JP5167872B2 - Light emitting element array chip, light emitting element array chip manufacturing method, light emitting element head, and image forming apparatus - Google Patents

Description

  The present invention relates to a light emitting element array chip and the like, and more particularly to a light emitting element array chip in which a microlens is formed on a light emitting element.

  In image forming apparatuses such as printers, copiers, and facsimiles that employ an electrophotographic method, after obtaining an electrostatic latent image by irradiating image information onto a uniformly charged photoreceptor by optical recording means The electrostatic latent image is visualized by adding toner, and the image is formed by transferring and fixing on the recording paper. As such an optical recording means, in addition to an optical scanning method in which a laser beam is scanned in a main scanning direction using a laser for exposure, in recent years, a large number of LED (Light Emitting Diode) array light sources are arranged in the main scanning direction. An optical recording means using an LED head is employed.

  The image forming apparatus using the LED array light source does not require a scanning space and does not require a drive system, as compared with an optical scanning type image forming apparatus, so that the entire image forming apparatus is downsized and reliable. There is an advantage of improvement. In addition, there is an advantage that it is resistant to deformation of the optical system due to vibration and heat.

On the other hand, since each LED element in the LED array light source has a wide light emission angle, it is difficult for light to efficiently enter the photosensitive drum.
For example, in Patent Document 1, a micro-reflecting optical system in which openings in which an in-plane cross-sectional shape of the optical element substrate is tapered toward the light emitting element array side is linearly arranged corresponding to each light emitting element. Element arrays have been proposed.

  In Patent Document 2, a microlens array corresponding to each LED array is formed, and the light emitted from the LED array passes through the microlens array to reduce the divergence angle. There has been proposed an LED printer head that forms an image.

JP-A-11-227248 JP 2001-205845 A

When incorporating the light emitting element array chip into the light emitting element head, high accuracy is required for the mounting position.
It is an object of the present invention to make it possible to mount with high positional accuracy by making it difficult to generate contact when handling with a jig used when a light emitting element array chip is incorporated into a light emitting element head, and efficiency. The object is to provide a light emitting element array chip or the like that can often produce light emitting element heads.

According to a first aspect of the present invention, there is provided a substrate having a rectangular shape, a light emitting element formed on the substrate and arranged linearly on one long side of the rectangle, a light emitting element formed on the light emitting element, and a transparent resin And a convex portion formed on the substrate and disposed on the other long side where the rectangular light emitting elements are not arranged, and the rectangular short side of the convex portion, The light-emitting element array chip is characterized in that the maximum cross-sectional shape when cut in parallel and the maximum cross-sectional shape when cut in parallel with the short side of the rectangle of the microlens are in a line-symmetric relationship .

The invention according to claim 2 is the light emitting element array chip according to claim 1, wherein the convex portion is divided into a plurality of regions .
According to a third aspect of the present invention, there is provided a substrate having a rectangular shape, a light emitting element formed on the substrate and arranged linearly on one long side of the rectangle, a transparent resin formed on the light emitting element, And a convex portion formed on the substrate and disposed on the other long side where the rectangular light emitting elements are not arranged, and the shape of the convex portion and the microlens The shape is a light emitting element array chip characterized by being substantially the same.
According to a fourth aspect of the present invention, there is provided a substrate having a rectangular shape, a light emitting element formed on the substrate and arranged linearly on one long side of the rectangle, a transparent resin formed on the light emitting element, And a convex part formed on the substrate and arranged on the other long side where the rectangular light emitting elements are not arranged, the convex part being the transparent resin The light emitting element array chip is formed of different materials.
The invention according to claim 5 includes a step of linearly forming a light emitting element on one long side of the rectangular substrate, and a step of forming a microlens made of a transparent resin on the light emitting element. look including a step of forming a convex portion on the other long side of the light emitting element of the rectangular are not arranged, the convex portion may be formed from a material different from that of the said transparent resin It is a manufacturing method of a light emitting element array chip.

The invention according to claim 6 includes: a light emitting element array in which a plurality of light emitting element array chips are arranged in a main scanning direction; and an optical element that forms an image of a light output of the light emitting element array. The chip includes a substrate having a rectangular shape, a light emitting element formed on the substrate and linearly arranged on one long side of the rectangle, a microlens made of a transparent resin and formed on the light emitting element, A convex portion formed on the substrate and disposed on the other long side where the rectangular light emitting elements are not arranged, and a maximum cross section when cut parallel to the rectangular short side of the convex portion The light emitting element head is characterized in that the shape and the maximum cross-sectional shape when cut in parallel with the short side of the rectangle of the microlens are in a line-symmetric relationship .

The invention according to claim 7, wherein the light emitting element array chip is a light-emitting element head according to claim 6, characterized in that a self-scanning light-emitting device array chips.

