TW200909229A - Line head and image forming apparatus using the same - Google Patents

Abstract

A line head includes: a positive lens system having two lenses with positive refractive power; a lens array in which a plurality of the positive lens systems are arrayed in a first direction; a light emitter array in which a plurality of light-emitting elements are arrayed on an object side of the lens array so as to correspond to the one positive lens system; and an aperture plate that forms an aperture diaphragm at the position of an object-side focal point of the positive lens system. An object-side surface of an object-side lens of the positive lens system is positioned close to the object-side focal point.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a linear print head and an image forming apparatus using the same, and more particularly to a method of projecting a row of light-emitting elements onto an illuminated surface using a microlens array. A linear print head for forming an image spot (sp〇t) and an image forming apparatus using the same. [Prior Art] Conventionally, Patent Document 1 proposes an optical writing head and a light reading head for optically opposite printing, in which a plurality of LED array wafers are arranged in the direction of the LED array. And the positive lens disposed corresponding to the LED array of each LED array chip is enlarged and projected on the photoreceptor, and the images of the light-emitting image points (_) at the end portions of the adjacent LED array wafers on the photoreceptor are identical to each other. The inter-image pitch (Pitch) of the illuminating image points of the brush array wafer is adjacent to the same pitch and imaged. Further, in Patent Document 2, there is proposed a configuration in Patent Document 1, in which a positive lens is formed by two lenses and a depth of focus is made deeper so that the projection light is close to the parallel light. / In addition, Patent Document 3 proposes an optical write linear print head in which the LED array wafer is arranged in a gap of 2 隔 between the gaps of the 阵列 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃 仃On the other side of each LED array wafer, two rows of positive lenses are arranged as =/+ and η correspond to _1, and the home of the illuminating image dot array on the photoreceptor is '""" [Patent Document 1] 专利 [Patent Document 2J Japanese Patent Application Laid-Open No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. Solving the problem] # #知技术巾' Even on the ideal image surface, even if the array of light-emitting pixels is integrated at equal intervals, 'If the image surface moves back and forth in the direction of the optical axis of the lens due to vibration of the photoreceptor, etc. The positional shift of the illuminating image points on the photoreceptor is generated, and the distance between the scanning lines drawn by the illuminating image point array in the sub-scanning direction is uneven (the distance between the main scanning directions is uneven). Further, when the image angle of each lens is increased, the amount of light in the vicinity is reduced (shading, shielding) in accordance with the fourth-order law of cos. In order to prevent the unevenness of the density of the printed image caused by the masking, it is necessary to make the amount of light of each pixel (light-emitting image point) of the image plane set, but it is necessary to change the light source (lighting image point) according to each of the light-emitting image points. The amount of light is corrected to cover. However, since the light-emission intensity of the light source pixel (light-emitting image point) affects the life characteristics, if the shadow of the optical drop system becomes large, even if the light amount is adjusted for each light-emitting image point, the image plane is obtained at the beginning. The amount of light will also cause an uneven amount of light at intervals of the illuminating image points, which will result in uneven image density. The present invention has been made in view of such a problem in the prior art, and an object of the invention is to provide an optical write line in which a plurality of light-emitting elements in a row are arranged in correspondence with respective lenses of a plurality of positive lenses arranged in an array. In the printing head, even if the writing surface is changed in the optical axis direction, unevenness in positional shift based on the light-emitting image point does not occur. Another object of the present invention is to prevent density unevenness caused by shadowing between imaging spots of respective lenses. I32764.doc 200909229

Further, the present invention $B also provides an image forming dream head using such an optical writing linear print head. And the optical printing of the light having the opposite optical path is read. [Technical means for solving the problem] The linear printing head of the present invention which achieves the above object is characterized in that the positive lens system has positive refractive power. a lens array, wherein: i is configured to arrange a plurality of positive lens systems in a first direction; an illuminant array, which is <,, +, , *, on the object side of the lens array relative to 1 The positive lens system is configured with a plurality of light-emitting elements; and an aperture plate forming an object-side focus aperture stop of the positive lens system; and an object-side surface of the object-side lens of the positive lens system is located close to the object-side focus At the office. According to this configuration, even if the writing surface changes in the optical axis direction, unevenness in positional shift based on the light-emitting image point does not occur. In addition, the image angle from the plurality of first-hand elements to the positive lens system can be emitted. The effect of the masking is reduced to reduce the deterioration of the formed image. Further, it is preferable that the object-side surface of the lens on the object side of the positive lens system is within ±10% of the distance from the point of the positive lens system with respect to the object-side focus. In this way, even if the writing surface is changed in the direction of the light vehicle, the unevenness of the positional shift based on the light-emitting image point is not substantially generated. Furthermore, the complex light-emitting element can be incident on the positive lens system. The image angle is reduced to reduce the shadowing and the image is prevented from deteriorating. ~ 132764.doc 200909229 In addition, the aforementioned lens system can be formed by a lens group. With such a configuration, it is easy to make aberration correction even if it is easy to manufacture each lens array. Further, among the two lenses, the image side surface of the lens on the object side may be formed by a flat surface. According to this configuration, since the interval between the front main surface of the lens on the image side and the main surface on the rear side of the object side can be made wider, the image angle can be further reduced to further reduce the influence of the shadow. Further, since the lens having the curvature on both sides is formed only by the surface of the lens on the object side, the manufacturing is easier. Further, at least the object side surface of the lens on the object side of the positive lens system may be formed by a convex surface, and a portion including the top surface of the convex surface may be disposed deep into the opening of the aperture plate. According to this configuration, since the interval between the front main surface of the lens on the image side and the main surface on the rear side of the object side can be made wider, the image angle can be further reduced to further reduce the influence of the shadow. In this case T, it is possible to form the aperture plate by forming a light-shielding member on the object side surface of the lens array. According to this configuration, by integrally forming the diaphragm plate on the surface of the lens, the positioning and assembly of the diaphragm plate can be easily performed, and the center of the diaphragm and the optical axis of the lens can be controlled by thermal expansion or the like. Further, at least the image side surface of the lens on the image side of the positive lens system is preferably a flat surface. By thus configuring 'the surface of the lens closest to the image plane can be flat 132764.doc 200909229 surface' and the foreign matter adhering to the dust or toner of the exit surface can be simply cleaned, and Improve deaning. Further, the shape of the aperture stop is preferably a shape that restricts at least the opening diameter of the first direction. With such a configuration, it is possible to spur the temple 5 丨, ±, ^ to correspond to at least the positional shift of the image point outside the axis, which becomes the main scanning direction of the problem. r\

Further, it is preferable that the plurality of light-emitting elements are formed so as to be arranged in a plurality of light-emitting elements arranged in the second direction of the first direction of the soil direction. With such a configuration, it is possible to form an image with a higher density of the imaged pixels. Further, the above-mentioned plurality of light-emitting elements are preferably arranged so as to be formed in a group of light-emitting bodies spaced apart from each other. By configuring in this way, it is possible to form an image having a higher density corresponding to the imaged image point, and it is possible to prevent the amount of light from being caused by the influence of the vignetting of the image of the end light-emitting image point in each of the plurality of light-emitting elements. reduce. The above-mentioned light-emitting element is preferably made of an organic element. The error is thus configured to correspond to an image that is uniform in the plane. Further, the light-emitting element is preferably made of lED. In this way, it is also possible to form an image forming apparatus in addition to the linear printing head using the LED array, and at least two or more lines are disposed around the image carrier. The image forming station of each of the image forming units of the print head, the developing mechanism, and the transfer mechanism performs the image pattern 132764.doc -10- 200909229 by the transfer medium through each station. By doing so, it is possible to form a small-sized and less-dissolved printer; ^Cage> θ image-like vehicle and image inferior image forming apparatus. The present invention is a linear print head having a feature of two lenses having positive refractive power; a lens array of lens lenses, an array of photoreceptors in a second direction, and a front lens system;

/, on the image side of the 逑 lens array, a plurality of light receiving elements are disposed for each of the foregoing positive lens systems; and an aperture plate forming a position aperture of the image side focus of the positive lens system; and an image side of the uranium positive lens system The aforementioned image side focus. The image side of the lens is located near the outer corner

