JPH04112161A - Image forming device - Google Patents

Abstract

PURPOSE:To horizontally place a sheet member even if the placed sheet member is dried and warped up by constituting a discharge/loading member which loads the sheet member discharged by a discharge means so that the sheet loading surface is curved upward. CONSTITUTION:After the recording by a recording head, a sheet member 3 is discharged on a discharge tray 10 by a discharge roller 9a as discharge means and a discharge roll 9b. At this time, the sheet member 3 is placed along the projection surface of the discharge tray 10 as shown by 3a, since moisture is rich immediately after discharge and the sheet member 3 is not tough. As moisture is evaporated and toughness is restored, both the edge parts are floated upward as shown by 3b. Since both the edge parts of the discharge tray 10 are lower by a height H than that at the center part, the sheet member 3 can be placed in a nearly horizontal state, even if the sheet member 3 is dried and warped up. Accordingly, the sheet member 3 placed on the discharge tray 10 can be easily taken up, and the obstruction for the sheet member 3 which is to be discharged next can be prevented.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, a printer, etc., and an image forming apparatus used as an output device for such multifunction machines, workstations, etc. be.

<Prior Art> Conventionally, image forming apparatuses such as copying machines and printers generally feed a sheet material from a paper feeder, form an image according to image information using an image forming means, and then remove the sheet material from the apparatus using an ejecting means. The device is configured to eject to an ejection tray provided in the.

For example, as shown in FIG. 6(a), an image forming apparatus 50
The discharge tray 52 provided on the downstream side of the discharge rollers 51a and 51b was configured such that its cross-sectional shape perpendicular to the sheet conveyance direction was a horizontal plane. Furthermore, even if small rib-like protrusions were provided on the surface of the discharge tray 52, the line connecting the tops of the protrusions was substantially horizontal.

<Problems to be Solved by the Invention> However, with the above configuration, for example, in an inkjet type or bubble jet type image forming apparatus, a large amount of ink containing moisture is ejected onto the sheet material 53. Since the printed side stretches and the back side remains unchanged, it curls downward (convex toward the printed side) during image formation.

However, when the sheet material 53 is discharged onto the discharge tray 52 and the moisture gradually evaporates, the sheet material 53 is discharged onto the discharge tray 52 and the water content gradually evaporates.
Curl upward (convex to the back side) as shown in 3a to 53b. If the sheet material 53 curled in this manner is left undisturbed, it may become difficult to handle because it may obstruct the next sheet material to be ejected or the edges may curl up.

An object of the present invention is to solve the above-mentioned conventional problems by curving the sheet stacking surface of the discharge stacking member upward for stacking sheet materials after being discharged, so that even if the stacked sheet materials dry, they can be stacked horizontally. The aim is to provide an image forming apparatus that can.

”〈Means for Solving the Problems〉 A typical means according to the present invention for solving the above problems includes a feeding means for feeding a sheet material, and a sheet fed by the feeding means. An image forming means for forming an image on a material according to image information, a discharging means for discharging the sheet material after the image formation, and a discharging and stacking member for stacking the sheet material discharged by the discharging means. The discharge stacking member has a sheet stacking surface curved upward.

<Operation> In the above means, the discharge stacking member for stacking the sheet materials discharged by the discharge means is configured such that the sheet loading surface curves upward, so that the loaded sheet materials dry and warp. It can also be placed horizontally.

<Embodiment> Next, an embodiment of the present invention in which the above means is applied to a line type bubble jet recording apparatus will be described.

1(a) and (b) are explanatory diagrams of the ejection tray, FIG. 2 is a sectional explanatory diagram showing the schematic configuration of the recording apparatus, FIG. 3 is an explanatory diagram of the configuration of the recording head, and FIGS. 4(a) to ( 6) is an explanatory diagram of the bubble jet recording principle.

First, the general structure of the recording device will be explained with reference to FIG. 2. The recording device is composed of a document reading section A and a recording section B. configured to record.

The document reading section A has a built-in part of a scanner that scans the document 1 with the document scanning unit 2, reads the document image, and converts it into an electrical signal.

The document scanning unit 2 includes a rod array lens 2a.
, 1-magnification color separation line sensor (color image sensor)
2b and an exposure means 2c are built in. When the document scanning unit 2 is moved and scanned in the direction of arrow X to read the image of the document 1 on the document table, the exposure lamp is turned on and the reflected light from the document 1 is guided to the rod array lens 2a. The light is focused on the same-magnification color separation line sensor 2b, which is a color information reading sensor, and the color image information of the original 1 is converted into an electrical digital signal. This digital signal is sent as a drive signal to recording section B, which will be described later.