The invention according to claim 8 includes a toner image forming unit that forms a toner image, a transfer unit that transfers the toner image to a recording medium, and a fixing unit that fixes the toner image to the recording medium. The toner image forming unit includes a substrate having a rectangular shape, a light emitting element formed on the substrate and linearly arranged on one long side of the rectangle, and a microlens made of a transparent resin formed on the light emitting element. A light emitting element array chip formed on the substrate and formed on the other long side where the rectangular light emitting elements are not arranged, and the rectangular short of the convex part. In the image forming apparatus, the maximum cross-sectional shape when cut in parallel with the side and the maximum cross-sectional shape when cut in parallel with the short side of the rectangle of the microlens are in a line-symmetric relationship. .

According to the first aspect of the present invention, when handling with a jig used for incorporation into the light emitting element head, it is possible to make it difficult to produce a single contact, and therefore mounting on the light emitting element head with higher positional accuracy. The light emitting element array chip which can be realized is realizable.
According to the invention of claim 2, even when it is desired to arrange an alignment mark for alignment in the vicinity of the central portion of the light emitting element array chip, it can be easily dealt with.
According to the invention of claim 3, when handling with a jig used when incorporating into a light emitting element head, it is possible to make it difficult to produce a piece per piece, and therefore mounting to the light emitting element head with higher positional accuracy. In addition, by making the shape of the convex portion substantially the same as the shape of the microlens, it is possible to realize a light emitting element array chip capable of designing the convex portion more easily.
According to invention of Claim 4 , when handling with the jig | tool used when incorporating in a light emitting element head, it can make it hard to produce per piece, Therefore, it mounts in a light emitting element head with higher positional accuracy. In addition, a light emitting element array chip that can increase the degree of freedom of the material used for the convex portion can be realized .
According to invention of Claim 5 , after forming a micro lens, a convex part can be formed by add-on, and while correction of a convex part is easy, freedom degree is made high about the material used for a convex part. The manufacturing method of the light emitting element array chip which can be provided can be provided.
According to the invention of claim 6 , since the light emitting element array chip can be mounted with higher positional accuracy by the light emitting element head than in the case where this configuration is not adopted, the variation in the amount of emitted light is smaller. A light emitting element head can be realized.
According to the invention of claim 7 , a smaller light emitting element head can be realized by using the self-scanning light emitting element array chip as the light emitting element array chip.
According to the eighth aspect of the present invention, since the light emitting element head having a smaller variation in the amount of emitted light is provided as compared with the case where this configuration is not adopted, an image forming apparatus having higher image quality can be realized.

  Embodiments of the present invention will be described below. However, the present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist. Also, the drawings used are used to describe the present embodiment and do not represent the actual size.

FIG. 1 is a diagram illustrating an overall configuration of an image forming apparatus to which the exemplary embodiment is applied.
An image forming apparatus 1 shown in FIG. 1 is an image forming apparatus generally called a tandem type, and performs image formation corresponding to gradation data of each color, and image output control for controlling the image process system 10. An image processing unit (IPS: Image Processing) which is connected to a unit 30, for example, a personal computer (PC) 2 or an image reading device (IIT: Image Input Terminal) 3 and performs predetermined image processing on image data received therefrom. System) 40.

  The image processing system 10 includes an image forming unit 11 as an example of a toner image forming unit including a plurality of engines arranged in parallel at a constant interval in the horizontal direction. The image forming unit 11 is composed of four image forming units 11Y, 11M, 11C, and 11K of yellow (Y), magenta (M), cyan (C), and black (K). A photosensitive drum 12 that is an image holding member (photosensitive member) that forms an image by forming an image, a charger 13 that uniformly charges the surface of the photosensitive drum 12, and a photosensitive drum that is charged by the charger 13. The light emitting device head 14 is a light emitting device that exposes a light source 12 and a developing device 15 that develops a latent image obtained by the light emitting device head 14. Further, the image process system 10 multiplex-transfers each color toner image formed on the photosensitive drum 12 of each image forming unit 11Y, 11M, 11C, 11K onto a recording sheet as an example of a recording medium. A sheet conveying belt 21 that conveys the recording sheet, a driving roll 22 that is a roll for driving the sheet conveying belt 21, and a transfer roll 23 as an example of a transfer unit that transfers the toner image on the photosensitive drum 12 to the recording sheet are provided. Yes.

  Image signals input from the PC 2 or IIT 3 are subjected to image processing by the image processing unit 40 and supplied to the image forming units 11Y, 11M, 11C, and 11K through the interface. The image process system 10 operates based on a control signal such as a synchronization signal supplied from the image output control unit 30. First, in the yellow image forming unit 11Y, an electrostatic latent image is formed by the light emitting element head 14 on the surface of the photosensitive drum 12 charged by the charger 13 based on the image signal obtained from the image processing unit 40. . A yellow toner image is formed on the formed electrostatic latent image by the developing device 15, and the formed yellow toner image is transferred to a recording sheet on a sheet conveying belt 21 that rotates in the direction of the arrow in the figure. 23 is transferred. Similarly, magenta, cyan, and black toner images are formed on the respective photosensitive drums 12 and are multiple-transferred onto the recording paper on the paper transport belt 21 using the transfer roll 23. The multiple transferred toner image on the recording paper is conveyed to a fixing device 24 as an example of a fixing unit, and is fixed on the recording paper by heat and pressure.