Lj is constructed in such a manner that even in the optical reading linear print head, the reading surface is offset in the optical axis direction, and the positional deviation of the reading spot is not generated. The image of the positive lens system is reduced by the reflection path to reduce the influence of the shadow, and the deterioration of the read image can be prevented. Further, each of the positive lens systems constituting the lens array is formed of two lens groups of positive refractive power, and may be a composite lens system formed by the two lens groups (the respective lens systems are positively refractive) The lens group is made up). [Embodiment] Before explaining the optical system of the linear printing head of the present invention in detail, the arrangement of the light-emitting elements and the timing of light emission will be briefly described. Fig. 4 is an explanatory view showing the correspondence relationship between the illuminator array 1 according to the embodiment of the present invention and the microlens 5 having a negative optical magnification. In the linear print head of the embodiment I32764.doc 200909229, two rows of light-emitting elements are associated with one microlens 5. However, since the 'lens 5 is an imaging element whose optical magnification is negative (inverted imaging), the position of the light-emitting element is reversed in the main scanning direction and the sub-scanning direction. That is, in the configuration of Fig. 1, even-numbered light-emitting elements (8, 6, 4, 2) are arranged on the upstream side (first row) of the image carrier moving direction, and on the same downstream side (second The light-emitting elements (7, 5, 3, 1} of the odd-numbered array are arranged in a row. Further, the light-emitting elements having a larger number are arranged on the head side before the main scanning direction. Figs. 1 to 3 are lines of this embodiment. A perspective view of a portion corresponding to a microlens of the print head. As shown in Fig. 2, an image spot 8a of the image carrier 41 corresponding to the odd-numbered light-emitting elements 2 arranged on the downstream side of the image carrier 41 is formed. In the position where the main scanning direction is reversed, R is the moving direction of the image carrier μ. Further, as shown in Fig. 3, the even-numbered light-emitting elements 2 arranged on the upstream side (first row) of the image carrier 4i are The imaging spot 8b of the corresponding image carrier 41 is formed at a position on the downstream side of the inversion of the sub-scanning direction. However, in the main scanning direction, the position of the imaging spot from the front side is the glare element 1. The numbers of ~8 correspond in order. Therefore, in this case, it can be understood by adjusting the image. The timing of forming the imaging spot in the sub-scanning direction can form an imaging spot in the main scanning direction. Figure 5 is a memory tab for the linear buffer that stores the image data. Illustrated diagram of the example of Fig. 5. The memory form (7) of Fig. 5 is reversed in the main scanning direction with respect to the number of the light-emitting elements of Fig. 4. In Fig. 5, the memory form stored in the linear buffer The first image data (1, 3, 5, 7) corresponding to the light-emitting elements on the upstream side (the first row) of the image carrier 41 is read first in the bead material to cause the light-emitting element to emit light. 132764.doc -12- 200909229 After 'T hours, read the second image data, 4, 6, 8) corresponding to the light-emitting elements stored on the downstream side (the second line) of the image carrier 4丨 of the memory address. Make it shine. Thus, as shown by the position of 8 in Fig. 6, the imaging spot of the first line on the image carrier is formed in the main scanning direction with the imaging spot of the second line. Fig. 1 is a perspective view conceptually showing an example in which image data is read out at the timing of Fig. 5 to form an image spot. Referring to Fig. 5, the light-emitting elements on the upstream side (first row) of the image carrier 41 are first illuminated to form an image spot on the image carrier 41. Next, after a specific timing τ has elapsed, the odd-numbered light-emitting elements on the downstream side (the second row) of the image carrier 41 are caused to emit light, and an image spot is formed on the image carrier. In this case, the imaging spot point formed by the odd-numbered light-emitting elements is shown in Fig. 6 in the main scanning direction at the position of 8 instead of the position 8a illustrated in Fig. 2. Fig. 7 is an explanatory view showing an outline of an example of using an illuminant array as a linear printing head. In FIG. 7, in the illuminator array ,, the light-emitting element row 3 in which the plurality of light-emitting elements 2 are arranged in the main scanning direction is provided with a plurality of rows in the sub-scanning direction to form an illuminant block (bl〇ck) 4 (refer to the figure). 4). In the example of Fig. 7, the illuminant block 4 is formed by arranging four rows of light-emitting elements 3 of the four light-emitting elements 2 in the main scanning direction in two rows in the sub-scanning direction (see Fig. 4). The illuminant block 4 is mostly disposed in the illuminant array 1, and each illuminant block 4 is disposed corresponding to the microlens 5. The microlens 5 is provided in plural in the main scanning direction and the sub-scanning direction of the illuminant array 1 to form a microlens array (MLA, which is inspected by ([(四)八咖咖. This MLA6 is before the main scanning direction in the sub-scanning direction. The position is arranged in the row of 132764.doc •13·200909229. The arrangement of the MLA 6 corresponds to the case where the light-emitting elements are arranged in a staggered manner in the illuminator array. In the example of Fig. 7, the arrangement is in the sub-scanning direction. Line ML A6, except that each unit block 4' corresponding to each of the three rows of the sub-scanning direction of ML A6 is divided into group a, group B, group C for convenience of explanation. As described above, A plurality of light-emitting elements 2 are disposed in the microlens 5 having a negative optical magnification, and in the case where the plurality of lines are arranged in the sub-scanning direction, 'in order to form a line of imaging spots in the main scanning direction of the image carrier 41' The following image data control: (丨) inversion of the sub-scanning direction, (2) inversion of the main scanning direction, (3) illumination timing adjustment of the plurality of rows of light-emitting elements in the lens, (4) illumination between groups The illumination timing of the component is adjusted. 8 is an explanatory view showing an imaging position in the case where the exposure surface of the image carrier is irradiated through the microlens 5 by the output light of each of the light-emitting elements 2 in the configuration of FIG. 7. In Fig. 8, it is shown in Fig. 7. In the illuminant array i, a unit block that is divided into a group A, a group B, and a group C is disposed, and each unit block 4 of the group A, the group B, and the group C is disposed. The light-emitting element row is divided into an upstream side (first row;) and a downstream side (second row) of the image carrier 41, and an even-numbered light-emitting element is allocated to the first row, and an odd-numbered light-emitting element is assigned to the second row. The group A is formed by forming the imaging spot on the image carrier 41 in the main scanning direction and the sub-scanning direction by operating the respective light-emitting elements 2 as described with reference to FIGS. 1 to 3. Then, the same line of the imaging spot in the main scanning direction is formed on the image carrier 41 in the order of 1 to 8. Hereinafter, the image carrier 41 is moved in the sub-scanning direction for a specific time and the processing of the group B is also performed. .doc •14- 200909229 The 'image carrier 4丨 shifts in the sub-scan direction (4) and executes the group c Processing, whereby the imaging spots based on the input image data are formed in the same row in the main scanning direction in the order of (10). Fig. 9 is a view showing the state of formation of the imaging spot in the sub-scanning direction in Fig. 8. The monthly graph S is the moving speed of the image carrier 41, and the dl is the interval of the light emitting elements of the second row of the group "the eighth row", which are the light emitting components and groups of the second row of the group a. The interval between the light-emitting elements in the second row of B is the interval between the light-emitting elements of the second row of group B and the light-emitting elements of the second row of group c, and T1 is the second row of group A. The time from the light-emitting of the light-emitting element to the time when the light-emitting element emits light, the imaging position of the light-emitting element of the second row of group a moves to the image of the light-emitting element of the second row of group B. At the time of the position, T3 is the time when the imaging position formed by the light-emitting elements of the second row of the group A moves to the imaging position of the light-emitting elements of the second row of the group C. The T1 system can be obtained in the following manner. T2 and T3 can also be obtained by changing dl to d2 and d3.

