weight of ink droplets does not vary between products even when the on-resistance of the switching element varies, and a method of manufacturing the same.

It is a further object of the present invention to provide an ink jet recording apparatus in which the weight of ink droplets does not vary between products even when the wiring resistance of the wiring substrate varies, and a method of manufacturing the same.

[0011]

In order to solve the above-mentioned problems, a pressure generating chamber communicating with each of a plurality of nozzle openings is provided. Each of the pressure generating chambers is turned on / off based on recording data.
A switching element that is turned off, and a pressure generating element that presses the ink in the pressure generating chamber by applying a drive signal via the switching element when the switching element is turned on, and ejects an ink droplet from the nozzle opening. In the ink jet recording apparatus having a recording head including: and a driving signal generation unit that generates the driving signal, the on-resistance level of the switching element is provided on a wiring board on which a head driving IC including the switching element is mounted. Inspection wirings for inspecting are formed.

In the present invention, in some cases, the on-resistance of the switching element is directly measured using the inspection wiring, and the on-resistance level of the switching element is inspected on the head driving IC. Therefore, there is a case where an on-resistance inspection element formed with the same structure as the switching element is built in. In this case, an inspection wiring is formed for the on-resistance inspection element.

According to the present invention, the on-resistance level of the switching element can be inspected directly or via the on-resistance inspection element using the inspection wiring. Can be adjusted. Therefore, even if the ON resistance of the switching element varies, the waveform of the drive signal actually applied to the pressure generating element can be kept constant, so that the weight of the ink droplets can be reliably prevented from varying for each inkjet recording apparatus. be able to. Also, when the on-resistance level of the switching element is inspected using the inspection wiring formed on the wiring board, even if the resistance of the wiring pattern formed on the wiring board varies for each wiring board, it is taken into account. This means that the waveform of the drive signal has been adjusted. Therefore, even if the wiring resistance of the wiring board varies, the waveform of the drive signal actually applied to the pressure generating element can be kept constant, so that an ink jet recording apparatus in which the weight of ink droplets does not vary between products is provided. can do.

In the present invention, the waveform of the drive signal may be automatically adjusted using the result of directly inspecting the on-resistance level of the switching element or through the on-resistance inspection element. To this end, control means for controlling the waveform of the drive signal generated by the drive signal generation means based on a result of inspection of the on-resistance level of the switching element is formed.

In the present invention, the recording head includes:
The inspection result of the on-resistance level of the switching element may be displayed, and the waveform of the drive signal may be adjusted to the on-resistance level of the switching element in the manufacturing process of the inkjet recording apparatus based on the inspection result.

Such an ink jet device can be manufactured, for example, by the following method. That is, in the present invention, the pressure generating chambers communicating with the plurality of nozzle openings, respectively, correspond to each of the pressure generating chambers, and are turned on / off based on the recording data.
A switching element that is turned off, and a pressure generating element that presses ink in the pressure generating chamber and discharges an ink droplet from the nozzle opening by applying a drive signal via the switching element when the switching element is turned on. In a method for manufacturing an ink jet recording apparatus having a recording head comprising: and a drive signal generating means for generating the drive signal, an on-resistance level of the switching element is inspected, and based on the inspection result, the on-state of the switching element is turned on. It is characterized in that the resistance level and the waveform of the drive signal are matched.

In the present invention, an on-resistance inspection element formed to have the same structure as the switching element is incorporated in the head driving IC incorporating the switching element in order to inspect the on-resistance level of the switching element. In addition, the on-resistance level of the switching element may be inspected based on the measurement result of the on-resistance of the on-resistance inspection element.

In utilizing such an inspection result, an on-resistance level inspection unit for the switching element and a control unit for controlling a waveform of the drive signal generated by the drive signal generation unit are formed. The control unit controls the drive signal generation unit to adjust the waveform of the drive signal to the ON resistance level of the switching element based on the inspection result of the ON resistance level of the switching element using an inspection unit. Is also good.

