JP6135211B2 - Scanner device - Google Patents

Description

  The present invention relates to a scanner device using an illumination device in which a plurality of pseudo white LEDs made of a blue LED chip and a yellow phosphor are arranged in a main scanning direction.

  As a conventional lighting device, one using a pseudo white LED including a blue LED chip and a yellow phosphor is known. In the pseudo white LED, when blue light from the blue LED chip passes through the yellow phosphor, the yellow phosphor is excited by the blue light to generate yellow fluorescence. Thereby, in the pseudo white LED, the yellow fluorescence and the blue color transmitted through the yellow phosphor are combined to form white light, and this white light is emitted (for example, see Patent Documents 1 to 4).

  In the plurality of pseudo white LEDs of the illumination device, the ratio of the blue light transmitted through the phosphor slightly varies depending on the amount of blue light emitted and the distance through which the blue light phosphor passes. For this reason, the color (color tone) such as spectral characteristics or chromaticity varies for each pseudo white LED. When image reading is performed without taking this color variation of the light source into consideration, color variations such as pure white, yellowish white, and blueish white occur, and there is a possibility that the reading quality may deteriorate.

  An illumination device for eliminating such variations in color tone is known. For example, an illumination unit disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2009-169198) is known as an illumination device for eliminating variations in color tone. In this illumination unit, a plurality of light sources for irradiating illumination light toward the document surface are arranged in a line. In addition, in this illumination unit, a variation in color is reduced by adopting a configuration in which a light beam spreading in the light source arrangement direction is irradiated in the light source arrangement direction so as to irradiate the document surface.

  In this configuration, if the chromaticity variation of the pseudo white LED is large, the color will be different from place to place. For this reason, variation in color tone is suppressed by selecting and using pseudo white LEDs whose color difference corresponding to the light emission angle is a predetermined value or less.

  However, when the chromaticity variation is limited, since it is necessary to select a pseudo white LED in which the color difference corresponding to the emission angle is equal to or less than a predetermined value as in Patent Document 1, the unit price increases, which is not preferable.

  In Patent Document 3 (Japanese Patent No. 4511634), a blue-side pseudo white LED and a yellow-side pseudo white LED are arranged adjacent to each other, and at least one of them is an illumination optical system that performs color control by PWM control.

  In this illumination optical system, variations in color tone occur mainly due to variations in the emission wavelength of the blue light emitting element. The dispersion in the longitudinal direction (arrow line B) at this time is mainly caused by the amount of fluorescent particles mixed in the covering member and dispersion of the dispersion. In order to reduce this variation, it is preferable to use a pseudo white LED that ranks and selects the emission color in a desired chromaticity range in terms of center color tone, color tone unevenness, and the like.

  However, in the case of the configuration using only the pseudo white LED of a specific ranked product, there is a problem that other rank products are unnecessary and the total cost for obtaining the pseudo white LED is high.

  For this reason, in Patent Document 3, the yield of pseudo white LEDs is increased by combining pseudo white LEDs that emit light with a wide range of whiteness that deviates from the desired whiteness, thereby increasing the availability of pseudo white LEDs with a wide range of chromaticities. We are also thinking about improving it.

  However, when pseudo white LEDs having such a wide range of chromaticity variations are received, a process of selecting pseudo white LEDs that can be input when producing a lighting unit occurs. Also in this case, there is a problem that the total cost for the process of selecting the pseudo white LED is high.

  Provided is an illumination device that does not require a step of selecting pseudo white LEDs in order to reduce chromaticity variations on a document surface even if chromaticity variations are large in such an illumination optical system using a plurality of pseudo white LEDs. It is desirable to be able to do it.

  By the way, Patent Document 2 (Japanese Unexamined Patent Application Publication No. 2009-245902) discloses a planar illumination device and a liquid crystal display device in which illumination light from a pseudo white LED and blue illumination light from a blue LED arranged in the vicinity thereof are mixed. Is disclosed. The planar illumination device and the liquid crystal display device can emit light with improved color reproducibility, and can display a high-quality image from the liquid crystal display panel.

  In this planar illumination device, the irradiated portion of the contact glass of the liquid crystal display panel is irradiated with a light source unit in which pseudo white LEDs and blue LEDs are alternately arranged in a straight line (line shape).

  However, correction of chromaticity variation in the main scanning direction is not necessarily considered.

  Therefore, the present invention provides a scanner device that can reduce chromaticity variation on a document surface by using a correction blue LED even if chromaticity variation is large in an illumination optical system using a plurality of pseudo white LEDs. It is intended to do.

In order to achieve this object, a scanner device of the present invention comprises a first blue LED that emits blue light and a phosphor that absorbs light from the first blue LED and fluoresces light in a yellow wavelength band. A plurality of pseudo white LEDs, a plurality of second blue LEDs emitting blue light, a first illumination optical system for illuminating the irradiated portion with light from the pseudo white LEDs, and the second blue color A second illumination optical system that illuminates the irradiated portion with light from the LED, a line sensor that reads the light from the irradiated portion, and a reading optical system that propagates the light from the irradiated portion to the line sensor A predetermined blue LED among the second blue LEDs so that the balance of the red output, green output and blue output of the line sensor when the pseudo white LED is lit is within a predetermined range. Appropriate amount Shining in an amount, and characterized Rukoto for dimming all of the pseudo-white LED.

  According to this configuration, even if there is a large chromaticity variation in an illumination optical system using a plurality of pseudo white LEDs, the chromaticity variation on the document surface can be reduced by using the correction blue LED.

It is a schematic explanatory drawing which shows Example 1 of the scanner apparatus using the illumination optical system which concerns on embodiment of this invention. FIG. 2 is a plan view of the light source unit of FIG. 1, which is an optical system in which a plurality of pseudo white LEDs and second blue LEDs are arranged in a line. FIG. 3 is a control circuit diagram of the light source unit in FIG. 2. The distance and chromaticity Cx. Of the plurality of pseudo white LEDs located in the main scanning direction from the center of the light source unit in the main scanning direction (main scanning reference position Bp). It is explanatory drawing which shows the relationship with Cy, Comprising: It is explanatory drawing explaining illumination nonuniformity. The distance and chromaticity Cx. Of the plurality of pseudo white LEDs positioned in the main scanning direction from the center in the main scanning direction (main scanning reference position Bp) of the light source unit after the illumination unevenness in FIG. It is explanatory drawing which shows the relationship with Cy. The distance and chromaticity Cx. Of the plurality of pseudo white LEDs positioned in the main scanning direction from the center (main scanning reference position Bp) of the light source unit in the second embodiment. It is explanatory drawing which shows the relationship with Cy, Comprising: It is explanatory drawing explaining the other example of illumination nonuniformity. The distance and chromaticity Cx. Of the plurality of pseudo white LEDs positioned in the main scanning direction from the center in the main scanning direction (main scanning reference position Bp) of the light source unit after the illumination unevenness in FIG. It is explanatory drawing which shows the relationship with Cy. It is a top view which shows the other example of the light source unit of the optical system in which several pseudo white LED and 2nd blue LED in Example 3 were arranged in the shape of a line. The distance and chromaticity Cx. Of the plurality of pseudo white LEDs located in the main scanning direction from the center of the light source unit in the main scanning direction (main scanning reference position Bp). It is explanatory drawing which shows the relationship with Cy, Comprising: It is explanatory drawing explaining the further another example of illumination nonuniformity. FIG. 9 is a light intensity characteristic diagram showing the cause of uneven illumination in the light source unit of FIG. 8, that is, the relationship between the peak wavelength of a pseudo white LED and its intensity. The distance and chromaticity Cx. Of the plurality of pseudo white LEDs located in the main scanning direction from the center in the main scanning direction (main scanning reference position Bp) of the light source unit after the illumination unevenness in FIG. It is explanatory drawing which shows the relationship with Cy. It is a schematic explanatory drawing which shows Example 4 of the scanner apparatus using the illumination optical system which concerns on embodiment of this invention. It is a top view of Example 5 which shows the further another example of the light source unit of the optical system in which several pseudo white LED and 2nd blue LED were arranged in the shape of a line. It is a relative chromaticity distribution figure of the line sensor for demonstrating Example 6 of the scanner apparatus of this invention.