Tl = l(dlxp) / s| Here, the parameters are as follows. Dl : the distance S of the sub-scanning direction of the light-emitting element: the moving speed of the imaging surface (image carrier) β: the magnification of the lens is after the time T2 of the time when the light-emitting elements of the second row of the group 发光 are illuminated in FIG. The light-emitting elements of the second row of the group B are caused to emit light. Further, the light-emitting elements of the second row of the group c are caused to emit light after the time from T2 to T3. Groups 132764.doc • 15- 200909229 No.! The light-emitting elements in the row emit light after being emitted from the light-emitting elements of the second row. By performing such a process, as shown in Fig. 8, the image spot formed by the two-dimensional illuminator of the illuminant array is formed, and one line is formed on the image carrier. Fig. 10 is a view showing an example in which the main broom of the image carrier is formed by reversing the imaging spot in the case where the microlenses 5 are arranged in plural, and the image forming apparatus can be constructed by using the above linear print head. In the embodiment, the above-mentioned linear print head can be used to expose four photoreceptors in four linear print heads, and at the same time, an image of four colors is transferred to one endless intermediate transfer belt. (belt) (intermediate transfer medium) is a tandem type color printer (image forming apparatus). Fig. u is a longitudinal sectional side view showing an example of a tandem image forming apparatus using an organic EL element as a light-emitting element. In the image forming apparatus, four linear print heads HHK, 101C, 101A, and 1〇1γ having the same configuration are disposed in the same four photoreceptor drums (image carriers). The image forming apparatus of the tandem type is formed by the exposure positions of 4ικ, 41C, 41Μ, and 41Υ. As shown in FIG. 11, the image forming apparatus is provided with a driving roller 51 (r〇Uer) 5i, a driven roller 52, and a tension roller 53, and is provided with a tension by a tension roller 53, and is stretched. The intermediate transfer belt (intermediate transfer medium) 5 rpm is driven in the direction of the arrow (counterclockwise). The photoconductors 41K, 41C, 41M, and 41Y having the photosensitive layer are disposed on the peripheral surface of the intermediate image of the four image carriers at a predetermined interval with respect to the intermediate transfer belt 50. The K, C, μ, and Υ attached after the above symbols refer to black, cyan, magenta, and yellow, respectively, indicating black, 132764.doc 16 200909229 blue green, deep red, yellow multipurpose Xicheng p secret media "touch the first body. The same is true for other components. Photoreceptor 41K, 41C, 41M ^ 'r 〆 系 与 中间 中间 中间 中间 中间 中间 中间 中间 中间 中间 中间 中间 中间 中间 中间 中间Rotary drive in the direction of the r r 。 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 And the above-described linear print head 101 of the present invention (K, by means of the charging mechanism 42 (Κ, Υ)-like charged outer peripheral surface, the photoreceptor 4 shape, and the μ rotation are synchronized and sequentially scanned in line. C, Μ, Υ). The present invention has a developing device called a toner for the electrostatic latent image of the linear printing head 101 (K, c, Μ, ). And made a visible image (toner image); as a transfer mechanism

i \ KJ primary transfer view 4^, ^, 丫), which sequentially transfers the toner image developed by the developing device 44 (K, C, M, Y) to the middle of a printing object The printing tape 50; and a cleaning device 46 (K, C, Μ, Y) as a cleaning mechanism removes the toner remaining on the surface of the photoreceptor, c, Μ, Υ) after the transfer. Here, each of the linear printing heads 1〇1 (K, c, M, Y) is called k, c, Μ along the photoreceptor in the array direction of the linear printing heads HH (K, C, Μ, Y). Y) is set in the way of the bus. Further, the peak wavelengths of the energizing energies of the respective linear printings, C, Μ, and Υ are set to substantially match the sensitivity peak wavelengths of the photoconductors c, Μ, and Υ. The shirt set 4 4 (Κ, C, Μ, V, at point 丨丨 & from L Μ, Y) is, for example, a non-magnetic toner as a developer, and the one-component developer is, for example, Supply Yukun Chao 132764.doc 200909229 Display (4) handling, and to limit the adhesion of the blade (bIade): the thickness of the film of the toner, so that the developing roller contacts or push the dust;: surface tan m, thereby developing The agent is attached to the potential level of the photoreceptor 4ι (κ = body Μ, Υ).叩", 贝 〜 as a slave powder image development by the four-color monochrome toner image forming station formed by the black 'dark red, yellow each toner image by applying to = 45 (K, C, Μ, Υ, 夕一 a silk e-release roller-human transfer bias is sequentially transferred to the transfer belt 50 in sequence, and sequentially overlaps on the inter-transfer (four) to become a full stone powder The image is secondarily transferred onto the recording medium P such as paper in the secondary transfer roller 66, and is fixed on the recording medium by the pair of rollers belonging to the fixing portion And discharged by the paper discharge tray 62 toward the paper discharge tray 68 formed on the upper portion of the apparatus. In addition, in Fig. 11, 63 is a paper feed (10) a_e in which a plurality of sheets of recording medium P are stacked and held. 64 is a pickup roller that transports the recording medium p one by one from the paper feed cassette 63 (pick #_call, 65 is a predetermined recording medium p pair; n, oblique PI 66 is supplied to the secondary transfer portion) The gate roller (gate Π 66 is a two-reading roller as a primary transfer mechanism that forms a secondary transfer portion between the intermediate transfer belt and the intermediate transfer belt 5, and the 67 is to leave the second transfer after the second transfer Printing tape 5 〇 $ 矣 & cleaning blade ι "surface - removed as a cleaning mechanism - again, the present invention relates to the optical system of the above linear printing head (optical writing linear printing head). First from Fig. 12 is a diagram for explaining the basic principle of the present invention. Fig. 12 is a table 132764.doc 200909229 showing an end light-emitting element arranged in a line-shaped light-emitting element row in a linear print head = The relationship between the microlens 5 projecting the row of the light-emitting elements and the photoreceptor (image carrier) 41 for projecting the light-emitting elements, (4) is the clearing of the present invention, and (b) is the case of the conventional example. In the conventional example of Fig. i2(b), since the opening of the microlens 5 is defined by its outer shape, the imaging spot 8x of the image on the photoreceptor 41 at the end of the light-emitting member 2X, The image is formed on a straight line passing through the center of the end light-emitting element h and the microlens 5. Therefore, if the port is caused by vibration of the photoreceptor or the like, the surface of the photoreceptor 41 belonging to the image surface is in front of and behind the optical axis of the lens. Moving to move to the image of the figure 41, the image on the photoreceptor 41 The position of the light spot 8χ becomes the position 8x′ on the straight line and the positional shift of the imaging spot is generated, and the distance between the scanning lines drawn by the imaging spot relative to the sub-scanning direction is generated. All (the distance between the imaging spots in the main scanning direction is uneven). Therefore, in the present invention, as shown in FIG. 12(a), the aperture stop 丨丨 is arranged at the position of the front side focus F of the microlens 5 to be The optical axis 〇_〇, coaxial. If such an aperture stop 丨丨 is disposed at the front focus F position of the microlens 5, the chief ray 12 from the end light-emitting element 2x passes through the center of the aperture stop , The lens 5 is refracted and proceeds in parallel with the optical axis 〇_〇', and even if the photoreceptor 41 moves to the position of the optical axis 〇_〇· direction 41, the position of the imaging spot 8x on the photoconductor 41 becomes micro The position 8x of the chief ray 12 after the lens 5 is refracted does not cause a positional shift of the imaging spot 8x even if the position of the photoreceptor 41 vibrates back and forth. Therefore, the distance between the imaging spots 8X in the main scanning direction as in the conventional scanning direction is not caused, and the unevenness between the scanning lines drawn in the sub-scanning direction at the imaging spot 不会 does not cause unevenness. 132764.doc • 19· 200909229 That is, the present invention is a method in which a plurality of light-emitting elements are arranged in a line shape in a main scanning direction, and a positive lens system is disposed corresponding to the plurality of light-emitting elements, by performing an image of the light-emitting elements (Array of imaging spots) A linear print head that is projected onto a projection surface (photoreceptor) to form an image, and the projection optical system is configured to be so-called telecentric with respect to the image side, thereby making the projection surface The position of the (photoreceptor) does not cause the positional deviation of the imaged Z point even if it is shifted in the optical axis direction, and the deterioration of the formed image is prevented. Γ Ο In addition, the function of the aperture stop 11 is to limit the positional deviation of the imaging spot at least outside the axis (the shape of the opening diameter of the main scanning side). In the case of arranging an array of i-line light-emitting elements with respect to one positive lens system, the shape of the aperture of the main scanning direction may be limited. The above-described embodiment of the present invention. In the case where the two rows are arranged close to the sub-scan (closed, it is also possible to limit the main scanning side = the opening diameter of the report can be 丄 丄 土 土 土 土 ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... Therefore, the opening of the direction may be a circular, elliptical or rectangular opening shape. /Hearter j: 'In the description of Fig. 12, the microlens 5 is i-shaped, but the image is In the case of two positive lens arrangements, the difference lens is formed by a lens system which is preferably in the case of nr u, and the two lenses constituting the microlens 5 are recorded.彻# & positive lens is considered as a thin wall ^ sacrifice and its image side telecentric The image angle of the light emitted by the soil 2x. First, the light-emitting element 132764.doc •20- 200909229 First, the symbol of each parameter is first defined as shown in Fig. 13. Now, that is, measured from the optical axis Ο-CV The angle θ is turned to the right to be positive, and from the _ nine-axis 〇-〇, the measured image is still positive above h, and the optical axis measured from the thin-walled lens is right-right, and The small letter I after the symbol, the small word after the number 'symbol', and the image side refers to the parameter of the object side.

