JPH06271093A - Paper feeding cassette and image forming device - Google Patents

Abstract

PURPOSE:To carry out printing by providing a paper feeding cassette which has a simple mechanism and can easily carry our the dimension control and can reduce the dimension of an expensive frictional member, judging the kind of a paper sheet, and automatically selecting the printing mode (printing starting position, number of printing digits, printing speed, etc.) suitable for the kind of the paper. CONSTITUTION:A recessed part 5b is formed at a part of the upper surface 5a in the vicinity of the front edge side of a press contact plate 5, and a frictional member 2 is installed at the recessed part 5b, and the upper surface 2a of the frictional member 2 is arranged higher than the upper surface 5a of the press contact plate 5, and a projection part 3 which projects higher than the upper surface 2a of the frictional member 2 is formed immediately before the paper insertion port side of the recessed part 5b. Further, as for a paper feeding cassette in which a pair of guide members 4 and 4 for positioning the side edge of a paper sheet 8 according to the width of the paper 8 are arranged slidably in the lateral direction, a pressing member 7b for driving a detector 6 installed on a printer according to the shift of the guide member 4 is installed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed cassette capable of accommodating a plurality of types of paper sheets, and an image forming apparatus such as a printer, a copying machine, a facsimile machine, etc. equipped with the paper feed cassette.

[0002]

2. Description of the Related Art As a conventional technique, for example, FIGS.
There is a first conventional paper feed cassette shown in FIG. Figure 8 here
FIG. 8A is an enlarged vertical sectional view in the vicinity of the friction member at the front end portion of the pressure contact plate of FIG. 7. Further, FIG. 2B is a line AA of FIG.
It is sectional drawing which followed the line.

In the conventional paper feed cassette, a paper feed cassette for separating a plurality of sheets of paper one by one and conveying them to the recording section is conventionally known as one having a structure shown in FIG. A pressure contact plate 5 is provided at the bottom of the cassette body 1 so that the vicinity of the front end can be moved up and down. A plurality of sheets 8 are stored in the pressure contact plate 5, and the pressure contact plate 5 lifts the sheet upward to feed the uppermost sheet. It is adapted to be pressed by the paper roller 9. Further, a concave portion 5b is formed on the upper surface 5a of the pressure contact plate 5 at a position facing the paper feed roller 9. A friction member 2 is attached to the concave portion 5b so that a plurality of sheets mounted on the pressure contact plate 5 are not separated and fed at one time, and the upper surface 2a of the friction member 2 is attached to the upper surface 2a of the pressure contact plate 5. It is arranged so as to be substantially flush with the upper surface 5a. Further, the friction coefficient between the paper 8 and the friction member 2 is made larger than the friction coefficient between the papers.

However, in such a conventional paper feeding cassette, as shown in FIGS. 8A and 8B, the upper surface 2a of the friction member 2 is arranged at substantially the same height as the upper surface 5a of the pressure contact plate 5. Therefore, as shown in FIG. 9, the sheet 8 is placed on the upper surface 5a of the pressure contact plate 5 from the rear end side to the front end side of the pressure contact plate 5.
When sliding and replenishing along the sheet, there is a gap between the pressure contact plate 5 and the end surface 2b of the friction member 2, and if the leading edge of the sheet located below goes down as much as possible, friction will occur. There is a problem that the end surface 2b of the member 2 is caught, the advance of the sheet 5 is blocked, and the leading edge of the sheet is broken. Further, when the printer prints the paper with the front end folded, there is a problem that the paper is skewed or torn.

In order to solve such a problem, when the height of the upper surface 2a of the friction member 2 is made lower than the upper surface 5a of the pressure contact plate 5, the paper 8 is supported on the upper surface of the pressure contact plate 5 around the friction member 2. Therefore, it becomes difficult for the paper 8 to contact the friction member 2,
The friction effect between the friction member 2 and the paper 8 is reduced. In addition, there is a problem that the lowermost sheet may stick to the pressure contact plate 5 due to static electricity between the lowermost sheet and the pressure contact plate 5, and the sheet may not be discharged.

In order to solve such a problem, the following improvement measures have been proposed.