Further, after mounting the head driving IC incorporating the switching element on a wiring board, an on-resistance level of the switching element is inspected in a state of the wiring board, and thereafter, the head driving IC is By attaching an indication of the on-resistance level of the switching element to the recording head equipped with, the waveform of the drive signal based on the indication when assembling an ink jet recording apparatus using the recording head. And the on-resistance level of the switching element.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An ink jet recording apparatus to which the present invention is applied will be described with reference to the drawings.

Embodiment 1 (Overall Configuration) FIG. 1 is a perspective view showing a main part of an ink jet recording apparatus.

As shown in FIG. 1, in the ink jet recording apparatus 100, a carriage 111 is connected to a pulse motor 113 via a timing belt 112, and is guided by a guide member 114 to reciprocate in the paper width direction of the recording paper 115. It is configured as follows. The ink jet recording head 10 is attached to a surface of the carriage 111 facing the recording paper 115, in the example shown in FIG. The recording head 10 receives supply of ink from an ink cartridge 117 mounted on the upper portion of the carriage 111 and moves the recording paper 1 in accordance with the movement of the carriage 111.
15 to form dots by ejecting ink droplets onto the recording paper 1
15 to print images and characters. Further, a capping device 11 is provided in a non-printing area of the ink jet recording apparatus 100.
The nozzle 8 is configured to seal the nozzle opening of the recording head 10 during a pause, and receive ink droplets from the recording head 10 due to a flushing operation performed during a printing operation. Further, a wiping device 119 is disposed in the vicinity of the capping device 118. The wiping device 119 wipes the surface of the recording head 10 with a blade or the like to wipe off ink residue and paper dust adhering thereto. Have been.

FIG. 2 is a functional block diagram of the ink jet recording apparatus of the present embodiment.

In FIG. 2, the ink jet recording apparatus 1
00 is the print controller 1 and print engine 2
It is composed of The print controller 1 is an interface 3 for receiving recording data including multi-level hierarchical information from a host computer (not shown) or the like.
A RAM 4 for storing various data such as recording data including multi-level hierarchical information, a ROM 5 for storing routines for performing various data processing, a control unit 6 including a CPU and the like, an oscillation circuit 7, A drive signal generation circuit 8 including a power supply generation unit 80 capable of generating a power supply of each potential for generating a drive signal COM to the print head 10, print data SI (record data) developed into dot pattern data, and drive An interface 9 for transmitting the signal COM to the print engine 2.

Print data including multi-level hierarchical information sent from a host computer or the like is held in a reception buffer 4A inside the printing apparatus via the interface 3. The recording data held in the receiving buffer 4A is sent to the intermediate buffer 4B after the command analysis. In the intermediate buffer 4B, the recording data in the intermediate format converted into the intermediate code by the control unit 6 is held, and the process of adding the printing position, the type of modification, the size, the font address, etc. of each character is controlled. This is performed by the unit 6. Next, the control unit 6 analyzes the recording data in the intermediate buffer 4B and decodes the binarized dot pattern data obtained by decoding the hierarchical data as described later, to the output buffer 4C.
And store it.

When dot pattern data corresponding to one scan of the recording head 10 is obtained, the dot pattern data is transferred to the recording head 1 via the interface 9.
0 is serially transferred. When dot pattern data corresponding to one scan is output from the output buffer 4C, the contents of the intermediate buffer 4B are deleted, and the next intermediate code conversion is performed. Here, the print data developed into the dot pattern data is composed of, for example, 2 bits as gradation data for each nozzle opening, as described later.

The print engine 2 includes a recording head 10
And a paper feed mechanism 11 and a carriage mechanism 12. The paper feed mechanism 11 includes a paper feed motor, a paper feed roller, and the like, and sequentially feeds a recording medium such as a recording paper to perform sub-scanning. The carriage mechanism 12
As described with reference to FIG. 1, the carriage 111 on which the recording head 10 is mounted and the pulse motor 11
3 and the like, and the main scanning of the recording head 10 is performed.