  Embodiments of a scanner device using an illumination optical system according to the present invention will be described below with reference to the drawings.

(Example 1; Principle 1 of the invention)
[Constitution]
<Overall schematic configuration of scanner device>
FIG. 1 is a schematic explanatory diagram of a scanner device using an illumination optical system according to an embodiment of the present invention. FIG. 2 shows a light source unit of the illumination optical system shown in FIG.

  In FIG. 1, the left-right direction is the X-axis direction of the scanner device, the direction perpendicular to the paper surface is the Y-axis direction of the scanner device, and the vertical direction of the paper surface is the Z-axis direction of the scanner device. The configuration will be described with the Y-axis direction as the main scanning direction of the scanner device and the X-axis direction as the sub-operation direction of the scanner device.

In FIG. 1, reference numeral 1 denotes a contact glass of a scanner device on which a read document is placed, and 2 denotes a document placement surface of a contact glass 1 on which the read document is placed. Reference numeral 3 denotes an illumination optical system (illumination device) that irradiates a reading document (not shown) placed on the document placing surface 2 with illumination light for reading the document. Further, reference numeral 4 denotes a mirror extending linearly in the Y-axis direction (main scanning direction). By folding back a part of the light emitted from the light guide plate 6 and irradiating the read original surface on the original placement surface 2 Irradiation from both directions (+ X direction and -X direction).
The reflected light reflected from the reading document (not shown) is guided to the reading optical system 11 for reading the document. The reading optical system 11 includes a line sensor 21 and a guide optical system (light receiving optical system) 11 a that guides reflected light from a reading document (not shown) on the document placement surface 2 to the line sensor 21. The guide optical system 11 a includes a reduction optical lens 12 and a light guide device (light reflection device) M that guides reflected light from a reading document (not shown) on the document placement surface 2 to the reduction optical lens 12. . The light guide device M includes a plurality of first mirrors M1, second mirrors M2, and third mirrors M3 as light reflecting members (light guiding members).

<Illumination optical system 3>
The illumination optical system 3 includes a light source unit 5 that extends linearly in the Y-axis direction (main scanning direction), and an illumination light from the light source unit 5 that extends linearly in the Y-axis direction (main scanning direction). 2 has a light guide plate (illumination optical system) 6 to be led. The light source unit 5 is driven and controlled by a control circuit (control device) 20.

  The light source unit 5 and the light guide plate 6 are held by a moving member (not shown) that is driven back and forth in the X-axis direction (sub-scanning direction).

  The light source unit 5 is attached to a moving member (not shown) that extends in the Y-axis direction (main scanning direction) in FIGS. 1 and 2 and is driven to move back and forth in the X-axis direction (sub-scanning direction) in FIG. A mounting board 7 is provided. The light source unit 5 is positioned between a plurality of pseudo white LEDs 8 mounted on the mounting board 7 at a predetermined interval in the Y-axis direction (main scanning direction) and adjacent ones of the plurality of pseudo white LEDs 8. A plurality of blue LEDs 9 mounted on the mounting board 7.

  The pseudo white LED 8 includes a blue LED chip for pseudo white and a blue phosphor through which blue light from the blue LED chip is transmitted. When the blue light from the blue LED chip passes through the yellow phosphor, the pseudo white LED 8 excites the yellow phosphor with the blue light to generate yellow fluorescence. Thereby, in pseudo white LED8, yellow fluorescence and blue which permeate | transmits a yellow fluorescent substance are synthesize | combined, and are radiate | emitted as white light. A known configuration can be adopted for the pseudo white LED 8.

  In this embodiment, for example, as shown in FIGS. 2 and 2A, 50 pseudo white LEDs 8 (Wi, i = 1, 2, 3... 50 in FIGS. 2 and 2A) are provided and adjacent to each other. A blue LED 9 is arranged in the gap between the pseudo white LEDs 8 and 8. Therefore, in this embodiment, 49 blue LEDs 9 (Bi, i = 1, 2, 3,... N 49 in FIGS. 2 and 2A) are mounted. The plurality of pseudo white LEDs 8 and blue LEDs 9 are both mounted at a predetermined pitch P1. In this embodiment, both the pseudo white LED 8 and the blue LED 9 have a predetermined pitch P1 of 6 mm. The pseudo white LED 8 includes a first blue LED (not shown) for fluorescence excitation and a yellow phosphor (not shown) covering the periphery of the first blue LED (not shown) for fluorescence excitation. I have. Since a known configuration can be adopted for this configuration, detailed illustration thereof is omitted.

  The plurality of pseudo white LEDs 8 and the plurality of blue LEDs 9 are configured such that the light emission amounts are controlled by the control circuit (control device) 20 as shown in FIG. 2A.

  In this embodiment, 50 pseudo white LEDs 8 and 49 blue LEDs 9 are used. However, the number of 49 pseudo white LEDs 8 and blue LEDs 9 is not limited to 50 and 49. In this embodiment, the plurality of pseudo white LEDs 8 are arranged at a predetermined pitch P1 in the Y-axis direction which is the main scanning direction as described above.

  Illumination light emitted from the pseudo white LED 8 of the light source unit 5 is guided to the document placing surface 2 by the light guide plate 6 and the mirror 4. The blue illumination light emitted from the blue LED 9 (second blue LED) of the light source unit 5 is guided to the document placement surface 2 by the light guide plate 6 and the mirror 4. The light guide plate 6 and the mirror 4 include a first illumination optical system that guides the illumination light emitted from the pseudo white LED 8 to the document placement surface 2 and the blue illumination light emitted from the blue LED 9 to the document placement surface 2. The second illumination optical system is also used.

