JP2003069791A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize power consumption by turning on a lamp for original read only on one side when reading the original having an image for reading only on one side in an image forming device, with which the front side and rear side of the original can be simultaneously read. SOLUTION: This device has an automatic original feeding device for feeding a plurality of originals continuously to a reading part, two image reading parts for front side reading and rear side reading for simultaneously reading the front side and rear side of a double sided original, an irradiation means for irradiating the original provided before the reading means and a detection means for detecting the quantity of transmitted from the original irradiated with the irradiation means and when the quantity of transmitted light detected by the detection means is greater than a specified value, both the sides of the original are not read but only one side is read.

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 capable of simultaneously reading double-sided originals, and more particularly to an image forming apparatus as an image reading unit of a digital copying machine capable of double-sided copying.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus capable of reading a two-sided original has a mechanism for mechanically reversing the original to read an image one side at a time. There was a problem that it was damaged and the speed per page was slower than in the case of one side. Therefore, an image forming apparatus capable of simultaneously reading a double-sided original has been proposed.

[0003]

However, when such an image forming apparatus is used as a reading device of a digital copying machine, there is an opportunity to read not only double-sided originals but also single-sided originals.

As an original having an image only on one side, for example, an original such as OHP paper or thin paper in which an image is formed on both sides of which a back side image is transparent is conceivable. As in the case of the double-sided original, when the two original reading lamps are turned on at the same time for the front and back sides, useless power is generated.

[0005]

In order to solve the above problems, the image forming apparatus of the present invention has the following configuration.

(1) An automatic document feeder for continuously feeding a plurality of documents to a reading means, and a front-side reading and a back-side reading for simultaneously reading the front and back sides of a double-sided document And two image reading units of
After the read image is formed as a latent image on a photoconductor by an electrophotographic method, it is developed with toner and transferred onto a transfer material, and the toner image on the transfer material is fixed by a heating / pressurizing means, thereby transferring the transfer material. An image forming apparatus for forming an image thereon has an irradiation unit provided in front of the image reading unit for irradiating a document, and a detection unit for detecting the amount of transmitted light from the document irradiated by the irradiation unit. If the amount of transmitted light detected by the detecting means is larger than the specified value, only one side of the document is read without reading both sides.

(2) When the amount of transmitted light detected by the detecting means is larger than the specified value, the copying operation is stopped and a display for selecting whether to read only one side of the original is displayed on the display section. The image forming apparatus described in (1) above.

(3) When the amount of transmitted light detected by the detecting means is larger than the specified value, the copying operation is stopped and a display for selecting whether to read only one side of the original is displayed on the display unit. The image forming apparatus according to the above (2), wherein only one side of the original is read when no key is input for a predetermined time.

(4) When the amount of transmitted light detected by the detecting means is larger than the specified value, the copying operation is stopped, and a display for selecting whether to read only one side of the original is displayed on the display unit. The image forming apparatus according to the above (2), wherein both sides of the original are read when no key is input for a predetermined time.

(5) When the amount of transmitted light detected by the detecting means is larger than the specified value, the copying operation is stopped and a display for selecting whether to read only one side of the original is displayed on the display unit. The image forming apparatus according to (2) above, wherein it is possible to set whether to read only one side or both sides of the original when no key is input for a predetermined time.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

[0012]

1 is an example of a digital copying machine using the reading device of the present invention.

The document placing portion 20 of the automatic document feeder 201
The document placed on the No. 3 is separated by the paper feed roller 204,
After being fed, the document irradiation unit 215 and the document irradiation unit 21
The sheet is conveyed between the photo-detecting elements 216 that detect the amount of transmitted light from the document, which is irradiated by the sheet No. 5, and is conveyed to the front surface reading device 202 via the conveyance guide 206. Further, it is conveyed at a constant speed by the conveyor belt 208, and is ejected to the outside by the paper ejection roller 205. During this period, the image on the surface of the document illuminated by the illumination system 209 at the reading position of the reading device 202 is converted into an image signal by the image reading unit 213 by the optical system including the reflection mirrors 210, 211, and 212. The image reading unit 213 is a lens and a photoelectric conversion element C.
It is composed of a drive circuit for a CD and a CCD. On the other hand, the image on the back side of the document is converted into an image signal by the image reading unit 207.
When reading an original, the original is conveyed at a constant speed, the reading system is stopped and the original is read in the flow reading mode, and the original is read by the reading device 202.
There is a fixed mode in which the illumination system 209 and the mirrors 210, 211, and 212 are moved at a constant speed and read by being placed on the original glass table 214. During double-sided scanning, both sides are scanned in the flow scanning mode. When single-sided, you can read in either fixed mode or non-stop reading mode. Normally, a sheet-shaped document is read in the flow-reading mode, and a bound document is read in the fixed mode.

