CN107042690A

CN107042690A - Drive dynamic control device, droplet drying device and the image processing system of light-emitting component

Info

Publication number: CN107042690A
Application number: CN201710020589.5A
Authority: CN
Inventors: 藤本贵士; 池田周穗; 矶崎准; 坂本朗
Original assignee: Fuji Xerox Co Ltd
Current assignee: Fujifilm Business Innovation Corp
Priority date: 2016-02-05
Filing date: 2017-01-12
Publication date: 2017-08-15
Anticipated expiration: 2037-01-12
Also published as: CN107042690B

Abstract

Drive dynamic control device, droplet drying device and image processing system there is provided semiconductor light-emitting elements.The drive dynamic control device includes：Multiple current generating units, it respectively supplies driving current to multiple semiconductor light-emitting elements groups, include the acceptance division for receiving switching signal respectively, and driving current is controlled according to switching signal, each in multiple semiconductor light-emitting elements groups includes at least one semiconductor light-emitting elements；Switching signal generation unit, it generates multiple switch signal according to the desired value of driving current, and multiple switch signal is respectively fed into multiple acceptance divisions；And voltage source, it has series relationship with current generating unit and semiconductor light-emitting elements group.

Description

Drive dynamic control device, droplet drying device and the image processing system of light-emitting component

Technical field

The present invention relates to the drive dynamic control device of semiconductor light-emitting elements, droplet drying device and image processing system.

Background technology

Patent document 1 (No. 4461576 Japan Patent) discloses a kind of LED light source device, the LED light source device bag Include：LED load, it includes the two or more LED strips connection circuit being connected in parallel or two be connected in parallel or two LED inverse parallel circuits above, wherein, each LED strip connection circuit is respectively provided with the multiple LED being connected in series, each LED inverse parallels Circuit is respectively provided with multiple LED of inverse parallel connection；Power subsystem, its supply electric power is so as to light LED load；Circuit elements Part, it is connected to each LED strip connection circuit or each LED inverse parallels circuit；Comparing unit, it detects each circuit element Load voltage and detect the minimum voltage in the load voltage of each circuit element；And control unit, it controls power supply list First minimum voltage with the load voltage for the circuit element for causing comparing unit to detect joins circuit less than LED strip or LED is anti- The forward voltage of the LED array of parallel circuit.

The content of the invention

The purpose of the exemplary embodiment of the present invention is the provision of the drive control dress of such semiconductor light-emitting elements Put, droplet drying device and image processing system：With the feelings for the current source that driving is provided for for each semiconductor light-emitting elements Condition is compared, and which reduces circuit size, further increases electrical efficiency, and also can more stably supply even if load change To driving current.

[1] an aspect of of the present present invention provides a kind of drive dynamic control device of semiconductor light-emitting elements, including：

Multiple current generating units, driving current is supplied to multiple semiconductor light-emitting elements groups, included respectively by it respectively The acceptance division of switching signal is received, and driving current is controlled according to switching signal, it is every in multiple semiconductor light-emitting elements groups One includes at least one semiconductor light-emitting elements；

Switching signal generation unit, it generates multiple switch signal according to the desired value of driving current, and will be multiple Switching signal is respectively fed to multiple acceptance divisions；And

Voltage source, it has series relationship with current generating unit and semiconductor light-emitting elements group.

[2] drive dynamic control device according to [1] can have following configuration：

Each switching signal is binary digital signal, and

Switching signal generation unit is by extinguishing light according to semiconductor light-emitting elements group and being used for semiconductor when sending light The desired value of the driving current of light emitting device group and change at least one in the pulse width and pulse period of data signal, come Generate each switching signal.

[3] drive dynamic control device according to [2] can also include：

Switch time computing unit, it calculates at least one in pulse width and pulse period according to desired value.

[4] drive dynamic control device according to [3] can also include：

Unit is corrected, it utilizes semiconductor light-emitting elements group, voltage source, current generating unit and switching signal generation unit In the characteristic of at least one come correction pulse width and at least one in the pulse period, these characteristics are to calculate switch time Unit is calculated needed for pulse width and at least one in the pulse period.

[5] drive dynamic control device according to [4] can also include：

Monitoring unit, it monitors the photoelectric characteristic of multiple semiconductor light-emitting elements groups,

Wherein, correction unit according to the monitoring result of monitoring unit come correction pulse width and in the pulse period at least one It is individual.

[6] drive dynamic control device described in any one of basis [1] into [5] can have following configuration：

Each in multiple semiconductor light-emitting elements groups includes the multiple semiconductor light-emitting elements being connected in series, and

For each in multiple semiconductor light-emitting elements groups, current generating unit includes：Switch element, it, which has, connects Control terminal in receipts portion；Inductor, its be connected to the lead-out terminal of switch element and with multiple semiconductor light-emitting elements groups One have parallel relationship；And capacitor, it is connected in parallel with one in multiple semiconductor light-emitting elements groups.

[7] drive dynamic control device according to any one of [1] to [5] can have following configuration：

For each in multiple semiconductor light-emitting elements groups, current generating unit includes：Switch element, it, which has, connects Control terminal in receipts portion；Inductor, it is connected between one in switch element and multiple semiconductor light-emitting elements groups, and And have from switch element to the equivalent inductance component of the wire of one in multiple semiconductor light-emitting elements groups；And two pole Pipe, it is connected in parallel with one in multiple semiconductor light-emitting elements groups.

[8] drive dynamic control device according to [6] or [7] can also include at least one of the following：

Current detecting unit, it is connected between the cathode side of each in multiple semiconductor light-emitting elements groups and ground, And the electric current of one in the excessively multiple semiconductor light-emitting elements groups of detection stream；And voltage detection unit, it is connected to multiple Between the anode-side of one and ground in semiconductor light-emitting elements group, and detect one in multiple semiconductor light-emitting elements groups Two terminals between voltage.

[9] drive dynamic control device according to any one of [6] to [8] can also include：Unit is clamped down on, it is clamped down on out Close the voltage of the lead-out terminal of element.

[10] drive dynamic control device according to [9] can have following configuration：

Clamping down on unit includes the detection unit that the electric current for clamping down on unit is flowed through in detection, and the electricity detected in detection unit In the case that stream is more than set-point, the operation of multiple current generating units is stopped.

[11] drive dynamic control device according to any one of [6] to [10] can also include：

Input electric cur- rent measure unit, it detects the electric current for the input terminal for flowing through switch element,

Wherein, in the case where the electric current that input electric cur- rent measure unit is detected is more than set-point, multiple electric current generations are single The operation of member is stopped.

[12] drive dynamic control device according to any one of [1] to [11] can have following configuration：

Switching signal generation unit make it that the respective timing of multiple switch signal is different from each other, and will have different timing Multiple switch signal provide respectively to acceptance division.

[13] drive dynamic control device according to any one of [1] to [12] can have following configuration：

Semiconductor light-emitting elements are semiconductor lasers, and

Switching signal generation unit generates switching signal, to cause driving current to change in semiconductor laser from OFF state It is changed into flowing before the timing of luminance, so that driving current is in the timing nonoscillatory or does not postpone, the wherein driving current It is defined as being less than during the period is limited the electric current of the threshold current of semiconductor laser.

[14] drive dynamic control device according to any one of [1] to [13] can have following configuration：

Semiconductor light-emitting elements are light emitting diodes.

[15] another aspect provides a kind of droplet drying device, it includes：

Multiple semiconductor light-emitting elements；And

Drive dynamic control device according to any one of [1] to [14].

[16] it is yet another aspect of the present invention to provide a kind of image processing system, it includes：

Image formation unit, it sprays drop according to image information and formed on the recording medium according to image information Image；And

Droplet drying device according to [15], wherein, droplet drying device makes image formation unit be ejected into record Droplet drying on medium.

Using the configuration of [1], [15] and [16], the drive control there is provided such semiconductor light-emitting elements is resulted in The effect of device, droplet drying device and image processing system：Electricity with being provided for from driving to each semiconductor light-emitting elements The situation in stream source is compared, and drive dynamic control device, droplet drying device and the image processing system of the semiconductor light-emitting elements reduce Circuit size, further increases electrical efficiency, and also can more stably supply driving current even if load change.

Using the configuration of [2], following effect is resulted in：Compared with switching signal is the configuration of analog signal, due to right The control of driving current can be performed by data signal, therefore the control is easier.

Using the configuration of [3], following effect is resulted in：Compared with the constant-current source using negative feedback control, do not produce Due to circuit load caused by overshoot etc. as caused by negative feedback control." overshoot " generally refers to signal level (voltage, electricity Stream) rise to the level higher more temporarily than the signal level limited.In contrast, signal level is down to the signal electricity than limiting temporarily Put down lower level and be referred to as undershoot.

Using the configuration of [4], following effect is resulted in：With ignore individual difference in the state of correction pulse width and The situation in cycle is compared, and more correctly determines the initial value of driving current.

Using the configuration of [5], following effect is resulted in：Situation with carrying out correction pulse width by using initial characteristic Compare, reflect the change of time response.

Using the configuration of [6], following effect is resulted in：With configuring electric current generation in the case of without using switch element The situation of unit is compared, and realizes high efficiency.

