JP4208782B2 - Illumination device, contact-type image sensor, and image forming apparatus including the same - Google Patents

Description

  The present invention relates to a lighting device, a contact image sensor, and an image forming apparatus including the same.

  An image forming apparatus such as a copying machine or a facsimile machine has an image reading device, and the image reading device has an image sensor. As shown in FIGS. 6 and 7, the conventional contact image sensor 50 includes a box-shaped frame 51, a light guide 52 made of acrylic resin having high transparency, an opening 53, and the light guide 52. A light guide cover 54 (FIG. 8) accommodated so as to partially cover through the air layer, and disposed in the frame 51 adjacent to the end face of the light guide 52. The light guide 52 includes a light source 55 made of a light emitting element such as an LED that makes light incident from the end face thereof. The light guide cover 54 has an opening shape on the light source 55 side end surface.

  The light guide cover 54 has good reflectivity and is formed of, for example, a white material. As illustrated in FIG. 8, light leaked from the light guide 52 at a portion other than the opening 53 is guided to the light guide 52. It returns to the inside and plays the role of improving the light utilization efficiency.

  The light guide 52, the light guide cover 54, and the light source 55 constitute an illumination device.

  Light that enters the light guide 52 from the light source 55 is guided in the longitudinal direction of the light guide 52 by repeating total reflection in the light guide 52. A part of the light guide 52 is provided with a diffusing surface 56 (FIG. 7) along the longitudinal direction. When light that has undergone total reflection is incident on the diffusing surface 56, the incident light is diffused, Part of it illuminates the document.

  As shown in FIG. 7, the contact image sensor 50 further reflects a sensor array 57 arranged in the frame 51, a line sensor 58 arranged on the sensor array 57, and a reading line 59 from a document (not shown). A lot lens array 60 for forming an image of the light on the line sensor 58. The line sensor 58 receives light reflected from the light guide 52 toward the document and performs photoelectric conversion.

  The light emitted from the light guide 52 through the opening 53 is reflected from a document (not shown) on the reading line 59, and the reflected light is reflected on the line sensor 58 arranged in the sensor array 57 by the rod lens array 60. Imaged. The line sensor 58 reads the original by converting the imaged light into an electrical signal and outputting it.

  No suitable prior art document information is found.

  However, since the light guide 52 is made of acrylic resin, the dimensions may change due to changes in temperature and humidity, and the light guide 52 may be damaged due to interference with the light guide cover 54. On the opposite side, a gap 61 is provided between the end face of the light guide 52 and the light guide cover 54 (FIG. 8). By providing this gap 61, the lighting device becomes large, and thus a contact image sensor. This is a disadvantage for the miniaturization that is a feature of.

  An object of the present invention is to provide an illuminating device and a contact image sensor that can be reduced in size, and an image forming apparatus including them.

In order to achieve the above object, an illumination device according to claim 1 is a light source and a long light-transmitting light guide that receives light of the light source from one end face and guides the received light. And a light-impermeable light guide cover that accommodates the light guide so as to partially cover the light guide, wherein the light guide cover includes the one end face on the light source side and the one end face the other end face, respectively opening shape der opposing side of is, the light guide body, which has at least two protrusions in the longitudinal direction, the light guide cover, the protrusions along the longitudinal direction Each of the pair of protrusions and the recesses to be engaged on the other end face side of the pair of the protrusions and the recesses to be engaged on the one end face side. It is characterized by being larger than the gap of the set .

  The lighting device according to claim 2 is the lighting device according to claim 1, wherein the light guide is made of acrylic resin.

The illumination device according to claim 3 is a light source, a long light-transmitting light guide that receives light of the light source from one end face and guides the received light, and a part of the light guide. And a light-impermeable light guide cover that is received so as to cover the light guide cover, the light guide cover has one end surface on the light source side and the other end surface on the opposite side of the one end surface, respectively. The light source member is provided with a light source member including the light source, the light source member includes a protrusion, the light guide includes a groove that engages with the protrusion, and the light guide cover includes: A hook portion for locking the light source member is provided.

In order to achieve the above object, a contact image sensor according to claim 4 includes the illumination device according to any one of claims 1 to 3 and a frame that supports the light guide cover.
The light guide cover has at least two convex portions or concave portions, and the frame is
There is at least two concave portions or convex portions that engage with the convex portions or concave portions of the light guide cover, and the gap between the pair of convex portions and concave portions that is engaged on the other end surface side is the one end surface. It is larger than the gap of the set of the convex part and the concave part engaged on the side.

In order to achieve the above object, an image forming apparatus according to a fifth aspect includes the contact image sensor according to the fourth aspect.

According to the illumination device according to claim 1 and the contact image sensor according to claim 4 , the light guide cover has an opening shape on one end surface on the light source side and on the other end surface on the opposite side of the one end surface. Therefore, it can be downsized. Further, the gap between the pair of convex portions and concave portions engaged on the other end surface side is larger than the gap between the pair of convex portions and concave portions engaged on the one end surface side. Expansion and contraction can be released to the other end surface side from a set of convex and concave portions engaged on one end surface side.

