JPH04167657A - Image forming device - Google Patents

Abstract

PURPOSE:To shorten the time required to terminate printing after reception of a print request in the standby state by providing a function which preliminarily confirms that a scanner motor can be driven with a prescribed rotational frequency and stores the confirmation result. CONSTITUTION:A driving means is driven before reception of a print request from a picture information generating means, and a storage means is provided where it is stored that a rotating polygonal mirror 3 is rotated with a prescribed rotational frequency. The driving means is driven after reception of the print request, and the quantity of light of a laser is adjusted based on the result in the storage means in parallel with the start of rotation of the rotating polygonal mirror 3. Consequently, the light quantity adjusting time having an influence upon the first print time is shortened to shorten the first print time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus that forms an image by scanning a light beam.

[Conventional technology]

A general image forming apparatus of this type has a configuration as shown in FIG. Here, 1 is a photoreceptor drum that is an electrostatic latent image carrier, 2 is a semiconductor laser that is a light source, 3 is a polygon scanner that scans a light beam, 4 is an optical lens, and 5 is a charger that uniformly charges the photoreceptor drum. 6 is a developing device that develops the formed electrostatic latent image with toner; 7 is a transfer roller that transfers the toner image formed on the photoreceptor drum 1 onto paper that is a recording medium; 8 is a transfer roller that transfers it to the paper a fixing roller for fusing the toner images; 9 a paper cassette for loading paper; 10;
1 is a paper feed roller that feeds the paper in the paper cassette 9 into the paper transport path; 11 is a paper presence/absence detection sensor that detects that the paper has been fed; 12 is a sensor that once hits the paper to correct the skew of the paper; A registration roller 13 synchronizes the irradiation of image data onto the photoconductor tram 1 with paper conveyance, and a paper ejection sensor 13 for recognizing that the paper has been ejected.

Next, the actual printing operation with the above configuration will be explained with reference to the flowchart of FIG. 8 and the timing chart of FIG. 9.

FIG. 8 is a control flowchart from power-on to completion of one page printing. When the power is turned on (time tl in Figure 9), (a) its own RAM and other memory,
Initialize each mechanical section. Next, (b) start warming up the fixing heater to a specified temperature. When the warm-up is completed, (c) it becomes possible to receive a print request signal from the printer controller (time t2 in FIG. 9). Upon receiving the print request signal (time t3 in Figure 9)
), (d) Output of scanner motor drive start command, (e
) Outputting a drive command for the transport motor, and (f) outputting commands for starting up each high voltage are performed sequentially. Next, (g) determine whether the scanner motor has risen to the specified rotation speed, and if the specified rotation speed has been reached and the scanner ready has received the signal from the scanner motor drive unit (time t4 in Figure 9), ( h) Start increasing the amount of laser light until it reaches a specified value. After that, (1) when the light amount reaches the specified value (9th
Time t5) in Figure 9), (j) Output the paper feed command from the paper cassette. Time t5) in Figure 9, (k) Wait for the paper to reach the registration sensor, and once it reaches the registration sensor, wait for a predetermined time TI for skew correction. After waiting for (sec), the paper feed roller is stopped (time t6 in FIG. 9), and 1) a vertical synchronization request signal that requests a vertical synchronization signal, which is an image output synchronization signal, from the printer controller (not shown); Output. (m) Once the vertical synchronization signal is received from the printer controller, (n) laser irradiation to the photosensitive drum is started. (o) If the paper ejection sensor detects paper ejection (
At time t7) in FIG. 9, each drive section is stopped to finish printing one page.

[Problem that the invention is trying to solve]

However, in the above conventional example, after receiving a print request signal, the transport motor and scanner motor are driven, and then the scanner waits for the specified rotation speed to be reached, and then the laser light intensity is adjusted. The time from receiving a request to completing printing (hereinafter referred to as first print time) was long.

Therefore, an object of the present invention is to provide an image forming apparatus that can shorten the first print time.

[Means and effects for solving the problem] According to the present invention, the drive means is driven before a printing request is received from the image information generation means, and a memory for storing that the rotating polygon mirror rotates at a predetermined number of rotations is provided. Means are provided. After receiving a printing request, the driving means is driven, and while the rotating polygon mirror is starting to rotate, the amount of laser light is adjusted in parallel based on the result in the storage means. Therefore, we have removed the light intensity adjustment time that previously affected the first print time.
The time required for first printing can be significantly shortened.

〔Example〕

FIG. 2 is a schematic diagram of an image forming apparatus applied to the first embodiment of the present invention. This is the same as that shown in the conventional example described above, and explanation of each function will be omitted here.

FIG. 1 is a block diagram of a control system that controls each mechanical section.

