JPH0392367A - Image forming device - Google Patents

Abstract

PURPOSE:To enable an individual image forming unit to be used as an independent one side printer in the case where one device has a plurality of image forming units by a method wherein independent image formation to be performed on individual transfer material is selectely constructed by respective image forming units. CONSTITUTION:(1) Face up paper delivery by one side printing, (2) face down paper delivery by one side printing, etc., are made capable of being selected by indication with a host computer for a laser printer. For example in the case of (1), face up paper delivery by one side printing can be performed even with an engine unit 18a parallel to one side printing (image forming) processing of an engine unit 18, and a transfer material 9a fed from a paper feed cassette 5a to the engine unit 18a, after forming the image, is delivered to a delivery tray 26a. Therefore, in the case where, for instance, interruption handling is performed, an interruption print can be obtained with one side engine unit 18a without discontinuing formation of the image which is now being processed with another engine unit 18.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus, such as a laser printer, an LED printer, an inkjet printer, a copying machine, and a word processor, which print on cut sheets, for example.

(Prior Art) Conventionally, as this type of image forming apparatus, there is a printer used as an output device of a personal computer, for example. As the cheapest and most widespread on the market,
Examples include wire dot printers. Other methods include laser printers and inkjet printers. LED
Printers and other devices called page printers are in high demand in the market due to their characteristics such as quietness, high speed, and high image quality. In addition to the above-mentioned characteristics, the cost reduction due to mass production has progressed, and the popularity of page printers has recently been increasing.

Furthermore, as computers with faster processing speeds appear year by year, printers are also required to have higher functionality and multifunctionality. For example, the printing speed is fast. Ichijipu I1-/Toka et al. Meirabu 11 sotohyaku, large capacity paper feed and ejection,
There is a demand for differentiated printers with high added value, such as multi-stage paper feeding and network support.

(Problem to be Solved by the Invention) However, in the case of the above-mentioned conventional technology, one printer cannot process one JOBL/;
Because B could not be processed simultaneously, two types of J
When processing OBs, it was necessary to process them one by one.

For example, when processing an interrupt JOB, that is, a JOB (■) while processing a JOB (■), it is necessary to finish processing the JOB (■) in the middle of the JOB (■), and then process and complete the JOB (■) again. Ta.

Furthermore, if a conventional printer malfunctions and becomes inoperable while processing a single-sided printing job, all functions of the printer must be interrupted at that point.

Furthermore, when a user wants to increase the number of prints in a single-sided printing job, they are required to purchase two identical printers in order to increase the processing speed.

The present invention has been made to solve the problems of the prior art described above, and its purpose is to convert each image forming unit into an independent single-sided printer when one device has a plurality of image forming units. An object of the present invention is to provide an image forming apparatus that can be used as an image forming apparatus.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, at least two or more independent image forming units are connected, and a series of image forming units are formed on one transfer material through the connected image forming units. The present invention is characterized in that it is configured such that it is possible to freely select between image formation and independent image formation performed on individual transfer materials by each image forming unit in a connected state.

In addition, when image forming units are connected, there is a standby system in which the supply of transfer material to the downstream image forming unit is temporarily on standby during the transport path of the transfer material from the upstream image forming unit to the downstream image forming unit. It is effective to have a mechanism.

(Function) In the present invention having the above configuration, when the image forming apparatus or units are connected, when viewed as a single image forming apparatus, it can support high functions and multi-functions such as double-sided printing, multiplex printing, color printing, etc. When looking at each image forming unit, parallel processing becomes possible for each unit.

Further, by temporarily putting the transfer material on hold from the upstream side to the downstream side of the image forming unit by the standby mechanism, the transfer material can be supplied in accordance with the processing timing of the downstream image forming unit.

(Examples) The present invention will be described below based on illustrated examples. FIG. 1 is a sectional view showing the main parts of a laser printer as an image forming device according to an embodiment of the present invention.

The laser beam is oscillated and scanned from the laser scanner L7 in response to the signal from the host computer. 4. The laser beam is reflected by the folding mirror 2 and forms a latent image on the photosensitive drum 3. This latent image is developed with developing toner (not shown), and a visible image is formed on the photosensitive drum 3, which is rotating in the direction of the arrow. Note that the photosensitive drum 3 constitutes a process cartridge 4 together with a developing device, a cleaner, a primary charger, etc., and images are formed by a known electrophotographic method.

On the other hand, the transfer material 9 stacked on the middle plate 7.8 of each of the upper and lower paper feed cassettes 5 and 6 is transferred by a known separation paper feed mechanism, that is, the rotation of each upper and lower paper feed roller 10.1l; When the feed rollers 10, 11 rotate, they interact with the separation pads 12, 13 that are in contact with them at a suitable angle and pressure.
The transfer materials 9 in the paper feed cassette selected to be fed are sequentially separated and fed from above.