FIG. 10 shows a pressure contact plate of a second conventional example of a sheet feeding cassette shown in Japanese Utility Model Publication No. 1-24029. In FIG. 10, (a) shows a front end portion of the pressure contact plate. It is an expanded longitudinal cross-sectional view of the friction member vicinity, (b) is the figure seen from the V direction in the figure of (a). The pressure contact plate 5 is provided with a recess 5b at a position facing a sheet feeding roller (not shown), and the bottom surface of the recess 5b is inclined upward toward the front.
The rear end 2b of the friction member 2 attached to the recess 5b is lower than the upper surface 5a of the pressure contact plate 5, and the front end 2c of the friction member 2 is higher than the upper surface 5a of the pressure contact plate 5.

[0008]

However, in the above-mentioned paper feeding cassette, the rear end 2b of the friction member 2 is used.
Since the vicinity is lower than the upper surface 5a of the pressure contact plate 5, when the paper 8 becomes small, wrinkles are likely to occur in the paper 8 when the paper 8 is pressed against the paper feed roller and advanced, and the rear end 2b of the friction member 2 is also formed. Since the neighboring portion is lower than the upper surface 5a of the pressure contact plate 5, there is a problem that the original purpose of the friction member 2, the friction effect, is not exhibited and the material is wasted.

Further, the shape of the tip of the pressure contact plate 5 is complicated and difficult to process as described above, and the location where the paper feed roller and the friction member 2 contact each other needs to be higher than the upper surface 5a of the pressure contact plate 5. However, since the paper feed roller or the pressure contact plate 5 moves when the paper 8 is stored, there is a problem that dimensional control is very difficult.

Further, in the sheet feeding cassettes as in the first and second conventional examples, the types of sheets (size and orientation such as horizontal and vertical) that can be stored in each sheet feeding cassette are determined. A person who operates the printer selects the print start position and the print speed corresponding to the type of the paper on the operation panel of the printer from various papers stored in the paper feed cassettes. Alternatively, it is necessary to input a predetermined print start position and a command (code) corresponding to the print start position and the print speed to the printer using a personal computer or the like. Further, when such an operation or setting mistake is made, the paper becomes defective in printing, resulting in a waste of time and paper.

When the paper feed cassette is attached to the printer main body, the type of the stored paper may not be known, so that the paper type can be confirmed after the paper feed cassette is attached to the printer main body. For this reason, it is necessary to provide a mechanism for displaying the type of paper on the paper feed cassette itself so that the appearance of the paper feed cassette can be seen after mounting, and there is also a problem that the structure is complicated and expensive.

The present invention has been made in view of the above problems, and has a simple mechanism, easy size control, and a paper feed cassette capable of reducing the size of an expensive friction member. It is an object of the present invention to provide an image forming apparatus capable of distinguishing a type and automatically selecting and printing a print mode (print start position, print digit number, stamp speed, etc.) suitable for the type of paper. is there.

[0013]

In order to solve the above-mentioned problems, a paper feed cassette according to claim 1 of the present invention is a cassette body capable of accommodating a plurality of paper sheets, and a front end side of the paper sheet is a lower side. In a paper feed cassette provided with a pressure contact plate for lifting the uppermost sheet from above and pressing it against the feeding means, a recess is provided in the upper surface near the front end side of the pressure contact plate, and a friction member is attached to this recess to attach the upper surface of the friction member. It is characterized in that it is formed so as to be higher than the upper surface of the pressure contact plate, and that a convex portion protruding further higher than the upper surface of the friction member is formed immediately before the concave portion of the pressure contact plate.

An image forming apparatus according to a second aspect of the invention is
The paper feed cassette according to claim 1 is provided.

The paper feed cassette according to claim 3 is
A cassette body that can store a plurality of sheets and a slide body that is slidable in the width direction of the sheet in the cassette body. The side edge of the sheet is positioned according to the width of the sheets stored in the cassette body. A paper feed cassette having a paper width detector and a discriminating means for discriminating a paper type based on a detection signal from the detector, the cassette main body comprising: Is provided with a pressing member that drives the paper width detector of the image forming apparatus in conjunction with the guide member.

An image forming apparatus according to a fourth aspect of the invention is
An image forming apparatus comprising the paper feed cassette according to claim 3, wherein the determination unit is stored in the paper feed cassette based on a storage unit that stores a plurality of types of print modes and a detection result of the detector. A determination control unit that determines the type of the selected sheet, selects a print mode suitable for the determined sheet from the storage unit, and controls the printing operation according to the selected print mode. And

An image forming apparatus according to a fifth aspect is
It is characterized in that the print mode includes print start position, print digit number, and print speed setting values.

