JP3074090U - Image sensor with infrared light source and dynamic critical module coupled thereto - Google Patents

Abstract

(57) [Summary] (Modified) [PROBLEMS] To easily convert an analog output signal into a digital signal in a dynamic critical module of a scanning device that removes a color background in a scanning document using infrared light as irradiation light. I do. A dynamic critical module for binarizing an analog video signal formed by a standard CIS to form a digital output includes a comparator circuit and a follower bandpass filter circuit. An average background signal of the scanned image is formed by the follower bandpass filter circuit. The comparator circuit compares the output signal of the CIS with the average background signal. If the output signal of the CIS is brighter than the average background signal, the digital signal is set to 1. Conversely, if it is dark, the digital signal is set to zero.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a type of scanning device, and more particularly, to a module used with a CIS scanner, which is used to provide a dynamic critical level of image scanning. In addition, the use of an infrared light source improves the discrimination of the scanning device. In this specification, a CIS or contact image sensor module is described by way of a typical example of a scanning device, provided that the invention is not limited to the image sensing of other scanning devices such as a CCD array, a photodiode array or an active pixel array. Applies to modules.

[0002]

[Prior art]

 Current imaging technology is already at the stage where sufficiently accurate and inexpensive scanning devices can be manufactured. These systems are simple in construction and low in manufacturing costs, but produce extremely accurate scan results. One revolutionary advance in imaging technology is the use of a full width contact image sensor (CIS) system. These systems not only significantly reduce the space required for the system, but also provide good reproduction images through the use of linear adjacent mixed sensor arrays.

FIG. 1 shows a type of full width CIS system. Early imaging systems required the use of optical reduction systems due to limited sensor width. However, in the full-width system, a full-width lens rod 52 is used instead of the optical reduction system. It scans documents in a one-to-one manner. Thus, the lens rod 52 and the image sensor 54 array have the same width and are equal to or greater than the width of the scanned document. Due to this precise arrangement, the device reduces the distance of the image sensor 54 from the scanning document to less than 2 cm.

In this full width CIS system, a light source (eg, an LED bar 56 shown) illuminates and reflects a scanned document. The reflected light directly passes through the full-width lens rod 52 and then enters the full-width image sensor 54 array. The independent sensors in this array are sequentially activated to detect the light level of all scan lines. Traditionally, a yellow-green LED is used for the LED rod 56.

FIG. 2 is a display diagram of the operation system of FIG. The system uses multiple, independent sensing chips on a single substrate that are interconnected, the number of independent sensing chips being selected according to the dimensions of the operating literature. In the illustration, 13 independent sensing chips are used, each one of which has 96 sensing elements. This array thus has 1248 pixel elements on each scan line. The CIS system further comprises one signal processing device, which in turn activates this independent sensing chip and processes the signals output from it.

FIG. 3 is a sequence diagram of FIGS. 1 and 2.

[0007] The structure and function of the CIS module are described in detail in Taiwan Patent Application Nos. 86218159 and 87106875 filed by the present applicant, and a description thereof will not be repeated.

As mentioned above, the scanning module is a well-developed effective and practical technology. In particular, it is particularly accurate when scanning monochrome documents. It uses a single background level (white) as a reference value, generates an output signal, does not require large storage capacity, and is extremely saving in use. However, when scanning documents with multiple colors or gray scales, the required storage space can be surprising. Taking 8 1/2 x 11 paper with a scanning resolution of 300 dpi as an example, approximately 8.5 million data bits are required. As can be seen, it is very important to consider the data capacity.

Further, special care must be taken when transmitting a scanned image to a distant place. In such applications, it is often necessary to compress the data for transmission.

In addition to the transmission applications described above, many other scanning applications operate this compressed data output function. This function can be applied to peripheral circuits that are small, have low manufacturing costs, and require relatively few output pins. Taking a case where a check is scanned in a store as an example, it is common in the United States and Europe to treat a check as money, and therefore, in such an area, an automatic scanning system is installed in most retail stores. This application requires only one inexpensive scanner to be installed. However, one major problem arises when scanning documents, such as checks, is that there is a wide variety of rich variability in the document background. Currently, most literature is color-designed and tends to replace traditional monochrome literature. As a result, checks have come to have an infinite variety and form of background.