After being fed, the transfer material 9 that has reached the pair of registration rollers 14 is temporarily stopped there, and the skew is corrected by creating an appropriate loop, and the leading edge of the transfer material is reliably guided to the roller nip.

Here, the transfer material 9 is synchronized with the image information on the photosensitive drum 3 described above, and is conveyed toward the transfer roller 15 when the registration roller pair 14 starts rotating. The image information is then transferred onto the transfer material 9 by passing through the nip formed by the photosensitive drum 3 and the transfer roller 15. The toner image transferred onto the transfer material 9 is fixed by passing through a thermal fixing device 16 .

Now, the laser scanner 1, heat fixing device 16, etc. mentioned above are as follows.
For example, they are positioned in an engine unit frame 17 (shaded area in the figure) which is integrally formed of glass-reinforced plastic. The fixing device 16 and the process cartridge 4 are
By positioning and fixing the engine unit to the frame 17, gears (not shown) are connected and driving force is transmitted to each gear. For example, when the engine unit frame 17 is attached to the main body,
A gear below the developing unit (not shown) meshes with a drive gear of a pair of registration rollers 14, which is a main body part, so that driving force is supplied from the main body.

In this way, as shown in FIG. 2, the engine unit 18 as an image forming unit is attached to the main body of the apparatus. The upper frame 1 of the engine unit 18 in the installed state
9 is rotatable around a hinge 20, and has a locking mechanism (not shown) between the engine unit frame 17 and can be opened and closed as an upper cover. Further, the folding mirror 2 and the process cartridge 4 can be held below the upper frame l9, and these are positioned at predetermined positions by closing the upper frame l9. When removing a jam or replacing the process cartridge 4, maintenance is performed by opening and closing the upper frame 19.

Next, with reference to FIG. 2, positioning of the engine unit 18 with respect to the main body will be described.

A relatively rigid main stay 21 made of, for example, an iron plate with a thickness of about 2 mm is arranged below the main body. This main stay 21 connects left and right main body side plates (not shown).

On the bottom surface of the engine unit l8, that is, vertically below the engine unit frame 17 and the center of the photosensitive drum 3, a boss 22 having a diameter of 6φ, for example, projects toward the front and back in FIG. Main stay 2 for these bosses 22
1 has two holes corresponding to the bosses 22 on the front and rear sides and two round holes. These fit into each other;
It is positioned and fixed at a predetermined location with screws or the like.

Furthermore, in the present invention, as shown in FIG. 3, another engine unit 18a is fixed with the engine unit 18 rotated 180@ to the left and right. Note that the engine unit 18 side and M-4 or corresponding parts are given the same reference numerals with the suffix a.

In the figure, the main stay 21 is located vertically above the center of the photosensitive drum 3 on the upper frame 19 of the engine unit 18.
A circular hole for positioning and a round elongated hole for positioning are provided, similar to those drilled in .

A boss 2 for positioning the engine unit frame 17a is attached to them.
2a is the ■Matching screw 1} - on the flute C7. , -r, engineering) The engine unit 18 and the engine unit 18a are connected and fixed. The conveyance direction of the transfer material 9 discharged from the engine unit 18 is switched by a flapper 23 which changes its direction between the solid line and the broken line using a solenoid (not shown).

In the laser printer having the above configuration, the following printing (image forming) operations can be selected according to instructions from a host computer (not shown).

That is, 1) Face-up paper output with single-sided printing 2) Face-down paper output with single-sided printing 3) Double-sided printing There are three cases.

In case 1), there is a gap between the flapper 23 and the guide plate 24, as shown by the solid line in FIG. 3, and the transfer material 9 fixed by the fixing device 16 shown in FIG. versus 25
As a result, the paper is ejected onto the paper ejection tray 26. At this time, the transfer material 9 discharged onto the paper discharge tray 26 is printed by the engine unit 18, and the operator can confirm the image.

In the case of 1), in parallel with the one-sided printing (image formation) processing of the engine unit 18, the engine unit 18a
However, face-up paper discharge is possible with single-sided printing, and the transfer material 9a fed from the paper feed cassette 5a to the engine unit 18a is discharged to the paper discharge tray 26a after image formation. That is, in the laser printer according to the present invention, with the engine units l8 and 18a connected, each engine unit 18.18a prints individual transfer materials 9, 9.
It is possible to perform image formation independent of a. Therefore,
For example, when interrupt processing is performed, an interrupt print can be obtained using the other engine unit without interrupting the image formation currently being processed by one engine unit. Furthermore, in the case of single-sided printing, the processing speed can be significantly reduced by outputting the same image using the engine units 18 and 18a.