  In addition, illumination light from the plurality of pseudo white LEDs 8 and blue LEDs 9 is applied to a read document (not shown) on the document placement surface 2. Reflected light from a reading document (not shown) on the document placing surface 2 is guided to a reading optical system (not shown in FIG. 1) and a line sensor (reading unit, not shown in FIG. 1) 21 in FIG. 2A. . This reflected light is read by the line sensor (reading unit) 21 in FIG. 2A.

  When such illumination light is irradiated, a reference white plate (not shown) is provided on the document placement surface 2 in place of the document. As a result, the chromaticity of the surface to be irradiated (document surface) from the output of R, G, B from the line sensor (reading unit) 21 in FIG. 2A to the reference white plate (not shown) on the document placement surface 2 is increased. Detected.

  Here, when the plurality of pseudo white LEDs 8 are turned on with the blue LEDs 9 turned off, and the reference white plate (not shown) on the document placement surface 2 is illuminated only by the illumination light of the plurality of pseudo white LEDs 8, It is possible to detect the chromaticity of the illuminated surface (original surface) by only the white LED 8.

  FIG. 3 is a graph showing the chromaticity of the surface to be irradiated (original surface) on a reference white plate (not shown) on the original placement surface 2 in the main scanning direction (Y-axis direction in FIG. 1). . In this graphing, ray tracing calculation was performed using Light Tools version 7.2 as a ray tracing simulator.

  In FIG. 3, the center position of the array of the plurality of pseudo white LEDs 8 in the main scanning direction is defined as a main scanning reference position Bp which is a “0” position in the main scanning direction, and the main scanning reference position Bp is the main scanning direction in the main scanning direction. The chromaticities Cx and Cy at the scanning position are shown.

  In FIG. 3, the upper array of squares having diagonals in the vertical and horizontal directions indicates chromaticity Cx, and the lower square array indicates chromaticity Cy. This also applies to FIGS. 4, 5, 6, 8, and 10 below.

  Of the 50 pseudo white LEDs 8 described above, only the pseudo white LED 8 located at the main scanning position at the detection distance where the chromaticity change is detected from the main scanning reference position Bp has a different emission spectrum (that is, chromaticity). That is, the peak wavelength of the blue wavelength band of the pseudo white LED 8 located at the main scanning position of the detection distance at which the chromaticity change is detected from the main scanning reference position Bp is shifted to the long wavelength side by 5 nm.

  In this embodiment, only the pseudo white LED 8 located at the main scanning position 87 mm from the main scanning reference position Bp among the 50 pseudo white LEDs 8 has a different emission spectrum (that is, chromaticity). That is, only the pseudo white LED 8 at this position shifts the peak wavelength of the blue wavelength band by 5 nm toward the long wavelength side.

  As for the chromaticity of the pseudo white LED 8 located at the main scanning position 87 mm, the coordinates x and y are larger than the others because the peak wavelength of the blue band is shifted to the long wavelength. In this state, even if a single color document is read, the color of the illumination light near the main scanning position of 87 mm is different, causing a color shift.

  The spectrum of the 49 blue LEDs 9 mounted on the mounting board 7 has the same blue band as the blue LED (not shown) for fluorescence excitation of the pseudo white LED 8.

  In this embodiment, the peak wavelength of the blue wavelength band of the pseudo white LED 8 located at the main scanning position 87 mm from the main scanning reference position Bp among the 50 pseudo white LEDs 8 is shifted by 5 nm toward the long wavelength side. . As a result, only the pseudo white LED 8 located at the main scanning position 87 mm from the main scanning reference position Bp has a different emission spectrum (that is, chromaticity).

  Therefore, the control circuit 20 sets the blue LED 9 closest to the main scanning position 87 mm among the plurality of blue LEDs 9, that is, only the blue LED 9 located 90 mm from the main scanning reference position Bp to 0.07 times the pseudo white LED 8. It is made to emit light with the amount of emitted light. The chromaticity distribution on the original surface at this time is as shown in FIG. 4, and color unevenness around 87 mm can be reduced.

  In this embodiment, only the blue LED 9 located 90 mm from the main scanning reference position Bp is caused to emit light with a light emission amount 0.07 times that of the pseudo white LED 8. However, the light emission amount of the blue LED 9 is different from the shift amount of the peak wavelength in the blue wavelength band of the pseudo white LED 8, and is not limited to 0.07 times the light emission amount. That is, the light emission amount of the blue LED 9 is controlled so as to reduce the color unevenness according to the shift amount of the peak wavelength of the blue wavelength band of the pseudo white LED 8.

  In order to perform such control by the control circuit 20, correction data is set based on a test value or the like obtained in advance according to the shift amount of the peak wavelength in the blue wavelength band of the pseudo white LED 8, and the correction data Is stored in the memory 22.

  The control circuit 20 can execute light emission control of the blue LED 9 for reducing color unevenness based on correction data stored in the memory 22 (storage unit which is a recording unit). That is, based on the chromaticity information from the line sensor 21, the control circuit 20 shifts the position of the pseudo white LED 8 where the color unevenness occurs and the peak wavelength shift of the blue wavelength band of the pseudo white LED 8 at this position. Find color unevenness information. The positional color unevenness information is stored in the memory 22. On the other hand, the control circuit 20 obtains the position of the blue LED 9 for correction and the amount of light emission that minimizes the color unevenness from the correction data recorded in the memory 22 based on the obtained color unevenness information. The light emission control of the blue LED 9 is performed with the obtained light emission amount.

  In this embodiment, of the 50 pseudo white LEDs 8, only the pseudo white LED 8 located at the main scanning position of 87 mm in this embodiment from the main scanning reference position Bp has a light emission spectrum (that is, chromaticity). ) Is different on the long wavelength side. However, the emission spectrum (that is, chromaticity) of the pseudo white LED 8 located at a distance other than the main scanning position of 87 mm may be different on the long wavelength side. In this case, the light emission amount of the blue LED 9 closest to the pseudo white LED 8 is also controlled for the pseudo white LED 8 located at a distance other than the main scanning position of 87 mm.

  As described above, when the control circuit 20 detects a pseudo white LED 8 having a different chromaticity on the long wavelength side among the plurality of pseudo white LEDs 8, the control circuit 20 performs control to reduce color unevenness in the chromaticity distribution on the document surface. At this time, the control circuit 20 determines the light emission amount of the blue LED 9 closest to the detection distance at which the detected pseudo-white LED 8 having a different chromaticity detected the chromaticity change from the main scanning reference position Bp to the chromaticity distribution of the document surface. Control to minimize color unevenness.

(Example 2)
As a modification of the first embodiment, correction when the blue band peak wavelength of the pseudo white LED 8 located at the main scanning position 87 mm from the main scanning reference position Bp is shifted by 5 nm to the short wavelength side will be described.