  FIG. 2 is a diagram illustrating a configuration of the light emitting element head 14 to which the exemplary embodiment is applied. The light emitting element head 14 supports the light emitting element array 51 in which a large number of LEDs are arranged as a recording element (light emitting element), and a print on which a circuit for controlling the driving of the light emitting element array 51 is formed. The substrate 52 includes a SELFOC lens array (SLA: registered trademark) 53 that is an optical element that forms an image of the light output emitted from each LED on the photosensitive drum 12, and the printed circuit board 52 and the SELFOC lens array 53 are It is held by the housing 54. The light emitting element array 51 includes LEDs arranged in the number of pixels in the main scanning direction. For example, when an A3 size short (297 mm) is used as the main scanning direction, 7040 LEDs are arranged at intervals of about 42.3 μm at a resolution of 600 dpi. In the present embodiment, the LEDs are arranged in a straight line, and in fact, 7680 LEDs are arranged in consideration of a side registration shift or the like.

FIG. 3 is a schematic diagram illustrating the structure of the light emitting element array 51.
In the light emitting element array 51 shown in FIG. 3, a plurality of light emitting element array chips 100 are arranged in a staggered pattern in the main scanning direction.
The light emitting element array chip 100 includes a bonding pad 101 which is a rectangular shape on a substrate 105 and is a space for wiring and the like on both sides. By providing the bonding pad 101 in this way, there is an advantage that the chip width can be reduced to a width almost required by the bonding pad 101 itself.
In the region between the bonding pads 101 on both sides of the light emitting element array chip 100, the LEDs 102 as light emitting elements are arranged linearly at equal intervals along the long side of the rectangle in the main scanning direction. Here, the LED 102 is arranged close to one of the long sides of the light emitting element array chip 100. The odd-numbered light-emitting element array chip 100 and the even-numbered light-emitting element array chip 100 are arranged so that the LEDs 102 face each other and the bonding pads 101 are overlapped. With this arrangement, all the LEDs 102 can be arranged at equal intervals in the main scanning direction.
A microlens 103 (not shown) is attached on each LED 102.

  FIGS. 4A to 4B are diagrams illustrating a first example of the light emitting element array chip 100 to which the exemplary embodiment is applied. Here, FIG. 4A is a view of the light emitting element array chip 100 as seen from the direction in which the light of the LED 102 is emitted. Moreover, FIG.4 (b) is AA sectional drawing of Fig.4 (a).

  As described above, in the light emitting element array chip 100, the bonding pads 101 are arranged on both sides of the substrate 105, and in the region sandwiched between the bonding pads 101 on both sides, the LED 102 is one of the rectangular light emitting element array chips 100. The long side is linearly arranged at equal intervals. Each LED 102 is formed with a microlens 103 on the light emitting side. Further, a convex portion 104 is formed on the other long side where the LEDs 102 of the rectangular light emitting element array chip 100 are not arranged.

The microlens 103 collects the light emitted from the LED 102 and allows the light to efficiently enter the photosensitive drum 12 (see FIG. 2).
The microlens 103 is made of a transparent resin such as a photocurable resin, and the surface thereof preferably has an aspherical shape in order to collect light more efficiently. Further, the size, thickness, focal length, and the like of the microlens 103 are appropriately determined depending on the wavelength of the LED 102 used, the refractive index of the photocurable resin used, and the like.

In the example shown in FIGS. 4A and 4B, the convex portion 104 is a dummy lens having substantially the same shape as the microlens 103. This dummy lens is in a line-symmetric relationship with the microlens 103, and the height from the substrate 105 is the same.
When this convex portion 104 is formed, the light emitting element array chip 100 can be mounted with high positional accuracy when the light emitting element array chip 100 is incorporated into the light emitting element head 14 (see FIG. 2), and mounting deviation is less likely to occur.

FIGS. 5A and 5B are diagrams illustrating a difference between the case where the convex portion 104 is formed on the light emitting element array chip and the case where the convex portion 104 is not formed when the light emitting element array chip is handled for mounting. It is.
Here, in FIG. 5A, when the convex portion 104 is not formed on the light emitting element array chip, the state when the light emitting element array chip is handled using a mounting jig called a collet is shown. It is shown. The collet 110 has a suction port (not shown), and a vacuum is drawn through the suction port, so that the recess 111 formed in the collet 110 can be in a reduced pressure state. And by making the recessed part 111 into a pressure-reduced state, the light emitting element array chip can be sucked and handled and carried.

  Here, if the light emitting element array chip does not have the convex portion 104, the microlens 103 is provided when the light emitting element array chip is sucked. Therefore, as shown in FIG. 5A, the light emitting element array chip, the collet 110, May cause a so-called half-cut and cannot be held horizontally with respect to a predetermined reference plane. In this case, when the light emitting element array chip is incorporated in the light emitting element head 14 (see FIG. 2), the light emitting element array chip is easily mounted in a tilted state with respect to a predetermined reference surface, and the positional accuracy is deteriorated. When the light emitting element head 14 is manufactured as it is, there arises a problem that the variation in the amount of light emitted from the light emitting element head 14 becomes large.

