JP3364252B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus which is developed using a toner powder and which can be applied to a printing apparatus whose resolution can be changed. 2. Description of the Related Art Conventionally, the diameter of toner particles used in a printing device such as a laser printer has a resolution of 10 μm at 300 dpi.
It is required to have a particle diameter of about 5 m at about 600 mpi and 600 dpi, and the toner particles have been manufactured so that the diameter of the toner particles is as uniform as possible around 10 μm or 5 μm for each resolution. [0003] Usually, a toner cartridge containing small-sized toner particles and a toner cartridge containing large-sized toner particles are manufactured and sold. In a printing apparatus that changes the printing method according to the toner particle size, for example, as shown in JP-A-3-163476, a notch for determining the toner particle size is provided in a toner cartridge.
A discriminating means such as a mark is provided, and the discriminating means is read by a sensor to determine the toner particle diameter. [0004] However, the toner contained in the toner cartridge is not limited to 5 μm or 10 μm as shown in the distribution diagrams of FIGS. The toner of a certain range is stored. It is more difficult to reduce the dispersion of the particle size distribution of the toner as the diameter is reduced, and the number of manufacturing steps is increased and the manufacturing cost is increased. Even if the dispersion of the particle size distribution of the toner is suppressed to a small range, the general characteristic of toner development is that toner having a small particle diameter tends to be consumed first. There is a problem that the amount of toner particles increases and image quality deteriorates. Therefore, even if the particle size of the toner stored in each toner cartridge is determined as in the prior art, it is not possible to prevent the deterioration of the image quality near the toner end. For this reason, conventionally, a means for notifying the operator of toner replacement, that is, replacement of the toner cartridge, before the toner end is approached and the image quality is degraded is provided. However, if the toner is replaced in response to the above-mentioned notification, there is a problem that although the image quality is slightly deteriorated, the toner still usable for printing is wasted. Further, conventionally, when viewed from a host computer connected to a printing apparatus, it is not possible to determine whether the toner of the printing apparatus is small-sized or large-sized. High-resolution (high-resolution) mode printing was performed, resulting in low-quality printing such as so-called "character collapse". In a laser printer, the resolution in the main scanning direction is usually changed by changing the rotation speed of a polygon mirror, which is an optical deflector, while keeping the rotation speed of the photosensitive member constant. The rotation speed of the mirror is increasing. An increase in the number of rotations of the polygon mirror shortens the life of the polygon motor that drives the polygon mirror to rotate. In a conventional laser printer, when the polygon mirror continues to rotate even during standby for printing, even if the small-diameter toner is already used up and high-resolution printing cannot be performed, the polygon is rotated at the high-resolution mode rotation speed. The motor is driven to rotate, which is problematic in terms of durability. An object of the present invention is to provide an image forming apparatus which can solve various problems caused by the presence of a particle size distribution in a toner. [0012] In order to achieve the above object, the present invention is configured to form an image by receiving image data from a host device, and to perform development using toner powder. In an image forming apparatus capable of forming an image and changing the resolution of the image formation, a detecting means for detecting a remaining amount of the toner powder, and the remaining amount of the toner powder is determined by a predetermined amount based on a detection result from the detecting means. And control means for controlling the operation of the image forming member so as to reduce the resolution at the time of image formation when the amount of toner powder becomes lower than the predetermined value. Information indicating that the remaining amount is equal to or less than the predetermined amount and the resolution of image formation is reduced can be transmitted to the host device .
The host device to change the resolution.
When a request is received, the control means switches to the high resolution mode.
It is characterized in that a change in image resolution is set . According to the above-mentioned means, when the remaining amount of the stored toner decreases, the amount of the large-diameter particles increases, and when the remaining amount of the toner decreases, Since the quality of the formed image, that is, the resolution is automatically set to be low, it is possible to prevent low-quality image formation due to high-resolution image formation using large-diameter toner, and By doing so, it is possible to use the toner immediately before the toner end, so that wasteful disposal of the toner is eliminated,
Further, even if the dispersion of the particle size distribution of the toner is large, troubles in image formation due to the difference in the particle size of the toner can be avoided as described above. The use of toner manufactured at a low cost becomes possible. Further, when it is detected that the remaining amount of the toner stored in the toner cartridge or the like has fallen below a predetermined amount, a warning signal is sent to the host device indicating that high-resolution printing cannot be performed. If there is no request to change the resolution from the host device, print operation at low resolution
And accepts a request to change the resolution from the host
If high resolution printing is required, high quality
To enable the printing operation in the resolution mode, or to replace the toner cartridge, that is, store the toner cartridge in another place and perform high-quality printing by replacing the toner cartridge with a new toner cartridge. Becomes possible. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a control system of a laser printer which is an embodiment of an image forming apparatus of the present invention, wherein 1 is an image forming apparatus main body, and 2 is a host device connected to the image forming apparatus. The image forming apparatus main body 1, which is a host computer, includes a toner end sensor 3, which is a detecting means for detecting the remaining amount of toner powder stored in a toner cartridge described later, and a laser diode ( A D / A (digital / analog) converter 6 for adjusting the amount of laser beam emitted from the LD 5, beam diameter changing means 7 for changing the diameter of the laser beam in accordance with a change in resolution, and a polygon motor 8 PLL (P
