MAGNIFICATION SELECTING DEVICE

Abstract: A magnification selecting device (20-22) which is capable of continuously varying magnifications by operating either UP (18) or DOWN (19) key and also slowing down the speed of varying magnifications only when these magnifications are in a position close to the predetermined magnification.

Description: BACKGROUND OF THE INVENTION The present invention relates to a magnification selecting device, more particularly, to a magnification selecting device which is capable of continuously varying magnifications by operating either an UP key or a DOWN key. A prior art presents in its Japanese Patent Laid Open Publication No. 220722 of 1984 a mechanism related to the image generating apparatus such as an electrophotographic copying machine, which is provided with the UP and DOWN keys for finely selecting magnifications so that the magnification can continuously be increased or decreased by selectively operating either of these keys. This apparatus is also provided with stationary magnification keys for selecting any of those magnifications which are frequently made available for either enlarging or reducing between papers of standard sizes so that any desired magnification can easily be selected by operating any of the stationary magnification keys. Since the image generating apparatus mentioned above is provided with the stationary magnification keys in addition to the UP and DOWN keys, the operational characteristic can certainly be improved. On the other hand, unless the number of keys on the operation panel is minimized, operation of other keys including an effort for finding the keys to be operated unavoidably involves complexity to conversely lower the total operational characteristics. As a result, the number of stationary magnification keys should be reduced. If the kind and number of the stationary magnification keys were minimized, there will be a number of such stationary magnifications that cannot be accessed by operation of the stationary magnification keys, while any of these stationary magnifications should carefully be selected by operating either of the UP and DOWN keys. When selecting the desired magnification by operating either of the UP and DOWN keys, since the conventional apparatus allows the UP and DOWN keys to set minimum of 64% through a maximum of 141% by 1% graduation, when varying magnifications by operating either of these UP and DOWN keys, magnification varies itself at a considerably fast speed like milliseconds/% for example, and as a result, it is extremely difficult for the operator to precisely control the timing to stop the operation of either of these UP and DOWN keys while watching the magnification display. Actually, the desired magnification is easily passed when the key operation is stopped. To correctly set the magnification to the desired value, the operator is obliged to repeat operations of the UP and DOWN keys many times, thus eventually resulting in the poor operational characteristic for correctly selecting the aimed magnification. In addition, when operating the copying machine for generating picture image by using a stationary magnification, a certain amount of blank portion may have to be provided in the edge portion of the generated image. When this is actually needed, after selecting the desired magnification by operating one of the stationary magnification key, the operator is then obliged to diminish the magnification by several percents by operating the DOWN key, thus unavoidably facing poor operational characteristic for selecting the aimed magnification as mentioned above. EP-B-127 867 discloses a copying machine having two-speed buttons which allow the operator to change the magnification ratios dependent how long one of these buttons is pressed. But in contrast to the present invention there is no slowing down of the changing of the magnification ratios when an actual magnification ratio is close to a predetermined one. SUMMARY OF THE INVENTION An object of the present invention is to allow the operator to easily identify the timing needed for stopping the operation of either the UP and DOWN key when selecting the desired magnification. A still further object of the present invention is to allow the operator to easily select any magnification for enlarging or reducing between standard size-papers which are frequently made available. A still further object of the present invention is to securely inhibit prolongation of time needed for selecting the desired magnification. According to the present invention these objects are achieved by the features recited in the characterizing part of claim 1. To securely achieve those objects mentioned above, the magnification selecting device embodied in the present invention causes magnifications to continuously vary themselves by selectively operating either the UP or DOWN keys, and varying speed of magnifications which are continuously varied by key operation is slowed down only when reaching a certain magnification close to the aimed magnification. However, the aimed magnification should preferably be the one for enlarging or reducing between standard size-papers which are very frequently made available. Using the magnification selecting device of the present invention, magnifications can continuously be