  FIG. 5 shows the chromaticity distribution in the main scanning direction when 50 pseudo white LEDs 8 are illuminated. In FIG. 5, the light from the pseudo white LED 8 located at the main scanning position 87 mm from the main scanning reference position Bp has both chromaticity coordinates x and y smaller, and color unevenness (color color) as shown in the distribution of FIG. Shift). Also in the present embodiment, the correction blue LED is the same as the spectrum of 49 blue bands of the same spectrum among the plurality of pseudo white LEDs 8 as in the first embodiment.

  In this example, 48 blue LEDs 9 other than the blue LED 9 located 90 mm from the main scanning reference position Bp were illuminated with a light emission amount 0.07 times that of the pseudo white LED 8. As a result of the ray tracing calculation, the chromaticity shift was reduced as shown in FIG.

  In Example 1 and Example 2, the spectrum of the blue LED 9 for correction is set to coincide with the shortest wavelength of the peak wavelength variation of the blue band of the pseudo white LED 8. It is desirable that the emission spectra of the plurality of LEDs for correction are equal. If the pseudo white LED 8 is in the variation of the peak wavelength of the blue band, the correction effect is weakened. The effect is increased when the pseudo white LED 8 has a blue band peak wavelength variation of less than a short wavelength or a variation of greater than a long wavelength.

  In this embodiment as well, the blue LEDs 9 other than the blue LED 9 located 90 mm from the main scanning reference position Bp emit light with a light emission amount 0.07 times that of the pseudo white LED 8. However, there is a chromaticity shift even when the peak wavelength of the blue wavelength band of the pseudo white LED 8 located at the main scanning position 90 mm from the main scanning reference position Bp is shifted to the short wavelength side. In order to reduce this chromaticity shift, it is necessary to vary the light emission amounts of the blue LEDs 9 other than the blue LED 9 located 90 mm from the main scanning reference position Bp. The light emission amount at this time is not limited to the light emission amount of 0.07 times.

  That is, the amount of light emitted from the blue LEDs 9 of the blue LEDs 9 other than the blue LED 9 located 90 mm from the main scanning reference position Bp reduces color unevenness according to the shift amount of the peak wavelength of the blue wavelength band of the pseudo white LED 8. Control to do.

  In order to perform this control, correction data is set based on a test value or the like obtained in advance according to the shift amount of the peak wavelength of the blue wavelength band of the pseudo white LED 8, and the correction data is stored in the memory 22. Shall be kept.

  Thereby, the control of the light emission amount of the blue LED 9 for reducing the color unevenness can be executed based on the correction data stored in the memory 22. That is, based on the chromaticity information from the line sensor 21, the control circuit 20 shifts the position of the pseudo white LED 8 where the color unevenness occurs and the peak wavelength shift of the blue wavelength band of the pseudo white LED 8 at this position. Find color unevenness information. The position, color unevenness information, and the like are stored in the memory 22. On the other hand, the control circuit 20 obtains the position and light emission amount of the correction blue LED 9 that minimizes the color unevenness from the correction data recorded in the memory 22 based on the obtained color unevenness information, and determines the blue color at the obtained position. The light emission is controlled by the obtained light emission amount of the LED 9.

  In this embodiment, of the 50 pseudo white LEDs 8, only the pseudo white LED 8 located at the main scanning position of 87 mm in this embodiment from the main scanning reference position Bp has a light emission spectrum (that is, chromaticity). ) Is different for short wavelengths. However, the emission spectrum (that is, chromaticity) of the pseudo white LED 8 located at a distance other than the main scanning position of 87 mm may be different in a short wavelength. In this case, even for the pseudo white LED 8 located at a distance other than the main scanning position of 87 mm, color unevenness can be reduced by controlling the light emission amount of the blue LED 9 other than the blue LED 9 closest to the pseudo white LED 8.

  In this way, the control circuit 20 detects the pseudo white LED 8 having a different chromaticity on the short wavelength side among the plurality of pseudo white LEDs 8. Then, the control circuit 20 controls the light emission amount of the blue LEDs 9 other than the blue LED 9 in which the detected pseudo white LED 8 having different chromaticity is closest to the chromaticity change detection distance from the main scanning reference position Bp. As a result, color unevenness in the chromaticity distribution on the document surface can be reduced.

(Example 3)
As a modification of the first and second embodiments, a case where the yellow wavelength band is different will be described as a third embodiment.

  FIG. 7 shows the LEDs on the mounting board 7 of this embodiment. 30 pseudo white LEDs 8 (Wi, i = 1, 2, 3,... 30) and 15 blue LEDs 9 (Bi, i = 1, 2, 3,... 15) are used. The mounting pitch was 10 mm for the pseudo white LEDs 8 and 20 mm for the blue LEDs 9.

  As shown in FIG. 7, one pseudo white LED 8 is provided at the end of the mounting board 7 in this embodiment. Moreover, one blue LED 9 is provided at the end of the mounting board 7 from the one pseudo white LED 8 at the end toward the center in the main scanning direction.

  On the mounting board 7, two pseudo white LEDs 8 and one blue LED 9 are alternately arranged in the main scanning direction next to one blue LED 9 at the end. In this configuration, two pseudo white LEDs 8 are arranged between the blue LEDs 9 and 9 except that one pseudo white LED 8 is arranged at the end. In this way, 30 pseudo white LEDs 8 are arranged in the longitudinal direction of the mounting board 7. In this embodiment, the number of pseudo white LEDs 8 is 30, but the number is not limited to this number. In short, it is only necessary that two pseudo white LEDs 8 are arranged between the blue LEDs 9 and 9 except that one pseudo white LED 8 is arranged at the end.

  In addition, the spectrum of the correction blue LED 9 is the same as the blue band spectrum component of the 30 pseudo white LEDs 8.

  Among the pseudo white LEDs 8, the seventh pseudo white LED 8 (W7) from the end located 90 mm from the main scanning reference position Bp has a spectral intensity in the yellow band of 1. as compared with the remaining 29 pseudo white LEDs 8. 7 times larger (FIG. 9). In this case, as shown in FIG. 8, in the chromaticity distribution at the main scanning position, the vicinity of the main scanning position of 90 mm is a large numerical value for both chromaticity coordinates x and y, and chromaticity unevenness occurs.

  Among the plurality of correction blue LEDs 9, the third (B3) blue LED 9 from the end is illuminated with a light quantity 1/60 times that of the pseudo white LED 8, and the fourth (B4) blue LED 9 from the end is the pseudo white LED 8 1/30 times the amount of light. The chromaticity distribution on the document surface at this time is as shown in FIG. 10, and chromaticity unevenness was reduced.

  In this embodiment, although the number of blue LEDs 9 is half that of the pseudo white LEDs 8, the same effect as in Embodiments 1 and 2 can be obtained by causing the predetermined blue LEDs 9 to emit light with an appropriate amount of light. It was.

