Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G15/00—Apparatus for electrographic processes using a charge pattern
  • G03G15/04—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G15/00—Apparatus for electrographic processes using a charge pattern
  • G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
  • G03G15/32—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the charge pattern is formed dotwise, e.g. by a thermal head
  • G03G15/326—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the charge pattern is formed dotwise, e.g. by a thermal head by application of light, e.g. using a LED array
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G15/00—Apparatus for electrographic processes using a charge pattern
  • G03G15/04—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material
  • G03G15/04036—Details of illuminating systems, e.g. lamps, reflectors
  • G03G15/04045—Details of illuminating systems, e.g. lamps, reflectors for exposing image information provided otherwise than by directly projecting the original image onto the photoconductive recording material, e.g. digital copiers
  • G03G15/04054—Details of illuminating systems, e.g. lamps, reflectors for exposing image information provided otherwise than by directly projecting the original image onto the photoconductive recording material, e.g. digital copiers by LED arrays

Definitions

• the present invention relates to an exposure light source that is mounted to a copier, a scanner, a multi-functional device or the like and, more particularly, to an exposure light source, which adopts Light Emitting Diodes (LEDs), which have recently attracted attention, in order to increase the lifespan of the light source and realize lower consumption of power.
• LEDs Light Emitting Diodes
• a copying process includes a charging step, an exposing step, a developing step, a transferring step, a fusing step, a cleaning step.
• the charging step is a step of charging the surface of a drum with negative charges by applying a high negative voltage to the surface of the drum, and thus ionizing the surrounding air.
• the exposing step which is pertinent to the present invention, is a step of forming the image of an original on the surface of the drum by tuning on a lamp, having an excellent instantaneous lighting characteristic, thus enabling the image to be reflected by a mirror and to pass through a lens. That is, the exposing step is a reading step of accurately converting image data, which corresponds to the image of an original, into digital signals using a Complementary Metal-Oxide Semiconductor (CMOS) image sensor and transmitting the digital signals to an image processing unit.
• CMOS Complementary Metal-Oxide Semiconductor
• the developing step is a step of converting a virtual image into a real image in such a way that, when a toner is charged with positive charges and is brought close to the negative charges of the drum, the toner having positive charges is applied to the drum, having negative charges.
• the transferring step is a step of applying the toner to a sheet of paper by applying a high negative voltage to the sheet of paper, in order to transfer the charges, which are formed on the surface of the drum, that is, a toner image, to the sheet of paper.
• the fusing step is a step of completely fusing the toner image, which is applied to the paper, onto the sheet of paper by applying high heat and pressure to the sheet of paper.
• the cleaning step is a step of neutralizing and removing residual toner, which remains on the surface of the drum after the transferring and fusing steps, by emitting light, which is radiated from an erasing lamp, onto the drum.
• CCFLs Cold Cathode Fluorescent Lamps
• an LED has recently attracted attention because it has characteristics of ultra-power savings, continuous usability for a long time, shock resistance, small size, small thickness, light weight, highly repetition rate and pulse operation using a stable Direct Current (DC) lighting method, and low incidence of eye strain, entails no danger of fire because there is no thermal emission, has a very fast switching speed, can be used semi-permanently, and is an environment-friendly device which does not use discharge gases such as hydrargyrum and sodium.
• DC Direct Current
• the LED is widely used as a next-generation digital light source, which can overcome the limitations of an existing analog light source, such as a halogen lamp or a xenon lamp, in various fields.
• LED which can even be used as a headlight for vehicles, has been developed and is used in practice.
• various types of LEDs ranging from red, blue and yellow LEDs to a white LED, which emits white light similar to natural radiation, are manufactured.
• the present invention is proposed to provide a technology that is highly advanced when compared with the conventional light source adopting LEDs, in parti cular, the exposure light source, thus improving the lighting characteristic and the quality of brightness so that no problem of reading is caused. Disclosure of Invention Technical Problem
• the present invention is directed to provide an exposure LED light source, which includes a casing, a Printed Circuit Board (PCB), on which a plurality of LEDs is mounted, one or more LED bars, each of which is provided with a transparent lens, and a fastening member, which is used to mount the LED bars in a copier such that light can be emitted at a predetermined angle.