[0011] Traditionally, scanning devices that eliminate color backgrounds and have only black or gray data identification have utilized special light sources. The use of RGB light is very convenient, however, the RGB light source is very expensive, so that a CIS system using an RGB light source was not practical. In addition, there is a white-cathode cathode ray tube as a light source to achieve the above-mentioned function, which requires a ballaster, and it is not stable unless the light is output after a long period of time when the device is turned on. Due to such technical limitations, the application of the white cold cathode fluorescent lamp was not practical.

[0012]

[Problems to be solved by the invention]

 It is an object of the invention to provide a kind of circuit which processes the analog output of the scanning device and outputs the compressed digital data of this scanning pixel.

Another object of the present invention is to make the above-described circuit a circuit having a small space, a simple manufacturing process, and a low cost.

Another object of the present invention is to provide a module including the above-described circuit of the present invention, and to reduce the composition of the number of output pins to a minimum.

The present invention further provides a scanning device having excellent distinguishing characteristics, wherein the scanning device is capable of distinguishing a background of a color graphic from a black or gray character.

[0016]

[Means for Solving the Problems]

 According to a first aspect of the present invention, in the dynamic critical module coupled with the contact type image sensing module, the dynamic critical module includes an analog circuit composed of a comparator and a follower low bandpass filter, and the analog circuit includes the analog circuit. Processing the analog input video signal transmitted from the contact image sensing module, and outputting a binary digital signal, wherein the dynamic critical module establishes a variable average background level with the input video signal, thereby In digitizing the input video signal, the comparator compares the input video signal with the average background level to generate an output signal, the input video signal forming a bright area of the scanned image. If there is, the value of the output signal of the comparator is set to 1, and conversely, the input video signal If it is formed, the output signal of the comparator is set to 0, and the contact type image sensing module includes one light source, and the light source emits light belonging to an infrared light range. It is a dynamic criticality module that is combined with a contact type image sensing module. According to a second aspect of the present invention, there is provided a dynamic critical module coupled with the contact type image sensing module according to the first aspect, wherein the wavelength of the light emitted from the light source is within a range of 880 ± 70 nm. I have. The invention according to claim 3 is a dynamic critical module coupled to a contact-type image sensing module, wherein the dynamic critical module includes a follower low bandpass filter circuit and a comparator circuit, and the follower low bandpass filter circuit includes one. One buffer circuit and one start critical bias circuit, the comparator circuit and the follower low bandpass filter circuit form one analog circuit, and the input video signal formed by the contact type image sensing module is averaged. After that, the potential value of the starting critical bias circuit and the follower low bandpass filter circuit are summed, and one reference background signal is generated, and the reference background signal is connected to the input video signal via a buffer amplifier. Isolated, the reference background signal is transmitted to a first input of the comparator circuit; If the second input of the comparator circuit directly receives the input video signal and the comparator circuit generates an output signal, and the input video signal forms a bright area of the scanned image, the output of the comparator circuit If the value of the signal is 1, and if the input video signal forms a dark portion of the scanned image, the output signal of the comparator is set to 0, and the contact type image sensing module uses one light source. A dynamic critical module coupled to the contact type image sensing module, wherein the light source emits light belonging to an infrared light range. According to a fourth aspect of the present invention, there is provided a dynamic criticality module coupled with the contact type image sensing module according to the third aspect, wherein a wavelength of light emitted from the light source is within a range of 880 ± 70 nm. I have. According to a fifth aspect of the present invention, there is provided a dynamic critical module combined with an image sensing module using a CCD array, a photodiode array or an active pixel array, wherein the dynamic critical module includes one comparator and one follower low bandpass. An analog circuit composed of a filter, the analog circuit processes an analog input video signal transmitted by the image sensing module and outputs a binary digital signal, and the dynamic critical module outputs the input video signal. Establishes one variable average background level