The recording head 10 has a plurality of nozzle openings in the sub-scanning direction, and discharges ink droplets from each nozzle opening at a predetermined timing. In the recording head 10, print data developed into dot pattern data is serially transferred from the interface 9 to the shift register 13 in synchronization with SI and a clock signal (CLK) from the oscillation circuit 7. The serially transferred print data SI is temporarily latched by the latch circuit 14.
The latched print data SI is boosted by the level shifter 15 as a voltage amplifier to a voltage that can drive the switch circuit 16, for example, a predetermined voltage of about several tens of volts. The print data boosted to a predetermined voltage is given to the switch circuit 16. A drive signal (COM) from the drive signal generation circuit 8 is applied to an input side of the switch circuit 16, and a piezoelectric vibrator 17 as a pressure generating element is connected to an output side of the switch circuit 16. .

Here, the print data SI controls the operation of the switch circuit 16. For example, while the print data applied to the switch circuit 16 is “1”, the drive signal C
OM is applied to the piezoelectric vibrator 17, and the piezoelectric vibrator 17 expands and contracts according to this signal. On the other hand, while the print data applied to the switch circuit 16 is “0”, the supply of the drive signal COM to the piezoelectric vibrator 17 is cut off.

In the recording head 10 thus configured, the shift register circuit 13 and the latch circuit 1 shown in FIG.
4, the level shifter 15, the switch circuit 16, and the piezoelectric vibrator 17 are elements 13A to 13N, 14A to 14 corresponding to each nozzle opening of the recording head 10, as shown in FIG.
N, 15A-15N, 16A-16N, 17A-17N
Out of which, the elements 13A to 13N, 14A to 14N, and 15A constituting the shift register circuit 13, the latch circuit 14, the level shifter 15, and the switch circuit 16
15N and 16A to 16N are built in the head driving IC 101. The head driving IC 101 is mounted on the flexible wiring board 102 and then mounted on the recording head 10.

Here, the switching elements 16A to 16N
And the piezoelectric vibrators 17A to 17N are connected in series. Therefore, when the bit data applied to each of the switching elements 16A to 16N is "1", the switching elements 16A to 16N are turned on, and the drive signal COM is applied to the piezoelectric vibrator 1 via the switching elements 16A to 16N.
7A to 17N and applied to each of the piezoelectric vibrators 17A to 17N.
Is displaced according to the waveform of the drive signal COM. Conversely, when the bit data applied to each of the switching elements 16A to 16N is "0", the switching elements 16A to 16N are turned off, and the drive signals to the respective piezoelectric vibrators 17A to 17N are cut off. The vibrators 17A to 17N hold the charge immediately before.

FIG. 4A is an enlarged sectional view showing one of the actuators formed on the recording head 10. As shown in FIG.

In FIG. 4A, in the recording head 10, nozzle openings 211 are formed in a nozzle opening plate 210, and a passage forming plate 212 is formed with a through hole that defines a pressure generating chamber 213, A through hole or groove that defines two ink supply ports 214 communicating on both sides, and a through hole that defines two common ink chambers 215 respectively communicating with these ink supply ports 214 are formed. The vibration plate 216 is formed of an elastically deformable thin plate, abuts against a tip of a pressure generating element such as a piezo element (pressure generating element), and is integrally formed in a liquid-tight manner with the nozzle opening plate 210 with the flow path forming plate 212 interposed therebetween. Fixed, channel unit 2
18.

The base 219 is formed with an accommodation chamber 220 for accommodating the piezoelectric vibrator 17 so as to be able to vibrate and an opening 221 for supporting the flow path unit 218, exposing the tip of the piezoelectric vibrator 17 from the opening 221. In this state, the piezoelectric vibrator 17 is fixed by the fixed wiring board 222. Also, the base 219
In the state where the island portion 216a of the vibration plate 216 is in contact with the piezoelectric vibrator 17, the flow path unit 218 is opened.
1, the recording heads 10 are combined.

