JP6729082B2 - Image forming apparatus and control method - Google Patents

Description

The present invention relates to an image forming apparatus and a control method, and more particularly to an image forming apparatus and an control method for forming an image on an envelope.

In recent years, the use of copiers and printers has expanded, and it is required to support not only plain paper but also various media such as envelopes.

However, there are various types of envelopes. In particular, the flaps of envelopes have no standard and various shapes. If the setting regarding the shape of the envelope input by the user to the image forming apparatus and the shape of the actually used envelope are different, the image cannot be properly formed. In particular, when the settings are not made correctly when the envelope is conveyed with the flap open, the influence is great.

With respect to such a problem, in the printing apparatus disclosed in Patent Document 1, the envelope size stored in the manual feed tray is set to the opening width of the pair of guides that regulate the width direction and the standard size of the envelope set by the user. The size of the flap is specified based on the difference between and.

JP, 2013-169769, A

However, in the printing apparatus of Patent Document 1, if the user makes a mistake in selecting or inputting the size of the envelope and cannot set it properly, the size of the flap of the envelope cannot be correctly specified. There is also a problem that the device cannot correctly recognize the mistake of the flap orientation.

The present invention has been made in view of the above circumstances, and provides means for appropriately determining whether or not a conveyed recording medium is an envelope and automatically determining the length and orientation of the flap of the envelope. The purpose is to do.

The above object of the present invention can be achieved by the following means.

(1) a paper feed unit having a paper feed tray capable of storing a plurality of recording media;
A transport unit that has a transport path and transports the recording medium fed from the paper feed unit in the transport path;
An image forming unit that forms an image on the conveyed recording medium,
A detection unit that detects an end position in the width direction orthogonal to the conveyance direction of the recording medium that is conveyed in the conveyance path;
Whether a continuous edge line corresponding to the end position of the recording medium is detected by the time change of the end position detected by the detection unit , and whether the recording medium conveyed by the change of the angle of the edge line is an envelope or not And a control unit that determines at least one of the length and the direction of the flap of the envelope in the transport direction when determining that the envelope is the envelope,
An image forming apparatus including.

(2) The image forming apparatus according to (1), wherein the control unit changes the position of the image formed on the envelope according to the determined length and orientation of the flap.

(3) In the above (1) or (2), the control unit delays the image writing timing by the length of the flap if the direction of the flap is the leading end side of the envelope to be conveyed. The image forming apparatus described.

(4) The detection area of the detection unit is provided on the upstream side of the image forming unit in the conveyance path, and the detection unit also serves as a skew detection unit that detects the skew amount of the recording medium conveyed. The image forming apparatus according to any one of (1) to (3) above.

(5) The control unit interrupts the printing when the orientation of the flap in the print settings of the print job for printing using the envelope is different from the determined orientation of the flap. From the above (1), The image forming apparatus according to any one of (4).

(6) The detection unit is a line sensor including a plurality of photoelectric conversion elements arranged side by side in a direction intersecting the transport direction of the recording medium,
The control unit, by the output of the line sensor, when it is determined that the envelope, further inside the end of the envelope, when detecting a continuous edge corresponding to the step of the envelope, The image forming apparatus according to any one of (1) to (5) above, which determines that the envelope is conveyed with its back surface facing the line sensor.

(7) The control unit suspends the printing when the front and back of the envelope in the print setting of the print job for printing using the envelope are different from the front and back of the determined envelope. Image forming apparatus.

(8) When the control unit executes a print job with print settings using the envelope, when the image size of the image data of the print job is larger than the size of the main body unit excluding the flap of the envelope, The image according to any one of (1) to (7) above, which notifies the user of a warning or executes the print job by changing the image size so as to be equal to or smaller than the size of the main body section. Forming equipment.

(9) The control unit notifies the user of a warning when it is not possible to determine the presence of the flap of the envelope when executing the print job of the print setting using the envelope. From the above (1) to (7) The image forming apparatus according to any one of 1) to 10).

(10) A control method for an image forming apparatus, comprising: a detection unit configured to detect an end position in a width direction orthogonal to a conveyance direction of a recording medium conveyed in a conveyance path,
Whether a continuous edge line corresponding to the end position of the recording medium is detected by the time change of the end position detected by the detection unit , and whether the recording medium conveyed by the change of the angle of the edge line is an envelope or not To determine whether
A step of determining at least one of the length and the direction in the transport direction of the flap of the envelope when it is determined to be the envelope;
Control method including.

