JPS6218533A - Original supporting device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of unnecessary reflection irregularity by adsorbing and holding stably an original on a supporting stand by negative pressure. CONSTITUTION:When a device power source is turned on, a discharging fan 53 starts its operation. Since initially a control valve 54 is closed, a hollow box 41 does not become negative pressure, and therefore negative pressure suction force does not occur. Accordingly the original can be freely moved at any position on a mesh 43, and can be easily disposed at a desired position. When a command circuit 61 including a scan start switch, etc., operates, a negative pressure command circuit 62 generates a signal, and a valve opening and closing circuit 63 operates to open the valve 54. Consequently the negative pressure acts on the original supporting surface A of the hollow box 41 to attract the original, which is supported in a plane state.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a document support device for an optical scanning reader;
In particular, the present invention relates to means for stably holding a document during optical scanning.

[Conventional technology]

A device that optically scans a document original such as a sheet document or a thick book and electrically reads the jq information is known as a document scanner, and a device that reproduces the above information as a hard copy is called a photocopier. It is known as a machine. In these optical scanning reading devices, the original is usually placed face down on an original table made of a glass plate with the surface to be scanned facing downward, and optical scanning is performed. With devices that require such settings, it is necessary to turn the document over, which makes the work cumbersome, and makes it difficult to judge whether the scanned surface is accurately positioned at a predetermined position. It is easy to cause an illusion, ■ The glass plate is easily soiled by the scanned surface of the original, and if it is soiled, the same problem will occur even if the original to be scanned afterwards is not soiled. In order to keep the document in close contact with the board, it is necessary to cover the outer surface of the document with a cover, which is a cumbersome task.
There are various drawbacks such as.

In order to overcome these drawbacks, there is a copying machine that is capable of scanning with the surface to be scanned facing upward.

Figure 5 is a monthly copy machine published by Xerox.
It is a diagram showing the configuration of a copying machine described in Volume 12, Volume 4, Page 10.

In FIG. 5, reference numeral 10 denotes a document table assembly, in which a pressurizing means 1 consisting of a spring or the like is placed in a stone table frame 11.
A document support plate 13 is installed horizontally through the document support plate 13, and a document 14, such as a thick book, is placed on the document support plate 13 with the surface to be scanned facing upward. It is pressed down with a glass plate 15. The entire document table assembly 10 is provided so as to be movable in the horizontal direction as shown by the arrow.

On the other hand, 16 is a lighting lamp; 17. “18 is a reflective mirror,
19 is an original image projection lens, 20.21 is a reflection mirror, 2
2 indicates the copying machine engine part.

In the above apparatus, the original 14 is placed on the original support plate 13 with the original holding glass plate 15 open, and then the glass plate 15 is closed to set the original as shown. At this time, the original 14 is pressed down by the glass plate 15 and has a planar shape along the glass surface. Optical scanning is performed by moving the document table assembly 10 relative to the fixedly arranged illumination lamp 16 to copying machine engine section 22.

According to the apparatus shown in FIG. 5, the scanned surface of the original 14 is set facing upward, so there is no need to turn the original 14 upside down. Therefore, it can be easily determined whether the position of the scanned surface of the original 14 is accurate or not.

[Problem that the invention seeks to solve]

However, in the apparatus shown in FIG. 5, the document 14 must be held down by the glass plate 15, and therefore the glass plate 15 must be opened and closed for scanning each time the document 14 is replaced. Therefore, there still remains the problem that the glass plate 15 is easily soiled and problems are likely to occur due to the soiling. Also manuscript 1
When the position of the scanned surface 4 is not favorable, the glass plate 15 must be scanned open and closed in order to correct it. Correcting work for this purpose has to be carried out quite frequently, and there is a problem in that the workability is very poor.

Therefore, the present invention is capable of stably holding an original with the scanned side of the original facing upward, which does not cause problems when setting the original with the scanned side facing downward, and also allows the original to be scanned while being held down. To provide a document support device that does not require any glass plate or the like to attach a document, allows extremely easy setting and release scanning of a document, and can realize high-quality optical scanning.

[Means for solving problems]

In order to solve the above problems and achieve the objects, the present invention is characterized by taking the following measures.

