JP4424289B2 - Contact image sensor - Google Patents

Description

  The present invention relates to a contact image sensor using a one-dimensional line sensor used in a scanner, a bill discriminator, or the like, which is an image reading device.

  In the image reading apparatus, a white reference plate for shading correction is provided at a position opposite to the image sensor with a medium to be read (document or the like) interposed therebetween, and an output read from the white reference plate before reading the document is referred to. In general, sensitivity nonuniformity correction is performed. For example, in FIG. 1 of Japanese Patent Application Laid-Open No. 2004-61864 (see Patent Document 1), an appropriate shading correction is performed, and the white reference plate does not become an obstruction in document conveyance, and extra light such as flare does not enter. As a document reading apparatus having no document lift, the rotating body 4 that rotates around the fulcrum 5 when the document 6 passes over the image sensor 1 is used as a white reference plate for shading correction, and the rotating body 4 is a plurality of steps 4d. , 4e and a plurality of white reference surfaces 4a, 4b, 4c are disclosed.

  Further, FIG. 1 (see Patent Document 2) of Japanese Patent Laid-Open No. 9-270884 discloses an image reading apparatus 1 that can improve the image quality without scratching the white reference plate with a document. A contact glass 4 a is attached to the upper surface of the contact image sensor 4, and a contact glass 7 is disposed on the contact glass 4 a with a predetermined gap δ by a gap member 11. The white reference plate 8 is disposed in close contact with the back surface of the contact glass 7, and the surface of the white reference plate 8 on the contact glass 7 side is white. On the back surface of the white reference plate 8, a plane regulation structure 9 that improves the flatness of the white reference plate 8 is disposed, and the plane regulation structure 9 is pressed against the white reference plate 8 by a pressure spring 10. The contact image sensor 4 reads an image of the document 6 conveyed between the contact glass 4 a and the contact glass 7 by the conveyance roller 12 and the conveyance driven roller 13. What is discharged by the paper driven roller 15 is disclosed.

JP 2004-61864 A (FIG. 1)

Japanese Patent Laid-Open No. 9-270884 (FIG. 1)

  However, in the device described in Patent Document 1, the white reference mechanism is installed outside the image sensor, and therefore, the white reference portion is contaminated when the document passes between the white reference mechanism and the image sensor. If they are attached, an error occurs in the shading data, and as a result, there is a problem that the shading correction is not performed accurately.

  Further, in the document described in Patent Document 2, it is possible to prevent the white reference member from being scratched or soiled on the document, but the white reference member is provided at the upper part of the reading area of the image sensor. However, there is a problem that it cannot be applied as a reading means using transmitted light.

  The present invention has been made in order to solve the above-described problems, and reduces shading of the white reference portion and enables accurate shading correction and the like even with reading means using transmitted light as well as reflected light. An object is to provide a contact image sensor.

According to the first aspect of the present invention, a contact image sensor includes a light source that irradiates light on a document, a lens that focuses light from the document, a light receiving unit that photoelectrically converts light focused by the lens, and the light receiving unit. a reference member is inserted into the focusing area for focusing the light, is released into the focus region outside provided in the light transmitting member by said lens between the sensor substrate for mounting a, originals and the lens, the lower A housing that supports the lens and the sensor substrate in a region and supports both ends of the transmission body in a region in which a side wall is extended from the lower region over a reading width so that the upper region can be elastically deformed. A slide mechanism unit that moves the upper region of the housing in the document transport direction or in the opposite direction to place the reference member in or out of the focusing region for focusing the light of the lens. Tama It is.

A contact image sensor according to a second aspect of the present invention includes a light source that irradiates light on a document, a lens that focuses light transmitted through the document, a light receiving unit that photoelectrically converts light focused by the lens, and the light reception A reference board provided on the transmission body, which is inserted into a focusing area for focusing light by the lens between the document and the lens and is detached from the focusing area; A housing that supports the lens and the sensor substrate in a region and supports both ends of the transmission body in a region in which a side wall is extended from the lower region over a reading width so that the upper region can be elastically deformed. A slide mechanism unit that moves the upper region of the housing in the document transport direction or in the opposite direction to place the reference member in or out of the focusing region for focusing the light of the lens. It is intended.