According to the present invention, it is determined whether or not the conveyed recording medium is an envelope based on the time change of the end position of the recording medium detected by the detection unit, and the flap of the envelope is determined when it is determined to be the envelope. At least one of the length and the direction in the transport direction of is determined. By doing so, it becomes possible to automatically determine the length and direction of the flap of the envelope.

FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a block diagram showing a hardware configuration of the image forming apparatus. It is a schematic diagram explaining each part of an envelope. It is a figure which shows the output of the envelope and the line sensor which were conveyed. It is a figure which shows the output of the envelope and line sensor conveyed by skewing. It is a figure which shows the output of the envelope and the line sensor which were conveyed. It is a schematic diagram explaining the change of the light-receiving amount in the level difference of an envelope. It is a flow chart which shows the control method concerning a 1st embodiment. It is a flow chart which shows the control method concerning a 1st embodiment. It is an example of a warning display displayed on the operation display unit. It is an example of a warning display displayed on the operation display unit. It is a flow chart which shows the control method concerning a 2nd embodiment. It is a figure which shows the arrangement position of a pair of line sensor which concerns on a modification.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description. Further, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may differ from the actual ratios.

FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram showing the hardware configuration of the image forming apparatus.

As shown in FIG. 1, the image forming apparatus 100 includes an image forming apparatus body 10a, a sheet feeding device 10b, and a post-processing device 10c. In the accompanying drawings, the vertical direction is the Z direction, the front/back direction of the image forming apparatus 100 is the Y direction, and the direction orthogonal to these Y and Z directions is the X direction. In the following description, the X direction may be referred to as the conveyance direction of the recording medium, and the Y direction may be referred to as the width direction of the recording medium. In this paper, the term "recording medium" is used as a generic term for plain paper and envelopes.

As shown in FIG. 2, the image forming apparatus 100 has a hardware configuration including a control unit 110, a storage unit 120, an operation display unit 130, a paper feeding unit 140, a transport unit 150, an image forming unit 160, line sensors 171, 172, and And a post-processing unit 180, which are connected to each other via a signal line such as a bus for exchanging signals.

The control unit 110 is a CPU and controls various parts of the device and performs various arithmetic processes according to a program.

The storage unit 120 includes a ROM that stores various programs and various data in advance, a RAM that temporarily stores the programs and various data as a work area, and a hard disk that stores various programs and various data.

The operation display unit 130 includes a touch panel, a numeric keypad, a start button, a stop button, and the like, and is used for displaying various information such as a warning display and for inputting various settings and instructions.

The paper feed unit 140 includes a plurality of paper feed trays 141. Each of the paper feed trays 141 accommodates a plurality of recording media (plain paper 21 or envelope 22) and sends the recording media one by one to the downstream transport path. The user can input, through the operation display unit 130, the paper setting indicating the information of the recording medium stored in each paper feed tray 141. This paper setting includes the types, sizes, and weights of the plain paper 21 and the envelope 22. Further, in the case of an envelope, the direction of the flap and the size of the flap with respect to the conveying direction of the stored envelope can be further set.

The transport unit 150 includes transport paths 151, 152, 153, 154, a plurality of transport roller pairs arranged along these transport paths, and a drive motor (not shown) that drives these transport roller pairs. The recording mediums fed one by one from the paper feeding unit 140 are conveyed along the conveyance path 151. Then, the registration roller 159 in the conveyance path 151 stops and re-conveys the sheet so that the sheet is conveyed to the image forming unit 160 in synchronization with the image forming timing. When images are formed on both sides, the recording medium having the image formed on the front surface (first surface) by the image forming unit 160 is conveyed along the switchback conveyance path 152, and after being turned upside down, An image is formed on the back surface (second surface) by the image forming unit 160 that has been conveyed again. The recording medium on which the image is formed is discharged to the discharge tray 155 via the transport path 153. Alternatively, the sheet is discharged to the discharge tray 156 via the transport path 154. The discharge tray 155 moves up and down in the direction of the arrow shown in FIG. The discharge tray 156 is a spare discharge tray and is also used as a purge tray.

