Driving device and recording device

Abstract

To provide a technique that is advantageous in decreasing sensitivity of visually recognizing unevenness caused by variations in driving amounts to load elements.SOLUTION: A driving device is provided with a plurality of load blocks each including a load element, a plurality of driving circuits for driving the plurality of load blocks, and a connection circuit through which the plurality of load blocks are connected to the plurality of respective driving circuits, where the connection circuit switches combinations for connecting each of the plurality of load blocks to each of the plurality of driving circuits.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a drive device and a recording device. [Background technology]

[0002] When driving load elements such as resistors and light-emitting elements to record images, the characteristics of the load elements may vary, causing unevenness in the recorded image. Patent Document 1 shows that unevenness can be suppressed by providing a pseudo-random number generating circuit and an LED characteristic variation data memory that stores the characteristic variations of each LED element, and injecting random noise according to the characteristics of each LED element into the input image data. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-090571 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is a possibility that the characteristics may vary not only among the load elements but also among the multiple drive circuits for driving the respective load elements. When the characteristics vary among the multiple drive circuits, the drive amounts with which the drive circuits drive the load elements may vary among the multiple load elements, which may result in unevenness in the recorded image.

[0005] An object of the present invention is to provide a technique that is advantageous in reducing the visual sensitivity of unevenness caused by variations in the amount of drive for load elements. [Means for solving the problem]

[0006] In view of the above problems, a driving device according to an embodiment of the present invention is a driving device comprising a plurality of load blocks, each of which includes a load element, a plurality of driving circuits that drive the plurality of load blocks, and a connection circuit that connects the plurality of load blocks to the plurality of driving circuits, respectively, wherein the connection circuit switches the combination of connections between each of the plurality of load blocks and each of the plurality of driving circuits. Effect of the Invention

[0007] According to the present invention, it is possible to provide a technique that is advantageous in reducing the visual sensitivity of unevenness caused by variations in the drive amount for load elements. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a diagram showing a configuration example of a drive device according to the present embodiment. [Diagram 2] 2A to 2C are diagrams illustrating the effect of the drive device of FIG. 1. [Diagram 3] 2A to 2C are a circuit diagram showing an example of the configuration of a connection circuit of the driving device of FIG. 1, a diagram showing an example of a connection combination, and a timing chart showing the operation. [Figure 4] FIG. 2 is a diagram showing a modification of the drive device in FIG. 1. [Diagram 5] 4 is a circuit diagram showing a modified example of the connection circuit of FIG. 3, a diagram showing an example of a combination of connections, and a timing chart showing the operation. [Figure 6] FIG. 2 is a diagram showing an example of the configuration of a recording apparatus including the drive device shown in FIG. [Figure 7] 7 is a diagram for explaining the arrangement of an exposure head and a photosensitive drum of the recording apparatus in FIG. 6. [Figure 8] FIG. 7 is a diagram showing an example of the configuration of an exposure head of the recording apparatus of FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0010] A driving device according to an embodiment of the present disclosure will be described with reference to Figs. 1 to 5. Fig. 1 is a diagram showing an example of the configuration of a driving device 80 in this embodiment. The driving device 80 includes a plurality of driving circuits 30 that drive a plurality of load blocks 20 each including a load element 23. In the configuration shown in Fig. 1, n driving circuits 30 are arranged in the driving device 80. Here, when a specific driving circuit among the plurality of driving circuits 30 is indicated, a subscript is added after the reference number, such as "driving circuit 30-1". When no particular distinction is made, it is written as "driving circuit 30". The same applies to other components.

[0011] Each of the multiple drive circuits 30 includes a transistor 31 that passes a current corresponding to a voltage signal. A common voltage signal Vb1 is input to a gate terminal of the transistor 31, and the transistor 31 passes a current corresponding to the voltage signal Vb1. In the configuration shown in Fig. 1, the drive circuit 30 is composed of the transistor 31, which is an nMOS transistor. The transistor 31 has the same structure in each drive circuit 30, and can generate drain currents of basically the same magnitude.

