Image reading device and image forming device

Abstract

To provide an image reading device that can reduce image reading time compared with a configuration that performs an image reading operation for each of a plurality of light sources irradiating an image reading target with rays of light at different angles.SOLUTION: An image reading device 12 comprises: a plurality of light sources 30 and 32 that irradiates an image reading target M with rays of light at different angles; and a switching mechanism 34 that sequentially switches light OP1 and light OP2 made incident on the image reading target M from the plurality of light sources 30 and 32 in an image reading operation for the image reading target M.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to an image reading device that reads an image and an image forming device including the image reading device.

Background Art

[0002] Patent Document 1 discloses an imaging device including: an irradiation unit that irradiates an object to be imaged with light; a first imaging unit that forms an image of diffusely reflected light from the object to be imaged irradiated with light by the irradiation unit; a second imaging unit that forms an image of specularly reflected light from the object to be imaged irradiated with light by the irradiation unit; an imaging unit that receives the light imaged by the first or second imaging unit and generates an image signal corresponding to the light; an image data generation unit that synthesizes a first image signal generated by the imaging unit in response to the light imaged by the first imaging unit and a second image signal generated by the imaging unit in response to the light imaged by the second imaging unit to generate image data; and an image data output unit that outputs the image data generated by the image data generation unit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, a technique of performing an image reading operation for each light source on an image reading target and synthesizing the obtained image signals is known. However, an image reading operation is required for each light source, and shortening of the image reading time is desired.

[0005] An object of the present disclosure is to obtain an image reading device capable of shortening an image reading time as compared with a configuration in which an image reading operation is performed for a plurality of light sources that irradiate light on an image reading target at different angles. [Means for solving the problem]

[0006] The image reading device according to the first embodiment includes a plurality of light sources that irradiate the image to be read at different angles, and a switching mechanism that sequentially switches the light incident on the image to be read from the plurality of light sources during an image reading operation on the image to be read.

[0007] The image reading device of the second embodiment includes a control unit in the image reading device of the first embodiment that controls the lighting of the plurality of light sources and lights up the plurality of light sources sequentially during the image reading operation.

[0008] In the third embodiment of the image reading device, the control unit, in the image reading device of the second embodiment, sets the illumination times of the plurality of light sources to be different.

[0009] The fourth embodiment of the image reading device is an image reading device of the third embodiment in which the plurality of light sources include a first light source and a second light source having a smaller angle of incidence of light to the image to be read than the first light source, and the control unit makes the illumination time of the second light source shorter than the illumination time of the first light source.

[0010] The fifth embodiment of the image reading device is an image reading device of the fourth embodiment in which the control unit causes the processing of the image obtained by the first light source and the image obtained by the second light source to be different.

[0011] The sixth embodiment of the image reading device is an image reading device of the first embodiment in which the switching mechanism includes a light-shielding member that blocks light emitted from the plurality of light sources, and by blocking the light from the light sources with the light-shielding member, the light incident on the image reading target from the plurality of light sources is switched sequentially.

[0012] The image reading device of the seventh embodiment is an image reading device of the sixth embodiment in which the light-shielding time of the multiple light sources by the light-shielding member is different for each of them.

[0013] The eighth image forming apparatus comprises an image reading device according to any one of the first to seventh embodiments for reading an image from a document to be read, and an image forming unit for forming an image on a recording medium based on the read image information. [Effects of the Invention]

[0014] In the first embodiment of the image reading device, the image reading time can be shortened compared to a configuration in which the image reading operation is performed for each of the multiple light sources that irradiate the image to be read at different angles.

[0015] In the second embodiment of the image reading device, compared to a configuration in which the light incident on the image reading target is switched by moving or rotating the light source, variations in the angle of incidence of light on the image reading target can be suppressed.

[0016] In the third embodiment of the image reading device, the image reading time can be shortened compared to a configuration in which the illumination time of multiple light sources is the same.

[0017] In the fourth embodiment of the image reading device, the image reading time can be shortened compared to a configuration in which the illumination times of the first light source and the second light source are the same.

[0018] In the fifth embodiment of the image reading device, the image reading time can be shortened compared to a configuration in which the processing of images obtained by the first light source and images obtained by the second light source are the same.