  In this embodiment as well, the seventh pseudo white LED 8 (W7) from the end located 90 mm from the main scanning reference position Bp to the main scanning position is more than the remaining 29 pseudo white LEDs 8 than the spectral intensity of the yellow band. It can be big. In this case, the light emission amount of the third (B3) blue LED 9 from the end is not limited to 1/60 times that of the pseudo white LED 8 described above. Moreover, the light emission amount of the fourth (B4) blue LED 9 from the end and the pseudo white LED 8 is not limited to 1/30 times that of the above-described pseudo white LED.

  For example, the seventh pseudo white LED 8 (W7) from the end located at the main scanning position 90 mm from the main scanning reference position Bp has a spectrum intensity other than 1.7 times that of the remaining 29 pseudo white LEDs 8 other than 1.7 times. It may be a size. In this case, the state of chromaticity unevenness is also significantly different from 1.7 times the spectral intensity of the yellow band. Even in this case, the light emission amount of the third (B3) blue LED 9 from the end is not limited to 1/60 times that of the pseudo white LED 8 described above. Further, the light emission amount of the fourth (B4) blue LED 9 from the end and the pseudo white LED 8 is not limited to 1/60 times and 1/30 times that of the pseudo white LED described above. In short, the amount of light emitted from the pseudo white LED 8 and the fourth (B4) blue LED 9 from the end is controlled so as to eliminate color unevenness.

  As described above, the seventh pseudo white LED 8 (W7) from the end has a spectral intensity of 1.7 times larger in the yellow band than the remaining 29 pseudo white LEDs 8, and the vicinity of the main scanning position of 90 mm is the chromaticity coordinate x. , Y are large numerical values. This indicates that chromaticity unevenness occurs. In the present embodiment, correction of color unevenness when such chromaticity unevenness has occurred has been described.

  However, this correction is not limited to the pseudo white LED 8 at the main scanning position of 90 mm.

  For example, the spectral intensity of the yellow band of the pseudo white LED 8 at the main scanning position at a distance other than the main scanning position of 90 mm may be greater than the spectral intensity of the yellow band of the other pseudo white LED 8. In this case, the light emission amount of the pair of blue LEDs 9 and 9 sandwiching the pseudo white LED 8 having a large spectrum intensity in the yellow band is controlled to be smaller than the light emission amount of the pseudo white LED 8. Moreover, in addition to this, the light emission amount of the blue LED 9 on the side close to the pseudo white LED 8 having a large spectrum intensity in the yellow band is largely controlled. In this way, color unevenness can be reduced by controlling the light emission amount of the blue LED 9 far from the pseudo white LED 8 having a large spectrum intensity in the yellow band to a small value. The control of the light emission amount of the blue LED 9 is executed by the control circuit 20.

  Also in this case, correction data is set based on a test value obtained in advance according to the spectral intensity of the yellow band, and the correction data is stored in the memory 22. Then, based on the correction data stored in the memory 22, the control circuit 20 controls the light emission amount of the blue LED 9.

  That is, based on the chromaticity information from the line sensor 21, the control circuit 20 shifts the position of the pseudo white LED 8 where the color unevenness occurs and the peak wavelength shift of the blue wavelength band of the pseudo white LED 8 at this position. Find color unevenness information. Then, the control circuit 20 records correction data in the memory 22 based on the obtained color unevenness information. In addition, the control circuit 20 obtains the position and the light emission amount of the correction blue LED 9 that minimizes color unevenness from the correction data recorded in the memory 22, and emits light with the obtained light emission amount of the blue LED 9 at the obtained position. Control.

  As described above, the spectral intensity of one yellow band of a plurality (two in the present embodiment) of pseudo white LEDs 8 positioned between the correction blue LEDs 9 and 9 is the spectral intensity of the yellow band of the other pseudo white LEDs 8. May be larger. In this case, chromaticity unevenness occurs.

  In this embodiment, color unevenness is reduced by controlling the amount of light emitted by the pair of blue LEDs 9 and 9 sandwiching the pseudo white LED 8 whose spectral intensity in the yellow band is larger than the spectral intensity in the yellow band of the pseudo white LED 8.

  In this case, the light emission amount of the pair of blue LEDs 9 and 9 sandwiching the pseudo white LED 8 having a large spectrum intensity in the yellow band is controlled to be smaller than the light emission amount of the pseudo white LED 8. In addition, at this time, the light emission amount of the blue LED 9 closer to the pseudo white LED 8 having a large yellow band spectral intensity is increased, and the light emission amount of the blue LED 9 farther from the pseudo white LED 8 having a higher yellow band spectral intensity is decreased. ing.

  In the first to third embodiments, the pseudo white LED 8 and the correction blue LED 9 are laid out linearly on one mounting board.

  However, even if the correction blue LED 9 is shifted in a direction perpendicular to the main scanning direction, the chromaticity unevenness can be reduced by causing the blue LED 9 at a predetermined position to emit light with an appropriate amount of light emission. Furthermore, the blue LED 9 and the pseudo white LED 8 may be separate mounting boards.

Example 4
FIG. 11 is a schematic explanatory diagram of a scanner device for explaining the fourth embodiment.

  The scanner device includes a contact glass 1 on which a document is placed, an illumination device 10 that irradiates a document on the document placement surface 2 of the contact glass 1 with illumination light for reading, and a document placement surface 2 of the contact glass 1. A reading optical system (reading device) 11 that reads a document from reflected light from the document is provided.

  The illumination device 10 includes a pseudo white LED 8 and a first illumination optical system 10a, a correction second blue LED 9 and a second illumination optical system 10b. The first illumination optical system 10a and the second illumination optical system 10b both use light guide plates.

  The reading optical system 11 includes a line sensor 21 that reads a document from reflected light of illumination light that is irradiated and reflected on the document on the document placement surface 2, and a reflection from the document on the document placement surface 2 to the line sensor 21. It has a guide optical system (light receiving optical system) 11a for guiding light.

  The guide optical system 11 a guides the reflected light of the illumination light from the original to the reduction optical lens 12 when the reduction optical lens 12 and the original on the original placement surface 2 of the contact glass 1 are irradiated with illumination light. A guide device (light reflecting device) M is provided. The light guide device M includes a plurality of first mirrors M1, second mirrors M2, and third mirrors M3 as light reflecting members (light guiding members).

  The reflected light beam reduced by the reduction optical lens 12 is reduced and projected onto the line sensor 21, and a line-like original image formed by reflected light of an original (not shown) on the original placement surface 2 of the contact glass 1 is lined. An image is formed on the sensor 21. In addition, since a well-known structure can be employ | adopted for the line sensor 21 electrical system, illustration and description are abbreviate | omitted.

  The procedure for correcting the chromaticity unevenness with this scanner device is as follows.

  First, a reference white plate (not shown) is placed on the document placement surface 2 of the contact glass 1, and the pseudo white LED 8 is turned on. The illumination light from the pseudo white LED 8 is applied to a reference white plate (not shown) on the document placement surface 2 of the contact glass 1 via the first illumination optical system 10a, and is emitted from the reference white plate (not shown). Reflected.