  According to the illumination device of the second aspect, since the light guide is made of acrylic resin, it can be surely downsized.

According to the illumination device of the third aspect, the light guide cover can be miniaturized because one end surface on the light source side and the other end surface on the opposite side of the one end surface have an opening shape. Moreover, since the light source has a protrusion, the light guide has a groove that engages with the protrusion, and the light guide cover includes a hook that locks the light source, the light source can be accurately positioned. .

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view schematically showing a facsimile apparatus including a contact image sensor unit according to an embodiment of the present invention.

  1 includes a main body 101, an operation panel 102 attached to the main body 101 so as to be openable and closable, and provided in the main body 101 below the operation panel 102, and feeds a document PP toward a reading position. A feeding roller 103; a separation piece 104 which is attached to the operation panel 102 and is urged toward the feeding roller 103 to separate the original PP fed one by one by the feeding roller 103; A contact type image sensor 200 as a reading device for reading an image of a document PP to be fed and fed to the operation panel 102 at a reading position, and a document PP to be fed to the contact type image sensor 200 at a reading position. A platen roller that regulates the surface to be read and conveys the original PP And a 105.

  The operation panel 102 is provided with switches and messages for performing operation input as input / output means, and a display unit for notifying the state of the apparatus.

  The main body 101 of the facsimile apparatus 100 also accommodates a roll paper P as a recording medium. The recording head 106 forms an image on the roll paper P at the recording position, and the roll paper with respect to the recording head 106 at the recording position. A platen roller 107 that regulates the P recording surface and conveys the roll paper P is provided. The recording head 106 reproduces image information read by the contact image sensor 200 or image information transmitted from the outside.

  The main body 101 further includes a system control board 108 including a control unit that controls each unit, a photoelectric conversion element drive circuit, an image information processing unit, a transmission / reception unit, and the like, and a power source 109.

  2 is a perspective view schematically showing the contact image sensor 200 in FIG. 1, and FIG. 3 is a cross-sectional view taken along line III-III in FIG.

  2 and 3, the contact image sensor 200 includes a box-shaped frame 201, a highly transparent acrylic resin light guide 202, an opening 203, and the light guide 202 through an air layer. The light guide cover 204 (FIGS. 4 and 5) housed so as to partially cover the frame 201 and the frame 201 is disposed adjacent to the end surface of the light guide body 202 and guided. And a light source member 205 having a light source 205a composed of a light emitting element such as an LED that enters the light body 202 from its end face.

  The light guide cover 204 has good reflectivity and is formed of, for example, a white material. As illustrated in FIG. 4, light leaked from the light guide 202 at a portion other than the opening 203 is guided to the light guide 202. It returns to the inside and plays the role of improving the light utilization efficiency.

  The light guide 202, the light guide cover 204, and the light source 205 constitute an illumination device.

  The light incident on the light guide 202 from the light source 205 a is guided in the longitudinal direction of the light guide 202 by repeating total reflection in the light guide 202. A part of the light guide 202 is provided with a diffusion surface 206 (FIG. 3) along the longitudinal direction. When light that has undergone total reflection is incident on the diffusion surface 206, the incident light is diffused, Part of it illuminates the document.

  As shown in FIG. 3, the contact image sensor 200 further includes a sensor array 207 arranged in the frame 201, a line sensor 208 arranged on the sensor array 207, and a position of a reading line 209 for reading a document (not shown). And a lot lens array 210 that forms an image on the line sensor 208. The line sensor 208 receives light reflected from the original from the light guide 202 toward the original and performs photoelectric conversion.

  The light emitted from the light guide cover 204 through the opening 203 irradiates a document (not shown) on the reading line 209, and the reflected light is reflected on the line sensor 208 arranged on the sensor array 207 by the rod lens array 210. Is imaged. The line sensor 208 converts the imaged light into an electrical signal and outputs it to read the original.

  The light guide cover 204 has an opening shape on the end surface 204a on the light source 205a side and the end surface 204b on the opposite side thereof. Thereby, even if the light guide 202 changes its dimensions due to changes in temperature and humidity, it can avoid interference with the light guide cover 204 and thus can be prevented from being damaged.

  Further, since the light guide cover 204 has an opening shape also on the end surface 204b side, the position of the opening end surface 204b of the light guide cover 204 can be made the same position as the end surface 202b of the light guide 202, as shown in FIG. The gap dimension 61 between the light guide 52 and the light guide cover 54 and the wall thickness dimension 62 of the light guide cover 54 can be reduced, and the overall length dimension in the longitudinal direction of the illuminating device, and hence the contact image sensor 200, can be shortened. Can do.