A contact image sensor according to a third aspect of the invention includes a light source that irradiates light on a document, a lens that focuses light from the document , a light receiving unit that photoelectrically converts light focused by the lens, and the light receiving unit. a sensor substrate for placing the inserts into the focusing area for focusing the light by the lens between the originals and the lens, and the reference member to be released into the focus region outside the transmission provided with the reference member A cover that extends in a direction perpendicular to the conveyance direction of the document and in a direction orthogonal thereto, and has a telescopic part and a terminal part, and passes the light through the lens, and fixes the terminal part of the cover. A focusing area for focusing the light of the lens by sliding the expansion / contraction part of the cover and moving it in the document transport direction or in the opposite direction by sliding the casing supporting the lens and the sensor substrate In or on its focusing area It is obtained by a sliding mechanism which is arranged outside.

A contact image sensor according to a fourth aspect of the present invention is the contact image sensor according to the third aspect , wherein the expansion / contraction portion of the cover is made of a plastic material .

  In the contact image sensor according to a fifth aspect of the invention, the reference member is a white reference member that reflects light, a black reference member that absorbs light, or a translucent reference member in which light transmittance is set in advance. Item 5. The method according to any one of Items 1 to 4.

As described above, according to the present invention, the reference medium for creating the reference data at the time of shading correction or the like is installed in a part of the contact image sensor, so that the reference medium of the system main body dedicated to the document conveying unit Therefore, there is an advantage that it is possible to save the system and to easily install a transmission light source or the like on the document conveying surface.

Moreover, according to the invention which concerns on Claims 3-4, since the expansion-contraction part (elastic member) was provided in the cover used as a permeation | transmission body, the sliding load by a slide mechanism part can be reduced and wear deterioration can also be prevented.

  Further, according to the invention according to claim 5, by using a reference medium corresponding to the background color of the document or the transmission light source, it can be applied to any of white reference correction, black reference correction and halftone reference correction, and combinations thereof are also possible. Since this is possible, correction using reference data that meets the specifications of the document is possible.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to FIG. FIG. 1 is a cross-sectional configuration diagram of a contact image sensor according to a first embodiment. In FIG. 1, reference numeral 1 denotes a light source, 1a denotes an emission unit that emits light from the light source 1, and 1b blocks unnecessary light from the light source. 1c is a plurality of electrode terminals for driving the light source 1, 2 is a transparent body using a plastic or glass material that transmits light from the light source 1, and 3 is a medium to be read. A manuscript that is image information of banknotes, securities, general documents, etc., 4 is a lens composed of a rod lens array that focuses reflected light or transmitted light from the manuscript, and 5 is focused by the lens 4 A photoelectric conversion unit composed of a semiconductor chip that receives light and a light receiving unit on which the drive circuit is mounted, 6 is a sensor substrate that processes the photoelectric conversion output received by the light receiving unit 5, and 7 is mounted on the sensor substrate 6. 7a is an input / output signal interface connector including a photoelectric conversion output and its signal processing output, and 7b is an ASIC (Application Specific Integrated Circuit) that performs signal processing in conjunction with the CPU and RAM. is there.

  Reference numeral 8 denotes a casing made of plastic or the like for housing or holding the lens 4 or the sensor substrate 6, and 9 denotes an extension spring that is interposed between the casing 8 and the transmission body 2 and has one end fixed to the casing 8. Is a slide pin that slides the transmissive body 2 in parallel with the conveyance surface of the document 3, and constitutes a slide mechanism. 11 is a conveyance guide that moves in conjunction with the slide pin 10, 12 is a white reference member for correction (reference medium) printed on the transparent body 2, and 13 is a reading system device main body (such as a bill discriminator). (Not shown), a support base 14 for fixing, a fixing means 14 including screws for fixing the housing 8 and the support base 13, and a pulley 15 for conveying the document 3.

