JP2006082451A - Position adjusting method of line head and position adjuster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for adjusting the position of a line head with reference to a lens array, and to provide a position adjuster. <P>SOLUTION: The fiber (rod lens) 68 of a rod lens array 65 is illuminated by the light emitting section 63 of a glass substrate 62 or an external light source, and the rod lens array 65 and its image are photographed from the imaging surface 91a side by means of a CCD camera 90. Photographed images are displayed on a display, and the position of an alignment member formed on the glass substrate is adjusted to the reference position of the rod lens array by second position adjusting means, i.e. adjusting pins 81 and 82. Since the position of the glass substrate 62 is adjusted previously by a first position adjusting means (X, Y drive handler 96 on Fig. 4), accuracy of positional adjustment is enhanced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a line head position adjusting method and a position adjusting apparatus for detecting a positional deviation of a light emitting element with respect to an optical system and adjusting the position in a line head using a light emitting element such as an organic EL element. .

  In a tandem or rotary image forming apparatus, a method of providing a scanning optical system as an exposure device and a method of using a light emitting element array are known. In the method using the light emitting element array, it is necessary to align the light emitting element and the lens. For example, Patent Document 1 describes an example in which a mark for indicating the center position of a lens is provided on a lens holder for positioning an image array having a plurality of light emitters and a monocular lens. Japanese Patent Application Laid-Open No. H10-228688 describes that the total light amount distribution is measured while causing all the light emitting elements to emit light, and the lens array position is adjusted.

JP-A-7-186444 Japanese Patent Laid-Open No. 10-16291

  In the case of using such an optical system, the imaging optical system of the line head is generally an equal-magnification optical system using a rod lens array having two rows of rod lenses as shown in the explanatory diagram of FIG. Used. In FIG. 16, 84 and 84 are rod lenses arranged in two rows. In this rod lens array, the center line of the rod lens array parallel to the main scanning direction needs to coincide with the position of the light emitting element in the sub scanning direction, but this position may be shifted.

  In FIG. L is the center line of the rod lens array, and A is the position of the light emitting element. An example in which the position of the light emitting element is shifted from the center line C.I. An example of deviation from L by 0.2 mm is shown. As described above, when the position of the light emitting element is deviated from the center line of the rod lens array, the light amount varies. FIG. 17A is a characteristic diagram showing light amount variation in the main scanning direction, and FIG. 17B is a characteristic diagram showing light amount distribution data in the sub-scanning direction. As shown in FIG. 17B, when the position of the light emitting element is shifted in the sub-scanning direction, the variation in the light amount occurs symmetrically with respect to the shift amount.

  In FIG. 16, the diameter of the rod lens is 0.56 mm. In this case, the variation in the amount of light in the main scanning direction in FIG. 17A is that if the deviation between the position of the light emitting element and the center line of the rod lens array is 0, the unevenness of the amount of light as in the characteristic Da is the diameter of the rod lens. It is 0.28 of 1/2. When the amount of deviation between the two is 0.1 mm, the period of unevenness in the amount of light is the sum of 0.28 mm, which is 1/2 the diameter of the rod lens, and 0.56 mm, which is the diameter, as in the characteristic Db. In this case, the light amount unevenness cycle is twice as long as the deviation amount is zero. When the amount of deviation between the two is 0.2 mm, the period of unevenness in the amount of light is 0.56 mm in diameter of the rod lens as in the characteristic Dc.

  As described above, when the position of the light emitting element deviates from the center line of the rod lens array, the following problem occurs. (1) The period of unevenness in the amount of light passing through the rod lens is doubled, making it easy to recognize the unevenness in the amount of light and making the deterioration of the image quality clear. (2) Unevenness in the amount of light passing through the rod lens increases. (3) The amount of light passing through the rod lens decreases. (4) The imaging performance deteriorates, and the spot diameter increases or varies.

  In a line head using LEDs as described in Patent Document 1 as a conventional light emitting element, an image array is mounted on a substrate to constitute a line head. For this reason, the pixel column of the light emitting unit does not become a straight line due to a mounting error, and it is difficult to align the center line of the lens array for all the light emitting pixels. Further, the unevenness in the amount of light of the light emitting unit itself is larger than the unevenness in the amount of transmitted light of the lens array, and in order to correct this, as described in Patent Document 2, one light emitting element is used based on the amount of light after passing through the head. It was necessary to perform light amount correction control on the individual and correct both the light amount unevenness of the light emitting unit itself and the transmitted light amount unevenness of the lens array. There is also a problem that the spot diameter cannot be corrected.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to detect the positional deviation of the light emitting section with reference to the lens array and adjust the position to the normal position. It is to provide a method and a position adjusting device.

  In order to achieve the above object, a method for adjusting the position of a line head according to the first embodiment of the present invention includes a step of fixing a lens array to a fixing means, a light emitting section in which a plurality of light emitting elements are arranged, and an alignment member. Aligning the position of the alignment member of the formed transparent single substrate to the reference position of the lens array by a first position adjusting means, and illuminating the lens array from the transparent substrate side A step of photographing an image formed by the lens array, a step of displaying the photographed image on a display means, and a second position adjustment based on the image of the lens array displayed on the display means Adjusting the position of the alignment member formed on the transparent substrate by means. As described above, the position of the transparent substrate with respect to the lens array is adjusted by the first position adjusting unit, and then the position of the transparent substrate is adjusted by the second position adjusting unit. For this reason, the position of the transparent substrate, that is, the position of the light emitting unit can be adjusted with high accuracy.

