JPH01290440A - Liquid jet recording device - Google Patents

Abstract

PURPOSE:To obtain an image whose quality is always table regardless of the difference in absorption of a material to be recorded and the dot density of recording data by arranging a plurality of recording heads of different discharge capacities. CONSTITUTION:Recording heads 1a-1d aligned in such a manner that their discharge ports are arranged in a direction where a material to be recorded P is transported, demonstrate increasingly larger ink discharge amounts in that mentioned order. If the material to be recorded P is plain paper, for instance, the recording head 1b is selected for recording. In addition, if the material to be recorded P is paper with low absorption such as OHP form, the recording head 1a whose discharge amount is the smallest is selected for recording. If the material to be recorded P is paper with high absorption such as coated paper, the recording head 1c with a large discharge amount is selected for recording. Furthermore, if image data with a high dot density or solid records are to be obtained, the recording head with a smaller discharge amount than for printing characters at low dot density is selected. Thus recording with constantly stable quality can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application!l!IF) The present invention relates to a liquid jet recording device that performs recording by jetting a recording liquid such as ink. Although it is possible to highly integrate ejection ports as in an inkjet printer using an inkjet device, it is suitable for use in a liquid jet recording device in which the dot modulation is relatively short.

(Prior Art) Liquid jet recording devices, particularly inkjet printers that use ink as the recording liquid, use plain paper, coated paper coated to improve fixing properties, and even OH
It has the advantage that various recording materials such as P film (OHP paper) can be selected as the alignment medium.

(Problem to be Solved by the Invention) However, the diameter of the recorded dots varies depending on the ink absorbency of the recording material, so stable recording output cannot be achieved regardless of the type of recording material. There are cases.

That is, if the recording material has good absorbency such as coated paper, it will be suitable for recording, but plain paper.

With OHP paper, ink droplets may smear or be repelled, resulting in a decrease in recording quality.

On the other hand, even if the recording material is the same, if the recorded information is different, that is, image data with a high dot density or "solid" recording, bleeding will be more severe than in character recording with a low dot density, and the fixation of the recording will deteriorate. It may not be possible to improve quality.

[Means to solve the problem]

In order to solve this problem, the present invention includes a plurality of print heads that eject different amounts of liquid when driven, and a selection means that selects the print head to be used during printing.

[For production]

According to the present invention, by providing a plurality of recording heads capable of recording with different amounts of ejected liquid, if the recording head is appropriately selected according to the difference in the recording material or the difference in recording information, stable recording can be achieved at all times. It becomes possible to record quality.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a liquid jet recording apparatus according to an embodiment of the present invention. Here, 1axld refers to an ejection element that includes an ejection port for recording liquid (ink), a liquid path communicating with the ejection port, and an electrothermal conversion element as an ejection energy generating means disposed in the liquid path. This is a recording head in which the exits are aligned in the conveyance direction LF (sub-scanning direction) of the recording material P. In this example, the recording disks 1a to 1d are configured to obtain a larger ink ejection amount in this order, that is, to obtain a larger dot diameter in this order for the same recording material.

Reference numeral 10 is a carriage on which a recording head 1axld is mounted and moves in a predetermined direction CR (main scanning direction) with respect to the recording material P;
A wire stretched between 2A and 128, and 13 a carriage motor connected to the pulley 12B and driving the carriage 10 via the wire 11. 14 is the carriage lO
This is a guide that guides you through the journey.

Reference numerals 15 and 16 denote a pair of rollers provided before and after the recording positions of the recording heads 1a to 1d, which nip and convey the recording material P. 17 is coupled to one roller of the roller pair 16;
This is a line feed motor that transports the recording material P in the LF force direction, and is controlled so that it is fed by the ejection port array width of one recording head after one main scan.

Reference numeral 18 denotes a board on which control circuits and other components of the main body of the inkjet recording apparatus are mounted, and reference numeral 19 denotes an operation panel, which includes switches such as an online switch with the host device and a line feed switch, a display for displaying messages, and the like.

A host computer H serves as a recording data supply source for the apparatus, and also generates commands for switching and selecting the recording head to be used depending on the type of recording material and recording data.

FIG. 2 shows an example of the configuration of recording heads 1a-1d. Here, 25 is an ink discharge port, 26 is a liquid path communicating with the ink discharge port 25, and is provided with an electrothermal conversion element that generates heat when energized by a driver 27. Due to this heat generation, the liquid path 2
Bubbles are generated within the recording material P (indicated by reference numeral 24), and as a result, ink (rj422) is ejected toward the recording material P.

