JPH07177310A - Image forming device - Google Patents

Abstract

(57) [Summary] [Object] To provide an image forming apparatus capable of reducing glare to a user even when a prescan for detecting a document size is performed. A transparent original plate 91, a CCD sensor 36 for outputting multi-valued data corresponding to the intensity of light reflected from the original plate on which an original is placed, and this light receiving means for outputting. Image forming means for forming an image based on multi-valued data and multi-valued data output from the light receiving element are compared with a reference value, and information is formed to form information indicating a magnitude relationship with the reference value. Means and an identifying means for identifying the original area and the area outside the original based on the information formed by the information forming means,
When the image forming mode is set by the setting means 23, the exposure intensity by the exposing means is set to the first intensity, and when the original area identification mode is set by the setting means, the exposing means is set. And an exposure intensity control means for controlling the exposure intensity by the second intensity lower than the first intensity.

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 such as a digital copier having a document size detecting function for detecting a document size.

[0002]

2. Description of the Related Art Recently, copying machines using digital technology have been developed and put into practical use. That is, an image from a document is read by a CCD (charge coupled device) type line sensor, and a signal from the line sensor is quantized and processed.

Some of such digital copying machines are provided with a document size detecting function for automatically detecting the size of a document placed on a document table. This document size detection function detects the difference in reflectance between the original and the cover by incorporating the output value of the CCD sensor due to the difference in the reflectance between the original and the cover at the time of pre-scanning by providing the original cover with a coating or a reflector. By doing so, the document size is detected by prescanning.

[0004]

When copying a book with a copying machine, the copying machine is carried out with the original cover open. However, a prescan for detecting the size of the original is used. There was the problem that it was very dazzling and unpleasant for The.

The present invention has been made in view of the above points, and an object thereof is to provide an image forming apparatus capable of reducing glare to a user even when a prescan for detecting a document size is performed. To provide.

[0006]

According to a first aspect of the present invention, there is provided a multi-valued image forming apparatus corresponding to a translucent document table and a reflected light intensity from the document table on which a document is placed. The light receiving means for outputting the data, the image forming means for forming an image based on the multivalued data output by the light receiving means, and the multivalued data output by the light receiving element are compared with a reference value. Information forming means for forming information indicating the magnitude relation with the reference value, identifying means for identifying the original area and the outside area of the original based on the information formed by the information forming means, and the original area by the identifying means. Setting means for setting one of the original area identification mode for identifying the image forming mode and the image forming mode for forming an image by the image forming means, and the image forming mode is set by the setting means. In the case of When the original area identification mode is set by the setting means, there is provided a control means for setting the exposure intensity of the exposure means to a second intensity lower than the first intensity, and the information forming means. The reference value is a value corresponding to the second intensity.

According to another aspect of the image forming apparatus of the present invention, a light-transmitting document table and a light receiving means for outputting multi-valued data corresponding to the intensity of light reflected from the document table on which the document is placed. When,
The image forming means for forming an image based on the multi-valued data output by the light receiving means and the multi-valued data output by the light receiving element are compared with a reference value to show the magnitude relationship with the reference value. Information forming means for forming information, identifying means for identifying an original area and an area outside the original based on the information formed by the information forming means, and an original area identifying mode for identifying the original area by the identifying means. Setting means for setting either one of the image forming mode and the image forming mode in which the image forming means forms an image, and when the document area identification mode is set by this setting means, the exposure means of the exposing means is set. A control means for weakening the exposure intensity, reading multi-valued data output from the light receiving means, and setting an optimum value from the image data of the original area and the area outside the original as a reference value of the information forming means. Is provided.