  The line head position adjusting method according to the second embodiment of the present invention includes a step of fixing a lens array to a fixing unit, a step of illuminating the lens array from the transparent substrate side, and a step of photographing the lens array. A step of displaying a photographed image of the lens array on a display means, a step of setting a reference position from the displayed image of the lens array, and a light emitting portion and a positioning member in which a plurality of light emitting elements are arranged. A step of illuminating the formed transparent substrate; a step of photographing the transparent substrate; a step of displaying an image of the photographed transparent substrate on the display means; and a step of displaying the lens array from the displayed image of the transparent substrate. A step of setting a comparison position to be compared with a reference position and an image of the display means are observed, and the comparison position of the transparent substrate is overlapped with the reference position of the lens array. A step of adjusting the position of the transparent substrate by a first position adjusting unit; a step of photographing an image formed by the lens array; a step of displaying the photographed image on a display unit; And adjusting the position of the alignment member formed on the transparent substrate by the second position adjusting means with the displayed image of the lens array as a reference. As described above, in the line head position adjusting method according to the second embodiment of the present invention, the lens array and the transparent substrate are separately photographed separately, and the photographed image is displayed on the display means. A position and a contrast position are set. Therefore, the position adjustment of the light emitting unit with respect to the lens array by the first position adjustment unit can be performed with high accuracy.

  The line head position adjusting method of the present invention is characterized in that the image forming position by the lens array is adjusted by changing the image plane focal depth by the first position adjusting means. As described above, since the image is taken by changing the focal depth of the imaging plane of the photographing unit and displayed on the display unit, the positional deviation of the light emitting unit can be observed with high accuracy.

  The line head position adjustment method of the present invention is characterized in that an image of the lens array is photographed by transmitted light from the transparent substrate. Thus, since the transmitted light from the transparent substrate is used, the position of the transparent substrate can be adjusted with high accuracy when an external light source is used.

  The line head position adjusting method of the present invention is characterized in that an image of the lens array is photographed by the output light of the light emitting element from the transparent substrate. As described above, since the output light of the light emitting element is used, an external light source is unnecessary and the cost can be reduced.

  In the line head position adjusting method of the present invention, the second position adjusting means adjusts the position of the transparent substrate in the sub-scanning direction. For this reason, the image quality can be improved by preventing the positional deviation of the light emitting portion in the sub-scanning direction.

  The line head position adjusting method of the present invention is characterized in that the alignment member is an alignment mark formed directly on the transparent substrate. Thus, since the alignment mark is directly formed on the transparent substrate together with the light emitting portion, no positional deviation occurs. Therefore, the position of the transparent substrate can be accurately adjusted with respect to the lens array.

  The line head position adjusting method of the present invention is characterized in that the lens array is provided in a plurality of rows in the sub-scanning direction. For this reason, in a line head having a configuration in which a plurality of lens arrays are provided in the sub-scanning direction, it is possible to prevent image quality unevenness.

  In the line head position adjustment method of the present invention, the position adjustment reference with respect to the transparent substrate may be the center of the fiber diameter of the lens in the lens array image displayed on the display means, or the center line thereof. Features. As described above, the position adjustment reference is set to the center of the fiber diameter of the lens or its center line, so that the transparent substrate can be easily aligned.

  The line head position adjusting method of the present invention is characterized in that the lens array is a rod lens array. Since the rod lens has a short focal length and is advantageous for condensing, it is suitable as an optical system component of the image forming apparatus. For this reason, in a practical line head using a rod lens array, it is possible to prevent displacement of the light emitting portion.

  The line head position adjusting method of the present invention is characterized in that the light emitting element is an organic EL element. Thus, since the organic EL element which can manufacture linearity favorably on a process is used as the light emitting element, the position of the light emitting part can be accurately positioned with respect to the lens array.

  In the line head position adjusting device according to the present invention, a light emitting section in which a plurality of light emitting elements are arranged on a single transparent substrate and an alignment member are formed, and a lens array holding means on which output light from the light emitting section is incident The line head is provided with a photographing means for the line head, a display means for an image photographed by the photographing means, and the transparent substrate is moved in the main scanning direction and the sub-scanning direction to the reference position of the lens array. A first position adjusting means for adjusting the position; and an illuminating means for illuminating the lens array from the light emitting part side of the transparent substrate, the lens array being illuminated by the illuminating means, and the lens array and the transparent substrate The image of the transmitted light or the output light is photographed from the imaging surface side by the photographing means, the photographed image is displayed on the display means, and the second position adjusting means Wherein adjusting the position of the transparent substrate to form the alignment member to the reference position of the serial lens array, and adjusts the position relative to the lens array of the transparent substrate. Thus, in the embodiment of the present invention, since the first position adjusting means and the second position adjusting means are provided, a position adjustment device for a line head capable of adjusting the position of the light emitting section with high accuracy is provided. be able to.

  In the line head position adjusting device according to the present invention, the first position adjusting unit adjusts the image forming position by the lens array by changing the focal depth of the image forming surface. As described above, since the focal depth of the image plane is changed, a line head position adjusting device capable of adjusting the position of the light emitting section with high accuracy is obtained.