The image forming unit 160 forms an image by, for example, an electrophotographic method. The image forming unit 160 includes a writing unit, an intermediate transfer belt, a developing unit corresponding to a plurality of colors, a secondary transfer unit, a fixing device, and the like.

(Line sensors 171, 172)
The line sensor 171 is arranged in the conveyance path 151 on the downstream side of the sheet feeding tray 141 of the sheet feeding device 10b in the conveyance direction and on the upstream side of the image forming unit 160, and an image on the front surface (first surface). The edge position of the recording medium is detected during formation. The line sensor 172 is arranged in the transport path 152, and detects the end position of the recording medium during image formation on the back surface (second surface). Since the two line sensors 171 and 172 have the same configuration, the configuration will be described below with the line sensor 171 as a representative.

The line sensor 171 is an image sensor in which photoelectric conversion elements configured of CIS (Contact Image Sensor) or the like are arranged in a line in a line or in a plurality of lines, and read a one-dimensional image. The line sensor 171 has optical elements such as a light emitting element and a lens array, which are arranged along the row of the photoelectric conversion elements. The light emitting element irradiates the object (recording medium) with uniform light in the extending direction of the row.

In both the line sensors 171, 172, the rows of photoelectric conversion elements are arranged so as to extend in a direction intersecting the conveyance direction of the recording medium, preferably in a width direction (hereinafter, simply referred to as “width direction”) orthogonal to the conveyance direction of the recording medium. It is arranged.

The arrangement positions of the line sensors 171 and 172 in the conveyance direction in the conveyance paths 151 and 152 are such that when the front end of the envelope 22 having the maximum length that can be fed to the registration roller 159 reaches the rear end of the envelope 22. It is preferable that the detection positions of the sensors 171 and 172 are arranged so that they are already out. Further, the line sensor 171 is arranged above the transport path 151, and the reading surface is the first surface of the recording medium. The line sensor 172 is arranged below the transport path 152, and the reading surface is the second surface of the recording medium.

In the present embodiment, the line sensors 171 and 172 are used as a “detection unit” that detects the edge position of the recording medium in order to determine the size and orientation of the flap of the envelope, which will be described later. It also serves as a skew detector for skew correction (skew correction) (see FIG. 5 described later).

When skew correction is performed, the conveyed recording medium is subjected to the RIP-processed image by the image control circuit in the control unit 110 so as to cancel the skew direction according to the tilt direction and the skew amount detected by the line sensor 171. Image processing of two-dimensional position correction is performed on the data. Alternatively, the registration roller 159, which is divided into left and right in the width direction according to the tilt direction and the skew amount, is rotated in a state where the left and right are slightly different in rotational speed.

The post-processing unit 180 performs post-processing on the plain paper 21 on which the image is formed by the image forming unit 160. As the post-processing, there is, for example, a side-stitching process, where stapling is performed at a position spaced a predetermined distance from the edge of a sheet bundle in which a plurality of plain papers 21 are bundled, and the sheet bundle is side-stitched to form a booklet. .. The formed booklet is discharged onto the discharge tray 155.

The communication unit 190 is an interface for communicating with a PC terminal or the like via a network such as a LAN, and receives a print job from, for example, a PC terminal operated by a user.

(Judgment method of envelope flap direction and length)
Hereinafter, a method for determining the orientation and length of the flap of the envelope will be described with reference to FIGS. 3 and 4. FIG. 3 is a schematic diagram illustrating each part of the envelope. FIG. 4 is a diagram showing the output of the conveyed envelope and line sensor.

As shown in FIGS. 3A and 3B, the envelope 22 is composed of a main body portion 221 and a flap 222. In the present embodiment, the length of the flap 222 in the longitudinal direction in the case of a Japanese envelope as shown in FIG. 3 and in the lateral direction in the case of a Western envelope is defined as the flap length D2. More specifically, the flap length D2 is the length of the flap 222 in the opening direction (X direction in FIG. 4 described later) when the flap 222 is open. The length of the main body portion 221 in the same direction is referred to as the main body length D1, and the combined length is referred to as the total length D3. Further, on the back surface side of the envelope 22 in FIG. 3B, there is a step (also referred to as “shoulder”) 223 on the flap 222 side of the main body portion 221. In this embodiment, it is premised that the flap 222 of the envelope 22 is fed with the flap 222 open.