[0019] In the sixth embodiment of the image reading device, compared to a configuration in which the light incident on the image reading target is switched by moving or rotating the light source, variations in the angle of incidence of light on the image reading target can be suppressed.

[0020] In the seventh embodiment of the image reading device, the image reading time can be shortened compared to a configuration in which the shading time of multiple light sources is the same.

[0021] In the eighth embodiment of the image forming apparatus, an image with texture can be formed on the recording medium. [Brief explanation of the drawing]

[0022] [Figure 1] This is a diagram showing the device configuration of an image forming apparatus according to an embodiment of the present disclosure. [Figure 2] This is a functional block diagram of an image forming apparatus according to an embodiment of the present disclosure. [Figure 3] This is a diagram showing the device configuration of an image reading apparatus according to an embodiment of the present disclosure, and shows a scanning operation in which light from a first light source is incident on an image reading target. [Figure 4] This is a diagram showing the device configuration of the image reading apparatus shown in FIG. 3, and shows a scanning operation in which light from a second light source is incident on an image reading target. [Figure 5] This is a diagram showing the time required for the scan of Example 1 in which a single scan operation is performed while sequentially lighting a plurality of light sources. [Figure 6] This is a diagram showing the time required for the scan of Example 2 in which a single scan operation is performed while sequentially lighting a plurality of light sources. [Figure 7] This is a diagram showing the time required for the scan of Example 3 in which a single scan operation is performed while sequentially lighting a plurality of light sources. [Figure 8] This is a diagram showing the device configuration of an image reading apparatus according to another embodiment of the present disclosure, and shows a scanning operation in which light from a first light source is incident on an image reading target. [Figure 9] This is a diagram showing the device configuration of the image reading apparatus shown in FIG. 8, and shows a scanning operation in which light from a second light source is incident on an image reading target.

Mode for Carrying Out the Invention

[0023] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0024] FIG. 2 shows a block diagram showing the functional configuration of an image forming apparatus 10 according to the present embodiment. The image forming apparatus 10 includes an image reading unit 12 and an image forming unit 14. Note that the image reading unit 12 of the present embodiment is an example of the image reading apparatus in the present disclosure.

[0025] The image reading unit 12 has the function of reading an image from the object to be read. Specifically, the image reading unit 12 optically reads the surface characteristics of the object to be read and generates image information representing the reading result. Examples of objects to be read include flat objects such as paper and textiles. The object to be read may also be a three-dimensional object. In this embodiment, a document M having an image on its surface is used as an example of the object to be read.

[0026] The image forming unit 14 has the function of forming an image on a recording medium P such as paper based on the image information read by the image reading unit 12.

[0027] Furthermore, the image forming apparatus 10 also includes a control unit 16, a storage unit 18, an image processing unit 20, an operation unit 22, and an input / output unit 24.

[0028] The control unit 16 has the function of controlling the operation of each part of the image forming apparatus 10. In this embodiment, the control unit 16 is composed of a computer in which a CPU (Central Processing Unit), ROM (Read-only Memory), RAM (Random Access Memory), etc., are connected to each other via a bus so as to be able to communicate with each other. The control unit 16 controls the operation of each part of the image forming apparatus 10 by executing various programs PRG stored in the storage unit 18.

[0029] The storage unit 18 has the function of storing the aforementioned program PRG, etc. In this embodiment, the storage unit 18 is, for example, a storage device such as an HDD (Hard Disk Drive), SSD (Solid State Drive), or flash memory, and stores the aforementioned program PRG, etc. The aforementioned program PRG may be stored in the aforementioned ROM.

[0030] The image processing unit 20 has the function of generating image information by applying the set image processing to the image signal generated by the image reading unit 12 and outputting it to the image forming unit 14. This image processing unit 20 is equipped with, for example, multiple image processing circuits such as ASICs (Application Specific Integrated Circuits) and LSIs (Large Scale Integrations), and an image memory for temporarily storing image data, and performs various image processing using each image processing circuit. The image processing unit 20 may also output image data to the input / output unit 24 or the operation unit 22 as needed.