According to another aspect of the image forming apparatus of the present invention, a light-transmitting document table and a light receiving means for outputting multi-valued data corresponding to the intensity of light reflected from the document table on which the document is placed. When,
The image forming means for forming an image based on the multi-valued data output by the light receiving means and the multi-valued data output by the light receiving element are compared with a reference value to show the magnitude relationship with the reference value. Information forming means for forming information, identifying means for identifying an original area and an area outside the original based on the information formed by the information forming means, and an original area identifying mode for identifying the original area by the identifying means. Mode, and a setting means for setting either one of the image forming mode in which the image forming means forms an image, and the paper size is selected from the document area identified by the identifying means, and the light receiving means is selected for this sheet. It is characterized in that it has a control means for forming an image after moving the image of the document read by.

According to another aspect of the image forming apparatus of the present invention, a light-transmitting original table and a light receiving means for outputting multi-valued data corresponding to the intensity of reflected light from the original table on which the original is placed. When,
The image forming means for forming an image based on the multi-valued data output by the light receiving means and the multi-valued data output by the light receiving element are compared with a reference value to show the magnitude relationship with the reference value. Information forming means for forming information, identifying means for identifying an original area and an area outside the original based on the information formed by the information forming means, and an original area identifying mode for identifying the original area by the identifying means. Setting means for setting either one of the image forming mode and the image forming mode in which the image forming means forms an image, a storing means for storing the reference value, and the original area identifying mode by the setting means. Is set, the exposure intensity of the exposure means is set to a second intensity lower than the first intensity, and the multivalued data output from the light receiving means is compared with the reference value stored in the storage means. Control means for And it features.

According to a fifth aspect of the present invention, there is provided an image forming apparatus which receives multi-valued data in response to a light transmissive document table and reflected light intensity from the document table on which the document is placed. When,
The image forming means for forming an image based on the multi-valued data output by the light receiving means and the multi-valued data output by the light receiving element are compared with a reference value to show the magnitude relationship with the reference value. Information forming means for forming information, identifying means for identifying an original area and an area outside the original based on the information formed by the information forming means, and an original area identifying mode for identifying the original area by the identifying means. Mode, and setting means for setting either one of the image forming mode in which the image forming means forms an image, setting means for increasing / decreasing the reference value, and the original area identifying mode in the setting means. Mode is set,
The exposure intensity by the exposure means is set to a second intensity lower than the first intensity.
Control means for comparing the multi-valued data output from the light receiving means with the reference value set by the setting means.

[0011]

When the document position detection mode is set, the light amount of the fluorescent lamp is weakened to reduce the user's feeling of glare of the fluorescent lamp.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image forming apparatus according to an embodiment of the present invention will be described below with reference to the drawings. 1 is an overall block diagram of the control system of the digital copying machine, FIG. 2 is a flow chart showing the control contents of one embodiment, FIG. 3 is a sectional view showing the structure of the digital copying machine, and FIG. It is a figure for explaining.

In FIG. 1, 11 is a main CPU (central processing unit). This main CPU 11 is a control panel CPU 1
2. The scanner CPU 13 and the printer CPU 14 are connected via a communication line. The main CPU 11 is these control panel CPU 12, scanner CPU 13, printer CP
U14 is controlled comprehensively and copying is performed.

A ROM (read only memory) 21, a RAM (random access memory) 22, and a control panel (operation board) 23 are connected to the control panel CPU 12. The control panel CPU 12 detects the switches on the control panel 23, turns on and off the LEDs, and controls the display. For example, a switch for setting the document size detection mode is provided on the control panel 23.

The scanner CPU 13 has ROM 31, R
AM32, control part 3 of mechanical controller such as motor and solenoid
3, analog document image data stored in ADF (auto document feeder) 34, editor (coordinate input device) 35, and CCD sensor 36, for example, 8-bit image data
A / D circuit (analog / digital conversion circuit) 37 and SHD (shading correction circuit) circuit 3 for converting into digital data
8. The line memory 39 is connected and controls them.