Using the configuration of [7], compared with the situation that current generating unit includes inductance element, it can be given birth to by using electric current Carry out the operation of phase shift to significantly decrease noise into unit.

Using the configuration of [8], following effect is resulted in：With not including light-emitting component current detecting unit and luminous member The situation of part voltage detection unit is compared, and the time of the characteristic of semiconductor light-emitting elements changes the control being reflected as to driving current System.

Using the configuration of [9], following effect is resulted in：Compared with without including clamping down on the situation of unit, or even half , also can protection circuit in the case of the short circuit of conductor light-emitting component.

Using the configuration of [10], following effect is resulted in：Compared with not including the situation of detection unit, or even half , also can more reliably protection circuit in the case of the short circuit of conductor light-emitting component.

Using the configuration of [11], following effect is resulted in：Compared with not including the situation of input electric cur- rent measure unit, , also can protection circuit even in the case of inductor short circuit.

Using the configuration of [12], following effect is resulted in：It is supplied to each switching signal in same timing many The situation of each in individual acceptance division is compared, and reduces potential change, the potential change or electromagnetic noise on ground of voltage source.

Using the configuration of [13], following effect is resulted in：It is directly disposed as exceeding semiconductor laser with driving current The situation of the value of the threshold current of device is compared, and reduces the ring or delay of the waveform of the driving current of semiconductor laser.

Using the configuration of [14], following effect is resulted in：It is used as the feelings of semiconductor light-emitting elements with semiconductor laser Condition is compared, and reduces cost.

Brief description of the drawings

The exemplary embodiment of the present invention will be described in detail based on accompanying drawing, in the accompanying drawings：

Fig. 1 is schematically matching somebody with somebody for the example for the main dispensing unit for showing the ink-jet recording apparatus according to exemplary embodiment Put figure；

Fig. 2 is the plan of the example for the photoirradiated surface for showing the droplet drying device according to exemplary embodiment；

Fig. 3 is showing for the configuration for the drive dynamic control device for showing the semiconductor light-emitting elements according to the first exemplary embodiment The block diagram of example；

Fig. 4 is to show the counter in the drive dynamic control device according to the semiconductor light-emitting elements of the first exemplary embodiment Output timing diagram；

Fig. 5 is to show the switch electricity in the drive dynamic control device according to the semiconductor light-emitting elements of the first exemplary embodiment The circuit diagram of the example in source；

Fig. 6 is to show the switch electricity in the drive dynamic control device according to the semiconductor light-emitting elements of the second exemplary embodiment The circuit diagram of the example in source；

Fig. 7 is showing for the configuration for the drive dynamic control device for showing the semiconductor light-emitting elements according to the 4th exemplary embodiment The block diagram of example；

Fig. 8 is to show the counter in the drive dynamic control device according to the semiconductor light-emitting elements of the 4th exemplary embodiment Output timing diagram；

Fig. 9 is shown in the semiconductor light-emitting elements drive dynamic control device according to the modified example of the 4th exemplary embodiment Switching Power Supply example circuit diagram；

Figure 10 is the configuration for the drive dynamic control device for showing the semiconductor light-emitting elements according to the 5th exemplary embodiment The block diagram of example；And

Figure 11 is the circuit diagram of the configuration for the drive dynamic control device for showing the semiconductor light-emitting elements according to comparative example.

Embodiment

Hereinafter, the exemplary embodiment of the present invention is described with reference to the accompanying drawings.In the exemplary embodiment, will be in ink-jet side It is described as example in the form of the image processing system of the exemplary embodiment according to the present invention in the tape deck of method.

(the first exemplary embodiment)

Referring to figs. 1 to Fig. 5 (" half will hereinafter, be sometimes referred to as to describe the drive dynamic control device of semiconductor light-emitting elements Conductor light-emitting component drive dynamic control device "), ink-jet countermeasure set and image processing system.

First, the ink-jet recording apparatus 12 according to the present exemplary embodiment is described into reference picture 1.Fig. 1 is shown according to this The schematic configuration diagram of the example of the main dispensing unit of the ink-jet recording apparatus 12 of exemplary embodiment.

Ink-jet recording apparatus 12 include such as two groups image formation units 20A and 20B, control unit 22, memory cell 30, Feeding-in roll 80, distributing roller 90 and conveying roller 99.

In addition, image formation unit 20A includes such as head drive unit 40A, printhead 50A and droplet drying device 70A.

In an identical manner, image formation unit 20B includes such as head drive unit 40B, printhead 50B and droplet drying Device 70B.

Hereinafter, the common component in it need not be included within image formation unit 20A and image formation unit 20B with In the case of image formation unit 20A and image formation unit 20B differentiations, symbol " A " and symbol at ellipsis end “B”.Symbol " A " and symbol " B " are represented with the component similarly configured, but are enclosed to distinguish it in ink-jet recording apparatus 12 Position.

Control unit 22 is by driving such as paper sheet delivery motor (not shown) to control the mechanism coupling via such as gear It is bonded to the rotation of the conveying roller 99 of paper sheet delivery motor.Elongated paper (continuous form) P is used as note in sheet transport direction Recording medium is on roller for conveying paper sheets 80, and according to the rotation of conveying roller 99 come in the sheet transport direction shown in Fig. 1 Convey paper P.Hereinafter, it can be referred to as " continuous form machine " using the image processing system of continuous form.

Control unit 22 obtains the image information being stored in memory cell 30, and is based on being included in for each pixel Image information in the colouring information of image control image formation unit 20A.Therefore, image shape corresponding with image information Into on the image forming surface of the side in paper P.

Specifically, the control head drive unit of control unit 22 40A.In addition, fixed in the ink droplet injection that control unit 22 is indicated When, head drive unit 40A is by driving the printhead 50A coupled to head drive unit 40A to cause ink droplet to be sprayed from printhead 50A Go out.Therefore, formed corresponding to the image of image information on the image forming surface of paper P side.

In addition, the image information of image of the control unit 22 by using formation in ink-jet recording apparatus 12 is outer to generate Portion's controlling value, it is for controlling the luminous of droplet drying device 70A and 70B explained below semiconductor light-emitting elements Signal.

Being included in the colouring information of the image in the image information for each pixel includes uniquely showing the face of pixel The information of color.In the present example embodiment, as an example, according in yellow (Y), magenta (M), cyan (C) and black (K) The concentration of each show the information of the image for each pixel, but the uniquely color of displaying image can be used Other method for expressing.

Printhead 50A includes four printheads corresponding with Y colors, M colors, C colors and these four colors of K colors respectively 50AY, 50AM, 50AC and 50AK, and from printhead 50A spray as corresponding color drop ink droplet.For in printhead The driving method that ink droplet is sprayed in 50A is not particularly limited, but the known formula of such as so-called hot method of application or piezoelectric approach Method.

Droplet drying device 70A is configured as including semiconductor light-emitting elements drive dynamic control device 60A and semiconductor light emitting Element arrays 76A.Semiconductor light-emitting element array 76A includes multiple semiconductor light-emitting elements 72, and generates as making The irradiation light of the thermal source of the image dried formed on paper P.Semiconductor light-emitting elements drive dynamic control device 60A is based on come automatic control The instruction of unit 22 processed passes through the hair for each semiconductor light-emitting elements for being switched on or off constituting semiconductor light-emitting element array 76A Light, to control droplet drying device 70A luminous quantity.Semiconductor light-emitting elements as the thermal source according to the present exemplary embodiment It is not specifically limited to use such as semiconductor laser or light emitting diode (LED), but in the present example embodiment using partly leading Body laser.It is not specifically limited to use edge emitting type semiconductor laser according to the semiconductor laser of the present exemplary embodiment Device, Vcsel (VCSEL) etc..In addition, in the case where having used semiconductor laser, selecting wavelength band To effectively absorb ink droplet.

In addition, control unit 22 controls semiconductor light-emitting elements drive dynamic control device 60A, so as to get profit with dry from ink droplet Dry device 70A irradiation light irradiates the image forming surface of paper P side, so that the heating (application heat) for passing through irradiation light Dry the ink droplet for the image to be formed on paper P, and the image is fixed on paper P.In addition, control unit 22 is based on Image information and control laser irradiation be switched on or off with maintain such as semiconductor light-emitting elements driving current.Pass through The amount of driving current is controlled, the light output of semiconductor light-emitting elements can be adjusted.

Set based on the angle of radiation of semiconductor light-emitting elements 72 and the width of radiation areas droplet drying device 70A with The distance between paper P (reference picture 2).

Hereafter, paper P is transported to towards image formation unit 20B position according to the rotation of conveying roller 99.Now, Conveying paper P with cause from different other image forming surfaces of image forming surface of image formation unit 20A formation images towards Image formation unit 20B.

Control unit 22 to control image formation unit 20B with above-mentioned image formation unit 20A identical modes, because And, image formation corresponding with image information is on paper P other image forming surfaces.In this manner, ink-jet recording apparatus 12 Including two groups of image formation unit 20A and image formation unit 20B with the duplex printing corresponding to paper P.Certainly, do not needing In the case of duplex printing, ink-jet recording apparatus 12 can have only offer image formation unit 20A to be formed without image Unit 20B form.