[0018]

In the paper feed cassette according to the present invention, a recess is provided in the upper surface near the front end side of the pressure contact plate, a friction member is attached to this recess, and the upper surface of the friction member is formed higher than the upper surface of the pressure contact plate. Thus, it is possible to reliably feed the last sheet. Even when the paper is slid and replenished in the paper feed cassette, by forming a convex portion that protrudes higher than the upper surface of the friction member immediately before the concave portion of the pressure contact plate,
Even if the leading edge of the sheet is slightly lowered, the sheet can be smoothly replenished without being caught by the end surface of the friction member. In addition, since the mechanism is simple, size control is easy, and since the paper comes into contact with the entire surface of the friction member, the friction effect can be fully exerted, the separation of the paper is ensured, and the expensive friction member is used. Can be smaller.

Further, in the image forming apparatus according to the second aspect, the sheet feeding cassette according to the first aspect is provided,
Paper can be fed smoothly, and even the last sheet can be fed reliably to print stably.

Further, in the paper feed cassette according to the present invention, a cassette body mounted in the image forming apparatus having a paper width detector and a discriminating means for discriminating the kind of the paper based on the detection signal of the detector. In addition, a guide member for positioning the side edge of the paper is slidably arranged in the lateral direction of the paper width according to the width of the paper stored therein, and the guide member interlocks with the guide member. By providing the pressing member that drives the paper width detector, it is possible to automatically determine the type (size and orientation such as horizontal or vertical) of the paper stored in the paper feed cassette.

Further, in the image forming apparatus according to the present invention, the type of the paper stored in the cassette body is discriminated based on the detection result of the detector, and the print mode suitable for the discriminated paper type is selected. It is possible to select from a storage unit in which a plurality of types of print modes are stored and to execute the printing operation in this selected print mode.

Further, in the image forming apparatus according to the fifth aspect, the printing operation is performed by selecting the print start position, the number of print digits, the stamp speed, etc., which are suitable for the size and type of the paper stored in the cassette body. Can be executed.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a plan view of a paper feed cassette and a paper guide member of a printer body as seen from above, showing an embodiment of the present invention. Referring to FIG. 1, a pressure contact plate 5 for lifting the sheet 8 upward is provided at the bottom of the cassette body 1. The pressure contact plate 5 has a friction member 2 and a protruding portion 3 protruding therefrom.
Is provided. Further, on both sides of the cassette body 1, a pair of guide members 4, 4 movable in the left-right direction in FIG. 1 are arranged. Further, the cassette body 1 is provided with a pressing member 7 having a function of pressing a switch of a detector 6 provided on the printer body side when the cassette body 1 is mounted on the printer body as described later. There is. The pressing member 7 is composed of a first pressing member 7a fixed to the cassette body 1 and a second pressing member 7b movable together with one of the guide members 4 and 4, and the second pressing member 7b. Is provided at the tip of an arm portion 4a extending from the left guide member 4 in FIG. 1 to the front end side of the cassette body 1 under the pressure plate 5. Further, reference numeral 10 is a paper guide member provided on the printer body side (not shown) as an image forming apparatus, and the paper guide member 10 is provided with a detector 6.

FIG. 2 is an enlarged vertical cross-sectional view of the vicinity of the friction member 2 at the front end portion of the pressure contact plate 5 of FIG. A concave portion 5b having a bottom surface parallel to the upper surface 5a is provided on the upper surface 5a of the pressure contact plate 5 facing the sheet feeding roller 9, the friction member 2 is attached to the concave portion 5b, and the upper surface 2a of the friction member 2 is attached to the pressure contact plate 5. A convex portion 3 is formed to be higher than the upper surface 5a, and immediately before the concave portion 5b of the pressure contact plate 5, a convex portion 3 protruding further higher than the upper surface 5a of the friction member 2 is formed. Therefore, even when the paper 8 is slid in the cassette body 1 from the rear end side of the pressure contact plate 5 toward the front end side along the upper surface 5a of the pressure contact plate 5, the leading end of the paper 8 is slightly lowered. However, the sheet 8 can be replenished smoothly without being caught by the end surface 2b of the friction member 2.

