JPH01192265A - Picture processor - Google Patents

Abstract

PURPOSE:To attain MTF correction without deforming contour by devising the processing unit so that the contour correction in the subscanning direction uniquely with respect to the contour correction in the main scanning and emphasizing the contour correction in the subscanning direction with respect to the contour correction in the main scanning direction. CONSTITUTION:A convolution filter using a picture data of, e.g., 3X3 picture elements is used as a resolution correction means 450. The filter coefficient in the main and subscanning directions differs from each other and the filter coefficients in the main and subscanning directions are set independently. Moreover, some emphasis is applied to the correction in the sub scanning direction more than that in the main scanning direction. Thus, the reproducibility of lateral lines is improved and the MTF correction with high quality is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a simple electrophotographic method that separates image information into a plurality of colors, performs image processing, and then records it as a monochrome image. The present invention relates to an image processing apparatus for outputting images that is suitable for application to copying machines and the like, and particularly to an image processing apparatus that can record a normal image as a hollow image.

[Background of the Invention] In a simple electrophotographic copying machine, whether the original is black and white or color, regardless of the presence or absence of a multicolor original, it performs monochrome processing from the beginning and then copies the original. I try to do that.

The 109th copy machine makes color copies of multicolor originals.
An image processing apparatus configured as shown in the figure is known.

In the same figure, color image information is separated into white and cyan, each of which is transmitted to an image sensor 100 such as a CCD.
, 105 and photoelectrically converted.

The white and cyan color signals are supplied to a subtracter 2, from which the red signal is color-discriminated, and these color signals are respectively sent to the AG.
After the gain is adjusted with C[I approximately 3, 4.5, it is binarized in binarization circuits 6, 7.8. The binary output is reconverted into, for example, red and black color signals in the arithmetic circuit 9, and these are supplied as image signals to a color copying device (an output device having a rotating drum), thereby reproducing a color image. Ru.

[Problems to be Solved by the Invention] By the way, in an image processing device as shown in FIG. 109, the resolution is corrected by detecting contour information of an image signal and emphasizing the contour, thereby sharpening the image. The means are already known.

As is well known, the existing resolution correction only involves sharpening the image, and therefore, with this method, it is impossible to obtain an image with the interior of the input image erased, that is, a hollow image.

Furthermore, even with a processing means capable of performing such hollow processing, even if the same degree of correction is performed in each of the main scanning direction (horizontal direction) and the sub-scanning direction (vertical direction), the following problems will occur. For these reasons, it is not possible to obtain a hollow image that can be put to practical use.

That is, if the same degree of correction is performed in both the main and sub-scanning directions, thin horizontal lines and the like cannot be sufficiently reproduced in the hollow state.

To solve this problem, if sufficient correction is made in both directions,
Since noise in the main scanning direction is also treated as an image signal, it has the disadvantage of deteriorating image quality.

Therefore, the present invention solves these conventional problems with a simple structure, and provides an image processing apparatus that is capable of obtaining high-quality images that are particularly subjected to hollow processing in an image processing apparatus for monochrome recording. This paper proposes a processing device.

[Means for Solving the Problems] In order to solve the above-mentioned problems, an image processing device according to the present invention includes an imaging means for imaging image information of a document, and a density change of an image signal obtained from the imaging means. It has a hollowing processing means for extracting a portion and processing the image signal for hollowing out, and a means for visualizing the image based on the hollowed out image signal, and the hollowing processing means has a sub-scanning process. This method is characterized in that the image signal related to the direction is processed more strongly than the image signal related to the main scanning direction.

[Function] The image information of the optically captured original is separated into multiple colors. The color-separated image information is photoelectrically converted by a reading means such as a CCD.

The photoelectrically converted image signal is converted into an image signal having color information and density information of the image.

Image processing such as color ghost correction is performed on the color information.

Various image processing such as enlargement/reduction processing and resolution processing is performed on the density information, and it is also decided whether to copy all colors to a black and white image or to copy a specific color image to a black and white image. The treatment specified will be done accordingly.

The hollow processing is executed simultaneously with these processes or independently. A means for resolution correction (a convolution filter) can be used as the means for the hollowing process, and the coefficients thereof are set for the hollowing process.

At the stage where such image processing is completed, multivalue processing is executed. The image is visualized based on the multivalued signal.

Therefore, the image is visualized using fewer colors than the color separation means, and this is developed.

Since the valid color of the image is specified externally, it is possible to copy the image with only a specific color erased.

Since image processing is performed before multi-value conversion is completed, there is no risk of image quality deterioration even if enlargement/reduction processing is performed.

[Embodiment] Hereinafter, an example of an image processing apparatus according to the present invention will be described in detail with reference to FIG. 1 and subsequent figures.

FIG. 1 shows a schematic configuration of an image processing apparatus according to the present invention.

The color image information (optical image) of the original 52 is separated into two color separated images by the dichroic mirror 55. In this example, the image is separated into a red R color separation image and a cyan cy color separation image. Therefore, the cutoff of the dichroic mirror 55 used is about 540 to 600 nm.

As a result, the red component becomes transmitted light, and the cyan component becomes reflected light.

The color separated images of red R and cyan Cy are supplied to an image reading means, for example, C0D104.105, and image signals of only the red component R and cyan component cy are output from each image reading means, for example.

The image signals R and Cy are supplied to A/D converters 60A and 60B, where they are converted into digital signals of a predetermined number of bits, 6 bits in this example. Shading correction can be done at the same time as A/D conversion. 15A + 15B indicates a shading correction data creation circuit. Details of the shading correction will be described later.

The shading-corrected digital image (No. i is extracted by the area extraction circuit 30 for only No. 43 of the maximum document size width, and is supplied to the next stage color discrimination circuit 35. When the maximum document width to be handled is 84 size, The size signal B4 generated by a timing signal generating means (not shown) of the system is used as the signal No. 518.

Here, if the digital image signals subjected to shedding correction are VR and VC, respectively, these image signals VR.

VC is supplied to a color discrimination circuit 35 and can be discriminated into a plurality of color signals.

In this example, a case is illustrated in which the signal is configured to be separated into three color signals: red, blue, and black.

That is, no matter what color the original is, each pixel is assigned to one of red, blue, and black. When this process is performed, each part of the document is recognized as a red, helmet, or black color part. Note that this color discrimination process also includes changing red, blue, and black to other colors, or in general, using four or more colors.

Each discriminated color signal is composed of color code data (3-bit data) indicating its color information and its density data (6-bit data). The data for each of these color signals is stored in a color discrimination map in a ROM, for example.

The color-discriminated image data is transferred to a color image processing step.

First, it is supplied to the next-stage color ghost correction means 300, where color ghosts in the main scanning direction (horizontal scanning direction) and sub-scanning direction (drum rotation direction) are corrected.

This is because unnecessary color ghosts occur during color discrimination, especially around black characters.

Depending on the configuration of the color separation map, red or blue color appears around the edges of black characters. Image quality is improved by removing color ghosts. Color ghost processing applies only to color code data.

Even when copying in monochrome, for example, if the function is to erase one color part and copy, a color ghost correction circuit is required as in this example.

300A indicates a color ghost correction circuit in the main scanning direction, and 300B indicates a color ghost correction circuit in the sub-scanning direction.

When performing color ghost correction using image data for 7 bits in the horizontal direction and 7 lines in the vertical direction, a 7-bit shift register 301 and a memory 310 for 7 or 8 lines are used, respectively, as shown in the figure. will be done.

In addition to color ghost correction, image processing includes specific area extraction/erasing/filling means 420, enlargement/reduction processing means (variable magnification means) 1, and resolution correction means 4 including hollow processing.
50, a hatching processing means 440, an inversion means 460, and a multi-value conversion means 600 for multi-value conversion.

Extraction/erasing/filling processing of a specific area is performed based on color code data, but other image processing is performed only using density data.

An example of region extraction will be described next. The area extraction circuit 500 is for detecting an original image area marked with a color marker on a document or the like.

The area extraction circuit 500 outputs a signal (area signal) indicating the area surrounded by the color marker, and this signal enters the extraction/erasing/filling circuit 420.

Here, a signal for extraction, erasure, and filling is created according to the area-extracted signal.

At this time, this signal creation is performed according to instructions for inside/outside the marker area.

Next, this signal passes through the enlarging/reducing circuit 1 and undergoes enlarging/reducing processing as necessary.

Since the data necessary for the enlargement/reduction process has been obtained by the processing means 420, it is only necessary to process this output data.

A magnification instruction is set for the enlargement/reduction circuit 1 by the CPU. Enlargement/reduction processing is performed in the main scanning direction by electrical processing, and in the sub-scanning direction by controlling the scanning speed of the optical system.

The image data after scaling is then subjected to resolution correction (MTF correction) processing.

The reason for performing MTF correction is that the aperture size of the CCD 104°/105 may become larger in the sub-scanning direction, as well as the deterioration of sharpness in transmission systems such as lenses, and the integration of optical signals in the sub-scanning direction. This is because the MTF deterioration in the sub-scanning direction is more significant than in the main-scanning direction in order to obtain a signal in the sub-scanning direction.

Therefore, skipping and blurring of characters can be corrected.

On the other hand, as described later, this MTF correction uses a 3×3 convolution filter, but by switching this filter coefficient to differentiation (edge detection),
It is possible to extract data only from the edges. This is called middle cutting.

After performing these processes on the necessary areas, the image data is input to the shading circuit 440. Here, the required area is shaded.

Next, the image data is input to an inversion circuit 460, where only necessary areas are inverted. After that, the multi-value conversion means 60
At 0, the image data can be multivalued.

On the other hand, the threshold value for this multi-value conversion is determined in real time by automatic threshold value setting means (EE means) 600B.

The image data multivalued by the multivalue conversion means 600A is supplied to the output device 70 via the interface circuit 40.

As will be described later, the interface circuit 40 has first and second interfaces 41 and 42, and the second interface circuit 42 is for receiving patch image data and the like used for controlling toner density. be.

As the output device 70, a laser recording device or the like can be used. When a laser recording device is used, a multivalued image can be converted into a predetermined optical signal, and
This can be modulated based on multilevel data.

As the developing device, an electrophotographic copying machine is used. In this example, two-component development and reversal development are employed. In this example, in order to reduce the size of the device, a dot image is developed on an OPC photoreceptor (drum) for image formation in one rotation of the drum, transfer is performed once after development, and the image is printed on recording paper such as plain paper. The image is transferred as a monochrome image.

Therefore, according to the image processing apparatus shown in FIG. 1, appropriate image processing can be performed for each color for multiple colors, processing such as color erasure is possible, multi-value recording, etc. can be used, A device with features such as high image quality and low cost can be realized.

Next, the configuration of each part of the image processing apparatus according to the present invention configured as described above will be explained in detail.

First, a simplified copying machine suitable for application to the present invention will be explained with reference to FIG. 2 and subsequent figures.

A simple copying machine separates color information into about three types of color information and then records this as a monochrome image.

In this example, black BK is used as the three types of color information to be separated.
, red R and blue B are illustrated.

By turning on the copy button on the device, the document reading section A
is driven.

First, a document on document table 81 is optically scanned by an optical system.

This optical system consists of a carriage 84. ■It is composed of mirrors 89 and 89゛.

A halogen lamp is used as a light source. However, it is also possible to use commercially available warm white fluorescent lamps, and in this case, these fluorescent lamps are turned on and driven by a high frequency power source of about 40 kHz to prevent flickering. In addition, in order to maintain a constant temperature of the tube wall or to promote warm-up, it is necessary to use a heater using a POSISTOR.

A standard white plate 97 is placed on the upper surface side of the left end of the platen glass 81.
is provided. This is because the image signal is normalized to a white signal by optically scanning the standard white plate 97.

The carriage 84 and the V mirrors 89 and 89 are caused to travel on slide rails (not shown) at predetermined speeds and in predetermined directions, respectively, by a stepping motor 90.

Optical information (image information) obtained by irradiating the original with the light source 85 is guided to the optical information conversion unit 100 via the reflecting mirror 87 and the (1) mirror 89°89°.

The optical information conversion unit 100 includes a lens 801, a prism 802, a dichroic mirror 55, a CCD 104 on which a red color-separated image is projected, and a CCD 105 on which a cyan color-separated image is projected.

An optical signal obtained from the optical system is focused by a lens 801, and separated into red optical information and cyan optical information by a dichroic mirror 55 provided in the prism 802 described above.

Each color separated image is converted into an electrical signal (image signal) by being focused on the light receiving surface of each CCD 104, 105. The image signal is output to the writing section B after being subjected to the various signal processing described above in the signal processing system.

It has a writing section BLt deflector 935. Deflector 935
In addition to a galvanometer mirror, a rotating polygon mirror, etc., a deflector made of an optical deflector using crystal or the like may be used. The laser beam modulated by the image signal is deflected and scanned by this deflector 935.

When the deflection scan is completed, the beam scan is detected by a laser beam index sensor (not shown), and beam modulation using the image signal is started.

The modulated beam is scanned by a charger 121 over an image forming member (photosensitive drum) 110 which has been given a negative charge.

Here, the main scanning by the laser beam and the image forming body 110 are performed.
By the sub-scanning by zero rotation, an electrostatic image corresponding to the image signal is completely formed on the image forming body 110.

This electrostatic image is developed by a developing device 1z3 containing black toner. A predetermined bias voltage from a high voltage source has been applied to the developing device 123.

A black and white image is formed by development.

Toner replenishment of the developing device 123 is performed by controlling a toner replenishing means (not shown) based on a command signal from a system control CPU (not shown), thereby replenishing toner when necessary.

On the other hand, the recording paper P fed from the paper feeding device 141 via the feed roll 142 and the timing roll 143 is
The image forming member 110 is conveyed onto the surface of the image forming member 110 while being timed with the rotation of the image forming member 110 . Then, the multicolor toner image is transferred onto the recording paper P by the transfer w1130 to which a high voltage is applied from the high voltage power supply, and the multicolor toner image is transferred onto the recording paper P. i
It is separated by the II pole 131.

The separated recording paper P is conveyed to the fixing device 132, where it undergoes a fixing process and a color image is obtained.

The image forming body 110 after the transfer is transferred to a cleaning device 126
is cleaned and prepared for the next imaging process.

In the cleaning device 126, a predetermined DC voltage is applied to a metal roll 128 provided on the blade 127 in order to facilitate recovery of the toner cleaned by the blade 127. This metal roll 128 is the image forming body 1
10 in a non-contact manner.

After the cleaning is completed, the blade 127 is released from the pressure bonding, but in order to remove unnecessary toner that is left behind when the blade 127 is released, an auxiliary cleaning roller 129 is further provided, and this roller 129 is rotated in the opposite direction to the image forming body 110 and the pressure bonding is performed. By doing this, unnecessary toner can be thoroughly cleaned and removed.

The transmittance characteristics of the dichroic mirror 55 described above are
Figure 4 shows the emission spectrum of the combination of light source and infrared (IR) cut filter, and CCD104.10
The spectral sensitivity characteristics of No. 5 are shown in FIG.

The reason why shedding correction is necessary is as follows.

