JP2003122194A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a transfer sheet from being soiled via a transfer roller in the case that printing is performed outside a predetermined area when an electrophotographic image forming apparatus prints on an irregular size transfer sheet such as tab paper or separation paper. SOLUTION: A shape recording part in which transfer-sheet shape information is recorded is provided on a transfer sheet. The main body of the image forming apparatus incorporates a shape information reader.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer,
The present invention relates to a sheet feeding device provided in an image forming apparatus such as a facsimile.

[0002]

2. Description of the Related Art Conventionally, when an image is printed on atypical paper such as tab paper or partition paper, the user inputs paper information from an operation unit for making various settings of the image forming apparatus.

Further, when printing is performed in the image forming section, for example, when printing is performed on tab portions of tab paper, a toner image is formed on all tab portions as shown in FIG.

[0004]

However, when images are formed on all the tab portions as described above, the toner image other than the printable tab portions is transferred to the transfer roller.
The transfer roller has a cleaning member for cleaning the roller,
If the image formation as described above is continuously performed, the transfer roller and the cleaning member are deteriorated and worn out significantly. Finally, the toner that cannot be completely cleaned appears as dirt on the back side of the tab sheet.

The present invention has been made in view of the above problems. By providing a shape recording section for recording shape information of the transfer sheet itself on the transfer sheet and providing a shape information reading section in the main body of the image forming apparatus, It is possible to avoid forming a toner image on an unnecessary portion and obtain a high quality image.

[0006]

A sheet accommodating means for stacking a plurality of sheets and a sheet feeding means for feeding the sheets to the main body of the image forming apparatus are provided, and the sheet has a shape in which a sheet shape is recorded. A sheet feeding device comprising a recording unit, and a shape reading unit for reading information of the shape recording unit downstream of the sheet feeding unit in the conveying direction.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) FIG. 1 is a sectional view of an image forming apparatus equipped with a sheet feeding apparatus according to Embodiment 1 of the present invention.

In FIG. 1, reference numeral 1 denotes a copying machine main body, and an original table 2 made of a transparent glass plate fixedly provided on the copying machine main body 1. Reference numeral 3 denotes a document pressure plate, which presses and fixes the document O placed at a predetermined position on the document table 2 with the image surface facing downward. A lamp 4 for illuminating the original O is provided below the original table 2, and reflecting mirrors 5, 6, 7, 8 for guiding an optical image of the illuminated original O to the photosensitive drum 12.
An optical system including 9 and 10 and an imaging lens 11 is provided. The lamp 4 and the reflection mirrors 4, 5, 6,
Reference numeral 7 moves in the direction of arrow a at a predetermined speed to scan the document O.

The image forming section includes a photosensitive drum 12 and a charger 13 for uniformly charging the surface of the photosensitive drum 12.
And a development for forming a toner image to be transferred onto the sheet S by developing the electrostatic latent image formed by the optical image emitted from the optical system on the surface of the photosensitive drum 12 charged by the charger 13. And a transfer charger 1 for transferring the toner image developed on the surface of the photosensitive drum 12 to the sheet S.
9, a separation charger 20 for separating the sheet S having the toner image transferred from the photosensitive drum 12, and a cleaner 26 for removing the toner remaining on the photosensitive drum 12 after the toner image is transferred. ing.

On the downstream side of the image forming section, a conveying section 21 for conveying the sheet S having the toner image transferred thereon, and a conveying section 2
A fixing device 22 for fixing the image on the sheet S conveyed by 1 as a permanent image is provided. Further, a discharge roller 24 for discharging the sheet S having the image fixed by the fixing device 22 from the copying machine main body 1 is provided, and the sheet discharged by the discharging roller 24 is provided outside the copying machine main body 1. A discharge tray 25 for receiving S is provided.

Next, the details of the present invention will be described with reference to FIGS. 2 to 4 when the transfer sheet S is a tab sheet.

FIG. 2 shows one of the transfer sheets S, and the transfer sheet S is provided with a tab portion S1 and a tab shape recording portion S2. On S2, a rectangular light-shielding bar S3 having a lower reflectance than the surface of the transfer paper S is printed.

FIG. 3 is a cross-sectional view of the periphery of the sheet feeding portion of the image forming apparatus main body 1. The transfer sheet S is accommodated in the sheet cassette 101, and is conveyed to the image forming unit by a sheet feeding roller included in the sheet feeding unit 102. A transport guide 104 and a vertical path door 103 are arranged downstream of the paper feeding unit 102. When a paper jam occurs, the vertical path door 103 rotates around A in the B direction, and the jammed transfer paper S
Can be removed.

After the paper jam processing, it is fixed at a predetermined position shown in FIG. 3 by a lock member (not shown). Then, transport rollers 105a and 106a are provided on the transport guide 104 to transport the transfer sheet S to the image forming unit, and rotate in a predetermined rotation direction. In addition, the transport roller 1
Driven rollers 105b and 106b, which are associated with the conveyance rollers, are disposed inside the vertical path door 103 so as to face the rollers 05a and 106a. Further, a transfer paper shape reading unit 107 having a built-in reflective sensor is fixed to the conveyance guide 104 between the conveyance rollers 105a and 106a.

Then, as shown in FIG. 4 (a view from the arrow C in FIG. 3), a slit is formed in the conveyance guide 104, and the shape information S2 recorded on the transfer sheet S can be read from the slit. ing.

