JP2007152901A - Image formation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost simply-structured lock mechanism of a release lever. <P>SOLUTION: The mechanism includes an openable/closeable cover, a lock member which is movable depending upon whether the cover keeps open or closed, and a groove at a portion of the lock member so as to be engaged with a portion of the release lever or a member on the release lever. The groove has a shape so that the release lever is rotatable when the cover keeps open and the release lever is not rotatable when the cover keeps closed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention proposes a new lock mechanism in an image forming apparatus in which a lock mechanism is mounted on a pinch roller pressure release lever of a paper feed roller.

  Conventionally, various recording apparatuses that perform recording on recording media such as paper and OHP sheets have been proposed. Among these, recording apparatuses that perform recording in accordance with an ink jet method directly eject ink from a recording head onto recording paper. Since it has advantages such as low running cost and quiet recording operation, it has been widely used.

  Initially, printing was only for a single color (especially black), but in recent years it has become more colored by mounting multiple heads, and further, the nozzle array has become wider and the number of mounted heads has increased, resulting in higher speed and higher image quality. It has become possible.

  In the ink jet printing apparatus that has been developed in this way, the carriage on which the head is mounted has become larger and the weight has become heavier. Furthermore, in order to cope with high speed, the moving speed of the carriage is steadily increasing.

  In addition, since it is necessary to always maintain high image quality, operations such as preliminary ejection to prevent clogging of the head and undischarge detection to detect the head status have been performed. In addition to printing, there are many cases where the carriage is moved during standby or before and after printing. In order to prevent the user from touching the carriage easily in response to such a large and high-speed carriage operation, and to prevent the front cover from being easily opened during pre-printing and post-processing, At present, printers with locks are appearing.

  Further, not only the front cover is locked, but also a lock mechanism may be mounted on the pressure release lever of the conveyance roller pair for conveying the paper. (See Patent Document 1) This was invented in order to prevent the apparatus from becoming large, but it was done because the print head and spur would collide when the pressure of the roller pair was released during printing. Is. In addition, since a highly accurate conveyance is required during printing, the lever locking mechanism is necessary because the printed matter being printed is wasted if the user accidentally releases the lever. Become.

Conventional lock mechanisms include a mechanism that moves the lock pin by an electric means such as a solenoid, or a mechanism (Patent Document 1) that releases the lock pin only when the print head is at the home position. there were.
JP-A-11-91179 (page 2)

  However, when using a solenoid, in addition to the cost of the solenoid alone, a separate electric circuit is required, and the power supply cost increases due to the need for an increase in power capacity, resulting in a high cost for the main body of the device. It was.

  In addition, when the pressure release lever can be operated only when in the home position described in Patent Document 1, there is no increase in electrical cost, but the print head cannot return to the home position due to some trouble or conveyance jam. In an abnormal state, it was not possible to release the pressure of the roller, which sometimes caused inconvenience.

  SUMMARY OF THE INVENTION An object of the present invention is to propose an image forming apparatus equipped with a release lever lock mechanism that regulates the operation of a pressure release lever by an inexpensive method.

  Therefore, in the present invention, there is a cover that can be opened and closed, a lock member that can be moved depending on the open / closed state of the cover, and a groove that engages with a part of the release lever or a member on the release lever. In the image forming apparatus, the groove shape is such that the release lever can rotate when the cover is open, and the release lever cannot rotate when the cover is closed. is there.

  Further, the image forming apparatus is an ink jet printer that performs printing by ejecting ink onto a print medium using an ink jet technique.

  It is to propose a pressure release lever locking mechanism that is interlocked with the opening and closing operation of the front cover with an inexpensive and simple configuration.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  First, a printer according to an embodiment of the present invention will be described. FIG. 1 is an overall view of an ink jet printer. There is a roll paper 5 wound in the form of a roll in front of the main body, and the paper is once taken into the main body 1 and printed out in the U-turn. In FIG. 1, reference numeral 2 denotes a front cover, which is opened when a user sets roll paper or performs jam processing.

  FIG. 2 shows a state in which the front cover 2 is opened, and the inside can be seen.

  Inside is a carriage 4 on which a print head is mounted, and performs printing while reciprocating along the rails 7 in the directions of arrows C and D. A sheet (not shown) is conveyed in the direction of arrow E. The paper is transported in a certain amount E direction and is temporarily stopped, and printing is performed for the amount of paper transport while the carriage moves in the directions of arrows C and D. By repeating this, printing is performed.

  Such a printing method is generally called a serial printer.

  Next, the ejection principle of the inkjet head used in the printing unit of the above embodiment will be described. An inkjet head generally has a fine liquid discharge port (orifice), a liquid path (ink path), an energy action part provided in a part of the liquid path, and energy that generates thermal energy that acts on the liquid in the action part. The generating element is provided so as to be replaceable with respect to the carriage.

  Other energy generating elements that generate such energy include those using an electromechanical transducer such as a piezo element, irradiating electromagnetic waves such as lasers, absorbing the liquid there, and generating heat. There are known ones that discharge and fly droplets by the action of the above. Among them, the method of discharging liquid by the thermal energy generated by the electrothermal conversion element as in the above embodiment can arrange the liquid discharge ports (orifices) of the ink jet head with high density, so that printing with high resolution can be performed. Suitable for doing.

