JP2862438B2 - Image recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus for recording an image using a developer, such as an electrophotographic recording apparatus.

[0002]

2. Description of the Related Art In an electrophotographic recording apparatus, an image is recorded by using toner. However, the toner is consumed as the image is recorded, and the amount of toner stored in a storage container decreases. Then, when the toner is exhausted from the storage container, an image cannot be recorded as a matter of course. Therefore, a detector is provided in the storage container to monitor the remaining amount of toner.

However, if a detector is provided to detect the presence or absence of toner in the storage container, it is not known until the toner is exhausted, and therefore, no recording operation can be performed between the time when the toner is exhausted and the time when the toner is supplied. I will.

Therefore, a detector is provided so as to detect that the remaining amount of toner in the storage container is equal to or less than a predetermined amount. I do. In this state, since the toner remains in the storage container, the recording operation can be performed even before the toner is supplied. However, if toner is not replenished in this state, even if the toner in the storage container runs out, it cannot be detected, and after the toner in the storage container runs out, the recording density Is reduced. In addition, in the worst case, there is a possibility that the apparatus may be damaged by continuing the operation with no toner.

Conventionally, in order to prevent this point, the number of images that can be recorded using the toner having the remaining amount of toner (the predetermined amount) when the detector detects that the remaining amount of toner is low is fixed in advance. The recording operation is stopped when the above-described number of recordings are performed without toner supply after the detection by the detector.

However, the amount of toner used per image varies depending on the black ratio and black density of the image. For this reason,
The recordable number of sheets with the predetermined amount of toner is such that only images having a high black ratio or black density are recorded, and as shown in FIG. It is set low. In FIG. 4, what is indicated by Z is a set value of the recordable number of sheets with the predetermined amount of toner. However, the black ratio and the black density are low in the actual image.
2B, there are many images in which the toner usage rate is low.
Therefore, if the recording operation is stopped at the time when the recording of the Z sheets is performed, the apparatus stops even though the toner remains sufficiently.

There is a method of providing a plurality of detectors for respectively detecting that the remaining amount of toner is equal to or less than a predetermined amount and that the toner has been used up. However, this increases the size of the apparatus and increases the cost, which is not preferable. .

[0008]

As described above, conventionally,
After the detector detects that the remaining amount of the developer has become equal to or less than the predetermined amount, the recording of the number of sheets that can be recorded using the predetermined amount of the developer is performed without replenishing the developer. The recording is stopped accordingly, but the recordable number is
Since the image is set on the assumption that the image has a high black ratio or black density, there is a problem that the recording must be stopped in spite of the fact that the developer remains.

The present invention has been made in view of such circumstances, and an object of the present invention is to make it possible to maintain the remaining developer even after the remaining amount of the developer becomes a predetermined amount or less. An object of the present invention is to provide an image recording apparatus capable of recording more images by effectively using the image recording apparatus.

[0010]

According to the present invention, for example, the amount of developer in a storage container such as a hopper is reduced to a predetermined amount or less by a developer detecting means such as a toner sensor. And a first counting unit for counting the number of recordings until the developer detecting unit detects that the amount of the developer in the storage container has become equal to or less than a predetermined amount. After the detecting means detects that the amount of the developer in the storage container has become equal to or less than a predetermined amount, the remaining amount of the predetermined amount is determined based on the count value of the first counting means, the predetermined amount, and the replenishment amount. A recordable sheet number determining unit that determines a recordable number of sheets using a developer; a supply detecting unit that detects that the developer is supplied to the developing container; and a developer detecting unit. A second counting unit that counts the number of recordings after the amount of the developer in the storage container has been detected to be equal to or less than a predetermined amount; and a count value of the second counting unit is determined by the recordable number determination unit. A recording prohibition control unit for prohibiting execution of a recording operation when the replenishment detection unit does not detect the replenishment of the developer to the developing container until the number of sheets reaches the determined number.