  On the other hand, FIG. 5B illustrates a case where the light emitting element array chip 100 on which the convex portions 104 are formed is handled for mounting using the collet 110. Since the light emitting element array chip 100 has the convex portion 104, the light emitting element array chip 100 and the collet 110 as described with reference to FIG. It is easy to carry while keeping the surface horizontal. If the light emitting element array chip 100 is incorporated in the light emitting element head 14 in this state, it becomes easy to mount the light emitting element array chip 100 with high positional accuracy.

  In the example shown in FIGS. 4A to 4B described above, the convex portion 104 is a dummy lens having substantially the same shape as the microlens 103, but the shape of the convex portion 104 is limited to this. It is not a thing.

  FIGS. 6A to 6B are diagrams illustrating a second example of the light emitting element array chip 100 to which the exemplary embodiment is applied. Here, FIG. 6A is a view of the light emitting element array chip 100 as seen from the direction in which the light of the LED 102 is emitted. FIG. 6B is a cross-sectional view taken along the line BB in FIG.

  In the example shown in FIGS. 6A to 6B, a lenticular lens shape is adopted as the convex portion 104 instead of the dummy lens shown in FIGS. 4A to 4B. As shown in FIG. 6B, the convex portion 104 has a maximum cross-sectional shape of the microlens 103 and the convex portion 104 when the convex portion 104 is cut in parallel to the short side of the rectangular light emitting element array chip 100. The maximum cross-sectional shape is axisymmetric. By adopting this shape, as in the case where the above-described dummy lens is formed as the convex portion 104, when the light emitting element array chip 100 is handled by the collet 110 (see FIG. 5), it is difficult for one-sided contact to occur. Therefore, the light emitting element array chip 100 can be easily carried while being held horizontally with respect to a predetermined reference plane, and the light emitting element array chip 100 can be mounted with high positional accuracy.

  FIGS. 7A to 7B are diagrams illustrating a third example of the light emitting element array chip 100 to which the exemplary embodiment is applied. Here, FIG. 7A is a view of the light emitting element array chip 100 as seen from the direction in which the light of the LED 102 is emitted. Moreover, FIG.7 (b) is CC sectional drawing of Fig.7 (a).

  In the example shown in FIGS. 7A to 7B, dummy lenses are used as the convex portions 104 as in the case shown in FIGS. 4A to 4B, but the number is two. . This is because when the light emitting element array chip 100 is handled by the collet 110 (see FIG. 5), at least two pieces are sufficient to achieve the object of making it difficult to produce a single piece. By adopting this form, the convex portion 104 formed by a dummy lens and formed in a plurality of regions can have a gap therebetween. Therefore, for example, even when an alignment mark for alignment is desired to be arranged near the center of the light emitting element array chip 100, it can be easily handled.

  Further, FIGS. 8A to 8D are diagrams illustrating fourth to sixth examples of the light emitting element array chip 100 to which the exemplary embodiment is applied. Here, FIGS. 8A to 8C are views of the light emitting element array chip 100 viewed from the direction in which the light of the LED 102 is emitted. FIG. 8D is a DD cross-sectional view of the light-emitting element array chip 100 shown in FIGS.

  In the example shown in FIGS. 8A to 8D, a U-shaped microlens is used as the microlens 103 instead of a substantially hemispherical one. By making the microlens 103 into such a shape, the light emitted from the LED 102 can be collected more efficiently. Even when the microlens 103 having this shape is employed, a problem per one piece similar to the case of employing the substantially hemispherical microlens 103 occurs when handling by the collet 110 (see FIG. 5). Therefore, by providing the convex portion 104 on the other long side that is different from the one long side forming the microlens 103, it is difficult for the one-side contact to occur.

  Among these, in the fourth example of the light emitting element array chip 100 to which the present embodiment shown in FIG. 8A is applied, the convex portion 104 has substantially the same shape as the U-shaped microlens 103. A dummy lens is arranged. Further, in the fifth example of the light emitting element array chip 100 to which the present embodiment shown in FIG. 8B is applied, the convex portion 104 is formed in the shape of a lenticular lens. The maximum cross-sectional shape of the convex portion 104 has a line-symmetric relationship with the maximum cross-sectional shape of the U-shaped microlens 103. In the sixth example of the light emitting element array chip 100 to which the present embodiment shown in FIG. 8C is applied, a dummy lens is used as the convex portion 104 as in the case shown in FIG. However, the number is two.

As a material for forming the convex portion 104, a transparent resin which is the same material as the microlens 103 may be used, or a different material may be used.
And when forming the convex part 104 with the transparent resin similar to the micro lens 103, the convex part 104 can also be shape | molded integrally with the micro lens 103. FIG.

