JP3011942B2 - Digital image output device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus such as a laser printer or the like, which optically reads document image information using a line image sensor such as a digital copying machine or a facsimile and converts it into an electric signal. The present invention relates to a digital image output device for outputting to a computer.

2. Description of the Related Art In recent years, such devices have been provided with an image editing function,
Various image processing is possible. As one of the functions, there is a marker area editing function for designating an area on a document with a marker and performing image processing on a marker area surrounded by the marker. The processing contents include erasing inside the marker area, erasing outside the marker area, marker area centering, and marker area cornering.

When performing image processing on such a marker area, it is necessary to detect the marker area attached to the document.
Since the marker is read by the line image sensor separately from the document image, the marker is generally set to a halftone density.

Problems to be Solved by the Invention However, there is a case where the density of the marker approaches the density of the marker due to the generation of dirt on the document pressing plate and the conveyance belt in the automatic document conveyance device (ADF). If it is attempted to detect the marker area in such a state, there is a possibility that a stained portion such as a pressure plate outside the document is also detected as a marker. That is, an error occurs in the position detection of the marker area. When such an error occurs,
In particular, in the case of movement processing such as marker area centering and marker area cornering, an undesired strange processing result may be obtained.

A digital image output device that optically reads original image information using a line image sensor, converts the original image information into an electric signal, and outputs the electric signal. A size detecting means for detecting a document size prior to reading of the document image information, a marker area detecting means for detecting a position of the marker area, ,
A detection range varying unit that varies a marker region detection range by the marker region detection unit in accordance with a document size detected by the size detection unit; an editing processing unit that performs editing processing on document image information of the detected marker region; Was provided.

In this case, the editing processing by the editing processing means is, for example, image moving processing.

The position of the marker area to be edited by the editing means is detected by the marker area detecting means. Prior to this detection, the document size is detected in advance by the size detection means, and the detection range changing means changes the marker area detection range to be within the document according to the document size. Therefore, even if the original platen or the conveyance belt is stained with the same density as that of the marker, if it is outside the original, it is not a marker detection target and erroneous detection is prevented. As a result, if the editing processing by the editing processing means is, for example, image movement processing such as centering of a marker area, dirt or the like outside the original is not included as the marker area, and only the marker area on the original is regarded as the target. Therefore, the desired processing is correctly performed.

Embodiment An embodiment of the present invention will be described with reference to the drawings.

First, the configuration and operation of a scanner unit of a digital copying machine to which the present invention is applied will be described with reference to FIG. First, a document to be read is placed on the contact glass 1 and illuminated by the fluorescent lamp 2. Numeral 3 denotes a heater for fluorescent light, and numeral 4 denotes a facing reflection plate. Light reflected from the original is imaged on a line image sensor (CCD) 9 via first, second, third mirrors 5, 6, 7 and an imaging lens 8. Here, the fluorescent lamp 2 and the first mirror 5 are mounted on the first scanner 10, and scan the lower surface of the contact glass 1 from the right side (home position side) to the left side. The second and third mirrors 6 and 7 are mounted on the second scanner 11 and scan in the same direction at half the speed of the first scanner 10. Subscanning of the document surface is performed by such scanning movement of the optical system, and two-dimensional reading is performed.

In the case of the present embodiment, the resolution of image reading is set to 16 pixels / mm, and it is possible to read an original of A3 size (297 mm × 420 mm). Therefore, A3 size short side 297m
To read m in the main scanning direction, a CCD 9 having 5000 pixels is used. The data of the input light of the CCD 9 is output in two series of an even dot and an odd dot. The electric signal read by the photoelectric conversion by the CCD 9 is amplified by an amplifier, and then two-system signals are synthesized. According to the AGC data, the electric signal is again returned to a certain level, as shown in FIG. It is amplified by the amplifier 12. After amplification, the A / D converter 13 converts the data into 6-bit digital data D01 to D06. The processing up to the A / D converter 13 is performed by the image reading plate 14 on which the CCD 9 is mounted.