  In the line head position adjusting apparatus of the present invention, the alignment member is an alignment mark formed directly on the transparent substrate. Thus, since the position adjustment of the transparent substrate is performed using the alignment mark provided in the vicinity of the light emitting part, the position of the light emitting part with respect to the lens array can be adjusted without error.

  In the line head position adjusting device of the present invention, the lens array is a rod lens array. Since the rod lens has a short focal length and is advantageous for condensing, it is suitable as an optical system component of the image forming apparatus. Therefore, it is possible to configure a line head position adjusting device that improves the image quality in a practical line head using a rod lens array.

  In the line head position adjusting apparatus of the present invention, the light emitting element is an organic EL element. For this reason, in a line head using an organic EL element, it is possible to constitute a position adjustment device for a line head that prevents the light emitting portion from being displaced and improves the image quality.

  According to the position adjustment method and the position adjustment apparatus of the line head of the present invention, the first position adjustment means and the second position adjustment means are provided, and the second position adjustment is performed after the position adjustment by the first position adjustment means. Fine adjustment by means is performed. For this reason, it is possible to accurately adjust the position of the light emitting unit with reference to the lens array, and as a result, it is possible to obtain a line head on which a high-quality image is formed.

  The present invention will be described below with reference to the drawings. FIG. 11 is a vertical side view showing an example of an image forming apparatus in which a line head whose position is adjusted according to the present invention is used. In this embodiment, an intermediate transfer belt is used as the transfer belt. In FIG. 11, the image forming apparatus 1 of the present embodiment is mounted on a housing body 2, a first opening / closing member 3 that is openably / closably attached to the front surface of the housing body 2, and on an upper surface of the housing body 2. And a second opening / closing member 4 (also serving as a paper discharge tray). Further, the first opening / closing member 3 is provided with an opening / closing lid 3 ′ attached to the front surface of the housing body 2 so as to be freely opened and closed.

  In the housing body 2, an electrical component box 5 containing a power circuit board and a control circuit board, an image forming unit 6, a blower fan 7, a transfer belt unit 9, and a paper feeding unit 10 are disposed. In addition, a secondary transfer unit 11, a fixing unit 12, and a recording medium transport unit 13 are disposed in the first opening / closing member 3.

  The transfer belt unit 9 is disposed below the housing body 2 and is driven to rotate by a drive source (not shown), a driven roller 15 disposed obliquely above the drive roller 14, and the two rollers. An intermediate transfer belt 16 that is stretched between 14 and 15 and driven to circulate in the direction of the arrow shown in the figure, and a cleaning means 17 that comes into contact with and separates from the surface of the intermediate transfer belt 16.

  A primary transfer member 21 composed of a leaf spring electrode is brought into contact with the image carrier 20 of each image forming station Y, M, C, K by its elastic force, and a transfer bias is applied to the primary transfer member 21. ing. A test pattern sensor 18 is installed in the transfer belt unit 9 in the vicinity of the drive roller 14. The image forming unit 6 includes a plurality of (four in this embodiment) image forming stations Y (for yellow), M (for magenta), C (for cyan), and K (for black) that form images of different colors. Each of the image forming stations Y, M, C, and K includes an image carrier 20 including a photosensitive drum, and a charging unit 22 and an image writing unit (line head) disposed around the image carrier 20. ) 23 and developing means 24.

  The image carrier 20 is rotationally driven in the conveyance direction of the intermediate transfer belt 16 as indicated by the arrows in the figure. The charging means 22 is composed of a conductive brush roller connected to a high voltage generation source, and the outer periphery of the brush is opposite to the image bearing member 20 as a photosensitive member at a peripheral speed of 2 to 3 times. The surface of the image carrier 20 is uniformly charged by contact rotation.

  The image writing means 23 uses an organic EL element array in which organic EL elements are arranged in a line in the axial direction of the image carrier 20. The line head using the organic EL element array has an advantage that the optical path length is shorter and more compact than the laser scanning optical system, can be disposed close to the image carrier 20, and the entire apparatus can be downsized. . In the present embodiment, the image carrier 20, the charging unit 22, and the image writing unit 23 of each image forming station Y, M, C, and K are unitized as one image carrier unit 25.

  Next, details of the developing unit 24 will be described on behalf of the image forming station K. The developing unit 24 includes a toner storage container 26 that stores toner (hatched portion in the drawing), a toner storage part 27 formed in the toner storage container 26, and a toner stirring member disposed in the toner storage part 27. 29, and a partition member 30 that is partitioned and formed on the upper portion of the toner storage portion 27. Further, the toner supply roller 31 disposed above the partition member 30, the blade 32 provided on the partition member 30 and in contact with the toner supply roller 31, and the toner supply roller 31 and the image carrier 20 are in contact with each other. And a regulating blade 34 that is in contact with the developing roller 33.

  The paper feed unit 10 includes a paper feed unit including a paper feed cassette 35 in which the recording media P are stacked and held, and a pickup roller 36 that feeds the recording media P from the paper feed cassette 35 one by one. In the first opening / closing member 3, a registration roller pair 37 that regulates the feeding timing of the recording medium P to the secondary transfer portion, and a secondary transfer unit that is pressed against the drive roller 14 and the intermediate transfer belt 16. A secondary transfer unit 11, a fixing unit 12, a recording medium conveyance unit 13, a paper discharge roller pair 39, and a duplex printing conveyance path 40 are provided.