  The reflected light of the illumination light from the reference white plate (not shown) is guided to the reduction optical lens 12 by the first mirror M1, the second mirror M2, and the third mirror M3 of the reading optical system 11. The reflected light is reduced by the reduction optical lens 12 and is incident on the line sensor 21. The line sensor 21 checks the unevenness of the ratio of R, G, B corresponding to the chromaticity unevenness from the R, G, B output, and thereby R, G, B of the reflected light from the reference white plate (not shown). The color, that is, chromaticity is read.

  At this time, the chromaticity shift direction at the position where the unacceptable unevenness occurs (main scanning position), that is, the increase / decrease direction of the chromaticity coordinates x and y, and the spectrum of the correction blue LED 9 are closer to the short wavelength or the long wavelength. The blue LED 9 to emit light is determined depending on whether or not.

  Then, the light emission amount of the blue LED 9 is controlled so that the chromaticity unevenness, that is, the unevenness of the R, G, B ratio is improved to an acceptable level.

  This embodiment shows an example in which a reduction optical system type is applied to a reading optical system 11 using a light guide device M having a plurality of first to third mirrors and a reduction optical lens 12. However, even if the control of the light emission amount of the blue LED 9 of this embodiment is applied to a reading optical system using a self-magnification optical system type, so-called contact image sensor (CIS), when the self-focus lens and the line sensor are used. The effect of the invention remains unchanged.

  In addition to the light guide plate, the first and second illumination optical systems 10a and 10b are applied with the control of the light emission amount of the blue LED 9 of this embodiment to various illumination methods such as a mirror, a rod lens, and a diffusion sheet. However, the effect of the present invention does not change.

(Example 5)
In the first embodiment, the pseudo white LED 8 and the blue LED 9 are arranged on a straight line at an equal pitch. However, the present invention is not necessarily limited to this. For example, as shown in FIG. 12, the pseudo white LED 8 and the blue LED 9 may be laid out not on a straight line. FIG. 12 shows a modification of the first embodiment.

  In Example 5 of FIG. 12, the illumination system is basically the same as that of FIG. 1 of Example 1, but the positions of the pseudo white LED 8 and the blue LED 9 arranged on the mounting board 7 are the same as those of FIG. Different.

  In other words, a plurality of pseudo white LEDs 8 and a plurality of correction blue LEDs 9 are mounted on the mounting board 7 of FIG. However, in FIG. 12, the arrangement of the plurality of pseudo white LEDs 8 and the plurality of correction blue LEDs 9 is different from the layout of FIG. 2, and the pseudo white LED 8 and the correction blue LED 9 are arranged on one straight line as in the first embodiment. Is not laid out.

  In this embodiment, the blue LED 9 for correction is mounted while being shifted in a direction orthogonal to the main scanning direction (left-right direction in FIG. 12). That is, the array line 8L of the plurality of pseudo white LEDs 8 and the array line 9L of the plurality of correction blue LEDs 9 are shifted and mounted in a direction orthogonal to the main scanning direction (left-right direction in FIG. 12). At this time, the array lines 8L of the plurality of pseudo white LEDs 8 and the array lines 9L of the plurality of correction blue LEDs 9 are arranged close to each other so as not to overlap.

  With this layout, the main scanning position and mounting pitch of the pseudo white LED 8 and the main scanning position and mounting pitch of the correction blue LED 9 can be set freely, and correction can be performed with the minimum number of blue LEDs 9. .

  When the pseudo white LEDs 8 are arranged at unequal pitches with respect to the main scanning direction as shown in FIG. 12, physical interference with the blue LEDs 9 can be avoided even at a short mounting pitch.

(Example 6)
In the sixth embodiment, in order to balance the R, G, B output of the reading line sensor (CCD) 21 in FIG. 2A, the chromaticity of other scanning positions with respect to the main scanning position of the reading line sensor (CCD) 21. An example of reducing unevenness is shown. In the sixth embodiment, the principle of correcting chromaticity unevenness is described in more detail using the mounting board 7 and the reading line sensor (CCD) 21 of the first embodiment and the configurations of the second and third embodiments. This is an example. In the first to third embodiments, the chromaticity unevenness is corrected at the main scanning position.

  In the second embodiment, as described above, 48 blue LEDs 9 other than the blue LED 9 located 90 mm from the main scanning reference position Bp of the mounting board 7 are emitted with a light emission amount 0.07 times that of the pseudo white LED 8. This is to be corrected.

  In the second embodiment, before correction, the plurality of pseudo white LEDs 8 are turned on with the blue LEDs 9 turned off by the control circuit 20 of FIG. 2A, and the original placement shown in FIG. A reference white plate (not shown) on the surface 2 is illuminated.

  The illumination light is reflected by a reference white plate (not shown) on the document placement surface 2 by this illumination, and the reflected light at this time is read by a reading line sensor (CCD) 21. At this time, an R, G, B output, that is, an output value of R, G, B luminance is obtained from the reading line sensor (CCD) 21, and this output is input to the control circuit 20. The control circuit 20 calculates the R, G, B output of the reading line sensor (CCD) 21.

  The reading line sensor (CCD) 21 is provided with red, green and blue color filters (not shown), and the relative sensitivity characteristics of these colors are as shown in FIG. As shown by the relative sensitivity characteristic line fB, the relative sensitivity characteristic of the reading line sensor (CCD) 21 using the blue color filter has sensitivity in the band of 400 nm to 550 nm, and has a sensitivity peak near 450 nm. Have. Further, the relative sensitivity characteristic of the reading line sensor (CCD) 21 using the green color filter has a sensitivity in a band of 450 nm to 640 nm as shown by a relative sensitivity characteristic line fG, and a sensitivity peak near 530 nm. Have Further, the relative sensitivity characteristic of the reading line sensor (CCD) 21 using the red color filter has sensitivity in the band of 550 nm to 800 nm as shown by the relative sensitivity characteristic line fR, and the sensitivity is around 620 to 650 nm. It has a peak.

  As described above, when the R, G, B output of the reading line sensor (CCD) 21 is calculated by the control circuit 20, color unevenness (chromaticity unevenness) occurs before correction as shown in FIG. To do. In the second embodiment, 48 of the 49 correction blue LEDs, except for one, are turned on with a light emission amount 0.07 times that of the pseudo white LED 8, thereby causing color unevenness as shown in FIG. It is corrected.

  Table 1 shows the R, G, B output values of the reading line sensor (CCD) 21 according to the second embodiment, that is, the R, G, B luminance output values in relation to the positions on the main scanning line. It becomes like this. In Table 1, the R output value, G output value, and B output value before and after correction of color unevenness (chromaticity unevenness) in Example 2 are shown as R output (red output), G output (green output). ) And B output (blue output).

