JPS60162380A - Recording device - Google Patents

Abstract

PURPOSE:To shorten a detection period density information and to shorten a recording time by starting a preparatory scan from a light exposure scan completion position in a device for adjusting a recording density. CONSTITUTION:A device is designed to start a preparatory scan of an original from its return position C by an optical scan system 12 when the device stops an optical scan system 12 at a return position C of a light exposure scan completion position and when it starts recording. Therefore the device makes the preparatory scan for original density detection while the optical scan system 12 shifts from the return position C to its home position A, and the device then makes a normal scan by shifting from its home position A to the return position C, thereby enabling shortening the time needed for reciprocation of the preparatory scan.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention provides a recording apparatus that detects the density of an original before recording and adjusts the recording density based on the detected original density information. This invention relates to a shortened recording device.

(b) Conventional technology Since the originals recorded by a recording device such as an electrophotographic copying machine have various background colors and image proportions, many conventional recording devices have been able to adjust the density depending on the document. The system is designed to ensure that the most suitable images can be obtained.

However, when there are many types of originals to be recorded at once, the work of adjusting the density becomes cumbersome, and if the adjustment is incorrect, the recorded data may be wasted. An apparatus has been developed that automatically adjusts the exposure amount and developing bias voltage based on the above information to obtain a recorded image with an appropriate density.

One of these types of automatic image density adjustment methods is a method in which a document to be recorded is preliminarily scanned, and the developing bias voltage during recording starting from the next main scan is adjusted based on the document density information obtained thereby (for example, JP-A No. 56-89751) is known, but since this method performs two preliminary scans before the main scan, it takes time to record one document and reduces the recording speed. be.

Therefore, in the document density information detection mode, the optical scanning system is moved in advance to the return position of the optical scanning system in the normal recording mode, and when the recording start button is pressed, the optical scanning system returns to the normal home position. A copying machine has been proposed in which a preliminary scan is performed to detect document density information, and after returning to the home position, a normal main scan is performed (for example, in Japanese Patent Laid-Open No. 56-897).
No. 52). In this way, the forward scanning time for preliminary scanning for detecting density information on the original can be shortened, so the recording time can be reduced to some extent, but even if the original size does not change, each time the original is Scanning will definitely be performed.

On the other hand, as a method to shorten the recording time, the home position of the optical scanning system is set to the opposite side (the right side) from the normal position (the left side of the apparatus when the user stands facing the recording apparatus).
A device has been proposed in which the forward movement of the optical scanning system performs preliminary scanning for detecting density information, and the backward movement performs main scanning (7'(
For example, Japanese Patent Application Laid-open No. 138740/1983). In this way, both preliminary scanning and main scanning can be performed in one reciprocating scan of the optical scanning system, which can significantly shorten the recording time. Therefore, when manufacturing, the optical system must be significantly changed between Isobune, which performs main scanning in the return operation, and a similar model that does not, which requires a great deal of effort in manufacturing design even though similar models are manufactured. It takes.

(c) Object and Structure of the Invention The present invention has been made in view of the above points, and is a recording device that detects the density of an original before recording and sets recording conditions based on the detected density information. The purpose is to shorten the recording time by shortening the time required for detection, and for this purpose, the optical scanning system is stopped at the exposure scan end position when the exposure scan of the document is completed, and when the recording start operation is performed thereafter, the optical scanning system is stopped at the exposure scan end position. The scanning system is configured to start preliminary scanning for detecting the density of the original from the exposure scanning end position. As a preferred embodiment of the present invention, there is a function to automatically feed the original to the exposure position. It is preferable that the optical scanning system is configured to stop the optical scanning system at the exposure scan end position if there is a document to be recorded next at the end of the exposure scan, and to return it to the home position if not.

) Example The present invention 2 will be explained below based on the drawings.

FIG. 1 shows an embodiment of a recording apparatus according to the present invention, which is equipped with an automatic document feeding function for automatically feeding documents.

