JP4332918B2 - Scanner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a scanner, and more particularly to a scanner that scans an image of a document with a copying machine, an image reading device, or the like and uses the scanning light for copying, image recording, or image reading.
[0002]
[Prior art]
The scanner has an exposure lamp that exposes the original and a scanning optical element such as a scanning mirror that picks up reflected light from the original and directs it toward a predetermined light receiving object, and the exposure lamp displays an image of the original that is stopped by the movement of the slider. The reflected light from the manuscript at each moving position is picked up while being exposed and illuminated, and the scanned light is received by, for example, a photoconductor or recording medium for copying or other image formation, or an optical sensor for image reading. Directing, image formation or image reading.
[0003]
Conventionally, a fluorescent lamp has been used as an exposure lamp, and an inverter is driven with an attenuation waveform in order to obtain high-luminance light emission. In this case, since the heat generation of the driver is a serious problem, the inverter is driven. The lighting driver is cooled by providing a heat radiating member or the like, and a relatively large heat radiating member is used for the size of the lighting driver for sufficient cooling.
[0004]
On the other hand, since the inverter drive is a high-frequency drive and the influence of noise is large, it is preferable to shorten the harness for connecting to the exposure lamp. U.S. Pat. No. 4,959,737 proposes mounting a lighting driving device on a slider. According to this, the harness can be shortened to reduce the influence of noise.
[0005]
[Problems to be solved by the invention]
The present inventors tried to use the conventional lighting driver mounted on a slider. However, since the lighting driver has the large heat radiating member, it is heavy, and a motor with a large torque is required to drive the slider on which it is mounted with a predetermined accuracy. This causes an increase in power consumption.
[0006]
An object of the present invention is to provide a scanner capable of sufficiently cooling a lighting driver with a small and lightweight heat radiating member to reduce the torque of a motor for driving a slider.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a scanner according to the present invention is a scanner having a scanning optical element directed to a light receiving object in a slider, and a heat radiating member made of a plate member is applied to a lighting driver, and the heat radiating member is attached to both ends. One feature is that the protrusions bent and raised between them protrude so as to protrude out of the slider .
[0008]
In this way, if the heat dissipation member applied to the lighting driver is a plate member, both ends are bent, and the protruding part cut and raised between them protrudes outside the slider, the heat dissipation member touches the atmosphere outside the slider. In addition to being easy to dissipate heat, each time the slider moves and scans the document with the exposure lamp and scanning optical element, the atmosphere outside the slider works as a cooling airflow by the relative movement with the atmosphere outside the slider, and the heat of the cooling member is easily taken away. The lighting driver can be sufficiently cooled by a small and lightweight heat radiating member, reducing the weight of the lighting driver including the heat radiating member, and reducing the motor torque required to drive the scanner with a predetermined accuracy. Can do.
[0009]
If the protrusion of the heat radiating member to the outside of the slider is a fin, the heat radiating property to the atmosphere outside the slider is high, and the heat radiating member can be made thinner and smaller, which is effective in reducing the driving torque of the slider. Also, if the fin is parallel to the slider moving direction, the relative movement direction between the fin and the slider outside atmosphere when the slider moves is the direction along the fin. Since they are in good contact with each other without being disturbed, heat is more easily taken away by the atmosphere outside the slider, heat dissipation is improved, and the size of the heat dissipation member can be further reduced.
[0010]
If the surface of the heat dissipating member is black, even if it protrudes from the slider, it is possible to reduce the occurrence of diffusely reflected light in the optical path of the imaging optical system by reflecting scattered light, etc. Such things can be reduced. In particular, if the heat radiating member is installed on the back of the scanning mirror, which is a scanning optical element, the heat radiating member is located outside the optical path of the imaging optical system and is separated from the optical path by the scanning optical element. The possibility of generating irregularly reflected light in the optical path can be almost eliminated.