  FIGS. 9A to 9D are views for explaining a preferable form when the convex portion 104 is formed integrally with the microlens 103, and is a seventh embodiment of the light emitting element array chip 100 to which the present embodiment is applied. A ninth example is shown. Here, FIGS. 9A to 9C are views of the light emitting element array chip 100 as seen from the direction in which the light of the LED 102 is emitted. FIG. 9D is a cross-sectional view taken along line EE of the light-emitting element array chip 100 illustrated in FIGS.

  In the seventh example of the light-emitting element array chip 100 to which the present embodiment shown in FIG. 9A is applied, the microlens 103 is substantially the same as in the example shown in FIGS. The dummy lens having the shape is formed as the convex portion 104. In the eighth example of the light emitting element array chip 100 to which the present embodiment shown in FIG. 9B is applied, the lenticular lens shape is similar to the example shown in FIGS. A protrusion is formed as a protrusion 104. Furthermore, in the ninth example of the light emitting element array chip 100 to which the present embodiment shown in FIG. 9C is applied, a dummy lens is provided as in the examples shown in FIGS. Two of them are formed as convex portions 104.

  On the other hand, the light-emitting element array chip 100 shown in FIGS. 9A to 9D includes FIGS. 4A to 4B, FIGS. 6A to 6B, and FIGS. 7A to 7B. Unlike the example shown in FIG. 5, when the microlens 103 is molded, the space between the microlens 103 and the convex portion 104 is filled with a transparent resin and integrated. By integrally molding the microlens 103 and the convex portion 104, the process conditions are facilitated, and an effect as a protective film made of a transparent resin can be expected.

  FIGS. 10A to 10B are diagrams illustrating a form in which the convex portion 104 is formed of a material different from that of the microlens 103. The light-emitting element array chip 100 to which the exemplary embodiment is applied is illustrated in FIGS. A tenth example is shown. Here, FIG. 10A is a view of the light emitting element array chip 100 as seen from the direction in which the light of the LED 102 is emitted. Moreover, FIG.10 (b) is FF sectional drawing of Fig.10 (a).

  The light emitting element array chip 100 to which this embodiment shown in FIGS. 10A to 10B is applied is substantially the same as the microlens 103 as in the example shown in FIGS. 4A to 4B. A dummy lens having a shape is formed as a convex portion 104. On the other hand, unlike the example described in FIGS. 4A to 4B, the convex portion 104 is formed of a resin different from the transparent resin forming the microlens 103. In this case, the convex portion 104 can be formed as an add-on after the microlens 103 is formed. For this reason, the convex portion 104 can be easily corrected, and there is no particular limitation on the material. Therefore, the degree of freedom in selecting the material is increased, such as using a material with low cost. In this embodiment, a resin is used as a preferable form, but when using a resin, it is not necessary to be a transparent resin. Various resins such as an ultraviolet curable resin, a natural curable resin, a thermosetting resin, and a thermoplastic resin can be used. For example, a polycarbonate resin can be used.

  FIGS. 11A to 11C also illustrate the form in which the convex portion 104 is formed of a material different from that of the microlens 103. The light emitting element array chip 100 to which this embodiment is applied is also illustrated in FIGS. The 11th-12th example was shown. Here, FIGS. 11A and 11B are views of the light emitting element array chip 100 viewed from the direction in which the light of the LED 102 is emitted. Moreover, FIG.11 (c) is GG sectional drawing of Fig.11 (a)-(b).

In the eleventh example of the light emitting element array chip 100 to which the present embodiment shown in FIG. 11A is applied, a lenticular lens shape is formed as the convex portion 104. At this time, the height from the substrate 105 of the portion where the convex portion 104 and the microlens 103 are in contact with the collet 110 (see FIG. 5) is made to coincide. In this way, the light emitting element array chip 100 can be easily carried while being held horizontally with respect to a predetermined reference plane, and the light emitting element array chip 100 can be mounted with high positional accuracy.
Furthermore, in the twelfth example of the light emitting element array chip 100 to which the present embodiment shown in FIG. 11B is applied, the convex portion 104 is divided into two regions. Also in this case, the height from the substrate 105 of the portion where the convex portion 104 and the microlens 103 are in contact with the collet 110 (see FIG. 5) is made to match.

  12A to 12B show a thirteenth example of the light emitting element array chip 100 to which the exemplary embodiment is applied. Here, FIG. 12A is a view of the light emitting element array chip 100 as seen from the direction in which the light of the LED 102 is emitted. Moreover, FIG.12 (b) is HH sectional drawing of Fig.12 (a).

In the light emitting element array chip 100 shown in FIGS. 12A to 12B, the convex portion 104 is formed of a resin different from the transparent resin that forms the microlens 103, as described above with reference to FIGS. b) The same as the examples given in FIGS. 11 (a) to 11 (c). However, the lower part of the convex part 104 is formed of a transparent resin, and a resin different from the transparent resin for forming the microlens 103 is laminated thereon to form the convex part 104. By adopting such a configuration, in addition to the advantages described with reference to FIGS. 10A to 10B, an effect as a protective film using the transparent resin described with reference to FIGS. 9A to 9C is expected. it can.
In FIGS. 12A to 12B, two dummy lenses are formed to form the convex portion 104. However, as described above, three or more dummy lenses may be used, or a lenticular lens shape may be used. Good.