  The fixing unit 12 includes a heating roller 45 that includes a heating element such as a halogen heater and is rotatable, a pressure roller 46 that presses and biases the heating roller 45, and is swingable on the pressure roller 46. A belt tension member 47 and a heat-resistant belt 49 stretched between the pressure roller 45 and the belt tension member 47. The color image secondarily transferred to the recording medium is fixed to the recording medium at a predetermined temperature at a nip formed by the heating roller 45 and the heat-resistant belt 49.

  FIG. 12 is a schematic perspective view showing the image writing unit 23 in an enlarged manner. The image writing unit 23 places the light emitting unit 63 of the organic EL element array 61 on the glass substrate 62. The light emitting unit 63 is driven by a driving circuit 88 using TFTs formed on the same glass substrate 62. The gradient index rod lens array (SLA) 65 constitutes an imaging optical system, and has a gradient index rod lens 84 arranged in front of the light emitting unit 63. In the present invention, the glass substrate 62 may be referred to as an EL substrate or an EL substrate light emitting array.

  Reference numeral 90 denotes a CCD camera for observing a positional shift between the light emitting unit 63 and the SLA 65. Reference numeral 87b denotes an alignment mark (alignment mark) formed on the glass substrate 62 in order to observe the positional deviation. The alignment mark 87a is also formed on the other end of the glass substrate 62. Details of the operation of the alignment marks 87a and 87b and the CCD camera 90 will be described later.

FIG. 13 is a cross-sectional view showing a configuration example in the vicinity of the light emitting portion 63 of the organic EL light emitting element array 61 shown in FIG. The organic EL light emitting element array 61 includes, for example, a staggered driving circuit 88 made of TFT (thin film transistor) made of polysilicon having a thickness of 50 nm for controlling light emission of each light emitting portion 63 on a glass substrate 62 having a thickness of 0.5 mm. Corresponding to each of the two rows of light emitting portions 63 in the arrangement, it is provided outside the margin. An insulating film 72 made of SiO ₂ having a thickness of about 100 nm is formed on the glass substrate 62 except for the contact hole on the drive circuit 88. In addition, an anode 73 made of ITO having a thickness of 150 nm is formed at the position of the light emitting portion 63 so as to be connected to the drive circuit 88 through the contact hole.

Next, another insulating film 74 made of SiO ₂ having a thickness of about 120 nm is formed in a portion corresponding to a position other than the light emitting portion 63, and a hole 76 corresponding to the light emitting portion 63 is formed thereon, and the thickness is 2 μm. A partition wall 75 made of polyimide is provided. A hole injection layer 77 having a thickness of 50 nm and a light emitting layer 78 having a thickness of 50 nm are formed in order from the anode 73 side in the hole 76 of the partition wall 75, and the upper surface of the light emitting layer 78, the inner surface of the hole 76, and the partition wall. A cathode first layer 79a made of Ca having a thickness of 100 nm and a cathode second layer 79b made of Al having a thickness of 200 nm are sequentially formed so as to cover the outer surface of 75.

  Then, the light emitting portion 63 of the organic EL light emitting element array 61 is configured by being covered with a cover glass 64 having a thickness of about 1 mm via an inert gas 80 such as nitrogen gas. Light emission from the light emitting unit 63 is performed on the glass substrate 62 side. Various known materials can be used as the material used for the light emitting layer 78 and the material used for the hole injection layer 77, and detailed description thereof is omitted. Such an organic EL light emitting element can be easily manufactured on a glass substrate, and thus the manufacturing cost can be reduced.

  FIG. 14 is an explanatory diagram illustrating an example of a process for adjusting the position of the line head. In FIG. 14A, the rod lens array 65 is inserted into the opening 60a formed in the central portion of the case 60, and the tip of the rod lens array 65 is locked by the stepped portion 60x provided in the opening 60a. Then, it is fixed to the case 60. The actual work is to insert the rod lens array 65 from the upper side of the opening 60a with the case 60 reversed from the illustrated state. In (b), the light emitting portion (not shown) mounted on the glass substrate 62 is sealed with the cover glass 64, the glass substrate 62 is inserted into the case 60, and the step portion 60y formed inside the case 60 is formed. Place. At this time, the glass substrate 62 is photographed by the CCD camera 90 as described with reference to FIGS. 1 and 4, and the image of the rod lens array 65 displayed on the display device is used as a reference for the X and Y drive handlers 96 ( The glass substrate 62 is moved in the X direction (sub-scanning direction) and the Y direction (main scanning direction) using the first position adjusting means. The first-stage alignment of the glass substrate 62 with respect to the rod lens array 65 is performed by operating the first position adjusting unit.

  With the glass substrate 62 placed in the case 60, the CCD camera 90 further photographs the alignment mark and observes the captured image on the display device. The presence or absence of a positional deviation between the alignment mark formed on the glass substrate 62 and the center line of the rod lens array 65 is confirmed. Adjust with the position adjustment means. For this reason, the glass substrate 62 whose position has been adjusted by the first position adjusting means in the first stage is finely adjusted in the X direction by the second position adjusting means, so that the center line position of the light emitting unit and the rod lens array are adjusted. 65 center line C.I. A second stage alignment with L is performed.