That is, the document support device of the present invention is a document support device for an optical scanning reader that supports and fixes a scanned document upward facing an optical scanning system, and has a plurality of openings in one side wall on the side that supports the document. a hollow box installed in a horizontal state; a mesh-like document support sheet member disposed on the outer surface of one side wall of the hollow box in which the opening is provided and having optically uniform reflection characteristics; The present invention is characterized by comprising negative pressure control means for maintaining the negative pressure in the box while the document is being scanned and releasing the negative pressure when the document is not being scanned.

[Effect]

By taking such measures, the original can be stably attracted and held on the support plate by negative pressure even without any member to hold down the original, and it is possible to prevent the occurrence of unnecessary reflection unevenness. .

〔Example〕

FIG. 1 is a diagram showing the configuration of a first embodiment of the present invention.

In FIG. 1, 30 is a movable optical scanning reading reassembly, 40 is a document support table, 50 is a negative pressure forming table,
60 is a negative pressure control circuit.

The movable optical scanning read rear assembly 30 includes a frame 31, document illumination lamps 32a, 32b, lamp shades 33a, 33b, a mirror 34, a document image projection lens 35, and a light receiving element consisting of a COD linear image sensor array, etc. 3G is integrally installed, and is provided so as to be able to reciprocate in the horizontal direction as shown by the arrow.

The document support stand 40 has a large number of openings 42 on one side wall of the document support side of a hollow box 41, and an optically uniform reflective surface is formed on the outer surface of the one side wall of the hollow box 41 provided with the openings 42. The meshes 43 are arranged so as to be overlapped with each other. The above mesh 43
As the material, it is possible to use a thin metal wire made of stainless steel or the like processed into a mesh shape, or an open-celled plastic foam member processed into a thin plate shape. The surface is uniformly whitened using a material with high reflectance.

The mesh 43 is detachably attached to the outer surface of one side wall of the hollow box 41. An exhaust port 44 is provided at one end of the hollow box 41.

The negative pressure forming mechanism 50 connects the exhaust port 44 to a duct 51°5.
2 to the exhaust fan 53, and the duct 5
A control valve 54 is interposed between the valves 1 and 52. Note that as the exhaust fan 53, a B-O-Bela fan is suitable.

The negative pressure υ control circuit 60 is a sequence controller for controlling the opening and closing of the control valve 54, and includes a scan start command circuit 61, a negative pressure control command circuit 62, a valve opening and closing circuit 63, a scan drive circuit 64, and a scan end detection circuit. It consists of 65.

Next, the operation and effects of the apparatus configured as described above will be explained.

When the device power is turned on, the exhaust fan 53 starts operating, but since the control valve 54 is initially in a closed state, the inside of the hollow box 41 does not become negative pressure and no negative pressure suction force is generated. Therefore, the document can be freely moved to any desired position on the mesh 43, and can be easily placed at a desired position.

When the command circuit 61 including the scan start switch etc. is activated,
The operation for a series of scans begins. Negative pressure control command circuit 6
2 issues a signal, which activates the valve opening/closing circuit 63 to open the valve 54. Therefore, negative pressure acts on the document support surface A of the hollow box 41 to attract the document and support the document in a flat state. On the other hand, upon receiving the scan start command, the scan drive circuit 6
4 operates to light up the illumination lamps 32a and 32b,
The scanning reading assembly 30 is moved. The above operation may be started at the same time as the valve 54 is opened by providing a run-up period for scanning, but after opening the valve 54 there is a slight margin of time, e.g. 0.5 to 1 second, when the original is placed on the support surface A. It is more reliable to delay the scan so that it is held sufficiently long before starting the scan. When the scanning read reassembly 30 moves to the right end in the figure and finishes scanning, the scanning end detection circuit 65 is activated based on a signal from a sensor that detects the movement of the scanning read reassembly 30, and outputs a signal. A signal is sent to pressure control command circuit 62 to close valve 54. Therefore, the negative pressure that was sucking the original onto the support surface A is automatically released. Then, the scanning reading reassembly 30 moves to the left in the figure and returns to the starting position.

In the above operation, the force to suction and hold the original on the support surface A is generated by the negative pressure suction force, but the mesh 43 installed on the numerous openings 42 provided on the upper wall of the hollow box 41 is effective. As a result, the suction force acts well on documents of various sizes, and the suction force acts evenly on the entire surface of the upper document.