A host computer 14 sends image coat data to the printer controller 15. The printer controller 15 develops image code data into a predetermined bitmap, monitors the status of the printer encoder 31, or instructs the operating conditions. The print control unit 10 controls each of the mechanical units 17 to 20 of the printer based on instructions from the printer controller 15. Each of the mechanical units 17 to 20 sends necessary data to the print control unit 16, and also controls the mechanical units 17 to 20 of the printer. It operates according to 16 instructions. The mechanical units 17 to 20 include a paper conveyance drive unit 17, a high voltage drive unit 18, a scanner motor drive unit I9, a laser drive unit 20, and the like. The paper conveyance drive section 17 is connected to the print control section 1
Based on the instructions 6, various rollers 21 are driven/stopped, and information from various sensors 22 such as the paper presence/absence sensor 11 is provided to the print control section 16. The high voltage drive unit 18 drives/stops each high voltage for charging, development, and transfer according to instructions from the print control unit, and also drives/stops the heater of the fixing device, and also provides temperature information of the heater necessary for controlling the print control unit. are being returned. The scanner motor drive section drives/stops the scanner motor 27 according to instructions from the print control section 16, and also sends back information as to whether the scanner motor has reached a specified rotation speed. The laser driving section 20 emits laser light based on the laser lighting signal sent from the print control section 16, and also sends back to the print control section 16 light amount information necessary for laser light amount adjustment.

Reference numeral 30 indicates a scanner motor drive unit 19 while the print control unit 16 starts up the fixing heater 26 after power is turned on.
After outputting the scanner start command, the scanner drive unit 1
This is a scanner ready storage unit for storing information when there is a return message stating that the scanner is ready within a predetermined time from the time of the scanner.

FIG. 3 is a flowchart showing the operations of the print control section from when the power is turned on until one page is printed.

First, when the power is turned on, (al) the printer is initialized, and (bl) the fixing heater starts warming up. Furthermore, (cl) starts driving the scanner motor, and (
di) Simultaneously start a timer that detects scanner motor failure. If the scanner does not become ready even after the timer counts up, failure processing is performed, and if it becomes ready, the contents of the memory called (el) SCN RDY flag are stored as "1" and the scanner motor is driven at the same time. Stop. Then, (fl) when the fixing heater becomes ready, (gl) the printer enters a print request waiting state.

When the print request is received, (hl) starts the scanner motor, (11) starts the transport motor, (jl) starts the charging high voltage, and (kl) if the content of the SCN RDY flag is "1". If so, start adjusting the laser light intensity. Thereafter, (11) when the light amount adjustment is completed, (ml) after a predetermined time T 2 (sec), (nl) the high voltages for development and transfer are sequentially raised. (01) When the scanner becomes ready, it starts picking up the paper and thereafter performs the same printing operation as in the conventional example shown in FIG. 8(k) onward. Here, the development transfer (nl) is performed after the light amount adjustment is completed because the photosensitive drum l produced by the laser light emitted when adjusting the light amount is
This is to prevent the upper latent image from being developed and to prevent the transfer roller from becoming dirty. Therefore, this problem can be solved by another method, that is, by starting the development transfer before performing the light I adjustment, and then turning off the development high pressure for the time corresponding to the position of the photoreceptor drum where the light I adjustment was performed. good. FIG. 4 is a timing chart showing the former control. In the figure, the power is turned on at time sl, the fixing heater becomes ready at time s2, and a print request is received at time s3. Both scanner motor ready and paper pickup are started at time S4, a vertical synchronization signal is received at time s6, and paper ejection ends at time S7. Therefore, the light amount is adjusted from 83 to S4, so compared to the conventional example, t4
The time corresponding to ~t5 is shortened. In this example, development is performed after S4. FIG. 5 is a timing chart showing control when the developing high pressure is turned off at a time corresponding to the position on the photoreceptor drum at which the light amount is adjusted. In this case, the only difference from the case shown in FIG. 4 is the timing of development and transfer;
It does not affect the time reduction from 4 to t5.

As mentioned above, warm-up of the fusing heater takes, for example, 10 to several tens of seconds, while startup of the scanner motor takes about a few seconds. Since this is sufficiently possible, this embodiment can shorten the first print time without having any effect on the time from power-on to becoming ready to accept print requests.

[Other Examples]

FIG. 6 shows a second embodiment of the present invention.

The printer mechanism and control block diagram are the same as those shown in the first embodiment.

FIG. 6 is a work flowchart of the print control section.

Here, processing is shown when the printer is in a print request waiting state and does not receive a print request signal even after a predetermined period of time has elapsed.

First, (C2) If there is no print request in the standby state, that is, in the print request waiting state, (b2) the scanner check request timer of T3 (sec) that has been set in advance is referred to and the count ends. If not, it is checked again whether there is a print request, and if the count has ended, (C2) the scanner motor is activated. At this time, if the (C2) scanner motor failure detection timer also starts and the scanner does not become ready by the time the failure timer counts up, (C2) SCN RDY
The flag is set to "φ" and (f2) predetermined scanner motor failure processing is performed. If the scanner becomes ready before the failure timer counts up, (C2) SCNRDY
Set the flag to 1 and (h2) stop the scanner motor.