  The auxiliary line indicating the optical axis is on the optical axis of the lens 4, and the optical information of the document 3 near the focal plane of the lens 4 is imaged on the light receiving unit 5 as information on the focusing area of the lens 4. In the first embodiment, the light source 1, the transmission body 2, the lens 4, the light receiving unit 5, the sensor substrate 6, the housing 8, and the correction reference member 12 are effective reading widths of the document 3 (effective reading widths in the main operation direction). ) Or more than the same length. In the drawings, the same reference numerals indicate the same or corresponding parts.

  FIG. 2 is a cross-sectional view of the main part of the transmission body 2. The reference medium 12 is installed in a region separated from the optical axis, printed on the transmission body 2 with a width of about 3.5 mm by a screen printing method using a thick film insulating paste using a commercially available glass material, and after firing. It is formed as a white pattern with a film thickness of about 30 μm. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

  Next, the operation will be described. In FIG. 1, a part of scattered reflected light from a read medium (original) 3 illuminated by a light source 1 is guided to a photoelectric conversion unit of a light receiving unit 5 by a lens 4, and the photoelectric conversion unit according to the light intensity. The electric signal is converted into an electric signal. The electric signal is subjected to signal processing by the sensor substrate 6 and finally outputted as an image signal from the connector 7 to the outside.

  FIG. 3 is a block diagram of a driving circuit of a contact image sensor (displayed as CIS) in the reading system main body. In synchronization with the system clock (SCLK) of the timing generator, an analog output (SO) photoelectrically converted by the light receiving unit 5 is obtained at the timing of the start signal (SI) synchronized with the CIS clock signal (CLK). The SO is analog-digital (A / D) converted by the ASIC 7b, and the correction circuit performs shading correction including sample and hold, all-bit correction, and the like. To correct the signal data, data is collected from the RAM area storing the signal data and the RAM area storing the reference data, and is processed. A document conveyance signal (DI) is sent each time the document is moved. Further, the CPU and the correction circuit of the ASIC 7b are collectively referred to as a signal processing unit.

  When correction is performed, it is used as a correction start signal in response to a change in the power supply voltage at the time of system start-up. At the time of correction, first, in order to operate the slide pin 10 of the slide mechanism unit installed outside the CIS, a 2-bit slide signal (SS) is sent from the ASIC 7b to be a PUSH or PULL signal of the slide pin 10. At the same time as the PUSH signal is sent, the ASIC 7b gives a signal to the light source driving unit, illuminates the light source 1, reads the reflected light from the white reference medium 12 within one period of the SI signal, and after reading them multiple times, Is stored in the RAM as a reference signal (reference data) for correcting each bit (pixel).

  FIG. 1 shows a normal reading mode, that is, a state in which the document 3 is read. The slide pin 10 of the mechanical control mechanism (sliding mechanism portion) from the outside does not exert a force on the transmission body 2, and the extension spring 9. Is in an extended state, and the reference medium for correction 12 provided in the transmissive body 2 is at a position off the optical axis of the lens 4. Accordingly, the document 3 is appropriately illuminated by the light source 1 without being blocked by the reference medium 12, and the reflected light is guided to the photoelectric conversion unit of the light receiving unit 5 through the lens 4 without being blocked by the reference medium 12.

  On the other hand, FIG. 4 is a cross-sectional configuration diagram of the contact image sensor according to the first embodiment, and shows a shading correction mode or an all-bit correction mode, that is, a state in which the reference medium 12 is read. The slide pin 10 exerts a force to push the transmission body 2 in the document conveying direction, the transmission body 2 slides on the housing 8, and the extension spring 9 is in a compressed state and is provided on the transmission body 2. The correction reference medium 12 is on the optical axis of the lens 4. Therefore, the reference medium 12 is illuminated by the light source 1 regardless of the image image of the document 3, and the reflected light is guided to the photoelectric conversion unit of the light receiving unit 5 through the lens 4.

