JPH03259107A - Optical unit - Google Patents

Abstract

PURPOSE:To obtain the optical unit with small-sized. lightweight constitution and sufficient strength, rigidity, and dust protection by clamping an optical element by a positioning means and fixing it at specific position when a housing is constituted. CONSTITUTION:Optical elements are mounted on respective support parts of a housing 12, a housing 14 is put on the housing 12 at a specific position, and both are fixed. When the optical elements are fixed by the support parts 38a and 42a, a pressing member such as a leaf spring is provided to the support part 42a and the optical elements are pressed and fixed. The optical unit 16, therefore, has sufficient strength, specially, torsional rigidity without being reinforced variously by increasing or decreasing the thickness of a reinforcing member, so that the small-sized, lightweight optical unit 16 which has sufficient strength and superior in dust protection is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an optical unit in which an optical system such as a light beam scanning optical system arranged in an image recording device or an image reading device is integrated into a unit.

<Prior Art> In various image recording devices and image reading devices, in order to increase the productivity of the device and to facilitate repair, maintenance, etc., a light beam light source, a light beam! , a main scanning optical system that includes various optical elements such as an optical deflector, mirrors, and lenses, which deflects the image information in the main scanning direction, and a recording material such as a document carrying image information, a stimulable phosphor sheet, or a photosensitive material. The sub-scanning conveyance system for conveying in the sub-scanning direction substantially orthogonal to the main-scanning direction is formed into a unit, and the apparatus is configured by combining the two.

Among the constituent units of such a device, an optical unit that is a unit of an optical system such as the above-mentioned main scanning optical system generally includes a light beam source for image recording or reading,
Various optical elements such as an optical deflector that reflects and deflects the light beam in the main scanning direction, lenses, light control members such as filters and apertures, and mirrors for adjusting the optical path, and optics that support these optical elements in predetermined positions. Consists of a light-shielding housing that serves as a surface plate and is open at the top, a fixing member that secures the optical element to the housing, and a dustproof lid that prevents dirt and dust from entering the unit. be done.

<Problems to be Solved by the Invention> In other words, the housing of such an optical unit is constructed by fixing a single plate-shaped lid to a casing whose top is open as described above.

However, since this housing is based on a casing with an opening at the top, it has the problem of low strength and rigidity, especially torsional rigidity, and the positioning of optical elements may be affected by impact during transportation or after installation. There is a risk that the position may be misaligned, or even breakage or malfunction may occur.

Therefore, in a typical optical unit, various reinforcing members are arranged on the casing that serves as the optical surface plate, and thick materials are used for each component such as the casing, the lid, and the reinforcing members.
The housing of the optical unit is constructed to have sufficient strength by taking reinforcing measures such as adding ribs to the casing and lid, or increasing the height of the side walls of the casing.

However, if such a method is used to improve the strength and rigidity of the optical unit, especially the housing, it is impossible to avoid an increase in the size and weight of the optical unit, which poses a problem.

An object of the present invention is to solve the problems of the prior art as described above, and has sufficient strength and rigidity without increasing size or weight (small size and light weight), and also has excellent dust resistance. The objective is to provide an optical unit.

<Means for Solving the Problems> In order to achieve the above object, the present invention comprises at least one optical element, a housing for accommodating the optical element, and a positioning system for the optical element provided at a predetermined position. and a pair of housings provided with means, and when the housing is constructed by combining the pair of housings, at least one optical element is fixed in a predetermined position by being held by the positioning means. An optical unit is provided.

<Operation of the Invention> In the optical unit of the present invention having the above-mentioned predetermined configuration, the housing constituting this unit is not composed of a housing and a plate-like unit as in conventional optical units, but is composed of a pair of housings. Configure the housing by combining the casings,
Furthermore, both of these casings function as optical surface plates.

That is, in the optical unit of the present invention, the positioning means and the fixing means for the optical element are formed or arranged on both of the pair of casings constituting the housing, and at least one optical element is sandwiched between the two casings. Place and fix in place.

Therefore, the optical unit of the present invention is different from the conventional optical unit in which the housing is constructed by fixing a plate-shaped casing to the casing, and the housing is constructed by fixing a pair of casings together. It has sufficient strength, especially high torsional rigidity, without the need for various reinforcements such as additions or increasing the thickness of component parts, and even though it is small and lightweight,
It is possible to obtain an optical unit that has sufficient strength and is also excellent in dust resistance.

Moreover, since the various optical elements are placed and fixed in predetermined positions by being sandwiched between the pair of housings that make up the housing, there are no need for plate springs or screws to fix the optical elements, which are unnecessary in conventional optical units. It is possible to significantly reduce the number of fixing members such as, etc., it is possible to increase the packaging density of optical elements, and it is also possible to reduce the size of the optical unit.

<Embodiments> Hereinafter, an optical unit according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

FIG. 1 is a schematic exploded perspective view when the optical unit of the present invention is applied to a light beam scanning unit, and FIG. 2 is an assembled sectional view thereof.

