JP2000206851A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of shortening a first copying time with a small power consumption. SOLUTION: The image forming device is provided with a semiconductor laser 20 for outputting light in accordance with an input image signal, a polygon mirror 24 for scanning an image carrier with the light outputted from the semiconductor laser 20, a polygon motor 25 for rotating the polygon mirror 24, and a main control part 205 for controlling the drive of the polygon motor 25. In this case, the polygon motor 25 is controlled by the main control part 205 so that the motor 25 may be driven earlier in timing than a coping start key is depressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image by forming a latent image by performing optical writing using a polygon mirror.

[0002]

2. Description of the Related Art Polyhedral mirrors (polygon mirrors) driven by motors
2. Description of the Related Art An image forming apparatus that forms a latent image on a photosensitive member by scanning a laser beam by rotating a laser beam is widely used in digital copying machines, facsimile machines, and the like. In a conventional image forming apparatus, a motor for rotating a polygon mirror (hereinafter, referred to as a polygon motor) is turned on after pressing a copy start key.

In order to solve this drawback, it has been proposed to shorten the first copy time by keeping the polygon motor on at all times. However, this type not only increases the power consumption but also extends the life of the polygon motor. There has been a problem that the motor noise becomes high because the polygon motor rotates at high speed even in a short state or in a standby state. Therefore, for example, Japanese Patent Application Laid-Open Nos. Hei 7-273951 and
As described in Japanese Patent Application Laid-Open No.-95461, a plurality of types of rotation speeds of the polygon motor are set, and the polygon motor is controlled to rotate at a low speed during a copy operation standby, and to rotate at a steady speed during a copy operation. If the operation necessary for the copying operation is not performed, or if a human body detecting means is provided and a person does not approach a position where copying can be performed, the polygon motor is stopped to shorten the first copy time and reduce the motor noise. It has also been proposed to lower it.

[0004]

However, even in the latter case, the polygon motor is rotated at least for a preset time during standby. For example, when the power is turned on, the polygon motor rotates without performing the copying operation immediately. Unnecessary rotation of the polygon motor is being performed. Such unnecessary rotation results in waste of power consumption and shortens the life of the polygon motor.

The present invention has been made in view of such circumstances of the prior art, and has as its object to eliminate the waiting time until the polygon motor reaches a steady rotation and to reduce the first copy time with low power consumption. It is an object of the present invention to provide an image forming apparatus capable of performing the above.

[0006]

In order to achieve the above object, a first means is a light output means for outputting light in accordance with an input image signal, and a light output from the light output means on an image carrier. An image forming apparatus comprising: a polygon mirror for scanning the polygon motor; a polygon motor for rotating the polygon mirror; and control means for controlling the driving of the polygon motor. It is characterized in that it is controlled so as to be driven at a timing earlier than the pressing of the key.

A second means is provided in the first means, wherein a counting means for measuring a time from when the polygon motor is driven to when the copy start key is pressed is provided, and the control means controls the counting means in advance. If the copy start key is not pressed for more than the set time,
The polygon motor is stopped.

A third means is the first or second means, wherein a key detecting means for detecting pressing of an arbitrary key on the operation panel is provided, and the control means detects the key pressing means from the key detecting means at the time of image formation standby. The polygon motor is driven when a key input signal is received.

A fourth means is provided in the first to third means, wherein a document placement detecting means for detecting that a document is placed on the document table is provided, and the control means is adapted to control the image forming apparatus in standby for image formation. The polygon motor is driven when there is document placement information from document placement detection means.

A fifth means is the first to fourth means, further comprising a human body detecting means for detecting that a person has approached the periphery of the image forming apparatus, and wherein the control means is configured to detect the human body during image formation standby. When the human body detection information is received from the means, the polygon motor is driven.

A sixth means according to the first to fifth means, further comprising an automatic document feeder, and a document detecting means for detecting that a document has been set on the automatic document feeder, The control means drives the polygon motor when there is document detection information from the document detection means during image formation standby.