Next, a method for manufacturing the light emitting element array chip 100 by forming the microlens 103 and the convex portion 104 on the LED 102 will be described.
FIGS. 13A to 13E and FIGS. 14A to 14E are diagrams illustrating a process of manufacturing the light emitting element array chip 100 by forming the microlens 103 on the LED 102.
This process is roughly divided into a process of creating a microlens mold 200 for forming the microlens 103 (FIGS. 13A to 13E), and the microlens mold 200 is actually used. It consists of the process (FIG. 14 (a)-(e)) which forms the microlens 103 in LED102 and produces the light emitting element array chip | tip 100. FIG. In this embodiment, the case where the convex portion 104 described with reference to FIGS. 10 to 12 is formed after the microlens 103 is formed will be described as an example.

First, the process of creating the microlens mold 200 will be described.
First, a chromium film 202 is formed on a substrate 201 made of quartz glass. The chromium film 202 can be formed by a method such as vapor deposition, and the thickness is preferably about 0.2 μm to 1 μm (FIG. 13A).

  Next, an opening 203 is provided in the chromium film 202 (FIG. 13B). The interval between the central portions of the openings 203 is the same as the interval between the central portions of the microlenses 103 (see FIG. 4), and can be set to, for example, about 42.3 μm. The opening 203 can be provided by a photolithography method. That is, a resist layer corresponding to the opening 203 is formed, and using this resist layer as a mask, a portion corresponding to the opening 203 of the chromium film 202 is removed by dry etching or wet etching. As dry etching, reactive ion etching (RIE) or inductively coupled plasma etching can be used. As wet etching, a method of immersing in dilute hydrochloric acid or dilute sulfuric acid can be used. Then, when the remaining resist layer is removed by using a resist removing solution or the like, an opening 203 is formed.

  Next, wet etching of the substrate 201 is performed. As the etchant, a hydrofluoric acid aqueous solution or the like can be used. At this time, the chromium film 202 functions as a mask, and the portion of the opening 203 is isotropically etched. As a result, a substantially hemispherical hole 204 is formed in the quartz glass substrate 201 (FIG. 13C). The shape of the substantially hemispherical hole 204 is a transfer shape of the microlens 103.

Next, the chromium film 202 is partially removed (FIG. 13D). For the removal of the chromium film 202, a dry etching method such as the above-described reactive ion etching (RIE) or inductively coupled plasma etching method or a wet etching method in which the film is immersed in dilute hydrochloric acid or dilute sulfuric acid can be used. For example, it can also be removed by applying an adhesive tape and peeling it off.
Then, in order to improve the releasability from the microlens mold 200 when forming the microlens 103, a mold release process is performed, and when forming the microlens 103, the microlens mold 200 is placed at a predetermined position. A spacer 205 for defining is formed (FIG. 13E).
This mold release treatment can be performed, for example, by a method in which a mold release film 206 is formed by coating a fluororesin such as Teflon (registered trademark). The spacer 205 can be formed by applying a single layer of spherical beads made of plastic or the like and having a particle size of about 10 μm.
The microlens mold 200 can be created by the series of steps as described above.

Next, a process of creating the microlens 103 on the LED 102 using the microlens mold 200 created as described above will be described.
First, a photo-curing resin 302 that is cured by ultraviolet (UV) is dropped onto a light-emitting element array chip 301 that is a light-emitting element array chip before the microlens 103 is formed (FIG. 14A )). At this time, the photocurable resin 302 may be made uniform on the light emitting element array chip 301 by performing spin coating or the like. The photo-curing resin used is not particularly limited as long as it transmits light emitted from the LED 102, but is not limited to a general epoxy-based photo-curing resin or acrylic photo-curing resin. Resin can be used.

Next, the photocurable resin 302 is developed by pressing the microlens mold 200 against the light emitting element array chip 301, and fine alignment is performed in the horizontal direction and the height direction (FIG. 14B). At this time, the photocurable resin 302 enters the hole 204 formed in the microlens mold 200 and becomes the shape of the microlens 103.
The alignment in the height direction is performed by pressing the microlens molding die 200 against the light emitting element array chip 301 with a predetermined pressure and bringing the light emitting element array chip 301 and the spacer 205 into contact with each other. The position in the height direction of the microlens mold 200 is defined by the spacer 205, and the thickness of the photocurable resin 302 can be made uniform as a whole. Further, the alignment in the horizontal direction can be performed by a method of aligning with a predetermined marker (not shown).

After the alignment of the microlens mold 200 is completed, the ultraviolet ray is irradiated to cure the photocurable resin 302. At this time, the chromium film 202 functions as a light shielding film, and selectively cures only necessary portions (FIG. 14C).
After the photocurable resin 302 is cured, the microlens mold 200 is released (FIG. 14D). Then, when the uncured photocurable resin 302 is removed by washing, a microlens 103 made of the cured photocurable resin 302 is formed on the LED 102 (FIG. 14E).

