Image reading device and image forming device

Abstract

To obtain an image reading device that can reduce cost compared with a configuration that makes rays of light incident on an image reading target from a plurality of light sources at different angles.SOLUTION: An image reading device comprises: a single light source that irradiates an image reading target with light; a travel change member that changes the direction of travel of the light from the light source to irradiate the image reading target with light at an incident angle different from the incident angle of the light with which the image reading target is directly irradiated by the light source; and a switching mechanism that switches the travel of the light from the light source to a light path through which the image reading target is directly irradiated with the light or a light path through which the image reading target is irradiated with the light via the travel change member.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 image reading device that reads a document image having different gloss levels or a document image having different gloss level regions within the same document, the image reading device including a platen on which a document image is set, a specular reflection light source for photoelectrically converting specular reflection light of the document image, a diffuse reflection light source for photoelectrically converting diffuse reflection light of the document image, a photoelectric conversion unit that photoelectrically converts reflected light from the document image on the platen, a control unit that performs specular reflection reading of the document image irradiated with light from the specular reflection light source and diffuse reflection reading of the document image irradiated with light from the diffuse reflection light source, and an output value correction unit that corrects each output value of specular reflection and diffuse reflection from the photoelectric conversion unit to a value suitable for reading. The output value correction unit is provided with a maximum output reference value set from an output value of the photoelectric conversion unit irradiated with light from the specular reflection light source onto a high gloss level reference surface, a first minimum output reference value set from an output value of the photoelectric conversion unit irradiated with light from the specular reflection light source onto a low gloss level reference surface, a second minimum output reference value set from a dark output value of the photoelectric conversion unit, a first correction data based on the first minimum output reference value and the maximum output reference value, and a second correction data based on the second minimum output reference value and the maximum output reference value. The control unit is configured to be able to select whether to correct with the first correction data or the second correction data when performing specular reflection reading of a document image.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, while it is possible to obtain image information for each angle of incidence by illuminating the image target from multiple light sources at different angles, the use of multiple light sources tends to increase costs.

[0005] The purpose of this disclosure is to provide an image reading device that can reduce costs compared to a configuration in which light is incident on the image to be read from multiple light sources at different angles. [Means for solving the problem]

[0006] The image reading device in the first embodiment includes a single light source that irradiates light onto an image to be read; a path changing member that changes the direction of light propagation from the light source and irradiates the image to be read at an incident angle different from the incident angle of light that is directly irradiated onto the image to be read from the light source; and a switching mechanism that switches the propagation of light from the light source to an optical path that directly irradiates the image to be read, or to an optical path that irradiates via the path changing member.

[0007] The image reading device of the second embodiment is an image reading device of the first embodiment in which the switching mechanism includes a light-shielding member that blocks the optical path from the light source to the image to be read, and switches the optical path irradiated onto the image to be read by blocking the other optical paths with the light-shielding member while leaving one of the plurality of optical paths open.

[0008] The third embodiment of the image reading device includes a housing that moves relative to the image reading target in the main scanning direction and the sub-scanning direction, in the image reading device of the first or second embodiment, and the light source and the movement changing member are fixed to the housing.

[0009] The image reading device of the fourth embodiment is an image reading device of the first embodiment, wherein the switching mechanism includes a rotation drive unit that rotates the light source with the sub-scanning direction as the axial direction, and by changing the direction of irradiation of light from the light source by driving the rotation drive unit, the propagation of light from the light source is switched to an optical path that directly irradiates the image reading target or an optical path that irradiates via the propagation changing member.

[0010] The fifth embodiment of the image reading device is an image reading device of the first or fourth embodiment, comprising a housing that moves relative to the image to be read in the main scanning direction and the sub-scanning direction, and the movement changing member is fixed to the housing.

[0011] The sixth embodiment of the image reading device is an image reading device of the fifth embodiment in which the switching mechanism comprises a contact portion provided on the light source and a contacted portion provided on the housing that the rotating light source contacts, and the rotation of the light source is stopped by the contact between the contact portion and the contacted portion, thereby fixing the direction of light irradiation from the light source.

