Lighting device and image reading device

Abstract

To improve the position accuracy of a rod lens.SOLUTION: An illuminating device comprises: a linear light source that extends in a first direction, and emits light in a second direction intersecting the first direction to illuminate an object with the light; a rod lens that is arranged separate in the second direction from the linear light source, extends in the first direction, and transmits the light emitted from the linear light source; and a support part that supports the rod lens. The support part includes a first surface that extends in a third direction intersecting the second direction when seen in the first direction, and a second surface that extends in a fourth direction intersecting the second direction and third direction when seen in the first direction. The rod lens is in contact with the first surface and the second surface.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a lighting device and an image reading device.

Background Art

[0002] Conventionally, an image reading device including a lighting device that emits light to illuminate an original surface of an original and a reading unit that reads light reflected from the original surface is known (see, for example, Patent Document 1). The lighting device includes a plurality of white LED light sources that emit light and a rod lens that condenses the light emitted from the white LED light sources.

Summary of the Invention

Problems to be Solved by the Invention

[0003] However, in the lighting device of Patent Document 1, there is room for improvement in that the man-hours for position adjustment increase in order to improve the relative position accuracy between the light source and the rod lens by adjusting the positions of the components.

[0004] An object of the present invention is to provide a lighting device capable of maintaining high relative position accuracy between a light source and a rod lens while suppressing an increase in man-hours for position adjustment of components.

Means for Solving the Problems

[0005] A lighting device according to an embodiment includes a linear light source that extends in a first direction and emits light in a second direction intersecting the first direction to irradiate an object with the light, a rod lens that is disposed apart from the linear light source in the second direction, extends in the first direction, and transmits the light emitted from the linear light source, and a support portion that supports the rod lens. The support portion includes a first surface that extends in a third direction intersecting the second direction when viewed in the first direction, and a second surface that extends in a fourth direction intersecting the second direction and the third direction when viewed in the first direction. The rod lens is At different positions on one side of the outer perimeter in contact with the first surface and the second surface.

Effects of the Invention

[0006] According to one embodiment of the lighting device, it is possible to provide a lighting device that can maintain high relative positional accuracy between the light source and the rod lens while suppressing the increase in man-hours required for adjusting the position of the parts. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view showing a colorimeter according to an embodiment. [Figure 2] This is a schematic diagram showing the color data acquisition unit. [Figure 3] This is a schematic diagram showing the lighting device from above. [Figure 4] This is a perspective view of the lighting fixture from below. [Figure 5] This is a side view showing the lighting device. [Figure 6] This is a schematic side view showing the rod lens and the lens contact surface. [Figure 7] This is a side view showing the rod lens retainer. [Figure 8] This is a schematic side view showing the lighting device, measuring surface, and height range. [Figure 9] This table shows the predicted effects of misalignment of the rod lens. [Figure 10] This is a schematic side view showing the misalignment of the rod lens. [Figure 11] This is a schematic diagram showing an image forming apparatus according to an embodiment. [Modes for carrying out the invention]

[0008] An embodiment of the present invention will be described below with reference to the drawings. In each drawing, arrows indicating the three orthogonal directions, namely the X-axis, Y-axis, and Z-axis, may be shown. The Y-axis direction is along the transport direction of the paper 100. The X-axis direction is intersecting the transport direction of the paper 100 and is along the width direction of the paper 100. The Z-axis direction is along the thickness direction of the paper 100.

[0009] <Color measurement device> Figure 1 is a perspective view showing a colorimeter according to an embodiment. The colorimeter 10 shown in Figure 1 includes a color data acquisition unit 20, a paper transport mechanism 30, a paper detection sensor 41, a color data acquisition unit transport mechanism 40, a calibration color chart 50, and a control device 300. The color data acquisition unit 20 is an example of an "image reading device". The control device 300 may be a control device of an image forming apparatus. The control device 300 controls the operation of the colorimeter 10.

[0010] The paper transport mechanism 30 transports the paper 100 in the Y-axis direction at a constant speed. The paper transport mechanism 30 includes, for example, a nip roller having two rollers. The paper transport mechanism 30 transports the paper 100 by rotating the nip roller while gripping the paper 100 with the nip roller.