Further, a fluorescent lamp 92 for scanning an original is connected to the scanner CPU 11 via a fluorescent lamp inverter 92a. This fluorescent light inverter 9
The reference numeral 2a has a function of switching the fluorescent lamp 92 on and off, and also has a function of switching the fluorescent lamp light amount. The light amount of the fluorescent lamp 92 is weak during the pre-scan in the document detection mode, and the fluorescent lamp during normal copying. The light quantity of 92 is controlled to be turned on at the appropriate reading light quantity (strong light quantity).

The printer CPU 14 includes a mechanical control unit 41 such as a motor, a solenoid and a switch, a RAM 42,
ROM 43, LCF (Large Cassette Feeder) 44,
Laser drive 4 for driving sorter 45 and laser light 46
7. A laser modulation circuit 48 is connected to control each part.

The main CPU 11 has a ROM 51 and a RAM 5
2. Data switching and buffer memory circuit 53 for switching to where to send the data read by the scanner, which data to send to the printer engine, and buffering, and an image processing circuit for performing image processing on image data 54, a compression / expansion circuit 55 for compressing / expanding image data, a compression memory 56 for storing data compressed by the compression / expansion circuit, a hard disk drive,
An I / F controller circuit 57 for interfacing with an optical disk drive and a facsimile adapter, a display memory circuit 59 for displaying on a display 58, and a printer controller for expanding code data from a personal computer 60 into image data. Circuit 61,
Page memory circuit 6 for storing image data page by page
2. Display font ROM 63 for expanding code data on the display 58, print font ROM 6 for expanding code data on the page memory
4 connected. In FIG. 3, a is a basic processing unit, b is a control panel, c is a scanner unit, and d is a printer engine. The RAM 52 also stores a reference value TH (shown in FIG. 4C) for detecting a document. Further, the ROM 51 stores a program for performing the processing shown in the flowchart of FIG.

Next, the internal structure of the digital copying machine will be described with reference to FIG. The digital copying machine includes a scanner section c for optically reading image information of an original, and a printer engine d for outputting the image information on a recording material, that is, a copy sheet, which is read by the scanner section c. There is.

The scanner section c includes an original placing table 91 on which an original to be copied is placed, a fluorescent lamp 92 as a light source for illuminating the original T placed on the placing table 91, and the fluorescent lamp 92. The CCD sensor 36 has the above-described CCD sensor that converts the reflected light into an image information signal by photoelectrically converting the reflected light from the original document T which is illuminated.

A reflector for efficiently focusing the illumination light from the fluorescent lamp 92 on the original T is arranged beside the fluorescent lamp 92. Further, between the fluorescent lamp 92 and the CCD sensor 36, a plurality of mirrors for bending an optical path through which the light traveling from the document T to the CCD sensor 36, that is, the reflected light from the document passes, and The reflected light is transferred to the CCD sensor 3
A lens or the like for focusing is arranged on the light collecting surface of 6.

An original document cover 91a for placing the original document in close contact with the above-mentioned original placing table 91 is arranged above the original placing table 91. This document retainer can be replaced with, for example, an SDF, a semi-automatic document feeder, or an ADF, an automatic document feeder, depending on the size or copying ability of the digital copying machine. A detection switch (not shown) for detecting the open / closed state of the original cover 91a is provided.

The image forming section d has a cylindrical shape and is rotatably formed in a desired direction via a motor or the like (not shown). The image forming section d is charged to a desired potential and is irradiated with a light beam. It has a photoelectric conversion element, that is, a photosensitive drum 93, in which the potential of the region irradiated with the light beam changes.

A charging device 94 for applying a desired electric potential to the drum 93 is provided around the photosensitive drum 93, and a laser unit 95 for outputting a laser beam which is turned on / off according to image information to the photosensitive drum 94. A developing device 96 for developing the electrostatic latent image formed on the photoconductor 94 by supplying a visualization agent, that is, toner by the laser beam from the laser unit 95, and the electrostatic latent image is developed through the developing device 96. Further, a transfer device 97 for transferring the toner image on the photoconductor 94 to a recording material fed from a recording material feeding portion, which will be described later, that is, a copy sheet is arranged in order.