  When the alignment in the second stage is completed, the glass substrate 62 is fixed to the case 60 with the adhesive 83 in (c). Next, the cover 66 is attached in (d), the cover 66 is pressed by the fixed plate spring 67, and the flange portion 67 a formed at the tip of the fixed plate spring 67 is locked to the stepped portion 60 z formed outside the case 60. And fix. The case 60 functions as a holding unit for the rod lens array 65.

  FIG. 15 is a cross-sectional view of the image writing unit 23 in the sub-scanning direction. The image writing means 23 includes an organic EL element array 61 attached facing the rear surface of the gradient index rod lens array 65 in the case 60, and an organic EL light emitting element array 61 in the rear surface of the case 60. And an opaque cover 66 for shielding the light. Further, the cover 66 is pressed against the back surface of the case 60 by the fixed plate spring 67, and the inside of the case 60 is sealed in a light-tight manner. That is, the glass substrate 62 is optically sealed with the case 60 by the fixed plate spring 67. A plurality of fixed leaf springs 67 are provided in the longitudinal direction of the case 60. Reference numeral 91 denotes an image surface formed on the image carrier.

  If a black paint that absorbs ultraviolet rays is applied to the inner surface of the housing (not shown) of the main body of the image forming apparatus that accommodates the case 60, the ultraviolet shielding effect on the organic EL element array 61 can be more reliably performed. Deterioration of the organic EL light emitting element can be prevented. The case 60 of the image writing means 23 is formed of an opaque member, and the back surface thereof is covered with an opaque cover 66.

  For this reason, the fluorescent lamp and the ultraviolet rays from the sun incident on the back surface of the organic EL element array 61 are prevented from reaching the light emitting part 63 of the organic EL element array 61. Reference numeral 83 denotes an adhesive for fixing the glass substrate 62 to the case 60. In FIG. 15, the position adjustment pins 81 and 82 and the knobs 86 and 87 described in FIG. 1 are not shown for simplicity.

  FIG. 5 is an explanatory diagram showing an example of a process flow for incorporating the rod lens array 65 into the case 60. Next, this process flow will be described. (A) A line head case (indicated by numeral 60 in FIG. 1) is set on a guide plate (not shown) of the position adjusting device. (B) The rod lens array 65 is set in the case groove (indicated by reference numeral 69 in FIG. 1). (C) Fixing to the case 60 while correcting the warp of the rod lens array 65. In this manner, the rod lens array 65 serving as a reference when aligning the EL substrate (glass substrate) is fixed.

  FIG. 6 is an explanatory diagram showing an example of an assembly process flow when the EL substrate (glass substrate 62) is assembled into the case 60. FIG. Next, this process flow will be described. (A) In the process as described with reference to FIG. 5, the case 60 in which the rod lens array 65 has been assembled is set on the guide plate (the reference numeral 93 in FIG. 4) of the position adjusting device. 4 is a member different from the guide plate described in the fixed flow (a) of FIG. The position of the case 60 in this case is a position reversed from the state in which the rod lens array described with reference to FIG. 5 is set. Such a reversing mechanism uses appropriate means such as material handling (material handling). (B) The output light of the light emitting unit formed on the transparent substrate or an external light source provided separately is lit from the transparent substrate side to illuminate the rod lens array 65, and a halftone image of the rod lens array 65 is formed on the image plane (see FIG. 1 of 91a) (FIGS. 7 and 8). Two points in the longitudinal direction (main scanning direction) of this image are taken from the image plane side by the CCD camera 90, and the image is recognized by the display device 100 of FIG. (C) Based on the planar image of the rod lens array 65 whose image has been recognized by the CCD camera 90, the center line position of the rod lens array 65 is calculated by a control unit (not shown).

  (D) An alignment mark (numbers 87a and 87b in FIG. 2 and FIG. 3) of the EL substrate light emitting array (glass substrate 62) or two points in the longitudinal direction of the EL substrate light emitting array are photographed by the CCD camera 90. The display device 100 recognizes an image. (E) Based on the planar image of the EL substrate light emitting array recognized by the CCD camera 90, the center line position of the EL substrate light emitting array is calculated by a control unit (not shown). 2 and 3, when the light emitting elements are arranged in two rows, the line connecting the center point positions of the two light emitting elements in the upper row and the two light emitting devices in the lower row The middle line of the lines connecting the center point positions is obtained as the center line.

  (F) The center line of the EL substrate light emitting array 62 is aligned with the center line position of the rod lens array 65 fixed to the case 60 by the X and Y drive handler (indicated by reference numeral 96 in FIG. 4). 62 is set in the case 60. In this process, the center line position of the rod lens array 65 obtained by calculation is displayed on the display device 100, and the displayed center line position of the rod lens array 65 and the center line of the EL substrate light emitting array 62 are displayed on the display device 100. On the screen (position adjustment in the first stage).

  (G) According to the method of the present embodiment, that is, by taking an image of the rod lens array by the CCD camera 90 and displaying the taken image on the display device, the X direction of the EL substrate light emitting array 62 with respect to the reference position of the rod lens array and The position is confirmed in the Y direction, and if there is a deviation, the position adjustment pins 81 and 82 in FIG. 1 are used to adjust the position in the X direction (second stage position adjustment). (H) When the second stage position adjustment is completed, the EL substrate 62 is fixed to the case 60 with the adhesive 83 (FIG. 15). In the example of FIG. 6, the lens array and the transparent substrate are individually photographed separately, the photographed image is displayed on the display means, and the respective reference position and contrast position are set. Therefore, the position of the light emitting unit can be accurately adjusted with respect to the lens array by the first position adjusting means (X, Y drive handler 96). Thereafter, the second position adjustment means (position adjustment pins 81 and 82) performs the second stage position adjustment, so that the position adjustment accuracy can be further improved.