[0011] The paper detection sensor 41 detects that the paper 100 is in a predetermined position. The paper detection sensor 41 detects, for example, that the paper 100 is in a predetermined position, which is the color data acquisition area 21. The paper detection sensor 41 detects, for example, that light is shone on the paper 100 and the reflected light is detected by a photodiode or the like. Based on the output of the paper detection sensor 41, the colorimeter 10 can detect that the paper 100 is in the position of the color data acquisition area 21 by the color data acquisition unit 20.

[0012] The color data acquisition unit transport mechanism 40 transports the color data acquisition unit 20 in the X-axis direction. The color data acquisition unit transport mechanism 40 may include, for example, a transport stage having a ball screw and a guide.

[0013] The calibration color chart 50 is used to calibrate the transformation matrix used to calculate spectral characteristics.

[0014] The colorimeter 10 may simultaneously acquire spectral characteristics at multiple positions in the Y-axis direction within the color data acquisition area 21 of the paper 100.

[0015] <Color data acquisition unit> FIG. 2 is a schematic diagram showing a color data acquisition unit. As shown in FIGS. 1 and 2, the color data acquisition unit 20 includes a line illumination light source 60, a reduction imaging lens 70, and a spectroscopic unit 80. As shown in FIG. 2, the color data acquisition unit 20 has an illumination unit 22 and a light receiving unit 23. The illumination unit 22 includes the line illumination light source 60. The light receiving unit 23 includes the reduction imaging lens 70 and the spectroscopic unit 80.

[0016] The line illumination light source 60 illuminates the color data acquisition area 21 with line-shaped light. The color data acquisition area 21 is an example of a "reference plane of the object". The line illumination light source 60 can irradiate the color data acquisition area 21 with light from a direction inclined at, for example, 45 degrees with respect to the X-axis direction when viewed in the Y-axis direction. The light irradiation direction by the line illumination light source 60 is an example of the optical axis direction. The inclination angle of the light is not limited to 45 degrees, and other angles may be used. The Y-axis direction is an example of the "first direction". The X-axis direction is an example of the "third direction". The optical axis direction by the line illumination light source 60 is an example of the "second direction".

[0017] The line illumination light source 60 may include, for example, a white LED array. LED is an abbreviation for "Light Emitting Diode" (light emitting diode). The white LED array has intensity, for example, over substantially the entire visible light range. Note that the line illumination light source 60 is not limited to those including LEDs, and may include, for example, fluorescent lamps such as cold cathode tubes or lamp light sources.

[0018] The line illumination light source 60 may emit light in a wavelength range necessary for spectroscopy and be capable of uniformly illuminating the entire color data acquisition area 21. The illumination unit 22 may include a collimating lens that condenses the light emitted from the line illumination light source 60. The collimating lens can condense the light emitted from the line illumination light source 60 and irradiate the sheet 100 with parallel light or convergent light.

[0019] The reduction-image lens 70 is positioned so that its optical axis is aligned with the Z-axis direction. The reduction-image lens 70 can image the reflected light from the paper 100, i.e., the reflected light beam, onto the incident surface of the spectral unit 80 at a predetermined magnification. Here, the reduction-image lens 70 may also have an image-side telecentric characteristic. By adding an image-side telecentric characteristic to the reduction-image lens 70, the principal ray of the light beam incident on the image surface can be made parallel to the optical axis. The reduction-image lens 70 may also be composed of multiple lenses. A rod lens can be used as the collimating lens.

[0020] Furthermore, the reduction-image lens 70 does not necessarily have to have an image-side telecentric characteristic. For example, by adjusting the positional relationship between each pinhole in the pinhole array and each lens in the lens array in accordance with the inclination of the principal ray at each position on the image plane, the principal ray of the light beam incident on the image plane can be easily made approximately parallel to the optical axis.

[0021] The spectral unit 80 has the function of spectrally analyzing the diffusely reflected light of light irradiated onto the paper 100, and the function of receiving the spectrally analyzed light and outputting a signal corresponding to the received light.