  Then, when the convex portion 104 is formed, the light emitting element array chip 100 of the present embodiment can be manufactured. In this case, the convex portion 104 can be formed by a method such as applying a resin forming the convex portion 104 and pressing a molding die for forming the convex portion 104.

  In the case where the convex portion 104 is molded integrally with the microlens 103, the hole portion having a position and a size corresponding to the convex portion 104 is formed in the microlens molding die 200 in the above-described steps (a) to (e). To form. When this microlens mold 200 is used to perform the operations described in the steps of FIGS. 14A to 14E, the microlens 103 is formed by the cured photocurable resin 302 and is convex. The portion 104 can be formed.

  In the present embodiment, it is preferable to use a self-scanning light emitting element array as the light emitting element array chip 100. The self-scanning light-emitting element array uses a light-emitting thyristor having a pnpn structure as a constituent element of the light-emitting element array, and is configured to realize self-scanning of the light-emitting element. No. 2-14584, JP-A-2-92650, and JP-A-2-92651. Japanese Patent Application Laid-Open No. 2-263668 discloses a self-scanning light emitting element array having a structure separated from a light emitting element array as a light emitting part using the transfer element array as a transfer part.

FIG. 15 is an equivalent circuit diagram of a separation type self-scanning light emitting element array. This self-scanning light emitting element array includes transfer thyristors T ₁ , T ₂ , T ₃ ,... And write light emitting thyristors L ₁ , L ₂ , L ₃ ,. The configuration of the transfer unit uses a diode connection. V _GK is a power supply (usually 5 V), and is connected to the gate electrodes G ₁ , G ₂ , G ₃ ,... Of each transfer thyristor through the load resistance _RL from the power line 72. Further, the gate electrodes G ₁ , G ₂ , G ₃ ,... Of the transfer thyristor are also connected to the gate electrode of the write light-emitting thyristor. The gate electrode of the transfer thyristor T ₁ is the start pulse phi _S is applied to the anode electrode of the transfer thyristor, transfer clock pulses φ1 alternately, .phi.2 is applied. These transfer clock pulses φ 1 and φ 2 are supplied via clock pulse lines 74 and 76. The anode electrode of the write light emitting thyristor, via a signal line 78, a write signal phi _I is added.

Next, the operation will be briefly described. First voltage of the transfer clock pulses φ1 to the transfer thyristor T ₂ at the high level is on. At this time, the potential of the gate electrode _{G 2} is lowered to approximately 0V from 5V to _{V GK.} The effect of this potential drop is transmitted by the diode D ₂ to the gate electrode G _3, and sets the potential of about 1V (forward threshold voltage of the diode D ₂ (equal to the diffusion potential)). However, the connection of the potential of the gate electrode G ₁ for the diode D ₁ is reverse biased state is not performed, the potential of the gate electrode G ₁ remains at 5V. ON potential of the write light emitting thyristor, since is approximated by a diffusion potential of the gate electrode potential + pn junction (approximately 1V), H-level voltage of the next transfer clock pulse φ2 turns on about 2V (the transfer thyristor T ₃ and a voltage) than necessary and about 4V (only the transfer thyristor T ₃ by setting the voltage) or less necessary to turn on the transfer thyristor T ₄ is turned on, other than the transfer thyristor for Can be left off. Therefore, the ON state is transferred by two transfer clock pulses.

The start pulse φ _S is a pulse for starting such a transfer operation. At the same time, the start pulse φ _{S is set} to L level (about 0 V), and at the same time, the transfer clock pulse φ 2 is set to H level (about 2 to about 4 V). , to turn on the transfer thyristor _{T 1.} Shortly thereafter, a start pulse φ _S is returned to the H level.

Assuming that the transfer thyristor T ₂ is in the ON state, the potential of the gate electrode G ₂ is, lower than V _{GK (here} assumed to 5V), becomes substantially 0V. Accordingly, the voltage of the write signal phi _I is, if the diffusion potential of the pn junction (approximately 1V) above, it is possible to write for the light-emitting thyristors L ₂ and the light-emitting state.

In contrast, the gate electrode _{wherein G 1} is about 5V, the gate electrode _{G 3} are approximately 1V. Accordingly, the write voltage of the write light-emitting thyristor L ₁ of about 6V, the write voltage of the write light-emitting thyristor L ₃ is about 2V. Now, the voltage of the write signal phi _I can write only to the write light-emitting thyristor _{L 2} is a range of 1 to 2 V. When the write light-emitting thyristor L ₂ is turned on, i.e., enters the emission state, the light emission intensity is decided to the amount of current flowing to the write signal phi _I, it is possible to image writing at any intensity. Further, in order to transfer the light-emitting state to the next writing-emitting thyristor is dropped to 0V the voltage of the write signal phi _I line once, once it is necessary to turn off the write light emitting thyristor emits light.

