JP2950839B2 - Control method of image forming apparatus - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for an image forming apparatus in which a facsimile function is added to a so-called digital copying machine, and more particularly to a control method for facsimile transmission.

(Prior art)

2. Description of the Related Art In recent years, a digital copying machine has been proposed in which a document reading device that reads a document image digitally and a page printer (for example, a laser printer) that records the image at a predetermined resolution in units of one page are combined.

By using such a digital copying machine, in addition to a simple copying operation, it is possible to copy an edited image or copy an image to which some processing has been processed. Further, the digital copying machine can be used as a hard copy device of an information processing device using a personal computer or the like, or can be used as a facsimile device with an additional communication function.

In general, digital copiers can read manuscripts up to A3 size, but the standard receivable size of conventional facsimile machines is B4 size or A4 size. For this reason, in an image forming apparatus in which a facsimile function is added to a digital copying machine, if the size of the transmission document is larger than the receivable size, it is necessary to reduce the transmission document and transmit it to the receiving side. The scaling at the time is realized by the same electrical scaling as when a reduced copy is performed by a digital copying machine.

In general, digital copiers have a high resolution, and the linear density of read images is set to 15.7 lines / mm (400 dpi). On the other hand, the linear density of transmission images of G3 facsimile machines is usually The scanning direction is 8 lines / mm and the sub-scanning direction is
It is set to 7.7 lines / mm and 3.85 lines / mm. Therefore,
In an image forming apparatus in which a facsimile function is added to a digital copying machine, it is necessary to convert a linear density of 15.7 lines / mm into a facsimile linear density at the time of facsimile transmission.

Therefore, in this type of image forming apparatus, a dedicated circuit for realizing such a linear density conversion has conventionally been incorporated.
If the line density conversion and the scaling were to be controlled by different circuits, the circuit configuration would inevitably become complicated.

〔Purpose〕

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-described disadvantages of the related art, and an image forming apparatus capable of performing facsimile transmission without making a circuit for externally performing image density conversion using a changing function of a document reading unit. It is an object to propose a control method of the device.

〔Constitution〕

The present invention relates to an original reading unit having a variable magnification function for converting an original image into an electric signal, reading the image, and performing reduction and enlargement, a copying unit for recording an image signal output from the original reading unit, In a method for controlling an image forming apparatus having a transmission unit for transmitting an image signal output from a reading unit via a public line, a scaling factor for reducing an original image is set to a combination of a receivable size and an original size. The magnification is set independently for each of the main scanning direction and the sub-scanning direction, the size of the document to be transmitted is detected, the receivable size responded from the receiving side via the transmission unit is detected, and the detected document is detected. Comparing the size with the receivable size, and if the receivable size is smaller than the size of the document, the setting is performed based on a combination of the document size and the receivable size. Reading the original image by the scaling factor that is characterized by to be transmitted to the receiving side.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 shows an image forming apparatus according to one embodiment of the present invention.

This image forming apparatus includes a document feeder 100 that conveys a document to a contact glass, a scanner 200 that separates an image of a document positioned on the contact glass at a predetermined resolution and performs photoelectric conversion, and an image read by the scanner 200. It is mainly composed of a copying apparatus 300 for recording on recording paper of any size stored in three paper cassettes, and has basically the same configuration as a well-known digital copying machine.

In the document feeder 100, documents placed on a document table 101 are sent out one by one by a feed roller 102, and are positioned at a predetermined position on a contact glass 201 by a transfer belt 103. When the image of the document is read, the document is removed from the contact glass 201 by the transport belt 103 and discharged to the discharge tray 104.

In the scanner 200, the image of the document positioned on the contact glass 201 is scanned in the direction of the arrow by the optical system 202, and an image obtained by the scanning (hereinafter, referred to as scan light) is formed by a line. An image is formed on the image sensor 203. Line image sensor 203
The optical system 202 separates scan light of a scan line of the optical system 202 into a predetermined number of pixels and photoelectrically converts data of each pixel, thereby forming electrical image information. The resolution of the scanner 200 is set to 15.7 lines / mm (400 dpi).