  FIG. 1 is a sectional view in the sub-scanning direction showing a schematic configuration example of a line head whose position is adjusted in the present invention. In FIG. 1, the rod lens array 65 is provided with a fiber 68 (corresponding to the position of the rod lens 84 in FIG. 8). As described above, the rod lens array 65 slides in the groove 69 of the case 60. Move to set in place. As shown in detail in FIG. 13, the organic EL element array 61 has a light emitting portion 63 formed by laminating an insulating layer 72, an anode 73, a cathode 79, and the like on a glass substrate 62. These electrodes are not shown.

  Lx is a working distance between the light emitting portion 63 and one fiber surface 68a of the rod lens array 65, and Ly is a working distance between the other fiber surface 68b of the rod lens array 65 and the image plane position 91a. The working distance is set so that Lx = Ly. The light emitting unit 63 or an external light source (not shown) is turned on to illuminate the rod lens array 65, and the halftone that passes through the rod lens of the rod lens array 65 with the output light of the light emitting unit 63 or the transmitted light of the glass substrate 62. An image is formed at the imaging plane position 91a. The halftone image (image formed by the rod lens array 65) formed at the image plane position 91a is photographed by the CCD camera 90, and the photographed image is displayed on the display device 100 of FIG. The halftone image at this time is an image of the light emitting unit 63 and the rod lenses 84a and 84b (when two rows of rod lenses are arranged as shown in FIG. 3).

  7 and 8 are explanatory diagrams showing examples of halftone images formed at the image plane position 91a. As will be described with reference to FIG. 4, the CCD camera 90 can be moved in the Z direction, that is, in the direction of the imaging plane position 91a by an X and Y drive handler. Therefore, the focal depth of the CCD camera 90 can be changed, and the positional deviation of the light emitting unit 63 with respect to the reference position of the lens array is confirmed by changing the focal depth. When the positional deviation (Lz) of the light emitting unit 63 is small, the image of the light emitting unit 63 is formed at substantially the center of the rod lenses 84a and 84b as shown in the imaging plane focus photograph of FIG. On the other hand, when the positional deviation (Lz) of the light emitting unit 63a is large, the image of the light emitting unit 63 is shifted from the center of the rod lenses 84a and 84b to one side as shown in the imaging plane focus photograph of FIG. Formed in position.

  FIG. 9 and FIG. 10 are explanatory diagrams showing the light emission state of the lens array surface (fiber surface) 68b as a lens array surface focus photograph. FIG. 9 shows a case where the positional deviation (Lz) of the light emitting portion is small, and the centers of the two rows of rod lenses 84a and 84b emit light. On the other hand, FIG. 10 shows a case where the positional deviation (Lz) of the light emitting portion is large, and one of the two rows of rod lenses 84a and 84b emits light. As described above, in the example of FIG. 1, the glass substrate 62 side is caused to emit light, and the focal plane photograph of the CCD camera 90 arranged on the imaging plane side is displayed on the display device 100, thereby confirming the positional deviation of the light emitting unit. is doing.

  In FIG. 1, alignment marks 87a and 87b as described in FIGS. 2 and 3 are formed on the glass substrate 62. FIG. For this reason, the alignment marks 87a and 87b are photographed by the CCD camera 90 with the transmitted light from the back surface side (surface opposite to the imaging surface) of the glass substrate 62, and the photographed images are displayed on the display device 100. Thus, the positional deviation of the light emitting unit can also be confirmed.

  The center line position of the glass substrate 62 is previously aligned with the center line position of the rod lens array 65 by the first position adjusting means as described above. Alignment marks 87a and 87b are formed on the glass substrate 62 placed on the case 60 (FIGS. 2 and 3), and the alignment marks are photographed by the CCD camera 90 and displayed on the display device. . Further, the position of the fiber surface 68a of the rod lens is photographed through the glass substrate 62 and displayed on the display device.

  Based on the alignment marks 87a and 87b of the glass substrate 62 displayed on the display device and the position of the fiber surface 68a (the center of the fiber diameter or its center line) of the rod lens, the position of the rod lens array 65 and the light emitting unit The position of the center line of 63, that is, the position of the center line of the EL substrate light-emitting array (glass substrate) 62 is confirmed to be misaligned. If there is a positional deviation between the two, alignment is performed by the position adjustment pins 81 and 82 (second position adjustment means).

  As described above, the position of the glass substrate 62 in the sub-scanning direction (X direction) is finely adjusted by the pair of position adjusting pins 81 and 82 provided on the left and right of the case 60. The position adjustment pins 81 and 82 are formed with inclined portions 81a and 82a. The adjustment pins 81 and 82 are moved from the outside of the case 60 using the knobs 86 and 87 to align the center line of the EL substrate light emitting array 62 with the center line of the rod lens array. Since the inclined portions 81a and 82a are formed on the pair of adjustment pins 81 and 82, the position of the glass substrate 62 in the sub-scanning direction can be accurately adjusted. Thus, the pair of position adjustment pins 81 and 82 function as second position adjustment means of the line head. As described above, in the present invention, since the position adjusting pins 81 and 82 of the second position adjusting means are provided in addition to the X and Y driving handlers 96 which are the first position adjusting means, more accurate. The position of the glass substrate, that is, the position of the light emitting portion with respect to the rod lens array can be adjusted.