That is, the document 3 is placed in the same environment as the state where the white reference medium 12 is installed at the position of the document 3. In this state, correction is performed by collecting shading correction data and the like based on the output from the photoelectric conversion unit. After the correction is performed, the force applied to the transmission body 2 by the slide mechanism portion is released, so that the transmission body 2 returns to the position shown in FIG. 1 by the extension force of the extension spring 9, and the normal reading mode is set. In the reading mode, the analog signal (SO) is processed into corrected data by signal processing of the ASIC 7b, and is transmitted as an image output signal to the reading system body outside the CIS.
In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

  Next, the non-uniformity of the photoelectric conversion output of the light receiving unit 5 will be described. Each of the light source 1, the transmission body 2, the lens 4, the photoelectric conversion unit of the light receiving unit 5, etc. has a specific non-uniformity in the reading width direction. That is, the light source 1 has illuminance non-uniformity, the transmissive body 2 and the lens 4 have non-uniform transmittance, and the photoelectric conversion unit has non-uniform conversion sensitivity. The non-uniformity in these photoelectric conversion units appears as multiplication of individual non-uniformities. Even if it is used with this non-uniformity, density unevenness or the like corresponding to the non-uniformity occurs, which is not practical. Therefore, it is common to read a reference medium for correction (correction reference member) such as a uniform white color before reading the document and perform electrical correction so that the output becomes uniform. This correction is generally called shading correction, and correction for all individual bits is called all-bit correction.

  These corrections are triggered by a document conveyance signal each time a document is read, activated by a reset signal after power supply voltage detection is performed when the power is turned on, or outside a reading mode period using a timer incorporated in an ASIC or the like. There is a method of periodically giving a correction instruction signal. Finally, the original reading data (signal data) is non-uniformly corrected with reference data and sent as image data (image output signal) to the reading system main body as an output of the signal processing unit of the ASIC.

Embodiment 2. FIG.
A second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a cross-sectional configuration diagram of the contact image sensor according to the second embodiment. In FIG. 5, reference numeral 80 denotes a casing made of plastic or the like for housing or holding the lens 4 and sensor substrate 6, and 90 is fixed at both ends. The extended spring 120 is provided with a notch in the transparent body 2 and a white reference medium with a white paint applied to the notch, and 130 reads the housing 80 and fixes it to the system equipment body (not shown). It is a support base. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

FIG. 6 is a cross-sectional view of a main part of the transmission body 2 of the contact image sensor according to the second embodiment. The reference medium 120 is installed in a region separated from the optical axis, and a commercially available white paint is poured into the groove width 3.5 mm of the cutout portion of the transmission body 2 and dried to form a white pattern having a film thickness of about 30 μm. . In the figure, the same reference numerals as those in FIG. 5 denote the same or corresponding parts.
FIG. 5 shows a normal reading mode, that is, a state in which the document 3 is read. The slide pin 10 of the slide mechanism portion from the outside does not exert a force on the casing 80, and the extension spring 90 is in the extended state. The correction reference medium 120 provided in the transmission body 2 is at a position off the optical axis of the lens 4. Therefore, the transmitted light of the document 3 illuminated by the light source 1 is guided to the photoelectric conversion unit of the light receiving unit 5 through the lens 4 without being blocked by the reference medium 120.

  On the other hand, FIG. 7 is a cross-sectional configuration diagram of the contact image sensor according to the second embodiment, and shows a shading correction mode or an all-bit correction mode, that is, a state in which the reference medium 120 is read. The slide pin 10 exerts a push force on the casing 80 in the document conveying direction, the upper portion of the casing 80 moves toward the document conveying direction, and the extension spring 90 is in a compressed state and is provided on the transmission body 2. The correction reference medium 120 is on the optical axis of the lens 4. Accordingly, in the state where the document 3 is not conveyed, the illumination light from the light source 1 is reflected by the reference medium 120, and the transmitted light is not generated, so this is set as the reference signal level at the time of correction.