(Waveform of Drive Signal) Each pulse forming the drive signal COM will be described with reference to FIG. In FIG. 4B, the drive signal COM for operating the piezoelectric vibrator 17 has a voltage value starting from the intermediate potential Vm (hold pulse 311), and then at time T1.
From time T2 to the maximum potential VPS at a constant gradient (charging pulse 312), and from time T2 to time T3, the maximum potential VPS is maintained for a predetermined time (hold pulse 313). Next, after falling from the time T3 to the time T4 with a constant slope to the lowest potential VLS (discharge pulse 3
14) The minimum potential VLS is maintained for a predetermined time from time T4 to time T5 (hold pulse 315). Then, from time T5 to time T6, the voltage value is the intermediate potential Vm.
(Charge pulse 316).

Accordingly, in FIG. 4A and FIG. 4B, when the charging pulse 312 is applied to the piezoelectric vibrator 17, the piezoelectric vibrator 17 bends in such a way as to expand the volume of the pressure generating chamber 213, and the pressure is generated. A negative pressure is generated in the chamber 213. As a result, when the meniscus retracts from the nozzle opening 211 and then applies the discharge pulse 314, the piezoelectric vibrator 17 bends in a direction to reduce the volume of the pressure generation chamber 213, and a positive pressure is generated in the pressure generation chamber 213. As a result, ink droplets are ejected from the nozzle openings 211. Then, after the hold pulse 315 is applied, the charging pulse 316 is applied to suppress the meniscus vibration.

(Inspection of On-Resistance Level of Switching Element) Ink-jet recording apparatus 100 thus configured
In this embodiment, as shown in FIGS. 2 and 3,
The switching elements 16A to 16N are provided on the head driving IC 101 mounted on the flexible wiring board 102.
In addition to the (switch circuit 16), an on-resistance inspection element 16X having the same structure as these switching elements 16A to 16N is formed by being formed simultaneously with these switching elements 16A to 16N. A load resistor 17X is connected in series to the test element 16X.

On the flexible wiring board 102, an inspection wiring 105 extending from between the on-resistance inspection element 16X and the load resistance 17X (one terminal of the on-resistance inspection element 16X) is formed. I have. Further, the on-resistance inspection element 1 is provided on the flexible wiring board 102.
A test wiring 106 for applying a test potential of +5 V, for example, is formed at the other terminal of 6X. Further, the inspection wiring 107 for applying a control potential for turning on the on-resistance inspection element 16X to the control terminal of the on-resistance inspection element 16X is formed on the flexible wiring board 102. These inspection wires 1
Terminals 105A, 105A,
6A and 107A are formed.
06A, 107A and the interface 9 (see FIG. 2), the inspection wirings 105, 106, 107.
The control unit 6 and the drive signal generation circuit 8
Are connected in circuit with the main board 104 configured.

An A / D converter 61 to which the potential of the inspection wiring 105 is input is formed on the main board 104 on the apparatus body side, and the output of the A / D converter 61 is input to the control unit 6. It has become.

In the ink jet recording apparatus 100 configured as described above, in the initial adjustment stage immediately after the assembly, the head driving IC 1 is used as described below.
01 switching elements 16A to 16N
The control unit 6 controls the power generation unit 80 of the drive signal generation circuit 8 to adjust the level of the power used when forming the drive signal COM based on the inspection result. . That is, in the initial adjustment process after the manufacture of the inkjet recording apparatus 100, the test signal lines 106 and 107 are received from the drive signal generation circuit 8 via the interface 9 and the terminals 106A and 107A.
Is supplied with a predetermined potential, and the on-resistance inspection element 16X is turned on. At this time, the on-resistance inspection element 16X
The potential between the load resistor 17X and the load resistor 17X is input to the A / D converter 61 via the test wiring 105, and the result is input to the control unit 6 as the test result of the on-resistance level of the switching elements 16A to 16N. You. As a result, the control unit 6 switches the switching elements 16A to 16A based on data set in advance in the lookup table 62 or the like.
The power supply generation unit 80 of the drive signal generation circuit 8 is controlled so as to generate a power supply conforming to the ON resistance level of N.