Since the lens system (microlens) 5 formed by the i-th positive lens L1 and the second positive lens is telecentric on the image side, the aperture 丨丨 is disposed such that the entrance pupil is located at the focus position before the lens system $. Therefore, the focal point distance of the lens system is set to ftotal, and the position of the light source (illuminant array 1) with respect to the main surface of the object side of the lens system is set to S. The width (full width) of the light-emitting element group between the end light-emitting elements 2 in the illuminant block 4 is set to w. The image angle ω of the end light-emitting element & refers to FIG. 14 and is expressed by the following formula (丨). W = (W 〇 / 2) / (-S0 - ftotal) (1) Here, the imaging spot group between the imaging spots 8 of the image of the end light-emitting element 2 在 on the photoreceptor surface (image surface) 41 The group width (full width) is set to Wi, the horizontal magnification is β, and the image plane position on the image side main surface of the lens system is set to Si and W. And S. It is expressed as shown in the following formula (2).

Wo^-Wi/p^-W^So/Sj (2) From the paraxial image, it can be written as i/Si=i/s〇+i/ftotal. Solve, then become S〇= Si*ftotal/(ft〇tal-Si) (4) If formula (1) is substituted into formulas (2) and (4), it can be written as ω = Wi/(2ft〇tai) 132764.doc 21 200909229 Here, the 'combined focal length ftQtal is set to f丨, the focal length of the second positive lens L2 is set to f丨, and the first positive lens is second. The distance between the positive lenses L2 is set to d /, and a 1 is expressed as the following formula (6)... (6) ft 〇ta 丨- fl ' (fl +f2-d)) If the formula (6) Substituting into the formula (5), it becomes... (7) If we look at the d丨 of the formula (7), in (f + f (丨t2)^d丨, 1 is as large as possible, and ω becomes In the case where the arrangement of the apertures is restricted by the object side by the structural constraints, etc., in order to set the image side telecentricity, the lens spacing is limited to the following formula '. 〇^ d, ^f2 In order to make the image angle 1 represented by the formula (7) as small as possible in the range of the formula (8), it is possible to make d 1 larger, and the risky person is to set d丨 as close as possible to f2. Value. At this time, the aperture u and the i The interval-based lens L1 approaches zero.

U If the foot f2 is substituted into the formula (6) and sorted out 'that is ^_=f2 (Fig. 15 is summarized above, in the aperture u as the two microlenses 5 disposed on the side of the (four) positive lens u by the illuminant array" In the review of the thin-walled lens, in order to reduce the amount of light in the periphery as much as possible by reducing the amount of light in the vicinity of the image side, the angle of the image of the optical system and the system is reduced. It is preferable to arrange the aperture 11 on the front focal plane of the lens system 5 formed by the two positive lenses L1, and to arrange the positive lens L1 close to the aperture ,, and at this time, the aperture U and the ith The lens L1 is close to the front focal plane of the second positive lens L2 as shown in Fig. 15. 132764.doc -22· 200909229 Although the above is a review of the thin-walled lens, the review continues to make the actual thick-walled lens. The system constitutes the situation.

In the lens system 5 in which the aperture 11 is disposed further forward (object side) than the i-th positive lens, even if two positive lenses L1 and L2 are used as thick-walled lenses, the lens system 5 and the image side are telecentric. Therefore, it is only necessary to arrange the aperture 丨丨 in the front focus position of the synthetic optical system of the two positive lenses L丨 and L2. Further, from the result of the review of the thin-walled lens described above, by arranging the first positive lens L1 close to the aperture 丨丨, the image angle can be reduced and the influence of the mask can be reduced. In the specific numerical example described later, the interval between the surface of the diaphragm 11 and the surface of the first positive lens L1 on the object side is set to zero. Further, in the thick-walled lens, the position of the main surface is changed by the power distribution of the incident surface (object side surface) and the emission surface (image surface side), but the first positive lens L1 is set. The convex positive lens having the incident surface is convex, and the rear main surface of the first positive lens L1 is closer to the incident surface than the two convex positive lenses. Therefore, the rear main surface of the first positive lens L1 and the front side of the second positive lens L2 can be provided. The interval between the main faces is wider. Further, in this case, the lens forming surface (curved surface) of the i-th positive lens L1 has one surface, and there is an advantage that manufacturing is easy. In the second embodiment, the numerical example of the specific numerical example described later is a convex positive lens in which the focal length of the first positive lens η is maintained as it is, and the maximum image angle is smaller than that in the first embodiment. In the case where the incident surface of the first positive lens L1 is the &amp; surface, the i-th positive lens L1 is disposed such that the incident surface of the first positive lens L1 penetrates the opening of the aperture n, that is, The point of the incident surface of the positive lens L1 is placed closer to the object side than the surface of the aperture 11, that is, the IJ will be the first positive lens L1 132764.doc -23 - 200909229 the rear main surface and the second positive lens L2 The interval between the front side main faces is made wider (Embodiment 3). In addition, in this case, the aperture is awkward! The arrangement position is the front focus position of the synthetic optical system of the positive lenses L1 and L2, but the front focus is sneaked into the first positive lens L1, and is concentrated on the i-th in the case where the parallel light is incident from the image side. In the positive lens L1, the diverging light is diverged from the condensing point, and the emission angle is weakened toward the incident surface of the first positive lens L1. The image viewed from the object side of the condensed light (diverging light) is a virtual image, but the surface on which the virtual image exists is the front side focal plane of the entire lens system. Therefore, by arranging the diaphragm 11 on the front focal plane, it is configured to be telecentric with the image side. Further, even if the aperture 11 is not disposed so that the incident surface of the i-th positive lens L1 penetrates into the opening of the aperture 11, it is disposed near the pole of the incident surface of the i-th positive lens Li instead of the incident of the first positive lens L1. The position of the surface can be reduced by arranging the aperture 11 ' on the side focal plane of the lens system 5 formed by the two positive lenses L1, L2, and the shadow of the optical system can be reduced, and the mask based on the (10) yoke can be reduced. Phenomenon (Example 4). As described above, a lens system in which a positive refractive power is formed by coaxially arranging two positive lenses is configured as the lens system 5, and the front focus of the synthetic optical system is placed at the first! In the vicinity of the incident surface of the positive lens L1, the aperture stop η is disposed at the front focus position, that is, it is configured to be telecentric with respect to the image side, and the position of the projection surface (photoreceptor) 41 is not shifted even in the optical axis direction. The positional shift of the imaging spot is generated. In addition, the amount of light in the periphery decreases as the c〇s4 law of the lens becomes larger. The shielding phenomenon is extremely small. It is difficult to cause the light-emitting element row to be arranged in a line shape in the illuminant array 1. The concentration of imaging spot 8 is not 132764.doc •24- 200909229. </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; The distance between the scan lines is not uniform, and the distance between the scan lines of the sub-scanning and the scanning lines 8 does not cause unevenness. It is difficult for the two poems to cause the obscuration of the conventional microlens 5 to cause the imaging spot 8

