JPH01100527A - Optical system device - Google Patents

Abstract

PURPOSE:To perform smooth operation with a small driving force by arranging the center of gravity at or nearby the sliding part of an optical system device and coupling a driving wire with it. CONSTITUTION:First and second moving optical frame bodies 2 and 4 have sliding parts 18 and 18', and 19 and 19' to be fitted onto guide shafts 14 and 14' and sliding parts 20 and 20' to be supported slidably on a guide rail 16 at both end parts. Then those 1st and 2nd moving frame bodies 2 and 4 further have weight parts 22 and 22' outside the sliding parts 18 and 19 so that the centers of gravity of those frame bodies are between the two guide shafts. Consequently, any rotary moment which induces play and vibration is no generated at the sliding parts, and consequently the excellent scan movement of the optical system device is secured.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an optical system device used in a copying machine, etc., and more specifically to an optical system device that moves on a sliding shaft called a guide shaft. Regarding the improvement of

(Prior art) One of the optical system devices using a sliding shaft called a guide shaft
The one shown in Figure 1 is widely used.

A guide shaft 102 and a guide rail 104 are provided in parallel to each other on the lower surface of the document table of the main body of the copying machine. As an optical system means, for example, an optical system frame 108 for mounting a reflecting mirror 106 has a sliding portion 109 that is slidable on the guide shaft 102 and is slidable on the guide rail 104. The portion 110 is provided in a slidably mounted state. This sliding part 109 is provided with a protruding part 112 in the opposite direction to the frame body 108, and the driving wire 112 is provided in the opposite direction to the frame body 108.
14 are connected.

The driving wire 114 is stretched parallel to the guide shaft 102 connected to a driving means (not shown).

When tension is applied to the drive wire 114 in the direction of arrow 116 in the figure from a drive means (not shown), the tension is transmitted to the frame 108 via the protrusion 112. The frame body 108 is structured to slide on the rod bar 102 and the guide rail 104 in the direction of arrow 116.

(Problems and technical issues of the prior art) In the prior art as described above, when the tension of the wire 114 is applied to the protrusion 112 to which the wire 114 is connected,
A force acts to cause the sliding portion 109 to slide in the same direction as the tension.

At this time, strictly speaking, since the tension does not directly act on the sliding portion 119, a rotation moment corresponding to the length of the protruding portion 112 acts on the sliding portion 119 from the sliding portion 119.

Therefore, if the machining accuracy of the sliding part 119 is not high enough,
This makes it difficult to operate the sliding portion 119 smoothly. Alternatively, in order to perform smooth operation, it is also necessary to increase the driving force itself applied to the wire. Moreover, increasing the machining accuracy will increase the manufacturing cost of the parts.

Naturally, if the operation is not performed smoothly, abnormal noises will be generated during the operation and only images of low quality will be obtained.

Therefore, it is an object of the present invention to solve these problems and provide an optical system device that has a simple configuration and can operate smoothly.

Another object of the present invention is to provide an optical system device that can operate smoothly with a light driving force.

(Structure of the Invention) In order to achieve the above-mentioned object, the present invention employs the following characteristic structure.

That is, the optical system device of the present invention has the following features: (a) An optical system that scans and moves the lower surface side of a contact glass on which optical system means such as an exposure lamp and a reflecting mirror are attached and on which a document is placed for image formation. In the device, (b) a guide shaft, (c) a guide rail provided parallel to the guide shaft, and (d) a sliding part slidably fitted on the guide shaft and moving on the guide rail. a frame body for attaching an optical system means, further comprising a weight part provided in a direction opposite to the moving part with respect to the sliding part so as to position the center of gravity at or near the sliding part; (e) A configuration is adopted in which a connecting portion for connecting the drive wire is provided near a position on the frame that is located on a line that passes through the center of gravity of the frame and is parallel to the scanning movement direction.

In other words, for an optical system device that uses a guide shaft and slides on the guide shaft, the center of gravity is located at or near the sliding part of the optical system device, and the driving wire is connected thereto. This configuration is adopted.

(Operation of the Invention) By employing the above-described configuration, the present invention operates as a moving optical system device such that it can operate smoothly without vibration or vibration.

That is, a weight (so-called balance weight) is provided on the sliding part fitted onto the guide shaft, and is positioned at the center of gravity of the entire frame and at or near the sliding part. Then, by providing a driving wire at or near the center of gravity,
The driving force of the wire acts directly on the sliding part, which is a part that moves directly.

By doing so, rotational moment that induces shaking or vibration is not generated in this sliding portion, and as a result, it is possible to ensure good scanning movement of the optical system device.

(Preferred embodiments of the invention) Preferred embodiments of the invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the optical system device according to the present invention, in which a first moving optical frame 2 and a second moving optical frame 4 are shown.
FIG. 4 is a diagram for explaining the driving relationship thereof.