value, and in digitizing the input video signal, the comparator compares the input video signal with the average background level value to generate an output signal; If the signal forms a bright area of the scanned image, the output of the comparator If the value of the force signal is 1, and if the input video signal forms a dark part of the scanned image, the output signal of the comparator is 0, and the image sensing module has one light source, The dynamic critical module combined with the image sensing module is characterized in that the light source emits light belonging to the infrared light range. According to a sixth aspect of the present invention, there is provided a dynamic criticality module to be combined with the image sensing module according to the fifth aspect, wherein a wavelength of light emitted from the light source is within a range of 880 ± 70 nm. According to a seventh aspect of the present invention, there is provided a dynamic critical module combined with an image sensing module using a CCD array, a photo diode array or an active pixel array, wherein the dynamic critical module comprises a follower low bandpass filter circuit and a comparator circuit. Wherein the follower low bandpass filter circuit comprises one buffer amplifier and one start critical bias circuit, the comparator circuit and the follower low bandpass filter circuit form one analog circuit, and the image sensing module comprises After the input video signal to be formed is averaged, it is summed with the potential value of the starting critical bias circuit and the follower low bandpass filter circuit, and one reference background signal is generated, and the reference background signal is buffer amplified. Isolated from the input video signal via the The reference background signal is transmitted to a first input of the comparator circuit, a second input of the comparator circuit directly receives the input video signal, and the comparator circuit generates an output signal, If the input video signal forms a bright area of the scanned image, the value of the output signal of the comparator is set to 1. Conversely, if the input video signal forms a dark area of the scanned image, the comparison is made. A dynamic critical module coupled to the image sensing module, characterized in that the output signal of the detector is zero and the image sensing module comprises a light source, the light source emitting light belonging to the infrared light range. Jules. The invention according to claim 8 is a dynamic criticality module combined with the image sensing module according to claim 7, wherein the wavelength of the light emitted from the light source is within a range of 880 ± 70 nm. According to a ninth aspect of the present invention, there is provided a contact-type image sensing module including a light source for emitting light belonging to an infrared light range and capable of eliminating a color background of a scanned document. A tenth aspect of the present invention is the contact type image sensing module according to the ninth aspect, wherein a wavelength of light emitted from the light source is within a range of 880 ± 70 nm. And According to an eleventh aspect of the present invention, there is provided an image sensing module using a CCD array, a photo diode array or an active pixel array, wherein the image sensing module can eliminate a color background of a scanning document and a light belonging to an infrared light range. The image sensing module features a light source capable of emitting light. According to a twelfth aspect of the present invention, there is provided the image sensing module according to the eleventh aspect, wherein a wavelength of light emitted from the light source is within a range of 880 ± 70 nm.

[0017]

[Embodiment of the invention]

 The present invention provides a dynamic critical binary A / D converter, or so-called follower digitizer circuit. This module circuit includes one comparator circuit and a followerlow bandpass filter circuit. The dynamic critical module receives the output signal of the CIS module and outputs one follower (variable) background signal. This follower background signal is further compared with the output signal of the CIS by one comparator. The output of this comparator is a binary output digital signal.

The circuit of the present invention is designed for use in conjunction with a scanning device, particularly a CIS system. And this circuit has a wide variety of applications to meet the requirements of pre-processing digitized video signals.

The circuit design of this dynamic critical module is fairly simple in practice. This circuit provides a low cost, low component density module and can be easily integrated with existing modules without increasing the size and manufacturing cost of the CIS module. This circuit occupies only half the space of existing digitizing circuits that perform similar functions.

In addition, the present invention uses the technology of an infrared (IR) light source, in particular, uses infrared light having a wavelength of 880 nm, thereby greatly improving the discriminating power of the scanning device. Scanners that use infrared light as a light source in this way can easily erase the color background in the check, and thus quickly and easily read the black or gray book entry data printed on the check.