[0011]
Further objects and features of the present invention will become apparent from the following detailed description and drawings. Each feature of the present invention can be used alone or in combination in various combinations as much as possible.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 7 together with an example thereof for understanding of the present invention.
[0013]
This embodiment is an example of a scanner that reads an image of a document with a digital copying machine. However, the present invention is not limited to this, and is generally applied to an image scanner with an analog copying machine, or a scanner with an image reader alone that records image read data on a recording medium or outputs it to other media. Can do.
[0014]
As shown in FIG. 1, the digital copying machine of the present embodiment is installed so that the photosensitive drum 1 is rotationally driven in the direction of arrow a in the approximate center of the apparatus main body 100. Around the photosensitive drum 1, a charging device 2 for forming an image by an electrophotographic process, a laser scanning optical system 3, a developing device 4, a transfer device 5, a paper separating device 6, and residual toner on the photosensitive drum 1 A cleaning device 7 that removes residual charges, an eraser 8 that removes residual charges, and the like are provided.
[0015]
Since the principle of the electrophotographic process is well known, a detailed description will be omitted and only an outline will be described. The laser scanning optical system 3 receives the image signal of the original D read by the image reading device 30, outputs a laser beam modulated in accordance with the image signal, and is charged by the charging device 2 of the photosensitive drum 1. Image exposure is performed. As a result, an electrostatic latent image corresponding to the image of the document D is formed on the photosensitive drum 1. The electrostatic latent image is then developed with toner and visualized, and is transferred and copied by the transfer device 5 onto a sheet conveyed here at a transfer portion between the transfer device 5 and the photosensitive drum 1. Residual toner is removed from the surface of the photosensitive drum 1 after the transfer by the cleaning device 7, residual charge is removed by the eraser 8, and the charging device 2 is charged again to repeat image formation. The sheet after copying by transfer is sent to the fixing device 18 by the conveying belt 17 and subjected to fixing processing by heating and / or pressurization, and is discharged to a discharge tray 20 outside the apparatus main body 100 by a discharge roller 19 after fixing.
[0016]
The apparatus main body 100 feeds the paper to be transferred to the transfer unit, and the paper cassettes 9 and 10 for storing and feeding the paper in the lower part of the apparatus main body 100 are respectively provided with corresponding paper feed rollers 11 and 10. 12 is provided. The papers in the paper feed cassettes 9 and 10 are selectively sent one by one by one rotation of the corresponding paper feed rollers 11 and 12 according to the paper size selection. The fed paper is temporarily stopped by the timing roller 16 and the leading end is aligned with the nip portion to correct the skew, and the rotation of the timing roller 16 is restarted and the paper is fed out at the timing when the paper is fed. In synchronization with the visible image, the visible image is transferred and copied to a predetermined position on the paper.
[0017]
The apparatus main body 100 is placed on the sheet feeding / conveying device 200, and the sheets in the sheet feeding cassettes 21-23 held by the sheet feeding / conveying device 200 are also fed to the sheet feeding rollers 13-15 according to the selection of the sheet size. The image is sent out by one rotational drive, conveyed to the transfer section, and used for transfer of a visible image.
[0018]
As shown in FIGS. 1 and 2, the basic configuration of the image reading device 30 includes a first slider 31 and a second slider 32 that are reciprocated in the direction of arrow b. As shown in FIGS. 1 and 3, the first slider 31 has an exposure lamp 50 that illuminates the document D, and a CCD for reading an image that is picked up by the reflected light from the document D at each moving position through a slit 54. The scanner is provided with a scanning mirror 51 as a scanning optical element directed toward the line sensor 25 to scan the document D so that the scanning light of the document D is sequentially imaged on the CCD line sensor 25.