Incidentally, in the downstream of the transfer device 97 around the photoconductor 94, the toner remaining on the surface of the photoconductor 93 is removed, and at the same time, the toner is generated on the photoconductor 93 by the laser beam. A cleaner unit 98 for erasing the change in the potential for the next image formation is arranged.

Between the developing device 96 and the transfer device 97, the copy sheet for transferring the toner image formed on the photoconductor 93 is fed toward the transfer device 97. A recording material feeding unit 99 is arranged.

Further, in the subsequent stage of the transfer device 97, in the direction in which the copy paper on which the toner image is transferred via the transfer device 97 is separated from the photoconductor 93, the toner is added to the copy paper. A fixing device 100 for fixing an image, and the fixing device 100 and the transfer device 9 described above.
7 is provided between the fixing device 10 and the copying paper.
A transport device 101 for transporting toward 0 is arranged.

Next, the operation of the embodiment of the present invention constructed as above will be described. When the power of the digital copying machine is turned on, the operation shown in FIG. 2 is started. First, initial setting is performed, and a standby state is set (step S
1). The user specifies from the control panel 23 whether or not to use the document position detection mode.

Next, it is determined by the control panel 23 whether or not the document position detection mode is designated (step S2).
If it is determined in step S2 that the document position detection mode is designated, it is detected whether the document cover 91a is open (step S3). When it is detected that the original document cover 91a is open, it is determined that the original document is placed on the original document table 91 by a sensor provided on the carriage or at the scanner bottom.
Alternatively, by slightly turning on the exposure lamp, the change in the output level of the CCD sensor 36 is detected (step S4).

Next, the mode of weak light quantity of the exposure lamp is set in the fluorescent lamp inverter 92a (step S5). And
When the light amount is weak, the carriage is operated to perform pre-scanning (step S6), and the main CPU 11 detects the change in the reflected light amount of the document from the output data of the CCD sensor 36 and determines the document size (step S7). ).

Here, FIG. 4 (A) shows a state in which the document T placed on the document table 91 is placed with the document cover 91a open. Fluorescent lamp 92
As shown in FIG. 4B, the output data of the CCD sensor 36 in the state where the light amount of the original is not dropped depends on whether the original T is present (original portion T1) and the original T is not present (original-free portion T0). Although there is a clear light amount difference ΔU, the output data of the CCD sensor 36 when the light amount of the fluorescent lamp 92 is reduced is only ΔV between and as shown in FIG. 4 (C).
However, as shown in the figure, the reference value TH for detecting the original can be detected by setting the reference value TH to an intermediate value of the light amounts of the original portion T1 and the original-free portion T0.

Here, this reference value TH is
A standard original is placed on the original placing table 91, the output data value of the CCD sensor 36 in the original portion T1 is Umax, and the output data value of the CCD sensor 36 in the original portion T0 is Umin.
In this case, A = (Umax + Umin) / 2 may be calculated and this A may be used as the reference value.

The A may be increased or decreased from the control panel 23. Then, it is determined whether the copy button of the control panel 23 is turned on (step S8).

Then, in the determination of step S8, the copy is made.
If it is determined that the button is turned on, the exposure lamp light amount normal mode is set to the fluorescent lamp inverter 92a (step S9).

Then, automatic paper selection, free registration,
A copy operation incorporating a function such as image movement is performed (step S10). The details of this copy operation will be described later.

If it is determined that the process is completed, the process returns to step S2 described above. Incidentally, the above-mentioned step S
If "NO" is determined in 2, the process proceeds to the above-described step S9, and normal copying is performed as the exposure lamp light amount normal mode.

