JPH04321019A - Image information reader with variable power function - Google Patents

Abstract

PURPOSE:To provide an image information reader with variable power function which can restrain the useless action of a cooling means concerning a variable power rate. CONSTITUTION:The image information reader with the variable power function is provided with an original platen 20, an optical system 22, a cooling fan 30, a magnification specifying means, an optical system driving means, a cooling fan driving means 54, and a laser outputting means 27. The cooling fan 30 cools the original platen 20. The magnification specifying means specifies the magnification of an image. The optical system driving means 53 slowly drives the optical system when the specified variable power rate is high, and quickly drives the optical system when it is low. The cooling fan driving means 54 strongly operates the cooling fan 30 when the specified variable power rate is high, and weakly operates the cooling fan 30 when it is low.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image information reading device, and more particularly to an image information reading device with a variable magnification function and equipped with a magnification specifying means.

0002

2. Description of the Related Art For example, as a conventional copying machine, there is already known a copying machine with a variable magnification function that enlarges or reduces copies based on input commands from a key panel. This type of copying machine with a variable magnification function includes a document placement section (for example, a contact glass) on which a document is placed, an optical system for reading image information including a lamp and a CCD, and an image read by the optical system. Some types include an image forming section that enlarges or reduces information based on a specified magnification ratio and copies it onto paper, and a cooling fan that cools the document placement section.

In this copying machine, when the magnification ratio is high (for example, 400%), the moving speed of the optical system is low;
Accordingly, the amount of heat received per unit area of the document placement section increases accordingly. On the other hand, when the magnification ratio is low (for example, 25%)
In this case, the moving speed of the optical system is high, and the amount of heat received per unit area of the document placement section is small.

However, in conventional copying machines, the cooling operation by the cooling fan is maintained constant even if the magnification ratio changes. Therefore, when the amount of heat received per unit area of the document placement area is highest (when the magnification ratio is highest)
However, the fan is always driven at high speed, regardless of the magnification ratio, to ensure that the document tray is sufficiently cooled. Therefore, with this configuration, noise cannot help but increase due to the high speed rotation of the fan.

As a configuration for changing the rotational speed of a cooling fan, Japanese Patent Laid-Open No. 62-262883 discloses a configuration in which the rotational speed is changed between copying operation and standby operation. Also, JP-A-63-159873 and Utility Model Application No. 64-
No. 34637 discloses a configuration in which the rotational speed of a cooling fan is changed depending on the number of copies.

However, even in these conventional configurations, the cooling fan is controlled regardless of the magnification ratio.
Especially when the magnification ratio is low, unnecessary noise is generated from the cooling fan.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image information reading device with a variable magnification function that can suppress unnecessary operation of a cooling means with respect to variable magnification.

[0008]

[Means for Solving the Problems] The present invention provides a document placing section, an image information reading means, a cooling means, a magnification specifying means, a driving means for the image information reading means, a driving means for the cooling means, and an output means.

[0009] The document placement section is for placing a document. The image information reading means is a means for reading image information by irradiating a document with light. The cooling means is a means for cooling the document placement section. The magnification specifying means is a means for specifying a magnification of the image. The image information reading means driving means is means for driving the image information reading means slowly when the specified magnification is high and fast when the specified magnification is low. The cooling means driving means is means for operating the cooling means weaker when the designated magnification is low than when it is high. The output means is a means for outputting the image information read by the image information reading means after performing processing corresponding to a designated magnification ratio.

0010

[Operation] In the image information reading device according to the present invention, an original is placed on the original placing section. On the other hand, the magnification of the image is specified by the magnification specifying means.

Next, the image information reading means driving means drives the image information reading means slowly when the specified magnification is high and fast when the specified magnification is low. The image information reading means irradiates light onto the document and reads image information under the control of the driving means. At this time, the cooling means cools the document placement section.