  That is, assuming that the white reference medium 120 is installed at the position of the document 3, correction is performed by collecting shading correction data and the like based on the output from the photoelectric conversion unit in this state. After the correction, the force applied to the housing 80 by the slide mechanism portion is released, so that the housing 80 returns to the position shown in FIG. 5 by the extension force of the extension spring 90, and the normal reading mode is set. In the figure, the same reference numerals as those in FIG. 5 denote the same or corresponding parts.

  Next, the structure of the housing 80 will be described. In the second embodiment, the slide pin 10 of the slide mechanism part is deformed and moved in the vicinity of the case 80 holding the transparent body 2, and the region of the case 80 holding the lens 4 and the sensor substrate 6 is deformed. In order to prevent this, the lower region of the casing 80 is located at both ends in the reading width direction of the transmission body 2 installed on the upper portion of the casing 80 from the lower region of the casing 80 that houses and holds the sensor substrate 6 including the lens 4. The side walls of the casing 80 are extended from the both ends of the transmission body 2 to be supported. That is, the housing 80 is elastically deformable at the top by extending the side wall of the housing 80.

  Therefore, the photoelectric conversion output from the correction reference member 120 is used as reference signal data by moving only the upper part of the casing 80 and moving the reference medium (correction reference member) 120 to the focusing region of the lens 4. The photoelectric conversion output from the document 3 is used as image data by removing the correction reference member from the focusing area. In the second embodiment, the white correction reference member 120 is used. However, in the CIS used in the transmission light source through the document 3, the correction reference member 120 is a black correction reference member that completely absorbs light. Even a member can be reference signal data.

  In the first and second embodiments, the correction reference member is installed on the document transport side of the transmission body 2. However, the correction reference member has a uniform wide pattern, so strictly speaking, the lens 4. It is not necessary to install the lens 4 at the focal position, and it may be a light converging region near the focal position of the lens 4. Therefore, as shown in FIG. 8, the correction reference member is installed on the lens 4 side of the transmission body 2 and is isolated from the conveyance region of the document 3, etc., so that the reference signal data due to dirt or scratches on the correction reference member is obtained. Inconvenience can be prevented and the reliability of data can be improved. Therefore, the stability of the reference signal data can be secured even if the correction reference member installed in the isolation region is a simple white tape or black tape.

Embodiment 3 FIG.
In the first embodiment, the case of collecting one type of reference data has been described. In the third embodiment, the case of collecting two types of white reference data and black reference data will be described.

  Embodiment 3 of the present invention will be described with reference to FIG. FIG. 9 is a cross-sectional view of the main part of the transmissive body 2 of the contact image sensor according to the third embodiment. In FIG. 9, 122 is a white correction reference member, and 123 is a black correction reference member. In the figure, the same reference numerals as those in FIG. 2 denote the same or corresponding parts. In the following description, FIGS. 1 and 3 are applied mutatis mutandis except for the correction reference member.

  Next, the configuration will be described. The white correction reference member 122 is installed in a region (outside the focusing region of the lens) that is separated from the optical axis, and is formed on the transmission body 2 by screen printing using a thick film insulating paste using a commercially available glass material. It is printed with a width of 3.5 mm and formed as a white pattern with a film thickness of about 30 μm after firing. The black correction reference member 123 is installed in a region (outer focusing region of the lens) separated from the optical axis on the opposite side of the white correction reference member 122, and is a thick film insulating paste using a commercially available carbon-containing glass material. Is printed with a width of about 7.0 mm on the transparent body 2 by a screen printing method, and is formed as a black pattern having a film thickness of about 30 μm after firing.

  Next, the operation will be described. When white correction is performed, a correction start signal is received in response to a change in the power supply voltage at the time of starting the system. At the time of white correction, first, in order to operate the slide pin 10 of the slide mechanism unit installed outside the CIS, a 2-bit slide signal (SS) is sent from the ASIC 7b to be a PUSH or PULL signal of the slide pin 10.