It is difficult to cause the imaging spot 8 to move in the sub-scanning direction to cause density unevenness between the scanning lines drawn. Further, 'in the above case, the position of the synthetic optical system of the positive lenses L1 and L2 is ', and the dot position is located close to the incident surface (near) of the first positive lens L1, but in the present invention, When the incident surface of the first positive lens L1 is within 1% of the soil of the combined focus distance ft〇ta| of the synthetic optical system, it is set to be close to or in the vicinity. However, in the case where the linear print head &lt; optical system, and the above-described image-side telecentric microlens 5 are arranged in only one line in the main scanning direction, the specific microlens 5 is configured so that The line-shaped light-emitting elements are formed by the imaging spot 8 χ of the image of the end light-emitting element 2 X and the interval between the imaging spots 8 邻接 adjacent to the adjacent microlens 5, and by! The distance between the imaging spots of the microlenses 5 is the same, and the imaging spot of the image of the end light-emitting element 2 is more sensitive to the light than the other imaging spots in the imaging spot. The effect is reduced. In order to avoid this, as shown in FIG. 1 to FIG. 1A, the illuminant blocks 4 are arranged at intervals in the main scanning direction, and the sub-scanning direction is configured to align the plurality of illuminant blocks 4, and The lens array 6 also has two dimensions of the microlens 5 disposed in the main scanning direction and the sub-scan 132764.doc -25-200909229 in correspondence with the arrangement of the illuminant blocks 4, thereby solving such an end. The problem that the amount of light of the imaging spot 8χ of the image of the light-emitting element 2x is lowered. The present invention is characterized in that a plurality of light-emitting elements are arranged in a line shape in the main scanning direction, and a positive lens system is disposed corresponding to the plurality of light-emitting elements, by which the image of the light-emitting element is imaged (imaged light) a line-shaped print head that is projected onto a technical shadow surface (photoreceptor) to form an image, which is formed by two positive lenses and is telecentric with the image side, and the object side The incident surface of the positive lens is disposed as close as possible to the aperture stop, and the position of the projection surface (photoreceptor) is not shifted even in the direction of the optical axis: the position of the light spot is shifted, and the imaging spot is further The density unevenness between the two is reduced, and the deterioration of the formed image is prevented. Dan, in terms of the function of the aperture stop U, as long as the heart is limited to at least the positional deviation of the imaging spot outside the axis becomes the problem direction (the shape of the opening diameter of the main scanning), so as in the conventional example (patent The document mode is configured such that the array of the satin light-emitting elements is disposed with respect to the i positive lens system as long as it is a shape that limits the opening diameter of the main scanning direction. The mode and the sub-scan of the above embodiment are In the case of the direction pole connection=set 2仃 array (Fig. 4), the shape of the main scanning direction port can be limited, but it is of course also possible to limit the shape of the sub-scanning direction I: It is a circular, elliptical or rectangular shape of the opening. Bed test........ You® 1), 槿忐 and , * μ τ , ΤΛ _ constitute each of the microlenses 5 Although the rust is formed by one lens, the fg hm ± 介 can also be formed by a two-piece upper lens disposed coaxially with a positive core cable system. 132764.doc -26 - 200909229 In addition, in the above description, the microlens 5 is in the scanning direction of the main scanning steering wheel. The axis-symmetric lens with the same focal length and focus position is the premise, but the lens system constituting the microlens 5 is formed by the system of deformation = mirror Unam〇rphic lens, and the main scanning direction and the sub-direction can be used. The focus distance is different from the magnification. In this case, the aperture stop 11 is disposed so as to be the image side in the main scanning direction (main scanning section), and the surface on the most object side of the synthetic optical system is located close to the aperture aperture U ( The position of the front side focus position of the synthetic optical system in the main scanning direction may be configured. Furthermore, although the above is an optical system for writing a linear print head, the optical path phase &amp; 'the plurality of light-receiving elements are arranged in a line in the main scanning direction, and a plurality of positive light-receiving elements are arranged in a positive lens, In the case where the image of the light-receiving element (the array of reading spots) is back-projected on the reading surface and the image is read by the optical reading linear print head, the projection may be performed by The optical system is formed by two positive lenses and is telecentric with the object side, and the incident surface of the positive lens on the image side is arranged as close as possible to the π aperture, so that the position of the reading surface is shifted even in the optical axis direction. The positional shift of the reading spot is not generated, and the density unevenness between readings is reduced to prevent deterioration of the formed read image. In this case, in Fig. 12 (4) and Fig. 15, the symbol (4) is a term-receiving surface, and the symbol 2 is an end light-receiving element, and the principle is the same as that of the optical system in which the optical writing head is printed. 〃 Next, an optical write line print head of an embodiment to which the principle of a # π _ 不 不 is applied will be described. Figure 16 is a perspective view showing a portion of 132764.doc -27- 200909229 which is a combination of the optical write head print head of this embodiment, and Fig. 7 and _ θ s 17 are along the side thereof. Scanning direction: The sectional view to be paid. Further, Fig. 18 is a plan view showing the arrangement of the illuminant array mirror array in this case. Further, Fig. 19 is a view showing a correspondence relationship between a &quot;solid&quot; mirror and its corresponding illuminant block.

In the present embodiment, as in the case of FIG. 4' FIG. 7, in the case of four main scanning directions, a plurality of rows 3 of light-emitting elements 2 in which the organic core members are arranged are arranged to form two rows. The illuminant block 4 is disposed in the sub-scanning direction, and the illuminant block 4 is provided with a plurality of illuminant arrays in the main scanning direction and the sub-scanning direction, and the illuminant block 4 is sub-scanned. The directions are arranged in a staggered manner from the head position before the main scanning direction. In the example of the figure, the illuminant block 4 is arranged in three rows in the sub-scanning direction. The illuminant array 1 is formed on the back surface of the glass substrate 20, and is driven by a driving circuit formed on the back surface of the same glass substrate 20. Further, the organic EL element (light-emitting element 2) on the back surface of the glass substrate is sealed by a sealing member 27. The glass substrate 20 is fitted into the receiving hole 22 provided in the elongated case 21, and the back cover 23 is covered and fixed by the fixing metal fitting 24. A positioning pin 25 provided at both ends of the elongated case 21 is fitted in a positioning hole of the opposite image forming apparatus body, and is inserted through the insertion hole 2 provided at both ends of the elongated case 21 6, the fixing screw is screwed into the screw hole of the image forming apparatus body to be fixed', whereby the optical writing linear printing head i is fixed at a specific position. Further, the surface of the glass substrate 20 of the phase body 2 is disposed so as to be aligned with the center of each of the illuminant blocks 4 of the illuminant array 1 via the first spacer 71. The aperture 31764.doc -28- 200909229 plate 30' of the opening 31 (Fig. 20, Fig. 21) is provided, and the second spacer 72 is interposed therebetween, and the illuminant block 4 of the positive lens and the illuminant array 1 is disposed. The center of the first microlens array 61 having the positive lens L1 as a constituent element is arranged in a lined manner, and the third spacer 73 is further interposed therebetween to form the entire lens L2 and the illuminant array! The second microlens array 62 having the positive lens as a constituent element is fixed in such a manner that the centers of the respective illuminant blocks 4 are aligned. Thus, the lens array for projecting the microlens 5 of the light-emitting element rows of the respective illuminant blocks 4 is formed by a combination of the ith microlens array 61 and the second microlens array 62. According to the present invention, the aperture plate is disposed in conformity with the object side (front side) of the synthetic lens system constituting the first microlens array 6A and the positive lens L 2 constituting the second microlens array 62. 30. Further, the object side focus of the microlens 5 (positive lens L1 + positive lens L2) is set so that the first spacer 71 and the second spacer 72 are the same as or close to the surface of the positive lens L1 on the object side. 3 The thickness of the partition 7 3 . The details of the aperture plate 30 are shown in Fig. 2 and Fig. 21. 20 is a plan view of the aperture plate 30 disposed corresponding to the illuminant block 4 of the illuminant array i. FIG. 21 is a view showing the opening 31 of the aperture plate 30 with respect to one illuminant block 4. . In the aperture plate 3, the centers (optical axes) of the microlenses 5 formed by the positive lens L1 and the positive lens L2 are aligned with the center of the illuminant block 4, and openings 31 are provided in this embodiment. The shape of each of the openings 31 is configured to limit the opening diameter in the main scanning direction to a substantially elliptical shape having a shape equal to or greater than the sub-scanning direction, but may be an opening shape such as a circular shape, an elliptical shape, or a rectangular shape as described above. . In the above embodiment, the organic 132764.doc -29-200909229 EL element provided on the back surface of the glass substrate 2 is used as the light-emitting element 2, and the so-called bottom emission of light emitted on the surface side of the glass substrate 20 is utilized ( Bottom emission) The optical light to be placed in the line print head is 01'. It is also possible to use an EL element or an LED in which the light-emitting element 2 is disposed on the surface of the substrate. However, in the above description, the illuminant array 1 is configured such that the light-emitting element row 3 in which the plurality of light-emitting elements 2 are arranged in the main scanning direction is arranged in the sub-scanning direction in the sub-scanning direction or in the plurality of rows, as shown in FIG. 7 and FIG. Luminescent block

r\ 2. G

* ’ 锨逯 锨逯 mirror 5 corresponds to the illuminant block 4. However, the light-emitting elements 2 are arranged in a continuous long line shape at a fine interval in the main scanning direction, and are controlled so as to emit only the light-emitting element group corresponding to the illuminant block 4 therein, thereby controlling the light-emitting element group. The light-emitting elements that do not emit light can be configured to form the same illuminant block as in the case of Figs. 7 and 18, and Fig. 22 shows a view corresponding to the case 18 of this case. In other words, as the illuminant array 1, the light-emitting elements 2 are arranged in a row of long-line light-emitting elements 3 which are continuous at a fine interval in the main scanning direction, and only the light-emitting elements passing through the formation of the microlens $ are formed. The group 2, the group of (denoted by 〇) is controlled by the group, and the group of the light-emitting elements (not shown) existing between the light-emitting elements 2 is not illuminated, and the illuminant block-based microlenses 5 are formed in the main Scanning direction of the matching mouth 2 (4) Xi Shi. 3仃 is arranged, and 2 rows of light-emitting elements Φ^λ are formed in a manner corresponding to each of the microlenses 5, and Ding 3 is in the direction of the field of the field, and the spleen is placed in the optical element row 3, and the light-emitting element 2 is Set to become the staggered West 2:: 各个 各个 各个 各个 各个 各个 各个 各个 各个 各个 各个 各个 各个 各个 各个 各个 各个 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 "8 illuminating elements between pieces 2 - no illuminating mode control 132764.doc • 30 · 200909229 In addition, in the above description, the full illuminant block is formed in order to depict a straight line extending in the main scanning direction In all of the light-emitting elements 2 and 2 of 4, in the case of the order lighting, the imaging spots 8 juxtaposed on the image carrier 41 are arranged in such a manner that they are adjacent to each other without much more between the illuminant blocks 4. However, in the light-emitting elements 2, 2 constituting the illuminant block 4, the illuminating 7G pieces 2, 2' constituting the illuminant block 4 are formed in such a manner that the imaging punctual point 8 is superimposed on the image carrier. The number and position are set to be redundant. By

