JPS59500609A - Ink supply and pressure adjustment device for hand-held ink, jet, and printers - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] This invention relates to ink jet printers, and in particular to so-called drop-on printers. This invention relates to an ink jet printer using a demand operation method.

Non-stamping printers use mechanical printing elements that are struck against the recording medium during printing. It has become very popular these days because it operates silently without having to hold it.

Among such non-stamping printers, ink jet printers are especially This is especially important because it allows high-speed recording on plain paper that does not require printing.

Many ink jet printing methods have been developed in the past. U.S. Patent No. 3, In the so-called continuous ink jet process as disclosed in No. 596,275, In this case, the ink is delivered under pressure to the nozzles of the print head, and each It generates a continuous stream of air that is injected through the nozzle. I hear it, 7. is separated by ejection for loading as a stream into the ink fountain. fly The ink reservoir is either allowed to strike the recording medium or is electrostatically deflected to prevent subsequent Either it is collected in the ghat for recirculation.

A second method, known as the electrostatic method, is described for example in U.S. Pat. No. 3,060,429. Disclosed in the issue. In this method, the ink in the nozzle is exposed to zero or low positive pressure. The ink puddle is created by electrostatic attraction, and the flight direction and direction of the ink puddle are and two pairs arranged to control the positioning of the recording medium to the desired position. It flies between the deflection electrodes.

A third method known as the drop-on-demand method is e.g. No. 4,125,845. The ink fountain produced by this method can be used to print electronic characters. Ink chamber caused by the energization of a piezoelectric element under the control of a generator or ejected by movement or shifting of the volume of ink within the channels. of volume The movement creates a pressure wave that propagates toward the nozzle and ejects the ink puddle.

The drop-on-demand method has a number of advantages over the other methods mentioned above. This person An ink jet printer using the method uses deflection means to control the flight of the ink pool. Simple structure that does not require an ink recovery system or an ink recovery system Can be done. Multi-nozzle print heads using this method are simple and compact. It is easy to manufacture and relatively easy to manufacture.

The pour-on-demand method holds the ink in the nozzle until the ink is ejected. In order to retain the ink inside the ink chamber or ink reservoir, a suitable negative pressure, In other words, it is required to maintain a stationary state at a pressure lower than atmospheric pressure. low pressure The value of value is critical. Even if the pressure is too low, even if the pressure is positive. The liquid will try to flow out of the nozzle. On the other hand, if the pressure is too low, the stationary In some situations air may be sucked out of the nozzle. For example, the lower pressure required for it Apply force to the ink fountain so that the height of the ink surface of the ink fountain is lower than the height of the nozzle. It may be obtained by gravity by lowering it. However, such in Positioning of the ink reservoir is not always easy to achieve and To the data or its print.

This may require complex changes to the board design. Besides, it is packaged It can be used to print on various objects such as bags, envelopes, carts or similar items. Hand-held ink jet printers that have to be tilted toward the It cannot be used on the feet.

The ink jet printer ink described in British Patent No. 2,063,175 Even if the ink in the container is brought to a lower pressure than atmospheric pressure, the ink will not leak from the nozzle. It's sea urchin. This is due to the elasticity of the ink container, which attempts to assume the shape of its maximum volume. achieved. In order to inflate the ink container, the embodiment uses a spring, a spring or a spring. and similar mechanical means (which, as a result of wear of those elements, This will lead to a shortened lifespan. Also, 4 These factors tend to be harsh, and small and compact handheld inkjet printers It cannot be easily used in short printers.

Disclosure of invention The object of the invention is to automatically carry out the necessary A small and compact ink jet printer that can obtain extremely low pressure. A drop-on-demand ink jet that can be configured as a printer. The aim is to provide a print printer.

According to this invention, it is selectively energized and can be activated instantly through the connected nozzle. a print head having at least one piezoelectric drive element adapted to eject droplets; and an ink droplet supplying ink to the print head. In a printer, the atmosphere is connected to the inside of the ink droplet, and one end is connected to the inside of the ink droplet. including capillary means arranged to operatively penetrate ink in said ink. In addition to providing the capillary means, the drops operationally prevent air from escaping, thereby This maintains a low pressure of ink against the nozzle, resulting in a low pressure when the ink droplet is ejected. An increase in pressure is prevented by the intake of air through the capillary means to the ink droplets. To provide an ink jet printer which can be stopped.

