JP4638192B2 - Line light source and contact image sensor using the same - Google Patents

Description

  The present invention relates to an image input device for reading an image such as a copying machine or a facsimile, and an image input / output device equipped with an illumination optical system for reading an image subjected to a special medium such as a color image or bill recognition. Relates to a line light source including a multicolor spectrum and a contact image sensor capable of reading a color image using the line light source.

  As a line light source used in a contact image sensor for reading image information such as a document, Japanese Patent Application Laid-Open No. 8-163320 discloses a columnar shape having a pentagon from which one corner of a rectangle is removed, and a part of the side surface. Discloses a rod-shaped illumination device provided with a light diffusion layer 31. FIG. 1 shows a light source 1 having a long cylindrical shape, and a fluorescent material 5 for converting ultraviolet light into visible light is formed in the upper layer of the reflective film 3 and concentrated irradiation light is emitted. An illuminating device including an opening 2 to be disclosed is disclosed.

  FIG. 3 shows a multicolor light source by disposing a plurality of light sources 22 at one end of the light guide 21, and a scatterer pattern by printing is provided on the back surface of the light guide 21. Is disclosed.

JP-A-8-163320

Japanese Patent Laid-Open No. 10-79835

JP 2003-346530 A

As an illumination optical system mounted on a conventional contact image sensor, Japanese Patent Application Laid-Open No. 8-163320 discloses a light diffusion layer as a reflective layer of a transparent rod for single light, and Japanese Patent Application Laid-Open No. 2003-346530 reflects light for a plurality of light sources. Reference is made to optical scatterers as layers, but no mention of visible light conversion of light.

  In JP-A-10-79835, visible light converted by a phosphor applied to the inner surface of a tube of an ultraviolet light source is radiated from the opening, but the uniformity of visible light emitted from a long cylindrical opening is as follows. Not touching.

In the present invention, the light emitted from the ultraviolet light source is efficiently totally reflected in the light guide, and the phosphor applied on the surface of the light guide is disposed in the long axis direction (main scanning direction) of the light guide. Line light source unit (line light source) that emits light with uniform intensity (brightness) distribution from the light emitting part to the original surface from the light converted from the visible light by the phosphor, and a close-contact image equipped with it An object is to provide a sensor (image sensor).

The line light source according to claim 1 is a line light source used in an apparatus for reading an image, wherein a light source that generates ultraviolet rays and an ultraviolet light shielding pattern are formed on a surface portion outside the effective illumination area, A columnar light guide that is disposed in the part and reflects and propagates ultraviolet rays incident on the inside in the major axis direction, and effective illumination of the light guide along the major axis direction on the surface of the light guide A plurality of phosphors having a plurality of luminescent colors provided in a line shape from one end to the other end of the region, and the light guide in the process of ultraviolet light propagating through the light guide The phosphor is irradiated with ultraviolet rays from the surface of the body, and the light generated by the phosphor forms a light-line-shaped emission part on the portion of the light guide that faces the phosphor through the light guide , UV light by the UV light shielding pattern Characterized in that to prevent radiated from the light guide as a direct emitted light before reaching the phosphor.

Line light source according to claim 2 is the line light source used in an apparatus for reading an image, a light source for generating ultraviolet rays, ultraviolet shielding pattern is formed on the surface portion of the outer effective illumination region, the end of the light source A columnar light guide that is disposed in the part and reflects and propagates ultraviolet light incident on the inside in the major axis direction, an outer cylinder that surrounds the light guide in the major axis direction, and the outer cylinder A plurality of phosphors each having a plurality of emission colors provided in a line-like manner from one end to the other end of the effective illumination region of the light guide along the major axis direction on the surface portion; In the process of propagating ultraviolet light through the light guide, ultraviolet light is irradiated from the surface of the light guide to the phosphor of the outer tube portion, and light generated by the phosphor is guided through the light guide. Light on the portion of the light body facing the phosphor Forming a line-shaped injection portion, ultraviolet by the ultraviolet light shielding pattern is characterized in that to prevent radiated from the light guide as a direct emitted light before reaching the phosphor.

