JPH04334473A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To realize the miniaturization of the title apparatus by constituting the apparatus so that recording is applied to a material to be recorded held on the circle of circumference centering around a carriage shaft by rotating a carriage having a memory means provided to the leading end part thereof around the carriage shaft. CONSTITUTION:A carriage guide 5 is formed to the circular arc member centering around a carriage shaft 4 and a tooth form 11 is formed to the inner peripheral surface of said guide 5 and the follower gear (idle gear) 10 meshed with the tooth form 11 is provided to the side surface of a carriage 1 in a freely rotatable manner. A material 7 to be recorded is held to the position of the circumferential surface centering around the carriage shaft 4 by a guide (not shown in a drawing) and fed in the direction parallel to the carriage shaft 4 by the rotation of a feed roller 6. A recording head 2 is mounted on the carriage 1 in positional relation such that a plurality of emitting orifices are arranged in the direction crossing the revolving and moving direction (main scanning direction) of the carriage 1 and driven on the basis of image data to form an image on the material 7 to be recorded.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to printers, copying machines,
The present invention relates to an image forming apparatus such as a facsimile machine or a workstation equipped with the facsimile machine.

0002

2. Description of the Related Art In this type of image forming apparatus, a recording means (recording head) is mounted on a carriage that reciprocates along a guide shaft installed in the main body of the apparatus. Move along the recording material (
An image is formed on the recording material (main scanning) by feeding the recording material in a direction (usually perpendicular) that intersects the image formation for one line each time the image formation for one line is completed. (recording) is used.

The recording means can be classified into inkjet type, wire dot type, thermal type, laser beam type, daisy wheel type, etc. depending on the recording method. The inkjet type performs recording by ejecting ink from a recording means (recording head) onto a recording material, and the recording means can be easily made compact, and high-definition images can be recorded at high speed. Advantages include being able to record on plain paper without requiring any special processing, producing less noise as it uses a non-impact method, and making it easy to form color images using multi-colored ink. have.

In particular, inkjet recording means that eject ink using thermal energy use electrothermal transducers, electrodes, and liquids formed on a substrate through semiconductor manufacturing processes such as etching, vapor deposition, and sputtering. By forming the channel walls, the top plate, etc., it is possible to easily manufacture a device having a high-density liquid channel arrangement (discharge port arrangement), and further compactness can be achieved.

[0005]

However, in the conventional image forming apparatus described above, since the recording means is reciprocated in the left and right direction in order to record on the recording material, the guide shaft and the conveyance roller (paper feeding roller) are A device with a length at least equal to the width of the recording material is required; as the width of the recording material increases, the main body of the device also becomes larger, and the dead space also increases because the recording means is moved back and forth in a straight line. There was the issue of putting it away.

[0006]

[Means for Solving the Problems] The present invention provides a recording medium that is held on a circumference centered on the carriage axis by rotating a carriage having a recording means mounted on the leading end thereof, around the carriage axis. By recording on the material, it is possible to shorten the guide shaft of the carriage.
This eliminates dead space in the main body of the device, making the device more compact. Note that in the above configuration, the recording material is fed parallel to the carriage axis, or
It is preferable that the carriage is made extendable and retractable so that the radius of rotation of the moving path of the recording means can be adjusted to correspond to the size of the recording material.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view of essential parts of an embodiment of an image forming apparatus to which the present invention is applied, and FIG. 2 is a side view of the image forming apparatus shown in FIG. 1 and 2, 1 is a carriage, 2 is a recording means (recording head) attached to the tip of the carriage 1, 3 is a motor for driving the carriage,
4 is a carriage shaft fixed to the carriage 1, 5 is a carriage guide, 6 is a roller for paper feeding (conveyance), and 7 is a recording material such as paper or a thin plastic plate. The carriage 1 is driven to rotate (for example, reciprocate) around the carriage shaft 4 by rotationally driving the carriage shaft 4 by the motor 3 via gear trains 8 and 9.

