JPH0469643A - Copying device - Google Patents

Abstract

PURPOSE:To always accurately stop an optical system at a home position by switching the control of the driving of the optical system from a 1st control means for controlling an entire copying device to a 2nd control means only at the time of braking the optical system. CONSTITUTION:When the output 101 of a photointerrupter 3 is switched from low to high, a braking start position is detected and the output 105 is switched to low, and a braking program is executed. Namely, an output pulse 111 from an encoder 11 is detected on demand to calculate the position of the optical system. A speed at the position which is previously calculated so as to stop the optical system at the home position is compared with a speed calculated from the wavelength of the pulse of the encoder at the point of time, and controlled variable such as the strength of the brake and the braking time of an optical system motor is decided based on the speed difference. By making the speed close to the speed which is previously calculated so as to stop the optical system to the home position, the optical system is accurately stopped at the home position. Then, the selecting input 105 of a selector 5 is switched to high and the control of the optical system motor is returned to a DC controller 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a copying apparatus configured to perform exposure scanning by moving an optical system.

[Prior Art] Conventionally, braking control of an optical system has been performed in parallel with other copying processes by a control means that controls the entire copying process. Method of time braking (referred to as the first conventional example) ■ An optical system position detection means that outputs a pulse every time the optical system advances a certain distance, and a predetermined output pulse of the optical system position detection means. The output pulse of the optical system position detection means is adjusted in advance by using an optical system speed adjusting means that matches the wavelengths of the two pulses by comparing the wavelengths of the pulses and increasing or decreasing the braking strength according to the difference. A method is used in which the speed of the optical system is reduced by matching a pulse with a prepared wavelength, and once the speed has decreased to a certain extent, a certain amount of braking is applied to stop the optical system (second conventional example). .

[Problem to be solved by the invention]

However, in the first conventional example, if the speed at the start of braking of the optical system changes due to a change in the internal state of the copying machine or a change in external conditions such as humidity or temperature, the optical system The drawback is that the optical system cannot be accurately stopped at a fixed position due to factors such as friction between the supporting rails and changes in drive torque due to temperature characteristics of the optical system motor.

In addition, in the second conventional example, even if the speed at the start of braking of the optical system changes, the speed can be set to a specific speed after a certain period of time, but the position of the optical system until reaching the constant speed is J: There is a drawback that continuous control is not possible. Furthermore, since there is a possibility of malfunction if the optical system motor rotates in reverse, a certain amount of braking must be applied when the speed of the optical system decreases to a certain extent, so ultimately the speed of the optical system must be constantly monitored. Therefore, it is difficult to accurately stop the optical system at a fixed position.

SUMMARY OF THE INVENTION In view of the above-mentioned points, an object of the present invention is to provide a copying apparatus that can always stop an optical system at an accurate position.

[Means to solve the problem]

The present invention provides a copying apparatus that performs exposure scanning of a document surface by moving an optical system, and includes a first control means that controls the first half of the copying process, and a first control means that controls the speed when braking the optical system and controls the speed necessary for the next copying operation. a second control means dedicated to braking the optical system for stopping the optical system at its initial position; and a switching means for switching to the second control means to perform braking only when braking the optical system. It is.

[For production]

The present invention includes a switching means for switching the control of the optical system from the first control means that controls the entire copying apparatus to the second control means, and only when the optical system is braked, the optical system is switched to the second control means. By switching the drive control of the optical system, the optical system can always be accurately stopped at the home position.

〔Example〕

The embodiment described below uses a copying apparatus configured to expose and scan a document placed on a fixed document tray by moving an optical system along the document tray. A first control means that controls the entire copying process including the control means, and a first control means that controls the speed when braking the optical system to accurately stop the optical system at an initial position (home position) for entering the next copying operation. a second control means exclusively for braking the optical system; a braking start position detection means for detecting the braking start position of the optical system; a speed detection means for detecting the speed of the optical system; and a first switching means for switching from the first control means to the second control means, and from the braking start position detection means, the speed detection means, and the switching means, the second control is performed only during optical system braking. This means that braking is performed by switching to other means.

Further, a runaway detection means detects runaway of the second control means, and when the runaway detection means detects runaway of the second control means, the braking control of the optical system is controlled from the second control means to the second control means. a switching means for switching to the first control means;
When the second control means goes out of control, the optical system can be stopped normally by switching to the control of the first control means.