As shown in FIG. 4A, the line sensor 171 is arranged so as to detect the back side from substantially the center of the envelope 22 in the width direction (Y direction). In the following, for ease of understanding, the foremost detection position of the detection area of the line sensor 171 is s0, the farthest detection position is s100, and values in accordance with the position are given in between. ..

When the envelope 22 is conveyed in the X direction with the flap 222 on the leading side in the state as shown in FIG. 4A, the front end of the flap 222 of the envelope 22 is at time t10, and the boundary between the flap 222 and the main body portion 221 is at time. At time t20, the rear end of the main body 221 passes through the detection area of the line sensor 171 at time t30.

FIG. 4B shows a time change of the output of the photoelectric conversion element at each of the detection positions s0, s70, s80, and s90 as a representative. At time t10, the outputs of the photoelectric conversion elements at the detection positions s0 and s70 change from off to on according to the arrival of the flap 222 in the detection area. Further, at time t20, the output of the photoelectric conversion element at the detection position s80 changes from off to on in response to the arrival of the widthwise end portion of the main body portion 221 in the detection region. At time t30, the outputs of the photoelectric conversion elements at the detection positions s0, s70, and s80 change from on to off as the rear end of the envelope 22 leaves the detection region. On the other hand, since the output of the photoelectric conversion element at the detection position s90 is outside the widthwise end of the envelope 22, the output remains off during the period from time t0 to t30.

FIG. 4C is a plot of the end position of the envelope 22 determined by the well-known edge determination processing such as threshold processing by the control unit 110 from the outputs of the photoelectric conversion elements at the detection positions s0 to s100.

As shown in FIG. 4C, the control unit 110 detects change points p1, p2, p3 in which the tendency of continuous edge lines corresponding to the detected end position changes. Specifically, the change point p1 at which the angle between the edge line e1 and the edge line e2 adjacent thereto is changed is detected. Similarly, the change point p2 is detected from the edge lines e2 and e3, and the change point p3 is detected from the edge lines e3 and e4. The change point p1 corresponds to the output of the detection position s70 at time t10 in FIG. The change point p2 corresponds to the output of the detection position s80 at time t20. The change point p3 corresponds to the output of the detection position s80 at time t30.

Then, the control unit 110 determines the front-back direction of the flap 222 from these change points p1, p2, p3. Specifically, t30-t20 and t20-t10 are compared to determine the flap orientation as follows.
When t30-t20>t20-t10, it is determined that the flap faces the leading end side with respect to the transport direction.
On the other hand, when t30-t20<t20-t10, it is determined that the flap 222 faces the rear end side with respect to the transport direction.

When it is determined that the flap 222 faces the tip side as shown in FIG. 4, the flap length D2 (mm) can be calculated from the following formula.
D2=V×(t20-t10)
Here, V is the transport speed (mm/sec) of the envelope 22.

As described above, in this embodiment, it is determined whether or not the conveyed recording medium is an envelope based on the time change of the end position detected by the detection unit, and the length and orientation of the flap of the envelope are automatically determined. Can be determined. As a result, the user can omit inputting some print settings related to the envelope, which improves convenience.

(Judgment of flap direction and length when the envelope is skewed)
Hereinafter, a method for determining the direction and length of the flap of the envelope when the envelope is conveyed obliquely will be described with reference to FIG. FIG. 5 is a diagram showing the outputs of the envelope and the line sensor conveyed obliquely.

First, the skew amount θ that is the inclination of the envelope 22 with respect to the transport direction is calculated. The skew amount θ can be calculated by the following equation (1).
θ=tan ⁻¹ ((s80−s50)/(t31−t21)×V) (1)
Here, "s80-s50" indicates the distance (mm) in the Y direction between the positions of s80 and s50 (the same applies hereinafter).
The flap length D2 can be calculated by the following equation (2).
D2=C×cos(θ+tan ⁻¹ (b/a)) (2)
Here, a=(t21−t11)×V, b=s80−s70, and C is the length of the slope of the flap 222 (see FIG. 5B).
The body length D1 of the body portion 221 of the envelope 22 can be calculated by the following equation (3).
D1=SQRT((s80-s50) ² +((t31-t21)*V) ² ) (3)
The calculated skew amount and the like are used for skew correction in the control method described later.