The image signal is processed by the image processing unit 217 and then reproduced on recording paper by the image reproducing apparatus 301 in page units. The image signal is modulated into an optical signal by the semiconductor laser 313 controlled by the image controller 300. The modulated laser light is an optical scanning device 31 using a polygon mirror.
1, the charger 31 via the mirrors 312a and 312b
The photosensitive drum 309 whose surface is uniformly charged by 0 is exposed to form an electrostatic latent image. The electrostatic latent image is the developing device 3
The toner image of 14 is developed, and the toner image is transferred to the recording paper by the transfer separator 315. The transfer paper is stored in the paper cassettes 302 and 304. Paper cassette 3
The transfer paper from 02 is painted by the paper feed roller 303,
The registration roller 3 is conveyed by the conveyance roller 306.
The timing with the image is adjusted by 08, and the image is conveyed to the transfer position of the photosensitive drum. On the other hand, the transfer paper of the paper cassette 304 is fed by the paper feed roller 305, and the transfer roller 3
07, 306, registration roller 308
By adjusting the timing with the image, the image is conveyed to the transfer position of the photosensitive drum. The recording paper onto which the toner image has been transferred is conveyed to the fixing device 318 by the conveyor belt 317, and the toner on the transfer paper is fixed.

When the single-sided mode is set, the transfer paper from the fixing device 318 is discharged outside the machine by the fixing paper discharge roller 319 and the paper discharge roller 324. When the double-sided mode is set, the transfer paper is the fixing paper discharge roller 319.
Is conveyed to the reversing path 325 by the reversing roller 321 via the conveying roller 320. Further, immediately after the trailing edge of the recording paper passes through the confluence point with the double-sided path 326, the rotation of the reversing roller 321 is reversed, so that the recording paper is reversed and is conveyed to the double-sided path 326. The transfer sheet conveyed to the double-sided path is conveyed by the rollers 322 and 323, and again through the conveying roller 306, the registration roller 308 adjusts the timing with the back side image, and then is transferred and fixed, and then discharged outside the machine.

Next, FIG. 2 shows a block diagram of the control system of this apparatus.

All of the apparatuses are system controllers 10
It is totally controlled by 1. The system controller 101 mainly exchanges data with the operation unit 102, that is, the user interface, in addition to the drive of each load in the device, the information collection analysis of the sensors and the image processing unit 217 and the image control unit 300 described above. Play the role of.
The internal configuration of the system controller 101 is equipped with the CPU 101a for performing the above-mentioned role, and
The PU 101a similarly executes various sequences related to a predetermined image forming sequence by a program stored in the ROM 101b mounted on the system controller 101. At that time, a RAM 101c is also mounted to store rewritable data that needs to be temporarily or permanently stored. RAM1
01c stores, for example, a high voltage set value to the high voltage control unit 105 described later, various data described later, image formation command information from the operation unit 102, and the like.

The first role of the system controller 101 is the image processing section 217, the image control section 300, and the operation section 1.
Data exchange with 02 will be described. Image processing unit 21
7, the image signal from the CCD (not shown) is subjected to image processing such as A / D conversion, S / H, shading correction, masking correction, scaling, and LOG conversion. In addition to sending the specification setting value data of each unit necessary for these image processings, a signal from each unit, for example, a document image density signal or the like is received, and the high voltage control unit 10 described later
5 and the image control unit 300 are controlled to make settings for optimal image formation. The image control unit 300 controls the laser optimally based on the definition of the image size for image formation and the digital video data subjected to the image processing. Make the required settings. The operation unit 102 obtains information such as a copy magnification and a density setting value set by the user, and also the state of the image forming apparatus, for example, information on the number of images formed or whether images are being formed, and occurrence of a jam. It sends out data to show the user and its location to the user.