• PCB Printed Circuit Board
• the present invention is directed to provide a light source, in which two LED bars are arranged on the fastening member at a predetermined angle, in order to provide a light source that can ensure a sufficient degree of light convergence and uniform light diffusion, which are related to original reading performance while solving both the problem of an increase in costs, which occurs when a specific LED having high brightness is adopted, and the problem of a decrease in original reading performance, which is caused by non-uniform brightness, which is exhibited through all of the LED bars when a specific high-brightness LED is adopted.
• the present invention is directed to provide an LED light source, which facilitates the assembly of a casing and a lens, constituting each LED bar, improves the light diffusion efficiency by applying lenslets to the lens, and increases convenience by employing a means of enabling the LED bars and the fastening member to be arranged at their correct positions at the same time.
• the present invention provides an exposure LED light source for copiers, including: one or more LED bars, each comprising: a plurality of LEDs; a rectangular PCB, which is configured such that the LEDs are mounted thereon at regular intervals; a box-type casing, which is configured such that the PCB is fastened to the bottom thereof; and a lens, which is provided in the upper portion of the casing; and a fastening member for mounting the LED bar thereto at a predetermined angle.
• the LED bars be configured such that two LED bars are mounted to the fastening member, and form an angle of 30 ⁇ 50 degrees with a fixed horizontal plane.
• the exposure LED light source for copiers includes a casing, a PCB, on which a plurality of LEDs is mounted, one or more LED bars, each of which is provided with a transparent lens, and a fastening member, which is used to mount the LED bars in a copier such that light can be emitted at a predetermined angle, and, in particular, provides a light source, in which two LED bars are arranged on the fastening member at a predetermined angle in order to solve both the problem of an increase in costs, which occurs when a specific LED having a high-brightness is adopted, and the problem of a decrease in original reading performance, which is caused by non-uniform brightness, which is exhibited through all of the LED bars when a specific high-brightness LED is adopted.
• the present invention can facilitate the assembly of a casing and a lens, which constitutes each LED bar, can improve the light diffusion efficiency by applying lenslets to the lens, and can increase convenience by employing a means of enabling the LED bars and the fastening member to be arranged at their correct positions at the same time.
• LED light source having a specific shape and structure will be described with reference to the accompanying drawings, it should be understood that the present invention can be varied and modified in various ways by those skilled in the art, and that such variations and modifications are included in the scope of the present invention.
• the LED light source according to the present invention may be applied not only to a copier, a multi-functional device and a scanner, but also to various printing devices, which adopt other copying processes.
• FIG. 1 is a conceptual view illustrating the principle of a copier structure
• FIGS. 2 and 3 are an assembled perspective view and an exploded perspective view of an LED bar of an exposure LED light source for copiers according to the present invention
• FIG. 4 is a perspective view of a lens that constitutes the exposure LED light source for copiers according to the present invention
• FIG. 5 is a perspective view a construction in which a lens is excluded from the
• FIG. 6 is a schematic sectional side view of the exposure LED light source for copiers according to the present invention
• FIG. 7 is a schematic diagram showing an experimental device, which is used to measure the brightness of the LED bar based on lenslet conditions of the lens according to the present invention
• FIG. 8 is a schematic diagram showing types of lenslets of the lens.
• FIGS. 9 and 10 are graphs showing the brightness simulation and the maximum brightness value of LED bars according to the lenslet types related to FIG. 8 and Table
• an exposure LED light source L for copiers according to the present invention includes one or more LED bars B (refer to
• FIGS. 2 to 5 each of which is formed by assembling a plurality of LEDs 10, a PCB
• the exposure LED light source L includes a fastening member F for arranging the LED bars B in a copier at a predetermined angle.
• white LEDs for example: model LMT5630A-W, (Lumens Co.,
• the PCB 20 is configured such that heat radiation holes 21 (two heat radiation holes) are provided around each LED 10 to ensure the stable driving of the
• the lens 40 have an approximately semicircular cross-section so as to not only uniformly diffuse light emitted from the LEDs 10 but also increase the condensing efficiency, and that it function as a convex lens.
• a plurality of repeated protrusion-type lenslets 45 is formed on the lower surface of the lens 40.
