JP2007311897A - Image reading apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reading apparatus for dissipating heat by a method different from a conventional method. <P>SOLUTION: An image reading section 10 includes a housing 11, a lamp 132, a lamp power supply 133, an imaging section 16, and an original carrying section 17. When the original carrying section 17 carries an original, the lamp 132 emits light to a position indicated by a point S<SB>2</SB>, and the imaging section 16 generates an image signal by receiving its reflected light. In this case, the lamp 132 and the lamp power supply 133 are located at a lower part of a frame member 111 of the housing 11. Since the frame member 111 made of aluminum is excellent in thermal conductivity, the frame member 111 efficiently dissipates heat caused in the lamp 132 and the lamp power supply 133 externally. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image reading apparatus and an image forming apparatus.

  In an image reading apparatus such as a scanner, a lamp, a driving unit thereof, and the like serve as a heat generation source to increase the internal temperature. In order to cool the inside of the image reader, external air is forcibly circulated by a blower such as a fan. However, if a blower is used, dust and dust such as paper dust enter or drive. There was an inconvenience that the sound became noise. Therefore, conventionally, efforts have been made to dissipate heat from the image reading apparatus without using a blower (fanless).

As a configuration for dissipating heat in the image reading device without a fan, for example, it is most common to provide a heat radiating hole (see, for example, Patent Document 1). When the hole is provided, noise can be suppressed and power consumption can be reduced as compared with the configuration provided with the blower, and a certain effect is recognized. However, even when a hole for heat dissipation is provided, dust and dust smaller than this hole are still easy to enter, and it is difficult to prevent this. Such dust and dust have a problem of deteriorating image quality when adhering to a member such as a platen glass or a lens of the image reading apparatus. In addition, dust and dust that has entered the interior not only takes time to remove these, but if left as it is, there is a risk of causing a short circuit in the circuit section and causing a failure.
Japanese Utility Model Publication No. 3-66263

  SUMMARY An advantage of some aspects of the invention is that it provides a technique for radiating heat in an image reading apparatus using a method different from the conventional method.

  In order to achieve the above object, an image reading apparatus according to the present invention includes a planar transmissive member having a horizontal transmissive region that transmits light, a frame member that forms an outer frame of the transmissive member, and a document. Document conveying means for conveying the document so as to face the transmission region of the transmissive member at a predetermined position, irradiation means for irradiating light to the document conveyed to the predetermined position by the document conveying means, and the irradiation Signal generating means for detecting reflected light reflected on the original document and generating an image signal representing the intensity of the reflected light. The irradiating means is provided at the predetermined position. When irradiating light, at least a part of the irradiating means is positioned so as to be included in a region obtained by orthogonally projecting the frame member from the vertical direction.

Further, in this aspect, the irradiating means is positioned so that the irradiating means is not included in a region obtained by orthogonally projecting the transmissive area of the transmissive member from the vertical direction when irradiating the predetermined position with light. It may be.
Alternatively, the irradiating unit may be positioned so that the entire irradiating unit is included in a region obtained by orthogonally projecting the frame member from the vertical direction when irradiating the predetermined position with light.

  In the image reading apparatus according to the present invention, the frame member may hold the transmitting member, and the document conveying unit may convey the document while contacting the frame member. Moreover, the structure provided with the cooling means which cools the said frame member may be sufficient. Examples of the cooling means include a heat sink and a heat pipe.

In the image reading apparatus according to the present invention, the irradiation unit includes a light emitting unit that emits light and a power supply unit that supplies energy for the light emitting unit to emit light. The light emitting unit and the power supply unit may be positioned so as to be included in a region obtained by orthogonal projection of the frame member from the vertical direction.
In this case, the transmission member has a quadrangular shape, and the light emitting unit is arranged so that the longitudinal direction thereof is parallel to any one side of the transmission member, and the power supply unit is arranged in the longitudinal direction of the light emitting unit. The structure arrange | positioned at any one or both of the direction both ends may be sufficient.

  The present invention can be specified not only as an image reading apparatus but also as an image forming apparatus. An image forming apparatus according to the present invention includes, for example, any one of the above-described image reading apparatuses and an image forming unit that forms an image representing the original on a sheet based on an image signal generated by the signal generating unit. Is.

  According to the present invention as described above, in the image reading apparatus, heat can be radiated by a method different from the conventional method.

  Embodiments of the present invention will be described below with reference to the drawings. In the embodiments described below, an image forming apparatus (copier) provided with an image reading apparatus will be described as an example of an image reading apparatus according to the present invention.

