JP2002323841A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate needless scanning and to shorten an image forming time by finishing the scanning of an original based on a signal showing the discharge of a recording material, as for a small-sized recording material. SOLUTION: As for the image forming device provided with an illuminating means for illuminating the original, a scanning means for scanning the original, a means for forming an optical image on a photoreceptor drum, an image forming means for forming an image on the recording material, a means for supplying the recording material, and a means for detecting the discharge of the recording material, a timing of switching the original scanning from the forward scanning to the renewal scanning and a timing of supplying the recording material are controlled based on a recording material signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly to a control of a scanning operation and a supply of a recording material.

[0002]

2. Description of the Related Art A conventional image forming apparatus comprises a paper feed sensor for feeding a recording material and a paper discharge sensor for confirming the discharge of the recording material.

In detecting the size of a recording material, the above-mentioned paper feed sensor has been used. In recent years, the paper feed sensor has been abolished in order to reduce the cost of image forming devices,
In some cases, a control method is used in which only a discharge of a recording material is confirmed by a discharge sensor.

In this method, since the size of the recording material cannot be detected, a full scanning operation is always performed regardless of the size of the recording material.

[0005]

In the above-described scanning method, the full scanning operation is always performed regardless of the size of the recording material. Therefore, in the case of a small-sized recording material, an unnecessary portion without the recording material is scanned, and there is a problem that the image forming time cannot be reduced.

[0006]

SUMMARY OF THE INVENTION The present invention is to solve the above problems. That is, an illuminating unit that illuminates the original, a scanning unit that scans the original, a unit that forms an optical image on the photosensitive drum, an image forming unit that forms a visible image on the recording material into a visible image, a unit that supplies the recording material, In an image forming apparatus having a detection unit for detecting recording material discharge in a recording material discharge unit, timing and recording of switching scanning of a document from forward to reverse based on a recording material discharge signal of the recording material discharge detecting unit. A control means is provided for shortening the image forming time of the small-size recording material by controlling the timing of supplying the material.

According to the present invention, the scanning range can be minimized according to the size of the recording material by controlling the scanning operation by detecting the recording material in the recording material discharge section, so that the image forming time can be shortened.

[0008]

FIG. 1 shows an embodiment of the present invention, 1 is a mirror base unit, 2 is a document illumination lamp, 3
Is a platen glass, 4 is a platen cover, 5 is a developing device, 6 is a transfer / separation charger, 7 is a photosensitive drum, 8 is a fixing device, 9 is a supply solenoid, 10 is a recording material cassette, and 11 is a discharge portion recording material. It is a sensor.

That is, the original glass table 3
While irradiating the original placed on the
By scanning the mirror base unit 1, the reflected light image is formed on the photosensitive drum 7 to form an electrostatic image.
The electrostatic image (electrostatic latent image) is visualized by the developing device 5 using a toner made of a resin or the like that softens and melts when heated.

At the same time, when the leading end of the toner image on the photosensitive drum 7 coincides with the leading end of the recording material on the transfer / separation charger 6, the supply solenoid 9 is driven, and the recording material is removed from the recording material cassette 10 by a known mechanism. Supply. next,
The toner image on the photosensitive drum 7 is transferred by the transfer separation charger 6
It is transferred onto a recording material. Finally, the recording material is heated and fixed by the fixing device 7 and discharged through the recording material sensor 11 in the discharge section.

FIG. 2 shows the structure of the discharge sensor shown in FIG.

In FIG. 2, reference numeral 12 denotes a transmission type photo interrupter, 13 denotes a light shielding member, and 14 denotes a recording material.

In a normal state (FIG. 2A), the light blocking member 13 blocks the optical path of the transmission type photointerrupter 12. When the recording material is conveyed to the discharge section (FIG. 2B), the light shielding member 13 is pushed up. Thereby, the optical path of the transmission type photointerrupter 12 is secured, and it is detected that the recording material is present in the discharge unit.

FIG. 3 shows a control circuit block diagram.
In FIG. 3, reference numeral 15 denotes a discharge sensor, 16 denotes a CPU,
Reference numeral 17 denotes a scanner drive circuit, 18 denotes a scanner unit, 19 denotes a supply solenoid drive circuit, 20 denotes a recording material supply unit, 21 denotes an operation panel, and 22 denotes a memory.