An automatic document feeder 2 is disposed on the recording apparatus main body 1, and an original platen glass 11 is provided on the upper surface of the recording apparatus main body 1. Documents are fed onto the original platen glass 11 inside as will be described later. An optical scanning system 12 consisting of an exposure rung 12g for scanning an original document, mirrors 12b + 12c for reflecting light reflected from the original document, and a lens 12d, and a rotating drum 13 having a photoreceptor 13a on its surface are provided. It is being Around the rotating drum 13, there is a charging electrode 14 that uniformly charges the photoreceptor 13a, and the photoreceptor 13 is charged by light reflected from the original.
a developing device 15 that develops the electrostatic latent image of the document formed on the document a into a visible image; a transfer electrode 17 that transfers the visible image onto the recording paper P fed from the paper feeding cassette 16; A separation electrode 18 that separates the recording paper P from the front surface of the photoconductor 13a after transfer, and a cleaning device 19 that removes residual toner on the photoconductor 13a are provided, and the recording paper carrying the visible image is transferred to the conveyance device 20. After being conveyed by the fixing device 21, the paper is fixed and discharged onto a paper discharge tray 22.

The apparatus main body 1 further includes a lens 12e and a density sensor 12f such as a photodiode or a phototransistor located at approximately the same position as the lens 12d and slightly laterally shifted from the optical axis. The light reflected from the document during preliminary scanning passes through the lens 12e and is received by the density sensor 12f. A density signal f1 corresponding to the original density is output from the density sensor 12f, and original density information is obtained by creating a density histogram based on this output.

On the other hand, the automatic document feeder 2 is placed on the document table glass II of the recording apparatus main body 1, and is provided with a position 2a at the center of the upper surface of the case 25 for placing the document G to be recorded.
A conveyor belt 2B stretched between a driving roller 26 and a driven roller 27, and a pair of feed rollers 29 for feeding out the document GE placed at the document placement position 2a one by one are provided inside the document storage device. Prior to the recording operation, the original G is placed at the placement position 2a, and the originals are fed one by one onto the original platen glass 11 in synchronization with the recording operation.

Inside the automatic document feeder 2, a reflective sensor 30 is disposed immediately downstream of the document feed roller 29 as a means for detecting the document size. The reflective sensor 30 is a well-known sensor composed of a light-emitting element and a light-receiving element, and is arranged at least twice in the width direction of the document (perpendicular to the document conveyance direction), and its output state (presence of output and output time) to the manuscript is? Can be detected. Further, the device 2 is provided with means for detecting the presence or absence of a document. This document detection means is a reflective sensor 31 that
They are arranged near the document feeding side of a, and a plurality of them are also arranged in the width direction of the document G. Since the output level of the sensor 31 is high while the original G is placed on the original placing table 2a, the presence or absence of the original can be detected by a change in the output level.

FIG. 2 shows a block diagram of the control circuit of the recording apparatus, in which the same reference numerals as in FIG. 1 indicate the same components.

Concentration information from a concentration sensor 12f for detecting document concentration provided inside the apparatus main body 1 is sent to a human output (Ilo) device 32.
The data is manually input and sent to the central processing unit (CPU) 33, where it is processed and stored in the RAM 34. CPU33
The arithmetic processing is performed according to a program stored in the ROM 35. On the other hand, from the automatic document feeder 2, data on the presence or absence of a document, its size, or the number of sheets to be fed from the document presence/absence detection means 30 and the document size detection means 31 are input to the I10 device 32, and similarly to the density information, the data is sent via the CPU 33. and recorded in the RAM 34. In this case, the presence or absence of a document is determined by the reflective sensor 31 provided in the automatic document feeder 2 described above.
The size of the document is detected by a reflective sensor 30 provided in the device 2.

