JP2000330218A - Image reader and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image reader and an image forming device capable of surely reducing the temperature rising caused when an illuminating means performs illuminating. SOLUTION: As to this image reader, whether an original lamp 3 illuminating an original 2 performs illuminating in the state of being fixed or driven can be switched according to whether the number of a sheet material on which the image of the original 2 is formed and which is ejected is one or two or more. An original lamp driving mechanism 7 which changes the stopping position of the lamp 3 and is controlled by a micro-computer 6 when the lamp 3 is fixed and performs illuminating and at least one of one or more prescribed conditions is satisfied is included.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus and an image forming apparatus, and more preferably, to reading an original by moving the original while fixing the illuminating means when the number of copies for the original is one. The present invention relates to an image reading apparatus having a so-called flow reading mechanism, and an image forming apparatus having such an image reading apparatus.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus having a mechanism for feeding a document such as a sheet material, when a plurality of copies of the same document are to be made, the document is read by scanning a document illumination lamp, and one copy of the same document is copied. When reading a document, the document illumination lamp was fixed and the document was read.

[0003] This is because, when comparing the high-speed performance required for a document illumination lamp and a mechanism for reciprocating a plurality of mirrors with the high-speed performance required for a mechanism for moving a document, the mechanism for moving the document is better. It is a widely used technology because high performance can be obtained at low cost.

[0004]

However, when the original illumination lamp is fixed and emits light, the temperature of the members near the lamp is increased due to the heat of the lamp, and it is necessary to reduce the temperature of the original platen glass. Having.

Further, at present, the amount of lamp light has been increasing along with the high performance of the image forming apparatus.
There is an increasing need to prevent the temperature of the platen glass from rising.

For example, the relationship between the surface temperature and the position of the platen glass in a conventional image forming apparatus will be described with reference to FIG. FIG. 3 shows a graph of the relationship between the surface temperature of the platen glass and the position in the conventional image forming apparatus.

As shown in FIG. 3, in the conventional image forming apparatus, when copying one image of a document, the document lamp 3 below the platen glass 1 is fixed at a fixed position. The surface temperature of the platen glass 1 at the position where the document lamp 3 is located was significantly higher than at other positions.

[0008] The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide an image reading apparatus and an image forming apparatus that can surely reduce a rise in temperature caused by illumination of an illumination unit.

[0009]

In order to achieve the above object, an image reading apparatus according to the present invention comprises: a document feeding means for feeding a document to an image reading unit; A scanning unit which is movable and illuminates the original by illuminating means and obtains image information of the original by reflected light thereof, wherein the scanning unit is stopped to read image information of the original in a feeding state; In the image reading apparatus for reading image information of a document, a plurality of stop positions of the scanning unit in the flow reading mode are provided, and the stop positions can be switched according to image reading conditions.

[0010] Further, one of the image reading conditions includes a condition that the number of the originals from which images are read by the image reading apparatus is equal to or more than a predetermined number per predetermined unit time. .

[0011] Further, at least one or more temperature detecting means for detecting temperatures at different positions of the image reading section,
One of the image reading conditions includes a condition that a temperature of the image reading unit detected by the temperature detecting unit is equal to or higher than a predetermined temperature.

[0012] Further, a plurality of position detecting means for detecting the stop position of the scanning section are provided.

Further, depending on whether the number of sheet materials on which the image of the original is formed and discharged is one or two or more, the flow reading mode and the scanning unit are moved and stopped. It is characterized by switching between a fixed reading mode for reading image information of a document in a state.

Further, in order to achieve the above object, an image forming apparatus according to the present invention is characterized by including an image forming means for forming an image of a document read by the image reading device on a sheet material.

Therefore, according to the image reading apparatus and the image forming apparatus of the present invention, even when the temperature of the document reading section is likely to rise, for example, when the document is read in the flowing reading mode, Since the stop position of the scanning unit that illuminates the original by the illuminating unit is switched according to the image reading conditions, it is possible to lower the maximum point temperature while avoiding concentrated temperature rise.