In addition, paper P is transported to distributing roller 90 according to the rotation of conveying roller 99, and on distributing roller 90.

In addition, ink is not particularly limited including water-based ink, oil-based ink of solvent evaporation etc., but the present exemplary embodiment, and And any type of ink can be used.

Next, reference picture 2 is described into the ink droplet drying device 70 according to the present exemplary embodiment.Fig. 2 is to show ink droplet The figure of the example of the photoirradiated surface of countermeasure set 70.The photoirradiated surface of droplet drying device 70 represents the image shape towards paper P Into the surface in face.

As shown in Fig. 2 multiple semiconductor light-emitting elements 72 in sheet transport direction and with sheet transport direction just It is arranged on the paper width direction for handing over (intersection) with grid pattern on the photoirradiated surface of droplet drying device 70, and hot coupling Close.The quantity and setting shape for the semiconductor light-emitting elements 72 being arranged on the photoirradiated surface of the droplet drying device 70 shown in Fig. 2 Shape is only example, and present exemplary embodiment not limited to this.

In addition, in the present example embodiment, will be by semiconductor light-emitting elements drive dynamic control device 60A and 60B (reference picture 1, hereinafter, semiconductor light-emitting elements drive dynamic control device 60A and 60B are collectively referred to as " semiconductor light-emitting elements drive control dress Put 60 ") units of light of control sets and is arranged in partly leading on paper width direction to plurality of semiconductor light-emitting elements 72 Body light-emitting component block (semiconductor light-emitting elements group) 74.Certainly, present exemplary embodiment not limited to this, and unit can be passed through Semiconductor light-emitting elements 72 control light quantity.In addition, the cloth of multiple semiconductor light-emitting elements 72 in semiconductor light-emitting elements block 74 Put direction and be not limited to paper width direction, and can be sheet transport direction.Semiconductor light-emitting elements 72 can be arranged in paper Open on width and the two directions of sheet transport direction.

In order to ensure required total light yield is dried, semiconductor light-emitting element array 76 can have following configuration： Multiple semiconductor light-emitting elements blocks 74 are arranged in sheet transport direction, and each semiconductor light-emitting elements block 74, which is respectively provided with, to be arranged in Semiconductor light-emitting elements 72 on paper width direction, as shown in Figure 2.Fig. 2 shows that a semiconductor light-emitting elements block 74 covers The form of whole region on lid paper width direction, but present exemplary embodiment not limited to this, and multiple semiconductor light emittings Member block 74 can cover the whole region on paper width direction in the state of arranged in series.Due to according to based on image letter The black coated weight of breath controls the luminous quantity of semiconductor light-emitting elements 72 or multiple semiconductor light-emitting elements blocks 74, therefore can hold Row is effective to be dried and prevents consumed energy.

Launch light, the heat that droplet drying device 70 is produced using irradiation light with formation image and towards the paper P of conveying (application heat) is measured to make black drying.Now, for example, control unit 22 is based on the image information when image is formed, according to spray Ink amount calculates the luminous quantity of semiconductor light-emitting elements block 74, the driving current of setting semiconductor light-emitting elements block 74 (setting with The lower current value Iset by description), and control semiconductor light-emitting elements drive dynamic control device 60 to cause set driving Electric current flows substantially.Therefore, drying process is performed according to for the appropriate heat of ink ejection amount.

Here, the use of the main purpose of the continuous form machine of above-mentioned ink jet-print head (printhead 50) is that reduction energy disappears Consumption, and have studied the side that interfering energy is only applied intermittently using droplet drying device around print area when needed Method.Hereinafter, the situation that drying energy is applied intermittently according to the instruction of control unit 22, using droplet drying device is claimed For " irradiating on demand ".

In the case where semiconductor laser is used to make black drying, semiconductor laser is arranged on paper width direction, And need using the power based on ink ejection amount, each semiconductor laser controlled according to ink-jet region, to cause laser Supply is especially with the drying energy needed for each unit area rapidly the continuous form machine of paper feeding.For example, partly leading Body laser by arranged for interval of 1.25mm on paper width direction in the case of, it is necessary to be distinguished with 500mm paper width Ground drives 400 semiconductor lasers.

Meanwhile, semiconductor laser is generally driven by the high electric current of the correlation (linear relationship) with light output.Thus, grind Following method is studied carefully：In the case of for making the semiconductor laser that ink is dried, current source is connected to each half The series circuit of the predetermined quantity of conductor laser, only semiconductor laser is connected in parallel with each other with current source and is further connected To current source, and under conditions of scheduled current, in the indicated timing independently each semiconductor laser of control on demand. According to this method, even if in the presence of 400 semiconductor lasers, semiconductor laser is divided in groups and each group is connected to one Individual voltage source.Therefore, the electric current of each semiconductor laser is flowed through in adjustment, so that the quantity of voltage source needed for reducing.Electric current Source-representation causes the circuit that specified constant current flows.

Figure 11 is the example of above-mentioned semiconductor light-emitting elements drive dynamic control device, and shows according to comparative example Semiconductor light-emitting elements drive dynamic control device 910.As shown in figure 11, semiconductor light-emitting elements drive dynamic control device 910 includes half Conductor light-emitting device array, wherein n semiconductor light-emitting elements block 900-1 to 900-n (is being referred to as, is being referred to as " semiconductor hair Optical element block 900 " and hereinafter with the case of identical in other configurations) be connected in parallel with each other, each semiconductor light emitting element Part block is respectively provided with the multiple semiconductor light-emitting elements 902 being connected in series.In addition, semiconductor light-emitting elements block 900-1 is to 900-n's Cathode side is connected to respectively is grounded the current source 906-1 of (being connected to the ground (GND)) extremely by resistor 904-1 to 904-n 906-n.In addition, semiconductor light-emitting elements block 900-1 to 900-n anode-side is commonly connected to export variable power subsystem 908 (voltage sources).

In addition, semiconductor light-emitting elements drive dynamic control device 910 has two ends of measurement semiconductor light-emitting elements block 900 Voltage Vi between two terminals of voltage Vd and resistor 904 between son (that is, flows through semiconductor light-emitting elements block 900 Electric current I1 to In) function.Voltage Vd and voltage Vi are transferred into the control list of semiconductor light-emitting elements drive dynamic control device 910 First (not shown).

Measured value of the control unit of semiconductor light-emitting elements drive dynamic control device 910 based on voltage Vd, use control letter Number Sv controls power subsystem 908, so as to control to semiconductor light-emitting elements block 900, be connected to semiconductor light-emitting elements The voltage that the current source 906 of block applies with the resistor 904 for being connected to semiconductor light-emitting elements block.In addition, control unit Measured value based on voltage Vi, using control signal Si come control electric current source 906, to flow through semiconductor light-emitting elements block 900 driving current I1 to In has predetermined value.That is, semiconductor light-emitting elements control device 910 is controlled using feedback (negative-feedback) Make to control semiconductor light-emitting elements block 900 substantially.

However, from the hot of the generation of current source 906 and the viewpoint effectively reduced, existing for semiconductor light-emitting elements driving The improved space of control device 910.That is, because multiple semiconductor light-emitting elements blocks 900 are connected to same power subsystem 908, Therefore by the driving current of the semiconductor light-emitting elements block 900 set according to dry ink amount in semiconductor light-emitting elements block Different from each other between 900, the characteristic of semiconductor light-emitting elements block 900 is even different from each other under identical setting electric current, or If at least one short circuit in the semiconductor light-emitting elements 902 for constituting semiconductor light-emitting elements block 900 and being connected in series, Voltage Vd between two terminals of semiconductor light-emitting elements block 900 is even also changed into respective difference under identical driving current Value.

Meanwhile, the voltage of power subsystem 908 is provided so that current source 906 even in partly leading with ceiling voltage Vd Also according to setting electric current output current in body light-emitting component block 900.Therefore, being connected to the semiconductor of same power subsystem 908 In the semiconductor light-emitting elements block 900 with low-voltage Vd among light-emitting component block 900, semiconductor light emitting element is connected to The burden differential voltage of current source 906 of part block, to cause setting electric current to flow, and the load causes current source 906 to generate heat.

According to condition, in the current source 906 of a semiconductor light-emitting elements block 900 is connected to, produced in current source 906 Raw heat is about 10W.In this case, it is necessary to area of dissipation big radiator or magnetism servo-electric motor water-cooling, and pole is not only existed Big installation limitation, and efficiency reduces, and reduced by only drying a part that ink is present energy expenditure on demand according to The effect penetrated can greatly weaken.

It is used as a kind of method solved the above problems, it is also considered that power subsystem 908 is connected to each semiconductor light emitting element Part block 900.In this case, power subsystem 908 needs to arrange by the quantity of semiconductor light-emitting elements block 900.In addition, Respectively multiple power subsystems 908 are needed to provide current source and voltage source.In this case, control circuit is respectively included in In each in power subsystem 908 in included current source and voltage source, in addition, in addition it is also necessary to control unit according to printing come Control all power subsystems 908.Therefore, circuit size and cost increase, and installation question generation.