  2 and 3 are plan views showing examples of arrangement of the organic EL element array 61 and the rod lens array 65. FIG. FIG. 2 is an example in which one row of rod lenses 84 is arranged in the rod lens array 65, and FIG. 3 is an example in which two rows of rod lenses 84 a and 84 b are arranged in the rod lens array 65. The present invention can cope with a case where the rod lens array 65 is arranged in one row and a case where the rod lens array 65 is arranged in two rows. 2 and 3, the light emitting units 63 are arranged in two rows in the sub-scanning direction. Further, alignment marks 87 a and 87 b are formed on both ends of the glass substrate 62. The light emitting units 63 are not limited to the example in which two rows are arranged in the sub-scanning direction as shown in FIGS. 2 and 3, and an arbitrary number of plural rows can be arranged.

  Since the alignment marks 87a and 87b can be formed in the same process as the light emitting element by, for example, a photolithography technique, the processing process when providing the alignment member on the glass substrate is simplified, and the cost can be reduced. Since the alignment marks 87a and 87b are directly formed on the glass substrate 62 together with the light emitting portion 63, no positional deviation occurs. For this reason, the position of the glass substrate 62 can be accurately adjusted with respect to the rod lens array 65. In the example of FIGS. 2 and 3, the alignment marks 87 a and 87 b are formed on the illustrated front surface side of the glass substrate 62, but may be formed on the opposite side (rear surface) of the glass substrate 62.

  FIG. 4 is an explanatory diagram showing a schematic configuration of the position adjusting device of the present invention. In FIG. 4, reference numeral 96 denotes an X and Y drive handler, which has a horizontal beam 96a and a vertical beam 96b. A fixing plate 95c is attached to the vertical beam 96b, and the EL substrate suction jig 94 is moved in the vertical direction (Z direction) by the guide rods 95a and 95b. The CCD camera 90 reciprocates in the horizontal direction (Y direction, main scanning direction) and the vertical direction (X direction, sub-scanning direction) by the X and Y drive handler 96 to position the EL substrate relative to the rod lens array. adjust. Reference numeral 93 denotes a guide plate for the case 60, which fixes the rod lens array 65 to the case 60 by the flow described in FIG. Thus, the case 60 functions as a fixing means for the rod lens array 65.

  An EL substrate (glass substrate on which an organic EL element is formed) 62 placed on an EL substrate guide plate 92 is adsorbed by an EL substrate adsorption jig 94 of an X and Y drive handler 96. When the X and Y drive handler 96 moves in the X direction and then in the Y direction, the EL substrate moves in the P direction as seen by the arrow and reaches the position of the case 60 in which the rod lens array is incorporated. The EL substrate is fixed to the case 60, and the case 60 is turned upside down so that the image plane is the upper side. Next, the light emitting element or an external light source (not shown) is turned on to illuminate the glass substrate 62 and the rod lens array 65.

  In this state, the X and Y drive handler 96 moves the CCD camera 90 above the image plane to capture a planar image of the glass substrate 62 arranged on the rod lens array 65 and the rod lens. At this time, the CCD camera 90 recognizes the alignment mark formed on the EL substrate by the transmitted light or reflected light of the EL substrate. The image taken by the CCD camera 90 is displayed on the display device 100, and the X and Y drive handler 96 is moved so that the center line position of the EL substrate 62 overlaps the center line of the rod lens array as described above. When the alignment is completed, the guide plate 92 is removed, and the EL substrate 62 is placed on the case 60. The X and Y drive handler 96 functions as a first position adjusting unit for the line head. In the example of FIG. 4, the EL substrate 62 is placed on the rod lens array 65 by the X and Y drive handler 96, and an image photographed from the image plane side by the CCD camera 90 is displayed on the display device 100. In the present invention, as described with reference to FIG. 6, the rod lens array 65 and the EL substrate 62 are individually photographed by the CCD camera 90 from the imaging plane side, and the photographed image is displayed on the display device 100. You can also.

  2 and 3, the alignment marks 87a and 87b are formed on both ends of the glass substrate 62. Instead of using the alignment marks, components (modules) formed in advance on the glass substrate 62 are used. ) And wiring (circuit pattern) may be applied for alignment. For example, when the cathode 79 and the partition 75 described in FIG. 13 are used as the module, it is not necessary to form the alignment marks 87a and 87b, and the cost can be reduced. Since such modules and wirings are also formed directly on the surface of the glass substrate 62 together with the light emitting portion 63, no positional deviation occurs. Therefore, even when the module or wiring is used, the position of the glass substrate 62 can be adjusted with respect to the rod lens array 65 with high accuracy.

  2 and 3, the alignment marks 87a and 87b have a cross shape. However, the alignment marks 87a and 87b can be appropriately set to be linear, circular, rectangular, or the like. Moreover, although the organic EL element was demonstrated to the example as a light emitting element formed in a glass substrate, the light emitting element of this invention is not limited to an organic EL element. For example, the present invention can be applied to a line head using a light emitting element of another form such as an inorganic EL element.