Contact image sensor according to claim 3, a light source for generating ultraviolet rays, are formed ultraviolet light shielding pattern on the surface portion of the outer effective illumination region, placing the light source to the end, the long axis of the UV incident on the inside A columnar light guide that propagates while reflecting in the direction, and a line extending from one end to the other end of the effective illumination region of the light guide along the major axis direction in the surface portion of the light guide A phosphor having a plurality of emission colors provided in a divided manner, and in the process of ultraviolet rays propagating through the light guide, the phosphor is irradiated with ultraviolet rays from the surface of the light guide, The light generated by the body passes through the light guide and forms a light-line-shaped emission part in the portion of the light guide facing the phosphor, and before the ultraviolet rays reach the phosphor by the ultraviolet light shielding pattern. As direct synchrotron radiation A line light source to prevent radiating from Kishirube the light, the irradiated from the emitting portion light to a subject, a lens for focusing the reflected light, the phosphor reflected light is focused by the lens at the light receiving surface And a sensor substrate having a light receiving element for receiving the light generated by filtering.

Contact image sensor according to claim 4 is according to claim 3, characterized in that a plurality of chips on a filter corresponding to the spectrum of the plurality of emission colors to the light receiving element.

The line light source according to claims 1 and 2 has a spectrum in which ultraviolet rays (ultraviolet light) are phosphors by a light guide having an ultraviolet light source installed at an end portion or a phosphor coated in a predetermined pattern on a surface of an outer cylinder portion. The converted and spectrally converted fluorescence is radiated as visible light from the light exit of the light guide to the original, so the original surface is irradiated with multicolored light converted to visible light by changing or adding the fluorescent color. It becomes possible to do. In addition, it is possible to prevent ultraviolet rays from being emitted directly from the light guide as emitted light before reaching the phosphor by the ultraviolet light shielding pattern outside the effective illumination area of the light guide. Note that the line light source according to claims 1 and 2 can irradiate illumination with a uniform luminance distribution in the main scanning direction by providing an appropriate pattern width and pattern gap across the illuminated line. There is .

In the contact image sensor according to claims 3 and 4 , the ultraviolet light is a phosphor by a phosphor disposed in a predetermined pattern in the main scanning direction along the surface of the light guide having an ultraviolet light source disposed at the end. Spectral conversion is performed, and the spectrum-converted fluorescence is irradiated as visible light to the subject from the light emitting portion of the light guide, and the reflected light from the subject is read by the light receiving element through the lens for focusing. Can be read . In addition, it is possible to prevent ultraviolet rays from being emitted directly from the light guide as emitted light before reaching the phosphor by the ultraviolet light shielding pattern outside the effective illumination area of the light guide. Further, the contact type image sensor according to claim 4 is configured to transmit pixel information of a document corresponding to each spectrum through a chip-on filter even when a special document (such as banknotes or securities) is read by combining fluorescence spectra. Since it is read by the light receiving element, it is possible to read for forgery recognition including a color image.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

Example 1.
Figure 1 is a cross-sectional view of a minor axis direction (sub scanning direction) of the contact type image sensor according to the present invention. DESCRIPTION OF SYMBOLS 1 is ultraviolet light source, such as LED, 2 is LED board which accommodates ultraviolet light source 1, 3 is the ultraviolet light (ultraviolet light) which injected from ultraviolet light source 1, and repeats total reflection over a major axis direction (main scanning direction), and propagates light A light guide to be emitted, 3a is an emission part of the light guide 3 that radiates (irradiates) the light in the light guide 3 to the outside, and 4 is a phosphor coated on the surface of the light guide 3 in the main scanning direction. 5 is a document as a subject, 6 is a lens formed of a rod lens array that focuses reflected light from the document 5, 7 is an image sensor (light receiving element) that receives light focused by the lens 6, and 8 is A sensor IC for forming a large number of light receiving elements 7 and sequentially driving photoelectric conversion outputs from the light receiving elements 7, 9 is a sensor substrate on which a plurality of sensor ICs 8 are linearly arranged, and 10 is a transmission plate as a document table or a document transport path (Glass plate), 11 is a lens 6 or sensor base 9 a receiving or holding to the housing, 12 pulley to convey the original 13 is a top plate which forms a part of the conveying path of the document.