In this way, by providing the optical system position detection means as shown in the second conventional example, the speed of the optical system can be detected at any time from the start of braking to the stop of the optical system, and the appropriate speed at that position can be detected. It has a second control means exclusively for braking the optical system, which suppresses the influence of environmental changes as described above and always accurately stops the optical system at a fixed position by comparing and correcting the optical system. a braking start position detecting means for detecting that the brake has reached a braking start position; and an optical system is transferred from the first control means, which controls the entire copying apparatus by the detection of the braking start position detecting means, to the second control means. By switching the drive control of the optical system to the second control means only when the optical system is braked, the optical system can always be accurately stopped at the Baum position. .

Next, embodiments of the present invention will be described in detail with reference to the drawings.

Figure 1 is a block diagram showing an embodiment of the present invention. Here, 1 is a DC controller which is the first control means and performs main control over the entire main body,
Regarding the driving of the optical system, a control signal is always output regardless of the presence or absence of the second control means. Reference numeral 2 denotes a microcomputer dedicated to optical system braking (hereinafter referred to as a braking microcomputer), which is a second control means, and outputs the optical system motor driver control signal shown below.

3 is a photo ink clubter that detects when the optical system has reached the position where braking should start, and is attached to the optical system braking starting position as shown in FIG. Then, the signal plays 1 and 12 attached to the optical system 9 cross, and the output is set to high.

5 is a selector, which inputs either the input 1 (203) or input 2 (204) signal to the select input 20.
5 is output to the output terminal 206 depending on whether it is high or low (
In this embodiment, when the select input is high, the manual
(203) and outputs input 2 (204) when low).

6 is an optical system motor driver that supplies a drive current to the optical system motor according to the control signal 108.

8 is an optical system motor that moves the optical system 9, and 9 is an optical system.

Reference numeral 11 denotes an encoder attached to the optical system morph in order to measure the speed of the optical system, and outputs a pulse signal to the output end 111 every time the axis of the optical system motor rotates a certain amount.

Next, the operation of this embodiment will be explained. Since the braking microcomputer 2 does not perform any control other than during braking, the optical system motor driver is driven by the control signal from the DC controller from the start of copying to the start of braking and after the optical system has stopped. This can be switched by the output 105 of the braking microcomputer 2. At the start of copying and after stopping the optical system, the braking microcomputer 2 sets the output 105 to high. From this, selector 5 has input 1
(203) That is, the control signal from the DC controller 1 is output to the optical system motor driver 6. Then, at the start of optical system braking, the braking microcomputer 2 sets the output 105 to low, thereby causing the selector 5 to output human power 2 (204), that is, the control signal 10 from the braking microcomputer 2
7 drives the optical system motor driver 6.

For this operation, the program of the braking microcomputer 2, as shown in FIG. When the vehicle enters reverse, it moves to the operation of repeatedly checking the output 101 of the photo ink club 3, and when the output +-01 of the photo ink club 3 switches from low to high, the braking start position is detected and the braking start position is detected. 05 is switched to low and the braking program is executed.

The braking program detects output pulses 111 from the encoder 11 at any time, calculates the position of the optical system at the time of detection from the number of pulses from the start of braking, and sets the optical system at that position to the home position in advance. The speed calculated to stop the motor at that point is compared with the speed calculated from the encoder pulse wavelength at that point, and the control variables such as the braking strength and braking time of the optical system motor are determined based on the speed difference. By approaching the speed calculated in advance to stop the optical system at the home position, the speed curve relative to the position of the optical system is made constant, and the optical system is accurately stopped at the Baum position.

Then, as the wavelength of the output 111 of the encoder 11 becomes large enough to indicate that the optical system has stopped, the selector power 105 of the selector 5 is switched to high and the optical system motor is controlled by the DC controller] and waits for the copy operation to start again.

Through this series of operations, it is possible to perform braking control at any time from the start of braking to the stop of the optical system, and to always accurately stop the optical system at the Baum position.

In the first embodiment, if the braking microcomputer 2 goes out of control for some reason, the optical system motor driver will not be able to obtain a normal control signal (this will cause the optical system to operate abnormally and be damaged. However, even when the optical system reaches the braking start position and is being controlled by the braking microcomputer 2, the DC controller 1 is not able to control it with accuracy as compared to the control by the braking microcomputer 2. However, the control signal for stopping the optical system is still output. Therefore, in the first embodiment, if the braking microcomputer 2 goes out of control for some reason, the braking control of the optical system can be transferred to the DC controller. , it is possible to prevent the optical system from running out of control.

