JPH05252393A - Image reader - Google Patents

Abstract

PURPOSE:To directly obtain plural image data obtained by separating only image parts in a specific density range by providing this image reader with plural binarizing means for binarizing signal voltages in accordance with a judged result whether each signal voltage is included within a reference voltage or not. CONSTITUTION:A reference voltage setting circuit 8 generates reference voltages 9 to 11. In this case, the voltages 9 to 11 are respectively set up to 1.5V, 1.0V and 0.5V. An image formed on an original is decomposed by the dendity of four steps in accordance with the quantity of light reflected from the original and detected by respective picture elements in a CCD 1. Namely when a signal voltage 3 outputted from an amplifier 2 in accordance with the quantity of light detected by a picture element 1a is 1.5 to 2.0V, 5V is outputted only from the output 22 of a binarizing circuit 4, and in the case of 1.0 to 1.5V, 5V is outputted only from the output 26 of a binarizing circuit 5. In the case of 0.5 to 1.0V signal voltage 3, 5V is outputted only from the output 33 of a binarizing circuit 6, and 0 to 0.5V signal voltage 3 allows the output of 5V only from the output 29 of a binarizing circuit 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device.

[0002]

2. Description of the Related Art Conventionally, an image reading apparatus decomposes each pixel of an image drawn on a document into a pixel having a density higher than a threshold value and a pixel having a density lower than the threshold value, and a binary digital image. It is either of a type of converting into a signal or a type of reading the gradation of density by converting the density of each pixel into a multi-valued digital signal.

[0003]

However, none of the types can generate image data in which only an image portion within a specific density range is separated from an image on a document. Therefore, if you want to separate only the image part within a specific density range from the image on the original, or if you want to decompose each image part within a plurality of different density ranges, convert the image density into a multi-value digital signal. It was necessary to use an image reading device of the type described above, load the image data generated by the image reading device into a personal computer, etc., and then select pixels within the density range again to generate new image data. ..

The present invention has been made to solve the above-described problems, and separates only an image portion within a specific density range from an image on a document without using an additional device, or a plurality of different images are separated from each other. It is an object of the present invention to provide an image reading apparatus capable of directly obtaining a plurality of image data separated for each image portion within the density range.

[0005]

To achieve this object, an image reading apparatus according to the present invention divides an image on a document into a plurality of pixels and generates a digital signal corresponding to the density of each pixel. A photoelectric conversion means for converting reflected light or transmitted light from the document into a signal voltage corresponding to the density of each pixel, reference voltage range setting means for setting three or more reference voltage ranges different from each other, and the signal A plurality of binarizing means for binarizing the signal voltage depending on whether or not the voltage is within the range of the reference voltage.

[0006]

In the image reading apparatus of the present invention having the above structure, the photoelectric conversion means converts the reflected light or the transmitted light from the original into a signal voltage corresponding to the density of each pixel. The reference voltage range setting means sets the reference voltage corresponding to the density range of the image on the document. The binarizing means binarizes the signal voltage depending on whether or not the signal voltage is within the range of the reference voltage, and separates a predetermined density range portion of the image on the original from other density range portions. Generates binary image data.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First, the configuration of the electronic circuit of the image reading apparatus of this embodiment will be described with reference to FIG. The electronic circuit of the image reading device comprises a well-known CCD 1, an amplifier circuit 2, binarization circuits 4, 5, 6, 7 and a reference voltage setting circuit 8. The connection between the components of this electronic circuit will be described. The CCD 1 is composed of a plurality of pixels arranged in a line, and outputs a voltage according to the amount of light received when each pixel receives the reflected light from the document, and the output of each pixel is an amplifier circuit. It is entered in 2. The output of the amplifier circuit 2 is input to the binarization circuits 4, 5, 6, 7. Further, among the reference voltages 9, 10, and 11 output from the reference voltage setting circuit 8, the reference voltage 9 is input to the binarization circuit 4, and the reference voltages 9 and 10 are input to the binarization circuit 5 for reference. The voltages 10 and 11 are input to the binarization circuit 6,
The reference voltage 11 is input to the binarization circuit 7.