[0022] The optical system illustrated in Figure 1 is a so-called 45 / 0 optical system in which illumination light emitted from a line illumination light source 60 is incident on the paper 100 at approximately a 45-degree angle, and the spectral unit 80 receives light diffusely reflected perpendicularly from the paper 100. However, the configuration of the optical system is not limited to that illustrated in Figure 1. For example, a so-called 0 / 45 optical system may be used in which illumination light emitted from a line illumination light source 60 is incident on the paper 100 perpendicularly, and the spectral unit 80 receives light diffused from the paper 100 in a 45-degree direction.

[0023] The color data acquisition unit 20 may include a white reference plate 51. The spectroscopic unit 80 may include a drive circuit, a CCD, and a spectroscopic element. The light receiving unit 23 may include a Peltier temperature control system, a scanner lens, and a UV / IR cut filter. The color data acquisition unit 20 may also include folding mirrors 25 and 26.

[0024] <Lighting equipment> Next, the lighting device 400 will be described with reference to Figures 3 to 5. Figure 3 is a schematic diagram showing the lighting device from above. Figure 4 is a perspective view showing the lighting device from below. Figure 5 is a side view showing the lighting device. The color data acquisition unit 20 includes the lighting device 400 as a line lighting light source 60.

[0025] The lighting device 400 comprises a side plate 410, a shaft 420, a metal plate 430, a rod lens 450, a rod lens retainer 460, and a white LED substrate 470. The side plate 410 is an example of a "support part". The white LED substrate 470 is an example of a "linear light source".

[0026] As shown in Figures 3 and 4, the lighting device 400 comprises a pair of side plates 410. The pair of side plates 410 are spaced apart from each other in the Y-axis direction. The thickness direction of the side plates 410 is aligned with the Y-axis direction. The axis 420 extends in the Y-axis direction and connects the pair of side plates 410.

[0027] As shown in Figures 4 and 5, the white LED substrate 470 is fixed to the metal plate 430. The white LED substrate 470 mounts a white LED array. The white LED array includes multiple LEDs arranged in the Y-axis direction. The white LED substrate 470 is fixed to the metal plate 430, for example, by screws. Heat generated from the white LED substrate 470 is transferred to the metal plate 430. The metal plate 430 dissipates the transferred heat. A heat sink, for example made of aluminum, may be attached to the metal plate 430. The heat from the metal plate 430 is dissipated by heat transfer to the heat sink.

[0028] The longitudinal direction of the metal plate 430 is aligned with the Y-axis direction. Both ends of the metal plate 430 in the longitudinal direction are supported by a pair of side plates 410. The metal plate 430 is provided with an opening into which the metal plate 430 fits. The side surfaces of the metal plate 430 may be in contact with the periphery of the opening of the side plate 410. The side surfaces of the metal plate 430 are surfaces aligned with the thickness direction of the metal plate 430 when viewed in the Y-axis direction. The pair of side surfaces of the metal plate 430 are surfaces that face each other in the short direction of the metal plate 430.

[0029] The bottom surface of the metal plate 430 may be in contact with the periphery of the opening of the side plate 410. The bottom surface of the metal plate 430 is the surface that intersects the plate thickness direction when viewed in the Y-axis direction and is positioned closer to the paper 100. The white LED substrate 470 is attached to the bottom surface of the metal plate 430.

[0030] The lighting device 400 may include a pressing member that presses the bottom surface of the metal plate 430 in the direction of the optical axis. A spring member can be used as the pressing member. The direction of the optical axis may also be the direction of emission of light emitted from the white LED substrate 470. The pressing member is attached to the side plate 410 and can press the metal plate 430 in the direction of the optical axis. The direction of the optical axis is an example of the "second direction".

[0031] The rod lens 450 is rod-shaped and extends in the Y-axis direction. The rod lens 450 transmits light in the diametrical direction intersecting the longitudinal direction of the rod lens 450. The rod lens 450 may be formed from, for example, acrylic resin (polymethyl methacrylate resin: PMMA). Acrylic resin is lightweight and has excellent light transmittance. The rod lens 450 may be formed from other materials.

[0032] The ends of the rod lens 450 are supported by a pair of side plates 410. The side plates 410 are provided with notches into which the rod lens 450 fits. When viewed in the Y-axis direction, the rod lens 450 is positioned away from the white LED substrate 470 in the optical axis direction. The notches into which the rod lens 450 is positioned are formed to penetrate the side plates 410 in the Y-axis direction. When viewed in the Y-axis direction, the notches may be formed to be recessed from the end in the Z-axis direction. The notches may be formed by a periphery extending in the Z-axis direction and a periphery extending in the X-axis direction.