The first moving optical frame, generally indicated by 2, supports optical means such as a light source 6 for irradiating the original, a reflecting mirror 8 for guiding the irradiated original image to the second moving optical frame 4, and so on. belongs to. On the other hand, the second movable optical frame, generally indicated by 4, reflects the original image coming from the first movable optical frame 2 to a lens unit (not shown) for forming the image onto a photoreceptor. This is for supporting optical means such as reflecting mirrors 10 and 12, which are arranged in a positional relationship such that their mirror surfaces are perpendicular to each other.

These two moving optical frames 2.4 basically have the same structure except for the optical means they support. That is, the guide shafts 14 and 14' provided in the main body of the image forming apparatus
These guide members 1 are connected using the aligned guide rails 16.
4.14", it has a structure that can reciprocate in the longitudinal direction of 16".

Specifically, the guide shaft 14.14.degree. and the guide rail 16 are provided parallel to each other with a distance somewhat longer than the width of the document size to be used. Guide shaft 1
4.14" is usually called a guide shaft, and in the specific example of the present invention, two shafts are used as shown in the figure.

The first and second moving optical frames 2, 4 are connected to this guide shaft 14.
．． 18.18", 1 sliding part fitted externally to 14"
9.19'' and sliding portions 20 and 20' that are slidably supported on the guide rail 16 at both ends of the frame body 2.4. body 2
．． 4 further includes a weight portion 2222 outside the sliding portion 1819 so that the center of gravity of these frames is positioned between the two guide shafts.

Such first and second moving optical frames 2.degree. 4 are arranged such that the first moving optical frame 2 moves during the second movement so as not to cause a change in the optical path length from the document surface to the photoreceptor surface during scanning exposure. Measures are taken to allow movement at twice the movement speed of the optical frame 4.

Specifically, it is configured to be able to achieve movement in the speed relationship described above using wire means as described below. That is, the wire 24 with its lower end 23 fixed at a predetermined position on the main body of the apparatus is attached to a driven pulley 25 rotatably provided between the two sliding parts 19° and 19° of the second moving optical frame 4. After wrapping it around the guide pulley 26, tension boob IJ 28 and drive drum 30 attached to the device main body, and then wrapping it around the guide pulley 32 attached to the device main body, the two parts of the first moving optical frame 2 are wrapped. It is connected to the wire connection part 34 located in the middle of the sliding part 18.18''.
4 is again wound around the driven pulley 25 of the second moving optical frame 4, and then the end of the wire 36 on the main body of the apparatus is fixed.

Thus, the driven pulley 25 acts as a moving pulley and the second
The moving optical frame 4 can move at a moving speed of 172 times that of the first moving optical frame 2.

The important features of this first embodiment are that two parallel guide shafts 14.14' are provided 1, and sliding parts 18.18' and 19.19'' of the moving optical frame 2.4 are provided. are fitted onto the respective guide shafts 14.14', and weights 22.22' are attached to the sliding parts 18.18° and 19.19'.
By attaching the frame 2.4, the center of gravity of the frame 2.4 is positioned between the sliding portions 18.18' and 19.19' of each frame 2.4. The center of gravity is stopped by positioning the wire connecting portion 34 and the driven pulley 26 in order to position the wires 24 and 36 in the vicinity of the center of gravity.

By arranging each member in such a positional relationship, the attractive force for moving the sliding frames 2 and 4 due to the rotational force of the drive drum 30 is applied to the center of gravity of the frames 2 and 4 via the wires 24 and 36. It will be added to the location or its neighboring locations. As a result, the frames 2 and 4 that slide on the guide shaft 14.14' do not generate torsional moments or rotational moments that act as resistance against movement about the guide shaft 14.14°. Since this can be suppressed to a generally good degree, the movement of these frames 2.4 can be made smooth.

In addition, in this first specific example, the guide shaft 14°14'
are arranged in approximately the same horizontal plane, and the sliding parts 18 and 18 are also arranged in the same horizontal plane.
', 19.19' were similarly arranged in the same horizontal plane; however, in this case, these guide shafts 14.14"
Since the surrounding space becomes larger, it is also possible to shift both 14, 14" so that they are not located in the same horizontal plane (represented as a cross-sectional view in FIG. 2). According to this modification, the conventional These frame drive mechanisms can be housed in a space no different from a drive mechanism that uses only one guide shaft.

Next, a second specific example will be shown in which the technical idea of the present invention is applied to use one guide shaft.

FIG. 3 is a perspective view showing a second specific example of the optical system device of the present invention, and only the periphery of the guide shaft, which is different from the first specific example, is disclosed.

The guide shaft, generally designated 40, has a hollow pipe shape. This hollow guide shaft 40 further has a first slit portion 44 in its upper part that corresponds to the sliding range of the second moving optical frame 42 and corresponds to the sliding range of the first moving optical frame 46. A second slit portion 48 is provided on the side frame body side to coincide with the second slit portion 48 .

