JP2605302B2 - Copier - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination device for exposing and scanning an original set in a copying machine, and uses a self-heating fluorescent lamp as a light source. Related to the device.

[Conventional technology]

2. Description of the Related Art A copying machine that forms a copy image on a sheet by performing a predetermined process on a reflected light image obtained by exposing and scanning a document surface has been provided.

Illumination device used for such a copier (illumination device installed near the platen for exposing and scanning the original surface)
An apparatus using a fluorescent lamp as a light source has been proposed.

By the way, as is well known, the amount of light emitted from a fluorescent lamp is
A sufficient amount of light cannot be stably obtained until the tube wall is sufficiently warmed, being affected by the temperature of the lamp tube wall.

As a method for solving this problem, that is, a method of heating a lamp by self-heating of a fluorescent lamp (self-heating method) has been proposed as one of methods for stably obtaining a sufficient amount of light in the lighting device. I have.

[Problems to be solved by the invention]

As described above, in a self-heating fluorescent lamp,
For a while after lighting, the tube wall is cold, so that a sufficient amount of light cannot be obtained.

For this reason, it has been proposed to warm the tube wall before exposure scanning by so-called preheating. That is, the pre-heat treatment means that the fluorescent lamp is turned on even if there is no input of the print key switch under the condition of a copy preparation command such as turning on a main power supply of the copying machine, and the light is turned on until a predetermined light amount is reached. By continuing, this means warming the fluorescent lamp.

However, in the conventional pre-heat treatment, after the fluorescent lamp is warmed and reaches a sufficient light amount, if there is no print switch input for instructing the start of copying, the warmed fluorescent lamp is turned off.

For this reason, if copying is to be performed with some time after completion of the preheating, it is necessary to wait for the preheating again, resulting in a large loss of time.

The present invention has been made in view of such circumstances, and in the case of using a self-heating type fluorescent lamp as a light source,
It is intended to reduce the above-mentioned loss time.

[Means and actions for solving the problems]

The present invention is a copier that exposes and scans a document surface placed on a document table, and includes a fluorescent lamp for illuminating a document for exposure scanning, and a lamp control unit that controls light emission of the fluorescent lamp. When the setting of the copy preparation state of the copying machine is instructed, a pre-heat treatment is performed on the lamp control means to cause the fluorescent lamp to emit light until the light amount of the fluorescent lamp reaches a predetermined light amount and is ready for copying. First instruction means for instructing execution, and a predetermined lighting state of the fluorescent lamp to maintain the copy enabled state after the light amount of the fluorescent lamp reaches the predetermined light amount by the pre-heat treatment by the first instruction means. Second command means for issuing a command to continue the time, third command means for issuing a command to turn off the fluorescent lamp if there is no copy command within the predetermined time, and the second command means If a copy command is issued within the predetermined time during which the light lamp is lit, a copy operation is immediately performed, and a copy command is issued after the fluorescent lamp is turned off by the third command means. And a copy control means for executing a copy operation after executing the pre-heat treatment according to the command of the first command means.

〔Example〕

 Hereinafter, embodiments of the present invention will be described.

<< Mechanism Description >> FIG. 1 is a configuration diagram of a copying machine having a fluorescent lamp exposure lamp according to the embodiment.

The illustrated copying machine has an optical system 101 in an upper part in the main body 100.
However, an image forming unit 102 is arranged at the lower part, and a sheet feeding cassette 200 is arranged at the left side of the main body 100 in the figure.

(I) Optical System 101 The optical system 101 scans a document set on the platen glass 16 by exposure, and forms a reflected light image from the document surface on the surface of the photosensitive drum 1 of the image forming unit 102. It is.

The optical system 101 includes a fluorescent lamp exposure lamp 3, reflection mirrors 11, 12, and 1.
The fluorescent lamp exposure lamp 3 and the reflecting mirror 11 have a speed of V / N (V; peripheral speed of the photosensitive drum 1, N; copying magnification). Reference numeral 13 denotes a V / 2N speed, each of which is driven by a motor M3 and reciprocates along the lower surface of the document table glass 16, thereby exposing and scanning the document.

In addition, setting of the copy magnification is performed by adjusting the positions of the lens 14 and the reflecting mirror 15, and correction of the image forming position is performed by adjusting the angle of the reflecting mirror 15. These are motors
Driven by M4. SW50 and SW51 are sensors for detecting the position of the moving body of the optical system.

(Ii) Image forming unit 102 The image forming unit 102 executes image forming by a so-called electrophotographic process. In other words, the image forming unit 102 develops an electrostatic latent image formed on the photosensitive drum 1 with toner, and Is transferred onto a copy sheet, fixed, and discharged.