Thereafter, image processing is performed in an IPU (Image Processing Unit). First, the illuminance unevenness of the fluorescent lamp 2
The shading correction unit 16 performs shading correction for correcting variations in sensitivity among the pixels of the CCD 9 and the like. For this processing, a reference white plate 17 is provided on the home position side of the contact glass 1, and by reading the reference white plate 17, shading data is obtained. After the shading correction, blurring due to the optical system is corrected by the MTF correction unit 18 and the magnification change unit 19, and the magnification is further processed. In the magnification changing process of the present embodiment, the magnification is changed by the electric signal processing in the main scanning direction, but the reading timing of the CCD 9 is kept normal in the sub-scanning direction, and the first and second scanners 10 and 10 are used.
This is performed by changing the sub-scanning speed of Step 11. Thereafter, if necessary, various processes such as black-and-white inversion and hollowing are performed, and the data is sent to a pulse width modulation circuit (not shown) via a binarization unit 20 and a gate 21. A pulse having a width corresponding to the density of an image is generated by the pulse width modulation circuit, sent to a laser driver, and a semiconductor laser is controlled to perform optical writing on a photosensitive member. The above processing is an operation in a normal digital copying mode.

Thus, in the present embodiment, the size detecting means 25 for detecting the document size is mounted. This size detection means 25
Is to share a scanner optical system including a CCD 9 and read the boundary between the yellow background of the manuscript pressing plate and the white background of the manuscript background by the CCD 9 and detect it as position data. For this reason, a size detecting white plate 26 provided near the home position and scanned, and a blue filter for yellow cut provided undulatingly in front of the imaging lens 8 are provided.
27 is included. The size detection operation by the size detection means 25 is performed by prescanning prior to the original document image scanning. First, as shown in FIG. 3, the filter solenoid 28 is turned on, and the lever 29 is sucked to bring the blue filter 27 up on the optical path in front of the imaging lens 8. In this state, the first and second scanners 10 and 11 perform full scanning at four times the speed of the original at the same time (4.
35mm), first the size detection white plate 26 is a blue filter
It is read by CCD9 through 27, and white level correction and shading correction are performed. And, using the difference with the yellow ground,
The size (position) of the document in the main scanning direction and the sub-scanning direction is detected. This processing is performed by GA3 in the IPU. The data of the detected document size is once sent to the optical control board. When the document size detection operation is completed, the solenoid
The blue filter 27 is turned off, and the blue filter 27 is returned by the return spring 30 to a state of being collapsed (a state of being out of the optical path). Note that AD
In the apparatus provided with F, the size of the document is detected by the size detection means mounted on the ADF when the document is set or transported, and the fixed size code is sent to the CPU of the optical control board.

Further, the image editing function of the present embodiment has a marker editing function for a marker area specified by a marker on a document by an operator. Editing processing means for this is not shown. The above document size detection operation is performed by prescanning in the automatic paper size selection mode or the like even in the normal copy mode. When image movement processing such as centering and marker area cornering is involved, the first prescan for this document size detection is performed prior to the original document image scanning, and the marker area is detected by the marker area detecting means 31. A second prescan for detecting the position is also performed. The markers are of halftone density.

In the second pre-scanning for detecting the position of the marker area, a signal MSVN for limiting the detection range of the marker area is output from GA1. Here, in the marker area editing mode, during normal marker editing, for example, during image processing without moving the image position, such as erasure in the marker area and erasure outside the marker area, this signal MSVN is shown in FIG. It is like. First, the main scanning direction becomes active from the position of the edge 7 mm of the contact glass 1 and is generated by a gate signal (turned on / off by a counter inside the GA 1) which is cut off 7 mm before the maximum document width. The sub-scanning direction is generated by a gate signal that is turned on / off by a frame signal FGATE from the CPU of the optical control plate that determines the valid period in the sub-scanning direction. The AND area of these gate signals in the main and sub-scanning directions indicates the signal MSVN, which is the marker area detection effective range E. This is the signal MSVN during normal editing.