[0031] The operation unit 22 has the function of sending input instructions from the operator to the control unit 16. In this embodiment, the operation unit 22 is equipped, for example, with a touch panel display and various buttons, and displays images based on image data output by the image processing unit 20, and sends input instructions from the operator to the control unit 16.

[0032] The input / output unit 24 has the function of exchanging data with an external device. In other words, the input / output unit 24 in this embodiment functions as an interface device.

[0033] (Image reading unit 12) Next, the image reading unit 12 will be described. Figures 1 and 3 show the configuration of the image reading unit 12.

[0034] The image reading unit 12 comprises a full-rate carriage 40, a half-rate carriage 42, an imaging optical system 44, a sensor 46, a platen glass 48, and a platen cover 50. The full-rate carriage 40 in this embodiment is an example of a housing in this disclosure.

[0035] As shown in Figures 1 and 3, the full-rate carriage 40 includes a light source 30, a light source 32, and a switching mechanism 34, which will be described later. The full-rate carriage 40 has the function of moving in the sub-scanning direction at a predetermined speed. Specifically, when the full-rate carriage 40 reads an image by alternately irradiating the document M with light from the light sources 30 and 32, it moves in the sub-scanning direction at a predetermined speed. In Figures 1 and 3, the sub-scanning direction is indicated by arrow C. Hereafter, the operation in which the full-rate carriage 40 reads the document M while moving in the sub-scanning direction will be referred to as the "scanning operation".

[0036] As shown in Figure 1, the half-rate carriage 42 is equipped with mirrors 52 and 54 and has the function of guiding light from the full-rate carriage 40 to the imaging optical system 44. The half-rate carriage 42 also has the function of moving in the sub-scanning direction at a predetermined speed. Specifically, when the full-rate carriage 40 illuminates the original document M with light from the light source 30 of the full-rate carriage 40 to read an image, the half-rate carriage 42 moves in the same direction as the full-rate carriage 40 at half the speed of the full-rate carriage 40.

[0037] The imaging optical system 44 has the function of forming an image of the reflected light from the original document M at the position of the sensor 46. As shown in Figure 1, the imaging optical system 44 is provided on the optical path connecting the mirror 54 and the sensor 46. The imaging optical system 44 is composed of a mirror, an imaging lens (for example, an fθ lens), and the like.

[0038] As shown in Figure 1, the sensor 46 receives reflected light formed by the imaging optical system 44 and has the function of generating an image signal corresponding to the received light. Specifically, the sensor 46 is composed of a light-receiving element such as a CCD (Charge Coupled Device) linear image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor, and converts the received light into a signal representing its intensity. The sensor 46 also has a color filter and generates image information representing the color of the original document M. The sensor 46 outputs the image information obtained by receiving the reflected light.

[0039] As shown in Figure 3, the platen glass 48 has the function of supporting the original document M, which is the object to be image read. This platen glass 48 is made of a transparent, flat glass plate. Note that the platen glass 48 is not limited to a glass plate; for example, it may be an acrylic plate or the like.

[0040] The platen cover 50 has the function of blocking external light. Specifically, as shown in Figure 1, the platen cover 50 covers the platen glass 48 in a manner that blocks external light.

[0041] The image reading unit 12 includes a light source 30, a light source 32, and a switching mechanism 34 inside the full-rate carriage 40.

[0042] As shown in Figure 3, the light source 30 has the function of irradiating light onto the original document M, which is the object to be image read in this embodiment. The light source 30 irradiates light onto the original document M from the rear side in the direction of movement of the full-rate carriage 40 with respect to the normal direction of the original document M at an incident angle θ1. The light source 30 is fixed to the full-rate carriage 40 so as to irradiate light onto the original document M at an incident angle θ1 (in other words, to cause light to be incident on it). The light source 30 is positioned so as not to obstruct the principal rays of the reflected light of the light irradiated onto the original document M. In this embodiment, as an example, the incident angle θ1 of the light from the light source 30 is set to 5°, but it is not limited to this. The light source 30 in this embodiment is an example of the second light source in this disclosure. In Figure 3, the optical path of the light irradiated from the light source 30 onto the original document M is indicated by the symbol OP1.