Also, (12) sets the scanner check request timer T3 (SeC) for the next check. If a print request is received during scanner check, please contact ( via ■).
32), (k2), (!2), etc., and print operation begins. Note that when a print request is received in (C2), the above-described print operation is the same as in the first embodiment. Also, when printing is finished, (
m2) Scanner check request timer T3 (SeC) again
is set and the printer is ready to print.

In this way, in this embodiment, only when the print waiting state continues for T3 (sec), the scanner motor is driven to check whether it is ready or not, and the latest SC is always updated.
The state of the NRDY flag will be held. FIG. 7 is a timing chart showing this control.

In the figure, the power is turned on at time rl, and the fixing heater becomes ready at time r2. T3 (sec) has passed since the fixing heater became ready and the printer was in a print waiting state, and time r3
When this happens, the scanner motor is driven, and when the scanner becomes ready, the scanner motor is stopped.

At time r4, a print request is received, and at time r5, printing of one page is completed in response to the print request. From this point on, the scanner check request timer is started again. Then, at time r6 after T3 (sec) has elapsed, the scanner motor is driven again to confirm the ready state.

In this embodiment, even in the print request waiting state where the state of the scanner motor is not confirmed, the scanner
), the scanner motor is checked for readiness every time (SCN_RDY) and the latest data (SCN RDY) is always held, thereby increasing the reliability of the scanner drive when adjusting the light amount during actual printing. Furthermore, based on the flowchart shown in Fig. 6, even if a print request is received while the scanner is rotating due to scanner check, the transition to the print scan can be made immediately, thereby improving the first print time without any negative effect on the print operation. be able to.

[Third Embodiment] In the first and second embodiments, the paper pickup operation is performed after the scanner becomes ready, but in some types of printers, the scanner motor and conveyance motor are activated after receiving a print request. There is also a model that picks up the paper as the scanner is driven, waits the paper at the registration roller until the scanner becomes ready and completes the light intensity adjustment, and then outputs a vertical synchronization signal after the light intensity adjustment is completed. By implementing the first or second embodiment even for such models, the first print can be improved. Furthermore, since a scanner malfunction can be detected earlier, a new effect is created in that when a print request comes, there is no need to pick up paper unnecessarily.

〔Effect of the invention〕

As explained above, by providing a function to confirm in advance that the scanner motor can be driven at a specified rotation speed and to store this information, the scanner can now adjust the laser light intensity, which was previously impossible to do unless the scanner was ready. This can be done before the printer becomes ready, and the time from standby to receiving a print request and completing printing (first print time) can be significantly shortened, greatly contributing to improved printer performance. be.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a configuration for controlling each mechanical part of an image forming apparatus according to a first embodiment of the present invention, FIG. 2 is a schematic diagram of an image forming apparatus to which the present invention is applied, and FIG. FIG. 4 is a timing chart for explaining the operation of the first embodiment of the invention; FIG. 5 is a control flowchart for explaining the operation of the first embodiment of the invention; FIG. FIG. 6 is a control flowchart for the second embodiment of the present invention. FIG. 7 is a timing chart for explaining the operation of the second embodiment of the present invention. FIG. 8 is a conventional image forming method. Apparatus Control Flowchart FIG. 9 is a timing chart for explaining the operation of a conventional image forming apparatus. 1...Photosensitive drum 2...Laser semiconductor 3...Rotating polygon mirror (polycon scanner) 5...Charging roller 6...Developer 7...Transfer roller 8...Fixing roller 16/Print Control unit 18...High voltage drive unit 20 Laser drive unit 30...Scanner ready storage unit

Claims (2)

[Claims] (1) In an image forming apparatus that forms an image by scanning a light beam modulated based on image information sent from an image information generating means with a rotating polygon mirror and irradiating it onto an electrostatic carrier, the light beam a light beam generating means for generating a light beam; a light amount adjusting means for adjusting the light amount of the light beam; a driving means for driving the rotating polygon mirror; and a detection means for detecting whether the rotation speed of the rotary polygon mirror is set to the predetermined number of rotations, and when a printing request is output from the image information generation means, the rotating polygon mirror is driven by the driving means, and the rotation speed of the rotary polygon mirror is An image forming apparatus characterized in that the light amount adjusting means starts a light amount adjusting operation before the rotational speed reaches a rotation speed of . (2) The image forming apparatus according to claim 1, further comprising a storage means for storing the detection result by the detection means, wherein the rotation is caused by the driving means in advance prior to a printing request from the image information generation means. A polygon mirror is driven and the detection result by the detection means is stored, and when a printing request is output from the image information generation means, the rotation speed of the rotating polygon mirror reaches a predetermined number of rotations. An image forming apparatus characterized in that the light amount adjustment operation started in accordance with the detection result stored in the storage means.