JPS6283770A - Automatic magnification setting device in image forming device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of the size cutting of the picture, etc., due to a calculating mistake by providing a control means to calculate the projecting magnification of an image in accordance with a detecting signal outputted from an original size detecting means and recording paper size detecting means. CONSTITUTION:When the hand supply is discriminated, in the recording paper size detecting means 35, the size of the recording paper is detected and the value is outputted to the control means 36. In the control means 36, the projecting magnification of the image is calculated based upon the recording paper size outputted from the recording paper size detecting means 35 and paper feeding cassettes 18 and 19 and the original size outputted from the original size detecting means 30. Thereafter, from the control means 36 to a lens 8, the control signal is outputted, the magnification of the lens 8 is set, and in accordance with the magnification, the copying action forming the picture at the recording paper is started. Thus, without generating the size cutting of the picture, the suitable picture can be easily formed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic magnification setting device for image forming apparatuses such as copying machines and printers.

(Prior Art) Conventionally, in an image forming apparatus equipped with a variable magnification function that changes the image projection magnification, as shown in Japanese Patent Application Laid-Open No. 57-185060, a document size detection signal and recording paper in a paper feed cassette are used. Some devices are configured to calculate the projection magnification of an image according to a size detection signal and automatically perform a magnification change operation. In the conventional device with this configuration, no consideration was given to the case where recording paper is fed from the manual feed tray.
For this reason, if the size of the manually fed recording paper and the document are different, the operator must calculate the projection magnification of the image, which is complicated, and may cause the image to be out of size due to calculation errors, or the recording paper may There is a problem in that more blank space than necessary is formed.

(Object of the Invention) The present invention has been made to solve the above-mentioned problems, and eliminates the need for the complicated operation of calculating the projection magnification of an image when feeding recording paper from a manual feed tray. An object of the present invention is to provide an automatic magnification setting device for an image forming apparatus that can prevent images from being out of size due to calculation errors.

(Structure of the Invention) The present invention provides an automatic magnification setting device for an image forming apparatus equipped with a manual feed tray that manually feeds recording paper, comprising: a document size detection means for detecting the size of a document; and a control means that calculates the projection magnification of the image according to the detection signals output from the document size detection means and the recording paper size detection means. be.

With this configuration, it is possible to accurately calculate the projection magnification of the image corresponding to the size of the manually fed recording paper and the document, and easily form an appropriate image without causing the image to be out of size.

(Embodiment) FIG. 1 shows a schematic diagram of an electrostatic copying machine according to an embodiment of the present invention. A document mounting table 3 consisting of a document presser 1 and a contact glass 2 is provided above the body of this electrostatic copying machine, and a document irradiation lamp 4 and a reflector 1 are provided below.
5. An optical system section 9 consisting of lenses 8, 6, and 8 is provided. Further, in the center of the body, a photoreceptor drum 10, a main charging device 11, a developing device 12, a transfer charging device 12 are provided.
a, an image forming section 15 equipped with a separation charging device 12b, a cleaning device 13, a static elimination lamp 14, etc. is formed, and a paper ejection tray 16 is provided on the left side of the machine body in the figure, and a manual feed tray is provided on the right side. A paper feed section 20 is provided which consists of a tray 17 and a paper feed cassette 18,19.

The recording paper is supplied from the paper feed section 20 via the paper feed roller 20a and the conveyance roller 20b, and is supplied to the image forming section 15 via the conveyance mechanism 24, which includes a registration roller 21, a guide plate 22, and a pre-transfer roller 23. Thereafter, the sheet is discharged onto the paper discharge tray 16 via a discharge mechanism 28 that includes a conveyance belt 25, a constant η roller 26, a discharge roller 27, and the like.

Further, below the contact glass 2, a document size detection means 30 consisting of a plurality of photosensors 29 is disposed, and each of the seven photosensors 29 detects the size of the document on the contact glass 2.
The document size is detected by detecting the rear end of the document A placed on top. Each of the seven sensors 29 is disposed facing the lower surface of the contact glass 2 at a predetermined angle of inclination in order to prevent malfunction due to reception of reflected light from the contact glass 2. In addition, in order to prevent the photosensor 29 from malfunctioning due to reception of reflected light from the bottom surface of the document presser 1 or incident light from the outside, it must be ) to activate the detection means 30 1ii11tI! It is desirable to do so.

As shown in FIG. 2, the manual tray 17 includes a tray main body 31 and a side edge regulating plate for recording paper supported so as to be slidable left and right along slide grooves 32 and 32 formed in the tray main body 31. 33, 33, and is configured to move the side edge regulating plates 33.degree. 33 in the width direction of the recording paper based on the center line according to the width size of the recording paper to be supplied. In addition, the side end regulating plate 33.33
is provided with a recording paper detection switch 34 consisting of a photo sensor, a limit switch, or the like. and,
The side edge regulating plates 33.33 are moved according to the recording paper placed on the tray main body 31, and when the detection switch 34 is turned on, the recording paper size detection means 35 moves the side edge regulating plates 33.33 between the side edge regulating plates 33.33. The size of the recording paper to be manually fed is detected by means such as detecting the distance between the recording paper and the recording paper.

