JPH04156165A - Image reader - Google Patents

Abstract

PURPOSE:To reduce the maintenance work to sweep away stuck dust or the like by providing a dustproof means which has the dustproof action for an image forming lens and/or an image pickup element. CONSTITUTION:Unless the reader is used for the purpose of converting picture information formed on image pickup elements 44a to 44c to an electric signal to read information, image forming lenses 28a and 28b and/or image pickup elements 44a to 44c are protected by the dustproof means. That is, the position of a turntable 24 is displaced until an image pickup unit 40 is brought into contact with a bracket 18 through a mobile base 36. As the result, image forming lenses 28a and 28b are protected from dust by a lens cover 30, and the image pickup unit 40 is protected from dust, which penetrates the unit 40 through an aperture part 31, by the turntable 24. Thus, the frequency in cleaning maintenance of image forming lenses 18a and 28b and image pickup elements 44a to 44c is reduced.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides a method for applying light to a document carrying image information.
The present invention relates to an image reading device that reads this transmitted light or reflected light using an optical/electrical conversion element.

[Prior Art] This type of device basically consists of a light source, an imaging lens, and an image sensor, and emits light from the light source onto a document carrying image information, and converts the transmitted light or reflected light into The light is focused by an imaging lens and imaged on an image sensor.

In this case, cliffs, etc. may adhere to the lens surface of the imaging lens and the imaging surface of the image sensor, which may prevent the image information from being read correctly from the document imaged on the image sensor. .

Therefore, maintenance work is required to remove dust and the like adhering to the imaging lens and the image sensor, and this maintenance work is dependent on human labor.

[Problem to be solved by the invention] Therefore, 1. Maintenance work for cleaning cliffs and the like adhering to the imaging lens and the image sensor is frequently required, and a large amount of maintenance cost is required.

The present invention solves this type of problem, reduces maintenance work for cleaning cliffs etc. attached to the imaging lens and image sensor, and significantly reduces labor costs for the maintenance work. An object of the present invention is to provide an image reading device capable of reading images.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a light source that irradiates light onto a document carrying image information, and a light source that irradiates light onto the document and transmits or reflects light irradiated onto the document. an imaging lens for condensing light; an imaging element for converting transmitted light or reflected light focused by the imaging lens into an electrical signal; and a dust-proof coating for the imaging lens and/or the imaging element. The present invention is characterized by comprising a dust-proofing means having a function.

[Function] In the image reading device according to the present invention, illumination light is irradiated from a light source to a document carrying image information, and this transmitted light or reflected light is focused by an imaging lens to form an image on an imaging device. .

The imaging lens and/or the imaging element are protected by a dustproof means except when in use, such as when image information formed on the imaging element is converted into an electrical signal and read. As a result, the imaging lens and the image sensor can be maintained in a clean state, so that high-quality images can be read over a long period of time, and the burden on maintenance work is reduced.

[Embodiments] Next, preferred embodiments of an image reading apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates an image reading device according to this embodiment. Housing 1 constituting the image reading device 10
1, a light-transmissive document table 12 made of a glass plate or the like is disposed so as to be movable forward and backward in the sub-scanning direction (direction of arrow M). A light source 14 constituting a transmitted illumination mechanism is provided above the document table 12 and extends in the main scanning direction substantially perpendicular to the direction of the arrow M, while a light source 14 emitted from the light source 14 is provided below the document table 12. Image reading unit 1 that photoelectrically reads the illumination light
6 is arranged.

The image reading section 16 includes a bracket 18, and the bracket 18 has a holding plate 19 extending at one end thereof. This bracket 18 is parallel and in the optical axis direction (
It engages with a ball screw 20 extending in the direction of the arrow X in FIG. .

A rotary table 24 that also serves as a dustproof member is supported on the upper part of the holding plate 19 via a support shaft 23, and a belt 27 that engages with a rotary drive source 26 fixed to the holding plate 19 is supported on this rotary table 24. is set up. In addition, in the figure, reference numeral 25 indicates a hole formed in the holding plate 19.

