JPH0355511A - Light beam scanner - Google Patents

Abstract

PURPOSE:To decrease the number of components and to reduce the cost by fitting a beam position sensor to a substrate where an electronic component for driving a light source part as the cover of a scanner unit frame is mounted. CONSTITUTION:The beam position sensor 18 is fitted to the substrate 42 where the electronic component mounting for driving the light source provided with the cover of the housing is mounted. This beam position sensor 18 is for obtaining the synchronizing signal of a main scanning beam and fitted on the reverse surface of the substrate 42 opposite the fitting position of a mirror 20 for the beam position sensor. Consequently, no dedicated substrate is provided, the number of components is decreased, and the cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application Fields The present invention provides a light beam scanning device using a rusk scan method, and more specifically, a light beam scanning device that uses a rusk scan method, and more specifically, a light beam scanning device that uses a light source, a light deflector, and a beam position sensor without providing a dedicated board. The present invention relates to a light beam scanning device that can be attached to an electronic component mounting board of a cover of a housing that integrally accommodates an image means.

Conventional technology> The Rusk scan method, which is a scanning method used in television picture tubes, etc., is a scanning method used in television picture tubes, etc., to finally transfer images such as text, pictures, photographs, and videos onto recording materials such as paper and film. It is used in an image scanning exposure device of an image recording device that obtains a visible image, and in a scanning reader that reads a document.

The following description will mainly be made using an image recording apparatus as an example. This Rusk scan method is also called the television scan method, and it scans the screen sequentially in a one-dimensional direction, for example, from left to right, and sub-scans it in a direction approximately perpendicular to the main scanning direction, for example, from top to bottom. This is a scanning method.

Conventionally, in an image scanning exposure apparatus using this Rusk scan method, a solid laser such as a semiconductor laser (LD), a laser light source such as a gas laser and a liquid laser, a light emitting element such as a light emitting diode (LED), and a mercury lamp, A light source such as a xenon lamp or a sodium lamp is used, and the light beam emitted from such a light source carries image information and is deflected one-dimensionally by a light deflector such as a polygon mirror or galvanometer mirror. At the same time as scanning, a recording material such as a photoreceptor or a photosensitive material is conveyed by a sub-scanning conveying means in a direction substantially perpendicular to the main scanning direction, sub-scanned, and exposed two-dimensionally. This exposed recording material is then processed by a processing device to finally obtain a two-dimensional visible image on paper, film, or the like.

Therefore, on the recording material, a large number of parallel main scanning lines are defined at regular intervals in the sub-scanning direction by the deflection of the optical deflector, thereby forming a striped rask at prescribed intervals. When obtaining a visible image on a recording material using such an image scanning exposure device, usually the main scanning line is started to be formed and/or
Alternatively, it is necessary to detect the completion time, and generally a beam position sensor placed on the scanning light beam is used as the beam position detection means.

The beam position sensor can be installed at a position where it can directly receive the light beam scanned by the optical deflector, or at a position where it can indirectly receive the scanning light beam whose angle and position have been adjusted using a mirror or glass fiber. There are things that can be attached to.

The mirror is mounted for a start sensor and/or an end sensor before or after the means for imaging the light beam scanned by the light deflector onto the photosensitive material.

Incidentally, image scanning exposure apparatuses generally house an optical system in a housing to prevent atmospheric pollution and to simplify maintenance.

Electronic components, such as electronic components for driving light sources, are
It is mounted on a board in a predetermined part of the housing, such as the board that forms the top surface of the housing. On the other hand, the beam position sensor, which is the beam position detection means, requires a lead wire, and this lead wire must be brought to the outside of the housing or to the board for electronic components. Conventionally, this beam position sensor is placed on the main scanning line outside the recording material, such as a photoreceptor, of an image exposure apparatus, as shown in FIG. 4, for example.

In the image exposure apparatus shown in the figure, a light beam emitted from a semiconductor laser 1 is reflected and deflected by an optical deflector (polygon deflector) 2 that rotates clockwise, and passes through a scanning lens (fθ lens) 3. After that, the top of the photoreceptor 4 is scanned from bottom to top.

Here, the beam position sensor 5 is usually provided with a substrate on an extension of the main scanning line on the photoreceptor 4 within a housing or frame (not shown) that accommodates these optical systems, and is placed on this substrate. , directly receives the scanning light beam.

In addition, in the image scanning exposure apparatus shown in FIG. 5, a beam position sensor mirror 7 is provided between the fθ lens 3 and the downward mirror 6, and the light beam is moved from the vicinity of the photoreceptor 4 to activate the scanning optical system. By guiding the beam to a predetermined position within the housing frame, the beam position sensor 5 can be provided at any position outside the optical system within the frame.

