JP2625702B2 - Optical printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of arranging a plurality of point light sources such as light emitting diodes in at least one row and selectively lighting these point light sources to form dots on a photoreceptor surface. The present invention relates to an optical printer that forms a divided image.

[Prior Art] In general, in this type of optical printer, light emitting diodes are used as point light sources, and the light emitting diodes are arranged in a plurality, in a row or in a plurality of rows to constitute an exposure device for image formation. A selfoc lens is arranged between the exposure device and the photoconductor, so that light from the exposure device is imaged on the photoconductor surface via the selfoc lens.

In this case, the relative distance relationship and the optical axis relationship between the exposure device and the SELFOC lens need to be set within a prescribed range with high accuracy. Therefore, conventionally, as shown in a longitudinal sectional view of FIG. 4, an exposing device 2 in which light emitting diodes are arranged in one row (or a plurality of rows) on a substrate 1 made of ceramic or the like in the depth direction of the figure is screwed to a spacer 3. Further, a selfoc lens 5 is sandwiched between the light emitting direction sides of the exposing unit 2 using inverted L-shaped angles 4a, 4b, and the angles 4a, 4b are structured to be screwed to the spacer 3, so that the exposing unit 2 and the selfoc lens 5
Is adjusted by shifting the SELFOC lens 5 in the direction of the arrow A, and the optical axis relationship is adjustable by shifting the angles 4a and 4b in the direction of the arrow while the spacer 3 is fixed. I have.

The exposure unit 2 and the selfoc lens 5 integrated in this manner are fixed to the housing frame by the angle indicated by the broken line of the spacer 3, and the image forming relationship with the photoconductor (not shown) is fixed.

[Problems to be Solved by the Invention] However, in the case of large optical printers such as A2 size, A1 size, and A0 size in which the size of the recordable paper is large, the length of the exposure unit, ie, the direction in which the light emitting diodes are arranged in one line However, since the length of the lens becomes long, the exposing device itself is bent by its own weight or heat generation, and the image forming relationship with the selfoc lens is changed, so that an image is not formed on the photosensitive member.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical printer that can maintain a normal image forming relationship even when a sheet size increases.

[Means for Solving the Problems] The present invention has a reference surface that regulates a relative distance relationship and an optical axis relationship between the exposure device and the SELFOC lens, and the exposure device and the SELFOC lens are provided on the reference surface. The above object is achieved by providing a heat-radiating / holding substrate for integrally holding the substrate by screwing or bonding.

[Operation] The exposure device and the SELFOC lens are integrally fixed to a reference plane that regulates the relative distance relationship and the optical axis relationship.
Therefore, as long as the holding substrate itself does not bend, the two are maintained in a normal imaging relationship, and heat is radiated.

Embodiment FIG. 1 is a perspective view of a main part showing an embodiment of the present invention. A light emitting diode chip (LED chip) 11 is arranged in a line on a substrate 10 made of ceramic or the like. Make up 12. Each LED chip 11 of the exposure unit 12 is connected to the signal line 1
3 electrically connects to the drive signal input terminal 14. Further, the substrate 10 is fixed to the mounting surface 16 of the holding substrate 15 made of, for example, an aluminum material, which also serves as heat radiation, by bonding or screwing. On the other hand, the SELFOC lens 17 configured by bundling a number of converging lenses is fixed to the mounting surface 19 by screwing or bonding with the incident surface side in contact with the vertical surface of the convex portion 18 provided on the holding substrate 15. ing. Reference numeral 20 denotes a photosensitive drum.

Here, the dimensional relationship between the mounting surfaces 16 and 19 is set as a reference surface that regulates the optical axis relationship between the exposure device 12 and the SELFOC lens 17 to a specified value. The dimensional relationship of the vertical plane of the convex portion 18 is set as a reference surface that regulates the relative processing relationship between the exposure device 12 and the SELFOC lens 17.

By fixing the exposure unit 12 and the SELFOC lens 17 by defining the reference plane in this manner, the exposure unit 12 does not bend unless the holding substrate 15 itself is bent, and the cross-sectional view of FIG. As shown in (1), a normal imaging relationship can always be maintained. In addition, heat is radiated, and the deflection can be suppressed to be small.

FIG. 3 is a perspective view showing another embodiment of the present invention in which the exposure device 12 and the SELFOC lens 17 are fixed using an L-shaped holding substrate 15 '. ′ Is fixed to the vertical surface of the holding substrate 15 ′ by the flat cable 22, and the signal terminal 25 of the light emitting diode is fixed to the vertical surface of the holding substrate 15 ′ by screwing. Have been. On the other hand, the SELFOC lens 17 is fixed to a mounting surface 24 formed by cutting out an end of a horizontal surface of the holding substrate 15 ′, and light emitted from the exposure unit 12 travels as shown by an arrow and enters the photoconductor 20. It is configured as follows.

In this configuration, the vertical surface of the holding substrate 15 'and the mounting surface
24 serves as a reference plane similar to the mounting surfaces 16 and 19 in FIG. 1 described above, and the height h of the notch in the mounting surface 24 is similar to the vertical plane of the convex portion 18 in FIG. It serves as a reference plane.

[Effects of the Invention] As described above, in the present invention, since the exposure device and the SELFOC lens are integrally fixed to the reference surface of the holding substrate, the present invention is intended for a large-sized sheet. Also, a normal image-forming relationship can be maintained without the exposure device being bent.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, and FIG.
FIG. 3 is a perspective view showing another embodiment of the present invention, and FIG. 4 is a cross-sectional view showing a conventional holding structure for an exposure device and a selfoc lens. 10 …… Substrate, 11 …… LED chip, 12 …… Exposure device, 13 ……
Signal line, 14 ... input terminal, 15 ... holding board, 16, 19, 24 ...
… Mounting surface, 17… Selfoc lens, 18… Protrusion, 20
... Photoconductor, 21 ... Spacer, 22 ... Flat cable, 23 ... Presser plate.

Claims (1)

(57) [Claims] 1. An image forming exposure apparatus in which a plurality of point light sources are arranged in at least one row. Each of the point light sources is selectively turned on in accordance with an image signal, and is applied to the surface of the photoreceptor via a selfoc lens (registered trademark). An optical printer for forming a dot-divided image upon incidence, comprising: a reference surface for regulating a relative distance relationship and an optical axis relationship between the exposing device and the SELFOC lens (registered trademark); And Selfoc Lens (registered trademark)
An optical printer comprising a holding substrate that also serves as a heat sink that integrally holds the substrate by screwing or bonding.