[0033] The side plate 410 has lens contact surfaces 411 and 412 that contact the side surface of the rod lens 450. The lens contact surfaces 411 and 412 form the periphery of the notch into which the rod lens 450 fits. Lens contact surface 411 is an example of a "first surface". Lens contact surface 412 is an example of a "second surface".

[0034] Figure 6 is a schematic side view showing the rod lens and the lens contact surface. As shown in Figure 6, the lens contact surface 411 includes a surface intersecting the Z-axis direction and is formed to align with the X-axis direction when viewed in the Y-axis direction. The lens contact surface 411 contacts the rod lens 450 in the Z-axis direction. The rod lens 450 contacts the lens contact surface 411, and its upward movement is suppressed. The Z-axis direction is an example of a "fourth direction".

[0035] The lens contact surface 412 is formed to intersect with the lens contact surface 411 when viewed in the Y-axis direction. The lens contact surface 412 includes a surface that intersects with the X-axis direction and is formed to align with the Z-axis direction when viewed in the Y-axis direction. The lens contact surface 412 contacts the rod lens 450 in the X-axis direction. The rod lens 450 contacts the lens contact surface 412, and its movement in the X-axis direction is suppressed.

[0036] As shown in Figure 5, the lighting device 400 comprises a plurality of white LED substrates 470. The plurality of white LED substrates 470 are spaced apart from each other in the X-axis direction. Similarly, the lighting device 400 comprises a plurality of rod lenses 450. The plurality of rod lenses 450 are spaced apart from each other in the X-axis direction. As shown in Figure 6, the lens contact surfaces 412 are located outside the two rod lenses 450 in the X-axis direction.

[0037] Figure 7 is a side view showing the rod lens retainer. The rod lens retainer 460 shown in Figure 7 is attached to the side plate 410 by means of screws, for example. The rod lens retainer 460 is plate-shaped, and the thickness direction of the rod lens retainer 460 is along the Y-axis direction. The rod lens retainer 460 is positioned on the outside of the side plate 410 in the Y-axis direction. When viewed in the Y-axis direction, the rod lens retainer 460 protrudes so as to overlap the notch in which the rod lens 450 is positioned.

[0038] The rod lens retainer 460 has a lens contact surface 461 that contacts the side surface of the rod lens 450. The lens contact surface 461 is an example of a "third surface". The lens contact surface 461 includes a surface intersecting the optical axis direction of the white LED substrate 470 and extends in a direction intersecting the X and Z axes when viewed in the Y axis direction. The lens contact surface 461 extends in a direction intersecting the lens contact surfaces 411 and 412 shown in Figure 6. The rod lens 450 contacts the lens contact surfaces 411, 412, and 461 at different positions in the circumferential direction of the rod lens 450. The rod lens retainer 460 is positioned between a pair of rod lenses 450 facing each other in the X axis direction. The lens contact surface 461 is formed to protrude on both sides in the X axis direction. The rod lens retainer 460 can support a pair of rod lenses 450 facing each other in the X axis direction. The lighting device 400 may include a pressing mechanism that presses the rod lens retainer 460 against the rod lens 450. The pressing mechanism may include, for example, a spring member.

[0039] <Effect of variations in rod lens diameter> Next, with reference to Figures 8 to 10, the effects of variations in the diameter of the rod lens 450 will be explained. Figure 8 is a schematic side view showing the illumination device, measurement surface, and height range. Figure 9 is a table showing the predicted effects of misalignment of the rod lens. Figure 10 is a schematic side view showing the misalignment of the rod lens.

[0040] As shown in Figure 8, when the dimensions of the rod lens 450 vary due to diameter tolerances, the optical properties of the illumination device 400 may be affected by the amount of shift in the diametrical direction ΔR, the amount of shift in the optical axis direction ΔV, and the amount of shift in the direction perpendicular to the optical axis ΔW. Figure 9 shows the predicted effects on the optical properties when the tolerance of the rod lens 450 in the diametrical direction ΔR is 5 times, the predicted effects on the optical properties when the tolerance of the rod lens 450 in the optical axis direction ΔV is 5 times, and the predicted effects on the optical properties when the tolerance of the rod lens 450 in the direction perpendicular to the optical axis ΔW is 5 times.

