JP3044560B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus that displays a mark indicating an area of a transferred document on a transfer sheet.

[Conventional technology]

Conventionally, in an image forming apparatus such as a digital copying machine, a margin portion generated on a transfer sheet when an aspect ratio of a document and a transfer sheet do not match, or when an irregular-size original is copied on the transfer sheet by scaling independently in length and width. An image forming apparatus has been proposed in which the image is distributed to the left and right sides of a transfer sheet to prevent the image transferred on the transfer sheet from being biased (Japanese Patent Laid-Open No. Sho 61-42668).

[Problems to be solved by the invention]

However, in the above-described image forming apparatus, it is difficult to determine the extent of the transferred original area after the transfer. For example, it is not easy to accurately cut and align the transfer paper during copy editing. Will be. Further, it is not possible to easily grasp what aspect ratio the image is independently scaled at the time of copy editing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus which solves the above-mentioned problem, and in which an original area is marked on a transfer sheet so that the original area on the transfer sheet can be identified.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a method for scanning an original placed on a contact glass in a state where the original is pressed by an original pressing surface having an intermediate color tone, and transferring an obtained image signal to a transfer paper. In the forming apparatus, a first threshold value storage unit that stores a first threshold value that is set in advance to detect a black portion of the document, and a second threshold value that is set in advance to detect a white background portion of the document.
A second threshold value storage unit for storing a threshold value;
A first data comparison unit that compares a threshold value, a second data comparison unit that compares the image signal with a second threshold value, and an identification to which a comparison result of the first data comparison unit and the second data comparison unit is input Means, mark forming means for recognizing a document area and a non-document area from the identification result of the identification means and forming a mark signal indicating the document area, and superimposing means for superimposing the mark signal on the image signal. is there.

[Action]

According to the image forming apparatus having the above configuration, the original placed on the contact glass is scanned while being pressed by the original pressing surface having the intermediate color tone, and an image signal is obtained. And
The first threshold value storage unit stores a first threshold value for detecting a black portion of the document, and the second threshold value storage unit stores a second threshold value in advance for detecting a white background portion of the document. A first data comparison unit that compares the threshold value, a second data comparison unit that compares the image signal with the second threshold value, and an identification unit that receives a comparison result of the first data comparison unit and the second data comparison unit. A mark forming means for recognizing a document area and a non-document area from the identification result of the identification means and forming a mark signal indicating the Sakai of both areas, and a superimposing means for superimposing the mark signal on the image signal, The first data comparison unit detects whether the image signal is a black portion or not, and outputs the detected signal to the identification unit. The second data comparison unit determines whether the image signal is a white background portion or a white background portion. Is detected and output to the identification means. When the first data comparison unit detects a black portion or the second data comparison unit detects a white background portion, the identification unit recognizes that the document region is the document region, detects that the first data comparison unit is not a black portion, and If the second data comparison section detects that the area is not a white background section, it recognizes that the area is a non-document area. Then, the document area and the non-document area are recognized from the identification result, and a mark signal indicating the document area is formed by the mark forming means. The mark signal is superimposed on the image signal by the superimposing means, and the mark signal, that is, the document area is transferred and displayed on the transfer paper together with the document image.

〔Example〕

FIG. 2 is a configuration diagram of a digital copying machine (image forming apparatus) according to the present invention.

The digital copying machine 21 has a contact glass 22 and a document holder 23 on its upper surface, and has an optical mechanism L and image forming means P inside.

The optical mechanism L includes a light source including a halogen lamp 24 and a reflection plate 25, reflection mirrors 26, 27, and 28, a lens unit 29, and a solid-state imaging device (hereinafter, referred to as a CCD) 1. And
When the transfer (copy) operation is started, the light from the light source is reflected by the original placed on the contact glass 22, and the reflected light is guided to the lens unit 29 via the reflecting mirrors 26, 27, and 28. After that, it is read by CCD1. The lower surface of the document holder 23 is formed in an intermediate color so as to be distinguishable from the document on the contact glass 22.

