JPH01133075A - Electrophotographic device of laser beam exposing system - Google Patents

Abstract

PURPOSE:To avert generation of trouble by the deficiency or run-out of a toner by reducing a development width to lower the image density when a means for detecting the residual amt. after consumption detects that the residual amt. of the toner is below the prescribed amt. while the operation is held selected at an economization consumption mode by a mode selecting means. CONSTITUTION:This device has an image control device 200 which processes image signals and controls the output, etc., thereof, the means 320 for detecting the residual amt. of the toner housed therein after consumption, and the mode switching means SW for switching the operation to an ordinary toner consumption mode and the economization consumption mode. The development width per 1 dot of a laser beam is reduced to lower the image density by the image control device 200 upon receiving of the detection signal from the means 32 for detecting the residual amt. after consumption when said means detects that the residual amt. of the toner is below the prescribed amt. while the operation is held switched to the economization mode by the mode switching means SW. The consumption of the toner is thereby substantially decreased and the inconvenience to cause infeasibility of signal reception by the run-out of the toner is averted.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a laser beam exposure type electrophotographic apparatus that can save the amount of toner used and consumed.

``Prior art'' The consumption of toner used in developing electrophotographic devices continues to increase.
If the remaining amount falls below a predetermined amount, a warning is issued to prompt the operator to replenish the toner, and the two developing units are alternately switched and driven to prevent problems due to toner shortage or toner exhaustion. I'm trying to avoid that.

"Problem to be Solved by the Invention" However, the above-mentioned warning from an electrophotographic device has a strong predictive character, and even if the operator does not replenish toner immediately after receiving a warning, problems in use may suddenly occur. However, in reality, when the image density decreases,
In many cases, toner is replenished for the first time, but in developing systems such as two-component developing systems, a state where the image density has decreased means that the toner concentration in the developing device has already fallen and carrier adhesion occurs.
If the amount of toner remaining falls below a predetermined amount due to wasteful operation until the image density is restored after toner replenishment, or the generation of powder smoke due to rapid toner replenishment, the image density may be forcibly reduced at an early stage. In addition, if the electrophotographic device is a facsimile device, it will be in operation all day long and will be in unattended operation, especially at night or on holidays, and it is better to replenish the toner. If a large amount of image data is received after the amount of image data falls below a predetermined amount, there is no opportunity to replenish toner even if the toner runs out, and reception becomes impossible. To avoid this, some devices automatically store toner in a storage device when the toner runs out, but this requires a sufficient storage capacity of the storage device and is expensive. Also, as mentioned above, the developing device is automatically switched,
In order to avoid running out of toner, there are problems that need to be solved, such as not only a space for installing a preliminary developing device but also a complicated switching drive mechanism.

"Means for Solving the Problems" The present invention aims to solve the above problems, and the specific means thereof include at least an image control system that processes image signals and controls their output, etc. Consumption of the device and stored toner! U amount detection means, and a mode switching means for switching between a normal toner consumption mode and an economizing consumption mode, the mode switching means switching to the economizing consumption mode; When the remaining amount is detected to be less than a predetermined amount, the image control device receiving the detection signal reduces the image density by reducing the development width per dot of the laser beam. It is something to do.

"Function" As clarified in the above description of the specific means, the present invention allows the mode switching means to switch to the toner saving consumption mode, and the remaining amount detected by the toner remaining amount detection means to be at a specified level. If the amount is below a fixed amount, the image control device reduces the drive current of the laser diode, lowers the laser diode's emission intensity, reduces the development width per dot, lowers the image density, and substantially reduces the toner. Reduce usage consumption.

"Example" An embodiment of the present invention will be described based on the accompanying drawings.

FIG. 1 is a schematic cross-sectional view of a facsimile device that is an example of a laser beam exposure type electrophotographic device, and the facsimile device includes an image input device 100, an image control device 20,
0 and an image output device 300.

The image input device 100 illuminates a document placed on a document platen glass 101 with a halogen lamp 102, and directs the reflected light to a first mirror 103. Second mirror 104. It is sequentially reflected by the third mirror 105 and guided to the lens 106.
The light is incident on 0D (imaging device) 107. When scanning a document, the halogen lamp 102. Each mirror 103,1
The image signal read by the image input device 100 that moves the 04, 105 in the scanning direction as well-known as a scanning system is sent via the image control device 200 to which necessary data such as date and page is added and transmitted over a telephone line. do.

As is well known, the image control device 200 performs editing as described above when transmitting an image signal, and also performs various image editing according to the paper size stored in the image output device 300 based on the received image signal. At the same time, we will also perform a collection of bibliography, etc., which will be mentioned later.

The image output device 300 includes a photoreceptor drum 301 that can be driven to rotate counterclockwise approximately at the center, and a charger 302 . Developing device 303. Transfer charger 304. Blade type cleaner device 305. Eraser lamps 306 and the like are sequentially arranged, and the received image signal is exposed on the photoreceptor drum 301 with a laser beam of 0N10FF emitted from a laser device section 307 composed of a scanner motor, a polygon mirror, a laser diode, etc. A paper cassette 309 equipped with a paper feed roller 308 is installed at the lower left side of the output device 300, and the transport path of the paper S stored in the cassette 309 is connected to a pair of timing rollers 310, a pair of fixing rollers 311, and a pair of ejection rollers. 312, and guide plates 313, 314, and 315 connecting each pair of rollers. Inside the toner hopper 316 of the developing device 303, a detection lever 321 of a toner consumption remaining amount detection device 320 that lowers one end as the supplied toner is consumed faces the detection lever 321, and a magnet 322 attached to the other end approaches the lead sensor 323. By doing so, it is detected that the remaining amount of toner consumption has become less than a predetermined amount. The installed position of the load sensor 323 can be adjusted up and down to adjust the amount of detected and consumed remaining amount of toner.