[0019]
As a result, the CCD line sensor 25 converts the image information of the original D to be formed into an electrical signal and sequentially inputs it to the laser scanning optical system 3. The laser scanning optical system 3 outputs a laser beam modulated in accordance with sequentially input image signals. This output is obtained by deflecting laser light in the direction of the rotation axis of the photosensitive drum 1 by a scanning optical element such as a polygon mirror, and outputting image data for each line of the CCD line sensor 25 in the direction of the rotation axis on the photosensitive drum 1. Repeat main scanning for writing. At the same time, the rotation of the photosensitive drum 1 in the direction of the arrow a is sub-scanned, and the image of the document D is exposed on the surface of the photosensitive drum 1, and a corresponding electrostatic latent image is formed.
[0020]
As shown in FIG. 1, the second slider 32 includes a pair of folding mirrors 27 and 28 that fold the scanning light from the scanning mirror 51 in the reverse direction and direct it toward the imaging lens 24, and the moving speed V of the first slider 31. The conjugate length by the imaging lens 24 is kept constant. As shown in FIG. 2, each of the first and second sliders 31 and 32 is fitted in the slide shaft 33 at one end and received by the slide rail 34 at the other end. It can be translated in the direction. The first and second sliders 31 and 32 are driven and moved by one stepping motor M1.
[0021]
A wire 38 wound around a driving pulley 37 driven by pulleys 35 and 36 and a timing belt 47 by a stepping motor M1 is used so that this movement satisfies the speed relationship. The drive pulley 37 is located in the moving region of the first and second sliders 31 and 32, and the wire 38 has a pair of one end 38 a located outside the moving region of the first and second sliders 31 and 32. After folding around the folding pulley 39 on the first slider 31 side of the folding pulleys 39, 40, the other end 38b is looped around the folding pulley 40 on the second slider 32 side. Wrapping. The one end 38 a side of the wire 38 folded back by the folding pulley 39 is fixed to the first slider 31 with a pin 61 or the like in the middle, and is further rotated forward with each other provided at one end of the second slider 32. The movable pulley 41a is freely wound around one of the movable pulleys 41a and 41b and is turned back, and is fixed to a fixed portion on the side of the return pulley 39 with a pin 62 or the like. The other end 38b side of the wire 38 folded back by the folding pulley 40 is halfway wrapped around the other moving pulley 41b at the end of the second slider 32 and fixed to the fixed portion on the folding loop pulley 40 side by a pin 63 or the like. I wear it.
[0022]
As a result, the first slider 31 is moved at the same speed V as it is driven and moved by the stepping motor M1. On the other hand, the second slider 32 moves in the same manner as the moving pulleys 41a and 41b are rotated by the wire 38 at a speed of V / 2, and the moving speed becomes V / 2. It is to be noted that a spring is provided between one end 38a and the other end 38b of the wire 38 and a fixing portion to the fixing portion to provide a buffer when the first and second sliders 31 and 32 are simultaneously driven. Is preferred. When the CCD line sensor 25 or the like as a light receiving target for the scanner is mounted on the first slider 31, the optical element that picks up the reflected light from the document D is a selfoc lens or the like, and the scanning light is the CCD line sensor 25. In this case, the second slider 32 and the imaging lens 24 are not necessary.
[0023]
The exposure lamp 50 provided in the first slider 31 is a fluorescent lamp, and uses a lighting driver 64 (FIG. 1, FIG. 3, FIG. 4A) that is inverter-driven with an attenuation waveform in order to obtain high luminance light emission. . On the other hand, since inverter driving is high-frequency driving and the influence of noise is large, it is preferable to shorten a harness (not shown) that connects to the exposure lamp 50. Therefore, as shown in FIGS. 1 and 3, the lighting driver 64 is mounted on the first slider 31, the exposure lamp 50 and the lighting driver 64 come close to each other, and the harness for connecting both is shortened and the influence of noise. Is trying to reduce.