Such a recording head can be constructed using the same technology as in the semiconductor manufacturing process, and is advantageous for high integration.
The amount of ink ejected is determined by the dimensions of each part, and it is difficult to perform dot modulation by changing the amount of ink ejected with one recording head. Therefore, in this example, the recording heads 1a to 1d are configured so that the amount of ink ejected varies in this order, and one of them is selected and used for recording depending on the type of recording material.

FIG. 3 shows the recording head 1a- in FIGS. 1 and 2.
This is an example of the configuration of the control system 1d, and this circuit can be provided on the board 18.

2a to 2d are drive circuits including the driver 27; 38 to 2d;
3d is a buffer circuit, and C of the recording heads la to Id.
It is used to align data in order to perform a recording operation corresponding to the arrangement position in the R direction. 5 is a selection circuit;
In response to a command from the host computer H, the destination of the recording data is switched to one of the buffers 38 to 3d.

In the above configuration, when the recording material P is plain paper, a command from the host computer H selects, for example, the recording head Ib to perform recording. Furthermore, when the recording material P has poor absorbency such as OHP paper, recording is performed by selecting the recording head la with a small ejection amount. Furthermore, when the recording material P is highly absorbent such as coated paper, the recording head lc with a large ejection amount is used.
Select to start recording.

FIGS. 4(A) to 4(0) respectively show recorded dots when recording is performed on the same type of recording material using the recording heads 1a to 1d.

In this case, coated paper is used as the recording material, and therefore, even in so-called "solid printing", the recording heads la and lb give an impression of being a little thin (FIGS. 3(A) and CB). This is because the amount of ink ejected is small, but when ejected onto plain paper, the permeability is low, so a dot with a moderate diameter will be formed on the paper surface.

FIG. 5 is an explanatory diagram of the penetration state of ink droplets.

FIG. 8 (8) shows a case where the recording material is coated paper Pc, and a large ink droplet 22C is obtained using the recording head lc. The same figure (B) shows the case where plain paper pb is used, and small droplets 22a are obtained using the recording head la.

Since the absorbency (permeability) differs depending on the recording material, the diameter of the dots formed on the recording material is approximately the same as shown in the figure, so it depends on the type of recording material. It is now possible to record stably.

Further, such selection of a recording head can be performed not only according to the recording material but also according to the type of recording data. In other words, image data with high dot density or "solid"
For recording, a recording head with a smaller ejection amount is selected than in the case of character printing in which recording is performed with a low dot density.

In the above embodiments, commands from the host computer are used as means for making the switching selection, but switch information from switches provided on the operation panel 19 may also be used, or switch information from the switch provided on the operation panel 19 may be used, or the type of recording material may be specified in the recording apparatus main body. It is also possible to provide a sensor that identifies the sensor and perform switching according to its output.

Further, in the above embodiment, the present invention is applied to a serial type recording device, but it is applicable to a recording device equipped with a fully multi-type recording head in which ejection ports are aligned across the width of the recording material. The present invention is also extremely effective and easy to apply. In this case, a plurality of recording heads having such a configuration may be provided.

Further, the number of recording heads and the arrangement order are not limited to the four recording heads arranged in order of ejection amount as shown above, but it goes without saying that any suitable number can be used in any suitable order. Furthermore, if a plurality of recording heads are used in combination during recording, it becomes possible to record not only in four stages as described above but also in many more stages.

〔Effect of the invention〕

As described above, according to the present invention, by arranging a plurality of recording heads with different ejection amounts, images of stable quality can always be produced regardless of differences in the absorbency of recording materials or dot densities of recorded data. The effect that can be obtained was obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a liquid jet recording device according to the present invention, FIG. 2 is a sectional view showing an example of the configuration of the recording head thereof, and FIG. 3 is a diagram showing a recording head drive system according to the present embodiment. A block diagram showing one configuration example, Figures 4 (8) to (D) are explanatory diagrams shown for comparing the results of recording with the recording head used in this example, Figures 5 (A) and (B) is an explanatory diagram for explaining dot formation due to differences in recording materials. la-ld... Recording head, 28-2d... Drive circuit, 38-3d... Buffer circuit, 5... Selection circuit, lO... Carriage, 13... Carriage motor, 18... - Substrate, 19... Operation panel, 22, 22a, 22c --- Ink iZ, 25.
...Discharge port, H...Host computer, P...Recording material. Fig. 2 Fig. 3 (A) (B) (D) (C) Fig. 4 (A) No. j (B) = N ~ 22° "Fig. 5

Claims (1)

Claims: 1) A liquid jet recording apparatus comprising: a plurality of recording heads ejecting different amounts of liquid when driven; and a selection means for selecting the recording head to be used during recording.