JPH0551149A - Image forming device - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent the output image from being chipped, misaligned, or jammed during transport due to a paper size setting error. [Structure] Slits 1a are provided along the sheet feeding direction A of the sheet feeding tray 1, resistors 2a and 2b are formed on the back surfaces on both sides of the slits 1a, and the sheet guides 3 are provided on the back surface of the sheet feeding tray 1 through the slits 1a. And the slider 4 are slidably mounted integrally, and the movable plate spring 5 attached to the slider 4 short-circuits the resistors 2a and 2b. Furthermore, the resistors 2a and 2b
One end of the connection terminals 7a, 7 of the tray receiver 6 on the apparatus body side.
The sheet size can be detected as resistance value information by contacting the sheet guide 3 with one end of the stacked sheets so that the sheet size can be connected to the sheet b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a printer, a copying machine,
The present invention relates to an image forming apparatus such as a facsimile, and more particularly to an image forming apparatus provided with a sheet size self-detecting unit.

[0002]

2. Description of the Related Art Conventionally, as this type of image forming apparatus,
As shown in FIG. 6, the paper size setting switch 1 provided on the operation panel 103 of the printer body 102 does not have a means for detecting the paper size on the paper feed tray 101 side.
The user operates 04 to set the paper size each time, or sets the paper size according to the paper size setting information from the host computer 105 connected to the apparatus main body 102. As shown in FIG. 5, a paper size detection bracket 107 having a shape that differs depending on the size of the paper to be stored on the side surface of the paper feed cassette 106 is provided, and the paper including a photointerrupter is correspondingly provided on the apparatus main body 102 side. In some cases, a size detection sensor 108 is provided to automatically detect and set the paper size.

[0003]

However, in such a conventional image forming apparatus, the former cannot detect the paper size by itself, so the paper size set by the paper size setting switch or the host computer is set. If the size of the paper actually set in the paper feed tray is different from that of the paper, not only the output image may be missing or misaligned, but also a jam may occur during paper transportation. In addition, the user must check the required paper size each time before setting the paper to be actually used.

In the latter case, it is necessary to prepare a paper feed cassette equipped with various types of brackets according to the size of the paper used, or to replace the brackets when changing the paper size. However, doing so requires a large amount of space for storage, and replacing the bracket is both cumbersome and may be forgotten. In either case, there is a problem in that it cannot be used for non-standard size paper.

The present invention has been made in view of the above points, and there is a lack of an output image due to a setting error of the paper size.
An object of the present invention is to provide an image forming apparatus capable of preventing misalignment or paper jam during transportation.

[0006]

In order to achieve the above object, the present invention provides an image forming apparatus having an apparatus main body and a paper feed tray detachably attached to the apparatus main body, in which the feeding direction of the paper feed tray is set. The resistance value continuously changes along at least one of the directions orthogonal to it, and a pair of resistors, one end of which is respectively connectable to the connection terminal on the side of the apparatus main body, and the above-mentioned resistors are short-circuited between these resistors. A sheet guide that is movably provided over the sheet feed tray and holds one side edge of the sheets stacked on the sheet feed tray by sliding along the resistor is provided. An image forming apparatus capable of specifying a paper size by detecting a resistance value between both connection terminals.

Further, the resistance value continuously changes along at least one of the paper feed direction of the paper feed tray and the direction orthogonal thereto, and one end of each of the resistor bodies is connectable to the connection terminal on the apparatus main body side. Along the resistor, the resistor is provided at a plurality of locations on the paper feed tray so that the resistor can be erected, and the resistors can be short-circuited. An image forming apparatus is also provided in which a paper guide for holding the paper is provided, and the paper size can be specified by detecting the resistance value between both connection terminals on the apparatus main body side.

Further, in the above image forming apparatus, it is preferable to provide a means for encoding and storing the length information and / or the width information of the specified paper size.

[0009]

With the image forming apparatus according to the present invention configured as described above, when the sheets are stacked at a predetermined position on the sheet feeding tray and the sheet guide is brought into contact with one end of the sheet, the position of the sheet guide is changed. Corresponding to the above, the resistance value between both terminals on the apparatus main body side changes, and it is possible to specify the desired paper size by detecting the position of the side edges of the paper in the length direction or width direction or both.

Further, in the case where the undulating sheet guide is provided at a plurality of positions along the pair of resistors formed on the sheet feeding tray, it becomes possible to specify a fixed sheet size with a simpler construction.

Further, in the above-mentioned image forming apparatus, if a means for storing the length information and / or the width information of the paper in a coded manner is provided, the transmission of the size information to / from the image processing apparatus is binary. The converted data will be in a form that is easy to handle.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be specifically described below with reference to the drawings. The first is an exploded perspective view showing an embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of the control device thereof.