Therefore, when the on-resistance levels of the switching elements 16A to 16N are at the normal level, the drive signal generation circuit 8 operates as described with reference to FIG.
When a recording operation is performed, a drive signal COM whose maximum potential and intermediate potential are VPS and Vm, respectively, is generated and output to the recording head 10. On the other hand, when the on-resistance levels of the switching elements 16A to 16N are high, the drive signal generation circuit 8 determines that the voltage drop in the switching elements 16A to 16N is large, as shown in FIG. A drive signal COM of the maximum potential VPSa and the intermediate potential Vma slightly higher than the maximum potential VPS and the intermediate potential Vm is generated and output to the recording head 10. The waveform of the drive signal COM at this time is represented by potentials 311a, 312a, 313a,
314a, 315, 316a, 317a.

Therefore, in the recording head 10, even if the on-resistance levels of the switching elements 16A to 16N are high and the voltage drop is large, the piezoelectric vibrators 17A to 17N are actually
Is equal to the standard state. When the on-resistance levels of the switching elements 16A to 16N are low, the drive signal generation circuit 8 determines that the voltage drop in the switching elements 16A to 16N is small, as shown in FIG. Further, a drive signal COM of the maximum potential VPSb and the intermediate potential Vmb slightly lower than the intermediate potential Vm is generated and output to the recording head 10. The waveform of the drive signal COM at this time is represented by potentials 311b, 312b,
313b, 314b, 315, 316b, and 317b. Therefore, in the recording head 10, even if the on-resistance levels of the switching elements 16A to 16N are small and the voltage drop is small, the potential actually applied to the piezoelectric vibrators 17A to 17N is equal to the standard state.

(Effect of this embodiment) As described above, in the ink jet recording apparatus 100 of this embodiment, the inspection wiring 105
The switching elements 16A to 16A-1
The 6N ON-resistance level is inspected via the ON-resistance inspection element 16X, and based on the inspection result, the drive signal COM
Automatically adjust the waveform of Therefore, the on-resistance levels of the switching elements 16A to 16N are lower than the head driving IC1.
The waveform (potential) of the drive signal COM that is actually applied to the piezoelectric vibrators 17A to 17N can be kept constant even if the drive signal COM varies from one to another or from one lot of the head drive IC 101. Therefore, it is possible to reliably prevent the weight of the ink droplet from being varied for each inkjet recording apparatus 100. In addition, using the inspection wirings 105, 106, and 107 formed on the flexible wiring board 102,
Since the on-resistance level of 16N is inspected, even if the resistance of the wiring pattern formed on the flexible wiring board 102 varies for each flexible wiring board 102, the waveform of the drive signal COM is adjusted in consideration of the variation. Become. Therefore, even if the wiring resistance of the flexible wiring board 102 varies, the waveform (potential) of the drive signal COM actually applied to the piezoelectric vibrators 17A to 17N can be kept constant. Therefore, even from this point, it is possible to reliably prevent the weight of the ink droplet from being varied for each inkjet recording apparatus 100.

[Embodiment 2] In this embodiment, since the basic configuration is the same as that of Embodiment 1, the corresponding parts are denoted by the same reference numerals and the description thereof is omitted.

FIG. 6 is a functional block diagram of the ink jet recording apparatus of this embodiment.

In FIG. 6, the ink jet printing apparatus 100 of the present embodiment also uses the control unit 6 to print print data including multi-level hierarchical information sent from a host computer or the like.
The data is serially transferred to the recording head 10 for each dot pattern data corresponding to one scan of the recording head 10. In the recording head 10, the print data SI developed into dot pattern data is serially transferred to a shift register 13 and then latched by a latch circuit 14. The latched print data SI is transmitted to a switch circuit 16 via a level shifter 15. Is applied to The drive signal COM from the drive signal generation circuit 8 is provided on the input side of the switch circuit 16.
Is applied, and a pressure generating element such as a piezoelectric vibrator 17 is connected to the output side of the switch circuit 16.