[0021]

【Example】

 Please refer to FIG. The dynamic critical module 10 of the present invention includes one analog circuit, which is used to digitize an analog video signal generated by a standard CIS to form a vinyl digital output. This circuit includes a comparator circuit 20 and a follower low bandpass filter circuit 30. The digitization process is completed by processing the signal output by the CIS by the dynamic criticality module 10 and tracking the background level of the scanned image. The digitalizer forms an average background signal, which is then compared with the output signal of the CIS using this comparator circuit 20. Comparing the CIS output signal with this reference signal causes comparator circuit 20 to generate a binary digital output signal.

FIG. 6 shows the digitization processing technique currently used to achieve a function similar to that of the dynamic critical module. 5 and 6 show the advantages of the present invention. To digitize the signal, an anti-alias filter 92 and an A / D converter 94 are provided at the input of the circuit. In contrast to the present invention, the present invention does not require this composition. In addition, the dynamic critical module circuit design utilizes a simple RC low bandpass filter 30 to replace the complex digital low bandpass filter equivalent circuit of known techniques. This known technique comprises a digital adder 96 and a delay coefficient memory 98 for feedback coefficients, which are connected by a feedback bus. The digital output of the low bandpass filter provides one reference for comparison, which is the other digital input signal received by the digital comparator 99 via the digital output bus from the A / D converter 94. is there. After these two digital signals are compared by comparator 99, one high or low potential output signal is generated, ie, a binary digitized signal on a single output line. . As a result, the corresponding signal processing in analog form and its analog part are rather complicated.

FIG. 7 is a circuit diagram in which the dynamic critical module 10 and the CIS module are combined. The two constituent parts of the dynamic critical module 10, the comparator circuit 20 and the follower-low bandpass filter circuit 30, are as shown in FIG. The CIS module circuit 5 generates an analog pixel signal, and the analog pixel signal is directly proportional to the reflected light level of the scanned document screen. This video signal is sent to the dynamic critical module 10 of the present invention.

The dynamic critical module 10 comprises two main functional circuits, a follower low bandpass filter circuit 30 and a comparator circuit 20. This follower low bandpass filter circuit 30 includes a buffer amplifier U3, an initial threshold bias (ITB) composition, a resistor R15 and a capacitor C10. According to the present embodiment, they are 10 kΩ and 0.1 μf, respectively. This ITB composition includes three resistors R6, R9, and R15, and in the present embodiment, the resistance values are 100 kΩ, 310 kΩ, and 10 kΩ, respectively. (The resistor R15 is also a composition element having a low bandpass filter function and an ITB function.) The buffer amplifier U3, which is the driving element of the follower low bandpass filter circuit 30, is a high resistance input buffer. The comparator 20 circuit includes a comparator U2 which is a driving element. The comparator circuit 20 compares the output signal of the follower low bandpass filter circuit 30 with the analog pixel signal output from the CIS module circuit 5.

The dynamic critical module 10 receives an analog pixel signal output from the CIS module circuit 5 at a connection point with a TV display (as shown in FIG. 5). The video signal is split into two tributaries at the TV junction. The first branch passes through the follower low bandpass filter circuit 30 to generate one reference voltage signal, which corresponds to the average background level of the video signal. The set value of the background level is determined by two functions of the follower low bandpass filter circuit 30, namely, (1) the response of the low bandpass filter portion in the circuit, and (2) the voltage value of the installed ITB bias. It is determined. (1) Time constant. The reference voltage signal is generated after passing through one low band pass filter, and the main role of the low band pass filter is to determine the time constant of the average of the input video signal. In addition, the low band pass filter also determines the tracking rate of the background signal. This time constant is determined by the values of C10 and R15, and the resulting image results are naturally related to this composition. In other words, the optical spatial frequency of this image component is filtered, and the required image frequency is selected as the background component. (2) ITB voltage setting. The reference voltage signal is output by the follower low bandpass filter circuit 30, which is basically completed by transmitting an image pixel signal through an integration function and an average. However, for example, one integrator, this follower low bandpass filter circuit 30 as well as the comparator cannot determine the decision level that separates the high or low level of the video signal. The ITB circuit adjusts the bias level, thereby providing a compensation voltage between the determined level and the average level. This ITB compensation voltage is adjusted according to the resistance values of the resistors R6, R9 and R15NO. As shown in FIGS. 7 and 8, the ITB voltage is determined by the ratio of these resistances and the voltage applied to its endpoint. Since the ITB voltage level occurs at the junction of the background signals to be drawn with R6, R9, R15 and C10, this average background level is increased or decreased by this ITB value. In other words, the ITB increases or decreases this reference voltage signal by one fixed amount.

