JPH04159949A - Paper feed device for image forming device - Google Patents

Abstract

PURPOSE:To prevent mutual close adhesion between recording paper sheets caused by electrification at the time of feeding a special recording paper easy to electrify and reduce a feed failure by controlling a paper feed mechanism so as to enlarge the paper feeding interval of the specific recording paper only for a period where a special cassette device is detected by a sensor. CONSTITUTION:When a special cassette 109a is set, a sensor 120 faces a part 121 to be detected to detect this, so that a control part judges that the cassette installed is the special cassette and a special recording paper is stored therein, and controls a paper feed mechanism 115a so as to extend the paper feeding interval. Thus, resulted from the static electricity between paper sheets mutually laid in laminated state and the attraction by the static electricity generated by friction at the time of feeding a preceding recording paper can be prevented. Consequently, a paper feed failure can be prevented, and reliability can be enhanced.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a paper feeding device that can eliminate paper feeding failures that occur due to charging of recording paper when feeding special recording paper. .

(Prior Art) Image forming apparatuses such as copying machines and printers take out recording paper one by one from a paper feed cassette, feed it to an image forming section centered on a photoreceptor, and apply toner onto the recording paper. Transfer the image,
A series of image forming steps are carried out by discharging the image after it has been fixed.

By the way, high-speed paper feeding devices used in high-speed copying machines feed recording paper at extremely short intervals, so if special paper that is easily charged, such as a second original, is stored in the cassette and continuous paper feeding is performed, Feeding of the subsequent recording paper is started before the static electricity generated on the subsequent recording paper due to friction with the previously fed recording paper is removed by natural discharge. Therefore, adhesion due to static electricity occurs between the subsequent recording paper and the recording paper immediately after it, and paper feeding failures such as jams and non-feeding are likely to occur.

Therefore, in conventional image forming apparatuses, this problem has been compensated for by restricting the types of recording paper that can be fed or by cutting down on transport specifications.

(Object of the Invention) The present invention has been made in view of the above, and even when feeding special recording paper that is easily charged, it is possible to prevent the occurrence of paper feeding failure by preventing the recording paper from adhering to each other due to charging. It is an object of the present invention to provide a paper feeding device that reduces the amount of paper used.

(Structure of the Invention) In order to achieve the above object, the present invention includes a paper feeding mechanism that takes out recording paper stored in a paper feeding cassette and feeds the paper to an image forming section;
In the image forming apparatus, the image forming apparatus is configured to determine whether or not the installed paper feed cassette is a special cassette that stores special recording paper that is easily charged. The recording medium may include a sensor for detecting the special recording paper, and the control unit controls the paper feeding mechanism to increase the feeding interval of the special recording paper only while the sensor detects attachment of the special cassette. .

Hereinafter, the present invention will be described in detail based on the preferred embodiments shown in the accompanying drawings.

FIG. 1 is a schematic illustration of the structure of a copying machine to which the paper feeding device of the present invention is applied. ing.

The copy processing unit A includes an automatic document transport bag 2101 that automatically places a plurality of set originals in a predetermined position, a lamp 102, a mirror 103 . 104 and a lens 105; a photoreceptor belt 106 that forms a latent image by exposing optical image information from the optical system; and a charging process for the photoreceptor belt 106 before exposure processing. Charger 107 and charged photoreceptor belt 1o
a developing device 108 that develops the static T4 latent image formed after performing the exposure processing for 6; and a transfer device that transfers the image developed by the developing device 108 onto the recording paper conveyed from the recording paper supply section 109. 110, a cleaning unit 111 that cleans the photoreceptor belt 106 after a series of copying processes are completed in preparation for the next copying process, a fixing device 112 that fixes the transferred image transferred onto the recording paper, and An output tray 113 that outputs and stacks recorded paper, a detection unit 118 (for example, a counter) that detects the amount of loaded recording paper on the output tray 113, and a recording paper supply unit 109 that includes a paper cassette (tray unit, etc.). It is composed of paper feeding mechanisms 115a to 115c such as feed rollers that take out paper and feed it toward the transfer device 110.