As described above, since the upper surface 2a of the friction member 2 is higher than the upper surface 5a of the pressure contact plate 5, the contact area between the lowermost sheet and the pressure contact plate 5 becomes smaller, and the upper surface 2a of the friction member 2 becomes lower. It comes into contact with the paper over almost the entire surface. Further, since the sheet 8 is lifted upward together with the pressure plate 5 by the action of the spring (not shown) provided between the back surface of the pressure plate 5 and the cassette body 1, the sheet 8 is surely fed. Since the contact area between the lowermost sheet and the pressure contact plate 5 is small,
There is no problem that this paper sticks to the pressure contact plate 5 due to the influence of static electricity and a paper feed failure occurs, and the paper can be reliably fed to the lowest paper by the driving force of the paper feed roller 9. Further, the sheet feeding cassette having the above-described structure has a simple mechanism and its size can be easily controlled.

FIG. 3 is a schematic vertical sectional view of the sheet feeding cassette of FIG. 1, in which the sheet 8 is slid on the cassette body 1 along the upper surface 5a from the rear end side to the front end side of the pressure contact plate 5. It shows the state of replenishment.

Referring to FIG. 1, a pair of guide members 4 and 4 are provided on both sides of the cassette body 1 so as to be slidable according to the width of the sheets to be stored. It is guided by a pair of guide members 4, 4.

A paper guide member 10 is attached to the printer body side (not shown). This paper guide member 10
Is provided with a detector 6, and this detector 6 has a plurality of switches SW1 and SW1 as shown in FIG.
2 and SW3 are provided.

On the other hand, the cassette main body 1 is provided with a first pressing member 7a and a second pressing member 7b for pressing the switch of the detector 6 provided on the printer main body side. The pressing member 7a is fixed to the cassette body 1. Further, the second pressing member 7b is connected to the guide member 4 in the space on the back side of the press plate 5 so as to interlock with the movement of one of the pair of guide members 4 and 4 (the left guide member in the drawing). Has been done.

Therefore, when the cassette body 1 is mounted on the printer body, the switch SW1 of the detector 6 is pressed by the first pressing member 7a, and the second pressing member 7b is moved by the movement of the guide member 4. Since it moves in conjunction with this, the switches SW2 and SW of the detector 6 on the printer body side are moved according to the position of the second pressing member 7b.
3 is pressed by the second pressing member 7b.

FIG. 4A shows a first embodiment of the present invention in which a paper feed cassette for cut sheets is mounted on the paper guide member 10 on the printer body side, and the first pressing member 7a of the cassette body 1 is mounted. , And a state in which the second pressing member 7b operates the detector 6 on the printer body side, and a functional block diagram connected to the detector 6. In addition, FIG.
As a second embodiment of the present invention, a paper feed cassette for a postcard is mounted on the paper guide portion 10 on the printer body side, and the first pressing member 7a and the second pressing member 7b of the cassette body 1 are on the printer body side. 2 shows a state in which the detector 6 of FIG. 4A and 4B, the pressing member 7a,
In order to make it easier to understand the positional relationship between 7b and each switch of the detector 6, a state is shown in which the pressing plate 5 is removed from the cassette body 1.

Referring to FIG. 4A, the storage unit 12 built in the printer body discriminates the type of paper (size and orientation such as horizontal and vertical) previously loaded in the paper feed cassette, The print mode (print start position, print digit number, stamp speed, etc.) suitable for the type of paper is stored.

Here, as a first embodiment of the present invention, a state is shown in which a paper feed cassette for cut sheets is mounted on the paper guide member 10 on the printer body side. As the pressing member of the cassette body 1, a first pressing member 7a fixed to the cassette body 1 for pressing the switch SW1 of the detector 6 by mounting the cassette body 1 on the guide member 10 on the printer body side, It is composed of a second pressing member 7b which is interlocked with the movement of the guide member 4 of the cassette body 1.

When A4 size cut sheets are stored in the cassette body 1 and the cassette body 1 is mounted in the printer body, the switch SW1 of the detector 6 is pressed by the first pressing member 7a. The switch SW2 is pressed by the second pressing member 7b.

When B5 size cut sheets are stored in the cassette body 1, the switch SW1 of the detector 6 is pressed by the first pressing member 7a. Further, the second pressing member 7b is moved to the right side in the drawing in conjunction with the movement of the left guide member 4 in FIG. 1, and is moved to the position to the right of the switch SW3 indicated by the alternate long and short dash line. . As a result,
SW2 is released by the pressing member 7b and turned off.