[Constitution]
FIG. 1 is a diagram illustrating an appearance of an image forming apparatus 1 according to an embodiment of the present invention. The configuration of the image forming apparatus 1 is roughly divided into an image reading unit 10, an image forming unit 20, an operation unit 30, and a control unit 40 described later. The image reading unit 10 has a so-called scanner function, and optically reads a document to generate an image signal representing the document. The image forming unit 20 has a so-called printer function, and forms an image represented by the image signal generated by the image reading unit 10 on a sheet-like object such as paper. As the image forming unit 20, for example, an electrophotographic printer is preferably used. The operation unit 30 is an interface for notifying the user of various information and receiving instructions from the user, and includes a touch panel and various buttons. In the following, of the two side surfaces perpendicular to the X direction in the figure, the surface on the side where the operation unit 30 is provided is referred to as “front surface”, and the surface opposite to the front surface is referred to as “back surface”. That's it.

  The configuration of the image reading unit 10 is shown from the front side as shown in FIG. In the drawing, the paper conveyance path is indicated by a broken line, and the light path is indicated by an alternate long and short dash line. The image reading unit 10 includes a housing 11, a platen 12, a full rate carriage 13, a half rate carriage 14, an imaging unit 15, an imaging unit 16, and a document conveying unit 17. In the following, the direction of the arrow X shown in FIG. 1 is referred to as “main scanning direction”, and the direction orthogonal to the main scanning direction, that is, the direction of arrow Y shown in FIG.

  The housing 11 accommodates the full-rate carriage 13, the half-rate carriage 14, the imaging unit 15, and the imaging unit 16 therein, and includes a plurality of frame members 111, 112, and 113. The frame members 111, 112, and 113 constitute the upper surface, side surface, and bottom surface (lower surface) of the housing 11, respectively. The frame member 111 is provided with an opening for fitting each member of the platen 12. The material of the frame member 111 is aluminum.

  The platen 12 includes platen glasses 121 and 123 and a guide member 122. The platen glasses 121 and 123 are plate-like members made of a material that transmits light, such as glass, and the surface thereof is horizontal. The platen glass 121 has the same size (width) as the original in the main scanning direction, and the platen glass 123 has the same size (width and length) as the original in the main scanning direction and the sub-scanning direction. ing. The platen glasses 121 and 123 are quadrilaterals whose sides are parallel to the main scanning direction or the sub-scanning direction. The guide member 122 has an inclined surface that forms a predetermined angle with respect to the horizontal surface of the platen glass 121, and guides the moving direction of the document along the inclined surface to a paper discharge tray 173 described later. The guide member 122 also has a function as a document positioning member when a document is placed on the platen glass 123.

  The full rate carriage 13 includes a holding member 131, a lamp 132, a lamp power source 133, a reflector 134, and a mirror 135. The holding member 131 is a box-shaped member that houses the lamp 132, the lamp power source 133, the reflector 134, and the mirror 135, and holds these members. The lamp 132 is a light source that irradiates the document and the reflector 134 with light. As the lamp 132, for example, a xenon fluorescent lamp can be used. The lamp power supply 133 is a drive circuit for causing the lamp 132 to emit light, and includes a transformer, a regulator, and the like. The transformer or regulator generates heat when the lamp 132 is caused to emit light. The reflector 134 is a reflecting plate having a flat or parabolic condensing surface, and condenses the irradiation light irradiated by the lamp 132 at the reading position of the document. The mirror 135 has a reflecting surface that reflects light, and further reflects the reflected light reflected from the document out of the light emitted from the lamp 132 and guides it to the half-rate carriage 14. Note that the lamp 132, the reflector 134, and the mirror 135 have substantially the same width as the platen glasses 121 and 123 in the main scanning direction.

  Here, FIG. 3 is a view showing the lamp 132 and the lamp power supply 133 of the full-rate carriage 13 from above. As shown in the figure, the lamps 132 are arranged so as to be parallel to the main scanning direction, and are substantially parallel to one side of the platen glass 121. The lamp power supply 133 is composed of circuit parts 133L and 133R located at both ends of the lamp 132, and these are connected by a conductor (not shown).

  When the lamp 132 and the circuit portions 133L and 133R are in the positions shown in FIGS. 2 and 3, that is, when irradiating light toward the platen glass 121, they are hidden under the frame member 111 when viewed from above. ing. That is, at this time, the lamp 132 and the circuit units 133L and 133R are all included in a region obtained by orthogonally projecting the frame member 111 in the vertical direction. The lamp 132 and the circuit units 133L and 133R are not included in the region obtained by orthogonally projecting the transmission region of the platen glass 121 in the vertical direction. Here, the “transmission region” refers to a region of the platen glass 121 that can transmit light from the lamp 132 upward. It is a region that is not shielded by (ie, does not overlap these members).