[0012] Here, the cooling means driving means operates the cooling means weaker when the specified magnification is low than when it is high. As a result, the document placement section is strongly cooled by the cooling means when strong cooling is required, and weakly cooled when weak cooling is sufficient. As a result, the document placement section is always well cooled by the cooling means, and the cooling means operates efficiently, so that unnecessary cooling operations by the cooling means are suppressed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a copying machine incorporating an embodiment of the present invention. In the figure, the copying machine has case 1,
Copy processing unit 2 located at the bottom of case 1 and case 1
The document reading section 3 is arranged at the upper part of the document reading section 3.

The copy processing section 2 has a photosensitive drum 4 on the surface of which an electrostatic latent image is formed. A main charger 5 , a developing device 6 , a transfer corona discharger 7 , a separation corona discharger 8 , and a cleaning device 9 are arranged around the photosensitive drum 4 . A pair of paper feed cassettes 10a and 10b are removably disposed in the case 1 on the right side of the corona discharger 7 in the figure. A paper feed cassette 10 is provided between the corona discharger 7 and the paper feed cassettes 10a and 10b.
A paper feed conveyance path 11 is provided for conveying the paper from a and 10b to the corona discharger 7 side. On the other hand, on the left side of the separation corona discharger 8 in the figure, in order from the corona discharger 8 side,
A conveyance device 12, a fixing device 13, and a paper discharge tray 14 are arranged.

The original reading section 3 has an original placing table 20 made of transparent glass arranged on the upper end surface of the case 1, and a document holder 21 arranged on the original placing table 20 so as to be openable and closable. An optical system 22 is located below the original table 20.
is located. The optical system 22 includes a lamp 23 as a light source and a CC that receives reflected light from the original as image information.
The image reading unit 25 includes an image reading unit 25 equipped with an image reading device D, and a mirror group 26 for guiding reflected light from the original to the CCD 24. A laser unit 27 is arranged between the copy processing section 2 and the optical system 22 to irradiate laser light onto the photosensitive drum 4 based on image information.

A cooling fan 30 is disposed below the document reading section 3 and to the left of the laser unit 27 in the figure. The cooling fan 30 is a fan unit that has an inlet on the side of the inlet 31 provided on the side surface of the case 1 and has an outlet on the side of the optical system 22 . The cooling fan 30 introduces outside air from the intake port 31 by rotating in the direction of the arrow, and discharges cooling air in the direction of the home position of the optical system 22 as shown by the arrow. As a result, optical system 2
The lower surface of the document table 20 near the home position of No. 2 is particularly strongly cooled.

A key panel 40 shown in FIG. 2 is arranged on the top surface of the case 1. The key panel 40 includes various keys such as a print key 41 for commanding the start of a copying operation, a variable magnification specification key 42 for specifying a variable magnification during copying, and a numeric keypad 43 for inputting a variable magnification in numbers. contains the key. Further, the key panel 40 is also provided with an LCD 44 for displaying numerical values such as a magnification ratio.

The above-mentioned copying machine has a control section 50 as shown in FIG. The control unit 50 includes a CPU, ROM, R
It is equipped with a microcomputer including AM, etc. The above-mentioned key panel 40 is connected to the I/O port 51 of the control unit 50.
, a lamp switch 52 for turning on/off the lamp 23, an optical system drive unit 53 including a stepping motor for horizontally moving the optical system 22, and a cooling fan 30 at a specified rotation speed. A rotating fan drive unit 54 and other input/output units are connected.

Next, the operation of the above-mentioned copying machine will be explained with reference to FIGS. 4 to 6.
This will be explained according to the control flowchart shown in FIG.

When the program starts, in step S1 of FIG. 4, initial settings are made such as setting the variable magnification to 100% (same size) and setting the number of copies to one. Once the initial settings are completed, the process moves to step S2. In step S2, it is determined whether the print key 41 on the key panel 40 has been pressed. If the print key 41 is not pressed, the copying operation is not started and the process moves to step S3. In step S3, it is determined whether the variable magnification designation key 42 has been pressed. If the magnification change designation key 42 is not pressed, the process moves to step S4 and other general processing is performed. When the process in step S4 is completed, the process returns to step S2.