One is for the optical system, and the other is for the CCD PRNU (Pho).
to Re5ponse Man Uniformit
y) This is because correction is necessary.

The COD, which is the second flexural structure, has a structure in which the number of pixels, usually about 2048 to 5000, is arranged in a line. It is generally difficult to make the characteristics of each pixel of this number uniform. Normally there is ±10% as PRNU,
This is because it is necessary to correct this sensitivity unevenness in order to achieve high image quality.

If there is shading, even if the same white document is imaged, only a white signal with a lower output level around the shading will be obtained as shown in FIG. 6A.

Therefore, in order to perform the shading correction, the optical system is first operated, and before starting the main scan, the white reference plate 97 is scanned to obtain a white signal (FIG. 6B), and this is used as the A/D conversion conversion amount reference signal. If used as a reference signal, the A/D conversion and quantization steps are modulated by this reference signal. That is, as shown in FIG. 6A, the quantization step is controlled so that the increments are small at the edges of the image and large at the center.

As a result, when the reference signal is A/D converted while being modulated in this manner, the output (analog output) becomes a constant output level as shown in FIG. 6C, and the shading distortion is corrected. In this way, the white signal captured before the main scan is used as a reference signal for shading correction.

FIG. 7 shows an example of the shading correction data creation circuit 15A.

In this example, the white reference plate 97 is imaged over two lines to be used as a reference signal, and the first buffer 16 is switched only during the period of these two lines. It is controlled to be active by a signal (FIG. 8B), and as a result, the A/D converted white signal is stored in the memory 19 via this first buffer 16.

When the normal image reading operation mode is entered, the image signal shown in FIG. 8A is output, and this is digitized by the A/D converter 60A. When the image reading operation mode is reached, the memory 19 is controlled to read mode, the second buffer 17 is controlled to be active, and the reference signal (white signal) read from the memory 19 is sent to the D/A converter. 2'O is converted into an analog signal, which is sent to the A/D converter 60.
It is used as a reference signal for A.

The A/D converter 60A is a parallel type A/D converter as shown in FIG.
A D converter is used, and the above-mentioned reference signal is applied to each of the parallel-configured comparators 61. Furthermore, this A/D
In the converter 60A, 62 is a reference signal forming means composed of a plurality of bleeder resistors, 63 is an encoder, and 64
is a latch circuit.

In order to control the second buffer 17 to be active only during the operation period, the OR output 0R1 (FIG. 8E) of the switching signal and the image valid signal is supplied via the OR circuit 21.

In this example, a third buffer 18 is provided, and during the horizontal blanking period, the A/D! I'm trying to change it.

Therefore, the inverter 22 outputs the
An output 0R2 (F in the figure) obtained by inverting the phase of R1 is supplied.

Therefore, since the reference signal for the comparator 61 can be modulated by the reference signal shown in G in the same figure, when the A/D-converted image data is converted into analog data, it becomes as shown in (2) in the same figure.

Note that if the white signals of all pixels of the COD are stored in the memory 19, the PRNU can be corrected at the same time.

Shading correction is performed independently for each red and cyan channel. For example, if the shore side white signal is used for correction of the cyan side signal, the PRNU of the shore side CCD is different from that of the cyan side, so the cyan side white signal after correction is This is because there is a possibility that a problem of increased variation in output may occur.

In FIG. 7, the horizontal blanking period HBLK is also subjected to A/D conversion using a reference signal having a predetermined reference level, and this is based on the following reason.

During shading correction, especially for A/D conversion operations outside the image valid period, the shading correction data stored in the 1-line memory is used as it is at the reference terminal 62a of the A/D converter 60A.
(FIG. 9), the A/D conversion range of the A/D converter 60A is approximately O, and the input signal and the reference signal for shading correction are roughly at the same potential.

Roughly speaking, this input signal contains quite a bit of noise N (FIG. 10A).

Since the A/D converter 60A sequentially performs determination based on the voltage fluctuations of the input image signal and the reference signal, the conversion range is approximately 0, so the determination result is either the maximum value of the output (high level) or The minimum value (low level) is determined.

If this fluctuation in output value occurs over a relatively short period of time due to the influence of noise, etc., the comparator of the A/D converter repeats on and off almost simultaneously, causing a large change in current as the A/D converter. occurs.

This change in current has a relatively high frequency and does not exist in the signal waveform, so there is a high possibility that it will affect the input signal as noise. Generally speaking, since a relatively large amount of current flows through the source, the impedance is low, and there is a high possibility that it will enter the power supply line or ground line as noise that is larger than normal.

Noise generated due to the values of the input signal of the A/D converter and the reference signal for shading correction (Figure 10B) mixes into the input signal black level, causing large fluctuations in the black level ( Figure C).

Therefore, in this example, the conversion range is prevented from becoming 0 at least during the black level period outside the image non-effective period to prevent noise from being mixed in.

In the embodiment, the voltage values set outside the image validity period are as follows:
The full scale value of the A/D is used to prevent the change range from becoming O■, and to prevent the shaded correction signal and the shaded correction signal from becoming the same voltage.

Through the above processing, A/D conversion and shading correction can be performed simultaneously. In such a correction method,
If the white power signal is 30 to 40% or more of the full scale of the A/D, correction is almost possible (FIG. 11A).

However, if a low white signal that exceeds this limit comes (for example, due to blackening or a decrease in light intensity due to long-term lighting), it is possible to correct it, but the image signal will be in the form of a large amount of noise superimposed, and it will remain as it is. It is practically difficult to use it in the form (
Figure 11B).

Using the red and cyan output signals corrected for shading as described above, next we perform color discrimination, that is, color separation! (multi-bit image data). Here, an example will be shown for three colors: black, red, and blue.

If a method is adopted in which the image signal is binarized and then color separated as in the conventional example, the data after color separation is a binary signal, which is inappropriate in view of performing various types of processing.

Here, the color is separated into S before being converted into 2@. A map as shown in FIG. 12 is prepared for color separation. The color separation map is a ROM (bipolar ROM). In this case, 6-bit image data V having halftone levels
A 3-bit color code (one designation of five colors: red, helmet, black, red marker, and blue marker) and density information are stored at the addresses given by R and VC. In other words, 1 image information = color code + density information.

For example, the concentration value is 30 levels (XXXO
I 1110) pixel is Blue = 001011110 = 05E Black = OOOO11110 = OLE White = 011011110 = ODE For white, DE or CO may be used, but DE is selected due to the continuity of density.

The above data is stored in each address as shown in FIG. 12A.

The reason why the R marker and B marker areas are included in the map in the same figure is because image processing is performed on specific areas, so it is necessary to detect the color markers written on the manuscript separately from other image data. This is because there is.

Of course, as shown in FIG. 12B, it is also possible to map color markers without distinguishing them from other color data.

Here, an example of the color code is shown in FIG.

The color code is red including white, helmet, black, white, red marker,
Since there are six colors for the ring marker, three bits are used, but it is clear that as the number of colors increases, the number of bits can be increased accordingly. Further, the density information is also 6 bits here, but 4 bits is practically sufficient for characters only. Therefore, it is clear that the number of bits may be changed depending on the target image.

The boundaries of color separation as shown in FIG. 12 must be determined by taking into consideration output fluctuations at the edge portions of lines.

This is because unnecessary colors called color ghosts, which are a type of color error, will occur at the edges of black characters and the like.

Since the color separation boundary is generally fixed, the color changes greatly depending on the setting of the boundary line. In particular, when performing color separation (multi-color), this effect is particularly large, and in order to prevent variations in the results, (a) Preventing fluctuations in the emission spectrum of the light source (b) Preventing chromatic aberration of the lens, etc. Prevention of Variation (c) It is particularly necessary to prevent variation in the cutoff wavelength of the dichroic prism.

(A) is not a big problem with halogen lamps, but
In the case of fluorescent lamps, +Ar spectrum may appear at low temperatures, and it is important to prevent this.

(b) will be discussed later.

Although (c) usually results in the problem of controlling film variations, it is preferable to keep it within ±15 nI, preferably within ±10 nm, with respect to the set cutoff wavelength. If this is not done, the boundary color between red and black or blue and black in the original image will vary greatly due to variations in the cutoff wavelength of the prism.

In this example, the color separation method uses two signals, VR and VC, and in this method, different color separation axes f 1 (VR, VC), f 2 (VR) are used.

VC) may also be used. When using the color separation axis in calculations, etc., depending on the calculation formula, if noise is superimposed on VR or VC, the addresses will be different compared to when there is no noise.
Care must be taken because isolated noise of different colors is likely to occur.

On the other hand, in practical use, there are cases where it is desired to extract a specific color, or to extract colors other than red, blue, and fish gear. For these cases, a color separation map different from this example is prepared, and one of the plurality of color separation maps is selected according to the request. Or 1 color! The ROM may be made removable and the required ROM (actually in the form of a ROM back) may be replaced.

The map for three colors is shown in FIGS. 13A and B, and the map for four colors is shown in FIG. 13C.

Next, color ghost correction means 3 removes color ghosts from the image data color-separated as described above.
00 will be explained.

There are many causes of color ghosts, but the main ones are: 1. Pixel misalignment between the two CCDs (installation accuracy, changes over time) 2. Cyan and red image magnification mismatch 3. Cyan and red power caused by lens chromatic aberration Level difference 4, noise. This will be explained below.

FIG. 15 shows an example of appearance of color ghosts.

The figure shows the color ghost that appears after color separation of the black kanji ``sexuality''.

As you can see from this example, as a color ghost,
As shown in FIGS. 16A to 16C, red and blue appear at the edge of the black line, black appears at the edge of the blue-green line, and black appears at the edge of the red line.

It is clear that color ghosts appear differently in other color combinations.

The reason why such a phenomenon occurs will be explained using the above example.

(See Figures 17 and 18) As shown in Figure 17, if the CCD alignment is not done precisely, when the colors are separated, as shown in Figure 18, the edges of black will be red and blue; A black ghost will appear at a red edge, and a black ghost will appear at a helmet edge.

Therefore, in order to prevent this, it is necessary to precisely align the two CODs. Normally, it is necessary to perform alignment within one pixel, preferably within 1/4 pixel.

In this example, this is achieved by aligning the two CODs on a jig and then fixing them with adhesive.

An example is shown in FIG. 19 and below.

The lens barrel 801 is attached to a holding member 8 as shown in FIG.
A single-shaped receiver opening at right angles toward the upper part of 01a is housed in a section, fixed by a fastener 801c, and then attached to a predetermined position on the device board 810.

The front part 8 of the prism 802 is attached to the rear side of the holding member 801a.
The mounting into which the prism 802b can be dropped is provided with a surface, and the prism 802 held by the mounting member 802a can be pressed against the surface and fixed by screwing.

Since the mounting surface can be formed by a simple machining process, the distance from the lens barrel 801 and the perpendicularity to the optical axis are extremely accurate, and the above-mentioned CCD 104. CCD
A predetermined optical image can be accurately formed on the light receiving surface of the lens 105.

How to determine the amount of perpendicularity deviation between the plane 801b of the lens barrel 801 perpendicular to the optical axis and the surface 802b of the prism 802 facing the lens (the amount of perpendicularity of the dichroic surface with respect to the lens optical axis) is determined as follows. , the resolution MTF obtained from the signal output of the white line part and the black line part with respect to the white background is given by MTF = (y-x/y+x) In 10 minutes, it decreased by around 30% (9%), and the angle further decreased by 30%.
It is important to maintain the surface accuracy during this period, as this will cause a drop of more than 50% (15%) per minute, which will hinder the extraction of black and white discrimination signals. ).

The CCDs 104 and 105 can be fixed to the prism 802 using adhesive through members 804 and 806.

FIG. 21 shows an embodiment showing a cross section of the main part, and the light splitting members are fixed symmetrically with adhesive on both sides of the prism 802. Members 804a and 804b (806a, 806b)
The CCDs 104 and 105 are fixed to the imaging section via adhesive.

As for the material of the mounting member, it is desirable to use a material with a small coefficient of linear expansion for two reasons. One is to prevent pixel misalignment due to temperature fluctuations, and the other is to prevent pixel misalignment from occurring due to temperature fluctuations.The other is to prevent pixel misalignment from occurring due to temperature fluctuations, and the other is to prevent the prism from cracking due to internal distortion due to the difference in linear expansion coefficient between the components. This is to prevent this from occurring.

The problem of pixel misalignment due to temperature fluctuations can be reduced by installing each CCD under exactly the same conditions with the components, but it is possible to reduce the pixel misalignment between CODs, but it is also necessary to have a small IIA expansion coefficient. be.

Normally, the linear expansion coefficient of a prism is around 7.4X10-' (optical glass BK-7), so the mounting material should be glass or ceramic material (7°O~8.4X10-').
8) and low thermal expansion alloys (e.g. Invar alloy (1~3X1
0-6), rainbow rest cast iron (4-10 x 10-6)), etc. are suitable, and aluminum material (25 x 10-6) is not so suitable.

In the above-mentioned embodiment, the prism and the mounting member are fixed, and the mounting member and the COD are fixed using adhesive, and the relative position of each COD is adjusted for the divided optical image, and the example shown in FIG. 21 is used. We decided to fix it tightly using adhesive as shown in the figure below.

In particular, in Fig. 21, even if iron (12 x 10-'') with a large coefficient of linear expansion is used as the mounting member, the dimension in the C direction is short in practical terms, so the elongation due to heat will not be affected much, and the elongation in the d direction is is the direction in which the line sensors are arranged, and since the prism material and the package material of the line sensor are ceramic materials, their linear expansion coefficients are the same, and with this configuration, no pixel misalignment occurred.

The adhesive is a two-component type adhesive or a photocurable adhesive, and an ultraviolet curable adhesive is particularly preferred.

In particular, photo-curable adhesives can speed up the curing time of the adhesive simply by changing the intensity of light, improving workability, reducing costs, and stabilizing the product. Among photo-curable adhesives, ultraviolet-curable adhesives in particular exhibit almost no thermal change even when exposed to ultraviolet rays, and can be stably cured.

Three Bond TB3060B (product name), Denka 1045K (product name), Norland 65 as light-curing adhesives
(trade name), etc., and irradiated with ultraviolet rays using a high-pressure mercury lamp, we were able to obtain good results in environmental tests, etc., which will be described later.

Also UV-curable urethane-based ThreeBond 3062
When using #4 B (trade name), LT350 (trade name), etc., it was possible to obtain an adhesive that was even more effective in terms of moisture and had strength compensation.

What is the overall positional deviation of the CCD using the above method, assuming 1 pixel is 7μ? It became possible to suppress it within /4=1.75μ.

ゝ ゝ 1, , - When a color original is targeted, there is an effect of chromatic aberration of the lens, etc. If the wavelength range of light is divided into two, cyan and red, for example, the second
As shown in FIG. 2, since the cyan-side imaging position F and the shore-side imaging position E are different, this phenomenon is particularly noticeable at high image heights. Depending on the lens, a shift amount of about one pixel may occur.

ゝ ゛・Nobe Unless a lens is designed to improve chromatic aberration, the MTF values for cyan and red may differ greatly due to the chromatic aberration of the lens. This is due to the difference in level of the COD output.

