JPH0723932B2 - Lighting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an image forming apparatus utilizing an electrostatographic process such as an electrophotographic copying machine, in which charge is removed from a non-image area on the surface of the image carrier. The present invention relates to a lighting device.

(Prior Art) Conventionally, as a device of this type, a plurality of LEDs (light emitting diodes) each including a transparent cylindrical portion and a convex lens-shaped light collecting portion at the irradiation side tip are arranged so as to face the surface of the image carrier. However, there is a method in which these LEDs are appropriately turned on to eliminate static electricity in the non-image area of the image carrier.

However, in this case, the light emitted from the condensing portion of the LED effectively removes electricity, but a part of the light flux projected from the cylindrical portion irradiates the image area and adversely affects image formation. In addition, there is a problem that a portion where the light amount is reduced occurs between the adjacent LEDs, resulting in insufficient static elimination.

Therefore, in order to solve the above-mentioned problems of the prior art, the present applicant transmits and diffuses light to the irradiation side tips of the light emitting elements 23 and 24 provided with the light emitting sources 21 and 22, as shown in FIG. In addition to providing rectangular transmission and diffusion treated surfaces 25 and 26, the light emitting element 2
At least around the irradiation side tip portions 27 and 28 of 3,24, reflection processing surfaces 29 and 30 for reflecting the light from the light emitting sources 21 and 22 to the transmission diffusion processing surfaces 25 and 26 are formed, and the light emitting element concerned. We have already proposed a configuration in which convex lenses 32 and 33 are arranged between the image carrier 31 and 23 and 24 (Japanese Patent Application No. 60-2187). As shown in FIG. 7, by forming the images of the transmission diffusion processing surfaces 25 and 26 on the image carrier 31 through the convex lenses 32 and 33, harmful light does not enter the image area, Moreover, the non-image areas B and C can be eliminated with the same light amount without any gap.

(Problems to be Solved by the Invention) However, in the above illumination device, as shown in FIG. 8, a position between the optical axes of the convex lenses 32 and 33 and the centers of the transmission diffusion processing surfaces 25 and 26 is set. If there is a displacement X, Y, and the image forming magnification of the convex lenses 32, 33 is M, the convex lenses 32, 33 are inverted images. 3
Since XM and YM corresponding to the imaging magnification occur in the same direction as the displacement direction of 3,
There is a problem that an unexposed region D represented by D = X (1 + M) + Y (1 + M) is generated.

The present invention has been made in order to solve such problems of the prior art, and an object of the present invention is to carry out image carrying even when there is a positional deviation between the transmission diffusion processing surface and the lens system. An object of the present invention is to provide an illuminating device capable of illuminating the body with no space and removing static electricity.

(Means for Solving the Problems) Therefore, in order to achieve the above-mentioned object, the present invention provides a light emitting element whose light emitting surface is subjected to transmission diffusion treatment, and light emitted from this light emitting element on an image carrier. A lens for forming an image on the
The lens is a gradient index lens for erecting the light emitted from the light emitting element on an image carrier.

(Example) Below, this invention is demonstrated based on the Example shown in figure. Third
In the figure, an image forming apparatus 2 using an illuminating device 1 according to the present invention is shown.
The image forming apparatus 2 is formed in the shape of a rotary cylinder, and is covered with a lens system 4 on the surface of an image carrier 3 which is uniformly charged beforehand by a charging unit (not shown). The image of the copy document M is formed to form an electrostatic latent image. Further, the image forming apparatus 2 is a so-called variable-magnification type image forming apparatus in which copies having different sizes can be obtained from the copy original M of the same size by adjusting the position of the lens system 4. ing. The scaling may be performed stepwise or continuously.

In this case, depending on the copy magnification, the width D is the image area in the illustrated case with respect to the effective image area width A of the image carrier 3, and the side edge areas B and C adjacent to the image area D are shown. The portion of is a non-image area.

The illuminating device 1 is arranged in the non-image areas B and C of the image carrier 3, and the illuminating device 1 includes the light emitting elements 5 and 6 and the lens as shown in FIGS. 1 and 2. It consists of 7,8. In this case, LEDs are used as the light emitting elements 5 and 6.

The light emitting elements 5 and 6 are formed in a substantially rectangular parallelepiped shape by a transparent member, and the irradiation side tip portions 9 and 10 thereof are thinned into a substantially square columnar shape, and the base end portion thereof, Light emitting chips 11 and 12 are embedded as light emitting sources. This irradiation side tip
The tip surfaces of 9,10 are formed in a rectangular shape similar to the cross section of the light emitting elements 5,6. Transmission diffusion processing surfaces 13 and 14 having a high efficiency and diffusing light are formed. In addition, the side surfaces of the irradiation side tip portions 9 and 10 are curved surfaces that are convexly curved outward, and the light from the light emitting chips 11 and 12 is reflected on the transmission diffusion processing surfaces 13 and 14 on the inner surface thereof. Reflection treated surfaces 15 and 16 are formed. The reflection processing surfaces 15 and 16 are formed into appropriate curved surfaces so that the light amount distributions of the transmission and diffusion processing surfaces 13 and 14 are uniform.

Lenses 7 and 8 are disposed between the light emitting elements 5 and 6 and the image carrier 3 configured as described above, and the lenses 7 and 8 are used for the transmission diffusion processing surface 13 of the light emitting elements 5 and 6. , 14 erect images on the image carrier 3
It consists of a gradient index lens (self-focusing lens: a product name of Nippon Sheet Glass) that is imaged on the top. The gradient index lenses 7 and 8 are, as shown in FIG.
In the case where the array pitch is p and the length of the transmission diffusion processing surfaces 13 and 14 is 1, an erect image is formed at an enlargement ratio of p / l. Normally, P> l, but P-1 = E is relatively small, so P
When ≈l, the enlargement ratio becomes close to 1.