In the recording head 10 thus configured, the shift register circuit 13 and the latch circuit 1 shown in FIG.
4, the level shifter 15, the switch circuit 16, and the piezoelectric vibrator 17 are elements 13A to 13N and 14A to 14N corresponding to each nozzle opening of the recording head 10, as shown in FIG.
N, 15A-15N, 16A-16N, 17A-17N
It is composed of Among these elements, elements 13A to 13N and 14A constituting the shift register circuit 13, the latch circuit 14, the level shifter 15, and the switch circuit 16
To 14N, 15A to 15N and 16A to 16N are built in the head driving IC 101, and the head driving IC 1
01 is mounted on the flexible wiring board 202,
Mounted on the recording head 10.

Here, the switching elements 16A to 16N
And the piezoelectric vibrators 17A to 17N are connected in series. Therefore, when the bit data applied to each of the switching elements 16A to 16N is "1", the switching elements 16A to 16N are turned on, and the drive signal COM is applied to the piezoelectric vibrator 1 via the switching elements 16A to 16N.
7A to 17N.

In the thus configured ink jet recording apparatus 100, also in this embodiment, as in the first embodiment,
As shown in FIG. 6 and FIG.
In addition to the switching elements 16A to 16N (switch circuit 16), the head driving IC 101 mounted on the switching element 02 is formed simultaneously with these switching elements 16A to 16N.
On-resistance inspection element 16X having the same structure as A to 16N
Are formed. A load resistor 17X is connected in series to the on-resistance inspection element 16X. On the flexible wiring board 102, the on-resistance inspection element 16X
A test wiring 105 is formed between the load resistance 17X and one end of the on-resistance test element 16X. Further, on the flexible wiring board 102, the inspection wiring 10 for applying an inspection potential of, for example, +5 V to the other terminal of the on-resistance inspection element 16X.
6 are formed. Further, the inspection wiring 107 for applying a control potential for turning on the on-resistance inspection element 16X to the control terminal of the on-resistance inspection element 16X is formed on the flexible wiring board 102. These inspection wirings 105, 106, and 107 include:
Terminals 105A, 106A and 107A are formed respectively.

However, in the present embodiment, unlike the first embodiment, these terminals 105A, 106A, 107A (inspection wirings 105, 106, 107) are not electrically connected to the apparatus main body side. An A / D converter or the like is not provided on the apparatus main body side.

In the ink jet recording apparatus 100 of the present embodiment configured as described above, the switching elements 16A to 16
After mounting the head driving IC 101 containing N on the flexible wiring board 102, the switching elements 16A to 16N
The on-resistance levels of the switching elements 16A to 16N are then indicated on the recording head 10 on which the switching elements 16A to 16N are mounted.

That is, the switching elements 16A to 16A
N is mounted on the flexible wiring board 102, and then the terminals 106A,
A predetermined potential is externally supplied to the test wirings 106 and 107 via 7A, and the on-resistance test element 16X is turned on. At this time, the potential between the on-resistance inspection element 16X and the load resistance 17X is determined by using the inspection wiring 105 and the terminal 1
05A, and the on-resistance levels of the switching elements 16A to 16N are ranked based on the measurement result. In addition, as shown in FIG.
A label 140 is displayed on the side surface 10A of the case of the recording head 10 on which the flexible wiring board 102 is mounted.

On the other hand, on the drive signal generating circuit 8 side of the apparatus main body, the waveform of the drive signal COM is changed according to the rank of the on-resistance of the switching elements 16A to 16N as described with reference to FIG. Adjustable in stages. Therefore, when the recording head 10 on which the seal 140 indicating that the on-resistance levels of the switching elements 16A to 16N are at the normal level is mounted, the drive signal generation circuit 8 outputs the maximum potential and the maximum potential as shown in FIG. A drive signal COM having an intermediate potential of VPS and Vm
Output. On the other hand, the switching element 16A
Seal 1 representing a rank with a high on-resistance level of ~ 16N
When the recording head 10 to which the recording head 10 is attached is mounted, the drive signal generating circuit 8 determines that the voltage drop at the switching elements 16A to 16N is large,
A drive signal COM of the maximum potential VPSa and the intermediate potential Vma higher than the PS and the intermediate potential Vm is generated and output to the recording head 10. The waveform of the drive signal COM at this time is changed to the potentials 311a, 312a, 313a, 314a, 3
15, 316a and 317a. Therefore, in the recording head 10, even if the on-resistance levels of the switching elements 16A to 16N are high and the voltage drop is large, the potential actually applied to the piezoelectric vibrators 17A to 17N is equal to the standard state.