[0043] As the light source 30, for example, white light such as a fluorescent lamp or a noble gas fluorescent lamp (xenon fluorescent lamp, etc.) may be used, or multiple white LEDs may be arranged in the main scanning direction and a diffuser plate or the like may be used to make the brightness distribution in the main scanning direction as uniform as possible.

[0044] As shown in Figure 4, the light source 32 has the function of irradiating the original document M with light at a different angle from the light source 30. The light source 32 irradiates the original document M with light from the front side in the direction of movement of the full-rate carriage 40 with respect to the normal direction of the original document M at an incident angle θ2. This light source 32 is fixed to the full-rate carriage 40 so as to irradiate the original document M with light at an incident angle θ2 (in other words, to cause light to be incident on it). The light source 32 is positioned so as not to obstruct the principal rays of the reflected light of the light irradiated onto the original document M. Also, the incident angle θ1 is a smaller angle than the incident angle θ2. In this embodiment, as an example, the incident angle θ2 of the light from the light source 32 is set to 45°, but it is not limited to this. The light source 32 in this embodiment is an example of the first light source in this disclosure. In Figure 4, the optical path of the light irradiated onto the original document M from the light source 32 is indicated by the symbol OP2.

[0045] As for the light source 32, similar to the light source 30, white light such as a fluorescent lamp or a rare gas fluorescent lamp (xenon fluorescent lamp, etc.) may be used, or multiple white LEDs may be arranged in the main scanning direction and a diffuser plate or the like may be used to make the brightness distribution in the main scanning direction as uniform as possible.

[0046] The switching mechanism 34 has the function of sequentially switching the light incident on the document M from multiple light sources during the image reading operation (scanning operation) of the document M. In this embodiment, the switching mechanism 34 sequentially switches the light incident on the document M by repeatedly turning on the light source 30 and the light source 32 in sequence during the scanning operation. In other words, the switching mechanism 34 alternately turns on the light source 30 and the light source 32 during the scanning operation to alternately switch the light incident on the document M. The switching mechanism 34 also includes a switching control unit 36. Note that the switching control unit 36 ​​in this embodiment is an example of a control unit in this disclosure.

[0047] The switching control unit 36 ​​controls the illumination of multiple light sources and has the function of illuminating the multiple light sources sequentially during scanning. In this embodiment, the switching control unit 36 ​​controls the power supplied to light sources 30 and 32, and the light sources light up when power is supplied and turn off when power is stopped. The switching control unit 36 ​​causes light sources 30 and 32 to light up alternately.

[0048] The scanning operation by the image reading unit 12 is controlled by the control unit 16. That is, when the control unit 16 starts the scanning operation by the image reading unit 12, the switching mechanism 34 (switching control unit 36) functions.

[0049] Furthermore, the switching control unit 36 ​​may control the lighting times of the multiple light sources to be different. Specifically, as shown in Figure 6, the switching control unit 36 ​​may make the lighting time of light source 30 shorter than the lighting time of light source 32.

[0050] Furthermore, the switching control unit 36 ​​may process the images obtained by light source 30 and the images obtained by light source 32 differently. Specifically, the processing of the image signal obtained when light source 30 is turned on may be different from the processing of the image signal obtained when light source 32 is turned on. For example, the processing of the image signal obtained when light source 30 is turned on may be simpler than the processing of the image signal obtained when light source 32 is turned on.

[0051] Furthermore, as shown in Figures 3 and 4, a mirror 39 is provided inside the full-rate carriage 40. The mirror 39 reflects the light reflected from the original document M to the half-rate carriage 42. This reflected light is then guided to the imaging optical system 44 via mirrors 52 and 54.

[0052] In this embodiment, the term "mirror" simply refers to a total internal reflection mirror.

[0053] The image reading unit 12 of this embodiment has the function of reading image information of the document M in a single scanning operation by alternately illuminating the document M with light sources 30 and 32. Here, the reflective component of the reflected light obtained from light source 30 mainly represents the texture of the document M. On the other hand, the reflective component of the reflected light obtained from light source 32 mainly represents the color of the document M. The texture referred to here includes the glossiness and unevenness of the document M. With this image reading unit 12, as described above, it is possible to obtain image information that represents both the color and texture of the document M in a single scanning operation.