In addition, the image recording device shown in FIG. 6 has a beam position sensor 5 attached to a board on which electronic components are mounted, such as one for driving a light source, so that a separate board for the beam position sensor is not required, and a fiber tube 8 is used to perform scanning. The light beam is guided from the main scanning line extension on the photoreceptor 4 to the beam position sensor 5.

Problems to be Solved by the Invention> By the way, the beam position sensor 5 shown in FIG. 4 has to be provided on or near the main scanning line on the outside in the longitudinal direction of the photoreceptor 4, and the size of the sensor and the size of the sensor substrate are limited. The problem is that the size is restricted. In addition, in the case of the one shown in Fig. 5, although the size of the sensor is not restricted, a board for the sensor is essential inside the housing or frame that houses the optical system, and lead wires must be routed from the board to the outside of the housing. The problem is that it is costly. Furthermore, although the sensor shown in FIG. 6 eliminates the need for a sensor substrate, it uses an expensive optical fiber, so there is a problem in that it is costly. In addition, if this continues, a two-part sensor that provides high accuracy cannot be applied.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to perform two-dimensional scanning using a rask scan method that uses a main scanning of a light beam by an optical deflector and a sub-scanning by conveying a recording material or a read document. In a light beam scanning device, a housing that integrally accommodates a beam position sensor, a light source, a light deflector, and an imaging means without providing a dedicated board;
That is, the object of the present invention is to provide a light beam scanning device that is attached to a substrate on which electronic components for driving a light source section, etc., which serve as a cover for a scanner unit frame are mounted.

Means for Solving the Problems> In order to achieve the above object, the present invention provides at least one light source, an optical deflector for scanning a light beam emitted from the light source, and a scanning method using the optical deflector. means for forming an image of the scanned light beam on a recording material or a read document; a beam position sensor for detecting the scan start and/or scan end timing of the scanned light beam; A light beam scanning device including a mirror guiding the sensor to the sensor, and a housing that integrally accommodates at least the light source, the optical deflector, the imaging means, and the mirror, wherein the beam position sensor is provided on a cover of the housing. The present invention provides a light beam scanning device which is attached to the electronic component mounting board for driving the light source.

Preferably, the beam position sensor is attached to an electronic component mounting surface of the substrate.

Further, it is preferable that the beam position sensor is a two-split sensor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A light beam scanning device according to the present invention will be described in detail below based on a preferred embodiment of an exposure device shown in the accompanying drawings.

FIGS. 1 and 2 are an explanatory sectional view and a plane layout diagram of essential parts of an embodiment of an image scanning exposure apparatus of the present invention.

As shown in FIGS. 1 and 2, the image scanning exposure apparatus 10 of the present invention basically includes a light source section 12, a surface tilt correction optical system 14, a light deflector (polygon mirror) 16, and a beam The beam position sensor 18 includes a position sensor 18, a beam position sensor mirror 20, an fθ lens 36 as an imaging means, and a scanner unit frame 44 that includes a housing that integrally accommodates these. It is attached to a substrate 42 on which electronic components 45 for driving the light source section 12, a member for adjusting the light source output, etc. are mounted, and this substrate 42 includes the light source section 12, an f-theta lens 36, and a downward cylindrical roller 38. This serves as a cover for the upper surface of the scanner unit frame 44 that integrally houses the scanner unit frame 44.

Since the image scanning exposure apparatus 10 of the present invention is capable of color image exposure, the light source section 12 has three colors, for example, yellow (
Y) light source 22Y5, magenta (M) light source 22M, cyan (C) light source 22C, their driving source (located above the board), and a collimator lens that adjusts the beam diameter of the light beam emitted from each light source. 24Y, 24M, 24C and Y
A main reflective mirror 26Y that reflects the light beam 23Y emitted from the Y light source 22Y in a predetermined direction, at least the Y light source 2
2Y, and reflects the light beam 23M from the M light source 22M in the same direction. A dichroic mirror 26C that transmits the light beam 23M and reflects the light beam 23C from the C light source 22C in the same direction, a cylindrical lens 30 for correcting surface tilt, and a reflecting mirror 26Y1 and a dichroic main mirror 26M and 26C to form a light beam 23Y. ,23
It is composed of a reflecting mirror 32 that reflects a light beam 27 in which M and 23C are unified toward a cylindrical lens 30. In the example shown in FIG. 1, for color image exposure, three color light sources 22Y, 22M, 22C, their driving sources, collimator lenses 24Y, 24M, . 24C, and three color light sources 22Y, 22M. A reflection mirror 26Y1 and a dichroic mirror 26M and 26C are provided to unify the light beams 23Y, 23M, and 23C emitted from the light source 22G, but in the case of monochrome image exposure, the light source, its driver, and collimator lens are provided. , only one set of reflective main beams is required.

