JPH04166854A - Electrophotographic printer - Google Patents

Abstract

PURPOSE:To enable printing on special paper by changing a process speed in the case that it is judged by a paper judging means that a manual paper feeding is selected. CONSTITUTION:Judgement whether manual paper feeding or automatic paper feeding is selected is carried out by a paper supply judgement means M1, and when the selection of manual feeding is judged, a process speed is changed by a process speed control means M2. In the case that it is judged that specific paper such as envelopes, thick paper and the like are manually fed, for example, an image forming speed by a polygonal mirror and the like as well as a paper supply speed being the process speed by a roller and the like are for example reduced. It is thus possible to improve perform printing on such special paper.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic printer having both manual paper feeding and automatic paper feeding.

[Prior Art] Conventionally, this type of electrophotographic printer has been provided with an automatic paper feeding mechanism that stacks a large number of sheets of normally used paper and automatically feeds the paper. In accordance with this automatic paper feeding, optimal printing conditions, such as printing speed for paper feeding, heat fixing, etc., are set in advance.

However, in these printers, which have become smaller in recent years, the paper transport path provided for automatic paper feeding is provided with a certain degree of curvature. When using paper such as paper, automatic paper feeding was difficult.

Therefore, in order to print on these special types of paper, in addition to the paper path for automatic paper feeding, a special path that does not put an extra load on the paper, such as a paper path with less curvature, is provided. These special papers were fed into the printing area by manual paper feeding from here [Problem to be solved by the invention] However, even if such a manual paper feeding path is provided, automatic paper feeding is not possible. When printing on special paper such as envelopes or thick paper under normal printing conditions, uneven printing or blurring may occur, making it difficult to print with good quality. Furthermore, under such printing conditions, paper jams are likely to occur, and printing must be stopped frequently.Furthermore, in the case of manual paper feeding, the user has to hold the paper in his/her hand while feeding it. There is a problem in that the paper feeding speed must be set to a low value because if the paper is fed at a high speed, the paper may cut the user's hand on the side edge of the paper.

The present invention has been made to solve the above-mentioned problems, and is an electrophotographic printer that can print well on special paper such as manually fed envelopes and cardboard, and can print safely and at high speed. The purpose is to provide.

[Means for Solving the Problems] In order to achieve this object, the present invention selectively switches between manual paper feeding and automatic paper feeding from a paper storage unit, as illustrated in FIG. In an electrophotographic printer that is used and prints at a predetermined process speed, the paper feed determination means M1 determines whether the manual paper feed or automatic paper feed is selected, and the paper feed determination means M] process speed control means M for changing the process speed when it is determined that the manual paper feeding is selected;
2, and an electrophotographic printer characterized by the following.

[Function] The present invention switches between manual paper feeding and automatic paper feeding, and print processing is executed at a predetermined process speed, that is, a predetermined speed when paper feeding, image formation, etc. are performed.

Then, the paper feed determining means M] determines whether manual paper feeding or automatic paper feeding is selected, and if it is determined that manual paper feeding is selected, the process speed is The process speed is changed to =4- by the control means M2.

For example, if it is determined that special paper such as envelopes or cardboard is being fed manually, the process speed, such as the paper feeding speed using rollers or the image forming speed using polygon mirrors, etc., may be reduced. , which makes it possible to print solid images on special paper.

In addition, in the present invention, since the process speed is changed in the case of manual paper feeding, in other words, the optimal printing conditions can be set for manual paper feeding and automatic paper feeding, so It is possible to set the printing speed higher in advance for automatic paper feeding without being limited by the printing speed.

[Example] Hereinafter, an example embodying the present invention will be described with reference to the drawings.

FIG. 2 shows the external appearance of the laser printer of this embodiment, and the external configuration of the laser printer will be explained based on this figure.

The laser printer is composed of an upper housing 2 and a lower housing 3. The upper housing 2 is connected to the lower housing 3 around a hinge portion (not shown) so as to be freely openable and closable.

