JPH03231269A - Recorder - Google Patents

Abstract

PURPOSE:To reduce density irregularities in an output image by providing a light-shielding member shielding a part of generated light from a fine light emitting segment array and uniformizing the distribution of a light quantity on a sensitized body over an array direction between the fine light emitting segment array and the sensitized body. CONSTITUTION:In an optical writing unit 13 provided to be opposed to the sensitized body 12, a phosphor dot array 14 is used as the fine light emitting segment array, and a roof mirror lens array 15 is used as an image-forming optical system. The light-shielding member 27 shielding a part of recording luminous flux is provided to face an optical path between the dustproof glass 26 of the unit 13 and the sensitized body 12. In the distribution of the light quantity in the array direction of the generated light of the phosphor dot array 14, for instance, when its brightness is high on both end parts in the array direction and low on the central part, the light-shielding member 27 is made into a shape so as to have a light-shielding part 27a advancing on the width of the recording luminous flux (d) and shielding a part of the luminous flux of both end sides greater as it goes to the end part side. Thus, the density irregularities in the output image are reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a solid-state scanning electrophotographic recording apparatus that performs optical writing and recording using a microscopic light-emitting segment array in pixel units, such as a phosphor dot array.

2. Description of the Related Art Conventionally, there is a recording apparatus of this type as shown in FIG. First, around the photoreceptor 1 which is rotationally driven in the direction of the arrow, according to the electrophotographic process, there is a charger 2, an optical writing unit including a micro light emitting segment array 3 and an imaging element 4, a developing device 5, a transfer charger 6, and a separation charger 7. , a cleaning device 8 and a static elimination lamp 9 are arranged in this order. Thereby, the light emitted from the minute light emitting segment array 3 in pixel units is modulated according to the image information, and the image forming element 4 causes the imaging element 4 to scan the surface of the photoreceptor 1 for exposure. At this time, the surface of the photoreceptor 1 has been uniformly charged by the charger 2, and an electrostatic latent image is formed by exposure. This is visualized by the developing device 5 and transferred by the action of the transfer charger 6 onto the transfer paper 10 fed at a predetermined timing. Thereafter, it is separated from the photoreceptor 1, subjected to fixing processing by the fixing device 11, and then discharged.

Here, the minute light emitting segment array 3 is L E
There are D arrays, liquid crystal shutter arrays (LSC arrays), phosphor dot arrays, etc. Further, as the imaging element 4, a SELFOC lens array, a roof mirror lens array, or the like is used. Further, as a recording method, a negative/positive recording method is adopted. That is, a portion of the surface of the photoreceptor 1, which is negatively charged, corresponding to an image area is exposed to light, and toner is attached to the portion where the surface potential of the photoreceptor has decreased due to this exposure, thereby developing the image.

Therefore, if there is a large variation in the light amount of each pixel of the micro light emitting segment array 3 that exposes the surface of the photoreceptor 1, there will be a large difference in the surface potential of the exposed portion, which will appear as density unevenness on the image, and the image will be distorted. This will reduce the quality.

Therefore, for example, JP-A No. 62-168321, JP-A No. 62-184759, JP-A No. 62-16846,
According to Publication No. 3, in a device using a phosphor dot array, it is possible to eliminate unevenness in the light intensity distribution (which tends to be low at the center and high at both ends) caused by differences in cathode filament voltage. In order to make the light intensity distribution uniform, the structure of the phosphor dot array itself and the electrical drive conditions are being devised. Also, actual fairness 1
According to Japanese Patent No. 21804, in an apparatus using an LED array, it is shown that variations in the amount of light of each LED array can be electrically corrected to make them almost at the same level.

Problems to be Solved by the Invention However, even if the structure of the phosphor dot array itself and the electrical drive conditions are devised (generally by varying the emission time), in reality, it is technically extremely difficult and requires a correction circuit. It is also complicated and requires a large electrical burden, making it expensive. This also applies to other micro light emitting segment arrays such as LED arrays.

Means for Solving the Problem The light emitted from a micro light emitting segment array in pixel units is modulated according to image information, and this modulated light is exposed and scanned onto the photoreceptor surface via an imaging optical system to form an electrostatic latent image. In a recording device that forms an electrostatic latent image and visualizes this electrostatic latent image,
The invention according to claim 1 provides a light shielding member having a light shielding portion formed in a shape that blocks part of the light generated from the micro light emitting segment array and makes the light amount distribution on the photoreceptor surface uniform in the array direction. It was provided between the micro light emitting segment array and the photoreceptor.

In the invention as claimed in claim 2, the light emitted from the micro light emitting segment array is inserted into the slit opening of a slit member such as a flare light prevention member or a dustproof member provided in the optical path between the micro light emitting segment array and the photoreceptor. A light-shielding portion was formed to have a shape that blocks a portion of the light to uniformize the light amount distribution on the photoreceptor surface in the array direction.