  At the same time as the PUSH signal is sent, the ASIC 7b gives a signal to the light source driving unit, illuminates the light source 1, reads the reflected light from the white correction reference member 122 within one period of the SI signal, and after reading a plurality of times. These average values are stored in the RAM as white reference signals for each bit (pixel).

  Next, the ASIC 7b sends the PULL signal and simultaneously gives a signal to the light source driving unit, illuminates the light source 1 again, reads the reflected light from the black correction reference member 123 within one period of the SI signal, and reads the signal a plurality of times. After that, the average value is stored in the RAM as a black correction reference signal for each bit (pixel). Next, the ASIC 7b stops sending the PULL signal and thereafter enters the reading mode.

  Next, after the original image is read, the white reference data and the black reference data stored in the RAM are processed by a well-known arithmetic expression to obtain a CIS output as a corrected image signal. As for the slide mechanism, since the slide signal (SS) from the ASIC 7b is a 2-bit digital signal, when the PUSH and PULL signals are not sent, the reading mode is set, and the extension spring 9 is in a half-extended state with respect to the transmission body 2. It is.

  When the black correction reference signal is collected, the black correction reference member 123 is printed wide so as to completely cover the focusing area of the lens 4.

  In the first and third embodiments, the correction reference member uses a thick film insulating paste to prevent dirt and scratches. However, in the reading system main body in which the transport system does not contact the transmission body 2, The thickness may be reduced, and general white and black shading tapes and paints may be used.

Embodiment 4 FIG.
A fourth embodiment of the present invention will be described with reference to FIG. FIG. 10 is a cross-sectional configuration diagram of the contact image sensor according to the fourth embodiment. In FIG. 10, reference numeral 111 denotes a color light source (light source), 111 a denotes an emission unit that emits light from the light source 111, and 111 b denotes from the light source. A light shielding member made of a white plastic material that shields unnecessary light, etc. 111c is a plurality of electrode terminals of R (red light emission), G (green light emission), and B (blue light emission) including a common electrode for driving the color light source 111 , 20 is a bellows-like cover, a transparent body using a translucent plastic material that transmits light from the light source 111, 20a is a hole provided in the transparent body 20, and 20b is formed of an elastic member. The expansion / contraction part of the transmissive body 20, a casing 81 made of plastic or the like for housing or holding the lens 4 or the sensor substrate 6, and a white reference member (white complement) printed on the transmissive body 20. Use reference member) 125 is the reference member of the printed on the transparent member 20 black (black correction reference member).

The auxiliary line indicating the optical axis is on the optical axis of the lens 4, and the optical information of the document 3 near the focal plane of the lens 4 is imaged on the light receiving unit 5 as information on the focusing area of the lens 4. Further, the light source 111 , the transmissive body 20, the lens 4, the light receiving unit 5, the sensor substrate 6, the casing 81, and the correction reference members 124 and 125 are effective reading widths (in the main scanning direction) of the document 3 in the fourth embodiment. It has a length equal to or greater than the effective reading width. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

  FIG. 11 is a plan view of a contact image sensor including a slide mechanism according to the fourth embodiment. In FIG. 11, reference numeral 131 denotes a CIS fixing holder, which is fixed to a reading system main body (not shown) with screws 14. .

  Next, the structure of the transmissive body 20 will be described. In the fourth embodiment, the transparent body 20 is directly slid together with the slide pin 10 of the slide mechanism unit to deform and move the transparent body 20, thereby switching between the reading mode and the correction mode.

  The transmissive body 20 is interposed between the document 3 and the lens 4, and focuses light from the document surface onto the lens 4, while the transmissive body 20 extends from the document surface in a region orthogonal to the document surface. A bellows-shaped expansion / contraction part made of an elastic member is provided, and the end of the expansion / contraction part is fixed to the casing 81 by a notch provided in the casing 81. In addition, a white correction reference member 124 and a black correction reference member 125 that are selectively provided in the vicinity of the focusing region of the lens 4 are provided in the reading width direction on the lens 4 side of the transmission body 20. . Accordingly, in the correction mode, the photoelectric conversion output from the correction reference member is collected as white and black reference signal data by moving the correction reference member to the focusing region of the lens 4. In the reading mode, the photoelectric conversion output from the document 3 is used as reading data by detaching the correction reference member from the focusing area of the lens 4.