[0011]

By taking such a measure, after the developer detecting means detects that the amount of the developer in the storage container has become equal to or less than the predetermined amount, the predetermined amount of the residual developer is used. The number of recordable sheets is determined by the above method, and the number of recordable sheets (count value of the second counting means) after the amount of the developer in the storage container becomes equal to or less than a predetermined amount reaches the determined number of recordable sheets. If the toner is not supplied, execution of the recording operation is prohibited.

Here, the number of recordable sheets is determined after the developer detecting means detects that the amount of the developer in the storage container has become equal to or less than a predetermined amount, and then the developer detecting means detects the number of recordable sheets in the storage container. It is variably determined based on the number of recordings (count value of the first counting means), the remaining amount of the developer (predetermined amount), and the replenishment amount of the developer until it is detected that the developer amount has become equal to or less than the predetermined amount. Therefore, the period from the time when the amount of the developer in the storage container becomes equal to or less than the predetermined amount to the time when the execution of the recording operation is prohibited is changed according to the actual usage ratio of the developer.

[0013]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically illustrating a main configuration of an electrophotographic recording apparatus configured by applying the image recording apparatus according to the present embodiment. In the figure, reference numeral 1 denotes a photosensitive drum. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are arranged around the photosensitive drum 1 along its peripheral surface. Although not shown in detail, the charging device 2 is, for example, a well-known scorotron discharger, and uniformly charges the surface of the photosensitive drum 1 to a predetermined potential.

The exposure device 3 is, for example, a well-known laser scanner or the like, although its detailed configuration is not shown, and partially exposes the surface of the photosensitive drum 1 in accordance with an image to be recorded.

The developing device 4 has a part in the opening of the hopper 41 storing the toner (not shown).
A cylindrical developing roller 42 is provided in a state of being located inside. A supply roller 43 is provided inside the hopper 41 in parallel with the developing roller 42. A developing bias of a predetermined voltage generated by a power supply 44 is applied to the developing roller 42 and the supply roller 43. Reference numeral 45 denotes a blade, which keeps the amount of the toner carried by the developing roller 42 and guided to the outside of the hopper 41 constant, and frictionally charges the toner. 46 is an agitator,
The toner in the hopper 41 is stirred and transported to the developing roller 42 and the supply roller 43. A toner sensor 47 is provided near the bottom of the hopper 41. The toner sensor 47 detects the presence or absence of toner at the installation position of the toner sensor 47. Reference numeral 48 denotes a toner pack, which is attached to an opening provided at an upper portion of the hopper 41.

The transfer device 5 is, for example, a well-known corotron-type charger, although the detailed configuration is not shown. The transfer device 5 is exposed to a recording paper (not shown) inserted between the transfer device 5 and the photosensitive drum 1. The toner image formed on the surface of the drum 1 is transferred. Although the detailed configuration of the cleaning unit 6 is omitted, the cleaning unit 6 scrapes and collects the toner adhered to the photosensitive drum 1.

Reference numeral 7 denotes a control unit which has, for example, a microcomputer as a main control circuit, and controls the electrophotographic recording apparatus as a whole. The control unit 7 has a function of monitoring toner in the hopper 41 of the developing device 4 in addition to a function of performing well-known general control in the electrophotographic recording apparatus. Reference numeral 8 denotes a display unit such as an LCD, for example, for performing various displays to the user.

Next, the toner monitoring process in the electrophotographic recording apparatus having the above-described configuration will be described according to the processing procedure of the control unit 7. First, as shown in FIG. 2, the controller 7 sets variables U, X1, and X2 managed by itself to "0" in step a. The variable U is the toner sensor 47
Indicates the used amount of toner from when “low toner remaining” is detected until the next “low toner remaining” is detected. The variable X <b> 1 indicates the number of recordings from the time when the “toner remaining amount” is detected by the toner sensor 47 until the next “toner remaining amount” is detected. The variable X2 indicates the number of recordings from when the “toner remaining amount” is detected by the toner sensor 47 to when toner is supplied.