  In addition, an inkjet head using an electrothermal conversion element can be easily downsized as a whole, and has the advantages of IC technology and micromachining technology that have made remarkable progress in technology and improvement in reliability in the recent semiconductor field. It can be used for a long time, and it is easy to make it long and flat (binarized), etc., so it is easy to make multi-nozzles and high-density mounting, and it is highly productive and inexpensive to manufacture. Can be provided.

  Ink jet heads manufactured through a semiconductor manufacturing process using an electrothermal conversion element as an energy generating means in this way generally have a liquid path corresponding to each ink discharge port, and the liquid path is provided for each liquid path. An electrothermal conversion element is provided as means for forming thermal droplets by applying thermal energy to the liquid to be filled and discharging the liquid from the corresponding ink discharge port, and each liquid path communicates with each liquid path. The liquid is supplied from the common liquid chamber.

  In addition, since detailed ink jet technology is well known, it will be easily understood by those skilled in the art from the following detailed description together with the accompanying drawings, and therefore will be omitted.

  FIG. 3 is a diagram for explaining the sheet conveying roller pairs 8 and 9 and the pressure releasing method thereof. Although it has already been described in FIG. 2 that the sheet is conveyed in the direction of the arrow E, the arrow E also indicates the direction of conveyance of the sheet in FIG. The conveying roller 8 is connected to a motor (not shown) as driving means via a timing belt, and the pinch roller 9 is positioned above the conveying roller 8. The pinch roller 9 rotates the release lever 6 in the direction of arrow F, so that the link shaft 10 rotates in the direction of arrow K, and lifts the pinch roller arm 91 to separate the pinch roller 9 from the conveying roller 8. The release lever 6 is used when setting paper or handling a jam. However, if pressure is released during conveyance or printing, the paper will not be gripped and cannot be conveyed properly. . Therefore, there are many cases in which a lock mechanism is mounted so that the user does not accidentally operate the release lever 6 during printing or conveyance.

  FIG. 6 shows a conventional locking mechanism. In this example, as shown in FIG. 6, a solenoid 1061 and a lock arm 1062 connected to the solenoid are used for locking. FIG. 6 shows a locked state. However, since a part of the lock arm 1062 protrudes on the rotation track of the release lever, the release lever 1100 cannot be rotated in the arrow Z direction. In this way, the release lever is locked. However, in the case of this configuration, a solenoid and other electric circuits are necessary, and the apparatus is complicated and expensive.

  Next, characteristic portions in the present invention will be described below.

  4 and 5 illustrate a release lever locking mechanism interlocked with the front cover 2. Characteristically, it is a groove shape 200 on the lock plate 20. The groove 200 is formed by combining two shapes. The first is a locus drawn by the lock pin 22 when the release lever is rotated while the lock plate 20 is not locked (the cover is open). The second is a locus drawn by the lock pin when the lock lever 20 is rotated while the release lever is in the roller pressure contact state. The combined shape becomes the groove 200.

  4, 5 (a) and (b) both show the unlocked state of the release lever. This state is a state in which the front cover 2 is opened, and the lock plate 20 is rotated in the arrow A direction around the rotation center 21. A lock pin 22 on the release lever is movable in a groove 200 on the lock plate 20. Accordingly, the release lever 6 can be operated in the directions of arrows I and J. As shown to (a), by moving to the arrow J direction, roller pair 8 and 9 will release pressure, and it will be in the state of (b). Conversely, by rotating the release lever 2 in the direction of arrow I from the state of (b), the state of (a) is restored.

  On the other hand, the state of FIGS. 4 and 5 (c) is a state in which the front cover 2 is closed. The lock plate 20 rotates in the direction of arrow B due to the weight of the front cover. That is, the pin 23 is pushed from the position 23a (broken line) to the position 23 (solid line). In this state, when the release lever 6 is to be moved in the arrow J direction, the lock pin 22 cannot move to the position 22a (broken line) due to the shape of the groove 200. Therefore, since the release lever 2 cannot move in the direction of arrow J, the lever cannot be rotated.

  Thus, according to the present invention, the lock mechanism can be formed with a simple configuration in conjunction with opening and closing of the front cover. Therefore, it is possible to propose a lock mechanism for the release lever 6 that is advantageous in terms of cost.

Overall view of ink jet printer according to the present invention Internal explanatory diagram of an inkjet printer according to the present invention The figure which shows the pressure release mechanism of a conveyance roller Diagram showing release lever locking mechanism Diagram showing release lever locking mechanism Figure showing a conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer apparatus 2 Front cover 20 Lock board 22 Lock pin 3 Cover detection part 4 Carriage 5 Roll paper 6 Release lever 7 Carriage rail 8 Conveyance roller 9 Pinch roller 91 Pinch roller arm 10 Pressure release shaft 200 Groove shape

Claims (2)

  There is a cover that can be opened and closed, a lock member that can be moved according to the open / closed state of the cover, and a groove that engages with a part of the release lever or a member on the release lever in a part of the lock member. An image forming apparatus characterized in that the release lever is rotatable when the cover is open, and the release lever is not rotatable when the cover is closed.   The image forming apparatus according to claim 1, wherein the image forming apparatus is an ink jet printer that performs printing by ejecting ink onto a print medium using an ink jet technique.

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