This invention is simple and low energy consumption, and has a built-in ink and a condenser. Drop-on hoaxes due to the fact that they can form units of This application is particularly suited to hand-held ink jet printers, for which the printed method is particularly suitable. I found it.

Brief description of the drawing The present invention will now be described in detail by way of example with reference to the following drawings.

FIG. 1 is a schematic partial cross-sectional view of a hand-held printer according to the invention.

Figure 2 reveals details of the printer inside the container along line 2-2 of the printer in Figure 1. A partial side view of the lower part of the printer shown in Figure 1 is shown by cutting out a portion of the container in order to It is a diagram.

Figure 3 shows an ink cartridge similar to that of Figure 2 with a different arrangement of the capillary means. 1 is a schematic partial cross-sectional view of a jet printer.

4 is a partial side view of the printer of FIG. 3 taken along line 4-4 of FIG. 3; FIG. .

FIG. 5 shows means for controlling the operations of the printers shown in FIGS. This is a block diagram drawn.

Figure 6 shows how stable low pressure is maintained in the printers shown in Figures 1 to 4. This is a useful illustration for explaining the law.

BEST MODE FOR CARRYING OUT THE INVENTION Referring to the figures, FIGS. 1 and 2 show a hand-held ink jet printer 90. is shown, and a hand-held ink jet printer 92 is shown in FIGS. 3 and 4. It's me. Each printer 90 and 92 is manually moved along the recording medium 110 to selective actuation or energization of the piezoelectric crystal drive elements of the print head 96. The device is configured to print alphanumeric characters on the media. The element 106 is located there. arranged to eject ink droplets through respective nozzles 102 connected to be done. The energization of the piezoelectric element 106 is controlled in a conventional and well known manner, as shown in FIG. Both will be briefly described later.

Each printer 90.921J print head 96 is housed at the tapered lower end. It includes a pen-shaped case or container 94. Print head 96 is connected to nozzle plate 10 Nozzles 102 and corresponding ink supply manifolds arranged in a line at 4 There are seven ink channels 98 each extending between the print head 100 and the print head 100. ink - Each channel 98 has a segment or section surrounded by a respective piezoelectric element 106. Including minutes. In order to accommodate the elements 106 within the container 94, every other insulator is The key channel 98 is arranged on two spreading planes, as shown in Fig. 2. be done.

Ink channel 98, manifold 100, nozzle plate 104 and piezoelectric element 1 The operating elements of the printhead 96, including 06, are adapted to fit the container 94. to be embedded or packed in blocks of appropriately shaped plastic material; Can be done. However, the blocks of plastic material have been omitted to simplify the diagram. This is an abbreviation.

The container 94 of each printer 90 or 92 has a wheel 108 rotatably mounted near its lower end. When the printer is rotated over the recording medium 110, the nozzle plate 104 and A necessary space can be maintained between the recording medium 110 and the recording medium 110. The car 108 also Serves as a timing wheel and is mounted within container 94 adjacent car 108. The optical reader 112 is arranged in operative relationship with an optical reader 112 . The reading device 112 is a car Read equally spaced lines or marks 113 (FIG. 2) extending radially on the sides of 108. arranged to take. Although not illustrated in detail, apparatus 112 may be conventional. It includes an LED and a phototransistor arranged to control the operation of the piezoelectric element 106. The printer generates a series of timing pulses that are used to Ru. Electrical conductors 114 for the piezoelectric element 106 and the dust removal device 112 are connected inside the container 94. are connected by an electrical cable 116 extending along.

The print head 96 of each printer 90°92 is shown schematically in FIG. and reader 112 are connected via cable 116 and conventional dry quad circuit 68. printer or data processing device and associated printer 8 Connected to control. The devices are responsive to timing signals from reader 112. to control the driver circuit 68 to print the desired characters. and character signals. A controller to control a handheld ink jet printer. The use of motion sensitive devices such as device 112 connected to a beater is known. example For example, it can be found in U.S. Patent No. 3,656,169 issued to T. Casio. can be done. However, regarding this, I will briefly describe this invention below. The timing signals generated by device 112 are sent to the computer for preprocessing. 90.92 movement. Conbeater and conventional character generation circuits are Controls driver circuitry in response to timing pulses to selectively energize piezoelectric elements do. The piezoelectric element 106 is energized by timing generated from the reading device 112. Since the speed of the printer moving over the recording medium 110 is However, uniform prints can always be produced. For the recording medium 110 During character printing, the dot positions in each row of characters are determined by the selected piezoelectric element 106. The printed image is printed by energizing one or more selected piezoelectric elements.