In addition, as another room for improvement, there is the power subsystem for being connected in parallel to multiple semiconductor light-emitting elements blocks 900 The problem of 908 response is reduced.Multiple semiconductor light-emitting elements blocks 900 to being arranged on paper width direction carry out by In the case of need to controlling so that ink is dried, if sprayed over its entire surface for example, changing into have without black white space Penetrate ink region, then the light output of semiconductor light-emitting elements block 900 from zero or close to zero output change into maximum output or Close to the output of maximum output.Therefore, the load current of power subsystem 908 also changes into maximum electricity from zero or close to zero electric current Stream or close to the electric current of maximum current.

Power subsystem 908 load current from be approximately zero increase to be approximately maximum current when, power subsystem 908 makes With feedback control come regulated output voltage, i.e. the electric current of current source 906 increases also by increase or reduction according to voltage Vd Or reduce the output of power subsystem 908, to reach desired value.However, now, ring, rising delay, overshoot etc. are produced, thus, The burden increase of current source 906.In contrast, it may occur however that due to the reduction of the voltage between two terminals of current source 906 And the problem of constant current can not be maintained.

If voltage is somewhat excessive, the voltage that only current source 906 is handled temporarily increases, thus, partly led in the absence of driving The problem of body light-emitting component block 900.However, if voltage is excessively not enough, current source 906 can not maintain electric current, and example Such as, in the head in paper P ink-jet region, the light output of semiconductor light-emitting elements block 900 does not increase to predetermined value and done Dry ability can be not enough.

In order to solve the above problems, the decoupling capacitance of output by increasing power subsystem 908 has been used come stable and transient The method of characteristic.However, if decoupling capacitance increases, phase margin reduces, and in contrast, control can be due to negative-feedback Control and it is unstable.As long as in this manner, controlling power subsystem 908 by using negative feedback control, it is difficult to avoid excessive Voltage changes.

As described above, from the viewpoint for the loss for needing to reduce current source 906, there is improvement semiconductor light-emitting elements driving control The space of device 910 processed, can control the driving current of each semiconductor light-emitting elements block 900 (semiconductor light-emitting elements 902), And even if load current changes, scheduled current also flows through each semiconductor light-emitting elements block 900.

Therefore, the present invention is using following configuration：Only power supply unit is arranged on each half in the case of no control unit In conductor light-emitting component block, control unit is concentrated on a unit, and multiple power supplys with high-density arrangement, it is independent in addition Control.Now, power supply is made up of switching regulator (switching regulator), thus, hereinafter, power supply is referred to as " Switching Power Supply ".The switching regulator can be used only the switching signal of switching transistor to control a power supply, carry out automatic control All control signals of unit processed are arranged in Switching Power Supply, and control unit is concentrated on a unit or some units On, thus simplify control unit.

That is, due to controlling to be concentrated in the case of no control unit and only power supply unit is arranged on each semiconductor In light-emitting component block, therefore Switching Power Supply is arranged by the quantity of semiconductor light-emitting elements block.Therefore, even if semiconductor light emitting element The terminal voltage of part block is different from each other, and each semiconductor light-emitting elements block is driven at optimum conditions, thus can reduce power supply Burden.In addition, the control unit of Switching Power Supply is not only provided in each Switching Power Supply, and is intensively set, thus letter Change control, and power supply is arranged in each semiconductor light-emitting elements block.

In addition, in the present invention, instead of the independent negative feedback control in each power circuit, in addition to control unit The part of inductor, switching transistor etc. is arranged in each Switching Power Supply.With the semiconductor light-emitting elements as target The corresponding switching signal of driving current by control unit use control parameter (the setting inductance of the inductor of such as Switching Power Supply Value, the maximum of transistor, photoelectric characteristic of semiconductor light-emitting elements etc.) concentrate generation, and it is supplied to each switch The switching transistor of power supply.

The control signal of Switching Power Supply is generated based on the target drive current and control parameter of semiconductor light-emitting elements block. In addition, passing through the characteristic that will can be concentrated before the generation such as the change of part, change of semiconductor light-emitting elements when safeguarding Actual measured value be reflected into correction unit, to maintain precise control.

In addition, by by over time change (such as, the characteristic of semiconductor light-emitting elements, used part it is bad Change, failure etc.) it is reflected into correction unit, for example it is connected to the resistors of semiconductor light-emitting elements by monitoring and correcting Terminal voltage, precise control is kept also for change over time, in addition, if it is desired, it is such as right to perform The processing of warning or the stopping of abnormal parameters.

In this manner, in the present invention, predefining load or used unit, thus performed by using control parameter Feedforward control.Due to not using negative feedback control, therefore inhibit excessive variation, and even in load current from minimum value In the case of increasing to maximum, the control is performed by using predetermined control parameter, thus excessive variation is reduced to minimum.

Next, reference picture 3 to Fig. 5 to be more fully described to the semiconductor light-emitting elements according to the present exemplary embodiment Drive dynamic control device 60.

Fig. 3 is the block diagram of the semiconductor light-emitting elements drive dynamic control device 60 according to the present exemplary embodiment.Such as Fig. 3 institutes Show, semiconductor light-emitting elements drive dynamic control device 60 is configured as including switching signal generation unit 100, n semiconductor light emitting Switching Power Supply 106-1 to 106-n that member block 74-1 is accordingly set to 74-n, with each semiconductor light-emitting elements block 74, Coefficient calculation unit 108 (correction unit), switch time computing unit 110, driving power supply 112 (voltage source) and control power supply 114。

Semiconductor light-emitting elements block 74 is multiple semiconductor light emitting elements by being serially connected on paper width direction The module that part (being in the present example embodiment semiconductor laser) 72 is constituted, and produce irradiation light to be formed as making The thermal energy source of image dried on paper P, description such as relevant with Fig. 2.

Switching Power Supply 106-1 to 106-n by from the switching signal Ss1 to Ssn that switching signal generation unit 100 is transmitted and It is switched on or cuts off, in addition, it exports the driving current with the amplitude based on switching signal Ss1 to Ssn to corresponding half Conductor light-emitting component block 74.Switching Power Supply 106 described in detail below.

Switching signal generation unit 100 is configured as including and each corresponding n displacement of semiconductor light-emitting elements block 74 Register (being referred to as in figure 3 " SR ") and n counter 104-1 to 104-n.

Shift register 102 is the buffer for the switch time signal St that interim storage represents switch time ts1 to tsn, Switch time is calculated by switch time computing unit 110 and is to turn on corresponding with each semiconductor light-emitting elements block 74 The time of each Switching power 106.Switch time signal St includes representing n switch time ts1 to tsn numerical data, and And with (by Fig. 3 " transmission CK " signs) transmitted from switch time computing unit 110 with series form together with transmission clock To shift register 102-1 to 102-n.In the present example embodiment, switch time ts1 to tsn is by correspondence counter 104-1 Form to 104-n counts is represented.

According to transmission clock come from shift register 102-1 to 102-n sequentially to being sent to shift register 102-1's Switch time, signal St was shifted, and was kept for time ts1 corresponding with shift register 102-1 to 102-n to tsn letter Breath.If signal is displaced into shift register 102- from shift register 102-1 according to the transmission clock of shift register 102 N, then complete setting and counter wait preset.

By doing so it is possible, each shift register 102 is set with the meter according to switch time ts (ts1 to tsn) The preset value of number device.I.e., in the present example embodiment, when the driving current of each semiconductor light-emitting elements block 74 is flowed through in setting Or each semiconductor light-emitting elements block 74 light quantity when, be shift register configuration switch time ts in advance, and when by making Performed with setting value during switch, semiconductor light-emitting elements block 74 is driven by predetermined drive currents or light quantity.

Counter 104-1 is to 104-n count pick up devices preset signal (being referred to as in figure 3 " preset ") and counter clock (be referred to as in figure 3 " counter CK "), and generate each of switching signal Ss1 into Ssn.Reset letter shown in Fig. 3 Number Reset forcibly reset count device 104.

Reference picture 3 is more fully described to switching signal Ss1 to Ssn generation.That is, self-corresponding shift register is carried out 102 counter preset value is loaded at the period of counter preset signal in counter 104.If counter preset value It is loaded into each counter 104, then the inside decrement value of setting counter corresponding with counter preset value, and according to Counting clock, internal decrement value is reduced to zero from initial value.Counter 104 exports low level signal when decrement value is zero, And the signal of high level is exported when decrement value is non-zero.That is, if counter preset value is loaded into counter 104, pass Depreciation is varied from zero value, and counter 104 exports the signal of high level, in switch time corresponding with counter preset value The signal of high level is maintained during ts, and counter 104 exported the signal of zero level in the past after switch time ts.Ginseng According to Fig. 4, counter 104 in the case where being loaded with counter preset value (time t1, t3 and t5 in Fig. 4) exports high level Signal, and keep high electric by counter preset value when being counted to inputting to the counter clock of counter 104 Flat signal.Then, decrement value vanishing, thus, counter 104 exports low level signal (time t2 and t4 in Fig. 4), And wait next counter preset value.That is, at the cycle of counter preset signal (preset), generation switching signal Ss1 is extremely Ssn as according to shift register 102 set value period connect signal, and using switching signal Ss1 to Ssn as Switching signal is supplied to the switch element T (reference picture 5) of Switching Power Supply 106.