varied by continuously operating either the UP or DOWN key. Since the device related to the present invention slows down the speed for varying magnification as soon as the actual magnification is close to the aimed magnification, the operator can securely set both the predetermined magnification and the approximates to it by properly controlling the timing needed for stopping operation of either the UP and DOWN key while watching the magnification display. If the operator specifies such a magnification which is frequently made available for either enlarging or reducing between papers of standard sizes, the operator can set not only the intended magnification, but he can also set a slightly diminished magnification needed for generating a certain blank portion in paper edges by properly controlling the timing needed for stopping the operation of either of the UP and DOWN keys while watching the magnification display. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be better understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention in which: Fig. 1 shows the flow charts describing operations needed for selecting the aimed magnification, Fig. 2 shows the block diagram denoting the electrical constitution of the magnification selecting device embodied in the present invention; Fig. 3 shows schematically the essential part of the operation panel of a copying machine incorporating the magnification selecting device embodied in the present invention; and Fig. 4 shows schematically the essential part of the copying machine incorporating the magnification selecting device related to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Fig. 4 is the schematic diagram denoting the essential part of the copying machine. An original 2 placed on the contact glass 1 is illuminated by the light source 3 which moves itself in the arrowed direction A shown in Fig. 4. Light reflected from the original 2 is then led to the external surface of the photoreceptor drum 9 via reflection mirrors 4 through 6, a lens 7, and another reflection mirror 8 before generating an electrostatic latent image corresponding to the original image. The reflection mirror 4 integrally moves together with the light source 3, whereas reflection mirrors 5 and 6 respectively move themselves in the same direction at half the speed of the light source 3. A corona charger 10, a developing device 11, a transfer charger 12, a separation charger 13, and a cleaner 14 are respectively disposed in the periphery of the photoreceptor drum 9 in the order mentioned above. The external surface of the photoreceptor drum 9 is uniformly charged by the corona charger 10. An electrostatic latent image is generated during exposure with light, which is then developed into a toner image by the developing device 11. The toner image is then transferred onto the copying paper 16 conveyed by the resist roller 15 by applying the transfer charger 12. The copied paper 16 is then peeled from the photoreceptor drum 9 by means of the separation charger 13, and finally, residual toner is collected from the surface of the photoreceptor drum 9 by using the cleaner 14. Fig. 3 is the schematic diagram denoting the operation panel of the copying machine which is provided with an UP key 18 and a DOWN key 19 in positions close to a magnification display 17. The detailed constitution of the operation panel is described below. The operation panel is provided with the following: A preheating key 23, a print activation key 24, a clear key 25, ten keys 26 for setting the number of papers to be copied, a key 27 for displaying the number of papers to be copied, an interruption key 28, an automatic magnification selecting key 29, an automatic copying paper size selecting key 30, an automatic copying density setting key 31, a manual copying density setting key 32, a display unit 33, a stored magnification display part 34, a stored magnification selecting key 35, a stored magnification reading key 36, a magnification memory key 37, an original size, selecting key 38, and a copying paper size selecting key 39. Of these, the display unit 33 is provided with a display 33a for indicating the number of papers to be copied or the number of copied papers, a status display 33b indicating the warming-up condition, interrupted condition, and diminished condition of toner amount, a paper-size display 33c, and the magnification display 17, respectively. Fig. 2 is the simplified block diagram of electrical constitution of the magnification selecting device related to the present invention. Activated UP-key signal and DOWN-key signal are respectively delivered to a microcomputer 20 via an I/O interface 21. Control signal from the microcomputer 20 is delivered to driver unit 22 which drives the magnification display 17. The magnification selecting device related to the present invention allows stationary magnifications to be stored in a memory 20a. Fig. 1 shows the flowchart describing operations needed for selecting the aimed magnification. When step 1 is entered, the microcomputer 20 identifies whether the UP-key 18 is depressed, or not. If it is depressed, step 2 is entered to allow the microcomputer 20 to identify whether the maximum magnification is present, or not. If it is present, the microcomputer 20 then identifies whether the