The ultraviolet light source 1, the LED board 2, the light guide 3 and the phosphor 4 applied to the light guide 3 are collectively referred to as a line light source (line light source unit) in this embodiment. Further, the pulley 12 and the top plate 13 are not normally incorporated in the contact image sensor.

FIG. 2 is an external view (schematic diagram) showing a configuration as a line light source unit when the ultraviolet light source 1 is installed at both ends of the light guide 3, and the light guide 3 is a transparent or translucent round bar (cylindrical). On the surface of the light guide 3 opposite to the phosphor 4 applied on the surface, there is an emission region (emission part) 3a that mainly emits light from the light guide 3 to the outside. Reference numeral 14 denotes a lead wire for supplying power to the ultraviolet light source 1, which is normally connected to a terminal such as a connector installed on the sensor substrate 9, and a low voltage source is supplied from the terminal (not shown). Is pulsed or DC driven.

Next, the operation will be described. FIG. 3 is an example of a printed pattern of the phosphor 4 applied to the surface of the light guide 3. The ultraviolet light emitted from the ultraviolet light source 1 travels in the main scanning direction while repeating total reflection inside the light guide 3, but a part of the ultraviolet light forms the phosphor 4 coated on the surface of the light guide 3. A part of the fluorescent paint that irradiates is also irradiated with visible light. As shown in FIG. 2, the fluorescent light is scattered and emitted radially to the fluorescent paint, and a line light source is formed by arranging these point lights in a line. In this embodiment, a wide pattern of the phosphor 4 is provided in the major axis direction as the distance from the ultraviolet light source 1 in the effective illumination area of the light guide 3 is set as each fluorescence emission area.

In addition, a certain gap is provided in the pattern to which the fluorescent paint is applied, and a region in which the ultraviolet light is efficiently totally reflected and propagated in the major axis direction of the light guide 3 is provided. That is, with respect to the pattern of the phosphor 4 having a substantially constant width in the minor axis direction of the light guide 3, the pattern 4N whose pattern width becomes narrower as the distance from the ultraviolet light source 1 increases in the major axis direction of the light guide 3. The phosphor patterns gradually increase in the order of the intermediate width pattern 4M and the wide pattern 4W.

By using the phosphor 4 having the pattern shape as described above, the ultraviolet light emitted from the ultraviolet light source 1 is converted into fluorescence, and the document is irradiated with fluorescence (visible light) from the emission unit 3a. The reflected ultraviolet light is propagated far to the long axis direction.

Next, the visible light irradiated from the emitting portion 3 a illuminates the original 5 through the glass plate 10 shown in FIG. 1, and a part of the visible light scattered by the original 5 is converged by the lens 6 and connected by the light receiving element 7. Image.

In FIG. 3, reference numeral 151 is provided outside the effective illumination area, and before the ultraviolet light emitted from the ultraviolet light source 1 reaches the phosphor 4 installed in the effective illumination area, the light guide 3 is directly emitted as light. It is the ultraviolet light shielding pattern which gave the ultraviolet cut paint which prevents the unnecessary radiation radiated from.

Over the main scanning direction of the light guide 3 from above, is illuminated with a uniform luminance distribution in the visible light in the main scanning direction from the exit portion 3a so was successively wider as the distance the pattern width of the phosphor 4 from the ultraviolet light source 1 .

Further, since the gap is provided between the patterns of the adjacent phosphors 4, it is possible to efficiently propagate the ultraviolet light far away in the main scanning direction by total reflection inside the light guide 3.

Example 2
A second embodiment of the present invention will be described below with reference to FIG. In the first embodiment, the ultraviolet light source 1 is installed at both ends of the light guide 3 in the long axis direction. However, in this embodiment, the phosphor 4 in the case where the ultraviolet light source 1 is installed at one end in the long axis direction of the light guide 3. A print pattern will be described. 3 denote the same or corresponding parts.

