JPH0568145B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image reading device that reads images using an image sensor. The present invention relates to an image reading device capable of reading images.

2. Description of the Related Art Some image reading devices used in facsimile machines, copying machines, and the like are equipped with a partial reading function that can read a portion of a document. By using the partial reading function, it is possible to read only the necessary information without cutting and pasting the document. For example, in the case of facsimile, it is possible to shorten the time for electronically transmitting the document and reduce costs.

FIG. 1 is a diagram for explaining the reading principle of a conventional image reading device that partially reads a document using handwritten marks. Manuscript 1 shown in figure a
It is assumed that graphic information such as characters and figures is written on one side of the screen. The operator uses a writing instrument that makes markings in a specific color to divide the boundary between unnecessary image information and necessary image information in the document 1 by a boundary line 2. This specific color uses a color that is not used as image information. If the document is written in black, the boundary line 2 is drawn with a red writing instrument, for example.

In this case, the image reading device includes a red reading section that separates and reads red image information (marking). Assume that a one-dimensional image sensor that reads a document is scanning a line indicated by a chain line 3. In this case, one line of image signal 4 (b in the figure) is output from the image sensor. The image signal 4 is supplied to the red reading section, and the border line 2
Two types of marking bit images (red image signals) 5 ₁ and 5 ₂ (c in the figure) are extracted by cutting the image.

The image reading device partially erases the image signal 4 in a designated mode based on these marking bit images 5 ₁ and 5 ₂ . In other words, when erasing information in the internal area surrounded by boundary line 2,
As shown in FIG. 3, erasing of the image signal 4 is started at the position where the first marking bit image ₅₁ is generated. Then, the process ends at the position where the next marking bit image ₅₂ is generated. In addition, when the information of only the internal area described _above is to remain, as shown in _FIG . The image signal 4 is erased for two parts. If the image signal 4 is selected for each scanning line in this way, partial reading will be performed for the area divided by the boundary line 2.

By the way, when there is little ink left in the writing instrument, a part of the border line 2 may become blurred in the form of a streak. Furthermore, when using an oil-based writing instrument, the ink marking the border line 2 and the printing ink representing characters, figures, etc., or the ink of the writing instrument and the ink marking the border line 2 may partially blend and bleed. . In such a case, shading occurs on the boundary line 2. Therefore, when the marking bit image is extracted and binarized in such a case, instead of two red image signals 5 ₁ and 5 ₂ as shown in Figure 2a, three red image signals as shown in Figure 2b are obtained. In some cases, a red image signal 6 which is subdivided in the above manner is obtained. Such a red image signal 6 cannot be used as a signal representing the starting point and ending point for partial image reading. That is, in conventional image reading devices, handwritten marks for specifying boundaries sometimes do not actually function. In addition, in such a case,
It is also possible to remove "fading" and "bleeding" by performing image reduction processing as disclosed in No. 43537. However, in such a method, if the mark is corrected by reduction processing and then enlarged, there is a risk that the mark may be misaligned, and it is not possible to perform reliable partial reading processing.

The present invention has been made in view of the above-mentioned circumstances, and even if the mark is "fainted" or "bleeded", the bit image of the marking that indicates the boundary for partial reading etc. is continuous within a predetermined range and reduced. It is an object of the present invention to provide an image reading device that can reliably perform image signal processing such as partial reading without performing any processing.

In the present invention, if the bit image of the marking after being read and binarized has a predetermined value representing the marking, the following N bits (N is an arbitrary integer) are modified to the predetermined value. The above-mentioned object is achieved by equipping an image reading device with a retouching circuit and performing partial processing of the image using a marking image retouched by the retouching circuit.

The present invention will be explained in detail with reference to Examples below.

FIG. 3 shows a multicolor copying machine using the image reading device of this embodiment. This multicolor copying machine includes a reading unit 12 that is arranged to be able to reciprocate on a rail 11. A fluorescent lamp 121 is provided within the reading unit 12 for illuminating the platen glass 13 from the bottom surface thereof. The document is fixed between the platen glass 13 and the platen cover 14, and when the fluorescent lamp 121 is turned on, the reading position thereof is illuminated. The light reflected from the original is split into two directions by a dichroic mirror 122, the wavelength is selected, and an image is formed on a first or second image sensor 125 or 126 via a lens 123 or 124.

The reading unit 12 is activated by the arrow at the beginning of the copying operation.
Starts movement in 16 directions (sub-scanning) and begins reading the original. First and second image sensor 1
The two types of image signals obtained by 24 and 125 are:
The signal is supplied to a color separation circuit (not shown) in the reading unit 12, where three types of image signals, a black image signal, a red image signal, and a cyan image signal, are created. Each image signal is a signal representing black, red, or cyan image information written on the original.