Next, the operation of the components of the electronic circuit will be described. Each pixel of the CCD 1 is arranged such that an image on a document (not shown) is formed on each pixel by a lens (not shown), and the CCD 1 sequentially generates a voltage proportional to the amount of light irradiated to each pixel. Output. The amplifier circuit 2 amplifies the voltage and outputs 0 V as the signal voltage 3 when the CCD 1 does not receive light, and the signal voltage 3 increases as the light amount increases, and when the maximum light amount is received, the signal voltage 3 is output. It is set to output 2V. The reference voltage setting circuit 8 generates reference voltages 9, 10, and 11. At this time, the reference voltage 9 is 1.5 V and the reference voltage 10
Is set to 1.0V and the reference voltage 11 is set to 0.5V. The binarization circuits 4, 5, 6, 7 binarize the signal voltage 3 by comparing the reference voltage input to each with the signal voltage 3.

Next, an embodiment of the reference voltage setting circuit 8 will be described with reference to FIG. Resistor 1 having the same resistance value
4, 15, 16, and 17 are connected in series, and the resistor 1
+ 2V is applied to the end on the 4 side, and the end on the resistor 17 side is grounded. As a result, 1.5V is applied to the connection point between the resistors 14 and 15, and 1.V is applied to the connection point between the resistors 15 and 16.
0V, 0.5V is generated at the connection point between the resistors 16 and 17.

Next, an embodiment of the binarization circuit 4 will be described with reference to FIG. The signal voltage 3 is input to the non-inverting input of the comparator 20 having an open collector output, the reference voltage 9 is input to the inverting input, and the output is pulled up to +5 V by the resistor 21. With this configuration, when the signal voltage 3 is higher than the reference voltage 9, the output 22 of the comparator 20 becomes 5V, and when the signal voltage 3 is lower than the reference voltage 9, the comparator 2
The output 22 of 0 becomes 0V. That is, the pixel within the density range where the signal voltage 3 obtained by amplifying the voltage generated by the pixel receiving the reflected light from the original document by the amplifier circuit 2 is larger than 1.5 V is 5 V, and the other density is 5 V. Pixels are separated into 0V and binarized.

Next, an embodiment of the binarization circuit 5 will be described with reference to FIG. The signal voltage 3 is input to the inverting input of the open collector output comparator 23, the reference voltage 9 is input to the non-inverting input, and the signal voltage 3 is inverted to the non-inverting input of the open collector output comparator 24. The reference voltage 10 is input to the input. The output of the comparator 23 and the output of the comparator 24 are connected to each other and further pulled up to 5V by the resistor 25. With this configuration, when the signal voltage 3 is higher than the reference voltage 9, the comparator 23
Output becomes 0V, and the signal voltage 3 becomes the reference voltage 9
When it is smaller, the output of the comparator 23 is open. When the signal voltage 3 is lower than the reference voltage 10, the output of the comparator 24 is 0V, and when the signal voltage 3 is higher than the reference voltage 10, the output of the comparator 24 is open.

Since the output of the comparator 23 and the output of the comparator 24 are connected to each other and further pulled up to + 5V by the resistor 25, the comparator 23
When both outputs of V and 24 are open, that is, when the signal voltage 3 is lower than the reference voltage 9 and higher than the reference voltage 10, the output 26 becomes 5V, and at least one of the comparators 23 and 24 outputs 0V. When, that is, when the signal voltage 3 is higher than the reference voltage 9 or lower than the reference voltage 10, the output 26
Becomes 0V. That is, the pixel within the concentration range where the signal voltage 3 obtained by amplifying the voltage generated by the pixel receiving the reflected light from the original document by the amplifier circuit 2 becomes 1.0V to 1.5V, becomes 5V, Pixels of other densities are separated into 0V and binarized.