Further, as one of the image reading conditions, the degree of temperature rise of the image reading section on which an original is placed is such that the contribution rate of the environmental temperature and the like is low and the contribution rate of the number of originals read per time is high. By using the information on the contribution of the number of read originals per time, which can be easily obtained, to judge the necessity of changing the stop position of the scanning unit, it is possible to more reliably and accurately raise the temperature. Can be reduced.

Further, the temperature of the image reading section is measured, and when the temperature rises above a predetermined temperature, the stop position of the scanning section is changed to read the image of the document. The temperature can be reliably reduced.

Further, since a plurality of position detecting means for detecting the position of the scanning unit are provided, for example, when the stopping position of the scanning unit with respect to the image reading unit is fixed at a plurality of points, the fixing position is accurately determined. It is possible to decide.

Further, the mode is switched between the flow reading mode and the fixed reading mode depending on whether the number of sheet materials on which an image of a document is formed and discharged is one or two or more. Appropriate image reading can be performed according to the sheet material to be formed.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of an image reading apparatus and an image forming apparatus according to the present invention will be described with reference to the drawings. First, FIG. 1 shows a schematic configuration diagram of an embodiment of an image reading apparatus according to the present invention. However, in FIG. 1, the same members as those shown in FIG. 3 are denoted by the same reference numerals.

In FIG. 1, reference numeral 1 denotes a platen glass as an image reading unit on which a document is placed, and 2 denotes a document as a sheet material. Here, the sheet material of the document 2 is paper,
Film, OHP, etc. are included. Reference numeral 20 denotes a sheet conveying device as a document feeding unit.

The image of the original 2 placed on the original platen glass 1 is generally read by illuminating the original 2 by reciprocating an original lamp 3 as illumination means. This is the fixed reading mode. The original lamp 3 is generally provided in a scanning unit (not shown).

Reference numeral 4 denotes a position detecting mechanism for detecting the position of the document lamp 3. The microcomputer 6 controls a document lamp driving mechanism 7 based on the position of the document lamp 3 detected by the position detecting mechanism 4, The document lamp 3 is stopped at a regular position.

That is, the original lamp 3 is driven by an original lamp driving mechanism 7 whose operation is controlled by the microcomputer 6. Therefore, the microcomputer 6 and the document lamp driving mechanism 7 constitute a fixed position changing unit.

Next, reference numerals 5a, 5b, and 5c denote temperature detecting means for detecting the temperature of the original platen glass 1, and transmit temperature information of the original platen glass 1 to the microcomputer 6. Here, in the example shown in FIG. 1, three examples of the temperature detecting means are shown. However, the image reading apparatus according to the present invention is limited to the case of three temperature detecting means. Instead, any number may be used.

In this case, if the number of temperature detecting means is small, the manufacturing cost of the image reading apparatus according to the present invention is small, and if the number is large, the temperature of the document glass 1 can be detected more precisely.

In some cases, the temperature detecting means may not be provided. That is, as described later, the temperature detecting means is used to determine the timing at which the fixed position of the document lamp 3 is changed by using the temperature. It doesn't have to be.

In the example shown in FIG. 1, one position detecting mechanism 4 is shown. However, in the image reading apparatus according to the present invention, the position detecting mechanism is limited to one. However, the number may be arbitrary.

In this case, if the number of the position detecting mechanisms is small, the manufacturing cost of the image reading apparatus according to the present invention is small, and if the number is large, the position of the document lamp 3 can be detected more precisely.

Next, the flow reading mode will be described.
This flow reading mode is performed by the sheet conveying device 20 in the present embodiment.

As shown in detail in FIG. 1, the sheet conveying device 20 is provided with a stacking tray 30 on which a bundle of originals is set. Further, the stacking tray 30 is provided with a feeding unit that constitutes one part of the document feeding unit.

The feeding means includes a half-moon roller 31, a separation / conveyance roller 32, a separation motor (not shown), a registration roller 33, an entire belt 34, a belt motor (not shown), a reversing roller, 35 and a transport motor (not shown).

On the other hand, on the right side of the sheet conveying device 20, there is provided a paper discharging means for discharging and stacking the read originals. The paper discharging means includes a paper discharging roller 36, a paper discharging tray 37, a paper discharging sensor, and the like.