In FIG. 4, 4 LW is an ultra-wide pattern of the phosphor 4. Ultraviolet light from the ultraviolet light source 1 installed at one end of the light guide 3 is sequentially converted into visible light by the patterns 4N, 4M, and 4W of the phosphor 4, and is uniform from the emission part 3a of the light guide 3. Since the ultraviolet light source 1 is not installed at the other end of the light guide 3, the pattern of the phosphor 4 in the vicinity of the other end (termination) is a pattern with respect to the major axis direction of the light guide 3. An ultra-wide pattern 4LW that is wider than 4W is used.

In addition, when a reflection layer for the total reflection light is newly provided at the terminal portion which is the other end of the light guide 3 to give total reflection reciprocating light, ultraviolet light or ultraviolet light is used at the terminal of the light guide 3. Since the contribution of visible light converted from is expected, the ultra-wide pattern 4LW may be a tapered printing pattern having a width that is shorter in the minor axis direction at the end portion of the light guide 3 and becomes wider as the distance from the end portion increases. .

From the above, by making the pattern width near the end portion of the light guide 3 extremely wide in the main scanning direction, the ultraviolet light near the end can be converted into almost visible light. Even when the ultraviolet light source 1 is installed only at one end, the line light source has a uniform luminance distribution near the end.

In addition, when there is end reflection of ultraviolet light, the pattern 4LW is tapered to ensure the uniformity of visible light irradiation near the end of the light guide 3.

Example 3
A third embodiment of the present invention will be described below with reference to FIG. In the first and second embodiments, visible light that emits single fluorescence has been described. In the third embodiment, a fluorescent paint that emits fluorescence of R (red), G (green), and B (blue) is used as a light guide. The case of applying to 3 will be described.

  In FIG. 5, 4R is a red light emitting phosphor, 4G is a green light emitting phosphor, and 4B is a blue light emitting phosphor. In the ultraviolet light source 1 installed at one end of the light guide 3 in the long axis direction, red light emitting fluorescence is emitted in each of the patterns 4N, 4M, 4W, and 4LW shown in FIG. The body 4R, the green light emitting phosphor 4G, and the blue light emitting phosphor are divided into three types. Each phosphor material may be a phosphor material that emits a necessary spectrum by inactivating various impurities in zinc sulfide (ZnS) or cadmium sulfide (CdS). However, in this embodiment, a cylindrical PC (4 mm in diameter) Since three types of fluorescent materials are printed on the (polycarbonate) light guide 3, a room temperature dry solidified fluorescent pigment is preferred.

From the above, it becomes possible to convert the ultraviolet light of the ultraviolet light source 1 into mixed white light including three types of spectrums of red, green and blue, and it is not necessary to mount several kinds of LED chips as light sources, and the LED mounting area Therefore, the cross-sectional shape of the light guide 3 can be narrowed, and a miniaturized white light line light source unit can be realized.

In this embodiment, each color light emitting phosphor is finely divided using the pattern 4N, pattern 4M, pattern 4W, and pattern 4LW shown in FIG. 4 as basic patterns. However, the basic pattern and the finely divided patterns are not only rectangular and rectangular, A pattern printed with circular dots or polygonal dots may be used, and even if the arrangement of the finely divided phosphors of each color light-emitting phosphor in the basic pattern is appropriately changed, there is a corresponding effect on the uniformity of the luminance distribution in the main scanning direction. .

Example 4
A fourth embodiment of the present invention will be described below with reference to FIGS. In Embodiments 1 to 3, the cylindrical light guide 3 has been described. In Embodiment 4, a polygonal light guide is described. 1 denote the same or corresponding parts.

Figure 6 is a sectional view of a sub-scanning direction of the contact type image sensor according to a fourth embodiment of the present invention, 21 LED boards 31 are lightguide polygonal prism, 31a 1 of the light guide 31 of the polygonal prism An emission part provided on the side, 41 is a phosphor installed on a surface substantially opposite to the emission part 31a, and 111 is a casing. In addition, 15 is a cover (outer cylinder part) mainly composed of a white opaque plastic material that covers the surface of the light guide 31 except the exit part 31a of the light guide 31.

In this embodiment, as shown in FIG. 7, the light guide 31 has a predetermined emission part 31a having one side of the polygonal light guide 31 as an area, and light is concentrated from the emission part 31a. Radiates. Further, since the cover 15 is provided around the light guide 31 in contact with the surface of the light guide 31, even if there is more complicated light scattering than the cylindrical light guide 3, the light is reflected by the cover 15. The visible light converted from the ultraviolet light can be efficiently emitted from the emitting portion 31a.