FIG. 5 shows an example of the shape recording section when the number of tabs is five. When the number of tabs is 5, 5 ≦ 2 ³ −1 (= 7), and therefore the light-shielding bar S3 needs only 3 bits.
Further, as tabs which are generally circulated, those having 5 tabs and 10 tabs are circulated. Therefore, when the two types are included, 5 + 10 ≦ 2 ⁴ −1 (= 15), so the light-shielding bar S3 has 4 bits. It'll be good if you know.

FIG. 6 shows an arrangement example of the light shielding bar S3 in the case of 4 bits.

Next, the shape of the light shielding bar S3 will be described with reference to FIG. 7 showing a detailed view of the shape recording portion S2 of the transfer sheet S.

The width of the light shielding bar S3 in the direction parallel to the carrying direction is L1, and the interval between the light shielding bars S3 is L2.

When the sampling frequency of the reflection type sensor incorporated in the shape reading unit 107 is f1 and the processing clock of the image forming apparatus is f2, f3 = min (f1, f
2) (min (f1, f2) indicates the one that is not larger than f1 and f2).

When the spot diameter of the reflection type sensor of the shape reading unit 107 is φD, and when the transfer speed of the transfer paper is V, the passage time of the sensor detection unit of the light shielding bar S3 is L1 / V and the light shielding is performed. The passage time of the sensor detection unit in the gap between the bars S3 is L2 / V. To read the skew bar S3 without false detection,

[0022]

[Equation 1]

The requirement is that

Here, the transfer paper conveyance speed is 300 mm / S,
Sensor sampling frequency f1 and processing clock f
Assuming that 2 is 500 Hz and the spot diameter is φ1, then L1, L2> 300/500 = 0.6.

Since φ1> 0.6, the light-shielding bar has a width of 1 m.
m or more is required.

Next, the image forming operation will be described.

1. When the image forming apparatus 1 starts, the transfer paper S is fed from the paper feed unit 102.

2. The fed transfer paper is conveyed by the guide 104.
Then, the sheet passes through the vertical path guide 103 and is conveyed to the main body of the image forming apparatus.

3. When the tab sheet is recognized by the shape reading unit 107, the tab sheet information read by the shape reading unit is transferred to the CPU, and the tab position is acquired from the tab position information table preset in the CPU.

4. The image forming unit prints on a predetermined tab portion based on the obtained tab position information.

[0031]

As described above, by recording the shape information on the transfer paper S and providing the shape information reading section in the image forming apparatus, it is possible to print at a predetermined tab position, which is a wasteful part. Since it is possible to avoid printing on the transfer sheet, it is possible to prevent the transfer sheet from being soiled, and it is possible to obtain a high-quality image.

In the present invention, the information of the tab position is described as the shape information of the transfer paper, but other irregular-shaped transfer paper,
For example, the shape information of four continuous postcard papers, 8 or 16-divided sticker print papers that are used by cutting out a part of the transfer papers, and tack papers may be included.

In the present invention, the light shielding bar S3 is printed on the transfer paper S, but the light shielding bar S3 may be replaced by a punch hole.

In the present invention, the light-shielding bar S3 is printed on the transfer sheet S and is detected by using the reflection type sensor. However, the light-shielding bar S3 may be replaced by a punch hole and the reflection type sensor may be replaced by a transmission type sensor.

In the present invention, the light-shielding bar S3 is printed on the transfer paper S and is detected by using the reflection type sensor. However, even if the light-shielding bar S3 is replaced with a magnetic substance paint and the reflection type sensor is replaced with a magnetic substance detecting device. good.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an image forming apparatus embodying the present invention.

FIG. 2 is a diagram showing a transfer sheet S according to the present invention.

FIG. 3 is a schematic cross-sectional view of the vicinity of a paper feed unit embodying the present invention.

FIG. 4 is a view taken in the direction of arrow C in FIG.

FIG. 5 is a pattern diagram of a skew bar S3 of the transfer sheet S according to the present invention.

FIG. 6 is a pattern diagram common to 5 and 10 tabs according to the present invention.

FIG. 7 is a detailed view of a shading bar S3 embodying the present invention.

[Explanation of symbols] 101 paper cassette 102 paper feeder 103 Vertical path guide 104 Transport guide 105 Transport roller pair 106 Conveyor roller pair 107 Shape reading unit S1 tab part S2 Shape recorder S3 shading bar

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H027 DC10 DE02 DE07 DE09 EC02                       EC06 EC07 EC18 EC20 ED06                       ED17 EE01 EE08 EF09 FD06                       FD10 ZA07                 3F048 AA01 AB01 BA06 BA11 BB03                       DC14

Claims (6)

[Claims] 1. An image forming apparatus having a shape recording unit for recording a sheet shape on a sheet for forming an image, and a shape reading unit for reading information of the shape recording unit inside the image forming apparatus. . 2. The image forming apparatus according to claim 1, wherein the shape recording unit is configured by a pattern whose reflectance is set lower than that of the sheet surface, and the shape reading unit is configured by an optical sensor. . 3. The image forming apparatus according to claim 2, wherein the sheet recording unit has at least one pattern having the low reflectance. 4. The image forming apparatus according to claim 1, wherein the shape recording unit includes one or more holes, and the shape reading unit includes an optical sensor. 5. An image forming apparatus, comprising: an image forming unit for forming an image on a sheet fed by the sheet feeding device of the image forming apparatus according to claim 1. Description: apparatus. 6. An image reading apparatus having an image reading unit for reading an image of a sheet fed by the sheet feeding device of the image forming apparatus according to claim 1. .