(Judgment of front and back of envelope)
Hereinafter, a method for determining the front and back of an envelope will be described with reference to FIGS. 6 and 7. FIG. 6 is a diagram showing the output of the conveyed envelope and line sensor. FIG. 7 is a schematic diagram for explaining a change in the amount of received light at the step 223 of the envelope.

FIG. 6A shows a state in which the back surface of the envelope 22 is conveyed in the X direction with the back surface facing upward, in other words, a state in which the back surface is conveyed toward the line sensor 171 side. 6A, similarly to FIG. 4A, the front end of the flap 222 of the envelope 22 is at time t10, the boundary between the flap 222 and the main body portion 221 is at time t20, and the rear end of the envelope 22 is at time t30. Each passes through the detection area of the line sensor 171. Further, as shown in FIG. 6A, the step 223 passes through the detection area of the line sensor 171 between times t20 and t23.

As shown in FIG. 7A, at time t20 at the detection position s70, the incident light from the line sensor 171 that irradiates the front sheet 221a of the envelope 22 is reflected as it is and reaches the photoelectric conversion element of the line sensor 171. On the other hand, as shown in FIG. 7B, at time t22 at the detection position s70, since the step 223 due to the back side paper 221b of the envelope is at the detection position s70, the incident light is scattered by the step 223 and the line sensor The amount of light reaching the photoelectric conversion element 171 decreases. The output at time t22 at the detection position s70 in FIG. 6B shows an intermediate output between on/off according to the decrease in the received light amount.

FIG. 6C is a plot of the end position of the envelope 22 and the step determined by the control unit 110 by a known edge determination process such as a threshold process from the outputs of the photoelectric conversion elements at the detection positions s0 to s100. is there. 6B, a step corresponding to the bottom flap at the rear end on the side opposite to the flap 222 is also detected, but as shown in FIG. 6C, the control unit 110 is close to the flap 222 side. Only the one step is detected, and the step on the far side is excluded from the detection target by the mask processing.

As shown in FIG. 6C, the control unit 110 detects change points p1, p2, p3, and p4 in which the tendency changes from the continuous edge line corresponding to the detected end position or step. The change points p1 to p3 are detected by the same processing as that in FIG. As for the change point p4, the change point p4 in which the angle changes is detected from the edge lines e5 and e6 formed by continuous step positions. In FIG. 6C, the change point p4 corresponds to the output of the detection position p20 at time t23.

Then, the control unit 110 has the edge lines e5 and e6 on the flap 222 side of the envelope 22 so that the conveyed envelope 22 is conveyed with its back surface facing the line sensor 171, that is, the envelope. 22 determines that the sheet is being conveyed in the direction in which the image is formed on the back surface.

As described above, in this embodiment, the inside and the outside of the envelope can be automatically determined according to whether or not there is a step existing on the side closer to the flap, which is convenient for the user. improves.

As described above, in the present embodiment, the control unit 110 determines the transport state of the envelope 22 based on the output of the line sensor 171. The conveyance state here includes the length of the flap 222, the direction with respect to the conveyance direction, the front and back of the envelope, and the skew amount. In addition, in the above description, the conveyance state of the envelope is determined by the output of the line sensor 171, but the same determination may be performed by the output of the line sensor 172. Next, a control method of the image forming apparatus 100 based on the determined conveyance state of the envelope will be described.

(Control method according to the first embodiment)
8A and 8B are flowcharts showing a control method of the image forming apparatus 100 executed by the control unit 110.

For example, printing is started by receiving a print job execution instruction from a PC terminal operated by the user. The print job includes a job ticket in which print settings such as the type of recording medium to be used are described, and image data that is a source of a print image. When printing using an envelope, the job ticket describes print settings relating to the size of the body of the envelope and the orientation of the front and back of the envelope. The direction of the flap with respect to the conveying direction of the envelope and the length of the flap are automatically determined (automatically detected) on the image forming apparatus 100 side as described later. However, the present invention is not limited to this, and the print setting may include the direction and length of the flap of the envelope.