Subsequently, in step b and step c, the control section 7 repeatedly generates a recording operation execution instruction and monitors whether or not the remaining amount of toner in the hopper 41 is equal to or less than a predetermined amount B.

Here, when an instruction to execute the recording operation is issued from the outside, the control unit 7 controls each unit in accordance with a well-known procedure to execute the recording operation in step d, and after the recording operation is completed, the control unit 7 sets the variable X1. The value is “X1 + 1”. Thereafter, the control unit 7 executes step b and step c.
Is repeated.

On the other hand, if the toner is reduced by performing the recording operation as described above, and the top of the toner in the hopper 41 is, for example, at the position indicated by the line C in FIG.
The toner sensor 47 cannot detect the toner, and the output of the toner sensor 47 is turned off. The controller 7 detects the change in the output of the toner sensor 47 and determines that the remaining amount of toner in the hopper 41 has become equal to or less than the predetermined amount B. Then, the process proceeds from step c to step e. Note that the predetermined amount B is the remaining amount of toner when the top of the toner in the hopper 41 is, for example, at the position indicated by the line indicated by C in FIG. This value is almost uniquely determined based on structural conditions such as the size of the hopper 41, and is set in advance based on the structural conditions.

In step e, the control unit 7 displays on the display unit 8 that the remaining amount of toner is low, and urges the user to supply toner. Subsequently, in step f, the control unit 7 sets the number Y of printable images using the predetermined amount B of toner to a variable U
(The amount of toner used) and the variable X1 (the number of prints) are taken into account. Specifically, it is obtained by calculating the equation Y = a.B / U.X1. Here, a is a coefficient set in advance. This coefficient a is [0 <a <1]
, For example, 0.7.

Since the variable U is the amount of toner used from the time when the toner sensor 47 detects "low toner remaining" to the next time when "low toner remaining" is detected, the variable U This corresponds to one toner supply amount. The amount of toner supplied to the hopper 41 at one time is a constant amount A as described later.

Supply of toner to the hopper 41 is performed as follows. That is, the toner pack 48 is a hollow box having one side open, and before the hopper 41 is mounted, the opening is closed with a film, and a fixed amount of toner A is stored therein. This toner pack 4
8 is mounted on the hopper 41 and the film is removed, so that the toner contained in the toner pack 48 falls into the hopper 41. Thus, a certain amount A of toner is supplied to the hopper 41.

As will be described later, the variable X1 is cleared to "0" each time "low toner remaining" is detected. Therefore, the value of the variable X1 is changed from the previous detection of "low toner remaining" to the current "toner remaining". Shows the number of recordings up to the detection of "small remaining amount". Therefore, according to the above equation, it is possible to record with a predetermined amount B of toner based on the amount of toner used per image from the previous detection of “low toner remaining” to the current detection of “low toner remaining”. A large number is required. In general, there are many similar images that a specific user desires to record, and the black ratio of each image is similar. That is, the amount of toner used per image is almost constant in many cases.
Accordingly, the recordable number Y obtained by the above equation is a value corresponding to the black ratio of the actual recorded image. Note that the coefficient a
The reason is that although the amount of toner used per image is almost constant, there is actually a difference between the images, and a margin is provided in anticipation of this difference. .

Subsequently, in step g, the controller 7 sets the variable X1 to the number of recordings from the detection of "low toner remaining" to the current detection of "low toner" in step g, as described above. Is set to "0", and in steps h to j, monitoring is repeatedly performed to determine whether or not the variable X2 is larger than the recordable number Y, to issue an instruction to execute the recording operation, and to determine whether or not toner has been supplied. I have.

Here, when an instruction to execute the recording operation is issued from the outside, the control unit 7 controls each unit according to a well-known procedure to execute the recording operation in step k, and after the recording operation ends, the variable X2 is set. The value is “X2 + 1”. Thereafter, the control unit 7 repeats the processing of Steps h to j.