A paper feed cassette 4 for loading ordinary paper is removably housed inside the lower housing 3. Above the paper feed cassette 4, there is a paper feed port 5 and a paper lower guide 6a.
A manual paper feed section 7 is provided which includes paper lateral guides 6b and 6C. Further, above the manual paper feed section 7, a control panel 9 is provided which includes a start button 9a and the like.

On the top of the laser printer 1, there is a face-down tray O for loading printed paper with the print side facing down.On the other hand, on the back side of the laser printer 1, there is a tray with the print side facing up. Face-up tray to be placed] 1
(Fig. 3) are arranged.

Next, the internal configuration of the laser printer 1 will be explained using FIG. 3.

Two paper conveyance paths, one for automatic paper feeding and one for manual paper feeding, are formed so as to traverse the interior of the laser printer.

Among these conveyance paths, the conveyance path for automatic paper feeding runs from an automatic sheet feeding section] 3 that automatically feeds paper, to a registration section 14 that adjusts the image transfer timing. Process cartridge 1
5 and an image transfer discharge device] 6] 7. Image fixing device 18 which heats and fixes the image. It is configured to reach the face-down tray 10 via a switching member 19 for switching the paper discharge path, a face-down paper discharge path 20, and the like.

On the other hand, the conveyance path for manual paper feeding starts from the manual paper feeding section 7.
The resist portion 14. Image transfer section]7. Image fixer 18. Switching member 19. The sheet is configured to reach the face-up tray 1 via the face-up paper discharge path 2].

Each configuration will be explained in detail below.

The automatic paper feed section 13 is provided in the lower housing 3 to automatically feed paper sheets one by one. It is composed of a half-moon-shaped paper feed roller 23, feed rollers 24, 25, and the like.

On the other hand, the manual paper feed unit 7 includes a manual feed detection sensor (switch) 27, which is turned on when manual paper is inserted, in addition to the above-mentioned paper feed port 5° paper lower guide 6a and paper horizontal guides 6b and 6c. It is composed of feed rollers 28, 29, etc. that transport the paper within the main body of the apparatus.

The registration section 14 includes a nip section 30 where the paper is temporarily placed on standby.
．． Registration upper roller 3] and registration lower roller 32
etc., both rollers 31. On the upstream side of 32,
A conveyance detection sensor 33 is arranged to detect the conveyance state of paper.

The paper transport path 34 from the manual paper feed section 7 and the paper transport path 35 from the automatic paper feed section 13 are configured to merge in front of the transport detection sensor 33.

The image transfer unit 7 forms and transfers images, and is composed of a process cartridge 15 and an image transfer discharger 6, which are disposed opposite to each other with a paper conveyance path 37 in between. This process cartridge 15 includes a drum-type electrophotographic photoreceptor (hereinafter referred to as drum) 38. Charger 39. Exposure section 40. Developing device 41. Each process such as the cleaning device 42 is combined into a cartridge.

A laser scanner unit 45 is arranged above the process cartridge 15 . This laser scanner unit 45 is for performing scanning exposure on the drum 38, and is composed of a semiconductor laser 462, a rotating pot mirror (polygon mirror) 47, an fθ lens 48, a reflecting mirror 49, and the like.

The image fixing device 18 is disposed on the downstream side of the paper conveyance path 37, and uses a heating roller 52 equipped with a heater 50 and a pressure roller 53 to heat and press the paper onto which the image has been transferred, thereby fixing the image. This is to establish the system.

The switching member]9 is provided on the downstream side of the image fixing device]8.
Image fixing device] Manually switch the ejection direction of the paper sent from the feed rollers 56 and 57 of 8 to the direction of arrow A or B to the face-down paper ejection path 20 or the face-up paper ejection path 2] The changes will be made to:

In addition, the laser printer configured as described above is equipped with an electronic control unit (ECU) shown in FIG. 4 to control its operation.
) 60 are provided.