As shown in FIG. 8A, first, the recording medium is conveyed from the paper feed tray 141 that stores the recording medium corresponding to the print settings of the print job, and the line sensor 171 reads the end position of the recording medium. Perform (S101).

The control unit 110 detects the edge line corresponding to the end of the envelope 22 from the output of the line sensor 171, and determines whether the edge line has a change point. Then, depending on the position of the change point, as described with reference to FIGS. 4 to 6, whether or not the conveyed recording medium is the envelope conveyed with the flap open according to the positional relationship of the change point. To judge. If it is an envelope (S102: YES), then it is determined whether the print setting is an envelope print mode using an envelope. If it is the envelope print mode (S103: YES), it is determined whether the envelope is conveyed while being inclined with respect to the conveying direction (S104). The determination as to whether or not it is tilted is made based on, for example, whether or not the skew amount θ (see FIG. 5B) is equal to or greater than a predetermined threshold value 0.5 degrees (gradient 0.9%). If the skew amount θ is equal to or more than the threshold value (S104: YES), the skew correction is performed by performing image processing such as two-dimensional position correction on the image data (S105).

Next, the orientation of the transported envelope 22 with respect to the transport direction of the flap 222 and the flap length D2 are determined (S106).

If there is a flap on the leading end side (downstream side) of the envelope 22 as shown in FIG. 4A (S107: YES), the image writing timing is set from the leading end position of the envelope 22, that is, the flap leading end position. It is delayed by the length D2 (S108).

Then, the front and back of the envelope 22 are determined by the method described in FIG. 6 (S109). If the image forming surface in the print settings and the front and back of the envelope 22 that is being conveyed through the conveying path 151 are matched (S110: YES), the registration roller 159 synchronizes the envelope 22 with the image forming timing to form an image. By re-conveying to the part 160, an image is formed on the envelope and the process ends (S111, end).

On the other hand, if it is determined that the conveyed recording medium is an envelope, but it is not the envelope print mode (S103: NO), or the determined front and back of the envelope do not match the image forming surface (S110). : NO), the printing is interrupted, and a warning display indicating that the recording medium is not appropriate is displayed to the user (S112). FIG. 9 is an example of a warning display displayed on the operation display unit 130 in such a case. In this case, the conveyed envelope is ejected to the ejection tray 156 for purging without forming an image.

When the front and back of the determined envelope do not match the image forming surface in the print setting (S110: NO), when images are formed on both sides of the envelope, the image data of the front and back are exchanged to form an image on the envelope. You may go.

(When the transported recording medium is not an envelope)
When it is determined that the recording medium conveyed in step S102 of FIG. 8A is not an envelope (S102: NO), the process of FIG. 8B is subsequently performed.

First, it is determined whether the print setting is the envelope print mode in which envelope print is set (S201). When it is determined that the plain paper is not the envelope, and the plain paper print mode is not the envelope print mode (S201: NO), the transported plain paper 21 is in the transport direction as in the processes of S104 and S105 described above. To determine whether or not it is being conveyed at an angle. If it is tilted (S203; YES), skew correction is performed by performing image processing such as two-dimensional position correction on the image data (S204). Then, the image forming unit 160 forms an image on the plain paper and ends (S205, end).

On the other hand, if the envelope print mode is set (S201: YES) even though it is not determined to be an envelope, printing is interrupted and a warning display indicating that the recording medium is not appropriate is displayed to the user (S202). ). FIG. 10 is an example of a warning display displayed on the operation display unit 130 in such a case. If the recording medium stored in the paper feed tray 141 is not an envelope, or if it is an envelope but is stored with the flap closed, the flap is opened to the user as shown in FIG. A warning display indicating that the envelope in the state needs to be stored in the paper feed tray 141 is displayed.

In this case, an image is not formed on the conveyed recording medium, and the recording medium is discharged to the discharge tray 156 for purging, and the process is completed.

As described above, in the present embodiment, the print setting, the type of the recording medium, and the conveyance are determined by determining whether the conveyed recording medium is an envelope based on the time change of the end position detected by the detection unit. It is possible to prevent the printing from being performed because the types of the printed recording media do not match.

Further, by automatically determining the length and direction of the flap of the envelope, the user can omit the print setting related to this information, which improves convenience.