In the present example embodiment, as shown in figure 3, switch time computing unit 110 is used from outside as outside control Value processed and the setting electric current value Iset that inputs are used as the polynomial function (switch time calculation expression) of variable to calculate out The pass time.Setting electric current value Iset is by image information (ink amount in each pixel of the control unit 22 based on the image formed Deng), paper sheet delivery speed etc. come the value of electric current that calculates drive each semiconductor light-emitting elements block 74.

By using the relevant parameter of characteristics inputted as control parameter and with semiconductor light-emitting elements (in figure 3 Referred to as " semiconductor light-emitting elements parameter "), the parameter relevant with power circuit (being referred to as in figure 3 " power circuit parameter ") and The parameter (be in figure 3 referred to as " driving parameter ") relevant with driving, to calculate the coefficient of switch time calculation expression.Coefficient meter Each of unit 108 in semiconductor light-emitting elements parameter, power circuit parameter and driving parameter is calculated to calculate during switch Between calculation expression coefficient.

Here, specifically, in the case of a semiconductor laser, semiconductor light-emitting elements parameter represents semiconductor light emitting element The characteristic of part, and as an example, be the parameter of forward voltage, internal resistor etc..Power circuit parameter with it is explained below The grade of driving power supply 112 it is relevant, and as an example, be input and the output voltage of power circuit.Driving parameter is opened with being used as The pwm signal of OFF signal Ss1 to Ssn standard is relevant, and as an example, is the cycle of the pwm pulse of the power supply of pwm signal And pulse width.These parameters represent the starting stage of semiconductor light-emitting elements, power circuit and drive circuit characteristic (just Beginning characteristic).

In the present example embodiment, to be used as the second order related to variable Iset multinomial for switch time calculation expression Formula.That is, following (expression formula 1) is used as switch time tsi corresponding with semiconductor light-emitting elements block 74-i (i=1 to n) (Iset) calculation expression.

(tsi(Iset))²=t0i+ α Iset+ β Iset²(expression formula 1)

Here, t0i is constant.Coefficient calculation unit 108 calculates the coefficient corresponding with semiconductor light-emitting elements block 74-i T0i, α and β.

Here, the reason for present exemplary embodiment is described by using polynomial function to calculate switch time ts. In the present exemplary embodiment, the switching regulator of such as Fig. 5 Switching Power Supply 106 is in transistor turns by energy from driving Power supply 112 applies to inductor, and applies energy to semiconductor light-emitting elements from inductor in transistor cutoff.In addition, When the transistor conducts, the electric current for flowing into inductor proportionally increases with the time, thus, when have passed through switch time tsi, The electric current for flowing through inductor is proportional to switch time tsi.Now, it is applied to the energy of inductor and flows through the electricity of transistor Stream it is square proportional, i.e. it is square proportional to switch time tsi, thus, semiconductor is applied in the state of cut-off The energy of light-emitting component is also square proportional to switch time tsi.In addition, by by two terminals of semiconductor light-emitting elements Between voltage streaming current is multiplied by obtain the energy of semiconductor light-emitting elements, and the voltage between terminal has with electric current Linear relationship (relation can be approximated to be (alpha+beta Iset)), thus, tsi square with (α Iset+ β Iset²) proportional. Therefore, if outside controlling value is the driving current (Iset) of semiconductor light-emitting elements block 74, what is be fitted to parameter In the case of, the driving current of semiconductor light-emitting elements block 74 is controlled by the counter preset value set to shift register 102.

Outside controlling value can use setting luminous quantity to substitute setting electric current value, and be used as becoming in setting luminous quantity In the case of amount, predetermined luminous quantity can be converted into corresponding setting electric current value.In more detail, in target by setting luminous quantity In the case of setting, setting uses the relation between polynomial driving current and luminous quantity.It is directed to based on the relation to calculate The driving current of the luminous quantity provided as outside controlling value, hereafter, switch time ts is calculated according to driving current, and can So that switch time ts is used as into the value that shift register 102 is set.

In the present example embodiment, as an example, describing by using including the second order function of three control parameters To calculate switch time ts form, but present exemplary embodiment not limited to this, it can use by using including one or two The second order function of individual parameter calculates switch time ts form.Furthermore, it is not necessary that control parameter is necessarily used, and this In the case of, setting electric current value Iset can be converted into direct corresponding switch time ts.

In addition, the driving power supply 112 shown in Fig. 3 be mainly used for driving each Switching Power Supply 106 voltage source (voltage- Vp), and power supply 114 is controlled to drive the circuit part in addition to Switching Power Supply 106.

In addition, including unshowned control according to the semiconductor light-emitting elements drive dynamic control device 60 of the present exemplary embodiment Unit (luminous controling unit), and controlling switch signal generation unit 100, semiconductor light-emitting elements block 74, Switching Power Supply 106th, in coefficient calculation unit 108, switch time computing unit 110, driving power supply (voltage source) 112 and control power supply 114 Each part.

Next, reference picture 5 to be described to the Switching Power Supply 106 (current generating unit) according to the present exemplary embodiment. Fig. 5 shows the example that semiconductor light-emitting elements block 74 is made up of four semiconductor light-emitting elements block 74-1 to 74-4.Each In semiconductor light-emitting elements block 74, multiple semiconductor light-emitting elements 72 (Fig. 5 shows 12 semiconductor light-emitting elements) series connection connect Connect, in addition, each semiconductor light-emitting elements block 74 is connected in parallel with each other.In the present example embodiment, semiconductor light-emitting elements The cathode side of block 74 is connected to GND.In addition, in the present example embodiment, semiconductor laser is used as semiconductor light emitting element Part 72, but LED can be used as described above.

As shown in figure 5, each of four Switching Power Supply 106-1 into 106-4 be configured as including inductor L1 to L4, Smoothing capacity device C1 to C4, reverse current blocking diode D1 to D4 and switch element T1 are to T4, and each Switching Power Supply A terminal be connected to each semiconductor light-emitting elements block 74.In addition, other terminals of each Switching Power Supply 106 are connected to drive Dynamic power supply 112.Driving power supply 112 receives exchange (AC) voltage as example, and use includes power factor correction circuit Known direct current (DC) power supply, thus, descriptions thereof will be omitted.

The control terminal N1 to N4 that switching signal Ss1 to Ss4 is input to each of switch element T1 into T4 (is received Part) (Fig. 5 illustrate only switching signal Ss1 as representative).Control terminal N1 to N4 is metal oxide half in switch element It is grid in the case of conductor (MOS) transistor, is base stage in the case where switch element is bipolar transistor, and in switch It in the case of igbt (IGBT) is grid that element, which is,.

Here, by characteristic of the description according to the Switching Power Supply 106 of the present exemplary embodiment.First, according to Switching Power Supply 106, in the case of the short circuit of semiconductor light-emitting elements 72, reduce semiconductor light-emitting elements 74 influence to light summation of block.Hereafter In, this characteristic is more fully described.

Based on the sheet according to the semiconductor light-emitting elements block 74 for including having 12 semiconductor lasers 72 being connected in series The analog result of the Switching Power Supply 106 of exemplary embodiment, the electric current for flowing through each semiconductor light-emitting elements 72 is normally about 1.4A, but in the case of two semiconductor light-emitting elements short circuits, electric current increases to the 1.68A of about 1.2 times of electric current.This In, driving current be 1.4A, while 12 semiconductor light-emitting elements 72 being connected in series are normal light in the case of, ignore half The threshold current of conductor light-emitting component 72, but if each light quantity quilt of semiconductor light-emitting elements 72 in the case of without short circuit Set as unit, then 1.4A corresponds to the light quantity of 12 semiconductor light-emitting elements 72.Then, or even in semiconductor light-emitting elements block In the case of two short circuits of semiconductor light-emitting elements 72 among 74, if driving current increases to 1.2 times, 10 semiconductors The light quantity of light-emitting component 72 increases to 1.2 times and is changed into the light quantity of 12 semiconductor light-emitting elements 72, and maintain with short circuit Amount identical light quantity before.In fact, short circuit can not possibly occur in semiconductor light-emitting elements 72 simultaneously, and if one Semiconductor light-emitting elements short circuit, the then further reduction of the difference between light quantity before and after short circuit.

As described above, the feelings of short circuit even occur in the semiconductor light-emitting elements 72 for constituting semiconductor light-emitting elements block 74 Under condition, in the Switching Power Supply 106 according to exemplary embodiment, semiconductor light-emitting elements 72 are prevented for following reasons Driving electric power total change.That is, when the electric current for flowing through inductor L (L1 to L4 in Fig. 5) increases, apply to inductor L Voltage remain constant and short-circuit numbers of with semiconductor light-emitting elements 72 are unrelated.Therefore, energy of the accumulation in inductor L It is constant, and when the electric current for flowing through inductor L reduces when semiconductor light-emitting elements 72 are driven, by corresponding to terminal electricity The electric current of pressure discharges energy of the accumulation in inductor L.In other words, in the Switching Power Supply 106 according to the present exemplary embodiment In, the energy of accumulation in the inductor remains constant, thus makes control stable.