The illustrated light beam scanning unit 10 is a light beam scanning unit commonly used in image recording devices, image reading devices, etc., and emits a light beam for image recording or reading and deflects it in the main scanning direction. and basically constitutes the housing of the light beam scanning unit 10.
A pair of light-shielding housings 12 and 14, and various optical elements that are positioned and fixed at predetermined positions within the housing by the housings 12 and 14, that is, in the illustrated example, a light source unit 16, a polygon mirror 18, and a lens 2Oa.
and 20b, and a downward mirror 22.

Such a light beam inspection unit 10 has holes 24a and 24b1 holes 26a and 26b1 holes 2aa formed in each housing.
and 28b1 and holes 3Oa and 30b, respectively, and combine the casings 12 and 14 as shown in FIG. After positioning the elements, some of the optical elements are held between supporting parts formed on both the housings, and each optical element is arranged at a predetermined position.

In the light beam scanning unit 10, a light beam (second
The light emitted from the light source unit 16 is reflected and deflected by the polygon mirror 18 in the main scanning direction (in the direction of arrow a in FIG. The focal point is adjusted so that it converges on a predetermined position, and the mirror 22 lowers the object to be scanned through the opening 32 of the housing 12, such as a recording material such as a photosensitive material or a stimulable phosphor sheet. The object is incident on a sub-scanning unit that sub-scans and conveys the object in a direction substantially perpendicular to the main scanning direction (in the direction indicated by the arrow in FIGS. 1 and 2), and the object to be scanned is two-dimensionally scanned.

In such a light beam scanning unit 10&:, the housing of the light beam scanning unit 10 is constituted by each combination of the casings 12 and 14.

The housing 12 includes a light source support part 34 that supports the light source unit 16, an opening part 36 that supports the polygon mirror 18,
A support portion 38a that supports the lens 20a, and a lens 20b
A support portion 38b that supports the mirror 22, and a support portion 40 that supports the downward mirror 22 are formed.

Kazuo, the housing 14 has a support part 42 that supports the lens 20a.
a, a support portion 42b that supports the lens 20b, and a support portion 44 that supports the downward mirror 22.

That is, in the illustrated light beam scanning unit 10, the light source unit 16 is fitted into the light source support part 34, and the polygon mirror 18 is fitted into the opening 36, so that
Further, the lens 20a is held by the support parts 38a and 42a, the lens 20b is held by the support parts 38b and 42b, and the standing mirror 22 is held by the support parts 40 and 44, respectively, so that they are positioned and fixed at a predetermined position. be done.

The optical unit of the present invention, typified by the light beam scanning unit 10 having such a configuration, does not require various housing reinforcement means such as adding a reinforcing member unlike conventional optical units. It has sufficient strength and rigidity, especially torsional rigidity.

In other words, as described above, in the conventional optical unit, an optical element is arranged and fixed at a predetermined position in a housing that is open at the top, and then a dustproof plate-shaped lid is fixed to the housing. Therefore, since the housing basically consists of a case that is open at the top, it is inevitable that the strength, especially the torsional rigidity, will be low, so it is necessary to add reinforcing members, make the structural members thicker, etc. It is necessary to take various reinforcing measures, and it is impossible to avoid an increase in the size and weight of the device.

On the other hand, the optical unit of the present invention consists of a pair of casings, and in the illustrated light beam scanning unit 10, a housing is constructed by combining and fixing a pair of casings 12 and 14. Rather than a lid, both the casings 12 and 14 serve as optical surface plates, and together they constitute a housing. Therefore, sufficient strength and rigidity can be obtained without taking various reinforcing measures. Furthermore, since each optical member is supported and fixed by a pair of housings, the number of means for fixing optical elements such as leaf springs and screws can be significantly reduced compared to conventional optical units. It can also be improved. Therefore, although the optical unit of the present invention has sufficient strength and rigidity, especially torsional rigidity,
Compared to conventional optical units, it can be made smaller and lighter.

There is no particular limitation on the material of the housings 12 and 14, and various metals such as aluminum, BMC (Bulk Molding
All materials commonly used in conventional optical units can be used, such as resins such as Compound. Further, as for the manufacturing method thereof, a known method such as casting, press molding, resin molding, etc. may be used depending on the material and shape of the housings 12 and 14.

When assembling such a light beam scanning unit 10, first, optical elements corresponding to each support portion of the housing 12 are placed (inserted). Then holes 24a and 2 are opened as described above.
4b, etc., and stack the housing 14 on the above-mentioned predetermined position on the housing 12, and fix the two together using means such as bolts and nuts.

When an optical element is clamped and fixed in a predetermined position as in the case of the supporting parts 38a and 42a, this supporting/fixing method involves directly clamping and fixing the optical element between both supporting parts as shown in FIG. For example, as shown in FIG. 3, a pressing member such as a leaf spring 46a (a leaf spring 46b on the support part 42b) or a spring may be provided on the support part 42a, so that one support part is pressed against the other support part. Alternatively, the optical element may be fixed by pressing the optical element.

Note that the optical element positioning means applicable to the present invention is as follows:
The present invention is not limited to the recesses and support parts as shown in the illustrated example, and all known positioning means such as positioning pins and protrusions can be used.