In the copying apparatus 300, a laser beam output from a laser writing unit 301 that scans a laser beam modulated by image information is applied to a drum-shaped photosensitive member 302.
Note that the recording resolution of the copying apparatus 300 is set to the same resolution as that of the scanner 200.

This photoconductor 302 is rotated in the direction of the arrow,
The surface is uniformly charged by a charging charger 303, and the charged surface is exposed to laser light to form an electrostatic latent image corresponding to a recorded image (image information). The toner phenomenon is caused by the container 304.

On the other hand, the recording sheets stacked on the selected one of the three paper feed cassettes 305, 306, 307 are the paper feed rollers 308, 309, 301 corresponding to the respective paper feed cassettes 305, 306, 307.
Are sent out one by one from the one located at the top. The recording paper sent out by the paper feed rollers 308, 309, 310 in this way is sent out to the photosensitive member 302 by the registration roller 311 at the timing when the leading end of the recording paper coincides with the leading end of the toner image.

The recording paper sent to the photoconductor 302 is transferred to the transfer charger 3.
After the toner image is transferred in close contact with the photoconductor 302 in 12,
The toner is separated from the photoconductor 302 by a separation charger 313, and the toner image is fixed on the surface by a fixing device 314. Then, the recording paper on which the fixing has been completed is conveyed to the discharge roller 317 via the distribution unit 315 and the reversing unit 316, and is discharged outside the apparatus.

The recording paper discharged outside the machine is stacked 319 for stacking the recording paper on which the copy image is recorded at the time of the copying operation, or stacking the recording paper on which the reception image is recorded at the time of facsimile reception, by finishing 318. Sorted into any of the 320.

The distributing section 315 sorts the recording paper on which the image is recorded into one of the reversing section 316, the discharge roller 317, and the transport section 321.
Roll the recording paper on which the image of the
It is for transporting to 311.

The residual toner on the surface of the photoconductor 302 is removed by the cleaning unit 322, and the residual charge is removed by the power supply lamp 323.

FIG. 3 is a block diagram schematically showing a control system of the image forming apparatus.

In the figure, the output image signal of the line image sensor in the scanner 200 is amplified to a predetermined amplitude by an AGC (variable gain control) amplifier, and converted to a digital signal of a predetermined number of bits by an analog / digital converter. To the image processing / control unit 11.

The image processing unit / control unit 11 performs shading correction processing for correcting variations in the level of image signals caused by variations in the characteristics of the optical system 202 of the scanner 200 and the light receiving characteristics of each bit of the line image sensor 203. Correction processing that corrects the difference between the image reading characteristics and the human visual characteristics by using the scanner to convert the image read by the scanner 200 into a visually optimal image, MTF correction processing that eliminates image blur, like a newspaper Halftone processing to properly render images of documents with dark background or dirty background, character / halftone separation to separate the character part to be binarized from the image to be halftoned Processing and other various image processing. The image information processed in this manner is sent to the laser printer 12, whereby the laser diode 18 generates a laser beam modulated in accordance with an image signal (image information). The laser diode 18 is provided in the laser writing unit 301 of the copying machine 300. Further, the image processing / control unit 11 also executes a scaling process for reducing and enlarging the image.

The image processing / control unit 11 is provided with an operation display unit (not shown). The image processing / control unit 11 has operation keys required when the image forming apparatus is used as a copying machine or a facsimile apparatus, and displays an operation state, an operation procedure, and the like. That is, the operation unit inputs, for example, a start key for starting a facsimile transmission operation, a copy key for starting a copying operation, a stop key for stopping a copying operation, and numerical data such as the number of copies and a telephone number. Numeric keypad, abbreviated keys for entering telephone numbers, mode keys for setting various operation modes of the facsimile machine, and
A guidance key or the like for selecting a selection item displayed on the display is provided. In addition, a liquid crystal display device or the like having a large degree of freedom in display is used as a display device, and message information of an operation procedure, numerical values input from ten keys, actual plural numbers, and the like are displayed.