A seventh means is the second means, further comprising means for changing a time setting until the polygon motor is stopped.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment is an example in which the image forming apparatus is applied to a digital copying machine. FIG. 1 is a schematic configuration diagram showing a configuration of a digital copying machine, FIG. 2 is a plan view showing a configuration of an optical writing unit in FIG. 1, and FIG. 3 is a block diagram showing a schematic configuration of the optical writing unit in FIG.

The digital copying machine according to this embodiment includes a copying machine main body (I) and an automatic document feeder (hereinafter referred to as an AD).
F) (II) and a sorter (III).

The ADF (II) includes a document table 103 on which a bundle of documents is placed, a contact glass 9 for optically reading the documents, and a discharge tray 10 for discharging the read documents.
1 and so on. The document bundle placed on the document table 103 is separated one by one by pressing a copy start key (not shown) on the operation panel 206 (FIG. 3), and is conveyed onto the contact glass 9. Contact glass 9
The document read above is discharged onto the discharge tray 101.

The copier body (I) comprises a first scanner comprising a reflecting mirror 1, a first mirror 2 and a light source 3, and a second mirror 4
A scanner for optically scanning the original on the contact glass 9 by a second scanner comprising a third mirror 5; and a reflected image from the scanner formed on a CCD 8 via a color filter 6 and a lens 7 to be electrically operated. A conversion unit for converting the signal into a signal. The image information converted into the electric signal by the conversion unit is A / D converted, subjected to various image processings by the image processing board 10, and converted into a digital signal. The copying machine main unit (I) includes an optical writing unit 31 for forming an electrostatic latent image on the photosensitive drum 40 based on the image information on which the image processing has been performed, and an electrostatic latent image formed on the photosensitive drum 40. The developing unit includes a developing unit including a black developing unit 42a and a color developing unit 42b for visualizing the image, and a fixing roller unit including a pair of a heat roller 64 and a pressure roller 65 for fixing a toner image on a sheet. Thus, the image information after the image processing is
The light is written on the photosensitive drum 40 in the form of a set of light points by raster scanning of laser light in the light writing unit 31,
An electrostatic latent image is formed. The electrostatic latent image on the photoreceptor drum 40 is visualized by a developing unit, and is supplied to the sheet cassettes 60a and 60b.
And 60c. The transferred sheet is sent to the fixing unit by the conveyor belt 63, where the toner image is fixed on the sheet and discharged to the sorter (III). A sheet reversing mechanism for transferring an image to both sides of a sheet is provided below the copier body (I).

The sorter (III) includes a plurality of distribution bins 111.
a, 111b... 111x, and the copier body (I)
The paper discharged from the storage bins is arranged such that the pages are aligned for each of the plurality of distribution bins. The configuration described above is a known configuration in a conventional digital copying machine, and therefore, a more detailed description is omitted.

The mechanical configuration of the optical writing unit 31 is shown in FIG.
As shown in detail in FIG.
0, a polygon mirror 24 for deflecting the laser light from the semiconductor laser 20, and a reflection mirror 27 for reflecting the laser light deflected from the polygon mirror 24 and irradiating the photosensitive drum 40 with the polygon mirror 24. . That is, the laser light emitted from the semiconductor laser 20 is compressed in the sub-scanning direction by the cylinder lens 22 and enters the polygon mirror 24 in a compressed form. The polygon mirror 24 has an accurate polygonal shape.
5 rotates at a constant speed in a constant direction. The reflected laser light incident on the polygon mirror 24 is deflected by the rotation of the polygon mirror 24. The deflected laser light sequentially enters the fθ lenses 26a, 26b, 26c. lenses 26a, 26b and 26c convert the scanning light having a constant angular velocity so as to scan at a constant speed on the photosensitive drum 40 and form an image on the photosensitive drum 40 so as to have a minimum light spot. It also has a correction function.

The optical writing section 31 is provided with a synchronization detecting plate 30. The synchronization detecting plate 30 is provided with the fθ lens 2
After passing through 6a, 26b, and 26c, the laser beam guided by the synchronization detection mirror 29 is incident outside the image area, and outputs a synchronization signal for generating a cue signal in the main scanning direction. After a certain period of time after the output of the synchronization signal, one line of image data is output. By repeating this operation, one image is formed.

