JP2009194253A - Method of manufacturing light-emitting element array chip, micro-lens molding die, light-emitting element head, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a light-emitting element array chip, and the like, in which high precision is achieved with respect to thickness, protrusion of a transparent resin is suppressed and a micro-lens including a suitable pattern can be formed in a light emitting element. <P>SOLUTION: The method of manufacturing a light-emitting element array chip 100 is characterized in that a micro-lens 103 is formed in an LED 102 by pressing a micro-lens molding die 200 onto a light-curing resin 302, measuring thickness of the micro-lens 103 by means of a spacer 205a and curing a light-curing resin 302, the micro-lens molding die 200 including a substrate; a plurality of holes 204 formed on a surface of the substrate and having a transferred shape of the micro-lens 103; and the spacer 205a formed in an outer circumferential area of the holes 204 and constituted of a metal thin film. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a light emitting element array chip, and more particularly to a method for manufacturing 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 laser light is scanned in the main scanning direction for exposure and in recent years, a number of LED (Light Emitting Diode) array light sources are arranged in the main scanning direction in recent years. An optical recording means using the LED head thus formed 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. In order to solve this point, for example, Patent Document 1 proposes a light emitting element array in which a microlens corresponding to each LED element is incorporated.

  When molding the microlens, high accuracy is required for the thickness of the resin or the like forming the microlens. As a method for realizing this accuracy, for example, in Patent Document 2, a stamper mold, a resin material, and a light irradiation device can be used to allow a resin to flow out to a relief pattern transfer surface that becomes a diffraction grating on an optical substrate and an outer peripheral portion. The first molding support part having a gap and the second molding support part capable of suppressing the outflow of the resin at the outer peripheral part are configured to be only a few μm higher than the first molding support part, and replica molding is performed. An optical element manufacturing method is disclosed in which a ring-shaped member is disposed so as to cover one molding support portion, and in particular, the first molding support portion is configured as a two-body structure with a strong member and applies a flattening pressure. ing.

  In Patent Document 3, a transparent substrate having a plurality of concave portions having a concave curved surface, a surface layer bonded to the surface of the transparent substrate provided with the concave portions via a resin layer, and the thickness of the resin layer are defined. A microlens substrate having a spacer made of spherical particles is used, and in the resin layer, a microlens substrate is disclosed in which a microlens is formed by a resin filled in a recess.

Japanese Patent Laid-Open No. 6-24042 JP 2006-95722 A JP 2001-188107 A

In the method using a spacer to define the thickness of the resin forming the microlens, high accuracy is required for the thickness of the spacer and a function for preventing the resin from protruding is required.
An object of the present invention is to provide a method for manufacturing a light-emitting element array chip and the like that can form a microlens having an appropriate pattern on the light-emitting element with high accuracy with respect to the thickness and suppressing protrusion of resin. There is to do.

The invention according to claim 1
A microlens mold having a substrate, a plurality of holes formed on the surface of the substrate and having a transfer shape in the shape of a microlens, and a spacer formed of a metal thin film formed in an outer peripheral region of the hole is a transparent resin. Press to
The spacer portion defines the thickness of the microlens,
A method of manufacturing a light-emitting element array chip, wherein the microlens is formed on a light-emitting element by curing the transparent resin.

The invention according to claim 2
The microlens mold has a rectangular shape,
The holes are arranged linearly along the long side of the rectangle,
2. The method of manufacturing a light emitting element array chip according to claim 1, wherein the spacer part is an end part of the hole part arranged in a straight line and is arranged on a short side of the rectangle. 3. .
The invention according to claim 3
The holes are arranged on one long side of the rectangle,
The method of manufacturing a light emitting element array chip according to claim 2, wherein the spacer portion is further arranged on the other long side of the rectangle.
The invention according to claim 4
The method of manufacturing a light emitting element array chip according to claim 1, wherein the spacer portion is divided into a plurality of regions.
The invention according to claim 5
The substrate further has a recess in the outer peripheral region of the hole,
The method of manufacturing a light emitting element array chip according to claim 1, wherein the spacer portion is disposed in the concave portion.
The invention according to claim 6
The method for manufacturing a light-emitting element array chip according to claim 1, wherein the transparent resin is a photocurable resin.
The invention according to claim 7 provides:
2. The method of manufacturing a light emitting element array chip according to claim 1, wherein the light emitting element array chip is a self-scanning light emitting element array chip.