The carriage guide 5 is an arcuate member having the carriage shaft 4 as its center, and has teeth 11 formed on its inner peripheral surface. On the other hand, a driven gear (idle gear) 12 that meshes with the tooth profile 11 of the carriage guide 5 is rotatably attached to the side surface of the carriage 1. Further, the recording material 7 is held by a guide (not shown) at a position on a circumferential surface centered on the carriage shaft 4, and is fed in a direction parallel to the carriage shaft 4 by rotation of the transport roller 6. Ru.

[0009] The recording head 2 is equipped with an electrothermal converter that generates thermal energy used to eject ink. Ink is ejected from an ejection port based on changes in the state of the ink, including the formation of bubbles due to film boiling that occurs in the ink. FIG. 3 is a perspective view schematically showing the structure of the recording head 2, and FIG. 4 is a partially exploded sectional view showing the structure of the ink ejection section of the recording head 2. As shown in FIG. In FIGS. 3 and 4, the recording material 7
A plurality of ejection ports 52 are formed at a predetermined pitch on the ejection port surface 51 facing each other with a predetermined gap (for example, approximately 0.5 to 1.5 mm), and a common liquid chamber 53 and each ejection port 52 are formed at a predetermined pitch. Exit 52
An electrothermal transducer (such as a heating resistor) 55 (FIG. 4) for generating energy for ejecting ink is disposed along the wall surface of each liquid path 54 that communicates with the ink. Figures 1 and 2
In the image forming apparatus, the recording head 2 is mounted on the carriage 1 in a positional relationship such that the plurality of ejection ports 52 are lined up in a direction intersecting the rotational movement direction (main scanning direction) of the carriage 1.
is installed on. In this way, the corresponding electrothermal converter 55 is driven (energized) based on the image signal or the ejection signal, and the ink 56 (FIG. 4) in the liquid path 54 is brought to film boiling, and the pressure generated at that time causes the ejection port 52 to A recording head 2 is configured to eject ink from.

In the above configuration, when recording (image formation) is performed, the rotation of the motor 3 is transmitted to the carriage shaft 4, and the carriage 1 follows an arcuate path around the shaft 4 along the carriage guide 5. While moving along (main scanning), an image is formed (recorded) on the recording material 7 by driving the recording means 2 based on image information. At this time, the recording material 7 needs to be positioned on the circumference around the carriage shaft 4, and after recording one line in the circumferential direction with the recording head 2, the paper feed roller 6 is driven to feed the recording material 7 by a predetermined amount.

According to the embodiment described above, the recording means (
Since the recording head) 2 performs recording while moving along an arcuate path around the carriage shaft 4, the length of the carriage shaft 4 is not affected by the dimensions of the recording material 7 such as the paper width. Compared to the conventional serial type image forming apparatus, the space for moving the carriage 1 can be reduced, and the apparatus main body can be made smaller.

FIG. 5 is a schematic side view showing another embodiment of an image forming apparatus to which the present invention is applied. In this embodiment, the carriage 1 is configured to be extendable and retractable by a slide mechanism. The carriage 1 shown by a solid line in FIG. 5 shows a contracted (short) state, and the carriage 1 shown by a two-dot chain line shows an extended (long) state. Although the embodiment of FIG. 5 differs from the embodiments of FIGS. 1 and 2 in the points described above, other parts have substantially the same configuration, and corresponding parts are designated by the same reference numerals and details thereof. Explanation will be omitted.

According to the embodiment shown in FIG. 5, in addition to obtaining the same effects as those of the previous embodiment, by extending the carriage 1, the rotation radius of the movement (main scanning) path of the recording head 2 can be adjusted. Therefore, the recording material 7 can have a larger paper width than the embodiments shown in FIGS. 1 and 2.
It becomes possible to record images even for. Conversely, when recording on a recording material with a narrow paper width, it is possible to further downsize the carriage 1 by shortening the carriage 1.