The polygon mirror 16 is an optical deflector for deflecting the light beam 27 in one-dimensional direction, and has a plurality of mirror surfaces 18a. The example shown in Figure 1 consists of eight mirror surfaces. The polygon mirror 16 is rotated at a constant speed by a drive source 34 such as a motor. Although the polygon main mirror 16 is used as the optical deflector in the present invention, any optical deflector that can deflect one optical beam in one dimension may be used. For example, a rotating mirror may be used. It is possible to use a galvanometer mirror that uses a swinging mirror, or the like.

A light beam 27 that has been deflected in one-dimensional direction by the polygon a mirror 16 is deflected from 27a to 27b, and the deflected light beams 27a to 27b are transmitted through a scanning lens 36 such as an fθ lens, which is an imaging means, mirror 3
The optical system is configured to form one main scanning line on the recording material 40 which is reflected by the main scanning line 8 and lowered to be transported by a sub-scanning transport means (not shown). Here, the main scanning line defines one rask.

At this time, the cylindrical lens 30 and the cylindrical roller 38 constitute a surface tilt correction optical system 14 that corrects the scanning position deviation caused by the surface tilt of the mirror surface 16a of the polygon mirror 16, and together with this, the scanning lens 36 focuses the light beams 27a to 27b deflected by the polygonal mirror 16 onto the surface of the recording material 40 through a cover glass 46. 46 is an opening 44 in the scanner unit frame 44
This is a cover glass provided to cover A and prevent contamination within the frame.

The deflected light beam directed downward by the cylindrical mirror 38 is imaged through a cover glass 46 onto a recording material 40 provided outside the scanner unit frame 44 . The beam position sensor 18 is the most characteristic part of the present invention, and is a part of the electronic component 4 for driving the light source section 12.
It is attached to a board 42 that carries 5 etc. The mounting position of the beam position sensor 18 is opposite to the mounting position of the beam position sensor a-lar 20 on the substrate 4.
Attach to the bottom of 2. Further, as shown in FIG. 3, an opening 42a is provided in the substrate 42, and the beam position sensor 18 is mounted on the electronic component mounting surface side of the substrate 42, that is, on the upper surface side, at a position where the light beam can be received through the opening 42a. You can also place In this case, the beam position sensor 18
Although it is advantageous in terms of maintenance because it is easy to conduct electrical wiring, it is necessary to make an opening 42a.

Here, the mounting position of the beam position sensor l8 may be any position as long as the scanning start timing and scanning end timing can be detected.
0 main scanning line and the optical position is the same as the sensor mounting position when provided outside the recording material 40, that is,
For example, it is preferable that the optical path length from the fθ lens 36 is at or near a position where the optical path lengths are equal.

The beam position sensor 18 is for obtaining a synchronization signal of the main scanning beam, and the method of obtaining the synchronization signal from timing signals such as scan start time and scan end time obtained by the beam position sensor 18 is known in the art. The synchronizing signal can be generated, for example, by the method disclosed by the applicant of the present invention in Japanese Patent Laid-Open No. 60-142320 and Japanese Patent Laid-open No. 60-142321.

The beam position sensor 1B used in the present invention may be any sensor as long as it can detect the beam position, and may be a commonly used Fuichi sensor, but preferably a two-split sensor. In this device, a highly accurate two-part sensor can be easily attached to the substrate 42, thereby improving beam position detection accuracy. The beam position sensor mirror 20 may be provided between the fθ lens 36 and the cylindrical mirror 38 or on the output side of the cylindrical mirror 38, and can adjust the angle and position of the light beam. Further, the beam position sensor mirror 20 may be integrated with the cover glass 46, and in this case, the position of the beam position sensor 18 must be adjustable on the substrate 42. In addition, when only the scan start timing of the light beam is detected, the start sensor a-ra 20a on the lower side as seen in FIG.
It is sufficient to provide only one beam position sensor and one beam position sensor corresponding to this mirror 20a. When only the scan end timing is to be detected, an end sensor mirror 20b (upper side in FIG. 1) and a sensor corresponding to this mirror 20b may be provided as the mirror 20.