Example 5 FIG.
A fifth embodiment of the present invention will be described below with reference to FIGS. In the first to fourth embodiments, the line light source unit that emits single and white light has been mainly described. In the fifth embodiment, the internal configuration of the contact image sensor that reads the single light and white light will be described. . 1 denote the same or corresponding parts.

In FIG. 8, semiconductor chips 8 are linearly arranged on the sensor substrate 9 in the main scanning direction, and a large number of light receiving elements 7 are formed on each semiconductor chip 8 in the main scanning direction as shown in FIG. 9. . In FIG. 10, 7R is a red filter, 7G is a green filter, and 7B is a blue filter. Each light receiving element 7 formed on the semiconductor chip 8 is formed by mixing each color pigment with gelatin on the light receiving surface. A chip-on filter is applied.

In this embodiment, the gelatin chip-on filter applied to the light receiving element 7 is red (wavelength: approximately 660 nm), green (wavelength: 525 nm), and blue (wavelength: 470 nm ± 10 nm). Is preferably a phosphor material corresponding to this filter color. When the line light source is white light of red, green and blue, the reflected white light from the document 5 is incident on each color filter of the light receiving element 7 constituting each pixel of the semiconductor chip 8 corresponding to the white light spectrum. , Dropout color occurs in each filter.

That is, the red filter 7R shields the red image of the document, the green filter 7G shields the green image of the document, and the blue filter 7B shields the blue image of the document. The color information is switched by the switching circuit during the reading period of one line by sequentially driving the shift register circuit, and is used as the color information from the red filter 7R, the green filter 7G, and the blue filter 7B of each light receiving element 7. In FIG. 8, reference numeral 16 denotes a connector (signal input / output terminal) that outputs pixel signals photoelectrically converted by the respective light receiving elements 7 in series and outputs them externally from the sensor substrate 9 as image information.

Next, the case where the line light source has a single spectrum will be described. When the spectral wavelength is 570 nm (yellowish green), the photoelectric conversion output that has passed through each filter on the light receiving element 7 becomes image information. Conversely, when the spectral wavelength of the line light source is 660 nm, for example, the same wavelength as that of the red filter 7R, the photoelectric conversion output via the red filter 7R cannot be used as image information. Therefore, the green filter 7G and the blue filter 7B become image information. When the line light source has a single spectrum, each color chip-on filter is not necessarily required.

From the above, it is possible to read a color original by reading the reflected light of the white light of the line light source unit by forming the chip-on filter on the light receiving element 7 in the contact image sensor. Further, since each color filter is provided on the surface of the light receiving element 7, each color information is incident at the same time, so that there is an advantage that high-speed color reading can be realized.

Example 6
In the fifth embodiment, the light receiving element 7 is mounted with a chip-on filter corresponding mainly to the spectrum of white light, but the light emitted from the line light source unit is, for example, the secondary spectrum in addition to the ultraviolet light (ultraviolet light) emitted from the ultraviolet light source 1. In other words, it is unnecessary light for image reading. Accordingly, in the sixth embodiment, a method for improving the deterioration of the image reading performance due to unnecessary light such as ultraviolet reflected light will be described.

FIG. 11 shows a case where an ultraviolet cut paint 51 is applied to an emission region (ejecting portion) facing the phosphor 4 of the cylindrical light guide 3 described in the first to third embodiments. By covering the ultraviolet absorber containing 400 nm, which is the longer wavelength region side of ultraviolet rays, and the wavelength of purple light with CeO2 (cerium oxide), light in these wavelength regions is prevented from entering the original surface. In the sixth embodiment, by setting the ultraviolet cut area to 460 nm or less, the image reading performance for the blue wavelength is remarkably improved in the color image reading described in the fifth embodiment.

Further, in the polygonal light guide 31 described in the fourth embodiment, as shown in FIG. 12, an ultraviolet cut paint 52 is applied to a dedicated exit surface (injection part) that is also one side of the light guide 31. Thus, the same effect as that of the cylindrical light guide 3 can be obtained.