The invention according to claim 8 provides:
A substrate,
A plurality of holes formed on the surface of the substrate and having a microlens-shaped transfer shape;
A spacer portion formed of a metal thin film that is formed in an outer peripheral region of the hole portion and defines a thickness of the microlens;
It is a microlens shaping | molding die characterized by having.

The invention according to claim 9 is:
The microlens mold has a rectangular shape,
The microlens molding die according to claim 8, wherein the spacer portion is disposed along a short side of the rectangle.

The invention according to claim 10 is:
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:
Transparent microlens mold having a substrate, a plurality of holes formed on the surface of the substrate and having a transfer shape in the shape of a microlens, and a spacer formed of a metal thin film formed in an outer peripheral region of the hole A light-emitting element head comprising a light-emitting element having a microlens formed by pressing a resin, defining a thickness of the microlens by the spacer portion, and curing the transparent resin.

The invention according to claim 11 is:
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:
Transparent microlens mold having a substrate, a plurality of holes formed on the surface of the substrate and having a transfer shape in the shape of a microlens, and a spacer formed of a metal thin film formed in an outer peripheral region of the hole An image forming apparatus comprising a light emitting element head in which a microlens is formed on a light emitting element by pressing the resin, defining the thickness of the microlens by the spacer portion, and curing the transparent resin. is there.

According to the first aspect of the present invention, it is possible to manufacture a light emitting element array chip in which microlenses having an appropriate pattern are formed on a light emitting element by suppressing the protrusion of the resin by using a metal thin film as the spacer portion.
According to the second aspect of the present invention, by arranging the spacer portion on the short side of the rectangular microlens molding die, the protrusion to the bonding pad or the like is suppressed, and the microlens having a more appropriate pattern is formed as the light emitting element. Can be formed.
According to the invention of claim 3, by providing the spacer portion on one long side of the rectangular microlens molding die, a microlens having higher accuracy with respect to the thickness can be formed in the light emitting element. it can.
According to the invention of claim 4, by dividing the spacer portion, the spacer portion having a higher degree of freedom can be arranged, thereby forming a microlens having higher accuracy with respect to the thickness. . In addition, it is possible to manufacture a light emitting element array chip that can further increase the area occupied by the light emitting elements.
According to the invention of claim 5, by arranging the spacer portion in the concave portion formed in the substrate, the thickness of the spacer portion can be reduced, and thus a microlens having a thinner thickness can be formed.
According to the sixth aspect of the present invention, the microlens can be easily formed on the light emitting element by using the photocurable resin as the transparent resin.
According to the seventh aspect of the present invention, a light emitting element array chip having a smaller size can be manufactured by using the light emitting element array chip as a self-scanning light emitting element array chip.
According to the invention of claim 8, by forming the spacer portion with a metal thin film, it is possible to form a microlens having an appropriate pattern with higher accuracy with respect to the thickness and suppressing protrusion of the resin. In addition, it is possible to realize a microlens mold in which a spacer portion with a higher degree of design freedom can be arranged.
According to the ninth aspect of the present invention, by arranging the spacer portion along the short side of the rectangular microlens molding die, the microlens having an appropriate pattern can be formed more easily by suppressing the protrusion of the resin. can do.
According to the invention of claim 10, since the microlens with higher accuracy with respect to the thickness can be formed on the light emitting element, a light emitting element head with higher light output intensity can be realized.
According to the eleventh aspect of the present invention, it is possible to provide a light emitting element head having a higher intensity of light output, so that an image forming apparatus having higher image quality can be realized.

  Hereinafter, the best mode (embodiment) for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist. Further, the drawings used are used for explaining the present embodiment, and do not represent actual sizes.

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 which is an image holding member (photosensitive member) for forming an image by forming an image, a charger 13 for uniformly charging the surface of the photosensitive drum 12, and a photosensitive drum 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.