Here, these compositions C10, R15, R9, and R6 having a regulating function, according to the principle of the present invention, generate only one interaction to generate a composition value that can be used in the apparatus. Please be careful. The design criteria of the present invention do not require the extra circuit cost, as described above, without completely isolating the two functions described above. If the ITB composition and the follower low bandpass filter are separated, the cost will be relatively high. To reduce the interaction between these compositions, the resistance values of R6 and R9 are much higher than the value of R15. Under these conditions, the time constant and ITB settings are adjustable with minimal interaction.

Inside the follower low bandpass filter circuit 30, the voltage levels of this video signal and the ITB circuit are averaged and summed at the junction of C10, R15, R9 and R6. After the voltage output from the follower low bandpass filter circuit 30 is buffered by the buffer amplifier U3, it is separated from the input video signal and supplied to the output point TR.

The reference signal output from the follower low bandpass filter circuit 30 to the point TR is connected to the opposite input terminal of the comparator U2. This signal is compared with the video signal output from the CIS module circuit 5, and this video signal is transmitted through the resistor R13 to the positive input terminal of the comparator U2. Thereafter, the comparator circuit 20 generates one output signal depending on whether or not the intensity of the input video signal is greater than the intensity of the output signal (reference signal) of the follower low bandpass filter circuit 30.

The digital output of the dynamic critical module 10 is binary, which is determined by the difference between the background reference signal and the input video signal. Meanwhile, the digital output obtained from the input video signal obtained in the relatively bright area of the scanned image is set to 1, and the digital output obtained from the input video signal obtained in the relatively dark area of the scanned image is set to 0. You.

The sequence diagram of the present invention is shown in FIG.

The present invention also provides a very precise binary digitized CIS module 10 manufactured using this extremely effective circuit design. As shown in FIG. 4, the dimensions of this module are only 25.6 mm × 110 mm × 13 mm.

One of the most important applications of the dynamic criticality module 10 coupled to the CIS of the present invention is a scanner for personal checks used in commerce. When applied to this product, the present inventors have realized that the biggest obstacle is how to identify the relevant background color or design of the printed product. All checks have data printed in black or gray, so it is important to consider how to more easily erase all other colors in the scanned data to process this black or gray image. Deserve.

One of the characteristics of an infrared (IR) light source is that its absorption by black or gray ink is particularly high, and that of color inks (RGB and other colors) is very high. The infrared light is almost completely absorbed by the black ink, and the infrared light absorption capacity of the gray ink is also about 80%. However, a large amount of infrared light is reflected by color ink, RGB, and other color inks. In addition, silicon-based sensors are very sensitive to infrared light. FIG. 10 shows the sensitivity of the silicon sensor to different light wavelengths. As shown in the figure, infrared light (wavelength about 880 ± 70 nm) is an excellent light source that can be used to eliminate color backgrounds in the literature. For example, when used to scan a bank check, it can hold important data printed in black or gray ink. Accordingly, the CIS system of the present invention is provided with an LED 40 capable of emitting infrared light, as shown in FIG. The wavelength of the light emitted from the LED 40 is 880 ± 70 nm.

The scanning device using the infrared light source of the present invention not only has relatively low power consumption, but also has a particularly low color consumption compared to the standard yellow-green LED employed in the well-known CIS system. Therefore, the reflectance of infrared light is several times higher.