When a black line is imaged, the cyan and red output signal levels at the center or edge of the line are quantized with 6 bits, and 1Vr-Vcl≦10 (level), preferably 1Vr-Vcl≦6 (level). It is preferable to take this into account when installing the CCD.

Although it is possible to reduce color ghosts to some extent through the measures described above, it is difficult to completely eliminate them in practice, considering the variations in lens performance during mass production and the variations in accuracy of CCD mounting. .

For this reason, color ghost correction is also performed electrically using the color code after color separation.

Color ghost removal is performed using the color pattern method.

This is because the color ghost color that appears is determined for the original color, such as original black → red, blue ghost, original red, blue → black ghost. In the case of the color pattern method, the color of the original image can be identified by examining the appearance (pattern) of the colors of the pixel of interest and its surrounding pixels to determine the color of the pixel of interest.

As an example, FIG. 23 shows the pixel of interest, the surrounding color pattern, and the determination of the color of the pixel of interest determined at that time.

In the first example, since both sides of the pixel of interest are white and black, the blue color of the pixel of interest can be determined to be a color ghost appearing at the black edge. Red in the third example is also determined to be a color ghost of black. Therefore, in both the first and third examples, the pixel of interest is changed to black.

On the other hand, in the second and fourth examples, it is not determined that a color ghost has appeared, and the color of the pixel of interest is output as is.

This type of processing is difficult to implement with an arithmetic circuit, so in this example, it is implemented in ROM and LUT (lookup table).
It is used in the format. One-dimensional and two-dimensional methods can be considered as color patterns, but if the number of colors is N and the number of peripheral pixels including the pixel of interest is M, the number of color patterns is NM. Therefore, if a two-dimensional pattern is used, the number of M will suddenly increase, making it impractical.

In other words, although a two-dimensional pattern cannot have a large number of peripheral pixels in each dimension (main scanning direction/sub scanning direction), the number of patterns increases.

FIG. 24 shows the relationship between size and number of color patterns.

In this example, the size is 1×7 in one dimension (that is, N
=4. M=7) color pattern is used, and color ghost removal is performed independently in the main scanning direction and the sub-scanning direction.

Here, if color markers are included, the number of colors is 6, that is, N = 6, but when performing color ghost correction, the marker color is
The red marker is corrected using the same process as the red marker, and the blue marker is corrected using the same process as the blue marker. Therefore, N=4.

For this purpose, the lower two bits of the red and blue marker color codes are set to be common to the lower two bits of the red and blue color codes.

At this time, since there is no difference in the appearance of color ghosts in the image between the main scanning direction and the sub-scanning direction, the same color pattern is used in the main scanning direction and the sub-scanning direction in this example.

The color pattern size is 1 x 7, but if the degree of color ghost appearance is small, 1 x 7 is selected.
It is also possible to use a smaller size color pattern, such as x5.

Color ghosts of up to 1 pixel can be removed with a color pattern of IX5 size, and color ghosts of up to 2 pixels can be removed with a color pattern of ×7 size.

When a 1×7 color pattern is used, the lower two bits of the color code are input as the ROM address. For example, in the color pattern below, the pattern for the lower two bits of the color code is white: white:
Blue: Blue: Black: Black: Black 11:11:01:01:OO:OO:00, and the address is D40. Also, the lower two bits of the black color code are stored at this address, as shown in Figure 23. has been done. The LUT is executed using the above method.

In reality, a 1x7 pattern requires a 14-bit address line, and a bipolar ROM with a 14-bit address input and a 2-bit color code output is sufficient, but such a large-capacity, high-speed ROM are not widely available on the market and are expensive.

In the embodiment, the ROM is selected using the first pixel, and LUT is performed using the codes of the remaining six pixels. In other words, two ROMs are used; the first ROM has black and blue beginnings, and the second ROM has red and white beginnings.

Start code Black (00), Blue (OL) Address content 00000000000000 (black black black black black black black) 00
111111111111 (black white white white white white white) 0100
0000000000 (blue black black black black black black) 011111
Start code of 11111111 (blue, white, white, white, white) Red (10), white (11) Address content 10000000000000 (red, black, black, black, black, black) 10
111111111111 (red white white white white white white) 1100
0000000000 (black and white black black black black black) 111111
11111111 (white, white, white, white, white) In the color pattern shown in FIG. 23, the first ROM is white, so the second ROM is selected.

If a high-speed ROM (large capacity) is available, all color patterns can be stored in the same ROM. The LUT may be performed by using four ROMs and switching the ROMs depending on the color of the first pixel.

Examples of high-capacity, high-speed bipolar ROMs include MB7143/7144 manufactured by Fujitsu.

When using a low-speed, large-capacity EPROM, it is also possible to transfer data to a plurality of SRAMs or the like before operation and perform color ghost correction using these SRAMs.

FIG. 25 shows an example of the color ghost correction means 300. Color ghost processing is performed in the main scanning direction (horizontal scanning direction)
This is performed in the sub-scanning direction (vertical scanning direction).

In this example, horizontal and vertical ghosts are removed using image data for 7 pixels in the horizontal direction and 7 lines in the vertical direction.

Color ghost processing applies only to the lower two bits of the color code of the image data.

Therefore, color! The color code read from the ROM is first supplied to the ghost correction circuit Wi300A in the main scanning direction. Therefore, the color code data is sequentially supplied to a 7-bit shift register 301 and parallelized. The parallel color code data for seven pixels is supplied to the horizontal ghost removal ROM 302, and ghost removal processing is performed for each pixel. An example of how the ROM 302 is used is as described above. When the ghost processing is completed, the data is latched by the latch circuit 303.

On the other hand, the density data output from the color 1i1ROM is supplied to the latch circuit 306 via a shift register 305 (7-bit configuration) for timing adjustment, and the density data is serially transferred following the color code data. Data transfer conditions are determined as follows.

The serially processed color code data and density data are supplied to a line memory unit 310 provided in the color ghost correction circuit 300B.

The line memory unit 310 is provided to remove vertical color ghosts using seven lines of image data.

Although the line memory is used for a total of 8 lines, this represents one means of real-time processing; of course, real-time processing is possible even for 7 lines.

The color code data and density data for eight lines can be separated in the subsequent gate circuit group 320. In the gate circuit group 320, gate circuits 321-328 are provided corresponding to the line memories 311-318, respectively.

The output data of the 8 line memories synchronized in the line memory section 310 is separated into color code data and density data in the gate circuit group 320, and the separated color code data is supplied to the selection circuit 330 for a total of 8 pieces of data. Among the line memories, color code data of seven line memories necessary for color ghost processing is selected. In this case, when line memories 311 to 317 are selected, line memory 3 is selected at the next processing timing.
The line memories that can be selected are sequentially shifted so that 12 to 318 can be selected.

The selected and synchronized 7-line memory worth of color code data is stored in the vertical ghost removal ROM in the next stage.
335 to remove vertical color ghosts.

Thereafter, it is latched by the latch circuit 356.

On the other hand, the density data separated by the gate circuit group 320 is directly supplied to the latch circuit 357, and the color code data and timing adjustment W! It will then be output. Also, the upper 1 bit of the color code is also stored in memory 31.
After being stored in 9, the timing is adjusted with the lower 2 bits and output in the same manner, and these data are combined to create one complete image information.

The image processing example to be described next is region extraction processing.

Region extraction processing is a process for extracting a designated region so that various image processing can be performed on an image (black image) within or outside an arbitrary region designated by a color marker. be.

Conventionally, a position is specified using a digitizer or the like, and then an original image is placed and scanning processing is started, and a switch for inputting position data is operated each time the position is specified. Further, the position specification is in a rectangular shape such as a square or a rectangle, and it is not possible to specify an arbitrary area.

In the marker area extraction process described below, an arbitrary area written with a marker is detected, and an image can be processed and copied within/outside the area specified by the marker.

For example, as shown in FIG. 26, if you specify the area a with a blue marker, this area a will be automatically detected and this area a
The contents will be copied. Copying cannot be done outside area a. A red marker may be used as the color marker.

In order to copy the image inside/outside the area a specified in this way, as shown in FIG. 27, the marker signals BP and RP indicating the color marker area and the area a! area signal QB',
QR" must be detected respectively.

Therefore, as shown in FIG.
is provided.

FIG. 28 shows a specific example of this, in which each bit of color code data obtained by scanning a color marker is supplied to a color marker detection circuit 501 to detect the presence or absence of a specific color marker.

In the embodiment, two types of markers, red and blue, are used, so there are two marker signals BP.

RP will be detected.

Each marker signal RP, BP is provided by a preprocessing circuit 502.50, respectively.
3, and is preprocessed to become a marker signal faithful to the designated area. Preprocessing is a type of signal waveform shaping process, and in the embodiment, the blurring correction circuits 504 and 50
7. Noise correction circuits 505 and 508 (both in the main scanning direction) and marker breakage correction circuit 50 in the sub-scanning direction
6,509 constitute preprocessing circuits 502 and 503.

Color marker blur correction corrects blur within 16 dots/mm, and noise correction is 8 dots+/++m
Missing data within the range will be corrected.

It is also possible to remove these processes by changing the thickness of the marker.

The waveform-shaped marker signals RP and BP are supplied to the area extraction section 520 together with the color code data, and a gate signal S for extracting density data formed based on the area signal indicating the inside of the specified area a is applied to each scanning line. output every time.

These more specific configurations will be explained below.

FIG. 29 shows an example of the color marker detection circuit 501. By scanning the color marker, the color of the marker itself can be detected.

The lower 2 bits of the blue color code data are °°01
The lower two bits of the red color code data are '10'.

Therefore, as shown in the figure, the lower 1 bit data and the middle 1 bit are phase inverted by an inverter 511 and are supplied to an AND circuit 513.

Similarly, the lower 1 bit whose phase is inverted by the inverter 512 and the middle 1 bit itself are supplied to the AND circuit 514.

Then, the AND output of the vertical valid area signal V-VALID and the size signal B4 obtained from the AND circuit 515 is supplied to the AND circuit 518 together with the upper 1 bit of the color code, and the color marker is determined.

The judgment data is used as a gate signal for each AND circuit 513.
, 514.

As a result, when the color marker is blue, the blue marker signal B has a pulse width corresponding to the thickness of the outline of the marker.
P is output from terminal 516.

Similarly, when the color marker is red, the red marker signal RP is output to the other terminal 517. An example of the marker signal is shown in FIG. 27.

An example of the area extraction section 520 is shown in FIG.

The area extraction unit 520 includes first and second area extraction units 520A.
, 520B, each of which is a data storage circuit 521A.
and area calculation circuit 522A, and data storage circuit 521B.
and a region calculation circuit 522B. First and second area extraction units 520A.

520B both have a function of extracting a red marker area in addition to a function of extracting a blue marker area. For convenience of explanation, region extraction of the helmet marker will be explained.

When forming a blue area signal, the area signal of the current scanning line is calculated and formed from the area signal obtained by scanning immediately before and the marker signal obtained by scanning the current scanning line.

For this purpose, it is necessary to perform arithmetic processing using a period of at least three lines. Therefore, the first data storage circuit 521A has the function of storing the area signal, which is the final data of the immediately preceding scanning line, over one line, and also from the marker signal BP obtained by scanning this area signal and the current scanning line. The formed first and second area signals (
In reality, it is necessary to have a function to memorize the NAND output) and a function to memorize the area signal of the current scanning line obtained by roughly processing these area signals.

Furthermore, in the embodiment, the second area signal is formed by reading the memory from the reverse direction, so the number of memories required to realize these memory functions is:
There will be 16 pieces in total. Roughly speaking, it is necessary to detect the red marker, so 32 line memories are required in total.

Therefore, the first data storage circuit 521A has 8
A pair of memories 525, 5 composed of line memories
It has 26. In order to switch and use these for each line, a pair of Schmitt trigger circuits 523, 5
24, a pair of data selectors 527 and 528 and a latch circuit 529 are provided.

In addition to the blue marker signal BP, the first data storage circuit 521A has a blue marker signal BP as an input signal, as well as a blue first area calculation circuit 530.
The three signals obtained at B are provided.

In the first region calculation circuit 530B, the immediately preceding region signal QB
The region signal QB' of the blue marker on the current scanning line n is formed from the marker signal BP on the current scanning line.

For convenience of explanation, considering scanning line n shown in FIG. 27, the relationship between area signal QB (this is the area signal of scanning line (n-1)) and marker signal BP is as shown in FIG. 31B.
, as shown in C. These signals are stored in memory 525 line by line.

In the next scanning line (n+1), these signals are read out via the data selector 527 and latch circuit 529 (E in the figure).

A pair of signals QB and BP are supplied to a NAND circuit 531,
The NAND output PB1 (F in the figure) is fully supplied to the preset terminal PR of the D-type flip-flop 532, and the immediately preceding area signal QB is supplied to its clear terminal CL. the result,
A first NAND output (first contour signal) BNO as shown in G in the figure is obtained.

The first NAND output BNO and marker signal BP are stored in memory 526 sequentially. Therefore, scanning line (n+1
), the Schmitt trigger circuit 524 is controlled to be active.

A similar processing operation is also executed at the same timing in the second area extraction unit 520B. However, all of the memories provided therein are address-controlled so that they can be written in the forward direction and read in the reverse direction.

Therefore, the output timing of the marker signal BP and the immediately preceding area signal QB is wl for the n line, whereas it is (n+
1) line becomes W2 and is read out a little faster (H, I in the figure). As a result, the second NAND output BNI becomes as shown in the figure. Marker signal BP and second
The NAND output BN1 is again stored in the data storage circuit 521B.

In the next scan line (n+2), the first NAND output B
No, the marker signal BP and the second NAND output BNI are read out (L to 0 in the figure).

Here, as described above, the memory provided in the second area extracting unit 520B is capable of writing in the forward direction and reading in the reverse direction, so in this example, the first NAND output BNI and the second
Read timing of NAND output BN2 W3. W4 matches.

Both are supplied to an AND circuit 533, and the AND output AB and marker signals B and P (N, O in the figure) are supplied to an OR circuit 534, thereby producing an OR output Q as shown in P in the figure.
B' is obtained.

This OR output QB' is nothing but a signal indicating the inside of the outline of the helmet marker drawn on the current scanning line n. In other words, this OR output becomes the area signal QB' of the current scanning line.

Since the area signal QB' is used as the immediately previous area signal QB on the next scanning line, the data storage circuit 521A
, 521B is easily understood.

Thus, a pair of NAND outputs BNO obtained by reversing the memory read direction.

By using BNI, marker areas can be detected accurately.

Since the detection of the red marker is exactly the same, the area calculation circuit 5
Description of 30R will be omitted. However, 535 is a NAND circuit, 536 is a D-type flip-flop, 537 is an AND circuit, and 538 is an OR circuit.

QR'' indicates a red marker area signal.

Schmitt trigger circuits 523, 524, memory 525.
The reason why a pair of data selectors 526 and data selectors 527 and 528 are provided is to take into consideration the case where a blue marker and a red marker exist at the same time. Therefore, these lines are alternately switched and used for each line by a two-line cycle switching signal supplied to terminals A and B.

The area signals QB=, QR' obtained at the output terminals are supplied to an area determination circuit 540 shown in FIG. 32.