Next, a sheet material 3 such as cut paper is placed at the bottom of the recording section B.
It is equipped with a cassette 4 which is loaded and stored. A pickup roller 5 constituting a feeding means for feeding the sheet material 3 is installed near the cassette 4.
The purpose is to feed the sheet materials 3 loaded and stored in the cassette 4 to the downstream side.

Sheet material 3 fed by the pickup roller 5
is conveyed to the belt conveyance section 7 after its skew is corrected by a pair of registration rollers 6a and 6b.

When the sheet material 3 passes through the conveyance section 7, a recording head 8 serving as a recording means is
is moved to a recording position opposite to the belt conveying section 7. At this time, the gap between the recording head 8 and the belt conveyance section 7 is generally kept at 1- or less. Then, the recording head 8 performs recording using each ink such as cyan, magenta, yellow, and black in accordance with the drive signal transmitted from the document reading section A.

The sheet material 3 after recording is discharged through a fixing discharge section 9, which is a discharge means, to a discharge tray 10, which is a discharge and stacking member provided outside the apparatus.

Incidentally, reference numeral 11 denotes a recovery cap portion for maintaining the recording head 8 in a state in which printing is possible at all times.

In the above configuration, since the printing range of the recording head 8 covers the width of the sheet, the entire image can be formed just by passing the sheet material 3 under the recording head 8, compared to a serial type recording head. High-speed printing is possible. Further, since the recording head 8 does not move during printing, stable recording can be performed.

Next, as the recording head 8, an inkjet recording method is suitably used.

The inkjet recording method includes a liquid ejection port for ejecting recording ink liquid as flying droplets, a liquid flow path communicating with the ejection port, and a part of this liquid flow path. and ejection energy generating means for providing ejection energy for causing the ink liquid to fly. The ejection energy generating means is then driven in accordance with the image signal to eject ink droplets and record an image.

As the ejection energy generation means, for example, a method using a pressure energy generation means such as an electromechanical transducer such as a piezo element, a method in which electromagnetic waves such as a laser are irradiated and absorbed by the ink liquid to generate heat, and the ink is ejected by the action of the heat generation. There is a method using an electromagnetic energy generating means that causes the ink to flow, or a method using a thermal energy generating means that heats the ink liquid using an electrothermal converter and ejects the ink. Among these methods, the method of ejecting ink using a thermal energy generating means such as an electrothermal converter is capable of high-resolution printing because liquid ejection ports can be arranged in a high density, and the print head is compact. It is suitable because it can also be

In this embodiment, a line-type bubble jet recording method, which is one of the inkjet recording methods described above, is used as a recording means.

FIG. 3 is an explanatory diagram of the configuration of the recording head 8 constituting the recording means, and FIGS. 4(a) to 4(b) are explanatory diagrams of the bubble jet recording principle.

In FIG. 3, an electrothermal converter (discharge heater) 8b and an electrode 8C made of aluminum or the like for supplying power to the converter 8b are formed on a silicon substrate 8a through semiconductor manufacturing process steps such as etching, vapor deposition, and sputtering. It is arranged with a membrane. It is constructed by adhering to this substrate 8a a top 81 having a partition wall 8e for partitioning a recording liquid channel (nozzle) 8d. Further, an ink cartridge for supplying ink to the recording pad 8 is replaceably attached to a predetermined position of the apparatus.

The ink supplied from the ink cartridge through the liquid supply pipe 8g is supplied to the connector 8h provided on the top plate 8f.
The common liquid chamber 81 in the recording head 8 is filled with the liquid, and from this common liquid chamber 81 it is guided into each nozzle 8d. Ink ejection ports 8d are formed in these nozzles 8d, and the ejection ports 8d1 are arranged at a predetermined pitch (e.g., ejection port density: 16 nozzles/ all). This makes it possible to configure a multi-nozzle bubble jet recording head 8 in which the ejection ports 8dl are provided over the entire recording width.

Here, the principle of ink flying in the bubble jet recording method will be explained with reference to FIGS. 4(a) to 4(Cb).