Effect The variation in the light intensity of the micro light emitting segment array is caused by the light blocking part of the light blocking member or the light blocking part of the slit member, which is formed in a shape that equalizes the light intensity distribution on the photoreceptor surface in the array direction, and some of the light with a large light intensity is It is made uniform by blocking light. Therefore, density unevenness in the output image is reduced. This can easily be done by devising the shape of the light shielding part.

In particular, according to the invention as set forth in claim 2, since a part of the dustproof member etc. provided in advance is utilized, it is possible to correct the light amount distribution without increasing the number of parts and saving space.

Embodiment A first embodiment of the present invention will be described with reference to FIGS. 1 to 4. The basic recording method shall be similar to that shown in FIG. The optical writing unit 13 of this embodiment, which is provided opposite to the photoreceptor 12, has a phosphor dot array 14 as a minute light emitting segment array, and a roof mirror lens array 15 as an imaging optical system. First, the phosphor dot array 14 is made by forming phosphors in a dot array shape on a glass substrate 16 and vacuum-sealing the dots with a face glass 17, so that each light emitting point 18 can selectively emit light (
The details are based on those described in the above-mentioned publication), and are attached to the bottom of the housing 19 of the optical writing unit 13. Here, the housing 19 has a slit opening 20 that is long in the array direction and allows the light generated from the light emitting points 18 to pass through.
is formed. This slit opening 2o also plays the role of preventing flare light. Such a phosphor dot array 14
is fixed to the bottom of the housing 19 by a rigid base 23 with screws 22 via an elastic member 21 from below.

Further, the roof mirror lens array 15 is composed of a roof mirror array 15a, an aperture plate 15b, and a lens array 15c, and is inserted into a groove formed in an elongated direction parallel to the phosphor dot array 14 on the upper side of the housing 19. , is pressed from the back side by a leaf spring 15d. Furthermore, a mirror 24 is provided above the phosphor dot array 14 to reflect the light generated from the light emitting point 18 and make it enter the roof mirror lens array 15 side. Further, at the front end of the housing 19, there is a slit opening 25 for preventing flare light, which allows only the recording light emitted from the roof mirror lens array 15 to pass through to the photoreceptor 12 side.
A slit member 25 having a diameter a is provided, and the slit opening 25a is closed by a dustproof glass 26.

Therefore, in this embodiment, a light shielding member 27 is provided to face the optical path between the dustproof glass 26 of the optical writing unit 13 and the photoreceptor 12 and to shield a part of the recording light flux. . This light shielding member 27 has a light intensity distribution in the array direction (main scanning direction) of the light generated by the phosphor dot array 14, as shown in FIG. 2(a), for example, as shown in FIG. If there is a
As shown in FIG. 3(a) or (b), it has a shape that includes a light shielding portion 27a that extends into the recording light beam width d and blocks a portion of the light beam on both end sides to a greater degree as the end side becomes closer. FIG. 3(a) shows an example of the light shielding member 14 having an open top end shape, and FIG. 3(b) having a slit structure with a recording beam width of 4 or more.

FIG. 4 shows the light shielding situation near the end when the light shielding member 14 shown in FIG. 3(a) is used, and the shaded area 28 is the light shielding area. Therefore, the light intensity becomes lower towards the edges due to the shielding, and becomes equal to the light intensity level near the center, and the light intensity distribution on the main scanning line as seen on the photoreceptor 12 is as shown in Figure 2 (
As shown in b), it becomes almost uniform.

In other words, even if there are variations in the light intensity distribution of the light generated from the phosphor dot array 14, the light shielding member 27, which is shaped so that the light intensity distribution seen on the photoreceptor 12 is uniform, is connected from the light emitting point 18 to the photoreceptor 12. By providing it facing into the optical path, the light amount distribution can be easily corrected to make it uniform. If space permits, the light shielding member 27 may be provided anywhere within the above range. Furthermore, the light shielding member 27 may be made of any material such as sheet metal or glass as long as it can shield light.

Furthermore, as shown in FIGS. 5 and 6, if a light shielding member 27 having light shielding portions 27a both above and below the recording beam width d is used, a more uniform light quantity distribution can be achieved.

Further, the shape of the light shielding part 27a of the light shielding member 27 is based on the light amount distribution characteristic of the phosphor dot array 14.
For example, in the case of the light intensity distribution shown in Figures 7(a) to (C), a shape that cancels out the uneven distribution as shown in Figures 8(a) to (C), respectively. Just take it as a thing.

Next, a second embodiment of the present invention will be described with reference to FIG. The embodiment described above uses a solid-state scanning type optical writing unit 13.
In addition, a light shielding member 27 is provided separately, but in an imaging optical system that uses a same-magnification imaging element such as a SELFOC lens array 15c or a roof mirror array 15a, the object and image distances are extremely short. Therefore, it may be difficult to insert and arrange the light shielding member 27 as described above into the empty space in the optical path. Therefore, in this embodiment, the shape of the slit opening 25a of the dustproof slit member 25 provided as a part of the optical writing unit 13 is devised without providing a separate light shielding member. That is, the shape of the slit opening 25a (=dustproof glass 26) is set so that it has a width such that it has a light shielding part 25b that blocks part of the light, similar to the shape of the slit opening of the light shielding member shown in FIG. 3(b), for example. The narrow shape makes the light amount distribution on the photoreceptor 12 uniform in the main scanning direction. According to this, it is extremely simple, and the light amount distribution can be corrected while keeping the space as before.