In other words, when the exhaust capacity of the exhaust fan 53 is constant, the smaller the total cross-sectional area of the openings 42, the more uniform the suction force at each part of the upper wall of the hollow box 41, but if the openings 42 are arranged with high density. If you try to do that, the total cross section will inevitably become larger. However, if the meshes 43 are overlapped, the same effect as that of reducing the total area of the openings 42 in proportion to the opening ratio of the meshes 43 can be obtained. As a result, there is an advantage that processing for forming the opening 42 is facilitated. Further, when the mesh 43 is not present, the suction force is generated only at the position of the opening 42, so that the edge of the document that is not aligned with the opening 42 is lifted up. In order to avoid this, the arrangement of the openings 42 can be made denser, but in that case, processing becomes difficult, and the upper wall of the box 41 needs to be made thinner, resulting in weaker strength. It becomes a thing.

However, an air flow path is formed by the mesh 43 between the document and the upper wall of the box 41 due to the back side where the mesh 43 is placed, and this flow path becomes negative pressure via the opening 42. Therefore, this flow path forming portion, that is, the portion where the original is placed, can be subjected to the pressure contact action of atmospheric pressure over the entire area of the original up to the end. For this reason,
The document is held well and there is no need to arrange the openings 42 in a high density manner.

On the other hand, it is desirable that the document support surface A has a high light reflectance, and the presence of the mesh 43 is advantageous in order to form such a highly reflective and uniform support surface. In other words, the presence of the mesh 43 makes the entire support surface a uniform support reflection surface, but if the mesh 43 does not exist, the opening 42 becomes a part where no light reflection occurs, and becomes a non-opening part. have different reflection conditions. Therefore, in the case of a thin sheet document, the small amount of light reflected from the opening 42 is noticeable and is read as a black portion. However, although the mesh 43 has a microscopically non-uniform structure, the planar gap between the openings 42
It can be made sufficiently smaller than . Therefore, from the viewpoint of non-uniformity of reflected light through the original, the non-uniformity will not be noticed if the mesh has a pitch of 1# or less. Note that since the mesh 43 has an uneven shape, dirt will adhere to it during long-term use.

However, since only the mesh 43 portion is removable and replaceable, it is possible to properly deal with stains.

In addition, although there are various sizes of sheet documents that can be applied to this document support device, it is recommended that the effective area of the opening formed in the document support surface be approximately 1/10 of the total document support area. A fan 5 that is easy and suitable and has an exhaust capacity that maintains negative pressure inside the hollow box under such opening conditions.
In combination with 3, the original is properly attracted and held well regardless of its size.

Incidentally, although the document is placed at a predetermined position on the mesh 43 with the surface to be scanned facing upward, it is preferable that the negative pressure suction force not be applied while the document is being moved to the predetermined position. Also, when removing the document from the mesh 43 after scanning, it is preferable that the negative pressure suction force not be applied. However, since the exhaust fan 53 is usually a motor fan, the exhaust fan 53 is 0N-O.
The inertia of the FF is large, and it is difficult to control its operation at high speed. Therefore, there is a problem that it is difficult to handle and scan the original. However, in this apparatus, a control valve 54 is provided, and the fan 53 is left in operation when the document support surface A is turned on.
Since the configuration is configured to control the formation and release of negative pressure at , it has the advantage of high responsiveness and is extremely suitable.

As described above, according to this embodiment, since scanning can be performed with the document surface facing upward, the document can be positioned accurately and efficiently, and positioning errors due to illusions can be avoided. Furthermore, since there is no need to use a glass plate for holding the document, there is no problem caused by dirt on the glass surface as in the conventional case, and the effort of opening and closing the document holding plate is eliminated, making it possible to change documents extremely smoothly. Eliminates operational hassles. In addition, the negative pressure suction action on the document support surface A is automatically generated in response to the scan start command, and is automatically terminated when the scan ends, making document handling operations easier. Become.

Note that the document support stand of this application is configured to support the document using negative pressure suction force, so it cannot handle booklet-like documents that are stacked together and stapled together, or documents that have their edges stapled together using a stapler. This cannot be maintained stably.