The image forming unit 102 includes a photosensitive drum 1 rotatably supported in a counterclockwise direction in the figure, and eraser lamps 2 and 4 disposed around the photosensitive drum 1, charging chargers 3 and 5, and a developing device. 6 (driven by the motor M2), the transfer charger 7, the separation charger 8, and the cleaning device 9, a transport belt 27 for transporting the copied copy paper, and a fixing device 28 for fixing the toner image on the transported paper. And a roller pair 29 for discharging the copy paper on which the image has been fixed from the image forming unit 102.
And

Reference numeral 73 denotes a pair of timing rollers for feeding a copy sheet to be fed between the photosensitive drum and the transfer charger at a predetermined timing in synchronization with the rotation of the photosensitive drum 1, and M1 is a main motor.

(Iii) Paper Cassette 200 The paper cassette 200 has an upper paper tray 20 and a lower paper tray 22 that store sheets of different sizes. After the paper in each tray is pulled out by the paper feed rollers 711 and 721, it is fed to the timing roller pair 73 of the image forming unit 102,
In accordance with a predetermined timing signal from the optical system 101, the photosensitive drum 1 is sent out between the photosensitive drum 1 and the transfer charger 7 in synchronization with the rotation of the photosensitive drum 1, and the image forming process is performed.

<< Description of Control Circuit >> FIGS. 2 and 3 are block diagrams of circuits for controlling the operation of the copying machine and the emission of the fluorescent lamp exposure lamp.

The control circuit includes a main body control unit that controls the operations of the image forming unit 102, the optical system 101, the paper feed mechanism, and the like;
And a fluorescent light control unit for controlling the light emission of the light source.

The main body control section includes various operation switches such as a main switch, a print key switch, and an exposure volume, various sensors installed in various parts of the copying machine to detect an operation state, and signals from other control CPUs (not shown). Enter.

Also, a signal for controlling the driving of various devices disposed around the photosensitive drum 1, a signal for controlling the driving of an optical system (excluding an exposure lamp), a main motor, a paper feeding system Signals for controlling the driving of various clutches, etc.
And signals for controlling the driving of various display elements are output.

The main body control unit is connected to the fluorescent lamp control unit via a bus and communicates with each other.

On the other hand, the fluorescent lamp control unit includes a sensor 30 that is installed near the fluorescent lamp exposure lamp 3 and detects the amount of light of the exposure lamp 3.
Is input via a photoelectric conversion circuit.

Further, the fluorescent lamp control unit 3 outputs a high frequency control signal for driving the fluorescent lamp exposure lamp 3 via a lighting circuit regulator. The light amount of the fluorescent lamp exposure lamp 3 is adjusted by adjusting the voltage applied to the fluorescent lamp 3 by adjusting the duty ratio of the high frequency control signal.

<< Description of Operation >> FIGS. 4 and 5 are flowcharts showing processing in the fluorescent light control CPU. Note that the processing in the CPU for controlling the main body employs a known processing, and a description thereof will be omitted.

For example, the fluorescent lamp control CPU starts processing when the power is turned on, and first performs an initial setting (S1).

Next, a signal for instructing the fluorescent lamp 3 to turn on "full" is generated (S3). That is, the duty ratio of the high frequency signal for driving the fluorescent lamp 3 is set to 100%, and the maximum driving voltage is applied to the fluorescent lamp 3. Thereby, preheating of the fluorescent lamp 3 is started. The adjustment of the fluorescent lamp driving voltage (described later) is performed by adjusting the duty ratio of the high frequency signal.

Further, an exposure volume input process is executed (S5). This is processing for setting the sensitivity level (reference voltage value) of the sensor 30 in accordance with the exposure volume value transmitted from the main body control unit. That is, the reference voltage value set in this step is the determination reference voltage value in S9 described later.

Next, the target value (the reference voltage value) of the light amount set by the exposure volume is compared with the actual light amount from the fluorescent lamp 3, and the process waits until the actual light amount reaches the target value (S7). , S9). That is, the actual light amount is detected by the sensor 30 and photoelectrically converted. Until the voltage value obtained by the photoelectric conversion matches the reference voltage value, in other words, the preheating is completed and a sufficient light amount is obtained. Wait until it is done.

If the actual light amount matches the target value as a result of the standby (S9; YES), a copy enable signal is output to the main body control unit (S11). When the copy enable signal is input, the main body controller cancels the "copy prohibited state due to inappropriate exposure light quantity".