  Next, the operation will be described. When correction is performed, as shown in the block diagram of FIG. 3, a correction start signal is received in response to a change in the power supply voltage at the time of starting up the system. At the time of white correction, first, in order to operate one slide pin 10 of the slide mechanism unit installed on both sides outside the CIS, a 2-bit slide signal (SS) is transmitted from the ASIC 7b to be a PUSH signal of the slide pin 10. . As shown in FIG. 11, the slide pin 10 is welded to the conveyance guide 11, and the tip is directly connected to the rotating shaft of the servo motor, and is movable by the reciprocating motion of the rotating shaft of the servo motor.

  At the same time as the PUSH signal is sent, the ASIC 7b gives a signal to the light source driving unit, illuminates the light source 111, reads the reflected light from the white correction reference member 124 within one period of the SI signal, and after reading a plurality of times. These average values are stored in the RAM as white reference signals for each bit (pixel). This is performed for each light source color.

  Next, in order to operate the other slide pin 10 of the slide mechanism unit installed on both sides outside the CIS, the ASIC 7b sends a PUSH signal and simultaneously gives a signal to the light source driving unit, illuminates the light source 111 again and outputs the SI signal. The reflected light from the black correction reference member 125 within one period is read, and after reading a plurality of times, the average value thereof is stored in the RAM as a black correction reference signal for each bit (pixel). This is performed for each light source color. Next, the ASIC 7b stops sending the PUSH signal, and then enters the reading mode. In addition, when one of the slide pins 10 of the slide mechanism unit on both sides is moved by the PUSH signal, the other slide pin 10 does not operate. Alternatively, it may be a PULL signal.

  Next, after the original image is read, the white reference data and the black reference data stored in the RAM are processed by a well-known arithmetic expression to obtain a CIS output as a corrected image signal. This is output in each light source color.

  In the fourth embodiment, in the reading mode, the white correction reference member 124 and the black correction reference member 125 are installed on the transmissive body 20 on both sides of the optical axis (optical axis line). The correction reference member may be installed in order on one side by increasing the movable distance, and the extendable portion of the cover 20 (transmitting body) may be moved by the slide pin 10.

  In the fourth embodiment, a hole 20a is provided in the cover (transmitter) 20, and in the reading mode, light passing through the hole 20a is read in accordance with the optical axis. However, the hole 20a is covered. In this way, a thin transparent plate may be adhered and fixed to prevent dust and the like, and when it is housed in the system body, the light receiving portion is not easily affected by external light or the like. Also good.

  In the third embodiment and the fourth embodiment, the correction reference member has been described in two colors of white and black. However, the correction reference member is not limited to these, and a correction reference member having a checkered halftone pattern is used as an intermediate. A reference signal for the key area may be obtained. In addition, a translucent reference member in which the light transmittance is set in advance is particularly effective in the CIS using the transmissive light source described in the second embodiment because a part of the transmitted light can be used as the reference data for correction. is there.

  In the first to fourth embodiments, the case where the light source is built in the CIS and the case where the light source is installed outside the CIS has been described. However, the correction reference member is used in a state where the light source is installed both inside and outside the CIS. Reference data may be collected.