Next, an embodiment of the binarization circuit 6 will be described with reference to FIG. The signal voltage 3 is input to the inverting input of the open collector output comparator 30, the reference voltage 10 is input to the non-inverting input, and the signal voltage 3 is inverted to the non-inverting input of the open collector output comparator 31. The reference voltage 11 is input to the input. Then, the output of the comparator 30 and the output of the comparator 31 are connected to each other, and the resistance 32 is 5 V
Has been pulled up. With this configuration, when the signal voltage 3 is higher than the reference voltage 10, the output of the comparator 30 is 0V, and when the signal voltage 3 is lower than the reference voltage 10, the output of the comparator 30 is open. When the signal voltage 3 is lower than the reference voltage 11, the output of the comparator 31 is 0V, and when the signal voltage 3 is higher than the reference voltage 11, the output of the comparator 31 is open.

Since the output of the comparator 30 and the output of the comparator 31 are connected to each other and further pulled up to + 5V by the resistor 32, the comparator 30
When both outputs of 3 and 31 are open, that is, when the signal voltage 3 is lower than the reference voltage 10 and higher than the reference voltage 11, the output 33 becomes 5V, and at least one of the comparators 30 and 31 outputs 0V. When
That is, when the signal voltage 3 is higher than the reference voltage 10 or lower than the reference voltage 11, the output 33 becomes 0V. That is, the pixel within the concentration range where the signal voltage 3 obtained by amplifying the voltage generated by the pixel receiving the reflected light from the original document by the amplifier circuit 2 becomes 0.5V to 1.0V becomes 5V, Pixels of other densities are separated into 0V and binarized.

Next, an embodiment of the binarization circuit 7 will be described with reference to FIG. The signal voltage 3 is input to the inverting input of the open collector output comparator 27, the reference voltage 11 is input to the non-inverting input, and the output is pulled up to 5V by the resistor 28. With this configuration, when the signal voltage 3 is lower than the reference voltage 11, the output 29 of the comparator 27 is 5V, and when the signal voltage 3 is higher than the reference voltage 11, the output 29 of the comparator 27 is 0V. That is, the pixel within the density range where the signal voltage 3 obtained by amplifying the voltage generated by the pixel that receives the reflected light from the original document by the amplifier circuit 2 is less than 0.5V is 5V, and the other density is 5V. Pixels are separated into 0V and binarized.

Since the image reading apparatus of this embodiment is constructed as described above, the image formed on the original is
According to the amount of light reflected from the document and received by each pixel of the CCD 1, it is decomposed into four levels of density. That is, if the signal voltage 3 output from the amplifier circuit 2 according to the amount of light received by the pixel 1a is 1.5V to 2.0V, only the output 22 of the binarization circuit 4 outputs 5V, and 1 0.0V
~ 1.5V, only the output 26 of the binarization circuit 5 is 5V
If 0.5V to 1.0V, only the output 33 of the binarization circuit 6 outputs 5V, and if 0V to 0.5V, only the output 29 of the binarization circuit 7 outputs 5V. Therefore, the output of the binarization circuit 4 obtains the image data in which only the portion with the lowest density is separated, and the output of the binarization circuit 7 contains the image data in which only the portion with the highest density is separated. Obtained,
The output of the binarization circuits 5 and 6 provides image data in which the intermediate density portion is separated. Therefore, it is possible to separate only an image portion within a specific density range from an image formed on a document, or directly obtain a plurality of image data separated for each image portion within a plurality of different density ranges. Become.

FIG. 7 shows an example of an image drawn on a document.
The region 40 having the lowest density is drawn with a density such that the output signal voltage 3 of the amplifier circuit 2 of the image reading apparatus of this embodiment is 1.5V to 2.0V. In the area 41, the output signal voltage 3 of the amplifier circuit 2 of the image reading apparatus of this embodiment is 1.
The density is drawn so as to be 0V to 1.5V. The area 42 is drawn at a density such that the output signal voltage 3 of the amplifier circuit 2 of the image reading apparatus of this embodiment is 0.5V to 1.0V. In the region 43 with the highest density, the output signal voltage 3 of the amplifier circuit 2 of the image reading apparatus of this embodiment is 0V to.
It is drawn at a concentration such that it becomes 0.5V.

When the image as described above is read by the image reading apparatus of this embodiment, as shown in FIGS. 8 to 11, the pixel 45 included in the area 40 as the output of the binarization circuit 4 is 5V (logic). Is 1), and the image data 44 in which the pixels included in the other areas are 0 V (logically 0) is obtained.