Specifically, if the setting direction of the semiconductor light-emitting elements 72 being connected in series of semiconductor light-emitting elements block 74 with Sheet transport direction is consistent, then it is thus non-lit up even in the short circuit of one of 12 semiconductor light-emitting elements in the case of, such as Really the electric current of other 11 semiconductor light-emitting elements 72 increases and thereby compensates for light quantity, and semiconductor is performed by the energy of accumulation The drying process of light-emitting component block 74.Therefore, unaffected (for example, generation of uneven drying etc.) is dried.

Specifically, in continuous form machine, printing paper P is rapidly conveyed, thus, sequentially sensed during timesharing The curtage of multiple semiconductor light-emitting elements and the pulse week that the curtage sensed reflection is arrived to Switching Power Supply In the case that the method for phase or pulse width is by use, the curtage of semiconductor light-emitting elements is abnormal.Therefore, it is different in drying Paper is conveyed when often, until abnormal current or voltage are reflected to pulse period or the pulse width of Switching Power Supply, thus, it is abnormal Partially change into loss.

In contrast, in the Switching Power Supply 106 according to the present exemplary embodiment, when performing control, by split The inductor L in powered-down source 106 operation compensates to increase driving current to insufficient light quantity.Thus, it is therefore prevented that It is lost caused by exception is dry.

In addition, being had according to the Switching Power Supply 106 of the present exemplary embodiment in the semiconductor light-emitting elements 72 being connected in series The characteristic provided protection against in the case of short circuit.That is, in the case where switch element T (T1 to T4) is connected, it is applied to out The energy of inductor L in powered-down source 106 is constant but constant due to its terminal voltage.Therefore, when shut-off switch element T, Hereafter when electric current flows into semiconductor light-emitting elements block 74 and thus released energy, energy in the inductor is only accumulated with most Large supply is to semiconductor light-emitting elements block 74.Therefore, in order to select inductor L, based on the condition in normal operating, pass through Maximum saturation electric current is determined to limit electric current.As a result, limited in case of a short circuit due to being deposited in semiconductor light-emitting elements 72 Electric current, thus provides the protection work(for the semiconductor light-emitting elements 72 in addition to the semiconductor light-emitting elements 72 of short circuit Energy.

(the second exemplary embodiment)

Reference picture 6 is described into the Switching Power Supply 106a according to the present exemplary embodiment.Fig. 6 shows Switching Power Supply 106a's Circuit diagram.Switching Power Supply 106a has is arranged on switch for the protection location of overcurrent and the detection unit of voltage and current Form in power supply 106.As representative, Fig. 6 shows one of multiple switch power supply 106a being connected in parallel and is connected in parallel One of semiconductor light-emitting elements block 74.

As shown in fig. 6, Switching Power Supply 106a includes protection location 304 and protection location 306.In addition, Switching Power Supply 106a The current detecting unit 308 (light-emitting component current detecting unit) of semiconductor light-emitting elements block 74-1 electric current is crossed including detection stream And (the light-emitting component electricity of voltage detection unit 310 of the voltage between detection semiconductor light-emitting elements block 74-1 two terminals Press detection unit), current detecting unit 308 and voltage detection unit 310 explained below.

Protection location 304 is such circuit：In the case where any one semiconductor light-emitting elements 72 has and disconnects failure, It protects semiconductor light-emitting elements 72 not influenceed by the increase of switch element T1 output voltage by clamping down on output voltage. As shown in fig. 6, protection location 304 is configured as including reverse current blocking diode D5, MOS transistor T5, Zener diode D6 and resistor R5.

According to the Switching Power Supply (106 or 106a) of the exemplary embodiment of the present invention according to different from general switch-type stabilized The feedback of device performs isopulse control (frequency and pulse width perseverance at once without performing Isobarically Control or current constant control It is fixed).Therefore, semiconductor light-emitting elements 72 disconnect in the case of, or semiconductor light-emitting elements block 74 be not connected and In the case of Switching Power Supply is powered, it is assumed that (the VCE or MOS of bipolar transistor between switch element T1 input and output The VDS of transistor) produce voltage and the thus situation of transistor damage higher than rated voltage.Therefore, in Switching Power Supply In 106a, the reverse current blocking diode D5 of protection location 304 clamps down on switch element T1 output, thus, it is therefore prevented that switch Element is damaged due to applying the voltage higher than rated voltage to switch element.Hereinafter, the configuration is referred to as " clamping down on circuit " (clamping down on unit).

In addition, the present exemplary embodiment includes detection unit, the detection unit is configured as including MOS transistor T5, together Receive and diode D6 and resistor R5 and detect electric current.In addition, detection unit detection clamp down on circuit than flowing through there is predetermined value The higher electric current of electric current, luminous controling unit (not shown) is sent to by detected signal (not shown), and stops opening Powered-down source 106a operation.In this manner, due to clamping down on circuit during the period before Switching Power Supply 106a operation stops May only have electrical dissipation characteristic, therefore Switching Power Supply 106a can be miniaturized or can prevent unwanted losses.

Protection location 306 is configured as including driver 300, comparator 302 and resistor R4.Driver 300 mainly has There is following function：Carry out driving switch element T1 using such as switching signal Ss1 signal (being referred to as in figure 6 " VPWM "), and The shutdown switch element T1 behaviour after the signal of the abnormality of electric current for the input side for representing to flow through switch element T1 is received Make.

As shown in fig. 6, crossing semiconductor light-emitting elements including detection stream according to the Switching Power Supply 106a of the present exemplary embodiment The current detecting unit 308 of block 74-1 electric current, but current detecting unit 308 can not detect electricity while driving current is detected The short circuit of sensor.

Therefore, switch element T1 input is connected to resistor R4 (the input electric cur- rent measure lists for current measurement Member), and comparator 302 whether there is the voltage between resistor R4 two terminals and the determination abnormality as electric current The reference voltage Vref of threshold value be compared.In the case where flowing through the measured value exception of resistor R4 electric current, comparator 302 output voltage maintains high level (or maintaining low level), and comparator 302 is notified in the main of switch element T1 The current anomaly of side.If driver 300 receives the signal for the abnormality for representing electric current, driver stops to switch element T1 Signal, and shutdown switch power supply 106a operation.

In this case, if intervening software until Switching Power Supply in process after the exception of electric current is detected 106a operation stops, then there is a possibility that excessive current has constantly flowed the scheduled time after inductor short circuit.Cause This, in the present example embodiment, detects signal come shutdown switch signal Ss1 using hardware approach, by current anomaly.

3rd exemplary embodiment)

The present exemplary embodiment is that the control for the driving current for crossing semiconductor light-emitting elements block 74-1 to 74-n with convection current has The form of pass, and the configuration of Switching Power Supply is identical with the configuration of the Switching Power Supply 106a shown in Fig. 6.Therefore, eliminate and originally show The diagram of example property embodiment.

In the case where semiconductor light-emitting elements are semiconductor laser, according to the so-called threshold value of specific currents output light Electric current Ith is present in electric current-light output characteristic.Therefore, in the case where semiconductor light-emitting elements 72 send light, semiconductor is worked as When light-emitting component block 74 is lighted, driving current is generally set to the electric current more than threshold current Ith.The present exemplary embodiment is Prevent the mistake for the driving current for flowing through semiconductor light-emitting elements block 74 that can occur in the configuration according to the present exemplary embodiment The form of punching.

Compared with above-mentioned general driving method, the present exemplary embodiment starts to switch switch element before execution is lighted T1 to Tn.More specifically, setting switching signal Ss1 to Ssn cycle and width so that or even flow through partly lead in normal state The peak point current of body light-emitting component block 74 is also equal to or less than the threshold current Ith of semiconductor light-emitting elements 72.According to from lighting Terminate to starting next time lighted, controlling switch signal Ss1 to Ssn cycle and width or whether carrying out lighting it It is preceding to perform switching.Specifically, the pulse width of signal of the input to switch element T1 to Tn is reduced, thus, electric current is limited For the electric current of the oscillation threshold less than or equal to semiconductor laser.

In the Switching Power Supply (106 or 106a) according to the present exemplary embodiment, considerably more than the electricity of normal current Stream flows through inductor L (L1 to Ln), to be superimposed the charging current that normal time charges to smoothing capacity device C (C1 to Cn).That is, In the driving current of semiconductor light-emitting elements block 74, switching signal Ss (Ss1 are applied immediately in switch element T (T1 to Tn) To Ssn) overshoot can be produced afterwards, to be generated when being released energy after more than the energy accumulation of normal energy in inductor L The voltage higher than normal voltage.

In contrast, in the present example embodiment, switch element T pre-coolings so that by semiconductor light emitting element Part block 74 reduces switching signal Ss pulse width before starting to light, the driving current of semiconductor light-emitting elements 72 is equal to or small In threshold current.At this point it is possible to be started and by basis with being performed quickly by providing polytype pulse width Driving switch element T is rapid to rise when scheduled time table based on image information is come switch pulse width.

Meanwhile, if the period that semiconductor light-emitting elements block 74 extinguishes is short, smoothing capacity device C terminal voltage is by putting Electricity and do not change.In this case, overshoot do not occur, thus, semiconductor light-emitting elements block 74 turn off period pre- In the case of in fixing time, switch element T does not have pre-cooling.Therefore, it is possible to reduce waste.According to based on the pre- of image information Fix time table to perform above-mentioned control, thus, it is possible to avoid the complex control of such as feedback control.