On the other hand, when the recording operation is repeated and the variable X2 exceeds the recordable number Y, the control section 7 shifts the processing from step h to step l. At this time, since the toner is not supplied to the hopper 41 and the recording has been performed up to the recordable number of sheets Y, there is almost no toner. Therefore, in step l, the control unit 7 prohibits the execution of the recording operation. In this prohibited state, the control unit 7
Does not perform the recording operation even if an instruction to execute the recording operation is issued from outside. Then, in step m, the controller 7 waits for toner supply.

When a new toner pack 48 is mounted on the hopper 41 and the toner is replenished as described above, the uppermost position of the toner in the hopper 41 is, for example, at the position indicated by the line D in FIG. As a result, the toner sensor 47 detects the toner, and the output is turned on. The controller 7 detects the change in the output of the toner sensor 47 and determines that the toner has been supplied. Then, the process proceeds from step m to step n. In step n, the controller 7 cancels the prohibition of the printing operation, and then shifts the processing to step o.

If the toner is replenished before the variable X2 exceeds the recordable number Y during the monitoring processing of steps h to j, the control unit 7 shifts the processing from step j to step o. Then, the execution of the recording operation is not prohibited.

In step o, the controller 7 determines whether or not the toner has been supplied for the first time. If this is not the first toner replenishment, the amount of toner used from the detection of “low toner remaining” to the next detection of “low toner remaining” is the same as the toner replenishment amount as described above. The controller 7 sets the variable U to the toner supply amount A in step p. When the toner is supplied for the first time, the toner is not present at all in the hopper 41 before the toner is supplied. The amount is smaller by the amount of B. Therefore, the control unit 7 determines in step q
The variable U is set to [AB].

After the processing of step p or step q, the control section 7 clears the variable X2 to "0" in step r. Thereafter, the control unit 7 shifts the processing to step b and repeats the processing from step b.

FIG. 3 is a diagram schematically showing an example of the transition of the remaining amount of toner in the hopper 41 when the above-described processing is performed. As shown in this figure, first, a section indicated by "F" (a section from the time when the remaining amount of toner falls below the predetermined amount B to the next time when the remaining amount of toner falls below the predetermined amount B; the same applies hereinafter).
And the section indicated by "g", the toner usage amounts U-2 and U-3
Are the same for the toner supply amount A, however, the number of recordings X1-2 in the section "F" is larger than the number of recordings X1-3 in the section "G". This indicates that the amount of toner used per image is smaller in the case of the section "F" than in the case of the section "G". Then, based on this relationship, in the case of the section “F”, the remaining amount of toner is the predetermined amount B.
Is smaller than the recordable number Y-3 in the case of the section “g”.

The section indicated by "e" indicates the section immediately after the first toner replenishment is performed.
Indicates that the toner usage amount U-1 is [AB] as described above.

As described above, according to the present embodiment, the number of recordable sheets until the execution of the recording operation after the "toner remaining amount" is detected by the toner sensor 47 is set to the previous "toner remaining amount". Since the amount of toner used and the number of recordings from the detection of "small" to the detection of "low toner remaining" are determined variably, the recordable number is optimally set according to the black ratio of the actual recorded image. be able to.

For example, in the conventional method, when the number of recordable sheets is 100 assuming a black ratio of 50% and the black ratio of the actual image is 5% on average, the coefficient a is set to 0.7. Even in this case, the recordable number of sheets Y in this embodiment is 700, which is greatly improved. This value is an accurate value since it is a value based on the black ratio of the actual image.

In this way, the remaining toner can be used efficiently, and more images can be recorded even after the detection of "low toner remaining". This allows
Even if the user does not notice the display urging the toner supply and does not supply the toner for a while, it is possible to prevent the execution of the recording operation from being stopped in a short time. Further, since the time until the execution of the printing operation is prohibited is as long as possible, the probability that the user notices the display prompting the toner supply before the execution of the printing operation is prohibited increases, and the execution of the printing operation is stopped. The number of cases in which a situation occurs is reduced.