[0035]

[Effects of the Invention] Overall, the image sensing module of the present invention employs infrared light as light for illuminating the scanning document, and achieves the purpose of removing the color background in the scanning document by the characteristics of the infrared light. I have. In addition, the kinetic critical module coupled to this image sensing module adopts an analog circuit composed of one comparator and one follower low bandpass filter, so that the present invention has the following advantages. . 1. One of the advantages of the present invention is that the analog output signal of the CIS scanner can be converted to a digital signal through simple steps. 2. Another advantage of the present invention is that the space required by the module is very small. 3. Yet another advantage of the present invention is that its output pin count composition can be reduced to a minimum. 4. Yet another advantage of the present invention is that the use of infrared light enhances the discrimination between color graphic backgrounds and black or gray characters.

The above description of the embodiments has been made in order to explain the purpose of the present invention and the achievement thereof, and does not limit the scope of the present invention. Modification of details that can be made based on the present invention or Any modifications shall fall within the scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a schematic representation of a traditional full width CIS system scanner.

FIG. 2 is an electric circuit diagram of an operation circuit of the scanning device of FIG.

FIG. 3 is a sequence diagram of the apparatus of FIGS. 1 and 2;

FIG. 4 is a view showing the appearance of a module having the circuit design of the present invention.

FIG. 5 is a functional block diagram of the present invention.

FIG. 6 is a block diagram of a well-known digitizing method to be compared with the present invention.

FIG. 7 is a circuit block diagram in which the present invention is installed in a CIS system.

FIG. 8 is an electric circuit diagram of the dynamic critical module of the present invention.

FIG. 9 is a sequence diagram of the dynamic criticality module of the present invention.

FIG. 10 is a diagram showing the sensitivity of a known silicon sensor to different light wavelengths.

FIG. 11 is a schematic diagram of a CIS system employing the infrared light source of the present invention.

[Explanation of symbols]

Reference Signs List 5 CIS module circuit 10 Dynamic critical module 20 Comparator circuit 30 Follower low band pass filter circuit 40 Infrared light source 52 Full width lens rod 54 Sensor 56 LED rod 92 Antialiasing filter 94 A / D converter 96 Digital adder 98 Delay storage memory 99 Digital comparator

 ──────────────────────────────────────────────────続 き Continued on the front page (73) Utility model holder 500280342 1933 O'Toole Ave. Suite A 107, San Jose, CA 95131, U.S. Pat. S. A. (72) Inventor Satoru Sea Tanaka United States of America San Jose 95131 San Jose Suite A 107 Autour Avenue 1933 (72) Inventor Sing Fu Tzen United States of America San Jose 95131 San Jose Suite A 107 Autour Avenue 1933 (72) Inventor Fen Thanh United States of America San Jose 95131 California San Jose Suite A 107 Autour Avenue 1933

Claims (12)

