JPS587361A - Liquid jet recording head - Google Patents

Abstract

PURPOSE:To permit a high speed recording with a high resolution by a method wherein resisting bodies, regulated in the resisting values thereof in accordance with the characteristics of corresponding electricity heat converting bodies so that the amounts of heat generated by each electricity heat converting bodies become uniform, are connected to each electricity heat converting bodies. CONSTITUTION:One end of the resisting body 206 and one end of the electricity heat converting body 205 are connected electrically with a wiring conductor 207. The resistance of a circuit from a pat 210 to the pat 211 is regulated in accordance with the electricity-heat converting characteristics of the corresponding electricity heat converting body and the amount of heat generated by each electricity heat converting body is brought into uniform. The resisting value of the resisting body is regulated by laser trimming or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a recording head K used in a liquid jet recording device.
The present invention relates to a liquid jet recording head of a type that ejects 1111 droplets and is suitable for use in devices such as IIL and 41KI single jet copying machines and reprinters.

Non-impact placement methods have recently attracted attention because they generate negligible noise during recording. Among them, high-speed recording is possible,
In addition, so-called inkjet recording (liquid jet recording method), which allows recording on plain paper without the need for special treatment such as fixing, is an extremely powerful recording method, and various methods have been used up until now. Proposals and devices to embody them were devised, and some were commercialized with the addition of improved Arashi, while others are still being worked on to put them into practical use.

Among them, the liquid jet recording method, which is described in, for example, JP-A No. 54-51837 and Deutsche Openschrift (DOL8) No. 2843064, uses thermal energy, which is the energy for forming droplets, to act on the liquid. In terms of obtaining the motive force for drop ejection, it differs from other liquid jet recording methods.
They have different characteristics.

That is, in the recording method disclosed in the above-mentioned publication, a round liquid subjected to the action of thermal energy undergoes a state change accompanied by a sharp increase in volume, and the acting force based on this state change causes the tip of the recording head to Droplets are ejected from the orifice, fly, and adhere to the recording member to perform recording.

In particular, the liquid jet recording method disclosed in DOL8 2843064 is
It is not a fool that is applied very effectively to the recording method, but the placement head is full! High-resolution g11tL can be easily realized by high-density multi-orifice with ne type.
1. It has the advantage of being able to obtain high-quality images at high speed.

In this way, the liquid jet recording method described above has nine excellent features, but in order to record high-resolution, high-quality images at even higher speeds, it is necessary to The flight speed and volume of the objects must be uniform.

In a recording head applied to the above-described recording method, the factor determining the flying speed and volume of the ejected droplet O is d, and the droplet formation energy is I! The size of the thermal energy acting on the liquid and the shape of the liquid flow path such as the orifice are determined. To explain this point using a diagram, the recording head applied to the above recording method has, for example, a structure as shown in FIG. teeth,
The heat action section 107, which is a droplet formation energy action section, is in contact with the liquid introduced in the direction of arrow A via the heat action surface 101, which is an energy action surface. Such a configuration is adopted for the purpose of causing the generated thermal energy as droplet formation energy to act effectively and efficiently on the liquid in the heat acting section 107.

For this purpose, it depends on the recording liquid used, but when using a recording liquid that uses ordinary water as a liquid medium, it is necessary to prevent electrical leakage between the electrodes 113 and 114 through the wrinkled mother liquid. In addition, in order to protect the heat generating resistor layer 111 from the recording liquid or from thermal oxidation, the upper layer 112 is formed at the time of head fabrication in order to protect the heat generating resistor layer 111 from the heat generating portion 108K.
11.

The principle of droplet formation in the notation method using such a recording head is that, as mentioned above, when electricity is turned on to the electric/thermal converter, the droplet is acted upon by thermal energy, which is the energy for forming the liquid cylinder. The recording liquid in the heat acting section 107 undergoes a state change accompanied by a rapid increase in volume, that is, the recording liquid in the heat acting section 107 changes to a vaporized state during an extremely instantaneous time when the recording liquid is below the level of a file. At 107 K, bubbles are instantaneously generated and grown, and the recording liquid present between the heat acting portion 107 and the orifice 105 is ejected as droplets. The amount of thermal energy applied to the recording liquid in the heat acting section 107, the surface area of the heat generating resistor layer 111,
Although it depends on the thickness, resistivity, and heat dissipation efficiency of the heat generating part 108 and its vicinity, in actual head manufacturing, these factors are adjusted to each heat generating part corresponding to the multi-orifice.
It is difficult to form them completely uniformly, and at the same time, requiring a high degree of uniformity reduces the manufacturing yield of the head and increases the manufacturing cost F. For the same reason, it has been difficult to always provide recording heads with the same ejection characteristics.

The present invention has been developed based on the merits of the present invention, and is a liquid jet recording method that is capable of recording images of higher speed, higher resolution, and higher quality than conventional methods. The purpose is to provide F.