UP-key 18 is depressed or not at step 1. In other words, when the maximum magnification is set, magnification cannot be varied by operating the UP-key. If the maximum magnification is not present, step 3 is entered to allow the microcomputer 20 to identify whether the UP-key ON flag is activated, or not. If it is identified by the microcomputer 20 that this flag remains inactivated, step 4 is entered to activate the UP-key ON flag. Next, step 5 is entered to activate a timer to proceed to step 6 in which zoom-up operation is executed for increasing magnification by 1%. When step 7 is entered, a zoom-up timer is activated. After activating the zoom-up timer, the system operation again returns to step 1 to follow up those identifications and operations mentioned above. If the microcomputer 20 identifies during step 3 that the UP-key ON flag is activated, the microcomputer 20 then identifies during step 8 whether the timer counting time set to be 500 milliseconds for example at step 5 is past, or not. If the above mentioned timer counting time is not yet past, the microcomputer 20 then activates those serial identifications and operations starting from step 1 on. Otherwise the above mentioned timer counting time is past, the microcomputer 20 then identifies at step 9 whether the magnification is in a range being less than any of the predetermined stationary magnifications by a maximum of 5 steps, i.e., by a maximum of 5%, or not. If the actual magnification is less than any of those predetermined stationary magnifications by a maximum of 5 steps or 5%, the microcomputer 20 then identifies at step 10 whether a specific duration such as 0.5 seconds for example preset by the zoom-up timer is already past, or not. If it is identified at step 10 that 0.5 seconds is not yet past, the controller system then follows up execution of those identifications and operations starting from step 1 on. When the microcomputer 20 identifies at step 9 that the actual magnification is not in a range less than any of those predetermined magnifications by a maximum of 5 steps or 5% or at step 10 that the preset 0.5 seconds is already past, the controller executes those serial identifications and operations starting from step 6 on. In addition, when the microcomputer 20 identifies at step 1 that the UP-key 18 is not depressed, the UP-key ON flag is reset at step 11. The microcomputer 20 then identifies at step 12 whether the DOWN-key 19 is depressed, or not. If it is already depressed, the microcomputer 20 then identifies at step 13 whether the minimum magnification is present, or not. If the minimum magnification is present, the controller system then executes those serial identifications and operations starting from step 1 on. When the minimum magnification is present, the magnification cannot be varied by operating the DOWN-key 19. If the minimum magnification is not present, the microcomputer 20 then identifies at step 14 whether the DOWN-key ON flag is activated, or not. If it is identified at step 14 that the DOWN key ON flag is not yet activated, the microcomputer 20 then activates it at step 15. Then, the microcomputer 20 activates the timer at step 16 and executes the zoom-down operation at step 17 for decreasing the magnification by 1%. The controller system then activates the zoom-down timer at step 18 before resuming the execution of those serial identifications and operations starting from step 1 on. Conversely, if the microcomputer 20 identifies at step 14 that the DOWN-key ON flag is already activated, the microcomputer 20 then identifies at step 19 whether the timer counting time set to be 500 milliseconds for example at step 16 is already past, or not. If it is not yet past, the controller system then executes those serial identifications and operations starting from step 1 on. If the preset time is already past, the microcomputer 20 then identifies at step 20 whether the actual magnification is in a range greater than any of those predetermined stationary magnifications by a maximum of 5 steps, i.e., by a maximum or 5%, or not. If it is in a range greater than any of those predetermined stationary magnifications by a maximum of 5 steps or 5%, the microcomputer 20 then identifies at step 21 whether a specific duration such as 0.5 seconds for example preset by the zoom timer is already past, or not. If it is identified at step 21 that 0.5 seconds of preset duration is not yet past, the controller system then executes those serial identifications and operations starting from step 1 on. Conversely, if it is identified that the actual magnification is not in a range greater than any of those predetermined magnifications by a maximum of 5 steps or 5%, at step 20 or that 0.5 seconds of the preset duration is already past at step 21, the controller system then executes those serial identifications and operations starting from step 17 on. If the microcomputer 20 identifies at step 12 that the DOWN key 19 is not yet depressed, the DOWN-key ON flag is reset at step 22 to allow the controller system to execute those serial identifications and operations starting from step 1 on. Summarizing above, when either the UP-key 18 or DOWN-key 19 has been operated for a maximum of 500 milliseconds, the magnification can be varied by 1% graduation whenever either of