In addition, a timer that defines the lighting duration after the light quantity rises is set (S13), and during the duration of the timer,
Even if the print switch input for instructing the start of the copy operation is not made (S15; NO), the lighting state of the fluorescent lamp 3 is continued (S17; NO). Thus, after the light amount rises to a predetermined value and copying is enabled (see S3 to S11), even if the print switch input is not performed immediately, if the print switch input is continued for the duration of the timer, the print switch input is performed. Sometimes, the copying operation can be performed immediately. This is because the fluorescent lamp 3 is continuously heated by the lighting continuation. As the timer value, for example, a value of about ten seconds is set.

If a print switch input is detected during the timer continuation time (S15; YES), copy control is executed (S19, S21). Here, "copy control" is control for maintaining the actual light emission amount of the fluorescent lamp 3 at the target value set by the exposure volume during the copy operation execution time. In other words, the process of adjusting the duty ratio of the high-frequency drive signal in real time so as to reduce the deviation between the detected value and the target value while constantly comparing the value detected by the sensor 30 with the target value is performed. is there. Note that so-called “copy operation control” such as scanning control and control of devices around the photosensitive drum 1 is executed by the main body control unit.

After the "copy control" is completed, the timer for defining the lighting duration is set again (S23), and
As in S17, during the duration of the timer, even if no print switch input is made (S25; N
O), the lighting state of the fluorescent lamp 3 is continued (S27; NO). Thus, even if the next print switch input is not performed immediately after the copy is completed (see S21), the copy operation can be performed immediately at the next print switch input as long as the timer continues. Becomes

On the other hand, if it is determined in S17 or S27 that the timer has expired, in other words, if no print switch input has been made during the duration of the lighting continuation timer, the processes in S29 and thereafter are executed.

That is, the fluorescent lamp 3 is turned off (S29), and waits for the next print switch input (S31).

Further, when the next print switch input is detected (S31; YES), the same light amount rising process as in S3 to S9 is executed (S33 to S39), and the process proceeds to S19 to execute copy control.

As described above, the light amount control of the fluorescent lamp exposure lamp for the copying machine according to the present embodiment is executed.

〔effect〕

According to the present invention, a copy operation is executed immediately when a copy command is issued within the predetermined time by maintaining the copyable light amount for a predetermined time when the light amount at which copying is possible is reached by preheating. Machine. Therefore, even when copying is performed with a short interval after completion of preheating, the copying operation can be performed immediately within the above-described predetermined time.
This has the effect of preventing time loss.

In addition, since the self-heating method is adopted as the temperature control method of the fluorescent lamp, the number of parts is reduced as compared with the heater method.

Furthermore, since the advantage of using a fluorescent lamp as a light source, that is, heat generation is smaller than that of a halogen lamp,
The temperature rise near the platen glass is prevented, the mechanism is simplified, and power consumption is reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory view of the configuration of a copying machine on which the apparatus of the embodiment is mounted. FIG. 2 is a block diagram of a control circuit of the copying machine;
FIG. 3 is a block diagram of a control circuit of the apparatus of the embodiment. FIG. 4 and FIG. 5 are flowcharts showing the processing in the control CPU of the apparatus of the embodiment. 3 ... Fluorescent lamp, 30 ... Sensor

Claims (2)

(57) [Claims] 1. A copying machine for exposing and scanning a surface of a document placed on a document table, comprising: a fluorescent lamp for illuminating a document for exposure scanning; and a lamp control means for controlling light emission of the fluorescent lamp. When the setting of the copy preparation state of the copying machine is instructed, the control unit causes the lamp control unit to emit the fluorescent lamp until the light quantity of the fluorescent lamp reaches a predetermined light quantity and the copying machine is ready for copying. First instruction means for instructing execution of a pre-heat treatment, and after the light amount of the fluorescent lamp reaches the predetermined light amount by the pre-heat treatment by the first instruction means, to maintain the copy enabled state, A second command unit for issuing a command to keep the lighting state for a predetermined time; a third command unit for issuing a command to turn off the fluorescent lamp when there is no copy command within the predetermined time; and the second command unit. Therefore, if a copy command is issued within the predetermined time during which the fluorescent lamp is lit, the copying operation is immediately performed, and after the fluorescent lamp is turned off by the third command means, the copy command is issued. And a copying control means for executing a copying operation after executing the pre-heat treatment in accordance with the command of the first command means. 2. The copying machine according to claim 1, wherein the command for setting the copy preparation state is issued by turning on a main power supply of the copying machine.