[0012] The seventh embodiment of the image reading device reads image information multiple times with different angles of incidence of light on the image to be read, in an image reading device according to any one of the first to sixth embodiments.

[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, costs can be reduced compared to a configuration in which light is incident on the image to be read from multiple light sources at different angles.

[0015] In the image reading device of the second embodiment, the variation in the angle of incidence of light on the image to be read can be suppressed compared to a configuration in which the light source moves in a direction intersecting the main scanning direction.

[0016] In the third embodiment of the image reading device, the variation in the angle of incidence of light on the image to be read can be suppressed compared to a configuration in which the light source and the direction changing member move relative to the housing.

[0017] In the image reading device according to the fourth aspect, variation in the incident angle of light with respect to the image reading target can be suppressed as compared with a configuration in which the light source moves in a direction intersecting the main scanning direction.

[0018] In the image reading device according to the fifth aspect, variation in the incident angle of light with respect to the image reading target can be suppressed as compared with a configuration in which the travel changing member moves with respect to the housing.

[0019] In the image reading device according to the sixth aspect, variation in the incident angle of light with respect to the image reading target can be suppressed as compared with a configuration in which the rotation of the light source is stopped based on a preset rotation angle.

[0020] In the image reading device according to the seventh aspect, the texture of the image reading target can be read.

[0021] In the image forming device according to the eighth aspect, a textured image can be formed on a recording medium.

Brief Description of the Drawings

[0022] [[ID=二十二]] [Figure 1] It is a diagram showing the device configuration of an image forming device according to an embodiment of the present disclosure. [Figure 2] It is a functional block diagram of an image forming device according to an embodiment of the present disclosure. [Figure 3] It is a diagram showing the device configuration of an image reading device according to an embodiment of the present disclosure, and shows a scanning operation in which light from a light source is reflected by a reflection mirror and made to enter an image reading target. [Figure 4] It is a diagram showing the device configuration of the image reading device shown in FIG. 3, and shows a scanning operation in which light from a light source is directly made to enter an image reading target. [Figure 5] It is a flowchart for explaining the flow of acquiring image information having texture from an image reading target using an image reading device according to an embodiment of the present disclosure. [Figure 6] It is a diagram showing the device configuration of an image reading device according to other embodiments of the present disclosure. [Figure 7] It is a diagram showing the device configuration of an image reading device according to other embodiments of the present disclosure. [Figure 8] This figure shows the configuration of an image reading device according to another embodiment of the present disclosure, illustrating a scanning operation in which light from a light source is reflected by a reflective mirror and incident onto the image to be read. [Figure 9] Figure 8 shows the configuration of the image reading device, illustrating the scanning operation in which light from the light source is directly incident on the image to be read. [Figure 10] This figure shows the light source used in the image reading device shown in Figure 8, stopped at the first rotation position. [Figure 11] This figure shows the light source used in the image reading device shown in Figure 8, stopped at the second rotation position. [Figure 12] This is a flowchart illustrating the process of acquiring image information with texture from an image target using the image reading device shown in Figure 8. [Modes for carrying out the invention]

[0023] An embodiment of this disclosure will be described below with reference to the drawings.

[0024] Figure 2 shows a block diagram illustrating the functional configuration of the image forming apparatus 10 according to this embodiment. The image forming apparatus 10 comprises an image reading unit 12 and an image forming unit 14. Note that the image reading unit 12 in this embodiment is an example of an image reading device in this 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 (described later), a mirror 32, and a switching mechanism 34. 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 irradiates light from the light source 30 onto the document M and reads the image, 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 mirror 32, and a switching mechanism 34 inside the full-rate carriage 40. The mirror 32 in this embodiment is an example of a progression-changing member as described in this disclosure.

[0042] 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. This light source 30 is the only light source installed in the image reading unit 12. In other words, the image reading unit 12 has a single light source 30.