1 is a cross-sectional configuration diagram of a contact image sensor according to Embodiment 1 of the present invention. FIG. It is principal part sectional drawing of the transmission body of the contact | adherence image sensor by Embodiment 1 of this invention. 1 is a block diagram of a drive circuit for a contact image sensor according to Embodiment 1 of the present invention. FIG. 1 is a cross-sectional configuration diagram of a contact image sensor according to Embodiment 1 of the present invention. FIG. It is a section lineblock diagram of a contact type image sensor by Embodiment 2 of this invention. It is principal part sectional drawing of the permeation | transmission body of the contact type image sensor by Embodiment 2 of this invention. It is a section lineblock diagram of a contact type image sensor by Embodiment 2 of this invention. It is principal part sectional drawing of the permeation | transmission body of the contact type image sensor relevant to Embodiment 2 of this invention. It is principal part sectional drawing of the transmission body of the contact | adherence type image sensor by Embodiment 3 of this invention. It is a section lineblock diagram of a contact type image sensor by Embodiment 4 of this invention. It is a plane block diagram of the contact | adherence type image sensor by Embodiment 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source, 1a Ejection part, 1b Light-shielding member, 1c Electrode (electrode terminal), 2 Transmitter, 3 Medium to be read (original), 4 Lens, 5 Light-receiving part, 6 Sensor substrate, 7 Electronic component, 7a Connector, 7b ASIC , 8 housing, 9 extension spring, 10 slide pin, 11 transport guide, 12 reference medium (reference member for correction), 13 support base, 14 screw (fixing means), 15 pulley, 20 transparent body (cover), 20a empty Hole part, 20b expansion / contraction part (elastic member), 21 tape, 22 document guide, 80 case, 81 case, 90 extension spring, 111 light source, 111a emission part, 111b light shielding member, 111c electrode (electrode terminal), 120 reference Medium (reference member for correction), 121 White reference medium (reference member for white correction), 122 White reference medium (reference member for white correction), 123 Black reference Body (black correction reference member) 124 white reference medium (white correction reference member) 125 black reference medium (black correction reference member) 130 supporting base, 131 support table (fixed holder).

Claims (5)

A light source for illuminating a document, a lens for focusing the light from the document, and a light receiving unit for photoelectrically converting the focused light at the lens, and the sensor substrate for mounting the light receiving portion, originals and the lens wherein together and inserted into the focusing area for focusing the light, it is released into the focus region outside the reference member provided in the transmission member, for supporting said lens and said sensor substrate in the lower region by the lens between A side wall is extended from the lower area over the reading width so that the upper area can be elastically deformed, and a casing that supports both ends of the transparent body, and the upper area of the casing is set in the document transport direction or vice versa. A contact type image sensor comprising: a slide mechanism configured to move the reference member in or out of a focusing region for focusing the light of the lens by moving in a direction . A light source that irradiates light on a document, a lens that focuses light transmitted through the document, a light receiving unit that photoelectrically converts light focused by the lens, a sensor substrate on which the light receiving unit is placed, a document, and the lens A reference member provided in a transmission body, which is inserted into a focusing region for focusing light by the lens between the two and separated from the focusing region, and supports the lens and the sensor substrate in a lower region, and the A side wall is extended from the lower area over the reading width so that the upper area can be elastically deformed, and a casing that supports both ends of the transparent body, and the upper area of the casing is set in the document transport direction or vice versa. A contact type image sensor comprising: a slide mechanism configured to move the reference member in or out of a focusing region for focusing the light of the lens by moving in a direction . A light source for illuminating a document, a lens for focusing the light from the document, and a light receiving unit for photoelectrically converting the focused light at the lens, and the sensor substrate for mounting the light receiving portion, originals and the lens A reference member that is inserted into a converging region for converging light by the lens between the lens and being separated from the converging region, and a transmission portion provided with the reference member, and a document conveying direction and its opposite direction A cover having a telescopic part and a terminal part extending in an orthogonal region and passing light through the lens, and a housing for fixing the terminal part of the cover and supporting the lens and the sensor substrate And a sliding mechanism for locating the reference member in or out of the focusing area for focusing the light of the lens by sliding the expansion / contraction part of the cover in the document transport direction or in the opposite direction. With close contact Image sensor. The contact image sensor according to claim 3 , wherein the extendable portion of the cover is made of a plastic material .   The contact type image according to claim 1, wherein the reference member is a white reference member that reflects light, a black reference member that absorbs light, or a translucent reference member in which light transmittance is set in advance. Sensor.

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