When this multicolor copying machine performs the above-mentioned three-color recording, a black image signal is supplied to the B-color thermal head 16. The red image signal and the cyan color image signal are each individually delayed by a delay circuit and then supplied to the R color thermal head 17 or the C color thermal head 18. Each thermal head 16-18
, B fed out from supply rolls 19 to 21
Color, R color or C color ink donor sheet 23~
25 is now available. The B-color ink donor sheet 23 has a base paper coated on one side with black ink that has the property of fluidizing or sublimating when heated. Red ink having similar properties is applied to the R color ink donor sheet 24, and cyan ink having similar properties is applied to the C color ink donor sheet 25.

Each of the ink donor sheets 23 to 25 is
The recording paper is sequentially overlapped with the recording paper fed from the supply tray 27, and thermal transfer recording is performed by selectively driving the thermal heads 16 to 18. That is,
When the recording paper is guided by the guide 28 and passes between the B color thermal head 16 and the back roll 29, the B color ink donor sheet 23 is conveyed together with it, and black image information is recorded.

The recording paper on which black recording has been completed is transferred to the take-up roll 31.
B color ink donor sheet 2 being wound up
3 and are transported in a superimposed state. and 1
After being separated by a pair of rollers 32, 32, it is guided by a guide 33 and passes between the R color thermal head 17 and a back roll 34. At this time, the R color ink donor sheet 24 is conveyed together with this, and red image information is recorded.

The recording paper on which black and red recording has been completed is conveyed in a state where it is superimposed on the R color ink donor sheet 24 which is being wound up on the winding roll 35.
After passing through a pair of rollers 36, 36, it is guided by a guide 37 and passes between the C color thermal head 18 and the back roll 40. At this time, the C color ink donor sheet 25 is conveyed together with this,
Cyan image information is recorded.

The recording paper on which three colors have been recorded in this way is conveyed in a state where it is superimposed on the C-color ink donor sheet 25 which is being wound up on the take-up roll 38. After passing through a pair of rollers 39, 39, the paper is delivered to a discharge tray 41, and the entire process of three-color copying is completed.

A case in which partial reading of an image and recording thereof is performed using this three-color copying machine will be described next.

Prior to starting partial reading, the operator operates a partial reading operation panel located at the top of the three-color copying machine. As shown in FIG. 4, the partial reading operation panel 43
Four switches 431 to 434 are arranged. Of these, the first and second switches 431
-432 are switches for setting a color for specifying partial reading. Suppose you specify a part using red.
In this case, the operator presses the first switch 431.

The third and fourth switches 433, 434 are
This is a switch that sets the partial reading mode. When the third switch 433 is pressed, the mode becomes partial extraction mode. As shown in Figure 5, border line 2 is placed on document 1.
In the partial extraction mode, a copy 46 in which only the image information 45 inside the image information 45 is read is obtained. On the other hand, when the fourth switch is pressed, a copy 48 in which only the image information 47 outside the boundary line 2 is read is obtained. The operator sets the copier to one of the modes.

When the operation of the partial reading operation panel 43 is completed, the operator places the original on the platen 13 and then presses a start button to start copying. As a result, the scanner unit 12 starts moving, and image information is read line by line. This 3
When a color copying machine is set to partial reading mode,
Only black recording will be performed automatically.

FIG. 6 shows a circuit section for partial reading of this copying machine. When the operator sets the apparatus to specify a portion using red, both a black image signal 52 and a cyan color image signal 53 are supplied to the first image signal output circuit 51 from a color separation circuit (not shown). After these image signals 52 and 53 are logically summed, they are delayed by N/2 bits to synchronize with a modified marking bit image 66, which will be described later, to create a pseudo black image signal 54. The pseudo-black image signal 54 is created in order to reproduce information other than red on the original without missing any information.

On the other hand, the second image signal output circuit 56 is supplied with a red image signal 57 representing the color for which partial designation is to be performed from the color separation circuit. Second image signal output circuit 56
The circuit includes a delay element that delays the red image signal 57 by one bit, and an AND circuit that performs an AND operation between the bit output from this element and the current bit. This AND circuit creates a marking bit image 58 from which red noise has been removed.

A clock signal 59 for image signal transfer is supplied to the first and second image signal output circuits 51 and 56. The pseudo black image signal 5 is generated by the clock signal 59.
4 and marking bit image 58 are output one bit at a time at the same timing. Of these, the pseudo black image signal 54 is supplied to both a partial extraction processing circuit 61 for performing partial extraction processing and a partial erasure processing circuit 62 for performing partial erasure processing.

On the other hand, the marking bit image 58 is (N
+1) One of the input terminals of the input OR circuit 63,
The signal is supplied to both input terminals D of a first flip-flop circuit 65 ₁ of a shift register constituted by N stages of flip-flop circuits 65 ₁ to 65 _N. A clock signal 59 is supplied to each of the flip-flop circuits 65 ₁ to 65 _N , and the delayed marking bit images 64 ₁ to 64 _N outputted from the respective output terminals Q are as follows.
They are supplied to other input terminals of the OR circuit 63 in synchronization with each other.