these keys is operated. When either of these keys is continuously operated for more than 500 milliseconds, the magnification can continuously be varied by 1% graduation in response to the key-operating duration, thus effectively saving time needed for selecting the desired magnification. When continuously operating either of these UP and DOWN keys, if the magnification is in a range of a maximum of 5 steps preceding in the direction of varying magnification in reference to any of those predetermined stationary magnifications, the controller system then executes either zoom-up or zoom-down operation at specific intervals preset by either the zoom-up or the zoom-down timer. Consequently, when selecting a specific magnification which is significantly apart from any of the predetermined stationary magnifications, the desired magnification should be set by properly controlling the timing needed for stopping the key operation while visually watching the quickly-varying magnifications via the magnification display 17 as is normally done with any conventional magnification selecting devices. However, since the needs for executing such an extraordinary operation rarely occur, this is not a critical problem. Conversely, since the magnification selecting device embodied in the present invention causes magnifications to vary themselves at a slowed-down speed when the desired magnification is at a position close to any of those stationary magnifications for enlarging or reducing between standard size papers, e.g. A5, A4, B5, B4, etc, which are frequently made available, it is extremely easy for the operator to properly control the timing needed for stopping the key operation while watching the magnification display. And yet, the operator can easily select such a magnification approximating the stationary magnification in order to provide blank portion for papers to be copied. Furthermore, it is possible for the magnification selecting device related to the present invention to better facilitate selecting of a desired magnification by allowing the controller system to store other magnifications with keys 35 to 37. The magnification selecting device embodied in the present invention is also capable of slowing down the varying speed of magnifications in a range of those steps other than 5 steps centering the predetermined magnification as well as capable of setting the rate of slowing down the varying speed at a desired level other than those which are suggested by the preferred embodiments described earlier. Furthermore, it is also possible for the magnification selecting device reflecting the preferred embodiments described above to simplify the constitution of the operation panel by abbreviating the stored-memory display 34, the stored-magnification selecting key 35, the stored-magnification reading key 36, and the magnification memory key 37, respectively. In summary, the magnification selecting device reflecting the present invention slows down the variable speed of magnification when operating either of the UP and DOWN keys only in a position which is close to the predetermined stationary magnification. As a result, it is possible for the system to easily and securely set the desired magnification close to the predetermined stationary magnification without significantly lowering the total speed needed for selecting the magnification by properly controlling the timing needed for stopping the key operation while watching the magnification display, and yet by lessening the operating number of keys.

Claims: A magnification selecting device for selecting the magnification ratio between the size of an original image and that of the image on copy paper, comprising: an UP key (18) and a DOWN key (19) for increasing or decreasing the magnification ratios, which keys allow the operator to change the magnification ratios dependent on how long either one of these keys is pressed; and a magnification display (17) for displaying the actual magnification ratio; characterized by means for storing (20a) predetermined magnification ratios for enlarging or reducing between papers of standard sizes; and a microcomputer (20) for determining whether the actual magnification ratio in response to actuation either of the UP key (18) or the DOWN key (19) is in a range of a predetermined percentage of one of the said stored magnification, ratios, and for slowing down the speed of increasing or decreasing the magnification ratios when a magnification ratio is determined which is within said predetermined range of one of the stored magnification ratios. A magnification selecting device according to claim 1, characterized in that said microcomputer (20) slows down the speed of increasing or decreasing magnification ratios by enlarging or reducing a time interval between operations of either the UP key (18) or the DOWN key (19), while the changing of the magnification ratio is constant for each operation. A magnification selecting device according to claim 2, characterized in that said time interval is defined by a zoom-up timer or a zoom-down timer.

Inventors: ICHIHASHI, TAKAO, MAKIURA, YOSHINORI, OGAWA, SHUSAKU, WAKIKAIDO, TAKAHIRO, YAMAMOTO, HARUO
Applicants: MITA INDUSTRIAL CO., LTD.
Application year: 1986
Main classification: G03G15
IPC codes: G03G15, G06F3, G03G21, H03M11