  Returning to the description of the configuration shown in FIG. The half-rate carriage 14 includes a holding member 141 and mirrors 142 and 143, further reflects reflected light from the full-rate carriage 13 and guides it to the imaging unit 15. The holding member 141 is a box-shaped member that holds the mirrors 142 and 143. The mirrors 142 and 143 are members having a reflective surface similar to that of the mirror 135, and have approximately the same width as the platen glasses 121 and 123 in the main scanning direction.

  The full rate carriage 13 and the half rate carriage 14 are reciprocated in the sub-scanning direction by a drive unit (motor or the like) (not shown). The full-rate carriage 13 is moved in the sub-scanning direction at a predetermined speed, and the half-rate carriage 14 is moved in the sub-scanning direction at about half the speed of the full-rate carriage 13.

  The imaging unit 15 includes one or a plurality of lens members, and images reflected light from the original reflected by the full rate carriage 13 and the half rate carriage 14 at a position where the imaging unit 16 is located. The imaging unit 16 is a line sensor composed of a plurality of imaging elements arranged in the main scanning direction, senses the reflected light imaged by the imaging unit 15, and generates an image signal representing the intensity of the sensed reflected light. . As the image pickup device constituting the image pickup unit 16, for example, a device using a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) is suitable.

The document transport unit 17 includes a paper feed tray 171, a plurality of transport rolls 172, and a paper discharge tray 173. The paper feed tray 171 is configured to accommodate a plurality of originals to be read. The transport roll 172 is a roll member having the same width as that of the original in the main scanning direction, and is rotated by a driving unit (not shown) to convey the original one by one in the direction of arrow A in the figure. The document conveyed by the conveyance roll 172 contacts the platen glass 121 at a position indicated by a point S ₂ in the figure, and the moving direction is changed by the platen glass 121 and the guide member 122 to move to the sheet discharge tray 173. The paper discharge tray 173 is configured to be able to store a plurality of originals, and stores the read originals. The document transport unit 17 also functions as a cover member that covers the upper surface of the platen 12 and blocks outside light to facilitate reading of a document to be read.

  The operation of each unit of the image forming apparatus 1 is controlled by the control unit 40. That is, the configuration of the image forming apparatus 1 is shown in a block diagram as shown in FIG. The control unit 40 includes a CPU (Central Processing Unit) 41, a ROM (Read Only Memory) 42, a RAM (Random Access Memory) 43, and the like. In the control unit 40, the CPU 41 uses the RAM 43 as a work area to execute a program stored in the ROM 42 and controls the operation of each unit. The control unit 40 acquires the image signal generated in the image reading unit 10, converts the image signal into image data in a format that can be interpreted by the image forming unit 20, and supplies the image data to the image forming unit 20.

[Operation]
With the above configuration, the image forming apparatus 1 optically reads a document in accordance with an instruction from a user to generate an image signal, and forms an image according to the image signal on a sheet, thereby copying the document. Produce things. The image forming apparatus 1 has two types of reading modes depending on how to set (place) a document. The first mode is a mode that is executed when the user sets a document on the platen glass 123, and is a reading mode that is particularly suitable when there is only one document to be scanned. The second mode is a mode that is executed when the user sets a document on the document transport unit 17, and is a reading mode that is particularly suitable when there are a plurality of documents to be read.

When operating in the first mode, the control unit 40 of the image forming apparatus 1 performs scanning (reading) by moving the full-rate carriage 13 (and the half-rate carriage 14) without moving the document. When operating in the first mode, the position where scanning starts is the end of the guide member 122. That is, FIG. 5 shows the full rate carriage 13 and the half rate carriage 14 at this time. Therefore, the user is induced end of member 122 (i.e., the position indicated by the point S ₁ in this figure) is placed into to the document as Ategau to. Thereafter, the control unit 40 performs scanning by moving the full rate carriage 13 (and the half rate carriage 14) in the sub-scanning direction. That is, at this time, the reading position (the position where light is irradiated) changes continuously.

On the other hand, when operating in the second mode, the control unit 40 of the image forming apparatus 1 causes the document transport unit 17 to maintain the full rate carriage 13 (and the half rate carriage 14) at the position shown in FIG. Are transported one by one, and scanning is performed. In other words, when operating in the second mode, the reading position does not change from the position indicated by the point S ₂ in FIG. 2.