Now, suppose that the scanner unit 12 starts reading the boundary line (marking) at a certain point. Suppose that the markings are streaky and faded. In this case, the marking bit image 58, which should be continuous in the marking part, becomes discontinuous as shown in FIG. 7a. The OR circuit 63 uses this marking bit image 58 and the clock signal (FIG. 7b).
The marking bit images 64 ₁ to 64 _N delayed one bit at a time are logically ORed to output a corrected marking bit image 66 (FIG. 7c).

FIG. 7 shows the case where N is 6 as an example. In this case, marking bit image 5
8 is disconnected for less than six periods _T6 of clock signal 59, it will no longer appear in modified marking bit image 66. Figure a
The time at which the marking bit images 58 shown in FIG.
Since the marking bit image 66 is _T3 and two periods _T2 , the marking bit image 66 becomes a continuous signal. Of course, N can be set to any number depending on the writing instrument.

The partial area indication pulse generator 67 receives the marking bit image 66 and generates a partial area indication pulse 68 (seventh
Figure d) is output. Partial area indication pulse 68
is supplied as is to the partial extraction processing circuit 61,
The partial erase processing circuit 62 also includes an inverter 69.
It is supplied after having its logic state inverted by .
A processed signal 71 or 72 is supplied to each of the partial extraction processing circuit 61 and the partial deletion processing circuit 62. Of these, the first processing signal 71 is sent to the third switch 4 of the partial reading operation panel 43.
The second processed signal 72 is a signal that becomes an H level logic state when the fourth switch 434 is pressed. .

Partial extraction processing circuit 61 and partial deletion processing circuit 62
Each has a 3-input AND circuit, takes the logical product of three types of input signals, and outputs a read image signal 72 or 73. Third switch 43
3 indicates the partial extraction mode, the partial extraction processing circuit 61 outputs the read image signal 72.
is output and supplied to the B color thermal head 16 via the OR circuit 74. Also, the fourth switch 43
When the partial erase mode is instructed by 4, the read image signal 73 is output from the partial erase processing circuit 62.
is output and similarly supplied to the B color thermal head 16 via the OR circuit 74.

The B color thermal head 16 records partially extracted or partially erased image information on the recording paper supplied from the supply tray 27. After recording, the recording paper is sequentially conveyed by the B color ink donor sheet 23, the R color ink donor sheet 24, and the C color ink donor sheet 25, and is discharged onto the discharge tray 41. This completes the entire process of copying by partial reading.

As explained above, according to the present invention, even if "fading" or "bleeding" occurs in the marking, it can be corrected and a continuous mark can be obtained. Also, since there is no need to perform reduction processing,
Since partial reading of a document can be reliably performed without fear of marks being misaligned, the operator's mental burden on the writing instrument can be reduced and the operator can work more efficiently.

In the embodiment, partial reading (partial copying) of a document was explained as an example, but it is also possible to change the recording color inside and outside the partial area identified by the marking bit image, or to transfer image information in the partial area to other images. Of course, they are also free to perform processing such as exchanging information.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the principle of partial reading of an image using a marking bit image, and Figure 2 shows the cause of malfunction when handwritten markings become blurred or blurred using a conventional image reading device. Signal waveform diagrams for explanation, Figures 3 to 7
The figure is for explaining one embodiment of the present invention.
Of these, Fig. 3 is a schematic configuration diagram of a multicolor copying machine incorporating an image reading device, Fig. 4 is a plan view of the partial reading operation panel of this copying machine, and Fig. 5 shows two modes of partial reading. FIG. 6 is a block diagram showing a circuit portion for partial reading, and FIG. 7 is a signal waveform diagram of each part of this circuit. 1...Manuscript, 2...Border line (marking), 56...
Second image signal output circuit, 58... Marking bit image, 63... OR circuit, 65... Flip-flop circuit, 66... Modified marking bit image, 125... First image sensor, 126
...Second image sensor.

Claims (1)

[Scope of Claims] 1. An image having area boundaries defined by specific color markers is read line by line from a document, and at least two types of color information of the image are photoelectrically converted for each pixel and output as respective color image signals. a color separation circuit that receives a plurality of color image signals outputted from the photoelectric conversion means, detects a region boundary line portion formed by the specific color marker, and creates a binarized image bit signal; , an image processing circuit that identifies a specified area based on the image bit signal created by the color separation circuit, and processes a plurality of color image signals inputted from the photoelectric conversion means in accordance with this area; In the image reading device, a multi-stage shift register is provided between the color separation circuit and the image processing circuit, and an OR circuit that inputs output signals of each stage of the shift register and calculates a logical sum thereof; Image reading characterized in that the image bit signal created by the color separation circuit is synchronized pixel by pixel and taken into the shift register, and the output of the OR circuit is provided as a modified image bit signal to the image processing circuit. Device.