Such documents can be handled by superimposing a transparent plate larger than the size of the document on top of the document.

FIG. 2 is a perspective view showing a state in which the above means is used. In the figure, 70 is a plurality of originals stapled together, 71 is a sheet facing the original support stand 40, 72 is a scanned sheet, and 73 is a non-supported sheet that is not on the original support stand 40. . 74 is a transparent plate larger than the original size. The transparent plate 74 is made of a flexible and elastic material, such as hard vinyl chloride, polyester resin, or soft vinyl chloride softened with a plasticizer.

When the hollow box 41 of the document support table 40 is subjected to negative pressure with the transparent plate 74 placed on the original sheets 71 and 72 placed on the document support table 40 as described above, the mesh 4
Since the periphery of the transparent plate 74 that directly faces the transparent plate 74 is attracted, the original sheets 71 and 72 are held down by the transparent plate 74. At this time, the document support stand 4
If the stacked thickness of the original sheets 71 and 72 placed on the original sheet 72 is relatively thin, the entire area covered by the transparent plate 74 will be in a negative pressure state, and the transparent plate facing the original sheet 72 will be in a negative pressure state. Atmospheric pressure also acts on the portion 74 from the outside. Therefore, the center portion of the transparent plate 74 is also given a biasing force in the direction toward the document support table 40. As a result, the transparent plate 74 is placed in the central portion of the original sheets 71 and 72 without any gaps.
is held down by

Next, other embodiments of the present invention will be described. FIG. 3 shows a second embodiment of the present invention which makes it possible to easily construct a relatively large document support stand and to construct a negative pressure forming mechanism compactly.
It is a figure showing the composition of an example. Note that the same parts as in the first embodiment are given the same reference numerals, and detailed explanations will be omitted.

In FIG. 3, reference numeral 80 denotes a document table assembly that integrates a document support table and a negative pressure forming mechanism. hollow box 8
Although the upper surface of the hollow box 81 has the same structure as the first embodiment, a large-capacity propeller fan 82 is disposed at the center of the bottom surface of the hollow box 81.

A large opening 83 is formed in the bottom wall at a position other than the position where the propeller fan is disposed. A shutter plate 84 is slidably supported and disposed on the outer surface of the bottom wall as shown by the arrow. This shutter plate 84 has a hollow box 8
An opening 85 is formed to correspond to the large opening 83 provided in the bottom wall of 1, and the large opening 83 is opened and closed by being driven by a drive mechanism 86. The drive mechanism 86 is controlled by a control circuit 60 configured similarly to that shown in FIG. However, a shutter drive circuit 63 is used instead of the valve control circuit 63.

In this embodiment configured in this manner, during normal operation, the shutter plate 84 closes the large opening 83 as shown. Therefore, the document table assembly 80 is under negative pressure due to the propeller fan 82, and a negative pressure suction force is generated on the document support surface A. The control circuit 60 operates to drive the drive mechanism 8.
5 is activated, the shutter plate 84 moves to the right in the figure, and the openings 83 and 85 overlap. Then, since the hollow box 81 communicates with the outside air through the large-area openings 83 and 85, the inside of the hollow box 81 is at atmospheric pressure or weakly negative pressure. Therefore, the document suction force on the document support surface A is canceled or weakened to a level that does not cause any problem in moving or removing the document. In this way, the negative pressure inside the hollow box 81 is controlled by opening and closing the shutter plate 84, so the negative pressure inside the hollow box 81 can be controlled at high speed while the propeller fan 82 is continuously rotating. can. Furthermore, since the shutter plate 84 is provided at a location different from the duct of the exhaust fan 82, the large-diameter thin fan 84 shown in the figure
2 can be applied, which is also convenient for increasing the size of the original support surface A. Further, since the fan 82 is made thinner and integrated with the hollow box 81, the negative pressure forming mechanism becomes compact and the number of protrusions is reduced, which is advantageous in terms of the device configuration.