[0012] The current generated by the transistor 31 of the drive circuit 30 is supplied to each of the predetermined load blocks 20. A plurality of load elements 23 are arranged in each of the plurality of load blocks 20. In this embodiment, as shown in FIG. 1, the load elements 23 arranged in the plurality of load blocks 20 are arranged along one direction (hereinafter, sometimes referred to as the main scanning direction). In the configuration shown in FIG. 1, the number of load blocks 20 driven by the drive device 80 is also n, which is the same as the number of drive circuits 30. In other words, the number of the plurality of load blocks 20 and the number of the plurality of drive circuits 30 are the same. However, this is not limited to this, and for example, the number of drive circuits 30 arranged in the drive device 80 may be greater than the number of load blocks 20.

[0013] The load block 20 supplies the current supplied from the drive circuit 30 to the load elements 23 arranged in a line in the main scanning direction through a current mirror composed of transistors 21 and 22. In the configuration shown in FIG. 1, the transistors 21 and 22 are pMOS transistors. In each of the load blocks 20, the current mirror ratio of the current mirror composed of the transistors 21 and 22 is designed to be the same. That is, the amount of current supplied to each of the load elements 23 of all the load blocks 20 is basically the same. In this way, the load element 23 can be a current-driven element. In addition, in this embodiment, the load element 23 is described as being a light-emitting element. For example, the load element 23 is an LED having a current on / off switch. In this case, the load element 23 can also be called a light-emitting thyristor. However, the present invention is not limited to this, and the load element 23 may be other elements such as an organic light-emitting element or a resistor element.

[0014] The driving device 80 further includes a connection circuit 10 that connects the load blocks 20-1 to 20-n to a predetermined driving circuit among the driving circuits 30-1 to 30-n for each load block. The connection circuit 10 is configured as a switch network, the configuration of which will be described later. The connection circuit 10 switches the connection combination between each of the load blocks 20-1 to 20-n and each of the driving circuits 30-1 to 30-n. For example, the connection circuit 10 connects the load block 20-1 to the driving circuit 30-1 in a certain period, and connects the load block 20-1 to the driving circuit 30-2 in the next period. The connection circuit 10 may receive a control signal supplied from outside the driving device 80 and switch the connection combination between the load block 20 and the driving circuit 30. The connection circuit 10 may also use a clock signal as a control signal supplied from outside the driving device 80 to switch the connection combination between the load block 20 and the driving circuit 30 every time a predetermined number of clocks are input. The connection circuit 10 switches the one-to-one connection combination of the load block 20 and the drive circuit 30 in the current path formed by the load block 20 and the drive circuit 30.

[0015] 1 may be formed, for example, on a semiconductor substrate long in the main scanning direction. The substrate on which the circuit including the drive device 80 and the multiple load blocks 20 is arranged is disposed opposite a light receiving section that receives light emitted by the load elements 23. The surface of the light receiving section that receives the light from the load elements 23 moves in a direction (sub-scanning direction) that intersects with the main scanning direction. Examples of these configurations will be described later, but the light receiving section may be, for example, a photoconductor drum of a recording device such as an image forming device.

[0016] Here, the transistor 31 arranged in the drive circuit 30 has, for example, a variation in threshold voltage due to variations in the manufacturing process. Therefore, the drain current generated in response to the input of the common voltage signal Vb1 also has variations. If the drain current of the transistor 31 arranged in the drive circuit 30 varies, the current flowing to drive the load element 23 arranged in the load block 20 varies for each load block 20 to which current is supplied from the corresponding drive circuit 30. If the current flowing through the load element 23 varies for each load block 20, the light emission amount of the load element 23, which is a light emitting element, changes for each load block 20, resulting in uneven light amount for each load block 20.