Also, the device itself! Movement of the optical scanning system 11 inside? I10 is used for starting, stopping, forward rotation, and reverse rotation of the controlling motor 36.
It is controlled by a drive circuit 37 based on instructions from the device 32. For this purpose, an encoder 36a that detects the rotation speed of the motor 36 is attached to the motor shaft, and the rotation speed information of the motor 36 detected by the encoder 36a #
``jI10jI10 device and RA via CPU33
It is stored in M34. The CPU 33#-j also controls a series of recording cycles, but this point is not directly related to the gist of the present invention and will therefore be omitted.

Next, the operation of the recording apparatus according to the present invention will be explained using FIGS. 3 and 4. - As an example, the size is 84% B
A case will be described in which a desired number of documents are recorded by fully automatic feeding of three documents of size 5 and A4.

First, place B4%B in the document placement position 2a of the automatic document feeder 2.
Lay out three 5% A4 manuscripts in this order from top to bottom. If you press the record button on the operation panel here, B4 placed on the top
A document of the same size is conveyed onto the document table glass 11, and during this conveyance, the document size is detected by the sensor 30, and a size signal is sent to the CPU 33 via the I10 device 32. When the original is fed to a predetermined position on the original platen glass 11 of the recording device, this is detected by a miteroswitch (not shown) or the like and inputted to the CPU 33 manually. After a predetermined time determined by the program, a command to start the optical scanning system 12 is output from the I10 device 32 to the drive circuit 37. As a result, the motor 36 starts and the home position A
The optical scanning system 12 located at 1 begins to move and starts preliminary scanning for detecting the density of the document. The preliminary scan is performed by scanning the optical scanning system 12 by an amount corresponding to the minimum document size, for example, regardless of the size of the document on the document table glass 11, and after scanning, the document density information obtained by this preliminary scan is sent via the I10 device 32. The data is stored in the RAM 34 by the CPU 33. After the optical scanning thread 12d returns to the home position A, main scanning for exposing the original is started.

During this time, the motor 36 is rotated in the forward and reverse directions by the drive circuit 37 based on the control signal from the HI10 device 32. The optical scanning system 12 moves to a position determined based on document size information and document presence information stored in the RAM 34, that is, a return position. That is, in this case, since the original size is B4 and the presence of the next original is detected by the sensor 31 that detects the presence or absence of an original, the optical scanning system 12 moves to the return position B corresponding to the original size B4.
move to and stop there. During the main scan, recording is performed under recording conditions based on the document density information stored in the RAM 34 by normal electrophotographic processing. In this way, recording of the first document (size B4) is completed.

After the recording of the first document (size B4) is completed and the recording paper is ejected, the original document (size 85) is placed on the document table glass l.
l is fed on. When the document reaches a predetermined position on the document platen glass 11, a start command from the I10 device 32 causes the optical scanning system 12 to return to the return position 1tf where it had been stopped until then.
It starts from fiB toward home position A, and during this time it performs preliminary scanning for detecting density information. Concentration information is I1
The data is stored in the RAM 34 via the 0 device 32 and the CPU 33. After the optical scanning system 12 returns to the home position A, main scanning for exposing the original is started. B5 which has already been detected by the document size detection sensor 31 during main scanning
When the main scanning is completed, the document presence/absence detection sensor 31 has already scanned the next fiXI (+ chair A4).
Since the presence of is detected, it stops at the return position C, which is the end position of the main scan. The recording operation during the main scan is as usual.

In this way, the recording of the second original (size B5) is completed, and the original (size A4) of the original size is fed onto the original platen glass 11, and the recording paper is ejected.

As in the case of the second document described above, the optical scanning system 12 begins to move from the return position C, where it had been stopped, toward the home position A, and starts preliminary scanning. After the optical scanning system 12 reaches home position A, it is reversed and starts main scanning. The optical scanning system 12 moves by a distance corresponding to the A4 document size, and when it determines whether there is a next document at the return position, it does not stay at the return position and returns to the home page because there is no document to be recorded next. Return to position A.

In this way, three originals are recorded. Looking at the movement of the optical scanning system 12, the movement of the optical scanning system 12 for the first original is the same as in the case of a conventional normal recording device, but for the second and third originals. Regarding the original, the optical scanning system 12 is stopped at the return position, performs preliminary scanning to detect the density of the original while moving from the return position to the home position, and then performs main scanning when the home position is moved to the turn position. Therefore, the time required to complete the recording operation can be shortened even though the document density is detected.