Next, the driving of each load in the apparatus and the information collection and analysis of the sensors, which is the second role, will be described. In this device, a DC load such as a motor and a clutch / solenoid, and a sensor such as a photointerrupter and a microswitch are arranged in various places inside the device. In other words, various sensors are used to convey the transfer material and drive each unit by appropriately driving the motor and each DC load, and monitoring the operation thereof. Therefore, the system controller 101 causes the motor control unit 107 to control each motor based on signals from various sensors 109, and at the same time, causes the DC load control unit 108 to operate the clutch / solenoid to smoothly perform the image forming operation. Is proceeding to. Further, by sending various high voltage control signals to the high voltage control unit 105, a primary charger 310, which is various chargers forming the high voltage unit 106, an auxiliary charger (not shown),
Appropriate high voltage is applied to the transfer charger and the developing roller in the developing device 314. Further, each of the fixing rollers in the above-mentioned fixing device 318 has therein a beater 111 for heating the roller, and each heater thereof is ON / OFF controlled by the AC driver 110. At this time, each fixing roller is provided with a thermistor 1O4 for measuring the temperature thereof, and after the A / D 103 converts the resistance value change of the thermistor 104 according to the temperature change of each fixing roller into a voltage value, It is input to the system controller 101 as a digital value. The AC driver 110 described above is controlled based on this temperature data.

FIG. 3 is a block diagram for controlling the reading surface of the original by detecting the thickness of the original from the amount of transmitted light of the original, which is a feature of the present invention.

The document irradiation unit 215 includes a document irradiation LED 2
15a and a direct light amount light receiving portion 215b for detecting the direct light amount of the document irradiation LED. Original irradiation LED 21
The light detecting element 216 for detecting the amount of light transmitted from the document illuminated by 5a is provided at a position facing the document irradiating section 215 with the transfer sheet in between, and is a transmitted light amount detecting section for controlling these elements. The image processing unit 217 is included in the system controller.

The original irradiation LED is feedback-controlled by the light quantity control section 220 based on the light quantity directly detected by the light quantity receiving section 215b in order to always keep the light quantity constant.

The amount of transmitted light detected by the light detecting element 216 increases as the thickness of the original document decreases. The detected transmitted light amount is converted into an electric signal by the photoelectric conversion unit 218, and then the comparison unit 219 determines whether or not the transmitted light amount is higher than a specified value.

Here, the original is not a double-sided original, but an original having an image on only one side is, for example, an OHP sheet or a thin paper which is transparent on both sides when an image is formed on both sides.

The reference value to be compared with the detected light amount detected by the photo-detecting element 216 in the comparison section 219 is a threshold value of whether or not the document has a thickness capable of having a double-sided image, that is, here, the document is a double-sided document. It is possible to determine whether the document is a one-sided original.

Therefore, when the comparison unit 219 detects that the amount of transmitted light is higher than the specified value, the CPU 101a on the system controller 101 determines not to perform double-sided reading, and the front side reading device 202 reads only the front side. Control (when the amount of transmitted light is judged to be higher than the specified value, the copying operation is stopped, and a mode is displayed in which it is possible to select whether or not only the front side can be read on the operation unit. It can be switched by setting on the operation unit 102).

Next, the sequence of the present invention will be described with reference to FIG. It should be noted that this sequence is applied when a document is read using the automatic document reading device.

Reading of the original document is started by a key input from the operation unit 102, and in step S401, the transportation of the original document is started. Next, in step S402, the document irradiation LED for detecting the amount of transmitted light of the document is turned on, and in step S403, the amount of transmitted light is detected by the light detection element. After that, the irradiation LED is turned off, and in step S404, the detected light amount from the light detection element is compared with a specified value. If the detected light amount is larger than the specified value, it is determined that the original is a single-sided image, and in step S405, the original is detected. When reading, turn on the reading lamp for one side only. If the detected light amount is smaller than the specified value, it is determined that the original is a double-sided original, and the reading lamps are turned on for both sides when reading the original in step S406. In step S408, it is determined whether or not the document image read in step S407 is the last sheet. If it is not the last sheet, step S40
Returning to 1, the reading of the original is completed if it is the last sheet.