  The image forming units 11Y, 11M, 11C, and 11K have substantially the same configuration except for the toner stored in the developing device 15. 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 include: 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 has a rectangular shape and includes bonding pads 101 which are spaces 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.

4A and 4B are diagrams illustrating the structure of the light emitting element array chip 100. FIG.
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, the bonding pads 101 are arranged on both sides of the light emitting element array chip 100, and the LEDs 102 are arranged linearly at equal intervals in a region sandwiched between the bonding pads 101 on both sides. Each LED 102 is formed with a microlens 103 on the light emitting side. The microlens 103 condenses the light emitted from the LED 102 and can efficiently make the light incident on 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 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. 5 is an equivalent circuit diagram of a self-scanning light emitting element array of a separate type. 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 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.

Next, a method for forming the microlens 103 will be described. First, a conventional method will be described.
FIGS. 6A to 6E and FIGS. 7A to 7E are diagrams illustrating a conventional example of a process of forming the light emitting element array chip 100 by forming the microlens 103 on the LED 102. FIG.
This process is roughly divided into a process of creating a microlens mold 200 for forming the microlens 103 (FIGS. 6A to 6E), and the microlens mold 200 is actually used. The process includes the steps of forming the microlens 103 on the LED 102 and forming the light emitting element array chip 100 (FIGS. 7A to 7E).

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. 6A).

  Next, an opening 203 is provided in the chromium film 202 (FIG. 6B). 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, 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 layer 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. 6C). 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. 6D). 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. 6E).
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 photocurable resin 302 that is cured by ultraviolet (UV) is dropped onto the light emitting element array chip 301 on which the LEDs 102 are formed (FIG. 7A). 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 molding die 200 against the light emitting element array chip 301, and fine alignment is performed in the horizontal direction and the height direction (FIG. 7B). 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. 7C).
After the photocurable resin 302 is cured, the microlens mold 200 is released (FIG. 7D). Then, by removing the uncured photocurable resin 302 by washing, the light emitting element array chip 100 in which the microlens 103 made of the cured photocurable resin 302 is formed on the LED 102 can be manufactured (FIG. 7E). ).

According to the above manufacturing method, in FIG. 7C, when the photocurable resin 302 is selectively cured, the irradiated portion is selected by the chromium film 202 and the curing range is selected. However, when a spherical bead is used as the spacer 205 used as a height control method, the region where the photocurable resin 302 is developed cannot be controlled in detail, and light from the outside of the chromium film 202 is not emitted from the chromium film 202. There is a problem that the photocurable resin reacts with the photocurable resin 302 at the lower portion and the photocurable resin is cured at a portion other than the portion to be cured. That is, in the method of applying spherical beads as the spacers 205, the photocurable resin 302 enters the lower side of the chromium film 202 as shown in FIG. 7B. Then, as shown in FIG. 7C, when ultraviolet rays are irradiated to cure the photocurable resin 302, the ultraviolet rays pass through the gaps between the spherical beads constituting the spacer 205, and the chromium film 202 Go around the bottom. As a result, as shown in FIGS. 7D to 7E, the photocurable resin 302 is cured also in the portion where the photocurable resin 302 is not originally cured, and an extra protruding portion 303 is formed. It will be.
In addition, since the spacer 205 having a fine shape cannot be designed, the thickness of the spacer 205 varies, so that the microlens 103 cannot be formed with a uniform thickness.

Therefore, in the present embodiment, a spacer using a metal thin film is used as the spacer 205.
FIG. 8 is a diagram illustrating a first example of a microlens mold to which the present embodiment is applied.
The microlens mold 200 shown in FIG. 8 is an example in which spacers 205a made of metal thin films are provided on the two short sides of the rectangular microlens mold 200, respectively. This metal is, for example, chromium, and can be formed by a method such as sputtering or plating. The film thickness can be accurately controlled by the time for performing sputtering or plating.
By providing the spacer 205a made of a metal thin film in this manner, it is possible to suppress the entry of the photocurable resin 302 generated in FIG. 7B and to control the area where the photocurable resin 302 is developed in detail. . That is, when sputtering or plating is performed to form the spacer 205a, the position can be determined with high accuracy, and the photocurable resin 302 is unlikely to protrude from a predetermined position.