The facsimile control unit 13 executes a transmission control procedure for facsimile transmission, performs image compression / decompression, transmits a signal via a modem, and receives a signal via the modem.

The input data from the operation display unit is notified to the facsimile control unit 13 via the image processing / control unit 11, and the display data from the facsimile control unit 13 to the operation display unit is operated via the image processing / control unit 11. Output to the display unit.

Next, an operation when this image forming apparatus is used as a facsimile apparatus will be described.

In the facsimile transmission procedure, as shown in FIG. 4, the receiving side is called from the transmitting side (call signal CNG), and when the line is established, the receiving side indicates that the receiving side is a non-voice terminal. After responding to the calling station identification signal CED, a digital identification signal DIS indicating the receiving function of the own station is responded.

The transmitting side selects the function to be used for facsimile transmission from the content of the received digital identification signal DIS, displays it in the digital command signal DCS, notifies the receiving side, and sets the modem to the transmission speed selected at that time. Set the speed 1.
Perform 5 seconds of training (Training Check T
CF).

If the result of the modem training is good, the receiving side responds to the transmitting side with the reception preparation confirmation signal CFR, and prepares for image reception at the modem speed at that time.

The transmitting side that has received the reception preparation confirmation signal CFR transmits a training signal TNG corresponding to the training sequence according to the standard of the modem corresponding to the set modem speed, and then transmits the image information MSG of the first page, and transmits the subsequent page. If there is an image, the multi-page signal MPS is transmitted.

If the receiving side can properly receive the received image at that time, the receiving side responds with the message confirmation signal MCF and prepares for receiving the image of the next page.

The transmitting side that has received the message confirmation signal MCF transmits the image information of the second page after transmitting the training signal TNG again, and transmits a procedure end signal EOP when ending the transmission there.

The receiving side responds to the message confirmation signal MCF in the same manner as the first page, and the transmitting side responds to the message confirmation signal MCF.
When the CF is received, a disconnection command signal DCN is transmitted to disconnect the line, and the facsimile transmission ends.

Also, on the receiving side receiving this disconnection command signal DCN,
Hang up the line.

Now, when the operator sets the transmission document to the document 101 of the document conveyance device 100, selects the facsimile mode on the operation display section, inputs the destination, turns on the start key, and starts the transmission operation, the image processing is started. The / control unit 11 transfers the data input by the operator to the facsimile control unit 13 to start the facsimile transmission operation, and instructs the document conveyance device 100 to convey the transmission document. Thus, the scanner 200 starts scanning.

Now, considering the case where the operator selects the immediate transmission mode and selects one destination, the facsimile control unit 12 transfers the telephone number of the destination to the network control device and causes the destination to make a call. By executing the transmission control procedure described above, the receiving function of the destination is determined, and a function to be used is selected and notified to the destination.

At this time, the receivable size of the destination is compared with the size of the transmission document, and if the former is smaller than the latter, the image of the transmission document is reduced at a scaling factor corresponding to the receivable size of the destination before transmission. . The table shows the relationship between the receivable size, the size of the transmitted document, and the magnification.

In the table above, there are five types of receivable sizes (B4 to B6
As shown, the standard receivable size of the facsimile machine is B4 size or A4 size.

At the time of facsimile transmission, the transmission original is
Since it is read at a high resolution of 15.7 lines / mm by 0,
This needs to be converted to a linear density for facsimile transmission. In other words, the linear density of 15.7 lines / mm is changed to 8 lines / mm in the main scanning direction.
mm and 7.7 lines / mm in the sub-scanning direction. This density conversion process can be performed using the scaling factor function.
For example, if the linear density of 15.7 lines / mm is converted to 8 lines / mm, the image is read in the same way as when reducing at a magnification of 51%, and if it is converted to 7.7 lines / mm, the image is reduced by 49%. The image may be read in the same manner as at the time.