In FIG. 1, a slit 1a is provided along the sheet feeding direction A at the center of the sheet feeding tray 1 in the width direction, and the back surface of the slit 1a is continuously equidistant from both sides of the slit 1a in parallel with each other. Resistors 2a and 2b whose resistance values change are formed. Further, the slits 1a are inserted to integrally connect the paper guide 3 and the slider 4 to both front and back surfaces of the paper feed tray 1 via a shaft 4a, and a movable plate is provided between the upper surface of the slider 4 and the back surface of the paper feed tray 1. The movable leaf spring 5 is attached to the resistor 2 by engaging the spring 5.
Both a and 2b are slid together so that a part of them can be short-circuited.

On the other hand, a connection terminal 7 formed of a fixed leaf spring is provided in the tray receiving portion 6 on the apparatus main body side for receiving the paper feed tray 1.
a and 7b are provided, and the connection terminals 7a and 7b are connected to the resistor 2 when the paper feed tray 1 is attached to the tray receiving portion 6 of the apparatus main body.
By making pressure contact with one end of a and 2b and bringing the paper guide 3 into contact with the end of the paper stacked on the paper feed tray 1, resistance value information that changes according to each paper size can be transmitted to the apparatus main body side. It can be so.

FIG. 2 shows the configuration of the control device 30 provided in the main body of the device. In this control device 30, the resistance value information transmitted from the paper feed tray 1 side is combined with the reference voltage and the reference resistance. A / D converter 31 which converts the voltage into a binary signal and outputs it as a binary signal, and a controller 32 which receives the binary signal and outputs the signal itself or a signal obtained by further coding the signal. From the paper size storage unit 33 that stores the signal output from the control unit 32, the fixed size binarization information unit 34 that stores the binarized information of the fixed size in advance, and the sensors 40 other than the resistance value information. A sensor amplifier unit 35 that amplifies a signal and inputs it to the control unit 32, and a driver unit 3 that drives each motor and clutches 43 of the image forming apparatus according to the signal from the control unit 32.
It consists of 6 and 6.

Next, the operation of the embodiment having the above structure will be described. With the paper guide 3 retracted to the right as shown in FIG. 1, stack the paper on the paper feed tray 1 with the left edge of the paper aligned with a reference position (not shown) on the tray, and then load the paper guide 3. Move it to the left until it touches the right edge of the paper. As a result, the resistance values of the resistors 2a and 2b connected in series via the movable leaf spring 5 and input to the connection terminals 7a and 7b on the apparatus main body side continuously change according to the position of the paper guide 3. .

The resistance value information input to the main body of the apparatus is combined with the reference voltage and the reference resistance in the control device 30 shown in FIG. It is digitized and input to the control unit 32. Control unit 32
Then, the binarized signal itself or the binarized signal is further encoded and stored in the paper size storage unit 33. Table 1 shows an example of the encoding.

[0018]

[Table 1]

When encoding, the deviated positional deviation of the paper guide 3 is also taken into consideration, and the detected binarized signal is compared with the binarized information stored in advance in the standard size binarized information section 34. It may be converted into a standard size paper size code.

The binarized data or the coded data as described above is combined with the data input from the other sensors 40 through the sensor amplifier section 35 and the image processing device 41.
Is transmitted to the device 41 in response to a request from the device. As a result, the image processing device 41 is
Information of the currently stored paper size can be transmitted to the driver, the layout size of the image image can be determined based on the paper size data transmitted from the control device 30, and appropriate image image data can be generated. The motor clutches 43 are driven through the unit 36, and the layout image generated by the image processing device 41 based on the character and graphic information input from the host computer 42 is made to match the actual output image. It is possible to obtain an output image without misalignment, and it is possible to prevent a paper jam during transportation.

Next, FIG. 3 shows another embodiment of the present invention. In this embodiment, three openings 11a, 11b, 11c are formed in line in the paper feed direction A of the paper feed tray 11, and the paper feed direction A is formed in each of the openings 11a, 11b, 11c.
The shafts 14 that are orthogonal to the
The first, second, and third paper guides 13a, 13b,
13c are rotatably pivotably attached to each other so that they are in a position corresponding to sheets of a specific standard size, for example, A3, A4 and A5 sizes in a standing state.

Then, as shown in FIG. 4, each paper guide 1
Conductors 15 are respectively formed on 3a, 13b, and 13c,
When the conductor 15 stands up, the two conductors 12a and 12b formed on the back surface of the paper feed tray 1 are brought into contact with the conductors 15a and 12b so that the conductors 15 are connected to the tray receiving portion 16 of the apparatus main body. The terminals 17a and 17b are connected to each other.

In this embodiment, standard size sheets are stacked on the sheet feed tray 11 and the corresponding sheet guides are erected so that the resistance value information corresponding to each sheet can be obtained by the control device 30 shown in FIG. Can be input to the control device 30 to perform the same operation as that of the previous embodiment, and the resolution of the A / D converter 31 on the control device 30 side can be further reduced by the previous embodiment, so that it can be supplied at low cost. it can.