[0024]
On the other hand, the lighting driver 64 that drives the exposure lamp 50 with an inverter with an attenuation waveform causes a problem because the heat generated by the driver of the exposure lamp 50 is large, and the weight of the lighting driver 64 increases because of a cooling member that cools this. In addition, there is a problem that the weight of the first slider 31 increases and the required torque of the stepping motor M1 that drives the first slider 31 increases.
[0025]
Therefore, in the present embodiment, it is necessary for the stepping motor M1 that drives the first slider 31 by sufficiently cooling the lighting driver 64 by the small and lightweight heat radiating member 52 as shown in FIGS. To reduce the torque. Specifically, as shown in FIGS. 1 and 3 to 7, the heat dissipating member 52 of the lighting driver 64 is provided so as to protrude out of the first slider 31. When the heat radiating member 52 protrudes outside the first slider 31, the heat radiating member 52 easily touches the atmosphere outside the slider by the protruding portion 53 and radiates heat, and each time the first slider 31 moves at the speed V, the slider Since the atmosphere outside the slider works as a cooling flow due to the relative movement with the outside atmosphere and heat is easily taken away, the lighting driver 64 can be sufficiently cooled by the small and lightweight heat radiating member 52, and the lighting driving including the heat radiating member 52 is performed. The weight of the device 64 can be reduced, and the required torque of the stepping motor M1 that drives the first slider 31, which is a scanner, can be reduced.
[0026]
Therefore, the motor can be reduced in size, cost, and power consumption can be reduced. The heat radiating member 52 is preferably made of a material having good thermal conductivity, and the aluminum-based material is particularly suitable because it is lightweight. However, it is not restricted to this, The material and form can be selected freely. The heat radiation effect of the heat radiating member 52 is remarkably increased not only in the case where the atmosphere outside the slide is a cooling air flow but also in a blowing air flow such as exhaust.
[0027]
In the embodiment shown in FIGS. 1 to 4, the protrusion 53 of the heat radiating member 52 to the outside of the first slider 31 is a group of fins 53a as shown in FIGS. 4 (a) and 4 (b). As a result, the heat dissipation to the atmosphere outside the slider is enhanced, and the heat dissipation member 52 can be made thinner and smaller by that amount, which is effective in reducing the driving torque of the first slider 31. Further, if the fin 53a is parallel to the moving direction b of the first slider 31 as shown in FIG. 4A, the relative movement between the fin 53a and the atmosphere outside the slider when the first slider 31 moves. Since the direction is along the fin 53a, the wide flat portion of the fin 53a efficiently contacts with the outside atmosphere of the slider without disturbing the outside atmosphere of the slider. The heat dissipation is improved, and the heat dissipation member 52 can be further reduced in size. Even if the protrusion 53 does not have the form of the fin 53a but is formed long in the moving direction of the first slider 31, the same effect is exhibited.
[0028]
The surface of the heat dissipation member 52 is black. Thereby, even if the heat dissipation member 52 protrudes from the first slider 31, it is possible to reduce the occurrence of irregularly reflected light in the optical path of the imaging optical system by the imaging lens 24 or the like by reflecting scattered light or the like. It is possible to reduce the deterioration of image quality due to irregularly reflected light. In particular, when the heat dissipating member 52 is installed behind the scanning mirror 51 as the scanning optical element as shown in FIGS. 1 and 3, the heat dissipating member 52 is located outside the optical path of the imaging optical system, and this optical path Therefore, the possibility that the heat radiation member 52 generates irregularly reflected light in the optical path can be almost eliminated.
[0029]
In the embodiment shown in FIG. 4B, the heat dissipating member 52 is made of a plate member applied to the lower surface of the lighting driver 64 as shown in FIGS. 3 and 4A, and a large number of fins 53a face downward. In this embodiment, a protrusion 53 that protrudes integrally is formed. Each fin 53a may be retrofitted by welding, brazing, bonding, screwing, pinning, or the like, but if it is an integrally formed product such as extrusion molding, the structure is simple and the cost can be reduced.