[Utility model registration claims] 1. A dynamic critical module combined with a contact type image sensing module, wherein the dynamic critical module comprises an analog circuit composed of a comparator and a follower low bandpass filter, wherein the analog circuit comprises:
Processing the analog input video signal transmitted from the contact-type image sensing module, and outputting a binary digital signal, wherein the dynamic critical module establishes a variable average background level with the input video signal, whereby the input In digitizing a video signal, if the comparator compares the input video signal with the average background level to generate an output signal, and the input video signal forms a bright area of the scanned image, If the value of the output signal of the comparator is 1, and if the input video signal forms a dark portion of the scanned image, the output signal of the comparator is 0.
A dynamic critical module combined with the contact type image sensing module, wherein the contact type image sensing module includes one light source, and the light source emits light belonging to an infrared light range. 2. The wavelength of light emitted from the light source is 880 ±
The dynamic critical module combined with the contact type image sensing module according to claim 1, wherein the dynamic critical module is within a range of 70 nm. 3. A dynamic critical module coupled to a contact type image sensing module, the dynamic critical module including a follower low bandpass filter circuit and a comparator circuit, wherein the follower low bandpass filter circuit includes one buffer amplifier. A starting critical bias circuit, the comparator circuit and the follower low bandpass filter circuit forming an analog circuit, and the starting critical signal after the input video signal formed by the contact type image sensing module is averaged. The potential value of the bias circuit and the sum in the follower low bandpass filter circuit to generate a reference background signal, the reference background signal being isolated from the input video signal via a buffer amplifier, and A signal is transmitted to a first input of the comparator circuit; If the second input receives the input video signal directly and the comparator circuit generates an output signal, and the input video signal forms a bright area of the scanned image, the value of the output signal of the comparator is If the input video signal forms a dark portion of the scanned image, the output signal of the comparator is set to 0, and the contact type image sensing module has one light source, and the light source is red. A dynamic critical module combined with a contact type image sensing module, wherein the dynamic critical module emits light belonging to an external light range. 4. The wavelength of light emitted from the light source is 880 ±
The dynamic critical module combined with the contact type image sensing module according to claim 3, wherein the dynamic critical module is within a range of 70 nm. 5. A dynamic critical module combined with an image sensing module using a CCD array, a photo diode array or an active pixel array, wherein the dynamic critical module is composed of one comparator and one follower low bandpass filter. An analog circuit for processing an analog input video signal transmitted by the image sensing module and outputting a binary digital signal, wherein the dynamic critical module generates a variable average background level value according to the input video signal. And in the digitizing of the input video signal, the comparator compares the input video signal with the average background level value to generate an output signal, wherein the input video signal is a bright area of the scanned image. If it forms, the value of the output signal of the comparator If the input video signal forms a dark portion of the scanned image, the output signal of the comparator is set to 0, the image sensing module has one light source, and the light source is an infrared light. A dynamic critical module combined with an image sensing module, wherein the dynamic critical module emits light belonging to a range. 6. The wavelength of light emitted from the light source is 880 ±
The dynamic critical module combined with the image sensing module according to claim 5, wherein the dynamic critical module is within a range of 70 nm. 7. A dynamic critical module combined with an image sensing module using a CCD array, a photo diode array or an active pixel array, the dynamic critical module comprising a follower low bandpass filter circuit and a comparator circuit, The low bandpass filter circuit includes one buffer amplifier and one start critical bias circuit, the comparator circuit and the follower low bandpass filter circuit form one analog circuit, and the input video signal formed by the image sensing module is After averaging, the potential value of the onset critical bias circuit and the follower low bandpass filter circuit are summed, and one reference background signal is generated, and the reference background signal is supplied to the input video signal via a buffer amplifier Is isolated from the A background signal is transmitted to a first input of the comparator circuit, a second input of the comparator circuit receives the input video signal directly, the comparator circuit generates an output signal, and the input video signal is If the bright area of the scanned image is formed, the value of the output signal of the comparator is set to 1. On the other hand, if the input video signal is formed of a dark area of the scanned image, the output signal of the comparator is A dynamic critical module combined with the image sensing module, wherein the image sensing module has one light source, and the light source emits light belonging to an infrared light range. 8. The wavelength of light emitted from the light source is 880 ±
The dynamic critical module combined with the image sensing module according to claim 7, wherein the dynamic critical module is in a range of 70 nm. 9. A contact-type image sensing module capable of eliminating a color background of a scanned document, comprising a light source that emits light belonging to an infrared light range. 10. The wavelength of light emitted from the light source is 880.
10. The range of ± 70 nm.
A contact-type image sensing module capable of eliminating the color background of the scanning document described in (1). 11. An image sensing module using a CCD array, a photo diode array or an active pixel array, wherein the image sensing module can eliminate a color background of a scanned document,
An image sensing module comprising a light source capable of emitting light belonging to an infrared light range. 12. The wavelength of light emitted from the light source is 880.
2. The method according to claim 1, wherein said range is within ± 70 nm.
2. The image sensing module according to 1.