[0054] (Image forming unit 14) Next, the image forming unit 14 will be described. As shown in Figure 1, the image forming unit 14 of this embodiment includes image forming units 60A, 60B, 60C, and 60D, an intermediate transfer belt 62, primary transfer rolls 64A, 64B, 64C, and 64D, a secondary transfer roll 66, a backup roll 68, a paper feeding unit 70, and a fixing unit 72.

[0055] The intermediate transfer belt 62 is an endless belt member that circulates in the direction of arrow B in the figure.

[0056] The primary transfer rolls 64A, 64B, 64C, and 64D are biased towards the photoreceptor drums of the image forming units 60A, 60B, 60C, and 60D via the intermediate transfer belt 62. A toner image (i.e., a developer image) is formed on these photoreceptor drums, and this toner image is transferred to the intermediate transfer belt 62.

[0057] The secondary transfer roll 66 and the backup roll 68 are biased toward each other at a position where the intermediate transfer belt 62 faces the recording medium P such as paper, and transfer the toner image from the intermediate transfer belt 62 to the recording medium P.

[0058] The paper feeding unit 70 is equipped with paper trays 70A and 70B that house various recording media P, and supplies these recording media P during image formation.

[0059] The fixing unit 72 is equipped with a roll member for heating and pressurizing the recording medium P, and fixes the toner image transferred to the surface of the recording medium P using heat and pressure.

[0060] In this way, the image forming unit 14 forms an image on the recording medium P using each color toner.

[0061] Next, the operation of this embodiment will be described. In the image reading unit 12 of this embodiment, the switching mechanism 34 is used to sequentially switch the light incident on the document M from multiple light sources during the scanning operation of the document M. In other words, the switching mechanism 34 sequentially switches the optical path of the light during the scanning operation. Therefore, the image reading unit 12 of this embodiment can obtain image information with texture in a single scanning operation.

[0062] Here, we will explain, with reference to Figure 5, a comparative example in which scanning is performed for each of the multiple light sources that irradiate the original document M at different angles, and Example 1 in which scanning is performed while sequentially switching the light incident on the original document M from the multiple light sources.

[0063] As shown in Figure 5, in the comparative example, the first scan operation is performed by moving the full-rate carriage 40 in the sub-scanning direction with the light source 30 illuminated. After the first scan operation, the full-rate carriage 40 is returned to its initial position. Next, the second scan operation is performed by moving the full-rate carriage 40 in the sub-scanning direction with the light source 32 illuminated. After the second scan operation, the full-rate carriage 40 is returned to its initial position. Before the scan operation, calibration is performed using a white reference.

[0064] On the other hand, in Example 1, the light incident on the document M from light source 30 and light source 32 is repeatedly switched sequentially during the scanning operation. As a result, two types of image signals are obtained in a single scanning operation. That is, image information with texture is obtained. In addition, since Example 1 involves only one scanning operation compared to the comparative example, the time required to read image information with texture from the document M is shortened. In other words, the image reading unit 12 can shorten the image reading time (scanning time) from the document M compared to a configuration (comparative example) in which a scanning operation is performed for each of the multiple light sources that irradiate the document M at different angles.

[0065] As described above, the reduced image scanning time improves productivity. Furthermore, it prevents the operator from accidentally moving the original document (M) during scanning.

[0066] In the image reading unit 12 of this embodiment, the switching control unit 36 ​​controls the lighting of multiple light sources to light them sequentially during scanning. Specifically, the switching control unit 36 ​​controls the lighting of light sources 30 and 32 to light them sequentially (alternatingly) during scanning. Therefore, compared to a configuration in which the light incident on the original document M is switched by moving or rotating the light sources, the positions of light sources 30 and 32 with respect to the full-rate carriage 40 are fixed in the image reading unit 12, thus suppressing variations in the angle of incidence of light on the original document.

[0067] In the image reading unit 12 of this embodiment, if the switching control unit 36 ​​sets the illumination times of multiple light sources to be different, specifically, if the illumination time of light source 30 is shorter than that of light source 32, the image reading time from the original document M can be shortened compared to a configuration in which the illumination times of multiple light sources are the same.