When specifying a marker as shown in FIG. 33A, the area determination circuit 540 performs control so that, for example, only the area of the designated red marker is recorded as a black image, as shown in FIG. 33B. It is a means.

The area determination circuit 540 includes four flip-flops 541 to
544, and front-stage flip-flops 541 and 542
The area signal QB= latched at.

QR' is supplied to the corresponding NAND circuits 545 to 549, and the region signal QB'' is latched by the flip-flops 543 and 544 at the subsequent stage, and QR' is supplied to the corresponding NAND circuit 54.
5-549. And each NAND circuit 5
45 to 549 are supplied with color code data CC indicating black via an AND circuit 554. A CLR signal indicating image processing designation is supplied to the switching circuit 553.

If we consider the signal relationship on the scanning line n shown in FIG. 33A, we will see FIGS. 34 and 35.

Figure 34 shows what kind of FF outputs, Ql, Q2 (H,
L) shows the result.

Therefore, by the signals shown in FIG. 35A-C, the first NAND circuit 545 outputs the first NAND output M1 shown in the same figure.
is obtained. Similarly, the second NAND circuit 546 obtains a second NAND output M2 shown in G in the same figure based on the input signals shown in E to F in the same figure. As a result, the first AND circuit 551 outputs a gate signal s1 related to section II+ shown in H in the figure.

Similarly, the third NAND output M3 in the figure is obtained from the input signal I- in the figure, and the fourth NAND output M4 in the figure 0 is obtained from the input signals M and N in the figure.

As a result, the second AND circuit 552 outputs the gate signal S2 (P in the figure) related to sections II and IV.

Then, in response to the input signal Q-3 in the figure, the fifth NAND circuit 549 outputs the gate signal S3 (T in the figure) corresponding to the sections I and ■.

Gate signals 81 to S3 are selected in switching circuit 553 according to a CLR signal indicating image processing designation.

Therefore, when using the blue marker, the gate signal S1 is selected, thereby allowing the area signal to be formed using the helmet marker.

Similarly, when using the red marker, gate 48
When the black-only recording mode is selected, the gate signal S3 is selected, and when both red/blue markers are used, the gate signal S1. S2. All S3 are selected. Therefore, when the two colors are red/black, Sl.

S3 is selected, and the black image inside/outside the red marker is processed and recorded. Selection of the other two colors is done in the same way.

Gate signal 81 output from switching circuit 553
-S3 are all used as area signals S.

Furthermore, whether to use the inside or outside of this region signal S is selected by a marker inside/outside designation signal supplied to the terminal 558.

Therefore, region No. 18 S is directly supplied to the gate circuit 555 and is also supplied to the gate circuit 555 via the inverter 556.
57 and when the inside of the marker is specified, the gate circuit 555 opens and the area signal S itself can be output.

On the other hand, when the outside of the marker is specified, the other gate circuit 557 is opened and the inverted No. 48 of the area signal S is output.

Other examples of area extraction processing are shown below.

This processing simply refers to the detection of a specified area and the processing of image data or colors within the specified area, so extraction, erasure, inversion, filling, and any combination of these processes of partial areas are also applicable. It can be handled using a similar way of thinking.

It is also possible to predetermine the processing content for each color marker and perform the pre-booked processing on the detected area.

Although the background color of the original is white, it may be any other color.

As the color marker, red-based colors (orange, pink) and blue-based colors are suitable.

If it is not possible to write color markers directly on the original, the same effect can be achieved by marking on a transparent sheet.

Note that the area may be specified by filling out the necessary area as shown in FIG.

The processing means 420 selects a process (extraction/erasing/filling process) according to a process designation signal specified from the outside.

FIG. 37 is an example of the means 420.

In addition to the image data that has passed through the color ghost correction means 300, this means 420 also has input terminals 651* to which the regions No. 4z S created in the region extraction means 50O correspond, respectively.
652 can be supplied.

When the document is in color, the external QI5 specifies which color image information is to be subjected to processing such as extraction and erasure.

For this purpose, first, a minus number circuit 655 is provided, to which achromatic designation data is supplied together with the color code (lower two bits). Therefore, when the achromatic designating data and the color code match, the input image data is blocked by the gate circuit 656.

No. 390 shows what kind of processing can finally be executed by specifying achromatization. Here, when the achromatic designation code is °'o o o'', no achromatic process is performed and all image information of the original is recorded as a black and white image. Depending on the designation, only the blue image will be erased, and recording processing will be performed on the other input images.

In order to perform such processing, an output P as shown in FIG. 40 is obtained from the minus number circuit 655. Figure 40 shows the output P only for some achromatic modes.
An example of the relationship between

The image data gated by the gate circuit 656 is supplied to the multiplexer 657 and converted into image data corresponding to the processing designation signal.

When °°extraction°° processing is specified as a processing specification signal, image data will be output only while this is being obtained, and in the same way, in °° erasure processing, image data will be output only during that time. When the output is completely blocked and the processing of °°filling is specified, °°1°° is used instead of the input image data.
A signal (predetermined glue, C voltage) is output as image data.

Therefore, the multiplexer 657 is supplied with 10B power in addition to image data.

For image data that has not been subjected to the conversion process corresponding to the processing designation signal, only the area roughly related to the area signal S can be extracted.

Therefore, first, a converted signal for extraction or filling is supplied to the gate circuit 661 via the NOR circuit 660, thereby controlling the output state of the area signal S.

Image data is roughly gated by gated area No. 48S. 658 is a gate circuit for that purpose.

The image data output from this gate circuit 658 becomes the final output from the means 420.

FIG. 38 shows an example of a multiplexer 657, which can be composed of a plurality of gates 663 to 665 as shown.

In the case of filling processing, the gate circuit 663 is turned on and the predetermined DC level is output as image data of °°1°°.

Since the extraction and erasing processes are opposite processing operations, the gate circuit 664 is opened so that image data is output in the case of extraction, and the opposite operation occurs in the case of erasing.

Conversion processing such as extraction and deletion is performed according to external specifications.

FIG. 41 shows an example of this conversion process # control signal generation circuit 670. A conversion process designation signal is supplied to terminals a and b, which is decoded by a decoder 671 and converted into three signals. , its output is the AND circuit 672
.about.674 so that conversion processing control signals (extraction, erasure, filling) can be obtained only for the necessary areas.

An example of the decoder 671 is shown in FIG. For example, when the conversion processing designation signal is 'o o', the outputs C1d and e of the decoder 671 become 100°, which causes only the AND circuit 672 to be in an open state.This is the conversion process for extracting image data. It becomes a control signal.

The signals obtained by each AND circuit 672-674 are supplied to the corresponding terminals in FIG. 37.

The image data for which conversion processing such as extraction and erasure has been completed is then supplied to the scaling means (enlarging/reducing means) 1, where scaling processing is executed according to the specified magnification.

In this example, 0.5x to 2. O11! 1 up to t
．． This is a case where the image can be enlarged or reduced in 0% increments.

Here, also in this invention, in principle, the enlargement process increases the image data, and the reduction process is an interpolation process that thins out the image data. The enlargement/reduction processing in the main scanning direction shown in FIG. While the exposure time of the element is kept constant, the movement speed of the photoelectric conversion element or the sub-scanning direction is changed.

Slowing down the movement speed in the sub-scanning direction enlarges the original image,
If you speed it up, it will shrink.

An example of an enlarged/reduced image is shown in FIG.

FIG. 45 shows a specific example of the enlargement/reduction circuit 1.

In the same figure, the timing (number i generation time #i10 is for obtaining a timing signal etc. that controls the processing timing of the entire enlargement/reduction circuit 2, and this includes the CCD
Similarly to 104.105, the synchronous clock CLK
I, horizontal valid area signal H-VALID, vertical valid area signal V
-VALID and horizontal synchronization signal H-SYNC are supplied.

The timing signal generation circuit 10 first outputs a synchronization clock CLK2 that is output only during the period of the horizontal valid area signal H-VALID. This is the same frequency as the synchronization clock CLKI.

In general, memory control signals lN5EL and 0UTSEL are output to the memories provided in input buffer 400 and output buffer 350, respectively.

Image data D having 64 gradation levels is input to the input buffer 4.
00.

Input buffer 400 is provided based on the following reasons.

Firstly, since the number of image data used during enlargement processing increases compared to before processing, it is possible to effectively increase the processing speed after data increase without increasing the frequency of the basic clock. This is to do so.

Second, this is to ensure that an enlarged image during enlargement processing is recorded with the center as a reference.

Therefore, in order to satisfy the first condition during the enlargement process, the read clock RDC that can be fully supplied to this manual buffer 400 is
The frequency of L is lowered than the normal frequency. Then, in order to satisfy the second condition, the read start address is set according to the magnification. The details will be described later.

Image data D output according to the specified magnification/reduction ratio
are supplied to two cascade-connected latch circuits 11 and 12, and image data DI of two adjacent pixels of the image data D is outputted with 6-bit configuration, thus having a halftone level.

DO is latched at the timing of latch clock DLCK. The latch clock DLCK is the synchronous clock CLKI
It has the same frequency as .

Image data Do latched by latch circuits 11 and 12,
Di is a memory for interpolation data (ROM is used, hereinafter referred to as interpolation R)
It can be used as address data for 13 (referred to as OM).

The interpolation ROM 13 is an interpolation data table in which image data having a new halftone level referenced from two adjacent image data (hereinafter, this image data will be referred to as interpolation data SS) is stored.

As address data of the interpolation ROM 13, in addition to the above-mentioned pair of latch data Do and DI, interpolation selection data S
D is used.

700 is an interpolation data selection means that stores interpolation selection data SD and the like. As will be described in detail later, the interpolation selection data SD is used as address data for determining which data is to be used as interpolation data from among the data table group selected by the pair of latch data Do and DI.

The interpolation selection data SD is determined by the set magnification for enlargement/reduction, as will be described later.

FIG. 46 shows an example of interpolation data SS selected by latch data Do, DI and interpolation selection data SD. In the embodiment, interpolated data is obtained by linearly interpolating Do and DI data.

In FIG. 46, SS is interpolated data (6 bits) output with 64 gradation levels, and since the image data Do and DI used as latch data each have 64 gradation levels, they are used as interpolated data SS. is 64X
64=4096 different data blocks are included.

The figure shows the theoretical values (5 decimal places) obtained by linear interpolation at each step when DO=0, D1=F, and the actually stored interpolation data SS values for positive slope and negative slope. The case is shown below.

Then, the interpolated data SS output from the interpolation ROM 13 is latched by the latch circuit 14, and then outputted from the output puff 7'3.
50. The output buffer 350 is provided to process invalid data caused by a reduction in image data during image reduction. Roughly, when reducing the image,
This is to enable the reduced image to be recorded with the center of the recording paper P as a reference.

The final 6-bit data obtained from output buffer 350 is sent to MTF correction circuit 450.

FIG. 47 shows an example of the input buffer 400.

The input buffer 400 includes a pair of line memories 401.4.
02 are provided, and one line of image data D is supplied to each. The reason for providing the pair of line memories 401 and 402 is to alternately supply one line of image data so that writing and reading of image data can be processed in real time.

Line memories 401 and 402 have a capacity of 4096×8 bits. This capacity increases the resolution to 16
This is the value when the dots/mm is set and the maximum original size is 84 plates (the length of the paddle is 256 mm).

When writing data to the line memory, the write clock CL K2 is used, and when reading data, the read clock RDCLK is used. Supplied to counters 405 and 406'
be done.

The read clock RDCLK is set to a frequency different from the normal frequency when specifying the enlargement magnification. The frequency to be set differs depending on the specified magnification.

The first and second switches 403 and 404 are controlled in a complementary manner so that when one line memory is in the write mode, the other line memory is in the read mode. The switch control signal for this purpose is the control signal l generated by the timing signal generation circuit 10.
N5EL is used.

In this case, one of the signals can be completely supplied after being phase-inverted by the inverter 409. The control signal IH3EL is a rectangular wave signal whose period is two horizontal periods (see FIG. 63).

Here, even when enlarging an image, the enlarged image is
Since recording is performed with the center of the image as a reference, the writing start timing can be controlled according to the enlargement magnification during enlargement processing. Therefore, the clock CL K2 is output from the clock output control circuit 41, which is composed of a gate circuit, etc.
0 to the first and second switches 403, 404.

The control circuit 410 is supplied with preset data Po for controlling the write start timing.

This control circuit 410 is configured to count the clock CLK2 and output the clock CLK2 when its value matches the preset data PO. This limits the amount of data written to the input buffer 400, a detailed explanation of which will be given later.

The output from the line memories 401 and 402 is selected by the third switch 407, and then the latch circuit 11
is supplied to The above-mentioned control signal I) ISEL is used as the switching signal.

FIG. 48 shows an example of the output buffer 350.

Its configuration is almost the same as the input buffer 400, but the line memories 351 and 352 are 4096 x 8 bits in size because image data after enlargement/reduction is stored.

Further, 353, 354, and 357 are first to third switches, 355 and 356 are address counters, and 359 is an inverter.

The control signal for switch selection is the signal 0UTSEL (63rd signal) generated by the timing signal generation circuit 10.
(see figure) is used.

The frequency of the clock L CK2 is changed only when the reduction magnification is specified. Clock PCLK is an output bag! 70 synchronous clocks.

Address counters 355 and 356 are supplied with addressing data for setting their initial addresses. Therefore, as shown in the figure, the write start address data and the read start address data are sent to the respective counters 355.3 via the fourth and fifth switches 361, 382.
56.

In this case, the switch control signal 0UTSEL is controlled so that the write start address data and the read start address data can be supplied alternately for each line. The read start address is always designated as the O address, and the write start address is automatically changed according to the magnification so that the reduced image can always be recorded with the center as a reference. Details will be described later.

Both the write start address data and the read start address data can be supplied from a system control circuit (not shown).

Here, the processing operations of the input buffer 400 and the output buffer 350 will be explained with reference to FIGS. 49 to 51.

FIG. 49 shows the processing operation at the same magnification, and the frequency of the read clock RDCLK supplied to the input buffer 400 with respect to the synchronous clock CLKI in A of the same figure is the same as the frequency of the synchronous clock CLKI (B ). As a result, image data D shown in FIG.

As a result, interpolated data SS as shown in the figure is obtained.

This interpolated data SS is finally sent to the output buffer 350.
is supplied to and temporarily stored.

In this case, the frequency of the write clock LCK2 supplied to the output buffer 350 is the same as the frequency of the synchronous clock CLKI.

On the other hand, FIG. 50 shows the processing operation when the magnification is set to 2 times.

When the magnification is set to 1x or higher, the input buffer 40
Only the frequency of the read clock RDCLK to 0 is changed according to the set magnification.

When the magnification is set to 2, the frequency of the read clock RDCL supplied to the input buffer 400 is reduced to 1/2 with respect to the synchronous clock CLKI in A of the same figure (B of the same figure). As a result, image data D shown in FIG.
It is supplied as address data of OM13. As a result, one piece of interpolated data SS is obtained for one cycle of the synchronous clock CLKI as shown in the figure. This interpolated data SS is supplied to the output buffer 350 and temporarily stored.

