JPS6048384A - Led array head - Google Patents

Abstract

PURPOSE:To eliminate the lowering in image quality caused by the adhesion of toner to a light emitting part or an image forming element by preventing the penetration of toner or paper dust into a space where LED and the image forming element are opposed, by blocking said space form the open air by using a deformable seal member. CONSTITUTION:A large number of LEDs 17 are linearily arranged to a base board 18 comprising ceramic and a heat dissipating plate 19 is adhered to said base board 18. An image forming element 21 such as a SELFOC lens held by a holding member 20 is provided so as to be opposed to the aforementioned LEDs 17 to constitute an LED array head 5. In this case, an adjustment means 30 for adjusting the distance between the base board 18 and the holding member 20 such as a nut is provided and a deformable seal member (for example, comprising rubber of foamed urethane) 27 surrounding the space 32 between the LEDs 17 and a coupling element 21 is interposed between the base board 18 and the holding member 20. By this mechanism, the distance of a light emitting part and the image forming element 21 is adjusted to enable the optimum adjustment of a focal point. USE:An LED printer using electrophotographic system.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an LED array head in an LED printer using an electrophotographic method.

BACKGROUND OF THE INVENTION In recent years, printing devices have been actively developed, and one of them is a laser printer. However, since this method uses a laser device, a modulator, a deflection device, a special lens, etc., the structure becomes complicated and the entire device becomes large. In this regard, an electrophotographic optical writing printer can simplify the structure and reduce the size. In such an optical writing type printer, there is a risk that foreign matter such as 1-hener used in the developing device may adhere to the light source portion or the imaging element, resulting in a decrease in image quality.

Therefore, in printers using liquid crystal light valves,
As shown in Japanese Unexamined Patent Publication No. 57-70569, a sealing member is used to isolate the space between the liquid crystal light valve and the imaging lens from the outside air, thereby preventing toner from adhering to the liquid crystal light valve. . However, if the conjugate length of the imaging lens varies, it is necessary to adjust the distance between the liquid crystal light bulb and the imaging lens, but it is impossible to adjust the distance between them. Even if a distance W & adjustment means is provided, the adjustment and movement range will be restricted by the presence of the sealing body, making it meaningless and creating a gap that will impair the function of the sealing body. There is also. In the end, it is impossible to obtain an optimal imaging state because optimal focus adjustment is impossible.

Purpose The present invention has been made in view of the above points, and it is possible to prevent toner, paper waste, etc. from adhering to the light source part and the imaging element, and also to enable adjustment of pins 1 to 1 of the imaging element.
The object of the present invention is to obtain an LED array head that can improve image quality.

composition An embodiment of the present invention will be described based on the drawings.

First, FIG. 1 schematically shows an LED printer, in which a photoreceptor belt 3 is stretched between a driving roller 1 and a driven roller 2 that are driven in the direction of the arrow.
A charger 4 facing the photoreceptor belt 3 uniformly charges the surface of the photoreceptor belt 3, an exposure device 5 forming an electrostatic latent image on the photoreceptor belt 1-3 by selectively emitting light from an LED, and a latent image being visualized. A developing device 6 for imaging is provided. Further, a paper feed roller 8 is provided which takes out the transfer paper 7 at a predetermined timing, and the transfer paper 7 taken out by the paper feed roller 8 is sent to the transfer device 11 via a separation roller 9 and a registration roller 10. The developed image on the photoreceptor belt 3 is transferred onto the transfer paper 7 in this transfer device 11 . After transfer, transfer paper 7
is sent to a fixing device @12 where it is fixed, and then ejected by a paper ejection roller 13.

On the other hand, the surface of the photoreceptor bell 1-3 is treated by a static eliminator 14 and a cleaning device 15 in preparation for the next image formation. 16
is a back unroller that prevents the photoreceptor belt 3 from being dented or the like.

Here, the exposure device 5 is based on an LED array head, and as shown in FIGS. 2 to 4, a large number of L
a substrate 18 made of ceramic or the like on which EDs 17 are arranged in a linear manner;
A heat sink 19 and a holding member 20 to which this base FiL 8 is attached
It consists of an imaging element held by, for example, a SELFOC lens 21 or the like.

One end of a wire 22 for connection is bonded to the electrode (for example, the anode side) of each LED 17 arranged on the substrate 18, and the other end of this wire 22 is connected to a wiring pattern (not shown) in a 71-lix configuration on the substrate 18. A lead wire 23 connected to the outside is soldered to this wiring pattern. Further, another electrode (for example, the cathode side) of the LED 17 contacts a wiring pattern (not shown) in another layer on the substrate 18, and this wiring pattern is connected to a lead wire (not shown) at the end of the substrate 18. Connected to the outside world. Pins 24 having threaded portions are attached to both ends of the holding member 20, and a brush assembly 26 having brushes 25 whose tips come into contact with the photoreceptor bells 1 to 3 is attached to the lower part over the entire circumference. These brushes 25 prevent foreign matter such as toner and paper waste used in the developing device 6 from being blown onto the lower surface of the SELFOC lens 21.