In the above embodiment, the case where the paper size is specified by detecting the paper length information has been described.
Shows another embodiment of the present invention in which the paper size is specified by detecting the paper width information.

In this embodiment, slits 21a and 21b orthogonal to the center line of the paper feed tray 21 along the paper feed direction A are provided, and the slit 2 is formed on the back surface thereof.
Resistors 22a and 22b are formed on both sides of 1a, one end of each of the resistors 22a and 22b is bent at a right angle and guided to the leading end of the paper feed tray 21, and the apparatus main body side tray receiving portion 2 is formed.
6 connection terminals 27a and 27b.

A first paper guide 23a and a slider 24, which are similar to those of the embodiment shown in FIG. 1, are provided on the front and back of the paper feed tray 21 and are integrally connected through a slit 21a.
The movable leaf spring 25 provided on the slider 24 is connected to the resistor 22.
Both a and 22b are slidable. Further, by providing the second paper guide 23b that slides along the slit 22b and moving the first paper guide 23a,
The second paper guide 23b is allowed to move symmetrically with respect to the center line via an interlocking mechanism (not shown). According to this embodiment, the paper size can be specified by detecting the resistance value information in the width direction of the paper.

It is also possible to detect information in the width direction of the paper by arranging a resistor and a plurality of paper guides in a direction orthogonal to the paper feed direction A with the same configuration as the embodiment shown in FIG. And by combining these examples,
By simultaneously detecting the length information and the width information of the paper, it is possible to easily specify the paper size of any shape other than the standard size.

[0028]

As described above, the image forming apparatus according to the present invention detects the position of the paper guide that holds one side edge of the paper stacked on the paper feed tray as the resistance value information to detect the paper size. Since it is specified, the same paper tray can be used for all sizes of paper, both standard and non-standard, with a simple configuration. It is possible to prevent misalignment or paper jam during transportation.

Further, the paper feed tray provided with undulating paper guides at a plurality of positions can specify a fixed paper size with a simpler configuration, and the resistance values to be detected differ greatly. Therefore, there is no problem even if the resolution of the detection means on the apparatus main body side is roughened, and the production cost can be further reduced.

Further, in the above-mentioned image forming apparatus, if a means for storing the length information, width information and the like of the paper in a coded manner is provided, the size information is transmitted between the image forming apparatus and the image processing apparatus. It can be very convenient to handle.

[Brief description of drawings]

FIG. 1 is a partially exploded perspective view showing an embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of the same control device.

FIG. 3 is a perspective view showing another embodiment of the present invention.

FIG. 4 is a sectional view taken along line XX of FIG.

FIG. 5 is a partially exploded perspective view showing still another embodiment of the present invention.

FIG. 6 is a perspective view showing an example of a conventional image forming apparatus.

FIG. 7 is a perspective view showing another example of a conventional image forming apparatus.

[Explanation of symbols]

1,11,21 Paper feed tray 2a, 2b, 12a, 12b, 22a, 22b Resistor 3, 13a, 13b, 13c, 23a, 23b Paper guide 4, 24 Slider 5, 25 Movable leaf spring 6, 16, 26 Tray Receiver 7a, 7b, 17a, 17b, 27a, 27b Connection terminal

Claims (3)

[Claims] 1. An image forming apparatus having an apparatus main body and a paper feed tray detachable from the apparatus main body, wherein a resistance value is continuously provided along at least one of a paper feed direction of the paper feed tray and a direction orthogonal thereto. And a pair of resistors, one end of which is respectively connectable to the connection terminals on the apparatus main body side, and the pair of resistors are movably mounted on the paper feed tray so as to short-circuit these resistors, A paper guide that holds one side edge of the paper stacked on the paper feed tray by sliding along the paper guide is provided, and the paper size is detected by detecting the resistance value between both connection terminals on the apparatus main body side. An image forming apparatus characterized by being specified. 2. An image forming apparatus having an apparatus main body and a paper feed tray detachable from the apparatus main body, wherein a resistance value is continuously provided along at least one of a paper feed direction of the paper feed tray and a direction orthogonal thereto. Of a pair of resistors, one end of each of which is connectable to the connection terminal on the apparatus main body side, and the tray is provided so as to be capable of being undulated at a plurality of positions of the tray along the resistors, and by standing up between the resistors. And a paper guide that holds one side edge of the paper stacked on the paper feed tray, and detects the resistance value between both connection terminals of the main body of the device to identify the paper size. An image forming apparatus characterized by being capable of performing. 3. The image forming apparatus according to claim 1, further comprising means for encoding and storing length information or width information of the specified paper size or both of them.