Next, the copy operation (step S10) will be described in detail. In this copy operation, when the image data is compressed / decompressed, the image data can be compressed by the following two flows. (1) First, the analog image data read by the CCD sensor 36 is converted into multi-valued image data by the A / D circuit 37, and then the shading correction is performed by the SHD circuit 38. , Are stored in the line memory 39. The line data for one line stored in the line memory 39 is subjected to image switching through the data switching and the buffer memory 53, and then the compression / expansion circuit 55 performs compression / expansion of the image data. It is stored in the compression memory 56. (2) Image data input from the personal computer 60 is stored in the page memory via the printer controller 61. Then, the image data stored in the page memory is subjected to image processing by the image processing circuit 54 and then compressed.
After the image data is compressed and expanded by the expansion circuit 55, it is stored in the compression memory 56.

The compressed data can be sent to a hard disk drive, an optical disk drive, and a facsimile adapter (not shown) via the I / F controller 57.

In addition to the compressed data, the I / F controller 57 can also send normal uncompressed data. The image data can be expanded in the following two ways. (1) The compressed image data stored in the compression memory 56 is decompressed by the compression / decompression circuit 55, subjected to image processing by the image processing circuit 54, and then data switching and buffer memory 53. After being stored in the printer, the image is formed by being sent to the page memory of the printer engine d. (2) Hard disk drive / optical disk drive
The image data input from the facsimile adapter (not shown) is sent to the compression / expansion circuit 55 via the I / F controller 57 and the image data is expanded. Then, the decompressed image data is sent to the image processing circuit 54, subjected to image processing, and then sent to the printer d via the data switching and the buffer memory 53.

Next, the case of printing the image data from the personal computer 60 will be described. In this case, the image data output from the personal computer 60 is sent to the page memory of the printer engine d via the printer controller 61 and then printed out.

Further, the image data input from the scanner section c is input.
The case of outputting the data to the personal computer 60 will be described. First, the analog image data read by the CCD sensor 36 of the scanner section b is A / D converted by the A / D conversion circuit 36.
After conversion, shading correction is performed by the SHD circuit 38, timing adjustment is performed using the line memory 39, and data is switched and sent to the buffer memory 53. Then, it is output to the personal computer 60 via the I / F controller 57.

In addition, the present apparatus has a display 58, on which the data stored in the display memory 59 is displayed. The display memory 59 displays the image data read by the scanner section c, and the data read by the scanner section c is subjected to data switching and image processing (reduction) by the image processing section 54 via the buffer memory 53. After that, it outputs to the display memory 59.

The main CPU 11 can expand the data in the display font ROM 63 onto the display memory 59 and display character data such as characters on the display 58.

Further, the main CPU 11 makes the print font R
Expand the OM64 data on the page memory 62,
The combination with the image data from the scanner section b can be performed. It should be noted that the present invention is not limited to the above-described embodiments, but can be variously modified without departing from the scope of the present invention.

[0045]

As described in detail above, according to the present invention, when the prescan for detecting the document size is performed, the light amount of the fluorescent lamp is weakened, so that the document size is detected. Therefore, it is possible to provide the image forming apparatus capable of reducing the glare to the user by the pre-scanning.

[Brief description of drawings]

FIG. 1 is an overall block diagram of a control system of a digital copying machine according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the control contents of the embodiment.

FIG. 3 is a sectional view showing the structure of the digital copying machine of the embodiment.

FIG. 4 is a diagram for explaining a document detection process of the embodiment.

[Explanation of symbols]

11 ... Main CPU, 12 ... Control panel CPU, 13 ... Scanner CPU, 14 ... Printer CPU, 37 ... A / D circuit,
38 ... SHD circuit, 39 ... Line memory, 92 ... Fluorescent lamp, 92a ... Fluorescent lamp inverter.