The first slit portion 44 is also provided so that a driven pulley 52 rotatably attached to the upper surface of the sliding portion 50 of the second moving optical frame 42 can rotate even in the presence of the guide shaft 40. It is.

The slit portion 48 of the second option is the first movable optical frame 46
The drive wire connection portion 56 provided
Even when the guide shaft 40 is made to protrude from the sliding portion 54 into the hollow interior of the guide shaft 40, the sliding portion 54 is formed so as not to inhibit the sliding movement of the sliding portion 54.

When moving both the first and second movable optical frames 42 and 46, the center of gravity of the frame is applied as much as possible to the lower side so that the frame portion provided with the optical means does not turn upward. Sliding position 50.

A weight 60 is placed on each sliding portion 50 and 54 so as to bring the sliding portion closer to the
゜62 is attached.

In this second specific example, the drive wire 64 is wound or connected in the state shown in FIG.

First, a wire 64 fixed at a predetermined location on the image forming apparatus main body is wound around the driven pulley 52 of the second movable optical frame 42, and is inserted into the guide shaft 40 through the first slit portion 44 of the guide shaft 40. enter.

This wire 64 comes out of the guide shaft 40 again from the end of the guide shaft 40 and is wound around a driving rotating drum 69 via a guide pulley 66 and a tension pulley 68 fixed to the main body. After being wrapped around a guide pulley 70 fixed to the main body, the guide shaft 40 enters the guide shaft 40 again from the other end, and this guide shaft 40
It is connected to the wire connection part 56 of the first moving optical frame 46 inside. Another wire 72 connected to this connecting portion 56 is wound around the driven pulley 52 of the second movable optical frame 42 and then passed from the first slit portion 44 of the guide shaft 40 to the guide shaft 40. It comes out to the outside and is fixed in place on the main body.

According to this second specific example, the driving force of the wire can be directly transmitted to the sliding portions 50.54 of the first and second moving optical frames 42.46, and the center of gravity near this position can be directly transmitted. , it is possible to construct a dynamically smooth optical system device.

(Effects of the Invention) As described above, according to the present invention, it is possible to suppress the occurrence of blur and vibration when driving an optical system device, and as a result, it is possible to obtain a smooth scanning motion.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the optical system device according to the present invention, and FIG. 2 is a schematic diagram showing another embodiment of the optical system device according to the invention.
3 is a perspective view showing still another embodiment of the optical system device according to the invention; FIG. 4 is a schematic diagram showing a wire wrapping state of the specific example shown in FIG. 3; FIG. 5 1 is a perspective view showing a conventional optical system device. In the figure, the river fish numbers indicate the following contents. 2.4...Moving optical frame 14.14''...Guide shaft 16...Guide rail 22...Weight 34...Wire connection portion 36...Wire

Claims (3)

[Claims] (1) In an optical system device that attaches optical system means such as an exposure lamp and a reflector, and scans and moves the lower surface side of a contact glass on which a document is placed for image formation, the guide shaft; A guide rail provided in parallel, a sliding part slidably fitted onto the guide shaft, and a moving part that moves on the guide rail, and the sliding part is provided in a direction opposite to the moving part. a frame body for attaching the optical system means, and a driving wire positioned near the position of the frame body passing through the center of gravity of the frame body and located on a line parallel to the scanning movement direction. An optical system device characterized by having a winding part or a connecting part. (2) In an optical system device in which an optical system means such as an exposure lamp or a reflecting mirror is attached and the lower surface side of a contact glass for placing a document is scanned and moved for image formation, it is hollow and extends in its longitudinal direction. A guide shaft having a slit-shaped groove, a guide rail provided in parallel with the guide shaft, a sliding part slidably fitted on the guide shaft, and a moving part that moves on the guide rail. and a frame body for attaching the optical system means, further comprising a weight part provided in a direction opposite to the moving part with respect to the sliding part so that the center of gravity is located in the sliding part; Provided in the sliding part, extending from the slit-like groove of the guide shaft to the direction of the center axis of the guide shaft, positioned to include the center of gravity of the frame or a position near the center of gravity, and for scanning and moving the frame. 1. An optical system device comprising: a wire connection portion for connecting drive wires. (3) In an optical system device that attaches optical system means such as an exposure lamp and a reflector, and scans and moves the lower surface side of a contact glass on which a document is placed for image formation, two parallel The guide shaft includes a guide shaft, a guide rail provided parallel to the guide shaft, two sliding parts slidably fitted onto the two guide shafts, and a moving part that moves on the guide rail. 2
It further includes a weight part provided in the opposite direction to the moving part with respect to the sliding part so that the center of gravity is located between the two sliding parts, and a frame body for attaching the optical system means, and two parts of the frame body. 1. An optical system device comprising: a connecting portion for connecting a driving wire provided between the sliding portions and for scanningly moving the frame.