Additionally it is possible to by clamp down on flow through switch element T electric current prevent overshoot, with cause by controlling switch member Part T grid voltage (being in the case of a bipolar transistor base voltage), switch element T is in linear regional work.This In the case of, time of the heat in the range of linearity increases, but transistor will not only damaged after electric power is applied.

(the 4th exemplary embodiment)

Reference picture 7 and Fig. 8 are described to the semiconductor light-emitting elements drive dynamic control device 62 according to the present exemplary embodiment.Figure 7 be the block diagram of semiconductor light-emitting elements drive dynamic control device 62, and Fig. 8 is to show that counter preset signal is exported with counter Between time relationship timing diagram.Semiconductor light-emitting elements drive dynamic control device 60 uses the pre- confidence of counter of a phase Number, but the present exemplary embodiment is the form of the counter preset signal using four phases.

As shown in fig. 7, semiconductor light-emitting elements drive dynamic control device 62 includes switching signal generation unit 200, it is replaced The switching signal generation unit 100 (reference picture 3) of semiconductor light-emitting elements drive dynamic control device 60.Other configurations (that is, semiconductor Light-emitting component block 74, Switching Power Supply 106, coefficient calculation unit 108, switch time computing unit 110, driving power supply (voltage source) 112 and control power supply 114) it is identical with the other configurations of semiconductor light-emitting elements drive dynamic control device 60, thus, will omission to it Detailed description.

As shown in fig. 7, switching signal generation unit 200 also include respectively with semiconductor light-emitting elements block 74-1 to 74-n pairs The transistor 202-1 to 202-n and counter 204-1 to 204-n answered.In addition, with identical with switching signal generation unit 100 Mode, switch time signal St and transmission clock be input to shift register 202.

Meanwhile, counter preset signal Preset0, Preset1, Preset2 and Preset3 of four phases are input to Switching signal generation unit 200.Counter set to 0 in advance into counter preset 3 each be input to counting as described below Device 204.I.e., respectively, counter is set to 0 in advance is input to counter 204-1, and counter preset 1 is input to counter 204- 2, counter preset 2 is input to counter 204-3, and counter preset 3 is input to counter 204-4.Hereinafter, with Same way, counter is set to 0 in advance is input to counter 204-5, and counter preset 1 is input to counter 204-6, counter Preset 2 are input to counter 204-7, and counter preset 3 is input to counter 204-8.If semiconductor light emitting element The quantity n of part block 74 is four multiple, then counter preset 3 is input to counter 204-n, but in the present exemplary embodiment In, n can not be four multiple, thus, the counter preset signal of any phase can be input to counter 204-n.

If representing to be included in the signal of switch time ts1 to tsn in switch time signal St by transmitting clock Sequentially shift and be and set for shift transistor 202-1 to 202-n, then the counter with four phases is set to 0 to 4 in advance Individual count device 204-1 to 204-n is input in the case of its time-shifting.Therefore, incited somebody to action according to each counter is preset Switching signal Ss1 to Ssn is sent to Switching Power Supply 106-1 to 106-n from counter 204-1 to 204-n.Switching Power Supply 106-1 Driven to 106-n by the switching signal Ss1 to Ssn of time-shifting, thus, the switching current of time-shifting flows through each Switching Power Supply 106.However, in the present example embodiment, used the counter of four phases preset, thus, counter is pre- Put has identical timing in each four-counter is preset.

Here, it is example according to the preset number of phases 4 of the counter of the present exemplary embodiment, and if there is multiple Counter is preset, then according to the spirit of the present exemplary embodiment, obtains the effect according to the present exemplary embodiment.In addition, this Exemplary embodiment can be preset (i.e., using counter corresponding with semiconductor light-emitting elements block 74-1 to 74-n quantity Counter with n phases is preset) form.

Reference picture 8 is described in detail to the operation of switching signal generation unit 200.Counter of the generation with four phases The method of preset signal is not particularly limited, but in the present example embodiment, with by by the pre- confidence of counter shown in Fig. 8 Number pulse spacing T counter preset signals of the time interval generation with four phases that is divided into four sections and obtains.Change speech It, it is pre- for 90 ° of counter that the present exemplary embodiment generates phase with one another difference by the way that pulse spacing T is set as into a cycle Confidence number.

Inputted as shown in figure 8, counter is set to 0 in advance in time t5 to counter 204-1, thus, counter 204-1 output High level is changed into from low level.During the period of switch time ts1 only in counter 204-1, the meter with high level Number device output 0 is exported to Switching Power Supply 106-1 from counter 204-1, to be used as switching signal Ss1 ((a) to (c) in Fig. 8).

In the same manner, counter preset 1 is input to counter 204-2 in time t6, thus, counter 204-2's Counter output 1 is output to Switching Power Supply 106-2 as switching signal Ss2.Counter preset 2 is input to meter in time t7 Number device 204-3, thus, counter 204-3 counter export 2 as switching signal Ss3 and are output to Switching Power Supply 106-3. Counter preset 3 is input to counter 204-4 in time t8, thus, and counter 204-4 counter output 3 is used as switch Signal Ss4 is output to Switching Power Supply 106-4

((d) to (i) in Fig. 8).

As shown in figure 8, by the operation of above-mentioned switching signal generation unit 200 come defeated to counter to counter output 0 The timing (phase) for going out 3 is shifted.By doing so it is possible, the load of driving power supply 112 is not concentrated but balanced (scattered), thus, The ripple or noise of the voltage Vp of driving power supply 112 waveform is prevented to occur, and ground potential is stable.

(modified example of the 4th exemplary embodiment)

Reference picture 9 is described into this example.This example has the Switching Power Supply of semiconductor light-emitting elements drive dynamic control device 62 106 (Switching Power Supply 106-1,106-2,106-3 and 106-4 general digitals) be switched on and off power supply 107 (Switching Power Supply 107-1, 107-2,107-3 and 107-4 general digital) replace form.Therefore, the configuration in addition to Switching Power Supply 107 is with partly leading Body light-emitting component drive dynamic control device 62 is identical, thus, reference picture 7 and Fig. 8 are carried out on partly leading including Switching Power Supply 107 The description of body light-emitting component drive dynamic control device.

As shown in figure 9, being both configured to include posting according to each of the Switching Power Supply 107-1 of this example into 107-4 Raw inductor Ls1 to Ls4, regeneration diode Dp1 to Dp4 and switch element T1 to T4.One terminal of Switching Power Supply 107 connects Semiconductor light-emitting elements block 74 is connected to, and other terminals of Switching Power Supply 107 are connected to driving power supply 112.

Parasitic inductor Ls1 to Ls4 is to be denoted as inductor, from switch element T1 to T4 to semiconductor light emitting respectively The equivalence element of the inductance component of member block 74-1 to 74-4 wire.Semiconductor light-emitting elements block 74-1 to 74-4 is typically set It is set to and is separated with semiconductor light-emitting elements drive dynamic control device 62 for electrical lysis etc..In this case, from switch member The inductance component of wires of the part T1 to T4 to semiconductor light-emitting elements block 74-1 to 74-4 also depends on the width of wire, but is driving It can not ignore during dynamic semiconductor light-emitting elements block 74-1 to 74-4.Therefore, in this example, parasitic inductor Ls1 to Ls4 is set It is set to circuit element.

As shown in figure 9, in the way of different from Switching Power Supply 106, Switching Power Supply 107 does not include inductor (Fig. 5 inductance Device L1 to L4) as element, and switch element T1 to T4 is arranged in power supply 112 and the semiconductor light-emitting elements block as load 74-1 is between 74-4.In addition, by inputting the switching signal Ss1 of the control terminal N1 to N4 to switch element T1 to T4 extremely Ss4 carrys out the average value that controlling stream crosses semiconductor light-emitting elements block 74-1 to 74-4 electric current, without being shifted to phase.According to The semiconductor light-emitting elements drive dynamic control device of this example is especially effective in such a situa-tion.

That is, as described in this example, inductor L1 to L4 switch electricity is not included for as shown in Figure 9 Source, it is more effective come the method for equally loaded by being shifted to phase.That is, the circuit shown in 9 does not include inductor L1 to L4, Thus, when switching switch element T1 to T4, the difference coefficient dI/dt for flowing through the electric current I of load is quite big.Therefore, if institute The timing for having semiconductor light-emitting elements block 74-1 to 74-4 to connect overlaps each other, then excessive noise may be superposed on one another, and Semiconductor light-emitting elements drive dynamic control device may perform abnormal operation etc..Now, according to semiconductor light-emitting elements block 74-1 extremely The semiconductor light-emitting elements drive dynamic control device of the switching phase of each in 74-4 this example different from each other, effectively prevents Noise generation is stopped.

(the 5th exemplary embodiment)

Reference picture 10 is described into the semiconductor light-emitting elements drive dynamic control device 64 according to the present exemplary embodiment.Semiconductor Light-emitting component drive dynamic control device 64 has following form：Obtain for correcting switch time calculation expression (expression formula 1) The monitoring unit of coefficient t0i, α and β various types of monitor values is arranged on the semiconductor light-emitting elements drive control shown in Fig. 3 In device 60.