FIG. 4 is a diagram showing a third embodiment in which the present invention is applied to a copying machine. Note that the document support assembly 80 in this embodiment has the configuration shown in FIG. 3. 91.92 in FIG. 4 is the first point of the optical scanning system. A second movable unit is shown. The first unit 91 is the illumination lamp 9
3a, 93b and a scanning mirror 94 are housed integrally in a frame 95, and are provided so as to be able to reciprocate in the direction of the arrow. The second unit 92 integrally houses mirrors 96 and 97 within a frame 98, and is provided so as to be able to reciprocate in the direction of the arrow. 9 is the Hara image projection lens, 10
0, 101, and 102 are reflecting mirrors, which are fixedly supported during exposure scanning.

Reference numeral 103 denotes an engine portion of the copying apparatus, in which a developing unit 105, a transfer unit 106, etc. are arranged around an electrophotographic photosensitive drum 104, and paper cassettes 107, 1
The paper path from 08 to the paper output tray 109 includes a paper guide 110, a feed roller 111, and a belt paper feed device 1.
12, a fixing unit 113, etc. are arranged.

The copy operation is performed while operating the copy 11292 section 103.
1st. By moving the second exposure scanning units 91 and 92, exposure scanning is performed on the document supported on the document table assembly 80. The first unit 91 and the second unit 92 move in the same direction, but by setting the moving speed of the latter to 1/2 of that of the former, the optical path length from the scanned surface of the original to the lens 99 can be reduced. It is always kept constant.

Negative pressure control of the document table assembly 80 is performed under the control of the control circuit 120. This control circuit 120 includes a start circuit 121 including a copy start circuit, etc., a command circuit 122 that sends out a negative pressure control command for the document table assembly 80, and a shutter drive circuit 123 that drives a shutter plate in response to the command signal from this command circuit 122. , a copying unit control circuit 124 that controls the operation of each part of the copying machine engine, a scanning end detection circuit 125 that detects the end of document scanning and sends a signal, sets the number of copies, and detects the number of copies that have been completed in the power run 1. - Set, count circuit 12
It consists of 6. In a copying machine, it is often the case that multiple copies are made from the same original. Preferably, the negative pressure is released when scanning for the final copy from the printer is completed.

Therefore, in the control circuit 120 of this embodiment, the signal from the scanning end detection circuit 125 and the number of copies are set.

Find the AND condition with the signal from the count circuit 126,
The configuration is such that an operation command is given to the negative pressure control command circuit 122 when the scanning end signal for forming the final copy from the same original is recognized. The output of the shutter drive circuit 123 in the control circuit 120 is supplied to the shutter drive mechanism 8e. Note that a work table 130 for manipulating documents is provided at a position adjacent to the document table assembly 80. Note that although the embodiment shown in FIG. M4 shows a device in which the document table assembly 80 is fixed, The second optical system units 91 and 92 are fixed, and the document table assembly 80
Of course, it may be configured to move.

〔Effect of the invention〕

According to the present invention, the document can be held down stably by negative pressure on the support plate even without any member, and the occurrence of unnecessary reflection unevenness can be prevented. In this way, the document can be stably held with the surface to be scanned facing upward, and there is no problem when setting the document with the surface to be scanned facing downward. It is possible to provide a document support device that does not require any glass plate or the like, allows extremely easy document setting and release operations, and is capable of realizing high-quality optical scanning.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a first embodiment of the present invention, FIG. 2 is a perspective view showing an example of the document support state of the same embodiment, and FIG. 3 is a diagram showing the configuration of the second embodiment of the present invention. FIG. 4 is a diagram showing the configuration of a third embodiment of the present invention, and FIG. 5 is a schematic side view showing a conventional example. 30... Optical scanning reading reassembly, 40...
Original support stand, 50...Negative pressure formation mechanism, 60.120.
...Control circuit. 80...Original table assembly. Applicant's representative Patent attorney Atsushi Tsuboi ~ Figure 2

Claims (1)

[Claims] In a document support device for an optical scanning reader that supports and fixes a scanned document upward facing an optical scanning system, a hollow box is installed in a horizontal state with a plurality of openings in one side wall on the side that supports the document. and a mesh document supporting sheet member having optically uniform reflection characteristics, which is disposed on the outer surface of one side wall of the hollow box where the opening is provided, and a negative pressure is applied to the hollow box while the document is being scanned. A document support device characterized by comprising negative pressure control means for maintaining the negative pressure and releasing the negative pressure when the document is not scanned.