In this case, the frequency of the write clock LCK2 supplied to the output buffer 350 is the same as the frequency of the synchronous clock CLKI (see E in the figure).

In this way, even if a magnification of 1x or more is selected, the enlargement process is performed by lowering the frequency of the read clock RDCLK, so all clocks other than the clock RDCLK supplied to the input buffer 400 remain as the basic clocks. Processing operations can be executed.

Therefore, as the enlargement/reduction circuit 1, it is not necessary to use circuit elements with high operating speed.

Of course, even if the input buffer 400 can be used, its clock frequency is lower than the clock frequency at the same magnification, so
All circuit elements do not need to operate at high speed.

At the time of reduction, for example, when reducing an image by 0.5 times, the read clock RDCLK to the input buffer 400 is supplied to the output buffer 350 instead of being the same as the synchronous clock CLKI, as shown in FIG. The frequency of the write clock LCK2 is reduced to 1/2. As a result, the writing timing of the interpolated data SS becomes once every two cycles, so that excess image data is thinned out and stored in the output buffer 350.

Note that details of the enlargement/reduction processing operation will be described later.

The interpolated data selection means 700 shown in FIG. 45 is composed of a data selection signal write circuit 710 and a data selection memory 720. Data selection signal write circuit 7
10 includes interpolation selection data SD determined by the magnification and a processing timing signal TD for controlling such that the interpolation selection data SD is output at a timing corresponding to the magnification.
are stored in each block.

Since the interpolation selection data SD has a large capacity, a large capacity ROM is used for its write circuit 710. In this case, a dedicated ROM can be used, but the ROM for the control program included in the system control circuit
M may also be used.

The data selection memory 720 stores data SD and T according to the magnification designation among the interpolation selection data SD1 processing timing signal TD stored in the interpolation selection data writing circuit 710.
Used to write D.

Therefore, the interpolation selection data SD during actual image processing
The interpolation selection data written in this data selection memory 720 is used.

For this reason, as the data selection memory 720, a static RAM or the like that can be written and read at high speed is used.

The magnification designation data and the magnification set pulse DS are each supplied to the write circuit '#1710.

On the other hand, interpolation selection data SD to data selection memory 720
, when writing the processing timing signal TD, the write circuit 7
The clock 5ETCLK on the 10 side is used. Therefore, as shown in FIG. 45, a clock selection circuit 730 is provided on the data selection memory 720 side, and the synchronous clock CL K2 and the write clock 5ETCLK from the write circuit 710 are selected.

The selected clock is counted by a counter 740,
The output is used as address data in the data selection memory 72.
0 to 12-bit address terminals AO to All.

Here, the counter 740 is configured to generate a carry pulse when counting 4,096 clocks (therefore, 4,096,096 pixel counters).

The carry pulse is the transfer end signal (write end signal) C3
(Figure 53B).

FIG. 52 shows an example of the write circuit 710.

In the figure, 711 is a data ROM, which stores interpolation selection data SD and processing timing signal TD as shown in FIGS. 54 and 55.

Here, prior to image reading, interpolation selection data SD etc. stored in the write circuit 710 are data set based on a data set pulse (magnification set pulse) DS (FIG. 53A) after a magnification is specified from outside. ROM71
1 data is transferred to data selection memory 720.

The data set pulse DS is supplied to a control circuit 712 shown in FIG. 52 to generate a write enable control signal ES shown in FIG. 53C.

The control signal ES is completely supplied to the counter 713,
Clock 5ET from oscillation circuit 714 supplied to this
CLK count state is controlled (Figure 53, E)
). Control signal ES is °0゛.

During the period, the interpolation selection data SD corresponding to the addresses AO to 6 by the counter 713 and the addresses A7 to A13 by the specified magnification, and the processing timing signal TD are repeated in block units (Figures 54 and 55 - dot-dashed line area). Thus, 4096 pieces of data corresponding to one line are written into the data selection memory.

Here, when the magnification is 160% as shown in FIG.
00 pixels worth of data) will be repeated.

Furthermore, since the data ROM 711 has a slow access time, it is read out using a clock having a lower frequency than the normal reading speed. The write timing is synchronized with data transfer lock 5ETCLK.

Note that the buffer circuit 715 receives the signal from the data ROM 711 in the image reading state from the data selection memory 7.
20 and the synchronization circuit 750 side to be described later, and the control signal ES is set to O'.

It is active only during the period of .

The control signal ES is also applied to the data selection memory 720.
It is also used as an enable signal for writing to (see FIG. 45).

When writing of the data (4096 pieces of data) to the data selection memory 720 is completed, a transfer end signal C8 is output from the counter 740, thereby ending the data writing period (see FIG. 53).

Thereafter, the normal image processing mode is entered, and the interpolation selection data SD and processing timing signal T are stored in the data selection memory 720.
D is read out and supplied to the synchronization circuit 750 at the subsequent stage.

The counter 713 is cleared by a clear signal CLR (F in the figure), but this clearing timing differs depending on the magnification.

Note that when the reduction magnification is used, the image becomes as shown in H in FIG. 53. G and H in the same figure are counter 7 when the magnification is 80%.
13 shows the relationship between the address data No. 13 and the clear signal CLR supplied thereto.

The processing timing signal TD is the interpolated data S as described above.
It is selected as °°1°° when S exists, and as °°0°° when it does not exist or when data is to be thinned out.

FIG. 56 shows an example of the synchronization circuit 750 in FIG. 45.

The synchronous circuit 750 includes a plurality of latch circuits 7 as shown in the figure.
51 to 755 and a plurality of AND gates 361 to 364, and the interpolation selection data SD is sent to the latch circuit 751.7.
52 and 755 in sequence.

On the other hand, data of bit 1 of the processing timing signal TD can be latched sequentially by latch circuits 751 to 754. On the other hand, the data of bit O is stored in latch circuits 751 and 752.
It is latched with.

The synchronous clock CLK2 is applied to the latch circuits 751 to 754, and the remaining latch circuits 755 and AND gates 761 to 7
64 is supplied with a phase-inverted synchronization clock CLK2 as a latch clock.

On the other hand, the latched processing timing signal TD is supplied to the plurality of AND gates 761 to 764. The output of the AND gate 761 is supplied as the read clock RDCLK of the input buffer 400, and the output of the AND gate 762 is supplied as the latch clock DLCK of the latch circuits 11 and 12.

Similarly, the output of the AND gate 764 is sent to the output buffer 35.
It is supplied as the write clock LCK2 of 0, and the output of the AND gate 763 is supplied as the latch clock LCKI of the latch circuit 14.

Here, when the processing timing signal TD is °°1°, the AND gates 761 to 764 are open, and when the processing timing signal TD is °°0°, they are closed.

By configuring the synchronization circuit 750 in this way, it is possible to generate read and write clocks having a frequency according to the specified magnification. A specific example will be explained below.

FIG. 57 shows a timing chart when a magnification of 160% is selected.

First, as shown in FIG. 59, 4 bits of the data output from the data selection memory 720 are interpolation selection data SD, and of the remaining 4 bits, bit O is the read clock for the input buffer 400. R.D.
CLK and is used as data for the latch clock DLCK for the latch circuits 11 and 12.

Further, bit 1 is used as a write clock LCK2 to the output buffer 350 and a latch clock LCKI to the latch circuit 14. . Bit 2 is data ROM
It can be used as a repeat signal to the counter 711 and a clear signal CLR to the counter 714. . Bit 3 is an unused bit in this example.

When the magnification is 160%, the interpolation selection data SD shown in FIG. 57B is output from the data selection memory 720, and the data shown in FIG. Output.

Both B and C in the same figure show interpolation selection data SD.
C shows the timing before latching by the latch circuit 751, and C shows the timing after latching.

Therefore, the latch circuit 752 at the next stage outputs each signal delayed by one cycle as shown in F to H in the figure. Since the interpolation selection data SD is roughly latched by the latch circuit 755, it is delayed by roughly one cycle, so the result is as shown in FIG. The interpolation selection data SD shown in FIG. 1I is supplied to the interpolation ROM 13 as address data.

The AND gates 761 and 762 are supplied with the processing timing No. 48 TD of bit O shown in G in the same figure, so if these are ANDed with the synchronization clock CLK2 of the opposite phase, the result is shown in J and K in the same figure. Read clock RDCLK
and latch clock DLCK are obtained.

In addition, since the processing timing signal TD of bit 1 is latched in the latch circuits 753 and 754 (M in the figure), the signal from the AND gates 763 and 764 is N in the figure.
, lock as shown in O and CK1. LCK2 is output. These clocks LCKl, LCK2Lt
Although the clocks have opposite phases to each other, their frequency is the same as that of the synchronous clock CLKI.

In this manner, when the enlargement factor is selected, only the frequency of the read clock RDCLK supplied to the input buffer 400 can be changed.

FIG. 58 is a timing chart when reducing the size to 80%.

In this case, the data selection memory 720 outputs the interpolation selection data SD shown in FIG. 3B, and the data shown in FIG.

Readout clock R supplied to the cover sofa 400
DCLK and the latch clock DLC to the latch circuits 11 and 12 are as shown in FIG. That is, these frequencies do not change.

On the other hand, since the latch ([f753, 754 in the same figure) outputs the latch clock shown in H, the AND gate 763 outputs the latch clock LCKI shown in N in the same figure.
will be obtained. And the other AND gate 7
From 64, a write a block LCK2 shown in O in the same figure is obtained.

In this way, when reducing an image, only the frequency of writing to the output buffer 350 can be changed according to the set magnification.

As mentioned at the beginning, in order to record an enlarged/reduced image based on the center stand of the recording paper P, it is necessary to control the write start timing of the input buffer 400 or the read start timing of the output buffer 350. Bye. The reason for this will be explained next.

As mentioned above, the maximum image reading size of the CCDs 104 and 105 is 84 format, and the resolution is 16 dots/
If it is assumed to be am, the memory capacity for one line is 4096 bits. Therefore, line memory 401.
402 and 351.352 need only have a capacity of 4096 bits.

At the same magnification, line data with a capacity of 4096 bits is supplied as is to the output buffer 350 side, and then sent to the output device 7.
It will be supplied to 0.

On the other hand, when enlarging an image, the amount of image data in the input buffer 400 increases according to the magnification, and the increased image data can be supplied to the output buffer 350.
If left as is, the image data will overflow, making it impossible to store all the necessary image data in the output buffer 350, and also making it impossible to record the image with the center as the reference.

When the original image is enlarged twice, the amount of image data becomes twice the original image data due to interpolation processing. , Therefore, the amount of data written to the input buffer 400 is limited to 1/2 in advance.

On the other hand, the 2048th bit of the image data corresponds to 1/2 of the capacity (4096 bits) of an effective horizontal line (effective length) in 84 format, and corresponds exactly to the center a of the recorded image.

For this reason, a total of 2048 bits from the 1024th bit to the 3072nd bit of the input image data are stored in the input buffer 400 as shown in FIG. 60A.
By writing sequentially from the address, even if the amount of data is doubled by interpolation processing, all of the image data can be written to the output buffer 350 (FIG. 3B).

In this case, as shown in FIG. 60B, the image data after interpolation processing is data that has been enlarged around the center Ω of the image, so there may be cases where a part of the image that is needed is missing and cannot be recorded. Never.

Therefore, when enlarging, if the write start address of the input buffer 400 is controlled according to the set magnification, it is possible to record the image on the recording paper P with the center of the image as the center, as shown in Fig. 61. can.

Therefore, the preset data Po for enlargement is set as follows.

Preset data P.

” (4096x magnification magnification - 4096) / 2
FIG. 61C shows an example of recording at the same magnification.

During the reduction process, as shown in FIG. 60C, the input buffer 4
Writing and reading data to 00 is the same as when the data is at the same magnification, and data is written from the O address and read from the O address.

Then, when the image is reduced by 0.5 times, the image data for one line is reduced to 1/2 by interpolation processing,
This image data is written to output buffer 350.

If the read image data is written as is to the output buffer 350, the image data will be written from the O address of the output buffer 350 as shown in Figure E, and the image data from this O address will be recorded. paper P
Since the images will be recorded sequentially from one side of the
4. If it is done as shown in Figure A, it will not be recorded.

To avoid this, the write start address should be set to the 1024th address (D in the figure).

Then, if the read start address is set to 0 address, empty data (corresponding to white) is recorded up to the 1024th bit, so the recorded image will be the 61st bit.
As shown in FIG. A, the reduced image is completely recorded around the center a of the recording paper P. The read start address is set by preset data Po.

Therefore, the write start address of the output buffer 350 is set as follows: Write start address=(409B-4096X reduction magnification)/2.

For this reason, if the write start timing (preset data Po) of the input buffer 400 and the write start address of the output buffer 350 are appropriately selected according to the enlargement/reduction magnification, a line memory with a capacity of one line can be created. It is also possible to realize central reference recording processing.

FIG. 62 shows an example of setting the write start address data and preset data Po.

FIG. 63 shows an example of the processing operation described above.

As shown in D-G in the same figure, both the preset data P0 and the write start address are
Set in synchronization with YNC.

The write and read timing for the input buffer 400 is shown in E in the same figure. Similarly, output buffer 35
The write and read timing for 0 is shown in Figure F,
Shown in G.

As described above, the control signals 1N5EL and 0UTSEL are rectangular wave signals whose period is two horizontal periods.

A timing chart of signals in each part during interpolation processing is shown in FIG. 64.

The original image data obtained from CCD104.105 is converted into Do(0), DI(F), D2(F)
, D3(0), D4(0) (the gradation level of each image data is shown in parentheses).

When the read clock RDCLK is supplied to the input buffer 400, image data D is output after access time tl (64th mA, B), and this is the latch clock D.
It is latched by LCK (C in the same figure).

Dl(F) from the latch circuit 11 in synchronization with the latch clock.
) is output, the latch circuit 12 outputs D O
(0) is output (E in the same figure).

Note that the latch clock DLCK is the synchronous clock CLKI.
It is only one cycle behind.

On the other hand, according to the magnification signal set externally, the interpolation selection data SD is O;28i10i38;... (64th
Figure F) can be output.

As a result, from the interpolation ROM 13, image data DO, D
The interpolation data table is referred to by I and the interpolation selection data SD, and the necessary interpolation data SS (G in the figure) can be output. Therefore, the interpolated data SS are 0 (So), 9 (S+), F (S2)
, F (S3).

8 (S4), 0 (Ss), etc.

The read interpolation data SS is sequentially sent to the latch circuit 14 (H and I in the figure). Binarized interpolated data SS
is the output buffer 35 by the write clock LCK2.
0 (J in the same figure).

K).

In FIG. 64, t2 is the access time of the interpolation ROM 13, and t3 is the access time of the output buffer 350.

Next, the reduction process will be explained. FIG. 65 shows a timing chart of signals when the reduction rate is 80%.

It is assumed that the gradation level of the image data is the same as in the case of the enlargement process described above.

Then, two adjacent image data (for example, image data DI, Do) are supplied from the latch circuits 11 and 12 as address signals to the interpolation ROM 13, and the externally set reduction magnification (80%) is used for data selection signal writing. The fact that the circuit 710 can be fully supplied is the same as in the case of the enlargement processing described above.