The area 41 is output as the output of the binarization circuit 5.
The pixel 47 included in is 5V (1 in logic),
Pixels included in other areas are 0V (logically 0)
The image data 46 is obtained.

Further, as an output of the binarization circuit 6, a region 42
Pixel 49 included in is 5V (1 as logic),
Pixels included in other areas are 0V (logically 0)
The image data 48 is obtained.

Further, as an output of the binarization circuit 7, a region 43
The pixel 51 included in is 5V (1 as a logic),
Pixels included in other areas are 0V (logically 0)
The image data 50 is obtained.

As described above, according to the image reading apparatus of the present invention, image data for each predetermined density area can be easily obtained from the image drawn on the original.

Thus, for example, in an embroidery sewing machine, by associating each of the image data 44, 46, 48, 50 with a thread of an arbitrary color, the embroidery data can be easily created from a handwritten image.

In this embodiment, the amplifier circuit 2 is set so that the signal voltage 3 becomes 0 V when the CCD 1 receives no light and the signal voltage 3 becomes 2 V when the maximum amount of light is received. Accordingly, the reference voltage range is 0V and 2
The values of the signal voltage 3 and the reference voltages 9, 10, 11 are not limited to those of the present embodiment, although the values are set so as to be divided into four equal parts. The reference voltage ranges need not be evenly spaced, and may be variable according to the density of the image drawn on the original.

Further, the four generated binary images can be output in parallel as in the present embodiment or serially through a parallel-serial converter.

[0027]

As is apparent from the above description, according to the image reading apparatus of the present invention, only an image portion within a specific density range is separated from an image on a document or a plurality of different density ranges are included. It is possible to directly obtain a plurality of image data separated for each image portion.

[Brief description of drawings]

FIG. 1 is a block diagram of an electronic circuit of an image reading apparatus embodying the present invention.

FIG. 2 is a circuit diagram showing an example of a reference voltage setting circuit that constitutes an electronic circuit of the image reading apparatus of this embodiment.

FIG. 3 is a circuit diagram showing an example of a binarization circuit which constitutes an electronic circuit of the image reading apparatus of this embodiment.

FIG. 4 is a circuit diagram showing an example of a binarization circuit which constitutes an electronic circuit of the image reading apparatus of this embodiment.

FIG. 5 is a circuit diagram showing an example of a binarization circuit which constitutes an electronic circuit of the image reading apparatus of this embodiment.

FIG. 6 is a circuit diagram showing an example of a binarization circuit which constitutes an electronic circuit of the image reading apparatus of this embodiment.

FIG. 7 is an example of an image read by the image reading apparatus of the present embodiment.

8 is an example of image data of an image when the image shown in FIG. 7 is read by the image reading apparatus of the present embodiment.

9 is an example of image data of an image when the image shown in FIG. 7 is read by the image reading apparatus of the present embodiment.

FIG. 10 is an example of image data of an image when the image shown in FIG. 7 is read by the image reading apparatus of the present embodiment.

FIG. 11 is an example of image data of an image when the image shown in FIG. 7 is read by the image reading apparatus of the present embodiment.

[Explanation of symbols]

 1 CCD 2 Amplifying circuit 3 Signal voltage 4 Binarizing circuit 5 Binarizing circuit 6 Binarizing circuit 7 Binarizing circuit 8 Reference voltage setting circuit 9 Reference voltage 10 Reference voltage 11 Reference voltage 20 Comparator 23 Comparator 24 Comparator 27 Comparator 30 comparator 31 comparator

Claims (1)

[Claims] 1. An image reading apparatus that divides an image on a document into a plurality of pixels to generate a digital signal corresponding to the density of each pixel, wherein reflected light or transmitted light from the document corresponds to the density of each pixel. Photoelectric conversion means for converting into a signal voltage; reference voltage range setting means for setting three or more reference voltage ranges different from each other; and binarizing the signal voltage depending on whether or not the signal voltage is within the range of the reference voltage. An image reading apparatus having a plurality of binarizing means for performing the image reading.