The rotary table 24 is made of a circular plate, and imaging lenses 28a and 28b are disposed on the circular plate, spaced apart from each other at equal angles.
The distances from the supporting shaft 23 to the respective centers are selected so that the centers thereof can be arranged on the optical axis P.

Next, a lens cover 30, which is a lens housing section, is fixed to the holding plate 19. This lens cover 30
is provided with an opening 31 through which the luminous flux of the illumination light passes, and the surface perpendicular to the optical axis is arranged so as to face the respective imaging lenses 28a and 28b when the imaging lenses 28a and 28b are rotationally displaced. It is set up.

Further, a ball screw 32 extending in the optical axis direction parallel to the ball screw 20 is rotatably supported on the bracket 18, and a rotational drive source 34, which is a driving means for the imaging unit, is connected to an end of the ball screw 32. are doing. The movable base 36 is engaged with the ball screw 32, and the imaging unit 40 is held on the movable base 36.

The imaging unit 40 includes a color separation prism 42 and CCDs 44a to 44C, which are imaging elements fixed to the color separation prism 42. The illumination light incident on this color separation prism 42 is 3
The light is separated into two directions and introduced into the CCDs 44a to 44c.

The image reading device according to this embodiment is basically constructed as described above, and its operation and effects will be explained next with reference to FIGS. 1 to 3.

When the image reading device 10 is powered on and the light source 14 is energized, the image reading unit 16 and movable parts such as the unillustrated transport unit of the document table 12 move to their home positions.

For example, as shown in FIG. 2a, in the image reading unit 16, the rotating table 24 rotates via the belt 27 under the driving action of the rotational drive source 26, and the imaging lens 28a is positioned on the optical axis. be done. Further, the ball screw 32 rotates in a predetermined direction under the driving action of the rotational drive source 34, and the imaging unit 40 held on the movable base 36 is moved in the optical axis direction (see arrow X in FIG.
direction) and is set at a predetermined home position.

When these are completed, the imaging lenses 28a, 28b and the imaging unit 40 are temporarily retracted to the dust-proof position, and are put on standby for pre-scanning and main scanning.

That is, as shown in FIG. 2, the rotary table 24 is rotated in the right direction (in the direction of arrow Y in FIG. 2b) with respect to the traveling direction of the illumination light under the driving action of the rotary drive source 26. The imaging lens 28a, which is on the optical axis and is disposed in the opening 31 of the lens cover 30, is retracted to a position deviating from the opening 31, so that a part of the rotating table 24 between the imaging lenses 28a and 28b is removed. When the rotating table 24 is displaced to the position corresponding to the opening 31, the rotating table 24 is stopped. In other words, the hole 25 is connected to the rotary table 24
is partially shielded.

Therefore, the imaging lenses 28a and 28b are attached to the lens cover 30.
The imaging unit 40 is protected from dust entering through the opening 31 by the rotary table 24.

Next, the ball screw 32 is rotated in a predetermined direction under the action of the rotational drive source 34, and the imaging unit 40 is moved to the bracket 18 via the movable table 36 that is engaged with the ball screw 32, as shown in FIG. is displaced until it touches. As a result, the distance between the holding plate 19 and the imaging unit 40 is reduced as much as possible, and dust and the like do not enter through the gap between the imaging unit 40 and the bracket 18, and as a result, the CCDs 44a to 44C
The imaging unit 40 consisting of the color separation prism 42 is now dust-proof.

Therefore, when the operator places the document S carrying image information on the document table 12 and issues pre-scan and main scan operation commands, the image forming lenses 28a and 28b are rotated under the action of the rotational drive source 260. For example, an imaging lens 28b corresponding to a desired imaging magnification is positioned on the optical axis and in the opening 31 of the lens cover 30. Further, the imaging unit 40 is displaced in the X direction under the action of the rotary drive source 34 and positioned at a predetermined position according to a desired imaging magnification.