In order to achieve the above object, the present invention was developed by examining various angles, actually designing and manufacturing a wide variety of recording heads, and repeatedly conducting experiments from various angles. It was discovered that the flying speed and droplet O volume of the ejected droplets change depending on the electrical energy given to the heating resistance layer, and by controlling the given electrical energy, the droplets can be controlled within a certain allowable range. This was based on the discovery that it was possible to maintain the flight speed and volume at a constant value.

A liquid jet recording head according to the present invention has a plurality of orifices provided for ejecting liquid, and is provided corresponding to each of the plurality of orifices and communicates with the corresponding orifice to form flying droplets. A plurality of heat acting parts which are parts where thermal energy acts on the liquid to cause the heat to act on the liquid, and electricity and heat provided for each heat acting part as means for generating thermal energy acting on the liquid filling the heat acting parts. A plurality of converters are electrically connected to each electric/thermal converter, and the corresponding electric/thermal converters are connected so that the amount of heat generated by each electric/thermal converter is uniform. It is characterized by having a plurality of resistors whose resistance values are adjusted according to the electrical/thermal conversion characteristics.

According to the liquid jet recording head of the present invention having such characteristics, the amount of heat generated by the electrothermal converter is constant, the heat generation temperature is kept at a uniform constant value, and the flying speed or volume of the ejected droplets is kept constant. It can be done.

In addition, in a multi-orifice head that includes a plurality of liquid discharge orifices and a heat acting part provided for each orifice, the volume and flight speed of the liquid droplets discharged from each orifice can be made uniform, and the droplet can be discharged at a high speed. High resolution and high quality otia images can be recorded at high speed. Furthermore, in the past, the ejection condition of droplets ejected from each orimeter of the print head was uneven and the print head was unsuitable for printing high-quality aSS, which occurred during the manufacturing process, resulting in poor yield. However, in the present invention, the state of droplet O ejection from each orifice can be easily adjusted uniformly after the recording head OI is manufactured, which improves the yield during the recording head manufacturing process and reduces the price. I can contribute.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 2(a) is a schematic plan view of an electrothermal converter of a liquid jet recording head to which the present invention is applied, viewed from the surface side;
FIG. 6) is a schematic cross-sectional view taken along the section indicated by the dashed line XY in FIG. 2(a). The recording head shown in the figure is the! Cover one side with a predetermined number of grooved plates! When combined, it has a structure in which a liquid flow path of a liquid discharge part including an orifice for ejecting liquid and a heat acting part is formed. (A) is omitted in Xun), and is virtually indicated by a dotted line in Fig. 2 (6). In FIG. 2(a), the diagonal line between K and S is a portion that becomes a recording liquid flow path and a common liquid chamber, and an upper protective layer 204 is formed therein. The electric/thermal converter 20g is a lower layer 202 provided on the substrate 3)1,
It is composed of a heating resistance layer 203 provided on the lower layer 202 and an upper protective layer 204 provided on the wrinkled heating resistance layer 203.

A resistor 206 is provided on the substrate 201 at a position 9 positions apart from the electric/thermal converter 20B, where the grooved plate is not provided, and one end 04 of the resistor 206 has a resistor 206 at the other end.
One end of the wiring conductor 208 is provided), the wiring conductor go
At the other end, an electrode 210-IIX is formed. The other end of the resistor 206 is connected to an electrode 211 via a wiring conductor 209. Now, when a pulse voltage is applied to the pads 210 and 211 by the driving power source, the electric/thermal converter 205 generates heat depending on the value of the current passing therethrough, and the temperature of the heat acting surface 212 increases. The current value in this case is determined by the circuit resistance ranging from 210 to 211 K. Therefore, the resistor 206 is
Mechanical, physical, chemical, sand gellast, anodizing, etc.
By performing p-toming in a practical manner, the current flowing through the p1 electric/thermal converter 205K can be reduced, and the heat generation temperature can be lowered.

jI3 diagram is the main version 1! This figure shows an example of a resistance trimming method for keeping the surface temperature of the heat acting surface of the electric/thermal converter of the recording head at a constant value according to JlK. Drive power supply 304) Lead terminals 307, 30 for pulse voltage
8) When applied to the recording head 301 (the grooved plate has not yet been installed), the surface temperature of the electric/thermal converter 3020 rises, but this surface temperature is detected by the infrared thermometer 305 K, and the converted The electrical signal is fed back to the control unit of the laser trimming device, and compared with the electrical signal corresponding to a preset degree, the scanning of the laser beam that is irradiated (by the laser trimming device) is controlled. By changing the resistance value of the resistor 3030, electricity
The surface temperature of the heat converter 3020 is set to a predetermined value. By repeating this for each segment, it is possible to equalize the temperature of all the heat generating parts in the seek recording head, so that the heating state of the brass liquid is uniform and it is discharged from the orifice. The flying speed and volume of the droplet O become uniform.

FIG. 4 shows another embodiment of the recording head resistor trimming method according to the present invention. Recording head 4
Introducing 01KIe cone liquid and driving electric/thermal converter 403
The liquid is ejected from the KA orifice 404 and a flying droplet 405 is formed.