As shown in Figure 10, as an example, semiconductor light-emitting elements drive dynamic control device 64 includes being used to monitor that semiconductor is sent out The monitoring unit 78-1 to 78-n of each characteristics of the optical element block 74-1 into 74-n.Supervised by monitoring unit 78-1 to 78-n Depending on result be input to switch time computing unit 110.Other configurations and semiconductor light-emitting elements drive dynamic control device 60 Other configurations are identical, thus, detailed description will be omitted.

Electrical characteristics, light characteristic of semiconductor light-emitting elements 72 etc. are monitored according to the monitoring unit 78 of the present exemplary embodiment. The result monitored is input to switch time computing unit 110, and is compared with outside controlling value (Iset).In conduct Comparative result and exist displacement in the case of, correction switch time calculation expression (expression formula 1) coefficient t0i, α and β, from And, semiconductor light-emitting elements deterioration over time or characteristic variations, the characteristic variations of the part of power circuit etc. are incorporated to these In coefficient.Therefore, switching signal Ss1 to Ssn accuracy increase.

Reference picture 6 is described to the current detecting unit (light-emitting component current detecting unit) of semiconductor light-emitting elements block 74 308 and voltage detection unit (light-emitting component voltage detection unit) 310 be used as the monitoring unit 78 according to the present exemplary embodiment Example.As shown in fig. 6, current detecting unit 308 is by being connected between the cathode side and GND of semiconductor light-emitting elements block 74 Resistor R1 is constituted.In addition, resistor R1 terminal voltage is input to switch time computing unit as standby current value IM 110.In addition, as shown in fig. 6, voltage detection unit 310 is by being connected between the anode-side and GND of semiconductor light-emitting elements block 74 Resistor R2 and resistor R3 constitute.In addition, the voltage shared by resistor R2 and resistor R3 is as monitoring magnitude of voltage VM It is input to switch time computing unit 110.

For example, in the case where the characteristic of semiconductor light-emitting elements 72 changes over time, standby current value IM and monitoring Magnitude of voltage VM changes relative to initial value, thus, switch time computing unit 110 detects the difference between them, and difference is anti- Reflect to switch time calculation expression (expression formula 1), and correction coefficient t0i, α and β.

Compared with comparative example, according to the current detecting unit 308 and voltage detection unit 310 of the present exemplary embodiment more Measurement is performed exactly.Hereinafter, reason will be described.

In the case where measuring voltage and current, if as the terminal of benchmark, for example, GND and the GND of measuring system are not Matching, then need the additional circuit of such as difference amplifier.In contrast, in the semiconductor light emitting according to the present exemplary embodiment In element drives control device, the cathode side of semiconductor light-emitting elements block 74 is connected to GND, thus, by negative electrode and GND it Between the resistor for current measurement is inserted to carry out Direct Current measurement.

By the way that influence, loss and measurement accuracy for voltage measurement are accounted for the electricity for current measurement Resistance device R1 resistance value is set as such as about 0.01 Ω to 0.1 Ω value.Due to flowing through the electricity of semiconductor light-emitting elements block 74 The value of stream is generally large, so if the influence that GND current potential changes to measurement accuracy is accounted for, then measures and uses simultaneously In the resistor R1 of current measurement two terminals, so that according to resistor R1 current potential and resistance value come calculating current value.Together When, equally in the voltage detection unit 310 of the driving voltage of measurement semiconductor light-emitting elements block 74, semiconductor light-emitting elements block 74 cathode side is always GND, thus measures the current potential in anode-side also by using the GND of measuring system as benchmark.

The above description of the exemplary embodiment of the present invention is provided for the purpose of illustration and description.It is not intended to pair The present invention is elaborated or limited the invention to exact form disclosed.It is clear that many variations and modifications for Those skilled in the art are obvious.It is that the principle and its reality in order to be best described by the present invention are answered to select and describe embodiment With so that those skilled in the art are according to various embodiments and by being suitable for the various modifications of desired special-purpose Understand the present invention.The scope of the present invention is limited by appended claims and its equivalent.

Claims

1. a kind of drive dynamic control device of semiconductor light-emitting elements, including：

Multiple current generating units, it respectively supplies driving current to multiple semiconductor light-emitting elements groups, respectively including receiving The acceptance division of switching signal, and the driving current, the multiple semiconductor light-emitting elements are controlled according to the switching signal Each in group includes at least one semiconductor light-emitting elements；

Switching signal generation unit, it generates multiple switch signal according to the desired value of the driving current, and will be described Multiple switch signal is respectively fed to multiple acceptance divisions；And

Voltage source, it has series relationship with the current generating unit and the semiconductor light-emitting elements group.

2. drive dynamic control device according to claim 1,

Wherein, each switching signal is binary digital signal, and

Wherein, for institute when the switching signal generation unit is by extinguishing light according to semiconductor light-emitting elements group and sending light State the desired value of the driving current of semiconductor light-emitting elements group and change in the pulse width and pulse period of the data signal At least one, to generate each switching signal.

3. drive dynamic control device according to claim 2, in addition to：

Switch time computing unit, its calculated according to the desired value pulse width and in the pulse period at least One.

4. drive dynamic control device according to claim 3, in addition to：

Unit is corrected, it utilizes the semiconductor light-emitting elements group, the voltage source, the current generating unit and the switch The characteristic of at least one in signal generation unit corrects at least one in the pulse width and the pulse period, this A little characteristics are needed for the switch time computing unit calculates the pulse width and at least one in the pulse period.

5. drive dynamic control device according to claim 4, in addition to：

Monitoring unit, it monitors the photoelectric characteristic of the multiple semiconductor light-emitting elements group,

Wherein, the correction unit corrects the pulse width and pulse week according to the monitoring result of the monitoring unit At least one interim.

6. drive dynamic control device according to any one of claim 1 to 5,

Wherein, each in the multiple semiconductor light-emitting elements group includes the multiple semiconductor light emitting elements being connected in series Part, and

For each in the multiple semiconductor light-emitting elements group, the current generating unit includes：Switch element, it has There is the control terminal in the acceptance division；Inductor, it is connected to the lead-out terminal of the switch element and with the multiple half One in conductor light emitting device group has parallel relationship；And capacitor, its with the multiple semiconductor light-emitting elements group One be connected in parallel.

7. drive dynamic control device according to any one of claim 1 to 5,

For each in the multiple semiconductor light-emitting elements group, the current generating unit includes：Switch element, it has There is the control terminal in the acceptance division；Inductor, it is connected to the switch element and the multiple semiconductor light-emitting elements Between one in group, and with from the switch element to the wire of one in the multiple semiconductor light-emitting elements group Equivalent inductance component；And diode, it is connected in parallel with one in the multiple semiconductor light-emitting elements group.

8. the drive dynamic control device according to claim 6 or 7, in addition at least one of the following：

Current detecting unit, it is connected between the cathode side of each in the multiple semiconductor light-emitting elements group and ground, And detect the electric current of one flowed through in the multiple semiconductor light-emitting elements group；And voltage detection unit, it is connected to Between the anode-side of one and ground in the multiple semiconductor light-emitting elements group, and detect the multiple semiconductor light emitting element The voltage between two terminals of one in part group.

9. the drive dynamic control device according to any one of claim 6 to 8, in addition to：

Unit is clamped down on, it clamps down on the voltage of the lead-out terminal of the switch element.

10. drive dynamic control device according to claim 9,

Wherein, the unit of clamping down on includes the detection unit that the electric current for clamping down on unit is flowed through in detection, and in the detection In the case that the electric current that unit is detected is more than set-point, the operation of the multiple current generating unit is stopped.

11. the drive dynamic control device according to any one of claim 6 to 10, in addition to：

Input electric cur- rent measure unit, it detects the electric current for the input terminal for flowing through the switch element,

Wherein, in the case where the electric current that the input electric cur- rent measure unit is detected is more than set-point, the multiple electric current life Operation into unit is stopped.

12. the drive dynamic control device according to any one of claim 1 to 11,

Wherein, the switching signal generation unit make it that the respective timing of the multiple switching signal is different from each other, and will tool The multiple switching signal for having different timing is provided to the acceptance division respectively.

13. the drive dynamic control device according to any one of claim 1 to 12,

Wherein, the semiconductor light-emitting elements are semiconductor lasers, and

Wherein, switching signal generation unit generation switching signal, with cause driving current the semiconductor laser from OFF state flows before changing into the timing of luminance, so that the driving current is in the timing nonoscillatory or does not prolong Late, wherein the driving current is defined as being less than during the period is limited the electricity of the threshold current of the semiconductor laser Stream.

14. the drive dynamic control device according to any one of claim 1 to 12,

Wherein, the semiconductor light-emitting elements are light emitting diodes.

15. a kind of droplet drying device, it includes：

Multiple semiconductor light-emitting elements；And

Drive dynamic control device according to any one of claim 1 to 14.

16. a kind of image processing system, it includes：

Image formation unit, it sprays drop according to image information and formed on the recording medium according to described image information Image；And

Droplet drying device according to claim 15, wherein, the droplet drying device makes described image formation unit It is ejected into the droplet drying in the recording medium.