This ECU 60 includes well-known RAM 60a and ROM 60b.
, a CPU 60c, an input port 0d, an output port 0e, and a pass line 60f connecting them. Note that the ROM 60b stores the paper feeding speed, the rotation speed of the polygon mirror 47, etc., depending on whether automatic paper feeding or manual paper feeding is used.

A manual feed detection sensor 27 that detects the supply of paper from the manual paper feed section 7 and a conveyance detection sensor 33 that detects the arrival of the paper at the registration section]4 are connected to the input port 0d. On the other hand, a conveyance drive motor 62 that drives each feed roller etc. is connected to the output port 0e via a conveyance drive circuit 61. A heater drive circuit 64 that controls the voltage applied to the heater 50 is also connected. Polygon mirror drive motors 66 for driving the polygon mirrors 47 are connected to each other via a polygon mirror drive circuit 65.

Next, the operation of the laser printer of this embodiment having the above configuration will be explained.

i) First, we will explain the case of automatic paper feeding, but usually the paper feeding speed and polygon mirror 4 are adjusted depending on the automatic paper feeding.
A rotation speed of 7 or the like is set, and the paper conveyance path is also adjusted to the face-down paper discharge path 20.

First, when the start button 9a is pressed, paper is fed from the paper feed cassette 4, and here, the half-moon paper feed roller 23
As a result, the sheets in the paper feed cassette 4 are sent out toward the registration section 141 one by one with each rotation.

The paper sent out from the paper feed cassette 4 passes through the conveyance detection sensor 33, and after the leading edge is once received by the nip portion 30 of the registration rollers 31 and 32, which are stopped at that point, the paper is rotated at a predetermined timing. The driven registration rollers 31 and 32 transport the image toward the image transfer section 17 .

Image recording in this image transfer section 17 is performed as follows.

The drum 38 is driven to rotate in the direction of arrow C. The entire surface of the drum 38 is pre-exposed by a pre-exposure lamp 43 (FIG. 3).
and is charged by a charger 39. Next, the exposure section 40
By receiving laser scanning exposure at
An electrostatic latent image of the target image is formed on the circumferential surface of 8.

For this laser beam scanning exposure, a laser beam is output from the semiconductor laser 46 to the polygon mirror 47 . Then, the scanning speed relative to the rotation angle of the polygon mirror 47 is converted to a substantially constant speed by the fθ lens 48.The output direction is changed via the reflection mirror 49, and the scanning exposure of the laser beam to the surface of the drum 38 is changed. It will be done.

The electrostatic latent image formed on the drum 38 in this manner is developed with toner by a developing device 41 and is transported between the drum 38 and the image transfer discharger 16.

Then, by discharging the image transfer discharge device 6, the image after toner development is sequentially transferred. The sheet of paper that has received the toner image transfer is then sequentially separated from the surface of the drum 38.
The paper is introduced into the image fixing device 18 via the paper transport path 37.

In the image fixing device 18, the image is fixed by controlling the supply of power to the heater 50 so that the surface temperature of the heating roller 52 is constant.

Thereafter, the printed paper conveyed by the rollers 56 and 57 of the image fixing device 18 is guided by the switching member 19 to the face-down paper discharge path 20, and the printed paper is placed on the face-down tray 10 at the top of the main body. It is discharged with the side facing down.

11) Next, the case of manual paper feeding will be explained with reference to the flowchart in FIG.

When feeding paper manually, first, manually (2) switch the switching member 1.
9 in the direction of arrow B to change the paper conveyance path to the face-up paper discharge path 21 side.

Then, when paper to be manually fed is inserted into the paper feed port 5, a switch that is the manual feed detection sensor 27 is turned on, and the insertion of the paper is detected (step 100).

Based on the signal from the manual feed detection sensor 27, the following manual feed mode setting is performed in the ECU 60.