Possible methods for detecting the recording paper size include a method using a potentiometer provided between the side edge regulating plates 33 and a method detecting the position of the side edge regulating plate 33 using a reed switch provided at a predetermined position. It will be done.

Detection signals outputted from the recording paper size detection means 35, original size detection means 30, and cassette detection means 20C for detecting the recording paper size in the paper feed cassette are input to the control means 36. Then, the i, II control means 36 calculates the projection magnification of the image, and according to this value, a control signal is output to the lens 8 of the optical system section 9, and the lens 8 is set to a predetermined magnification.

In the above configuration, the control operation when performing automatic magnification setting control will be explained based on the flowchart shown in FIG. 3. First, it is determined whether or not to manually feed recording paper to be used from the manual feed tray 17 (step S1). And paper feed cassette 18 instead of manual feed
．． If it is determined that the paper will be automatically fed from 19,
The size of the recording paper accommodated in the selected cassette is output from the cassette detection means 20C (step S2).

In addition, the above step S1. When it is determined that manual feeding is to be performed, the recording paper size detection means 35
In step S3), the recording paper size is detected and the detected value is output to the control means 36.

Then, in this control means 36, an image is projected based on the recording paper size output from the recording paper size detection means 35 or the paper feed cassette 18, 19, and the original size output from the original size detection means 30. A magnification is calculated (step 84). After that, the control means 3
6 outputs a control signal to the lens 8 to set the magnification of the lens 8 (step S5), and a copying operation for forming an image on recording paper according to this magnification is started (step So
).

In this way, the manual feed tray 17 is provided with the recording paper size detection means 35, and the image is projected based on the signal values output from the detection means 35 and the document size detection means 30 provided opposite to the lower surface of the contact glass 2. Increase the magnification to 1qIl
Since the calculation is performed in one unit 36, an appropriate image can be formed on the PJwi without causing the image to be out of size even when the recording paper is manually fed.

In particular, in an image forming apparatus having an optical system section 9 with a stepless magnification function, it is possible to easily and accurately set the image projection magnification even when manually feeding recording paper of a non-standard, special size. There is an advantage.

In the above embodiment, a center reference type one-sheet device that supplies recording paper with reference to the center line has been described, but the present invention provides a single-sided paper device that supplies recording paper with one side of the recording paper as a reference. The same applies to the standard type.

Further, in the case where the document feeder is provided with a document feeder that automatically feeds the document onto the contact glass 2, the document feeder may be provided with document size detection means.

That is, as shown in FIG. 4, a side edge detection sensor 50 is attached to a side edge regulating plate or the like and is disposed so as to be movable left and right.
．． 50 detects the side edge of the document, detects the width of the document by calculating the distance between both side edge detection sensors 50 and 50, and detects the front edge and back edge of the document. A document size detection means may be provided that calculates the quality of the document by means such as detecting the document conveyance time according to the output signal from the sensor 51. In this way, when the document feeder is provided with the document size detection means, the document size can be accurately detected even when a document of a special size outside the standard is fed, and this document size and
There is an advantage that the image projection magnification can be easily and accurately set in accordance with the recording paper size detected by the recording paper size detection means 35.

(Effects of the Invention) As described above, the present invention provides detection signals output from the recording paper size detection means provided in the manual feed tray and the document size detection means provided opposite to the lower surface of the conductive glass. Based on this, the projection magnification of the image is calculated in the t4t1 means, so even when recording paper is manually fed, an appropriate image can be easily formed without causing the image to be out of size. Furthermore, even when manually feeding recording paper of a non-standard size, the projection magnification of the image can be easily and accurately set.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an embodiment of the present invention, Fig. 2 is a plan view of the manual feed tray, Fig. 3 is a flowchart for coordinating the AIL control, and Fig. 4 is another example of the body detection device used in Oi. It is a perspective view showing an example. 17... Manual feed tray, 30... Document size detection means, 35... Recording paper size detection means, 36... Control means. Patent applicant Agent: Sanda Kogyo Co., Ltd.
Patent Attorney Etsushi Kotani Patent Attorney Cho 1) Masamukai Patent Attorney Yasuo Itaya Figure 2 8

Claims (1)

[Claims] 1. An automatic magnification setting device for an image forming apparatus equipped with a manual feed tray for manually feeding recording paper, comprising a document size detection means for detecting the size of a document, and a size of the recording paper fed from the manual feed tray. an image forming apparatus comprising: a recording paper size detecting means for detecting a recording paper size; and a control means for calculating a projection magnification of an image according to detection signals output from the document size detecting means and the recording paper size detecting means. Automatic magnification setting device.