Example 7
In the first to sixth embodiments, the line light source is installed in the vicinity of the document surface independently of the sensor substrate 9, but in the seventh embodiment, a case where the line light source is shared with the sensor substrate 9 will be described with reference to FIG. The same reference numerals as those in FIG. 8 denote the same or corresponding parts.

In FIG. 13, 100 is an ultraviolet LED chip, and 91 is a sensor substrate in which the ultraviolet LED chip 100 is installed on both sides of the semiconductor chip 8. In FIG. 13, since the ultraviolet LED chip 100 is directly connected to the sensor substrate 91 by a wire bond method, the LED board and the lead wire for the ultraviolet light source are unnecessary, and the light source power is directly supplied from the connector 16.

Figure 14 is a sub-scanning direction cross-sectional view of a contact image sensor incorporating the sensor substrate 91 shown in FIG. 13. Reference numeral 17 denotes a transparent cap made of a resin having a lens effect for condensing the emitted light of the ultraviolet LED chip 100. 32 is a vertical light guide whose one end is close to the ultraviolet LED chip 100, 32 a is an emission part of the vertical light guide 32, 42 is the other end of the vertical light guide 32, and in the vicinity of the document surface. An installed phosphor, 112 is a casing. 1 denote the same or corresponding parts.

FIG. 15 is a cross-sectional view in the main scanning direction when one end of the vertical light guide 32 is installed in the vicinity of the ultraviolet LED chip 100 on the sensor substrate 91. Further, in the vertical light guide 32 of the present embodiment, as illustrated in FIG. 16, description will be made by dividing into regions of a light carrying portion and a light bending irradiation portion. Reference numeral 42a denotes a waveform pattern of the phosphor applied to the light bending irradiation portion of the vertical light guide 32.

14, 15, and 16, the ultraviolet LED chip 100 is installed at one end of the light guide 32 corresponding to the light carrying portion, and the phosphors 42 are applied to both sides of the surface of the light guide 32 corresponding to the light bending irradiation portion. The ultraviolet light irradiated from the ultraviolet LED chip 100 reaches the light bending irradiation part by total reflection in the light transporting part, and the fluorescent light 42 applied to the outer surface of the light bending irradiation part causes visible light to be emitted from the light bending irradiation part. Total scattering occurs, and high-luminance visible light is irradiated onto the document 5 from the emitting portion 32a.

By the way, in the case of a contact type image sensor that reads an A4 size document such as 216 mm, the size of the vertical light guide 32 in the main scanning direction is 224 mm as shown in FIG. Since the chips 100 are distributed at equal intervals of the pitch L, the irradiation range of one ultraviolet LED chip 100 is 32 mm. Therefore, when the light emission luminance at the center of the irradiation axis of each ultraviolet LED chip 100 is high, the print pattern of the phosphor 42 applied to the vertical light guide 32 is narrow in the vicinity of the irradiation axis and becomes wider as it goes away. A substantially waveform pattern is preferred.

Conversely, when there is a connecting member such as a relatively wide electrode pattern or a wire bond line on the depletion layer that emits ultraviolet light of the ultraviolet LED chip 100, or when there is mutual irradiation from the adjacent ultraviolet LED chip 100. A waveform pattern 42a shown in FIG. 16 is preferable in which the vicinity of the irradiation axis is wide and the width becomes narrower as the distance from the irradiation axis increases.

Further, when the number of ultraviolet LED chips 100 to be installed on the sensor substrate 91 is large and the irradiation range (L) is further narrow, the emission portion 32a is also formed as a rectangular pattern 42N shown in FIG. 17 having a constant pattern width and an equal pitch. The uniformity of visible light irradiation from can be ensured. The uniformity can be ensured even if the rectangular pattern 42N is divided and formed with a large number of printing dots.

In this embodiment, the phosphors 42 are applied on both sides of the light bending irradiation portion of the vertical light guide 32, but only in the main scanning direction on the upper surface side of the light bending irradiation portion where the ultraviolet light from the light transporting portion is directly reflected. Even if applied along, there is a corresponding effect.