For example, even if the imaging spots 8 belonging to the image of the light-emitting element 2 in the vicinity of the end portion of the illuminant block 4 are uneven in density, they can be corrected by overlapping them. FIG. 23 is an example in which, in the case of the illuminant array [in the case of the configuration of FIG. 22, the light-emitting elements 2 constituting each of the illuminant blocks 4 are added to each other (the light-emitting elements 2a). Further, an example in which the lines of the imaging light spots 8 juxtaposed on the image carrier 41 are exposed by the adjacent microlenses 5 at the end portions by only 41 imaging spots 8 are exposed. 23 is a diagram showing the end portion of the light-emitting element 2a on the opposite side of the illuminant block 4 adjacent to the illuminator array 1 side (the light-emitting element between the broken lines), but the figure is correct in the microlens. The imaging magnification of 5 is -1 times. However, the microlens arrays 61, 62 used in the optical writing linear print heads of the present invention may be used in any of the known components, but Fig. 24 is a view showing the first microlenses. The array 61 and the second microlens array 62 are cross-sectional views obtained in the main scanning direction in the case where the microlenses L1 and L2 are aligned in a coaxial manner to form an array of the microlenses 5 (Fig. 6 and Fig. 17). In this example, it is arranged neatly on the one surface (object side) of the 132764.doc 31 · 200909229 glass substrate 34 of each of the microlens arrays 61 and 62, and is formed by the transparent resin 1 and the t lens surface 35. Each of the microlenses 11 and L2. In this case, by using the surface on the image side of the second microlens array 62 as a flat surface, even if it is used as a microlens array of a linear print head of an image forming apparatus, even if it is apparent, the toner is scattered. The plane attached to the microlens array can also be easily cleaned to improve cleanliness. Next, the specific number (4) of the optical system used in the above embodiment is shown as Examples 1 to 4. 25(a) and (b) are cross-sectional views in the main scanning direction and the sub-scanning direction of the optical system corresponding to the microlenses $ of the embodiment, and the glass substrate is not disposed on the emission side of the light-emitting element 2. The microlens 5 is a synthetic lens system formed by two convex positive lenses L1 and two convex positive lenses L2, and the aperture plate is disposed in a synthetic lens system formed by two convex positive lenses L1 and two convex positive lenses L2. The object side (front side) focus becomes the telecentric side with respect to the image side, and the microlens 5 of the lens surface (convex surface) of the object side of the convex positive lens L1 on the object side coincides with the object side focus. . The numerical data of this embodiment is shown below, but from the side of the illuminant block 4 toward the side of the photoreceptor (image surface) 41, Γι, η. · · is the radius of curvature (mm) of each optical surface, Dl, d2··· is the interval between the optical surfaces (mm), Μ, ndr·. is the refractive index of the d line of each transparent medium, ^, μ is the Abbe number of each transparent medium (Abbe Number ). In addition, ', Ο ^ ^ is the surface of the optical surface, the optical surface Γ 系 is the illuminant block (object surface 光, photon surface I &quot; 2 is the aperture plate 3 〇 opening 3 丨, r3, q is two convex The object side surface, the image side surface, the optical surface 〇, and the Q system of the positive lens L1 are both convex and transparent. 132764.doc -32- 200909229 The object side surface, the image side surface, and the optical surface of the mirror L are Photoreceptor (like the surface of the river. On the other hand, the two convex positive lens objects are aspherical, but the aspherical shape is set to the distance from the optical axis, with cr/[l + y~ { 1-(1+K)c2r2}]+Ar4 is expressed. Only c is the curvature on the optical axis (1/r), the κ system is the K〇nig coefficient, and the A system is the aspheric surface of 4 times. Coefficient. In the numerical data below, ruler 3,

As is a two convex positive lens! The respective König coefficient of the surface of the object side is 4 aspheric coefficients. 26(a) and 26(b) are cross-sectional views in the main scanning direction and the sub-scanning direction of the optical system corresponding to the one microlens 5 of the second embodiment, and the glass substrate is not disposed on the emission side of the light-emitting element 2. The microlens 5 is a synthetic lens system formed by two convex positive lenses L1 and two convex positive lenses L2, and the aperture plate 3 is disposed in a synthetic lens formed by the two convex positive lenses L1 and the two convex positive lenses L2. The object side (front side) focus of the system is a telecentric with the image side, and the microlens 5 of the lens surface (convex surface) on the object side of the convex flat lens L1 coincides with the object side focus. This embodiment is relative to the first embodiment, so that the first! In the case where the positive lens is a convex flat lens while the focal length is maintained as it is, the maximum image angle is smaller than that of the first embodiment. Further, the distance from the illuminant block 4 to the diaphragm plate 30 is adjusted in such a manner that the image forming state of the image plane becomes better. By forming the first positive lens L1 as a convex flat lens, the lens forming surface as the first microlens array 61 is only a one-sided surface, which is advantageous in that it is easy to manufacture. The numerical data of this embodiment is shown below, but from the side of the illuminant block 4 132764.doc -33- 200909229 toward the photoreceptor (image surface) 41, Γι, rr. ' is the optical surface. The radius of curvature (mm), d, and d2··· are the intervals (mm), nd丨, nd2 between the optical surfaces, which are the refractions of the d-line of each transparent medium, U d, V d 1, V d 2 . _, 系, 〇··· is also set to indicate the Abbe number of the optical medium for each transparent medium. In addition

The face of the 'light # face is the illuminant block (object face) 4, &amp; the face is the opening 31 of the aperture plate 30, the 〇, 〇 is the surface of the object of the two convex flat lens ^, image The side surface and the optical surface are two convex positive lenses [the object side surface, the image side surface, and the optical surface Γ are photoreceptors (image surface) 41). In addition, although the object-side surface of the two convex flat lens L1 is aspherical, the aspherical shape is crVfl + ^f {1-(1+K)c2r2} when the distance from the optical axis is set to r. ]+Ar4

To represent. The c-system is the curvature on the optical axis (1/r), the κ system is the König coefficient, and the A system is the aspheric coefficient of 4 times. In the numerical data described below, &amp;~ is the König coefficient of the surface of the object side of the two convex flat lens L1, which is the aspheric coefficient of 4 times. 27(a) and 27(b) are cross-sectional views in the main scanning direction and the sub-scanning direction of the optical system corresponding to the microlenses 5 of the third embodiment, and the glass substrate is not disposed on the emission side of the light-emitting element 2. The microlens 5 is a synthetic lens system formed by two convex flat lenses L1 and two convex positive lenses L2, and the aperture plate 3 is disposed on a synthetic lens formed by two convex flat lenses and two convex positive lenses. The object side (the side of the object) has a telecentricity with respect to the image side, and the convex surface of the object side of the flat lens L1 is an example of the microlens 5 that penetrates into the opening 3 of the aperture plate 3 . Also I7 comes to the apex of the incident surface (convex surface) of the convex flat lens L1 to I32764.doc • 34·

The refractive index, V d 1 , V d 2, ..., 'IV •• is also set to indicate that the surface of the object side of the optically convex positive lens L 1 is an aspherical ball when the distance from the optical axis is r. By placing the 200909229 on the object side of the surface of the aperture plate 30, the distance between the rear main surface of the convex flat lens L1 and the front main surface of the two convex positive lenses L2 can be made more visible. In addition, in this case, the arrangement position of the aperture plate 30 is the front side focus 4 of the synthetic lens system formed by the convex positive lens L1 and the two convex positive lenses L2. The side focus is submerged into the convex flat lens L1. In the case where the image is condensed in the convex flat lens from the incident "parallel light" and then becomes divergent light diverging from the condensing point, the emission angle is weakened on the incident surface (convex surface) of the convex flat lens 而The object side exits. The image viewed from the object side of the condensed light (diverging light) is a virtual image, but the surface where the virtual image exists is the front side focal plane of the entire lens system. Therefore, by the aperture plate 3 The il side focal plane is arranged to be telecentric with the image side. The numerical data of the yoke example is shown below, but from the side of the illuminant block 4 toward the photoreceptor (image surface) 41 side, Ri, r2... is the radius of curvature (mm), dl, d2··· of each optical surface, is the interval between each optical surface (mm), η〇ι, ndr·· is the transparent medium? The line is the Abbe number of each transparent medium. In addition, the 'optical surface' is an illuminant block ( The object surface) 4, the optical surface 2 is the opening of the aperture plate 30 σ 31, r3, r4 is the surface of the two convex flat lens object side, the image side S, the optical surface Γ 5, the Γ 6 system is the two convex positive correction The surface on the object side, the surface on the image side, and the optical surface (10) are photoreceptors (image surface) 41. In addition, the surface is only a spherical shape cr2/[l + , f {l-(l+K)c2r2}]+Ar4 To show that c is the curvature on the optical axis (丨/r)