[0043] The light source 30 illuminates the original document M with light from the front of the full-rate carriage 40 in the direction of movement relative to the normal direction of the original document M, at an incident angle θ2. The light source 30 is fixed to the full-rate carriage 40 so as to illuminate the original document M with light at an incident angle θ2 (in other words, to cause light to be incident on it). In this embodiment, as an example, the incident angle θ2 of the light from the light source 30 is set to 45°, but it is not limited to this.

[0044] 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.

[0045] As shown in Figure 3, the mirror 32 has the function of changing the direction of light propagation from the light source 30, and irradiating the document M with light at an incident angle θ1 that is different from the incident angle θ2 of the light that is directly irradiated onto the document M from the light source 30. The mirror 32 is positioned so as not to obstruct the principal rays of the reflected light of the light irradiated onto the document M. The mirror 32 is also fixed to the full-rate carriage 40 so as to reflect the light from the light source 30 and irradiate the document M with light at an incident angle θ1 (in other words, to cause the light to incident on the document M). In this embodiment, as an example, the incident angle θ1 of the light reflected by the mirror 32 is set to 5°, but it is not limited to this.

[0046] The switching mechanism 34 has the function of switching the propagation of light from the light source 30 to either an optical path OP1 (see Figure 4) that directly illuminates the document M, or an optical path OP2 (see Figure 3) that illuminates the document M via the mirror 32. The switching mechanism 34 of this embodiment is equipped with a light-shielding member that blocks the optical path from the light source 30 to the document M, and switches the optical path that illuminates the document M by blocking the other optical paths with the light-shielding member while leaving one optical path open. Specifically, the switching mechanism 34 is equipped with a first light-shielding member 36 that blocks the optical path OP1 that directly illuminates the document M with light from the light source 30, and a second light-shielding member 38 that blocks the optical path OP2 that illuminates the document M with light from the light source 30 via the mirror 32.

[0047] As shown in Figures 3 and 4, the first light-shielding member 36 is positioned on the reflective surface of the mirror 32. This first light-shielding member 36 is a dimming member that has the function of adjusting the transmittance of light. In this embodiment, the first light-shielding member 36 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 36 is performed by the control unit 16. In this embodiment, as an example, the first light-shielding member 36 is positioned on the reflective surface of the mirror 32, but this disclosure is not limited thereto, and the first light-shielding member 36 may be located away from the mirror 32. That is, as long as the first light-shielding member 36 is positioned on the optical path from the light source 30 to the mirror 32, its position is not particularly limited. Furthermore, as shown in Figures 3 and 4, the first light-shielding member 36 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.

[0048] As shown in Figures 3 and 4, the second light-shielding member 38 is positioned on the optical path from the light source 30 to the original document M. This second light-shielding member 38 is a dimming member that has the function of adjusting the transmittance of light. In this embodiment, the second light-shielding member 38 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 second light-shielding member 38 is performed by the control unit 16. Furthermore, as shown in Figures 3 and 4, the second light-shielding member 38 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.

[0049] Furthermore, 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.

[0050] In this embodiment, the term "mirror" refers to a total internal reflection mirror.

[0051] In this embodiment, the image reading unit 12 has the function of reading image information multiple times by varying the angle of incidence of light on the original document M. Specifically, the image reading unit 12 performs a first scanning operation, which is a scanning operation in which light from the light source 30 is reflected by the mirror 32 and incident on the original document M, and reading is performed using the reflected light from the original document M; and a second scanning operation, which is a scanning operation in which light from the light source 30 is directly incident on the original document M, and reading is performed using the reflected light from the original document M. The reflective component of the reflected light obtained in the first scanning operation mainly represents the texture of the original document M. On the other hand, the reflective component of the reflected light obtained in the second scanning operation mainly represents the color of the original document M. The texture referred to here includes the glossiness and unevenness of the original document M.