[0029]

As described above, according to the present invention,
In an image forming apparatus capable of simultaneously reading the front side and the back side of an original, when reading an original having an image on only one side, the lamp for reading the original is turned on only on one side to minimize power consumption. be able to.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an image forming apparatus according to the present invention.

FIG. 2 is a block diagram showing control of an apparatus in image formation.

FIG. 3 is a block diagram for detecting the amount of transmitted light of a document, which is a feature of the present invention.

FIG. 4 is a flowchart of control according to the present invention.

[Explanation of symbols]

101 system controller 101a CPU 101b ROM 101c RAM 102 Operation unit 103 A / D 104 thermistor 105 High voltage controller 106 High voltage unit 107 Motor control unit 108 DC load control unit 109 Various sensors 110 AC driver 111 heater 201 Automatic document feeder 203 Document Placement Section 204 paper feed roller 205 paper ejection roller 206 Transport guide 208 Conveyor belt 209 Lighting system 210, 211, 212 Reflective mirror 213 Image reading unit 214 Document glass stand 217 Image processing unit 218 Photoelectric conversion unit 219 Comparison Department 220 Perfume control unit 300 image controller 301 image reproducing device 302 paper cassette 303 paper feed roller 304 paper cassette 305 Paper feed roller 306, 307 Conveyor roller 308 Registration roller 309 Photosensitive drum 310 Charger 311 Optical scanning device 312a, 312b Mirror 313 Semiconductor laser 314 Developer 315 Transfer Separator 317 Conveyor belt 318 Fixer 319 Fixing paper ejection roller 320 transport roller 321 Reversing roller 322, 323 roller 324 Paper ejection roller 325 Reverse Path

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H028 BA03 BB04 BB08 BD03                 2H076 AA04 AA07 AA58 BA15 BA24                       BA47 BA58 BA63 BA66 BA87                       BB09                 5B047 AA01 BA01 BA07 BB02 BC11                       BC14 CA05 CA19 CB05 CB16                 5C051 AA01 BA03 DA03 DB01 DB28                       DC05 DC07 DE02 DE29 EA09                       FA01                 5C072 AA01 BA06 CA05 CA12 EA05                       RA20 WA02 XA01

Claims (5)

[Claims] 1. An automatic document feeder for continuously feeding a plurality of originals to a reading means, and a front side reading side and a back side reading side for simultaneously reading the front side and the back side of a double-sided original. It has two image reading sections, and the read image is formed as a latent image on a photoconductor by an electrophotographic method, then developed with toner and transferred onto a transfer material,
In an image forming apparatus for forming an image on a transfer material by fixing a toner image on the transfer material by a heating and pressing means, an irradiation means for irradiating a document provided in front of the image reading means, and an irradiation means. When the amount of transmitted light detected by the detection unit is larger than a specified value, only one side of the original is read, not the both sides of the original. An image forming apparatus characterized by. 2. When the amount of transmitted light detected by the detecting means is larger than a prescribed value, the copying operation is stopped and a display for selecting whether or not only one side of the original is read is displayed on the display section. The image forming apparatus according to claim 1. 3. When the amount of transmitted light detected by the detecting means is larger than a specified value, the copying operation is stopped, and a display for selecting whether or not only one side of the original is read is displayed on the display unit and then a predetermined value is displayed. 3. The image forming apparatus according to claim 2, wherein only one side of the original is read when no time key input is performed. 4. When the amount of transmitted light detected by the detecting means is larger than a specified value, the copying operation is stopped, and a display for selecting whether or not only one side of the original is read is displayed on the display unit, and then a predetermined value is displayed. 3. The document is read on both sides when no time key input is performed.
The image forming apparatus described. 5. When the amount of transmitted light detected by the detecting means is larger than a specified value, the copying operation is stopped, and a display for selecting whether or not only one side of the original is read is displayed on the display unit, and then a predetermined value is displayed. 3. The image forming apparatus according to claim 2, wherein it is possible to set whether to read only one side of the document or both sides of the document when no time key input is performed.