[0030]
In the embodiment shown in FIG. 5, the protruding portion 53 of the heat radiating member 52 made of a plate member is formed by fins 53a formed by bending both sides, and fins 53a cut and raised between them. This does not complicate the structure. In the embodiment shown in FIG. 6, the heat radiation member 52 made of a plate member is bonded to both side surfaces of the lighting driver 64 and is extended downward to form the fins 53a to form the protrusions 53. 52 and the plate-like heat radiating member 52 applied to the lower surface of the lighting driver 64 are connected at both ends thereof so that the heat of the lighting driver 64 can be dissipated and cooled. It is also possible to increase the number of fins 53a by providing fins 53a that are integrally molded, cut or raised, or retrofitted as indicated by phantom lines on the lower surface of the heat radiation member 52 applied to the lower surface of the lighting driver 64. . In the embodiment shown in FIG. 7, the protruding portion 53 has the simplest shape. The protruding portion 53 that forms a fin 53a by bending a plate-like heat radiation member 53 bonded to the lower surface of the lighting driver 64 into an L shape. Is forming. Moreover, as shown by a virtual line, it is good also as the protrusion part 53 which bent the both sides and formed the two fins 53a. In short, the shape and number of the protrusions 53 may be designed in various ways according to the required degree of heat dissipation.
[0031]
The protruding portion 53 of the heat radiating member 52 may protrude outward from any side of the first slider 31. However, if the protruding portion 53 protrudes downward, it is easy to effectively use the surrounding dead space and can be protruded in a wider range. It is easy to cool the lighting driver 64 mounted on the slider 31.
[0032]
【The invention's effect】
According to the scanner of the present invention, the heat dissipating member applied to the lighting driver is formed of a plate member, bent at both ends, and exposed to the outside atmosphere of the slider by protruding the protruding portion cut out between them to the outside of the slider. It is easy to dissipate heat, and every time the slider moves, the atmosphere outside the slider works as a cooling airflow and the heat of the heat dissipating member is easily taken away. Since the torque of the motor necessary for reducing the weight of the lighting driver and driving the scanner with a predetermined accuracy is reduced, the motor can be reduced in size, cost, and power consumption.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a digital copying machine employing a scanner according to a typical embodiment of the present invention.
2 is a perspective view showing a scanning optical system of the copying machine of FIG. 1. FIG.
3 is a transverse sectional view of the scanning optical system of FIG.
4 shows the scanning optical system of FIG. 2, in which (a) is a bottom view of the first slider as viewed mainly, and (b) shows one embodiment of a heat radiating member provided in the first slider. It is a cross-sectional view.
FIG. 5 is a cross-sectional view showing another embodiment of the heat radiating member.
FIG. 6 is a perspective view showing another embodiment of the heat radiating member.
FIG. 7 is a side view showing another embodiment of the heat dissipating member.
[Explanation of symbols]
D Document 3 Laser Scanning Optical System 24 Imaging Lens 25 CCD Line Sensor 30 Image Reading Device 31 First Slider 50 Exposure Lamp 51 Scanning Mirror 52 Heat Dissipation Member 53 Projection 53a Fin 64 Lighting Driver

Claims (5)

In a scanner provided with an exposure lamp that exposes a document, a lighting driver that lights and drives the scanner, and a scanning optical element that picks up reflected light from the document and directs it toward a light receiving target.
A scanner characterized in that a heat radiating member made of a plate member is applied to the lighting driver , the heat radiating member is bent at both ends, and a protruding portion cut and raised between the radiating members protrudes outside the slider .   The scanner according to claim 1, wherein the protrusion of the heat dissipating member to the outside of the slider is a fin.   The scanner according to claim 1, wherein the protrusion is parallel to the moving direction of the slider.   The scanner according to claim 1, wherein the heat dissipating member is black.   The scanner according to claim 1, wherein the heat dissipating member is installed on the back of a scanning mirror as a scanning optical element.

Images