When obtaining the R output (R output value), G output (G output value), and B output (B output value) in Table 1, the center in the main scanning direction is set as the main scanning reference position Bp, and the main scanning reference position Bp is set as the main scanning reference position Bp. As “0”, a distance from the main scanning reference position Bp is x (a distance from the main scanning reference position Bp by a predetermined distance). In Table 1, the distance x is x = 87 mm.

  In addition, Table 1 shows the output when normalized based on the R output value before correction, that is, the R output, G output, and B output obtained using the R output value before correction as the reference output. In this normalization, in Table 1, the R output at the distance “0” in the main scanning direction (center in the main scanning direction) is set as the reference output “1.00”.

  Moreover, in Table 1, the G output and B output at the distance “0” and the R output, G output, and B output at the distance x = 87 mm are respectively obtained as ratios of the reference output “1.00”. Each output is obtained before and after the correction in the second embodiment.

(R output, G output, B output before correction in the second embodiment)
Before correction in the second embodiment, as shown in Table 1, the G output at the distance “0” is “1.08”, and the B output at the distance “0” is “1.09”. Further, before the correction in the second embodiment, the R output at the distance x = 87 mm is “1.00”, the G output at the distance x = 87 mm is “1.08”, and the B output at the distance x = 87 mm is “1”. .09 ".

  Further, before the correction in the second embodiment, the difference between the R output at the distance “0” and the R output at the distance x is “0.00”, and the difference between the G output at the distance “0” and the G output at the distance x is “ 0.00 ”, and the difference between the B output at the distance“ 0 ”and the B output at the distance x is“ 0.00 ”.

(R output, G output, B output after correction in Example 2)
After the correction in the second embodiment, as shown in Table 1, the R output at the distance “0” is “1.00”, the G output at the distance “0” is “1.08”, and the B output at the distance “0” is B. The output is “1.17”. Further, after the correction in the second embodiment, the R output at the distance x = 87 mm is “1.00”, the G output at the distance x = 87 mm is “1.08”, and the B output at the distance x = 87 mm is “1”. .17 ".

  After the correction in the second embodiment, the difference between the R output at the distance “0” and the R output at the distance x is “0.00”, and the difference between the G output at the distance “0” and the G output at the distance x is “0.00”. 0.00 ”, and the difference between the B output at the distance“ 0 ”and the B output at the distance x is“ 0.00 ”.

  As can be seen from Table 1, when the R, G, and B outputs of the reading line sensor (CCD) 21 are viewed (standardized by the red output before correction), color irregularity occurs before and after correction. Even at the scanning position x = 87 mm, the output balance of the R output, the G output, and the B output does not change even when x = 0 mm away from the position.

  However, before correction of the reading line sensor (CCD) 21 in the third embodiment, chromaticity unevenness occurs in the output balance of the R output, the G output, and the B output. Table 2 shows the R, G, and B output values before and after correction of the reading line sensor (CCD) 21 in Example 3 in relation to positions on the main scanning line.

This table 2 shows the standard output of the R output, the G output, and the B output normalized by the R output “red output” before correction, that is, the R output when the distance x in the main scanning direction is “0”, similarly to the table 1. “1.00”. Further, the G output and B output at the distance x = 0, and the R output, G output, and B output at the distance x = 87 mm are obtained.

(R output, G output, B output before correction in Example 3)
Before the correction in the third embodiment, as shown in Table 2, the G output at the distance “0” is “1.08”, and the B output at the distance “0” is “1.03”. Further, before the correction in the second embodiment, the R output at the distance x = 87 mm is “1.00”, the G output at the distance x = 87 mm is “1.08”, and the B output at the distance x = 87 mm is “0”. .99 ".

  Further, before the correction in the third embodiment, the difference between the R output at the distance “0” and the R output at the distance x is “0.00”, and the difference between the G output at the distance “0” and the G output at the distance x is “ −0.01 ”, and the difference between the B output at the distance“ 0 ”and the B output at the distance x is“ −0.05 ”.

  In the case of Example 3, before correction, as shown in Table 2, B output of x = 0 mm (normalized by R output before correction, that is, R output at x = 0 before correction was used as a reference output) (The ratio of the B output to the reference output) is 1.03, the B output at x = 87 mm is 0.99 with respect to the reference output, and the difference between the B output at x = 0 and the B output at x = 87 mm Was uneven with respect to the main scanning position of −0.05.

  Further, the difference between the R output at x = 0 mm and the R output at x = 87 mm before correction was “0” as shown in Table 2, but after correction, the R output at x = 0 mm and x = 87 mm. As shown in Table 2, the difference in R output is 0.03.

(R output, G output, B output after correction in Example 3)
Therefore, when the control circuit 20 controls the lighting of the 50 pseudo white LEDs 8, all the 50 pseudo white LEDs 8 are uniformly controlled to be dimmed to a predetermined amount (0.99 times). With this control, after the correction in the third embodiment, as shown in Table 2, the R output at the distance “0” is “1.00”, the G output at the distance “0” is “1.11”, and the distance “ The B output at “0” is “1.06”. Further, after the correction in the third embodiment, the R output at the distance x = 87 mm is “1.03”, the G output at the distance x = 87 mm is “1.12”, and the B output at the distance x = 87 mm is “1”. .05 ".

  Further, after the correction in the third embodiment, the difference between the R output at the distance “0” and the R output at the distance x is “0.02”, and the difference between the G output at the distance “0” and the G output at the distance x is “0.0”. 0.00 ”, and the difference between the B output at the distance“ 0 ”and the B output at the distance x is“ −0.02 ”.

  As can be seen from Table 2, all 50 pseudo white LEDs 8 are uniformly controlled to be dimmed to a predetermined amount (0.99 times), so that the unevenness of the main scanning position of the R output is reduced to 0.02. The unevenness of the main scanning position of the output was -0.02, and the RGB balance, that is, the balance of R output, G output, and B output was improved.

  As in this embodiment, when the number of correction blue LEDs 9 to be lit is small, the RGB output tends to be uneven at the main scanning position, and this unevenness is suppressed when the pseudo white LED 8 is dimmed by a predetermined amount.

(Supplementary explanation 1)
As described above, according to the embodiment of the present invention, even if the chromaticity variation is large in the illumination optical system using a plurality of pseudo white LEDs, the chromaticity variation on the document surface is reduced by using the correction blue LED. The purpose is to let you.

  For this reason, the scanner device according to the embodiment of the present invention includes a first white LED that emits blue light and a pseudo white LED 8 that includes a phosphor that absorbs the first blue light and fluoresces light in the yellow wavelength band. A plurality of second blue LEDs 9 that emit blue light, a first illumination optical system (light guide plates 6, 10a) that illuminates the irradiated portion with light from the pseudo white LED 8, and A second illumination optical system (light guide plates 6 and 10b) for illuminating the irradiated portion with light from the second blue LED, a line sensor 21 for reading light from the irradiated portion, and the line sensor 21 to the irradiated portion. A guide reading optical system 11a for propagating light from the irradiation unit.