[0041] <When the tolerance of the diameter ΔR of the rod lens is 5 times> The target value for the main scan minimum illuminance ratio is, for example, 0.9 or higher. The main scan minimum illuminance ratio is the ratio of the "main scan minimum illuminance value" to the "main scan maximum illuminance value" (main scan minimum illuminance ratio = main scan minimum illuminance value / main scan maximum illuminance value). In the conventional technology, the main scan minimum illuminance ratio was, for example, around 0.97. The structural difference between the "conventional technology" and the "magnified" version is the difference in the tolerance of the rod lens diameter. The tolerance of the rod lens diameter in the conventional technology is φ12 ± 0.1 mm. The tolerance of the rod lens diameter in the magnified version is φ12 ± 0.5 mm.

[0042] The "minimum illumination ratio for main scan after magnification" was between 0.97 and 0.98. The evaluation was "○". An evaluation of "○" was given when the "target value was met," and an evaluation of "×" was given when the "target value was not met."

[0043] The target value for the height range A1 with an illuminance ratio of 0.99 or higher is ±0.25 mm or more. In the Z-axis direction, the position of the measurement surface Q1 is set to "0". The measurement surface Q1 may be the image surface of paper 100. A height range A1 of ±0.25 mm or more means that when the position of the measurement surface Q1 changes by a certain amount, the range of variation is 0.5 mm (= 0.25 mm × 2) or more. Since the thickness varies depending on the paper, if we try to accommodate paper thicknesses from 0.1 mm to 0.6 mm, the range of variation will be 0.5 mm. If the height range A1 is ±0.25 mm or more, it is possible to accommodate paper with different thicknesses (0.1 mm to 0.6 mm) as described above. Alternatively, if the height range A1 is ±0.25 mm or more, a stable illuminance ratio can be ensured even if paper 100 lifts.

[0044] In the conventional technology, the height range A1 with an illuminance ratio of 0.99 or higher was, for example, "-0.26 mm or more and 0.33 mm or less". The "height range A1 with an illuminance ratio of 0.99 or higher after magnification" was "-0.26 mm or more and 0.33 mm or less". There was no change between the "conventional" and "magnified" versions. The evaluation was "〇".

[0045] <When the tolerance for the optical axis ΔV of the rod lens is 5 times> The target value for the minimum illuminance ratio for main scan is, for example, 0.9 or higher. In conventional technology, the minimum illuminance ratio for main scan was, for example, around 0.97. The "minimum illuminance ratio for main scan after magnification" was between 0.97 and 0.98. The evaluation was "〇".

[0046] The target value for the height range A1 with an illuminance ratio of 0.99 or higher is ±0.25 mm or more. In the conventional technology, the height range A1 with an illuminance ratio of 0.99 or higher was, for example, "-0.26 mm or more and 0.33 mm or less". The "height range A1 with an illuminance ratio of 0.99 or higher after expansion" was "-0.26 mm or more and 0.33 mm or less". There was no change between the "conventional" and "expanded" versions. The evaluation was "〇".

[0047] <When the tolerance of the rod lens in the direction perpendicular to the optical axis ΔW is 5 times> The target value for the minimum illuminance ratio for main scan is, for example, 0.9 or higher. In conventional technology, the minimum illuminance ratio for main scan was, for example, around 0.97. The "minimum illuminance ratio for main scan after magnification" was between 0.97 and 0.98. The evaluation was "〇".

[0048] The target value for the height range A1 with an illuminance ratio of 0.99 or higher is ±0.25 mm or more. In the conventional technology, the height range A1 with an illuminance ratio of 0.99 or higher was, for example, "-0.26 mm or more and 0.33 mm or less". The "height range A1 with an illuminance ratio of 0.99 or higher after magnification" was "0 mm". The target value of "±0.25 mm or more" means "0.25 mm or more" and "-0.25 mm or less". The evaluation was "×".