In a steady state, as shown in FIG. 4, the surface tension and external pressure of the ink 12 filled in the nozzle 8d are balanced on the ejection port surface. When the ink 12 is ejected in this state, Electricity is applied to the electrothermal converter 8b in the nozzle 8d to cause the ink in the nozzle 8d to rapidly rise in temperature beyond nuclear boiling.As shown in FIG. 4(b),
The ink adjacent to the electrothermal converter 8b is heated to form microbubbles 13, and the ink 12 in the heated portion is vaporized to cause film boiling, and the bubbles are formed as shown in FIG. 4(C). Engineering 3 grows at an exponential rate.

When the bubble 13 grows to the maximum as shown in FIG. 4(d), an ink droplet is pushed out from the ejection opening 8d1 in the nozzle 8d. When the electricity is turned off to the electrothermal converter 8b, the grown bubbles 13 are cooled and contracted by the ink 12 in the nozzle 8d, as shown in FIG. 4(e). Droplets fly from the discharge port 8dl. Furthermore, as shown in FIG. 4(f), the ink contacts the surface of the electrothermal converter 8b and is rapidly cooled, causing bubbles 13.
disappears or shrinks to an almost negligible volume. When the bubble 13 contracts, ink is supplied from the common liquid chamber 8g into the nozzle 8d by capillary action, as shown in FIG. 4 (80), in preparation for the next energization.

Therefore, an ink image is recorded on the sheet material 3 by energizing the electrothermal transducer 8b according to the image information in synchronization with the conveyance of the sorting material 3.

In the inkjet recording method, the recovery camp 11 is provided at the end of the movement range of the recording head 8 as described above.
It is preferable to provide

The recovery cap portion 11 has the function of covering the ink ejection surface of the print head 8 during non-printing, thereby preventing the ink near the ejection ports of the print head 8 from drying out and from solidifying accordingly. .

In addition, it is recommended to connect a pump to this recovery means and drive the pump in order to prevent ink discharge failure, removal, or the like, and use its suction force to suck ink from the discharge port and perform recovery processing. FIGS. 1(a) and 1(g) show the structure of the ejection tray 10 installed in the above-mentioned recording apparatus.
).

The sheet stacking surface of the discharge tray 10 is curved upward (convex) as shown in FIG. 1 et al. That is, tray 10
The central portion of the cross section perpendicular to the sheet conveyance direction is configured to be higher by a height H than both end portions. The height difference H between the curved top and end depends on the type of sheet material 3, but is preferably about 5 to 50 mm.

In FIG. 1(a), after the sheet material 3 is recorded by the recording head 8, a discharge roller 9 serving as a discharge means
a and discharge rollers 9b onto the discharge tray 10.

At this time, as shown in FIG. 1(b), the sheet material 3 has a high moisture content immediately after being discharged and is not strained, so that it is placed along the convex surface of the discharge tray 10 as shown in 3a. However, as the water evaporates and the strainer returns, the ends begin to float upwards, as shown in 3b.

However, since both ends of the discharge tray 10 are made lower than the center by the height H in advance, even if the sheet material 3 dries and warps, it can be placed in a nearly horizontal state.

Therefore, the sheet material 3 stacked on the discharge tray 10 can be easily picked up, and can be prevented from interfering with the next sheet material 3 to be discharged.

<Other Embodiments> Next, other embodiments of the discharge/loading member in the above embodiment will be described with reference to FIGS. 5(a) and 5(b).

In this embodiment, as shown in FIG. 5(a), the ejection tray 14
A plurality of ribs 14a having different heights are formed on the sheet loading surface.

As shown in FIG. 5, the height of the rib 14a is highest at the center of the cross section perpendicular to the sheet conveying direction of the tray 1O, and decreases as it approaches both ends 5. That is, the loading surface of the sheet material 3 formed by connecting the tops of the ribs 14a is curved upward. - According to the above configuration, after the sheet material 3 is discharged onto the discharge tray 14, the gap between the ribs 14a is formed on the back side, so that the ink can be dried quickly. Moreover, it is possible to easily pick up the sheet material 3 stacked on the discharge tray 14 by inserting a finger into the gap.

Although each of the above embodiments has been described with respect to a tray that is applied alone to an image forming apparatus, the present invention is not limited to this, and can also be applied to, for example, a sorter bin having a plurality of movably mounted trays. .

Further, as for the configuration of the recording means, in addition to the combination of the above-mentioned discharge hole, liquid path, and electrothermal converter, the heat acting part is arranged in a bending area. It is also possible to employ those disclosed in Japanese Patent No. 59-123670 and the like.