In any case where A4 size and B5 size cut sheets are stored in the cassette body 1,
The switch SW3 of the detector 6 is always off.

FIG. 4B shows a second embodiment of the present invention in which a paper feed cassette for postcards is mounted on the paper guide member 10 on the printer body side. The pressing member of the cassette body 1 is a first member fixed to the cassette body 1 that presses the switch SW2 of the detector 6 by mounting the cassette body 1 on the guide member 10 on the printer body side.
And a second pressing member 7b that interlocks with the movement of the guide member 4 of the cassette body 1.

When the postcard is stored horizontally in the cassette body 1 and the cassette body 1 is mounted on the printer body, the switch SW2 of the detector 6 is pressed by the first pressing member 7a. The switch SW3 is the second
It is pressed by the pressing member 7b.

When the postcard is stored vertically in the cassette body 1 and the cassette body 1 is mounted in the printer body, the switch SW2 of the detector 6 is pressed by the first pressing member 7a. It Further, the second pressing member 7b is moved to the right side in the drawing in conjunction with the movement of the left guide member 4 in FIG. 1, and is moved to the position to the right of the switch SW3 indicated by the alternate long and short dash line. . As a result,
SW3 is released by the pressing member 7b and is turned off.

It should be noted that the switch SW1 of the detector 6 is always in the OFF state when the postcard is stored in the cassette body 1 either horizontally or vertically.

On the other hand, when the paper feed cassette is not attached to the paper guide member 10 on the printer body side, the detector 6
None of the switches SW1, SW2, and SW3 are turned off because they are not pressed by the first fixed pressing member 7a and the second pressing member 7b of the cassette body 1.

As a result, the switches SW1 and S1 of the detector 6 on the printer body side are pressed by the pressing member 7 (first pressing member 7a and second pressing member 7b) on the side of the paper feed cassette.
Detect which switch of W2 and SW3 is pressed,
The detection signal of the detector 6 is input to the storage unit 12 via the discrimination control unit 11 that discriminates the paper type based on this signal, and the printer is suitable for the paper type stored in advance from the storage unit 12. It is possible to select a printing mode and drive the recording head 14 by the printing operation control unit 13 based on the selected mode to perform desired printing.

FIG. 5 shows a third embodiment of the present invention in which a paper feed cassette for cut sheets is attached to the paper guide member 10 on the printer body side. In this embodiment,
The pressing member is composed only of the movable pressing member 7b which moves in conjunction with the movement of the guide member 4, and when a letter size cut sheet is stored in the cassette body 1, the switch SW1 of the detector 6 is set to the cassette body. It is pressed by the pressing member 7b that interlocks with the movement of the first guide member 4. At this time, the switch SW2 is in the OFF state without being pressed by the pressing member 7b.

When A4 size cut sheets are stored in the cassette body 1, the switch S of the detector 6 is used.
W2 is pressed by the pressing member 7b. At this time, the switch SW1 is released from the pressing member 7b and turned off.

Further, when the B5 size cut sheet is stored in the cassette body 1, the pressing member 7b is moved to the right side as shown by the one-dot chain line in the drawing, so that the right side of the switch SW2. It will move to one position. As a result, the switches SW1 and SW2 are pressed by the pressing member 7.
It is not pressed by b and is turned off.

As a result, the pressing member 7 of the paper feed cassette
Each switch SW of the detector 6 on the printer body side by b
It detects which switch of SW1 and SW2 is pressed, and operates as described in the first and second embodiments of the present invention. Therefore, the printer determines the type of each of the letter size, A4 size, and B5 size sheets stored in the cassette body 1,
Select each print mode suitable for these paper types,
It is possible to print as desired.

FIG. 6 shows an example of the print mode selection operation of the printers of the first and second embodiments, in which the switches SW1, SW2 and SW3 of the detector 6 are turned ON / O.
Depending on the state of the FF, each print mode (print start position, print digit number, print speed, etc.) suitable for the size and type of paper when the printer prints is selected as shown.

[0049]

As described above, in the paper feed cassette of the present invention, the mechanism is simple, the dimensional control is easy, the expensive friction member can be made small, and the leading end of the paper is slightly lowered. Even if it goes down, the paper can be smoothly fed into the paper feed cassette without being scratched by the end surface of the friction member, and the separation operation of stacked paper can be performed well, and the last paper can be reliably It has an excellent effect that it can be separated and fed.