Of course, in the case of detecting both the scan start time and the scan end time, two mirrors 20a and 20b and corresponding sensors are required. In addition, in the above explanation, the effective scanning width (
Although the scanning light beam corresponding to the outside of the main scanning line segment llI1) on the recording material is detected using the mirror 20 and the sensor 18, a half mirror is arranged that acts on the entire beam width of the scanning light beam. However, a synchronization signal may be obtained by disposing the half mirror (correspondingly, a plurality of sensors or a two-split sensor, for example, a two-split sensor) on the substrate 42 to detect the scan start time and/or scan end time. Alternatively, by arranging the grid and the photodetector or sensor on the substrate 42,
A direct synchronization signal may also be obtained.

Although the image scanning exposure apparatus according to the present invention has been described using the color image scanning exposure apparatus shown in FIG. 1 as a representative example, the present invention is not limited thereto, and the light beam scanning apparatus of the present invention can be used. It can be modified as appropriate depending on the image recording device or reading device that can perform the image recording. In addition, such an image recording device may be a color or monochrome copying device, or a variety of image processing devices having an image reading unit, such as a computer, a video camera, or an optical disk. The processing device may be a color or monochrome printer that receives the processed color or monochrome image information and records a color or monochrome image. The recording material used may be a photosensitive drum or a color or monochrome photosensitive material as described above. Therefore, the image recording apparatus to which the present invention can be applied may be either color or monochrome, but for example, the image recording apparatus disclosed in Japanese Patent Application No. 63-241-552 filed by the present applicant is suitable. First, electrophotographic image recording devices, silver salt photographic image recording devices, thermal transfer image recording devices, inkjet image recording devices, laser printers, laser copying devices, video printers, video copying devices, and various other photosensitive materials. For example, image recording apparatuses using photosensitive pressure-sensitive materials, photosensitive resin materials, etc. can be mentioned.

Although the light beam scanning device according to the present invention is basically configured as described above, the present invention is not limited to this, and various improvements and changes in design can be made without departing from the gist of the present invention. Of course, this is possible.

Effects of the Invention> Since the present invention is configured as described above, the above-mentioned recording is performed using a rask scanning method that uses a main scanning of a light beam by an optical deflector and a sub-scanning by conveying a recording material or a read document. As a light beam scanning device that two-dimensionally exposes a material or a document to be read, a beam position sensor is integrated with a light source, a light deflector, and an imaging means without providing a dedicated board in the housing of this light beam scanning device. It can be attached to the board of the cover of the housing to be accommodated, reducing the number of parts and making maintenance easier.
It can be made more compact and costs can be reduced. Furthermore, the two-split sensor can be easily attached, and the light beam position can be detected with high accuracy.

[Brief explanation of drawings]

FIG. 1 is an explanatory sectional view of an embodiment of an image scanning exposure apparatus according to the present invention. FIG. 2 is a plan layout of essential parts of an embodiment of the image scanning exposure apparatus according to the present invention. FIG. 3 is a partial cross-sectional view of another embodiment of the invention. 4 to 6 are explanatory diagrams of main parts of a conventional image scanning exposure apparatus. Explanation of symbols! ... Semiconductor laser, 2... Optical deflector (borigon deflector), 3... Scanning lens (fθ lens), 4... Photoconductor, 5... Beam position sensor, 6... Falling down. Mirror 7... Beam position sensor mirror '8... Fiber tube, 10... Image scanning exposure device, 12... Light source section, 14... Surface tilt correction optical system, 16... Light deflection Vessel (polygon mirror), 16a...
Mirror surface, 18... Beam position sensor, 20... Mirror 20a for beam position sensor... Mirror 20b for start sensor... For end sensor [ra 22Y, 22M, 22C-... Light source, 24Y, 24M, 24C...Collimator lens, 26Y...Reflection mirror 26M, 26C...Dichroic mirror 27, 27a
, 27b... Light beam, 30... Cylindrical lens, 32... Reflective mirror 34... Drive source, 36... Scanning lens (fθ lens), 38... Cylindrical lens 40... ...Recording material, 42...Substrate, 42a...Opening hole, 44...Scanner unit frame 44a...Opening hole, 45...Drive electronic component, 46...Cover glass FIG. 3 FIG. 4 FIG. 5 4 FfG. 6

Claims (1)

[Claims] (1) At least one light source, a light deflector that scans the light beam emitted from the light source, and means for forming an image of the light beam scanned by the light deflector onto a recording material or a read document. a beam position sensor that detects the scan start and/or scan end timing of the scanned light beam; a mirror that guides the light beam to the beam position sensor; and at least the light source, the optical deflector, and the image forming device. A light beam scanning device having a housing that integrally accommodates the means and the mirror, characterized in that the beam position sensor is attached to a board for mounting an electronic component for driving the light source, which is provided on a cover of the housing. A light beam scanning device.