[0068] Here, with reference to Figure 6, we will describe two embodiments: Embodiment 1, in which the lighting time of light source 30 and the lighting time of light source 32 are the same, and Embodiment 2, in which the lighting time of light source 30 is shorter than the lighting time of light source 32. First, the angle of incidence of the light incident on the document M from light source 30 is smaller than that of the light incident on the document M from light source 32. Specifically, in this embodiment, the angle of incidence θ1 is 5°. Therefore, the reflected light from light source 30 onto the document M has a large specular reflection component, and sufficient image information (information regarding texture) can be obtained even if the lighting time is shortened. Accordingly, in Embodiment 2, compared to the configuration in which the lighting times of multiple light sources are the same (Embodiment 1), the image reading time from the document M can be shortened by making the lighting time of light source 30 shorter than the lighting time of light source 32.

[0069] Furthermore, in the image reading unit 12 of this embodiment, if the switching control unit 36 ​​processes the image signal obtained from the light source 30 and the image signal obtained from the light source 32 differently, the image reading time from the original document M can be shortened compared to a configuration in which the image signals obtained from the light source 30 and the image signals obtained from the light source 32 are processed in the same way.

[0070] Here, with reference to Figure 7, we will describe two embodiments: Embodiment 2, in which the processing of the image signal obtained by light source 30 and the image signal obtained by light source 32 are the same, and Embodiment 3, in which the processing of the image signal obtained by light source 30 is simplified compared to the processing of the image signal obtained by light source 32. First, the image information obtained by light source 30 is image information related to texture. If the image information related to texture is determined, for example, by the presence or absence of gloss, the irradiation time of light from light source 30 can be further shortened. That is, by making the processing of the image information obtained by light source 30 a simple process of determining the presence or absence of gloss, the illumination time of light source 30 can be further shortened. Therefore, in Embodiment 3, compared to the same configuration (Embodiment 2) in which the processing of the image signal obtained by light source 30 and the image signal obtained by light source 32 are the same, the illumination time of light source 30 is made shorter than the illumination time of light source 32, thereby shortening the image reading time from the original document M.

[0071] In the image forming apparatus 10 of this embodiment, the image reading unit 12 reads an image with texture from the original document M. Then, the image forming unit 14 forms an image on the recording medium based on the read image information with texture. In this way, the image forming apparatus 10 forms an image with texture on the recording medium P.

[0072] <Other Embodiments> (Image reading unit 82) In the image reading unit 12 of the above embodiment, the switching mechanism 34 controls the illumination of the light sources 30 and 32 to switch between optical paths OP1 and OP2, but this disclosure is not limited to this configuration. For example, as shown in the image reading unit 82 in Figures 8 and 9, the switching mechanism 84 may switch between optical paths OP1 and OP2.

[0073] Specifically, the image reading unit 82 includes a light source 30, a light source 32, a mirror 39, a first light-shielding member 86, and a second light-shielding member 88 inside the full-rate carriage 40. The first light-shielding member 86 and the second light-shielding member 88 are examples of light-shielding members in this disclosure.

[0074] The switching mechanism 84 includes a first light-shielding member 86 and a second light-shielding member 88. These first light-shielding member 86 and second light-shielding member 88 block light from the light source.

[0075] As shown in Figure 8, the first light-shielding member 86 is positioned on the optical path OP1. This first light-shielding member 86 is a dimming member that has the function of adjusting the transmittance of light. In this embodiment, the first light-shielding member 86 can be switched between transparent and opaque to light from the light source 30 by switching the electricity ON / OFF. The ON / OFF control of the first light-shielding member 86 is performed by the switching control unit 90. The position of the first light-shielding member 86 is not particularly limited as long as it is positioned on the optical path OP1. Also, as shown in Figure 8, the first light-shielding member 86 in this embodiment is a film-like or plate-like member, but its shape is not particularly limited as long as it has the function of blocking light from the light source 30.

[0076] As shown in Figure 9, the second light-shielding member 88 is positioned on the optical path OP2. This second light-shielding member 88 is a dimming member that has the function of adjusting the transmittance of light. In this embodiment, the second light-shielding member 88 can be switched between transparent and opaque to light from the light source 32 by switching the electricity ON / OFF. The ON / OFF control of the second light-shielding member 88 is performed by the switching control unit 90. The position of the second light-shielding member 88 is not particularly limited as long as it is positioned on the optical path OP2. Also, as shown in Figure 9, the second light-shielding member 88 in this embodiment is a film-like or plate-like member, but its shape is not particularly limited as long as it has the function of blocking light from the light source 32.