A seal member 27 is interposed between the holding member 20 and the heat sink 19, and a compression spring 2 is attached to the pin 24.
8 and then attach the heat dissipation Fi19 62 to these pins 24.
9 and screwed together with a nut 1-30, which is an adjustment means. Note that the seal member 2
7 is formed into a frame shape with an opening 31 in the center, and this sealing member 27 and the substrate 18 facing vertically
The space 32 surrounded by the holding member 20 and the like is maintained in a state of being isolated from the outside air. Therefore, entry of 1-ner and paper waste into the space 32 is prevented, and the LED
17 to the light emitting part and the top surface of the SELFOC lens 21.
This prevents the adhesion of toner, etc. Further, the seal member 27
is formed of various easily deformable rubbers, foamed urethane, etc., and the sealing member 27 is compressed and deformed depending on the degree of tightening of the neck 1-30, and the optimum distance between the light emitting part of the LED 1.7 and the Selfoc lens 21 is set. Make adjustments. The thickness of the sealing member 27 is the same as that of the LED1.
Even when the light emitting section 7 and the SELFOC lens 21 are adjusted to the maximum distance, the space 32 is maintained in a compressed state, and the space 32 is always kept isolated from the outside air. Furthermore, the gap 1 of the sealing member 27
31 is a sufficiently large opening that does not obstruct the optical path of the LED 17 and does not touch the wire 22 even when the sealing member 27 is deformed due to compression.

Therefore, deformation or disconnection of the wire 22 does not occur.

Pins 33 having threaded portions are firmly planted at both ends of the heat sink 19, and after fitting the compression springs 34, these pins 33 are inserted into the holes 37 of the blocks 35 and 36, and nuts 38 are screwed into them. . A pair of blocks 35.3G fixed to both ends of the heat sink 19 are connected by a plate 39 located above the heat sink 19. Furthermore, this board 3
Numeral 9 is fixedly attached to a rail, which will be described later, and the optimum distance between the self-off lens 21 and the photoreceptor bell h3 can be adjusted by tightening the nut 1-38.

The exposure device 5 configured in this way has a rail 4 fixed between the side plates 40 and 41 of the printer body shown in FIG.
2 by engaging the bent portion 43 of the plate 39 with the edge 44 of the rail 42. This support is
This is done by pushing in the bent part 43 from the direction of arrow A while engaging the edge 44, inserting the pin 45 fixed in one of the blocks 35 into the hole 46 of the side plate 40, and inserting the pin 45 into the hole 46 of the other block 36. 47 and the screw hole 48 of the side plate 41 and tighten the screw (not shown) to fix the exposure device 5. Note that the distance adjustment using the Nara 1-30.38 may be performed after the exposure device 5 is fixed.
Since it is difficult to confirm the best imaging condition, it is preferable to adjust the focus in advance using an adjustment jig (not shown) using the pin 45 and the hole 47 as a reference.

A cooling fan motor 49 is installed outside the side plate 40, and the air blown from the fan motor 49 flows through the hole 50 of the side plate 40 into a duct formed in the exposure device @5. ) A portion passes through the shell 51 and reaches the hole 52 of the side plate 41, where it is discharged outside the printer body. This Doug 1 part 51
is formed by the plate 39 and a pair of heat dissipating fins 53 having a long height dimension cut out on the back surface of the heat dissipation plate 19, and the heat dissipation plate 19 further includes a plurality of heat dissipation fins 53 located between the fins 53. A rectangular fin 54 with a short height dimension is provided. The wind from the fan motor 49 cools each fin 53, 54, prevents a temperature rise due to the light emission of the LED 17, and prevents a change in the emission wavelength of the LED 17 due to a temperature change.

Effects The present invention can prevent toner and paper waste from entering into this space by using a sealing member to isolate the space where the LED and the imaging element face each other like a double series from the outside air. Therefore, it is possible to prevent the image quality from deteriorating due to the adhesion of 1 henna to the light emitting part and the imaging element of L E I).In addition, since the seal member is made of a deformable material, the light emitting It is possible to perform optimal pin 1 adjustment by adjusting the distance between the lens and the imaging element, thereby improving the image quality.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG.
A schematic side view of the D printer, FIG. 2 is an enlarged vertical cross-sectional side view of the exposure device, and FIG. 3 is a vertical cross-sectional front view showing a part of the exposure device. FIG. 5 is a perspective view of a support device that supports the exposure device. 17...LED, 18...Substrate, 20...Holding member. 21 ・Selfoc lens (imaging element), 27...
Seal member, 30...Nut (adjustment means), 32-Space Applicant Rico Co., Ltd.-

Claims (1)

[Claims] A large number of LEDs are linearly arranged on a substrate, an imaging element held by a holding member is provided facing the LED, and an adjusting means for adjusting the distance between the substrate and the holding member is provided. between the substrate of the LED and the holding member.
Qtitl is an LED array head in which a deformable sealing member surrounding a space between the image forming element and the image forming element is interposed.