[0052] The image reading unit 12 in this embodiment performs two scanning operations, a first scan operation and a second scan operation, and generates image information by combining the image signals obtained from each scanning operation. The image information obtained in this way represents both the color and texture of the original document M.

[0053] Next, an example of a method for acquiring image information with texture from a document M using the image reading unit 12 will be described. Figure 5 shows a float chart for acquiring image information with texture from a document M using the image reading unit 12. In the following description, the operation of each part constituting the image reading unit 12 is controlled by the control unit 16.

[0054] In step S200, light source 30 is turned on.

[0055] In step S202, the switching mechanism 34 switches the optical path of light from the light source 30 to optical path OP1. Specifically, the first light-shielding member 36 opens optical path OP1, and the second light-shielding member 38 blocks and closes optical path OP2. That is, the first light-shielding member 36 becomes transparent by electrical control and transmits light, and the second light-shielding member 38 becomes opaque by electrical control and prevents light transmission.

[0056] In step S204, light from the light source 30 is incident on the document M at an incident angle θ1 via the optical path OP1, and in this state, the full-rate carriage 40 moves in the sub-scanning direction to scan the document M. The scanning operation performed in this step is the first scanning operation described above. The image signal obtained in the first scanning operation is sent to the image processing unit 20. Once the scanning in this step is complete, the process proceeds to step S206.

[0057] In step S206, the switching mechanism 34 switches the optical path of light from the light source 30 to optical path OP2. Specifically, the first light-shielding member 36 blocks and closes optical path OP1, and the second light-shielding member 38 opens optical path OP2. That is, the second light-shielding member 38 becomes transparent by electrical control and transmits light, while the first light-shielding member 36 becomes opaque by electrical control and prevents light transmission.

[0058] In step S208, light from the light source 30 is incident on the document M at an incident angle θ2 via the optical path OP2, and in this state, the full-rate carriage 40 moves in the sub-scanning direction to scan the document M. The scanning operation performed in this step is the second scanning operation described above. The image signal obtained in the second scanning operation is sent to the image processing unit 20. Once the scanning in this step is complete, the process proceeds to step S210.

[0059] In step S210, the light source 30 is turned off.

[0060] In step S212, the image signal obtained in the first scan operation and the image signal obtained in the second scan operation are combined to generate image information with a sense of texture.

[0061] In this embodiment, image information with texture can be obtained from the original document M. Here, the image signal obtained in the first scan operation is an image signal for detecting the texture of the original document M. The image signal obtained in the second scan operation is an image signal for detecting the color information of the original document M. From these, the image information obtained by combining the first and second image signals becomes image information that can represent the color and texture of the original document M. This makes it possible to read the color and texture from the original document M more accurately.

[0062] In the image reading unit 12 described above, the second scan operation is performed after the first scan operation when reading the original document M. However, this disclosure is not limited to this, and the first scan operation may be performed after the second scan operation. Even in this case, image information with a sense of texture can be generated.

[0063] (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.

[0064] The intermediate transfer belt 62 is an endless belt member that circulates in the direction of arrow B in the figure.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] In this way, the image forming unit 14 forms an image on the recording medium P using each color toner.

[0070] Next, the operation of this embodiment will be described. In the image reading unit 12 of this embodiment, the switching mechanism 34 allows the light propagation from a single light source 30 to be switched between an optical path OP2 that directly illuminates the original document M and an optical path OP1 that illuminates it via a mirror 32. Therefore, the image reading unit 12 of this embodiment can obtain image information with texture even without having multiple light sources. In other words, compared to a configuration in which light is incident on the original document M from multiple light sources at different angles, the image reading unit 12 allows the incident angle on the original document M to be switched (the optical path to be switched) even with a single light source, thus reducing the cost of the device.

[0071] Furthermore, in the image reading unit 12 of this embodiment, the light source 30 is a single unit. Therefore, compared to a configuration with multiple light sources, for example, there is no need to consider the effects of variations in the chromaticity of each light source, and image processing can be simplified.