In case 2), after printing is performed by the engine unit 18, the flapper 23 becomes as shown by the broken line in FIG. 3, and the transfer material 9
is turned upward and supplied to the engine unit 18a. However, in this case, the transfer material 9 is discharged onto the paper discharge tray 26a without printing in the engine unit 18a. Therefore, the transfer materials 9 are placed on the paper discharge tray 26a with the printing surfaces facing downward (face down) and arranged in page order when viewed from the printing surfaces. In this manner, in the laser printer according to the present invention, the independent engine units 18, 18a are connected, and the connected engine units 18, 18a are connected to each other.
．． A series of image shapes (single-sided printing) can be performed on one transfer material 9 through 18a.

In case 3), similarly to case 2), after the engine unit 18 prints, the flapper 23 becomes as shown by the broken line in FIG. 3, and the transfer material 9 changes direction upward and is transferred to the engine unit 18a. Supplied. However, in the case of 3), after the transfer material 9 is printed on the back side by the engine unit 18a, it is discharged onto the paper discharge tray 26a. In this way, in the laser printer according to the present invention, the engine unit 181
A series of image formation (double-sided printing) can be performed on one transfer material 9 through 8a.

FIG. 4 shows a laser printer as an image forming apparatus according to another embodiment of the present invention, from the upstream engine unit 18 to the downstream engine unit 18a.
FIG. 3 is a partially enlarged view of a connecting conveyance path 27 for the transfer material 9 until the transfer material 9 reaches the position shown in FIG.

In the figures, the same or equivalent parts as in the above embodiment are given the same reference numerals.

In this embodiment, a standby roller 3l as a standby mechanism is provided in the connecting conveyance path 27 and upstream of the pair of registration rollers 14a included in the engine unit 18a. and,
The supply of the transfer material 9 to the engine unit 18a is temporarily put on standby by the standby roller 31. The reason for this structure is as follows. That is, in the embodiment described above, the transfer material 9 transferred by the engine unit 8 was immediately fed to the engine unit 18a, and image formation was subsequently performed. According to the configuration of the above embodiment, the storage device of the main body must have a storage capacity for two pages on both sides.

However, according to this embodiment, after printing is performed by the engine unit 18, the transfer material 9 is made to wait by the standby roller 31, and during this time, the stored information of the first page is erased and the information of the second page is memorized. By doing so, the storage capacity of the main body storage device can be half that of the first embodiment. Therefore, information from a host computer (not shown) is transferred to, for example, an EP-R.
If stored in OM, EP-R per unit
Although the price of OM is expensive, the cost of the printer itself is reduced because the storage capacity is halved.

Further, colored paper is discharged from the paper feed cassette 5a without being printed by the engine unit 18a, and later the transfer material 9 by the engine unit 18, which has been kept on standby by the standby roller 31, is discharged to the paper discharge tray 26a, and the printed matter is Sorting is possible by inserting colored paper between them.

In the above embodiment, two image forming units are connected, but the present invention is not limited to this.
It is also possible to implement a stage structure or a four-stage structure.

In addition to laser printers, we also have LED printers. The present invention can also be applied to image forming apparatuses such as inkjet printers, copying machines, and word processors.

(Effects of the Invention) The present invention has the above-described structure and operation, and allows image forming units to be added according to required functions, and each image forming unit constituting one image forming apparatus. can be used as an independent single-sided printer. Therefore, by using a single image forming unit, a plurality of single-sided printing processes can be performed in parallel, and the processing time for single-sided printing can be significantly shortened. For this reason,
The number of prints per unit time can be increased.

In addition, since each image forming unit that makes up the image forming apparatus can be used independently, even if interrupt processing or one of the units fails, processing can be continued with other units, eliminating wasted time. can be reduced.

In addition, by temporarily holding the supply of transfer material from the upstream side of the image forming unit to the downstream side using the standby mechanism, the transfer material can be supplied in accordance with the processing timing of the downstream image forming unit. Timing can be controlled.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the main parts of a laser printer as an image forming apparatus according to an embodiment of the present invention, FIG. 2 is a view showing the device configuration when there is one image forming unit, and FIG. 2 is a block diagram showing another image forming unit connected to the apparatus shown in FIG. 2, and FIG. 4 is a partially enlarged view of an image forming apparatus according to another embodiment of the present invention. Description of symbols 9, 9a...Transfer material 18.18a...Engine unit (image forming unit) 27...Connection conveyance path 3 1...Standby roller (standby mechanism)

Claims (2)

[Claims] (1) At least two or more independent image forming units are connected, and a series of image formation is performed on one transfer material through the connected image forming units, and a series of image formation is performed on a single transfer material by each image forming unit in the connected state. An image forming apparatus characterized in that an image forming apparatus is configured such that independent image formation is selectively performed. (2) When the image forming units are connected, the supply of transfer material to the downstream image forming unit is temporarily put on standby during the connected conveyance path of the transfer material from the upstream image forming unit to the downstream image forming unit. 2. The image forming apparatus according to claim 1, further comprising a standby mechanism for causing the image forming apparatus to wait.