Image forming device

The device is constituted so that, when a non-processing period continues for more than a predetermined time in a normal mode, in which an image forming process is possible, the image forming device switches to a power saving mode, in which power consumption is reduced, two types of LEDs 8a and 8b that have display colors that differ from one another being provided, and each light source 8a and 8b being selectively illuminated by the mode notification means 13 according to the normal mode and the power saving mode.

FIELD OF THE INVENTION

The present invention relates to an image forming device such as a copier, a printer or a facsimile machine; more specifically, it relates to an image forming device allowing an observer to clearly distinguish between a normal mode in which image forming processes are possible, a power saving mode in which power consumption is reduced, and a power source off mode in which the power switch is off.

BACKGROUND INFORMATION

In general, in order to reduce wasteful power consumption, some image forming devices such as copiers, printers, facsimile devices or multi-function machines, are constituted so to be able to switch to a power saving mode if a period in which no processing is performed continues for a predetermined amount of time in a normal mode, in which image forming processes are possible. For instance, when a copier is switched to the power saving mode, processes such as reducing the temperature of the fixing roller are performed.

Conventionally, this type of image forming device is provided with an operation panel for performing various setting operations. Thus, switches for various setting operations, a liquid crystal display unit for verifying setting operations and the like, are located on this operation panel.

In this case, in the prior art, a control process is carried out, in which a backlight light source, consisting of an LED or the like in the liquid crystal display unit that is provided on the control panel, is illuminated in the normal mode, but in the power saving mode, the backlight light source is turned off.

However, when in such a power saving mode, if a control process that turns off a backlight light source in the liquid crystal display unit is performed, it is difficult to distinguish this situation from a situation in which the power switch for the main power source is off. Thus, confusion arises, and the user may be misled into thinking that the power switch is off, and may turn the power switch on and off again, when in reality the device was merely switched to power saving mode.

The present invention was devised in view of the above problem, and an object thereof is to provide an image forming device with better usability than was conventional, by allowing an observer to clearly recognize which state the device is currently in: normal mode, power saving mode or power source off mode.

SUMMARY OF THE INVENTION

The present invention assumes an image forming device constituted so that, when a non-processing period continues for more than a predetermined amount of time in a normal mode, in which an image forming process is possible, the image forming device switches to a power saving mode, in which power consumption is reduced. Then, the present invention comprises a mode notification means for making the display color or display mode of a light source differ according to the normal mode and the power saving mode.

In this case, the mode notification means can have a constitution comprising two types of light sources having display colors that are different from one another, and an illumination drive means for switching between and driving the illumination of the each light source according to the normal mode and the power saving mode.

Alternatively, the mode notification means can have a constitution comprising a single light source and an illumination drive means for switching the display mode of the light source according to the normal mode and the power saving mode. Then, the light source can be used as a backlight for a liquid crystal display unit provided on the control panel.

According to the present invention, as the mode notification means makes the display color or the display mode of the light source differ according to the normal mode, in which an image forming process is possible, and the power saving mode, in which the power consumption is reduced, not only is it possible to clearly distinguish between the normal mode and the power saving mode, but it is also possible for an observer to clearly understand whether or not the power switch is off. Therefore, it is possible to improve usability by eliminating the confusion which was conventional, such as a user being misled into thinking that the power switch is off, and turning the power switch on and off again, when in reality the device was merely switched to power saving mode.

In particular, by switching between and driving the illumination of two types of light sources having display colors that differ from one another according to the normal mode and the power saving mode, the difference between these operating modes can be clearly understood by an observer at a glance, based on the difference in the illumination colors of the light source.

In addition, switching the display mode of the light source according to the normal mode and the power saving mode, can be implemented using a single light source, which is inexpensive.

In addition, when used for a backlight light source for a liquid crystal display unit provided on a control panel, in general, it is generally very easy to determine, simply by looking at the control panel, which is located at a noticeable position, whether the device is the normal mode, the power saving mode or the power source off mode.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1is a perspective view showing the overall structure of a copier, as an image forming device in one embodiment of the present invention, andFIG. 2is a plan view of a control panel in the same copier.

In this embodiment, a copier1comprises a main body housing2, this main body housing2having a lower housing2a, an upper housing2b, and a connecting housing2cthat interconnects both parts2aand2b. Then, a paper tray, a transport mechanism, a transfer mechanism unit, a fixing mechanism unit and the like, which are not shown, are provided in the lower housing2aand the connecting housing2c. In addition, a reading mechanism, which is not shown, for reading a document, and a document feeding device3for automatically transporting documents are provided in the upper housing2b, and a control panel4is further provided on the front side. In addition, note that T is a sheet receiving tray to which sheets are output after copying.

A switch5and a button6for various setting operations, a liquid crystal display unit7consisting of an LCD for verifying operations and the like, are located on the control panel4. Then, two types of LEDs8aand8bare provided on the liquid crystal display unit7as a backlight light source therefor, having display colors that differ from one another.

That is to say, the LED8a, on one hand, is to be used for normal mode display and, for instance, one having a drive voltage of 5V and emitting white light, is used (hereinafter, this LED8awill be referred to as the normal mode LED). The LED8b, on the other hand, is to be used for power saving mode display and, for instance, one with a drive voltage of 3.3V and emitting green light, is used (hereinafter, this LED8bwill be referred to as the power saving mode LED). Thus, the normal mode LED8aand the power saving mode LED8bhave different display colors; furthermore, the power saving mode LED8bconsumes less power when lit than the normal mode LED8a.

Note that LEDs8aand8bare used as light sources; however, not only LEDs, but also other light sources, such as incandescent lamps, can also be used, so long as the one used for normal mode display and the one used for power saving mode display have different display colors and power consumption is also different for each mode.

FIG. 3is a block diagram showing the operating mode switching control system of this copier.