A reference clock generation timer 10 for setting in the Hase Locked Loop 9 is provided. Further, 11 is a polygon mirror which is an optical deflector rotated by the polygon motor 8, and 12 is optically scanned by a laser beam deflected by the polygon mirror 11 to form a latent image in a known manner. A photoreceptor 13 is a toner cartridge for supplying toner to a developing device (not shown) installed near the photoreceptor 12, and 14 is a CPU (central processing unit) for transmitting and receiving signals to and from the above-described members. The printing operation based on the toner end sensor 3 in the above embodiment will be described with reference to the flowchart of FIG. That is, the toner end sensor 3 detects the remaining amount of toner in the toner cartridge 13, and when it is detected that the remaining amount of toner is less than a predetermined amount (S
1) The CPU 14 determines that only relatively large-sized toner powder remains in the toner cartridge 13, and first issues a warning signal (particle size information) to the host computer 2 indicating that printing at 600 dpi at high resolution is no longer possible. ) (S2). Further, the CPU 14 sends a signal relating to the particle diameter information to the D / A converter 6, the beam diameter changing means 7, and the reference clock generation timer 10 to change the quality of the formed image (to change the resolution to 300 dpi). In step S3, the light emission amount is adjusted, the laser beam diameter is changed, and the rotation speed of the polygon motor 8 is reduced (S3). Here, a request to change the resolution is received from the host computer 2, and if there is a change request (YES in S4),
Even if high quality printing cannot be expected, the CPU 14
A change signal is sent to the converter 6, the beam diameter changing means 7, and the reference clock generation timer 10 to change the resolution from 300 dpi mode to 600 dpi mode (S5).
(YES in 6), the printing operation is performed (S7). Of course, if there is no change request in step (S4) (NO in S4), the CPU 14 performs a printing operation when a print request is made in the 300 dpi mode (YES in S6) (S7). ). If it is desired to perform high-quality printing at a resolution of 600 dpi in a state where the remaining amount of toner is equal to or less than the predetermined amount in step (S1), the toner cartridge 13 is stored in another place and a new toner cartridge is stored. Replace and print. When printing with a resolution of 300 dpi, the toner cartridge 13 can be used again. As described above, in this embodiment, the toner which has been wasted conventionally because of its large particle size can be used at the time of low-resolution printing output, and the running cost of using the toner can be reduced. . As shown in FIG. 3C, even if the dispersion of the toner particle size is widened and the proportion of the toner having a relatively large particle size is increased, the toner end is adjusted by adjusting the resolution as described above. Since the toner can be used effectively, the toner manufacturing cost can be reduced as compared with the conventional toner in which the particle size distribution of the toner is narrowed. Since the host computer 2 can determine whether high-resolution printing is possible before the printing operation,
It is possible to prevent low-quality print output such as "character collapse" that is likely to occur in high-resolution print output using a large particle size toner. In a state where high-resolution printing is impossible,
Since the number of rotations of the polygon motor 8 is reduced during the standby for printing by setting the low resolution mode, the load on the polygon motor 8 and its related members can be reduced, so that the durability can be improved. As described above, according to the image forming apparatus of the present invention, when the amount of stored toner decreases, the amount of large-diameter particles increases. Therefore, since the toner particle diameter information can be obtained in response to the decrease in the remaining amount of toner, by changing the setting to a low resolution when the remaining amount of toner is low,
Since image formation of low quality can be prevented and troubles in image formation due to differences in toner particle diameter can be avoided, it is not necessary to suppress dispersion of the toner particle size distribution, and the toner manufacturing cost can be reduced. Further, when it is detected that the remaining amount of toner stored in the toner cartridge or the like has become equal to or less than a predetermined amount, a warning signal is sent to the host device indicating that high-resolution printing cannot be performed. If there is no request to change the resolution from the host device, printing operation with low resolution is performed.
When high resolution printing is requested from the host device.
Print operation in high resolution mode even if it is not high quality
Is performed, or the toner cartridge is replaced, that is, the toner cartridge is stored elsewhere,
High quality by replacing with a new toner cartridge
For example, printing can be performed by selecting a resolution, for example , printing can be performed. [0032]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of a control system of a laser printer which is an embodiment of an image forming apparatus of the present invention. FIG. 2 is a flowchart of a printing operation based on a toner end sensor in the embodiment. FIG. 3 is a distribution diagram illustrating an example of a particle size distribution of a toner. [Description of Signs] 1 ... Image Forming Apparatus Main Body 2 ... Host Computer (Host Apparatus) 3 ... Toner End Sensor (Detecting Means)
4 Driver, 5 LD (laser diode), 6 D
/ A converter, 7: beam diameter changing means, 8: polygon motor, 9: PLL (Phase Locked Loop), 10: reference clock generation timer, 11: polygon mirror (optical deflector), 12: photoconductor, 13 ... Toner cartridge, 14
... CPU (central processing unit).

──────────────────────────────────────────────────続 き Continued on the front page (58) Investigated field (Int.Cl. ⁷ , DB name) G03G 15/00 303 G03G 21/00 370-540 G03G 15/04 B41J 29/46 B41J 2/44 G03G 15 / 08 H04N 1/113

Claims (1)

(57) [Claim 1] An image forming apparatus receives image data from a host device and forms an image. The image forming apparatus performs development using toner powder to form an image. In an image forming apparatus capable of changing the resolution, a detecting means for detecting the remaining amount of the toner powder, and an image forming apparatus, based on a detection result from the detecting means, when the remaining amount of the toner powder becomes a predetermined amount or less. Control means for controlling the operation of the image forming member so as to reduce the resolution at the time of the image formation. When the remaining amount of the toner powder becomes equal to or less than a predetermined amount, the remaining amount of the toner powder is equal to or less than the predetermined amount, and Information to the effect that the resolution of the formation is to be reduced can be transmitted to the host device, and when there is no request to change the resolution from the host device , the control means uses the low resolution.
The host device to change the resolution.
When a request is received, the control means switches to the high resolution mode.
An image forming apparatus for setting a change in image resolution .