FIGS. 9A to 9E are diagrams illustrating a process of manufacturing the light emitting element array chip 100 by forming the microlens 103 on the LED 102 using the microlens mold 200 shown in FIG.
The processes shown in FIGS. 9A to 9E correspond to the processes shown in FIGS. 7A to 7E, respectively, and the work to be performed is the same. However, since the microlens molding die 200 using the spacer 205a made of a metal thin film is used as the spacer, in FIG. 9B, the light below the chromium film 202 as shown in FIG. 7B. The entry of the curable resin 302 hardly occurs. In addition, since the spacer 205a is formed of a metal thin film, in FIG. 9C, ultraviolet rays are not easily circulated through the gaps between the beads that are generated when the beads are used. Therefore, it is easy to selectively cure the portion where the photo-curable resin 302 is originally to be cured, and as shown in FIGS. 9D to 9E, the protruding portion 303 generated in FIGS. 7D to 7E. Is also difficult to form.

FIGS. 10A and 10B are diagrams illustrating an example of a light emitting element array chip 100 in which the microlens 103 is formed using the microlens mold 200 shown in FIG.
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 BB sectional drawing of Fig.10 (a).
In the light emitting element array chip 100 shown in FIGS. 10A and 10B, the bonding pads 101 are disposed at both ends of the rectangular light emitting array chip 100 as described above, and the bonding pads 101 at both ends are disposed on the bonding pads 101 at both ends. The LED 102 is arranged in the sandwiched area. Then, the microlens 103 is formed by covering the entire region with the cured photocurable resin 302. At this time, it is preferable that the portion of the bonding pad 101 is not covered with the photocurable resin 302. By using the microlens mold 200 shown in FIG. 8, it is easy to suppress the photocurable resin 302 from protruding and curing to the bonding pad 101.

FIG. 11 is a diagram illustrating a second example of a microlens mold to which the present embodiment is applied.
A microlens mold 200 shown in FIG. 11 is provided with spacers 205b made of a metal thin film on the two short sides of the rectangular microlens mold 200, respectively. Further, a spacer 205c is provided on the long side opposite to the long side where the hole 204 of the microlens mold 200 is provided. By providing the spacer 205c in addition to the spacer 205b, it is possible to prevent the microlens molding die 200 from being deformed by its own weight or pressure when the microlens 103 is molded in FIG. 7B described above.
The spacer 205b is smaller in size than the spacer 205a shown in FIG. By using a metal thin film that can be formed by a method such as sputtering or plating as a spacer, it is possible to design freely for its position and size, so that a spacer having a fine shape can be designed. Therefore, the light emitting element array chip 100 that can increase the area occupied by the LEDs 102 (see FIG. 4) can be manufactured. In addition, such a finely shaped spacer has a small variation in thickness. Therefore, even when the microlens 103 is molded, the thickness variation is less likely to occur. Therefore, the characteristics such as the focal length of the microlens 103 are uniform.

FIG. 12 is a diagram illustrating a third example of a microlens mold to which the present embodiment is applied.
A microlens mold 200 shown in FIG. 12 is an example in which spacers 205d made of a metal thin film are provided on the two short sides of the rectangular microlens mold 200, respectively.
Compared to the spacer 205a shown in FIG. 8, the spacer 205d is divided into two parts. The size is smaller than that of the spacer 205a. By adopting the spacer 205d having such a shape, the position where the spacer 205d is disposed becomes more free, and the degree of freedom in designing the microlens 103 can be further increased.

FIG. 13 is a diagram illustrating a fourth example of a microlens mold to which the present embodiment is applied.
The microlens mold 200 shown in FIG. 13 is an example in which grooves 207 that are concave portions are provided on two short sides of the rectangular microlens mold 200, and spacers 205e are formed there.
By adopting such a structure, for example, the thickness of the microlens 103 must be very thin by design, and thus the spacer must be thinned, but it is difficult to form the spacer so thinly. It is effective in the case. That is, by providing the concave portion, the spacer can be formed so thin.

