JP2755709B2 - Inkjet printer - Google Patents

Description

The present invention relates to an improvement of an ink jet printer using an ink jet head.

(B) Prior art In the above-mentioned ink jet printer, considering the influence of the attractive force when the ink is ejected, it is preferable to mount the head downward as shown in, for example, JP-A-1-113251. In this case, there is a problem that ink is accumulated at the ejection port of the head during non-printing, which hinders ejection of ink at the time of printing, and that if the amount of ink accumulation increases, ink drops and soils the paper.

(C) Problems to be Solved by the Invention The present invention aims to prevent ink dripping from an ink jet head during standby during non-printing or the like.

(D) Means for Solving the Problems According to the present invention, a platen is arranged substantially horizontally, and an ink jet head is mounted above the platen. The ink jet head is directed downward with the nozzle facing the platen. It is configured to be rotatable between a printing position and a standby position where the nozzles are directed substantially horizontally.

(E) Function At the time of printing, the ink jet head is printed with its nozzle directed downward, while at the time of non-printing, the above-mentioned ink jet head is driven to rotate to a standby position where the nozzle is directed substantially in the horizontal direction. To prevent accumulation of ink in the nozzle portion.

(F) Embodiment An embodiment of the present invention will be described first with reference to FIGS. 1 and 2. (1) is a printer main body, an upper surface of which is opened (2).
A paper feed tray (4), a paper guide (5), a platen (6), and a paper discharge guide (7) are sequentially disposed in the opening (2) of the lower case (3). An automatic paper feed roller shaft (8) is provided on the paper guide (5) side of (4).
And a pair of upper and lower paper feed roller shafts (9) and (9) and paper discharge roller shafts (10) and (10) on the platen (6) paper guide (5) side and paper discharge tray (7) side, respectively. 10), and each of these roller shafts has a plurality of automatic paper feed rollers (11).
(11), (11), paper feed rollers (12), (12), (12), and paper discharge rollers (13), (13), (13).

(14) is an upper case attached to the opening (2) of the lower case (3) described below. The upper case is opposed to the upper side of the paper feed tray (4) and has a paper feed port (15) for inserting the printing paper (15). 16) is opened, and a cover (17) is pivotally supported so as to be openable and closable above the platen (6), and a viewing window (18) opened and closed by the cover is formed. A paper outlet (19) is formed at the lower end of the rear surface.

Reference numeral (20) denotes an ink jet head which is mounted at an appropriate position above the platen (6) by a shaft (21) so as to be freely slidable in the horizontal direction.
2) is a printing position where the nozzle (22) is turned substantially 90 ° above the printing position to face the nozzle (22) in a substantially horizontal direction while facing the platen (6). (The position shown by the broken line) and the head rotation motor (23)
Is driven to rotate via gears (24) and (24).

(25) is a carriage motor for moving the inkjet head (20) in the width direction of the printing paper (15), via a pair of pulleys (26) and (26) and a driving member (27) such as a wire or a belt. Move the inkjet head (20).

(28) a paper feed motor for rotating the paper feed roller shaft (9) via gears (29) and (29), and a belt (30) between the roller shaft and the discharge roller shaft (10). ) And the roller shafts (9) and (10) are linked by this belt.

Reference numeral (31) denotes an automatic paper feed motor for rotating the automatic paper feed roller shaft (8) via gears (32) and (32).

(33) controls the rotation of the head rotation motor (23), carriage motor (25), paper feed motor (28), automatic paper feed motor (31), etc., and controls the ink jet head (20), etc. When a power supply is turned off by turning off a power switch (not shown), for example, as shown in FIG. 3 (S1), this is detected and the ink jet head (20) is detected. The home position sensor (34) provided at the home position detects whether or not the inkjet head (20) is at the home position (S2). If not, the carriage motor (25) is operated to operate the inkjet head (20). ) To the home position (S3), and then the carriage sensor (35) turns ON
Is detected (S4), and if it is OFF, it is ON
The head rotation motor (23) is operated (S5) until the ink jet head (20) is rotated to the standby position, which is rotated approximately 90 ° from the printing position, and the carriage sensor (35) is turned on.
Then, the power supply to the head rotation motor (23) is stopped (S6).

In the above embodiment, the description will be given of the case where the power supply is turned off. However, for example, even when the printing operation is not performed for a predetermined time or more, the rotation of the ink jet head (20) may be controlled to the standby position. ) It is possible to prevent ink from being accumulated in the portion.

In the above embodiment, the ink jet head (20) is rotated above the platen (6) during standby.
For example, as shown in FIGS. 4 and 5, the platen (6)
A storage port (36) is provided at a position below the home position of the inkjet head (20), and the inkjet head (20) is rotated about 90 ° below the storage port (36) during the standby state to rotate the platen ( The platen body (1) may be housed below the housing (6), thereby reducing the height of the platen body (1).

(G) Effects of the Invention With the configuration according to the present invention, printing is performed with the nozzles of the inkjet head facing downward during printing, thereby preventing the effect of the attraction of ink droplets ejected from the nozzles and performing high-quality printing. When the printer is in a standby state where printing is not performed for a relatively long time, the
By rotating the nozzle so that the nozzle is in a substantially horizontal position, it is possible to reliably prevent the nozzle from clogging due to the ink reservoir at the nozzle portion and to prevent the ink from dripping onto the printing paper.

[Brief description of the drawings]

1 is a side longitudinal sectional view of the present invention, FIG. 2 is a plan view of the same, FIG. 3 is a flowchart of the same operation, FIG. 4 is a longitudinal sectional view of another embodiment, and FIG. FIG. 9 is a plan view showing another embodiment of the present invention. (6) Platen, (20) Inkjet head,
(22) Nozzle, (33) Control circuit.

Continuation of the front page (72) Inventor Ryuichi Okumura 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture Tottori Sanyo Electric Co., Ltd.

Claims (3)

(57) [Claims] A platen is arranged substantially horizontally, and an ink jet head is mounted above the platen. The ink jet head is provided with a printing position in which nozzles face downwards facing the platen, An ink jet printer characterized by being rotatable between a horizontal position and a standby position. 2. The ink jet printer according to claim 1, further comprising driving means for rotating said ink jet head to said standby position during non-printing and when power is turned off. 3. The ink jet printer according to claim 1, wherein said ink jet head is driven to rotate substantially 90 ° below said platen during standby.