[0077] The switching mechanism 84 includes a switching control unit 90. The switching control unit 90 electrically controls the first light-shielding member 86 and the second light-shielding member 88 to switch the light incident on the original document M. Therefore, in the image reading unit 82, both the light source 30 and the light source 32 are kept lit during scanning, and the light path is switched by the first light-shielding member 86 and the second light-shielding member 88. The switching control unit 90 may also control the power supply time to the first light-shielding member 86 and the second light-shielding member 88, similar to the switching control unit 36 ​​described above. With this configuration, the image reading unit 82 can obtain the same effects as the image reading unit 12.

[0078] The image forming unit 14 in the above-described embodiment is a tandem system equipped with four image forming units, but this disclosure is not limited thereto. The image forming unit 14 may also be a rotary type image forming unit. Alternatively, a paper transport belt may be provided instead of an intermediate transfer belt, and a configuration may be used in which the image is transferred directly from the photosensitive drum to the recording medium P without transferring to an intermediate transfer body (intermediate transfer belt).

[0079] In the above-described embodiment, an image reading unit 12 is provided on the upper part of the image forming apparatus 10, but this disclosure is not limited thereto. An image reading apparatus may be formed by an image reading unit 12, a control unit 16, a storage unit 18, and an image processing unit 20.

[0080] Furthermore, in the above-described embodiment, the full-rate carriage 40 moves in the sub-scanning direction to irradiate the document M placed on the platen glass 48 with light, but this disclosure is not limited to this. For example, the document M may move in the sub-scanning direction to irradiate the full-rate carriage 40 with light.

[0081] Furthermore, while the above-described embodiment involves irradiating the lower surface of the document M placed on the platen glass 48 with light, this disclosure is not limited to this configuration. For example, the document M placed on the table may be irradiated with light from a full-rate carriage 40 moving above the document M in the sub-scanning direction toward the upper surface of the document M.

[0082] Furthermore, although the above-described embodiment uses light sources 30 and 32, this disclosure is not limited to this configuration. For example, there may be one or more light sources other than light sources 30 and 32. Alternatively, the light from the light source may be guided to the original document M using a mirror or the like, and image information may be obtained from the reflected light.

[0083] This disclosure is not limited to the embodiments described above, and various modifications, changes, and improvements are possible without departing from its spirit. For example, the modifications shown above may be combined in any way. [Explanation of symbols]

[0084] 10 Image forming apparatus 12 Image reading unit (an example of an image reading device) 14 Image forming unit 30. Light source (an example of a second light source) 32. Light Source (An example of the first light source) 34 Switching mechanism 36 Switching Control Unit (Example of a control unit) 82 Image reading unit (an example of an image reading device) 84 Switching mechanism 86. First light-shielding member (an example of a light-shielding member) 88. Second light-shielding member (an example of a light-shielding member) 90 Switching control unit (an example of a control unit) θ1 Incident angle θ2 angle of incidence M Manuscript (an example of an image to be read) OP1 optical path OP2 optical path P recording medium

Claims

1. Multiple light sources that illuminate the image to be read at different angles, During a single image reading operation on the image reading target, a switching mechanism sequentially switches the light incident on the image reading target from the plurality of light sources while moving relative to the image reading target in the sub-scanning direction, Equipped with, The switching mechanism includes a control unit that controls the illumination of the plurality of light sources and illuminates the plurality of light sources sequentially during the image reading operation. The plurality of light sources include a first light source and a second light source having a smaller angle of incidence of light to the image reading target than the first light source. The control unit alternately lights up the first light source and the second light source in such a way that the lighting time of the second light source is shorter than the lighting time of the first light source during one image reading operation.

2. The image reading device according to claim 1, wherein the control unit processes the image obtained by the first light source and the image obtained by the second light source differently.

3. An image reading device according to claim 1 or claim 2, which reads an image from a document to be read, An image forming unit that forms an image on a recording medium based on the image information it reads, An image forming apparatus equipped with the following features.

Images