The electrical configuration of the optical writing unit 31 is as shown in FIG.
And a main control unit 202. The polygon motor drive circuit 201 drives the polygon motor 25 under the control of the main control unit 202. The main control unit 202 is a CPU 205 that performs various controls,
The memory 203 includes a memory 203 which is connected to a computer 05 and stores a program for controlling the copying operation and executing the operation of the present invention, and a counter 204 for measuring the pre-rotation time of the polygon motor 25. The main control unit 202 also receives a signal from the key input detection unit 207 via the operation panel 206, a signal from the human body detection unit 208 for detecting that a person approaches the digital copying machine, and an ADF (FIG. 1). Document set detection means 21 for detecting whether a document is set via ADF 209 corresponding to II)
0, opening / closing detecting means 2 for detecting opening / closing of a cover or a housing which is opened / closed when setting a document bundle in the ADF 209;
11 is received. The human body detecting means 208 is provided, for example, on the front panel of the housing of the copying machine main body (I), and detects infrared rays, ultrasonic waves, or the like.
This is to detect that a person is approaching. Also,
For example, when a document size detection sensor for detecting the size of a document is provided in the vicinity of the document table 103, the document set detection unit 210 may use this sensor.
The opening / closing detection means 211 may be provided with a sensor for detecting the opening / closing of the holding member near the opening / closing support portion of the holding member capable of opening / closing the document against the contact glass 9.

The operation of the above configuration will be further described with reference to the flowcharts of FIGS. FIG. 4 is a flowchart showing a copy operation in this embodiment, and FIG. 5 is a flowchart showing the operation of the standby process in FIG.

As shown in FIG. 4, in the copying operation, first, an initialization process is performed to initialize the apparatus (step 401), and a standby process described later is performed (step 402). When the standby process is completed and the copy operation becomes possible, the start key is checked on (step 403). When the start key is pressed, the counter 204 for measuring the pre-rotation time is stopped (step 40).
4) The copy operation is started (step 405). When the copy operation is completed, the process returns to the standby processing routine of step 402 again. As long as the start key is not turned on, the standby process is repeated any number of times.

The above standby state will be described with reference to FIG.
Counter 2 for measuring pre-rotation time of polygon motor 25
04 is started, that is, whether the counter 204 is 0 or not (step 5).
01). If it has not started, the operation panel 2
It is checked whether there is a key input from 06 (step 502). If there is no key input, it is checked whether the cover or the housing of the ADF 209 is opened to place the original on the contact glass 9. (Step 50
3). If the cover or the housing is not opened, it is further checked whether or not a document is set on the contact glass 9 (step 504).
Check whether the human body is detected by step 8 (step 5)
05). If a detection is detected in any of steps 502 to 505, the polygon motor 25 is turned on (step 506), and the counter 204 for measuring the pre-rotation time is started (step 50).
7), stop evaluation of the polygon motor 25 is performed (step 508).

The polygon motor 2 in step 508
In the stop evaluation of No. 5, the stop time of the polygon motor 25 set in the memory 203 in advance and the current counter value are evaluated, and if the stop time has already been exceeded, the polygon motor 25 is stopped (step 509). ), The counter 204 is stopped and cleared (step 410). The stop time of the polygon motor 25 can be changed by the user, so that a time corresponding to the user's use environment can be set, thereby providing an easy-to-use image forming apparatus suitable for the user's use environment. be able to.

If the counter 204 for measuring the pre-rotation time has already started, that is, if the counter 204 is not 0, and if any of steps 502 to 505 cannot be detected, the process jumps to step 508 and the polygon motor is started. 25 stop evaluations are performed. If the counter value of the counter 204 does not exceed the set time, the process directly exits and the process proceeds to step 40 in FIG.
The process proceeds to the start check of the start key 3.

[0026]

As is clear from the above description, according to the first aspect of the present invention, the polygon motor is driven earlier than the pressing of the copy start key. The time can be eliminated, whereby the first copy time can be reduced, and the power consumption can be suppressed.