In the case of reduction processing, both the read clock RDCLK and the latch clock DLCK have the same frequency as the synchronization clock CLK1, and are transferred from the input buffer 400 to the interpolation ROM 13.
The relationship between the signals up to this point is as shown in FIGS. 65A to 65F.

On the other hand, since the latch clock LCKI is as shown in G in the figure, the latch output becomes as shown in H in the figure.

Here, the write clock LCK2 is also the latch clock L.
Since the frequency is the same as that of CKI, data as shown in FIG. 1 will be written to the output buffer 350.

In the embodiment described above, if the magnification of enlargement or reduction is changed, the interpolation selection data SD output from the selection memory 720 for interpolation data changes, and the interpolation ROM 13 is addressed accordingly to read the corresponding interpolation data SS. It is clear that this will be output.

Incidentally, in the above description, the invention is applied to an image processing apparatus that reads an image based on the center of the document and records the image based on the center of the recording paper, but the present invention can also be applied to other image processing apparatuses. can do.

First, when both image reading and image recording are processed based on one side of the original (recording paper),
Image reading start position of CCD 104, 105 and recording start position (light scanning start position, for laser printers,
Since the recording beam start position of the laser beam is the same, the present invention can be applied without any problems.

Second, in an image processing apparatus of the type in which image reading is performed based on the center line of the document and image recording is processed based on one side of the recording paper, the readout start address of the input buffer 400 is as follows. become.

In this case, the preset data Po of the output buffer 350
is always O. On the other hand, the read start address cannot be determined only by the magnification signal. It varies depending on the size of the manuscript.

Therefore, in this type of image processing apparatus, the readout start address is determined from the specified magnification indicating the document size.

As shown in FIG. 66, the case where the size of the document 52 to be read is A4 size will be described below.

As mentioned above, when it is 16dots/+u+,
The number of bits for the composition width of A4 size is 210 mm x 16 ots/mm = 3360 pits, so if the maximum read document size is 84 size, the value obtained by multiplying the width Y in Fig. 66 by the magnification is the input value. This is the read start address for the buffer 400.

Therefore, the read start address is (4096-3300)/2=3G8 bits.

FIG. 68 shows the values of the write start address and preset data Po at any magnification.

However, the original size is A4.

The reason why the write start address and preset data Po are constant regardless of the magnification is because the image is recorded with one side as the reference.

Third, in an image processing apparatus of the type in which image reading is performed with one side as a reference and image recording is performed with reference to the center line q of the recording paper, as shown in FIG. The preset data Po and the write start address of the output buffer 350 are determined as follows.

That is, in the case of 4098>3360X magnification, write start address address is set, and in the opposite case, preset data Po is set.

Therefore, when 4096>3360X magnification, the write start address is: Write start address=(4096-3360X magnification)/2 At this time, preset data Po of the input buffer 400 is set to O.

On the other hand, when 4096<3360X magnification, preset data Po is preset data P.

= (336o-4096/magnification)/2. The write start address of the output buffer 350 at this time is O.

As a result, the write start address and preset data PO at any magnification have values as shown in FIG. 69.

In this way, the writing start address or preset data Po can be changed depending on the document reading or writing criteria.

The image data for which the enlargement/reduction processing has been completed is then supplied to resolution correction means 450, where resolution (MTF) correction is performed.

Since MTF correction is contour correction, if only this contour is left and the data inside it is erased, a hollow image will be obtained.

In this invention, even a hollow image can be recorded as a clear image.

Resolution correction is processed after color separation. First, this will be explained.

Conventionally, as described above, since the processing step is generally to perform color separation after binarizing image data, it has been necessary to perform resolution correction before the binarizing process. Therefore, in a device that uses a plurality of CCDs to capture color-separated images of a document, resolution correction must be performed in response to each COD output. In other words, it was necessary to prepare multiple circuits for resolution.

Moreover, since the MTF of the optical lens differs for each of the plurality of color separations, there is also a drawback that the parameters for MTF correction differ depending on the respective resolution correction circuits.

If resolution correction processing is performed after color separation and before multivalue processing as in this invention, since only one piece of information is handled, practical applications such as reduction of circuit scale and simplification of determination of correction parameters can be achieved. This will have the above advantages.

In general, the causes of MTF deterioration until an image is recorded and reproduced include problems in 1. the optical system 2, the optical travel system 3, the processing circuit 4, and the recording system, as shown below.

Regarding 1, the MTF of the lens (wavelength range, change with image height, permissible width of image forming position, processing accuracy), accuracy of prism surface 1, accuracy of COD mounting, warpage of CCD chip, spectrum fluctuation of light source This is because the performance of the optical system fluctuates due to such factors.

In the optical travel system (2), vibrations of optical mirrors and fluctuations in moving speed can be cited.

Regarding the processing circuit No. 3, there is distortion of the signal waveform due to capacitance components in the analog circuit, especially signal distortion caused by passing through a transmission line or the like.

The following points can be enumerated as the recording system problems mentioned in item 4.

・Beam diameter and beam shape of the laser beam ・Toner development characteristics on the photoreceptor drum (toner adhesion amount, toner concentration, toner particle size, toner color, etc.) ・Transfer characteristics (transfer rate, transfer characteristics to transfer paper, etc.)・Fixing characteristics (changes in toner diameter before and after toner fixation, etc.) Among these factors,! The optical system and its traveling system do not directly affect the deterioration of the 4-degree image.

FIG. 70 shows MTF values (before correction) in the main scanning direction and the sub-scanning direction when the optical system is driven. This characteristic is 2 to 16
These are measured values when scanning a black and white pattern with a spatial frequency up to dots/am.

The MTF in this case was defined and used as MTF=(W−BK)/(W×BK)(%). Here, W is a white signal and BK is a black signal.

As is clear from FIG. 70, the deterioration of MTF is more remarkable in the sub-scanning direction. In order to correct to the same extent, the amount of correction in the sub-scanning direction may be set to 2 to 4 times that in the main scanning direction. It is said that an MTF value of 30% or more is required to improve the reproducibility of fine line portions of images.

Therefore, when the resolution correction means is configured by adding weights to the pixel of interest and its surrounding pixels, the above-mentioned main and sub-scanning directions are corrected to the same degree, and the reproducibility of fine line parts is not deteriorated. In this case, a convolution filter using image data of 3×3 pixels may be employed as the resolution correction means.

If we write the filter elements on the left and the corresponding pixel positions (i, j) on the right, we get the following.

Focusing on the density I (ij) of the pixel (i, j), eight pixels around it are focused. At this time, (1-11J-1
)~(i+1.j+1), set the new concentration value to I(i
j)', I (ij)'=HI (f+Δ, j+Δ)X C(f
+Δ, j+Δ) Here, C(ij) is a filter coefficient, and C(ij)=a, blc, . . . i.

An example of filter coefficients for realizing the above-mentioned correction contents is shown below.

When it is desired to increase the amount of correction, the filter coefficients may be appropriately set accordingly.

FIG. 71 shows the correction results by the convolution filter using the correction coefficients in the above equation.

FIG. 72 is a circuit diagram showing an example of a resolution correction means 450 using this convolution filter.

Due to the use of a 3x3 matrix, 2 line memories 451 and 452 and 7 latch times @ $ 453~
457 is used up, and in the first adder 470, 1 row 2
An addition process is performed on the image data in the column and the third row and third column, and then a multiplication process by a predetermined coefficient is performed in a multiplier (bit shift circuit) 471.

The second adder 473 performs addition of the image data in the 2nd row, 1st column and the 2nd row, 2nd column, and then a multiplier 476 performs multiplication by a predetermined coefficient. This multiplication output and the multiplication output from the multiplier 471 can be multiplied by the adder 474.

Further, the image data of the second row and second column is supplied to the multiplier 472 configured with a 3-bit shift circuit to complete the multiplication process, and this and the addition output from the adder 474 are sent to the subtracter 47.
5, subtraction processing is performed.

Thereafter, the level is reduced to 1/2 by a divider 477 and normalized.

Modifications of the resolution correction means 450 are listed below.

A ROM or the like may be used instead of multiplication or addition/subtraction processing.

Resolution correction is performed after color ghost processing, but
The processing position does not matter as long as it is after color separation and before multivalue processing.

The line memory may be configured so that the line memory that can be used for color ghost correction is commonly used.

The power of the laser beam for image recording may be controlled simultaneously with the resolution correction. This improves the reproducibility, especially in fine line portions.

By the way, a control signal for hollowing is supplied to the terminal 478, and when this is supplied, each coefficient of the multipliers 471, 472 and 476, and the divider 477 is changed.

By changing the coefficients, only the changing points (only the contour parts) of the image can be detected. Therefore, when this MTF correction output is copied, an image is recorded in a hollow state.

To obtain a hollow image, the detection filter coefficients are convolved with 3×3 edges.

In other words, the image data Iij' at the time of hollow processing is as follows: I(ij)'=HI(i+Δ, j+Δ)XC(i+Δ
r J"Δ) The edge detection filter is configured to be able to perform stronger detection in the sub-scanning direction, as described above with respect to MTF correction.

However, if you make it too strong, noise components will also be detected, so you need to be careful.

For example, if detection is performed on a level signal that is higher than the unevenness of the background level, it will be difficult to detect at least the unevenness of the background, and good results can be obtained.

On the other hand, if the hollow processing is performed as is, the amount of change will be small, and unless the threshold value for multilevel conversion is set to a low value, data will be skipped and that portion will not be recorded. Therefore, for hollow data, it is necessary to select a value that simultaneously lowers the threshold value for multilevel conversion.

As is clear from the filter coefficients mentioned above, the reason why the filter coefficients in the main scanning direction and the sub-scanning direction are different, and the correction is applied more strongly in the sub-scanning direction than in the main scanning direction is as follows. Based on reason.

That is, if the same correction is applied in both the main and sub-scanning directions, it will not be possible to sufficiently reproduce, for example, a thin horizontal line with a hollow part.

This is because the contour in the sub-scanning direction has a waveform that is more rounded than in the main scanning direction, and even if the contour in this direction is slightly corrected, it will not be possible to correctly reproduce the horizontal line.

Furthermore, if strong correction is applied to each of the main and sub-scanning directions, noise present in the main-scanning direction is likely to be picked up, resulting in deterioration of image quality.

Therefore, in the present invention, as described above, filter coefficients in the main and sub-scanning directions can be set independently.

In addition to this, the correction is made more strongly in the sub-scanning direction than in the main scanning direction.

By doing so, the reproducibility of horizontal lines is improved, thereby making it possible to obtain a high-quality hollow image.

As mentioned above, MTF correction and hollow processing basically differ only in the correction coefficient, so they can be configured as shown in Figure 72, or they can be configured as independent circuits as shown in Figure 73. , it is also possible to have a configuration in which these are selected as appropriate.

In FIG. 73, 780 indicates hollowing means, the outputs of which are selected by gate circuits 781 and 782. Therefore, the region signal S is supplied to the gate circuit 781 via the inverter 783, and the inverted region signal S and the hollow designation signal are supplied to the AND circuit 784, and the AND output is supplied as the gate signal to the other gate circuit 782. Supplied as.

Therefore, when the area signal S as shown in FIG. 74 is obtained, the other gate circuit 782 is turned on in the processing section, and only the image data subjected to the hollow processing is output.

Next, shading will be explained.

A specific example of the shading will be described later, but this shading means 44
0 is configured as shown in FIG.

The shading means 440 has a pattern ROM 441 for shading, and by referring to the column address and row address thereof, the data for necessary shading processing is read out.

Therefore, a column counter 442 and a row counter 443 are provided, and the column address of the ROM 441 is specified by the counter output incremented by the line signal SH, and the row address of the ROM 441 is specified by the counter output incremented by the clock GK synchronized with 1 bell. Address is specified.

The mesh pattern data obtained by addressing is calculated with image data in an arithmetic circuit 444. The image data after processing will be shaded data.

The calculation is (63-
Image data)+(63-image data)=A, and 63-A=B The value is used as the image data after the arithmetic processing.

When the calculation result is a negative value, it is clamped to 0.

The arithmetic circuit 444 may be implemented using a ROM or the like.

In this case, if the pattern is created using a 4 x 4 matrix, the input is 6 bits for 16 values (4 bits), so 6 bits of data can be stored in a 10 bit (1024 address) address. An 8-bit ROMIK is sufficient.

Output image data for halftone shading and normal image data are selected by gate circuits 445 and 446, respectively.

Therefore, the area signal S is fully supplied to the gate circuit 445 via the inverter 447, and the inverted area signal and the shading designation signal are supplied to the AND circuit 448, and the gate circuit 446 is controlled by its output.

As a result, as shown in FIG. 76, when a shading designation signal is obtained, the other gate circuit 446 is opened during that designated area, and image data for shading is selectively output. A shaded image will be recorded.

Note that the repetition of addressing to the ROM 441 can be determined by the repetition period of the network pattern.

In this example, a 4×4 network pattern as shown in FIG. 77 is used, so the corresponding address designation is repeated. Therefore, the counters 442 and 443 are also quaternary counters.

FIG. 78 shows waveforms of original image data and pattern data before halftone processing, and an example of the output image at that time.

When this is shaded, it becomes as shown in FIG. 79.

The mesh pattern is not limited to the example shown in FIG.
It is also possible to prepare a plurality of ROMs and select one of them.

Next, the inversion processing means 460 will be explained with reference to FIG.

The inversion operation is performed by subtracting data as it is necessary to perform multi-value recording.

If we take four-value recording (generally even-value recording) as an example of multi-value recording, 2 bits is sufficient. Therefore, 00 white 11 black 01 r
4 ash inversion 10 111 ash 10 dark ash →
01 Light gray 11 Black 00 White, but in ternary recording (generally odd value recording), if the pits are inverted after multi-value recording, 00 White 11
Black 01 Gray Inverted 10 (?) 11
Black → 00 becomes white, making it difficult to process gray data. Therefore, in the example, even value recording is illustrated.

As shown in FIG. 80, a subtracter 461 is provided, and inversion processing is performed by this subtraction processing.

Through this inversion process, an inverted image as shown in FIG. 82 is obtained.

To select normal image data or inverted image data,
A pair of gate circuits 462 and 463 are provided, and a region signal S inverted by an inverter 464 causes the gate circuit 4 to
62 is controlled by WIJ. Then, as shown in FIG. 81, the inversion area signal S and the inversion processing signal are supplied to the gate circuit 465, and the output of the other gate circuit 463 controls aI+.
be done.

Therefore, within the designated inversion area, the other gate circuit 463 is opened and only inverted image data is output.

Next, automatic threshold value adjustment will be explained as image processing.

Conventionally, in order to set the threshold value of a recorded image, the threshold value was determined by operating a level selection button provided on an operation unit.

However, in determining these levels, it is often difficult for those who are not experienced in operating copying machines to set an appropriate level in a single operation. In other words, in the past, there were often unnecessary trial firings.

An automatic density method has been devised to overcome these drawbacks. In this method, before the main scanning of the original document, Briscan is executed to obtain density information, and based on this density information, the threshold value of the original document is determined.