[0072] In the image reading unit 12 of this embodiment, the optical paths OP1 and OP2 from the light source 30 to the original document M are switched by the first light-shielding member 36 and the second light-shielding member 38 provided by the switching mechanism 34. In this way, the image reading unit 12 can suppress variations in the angle of incidence of light on the original document M compared to a configuration in which the light source 30 moves in a direction intersecting the main scanning direction within the full-rate carriage 40.

[0073] Furthermore, in the image reading unit 12 of this embodiment, the light source 30 and the mirror 32 are fixed to the full-rate carriage 40. Therefore, the image reading unit 12 can more effectively suppress variations in the angle of incidence of light on the original document M compared to a configuration in which the light source 30 moves in a direction intersecting the main scanning direction within the full-rate carriage 40.

[0074] In this embodiment, the image reading unit 12 obtains an image signal by performing multiple scan operations with different angles of incidence of light on the original document M. Compared to a configuration that obtains an image signal by performing multiple scan operations with a single angle of incidence, for example, it is possible to read the texture of the original document M.

[0075] 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.

[0076] (Other embodiments) In the image reading unit 12 of the above embodiment, two scanning operations are performed: a first scan operation and a second scan operation. However, this disclosure is not limited to this configuration. For example, a mirror is provided on the full-rate carriage 40 that reflects light from the light source 30 and irradiates the original document M with light at different incident angles θ1 and θ2. A third scan operation may be performed based on the reflected light from this mirror onto the original document M. By performing multiple scan operations at multiple incident angles in this way, image information with a higher quality texture can be obtained.

[0077] (Image reading unit 82) In the image reading unit 12 of the above embodiment, the optical path OP1 and optical path OP2 are switched by a switching mechanism 34, but this disclosure is not limited thereto. For example, as in the image reading unit 82 shown in Figure 6, the optical path OP1 and optical path OP2 may be switched by a switching mechanism 84. This switching mechanism 84 comprises a first light-shielding member 86 and a second light-shielding member 88. The first light-shielding member 86 and the second light-shielding member 88 are each made of a material that does not allow light to pass through (opaque material). The first light-shielding member 86 is slidable between a light-shielding position that shields the optical path OP1 and a retracted position that is moved away from this light-shielding position. The second light-shielding member 88 is slidable between a light-shielding position that shields the optical path OP2 and a retracted position that is moved away from this light-shielding position. The sliding movement of the first light-shielding member 86 and the sliding movement of the second light-shielding member 88 are performed by a driving force from a drive unit (not shown) provided for each. The operation of the switching mechanism 84 is controlled by the control unit 16. As described above, by configuring the first light-shielding member 86 and the second light-shielding member 88 to slide, the angle (width) of the light that shines directly from the light source 30 towards the document M can be adjusted. In addition, the angle (width) of the light that shines from the light source 30 towards the document M via the mirror 32 can be adjusted.

[0078] (Image reading unit 92) Alternatively, as shown in the image reading unit 92 in Figure 7, the optical path OP1 and optical path OP2 may be switched by a switching mechanism 94. This switching mechanism 94 includes a first light-shielding member 96 and a second light-shielding member 98. The first light-shielding member 96 and the second light-shielding member 98 are both opaque materials that do not allow light to pass through. The first light-shielding member 96 is rotatable between a light-shielding position that blocks light from the optical path OP1 and a retracted position that is moved away from this light-shielding position. The second light-shielding member 98 is rotatable between a light-shielding position that blocks light from the optical path OP2 and a retracted position that is moved away from this light-shielding position. The rotational movement of the first light-shielding member 96 and the second light-shielding member 98 is performed by a driving force from a drive unit (not shown) provided for each. The operation of the switching mechanism 94 is controlled by the control unit 16. As described above, by configuring the first light-shielding member 96 and the second light-shielding member 98 to rotate, the angle (width) of the light that shines directly from the light source 30 towards the original document M can be adjusted. In addition, the angle (width) of the light that shines from the light source 30 towards the original document M via the mirror 32 can be adjusted.