Further, since the paper size can be detected by bringing the slidable guide member into contact with the side edge of the paper and setting the paper, it is possible to save the trouble of manually setting the paper size. The excellent effect that it is possible to prevent the occurrence of defective printing due to a setting error is obtained.

[Brief description of drawings]

FIG. 1 is a plan view of a paper feed cassette and a paper guide unit of a printer body as seen from above according to an embodiment of the present invention.

FIG. 2 is an enlarged vertical cross-sectional view of the vicinity of the friction member at the front end portion of the pressure contact plate of FIG.

FIG. 3 is a schematic vertical sectional view of FIG.

FIG. 4A is an explanatory diagram showing a state in which a paper feed cassette for cut sheets is mounted in a paper guide unit on the printer body side according to the first embodiment of the present invention, and functional blocks connected to the state; Is. FIG. 9B is an explanatory diagram showing a state in which a paper feed cassette for postcards is mounted on the paper guide portion on the printer body side as the second embodiment of the present invention.

FIG. 5 is an explanatory view showing a state in which a paper feed cassette for cut sheets is attached to a paper guide portion on the printer body side as a third embodiment of the present invention.

FIG. 6 shows an example of each size and type of paper and each printing mode selected according to the ON / OFF state of each switch of the detector in the printers of the first and second embodiments of the present invention. It is a thing.

FIG. 7 is a vertical sectional view showing a schematic configuration of a sheet feeding cassette of a first conventional example.

8A is an enlarged vertical sectional view of the vicinity of the friction member at the front end portion of the pressure contact plate of FIG. 7. FIG. (B) is sectional drawing which followed the AA line of FIG.

FIG. 9 is an explanatory diagram for explaining a problem in the first conventional example.

FIG. 10A is an enlarged vertical cross-sectional view of the vicinity of the friction member at the front end portion of the pressure contact plate of the sheet feeding cassette of the second conventional example.
(B) is a cross-sectional view as seen from the direction V in FIG.

[Explanation of symbols]

 1 cassette body 2 friction member 2a upper surface of friction member 2b rear end of friction member 2c front end of friction member 3 convex portion 4 guide member 4a arm portion of guide member 5 pressure contact plate 5a upper surface of pressure contact plate 5b pressure contact plate recess 6 printer Detector 7 Pressing member 7a First pressing member 7b Second pressing member 8 Paper 9 Paper feeding roller 10 Paper guide member on printer side 11 Discrimination control unit 12 Storage unit 13 Printing operation control unit 14 Recording head

Claims (5)

[Claims] 1. A paper feed cassette comprising a cassette body capable of accommodating a plurality of sheets of paper, wherein a pressure contact plate for lifting the front end side of the paper from below and pressing the uppermost paper into pressure contact with a delivery means is provided. A concave portion is provided on the upper surface near the front end side, a friction member is attached to the concave portion, the upper surface of the friction member is formed to be higher than the upper surface of the pressure contact plate, and the protrusion is higher than the upper surface of the friction member immediately before the concave portion of the pressure contact plate A paper feed cassette, characterized in that a convex portion is formed. 2. An image forming apparatus provided with the paper feed cassette according to claim 1. 3. A cassette main body capable of storing a plurality of sheets, and a sheet which is slidably arranged in the cassette main body in the width direction of the sheet and which corresponds to the width of the sheets stored in the cassette main body. And a guide member for positioning the side edge of the sheet, and a sheet width cassette mounted and used in an image forming apparatus having a sheet width detector and discriminating means for discriminating the type of sheet based on a detection signal of the detector. The paper feed cassette according to claim 1, wherein the cassette body is provided with a pressing member that drives the paper width detector of the image forming apparatus in association with the guide member. 4. An image forming apparatus provided with the paper feed cassette according to claim 3, wherein the discriminating unit supplies a storage unit storing a plurality of types of print modes and a detection result of the detector. A discriminating control unit for discriminating the type of the paper stored in the paper cassette, selecting a print mode suitable for the discriminated paper from the storage unit, and controlling the printing operation according to the selected print mode; An image forming apparatus comprising: 5. The image forming apparatus according to claim 4, wherein the print mode includes set values of a print start position, a print digit number, and a print speed.