[0049] Based on the above impact predictions, it was found that if the shift amount ΔW in the direction perpendicular to the optical axis of the rod lens 450 is suppressed, the optical characteristics of the lighting device 400 will not be affected even if the diameter tolerance is expanded fivefold from ±0.1 to ±0.5. In other words, since the diameter tolerance of the rod lens 450 can be expanded, the dimensional accuracy requirements for the rod lens 450 can be relaxed. This will reduce the manufacturing cost of the rod lens 450.

[0050] Figure 10 shows the rod lens 450 in the reference position and the rod lens 450B when it is shifted in the direction ΔW perpendicular to the optical axis from the reference position. The light is bent by the rod lens 450B which is shifted in the direction ΔW perpendicular to the optical axis. As a result, the illumination position of the light that has passed through the rod lens 450B is shifted upward in the Z-axis direction compared to the case of light that has passed through the rod lens 450 in the reference position.

[0051] As shown in Figure 6, in the lighting device 400, the rod lens 450 is positioned so as to contact the lens contact surfaces 411 and 412 of the side plate 410. Since the rod lens 450 is in contact with the lens contact surface 411 which is aligned with the X-axis direction when viewed in the Y-axis direction, movement of the rod lens 450 in the Z-axis direction is suppressed. Since the rod lens 450 is in contact with the lens contact surface 412 which is aligned with the Z-axis direction when viewed in the Y-axis direction, movement of the rod lens 450 in the X-axis direction is suppressed. In other words, by contacting the lens contact surfaces 411 and 412, the rod lens 450 is allowed to move in the optical axis direction ΔV, while movement in the direction perpendicular to the optical axis ΔW is restricted.

[0052] <Effects and Effects> In such a lighting device 400, the rod lens 450 is positioned to contact a lens contact surface 411 extending in the X-axis direction intersecting the optical axis direction, and a lens contact surface 412 extending in the Z-axis direction intersecting the optical axis direction and the X-axis direction. This suppresses movement of the rod lens 450 in the direction ΔW perpendicular to the optical axis, thereby maintaining high accuracy in the relative position between the white LED substrate 470 and the rod lens 450. In the lighting device 400, the positional accuracy of the rod lens 450 can be maintained by supporting the rod lens 450 so that it contacts the lens contact surfaces 411 and 412. Therefore, the increase in man-hours required for adjusting the relative position between the white LED substrate 470 and the rod lens 450 can be suppressed. In the lighting device 400, as described above, the diameter tolerance of the rod lens 450 can be expanded to five times that of conventional devices. In the lighting device 400, the increase in the cost of manufacturing the rod lens 450 can be suppressed.

[0053] In the lighting device 400, the lens contact surface 411 is arranged along the X-axis, which suppresses the movement of the rod lens 450 in a direction that intersects the image plane of the paper 100.

[0054] In the lighting device 400, since the lens contact surface 412 is arranged along the Z-axis direction, the movement of the rod lens 450 in the direction along the image plane of the paper 100 can be suppressed.

[0055] In the lighting device 400, the lens contact surfaces 411 and 412 are arranged to be orthogonal to each other, so that the movement of the rod lens 450 can be suppressed in two mutually orthogonal directions.

[0056] <Image forming apparatus> Next, the image forming apparatus will be described with reference to Figure 11. Figure 11 is a schematic diagram showing an image forming apparatus according to an embodiment. The image forming apparatus 200 shown in Figure 11 is, for example, an inkjet type image forming apparatus. The image forming apparatus 200 comprises an image forming unit 201, a paper feeding unit 202, a drying unit 203, and a paper discharge unit 204. The image forming apparatus 200 also comprises the colorimeter 10 described above. By including the colorimeter 10, the image forming apparatus 200 can acquire spectral characteristics and adjust image forming conditions in-line.

[0057] The image-forming unit 201 has a plurality of inkjet heads Gr, O, Y, M, Cy, and K. Inkjet head Gr ejects green ink. Inkjet head O ejects orange ink. Inkjet head Y ejects yellow ink. Inkjet head M ejects magenta ink. Inkjet head Cy ejects cyan ink. Inkjet head K ejects black ink.