The phosphor 42 has been described as having a single color. However, as shown in FIG. 18, the basic pattern is finely divided into a red light emitting phosphor 42R, a green light emitting phosphor 42G, and a blue light emitting phosphor 42B, and the phosphors are distributed and applied. By doing so, it is possible to irradiate a plurality of spectra such as white light emission. Further, in the case of fine division, there is a corresponding effect on the uniformity of the luminance distribution of visible light irradiation even if the arrangement position of each color light emitting phosphor in the basic pattern is appropriately changed.

In Embodiments 1 to 7 of the present invention, the phosphor is applied to the surface of the light guide. However, as shown in FIG. 19, a pattern in which the phosphor 43 is printed on the inner surface of the reflection sheet 18 as the outer cylinder is used as the light guide. The light guide 31 is covered with the cover 15 so that the pattern in which the phosphor 44 is printed on the inner surface of the cover 15 is in contact with the light guide 31 as shown in FIG. If a phosphor layer as a reflective layer is provided in contact with the surface to be coated, the same effect as that obtained when the phosphor is directly coated on the light guide surface is obtained.

In Embodiments 1 to 7 of the present invention, line light sources are installed on both sides of the original surface. However, when high-speed reading of 0.5 ms / line or more is not required, and due to unevenness of irradiation light due to unevenness of the original during document conveyance, In the case of a transport mechanism that does not cause deterioration in reading of a document image, the line light source unit and the ultraviolet LED chip 100 may be installed only on one side.

Further, in the first to seventh embodiments of the present invention, the light emission colors of red, green and blue phosphors are used to mainly explain white light at the time of reading a color image. It is also possible to fluoresce a longer wavelength longer than the red emission color by using a phosphor material such as CdSe or CdTe material according to the light spectrum.

A sub scanning direction cross-sectional view of a contact type image sensor according to the first embodiment of the present invention. It is a shape schematic diagram of the line light source unit used for the contact image sensor according to Embodiment 1 of the present invention. It is a pattern figure of the fluorescent substance apply | coated to the light guide which concerns on Example 1 of this invention. It is a pattern figure of the fluorescent substance apply | coated to the light guide which concerns on Example 2 of this invention. It is a pattern figure of the fluorescent substance apply | coated to the light guide which concerns on Example 3 of this invention. A sub scanning direction cross-sectional view of a contact type image sensor according to a fourth embodiment of the present invention. It is a shape schematic diagram of the line light source unit utilized for the contact type image sensor which concerns on Example 4 of this invention. It is a figure explaining the sensor board | substrate of the contact type image sensor which concerns on Example 5 of this invention. It is a figure explaining the semiconductor chip of the contact type image sensor which concerns on Example 5 of this invention. It is a figure explaining the light receiving element integrated in the semiconductor chip of the contact type image sensor which concerns on Example 5 of this invention. It is a shape schematic diagram of the line light source unit which apply | coated the ultraviolet cut paint to the cylindrical light guide used for the contact | adherence image sensor which concerns on Example 6 of this invention. It is a shape schematic diagram of the line light source unit which applied the ultraviolet cut paint to the polygonal column light guide used for the close contact type image sensor concerning Example 6 of this invention. It is a figure explaining the sensor substrate of the contact type image sensor which concerns on Example 7 of this invention. A sub scanning direction cross-sectional view of a contact type image sensor according to a seventh embodiment of the present invention. It is explanatory drawing at the time of incorporating a light guide on the sensor board | substrate of the contact type image sensor which concerns on Example 7 of this invention. It is an external appearance schematic diagram of the light guide of the contact type image sensor which concerns on Example 7 of this invention. It is an external appearance schematic diagram of the light guide body which apply | coated the fluorescent substance with equal pitch with the contact | adherence image sensor which concerns on Example 7 of this invention. It is an external appearance schematic diagram of the light guide body which apply | coated three types of fluorescent substance with the contact type image sensor which concerns on Example 7 of this invention. It is the external appearance schematic diagram which affixed the reflection sheet which apply | coated the fluorescent substance to the cylindrical light guide of this invention. It is the external appearance schematic diagram which attached the cover which apply | coated the fluorescent substance to the polygonal light guide of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultraviolet light source (ultraviolet LED), 2 LED board, 3 Light guide, 3a Ejection part, 4 Phosphor, 4N Narrow pattern, 4M Medium width pattern, 4W Wide pattern, 4LW Super wide pattern, 4R Red Light emitting phosphor, 4G green light emitting phosphor, 4B blue light emitting phosphor, 5 Subject (original), 6 Lens, 7 Image sensor (light receiving element), 7R Red filter, 7G green filter, 7B blue filter, 8 Sensor IC, 9 Sensor board, 10 Transmitter (glass plate), 11 Housing, 12 Pulley, 13 Top plate, 14 Lead wire, 15 Cover (outer cylinder part), 16 Connector, 17 Transparent cap, 18 Reflective sheet (outer cylinder part), 21 LED board, 31 polygonal light guide, 31a injection part, 32 vertical guide Light body, 32a emitting part, 41 phosphor, 42 phosphor, 42a waveform pattern, 42N rectangular pattern, 42R red light emitting phosphor, 42G green light emitting phosphor, 42B blue light emitting phosphor, 43 sheet inner surface phosphor, 44 Cover inner surface phosphor, 51 UV cut paint, 52 UV cut paint, 91 sensor substrate, 100 UV LED chip, 111 housing, 112 housing, 151 UV light shielding pattern.