FIG. 14 is a diagram illustrating a fifth example of a microlens molding die to which the present embodiment is applied.
The rectangular microlens molding die 200 has the same configuration as that of FIG. 13 in that grooves 207 that are concave portions are provided on the two short sides, and a spacer 205e is formed therein, but in addition to that, FIG. The illustrated microlens mold 200 is provided with a groove 207 on the long side opposite to the long side where the hole 204 of the rectangular microlens mold 200 is provided, and a spacer 205f. . This makes it easy to suppress the deformation of the microlens molding die 200 due to its own weight or pressure in FIG.

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 structure of the light emitting element array chip. It is an equivalent circuit diagram of a self-scanning light emitting element array of a separation type. It is a figure explaining the process of creating the microlens shaping | molding die for forming a microlens. It is the figure explaining the conventional example of the process of forming a microlens using a microlens shaping | molding die and manufacturing a light emitting element array chip. It is a figure explaining the 1st example of the microlens shaping | molding die to which this Embodiment is applied. It is the figure explaining the process of forming a microlens in LED using the microlens shaping | molding die shown in FIG. 8, and manufacturing a light emitting element array chip. It is the figure explaining the example of the light emitting element array chip | tip which formed the micro lens using the micro lens shaping | molding die shown in FIG. It is a figure explaining the 2nd example of the microlens shaping | molding die with which this Embodiment is applied. It is a figure explaining the 3rd example of the microlens shaping | molding die with which this Embodiment is applied. It is a figure explaining the 4th example of the microlens shaping | molding die with which this Embodiment is applied. It is a figure explaining the 5th example of the microlens shaping | molding die to which this Embodiment is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 11K, 11C, 11M, 11Y ... 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, 200 ... microlens mold, 201 ... substrate, 204 ... hole, 205 ... spacer, 302 ... photocurable resin

Claims (11)

A microlens mold having a substrate, a plurality of holes formed on the surface of the substrate and having a transfer shape in the shape of a microlens, and a spacer formed of a metal thin film formed in an outer peripheral region of the hole is a transparent resin. Press to
The spacer portion defines the thickness of the microlens,
A method of manufacturing a light-emitting element array chip, wherein the microlens is formed on a light-emitting element by curing the transparent resin. The microlens mold has a rectangular shape,
The holes are arranged linearly along the long side of the rectangle,
2. The method of manufacturing a light emitting element array chip according to claim 1, wherein the spacer portion is an end portion of the hole portion arranged in a straight line and is disposed on a short side of the rectangle. The holes are arranged on one long side of the rectangle,
The method of manufacturing a light emitting element array chip according to claim 2, wherein the spacer portion is further disposed on the other long side of the rectangle.   The method of manufacturing a light emitting element array chip according to claim 1, wherein the spacer portion is divided into a plurality of regions. The substrate further has a recess in the outer peripheral region of the hole,
The method of manufacturing a light emitting element array chip according to claim 1, wherein the spacer portion is disposed in the recess.   The method for manufacturing a light-emitting element array chip according to claim 1, wherein the transparent resin is a photocurable resin.   The method of manufacturing a light emitting element array chip according to claim 1, wherein the light emitting element array chip is a self-scanning light emitting element array chip. A substrate,
A plurality of holes formed on the surface of the substrate and having a microlens-shaped transfer shape;
A spacer portion formed of a metal thin film that is formed in an outer peripheral region of the hole portion and defines a thickness of the microlens;
A microlens molding die comprising: The microlens mold has a rectangular shape,
The microlens molding die according to claim 8, wherein the spacer portion is disposed along a short side of the rectangle. 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:
Transparent microlens mold having a substrate, a plurality of holes formed on the surface of the substrate and having a transfer shape in the shape of a microlens, and a spacer formed of a metal thin film formed in an outer peripheral region of the hole A light-emitting element head comprising: a light-emitting element having a microlens formed by pressing against a resin, defining a thickness of the microlens by the spacer portion, and curing the transparent resin. 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:
Transparent microlens mold having a substrate, a plurality of holes formed on the surface of the substrate and having a transfer shape in the shape of a microlens, and a spacer formed of a metal thin film formed in an outer peripheral region of the hole An image forming apparatus comprising a light emitting element head in which a microlens is formed on a light emitting element by pressing the resin, defining the thickness of the microlens by the spacer portion, and curing the transparent resin.

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