With the above configuration, the illumination device according to the present invention illuminates the surface of the image carrier as follows. That is, the light emitting elements 5 and 6 and the gradient index lenses 7 and 8 are arranged so that the light emitting elements 5 and 6 face the image carrier 3 as shown in FIG. The luminous flux emitted from the light emitting chips 11 and 12 of the light emitting elements 5 and 6 is applied to the transmission diffusion processing surfaces 13 and 14 directly or after being reflected by the reflection processing surfaces 15 and 16. Then, the transmission diffusion processing surfaces 13 and 14 diffuse the luminous flux and shine with high brightness, and at the same time transmit the light to become a rectangular secondary light source. The images of the transmission diffusion processing surfaces 13 and 14 which shine in a rectangular shape are erected on the image carrier 3 via the gradient index lenses 7 and 8.

Then, as shown in FIG. 6, the centers C ₁ and C ₂ of the transmissive diffusion treated surfaces 13 and 14 of the light emitting elements 5 and 6 and the gradient index lenses 7 and 8 are disposed.
Even if positional deviations X and Y in the opposite directions occur between the axes C ₃ and C ₄ of the gradient index lenses 7 and 8 when the magnification of the gradient index lenses 7 and 8 is M. Is an erect image, the image forming magnifications XM and YM are opposite to the direction of deviation of the gradient index lenses 7 and 8 with respect to the amounts of deviation X and Y of the gradient index lenses 7 and 8.
Is corrected, so that the unexposed area D on the image carrier 3 is corrected.
Becomes D = X (M-1) + Y (M-1). Note that this equation becomes D = X (1-M) + Y (1-M) when the displacement direction shown in FIG. 6 is matched with the displacement direction shown in FIG. Here, since M can be regarded as approximately 1 as described above, the area D where the charge is not removed even if the refractive index distribution type lenses 7 and 8 are displaced is so small as to be negligible (D≈0).

Moreover, as described above, the rectangular transmission and diffusion treated surface 1
The images of 3, 14 are formed on the image carrier 3, and the light from other parts does not reach the image carrier 3. Therefore, the surface of the image carrier 3 is illuminated in a shape similar to the transmission diffusion processing surfaces 15 and 16, and the other portions are not exposed to the light. Therefore, the light emitting elements 5 and 6 and the gradient index lenses 7 and 8 are arranged so that the areas illuminated by the light emitting elements 5 and 6 are adjacent to each other without a gap.
By adjusting the position of, the light amount distribution on the surface of the image carrier 3 can be such that no light leaks to the image area D and only the non-image areas B and C are uniformly illuminated, as shown in FIG. You can
The non-image areas B and C are uniformly discharged. The light from the light emitting elements 5 and 6 may be overlapped at the boundary between the non-image area B and the non-image area C by adjusting the magnification of the gradient index lenses 7 and 8.

In the illustrated embodiment, the case where the non-image areas B and C exist only on one side of the image area D on the image carrier 3 has been described, but on both sides of the image area D on the image carrier. It is needless to say that the present invention can be applied even when there is a non-image area.

Further, since the illuminating device of the present invention illuminates in a rectangular shape, the light emitting elements are arranged along the entire axial length of the image carrier, and the image carrier corresponding to the front end portion or the rear end portion beyond the image area is arranged. It can also be used when the body surface is irradiated with light to erase charges.

Further, in the illustrated embodiment, the case where the illumination device of the present invention is used to eliminate the static electricity in the non-image area caused by the reduction ratio has been described, but a plurality of light emitting elements of the present invention are arranged in the axial direction of the image carrier. By arranging the individual pieces and changing the light emission timing, it is possible to eliminate the charge on an arbitrary part of the image carrier.

(Effects of the Invention) The present invention has the above-described configuration and operation. Since the gradient index lens of the erect image formation is arranged between the transmission diffusion processing surface of the light emitting element and the image carrier, the transmission diffusion Even if there is an error in the relative position between the processing surface and the gradient index lens, the gradient index lens forms an image of the transmission diffusion processing surface on the image carrier so as to cancel this error. Even if there is an error in the mounting position of the rate distribution type lens, the image bearing member is illuminated without overlapping images or gaps, eliminating static electricity in the non-image area during zooming and erasing part of the image. Etc. can be performed in a sharp manner.

[Brief description of drawings]

1 to 4 relate to the present invention, FIG. 1 is a perspective view showing an illuminating device according to the present invention, FIG. 2 is a horizontal sectional view of the same, and FIG. 3 is an illuminating device according to the present invention. FIG. 4 is an explanatory view showing an image forming apparatus to which the above-mentioned illumination is applied, FIG. 4 is a graph showing a light amount distribution characteristic of the illumination device, FIGS. 5 and 6 are explanatory views showing the operation of the illumination device, FIG. 7 and FIG. FIG. 7 relates to a conventional example, FIG. 7 is a perspective view showing a conventional illuminating device, and FIG. 8 is an explanatory diagram showing an operation of the illuminating device. Explanation of symbols 1 ... Illumination device, 3 ... Image carrier 5,6 ... Light emitting element, 7,8 ... Gradient distribution type lens 9,10 ... Irradiation side tip part, 11, 12 ... Light emitting chip 13,14 …… Transmission diffusion surface 15,16 …… Reflection surface, B, C …… Non-image area

Claims (1)

[Claims] 1. A light emitting element having a light emitting surface whose transmission and diffusion processing is performed, and a lens for forming an image of light emitted from the light emitting element on an image carrier, and capable of eliminating charges on the image carrier. In the illumination device, the lens is a gradient index lens for erecting the light emitted from the light emitting element on an image carrier.