Further, a mode changeover switch SW is provided on the side of the facsimile machine to switch between a normal toner consumption mode and a toner saving consumption mode.

FIG. 2 is a simple control block diagram of the facsimile machine of this embodiment, in which the central processing unit CPU receives the switching signal of the mode changeover switch SW from the input port P1, and detects the remaining toner consumption amount detection device 320. When detecting the approach of t<-321, the output signal of the sensor 323 is input)
The control signals are input from the output ports P and P to the image control device 20, respectively.

FIG. 3 shows a block diagram of the image control device 200.

The image signal transmitted from the sending facsimile device via the transmission path is processed by the signal processing unit 201 of the image control bag ff200.
and sent to the laser diode control section 202. Reference numeral 203 denotes another control section, which includes the signal processing section 2
01 and the laser diode control unit 202 by issuing synchronization signals for reception and transmission, 204 and 205;
are the first and second laser diode drive power supplies, and the current values ILD for driving the laser diode 206 are set to 50 mA and 40 mA, respectively. 1st. The switching of the second laser diode drive power supplies 204 and 205 is performed by the CP
The switching is performed by a switching signal applied from the output port P of U to the switching section 207.

FIG. 4 is a flowchart showing the control routine of the apparatus of this embodiment.

Step (S 400) (Steps will be omitted below)
Then, it is determined whether the mode changeover switch is ON10FF, and if it is not FF, that is, the toner saving consumption mode, the laser diode 205 is driven by the second laser diode drive power source 203 (S402), and if it is ON, it is (S402). Proceed to S401) and read-t=n? 323 no 0
N10FF is determined, and if it is OFF, that is, the remaining amount of toner consumption is more than a predetermined amount, the process proceeds to (S402), and the laser diode 2 is turned on by the second laser diode drive power supply 203.
Drive 05. If it is ON in (S401), that is, if the remaining amount of toner is less than the predetermined amount, and if it is in the toner saving consumption mode (ON in S400), the second
Laser diode drive power supply 204 drives the laser diode 205 from the c knee. The process then proceeds to (S404) and calls other control routines that control printing, sheet feeding and discharging operations, and the like.

As described above, when the laser diode 205 is driven by the second laser diode drive power supply 204, the drive power supply IL. is reduced from the usual 50 mA to 40 mA, the emission intensity of the laser diode 205 is weakened, the development width per dot is reduced as shown in FIG. 5, and the exposed portion of the surface of the photosensitive drum 301 is Developing device 30
The potential difference (development gap) of the developing roller No. 3 becomes smaller, the amount of toner adhesion itself decreases, and therefore the amount of toner consumed also decreases. As the amount of toner adhesion decreases, the image density on the transfer paper also decreases, but as long as the decrease is to the extent shown in FIG. 5, the image will not become unreadable and will not cause any problems.

In addition, as another means of saving toner consumption, by controlling the light emission time of the laser diode 205 to be shortened, the exposure width to which toner adheres can be reduced, and toner consumption can be saved.

In addition, the drive current value of the laser diode 205 is set to 5
By keeping the current at 0 mA and lowering the charging potential of the charger 3°2 or lowering the output of the developing bias, the developing gap can be made smaller, the image density can be lowered, and toner consumption can be saved. can.

"Effects" As clarified in the description of the specific means and effects, the present invention provides at least an image control device that processes an image signal and controls its output, etc., and detects the remaining consumption amount of stored toner. and a mode switching means for switching between a normal toner consumption mode and an economizing consumption mode, the state being switched to the economizing consumption mode by the mode switching means,
When the remaining consumption amount detection means detects that the remaining amount of toner is less than a predetermined amount, the image control device that receives the detection signal reduces the driving current of the laser diode to reduce the development width per dot. Therefore, the mode switching means switches to the toner saving consumption mode, and when the toner consumption progresses and the remaining amount falls below a predetermined amount, the image density decreases and the operator is notified. This strongly urges you to replenish toner, so toner replenishment prevents you from running out of toner all the time, especially when it is not possible to replenish toner because a facsimile machine is left unattended at night or on holidays. Even if there is, the image density can be lowered and the amount of toner consumed can be substantially reduced, so it is possible to avoid the inconvenience of running out of toner midway and being unable to receive data.

[Brief explanation of the drawing]

The accompanying drawings show embodiments of the present invention; FIG. 1 is a sectional view showing an outline of a facsimile machine, FIG. 2 is a simple control block diagram of the same device, and FIG. 3 is a block diagram of an image control device 200. FIG. 4 is a flowchart showing the control routine, and FIG. 5 is an explanatory diagram showing the relationship between laser beam intensity and development width. 200 , Image control device, 203 , Second laser diode drive power source, 204 , Second laser diode drive power source, 205 , Laser diode, 320 . ,,) Remaining energy consumption detection device, 323
,,,Reed sensor, SW,,,mode changeover switch. Figure 2 Figure 4

Claims (1)

[Claims] At least an image control device that processes an image signal and controls its output, etc., a means for detecting the remaining consumption amount of stored toner, and a mode switching means for switching between a normal toner consumption mode and a saving consumption mode, When the mode switching means has switched to the saving consumption mode and the remaining consumption amount detecting means detects that the remaining amount of toner is less than a predetermined amount, the image control device receiving the detection signal causes the laser An electrophotographic apparatus using a laser beam exposure method, characterized in that image density is reduced by reducing the development width per dot of the beam.