The image forming means P includes a laser generator 31 and a polygon mirror.
32, reflector 33, photoconductor 34, charging device 35, blank lamp
36, a developing device 37, a transfer device 38, a separating device 39, a cleaning device 40, and the like. Then, a laser beam corresponding to the original read by the CDC 1 is emitted from the laser generator 31. On the other hand, the surface of the photoreceptor 34 is uniformly charged by the charging device 35, is exposed to the laser light passing through the polygon mirror 32 and the reflection mirror 33, and an electrostatic latent image is formed. Thereafter, the electrostatic latent image developed with the toner by the developing device 37 is transferred to a transfer sheet by a transfer device 38, and then separated by a separating device 39.
Is separated from the photoreceptor 34.

Further, as a sheet feeding mechanism, a sheet feeding cassette 41, a sheet feeding roller 42, and a registration roller pair 43 are arranged in this order from the upstream in the feeding direction. Is performed. As a fixing and discharging mechanism for the transfer paper after the transfer, a transport belt 44, a fixing device 45, a discharging roller 46, a discharging tray 47 and the like are provided. In addition, a transfer paper sensor is provided near the paper feed cassette 41 as necessary.
The size of the transfer paper fed to the photoreceptor 34 is detected. An automatic document feeder (not shown) is provided.
A plurality of documents may be sequentially and automatically sent between the contact glass 22 and the document holder 23.

Next, a block configuration showing an example of a control system of the digital copying machine 21 will be described with reference to FIG. In addition,
In this embodiment, the digital copying machine 21 identifies a document area in a first reading scan, and transfers (copies) a document image read in a second reading scan onto transfer paper.

The CCD 1 receives reflected light from a document on the contact glass 22 and outputs a density signal corresponding to the density of the document to the converter 2. The converter 2 converts an output signal from the CCD 1 into a digital signal and outputs the digital signal to the line memory 3. The line memory 3 temporarily stores the digital signal and outputs the digital signal to the switch 4. Switch 4 is 1
The digital signal from the line memory 3 is output to the determination unit 5 at the time of the second reading scan, and the digital signal is output to the image processing unit 11 at the time of the second reading scan.

The determination unit 5 includes a first threshold storage unit 51, a second threshold storage unit 52, a first data comparison unit 53, a second data comparison unit 54, and an AND circuit.
55 for identifying the area of the document.
That is, the first threshold storage unit 51 stores a preset first threshold, and the second threshold storage unit 52 stores a preset second threshold. The first threshold is a third threshold.
As shown in FIGS. 7A and 7B, the digital signal corresponding to the black portion A such as a character written on the original G is set to a value slightly larger than the digital signal corresponding to the black portion A. B
Is set to a value slightly smaller than the digital signal corresponding to.

The first data comparison unit 53 compares the first threshold value with the digital signal input from the line memory 3 through the switch 4. When the digital signal corresponding to the black portion A is input, the low level is input to the AND circuit 55. A signal is output, and when a digital signal corresponding to an intermediate color tone which is the white background portion B or the lower surface of the document presser 23 is input, an input level signal is output. The second data comparing section 54 compares the second threshold value with the digital signal from the line memory 3, and outputs a low-level signal to the AND circuit 55 when a digital signal corresponding to the white-order section B is input. When a digital signal corresponding to the black portion A or the intermediate tone is input, a high-level signal is output.

The AND circuit 55 outputs a document area identification signal.
As shown in FIG. 3C, the first and second data comparing units 53 and 5
When the intermediate tone, in which both of the output signals from the output signal 4 and the output signal from the output unit 4, are detected as a high-level signal, a high-level signal is output to the storage unit 6; The level signal is output to the storage unit 6.

The storage unit 6 includes a writing unit 61, a memory 62, and a reading unit 63, and stores the high or low level document area identification signal from the determination unit 5. That is, the writing unit 61 writes the document area identification signal into the memory 62. The memory 62 stores the document area identification signal from the writing unit 61. The reading section 63 reads the stored data from the memory 62 and outputs the data to the gate section 8 through the data buffer 7.

The gate unit 8 includes an inverter 81 and an AND circuit 82. When the document area identification signal from the storage unit 6 is at a low level, the digital image signal input from the image processing unit 11 through the data buffer 12 is laser-generated through the data buffer 9. Output to the container 31.