  When the image forming apparatus 1 performs scanning, the temperature of the full rate carriage 13 rises because the lamp 132 and the lamp power supply 133 generate heat. Therefore, in order to drive the lamp 132 stably, it is necessary to cool the full rate carriage 13 appropriately. Here, in the first mode, scanning is performed while the full-rate carriage 13 itself moves, so that heat is also dissipated with this movement. Therefore, in the first mode, the temperature of the lamp 132 and the lamp power supply 133 is relatively low.

  On the other hand, in the second mode, since the full rate carriage 13 is held without moving, the temperature of the full rate carriage 13 is more likely to rise than in the first mode. For this reason, in the second mode, the full-rate carriage 13 and its nearby members and air reach a high temperature in a relatively short time. And the air which became high temperature moves upwards.

  In the second mode, the full rate carriage 13 is held at the position shown in FIG. Since the frame member 111 is aluminum, the thermal conductivity is much higher than that of the platen glasses 121 and 123, and the heat dissipation is excellent. Therefore, the heat generated inside the full-rate carriage 13 is easily transmitted to the frame member 111 and is eventually dissipated to the other frame members 112 and 113 and the outside. As a result, the full rate carriage 13 effectively dissipates heat and suppresses an excessive increase in temperature.

  As described above, in this embodiment, when the image forming apparatus 1 operates in the second mode in which scanning is performed by moving a document without moving the full-rate carriage 13, the full-rate carriage 13 includes the frame member 111. Since it is located at the lower part, the heat generated in the full-rate carriage 13 is effectively dissipated to the housing 11. Therefore, according to the present embodiment, it is possible to suppress an excessive increase in temperature even under use conditions in which the temperature of the full-rate carriage 13 and the vicinity thereof is likely to increase.

[Modification]
In the above, the present invention has been described by exemplifying one preferred embodiment, but the present invention is not limited to the above-described embodiment, and can be implemented in various other modes. . In the present invention, for example, the following modifications can be applied to the above-described embodiment. These modifications can be combined as appropriate.

  In the above-described embodiment, the frame member 111 for heat dissipation has a shape surrounding the periphery of the platen 12, but the shape of the member for heat dissipation is not limited to this. For example, as shown in FIG. 6, the holding member 18 that holds the platen glass 121 may be a member for radiating heat. The holding member 18 has a groove for holding the platen glass 121 and is attached to the housing 11 with a screw or the like. The holding member 18 is preferably made of a material having high thermal conductivity such as aluminum.

  By providing such a holding member 18, it is easy to remove the platen glass 121. Therefore, when dust or dust enters the image forming apparatus 1, it becomes easy to remove it. Further, when reading is performed in the second mode described above, if the original is brought into contact with the holding member 18 and then conveyed to the reading position, the heat of the holding member 18 can be released to the original. Become.

  In order to further improve the heat dissipation effect, it is also effective to provide means for cooling the frame member 111 and the holding member 18 described above. As a means for cooling these members, for example, a heat sink or a heat pipe may be used. Here, FIG. 7 is a diagram illustrating an example in which a heat sink 181 is provided on the lower surface of the holding member 18. In this way, since the holding member 18 can come into contact with more air at the heat sink 181 portion, heat dissipation can be promoted.

  The heat sink 181 is preferably configured to be positioned on the back side of the image forming apparatus 1. In this way, the user does not get in the way when scanning. Further, in the case where the heat sink 181 is provided, a structure in which this portion protrudes from the housing 11 may be employed. For example, the width of the holding member 18 is configured to be longer than the width of the housing 11. In this way, heat dissipation can be further promoted.

  In the above-described embodiment, the frame member 111 is made of aluminum. Of course, a material other than aluminum may be used. In this case, of course, a material having high thermal conductivity is desirable. In addition, it becomes possible to improve the heat dissipation effect by using a material having high thermal conductivity for the member (for example, the frame member 112) that contacts the frame member 111.

  Further, in the above-described embodiment, the lamp power source 133 is divided and arranged at both ends of the lamp 132. In this configuration, it is desirable to provide a heat generating part such as a transformer or a regulator in the circuit part 133 </ b> R on the back side of the image forming apparatus 1. Of course, the transformer may be provided in the circuit unit 133L on the front side and the regulator may be provided in the circuit unit 133R on the back side so that heat is evenly dissipated.