[0058] The paper feeding unit 202 receives the paper 100 as the object to be printed. The paper feeding unit 202 supplies the paper 100 to the image-making unit 201.

[0059] The image-forming unit 201 ejects ink of the corresponding color onto the paper 100 based on the image information. The ink ejected from the inkjet adheres to the paper 100 and forms a visible image. The image-forming unit 201 supplies the ink-coated paper 100 to the drying unit 203.

[0060] The drying unit 203 dries the ink while transporting the paper 100. The drying unit 203 transports the dried paper 100 to the paper discharge unit 204. The paper discharge unit 204 discharges the paper 100. The paper discharge unit 204 may also store the paper 100 in a stacker.

[0061] A colorimeter 10 is provided in the paper discharge section 204. The colorimeter 10 is positioned opposite the image surface of the paper 100. The image surface of the paper 100 is the surface to which ink adheres. The colorimeter 10 operates when the image forming apparatus 200 is started, when the paper type of the paper 100 is changed, and during periodic inspections. Periodic inspections are performed, for example, after a certain period of operation. The colorimeter 10 can acquire the spectral characteristics of the image data of the paper 100 while it is being transported. Based on the acquired spectral characteristics data, the colorimeter 10 can monitor color unevenness and color fluctuations within the image surface of the paper 100.

[0062] The data acquired by the colorimeter 10 is output to the control unit of the image forming apparatus 200. Based on the monitoring results from the colorimeter 10, the control unit of the image forming apparatus 200 can adjust the amount of ink ejected from the inkjet head. Based on the monitoring results from the colorimeter 10, the control unit of the image forming apparatus 200 can adjust the image forming conditions and thus the image creation conditions. The control unit of the image forming apparatus 200 can function as an image evaluation device and improve color reproducibility.

[0063] Furthermore, the present invention is not limited to the embodiments described above, and various modifications are possible without departing from or altering the technical concept of the present invention.

[0064] In the above embodiment, the first direction is described as a direction along the Y-axis, but the first direction is not limited to the Y-axis and may be any other direction. In the above embodiment, the third direction is described as a direction along the X-axis, but the third direction is not limited to the X-axis and may be any other direction.

[0065] In the above embodiment, the fourth direction is described as a direction along the Z-axis, but the fourth direction is not limited to the Z-axis and may be any other direction. The fourth direction is described as a direction perpendicular to the third direction when viewed from the first direction, but the fourth direction is not limited to a direction perpendicular to the third direction and may be a direction intersecting the third direction.

[0066] In the above embodiment, the second direction is described as a direction inclined at 45 degrees with respect to the reference plane of the paper 100. However, the second direction is not limited to a direction inclined at 45 degrees with respect to the reference plane, and may be any other direction. For example, the second direction may be a direction perpendicular to the reference plane of the paper 100 when viewed from the first direction.

[0067] In the embodiments described above, the fifth direction is described as being perpendicular to the optical axis, but the fifth direction is not limited to this. The fifth direction may be, for example, a direction that intersects the optical axis direction when viewed from the first direction.

[0068] In the above embodiment, the lens contact surfaces 411 and 412 are described as being arranged orthogonally to each other, but the lens contact surfaces 411 and 412 are not limited to being orthogonal to each other and may intersect at other angles.

[0069] In the above embodiment, an image forming apparatus 200 equipped with an image reading device having an illumination device has been described, but the illumination device and the image reading device may be applied to apparatus other than an image forming apparatus.

[0070] In the above embodiment, the lighting device is exemplified as comprising multiple lighting units, each having a linear light source and a rod lens; however, the lighting device may comprise only one lighting unit. Furthermore, the lighting device may comprise three or more lighting units.