The image processing unit 10 processes the data stored in the memory 62, and transmits the document area identification signal, which is the storage data, to the operation unit.
The magnification process is performed so as to correspond to the magnification set by 13, and rewriting is performed via the writing unit 61. The image processing unit 10 forms a mark signal indicating the document area, and furthermore, the image processing unit 10 superimposes the mark signal on the digital image signal.
Output to 11 That is, the image processing unit 10
For example, by scanning the memory 62, of the stored data, an address at which the level is inverted is extracted as the edge of the document area, the document area on the transfer paper is identified from this address, and the document area is identified from the identification result. The mark signal shown is formed. The outline of the document area may be obtained by identifying the four corners of the document area from the address, and a mark signal may be formed based on the outline.

Then, the formed mark signal is displayed on the transfer paper as described later (see dotted line S in FIG. 4 and dotted line S ′ in FIG. 5).

The image processing unit 11 performs a scaling process on the digital image signal from the line memory 3 as necessary and outputs the digital image signal to the data buffer 12, and a digital image signal after the scaling process on the mark signal input from the image processing unit 10. Is superimposed in synchronization with.

The data buffer 7 transmits signals in synchronization with the data buffer 12, and the data buffer 9 transmits digital signals from the gate unit 8 in synchronization with the rotation of the polygon mirror 32.

The operation unit 13 has various operation keys and a display unit, and instructs and sets copy start, transfer paper size, magnification, and the like, and displays the setting contents and the like as necessary. The operation control unit 14 outputs various operation signals from the operation unit 13 to the image processing unit 10 and outputs display signals such as setting contents to the operation unit 13. Operation control unit
14 outputs a start signal to the scanning control unit 16 when the copy start is set by the operation unit 13 and changes the moving speed of the optical system so as to correspond to the magnification or independent magnification set by the operation unit 13. A control signal is output to the scanning control unit 16.

The scanning unit 15 scans the original by driving the optical system at a moving speed according to the set magnification. The scanning control unit 16 controls the scanning unit 15 according to a control signal from the operation control unit 14, and connects the switch 4 to the determination unit 5 during the first scanning of the original in response to the start signal. The digital image signal from the memory 3 is guided to the determination unit 5, and the switch 4 is connected to the image processing unit 11 side to guide the digital image signal from the line memory 3 to the image processing unit 11 at the time of the second scanning of the original document. I have to. The program memory 17 stores an operation program of the image processing unit 10.

 Next, the operation of the image forming apparatus will be described.

When the copy operation is started, scanning is started by the optical system from the reading start position of the first document reading, and the density signal from the CCD 1 is input to the conversion unit 2 and converted into a digital signal, which is input to the line memory 3. After that, it is input to the determination unit 5 through the switch 4. The determination unit 5 outputs a high-level signal to the intermediate tone of the document presser 23 and a low-level signal to the document area to the storage unit 6. Then, these document area identification signals are stored in the memory 62, and the data stored in the memory 62 is rewritten by the image processing unit 10 after performing scaling processing according to the set magnification. A mark signal is formed from the rewritten storage data as described above.

When the first reading scan is completed, the optical system returns to the reading scanning start position and the second reading scanning is started.
The image data is input to the image processing unit 11 through which the image data is scaled as necessary. On the other hand, the mark signal from the image processing unit 10 is synchronized with the digital image signal to the image processing unit 11, and the image processing unit
The image data is input to 11, superimposed on the digital image signal, and output from the image processing unit 11 to the gate unit 8 through the data buffer 12.

On the other hand, the stored data is sequentially read out from the memory 62 by the reading unit 63 and input to the gate unit 8 through the data buffer 7. The gate section 8 outputs a digital image signal and a mark signal indicating a document area, and outputs the signal to the laser generator 31 through the data buffer 9. Then, the document image is copied on the transfer paper, and a mark indicating the document area is displayed.

If the timing at which the mark signal is input to the gate unit 8 coincides with the timing at which the level of the data stored in the memory 62 is inverted, the output of the mark signal from the gate unit 8 becomes unstable. Alternatively, among the data stored in the memory 62, data near the document area may be changed to a low level. In this case, it is necessary to form a mark signal and store it in the image processing unit 10 before performing the low-level change processing.

Further, instead of changing the data in the vicinity of the document area, a mark signal is formed slightly smaller than the identified document area,
The timing at which the mark signal is input to the gate unit 8 may not coincide with the timing at which the level of the storage data is inverted.