The drawback of this method is that the density information of the document is detected by bliscanning. As a result, the time required for the first copy to be made becomes longer, and the productivity of copying is not significantly improved. Therefore, it is necessary to develop a method for setting in real time.

When attempting to set the density of a document in real time, it is conceivable to create a density histogram of the document.

Now, when a density histogram as shown in FIG. 83 is obtained from the density information, a threshold value for multileveling is calculated from the level giving the peak frequency in this density histogram. Therefore, when this means is adopted, the frequency at each density level must be counted, which tends to increase the circuit scale.

The following description will exemplify the threshold value determining means 600B that is capable of setting the optimum document density in real time without blisscanning and without increasing the circuit scale.

This threshold value determining means 600B is provided in association with the multi-value converting circuit 600A.

The key point is that the threshold value is determined for each line from the maximum value DH and minimum value DL of the density data in each scanning line. For color originals, because the three colors of blue, red, and black are separated, density data of pixels corresponding to the color currently being recorded is sampled.
The maximum and minimum values for each color can be calculated.

An example of a formula for calculating the threshold value T is shown.

T I = k r (D HD L ) + αt + D
L where, i = blue, red, black j = multivalue level = coefficient from 0.1 to 0.8, preferably 0.2 to 0.6 α = correction value 1 α value is for each color There is a difference. However, it is clear that the difference also depends on the value of the density data stored in the above-mentioned color separation map.

For example, k is 1/2 to 1/3 for black and 1/3 for red and blue.
It is about 2. α is -10 for black, 2 ~ for red and blue
It is about 6. Therefore, the multi-value threshold is D! (It is calculated differently for each multivalue level depending on the value of -DL and DL.

In the process of calculating the maximum or minimum value, it is possible that noise etc. may be mixed in. As a countermeasure for such cases, if the concentration data suddenly changes, use the previous concentration data as is without sampling. , or the average value of previous and subsequent concentration data may be used. Furthermore, in order to avoid a sudden change in the calculated threshold value, the average value of the already determined threshold values for a plurality of lines may be used as the threshold value for the current line.

It is also clear that in the case of multi-value conversion, it is sufficient to select α as a coefficient corresponding to each threshold value.

The reason for obtaining it in the above manner is as follows.

When copying an original image in a single color, the coefficient α is different for each color. In other words, there are mainly black characters in the original picture, and colored characters exist less frequently than this. Therefore, if the threshold value is determined according to black characters, the colored characters in the reproduced image will tend to jump out for red or blue. When matched with colored text, the black text becomes a bit crushed.

A specific example of the automatic threshold value determining means 600B will be explained next.

The example shown in FIG. 84 is a case where a ROM is prepared in which threshold values are stored for each color determined by the threshold value calculation formula described above, and the threshold value data is selected from the maximum and minimum values of the line.

In the figure, 611 indicates a ROM in which such multi-value threshold values are stored for each color. The density data can be supplied to the maximum value calculation circuit 612 and the minimum value calculation circuit 616 at the same time.

Since these are the same in content, the maximum value calculation circuit 61
The second configuration will be explained.

The density data of the current pixel and the density data of the previous pixel latched by the latch circuit 614 are supplied to the switching circuit 613. Then, the density data of the current pixel and the density data of the previous pixel are supplied to a comparator 615 for comparing their magnitude, and their levels are compared.
Any of the density data in front of the pixel is selected. When the density data of the original pixel is larger, the density data of the current pixel is selected based on the comparison output as shown in the figure.

Such a magnitude comparison operation is performed for all pixels of the line, and the maximum value DH of the line can be detected.

Similarly, in the minimum value calculation circuit 616, the minimum value DL of the line is detected from the comparison output indicating the minimum value obtained by the comparator 619.

Maximum and minimum values D1. obtained at the end of one line.
The threshold ROM 611 is addressed by DL. The threshold value for which color is selected is determined by this threshold value ROM611.
determined by the color designation signal supplied to the.

As shown in FIG. 85, the threshold value ROM 611 includes ROMs 621 to 623 that independently store threshold value data for each color.
may be prepared and configured so that they can be selected.

In this case, the encoder 62 encodes the color designation signal.
4 is required.

The threshold value may be calculated by sequentially calculating the above-mentioned calculation formula in real time. FIG. 86 is an example.

Maximum and minimum values DI, DL detected as described above
In the subtractor 3E unit 625, the calculation (DH-DL) is performed, and this is supplied to the first ROM 626 which stores 1 in the coefficient, and the multiplication process with the coefficient selected by color designation No. 48 is completed. The multiplied output ki (DH-D
L) and the initial value DL are added by an adder 627.

On the other hand, the data in the coefficient ROM 628 in which α1 is stored is selected by the color designation signal, and this and the addition output are supplied to the second adder 629, whereby the final threshold value T
1 is obtained.

Note that as a noise countermeasure, a preprocessing circuit such as an averaging circuit for density data may be provided. A post-processing circuit that averages the calculated threshold T1 may be provided.

In the case of this device, all threshold values are automatically calculated. The density of the line portion can be controlled by the developing bias voltage. Therefore, a switch (not shown) is provided to control this bias voltage.

When converting a photographic image into a multivalued image, a dither matrix such as 4X4, 8X8, etc. is prepared as the threshold value ROM 611, and the row, row, etc.
A counter output that specifies a column can be used. In this example, 4
It is converted into four values using three ×4 matrices.

The 4-valued image signal can be supplied to the output device 70 via the interface circuit 40. Next, the configuration and operation of this interface circuit 4o will be explained with reference to FIG. 87.

The interface circuit 40 is composed of a first interface 41 that receives 4-value data, and a second interface 42 that receives 4-value data sent from the first interface 41.

The first interface 41 includes a timing circuit 43
to the horizontal and vertical valid area signal H-VALID.

V-VALID is supplied, and at the same time, a clock of a predetermined frequency (6 MH, in this example) is supplied from the counter clock circuit 44.

As a result, 4-level data is sent to the second interface 42 in synchronization with the COD drive clock only during the period when the horizontal and vertical effective area signals are generated.

The counter clock circuit '#i44 generates a timing clock on the main scanning side synchronized with the optical index signal.

The second interface 42 is an interface for selecting the four-level data sent from the first interface 41 and other image data and sending the selected data to the output device 7o.

Other image data refers to the following image data.

The first is test pattern image data obtained from the test pattern generation circuit 46, and the second is test pattern image data obtained from the test pattern generation circuit 46.
Thirdly, it is control data obtained from the Busonta control circuit 45.

The test pattern image data is used when inspecting image processing, and the batch image data for toner density detection is used during batch processing.

Both the test pattern generation circuit 46 and the batch circuit 47 are driven based on the clock of the counter clock circuit 44, thereby adjusting the timing with the four-value data sent from the first interface 41.

The four-level data outputted from the second interface 42 is used by the output device 70 as a laser beam modulation signal.

FIG. 88 shows a specific example of the first interface 41, in which a pair of line memories 901 and 902 are used. This is to process four-value data in real time.

The pair of line memories 901 and 902 are fully supplied with an enable signal with two lines as one cycle, and are also supplied with predetermined address data from address counters 903 and 904, respectively. CK indicates a clock for the address counter (FIG. 89B).

The enable signal forming circuit 910 is provided with a first AND circuit 911 as shown in the figure, which includes the above-mentioned clock CK and a size signal B4 that can be handled by this device.
(In this example, the maximum size is 84.
) is supplied to form the first AND output AI (C in the same figure).

On the other hand, a D-type flip-flop 912 is provided, and as its clock, a line signal SH (D in the figure) is outputted once per l line in synchronization with the deflection timing of a deflector 935 provided in the output device 70. applied. As a result, it is assumed that outputs with the polarities shown in E and F in the figure (shown as Q and 'Q) are obtained from the Q and vine terminals.

■The output and the first AND output A1 are the first NAND circuit 91
3, the Q output and the first AND output A1 are connected to the second
The first and second NAND outputs N1 and N2 (G and H in the figure) respectively output from the NAND circuit 914 are supplied as enable signals to the line memories 901 and 902.

Therefore, each line memory 901, 902 is alternately set to the write enable state for each line.

The output state of each line memory 901, 902 is regulated by gate circuits 905, 906 having a three-state configuration. For this purpose, a Gutoy No. 8 forming circuit 920 is provided.

This forming circuit 920 consists of a pair of AND circuits 921 and 922.
and NAND circuits 923 and 924, and the Q and output and the horizontal effective area signal H-VALID (I in the same figure) are supplied to second and third AND circuits 921 and 922,
AND outputs A2 and A3 shown in J and K of the figure are formed.

Third and fourth NAND circuits 9 provided at the next stage
23,924 have these AND outputs A2. In addition to A3,
The vertical valid area signal V-VALID (L in the same figure) is commonly supplied, the third NAND output N3 (M in the same figure) is supplied to the gate circuit 905, and the fourth NAND output N4 (N in the same figure) is supplied to the other gate. is supplied to circuit 906.

As a result, in this case as well, the gate state can be controlled alternately for each line, and the four-level image data of each line is sequentially and alternately read out from the first interface 41.

Horizontal valid area signal H-VALID and vertical valid area signal V-V
The effective width in the horizontal and vertical directions is determined by ALID. Clock CK, horizontal effective area signal 1 (-VA
Both LID and vertical valid area signal V-VALID are
It is supplied from the output device 70 side.

FIG. 90 shows the peripheral circuit of the output device 70, in which the semiconductor laser 41931 is provided with its drive circuit 932,
The above-described four-value data is supplied to this drive circuit 932 as a modulation signal, and the laser beam is internally modulated by this modulation signal. The timing circuit 932 is configured to drive the laser drive circuit 932 only in the horizontal and vertical effective area sections.
Control II is performed by a control signal from 33. Further, a signal indicating the amount of light of the laser beam is fed back to the laser drive circuit 932, and the driving of the laser is controlled so that the amount of light of the beam is constant.

The scanning start point of the laser beam deflected by the octahedral polygon 935 is detected by the index sensor 936, and the index signal is converted into a voltage signal by the I/V amplifier 937, and then this index signal is sent to the counter clock circuit. 44, etc., to form a line signal SH and adjust the timing of optical main scanning.

Note that 934 is a polygon motor drive circuit, and its on/off signals are supplied from a timing circuit 933.

The image exposure means shown in FIG. 91 uses a laser beam scanner (light scanning device).

The laser beam scanner 940 has a laser 931 such as a semiconductor laser, and the laser 931 generates a color separated image (for example, 2
On/off control is performed based on the value data). laser 9
The laser beam emitted from 31 passes through mirrors 942 and 94.
Polygon 935 consisting of an octahedral rotating polygon mirror through 3
incident on .

The laser beam is deflected by this polygon 935,
This passes through the image forming f-θ lens 944 to the image forming body 1.
10 surfaces are irradiated.

945 and 946 are cylindrical lenses for correcting inclination angles.

The laser beam is directed to the image forming body 110 by the polygon 935.
The surface of the image is scanned at a constant speed in a predetermined direction a, and such scanning results in image exposure corresponding to the color separation image.

Note that the f-θ lens 944 is used to adjust the beam diameter on the image forming body 110 to a predetermined diameter.

As the polygon 935, a galvanometer mirror 1 optical crystal polarizer or the like can be used instead of a rotating polygon mirror.

The latent image created as described above is
A primary image is formed on the photoreceptor by positive reversal development. This situation is shown in FIG.

The electrostatic latent image formed on the image forming body 110 is developed by the developer attached to the image forming body 110.

Note that during development, the development bias signal is applied to the development sleeve (
(not shown). The developing bias signal consists of a DC component selected to have approximately the same potential as the potential of the non-exposed portion of the image forming body 110.

As a result, only the toner of the developer on the developing sleeve selectively transfers to the surface of the image forming member 1100, which has been made into a latent image, and is deposited on the surface of the image forming member 1100, thereby performing the development process.

FIG. 92 shows changes in the surface potential of the image forming body 110, taking as an example the case where the charging polarity is positive. P.H.
is the exposed area of the imaging pair, DA is the unexposed area of the imaging pair, DU
P indicates an increase in potential caused by the adhesion of positively charged toner T1 to the exposed area PH during the first development.

The image forming body 110 is uniformly charged by a charger and has a constant positive surface potential E.

Image exposure using a laser as an exposure source is applied, and the potential of the exposed portion PH decreases in accordance with the amount of light.

The electrostatic latent image thus formed is developed by a developing device to which a positive bias approximately equal to the surface potential E of the unexposed area is applied. As a result, the positively charged toner adheres to the exposed portion PH, which has a relatively low potential, and the first toner image is completely formed.

In the area where this toner image is formed, the potential increases by DUP due to the adhesion of the positively charged toner T1, but normally it does not have the same potential as the unexposed area DA.

Next, the image data is transferred onto a transfer paper P and roughly heated or pressurized to fix it, thereby obtaining recorded image data. In this case, the toner and charges remaining on the surface of the image forming body are cleaned and used for the next image forming body.

In addition to electrophotography, methods for forming latent images for image formation include methods in which charges are directly injected onto the image forming body using a multi-needle electrode, etc., and methods in which electrostatic latent images are formed by directly injecting charges onto the image forming body using a magnetic head. A method of forming an image, etc. can be used.

In this device, a two-component developer consisting of a non-magnetic toner and a magnetic carrier is preferred because it has the characteristics of easy control of triboelectric charging of the toner, excellent developability, and the ability to impart any color to the toner. used.

The various devices or circuits described above are all controlled by first and second control sections 200 and 250, as shown in FIG. 93. The explanation will start from the second control unit 250.

The second control unit 250 mainly controls the image reading system and its peripheral equipment, and 251 is a microcomputer (second microcomputer) for controlling the optical drive, and a microcomputer for controlling the main body. Various information signals are exchanged with the computer (first microcomputer) 201 through serial communication. Further, the optical scanning start signal sent from the first microcomputer 201 is directly supplied to the interrupt terminal of the second microcomputer 251.

The second microcomputer 251 uses a predetermined frequency (12Mf(z)) obtained from the reference clock generator 254.
Various command signals are generated in synchronization with the clock.

The second microcomputer 251 outputs a color designation signal and the like for color processing.

The second microcomputer 251 outputs the following control signals.

First, a control signal for turning on and off the drive circuits of the CCDs 104 and 105 is supplied to their power supply control circuits (not shown). Second, a predetermined control signal is supplied to the lighting control circuit 253 for the light source 85 for irradiating the document 52 with necessary light.

Thirdly, the carriage 8 provided on the image reading section A side
A control signal is also supplied to a drive circuit 252 that drives a stepping motor 90 for moving the 4 and V mirror units 89, 89''.

Data indicating the home position is input to the second microcomputer 251.

The first microcomputer 201 is mainly used to control the copying machine. FIG. 94 shows an example of an input system and an output system from a copying machine.

The operation/display unit 202 receives input data such as magnification designation, recording position designation, and recording color designation, and displays the contents thereof.

As the display means, an element such as an LED is used.

The paper size detection circuit 203 is used to detect and display the size of the cassette paper loaded in the tray, or to automatically select the paper size according to the size of the document.