[0079] (Image reading unit 102) In the image reading unit 12 of the above embodiment, the light source 30 is fixed within the full-rate carriage 40, and the optical path OP1 and optical path OP2 are switched by a switching mechanism 34 comprising a first light-shielding member 36 and a second light-shielding member 38. However, this disclosure is not limited to this configuration. For example, as shown in the image reading unit 102 in Figures 8 and 9, the optical path OP1 and optical path OP2 may be switched by a switching mechanism 104.

[0080] Specifically, the image reading unit 102 includes a light source 30, mirrors 32, 106, and 39 inside the full-rate carriage 40. Mirrors 32 and 106 are examples of progression-changing members in this disclosure. The light source 30 is rotatable in the axial direction of the sub-scanning direction by a switching mechanism 104. When the light source 30 is in the first rotation position as shown in Figure 8, light from the light source 30 is irradiated onto the document M via mirrors 106 and 32. Here, when the light source 30 is in the first rotation position, light is incident on the document M at an incident angle θ1. On the other hand, when the light source 30 is in the second rotation position as shown in Figure 9, light from the light source 30 is irradiated onto the document M at an incident angle θ2.

[0081] The switching mechanism 104 has the function of switching the propagation of light from the light source 30 to either an optical path OP2 (see Figure 9) that directly illuminates the document M, or an optical path OP1 (see Figure 8) that illuminates the document M via mirrors 106 and 32. The switching mechanism 104 in this embodiment includes a rotary drive unit 108 that rotates the light source 30 with the sub-scanning direction as the axial direction, and switches the propagation of light from the light source 30 to optical path OP1 or optical path OP2 by changing the direction of illumination of light from the light source 30 by driving the rotary drive unit 108. For example, an electric motor is used as the rotary drive unit 108.

[0082] Furthermore, the switching mechanism 104 includes a contact portion 110 provided on the light source 30 and a contacted portion 112 provided on the full-rate carriage 40, which the rotating light source 30 contacts. When the light source 30 rotates, the contact portion 110 of the light source 30 comes into contact with the contacted portion 112 of the full-rate carriage 40, thereby stopping the rotation of the light source 30. This fixes the direction of light irradiation from the light source 30. Specifically, as shown in Figures 10 and 11, the light source 30 is provided with a rotation axis 114, and the contact portion 110 is a projection protruding from the outer circumference of the end of the rotation axis 114, and is provided at two locations spaced apart in the circumferential direction of the rotation axis 114. As the light source 30 rotates, one of the contact portions 110 comes into contact with the contacted portion 112 provided on the full-rate carriage 40, and the light source 30 stops at the first rotation position (see Figure 10). On the other hand, when the light source 30 rotates in the opposite direction from the first rotation position (clockwise in Figure 11), the other contact portion 110 comes into contact with the contacted portion 112 provided on the full-rate carriage 40, and the light source 30 stops at the second rotation position.

[0083] Mirrors 32, 106, and 39 are fixed to the full-rate carriage 40.

[0084] Next, an example of a method for acquiring image information with texture from a document M using the image reading unit 102 will be described. Figure 12 shows a float chart for acquiring image information with texture from a document M using the image reading unit 102. In the following description, the operation of each part constituting the image reading unit 102 is controlled by the control unit 16.

[0085] In step S300, light source 30 is turned on.

[0086] In step S302, the switching mechanism 104 switches the optical path of the light from the light source 30 to optical path OP1. Specifically, the light source 30 rotates toward the first rotation position and stops at the first rotation position.

[0087] In step S304, light from the light source 30 is incident on the document M at an incident angle θ1 via the optical path OP1, and in this state, the full-rate carriage 40 moves in the sub-scanning direction to scan the document M. The scanning operation performed in this step is the first scan operation. The image signal obtained in the first scan operation is sent to the image processing unit 20. Once the scan in this step is complete, the process proceeds to step S306.