1 and 2, the ink reservoir 118 containing the ink 40 is connected to the printer 9. 0 prints are stored in the container 94 on top of the rad 96. capillary tract or tube 120 is attached to the ink reservoir 118, and the upper end of the tube 120 is open to the atmosphere. The lower end is operatively designed to penetrate into the ink 40 sealed in the ink reservoir 118. It extends towards the bottom of the ink sump 118. The filled ink reservoir 118 is filled with capillary tube 120 as well as It should be noted that there is no operational air leakage.

3 and 4, the printer 92 uses a capillary tube or channel 122. Ru. In this case, the lower end 123 of the tube 122 is open to the atmosphere, and the tube 122 is further opened to the atmosphere. The upper end of tube 122 extends through the body of print head 96 to print head 96 . The ink reservoir 124 is housed in a container 94 at the top of the ink reservoir 124 .

The upper end of the tube 122 is placed near the bottom of the ink reservoir 124 and is enclosed in the ink reservoir 124. The ink 40 is operatively infiltrated. The filled ink reservoir 124 is the capillary tube 1 It should be noted that there is no operational air leakage other than 22.

Operation of printer 90 (FIGS. 1 and 2) and printer 92 (FIGS. 3 and 4) When printing, first drain a small amount of ink from the ink reservoir 118 or 124, or must be ejected to set the low pressure at the nozzle 102 to an appropriate value. fire Once that value is determined, the low pressure is The value is maintained automatically. Print head nozzle 102 0 when the low pressure is about to increase due to the ejection of ink droplets through the bubbles into the air portion of the ink fountain 118 or 124 through the capillary tube 120 or 122. 9, which prevents an actual increase in low pressure.

In each of the printers 90, 92, the ink in the nozzle 102 relative to atmospheric pressure is The required low pressure is determined by the capillary force of the ink in the nozzle 102 and the capillary tube 120 or 122, and by the The hydrostatic pressure of the ink when in the operating position and the ink reservoir 118 or 124 is the result of the combination of the air part with the pneumatically low pressure. Inside the capillary 120 or 122 The capillary force or capillary action of the ink depends on the inner diameter of the limb canal, the surface tension of the ink, and the It depends on the adhesion between the pipe and the pipe.

The opening of the tube 120 or 122 in the ink reservoir 118 or 124 is submerged below the ink surface. Of course, it is important that the air that enters through the limb canal is The desired low pressure is maintained by utilizing the capillary action of the ink and the tube to resist this. Become. Moreover, the inner diameter of the tube 120 or 122 is made sufficiently small for the same reason as above. That is important. The tubes 120, 122 are made of glass or other materials such as glass. It can be made from any suitable material. For commonly available inks, glass The tube has an internal diameter of approximately 0.03 to 1.2 mm, and the nickel tube has an internal diameter of approximately 0.15 to 1.2 mm. It may be appropriate to have up to 0.9 mm.

FIG. 6 shows the ink supply system of each printer 90 and 92 shown in FIGS. 1 to 4. FIG. 3 shows a diagram of the stem low pressure regulation as a function of time. before printing starts , and during the preliminary period A, the interior of the ink fountain 118 or 124 is as shown at point (1). will start at normal atmospheric pressure. Therefore, the ink is energized by the element 106. 90.9'2 through the nozzle of the printer 90.9'2. Therefore , until the desired low pressure established by capillary tube 120 or 122 is achieved. The pressure in reservoir 118 or 124 is reduced. This is reflected in point (2) in the figure. When the inner diameter of the nozzle 102 is approximately 0.07 millimeters, the water column is normally below atmospheric pressure. It's probably 5 centimeters apart. At this point (2), preliminary period A ends; enters period B during which printing may occur. ink jet print ・The head 96 moves at point (2) until the ink in the ink reservoir 118 or 124 is empty. ) will operate normally at low pressures.

During operation of the printer 90 or 92, the low pressure tends to increase as ink is jetted. Immediately, the air bubble enters the ink reservoir 118 or 124 through the capillary tube 120 or 122. is maintained at the desired level. Air bubbles entering the ink reservoir 118 or 124 The amount of air in each ink reservoir is almost negligible compared to the amount of air in the ink reservoir. The low pressure is assumed to be constant and is represented by a straight line in the diagram.