  In addition, the lamp power supply 133 may be disposed at one end of the lamp 132 without being divided and disposed at both ends of the lamp 132. Alternatively, the lamp power supply 133 may be disposed below the lamp 132. In short, as long as the structure is located below the frame member 111, the specific position is not limited. The reason why the lamp power supply 133 is provided below the frame member 111 is to transmit heat generated in a heat generating part such as a transformer or a regulator to the frame member 111. In other words, in other words, the portion other than the heat generating portion may not be the lower portion of the frame member 111.

  Note that when there is a restriction on the arrangement of each member, the lamp 132 and the lamp power supply 133 do not have to be located below the frame member 111. In the present invention, if the main part of the lamp 132 or the lamp power supply 133 is positioned below the frame member 111, a certain heat dissipation effect can be obtained.

  In the above-described embodiment, the position of the full-rate carriage 13 at the start of scanning is different in the first mode and the second mode, but may be the same position. Further, the image reading unit 10 is configured to include two carriages (the full rate carriage 13 and the half rate carriage 14), but the number of carriages may be one. Further, only the second mode described above is provided, that is, the positions of the respective members corresponding to the full rate carriage 13 and the half rate carriage 14 are fixed, and the conveyed document is read at the same position. May be.

  The above embodiment is an example in which the present invention is applied to a copying machine. However, the present invention can be applied to an image forming apparatus (for example, a facsimile machine) other than the copying machine. . The present invention can be applied not only to an image forming apparatus but also to an image reading apparatus such as a scanner.

1 is an external view of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration of an image reading unit in the image forming apparatus of the embodiment. It is a figure which shows the full rate carriage of the embodiment from the upper surface. FIG. 2 is a block diagram illustrating a configuration of an image forming apparatus according to the embodiment. FIG. 2 is a diagram illustrating a configuration of an image reading unit in the image forming apparatus of the embodiment. It is a figure which shows the modification of the image forming apparatus of the embodiment. It is a figure which shows the modification of the image forming apparatus of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 10 ... Image reading part, 11 ... Housing | casing, 111, 112, 113 ... Frame member, 12 ... Platen, 121 ... Platen glass, 122 ... Induction member, 123 ... Platen glass, 13 ... Full-rate carriage, 131: Holding member, 132: Lamp, 133: Lamp power supply, 133L, 133R ... Circuit unit, 134: Reflector, 135 ... Mirror, 14 ... Half-rate carriage, 141 ... Holding member, 142, 143 ... Mirror, 15 ... Imaging 16, the imaging unit, 17 the document conveying unit, 18 the holding member, 181 the heat sink, 20 the image forming unit, 30 the operation unit, and 40 the control unit.

Claims (8)

A transmission member having a horizontal transmission region that transmits light;
A frame member constituting an outer frame of the transmission member;
A document conveying means for conveying the document so that the document faces the transmission region of the transmission member at a predetermined position;
Irradiating means for irradiating light to the original conveyed to the predetermined position by the original conveying means;
Signal generating means for detecting reflected light reflected from the original among the light irradiated on the original by the irradiating means and generating an image signal representing the intensity of the reflected light; and
The image reading unit, wherein the irradiation unit is positioned so that at least a part of the irradiation unit is included in a region obtained by orthogonally projecting the frame member from the vertical direction when the predetermined position is irradiated with light. apparatus. The irradiation means includes
The image according to claim 1, wherein when irradiating light at the predetermined position, the irradiating unit is not included in an area obtained by orthogonally projecting a transmissive area of the transmissive member from a vertical direction. Reader. The irradiation means includes
2. The image reading apparatus according to claim 1, wherein when irradiating the predetermined position with light, the image forming apparatus is positioned such that the entire irradiation unit is included in a region orthogonally projected from the vertical direction of the frame member. . The frame member holds the transmission member,
The image reading apparatus according to claim 1, wherein the document conveying unit conveys the document while being in contact with the frame member.   The image reading apparatus according to claim 1, further comprising a cooling unit that cools the frame member. The irradiation means includes
A light emitting unit that emits light;
A power supply unit that supplies energy for the light emitting unit to emit light;
2. The image according to claim 1, wherein when the predetermined position is irradiated with light, the light emitting unit and the power supply unit are positioned so as to be included in a region obtained by orthogonally projecting the frame member from a vertical direction. Reader. The transmitting member is a quadrilateral,
The light emitting portion is arranged such that its longitudinal direction is parallel to any one side of the transmissive member,
The image reading apparatus according to claim 6, wherein the power supply unit is disposed at one or both of the longitudinal ends of the light emitting unit. An image reading apparatus according to any one of claims 1 to 7,
An image forming apparatus comprising: an image forming unit configured to form an image representing the original on a sheet based on the image signal generated by the signal generating unit.

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