[0088] In step S306, the switching mechanism 104 switches the optical path of the light from the light source 30 to optical path OP2. Specifically, the light source 30 rotates toward the second rotation position and stops at the second rotation position.

[0089] In step S308, light from the light source 30 is incident on the document M at an incident angle θ2 via the optical path OP2, and in this state, the full-rate carriage 40 moves in the sub-scanning direction to scan the document M. The scanning operation performed in this step is the second scan operation. The image signal obtained in the second scan operation is sent to the image processing unit 20. Once the scan in this step is complete, the process proceeds to step S310.

[0090] In step S310, the light source 30 is turned off.

[0091] In step S312, the image signal obtained in the first scan operation and the image signal obtained in the second scan operation are combined to generate image information with a sense of texture.

[0092] In this way, the image reading unit 102 can acquire image information with texture from the original document M, similar to the image reading unit 12.

[0093] In the image reading unit 102, the switching mechanism 104 rotates the light source 30 relative to the full-rate carriage 40. However, because the contact portion 110 is brought into contact with the contacted portion 112 to stop the light source 30 at a predetermined rotational position, variations in the angle of incidence of light on the original document M can be suppressed compared to a configuration in which the light source 30 moves in a direction intersecting the main scanning direction relative to the full-rate carriage 40. Furthermore, the image reading unit 102, like the image reading unit 12, can reduce the cost of the device.

[0094] The image reading unit of the above embodiment uses a mirror (total reflection mirror) as an example of a path-changing member, but this disclosure is not limited to this configuration. For example, a prism mirror may be used as an example of a path-changing member. Each surface of the prism mirror may be a mirror layer, a half-mirror layer, and an anti-reflective layer, and the optical path of light to the original document M may be switched by rotating the prism mirror with a switching mechanism.

[0095] 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).

[0096] In the embodiment described above, 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.

[0097] 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.

[0098] 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.

[0099] 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]

[0100] 10 Image forming apparatus 12 Image reading unit (an example of an image reading device) 14 Image forming unit 30 light source 32. Mirror (an example of a component that changes direction) 34 Switching mechanism 36. First light-shielding member (an example of a light-shielding member) 38. Second light-shielding member (an example of a light-shielding member) 40 Full-rate carriage (an example of a chassis) 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) 92 Image reading unit (an example of an image reading device) 94 Switching mechanism 96 First light-shielding member (an example of a light-shielding member) 98. Second light-shielding member (an example of a light-shielding member) 102 Image reading unit (an example of an image reading device) 104 Switching mechanism 106 Mirror (an example of a component that changes direction) 108 Rotary drive unit 110 Contact area 112 Contacted part θ1 Incident angle θ2 angle of incidence C Sub-scanning direction M Manuscript (an example of an image to be read) OP1 optical path OP2 optical path P recording medium

Claims

1. A single light source that illuminates the image to be read, A direction-changing member that changes the direction of light propagation from the light source and irradiates the image reading target with light at an incident angle different from the incident angle of light directly irradiated onto the image reading target from the light source, A switching mechanism that switches the propagation of light from the light source to either an optical path that directly illuminates the image to be read, or an optical path that illuminates via the propagation changing member, The aforementioned progression changing member is fixed to a housing that moves relative to the image reading target in the main scanning direction and the sub-scanning direction, Equipped with, The switching mechanism comprises a rotation drive unit that rotates the light source with the sub-scanning direction as the axial direction, a contact part provided on the light source, and a contacted part provided on the housing that the rotating light source contacts. The rotation drive unit changes the direction of light irradiation from the light source, thereby switching the propagation of light from the light source to either an optical path that directly irradiates the image reading target or an optical path that irradiates via the propagation changing member. Furthermore, the rotation of the light source is stopped by contact between the contact part and the contacted part, thereby fixing the direction of light irradiation from the light source. An image reading device that reads image information multiple times by varying the angle of incidence of light on the image reading target in order to read the texture of the image reading target.

2. An image reading device according to claim 1, 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