JPH04269549A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To eliminate the use of unnecessary ink and an unnecessary recording medium by detecting the ink droplet emitted from the nozzle of an ink jet head by a pair of sensors. CONSTITUTION:In an ink jet recording apparatus wherein a plurality of nozzle rows 2 are arranged and ink droplets 5 are emitted from said nozzle rows, a pair of photodetectors 3, 6 scanning in parallel to the ink nozzle rows are provided to detect whether or not an ink droplet is emitted at every one nozzle.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of an ink jet recording apparatus that forms an image on a recording medium by ejecting ink droplets.

0002

2. Description of the Related Art In an inkjet recording device that has a plurality of nozzle rows and ejects ink droplets from the nozzle rows, one method for eliminating ink clogging is to eject ink droplets at regular intervals. In addition, nozzle clogging was prevented by ejecting ink droplets after each operation.

[0003] In addition, when clogging occurs, an ink suction pump is attached to the nozzle row of the head to suck the ink, or pressure is applied from the ink tank to discharge the ink to eliminate the ink clogging. Was.

0004

However, in the above method, ink is wasted by ejecting ink even when nozzles are not clogged. If ink is frequently ejected to prevent clogging, the ink will be wasted rapidly and the ink will be wasted unnecessarily.

In addition, if the nozzle becomes clogged, after ejecting the ink onto the recording medium, the operator of the inkjet recording device visually confirms that the ink is clogged and removes the clogged ink. I had to do something to eliminate it. In this case, the recording medium was wasted and it took a long time to clear the clogging.

[0006]

[Purpose] The purpose of the present invention is to detect that ink is being ejected from a nozzle and automatically perform an operation to clear the clogging only when clogging occurs, thereby reducing the amount of ink and recording medium. An object of the present invention is to provide an inkjet recording device that reduces unnecessary waste.

[0007]

[Means for Solving the Problems] In an inkjet recording device that has a plurality of nozzle rows and ejects ink droplets from the nozzle rows, one scan is performed in parallel with the nozzle rows.
This is an inkjet recording device characterized by having a pair of photodetectors.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be explained below based on illustrated embodiments.

FIG. 1 shows a general view of an ink jet recording apparatus embodying the present invention. A head 1 having a nozzle row 2 with a plurality of nozzles arranged therein, a light emitting element 3 mounted at a position slightly away from the nozzle row 2, and parallel to a line connecting the nozzle rows 2 in a straight line; Lens 4 and light emitting element 3 for converting detection light 7 outputted from light emitting element 3 into parallel light
Similarly, it is composed of a light receiving element 6 mounted at a position on a straight line parallel to a line connecting the nozzle rows 2 in a straight line.

[0010] Before recording is performed by flying ink droplets onto a print medium, clogging of nozzles is detected at a position away from the print medium.

The detection light 7 output from the light emitting element 3 is turned into parallel light by the lens 4 and is emitted toward the light receiving element 6. First, before detecting ink droplets, it is checked whether the detection light 7 emitted from the light emitting element 3 can be detected by the light receiving element 6 without ink droplets being ejected from the nozzle array 2. After that, ink droplets 5 are emitted from the nozzles 8 of the nozzle row 2 arranged on a certain surface or edge of the head 1.
When the ink droplet 5 is ejected, the ink droplet 5 flies across the detection light 7 emitted from the light emitting element 3. At this time, the detection light 7 is blocked by the ink droplet 5, so that the amount of light reaching the light receiving element 6 is reduced. By detecting the change in the amount of light at that time using an electrical signal, it is detected whether or not ink has been ejected from the nozzle 8.

Similarly, by performing the same operation on other nozzles at different times, it is possible to detect which nozzle in the nozzle array 2 is clogged.

[0013] If no clogging is detected at this time, recording is performed on the printing medium. When clogging is detected, only the nozzle for which clogging has been detected is ejected several times while detecting whether ink droplets are being ejected to eliminate the clogging. If the clogging is not cleared even after ejecting the ink a certain number of times, the operation to clear the clogging using the ink pump is automatically performed.

[0014]

As described above, the present invention makes it possible to detect nozzle clogging by using a simple and inexpensive detector.

[0015] Therefore, since it is only necessary to automatically perform an operation to clear the clogging when clogging occurs, unnecessary waste of ink and recording media can be reduced.

[Brief explanation of the drawing]

[Fig. 1] An overview diagram including a cross section of the head according to the present invention.

[Explanation of symbols]

1 Head 2 Nozzle row 3 Light emitting element 4 Lens 5 Ink droplets 6 Photo receiving element 7 Detection light 8 Nozzle

Claims (1)

[Claims] 1. An inkjet recording apparatus that includes a plurality of nozzle rows and ejects ink droplets from the nozzle rows, comprising a pair of photodetectors that scan in parallel with the nozzle rows. Recording device.