Further, in the case of an envelope, the front and back can be automatically determined depending on whether or not there is a step existing on the side closer to the flap inside the end portion of the envelope. Then, when the result of the front/back determination is different from the print setting, the printing is interrupted and a warning is displayed to the user, so that incorrect printing can be prevented.

(Second embodiment)
Next, a second embodiment will be described with reference to FIG. FIG. 11 is a flowchart showing a control method of the image forming apparatus 100 executed by the control unit 110. The flowchart of the figure is a process executed following step S110 of FIG.

First, the control unit 110 compares the image size of the image data of the print job with the size of the main body unit 221 of the envelope 22 (S301). This size comparison may be performed by comparing lengths in the vertical and horizontal directions (XY directions), or by comparing only lengths in the transport direction (X direction). The body length D1, the flap length D2, and the total length D3 of the envelope, which are the lengths of the body portion 221 in the X direction (see FIG. 3 for all), are calculated from the times t10, t20, t30 and the transport speed V in FIG. can do. The length of the main body portion 221 in the Y direction (envelope width) can be calculated from the relative positional relationship of the coordinates of the detection position (for example, s80) corresponding to the end position of the envelope from the center of the sheet conveyance in the width direction. it can.

In the following description, the lengths in the carrying direction are compared. If the length (mm) of the image in the image of the image data in the X direction is equal to or less than the body length D1 of the envelope (S301: NO), there is no problem in image formation. Therefore, the process directly proceeds to step S111 in FIG. 8A and image formation is performed. ..

On the other hand, if the length (mm) of the image in the X direction is longer than the body length D1 of the envelope (S301: YES), if the image is formed with the image size as it is, the image will protrude from the envelope. A warning is displayed on the operation display unit 130 (not shown). In response to this warning display, if the user inputs an instruction to reduce the image size through the operation display unit 130 and continue printing (S302: YES), the image is displayed on the main body unit 221 of the envelope. The image size is changed so that can be accommodated (S303). Examples of image size changing methods include reduction and trimming. When images are formed using envelopes that are continuously fed from the same paper feed tray 141, the input of instructions by the user can be omitted for the second and subsequent sheets.

After that, the image is formed on the envelope with the changed image size, and the process ends (S304, end).

As described above, in the second embodiment, when the size of the main body portion 221 of the envelope in which the image size of the image data is determined is larger, a warning is given to the user or the size of the main body portion 221 is set to be smaller than or equal to the size of the main body portion 221. By changing the image size, it is possible to prevent the formation of an unintended inappropriate image.

(Modification 1)
In the first embodiment, the line sensor 171 detects the position of one end of the recording medium, but the position of both ends may be detected.

FIG. 12 shows an example in which a pair of line sensors 171a and 171b are arranged so as to detect both ends of the recording medium in the width direction. By using the pair of line sensors 171a and 171b, not only when the longitudinal direction of the envelope is conveyed in the conveying direction (X direction) as shown in FIG. 12A, but also when the envelope is conveyed as shown in FIG. It is possible to detect the orientation and size of the flap even when the flap is conveyed in the lateral direction. Further, when the flap 222 is conveyed in the width direction (Y direction) as shown in FIG. 12B, the image writing position may be shifted in the width direction according to the direction and length of the flap. Good.

(Modification 2)
In the first embodiment, the example in which the print settings regarding the size and orientation of the flap 222 of the envelope 22 can be omitted has been described, but the user may input these print settings. In this case, when the determined size and orientation of the flap 222 are different from the setting values of the print settings, the control unit 110 displays a warning on the operation display unit 130 or automatically determines according to the user's approval. The input setting value may be updated with the size and orientation.

(Modification 3)
Further, when a user executes a print job in which print settings relating to flap size and orientation are made, a warning is displayed if this flap orientation setting and the flap orientation determined by the control unit 110 are different. Printing may be interrupted at the same time. For example, in the print setting, when the flap is the leading edge, when it is determined that the determined flap is facing the trailing edge (negative in the X direction), or is facing left or right (positive/negative in the Y direction). If it is determined that the printing is stopped, the printing is stopped.