In this embodiment, in consideration of the above, a detection means for detecting runaway of the braking microcomputer 2 and a switching means for switching the braking control of the optical system to a DC controller when the detection means detects runaway are provided. Even when the braking microcomputer runs out of control, the optical system is prevented from running out of control (it is stopped). FIG. 2 shows the configuration of this embodiment.

FIG. 2 shows a configuration in which a reset IC circuit 4 and a display means 10 are added to the configuration of the first embodiment. This reset IC circuit 4 receives a reset signal 104 when the input of the pulse wave to the clock input terminal 201 stops for a certain period of time.
This outputs the following. The display means 10 is a display means for informing the user of a failure of the brake microcomputer 2 when the brake microcomputer 2 goes out of control. In addition, in this embodiment, by connecting the selector input terminal of the selector 5 to 5V via a resistor as shown in the figure, when the output capo-1-207 of the braking microcomputer 2 becomes high resistance, The select input 205 is configured to be high.

In addition to the program of the first embodiment, the program of the braking microcomputer 2 is configured to constantly switch the clock 103 of the reset IC circuit 4 between low and high levels.

As a result, while the braking microcomputer 2 is operating normally, a pulse signal is always input to the clock input terminal of the reset IC circuit 4, but if a runaway occurs, the clock input of the reset IC circuit 4 The pulse signal to the end stops, and the reset IC circuit 4 outputs the reset signal 104.

Therefore, when runaway of the brake microcomputer 2 is detected, the brake microcomputer 2 is reset. When the braking microcontroller is reset, its output port becomes a high-impedance roar. Therefore, the output 207 of the braking microcomputer 2 and the select input of the selector 5 are equivalent to being separated,
Since the selector input terminal input] and (203) are outputted from the output terminal 206, the DC controller] can control the optical system motor 8 (see FIG. 3).

By means of item 1, when the braking microcomputer 2 goes out of control, the optical system motor is automatically switched to the braking control of the DC controller 1, and the optical system is normally stopped. Further, the DC controller 1 detects a reset signal 104 from the reset IC circuit 4, detects runaway of the braking microcomputer 2, prohibits future copying operations, and uses the display means 10 to indicate the cause of the failure. indicates that it is a braking motor.

As described above, in this embodiment, even if the braking microcomputer 2 goes out of control, the optical system 9 can be stopped without being damaged.

(Effects of the Invention) As explained above, in the present invention, in addition to the control means for general control of the copying machine, a control means exclusively for braking the optical system is provided, and this is switched and used when braking. By doing so, the stopping accuracy of the optical system can be improved.

Furthermore, even if the second control means, which is a braking microcomputer, goes out of control, the optical system can be disabled by detecting this and switching control of the optical system motor to the DC controller (first control means). The optical system can be stopped without going into a controlled state.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the first embodiment of the present invention, Fig. 2 is a block diagram showing the second embodiment, Fig. 3 is a waveform diagram showing the operation of the second embodiment, and Fig. 4 is the operation of the first embodiment. FIG. 5 is a waveform diagram showing the conventional operation for the second embodiment. FIG. 6 is a flowchart showing the braking procedure of the optical system. FIG. 7 is an explanatory diagram of the braking start position. ]... DC controller, 2... Braking microcomputer, 3... Photo ink controller, 4... Reset IC circuit, 5... Selector, 6... Optical system motor driver, 8... - Optical system motor, 9... Optical system, 10... Display means, 11... Encoder, 12... Signal plate, 101... Optical system braking start signal, 102... Optical system forward/backward movement Control signal, 103... Braking microcomputer runaway detection pulse, 104
... Reset signal, 105 ... Selector switching signal, 106 ... DC controller side optical system drive control signal, 107 ... Braking microcomputer side optical system drive signal, 1.0
8... Optical system drive signal, 109... Optical system motor drive current, 111... Encoder output pulse. School of zoning

Claims (1)

[Scope of Claims] 1) A copying apparatus that performs exposure scanning of a document surface by moving an optical system, comprising: a first control means for controlling the entire copying process; and a first control means for controlling the speed when the optical system is braked to perform the next copying. a second control means exclusively for braking the optical system to stop the optical system at an initial position required during operation; and a switching means for switching to the second control means to perform braking only when braking the optical system. A copying device characterized by comprising: 2) The copying apparatus according to claim 1, further comprising: runaway detection means for detecting runaway of the second control means, and when the runaway detection means detects runaway of the second control means;
The braking control of the optical system is controlled from the second control means to the first control means.
1. A copying apparatus characterized in that the copying apparatus has means for switching to the second control means, and the optical system is normally stopped even if the second control means goes out of control.