Image forming system

Abstract

An image forming system, having means for storing usage histories of latent image carriers, developer, or the like and maintenance cycles of image forming apparatuses and having a function for selecting image forming apparatuses outputting an image based on the usage history data or the maintenance cycles, in order to achieve uniform output image qualities. By managing the usage histories so as to achieve approximately the same deteriorated conditions of the latent image carriers of the image forming apparatuses, the image forming apparatuses can be put in the same condition and thus the output image qualities can be approximately the same in the image forming apparatuses. Additionally, the maintenance cycles can be adjusted to be approximately the same in the image forming apparatuses. Otherwise, maintenance periods can be controlled so as not to overlap in the image forming apparatuses.

What is claimed is:  
     
         1 . An image forming system comprising: 
 communication means for interconnection; and    a plurality of electrophotographic image forming apparatuses each visualizing a latent image on a latent image carrier generated based on input image data by means of developer and transferring the visualized image to a recording material, which are connected via said communication means;    the image forming system having means for storing usage histories of the latent image carriers of the image forming apparatuses and having a function of selecting image forming apparatuses outputting the image based on the carrier usage history data stored in said storing means.    
     
     
         2 . The image forming system according to  claim 1 , wherein the usage history of said latent image carrier is based on the number of transferred pages obtained with reference to an operating time or recording materials.  
     
     
         3 . The image forming system according to  claim 1 , wherein the usage history of said latent image carrier is modified according to a characteristic of deterioration through use of each latent image carrier.  
     
     
         4 . The image forming system according to  claim 1 , wherein the image forming apparatuses outputting the image are selected so that the usage histories of the latent image carriers of the image forming apparatuses are approximately the same.  
     
     
         5 . An image forming system comprising: 
 communication means for interconnection; and    a plurality of electrophotographic image forming apparatuses each visualizing a latent image on a latent image carrier generated based on input image data by means of developer and transferring the visualized image to a recording material, which are connected via said communication means;    the image forming system having means for storing usage histories of the developer of the image forming apparatuses and having a function of selecting image forming apparatuses outputting the image based on the developer usage history data stored in said storing means.    
     
     
         6 . The image forming system according to  claim 5 , wherein the usage history of the developer is based on the number of transferred pages obtained with reference to an operating time of a developing device, which contains the developer and supplies it to the latent image carrier, or recording materials.  
     
     
         7 . The image forming system according to  claim 5 , wherein the usage history of the developer is modified according to a characteristic of deterioration through use of the developer.  
     
     
         8 . The image forming system according to  claim 5 , wherein the image forming apparatuses outputting the image are selected so that the usage histories of the developer are approximately the same in the image forming apparatuses.  
     
     
         9 . An image forming system comprising: 
 communication means for interconnection; and    a plurality of electrophotographic image forming apparatuses each visualizing a latent image on a latent image carrier generated based on input image data by means of developer and transferring the visualized image to a recording material, which are connected via said communication means;    the image forming system having means for storing usage histories after maintenance of the image forming apparatuses and having a function of selecting image forming apparatuses outputting the image based on the usage history data.    
     
     
         10 . The image forming system according to  claim 8 , wherein the usage history after maintenance is based on the number of transferred pages obtained with reference to an operating time for image formation of the image forming apparatus or recording materials.  
     
     
         11 . The image forming system according to  claim 9 , wherein the usage history after maintenance is modified according to a characteristic of deterioration through use of each image forming apparatus.  
     
     
         12 . The image forming system according to  claim 9 , wherein the image forming apparatuses outputting the image are selected so that the usage histories after maintenance are approximately the same in the image forming apparatuses.  
     
     
         13 . An image forming system comprising: 
 communication means, for interconnection; and    a plurality of electrophotographic image forming apparatuses each visualizing a latent image on a latent image carrier generated based on input image data by means of developer and transferring the visualized image to a recording material, which are connected via said communication means;    the image forming system having means for storing information on average photographic densities of developer after replacement and having a function of selecting image forming apparatuses outputting the image based on the average photographic densities obtained from the information.    
     
     
         14 . The image forming system according to  claim 13 , wherein the means for storing the information on the average photographic densities includes at least means for storing usage histories of the developer, means for calculating the photographic densities during image formation successively, and means for calculating the average photographic densities from the usage histories and the successively calculated photographic densities.  
     
     
         15 . The image forming system according to  claim 13 , wherein the image forming apparatuses outputting the image are selected so that the average photographic densities are approximately the same in the image forming apparatuses.  
     
     
         16 . An image forming system comprising: 
 communication means for interconnection; and    a plurality of electrophotographic image forming apparatuses each visualizing a latent image on a latent image carrier generated based on input image data by means of developer and transferring the visualized image to a recording material, which are connected via said communication means;    the image forming system having means for detecting amounts of remaining developer of the image forming apparatuses and means for calculating a black ratio of the image data and having a function of selecting image forming apparatuses outputting the image based on the remaining developer amount data and the black ratio data.    
     
     
         17 . The image forming system according to  claim 16 , wherein the image forming apparatuses outputting the image are selected so that the amounts of remaining developer after the image formation are approximately the same in the image forming apparatuses.  
     
     
         18 . The image forming system according to  claim 1 , wherein the developer contains color particles.  
     
     
         19 . The image forming system according to  claim 1 , wherein a part or all of the plurality of image forming apparatuses connected to each other via said communication means are of different models.  
     
     
         20 . The image forming system according to  claim 1 , further comprising a display unit for displaying a list of the image forming apparatuses selected for outputting the image.  
     
     
         21 . The image forming system according to  claim 20 , further comprising an operating unit for giving an instruction to execute the output with specifying a part or all of the image forming apparatuses displayed on said display unit.  
     
     
         22 . The image forming system according to  claim 1 , further comprising a host device control unit for selecting the image forming apparatuses outputting the image based on one of the data.  
     
     
         23 . The image forming system according to  claim 22 , wherein said host device control unit is incorporated in at least one of the image forming apparatuses.  
     
     
         24 . The image forming system according to  claim 22 , wherein said host device control unit is connected to said image forming apparatuses independently of the image forming apparatuses connected to each other.