(Modification 4)
In the present embodiment, the line sensor is used as the detection unit that detects the end position, and the end position of the recording medium such as the envelope is detected. However, the present invention is not limited to this. The end position of the recording medium may be detected by a transmissive optical sensor in which a plurality of sets of a light emitting portion and a light receiving portion are arranged in the up-down direction with the conveyance path interposed therebetween. A piezoelectric element may be used instead of the transmissive optical sensor. Further, the actuator may be arranged on the recording medium so as to come into contact with the end portion, and the movement of the actuator may detect the end position of the recording medium.

In addition, the present invention is defined by the contents described in the claims, and various modifications are possible.

The image forming apparatus and the control method for controlling the image forming apparatus according to the present invention are realized by a dedicated hardware circuit for executing each of the above-mentioned steps, or by a CPU executing a program describing each of the above-mentioned steps. be able to. When the present invention is implemented by the latter, the program for operating the image forming apparatus may be provided by a computer-readable recording medium such as a floppy (registered trademark) disk or a CD-ROM, or a network such as the Internet. It may be provided online via.

100 image forming apparatus 10a image forming apparatus main body 10b sheet feeding apparatus 10c post-processing apparatus 110 control section 120 storage section 130 operation display section 140 sheet feeding section 141 sheet feeding tray 150 conveying sections 151, 152, 153, 154, conveying path 155, 156 Ejection tray 159 Registration roller 160 Image forming unit 171, 171a, 171b, 172 Line sensor 180 Post-processing unit 190 Communication unit 22 Envelope 221 Main body 221a Front side paper 221b Back side paper 222 Flap 223 Step

Claims (10)

A paper feed unit having a paper feed tray capable of storing a plurality of recording media;
A transport unit that has a transport path and transports the recording medium fed from the paper feed unit in the transport path;
An image forming unit that forms an image on the conveyed recording medium,
A detection unit that detects an end position in the width direction orthogonal to the conveyance direction of the recording medium that is conveyed in the conveyance path;
Whether a continuous edge line corresponding to the end position of the recording medium is detected by the time change of the end position detected by the detection unit , and whether the recording medium conveyed by the change of the angle of the edge line is an envelope or not And a control unit that determines at least one of the length and the direction of the flap of the envelope in the transport direction when determining that the envelope is the envelope,
An image forming apparatus including. The image forming apparatus according to claim 1, wherein the control unit changes a position of an image formed on the envelope according to the determined length and direction of the flap. The image forming apparatus according to claim 1, wherein the control unit delays the image writing start timing by the length of the flap if the direction of the flap is on the leading end side of the envelope. .. The detection area of the detection unit is provided on the upstream side of the image forming unit in the conveyance path, and the detection unit also serves as a skew detection unit that detects a skew amount of a recording medium that is conveyed. The image forming apparatus according to claim 1. The control unit suspends the printing when the orientation of the flap in the print settings of the print job for printing using the envelope is different from the determined orientation of the flap. The image forming apparatus according to any one of the above. The detection unit is a line sensor including a plurality of photoelectric conversion elements arranged side by side in a direction intersecting the transport direction of the recording medium,
The control unit, by the output of the line sensor, when it is determined that the envelope, further inside the end of the envelope, when detecting a continuous edge corresponding to the step of the envelope, The image forming apparatus according to claim 1, wherein the envelope is determined to be conveyed with its back surface facing the line sensor. The image forming apparatus according to claim 6, wherein the control unit interrupts the printing when the front and back of the envelope in the print settings of the print job for printing using the envelope are different from the front and back of the determined envelope. .. When executing a print job with print settings using the envelope, the control unit warns the user when the image size of the image data of the print job is larger than the size of the main body unit excluding the flap of the envelope. The image forming apparatus according to any one of claims 1 to 7, wherein the print job is executed by notifying that the print job size is smaller than or equal to the size of the main body unit. 8. The control unit notifies the user of a warning when it is not possible to determine the flap of the envelope when executing a print job of a print setting using the envelope. The image forming apparatus described in 1. A control method for an image forming apparatus, comprising: a detection unit that detects an end position in a width direction orthogonal to a conveyance direction of a recording medium that is conveyed in a conveyance path,
Whether a continuous edge line corresponding to the end position of the recording medium is detected by the time change of the end position detected by the detection unit , and whether the recording medium conveyed by the change of the angle of the edge line is an envelope or not To determine whether
A step of determining at least one of the length and the direction in the transport direction of the flap of the envelope when it is determined to be the envelope;
Control method including.