Next, an example of displaying a document area by the operation of the image forming apparatus will be described with reference to FIGS. The display example of FIG. 4 shows a case where the vertical and horizontal independent magnifications are set, and the display example of FIG. 5 shows a case where an irregular-size original is copied onto a fixed-size transfer sheet without changing the aspect ratio. The independent scaling means that the aspect ratio and the width ratio of the original and the transfer paper are calculated, and the smaller ratio is automatically set as the conversion magnification.
(See FIG. 4). FIG. 5 shows a case where the width of the irregular-sized original G 'is reduced so as to match the width of the transfer sheet T, and a margin is formed at a lower portion of the transfer sheet T in the vertical direction.

In the display example shown in FIG. 4, the original G on which the character "A" is formed is scaled independently, and as a result, the original area is
, And a mark S indicating the document area is displayed on the left and right (considering the margin W) and below the character "A" after the independent scaling.

On the other hand, in the display example shown in FIG. 5, the size of the irregular size original G 'in which the character "A" is described in the reduced vertical direction is the transfer paper T.
Therefore, a mark S 'indicating a document area is displayed at a portion corresponding to the lower end of the document.

The position of the document copied on the transfer paper may be a position other than those shown in FIGS. That is, the position of the document may be based on, for example, the right end of the transfer paper,
It may be based on the center of the transfer paper. The form of the mark is not limited to a dotted line, and may be any form as long as it is a solid line or any other mark that can indicate a document area.

〔The invention's effect〕

According to the present invention, an original is scanned to obtain an image signal of an image area, a first data comparison unit detects whether the image signal is a black portion or not, outputs the image signal to an identification unit, The data comparing unit detects whether the image signal is a white background portion or a non-white background portion and outputs it to the identification unit. The identification unit detects that the first data comparison unit detects a black portion, or that the second data comparison unit When a white background portion is detected, the document region is recognized. When the first data comparison unit detects that the document is not a black portion, and when the second data comparison unit detects that it is not a white background portion, the non-document region is recognized. As a result, a mark indicating the image forming area corresponding to the original is displayed on the transfer paper, so that even if the original has an irregular size, the image forming area corresponding to the original on the transfer paper can be easily identified. Therefore, the transfer paper can be accurately trimmed based on the mark display during copy editing, and the copy editing work can be performed efficiently.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a control system of the image forming apparatus according to the present invention, FIG. 2 is a configuration diagram of the image forming apparatus according to the present invention, and FIG. 3 explains the operation of a determination unit according to the present invention. 4 and 5 are diagrams showing examples of display of marks on transfer paper. 1 ... CCD, 4 ... Switch, 5 ... Judgment unit, 6 ... Storage unit, 10,11 ... Image processing unit, 13 ... Operation unit, 14 ... Operation control unit, 15 ... Scanning unit, 16: Scan control unit, 31: Laser generator, 34: Photoconductor, S, S ': Mark.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Shioji 1-2-28 Tamazo, Chuo-ku, Osaka-shi, Osaka Inside Mita Kogyo Co., Ltd. (72) Inventor Masahiko Miyazaki 1-2-2 Tamazo, Chuo-ku, Osaka-shi, Osaka No. 28 Mita Kogyo Co., Ltd. (56) References JP-A-62-123464 (JP, A) JP-A-58-3370 (JP, A) JP-A-62-1221265 (JP, A) JP-A-62-1 221266 (JP, A) JP-A-63-280569 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 1/387 H04N 1/00

Claims (1)

(57) [Claims] An image forming apparatus which scans an original placed on a contact glass while being pressed by an original pressing surface having an intermediate color tone, and transfers an obtained image signal to transfer paper. A first threshold value storage unit that stores a first threshold value set in advance to detect a copy, a second threshold value storage unit that stores a second threshold value set in advance to detect a white background portion of the document, and the image signal A first data comparison unit that compares the image signal with a first threshold value, a second data comparison unit that compares the image signal with a second threshold value, and a comparison result of the first data comparison unit and the second data comparison unit. Identification means, a mark forming means for recognizing a document area and a non-document area from the identification result of the identification means and forming a mark signal indicating the document area, and a superimposing means for superimposing the mark signal on the image signal. Image characterized by Forming apparatus.