According to the second aspect of the present invention, if the copy start key is not pressed for a predetermined time after the polygon motor is turned on, the polygon motor is stopped.
It is possible to prevent a reduction in noise due to the polygon motor and a reduction in the life of the polygon motor.

According to the third aspect of the present invention, since the polygon motor is driven by pressing an arbitrary key on the operation panel, the waiting time until the polygon motor reaches a steady rotation can be eliminated, and the first copy time can be reduced. Can be shortened.

According to the fourth aspect of the present invention, since the polygon motor is driven when the document is placed on the document table,
The waiting time until the polygon motor reaches steady rotation can be eliminated, and the first copy time can be reduced.

According to the fifth aspect of the present invention, since the polygon motor is driven by the approach of a person to the image forming apparatus, the waiting time until the polygon motor reaches a steady rotation can be eliminated, and the first copy can be performed. Time can be reduced.

According to the sixth aspect of the present invention, since the polygon motor is driven by setting the original in the automatic document feeder, the waiting time until the polygon motor reaches the steady rotation can be eliminated, and the first copy can be performed. Time can be reduced.

According to the seventh aspect of the present invention, since the time for driving the polygon motor can be changed by the user, it is possible to provide a user-friendly image forming apparatus suitable for the user's use environment. it can.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a mechanical configuration of a digital copying machine according to an embodiment of an image forming apparatus of the present invention.

FIG. 2 is a plan view illustrating a structure of an optical writing unit in FIG. 1;

FIG. 3 is a block diagram illustrating a schematic configuration of an optical writing unit in FIG. 1;

FIG. 4 is a flowchart illustrating a copy operation according to the embodiment.

FIG. 5 is a flowchart illustrating an operation of a standby process in FIG. 4;

[Explanation of symbols]

 I Copier body II, 209 ADF 9 Contact glass 20 Semiconductor laser 24 Polygon mirror 25 Polygon motor 31 Optical writing unit 40 Photoreceptor drum 103 Document mounting table 201 Polygon motor drive circuit 202 Main control unit 203 Memory 204 Counter 205 CPU 205 Operation panel 207 Key input detecting means 208 Human body detecting means 210 Document set detecting means 211 Open / close detecting means

Claims (7)

[Claims] 1. A light output means for outputting light in accordance with an input image signal, a polygon mirror for scanning output light from the light output means on an image carrier, and rotating the polygon mirror. An image forming apparatus comprising: a polygon motor; and control means for controlling driving of the polygon motor, wherein the control means drives the polygon motor at a timing earlier than pressing a copy start key. apparatus. 2. The apparatus according to claim 1, further comprising: counting means for measuring a time from when the polygon motor is driven to when the copy start key is pressed, wherein the control means determines whether or not the copy start key is operated for a predetermined time by the counting means. 2. The image forming apparatus according to claim 1, wherein the polygon motor is stopped when the button is not pressed. And a key detecting means for detecting pressing of an arbitrary key on an operation panel, wherein said control means controls said polygon motor when a key input signal from said key detecting means is received during image formation standby. The image forming apparatus according to claim 1, wherein the image forming apparatus is driven. 4. An image forming apparatus according to claim 1, further comprising: a document placement detection unit configured to detect that a document is placed on the platen.
4. The image forming apparatus according to claim 1, wherein the polygon motor is driven when document placement information is received from the document placement detection unit during image formation standby. 5. 5. The image forming apparatus further comprises: a human body detecting unit that detects that a person has approached the periphery of the image forming apparatus, wherein the control unit is configured to perform the operation when the human body detecting information is received from the human body detecting unit during image formation standby. The image forming apparatus according to claim 1, wherein a polygon motor is driven. 6. An automatic document feeder, and document detecting means for detecting that a document has been set on the automatic document feeder, wherein the control means controls the document detecting means during image formation standby. The image forming apparatus according to any one of claims 1 to 5, wherein the polygon motor is driven when there is document detection information from the apparatus. 7. The image forming apparatus according to claim 2, further comprising: means for changing a time setting until the polygon motor is stopped.