The pressure adjustment of the ink jet printer according to this invention allows the printer to operate as described above. be achieved by using simple and cost-effective means. would have understood. This makes this invention work in a drop-on-demand manner. Especially suitable for use with small, compact, handheld ink jet printers. He will make it suitable.

Procedural amendment (formality) 1. Display of incidents paT/usss10o47s 2. Name of the invention Relationship to the incident: Patent applicant Address: 1-2-2-6 Akasaka, Minato-ku, Tokyo Number of inventions increased due to amendment 7. Subject of correction Specification Background of the invention The present invention relates to ink jet zero printers, and in particular to so-called drop-on printers. The present invention relates to an ink jet zero printer utilizing a demand operation method.

Non-stamping printers use mechanical printing elements that are struck against the recording medium during printing. It has become very popular these days because it operates silently without having to hold it.

Among such non-stamping printers, ink O-jet printers are especially This is especially important because it allows high-speed recording on plain paper that does not require printing.

Many ink jet printing methods have been developed in the past. U.S. Patent No. 3, In the so-called continuous ink O-jet method as disclosed in No. 596,275, In this case, the ink is delivered by pressure to the nozzles of the print O-head, and each Generates a continuous zero jet of ink that is sprayed through the nozzle. ink jet is separated by vibration to be loaded as a stream of ink droplets. Flying Lee The ink droplets are allowed to strike the recording medium or are electrostatically deflected for subsequent recirculation. They will either be gathered in Gata for Tamaki.

The second method, known as the electrostatic method, is based on research reports such as the U.S.

Claims (1)

[Claims] 1. Ejecting ink droplets through selectively energized and connected nozzles (102); a print head having at least one piezoelectric drive element (106) that an ink reservoir (112, 124) that supplies ink (40) to the lint head; In the ink jet printer, one of the ink reservoirs (118, 124) The ink tank is connected to the atmosphere at one end and one end is housed in the ink reservoir (118, 124). capillary means (120', 1) arranged to be operatively penetrated into the key (40); 22), said ink reservoir (118, 124) comprising said capillary means (120, 1, 22) and operatively prevents air leakage from said nozzle (102). A predetermined low pressure is maintained on the ink at The increase in pressure causes the ink reservoir ( 118°124) Ink that is prevented by air intake ・Jet printer. 2. Said capillary means removes air from said tube only when air from the atmosphere exceeds a predetermined low pressure. A tube (120 122, the ink jet printer according to claim 1. 3. The at least one piezoelectric drive element (106) and the ink reservoir (118, 12) 4) and said capillary means (120° 122); , wherein the nozzle (102) is positioned at one end of the container (94). The ink jet printer according to item 1 or 2. 4 The nozzle (102) and the recording medium (1) are attached to the one end of the container (94). 10) of the printer (90, 92) so as to maintain a predetermined space between the rotatably mounted to enable rotational movement on the recording medium (110); 4. The ink jet printer according to claim 3, comprising an inkjet printer (ios). 5. The said car (108) has equally spaced marks and works as a timing car, The marking wheel (10B) is sensitive to the mark and drives the at least one piezoelectric drive element (10B). 6) Generate a series of timing signals that are used to control the operation. Claim 4 arranged in operative relationship with an optical reader (112) arranged in a A plurality of ink channels surrounded by respective piezoelectric driving elements (106). (98), said nozzle having a straight line arranged on two spreading surfaces. The inch jet printer described in item 3 of the range. 7. The diameter of the nozzle ('102) is approximately 0.07mm-15 The pipe (120, 122) is made of glass, and the pipe (120, 122) is made of glass. 22) has an inner diameter in the range of about 0.3 to 1.2 mm IJ meters. The ink jet printer described in Section. 8. The diameter of the nozzle (102) is approximately 0.7 mm, and the diameter of the nozzle (102) is approximately 0.7 mm. 0,122) is 2, Kel and the inner diameter of said tube (120,122) is about 0.15 The ink jet printer according to claim 2, which is in the range of 0.09 to 0.9 mm. Rinta. 9. The pressure of the ink reservoir (118, 124) is operationally below atmospheric pressure at a water column of 2. Claim 7 or 8 sets the range between 5 cm and 5 cm. ink jet printer.