Furthermore, a third embodiment of the present invention will be explained with reference to FIG. This embodiment is similar to the above embodiment, but a light shielding portion is provided in a part of the slit opening 20 for preventing flare light in the housing 19 (which serves as a slit member in this embodiment) that forms a part of the optical writing unit 13. 20a and has the same function as the light shielding member 27.

Further, a fourth embodiment of the present invention will be explained with reference to FIG. In this embodiment, the light amount distribution in the main scanning direction on the photoreceptor 12 is made more uniform with higher precision.

That is, since the conventional light amount distribution correction is performed only by electrical correction, the electrical load is large, and if the amount of correction is large, the correction cannot be completed. Therefore,
In this embodiment, in order to reduce the electrical load, mechanical correction is performed using the light shielding member 27 or slit opening as in the above-mentioned embodiment, and electrical correction is further added. . That is, by mechanically correcting the uneven light intensity distribution as shown in FIG. 11(a) using the light shielding member 27, etc., the distribution is made uniform to a certain extent and coarsely adjusted as shown in FIG. 11(b). ), the amount of light that cannot be uniformized by mechanical correction is finely adjusted by adding conventional electrical correction, thereby achieving a uniform light amount distribution as shown in FIG. 3(C).

Effects of the Invention As described above, the present invention has a light shielding part formed in a shape that blocks part of the light generated from the micro light emitting segment array and makes the light amount distribution on the photoreceptor surface uniform in the array direction. Since a light shielding member is provided, or a light shielding part is formed at the slit opening of a slit member such as a flare light prevention member or a dustproof member provided in the optical path, variations in the amount of light that the micro light emitting segment array has can be prevented by the light shielding part. By blocking part of the light with a large amount of light, it is possible to make the light uniform, thereby reducing the density unevenness of the output image.This can be done simply by devising the shape of the light blocking part.In particular,
According to the invention as set forth in claim 2, since a part of the dustproof member etc. provided in advance is utilized, it is possible to correct the light intensity distribution without increasing the number of parts and saving space.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional side view showing the first embodiment of the present invention, and the second
3 is a front view showing the shape of the light shielding member, FIG. 4 is a vertical side view showing the light shielding situation, and FIG. 5 is a front view of the light shielding member showing a modified example. Fig. 6 is a vertical side view showing the light blocking situation, Fig. 7 is a characteristic diagram showing an example of uneven light intensity distribution, Fig. 8 is a front view showing the shape of the light blocking member corresponding to Fig. 7, and Fig. 7 is a characteristic diagram showing an example of uneven light distribution. 9] is a longitudinal side view showing a second embodiment of the present invention, Fig. 10 is a longitudinal side view showing a third embodiment of the present invention, and Fig. 11 is a longitudinal side view showing a fourth embodiment of the present invention. FIG. 12 is a side view showing the configuration of a general solid-state scanning recording device. 12・Photoreceptor, 14・・Minute light emitting segment array,
15... Imaging optical system, 20... Slit aperture, 20
a... Light shielding part, 25... Slit member, 25a...
・Slit opening, 25b... Light shielding part, 27... Light shielding member, 27a... Light shielding part Ryoganjin Co., Ltd.] Figure 2 Figure 3.3 Figure 7 Figure 7 Main figure 1b-0 7)” Figure collection JZ diagram, I, 1 O b 2 Pa J

Claims (1)

[Claims] 1. The light emitted from the micro light emitting segment array in pixel units is modulated according to image information, and the modulated light is exposed and scanned on the photoreceptor surface via an imaging optical system to generate electrostatic latent light. form an image,
In a recording device configured to visualize this electrostatic latent image, the shape is such that a portion of the light generated from the micro light emitting segment array is blocked to make the light amount distribution on the photoreceptor surface uniform across the array direction. 1. A recording apparatus characterized in that a light shielding member having a light shielding portion formed therein is provided between the micro light emitting segment array and the photoreceptor. 2. Modulating the light emitted from the micro light emitting segment array in pixel units according to image information, and exposing and scanning the modulated light onto the photoreceptor surface via an imaging optical system to form an electrostatic latent image;
In a recording device configured to visualize this electrostatic latent image, a slit of a slit member such as a flare light prevention member or a dustproof member provided in an optical path between the micro light emitting segment array and the photoreceptor. A recording device characterized in that a light shielding portion is formed in the opening in a shape that blocks part of the light generated from the micro light emitting segment array to make the light amount distribution on the photoreceptor surface uniform in the array direction.