If the operator presses the variable magnification specifying key 42 to change the copy magnification, the program moves from step S3 to step S5, and executes the magnification setting subroutine shown in FIG. In FIG. 5, step S6
Then, it is determined whether or not the numeric keypad 43 has been pressed. If the numeric keypad 43 is not pressed, the process moves to step S7. In step S7, it is determined whether the variable magnification designation key 42 has been pressed again. Pressing the magnification change designation key 42 at this stage means the end of the magnification setting subroutine. If the magnification change designation key 42 is not pressed, the program returns to step S6. Operator selects numeric keypad 4
If 3 is pressed, the program moves from step S6 to step S8. In step S8, a new magnification ratio is set based on input from the numeric keypad 43. When the process in step S8 is completed, the process returns to step S7. When the setting of the magnification ratio by pressing the numeric keypad 43 is completed, the operator presses the magnification ratio designation key 42 again. As a result, the program returns from step S7 to the main routine of FIG. 4, and the magnification change designation process is completed. In addition,
Here, let's assume that the maximum value of the magnification ratio is 400% and the minimum value is 2.
Assume that it is 5%.

Next, assume that the operator presses the print key 41 to instruct the start of a copying operation. As a result, the program moves from step S2 in FIG. 4 to step S9, and executes the copy subroutine in FIG. 6. In FIG. 6, in step S10, the set magnification is 3.
Determine whether it exceeds 00%. If the determination is Yes, the process moves to step S11. In step S11, the fan drive unit 54 (FIG. 3) is set to rotate the cooling fan 30 at high speed. In step S10, if the magnification ratio is 300% or less, the process moves to step S12. In step S12, it is determined whether the magnification ratio exceeds 50%. If the determination is Yes, the process moves to step S13. In step S13, the rotation speed of the cooling fan 30 is set to medium speed. If it is determined in step S12 that the magnification ratio is 50% or less, the process moves to step S14, and the rotational speed of the cooling fan 30 is set to a low speed.

Step S11, S13 or Step S
When the process in step S14 is completed, the process moves to step S15. In step S15, a copying operation is performed in which image information of the original placed on the original placing table 20 is read and a copy is created. Here, the lamp 23 is first turned on,
The optical system 22 moves along the original table 20. As a result, image information of the original on the original placing table 20 is inputted to the CCD 24 of the image reading section 25 as the intensity of light. The image information read by the image reading section 25 is converted into the intensity of laser light by the laser unit 27. Photosensitive drum 4 receives laser light from laser unit 27
An electrostatic latent image is formed on the surface. The formed electrostatic latent image is developed by the developing device 6, and the resulting toner image is transferred onto the paper fed from the paper feed cassettes 10a, 10b. The paper onto which the toner image has been transferred is transferred to the fixing device 1.
After the fixing process is performed in step 3, the sheet is discharged onto the paper discharge tray 14. The above-described copying operation is repeated according to the set number of copies.

In the copying operation, the moving speed of the optical system 22 varies depending on the set magnification ratio. For example, when the variable magnification is set to 400%, the optical system 22 is driven at 1/4 times the speed as compared to when the variable magnification is 100%. Further, when the magnification ratio is 25%, the optical system 22 is driven at a speed four times faster than when the magnification ratio is 100%. This is for enlarging the electrostatic latent image formed on the photosensitive drum 4 by four times or reducing it by one-fourth. As a result, when the magnification ratio is set to the reduction side (less than 100%), the amount of heat received from the lamp 23 per unit area of the document mounting table 20 decreases. On the other hand, when it is set to the enlargement side (exceeds 100%), the amount of heat received by the document mounting table 20 per unit area increases. However, in this embodiment, when the magnification ratio is high, the cooling fan 30 is rotated at high speed to provide strong cooling, so even though the amount of heat received per unit area of the document table 20 is increased, However, the document table 20 does not become overheated. On the other hand, if the magnification ratio becomes lower, the cooling fan 3
Since the rotation speed of 0 is set low, the noise from the cooling fan 30 is reduced. That is, in this embodiment, since the rotational speed of the cooling fan 30 can be suppressed to the necessary minimum,
The document mounting table 20 is maintained so as not to become overheated, and the noise from the cooling fan 30 is reduced.