In the marker area editing mode involving image movement processing such as the marker area centering and the marker area cornering described above, the optical control board indicates a mode for limiting the detection range of the marker area to GA1 in the IPU. Signal MKMD and document size data are sent in a command format. As a result, as shown in FIG.
With 32, the detection range of the marker area is changed according to the document size data, and a corrected signal MSVN is obtained. Here, the detection range changing means 32 outputs the clock CK2 in units of two pixels.
The comparator 34 receives the output of the main scanning counter 33 for counting the number of scans and the document size data XADRS in the main scanning direction as input and outputs document area data in the main scanning direction, and a sub-counter for counting a reference signal (line signal) MSYNC for each line. Scan counter 35
, And a comparator 36 that outputs document area data in the sub-scanning direction with the output of the sub-scanning direction document size data YADRS as input, and a gate circuit that inputs the outputs of the comparators 34 and 36 and the normal signal MSVN before correction. Consists of 37. The document size data XADRS, YADRS is sent in a command format. Therefore, the variably corrected signal MSVN obtained from the gate circuit 37 limits the normal signal MSVN, and only the area within the document is a marker area detection target.

The signal MSVN corrected and limited in this way is input to the marker address detection unit 38 shown in FIG. 5 in synchronization with the binarized document image information. The document size data is input via the timing controller 39.

As a result, the relationship between the variably corrected signal MSVN and the main scanning synchronization signal (line signal) MSYNC at the time of marker area centering or marker area cornering is as shown by a solid line in FIG. Normal signal MS before correction shown
It is limited compared to VN. Therefore, even if the original pressure plate or the conveyance belt has a stain of the same density as that of the marker, this is not detected as the original marker, and the address information indicating the marker area output to the CPU from the marker address detection unit 38 is not detected. Is correct data which is not affected by such contamination. In particular, during image processing involving image movement processing such as marker area centering, the marker area detection range is limited to within the document size range. And so on.

As described above, the present invention provides a size detecting unit for detecting a document size prior to reading document image information, a marker region detecting unit for detecting a position of a marker region, and a marker region by the marker region detecting unit. The detection range changing means for changing the detection range according to the document size and the editing processing means for editing the document image information of the detected marker area are provided, so that the effective range of the marker area detection is within the document range. Therefore, even if the original pressure plate or the conveyance belt of the automatic original conveyance device is stained with the same density as that of the marker, if the contamination is out of the original range, the marker area is not detected and the marker area is not detected. Erroneous detection can be prevented, and editing processing can be performed on a desired area. In the case of the moving process, a desired centering process or the like can be correctly performed by using only the marker region on the document as a processing target without including dirt outside the document as a marker region.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention. FIG. 1 is a circuit diagram of a detection range varying unit, FIG. 2 is a schematic configuration diagram of a scanner unit of a digital copying machine, and FIG. FIG. 4 is a perspective view of the filter mechanism, FIG. 4 is a plan view for explaining the meaning of the signal MSVN, FIG. 5 is a block diagram, and FIG. 6 is a timing chart. 9 ... line image sensor, 25 ... size detection means,
31: mark area detection means, 32: detection range variable means

Claims (2)

(57) [Claims] 1. A digital image output device for optically reading document image information using a line image sensor, converting the image information into an electric signal, and outputting the signal. The digital image output device is designated by surrounding a document with a halftone density marker. In an apparatus having an image editing function for document image information in a marker area, a size detecting means for detecting a document size prior to reading the document image information; a marker area detecting means for detecting a position of the marker area; A detection range varying unit that varies a marker region detection range by the marker region detection unit in accordance with a document size detected by the size detection unit; and an editing processing unit that performs editing processing on document image information of the detected marker region. A digital image output device characterized by being provided. 2. The digital image output device according to claim 1, wherein the editing processing by the editing processing means is an image moving processing.