1 is a diagram illustrating an overall configuration of an image forming apparatus to which the exemplary embodiment is applied. It is the figure which showed the structure of the light emitting element head to which this Embodiment is applied. It is the schematic explaining the structure of the light emitting element array. It is a figure explaining the 1st example of the light emitting element array chip to which this Embodiment is applied. It is the figure explaining the difference when a light emitting element array chip is handled for mounting by the case where a convex part is formed in the light emitting element array chip, and the case where it does not form. It is a figure explaining the 2nd example of the light emitting element array chip to which this Embodiment is applied. It is a figure explaining the 3rd example of the light emitting element array chip to which this Embodiment is applied. It is the figure explaining the 4th-6th example of the light emitting element array chip to which this Embodiment is applied. It is a figure explaining the preferable form in the case of shape | molding a convex part integrally with a micro lens, and is the figure which showed the 7th-9th example of the light emitting element array chip | tip with which this Embodiment is applied. It is a figure explaining the form which forms a convex part with a material different from a microlens, and is the figure which showed the 10th example of the light emitting element array chip to which this Embodiment is applied. It is a figure explaining the form which forms a convex part with a material different from a microlens, and is the figure which showed the 11th-12th example of the light emitting element array chip to which this Embodiment is applied. It is a 13th example of a light emitting element array chip to which this embodiment is applied. It is a figure explaining the process of creating the microlens shaping | molding die for forming a microlens. It is the figure explaining the process of forming a microlens using a microlens shaping | molding die and creating a light emitting element array chip. It is an equivalent circuit diagram of a separation type self-scanning light emitting element array.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 11Y, 11M, 11C, 11K ... Image forming unit, 14 ... Light emitting element head, 23 ... Transfer roll, 24 ... Fixing device, 51 ... Light emitting element array, 53 ... Selfoc lens array, 100 ... Light emission Element array chip, 101 ... bonding pad, 102 ... LED, 103 ... microlens, 104 ... convex, 105 ... substrate

Claims (8)

A substrate having a rectangular shape, and a light emitting element formed on the substrate and arranged linearly on one long side of the rectangle;
A microlens formed on the light emitting element and made of a transparent resin;
A convex part formed on the substrate and arranged on the other long side where the rectangular light emitting elements are not arranged,
Equipped with a,
The maximum cross-sectional shape when the convex portion is cut parallel to the short side of the rectangle and the maximum cross-sectional shape when the micro lens is cut parallel to the short side of the rectangle are in a line-symmetric relationship. A featured light emitting element array chip. The light emitting element array chip according to claim 1, wherein the convex portion is divided into a plurality of regions . A substrate having a rectangular shape, and a light emitting element formed on the substrate and arranged linearly on one long side of the rectangle;
A microlens formed on the light emitting element and made of a transparent resin;
A convex part formed on the substrate and arranged on the other long side where the rectangular light emitting elements are not arranged,
With
The light emitting element array chip, wherein the shape of the convex portion and the shape of the microlens are substantially the same. A substrate having a rectangular shape, and a light emitting element formed on the substrate and arranged linearly on one long side of the rectangle;
A microlens formed on the light emitting element and made of a transparent resin;
A convex part formed on the substrate and arranged on the other long side where the rectangular light emitting elements are not arranged,
With
The light emitting element array chip, wherein the convex portion is formed of a material different from the transparent resin. Forming a light emitting element linearly on one long side of the rectangle of the substrate having a rectangular shape;
Forming a microlens made of a transparent resin on the light emitting element;
Forming a convex part on the other long side where the rectangular light emitting elements are not arranged;
Only including,
The method for manufacturing a light-emitting element array chip, wherein the convex portion is formed of a material different from the transparent resin . A light emitting element array in which a plurality of light emitting element array chips are arranged in the main scanning direction;
An optical element for imaging the light output of the light emitting element array,
The light emitting element array chip is:
A substrate having a rectangular shape, a light emitting element formed on the substrate and linearly arranged on one long side of the rectangle, a microlens made of a transparent resin formed on the light emitting element, and the substrate A convex portion formed on the other long side where the rectangular light emitting elements are not arranged;
Equipped with a,
The maximum cross-sectional shape when the convex portion is cut parallel to the short side of the rectangle and the maximum cross-sectional shape when the micro lens is cut parallel to the short side of the rectangle are in a line-symmetric relationship. A light emitting element head characterized by the above. The light emitting element head according to claim 6 , wherein the light emitting element array chip is a self-scanning light emitting element array chip. Toner image forming means for forming a toner image;
Transfer means for transferring the toner image to a recording medium;
Fixing means for fixing the toner image to a recording medium,
The toner image forming unit includes:
A substrate having a rectangular shape, a light emitting element formed on the substrate and linearly arranged on one long side of the rectangle, a microlens made of a transparent resin formed on the light emitting element, and the substrate A light emitting element array chip formed with a convex portion arranged on the other long side where the light emitting elements of the rectangular shape are not arranged ,
The maximum cross-sectional shape when the convex portion is cut parallel to the short side of the rectangle and the maximum cross-sectional shape when the micro lens is cut parallel to the short side of the rectangle are in a line-symmetric relationship. An image forming apparatus.

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