When the recording head 10 to which the seal 140 indicating the rank in which the on-resistance levels of the switching elements 16A to 16N are low is mounted, it is determined that the voltage drop in the switching elements 16A to 16N is small, and the drive signal The generation circuit 8 generates a drive signal COM of the maximum potential VPSb and the intermediate potential Vmb lower than the standard maximum potential VPS and the intermediate potential Vm, and causes the print head 10 to output the drive signal COM. The waveform of the drive signal COM at this time is set to the potential 3
11b, 312b, 313b, 314b, 315, 31
6b and 317b. Therefore, in the recording head 10, even if the on-resistance levels of the switching elements 16A to 16N are small and the voltage drop is small, the piezoelectric vibrator 1
The potential applied to 7A-17N is equal to the standard state.

As described above, in the ink jet recording apparatus 100 of the present embodiment, the on-resistance levels of the switching elements 16A to 16N are adjusted by using the inspection wirings 105, 106, and 107 via the on-resistance inspection element 16X. Inspection is performed at the stage 102, and based on the inspection result, the waveform of the drive signal COM is changed to
00 in the manufacturing process. Therefore, even if the on-resistance levels of the switching elements 16A to 16N vary for each head driving IC 101 or for each lot of the head driving IC 101, the waveform (potential) of the driving signal COM actually applied to the piezoelectric vibrators 17A to 17N. ) Can be constant. Further, since the on-resistance levels of the switching elements 16A to 16N are inspected using the inspection wirings 105, 106, 107 formed on the flexible wiring board 102, the resistance of the wiring pattern formed on the flexible wiring board 102 is flexible. Wiring board 102
Even if it varies from one drive to another, the drive signal COM
This means that the waveform has been adjusted. Therefore, the piezoelectric vibrator 17
Since the waveform (potential) of the drive signal COM actually applied to A to 17N can be made constant, it is possible to reliably prevent the weight of the ink droplets from varying for each inkjet recording apparatus 100.

[Other Embodiments] In each of the above-described embodiments, the on-resistance is different from the switching elements 16A to 16N for supplying and stopping the application of the drive signal COM to the piezoelectric vibrators 17A to 17N in the recording head 10. The on-resistance level of the switching elements 16A to 16N was inspected based on the result of measuring the on-resistance of the on-resistance inspection element 16X. Crab inspection wiring is formed, and the switching elements 16A to
The ON resistance of 16N may be directly measured.

[0057]

As described above, according to the present invention, the on-resistance level of the switching element is inspected directly or through the on-resistance inspection element, and the waveform of the drive signal is adjusted based on the inspection result. . Therefore, even if the ON resistance of the switching element varies, the waveform of the drive signal actually applied to the pressure generating element can be kept constant, so that the weight of the ink droplets can be reliably prevented from varying for each inkjet recording apparatus. be able to.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of an ink jet recording apparatus to which the present invention is applied.

FIG. 2 is a block diagram of the ink jet recording apparatus according to Embodiment 1 of the present invention.

FIG. 3 is a block diagram of a drive circuit formed on a print head of the inkjet printing apparatus shown in FIG.

4A and 4B are a cross-sectional view of a piezoelectric vibrator formed on a recording head used in the ink jet recording apparatus shown in FIG. 1 and a waveform diagram of a drive signal applied to the piezoelectric vibrator. is there.

FIG. 5 is a perspective view of the ink jet recording apparatus shown in FIG.
FIG. 3 is an explanatory diagram showing that a waveform of a drive signal is adjusted in accordance with an on-resistance level of a switching element formed in a recording head.

FIG. 6 is a block diagram of an inkjet recording apparatus according to Embodiment 2 of the present invention.