[0071] One aspect of the present invention may be as follows: <1> A linear light source extending in a first direction and emitting light in a second direction, irradiating an object with the light, A rod lens is positioned away from the linear light source in the second direction and extending in the first direction, It comprises a support portion for supporting the rod lens, The aforementioned support portion is Viewed in the first direction, the first surface extends in a third direction that intersects the second direction, Viewed in the first direction, it includes a second surface extending in a fourth direction that intersects the second and third directions, The lighting device is characterized in that the rod lens is in contact with the first surface and the second surface. <2> The second direction is characterized in that, when viewed in the first direction, it follows a direction that is inclined at a 45-degree angle with respect to the reference plane of the object. <1> The lighting device described above. <3> The support portion is characterized by including a pair of side plates that are spaced apart from each other in the first direction. <1> or <2> The lighting device described above. <4> The third direction is characterized in that, when viewed in the first direction, it is a direction that aligns with the reference plane of the object. <1> ~ <3> A lighting device as described in any one of the following. <5> The fourth direction is characterized in that, when viewed from the first direction, it is a direction perpendicular to the third direction. <1> ~ <4> A lighting device as described in any one of the following. <6> Each of the multiple lighting units includes the linear light source and the rod lens, The plurality of lighting units are characterized in that they are arranged apart from each other in a direction along the reference plane of the object. <1> ~ <5> A lighting device as described in any one of the following. <7> The linear light source is characterized by including a plurality of white LED light sources arranged in the first direction. <1> ~ <6> A lighting device as described in any one of the following. <8> The lens retainer is attached to the support portion and, together with the support portion, supports the rod lens, The lens retainer includes a third surface that, when viewed in the first direction, extends in a fifth direction intersecting the third and fourth directions, The rod lens is characterized in that it is in contact with the third surface. <1> ~ <7> A lighting device as described in any one of the following. <9> the above <1> ~ <8> A lighting device described in any one of the following, An image reading device characterized by comprising a light receiving unit that receives the light emitted from the illumination device and reflected by the object. [Explanation of symbols]

[0072] 200 Image forming apparatus 400 Lighting devices 10 Colorimetric device 20-color data acquisition unit (image reading device) 21 Color data acquisition area (reference plane) 22 Lighting Section 23 Light receiving part 60-line lighting source (lighting unit) 100 sheets (objects) 410 Side plate (support part) 411 Lens contact surface (first surface) 412 Lens contact surface (second surface) 450 Rod Lens 460 Rod lens retainer 461 Lens contact surface (third surface) 470 White LED board (linear light source) 471 White LED light source ΔR Diameter direction ΔV Optical axis direction (second direction) ΔW is perpendicular to the optical axis (5th direction) XX axis direction (3rd direction) YY axis direction (first direction) ZZ axis direction (4th direction) [Prior art documents] [Patent Documents]

[0073] [License 1] Patent No. 2011-82969

Claims

1. A linear light source that extends in a first direction and emits light in a second direction intersecting the first direction, thereby irradiating an object with the light; A rod lens is positioned away from the linear light source in the second direction, extending in the first direction, and transmitting the light emitted from the linear light source, It comprises a support portion for supporting the rod lens, The aforementioned support portion is Viewed in the first direction, the first surface extends in a third direction that intersects the second direction, Viewed in the first direction, it includes a second surface extending in a fourth direction that intersects the second and third directions, The lighting device is characterized in that the rod lens is in contact with the first surface and the second surface at mutually different positions on one side of its outer circumference.

2. The lighting device according to claim 1, characterized in that the second direction is along a direction that is inclined at 45 degrees with respect to the reference plane of the object when viewed in the first direction.

3. The lighting device according to claim 1, characterized in that the support portion includes a pair of side plates arranged apart from each other in the first direction.

4. The lighting device according to claim 1, characterized in that the third direction is a direction that aligns with the reference plane of the object when viewed in the first direction.

5. The lighting device according to claim 1, characterized in that the fourth direction is a direction perpendicular to the third direction when viewed in the first direction.

6. Each of the multiple lighting units includes the linear light source and the rod lens, The lighting device according to claim 1, characterized in that the plurality of lighting units are arranged apart from each other in a direction along the reference plane of the object.

7. The lighting device according to claim 1, characterized in that the linear light source includes a plurality of white LED light sources arranged in the first direction.

8. The lens retainer is attached to the support portion and, together with the support portion, supports the rod lens, The lens retainer includes a third surface that, when viewed in the first direction, extends in a fifth direction intersecting the third and fourth directions, The lighting device according to claim 1, characterized in that the rod lens is in contact with the third surface.

9. A lighting device according to any one of claims 1 to 8, An image reading device characterized by comprising a light receiving unit that receives the light emitted from the illumination device and reflected by the object.

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