Image forming method including recycling of untransferred toner collected from image bearing member to developing means

An image forming method comprising the steps of;

• forming a latent image on an image bearing member;
• developing the latent image formed on the image bearing member with a developing means including a developing sleeve and a developer container containing a supply of toner, while applying an alternating electric field between said image bearing member and said developing sleeve;
• transferring the toner image from the image bearing member to a transfer medium with a transfer means to which a bias is applied;
• cleaning the image bearing member from which the toner image has been transferred to the transfer medium, to collect the toner remaining on the image bearing member as collected toner;
• and
• feeding the toner collected in said cleaning step to said developer container of said developing means for reuse by the developing means in a subsequent step of developing a latent image to form a toner image;
• wherein said supply toner and said collected toner comprise a binder resin and at least one of a magnetic powder and a colorant,
• (i) said supply toner having:
• a weight average particle diameter (D.sub.4) of from 4 .mu.m to 11 .mu.m;
• a supply toner coefficient A(S) of variation of number-base distribution of 20 to 40, which is a coefficient represented by the formula:
• A(S)=(S.sub.n /D.sub.1).times.100
• wherein S.sub.n represents a standard deviation of number-base distribution, and D.sub.1 represents a length average particle diameter (.mu.m) on the basis of number;
• and
• a supply toner coefficient B(S) of variation of volume-base distribution of 15 to 30, which is a coefficient represented by the formula:
• B(S)=(S.sub.W /D.sub.4).times.100
• wherein S.sub.W represents a standard deviation of volume-base distribution of such supply toner, and D.sub.4 represents a weight average particle diameter (.mu.m) on the basis of weight of said supply toner;
• (ii) said collected toner having:
• a collected toner coefficient A(R) of variation of number-base distribution of from 25 to 45, wherein the collected toner coefficient A(R) has the same definition as that of the supply toner coefficient A(S), and
• a collected toner coefficient B(R) of variation of volume-base distribution of from 15 to 35, wherein the collected toner coefficient B(R) has the same definition as that of the supply toner coefficient B(S);
• wherein A(R) and B(R) are determined by the above-given formulas used to determine the supply toner coefficients but using collected toner distribution data, and
• wherein a greatest peak and a second greatest peak in a histogram of volume-base distribution of the collected toner fall in the same particle diameter ranges as a greatest peak and a second greatest peak in a histogram of volume-base distribution of the supply toner having corresponding particle diameter ranges.