In the above embodiment, an inkjet head is used as the recording means (recording head) 2, but the present invention can also be applied to a wire dot head, a daisy wheel head, a thermal head, a laser beam head, etc. The present invention can be similarly applied to image forming apparatuses using recording heads of other types, and similar effects can be achieved. Further, in the above embodiments, the case of an image forming apparatus using one recording head 2 has been described as an example, but the present invention is applicable to color image forming apparatus equipped with a plurality of recording heads that record in different colors. It can be applied in the same way regardless of the number of recording heads, such as image forming apparatuses for gradation recording that use multiple recording heads with the same color but different densities, and can achieve the same effects. It's something you get.

Furthermore, in the case of an inkjet recording type, the recording means (recording head) 2 may be a replaceable cartridge type recording means that integrates a recording head and an ink tank, or a replaceable cartridge type recording means that combines a recording head and an ink tank. Various structures of recording means can be used, such as recording means that are separate and coupled via couplers and tubes, for example.

When the present invention is applied to an inkjet type image forming apparatus, it can be applied, for example, to one using a recording means (recording head) using an electromechanical transducer such as a piezo element. This provides excellent effects in an image forming apparatus that uses a recording device that uses thermal energy to eject ink. This is because, according to such a system, higher recording density and higher definition can be achieved.

For its typical configuration and principle, see, for example, US Pat. Nos. 4,723,129 and 4,740.
Preferably, this is done using the basic principles disclosed in the '796 specification. This method can be applied to both the so-called on-demand type and continuous type, but
In particular, in the case of the on-demand type, the electrothermal transducer placed corresponding to the sheet holding the liquid (ink) or the liquid path is required to respond to the recorded information and rapidly exceed nucleate boiling. By applying at least one drive signal that causes a temperature increase, the electrothermal transducer generates thermal energy that causes film boiling on the heat-active surface of the recording means (recording head), resulting in a pair of It is effective because it can form bubbles in the liquid (ink).

The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one drop. It is more preferable to use this drive signal in a pulse form, since the growth and contraction of bubbles can be carried out immediately and appropriately, so that ejection of liquid (ink) with particularly excellent responsiveness can be achieved. This pulse-shaped drive signal is described in US Pat.
Those described in Japanese Patent No. 463359 and Japanese Patent No. 4345262 are suitable. Incidentally, US Pat.
If the conditions described in No. 24 are adopted, even more excellent recording can be achieved.

In addition to the configuration of the recording head that combines ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4 disclose a configuration in which a heat acting part is arranged in a bending region.
A configuration using the specification of No. 459600 is also included in the present invention. In addition, Japanese Patent Application Laid-open No. 123670 of 1982 discloses a configuration in which a common slit is used as a discharge part for a plurality of electrothermal converters, and a hole that absorbs pressure waves of thermal energy is disclosed. The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 138461 of 1981, which discloses a configuration in which a discharge portion corresponds to a discharge portion. That is, regardless of the form of the recording head, according to the present invention, recording can be performed reliably and efficiently.

Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by a recording apparatus. Such a recording head may have a configuration in which the length is satisfied by a combination of a plurality of recording heads, or a configuration as a single recording head formed integrally. In addition, even with the serial type shown in the example above, the recording head is fixed to the device body, or by being attached to the device body, electrical connection to the device body and ink supply from the device body is possible. The present invention is also effective when using a replaceable chip type recording head or a cartridge type recording head in which an ink tank is integrally provided in the recording head itself.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus, to the present invention because the effects of the present invention can be further stabilized. Specifically, these are:
Capping means, cleaning means, pressure or suction means, preheating means using an electrothermal transducer or another heating element, or a combination thereof, and ejection other than recording for the recording head. It is also effective to perform a preliminary ejection mode to perform stable printing. Also,
Regarding the type and number of recording heads to be mounted, for example, in addition to one type that corresponds to a single color ink, a plurality of recording heads can be installed to correspond to a plurality of inks of different recording colors and densities. It may be something. That is,
For example, the recording mode of the recording device may be not only a recording mode for only the mainstream color such as black, but also a recording mode for multiple colors such as different colors, such as an integrated recording head or a combination of multiple heads. Alternatively, the present invention is also extremely effective for devices equipped with at least one full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid, but ink that solidifies at room temperature or below, softens or liquefies at room temperature, or ink jet In this method, the temperature of the ink itself is generally adjusted within the range of 30°C to 70°C to keep the viscosity of the ink within the stable ejection range. Any liquid may be used. In addition, the temperature rise caused by thermal energy can be actively prevented by using it as energy to change the state of the ink from a solid state to a liquid state, or ink that solidifies when left unused is used to prevent ink evaporation. In any case, the ink is liquefied by applying thermal energy according to the recording signal, and the liquid ink is ejected, or the ink already begins to solidify by the time it reaches the recording medium. The present invention is also applicable when using ink that is liquefied only by thermal energy.

[0023] The ink used in such a case is disclosed in Japanese Patent Application Laid-Open No. 1986-
56847 or Japanese Unexamined Patent Publication No. 60-71260, a form in which the porous sheet is held as a liquid or solid in the recesses or through holes and faces the electrothermal converter. You can also use it as In the present invention, the most effective method for each of the above-mentioned inks is to implement the above-mentioned film boiling method.

In addition, the inkjet recording apparatus according to the present invention can be used as an image output terminal for information processing equipment such as a computer, a copying apparatus combined with a reader, etc., and a facsimile apparatus having a transmission/reception function. It may also take the form of

[0025]

As is clear from the above description, according to the image forming apparatus of the present invention, by rotating the carriage, which has a recording means mounted at the tip thereof, about the carriage axis, Since the configuration is such that recording is performed on the recording material held on the circumference, it is possible to shorten the guide shaft of the carriage, eliminate dead space in the main body of the device, and achieve miniaturization of the device. An image forming apparatus is provided. According to another aspect of the present invention, in addition to the above configuration, the recording material is fed in parallel with the carriage axis, or the carriage is made extendable and retractable, thereby changing the movement path of the recording means. Since the rotation radius is adjustable to correspond to the size of the recording material, in addition to the above effects, a more efficient image forming apparatus is provided.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a main part configuration of an embodiment of an image forming apparatus to which the present invention is applied.

FIG. 2 is a side view of the image forming apparatus shown in FIG. 1;

3 is a perspective view of the recording means (recording head) shown in FIG. 1. FIG.

4 is a partial vertical sectional view showing the structure of an ink ejection section of the recording means of FIG. 3; FIG.

FIG. 5 is a side view showing main parts of another embodiment of an image forming apparatus to which the present invention is applied.

[Explanation of symbols]

1 Carriage 2 Recording means (recording head) 3
Carriage rotation motor 4 Carriage shaft 5 Carriage guide 6 Paper feed roller (conveyance roller) 7
Recording material 51 Discharge port surface 52 Discharge port 55 Electrothermal converter

Claims (5)

[Claims] 1. Recording is performed on a recording material held on a circumference centered on the carriage shaft by rotating a carriage having a recording means mounted on the tip thereof around the carriage shaft. Features of the image forming device. 2. The image forming apparatus according to claim 1, wherein the recording material is fed parallel to a carriage axis. 3. The image forming apparatus according to claim 1, wherein by making the carriage extendable and retractable, the rotation radius of the moving path of the recording means can be adjusted. 4. The image forming apparatus according to claim 1, wherein the recording means is an inkjet recording means including an electrothermal converter for generating thermal energy for ejecting ink. 5. The image forming apparatus according to claim 4, wherein the recording means ejects the ink from the ejection port by utilizing film boiling that occurs in the ink due to thermal energy applied by the electrothermal converter. Device.