That is, the user sets the number N of images to be formed and inputs a start key on the operation panel 21. The signal input here is taken into the CPU 16 and written into the memory 22. The image forming operation is started according to this signal.

First, the CPU 16 sends a signal to the supply solenoid drive circuit 19 at the timing set in the memory 22 to drive the recording material supply unit 20. Next, a control signal is sent to the scanner drive circuit 17 at the timing when the leading edge of the toner image on the photosensitive drum coincides with the leading edge of the recording material to drive the scanner unit 18.

Finally, the CPU 16 controls the discharge sensor 15.
After the recording material discharge signal is confirmed, the image forming operation is terminated.

FIG. 4 is a timing chart, and FIG. 5 is a flowchart.

FIG. 4A is a conventional timing chart, and FIG. 4B is a timing chart according to the present invention.

In the conventional method (A), first, a recording material is supplied. Next, scanning (advancing) of the optical system is started at a timing when the leading end of the toner image on the photosensitive drum and the leading end of the recording material coincide on the transfer separation charger. The reflected light image forms an electrostatic image on the photosensitive drum. This electrostatic image (electrostatic latent image) is visualized using toner, and the toner image on the photosensitive drum is transferred onto a recording material. The recording material is heated and fixed, and is discharged through a recording material sensor in a discharge section. Finally, when the optical system completes the full scan (forward), the operation of switching the scan (forward) of the optical system to the reverse is completed, and the image forming operation is completed.

According to the present invention (B), first, a recording material is supplied. Next, scanning (advancing) of the optical system is started at a timing when the leading end of the toner image on the photosensitive drum and the leading end of the recording material coincide on the transfer / separation charger. The reflected light image forms an electrostatic image on the photosensitive drum. This electrostatic image (electrostatic latent image) is visualized using toner, and the toner image on the photosensitive drum is transferred onto a recording material. The recording material is heated and fixed, and is discharged through a recording material sensor in a discharge section. Upon detecting the recording material discharge signal of the discharge unit recording material sensor, the operation of switching the scanning (forward) of the optical system to the reverse is completed, and the image forming operation is completed.

That is, by controlling the timing of switching the scanning of the original from forward to backward and the timing of supplying the recording material based on the recording material discharge signal of the recording material discharge detecting means, the recording material of small size can be used. In addition, it is possible to eliminate unnecessary scanning of a recording material and to reduce an image forming time.

[0023]

As described above, by controlling the timing of switching the scanning of the original from the forward to the reverse and the timing of supplying the recording material based on the recording material discharge signal of the recording material discharge detecting means, In small-sized recording materials, unnecessary scanning without recording materials is eliminated,
Image formation time can be reduced.

[Brief description of the drawings]

The drawings show one embodiment of the image forming apparatus of the present invention.

FIG. 1 Cross-sectional drawing

FIG. 2 is an enlarged view of a discharge section recording material sensor shown in FIG. 1;

FIG. 3 is a control block diagram.

FIG. 4 is a timing chart.

FIG. 5 Flow chart

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mirror stand unit 2 Original illumination lamp 3 Original table glass 4 Original table cover 5 Developing device 6 Transfer separation charger 7 Photosensitive drum 8 Fixing device 9 Recording material supply solenoid 10 Recording material cassette 11 Discharge part recording material sensor 12 Transmission type photo interrupter DESCRIPTION OF SYMBOLS 13 Shielding member 14 Recording material 15 Discharge part recording material sensor 16 CPU 17 Scanner drive circuit 18 Scanner unit 19 Recording material supply solenoid drive circuit 20 Recording material supply unit 21 Operation panel 22 Memory

Claims (1)

[Claims] 1. Illumination means for illuminating a document, scanning means for scanning the document, means for forming an optical image on a photosensitive drum, image forming means for forming a visible material on a recording material into a visible image, and supply of the recording material In the image forming apparatus having a detection unit for detecting discharge of a recording material in a recording material discharge unit, the scanning of the original is switched from forward to reverse based on a recording material discharge signal of the recording material discharge detection unit. An image forming apparatus for controlling a timing and a timing of supplying a recording material.