As means for attaching the light guide cover 204 to the light guide 202, holes 214 and 215 (concave portions) are provided in the top of the light guide cover 204, and the holes 214 and 215 of the light guide cover 204 are provided in the top of the light guide 202 . Protrusions 216 and 217 that are respectively engaged with each other, the longitudinal gap between the hole 214 and the convex part 216 is suppressed as much as possible to eliminate rattling, and the longitudinal gap between the hole 215 and the convex part 217 is changed with changes in temperature and humidity. It is more than the dimensional change of the light guide 202 with respect to the light guide cover 204 by. As a result, the expansion and contraction of the light guide 202 due to changes in temperature and humidity occurs starting from the positions of the hole 214 and the convex portion 216, and the expansion and contraction of the light guide 202 toward the end face 202b can be escaped. since is provided close to the longitudinal direction of the position of the hole 214 and the convex portion 216 to the light source 205a side, it is possible to reduce the dimensional change of the light source 205a side of the light guide body 202 further includes a light source 205a and the light guide The positional shift in the longitudinal direction of the end face of the body 202 is eliminated, and the light from the light source 205a can be reliably incident on the light guide 202.

In addition, as a means for positioning and attaching the light source member 205 to the light guide 202 and the light guide cover 204 , the light source member 205 is provided with a protrusion 221, and the light guide 202 and the light guide cover 204 are provided with a protrusion. A concave portion 222 that engages with the light source 221 is provided, and a hook portion 220 that hooks the light source member 205 on the light guide cover 204 is further provided. At this time, the light source member 205 may be provided with a concave portion, and the light guide 202 and the light guide cover 204 may be provided with a convex portion that engages with the concave portion of the light source member 205, and the effect is the same.

  As means for attaching the light guide cover 204 to the frame 201, the frame 201 is provided with hooks 223, 224 and grooves 225, 226, and the light guide cover 204 is engaged with the hooks 223, 224 and grooves 225, 226. A convex portion 227 is provided. The longitudinal dimension of the groove 225 and the convex part 227 provided on the hook 223 side eliminates rattling by suppressing the gap as much as possible, and the longitudinal dimension of the groove 226 and the convex part 227 provided on the hook 224 side indicates temperature and humidity. It is more than the dimensional change of the light guide 202 with respect to the light guide cover 204 by the change of this. Thereby, the expansion and contraction of the light guide 202 due to changes in temperature and humidity occurs starting from the position of the hook 224, and the expansion and contraction of the light guide 202 toward the end face 202b can be released.

  In addition, since the position of the hook 224 in the longitudinal direction is provided close to the light source 205 a side, the dimensional change of the light guide 202 on the light source 205 a side can be reduced, and furthermore, the light source 205 a and the light guide 202 202 can be reduced. The positional deviation in the longitudinal direction of the end face is eliminated, and the light from the light source 205a can be reliably incident on the light guide 202.

1 is a cross-sectional view of a facsimile apparatus including a contact image sensor according to an embodiment of the present invention. FIG. 2 is a perspective view of the contact image sensor in FIG. 1. It is sectional drawing which follows the line III-III of FIG. It is a perspective view of the illuminating device in FIG. It is a perspective view of the light guide cover in FIG. It is a perspective view of the conventional contact type image sensor. It is sectional drawing which follows the line VII-VII of FIG. It is a perspective view of the illuminating device in FIG.

Explanation of symbols

200 Contact Image Sensor 201 Frame 202 Light Guide 203 Opening 204 Light Guide Cover 205 Light Source 206 Diffusion Surface 207 Sensor Array
208 Line sensor 210 Rod lens array

Claims (5)

A light source, a long light-transmitting light guide that receives light of the light source from one end face and guides the received light, and a light source that is received so as to partially cover the light guide. In a lighting device comprising a transmissive light guide cover,
The light guide cover, Ri other end face, respectively opening shape der opposing side of the one end face and said one end face of the light source side,
The light guide has at least two convex portions along the longitudinal direction, and the light guide cover has at least two concave portions respectively engaged with the convex portions along the longitudinal direction, The lighting device is characterized in that a gap between the pair of convex portions and the concave portion engaged on the end surface side is larger than a gap between the pair of convex portions and the concave portion engaged on the one end surface side. apparatus.   The lighting device according to claim 1, wherein the light guide is made of acrylic resin. A light source, a long light-transmitting light guide that receives light of the light source from one end face and guides the received light, and a light source that is received so as to partially cover the light guide. In a lighting device comprising a transmissive light guide cover,
In the light guide cover, one end face on the light source side and the other end face on the opposite side of the one end face each have an opening shape,
A light source member including the light source, the light source member having a ridge portion, the light guide body having a groove portion engaged with the ridge portion, and the light guide body cover engaging the light source member. lighting apparatus characterized in that it comprises a hook portion for locking.   4. The lighting device according to claim 1, and a frame that supports the light guide cover, wherein the light guide cover has at least two convex portions or concave portions, and the frame. Has at least two concave portions or convex portions that engage with the convex portions or concave portions of the light guide cover, and the gap between the pair of convex portions and concave portions that engage on the other end surface side is the one A contact type image sensor characterized in that the contact type image sensor is larger than a gap between a pair of the convex portion and the concave portion which are engaged on the end face side. An image forming apparatus comprising the contact image sensor according to claim 4 .

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