In addition to the method of assembling the casings 12 and 14 to form a housing, in addition to the method of aligning the holes 24a and 24b and fixing them with screws, bolts, and nuts, there is also a method of forming recesses and protrusions at corresponding positions on each casing. Various known methods can be used, such as a method in which a housing is provided and the two are fitted together, a method in which one housing fits into the other housing, and the like.

Furthermore, when assembling the casings 12 and 14, in addition to the corners as shown in the illustrated example, by fixing them at important points such as points 46 and 46, the light beam scanning unit 10 ( optical unit).

The light source unit 16 emits a light beam in a predetermined direction, and in the illustrated example, a He-Ne laser 52 as a light beam source, a mirror 54, and a beam expander 56 are provided on a base 50. Fixed and configured.

The laser beam emitted from the He-Ne laser 52 is
The beam is reflected onto a predetermined optical path by the mirror 54, its beam diameter is adjusted by the beam expander 56, and then enters the polygon mirror 18 through the opening 58 of the housing 12.
In addition to the He--Ne laser, various known gas lasers and semiconductor lasers can be used as the light beam source that can be used in the present invention.

In addition to the beam expander, various adjustment parts such as collimator lenses are also installed.
The light beam source J may be configured to directly create a light beam on the polygon mirror 18 without going through various optical elements.

The laser beam incident on the polygon mirror 18 is
It is reflected and deflected in the main scanning direction shown by . The optical deflector is not limited to the illustrated polygon mirror 18, and any known optical deflector such as a galvanometer mirror or a resonant scanner can be used.

The light beam reflected and deflected in the main scanning direction by the polygon mirror 18 has its focus adjusted by the scanning lens 2o so that it converges on a predetermined position, and is lowered downward by the drop mirror 22 and is transmitted through the aperture 32 as shown in the figure. The object to be scanned, such as a photosensitive material or a stimulable phosphor sheet, which is conveyed in the sub-scanning direction indicated by the arrow 2, is scanned two-dimensionally, and image reading and image processing are performed. Recording is done.

In addition, the optical unit of the present invention... The optical elements arranged in the cut are not limited to those mentioned above, but may include, if necessary, cylindrical lenses and cylindrical mirrors that make up the optical system for correcting surface tilt, filters for adjusting the light beam, and apertures. ,
Furthermore, all necessary optical elements such as a condensing guide and a photodetector may be arranged in one place.

Such an optical unit of the present invention is disclosed in JP-A-55-12429 and JP-A-55-11 to which a stimulable phosphor sheet is applied.
Suitable for various uses, including radiation image information recording and reproducing systems disclosed in various publications such as No. 6340, image recording devices such as various printers and copying machines, and image reading devices commonly used in image recording devices. Applicable to

Although the optical unit and unit of the present invention have been described in detail above, the optical unit of the present invention is not limited to the above embodiments, and within the scope of the gist of the present invention,
Of course, various improvements and changes may be made.

<Effects of the Invention> As explained in detail above, the optical unit of the present invention has 1
．． A housing is made up of a pair of casings, and both of the casings that make up the housing have a function as an optical surface plate, and both of the pair of casings that make up this housing have a positioning means and a fixing means for the optical element. The optical element is formed or arranged, and by sandwiching the optical element between the two housings, it is arranged and fixed at a predetermined position.

Therefore, the optical unit of the present invention has sufficient strength, especially torsional rigidity, without the need for various types of reinforcement (improvement of housing strength) such as adding reinforcement parts or increasing the thickness of the constituent members. Unlike conventional optical knees, which require reinforcement of the housing strength, they are small, lightweight, and have sufficient strength.
Moreover, it is possible to obtain an optical unit that is excellent in dust resistance.

Moreover, since the optical element is fixed by being held between the pair of housings that make up the housing, the number of fixing parts such as leaf springs and screws that were required in the past to fix the optical element can be greatly reduced. It is possible to increase the packaging density of the optical stack f-, and to roughly reduce the size of the optical unit 7'.

[Brief explanation of drawings]

FIG. 1 is an exploded schematic perspective view of an example in which the optical unit according to the present invention is applied to a light beam scanning knee kit. 2 is a schematic cross-sectional view of the light beam scanning unit shown in FIG. 1. FIG. FIG. 3 is a schematic perspective view showing another example of the support section for the optical element of the light beam scanning unit shown in FIG. 1. Explanation of symbols 10...Light beam scanning unit)-, 2.14''...Housing, 16...Light source unit, 18...Polygon mirror 20...Scanning lens, 20a, 20b-- Lens , 22... Hanging mirrors 24a, 24b, 26m, 26b. 28a, 28b, 30a, 30b-... Hole, 32...
Opening, 34... Light source support part, 36... Opening, 38a, 38b, 40, 42a. 42b, 44... Support part, 46m, 46b... Leaf spring, 50... Base, 52... He-Ne laser, 54... Mirror 56... Beam expander FIG, 1

Claims (1)

[Claims] (1) At least one optical element and a pair of casings that constitute a housing for accommodating the optical element and are provided with positioning means for the optical element provided at a predetermined position, and the pair of casings are combined. An optical unit characterized in that, when constructing the housing, at least one optical element is fixed in a predetermined position by being held by the positioning means.