The half-moon roller 31 and the separation / conveyance roller 32 are rotated by a separation motor to separate documents one by one from the bottom of the document bundle on the stacking tray 30. The registration roller 33 and the entire belt 34 convey the separated documents rotated by the belt motor to the exposure position (sheet path c) on the document table glass 1 via the sheet paths a and b.

After the reading is completed, the original is discharged. There are a first discharge mode for discharging the original to the stacking tray 30 and a second discharge mode for discharging the original to the discharge tray 37. We will use them accordingly.

As described above, in the original 2 conveyed by the sheet conveying device 20 in the moving reading mode, the original itself moves, the original lamp 3 is stopped, and the original 2 is irradiated, so that the image is read. become.

Next, the operation of each member of the image reading apparatus shown in FIG. 1 will be described in more detail with reference to FIGS. FIG. 2 is a graph showing the relationship between the platen glass surface temperature and the position in the image reading apparatus according to the present invention shown in FIG. However, FIG. 2 shows, as an example, a case where there are three position detection mechanisms, that is, the position detection mechanisms 4a, 4b, and 4c.

In one embodiment of the image reading apparatus according to the present invention, when the number of copies of an original is one, an original provided with a so-called flow reading mechanism in which an original lamp is fixed and the original is moved to read the original is read. The gist of the reading device is that the fixing position of the document lamp is changed in a predetermined case.

That is, in the graph showing the surface temperature of the original platen glass in the prior art shown in FIG. 3 described above, if the original lamp 3 continues the copying operation at the fixed position, one point on the original platen glass 1 is concentrated. The temperature rose and the maximum temperature increased. On the other hand, as is clear from the graph of the platen glass surface temperature in the present invention shown in FIG. 2, in one embodiment of the image reading apparatus according to the present invention,
Since the fixing position of the document lamp 3 has been changed, the temperature rise of the document table glass 1 has been dispersed, and the maximum temperature has dropped.

The conditions for changing the fixing position of the document lamp 3 will be described below with reference to FIGS. 1 and 2.

First, one of the conditions for changing the position of the document lamp 3 is the lighting time of the document lamp 3 per a predetermined unit time.

That is, if the lighting time is long, it is determined that the temperature of the original platen glass and the like also rises remarkably.

Here, the lighting time can be obtained by the number of copying operations in a state where the document lamp 3 is fixed in a unit time calculated in the microcomputer 6. The stop position of the document lamp 3 is changed by the document lamp driving mechanism 7 based on this information.

One of the conditions for changing the position of the document lamp 3 is the temperature of the document glass 1.

That is, the document lamp 3 is moved when the temperature of the document table glass 1 becomes higher than a predetermined temperature.

In this case, a plurality of temperature detecting means for measuring the temperature of the document glass 1 are provided, for example, temperature detecting means 5a, 5b and 5c. When the temperature is equal to or higher than the temperature, the document lamp 3 is moved to the low temperature portion of the document table glass 1 by using the document lamp driving mechanism 7.

As is clear from the above description, in the embodiment of the image reading apparatus according to the present invention shown in FIGS. 1 and 2, when a predetermined condition is satisfied, a so-called flow reading is performed. Also, since the position of the document lamp 3 is changed, it is possible to reliably prevent the temperature of the document table glass 1 and the like from rising.

Here, in the image reading apparatus according to the present invention, not only one of the above conditions but also both of the above conditions may be satisfied. In this case, whether or not to move the document lamp 3 depends on the above condition 2
The document lamp 3 may be moved when both are satisfied, or the document lamp 3 may be moved when any one of the above conditions is satisfied.

In the example shown in FIG. 2, as described above, a plurality of position detecting mechanisms are provided in order to accurately stop the document lamp 3 at a plurality of points. Thus, the position of the document lamp 3 can be easily corrected.

On the other hand, in the above description, only the image reading apparatus has been described, but it is apparent that an image forming apparatus having the above image reading apparatus can be easily realized.