FIG. 7 shows an example of the effects of this embodiment. In FIG. 7, the horizontal axis is the distance from the home position H of the document placement table 20, and the vertical axis is the distance from the document placement table 20.
temperature. The broken line indicates the allowable upper limit temperature t1 of the document mounting table 20. The one-dot chain line A is an example of the temperature distribution when the magnification is high (when the fan rotates at high speed), and the two-dot chain line B is an example of the temperature distribution when the magnification is low (when the fan is rotated at low speed). Moreover, the distance D1 is the moving distance of the optical system 22 when the temperature distribution A is present, and the distance D2 is the moving distance of the optical system 22 when the temperature distribution is B. As is clear from FIG. 7, the solid line C showing the temperature distribution when the cooling fan 30 is operated in the same manner as before and the optical system 22 is moved by a distance D2 during a copying operation shows that there is wasted cooling. In contrast, in this embodiment, the noise can be reduced without exceeding the upper limit temperature t1 as in the temperature distributions A and B.

As described above, according to this embodiment, the noise of the cooling fan 30 can be reduced without causing the document table 20 to become overheated.

[Other embodiments] (a) In the above embodiments, the magnification ratio is 300% and 50%.
Although the rotational speed of the cooling fan 30 is changed after , the present invention is not limited thereto. For example, the rotation speed of the cooling fan may be changed between when the magnification is on the enlargement side, when it is on the reduction side, and when it is the same magnification.

(b) The rotational speed of the cooling fan is not limited to three stages as in the above embodiment, but the present invention can be implemented in the same manner even if there are two stages or four or more stages. can.

(c) In the above embodiment, the rotation speed of the cooling fan is changed using only the variable magnification as a parameter, but the number of copies may also be controlled as a parameter in addition to the variable magnification.

[0030]

The image information reading device with a variable magnification function according to the present invention is provided with a cooling means drive means that operates the cooling means strongly when the specified variable magnification is high and weakly when the specified variable magnification is low. Therefore, according to the present invention, unnecessary operation of the cooling means can be suppressed while maintaining sufficient cooling of the original document placing section.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical cross-sectional view of a copying machine employing an embodiment of the present invention.

FIG. 2 is a partial plan view of the key panel portion.

FIG. 3 is a schematic block diagram of its control unit.

FIG. 4 is a control flowchart.

FIG. 5 is a control flowchart.

FIG. 6 is a control flowchart.

FIG. 7 is a graph showing an example of temperature distribution in the document placement section.

[Explanation of symbols]

3. Original reading section 20 Original table 22 Optical system 23 Lamp 25 Image reading section 27 Laser unit 30 Cooling fan 42 Magnification ratio specification key 43 Numeric keypad 50 Control section 53 Optical system drive section 54 Fan drive section

Claims (1)

[Claims] Claims: 1. A document placement section for placing a document; image information reading means for reading image information by irradiating light onto the document; cooling means for cooling the document placement section; a magnification specifying means for specifying a magnification; an image information reading means drive means for driving the image information reading means slowly when the specified magnification is high and fast when the specified magnification is low; a cooling means driving means for operating the cooling means weaker than when the cooling means is high; and an output means for outputting the image information read by the image information reading means after performing processing corresponding to a specified magnification ratio; Image information reading device with variable magnification function.