  In addition, an appropriate amount of the predetermined blue LED 9 among the second blue LEDs 9 is set so that the balance of the red output, the green output, and the blue output of the line sensor 21 when the pseudo white LED 8 is lit is within a predetermined range. It is designed to emit light with the amount of light emitted.

  According to this configuration, the plurality of pseudo white LEDs 8 and the plurality of correction second blue LEDs 9 are used as light sources, and the red output, green output, and blue output balance of the line sensor 21 when the pseudo white LED 8 is turned on. Since the predetermined blue LED 9 can emit light with an appropriate amount of light emission among the plurality of correction second blue LEDs 9 so as to be in a predetermined range, the pseudo white LED 8 having large chromaticity variation is used. In addition, chromaticity variation on the document surface can be reduced.

(Supplementary explanation 2)
In the scanner device according to the embodiment of the present invention, the pseudo-white LED 8 composed of a first blue LED that emits blue light and a phosphor that absorbs the first blue light and fluoresces light in a yellow wavelength band is provided. A plurality of second blue LEDs 9 that emit blue light, a first illumination optical system (light guide plates 6 and 10a) that illuminates the irradiated portion with light from the pseudo white LED 8, and the first A second illumination optical system (light guide plates 6 and 10b) for illuminating the irradiated portion with light from the two blue LEDs 9, a line sensor 21 for reading light from the irradiated portion, and the line sensor 21 to the irradiated portion. A reading optical system 11 for propagating light from the unit is provided.

  In addition, an appropriate amount of the predetermined blue LED 9 among the second blue LEDs 9 is set so that the balance of the red output, the green output, and the blue output of the line sensor 21 when the pseudo white LED 8 is lit is within a predetermined range. It is made to emit light with the amount of emitted light, and all the pseudo white LEDs 8 are dimmed.

  According to this configuration, a predetermined blue LED is illuminated with an appropriate amount of light emission, and all the pseudo white LEDs are uniformly dimmed, so that even if the pseudo white LED 8 having a large chromaticity variation is used, the color on the document surface is increased. Variation, and even under the condition that the number of lighting of the correction blue LED is small, the chromaticity variation on the document surface, in particular, the R, G, B output position variation of the line sensor and the R, The imbalance between the G and B output ratios can be reduced.

(Supplementary explanation 3)
In order to achieve the above-mentioned supplementary explanation 1, the second blue LED has a peak wavelength that is the shortest wavelength among the plurality of first blue LEDs in the scanner device according to the embodiment of the present invention. Shorter or longer than the longest wavelength.

  According to this configuration, in addition to the configuration of Supplementary Explanation 1, the peak wavelength of the second blue LED 9 for correction is equal to or less than the shortest wavelength of the variation of the peak wavelength of the blue LED (not shown) used for the pseudo white LED 8. Alternatively, since the wavelength is longer than the longest wavelength, the chromaticity variation can be reliably reduced on the document surface even when the pseudo white LED 8 having a large chromaticity variation is used.

(Supplementary explanation 4)
Further, in the embodiment of the present invention, in addition to the purpose in Supplementary explanation 1, the object is not to increase the number of parts as compared with the conventional illumination optical system.

  For this reason, in the scanner device according to the embodiment of the present invention, the first illumination optical system and the second illumination optical system are common to one optical system (the light guide plate 6 in FIG. 1).

  According to this configuration, “because the first illumination optical system and the second illumination optical system are one optical system (light guide plate 6), the number of components can be the same as that of the conventional illumination optical system. It became so.

(Supplementary explanation 5)
Further, in the scanner device according to the embodiment of the present invention, in addition to the purposes of the supplementary explanations 1 to 3, the size of the scanner device is equivalent to that of the conventional light source portion.

  In order to achieve this object, in the scanner device according to the embodiment of the present invention, the pseudo white LED 8 (light source) and the second blue LED 9 (light source) are mounted on a single mounting board 7.

  According to this configuration, since “a plurality of pseudo white LEDs 8 and a plurality of second correction blue LEDs 9 are mounted on one mounting board 7, it is equivalent to the size of the conventional light source portion. I was able to do it.

(Supplementary explanation 6)
The scanner device according to the embodiment of the present invention aims to have a size equivalent to that of the conventional light source portion in addition to the purposes of the supplementary explanations 1 to 4 described above.

  Therefore, in the scanner device according to the embodiment of the present invention, the pseudo white LED 8 (light source) and the second blue LED 9 (light source) are alternately mounted on one mounting board 7.

  According to this configuration, since the pseudo white LED 8 and the second blue LED 9 for correction are alternately mounted on one mounting board (mounting substrate) 7, it is equivalent to the size of the conventional light source portion. Even if the pseudo white LED 8 having a large chromaticity variation can be used, the chromaticity variation can be reliably reduced on the document surface.

  For example, line illumination for detecting dust on a glass substrate (mother glass) of a liquid crystal display device (liquid crystal television) in an illumination optical system of an inspection device as well as a multifunction machine (copy machine) equipped with the image reading device. Can also be diverted.

DESCRIPTION OF SYMBOLS 1 Contact glass 2 Original mounting surface 3 Illumination optical system 4 Mirror 5 Light source unit 6 Light guide plate 7 Mounting board 8 Pseudo white LED
9 Blue LED (second blue LED)
8L array line 9L array line 10 Illuminating device 10a First illumination optical system 10b Second illumination optical system 11 Reading optical system 11a Guide optical system 12 Reduction optical lens 20 Control circuit 21 Line sensor

JP2009-169198A JP2009-245902 Japanese Patent No. 4511634 JP2011-193205A

Claims (5)

A plurality of pseudo-white LEDs made of a first blue LED that emits blue light and a phosphor that absorbs light from the first blue LED and fluoresces light in a yellow wavelength band;
A plurality of second blue LEDs emitting blue light;
A first illumination optical system that illuminates the irradiated portion with light from the pseudo white LED;
A second illumination optical system for illuminating the irradiated portion with light from the second blue LED;
In a scanner device comprising a line sensor that reads light from an irradiated portion and a reading optical system that propagates light from the irradiated portion to the line sensor,
A predetermined blue LED of the second blue LEDs is emitted with an appropriate amount of light emission so that the balance of the red output, the green output, and the blue output of the line sensor when the pseudo white LED is lit is within a predetermined range. A scanner device characterized in that it emits light and dimmes all the pseudo white LEDs. 2. The scanner device according to claim 1 , wherein a peak wavelength of the second blue LED is shorter than a shortest wavelength or longer than a longest wavelength among the peak wavelengths of the plurality of first blue LEDs. A scanner device characterized by the above. 2. The scanner device according to claim 1, wherein the first illumination optical system and the second illumination optical system are one optical system in common. 2. The scanner device according to claim 1 , wherein the pseudo white LED and the second blue LED are mounted on a single mounting board. 2. The scanner device according to claim 1 , wherein the pseudo white LED and the second blue LED are alternately mounted on a single mounting board.