The cassette zero sheet detection sensor 220 detects whether there are no sheets in the cassette. Similarly, the manual feed zero sheet detection sensor 222 detects the presence or absence of paper for manual feed in the manual feed mode.

The toner density detection sensor 221 detects the density of toner on the drum 110 or after fixing.

Further, the toner remaining amount detection sensor 223 individually detects the remaining amount of toner in each developing device, and when toner replenishment is necessary, a control is performed so that a toner replenishment display element provided on the operation unit lights up. Ru.

- The time stop sensor 224 is for detecting whether or not paper is correctly fed from the cassette to the second paper feed roller (not shown) during use of the copying machine.

Contrary to the above, the paper ejection sensor 225 is used to determine whether or not the fixed paper is correctly ejected to the outside.

The manual feed sensor 226 is used to detect whether a manual feed tray is set. If it is set, it will automatically switch to manual feed mode.

The sensor output obtained from each sensor as described above is taken into the first microcomputer 201, and necessary data is displayed on the operation/display unit 202, and the driving state of the copying machine is controlled as desired! 1 will be given.

In the case of copying, a developing motor 227 is provided, both of which can be controlled 81+ by command signals from the first microcomputer 201. Similarly, the drive state of the main motor (drum motor) 204 is controlled by a drive circuit 205 having a PLL configuration, and the drive state of this drive circuit 205 is also controlled by the control all signal from the first microcomputer 201. will be done.

During development, it is necessary to apply a predetermined high voltage to a developing device or the like during development. Therefore, high voltage power supply 2 for charging
28. A high-voltage power source 229 for development, a high-voltage power source 230 for transfer and separation, and a high-voltage power source 231 for the toner receiver are provided, and a predetermined high voltage is applied to them when necessary. become.

Note that 233 is a cleaning roller drive unit, 234 is a first paper feed roller drive unit, 235 is a second paper feed roller drive unit, and 232 is a cleaning pressure release motor. Roughly speaking, 236 is a drive section for the separation claw.

The second paper feed roller is used to transport the paper transported by the first paper feed roller to the electrostatic latent image formed on the drum 110.

The fixing heater 208 is controlled by a fixing heater on/off circuit 207 in accordance with a control signal from the first microcomputer 2.1.

The fixing temperature is read by the thermistor 209, and the first microcomputer 2
All can be controlled by 01.

206 is a clock circuit (approximately 12 MHz).

A nonvolatile memory 210 provided along with the first microcomputer 201 is used to store data that should be preserved even when the power is turned off. for example,
This includes total counter data and initial setting values.

In this way, the first and second microcomputers 20
1.251, various controls necessary for image formation are executed according to a predetermined sequence.

FIG. 95 is a timing chart schematically showing when recording an image.

Next, the operation/display section 202 of this device will be explained with reference to FIG. 96.

A is a copy switch, and by pressing this switch, a copying operation is performed in the above-described sequence.

Further, there is an LED below this switch, and when the red LED is lit, it indicates the "warming up" time, and when the green LED is lit, it enters the ready state.

The opening is a display section that displays the number of copies, a self-diagnosis mode, or an abnormal state and its location. It is composed of 7 segment LEDs and its contents are displayed numerically.

C is a group of keys for setting the number of copies, etc., instructing the self-diagnosis mode operation, interrupting the copying operation, clearing the set number of copies, etc. For example, by pressing number keys 4 and 7 and turning on the power switch, it is possible to enter self-diagnosis mode, and by inputting a specific number at this time,
For example, it is possible to independently rotate the motor of the developing device.

From this mode, it is possible to return to normal mode by inputting a specific number, or by turning the power off and then turning it on without pressing any keys.

In the normal mode, normal copying operations are possible, but by combining the numeric keys and the P button, operations such as printing out data and printing out test patterns are also possible. For example, the second interface 42
Connect the print controller to °' 52 P
” and turn on copying, the printer controller data will be output.

Similarly, the test pattern can be printed out by setting it to "53P". If the stop/clear key is pressed during the copy operation, the process moves to a post-rotation process operation, and after this operation is completed, the initial state is returned. The same holds true when making multiple copies.

The second key is the EE mode release key. Press this key
E. With the mode canceled, the threshold value can be manually adjusted by operating the keys.

When the E key is pressed, the threshold level of the entire image becomes the low threshold. By pressing the button once, the threshold value changes discretely from the normal threshold value to the next threshold value among the seven levels. At this time, the LED lights up.

The second key does the opposite.

is a key that instructs to perform partial area detection.
By pressing this key, the marker area on the document is detected. Designation of inside/outside the marker area is performed using the N key.

On the other hand, the key group in the table is a key group for specifying processing.

Using the functions described above, it is possible to perform various types of image processing as described below.

LE is a key that specifies color erasure, and is one of red, blue, and black.
It is possible to specify two colors.

In addition, this key can be used by combining the Chi and Nu keys.
It is possible to erase the color inside/outside the area specified by the color marker.

O is a key to set the fixed magnification, and by pressing this key, the L of each magnification displayed above this key will be displayed.
The ED is turned on and off, and the designated fixed magnification is set.

On the other hand, when setting an arbitrary magnification to change the zoom magnification, press the W key and use the Power, Yo, and Even keys to change the magnification independently in the vertical and horizontal directions. Alternatively, a process of changing at the same magnification as tII is selected.

For example, by pressing the "full screen" key and selecting the magnification using the switch, it is possible to set the same magnification in the vertical and horizontal directions (the magnification is shown on the display section).

On the other hand, if you press the ``vertical'' key in this state and select the magnification using the ``button'' key, the horizontal magnification will be the first magnification, the vertical magnification will be the magnification set after that, and so on. /I Independent magnification change can be realized.

Conversely, pressing the ``horizontal'' key instead of the ``vertical'' key has the same effect.

In a different method, the user may first press the "vertical" key to set the vertical magnification, and then press the "horizontal" key to set the magnification.

亙藍五星Enie If you want to do it in full screen, press the "Full screen" key and then press "
Press the "Reverse" key to copy (see Figure 97).

If you want to copy partially, press the "Partial" key and then the "Reverse" key to copy (see Figure 98).

° Mode 1 Press the “Partial” key, then press the “Inner” key to copy (
(See Figure 99).

) Mo1 ``Press the J key for the full screen, press the ``Energy'' key, and then copy (see Figure 100).

Press the "Partial" key, press the "In" key, press the "Energy" key, and then copy (see Figure 101).

1. Press the ``full screen'' key, then press the ``middle blank'' key, and then press the copy key (see Figure 102).

Press the ``Part 1'' key, then press the ``Near Middle'' key, and then press the Copy key (see Figure 103).

, ・Ha − ′ “Full surface”
key, press the "variable magnification" key, set the magnification, and then press the copy key (see Figures 104 and 105).

Press the "Partial" key, the "Inner" key, and the "Enlarge" key to copy (see Figure 106).

Gori Danji Namdo Press "part", "in" key, press "extract" key, and copy (see Figure 107).

ALL column i As for the function, it is the reverse of the extraction processing mode.

2゛... 几MO - ・Press the ``Full Screen'', ``Color Off'', and ``Red'' keys to copy (see Figure 108).

Furthermore, by using the key switch group, it is possible to instruct various operations for operation confirmation. For example, a) sxp: Scanner check 60P + copy; light source (halogen lamp) turned on, scanner optical system stopped, 1 + copy in this state; halogen left on, only the optical system moved in the sub-scanning direction at a speed slower than the normal speed .

However, when the copy switch is turned off, the optical system will stop at that position with the halogen on 2+copy; Same function as 1+copy, but the optical system will move in the opposite direction 3+copy; Regular scanning will continue with the halogen on. 61P+Copy: With the halogen turned off and the scanner optical system stopped, press 1 to 6+Copy in this state to perform the same operation as above.

This operation is canceled by pressing the stop/clear key. Further, during each operation, image data is output from each circuit, making it possible to check the signal level.

7XP: Printer section check 70P + copy; only the polygon motor rotates and the laser is turned on. Index signal can be checked, 1+copy in this state; Output 2+copy of printer controller data; Output 3+copy of test pattern data; Output of batch data is possible 71P+copy; Check mode related to recording section, 1+copy in this state Charger on 2+copy; Black developing device motor on, developer bias on 5+copy; Transfer pole on 6+copy; Cleaning blade crimping 7+copy; Cleaning blade released 8+copy; Cleaning roller application (voltage) 9+ copy; Separation pole on 10+ Copy; first paper feed motor turned on 11+copy; second paper feed motor turned on, etc. are performed. In this case, stop ・
This mode is canceled by pressing the /clear key. j
This type of self-diagnosis check is not limited to this example, and it is possible to perform such self-diagnosis checks, making it easier for service personnel to perform maintenance in the market, or by having users perform a simple check before going for maintenance. will be able to respond more quickly.

[Effects of the Invention] As explained above, according to the present invention, in an image processing apparatus for monochrome recording, it is possible to independently set contour correction in the sub-scanning direction with respect to contour correction in the main scanning direction. In addition, contour correction in the sub-scanning direction is emphasized more than contour correction in the main-scanning direction. 1 By doing this, even when cutting out particularly thin horizontal lines,
It is possible to perform hollow processing without destroying the outline.

Moreover, since noise in the main scanning direction is not processed as a contour component, high-quality images can be obtained.

Therefore, according to the present invention, it is possible to obtain a center facing image with good reproducibility.

In terms of configuration, it is also simple because the resolution correction filter can be used by changing only its coefficients.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of essential parts showing an example of an image processing device according to the present invention, FIG. 2 is a schematic configuration diagram of an electrophotographic copying device applicable to the present invention, and FIG. 3 is a transmittance characteristic of a dichroic mirror. Figure 4 is an emission spectrum curve diagram, Figure 5 is a spectral sensitivity characteristic diagram, Figure 6 is a shading correction characteristic diagram, Figure 7 is a system diagram of the shading circuit, Figure 8 is its waveform diagram, and Figure 9 is a diagram of the shading circuit. The figure is a system diagram of the A/D converter, Figures 10 and 11 are diagrams for explaining its operation, Figures 12 and 13 are diagrams each showing examples of color separation maps, and Figure 14 is a color code. 15 and 16 are illustrations of color ghosts, respectively. FIGS. 17 and 18 are illustrations of color ghost occurrence, respectively. FIG. 19 is a configuration diagram of the device for CCD installation. Figure 20 is a configuration diagram of the main parts, and Figure 21
The figure is a partial sectional view, FIG. 22 is an explanatory diagram of color ghost generation, FIGS. 23 and 24 are explanatory diagrams of color ghost correction, and FIG. 25 is a system diagram of color ghost correction means.
Figures 26 and 27 are explanatory diagrams of area specification, Figure 28 is a system diagram of the area extraction circuit, Figure 29 is a system diagram of the color marker detection circuit, Figure 30 is a system diagram of the area extraction section, and Figure 31 is a system diagram of the area extraction circuit. 32 is a system diagram of the area determination circuit, FIGS. 33 to 35 are diagrams explaining its operation, and FIG. 36 is a waveform diagram for explaining its operation.
The figure shows another example of area specification, Fig. 37 is a system diagram of the processing means, Fig. 38 is a system diagram of the multiplexer used for this, and Figs. 39 and 40 show the achromatic specification code and its 41 is a system diagram of the processing control signal generation circuit, FIG. 42 is a logical value table at that time, FIGS. 43 and 44 are explanatory diagrams of enlargement/reduction processing, and FIG. 45 is a diagram showing the processing contents. A system diagram showing a specific example of an enlargement/reduction circuit; FIG. 46 is a diagram showing an example of interpolation data used during enlargement/reduction processing;
Fig. 7 is a system diagram of the input buffer, Fig. 48 is a system diagram of the output buffer, Figs. Fig. 53 is a waveform diagram of the enlargement/reduction processing operation, Fig. 54 and Fig. 55 are diagrams showing the numerical values of interpolation data used for the enlargement/reduction processing, respectively, Fig. 56 is a system diagram of the synchronization circuit, and Fig. 57 and FIG. 58 are waveform diagrams for explaining the operation, FIG. 59 is a diagram showing the contents of the data ROM, FIG. 60 is a diagram showing the data input/output state of the human output buffer, and FIG. 61 is an enlarged view of the central reference.・An explanatory diagram of the reduction process, FIG. 62 is a diagram showing an example of data of the write start address when performing central reference recording, FIG. 63 is a waveform diagram to explain the processing operation in each case, and FIG. 64 65 is a waveform diagram for explaining the operation during image enlargement processing, FIG. 65 is a waveform diagram for explaining the operation during image reduction processing, and FIGS. 66 and 67 are diagrams showing other examples of image reading and image recording, respectively. , Figures 68 and 69 are diagrams showing the relationship between the write start address and preset data used at that time, Figures 70 and 71 are characteristic diagrams of MTF correction, respectively, and Figure 72 is a comparator for MTF correction. 3-filter system diagram, FIG. 73 is a system diagram showing an example of the hollow means, FIG. 74 is its operating waveform diagram, FIG. 75 is a system diagram of the shaded means, and FIG. 76 is its operating waveform diagram. Figure 77 is a diagram showing an example of a shading pattern, Figure 78
Figure 79 is a diagram showing the difference between the waveform diagram before and after hatching and the output data, Figure 80 is a system diagram of the inversion processing circuit, and Figure 8
1 and 82 are operation waveform diagrams at that time, FIG. 83 is a diagram of a density histogram, FIGS. 84 to 86 are a system diagram of the automatic threshold determination means, and FIG. 87 is a system diagram of the interface circuit. FIG. 88 is a system diagram of the first interface,
Fig. 89 is an operating waveform diagram, Fig. 90 is a system diagram of the output device, Fig. 91 is a configuration diagram of the laser beam scanner, and Fig. 92 is a diagram of the configuration of the laser beam scanner.
The figure is an explanatory diagram of the developing process, FIG. 93 is a block diagram of the second control section, FIG. 94 is a block diagram of the first control section, FIG. 95 is a waveform diagram for explaining its operation, and FIG. 96 is a block diagram of the first control section. FIGS. 97 to 108 are diagrams illustrating key operation processing, and FIG. 109 is a system diagram of a conventional device for explanation. 1... Enlargement/reduction processing operation 15, A+15B... Shading correction circuit 35...
- Color discrimination circuit 40...Interface circuits 60A, 60B...A/D converter 300...Color ghost correction means 450...Resolution correction means 420...Extraction and other processing means 440...Network Applying means 460...Reversing means 500...Region extracting means 600A...Multi-value conversion means 600B...Automatic threshold setting means 780...Hollowing processing means Patent applicant Konica Corporation

Claims (3)

[Claims] (1) An imaging means for capturing image information of a document, a hollow processing means for extracting a density change portion of an image signal obtained by the imaging means and processing the image signal for hollowing out, and an image subjected to hollowing processing. means for visualizing the image based on the signal, and the hollow processing means is characterized in that the image signal related to the sub-scanning direction is processed more strongly than the image signal related to the main scanning direction. image processing device. (2) The image processing apparatus according to claim 1, wherein the hollow processing means is incorporated in a part of the resolution correction means. (3) The image processing apparatus according to claim 1 or 2, wherein the hollow processing means uses a convolution filter.