The K system is the König coefficient, and A 132764.doc -35- 200909229 is the aspheric coefficient of 4 times. In the numerical data described below, κ3 and a3 are the König coefficients of the surface on the object side of the flat lens U, and are aspherical coefficients of 4 times. I7 makes it possible to form the aperture 30 on the surface of the convex surface of the incident surface of the first positive lens U in the case where it is difficult to form the aperture stop inside the lens L. That is, as shown in Fig. 28, the lens array of the microlens formed by the combination of the first microlens array 61 and the second microlens array 62

In the column (FIG. 16, FIG. 17, FIG. 24), for example, the edge portion (valley portion) between the convex surfaces of the incident surface of the first positive lens L1 on the object side of the first microlens array 61 is, for example, selective. By applying a light-shielding film to the ground, the diaphragm 30 can be integrally formed in the first microlens array 61. Further, in this embodiment, it is preferable that the distance between the rear main surface of the i-th positive lens and the front main surface of the second positive lens L2 is as close as possible and the image angle can be made smaller. 29(a) and 29(b) are cross-sectional views in the main scanning direction and the sub-scanning direction of the optical system corresponding to the one microlens 5 of the fourth embodiment, and the glass substrate is not disposed on the emission side of the light-emitting element 2. The microlens 5 is a synthetic lens system formed by a convex flat lens L1 and a convex flat lens L2, and the aperture plate 3 is disposed on the object side of the synthetic lens system formed by the convex flat lens L1 and the convex flat lens L2. The (front side) focus is on the image side, and the convex surface on the object side of the convex flat lens L1 is an example of the microlens 5 located away from the object side of the aperture plate 3A. In the present embodiment (the same applies to the third embodiment), in the present invention, the object side of the synthetic lens system formed by the positive lens L1 and the second positive lens L2 is not only the object of the first positive lens L1. The top of the side and the side of the object* 132764.doc •36- 200909229 point-to-point, even if the amount of light in the material '(4) is reduced, the C遮蔽s4 law of the lens becomes larger and the shadowing phenomenon becomes extremely small. However, it is difficult to cause density unevenness of the imaging spot 8 of the light-emitting element row in which the illuminant array m is arranged in a line shape. Further, as shown in the embodiment, by setting the surface on the image side of the second positive lens opening as a flat surface, the entire image side surface of the second microlens array 62 constituting the lens array of the microlens 5 can be set as the entire surface. When a flat surface, for example, a microlens array which is a linear print head of an image forming apparatus is used, even if the toner of the developer scatters and adheres to the plane of the microlens array, it can be easily cleaned to improve the cleanability. The numerical data of this embodiment is shown below, but from the side of the illuminant block 4 toward the side of the photoreceptor (image surface) 41, 'r!, 〇.. is the radius of curvature of each optical surface (mm) , d〗, d2··· is the interval between the optical surfaces (mm), ndi, nd2··′ is the refractive index of the d-line of each transparent medium, μ, μ is the Abbe number of each transparent medium. . Further, r, Ο, ... are also referred to as an optical surface, and the optical surface is an illuminant block (object surface) 4 and an optical surface. It is the opening 31 of the aperture plate 30, ο, “the surface on the object side of the convex flat lens ^, the surface on the image side, the optical surface Ο, and the h is the surface on the object side of the two convex positive lenses L. The surface and the optical surface are the photoreceptor (image surface) 41. In addition, the object sides of the convex flat lens L1 and the convex flat lens L2 are aspherical surfaces, but the aspherical shape is set to r when the distance from the optical axis is set to r. , is expressed by cr2/[l + , T{l-(l+K)c2r2}]+Ar4, but c is the curvature on the optical axis (1 / r), κ is the König coefficient, a system It is the aspheric coefficient of 4 times. In the following numerical data, Κ3 and 八3 are 132764.doc •37· 200909229 The König coefficient of the object side surface of the two convex flat lens L1 is 4 times. The spherical coefficient, K5, and As are the respective König coefficients of the surface on the object side of the convex flat lens [2], which are the aspherical coefficients of 4 times. Example 1 Γι=〇〇 (object surface) 1 = 6.6460 r2 = 〇 〇 (aperture) d2 = 0.0000 r3 = 3.4613 (aspherical) d3 = l .0000 nd) = 1.5168 vd, = 64.2 K3 = 0.0 A3 = -〇.〇i95 r4=-3.4613 d4=2.4564 r5=3.3896 d5=l .〇〇〇〇nd2=1.5168 vd 2 = 64.2 r6=-3.3896 d6=1.5000 r7=〇o (image surface) Wavelength 632.5nm First lens focal length 3.53 3 3mm Second lens focal length 3.4639mm Imaging spot group width (full width) 〇.4mm The first lens rear main surface to the second lens front main surface distance 3.1 5 1 2 mm The maximum image angle 3.608. Example 2 〇η=〇〇 (object surface) ¢1, =6.9201 r2=〇〇 (aperture) d2= 0.0000 ι·3 = 1·8200 (aspherical) d3=1.0000 ndl = 1.5168 vdl = 64.2 K3 = 〇.〇' A3 = -〇.03493 • Γ4=0° d4=2.4564 r5 = 3.3896 d5=l .〇〇 〇〇nd2=1.5168

Vd2 = 64·2 r6=-3.3896 d6=1.5000 r7 = 〇〇 (image surface) Use wavelength 632.5nm First lens focus distance 3.5333mm Second lens focus distance 3.463 9mm 132764.doc -38· 200909229 Imaging spot group Width (full width) 〇 jmm The first lens rear main surface ~ the second lens front main surface distance 3.4639mm The maximum image angle 3.308. Example 3 Γι=00 (object surface) ¢^ = 7.0578 r2=〇o (aperture) d2=-0.1300 r3=l.8200 (aspherical surface) d3= 1.0000 ndl = 1.5168 vdl = 64.2 K3 = 0.0 A3=-〇 .〇42〇Γ4=0° d4=2.5499 r5 = 3.3896 d5=1.0000 nd2=1.5168 vd2=64.2 r6=-3.3896 d6=1.5000 r7=〇〇 (image surface) Use wavelength 632.5nm First lens focal length 3.5333mm 2 lens focal length 3.4639mm imaging spot group width (full width) 〇.4mm 1st lens rear side main surface ~ 2nd lens front side main surface distance 3.5740mm maximum image angle 3.201. Example 4

J n=〇〇 (object surface) &lt;^ = 5.1280 Γ2=°° (aperture) d2=0.1871 r3 two 1.3472 (aspherical) d3 = l.〇〇〇〇ndi = 1.5168 vdl=64.2 K3-O.OOOO Α3=-〇· 04946 r4=〇〇d4=1.9000 r5 = 1.4225 (aspherical) d5 = 0.8500 nd2=l -5 168 vd2=64.2 K3=0.0000 A3=&quot;〇-1123 132764.doc -39- 200909229 r6 -〇〇d6=0.7500 r7=〇o (image surface) Wavelength 632.5nm First lens focal length 2.6154mm Second lens focal length 2.7616mm Imaging spot group width (full width) 0.4mm ^Lens rear main surface ~ The distance from the front side of the second lens is 2 56 〇〇 _ the maximum image angle is 4.46. However, in the optical system of the above-described optical writing human linear print head according to the present invention, in order to prevent light from the illuminant block 4 incident to the specific microlens 5 of the microlens array from entering the adjacent micro It is preferable to arrange a μ or a number of scintillation aperture plates between the illuminant array 1 and the aperture (four) in the optical path of the lens 5. This is shown in Figure 30! For example, the cross-sectional view taken by the main sweeping direction. In this case, six flashing aperture plates 32 are arranged in parallel with each other, and each of the flash aperture plates is provided with an opening 33 corresponding to the opening 31 of the aperture plate 30. The aperture of the aperture in the present invention refers to the opening σ31 of the aperture plate 3, and does not refer to the opening σ 33 of the flash 32. Although the linear print head of the present invention and the image using the same are formed: the present invention has been described based on the principle and the embodiment, but the present invention is not limited thereto: the specific embodiment can be variously modified. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 3 is a perspective view of a portion corresponding to one microlens of a linear printing head according to an embodiment of the present invention. The figure is a perspective view of a portion corresponding to a micro-transparent 132764.doc •40-200909229 mirror of the linear print head of the embodiment of the present invention. Fig. 3 is a perspective view showing a portion corresponding to one micro lens of the linear printing head of the embodiment of the present invention. Fig. 4 is an explanatory view showing the correspondence relationship between the illuminant array of the embodiment of the present invention and the microlens array having a negative optical magnification. Fig. 5 is an explanatory diagram showing an example of a memory form in which a linear buffer of image data is stored.