In this embodiment, an operating mode switching control system comprises an operating mode monitoring circuit11for monitoring whether the current device status is the normal mode or the power saving mode, an operating mode control circuit12for, based on the monitoring result of this operating mode monitoring circuit11, switching to the operating state in which the image copy processes are possible when the normal mode is assessed, and switching to the operating state that reduces power consumption, such as by lowering the temperature of the fixing roller, which is not shown, if the power saving mode is assessed, and a mode notification means13for external notification of whether the current device state is the normal mode or the power saving mode.

The operating mode monitoring circuit11comprises an internal timer or the like, not shown, and sends a trigger signal to the operating mode control circuit12to switch to the power saving mode if a non-processing period continues for more than a predetermined amount of time in normal mode.

In addition, the mode notification means13consists of the two LEDs8aand8b, and an illumination drive means14for switching between and driving each LED8aand8bin the normal mode and the power saving mode. Then, the illumination drive means14comprises a power supply source15afor the normal mode LED for lighting the normal mode LED8a, a power supply source15bfor the power saving mode LED for lighting the power saving mode LED8b, and an LED drive power supply source switching circuit16for selectively switching between the power supply sources15aand15baccording to the selection of either the normal mode or the power saving mode by the operating mode control circuit12.

Next, the control operations of the operating mode switching control system shown inFIG. 3will be explained with reference to the flowchart shown inFIG. 4. Note that, in this figure, the symbol S represents steps.

First, if a power switch, which is not shown, is turned on and the power supply is started, the operating mode monitoring circuit11assesses the normal mode, and as the operating mode control circuit12is given this assessment result, the operating mode control circuit12operates the LED drive power supply source switching circuit16so as to disconnect the power supply source15bfor the power saving mode LED and selects the power supply source15afor the normal mode LED (step1).

With this operation, power is supplied from the power supply source15afor the normal mode LED to the normal mode LED8a, so as to light the LED8awhich emits white light (step2). Therefore, suitable brightness for a backlight light source in the liquid crystal display unit7of the control panel4can be maintained. Simultaneously, the operating mode control circuit12switches to the normal mode, which is an operating state in which image copy processing is possible, for instance, by raising the temperature of the fixing roller and maintaining a temperature at which copying is possible (step3).

In this normal mode, if the non-processing period continues for more than a predetermined amount of time in normal mode, the operating mode monitoring device11sends a trigger signal to the operating mode control circuit12to switch to the power saving mode (step4).

In response to the trigger signal input from the operating mode monitoring device11, the operating mode control circuit12operates the LED drive power supply source switching circuit16so as to disconnect the power supply source15afor the normal mode LED and selects the power supply source15bfor the power saving mode LED (step5). This causes power saving mode LED power to be supplied from the power supply source15bto the power saving mode LED8b, so as to light the LED8bwhich emits green light (step6). Therefore, while the green power saving mode LED8bis lit, the current device status can be recognized as the power saving mode and not the power source off mode. Moreover, in this case, as the power consumption required to drive the power saving mode LED8bis less than that for the normal mode LED8a, this lighting mode is suited to the situation where the power saving mode is in use. Simultaneously, in response to the trigger signal input from the operating mode monitoring device11, the operating mode control circuit12switches to the power saving mode, which is an operating state in which the power consumption is kept low, for instance, by lowering the temperature of the fixing roller and the like (step7).

In this power saving mode, if a switch5or the like on the control panel4is operated, the operating mode monitoring device11sends a trigger signal to the operating mode control circuit12to return from the power saving mode to the normal mode (step8). In response, the operating mode control circuit12returns to step1, once again lighting the normal mode LED8aas described above, while at the same time, returning the operating state of the device to the normal mode.

Thus, in this embodiment, the normal mode in which image forming processes are possible and the power saving mode in which the power consumption is reduced can be clearly distinguished by an observer based on the difference in the color of light emitted by the two types of LEDs8aand8b. In addition, the difference between the power saving mode and the power source off mode can also be clearly distinguished based on whether or not the power saving mode LED8bis lit. Therefore, usability can be improved by eliminating confusion which was conventional, such as a user being misled into thinking that the power switch is off, and turning the power switch on and off again, when in reality the device was merely switched to power saving mode. Furthermore, as reduced power consumption suffices to drive the power saving mode LED8bas compared to the normal mode LED8a, the embodiment is also suited to the situation in which the power saving mode is in use.

Note that, in this embodiment, although two types of LEDs8aand8bwith different display colors are used to switch the illumination color between the normal mode and the power saving mode, the present invention is not limited to this and, for instance, a constitution such as shown inFIG. 5can also be adopted.

That is to say, inFIG. 5, the mode notification means13comprises a single LED8and an LED drive circuit17serving as the illumination drive means for switching the display mode of this LED8according to the normal mode and the power saving mode. Then, the LED drive circuit17performs control so that the LED8is continuously illuminated in the normal mode, while the LED8repeatedly flashes at a predetermined interval in the power saving mode.

Thus, in this case as well, an observer can easily distinguish between the normal mode, the power saving mode and the power source off mode, based on the difference in the lighting mode of the LED8, so that usability is improved compared to the conventional situation. Note that, in this case as well, the light source is not limited to the LED8, and other light sources such as incandescent lamps can also be used.

In addition, in this embodiment, although descriptions were given for cases where the light sources8a,8band8were used as backlights for the liquid crystal display unit7provided on the control panel4, the present invention is not limited to usage of the light sources as backlights and, for instance, a dedicated light source for mode identification can also be provided on the control panel4.

In addition, in this embodiment, although descriptions were given using the copier1as an image forming device, the present invention is not limited to such a copier and can be applied broadly to printers, facsimile devices, multi-function machines, other image forming devices or the like.