FIG. 4 compares the time required for recording between the recording device according to the present invention and the conventional recording device.
(A) is the conventional case, and ←) is the case of the present invention. In the illustrated example, three originals (size B4) are used as in the example above.
．． B5. A4), the vertical axis indicates the speed of the optical scanning system, and the positive direction indicates the direction away from the home position.
The negative direction is the direction closer to the home position. In the figure, the broken line portion indicates preliminary scanning for document density detection, the solid line portion indicates main scanning for document exposure, and the thick line portions are the actual document density detection period and document exposure period.

Further, time T is the time required for automatic document feeding, and this is the same in both the case of the present invention and the conventional case.

As can be seen from FIG. 4, according to the present invention, the total recording time until the recording of three original documents is completed can be reduced by 7 hours compared to the conventional case, which is a significantly long time.

In the above embodiment, the stop position of the optical scanning system at the end of preliminary scanning was set to the return position according to the document size.
It may be set at a position corresponding to the return position of the maximum original size. Furthermore, the present invention can also be applied to a recording apparatus that does not have an automatic document feeding function.

(E) Detailed Description of the Invention As described above, the present invention provides a recording apparatus that prescans a document to detect the density of the document prior to exposure scanning of the document, and adjusts the density based on the detected density information.
At the end of the exposure scan, the optical scanning system is stopped at position v of the exposure scanning path -r', and when recording is started thereafter, the optical scanning system is set to start preliminary scanning of the document from the end position of the exposure scan. Therefore, it is possible to shorten the time that the conventional optical scanning system required for the forward movement of the preliminary scan, and thus the recording time can be shortened by that amount. In addition, in a recording device having an automatic document feeding function, when the exposure scan of the document is completed, if there is a document to be recorded next, the optical scanning system is stopped at the exposure scan end position, and if there is no document, it is returned to the home position. It is preferable to restore the document, and by doing so, the recording time can be reduced considerably when the entire document is recorded.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the configuration of a recording apparatus equipped with an automatic document feeding function as an embodiment of the present invention, and FIG. 2 is a diagram showing the control of the optical scanning system of the recording apparatus according to the present invention Fig. 3 is a diagram showing the moving state of the optical scanning system of the recording device according to the present invention, and Fig. 4 is a diagram comparing the length of recording time, where (a) is the conventional case and (b) is the case according to the present invention. This is the case. 1... Recording device main body, 2... Automatic document feeder, 2
a... Original placement position, 11... Original platen glass, 12
...Optical scanning system, 12a...Exposure lamp, 12be
12c...Mirror, 12d+12e...Lens, 12f...Density sensor, 13...Rotating drum, 13a...Photoreceptor, 14...Charging electrode, 15...
Developing device, 16...Paper feed cassette, 17...Transfer electrode, 18...Separation electrode, 19...Cleaning device, 20...Transport device, 2]...Fixing device, 22...
・Paper discharge tray, 25... Case, 26... Drive roller,
27... Driven roller, 28... Conveyor belt, 29...
・・Feeding roller, 30. 31 ・・Reflection type sensor, 3
2... Input/output (Ilo) device, 33... CPU%
34...RAM, 35...ROM%36...Motor, 37...Drive circuit Patent applicant Konishi Roku Photo Industry Co., Ltd. Agent Patent attorney Hiroshi Suzuki Male Figure 1 Factor 2

Claims (1)

[Claims] In an optical scanning mobile recording device that pre-scans the original to detect the original density prior to exposure scanning of the original and adjusts the density based on the detected density information, the optical scanning system The apparatus is characterized by being provided with optical side scanning control means for causing the optical scanning system to start preliminary scanning of the document from the exposure scanning end position when the document is stopped at the exposure scanning end position and a recording start operation is performed. recording device.