Next, the illumination light derived from the light source 14 illuminates the document S, and the transmitted light of the document S is color-separated by the color separation prism 42 via the imaging lens 28b, and then the CCD
Images are formed on 42a to 42C and read out photoelectrically.

In this way, after the pre-scan and the main scan are completed, the next imaging process is performed, but if the next imaging process is started within a predetermined time, the imaging lens 28
b and the imaging unit 40 maintain their positions.

On the other hand, if the next operation command is not generated within a predetermined time after the pre-scan and main scan operations are completed, it is displaced to a predetermined dust-proof position. In other words, the displacement operation to the dust-proof position is performed by energizing the rotary drive source 26, 34 at the same time as forward bending.

As described above, when not in use, the rotary table 24 is rotated under the action of the rotary drive source 260, the imaging lenses 28a and 28b are retracted into the lens cover 30, and a part of the rotated rotary table 24 is rotated. The hole m25 will be shielded at this point. on the other hand,
Under the action of the rotary source 34, the imaging unit 40 is moved to a dust-proof position.

Therefore, dust and the like that enter through the opening 831 of the lens cover 30 do not adhere to the lens surfaces of the imaging lenses 28a and 28b, and similarly, since shoes and the like are blocked by the rotary table 24, the CCDs 44a to 44c There is no force of adhesion to the imaging unit 40 consisting of the color separation prism 42 and the color separation prism 42.

Note that in order to bring the bracket 18 and the imaging unit 40 into close contact with each other, dust and the like may invade through this gap and cause the imaging unit 4 to come into close contact with each other.
It does not stick to 0.

) [Effects of the Invention As described above, the image reading device according to the present invention has the following advantages:
It has the following effects or advantages.

By storing the imaging lens in a lens storage part that is a dust-proof means and protecting the image sensor with a dust-proof member, the transmitted light or reflected light of the image information is protected from J dust on the imaging lens and/or the image sensor that collects the image information. It is possible to prevent the adhesion of foreign matter, etc., and therefore it is possible to read the image as a high quality image.

Furthermore, since the frequency of cleaning and maintenance of the imaging lens and the image pickup element can be reduced, it is possible to significantly reduce the labor costs expended for this purpose.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal sectional view of an image reading device according to the present invention, and FIG. 2 shows the positional relationship between the imaging lens and the hole provided in the rotary table in an embodiment of the image reading device according to the present invention. Explanatory diagram: FIG. 3 is a partially omitted vertical cross-sectional view showing the relationship between the dust-proof position and the imaging position of the imaging unit in the embodiment of the image reading device according to the present invention. 10... Image reading device 12... Document table 14... Light source 16... Image reading unit 18... Bracket 19... Holding plate 20... Ball screw 22... Rotation drive source 24 ...Rotating table 25...Hole 26...Rotary drive source 28a128b...Imaging lens 30...Lens cover 31...Opening 34...Rotary drive source 36...Movable base 40... Imaging unit 42... Color separation prism 44 a to 44 c-CCD Patent applicant Fuji Photo Film Co., Ltd. Same as above
Fuji Photo Co., Ltd. Applicant's Representative Patent Attorney Takehiro Chiba Procedural Amendment f (Voluntary) February 16, 1991 Commissioner of the Japan Patent Office I, 1
, Incident Indication 2000 Patent Application No. 281513 2,
Title of the invention Image reading device 5, Date of amendment order Voluntary action 6, Subject of amendment Drawing (No. 11!!l)-1,

Claims (2)

[Claims] (1) A light source that irradiates light onto a document carrying image information, an imaging lens that collects transmitted light or reflected light of the light irradiated onto the document, and a transmitted light that is focused on the imaging lens. An image reading device comprising: an image sensor for converting light or reflected light into an electrical signal; and a dustproof means having a dustproof effect on the imaging lens and/or the image sensor. (2) In the image reading device according to claim 1, the dust-proofing means includes a lens housing part for retracting the imaging lens when not in use, and dust etc. adhering to the imaging element when the imaging lens is retracted. An image reading device characterized by comprising: a dustproof member that prevents dust from occurring;