Claims (4)

A line light source used in an apparatus for reading an image, and a light source that generates ultraviolet rays, and an ultraviolet light shielding pattern is formed on a surface portion outside the effective illumination area. A columnar light guide that reflects and propagates the ultraviolet rays in the long axis direction, and from one end portion to the other end portion of the effective illumination region of the light guide body along the long axis direction on the surface portion of the light guide body A plurality of phosphors having a plurality of emission colors provided by being divided and formed in a line shape, and ultraviolet rays from the surface of the light guide to the phosphors in a process of propagating the light guides. The light generated by the phosphor passes through the light guide to form a light-line-shaped emission portion in a portion of the light guide facing the phosphor, and the ultraviolet light is blocked by the ultraviolet light shielding pattern. Straight before reaching the body Line light source to prevent radiated from the light guide as emitted light. A line light source used in an apparatus for reading an image, and a light source that generates ultraviolet rays, and an ultraviolet light shielding pattern is formed on a surface portion outside the effective illumination area. A columnar light guide that reflects and propagates the ultraviolet rays in the long axis direction, an outer cylinder that surrounds the light guide in the long axis direction, and a surface portion of the outer cylinder along the long axis direction A plurality of phosphors having a plurality of emission colors provided in a line shape from one end to the other end of the effective illumination area of the light guide. In the process of propagating light, the phosphor of the outer tube portion is irradiated with ultraviolet rays from the surface of the light guide, and the light generated by the phosphor faces the phosphor of the light guide through the light guide. forming a line-shaped exit portion of the light in the portion, Serial line light source to prevent radiated from the light guide as a direct emitted light before the ultraviolet rays by the ultraviolet light shielding pattern reaching the phosphor. A light source that generates ultraviolet light, an ultraviolet light shielding pattern is formed on the surface portion outside the effective illumination area, the light source is arranged at the end, and a columnar light guide that propagates while reflecting the ultraviolet light incident inside in the major axis direction And a plurality of the light guides that are divided and formed in a line shape from one end to the other end of the effective illumination region of the light guide along the long axis direction in the surface portion of the light guide. A phosphor having a luminescent color; in the process of ultraviolet rays propagating through the light guide, the phosphor is irradiated with ultraviolet rays from the surface of the light guide, and light generated by the phosphor passes through the light guide. A light line-shaped emission part is formed in a portion of the light guide opposite to the phosphor, and ultraviolet rays are directly emitted from the light guide as radiated light before reaching the phosphor by the ultraviolet light shielding pattern. To prevent that A light source, a lens that irradiates the subject with light from the emitting unit, and focuses the reflected light, and a light receiving device that filters the reflected light focused by the lens and filters the light generated by the phosphor on the light receiving surface. A contact image sensor comprising a sensor substrate having an element. The contact type image sensor according to claim 3, wherein the light receiving element includes a plurality of chip-on filters corresponding to spectra of the plurality of emission colors.

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