Further, since the toner in the hopper 41 can be used as much as possible, when the developing device 2 needs to be replaced, the recording is performed until the execution of the recording operation is prohibited, and then the developing operation is performed. If the device 2 is replaced, waste of toner can be reduced.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the number of printable sheets until the execution of the printing operation after the detection of “low toner” is detected is changed from the detection of “low toner” to the next “low toner”. Although the section up to the detection is defined as one section and set independently for each section, information in each section may be stored and set comprehensively from such information.

In the above embodiment, the image recording apparatus of the present invention is applied to a dry-type electrophotographic recording apparatus. However, other than the electrophotographic recording apparatus, an apparatus for recording an image using a developer can be used. If so, the present invention can be applied to, for example, an electrostatic recording device or an ink jet printer. In addition, various modifications can be made without departing from the spirit of the present invention.

[0041]

According to the present invention, for example, as the control means of the control unit, it is detected that the amount of the developer in the storage container such as the hopper has become a predetermined amount or less by the developer detecting means such as the toner sensor. A first counting unit that counts the number of recordings until the developer detecting unit detects that the amount of the developer in the storage container has become equal to or less than a predetermined amount; and the developer detecting unit. After detecting that the amount of the developer in the storage container has become equal to or less than a predetermined amount, the predetermined amount of the residual developer is determined based on the count value of the first counting means, the predetermined amount, and the supply amount. Means for determining the number of sheets that can be recorded by using the above-mentioned method, replenishment detection means for detecting that the developer has been replenished to the developing container, and storage by the developer detection means. A second counting means for counting the number of recordings after it is detected that the developer amount in the container has become equal to or less than a predetermined amount, and a count value of the second counting means is determined by the recordable number determining means. Recording prohibition control means for prohibiting execution of a recording operation when replenishment of the developer to the developing container is not detected by the replenishment detection means until the number of sheets reaches the predetermined number. Even after the remaining amount becomes equal to or less than the predetermined amount, the image recording apparatus can record more images by effectively using the remaining developer.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a main configuration of an electrophotographic recording apparatus configured by applying an image recording apparatus according to an embodiment of the invention.

FIG. 2 is a flowchart illustrating a procedure of a toner monitoring process performed by a control unit in FIG. 1;

FIG. 3 is a diagram schematically illustrating an example of a transition of a remaining amount of toner in a hopper;

FIG. 4 is a diagram illustrating a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photosensitive drum, 4 ... Developing device, 41 ... Hopper, 47
... toner sensor, 48 ... toner pack, 7 ... control unit.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 15/08-15/09 G03G 21/00 510-512

Claims (1)

(57) [Claims] An image is recorded by using a developer stored in a storage container, and a developer detecting means for detecting that an amount of the developer in the storage container is equal to or less than a predetermined amount is provided. An image recording apparatus capable of replenishing the developing container with a predetermined amount of developer, wherein the developer detecting means detects that the amount of developer in the storage container has become a predetermined amount or less. A first counting means for counting the number of recordings until the developer detecting means detects that the amount of the developer in the storage container has become equal to or less than a predetermined amount; and After detecting that the amount of developer in the storage container has become equal to or less than a predetermined amount, the predetermined amount of residual developer is used based on the count value of the first counting means, the predetermined amount, and the replenishment amount. And recordable Means for variably determining the number of recordable sheets; supply detecting means for detecting that the developer has been supplied to the developing container; and developer amount in the storage container by the developer detecting means. A second counting means for counting the number of recordings after it is detected that the number of recordings has become equal to or less than a predetermined amount; and An image recording apparatus, further comprising: a recording inhibition control unit for inhibiting execution of a recording operation when the supply of the developer to the developing container is not detected by the supply detecting unit.