JPS63230429A - Image formation device - Google Patents

Abstract

PURPOSE:To make judgement as to whether a series of image formation processes under way is feasible or not by computing the number of sheets stacked in a stacking unit via a control part through the comparison of signals detected by and sent from the first and second sensing means. CONSTITUTION:Sheets 'S' are detected by a sheet feed sensor 9 and a signal detected thereby is transmitted to CPU 29. And CPU 29 counts the number of the sheets 'S' on the basis of the signal detected by the sheet feed sensor 9 and saves the counted number in RAM 30. Then, CPU 29 makes a comparison between the number of the sheets 'S' counted via the detected signal of another sheet feed sensor 5 and that counted via the detected signal of the sheet feed sensor 9, thereby calculating the number of the sheets 'S' remaining on a stack tray 6. The sheets 'S' are fed in a sequence from the stack tray 6 and when a remnant on the tray 6 has reached the predetermined number set up by an input part 31 and saved in RAM 30, a control part 27 feeds the predetermined number of the sheets 'S' from a sheet feed tray 2 to the stack tray 6.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to an image forming apparatus such as a copying machine or a laser beam printer. The present invention relates to an image forming apparatus including a storage device that temporarily stores sheets fed from a sheet storage device.

(B) Prior art In general, an image forming apparatus includes one sheet storage device such as a cassette in the flow from the sheet storage device to the image forming section, and sheets are directly transferred from the sheet storage device to the image forming unit. was being sent to.

Conventionally, the remaining amount of sheets stored in a storage device has been detected by optical detection means using transmitted light or detection means based on the thickness or weight of the sheets.

(c) Problem to be solved by the invention For B, when there are no sheets left in a cassette, etc., it is necessary to interrupt the image forming operation while feeding sheets into the cassette, which makes it difficult to efficiently It is an obstacle to work.

Therefore, in addition to a sheet storage device such as a cassette, an image forming apparatus is being considered that includes a storage device that temporarily stores sheets fed from the sheet storage device. Since the sheets are fed from the apparatus to the image forming means, it is not possible to compare the set number of sheets for image formation and the remaining amount of sheets to determine whether or not image formation is possible.

Further, when using an optical detection means and a detection means based on the thickness or weight of the sheet, it is difficult to accurately detect the sheets one by one because the number of sheets is indirectly detected.

(b) Means for solving the problem The present invention aims to solve the above-mentioned problems, and includes a storage device for storing a large number of sheets, and sheets fed from the storage device. - a storage device that stores sheets fed from a storage device; and a second detection device that detects sheets fed from the storage device. , a control unit that receives the detection signal of the second detection means and the detection signal of the first detection means, and the control unit receives the detection signal of the first detection means, and detects the sheet fed from the storage device based on the detection signal of the first detection means. ) and is configured to count the sheets fed from the storage device based on the detection signal of the second detection device, and the control unit is configured to count the sheets fed from the storage device based on the detection signal of the second detection device. The present invention is characterized in that the number of sheets stored in the storage device is calculated by comparing the detection signals from the storage device.

(e) Operation Based on the above-mentioned configuration, the sea I-
is fed and stored in a storage device. At this time, the sheet is detected by the first detection means, and a detection signal from the detection means is transmitted to the control section. Then, the sheet is fed from the storage device to the image forming section. At this time, the sheet is detected by the second detection means, and a detection signal from the detection means is transmitted to the control section. Then, the control section compares the detection signals from the first and second detection means and calculates the number of sheets remaining in the storage device.

(F) Examples Examples of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the laser beam printer 1 includes a paper feed tray 2 for storing sheets S, a paper feed roller 3 for feeding the sheet S from the tray 2, and a paper feed roller 3 for feeding the sheet S from the tray 2. A sheet fed by the roller 3 is downstream.
A paper feed sensor 5 for detecting S is provided. and,
A storage tray 6 for storing sheets fed from the paper feed tray 2 is provided downstream of the sensor 5, and the tray 6 includes a paper feed roller for feeding sheets S from the tray 6. 7 are arranged. Further, downstream of the roller 7, a paper feed sensor 9 for detecting the sheet S fed by the roller 7 is disposed, and downstream of the paper feed sensor 9, a pair of register rollers 10 is disposed. is installed. Furthermore, a photosensitive drum 11 is disposed downstream of the roller pair 10, and around the drum 1 are a primary charger 12, a secondary charger 13, a developer 15, and a transfer charger 16. and a cleaner 17 are provided. A fixing device 19 and a pair of discharge rollers 20 are disposed downstream of the photosensitive drum 11, and a discharge tray 21 is disposed downstream of the pair of rollers 20. Also, in the vicinity of the photosensitive drum 11, there is a laser scanner section 22 that sends optical signals to the drum 11.
is provided, and is composed of a scanner section 22, a semiconductor laser 23, a polygon mirror 25, and an imaging lens 26. Further, the laser beam printer 1 has a control section 27, which is operated by a CPU 29 that receives detection signals from the paper feed sensors 5 and 9, and a RAM (read/write memory) 30 that stores data. It is configured. Then, the CPU 29
It is configured to receive an input signal from 1 and output it to the display section 32.