Claims (5)

[Claims] 1. A light-transmitting original table, a light receiving means for outputting multivalued data corresponding to the intensity of light reflected from the original table on which the original is placed, and this light receiving means for outputting. Image forming means for forming an image based on multi-valued data and multi-valued data output from the light receiving element are compared with a reference value,
Information forming means for forming information indicating a magnitude relationship with the reference value, identifying means for identifying the original area and the outside area of the original based on the information formed by the information forming means, and the original by the identifying means. An original area identifying mode for identifying an area and an image forming mode for forming an image by the image forming means.
Setting means for setting either one of the two modes, and when the image forming mode is set by the setting means, the exposure intensity by the exposing means is set to the first intensity, and the original is set by the setting means. When the area identification mode is set, there is provided control means for setting the exposure intensity by the exposure means to a second intensity lower than the first intensity, and the reference value by the information forming means is the second intensity. An image forming apparatus having a value corresponding to. 2. A light transmissive document table, a light receiving means for outputting multi-valued data corresponding to the intensity of light reflected from the document table on which the document is placed, and this light receiving means for outputting. Image forming means for forming an image based on multi-valued data and multi-valued data output from the light receiving element are compared with a reference value,
Information forming means for forming information indicating a magnitude relationship with the reference value, identifying means for identifying the original area and the outside area of the original based on the information formed by the information forming means, and the original by the identifying means. An original area identifying mode for identifying an area and an image forming mode for forming an image by the image forming means.
Setting means for setting either one of the two modes, and when the original area identification mode is set by this setting means, the exposure intensity of the exposing means is weakened and the multi-value output from the light receiving means is set. An image forming apparatus comprising: a control unit that reads data and uses an optimum value as a reference value of the information forming unit based on image data of an original area and an area outside the original. 3. A light transmissive original table, a light receiving means for outputting multi-valued data corresponding to the intensity of reflected light from the original table on which the original is placed, and this light receiving means for outputting. Image forming means for forming an image based on multi-valued data and multi-valued data output from the light receiving element are compared with a reference value,
Information forming means for forming information indicating a magnitude relationship with the reference value, identifying means for identifying the original area and the outside area of the original based on the information formed by the information forming means, and the original by the identifying means. An original area identifying mode for identifying an area and an image forming mode for forming an image by the image forming means.
Setting means for setting either one of the read mode and the document size selected from the document area identified by the identifying means, and the image of the document read by the light receiving means is moved to this sheet, and then image formation is performed. An image forming apparatus including a control unit for controlling the image forming apparatus. 4. A light-transmitting original table, a light receiving means for outputting multivalued data corresponding to the intensity of reflected light from the original table on which the original is placed, and this light receiving means for outputting. Image forming means for forming an image based on multi-valued data and multi-valued data output from the light receiving element are compared with a reference value,
Information forming means for forming information indicating a magnitude relationship with the reference value, identifying means for identifying the original area and the outside area of the original based on the information formed by the information forming means, and the original by the identifying means. An original area identifying mode for identifying an area and an image forming mode for forming an image by the image forming means.
Setting means for setting either one of the two modes, the storage means for storing the reference value, and the setting of the document area identification mode by the setting means, the exposure intensity by the exposure means is set to the first value. Image forming apparatus having a second intensity lower than that of the control unit and comparing the multi-valued data output from the light receiving unit with a reference value stored in the storage unit. . 5. A translucent document table, a light receiving means for outputting multivalued data corresponding to the intensity of light reflected from the document table on which the document is placed, and this light receiving means for outputting. Image forming means for forming an image based on multi-valued data and multi-valued data output from the light receiving element are compared with a reference value,
Information forming means for forming information indicating a magnitude relationship with the reference value, identifying means for identifying the original area and the outside area of the original based on the information formed by the information forming means, and the original by the identifying means. An original area identifying mode for identifying an area and an image forming mode for forming an image by the image forming means.
Mode, setting means for setting the reference value to be increased or decreased, and when the original area identification mode is set by the setting means, the exposure intensity by the exposing means is set to An image forming apparatus having a second intensity lower than the intensity of 1 and a control means for comparing multi-valued data output from the light receiving means with a reference value set by the setting means. .