Further, the recording means described above is an i-2 installed in the recording device.
Although we have shown an example in which ink is supplied from the cartridge to the recording head, it is a disposable type in which an ink storage chamber is provided in the recording head, and the recording head is replaced when the ink in the ink storage chamber runs out. A (disposable type) recording head may also be used.Although the above-mentioned embodiments have exemplified a red-cell bubble jet recording method, it is also possible to apply the present invention to a serial type recording method.

Historically, the present invention is described as a recording means.
- There is no need to limit the recording method. For example, an ink notebook coated with hot-melt ink is heated according to an image signal,
The so-called thermal transfer recording method transfers molten ink to a recording notebook, the so-called thermal recording method heats a recording sheet that develops color with heat in accordance with an image signal, and the so-called so-called thermal recording method records by striking an ink ribbon with a wire according to an image signal. It is possible to adopt various recording methods such as wired, 51 recording methods, etc. 3 Therefore, the recording head can also be the above-mentioned Huffler:
Not limited to engineering, tohe, 7 de, for example 7 F to thermal
, a wire F' y head, a daisy wheel head, etc. can be used.

The form of the interjet or bubble jet recording apparatus described above can also be applied to a facsimile machine or the like having a transmission/reception function.

<Effects of the Invention> As described above, the present invention comprises a discharge stacking member for stacking sheet materials discharged by a discharge means such that the sheet loading surface is curved upward, so that the loaded sheets are Even if the wood dries and warps, it can be placed horizontally.

Therefore, the notebook material on the discharge stacking member can be easily handled.

In particular, when a plurality of J-shaped ribs are formed on the sorting and stacking surface of the discharging and stacking member, gaps between the ribs are formed on the back side after the sheet material is discharged onto the discharging and stacking member, so that the ink dries. can be accelerated. Further, there is an effect that it is easy to pick up the sheet material stacked on the discharge stacking member by inserting a finger into the gap.

[Brief explanation of drawings]

1(a) and (b) are explanatory diagrams of the ejection tray, FIG. 2 is a sectional explanatory diagram showing the schematic configuration of the recording apparatus, FIG. 3 is an explanatory diagram of the configuration of the recording throat, and FIGS. (6) is an explanatory diagram of the bubble jet recording principle, FIGS. 5(a) and (b) are explanatory diagrams of the other side of the discharge/loading member, and FIGS. 6(a) and (b) are explanatory diagrams of the conventional example. . A is a document reading section, B is a recording section, 1 is a document, 2 is a document scanning unit, 2a is a Rondo array lens, 2b is a same-magnification color separation line sensor, 2c is an exposure means, 3 is a sheet material, 4
is a cassette, 5 is a vinyl roller, 6a and 6b are a pair of registration rollers, 7 is a heald a feed section, 8 is a recording head,
8a is a substrate, 8b is an electrothermal converter, 8c is an electrode, 8d is a nozzle, 8a is a discharge port, 8e is a partition, 8f is a top plate, 8
g is the liquid supply pipe, 8h is the connector, 8I is the common liquid chamber, 9
is a fixing discharge section, 9a is a discharge roller, 9b is a discharge roller,
10.14 is a discharge tray, 11 is a recovery camp, 12 is ink, 13 is a bubble, and 14a is a rib.

Claims (5)

[Claims] (1) A feeding means for feeding the sheet material, an image forming means for forming an image on the sheet material fed by the feeding means according to image information, and discharging the sheet material after the image formation. and a discharge stacking member for stacking the sheet materials discharged by the discharge means, and the discharge stacking member has a sheet stacking surface curved upward. Image forming device. (2) The image forming apparatus according to claim 1, wherein the discharge stacking member has a plurality of ribs formed on a sheet stacking surface. (3) The image forming apparatus according to claim 1, wherein the image forming apparatus is of an inkjet type in which the image forming means forms an image by ejecting ink according to a signal. (4) The image forming apparatus is of an inkjet type in which the image forming means energizes an electrothermal converter in response to a signal, and uses thermal energy from the electrothermal converter to eject ink to form an image. The image forming apparatus according to claim (3). (5) In the image forming apparatus, the image forming means energizes the electrothermal transducer in response to a signal, and the ink is ejected from the ejection port by the growth of bubbles caused by heating exceeding film boiling by the electrothermal transducer. The image forming apparatus according to claim 4, which is a bubble jet type image forming apparatus that forms an image using a bubble jet method.