Since this embodiment has the above configuration, the paper feed h l
When sheets S... are stacked on tray 2 and a start key (not shown) is pressed, a predetermined number of sheets S out of the sheets S... stacked on paper feed tray 2 are fed to the paper feed roller 3. The paper is fed to the second paper feed tray 6 and stored therein. At this time, the sheet +-S is detected by the paper feed sensor 5, and the detection signal from the sensor 5 is transmitted to the CPU 29. and,
The CPU 29 counts the number of sheets S based on the detection signal of the paper feed sensor 5, and stores the count value in the RAM 30.
to be memorized. Next, the sheets I and S are fed from the storage J and Reiro to the pair of registration rollers 10 by the paper feed roller 7. At this time, the sheet S is detected by the paper feed sensor 9, and a detection signal from the sensor 9 is transmitted to the CPU 29. Then, the CPU 29 counts the number of sheets S based on the detection signal from the paper feed sensor 9 and stores it in the RAM 30. Next, the CPU 29 compares the number of sheets S counted based on the detection signal of the paper feed sensor 5 with the number of sheets S counted based on the detection signal of the paper feed sensor 9 to determine the remaining amount of sheets S in the storage tray 6. calculate. When an image signal is transmitted from an external device (not shown) to the # push section 27, the control section 27 transmits the image signal to the laser scanner section 22.
ζ uniformly by the primary charger 12 as a laser signal
ζ The charged photosensitive drum 11 is irradiated to form an electrostatic latent image. Next, the electrostatic latent image is turned into a visible image by the developing device 15. Then, the sheet S is conveyed by a pair of registration rollers 10 in synchronization with the visible image, and the transferred image is printed by a transfer charger 16. Further, the sheet S is fixed to the fixing device 1.
9, and the image is fixed by the fixing device 19.

Then, the sheet +-S is discharged onto a discharge tray 21 by a pair of discharge rollers 20.

Similarly, when the sheets S are sequentially fed from the storage tray 6 and the remaining amount of sheets S in the storage tray 6 reaches a predetermined number set by the input section 31 and stored in the RAM 30, the control section 27 controls the feeding. A predetermined number of sheets S... are fed from the paper tray 2 to the storage tray 6. Furthermore, the sheet S is fed from the storage tray 6, and the remaining amount of the tray 6 is stored in the RAM 3.
When the predetermined number of sheets stored in 0 is reached and there are no more sheets S in the paper feed tray 2, the control section 27 displays on the display section 32 that it is necessary to replenish the sheets S.

(g) As described in detail, the present invention provides an image forming system that includes a storage device that stores a large number of sheets, and a first detection means that detects sheets fed from the storage device. In the apparatus, a storage device that stores sheets fed from the storage device, a second detection device that detects the sheets fed from the storage device, and a detection signal of the second detection device and the second detection device are provided. a control unit that receives a detection signal from the first detection means, and is configured to count sheets fed from the storage device based on the detection signal from the first detection means; Based on the detection signal of the second detection means,
The control unit is configured to count the sheets fed from the storage device, and the control unit compares the detection signals from the first and second detection means to determine the number of sheets stored in the storage device. Since it is configured to calculate numbers, even when feeding sheets to the sheet storage device, image forming operations can be performed continuously without interruption due to the feeding of sheets from the storage device, improving efficiency. While being able to accurately detect the remaining amount of sheets one by one,
By comparing the set number of images to be formed and the remaining amount of sheets, it is possible to determine whether or not the series of image forming operations currently being performed is possible.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an image forming apparatus according to the present invention. DESCRIPTION OF SYMBOLS 1... Image forming apparatus, 2. Storage device, 5... First detection means, 6. Storage device, 9.. Second detection means, 27.. Control unit, S.. Sheet.

Claims (2)

[Claims] (1) In an image forming apparatus that includes a storage device that stores a large number of sheets and a first detection unit that detects sheets fed from the storage device, the sheets fed from the storage device are stored. a storage device that detects sheets fed from the storage device; a second detection device that detects sheets fed from the storage device; and a control unit that receives a detection signal from the second detection device and a detection signal from the first detection device. , configured to count the sheets fed from the storage device based on the detection signal of the first detection means, and to count the sheets fed from the storage device based on the detection signal of the second detection means. The apparatus is configured to count sheets fed from the apparatus, and the control unit calculates the number of sheets stored in the storage apparatus by comparing detection signals from the first and second detection means. An image forming apparatus characterized in that it is configured as follows. (2) The image forming apparatus according to claim 1, wherein the control section notifies the remaining amount of sheets.