• the lenslets 45 perform the same functions as those of the diffusion sheet and the prism sheet of a flat panel device, such as a Liquid Crystal display, which are well known, (which chiefly function as a kind of prism sheet), thus not only efficiently and uniformly diffusing light but also increasing the condensing efficiency.
• the casing 30 enables the PCB and the lens to be fastened thereto, and functions somewhat as a reflector while guaranteeing an appropriate distance between the lens and the LEDs, thus increasing the efficiency of the light, which is emitted from the light source (that is, the LEDs 10).
• an experimental LED bar which was configured such that three LEDs, namely, model LMT5630A-W (Lumens Co., Ltd.) (LED size: 5.6x3.0 D, power dissipation: 150 D, luminous intensity: 120 mD/20 D, viewing angle: more than 120 degrees), were arranged in the casing, was prepared as shown in the schematic diagram of FIG.
• a measuring device is located at the location of the original (for example, a distance of 4.5 D). Subsequently, the brightness of each LED bar is measured.
• the LED bar is classified into a discontinuous type, in which the triangular lenslets of the lens are discontinuous, and a continuous type, in which the triangular lenslets of the lens are continuous.
• [65] As can be seen from Table 2 and FIG. 9, it was verified that [Type 1] and [Type 2] lenses (in particular, [Type 1] glass), each having high maximum brightness and relatively uniform brightness over the entire lens of each LED bar, are preferred.
• a plurality of support bridges 33 (refer to FIG. 5) is formed between LEDS 10, which are mounted on the PCB 20, in the lower portion of the casing 30 of each LED bar B, so that the shock resistance of the product can be improved and, in addition, variation in the product can be prevented.
• a plurality of coupling protrusions is formed on the outer surface of the lens 40.
• a total of four coupling protrusion 41b and 41a is formed on two central side surfaces of the lens 40 and in the two ends of the lens 40.
• the central coupling protrusions 41b of the lens 40 are formed at an incline, so that the lens can be more easily coupled and separated.
• step projections 43 are formed along edges of the lens 40, and counter step projections 37, which are engaged with the respective step projections, are formed in the casing 30.
• the LED bars B of the above-described exposure LED light source are provided to replace the existing CCFLs, which are used for copiers. [74] Accordingly, the LED bars B must be mounted at the location at which the existing CCFLs, which are used for copiers. [74] Accordingly, the LED bars B must be mounted at the location at which the existing CCFLs, which are used for copiers. [74] Accordingly, the LED bars B must be mounted at the location at which the existing
• CCFLs are mounted. In this case, it is most important not to change the installation locations or the structures of other parts.
• the means for achieving the above-described purpose is the fastening member F.
• the fastening member F has a ' ⁇ '-shaped cross-section.
• Such a Selfoc lens which is a kind of GRIN lens (which is an abbreviation for "gradient-index rod lens”), is one of the most important optical elements in micro optics, is used for coupling with a light source, forming parallel light beams and performing condensing, and is chiefly manufactured using ion exchange.
• the Selfoc lens is a piece of rod-shaped optical glass, which enables continuous variation in a refractive index in the direction from the circumference thereof to the center thereof, and is adopted to increase the refractive index, and 'Selfoc' has come to be used as the generalized name in the related business since it was marketed under the product name 'Selfoc' by NSG Co., Ltd. of Japan 20 years ago.
• correct positional arrangement protrusions 31a are formed under the respective coupling bosses of the casing 30, and depressions 51, which are coupled with the respective correct positional arrangement protrusions, are formed in the fastening member F.
• the arrangement protrusions may be formed on the fastening member, and the depressions may be formed in the coupling bosses of the casing.
• one of the key points of the present invention is that two LED bars B are mounted on the fastening member F, and the mounting angle ⁇ formed between each LED bar and a fixed horizontal plane is 30 ⁇ 50 degrees (about 40 degrees in the drawing and in practice). This is to prevent problems, such as an increase in cost and non-uniform light diffusion attributable to light non-uniformity, from occurring in the case where a high-priced high-brightness LED is adopted as an exposure LED light source for copiers, and to provide advantages in cost efficiency by ensuring a sufficient and appropriate degree of light convergence and uniform light diffusion in original reading performance, even when an LED having a high brightness is adopted.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Light Sources And Details Of Projection-Printing Devices (AREA)
• Facsimile Scanning Arrangements (AREA)

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Publications (1)

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Citations (4)

Family Cites Families (3)

• 2007
  • 2007-02-09 KR KR1020070013468A patent/KR100718240B1/ko not_active IP Right Cessation
• 2008
  • 2008-02-11 WO PCT/KR2008/000776 patent/WO2008097056A1/en active Application Filing

Patent Citations (4)

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