Next, the large-volume paper feed section B has the same configuration as the above-mentioned recording paper supply section 109, and includes a storage section 114 that stores a large amount of recording paper in order to cope with the large demand for recording paper, and a storage section 114 that stores a large amount of recording paper. The paper feeding mechanism 115d conveys the printed recording paper in accordance with the transfer processing timing of the copy processing section A.

In this embodiment, one of the cassettes in the recording paper supply section 109 can be replaced with a special cassette 109a that stores special recording paper such as a second original drawing, and the special cassette is located near the special cassette 109a. A sensor 120 is arranged to detect paper feeding, and when the sensor 120 outputs a signal indicating that a special cassette is installed to a control unit 124 such as a microcomputer shown in FIG.
A characteristic feature of this configuration is that a control signal is output to the motor 125 that drives the mechanism 1158 to increase the paper feeding interval.

Next, the recording paper post-processing unit C transfers the ejected recording paper to a predetermined tray unit 1 after a series of copy processing by the copy processing NIA is completed.
16, and a pressure detection section 119 (for example, a counter) that detects the amount of one load of the tray section 116.

FIG. 2 is a diagram illustrating a specific configuration of a special cassette 109a that stores special recording paper such as a second original drawing, and a detection means for the cassette. Special cassette l 09a has a detected part such as a 1 degree marker different from the side wall of the cassette in the appropriate place! 21, and the special cassette 109a is in the position shown in FIG. A sensor 120 such as a reflective photon sensor is disposed at a position facing the detected portion 121 when mounted on the sensor. When the special cassette 109a is set, the sensor 120 faces the detected part 121 and detects it, so the control unit 124 determines that the installed cassette is a special cassette and that special recording paper is stored therein. The paper feeding mechanism 115a (motor 125) is controlled to widen the paper feeding interval.

If the set cassette is a normal cassette, the paper feeding mechanism 115 feeds paper at the normal paper feeding timing.
Control 8.

In general, the feeding interval for A4 size originals in normal mode is 30mm to 50mm, and in special cassette mode, the feeding interval is 50mm to 50mm.
The length should be approximately 0 to 100 mm. Therefore, in the special cassette mode, sufficient time can be secured between the feeding of the preceding recording paper and the start of feeding of the following recording paper, allowing the built-up charge to discharge naturally. can.

As shown in the flowchart of FIG. 4, in the present invention, in steps S1 and S2), it is detected whether or not the installed paper feed cassette is a special cassette containing special recording paper that is easily charged. In some cases, the paper feed interval is lengthened to allow time for natural discharge (step 3, S4), so the paper may attract static electricity between sheets in the 1-horizontal state, or the preceding recording paper may It is possible to prevent adhesion due to static electricity generated due to friction when paper is fed. As a result, paper feeding failures can be prevented and reliability can be improved.

(Effects of the Invention) As described above, according to the present invention, even when feeding special recording paper that is easily charged, it is possible to prevent paper sheets from coming into close contact with each other due to charging, thereby reducing the occurrence of paper feeding failures. I can do it.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the overall configuration of an image forming apparatus to which the present invention is applied, FIG. FIG. 4 is a control block diagram for controlling the paper feeding mechanism of the illustrated embodiment, and FIG. 4 is a flowchart showing the control procedure of the paper feeding device of the present invention. 115a to 115d...Paper feeding mechanism 109a...Special cassette 120...Sensor 1
21... Detected part 124... Control part 125...
motor

Claims (1)

[Scope of Claims] An image forming apparatus comprising: a paper feeding mechanism that takes out recording paper stored in a paper feeding cassette and feeds the paper to an image forming section; and a control section that controls driving of the paper feeding mechanism; The image forming apparatus includes a sensor that detects whether or not the installed paper feed cassette is a special cassette that stores special recording paper that is easily charged, and the control unit detects whether the sensor detects that the special cassette is installed. A paper feeding device for an image forming apparatus, characterized in that the paper feeding mechanism is controlled to increase the feeding interval of the special recording paper only while the special recording paper is being fed.