  The line head position adjusting method and position adjusting apparatus according to the present invention have been described based on several embodiments. However, the present invention is not limited to these embodiments, and various modifications are possible.

It is sectional drawing which shows the example of the line head applied to this invention. It is a top view of a glass substrate. It is a top view of a glass substrate. It is explanatory drawing which shows the example of the position adjustment apparatus of this invention. It is a process flow figure of lens array incorporation. It is a process flow figure of EL substrate incorporation. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. 1 is a longitudinal side view of an image forming apparatus in which a line head of the present invention is used. It is a schematic perspective view which expands and shows an image writing means. It is sectional drawing which shows the structural example of the light emission part vicinity. It is explanatory drawing which shows the example of positioning of a glass substrate. It is sectional drawing which shows the example which fixed the glass substrate. It is explanatory drawing which shows the example of the position shift of a light emission part. It is a characteristic view which shows light quantity variation.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 16 ... Intermediate transfer belt, 20 ... Image carrier, 23 ... Image writing means (line head), 61 ... Organic EL element array, 62 ... Glass substrate (EL substrate), 63... Light emitting part, 64 .. Cover glass, 65... Refraction index distribution type rod lens array (SLA), 81, 82. Distributed rod lens, 87a, 87b ... alignment mark (alignment mark), 88 ... drive circuit, 90 ... CCD camera, 91a ... imaging surface, 96 ... X, Y drive handler 100 ... Display device

Claims (16)

The step of fixing the lens array to the fixing means, and the position of the alignment member of the transparent single substrate on which the light emitting part in which a plurality of light emitting elements are arranged and the alignment member are formed are adjusted by the first position adjusting means. A step of adjusting and arranging the reference position of the array, a step of illuminating the lens array from the transparent substrate side, a step of photographing an image formed by the lens array, and displaying the photographed image on a display means And a step of adjusting the position of the alignment member formed on the transparent substrate by the second position adjustment means with reference to the image of the lens array displayed on the display means. And a method for adjusting the position of the line head. A step of fixing the lens array to the fixing unit, a step of illuminating the lens array from the transparent substrate side, a step of photographing the lens array, a step of displaying an image of the photographed lens array on a display unit, A step of setting a reference position from the image of the displayed lens array, a step of illuminating a transparent substrate on which a light emitting unit in which a plurality of light emitting elements are arranged and an alignment member are formed, a step of photographing the transparent substrate, A step of displaying the photographed image of the transparent substrate on the display means, a step of setting a contrast position to be compared with a reference position of the lens array from the displayed image of the transparent substrate, and an image of the display means And adjusting the position of the transparent substrate by the first position adjusting means so that the contrast position of the transparent substrate overlaps the reference position of the lens array. A step of photographing an image formed by the lens array, a step of displaying the photographed image on a display unit, and a second position adjusting unit on the basis of the image of the lens array displayed on the display unit Adjusting the position of the alignment member formed on the transparent substrate by the step of adjusting the position of the line head. The line head position adjustment method according to claim 1, wherein the image formation position by the lens array is adjusted by changing the image plane focal depth by the first position adjustment unit. The line head position adjusting method according to claim 1, wherein an image of the lens array is photographed by transmitted light from the transparent substrate. The line head position adjusting method according to claim 1, wherein an image of the lens array is photographed by output light of a light emitting element from the transparent substrate. 6. The line head position adjusting method according to claim 1, wherein the second position adjusting unit adjusts the position of the transparent substrate in a sub-scanning direction. The line head position adjusting method according to claim 1, wherein the alignment member is an alignment mark formed directly on the transparent substrate. The line head position adjusting method according to claim 1, wherein the lens array is provided in a plurality of rows in the sub-scanning direction. The reference for position adjustment with respect to the transparent substrate is the center of the fiber diameter of the lens in the image of the lens array displayed on the display means, or the center line thereof. A method for adjusting the position of the line head according to claim 1. 10. The line head position adjustment method according to claim 1, wherein the lens array is a rod lens array. The line head position adjusting method according to claim 1, wherein the light emitting element is an organic EL element. In a line head having a lens array holding unit on which a light emitting section in which a plurality of light emitting elements are arranged on a transparent single substrate and an alignment member are formed and the output light of the light emitting section is incident, Photographing means; display means for images taken by the photographing means; first position adjusting means for moving the transparent substrate in a main scanning direction and a sub-scanning direction to adjust the position to a reference position of the lens array; Illuminating means for illuminating the lens array from the light emitting portion side of the transparent substrate, illuminating the lens array with the illuminating means, and imaging the transmitted light or output light from the lens array and the transparent substrate. Photographed from the imaging plane side by the photographing means, the photographed image is displayed on the display means, and the transparent base is placed at the reference position of the lens array by the second position adjusting means. Adjust the position of the formed alignment members in, characterized in that to adjust the position relative to the lens array of the transparent substrate, the alignment arrangement of the line head. 13. The line head position adjusting device according to claim 12, wherein the first position adjusting unit adjusts an image forming position by the lens array by changing an image plane focal depth. 14. The line head position adjusting apparatus according to claim 12, wherein the alignment member is an alignment mark formed directly on the transparent substrate. 15. The position adjustment device for a line head according to claim 12, wherein the lens array is a rod lens array. The line head position adjusting apparatus according to claim 12, wherein the light emitting element is an organic EL element.

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