The flying speed of the formed droplet 4050 is detected by a photocoupler 406 installed in front of the orifice 404, and the signal is used to control the laser trimming device 407 to adjust the resistance value of the resistor 408. A recording head is manufactured that can eject droplets at a set flying speed of nine. In this way, the recording head is manufactured by detecting the flying speed of the droplet, controlling the laser beam so that it becomes constant, and adjusting the resistance value of the resistor 408. It is also possible to eliminate uneven discharge due to minute manufacturing variations in the shape of the groove or orifice.

In addition, in a multi-segment recording head equipped with transistors, diodes, etc. that drive the electric/thermal converter, the trimming of the resistor 408 also takes into account variations in the current flowing through the electric/thermal converter due to variations in these elements. This not only makes it possible to obtain a recording head with uniform ejection for all segments, but also eliminates the need to adjust the drive power supply unit by replacing the head.

Hereinafter, the present invention will be specifically explained according to Examples.

Example 1 K 8i0. on alumina substrate. The layer (lower layer) was formed to a thickness of 5 μm by sputtering, and then H was applied as a heating resistance layer.
fB, 1000mm thick with 1 aluminum as an electrode and 3
After laminating on 000All, selective etching gives 5
A 0-order K 8sO* layer with a heating resistor pattern of 0 μm x 200 μm was formed by sintering (by tuttering, 935
00A After laminating as a JIK film holding layer (upper layer) to form an electric/thermal converter on the substrate, the width is 50 μm x depth s.
o A glass plate with a J1mO groove cut thereon was bonded so that the groove and the heating resistor matched, and the recording head was then polished by polishing the end face of the orifice so that the distance between the tip of the heating resistor and the orifice was 250 sm. While supplying ink whose main components are black dye and water to this recording head,
A 0 μs, 38 VO rectangular voltage pulse printing signal is applied at a cycle of 15 m5, and the flying velocity V of the nine droplets discharged from the 32 orifice segments during running is plotted for each segment number N every two segments. is shown in Figure 4.

Figure #I5 (→ is the result when no trimming was performed for speed adjustment, but the variation in flight speed is approximately ±20
Six nine with X. Next, detect the velocity of nine droplets ejected from each orifice, and trim the adjustment resistor using laser beam trimming to adjust the droplet flight velocity of the other segments to the same velocity as the droplet with the slowest velocity. ), the alignment voltage was increased to 40V and the result was that the droplet flight speed of each segment was ±5X as shown in Figure 5(b).
K Osari 9. Images recorded with a recording head without trimming adjustment had poor image quality when the recording head was moved for high-speed recording, but with a recording head in which the ejection condition of each segment was aligned through trimming as described above, the image quality deteriorated. No deterioration in image quality was observed even when high-speed O running was performed.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are for explaining the structure of the recording head related to the present invention #4. FIG. 1(a) K is a schematic cross-sectional partial view taken at the part indicated by the dashed-dotted line XY, and FIGS. 2(a) and (b) are for explaining the structure of the recording head of the present invention. Figure 2 (Xun is a schematic plan view,
Figure 2 (b) is a schematic cross-sectional view when the cross section is taken at the part indicated by the dashed line X'Y' in Figure 2, and Figure 3 is,
A schematic explanatory diagram for explaining the first method of producing the recording head of the present invention, FIG. 4 is a schematic explanatory diagram for explaining the second method, FIG. 5(a), FIG. (B) is an explanatory diagram for explaining the results in each example of the present invention. 101-recording head, 102-electrical/thermal converter, 10
3--Substrate, 104--Grooved plate, 105--Orifice,
106--Liquid discharge part, 107--Heat action part, 108-Heat generation part, 109...Heat action surface, 11G...Lower layer,
111-Heating resistance layer, 112-・Upper layer, 113, 11
4-electrode layer, 201-substrate, 202--lower layer, 20
3-heating resistance layer, 204--upper layer, 205--electricity/thermal converter, 206--resistor, 207, 208-wiring conductor, 210,211--electrode para), 301-recording head, 3o2-electricity/thermal converter, 303...resistance element, 304-driving power source, 305--infrared temperature needle, 306
- Laser drilling device, 401 - Recording head, 409
-・Grooved plate. Applicant: Canon Co., Ltd. - S1 Agent: Gi Marushima -... ・To, 2, -" (α) 01 (θ (b)

Claims (1)

[Claims] A plurality of nine oriices are provided for discharging liquid, and a plurality of oriices are provided correspondingly to each of these plurality of oriices, communicating with the corresponding oriice, and thermal energy is applied to the liquid to form flying droplets. A plurality of heat effecting parts are provided for each heat effecting part, and an electric power source is provided as a means for generating thermal energy that acts on the liquid filling the heat effecting part.
A plurality of thermal converters are electrically connected to each electric/thermal converter, and the corresponding electric/thermal converters are connected so that the amount of heat generated by each electric/thermal converter is uniform. A liquid jet recording head characterized by having a number of resistors whose resistance values are adjusted according to electric/thermal conversion characteristics.