FIG. 7 is a block diagram of a drive circuit formed in a print head of the inkjet printing apparatus shown in FIG.

FIG. 8 shows an ink jet recording apparatus shown in FIG.
FIG. 3 is an explanatory diagram showing a state in which an on-resistance level of a switching element formed on a recording head is displayed on the recording head.

FIG. 9 is a block diagram of a conventional inkjet recording apparatus.

FIG. 10 is a block diagram of a drive circuit formed on a print head of the ink jet printing apparatus shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Print controller 2 Print engine 6 Control part 8 Drive signal generation circuit 10 Recording head 13 Siflo register 14 Latch circuit 15 Level shifter 16, 16A-16N Switching element 16X On-resistance inspection element 17, 17A-17N Piezoelectric vibrator (pressure generating element) 17X Load resistance 61 A / D converter 80 Power generation unit 101 Head drive IC 102 Flexible wiring board 105, 106, 107 Inspection wiring 105A, 106A, 107A Inspection wiring terminal COM Drive signal

Claims (8)

[Claims] 1. A pressure generating chamber communicating with a plurality of nozzle openings, a switching element corresponding to each of the pressure generating chambers, which is turned on / off based on print data, and a drive signal when the switching element is turned on. Is applied through the switching element to pressurize the ink in the pressure generating chamber to eject ink droplets from the nozzle openings, and a recording signal generating means for generating the driving signal In the inkjet recording apparatus having the above, an inspection wiring for inspecting an on-resistance level of the switching element is formed on a wiring board on which a head driving IC incorporating the switching element is mounted. Inkjet recording apparatus. 2. The head driving device according to claim 1, wherein
C also includes an on-resistance inspection element formed to have the same structure as the switching element for inspecting the on-resistance level of the switching element, and the inspection wiring is provided with respect to the on-resistance inspection element. An ink jet recording apparatus characterized by being formed by: 3. The control device according to claim 1, further comprising control means for controlling a waveform of the drive signal generated by the drive signal generation means based on an inspection result of an on-resistance level of the switching element. An ink jet recording apparatus characterized by the above-mentioned. 4. An ink jet recording apparatus according to claim 1, wherein an inspection result of an on-resistance level of said switching element is displayed on said recording head. 5. A pressure generating chamber communicating with a plurality of nozzle openings, a switching element corresponding to each of the pressure generating chambers, which is turned on / off based on print data, and a drive signal when the switching element is turned on. Is applied through the switching element to pressurize the ink in the pressure generating chamber to eject ink droplets from the nozzle openings, and a recording signal generating means for generating the driving signal In the method for manufacturing an ink jet recording apparatus having the above, an on-resistance level of the switching element is inspected, and based on the inspection result, an on-resistance level of the switching element and a waveform of the drive signal are matched. Of manufacturing an ink jet recording apparatus. 6. The on-resistance test according to claim 5, wherein the head drive IC having the switching element built therein has the same structure as the switching element for inspecting the on-resistance level of the switching element. A method for manufacturing an ink jet recording apparatus, further comprising: forming an element for use in inspection; and inspecting an on-resistance level of the switching element based on a measurement result of the on-resistance of the element for on-resistance inspection. 7. The inspection according to claim 5, wherein an inspection unit for checking an on-resistance level of the switching element and a control unit for controlling a waveform of the drive signal generated by the drive signal generation unit are formed. Controlling the drive signal generation means of the control means based on the test result of the on-resistance level of the switching element using means to adjust the waveform of the drive signal to the on-resistance level of the switching element. A method for manufacturing an ink jet recording apparatus. 8. The on-resistance level of the switching element according to claim 5, wherein after mounting the head driving IC including the switching element on the wiring board, the on-resistance level of the switching element is inspected in the state of the wiring board. Later, by attaching an indication of the on-resistance level of the switching element to the recording head on which the driving IC is mounted, the assembling of the ink-jet recording apparatus using the recording head can reduce the on-resistance level. Based on the display,
A method of manufacturing an ink jet recording apparatus, wherein a waveform of the drive signal is adapted to an on-resistance level of the switching element.