That is, an image read by the image reading apparatus shown in FIG. 1 is formed on, for example, a photoreceptor,
This image may be transferred to a sheet material. Of course, other image forming techniques, such as one that obtains image data using a CCD and forms an image based on this data or an inkjet type, may be used.

Accordingly, such an image forming apparatus is an embodiment of the image forming apparatus according to the present invention. Even in such an image forming apparatus, similarly to the above description, it is possible to reliably prevent a rise in the temperature of, for example, the platen glass.

[0053]

As is apparent from the above description, according to the present invention, the stop position of the scanning unit provided with the illuminating means is changed on the basis of a predetermined condition. It is possible to provide an image reading apparatus and an image forming apparatus capable of preventing concentration of one point and reliably reducing a rise in temperature.

Further, since the number of image readings per unit time is used as a condition for changing the position of the scanning unit, it is preferable to change the stop position of the scanning unit in order to reduce the temperature rise. It is possible to provide an image reading device and an image forming device that can determine the timing more easily.

Further, the temperature rise of the image reading section by the illumination means is actually measured by the temperature detection means, and this detected temperature is used as one of the conditions for changing the stop position of the scanning section. It is possible to provide an image reading apparatus and an image forming apparatus that can change a stop position of a scanning unit including an illumination unit at a timing with little influence on a variation factor.

Further, when the scanning section is fixed at a plurality of positions, a plurality of position detecting mechanisms for detecting the positions are provided,
It is possible to provide an image reading apparatus and an image forming apparatus that can change the position of a scanning unit including an illumination unit more accurately.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of an image reading apparatus according to the present invention.

FIG. 2 is a graph showing a relationship between a surface temperature and a position of an original platen glass in the image reading apparatus shown in FIG. 1;

FIG. 3 is a graph showing the relationship between the surface temperature of a platen glass and the position in a conventional image forming apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 platen glass 2 document 3 document lamp 4, 4a, 4b, 4c position detecting mechanism 5a, 5b, 5c temperature detecting means 6 microcomputer 7 document lamp driving mechanism 20 sheet transport device 30 loading tray 31 half moon roller 32 separation transport motor 33 resist Roller 34 Full belt 35 Reversing roller 36 Discharge roller 37 Discharge tray

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/107 F term (Reference) 2H027 DA11 DA23 FA18 FA20 FA22 JA11 JC04 2H076 AA04 AA33 AA58 2H108 AA19 CB01 HA00 5C072 AA01 AA03 AA05 CA02 CA09 CA10 EA05 LA04 NA01 NA05 RA04 9A001 HH34 JJ35 KK31 KK32 KK37 KK42

Claims (6)

[Claims] An original feeding unit configured to feed an original to an image reading unit; and a stop or a relative movement with respect to the image reading unit;
A scanning unit for illuminating the original by illuminating means and obtaining image information of the original by reflected light thereof, wherein the scanning unit is stopped to read the image information of the original in a feeding state, and the image information of the original in a flow reading mode is provided. An image reading apparatus that reads a plurality of scanning positions in the drift reading mode,
An image reading apparatus, wherein the stop position can be switched according to image reading conditions. 2. The image reading apparatus according to claim 1, wherein one of the image reading conditions includes a condition that the number of the documents read by the image reading device is equal to or more than a predetermined number per predetermined unit time. The image reading device according to claim 1. 3. The image reading unit according to claim 1, further comprising at least one or more temperature detecting means for detecting temperatures at different positions of the image reading unit, wherein the temperature of the image reading unit detected by the temperature detecting means is one of the image reading conditions. The image reading apparatus according to claim 1, further comprising a condition that the temperature is equal to or higher than a predetermined temperature. 4. The image reading apparatus according to claim 1, further comprising a plurality of position detecting means for detecting the stop position of the scanning unit. 5. The flow reading mode and moving and stopping the scanning unit depending on whether the number of sheet materials on which the image of the document is formed and discharged is one or two or more. The image reading apparatus according to claim 1, wherein the image reading apparatus switches between a fixed reading mode for reading image information of a document in a state. 6. An image forming apparatus, comprising: an image forming unit that forms an image of a document read by the image reading apparatus according to claim 1 on a sheet material.