Fig. 6 is an explanatory view showing a state in which an imaging spot formed by an odd number and an even number is formed in the main scanning direction. Fig. 7 is a schematic view showing the outline of an illuminant made of a linear printing head. Fig. 8 is a view showing an imaging position in the case where the output light of each of the light-emitting elements is irradiated through the microlens to the exposure surface of the image carrier in Fig. 7; Fig. 9 is a representation name; dark + Fig. 8 An illustration of the imaging spot shape of the middle descriptive direction. Human-Heart Center Fig. 10 is an explanatory diagram showing an example in which the main image of the image carrier is inverted by the imaging spot in the case of a μ μ s t 1 complex microlens. Fig. 11 is a schematic cross-sectional view of the overall composition of the image of the old palladium used in the image of the electrophotographic process using the table + + &amp; 1 Figure 12 (4) (b) is a diagram for explaining the basic principle of the present invention. Figure 3 is a diagram showing the definition of the symbols of each parameter. Fig. 4 is a view showing a lens system formed by the first positive lens and the second positive lens, and the lens system formed by the end of the image side, and the image angle of the pupil light-emitting element. 132764.doc 41 200909229 Fig. 15 is a view showing a configuration of a case where an optical system is constituted by a thin-walled lens system of the present invention. Fig. 16 is a perspective view showing a part of the configuration of the optical writing linear print head showing the first embodiment of the present invention. Figure 17 is a cross-sectional view taken along the sub-scanning direction of Figure 16 . Fig. 18 is a plan view showing the arrangement of the illuminant array and the microlens array in the case of Fig. 16. Fig. 19 is a view showing the correspondence relationship between the microlens of the table (4) and the corresponding illuminant block. Figure 20 is a plan view of the panel corresponding to the illuminant block of the illuminator array. The 尤®1 diagram is a diagram showing the opening of the aperture plate relative to the (four) illuminant blocks. Fig. 22 is a view corresponding to Fig. 18 in which the light-emitting elements are arranged in a row in the main scanning direction, and the light-emitting blocks are formed by controlling the light-emitting elements therein. Fig. 23 is a view showing an example in which the number of light-emitting elements constituting the illuminant block is increased so that the image forming wires of the illuminant blocks adjacent to each other on the image carrier are overlapped at the ends and exposed. Further, Fig. T is a cross-sectional view taken along the main scanning direction in the case where the microlens array is constituted by two microlens arrays. ^ () is a cross-sectional view of the main scanning direction and the sub-scanning direction which are corresponding to the one microlens of the first embodiment. The first dry graph (a) and (b) are the optical system 132764.doc -42· 200909229 corresponding to the microlens of the second embodiment. The main scanning insert m 01 (inspection of the scan direction). (a) and (b) are cross-sectional views of the optical direction of the optical system corresponding to the microlens of the main lens of the system, and the microlens of the third embodiment. A cross-sectional view taken in the main scanning direction of an example in which an aperture is integrally formed on the surface of the ith microlens array constituting the lens array of the microlens. Figs. (a) and (b) are the same as those of the fourth embodiment. 1 microlens corresponding to the optical system

A cross-sectional view of the main scanning direction and the sub-scanning direction. Figure 30 is a cross-sectional view taken along the main scanning direction of an example in which an optical aperture plate is disposed separately from the aperture plate in the optical system of the optical writing linear print head of the present invention. [Description of main component symbols] 1 illuminant array 2 illuminating element 2x end illuminating element or end illuminating element 2, illuminating element 2&quot; illuminating element 2a without illuminating image light superimposed on image carrier Light-emitting element 3 light-emitting element row 3' long-line light-emitting element row 4 in the main scanning direction illuminant block 5 microlens 132764.doc -43- 200909229 6 8 , 8a , 8b 8x 8x' 8x 10 Γ, 11 12 20 21 22 23 24 25 o 26 27 • 30 . 31 32 33 34 35 Microlens array imaging spot light-emitting end of the light-emitting element Imaging spot when the photoreceptor is offset at the end of the light-emitting element Position of the imaging spot of the end light-emitting element when the surface is offset. Memory form aperture aperture main light glass substrate long strip body hole back cover fixed fitting locating pin insertion hole sealing member aperture plate (aperture) aperture plate opening Flash aperture plate flash aperture plate opening glass substrate lens face 132764.doc -44- 200909229 41 photoreceptor (image carrier) or reading surface 41' photoreceptor Image carrier offset position 41 (K, C, Μ, Y) Photoreceptor drum (image carrier) 42 (Κ, C, Μ, Υ) Charging mechanism (corona charger) 44 (Κ, C, Μ, Υ) Developing device 45 (Κ, C, Μ, Υ) Primary transfer roller 50 Intermediate transfer belt 51 Driving roller 52 Passive roller 53 Pressure roller 55 Light-emitting element arrangement surface 55' Offset position of light-emitting element arrangement surface 61 First Microlens array 62 second microlens array 66 secondary transfer roller 71 first spacer 72 second spacer 73 third spacer 101, 101Κ, 101C, linear print head (optical write line print and 101 inch, 101 Υ F Microlens front side focus L1 1st (positive) lens L2 2nd (positive) lens 0-0' Lens optical axis 132764.doc -45-

Claims (1)

200909229 X. Patent application scope: 1. A linear printing head characterized by: a positive lens system 'two lenses having positive refractive power; a lens array' having a plurality of positive lens systems arranged in a first direction; a light body array in which a plurality of light-emitting elements are disposed on an object side of a lens array as described above with respect to a positive lens system; and an aperture plate that forms an aperture stop at a position of an object-side focus of the positive lens system, and The object side surface of the lens on the object side of the positive lens system is located close to the focus of the object side. 2. The linear print head of claim 1, wherein the object side surface of the lens on the object side of the positive lens system is ±10% of the combined focus distance of the positive lens system with respect to the object side focus. Within the scope. 3. A linear print head of item 1 or 2, wherein the lens is formed by a lens group. 4. The linear print head of the item 3, wherein the image side of the lens on the object side is formed by a flat surface. The linear print head according to any one of claims 1 to 4, wherein the surface of the object side of the lens on the object side of the positive lens system is formed by a convex surface and includes the convex surface The top portion is disposed deep inside the opening of the aperture plate. 6. The linear print head of claim 5, wherein the shutter member is integrally formed on the object side 132764.doc 200909229 of the lens array to constitute the aperture plate. The linear print head according to any one of claims 1 to 6, wherein at least the image side surface of the image side lens of the positive lens system is formed by a flat surface. The linear print head according to any one of claims 1 to 7, wherein the aperture of the aperture is shaped to limit at least the opening diameter of the second direction. The linear print head according to any one of claims 1 to 8, wherein the plurality of light-emitting elements are formed in a plurality of light-emitting element rows arranged in a second direction orthogonal to the second direction. 10. The linear print head according to any one of claims 1 to 9, wherein the plurality of light-emitting elements are disposed so as to be interposed between the light-emitting groups in the i-th direction. 11. The linear print head of any one of claims 1 to 10, wherein the light emitting element is formed of an organic EL element. 12. The linear print head of any one of clauses to (7) wherein the light-emitting element is formed by an LED. 13 An image forming apparatus </ RTI> characterized in that at least two or more are disposed around the image carrier, such as the ones of the claims 1 to 12, and the green color of the shell. And the developing medium performs image formation in a tandem manner by each station to form a linear printing head, and has the following features: a positive lens system having two lenses of positive refractive power; and each image forming unit of the transfer mechanism Image forming station, and .·- Transfer by transfer 14. 132764.doc 200909229 Lens array, re-recognition @ , ^ Configure the complex front positive lens system in the direction of the 1st; Receiver array, 1 too &amp; And (in the image side of the lens array, a plurality of light receiving elements are disposed for each of the positive lens systems; and an aperture plate that forms an aperture stop at a position of an image side focus of the positive lens system; and an image of the positive lens system The image side of the side lens is located close to the image side focus. 〇 132,764.doc