That is, in order to reduce the paper feeding speed, the rotation speed of the transport drive motor 62 is controlled to a low speed for manual feeding (step 1] O), and at the same time, in order to reduce the image forming speed, the rotation speed of the transport drive motor 62 is controlled to a low speed for manual feeding. The rotation speed of the drive motor 66 is controlled to a low speed for manual feeding (
Step 120). At this time, the drive of the half-moon paper feed roller 23 is stopped so that automatic paper feeding is not performed.

In this state, the paper inserted manually is moved by the feed rollers 28 and 29 to the registration section]4.
transported to. After that, as in the case of normal paper fed automatically, the manually fed paper passes through the conveyance detection sensor 33, and after the leading edge is once received by the nip section 30,
Registration roller 31 with reduced speed for manual feeding,
32 to the image transfer section]7.

In the image transfer section 17, the laser beam from the polygon mirror 47 whose speed has been reduced for manual feeding is used to expose the drum 38 whose speed has also been reduced, and the image is transferred in almost the same procedure as the automatic paper feeding described above. will be held.

Thereafter, the transferred paper sent from the image transfer unit 17 to the image fixing device 18 is sufficiently heated by the heating roller 52 and the pressure roller 53, whose speeds are also reduced, to fix the image. .

Then, the heat-fixed paper fed from the feed rollers 56 and 57 of the image fixing device 18 at a speed reduced for manual feeding is sent to the face-up paper ejection path 2 by the switching member 19. is placed on the upload tray 1].

In this way, the laser printer 1 of this embodiment uses the manual feed detection sensor 27 to detect whether or not manual paper feeding has been performed, and when manual paper feeding has been performed, the various rollers are Control is performed to reduce process speed such as speed and rotational speed of the polygon mirror 47. Therefore, even if the manually fed paper is a special paper such as an envelope or cardboard, high-quality printing can be easily performed.

In addition, in the case of manual paper feeding, since the process speed is reduced, the speed at which the paper is drawn into the device is low, so there is an advantage that the paper is not injured when manually feeding the paper.

Furthermore, this allows the printing speed to be set to a high speed that normally corresponds to automatic paper feeding, so it has the remarkable feature that the printing speed can be extremely fast.

In particular, by changing (for example, decreasing) the feeding speed of the heating roller 52 among the process speeds, the amount of heat applied to the paper can be changed, so that it is possible to suitably heat fix a special paper.

As another embodiment of the present invention, for example, the rotation speed of the polygon mirror 47 is substantially reduced by writing on one or every other surface depending on the number of surfaces of the polygon mirror 47. You can also do that.

[Effect of the invention 1] The present invention determines whether manual paper feeding or automatic paper feeding is selected, and changes the process speed if manual paper feeding is selected, so that special paper etc. cannot be fed manually. When paper is fed, high quality printing can be suitably performed. Also, by reducing the process speed, for example, it is possible to reduce the paper feed speed for manual feed, thereby preventing user injury, and furthermore, thereby, it is possible to preset the printing speed for automatic paper feed to be faster. I can do it.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing the present invention, FIG. 2 is a perspective view showing the laser printer of this embodiment, FIG. 3 is an explanatory diagram showing its internal structure, FIG. 4 is a block diagram showing the ECU, FIG. 5 is a flowchart showing control of manual paper feeding. 1...-Laser printer 27--Manual feed detection sensor 60...Electronic control unit (ECU) 6]...Transport drive motor 66...Polygon mirror drive motor

Claims (1)

[Scope of Claims] 1. An electrophotographic printer that prints at a predetermined process speed by selectively switching between manual paper feeding and automatic paper feeding from a paper storage unit, comprising: a paper feed determination unit that determines which paper feed is selected; and a process speed control that changes the process speed when the paper feed determination unit determines that the manual paper feed is selected. An electrophotographic printer comprising means and.