In order to perform such scaling and linear density conversion, the facsimile control unit 24 executes processing as shown in FIG.

In this process, first, the size of the transmission original placed on the contact glass 201 is determined. That is, at step S _1, first, the original is scanned once, reading a document size document on the contact glass. Next, the document size at step S ₂ determines one of A3, B4, A4. If it is determined in the step S ₂ A3 proceeds to step S _9, the process proceeds to step S ₂ and in the other cases A3. In the step S _3, the document size is determined whether B4 is, the process proceeds to step S ₇ when the B4, when other than B4 goes to step S _4.

In the step S _4, since the document at step S ₃ is selected to the following A4 size, only it is sent by changing the density reading is the destination. Therefore, 51% for the main scanning direction, the sub-scanning direction to set the magnification of 49%, and transmits connexion read at the magnification at step S _5, the read One data at step S _6.

In the step S _3, when the document is judged to B4 is
Judging a reception size at step S _7. When receiving size in this step S ₇ is determined not to be A4, the reception size is regarded as B4, the main scanning direction 51 in step S ₄
% And a magnification of 49% in the sub-scanning direction.
S _5, performs the operation of step S _6. Also, if the receiving size is A4
When it is determined that the size must be reduced from B4 size to A4 size, 42% in the main scanning direction and 40% in the sub-scanning direction.
Set the% magnification. Then, it transmits a read-step S ₆ in the magnification at step S _5.

Furthermore, the document in step S ₂ is determined to A3, step
When proceeding to S ₉ determines reception size in this step. Then, when the determined reception size is B4,
Main scanning direction by 44% at step S _10, sets the sub-scanning direction 42 percent magnification, the step S _5, is transmitted through the step S _6. Further, when it is determined that the reception size A4 at step S _9, the main scanning direction by 36% at step S _11, the sub-scanning direction 3
5% of the magnification is set, is transmitted via the step S ₅ and step S ₆ as well.

Thus, at step S _5, step S _4, step S _8, by reading an original in the magnification ratio set in step S ₁₀ and step S _11, it can also serve as a reduction and the density scaling.

As described above, according to the above-described embodiment, the conversion of the linear density can be easily realized by using the functions of the vertical and horizontal independent magnifications of the scanner 200. As a result, transmission from the digital copying machine to the facsimile becomes possible without providing the density conversion processing circuit.

〔effect〕

As is apparent from the above description, according to the present invention, when reducing the size of a document image, the magnification is set by a combination of the document size and the receivable size, and the main scanning direction and the sub-scanning direction are independently set. Since the scaling factor is set, the conversion of the linear density can be easily realized, and it is not necessary to provide a density conversion processing circuit separately from the scaling processing circuit, and the circuit configuration can be simplified.

[Brief description of the drawings]

The drawings are all for explaining the embodiments of the present invention.
The figure is a flowchart showing the reading procedure at the time of transmission.
The figure shows an example of a copying machine having a conversion function.
FIG. 4 is a block diagram showing a schematic control system of the copying machine, and FIG. 4 is a timing chart showing an example of a facsimile transmission procedure. 11 image processing / control unit, 12 printer unit, 13 facsimile control unit, 200 scanner unit.

Claims (1)

(57) [Claims] 1. An original image is read by exchanging it for an electric signal.
Document reading means having a scaling function for reducing and enlarging, copying means for recording an image signal outputted from the document reading means, and an image signal outputted from the document reading means via a public line. A method for controlling an image forming apparatus having a transmitting means for transmitting, wherein a scaling factor for reducing a document image is independently scaled in a main scanning direction and a sub-scanning direction based on a combination of a receivable size and a document size. The size of the document to be transmitted is detected, the receivable size responded from the receiving side via the transmission unit is detected, the detected document size is compared with the receivable size, and the receivable size is detected. If the size is smaller than the size of the original, the original image is read at the set magnification based on the combination of the original size and the receivable size,
A method for controlling an image forming apparatus, wherein the method is transmitted to a receiving side.