[0017] The unevenness in the amount of light for each load block 20 is recorded as a latent image on the photosensitive drum arranged opposite the substrate on which the load block 20 is formed, and finally appears as uneven light accumulation on the photosensitive drum. When the load element 23 is an LED with a built-in on / off switch for current, it generates light / dark latent image dots on the photosensitive drum. Here, the amount of light accumulation in the light data of the generated latent image dots is the same in terms of design. However, since the amount of drain current generated by the transistor 31 arranged in the above-mentioned drive circuit 30 varies, the variation also propagates to the amount of light accumulation that is proportional to the amount of current driving the load element 23, and this can cause uneven light accumulation for each load block 20 in the main scanning direction.

[0018] Next, the effect of the connection circuit 10 switching the combination of connections between the load blocks 20 and the drive circuits 30 will be described with reference to Figs. 2(a) to 2(d). Here, as shown in Fig. 2(a), the description will be given assuming that three load blocks 20 and three drive circuits 30 (load blocks 20-1 to 20-3, drive circuits 30-1 to 30-3) are arranged. Also, the length in the main scanning direction in which the load elements 23 of one load block 20 are arranged is assumed to be 1 mm. Also, as described above, the currents I1' to I3' generated by the transistors 31 of the drive circuits 30-1 to 30-3 are assumed to vary. That is, the currents I1' to I3' have a relationship of I1' ≠ I2' ≠ I3'.

[0019] FIG. 2(b) shows an image of the light reception result of the photosensitive drum when the connection circuit 10 does not switch the connection combination between the load block 20 and the drive circuit 30. In other words, the connection circuit 10 is not arranged between the load block 20 and the drive circuit 30, and the load block 20-1 is always connected to the drive circuit 30-1, the load block 20-2 is always connected to the drive circuit 30-2, and the load block 20-3 is always connected to the drive circuit 30-3. Since the currents I1' to I3' generated by the transistors 31 of the drive circuits 30-1 to 30-3 vary, the light emission amount of the light-emitting element, which is the load element 23, varies in the load blocks 20-1 to 20-3. Therefore, in the photosensitive drum, light accumulation unevenness occurs in the main scanning direction for each load block 20, and the light accumulation unevenness can be clearly seen in the sub-scanning direction, which is the moving direction of the photosensitive drum.

[0020] Fig. 2(c) shows a case where the connection circuit 10 sequentially switches the connection combinations between the load blocks 20-1 to 20-3 and the drive circuits 30-1 to 30-3. Fig. 2(d) shows the relationship between the currents I1 to I3 flowing through the load blocks 20-1 to 20-3 and the currents I1' to I3' generated by the drive circuits 30-1 to 30-3 in the configuration shown in Fig. 2(a) by switching the connection circuit 10. Fig. 2(d) can also be said to show the connection combinations between the load blocks 20-1 to 20-3 and the drive circuits 30-1 to 30-3.

[0021] The connection circuit 10 sequentially switches the combination of connections between the load block 20 and the drive circuit 30 in response to a control signal supplied from the outside of the drive device 80 shown in FIG. 2(d). In the example shown in FIG. 2(c), the connection circuit 10 switches the combination of connections between the load block 20 and the drive circuit 30 every time the photosensitive drum moves 10 μm in the sub-scanning direction. Here, the case where the connection circuit 10 switches the combination of connections between the load block 20 and the drive circuit 30 in response to the movement of the photosensitive drum in the sub-scanning direction is shown, but this is not limited to this. For example, the connection circuit 10 may switch the combination of connections between the load block 20 and the drive circuit 30 by time control. In this case, the combination of connections between the load block 20 and the drive circuit 30 may be switched, for example, at a predetermined time interval, at a predetermined timing, or at a random timing.

[0022] In the configuration shown in FIG. 2(c), the length of movement of the photosensitive drum in the sub-scanning direction while the connection circuit 10 switches the connection combination between the load block 20 and the drive circuit 30 is short. Therefore, the pitch at which the phosphorescence unevenness appears in the sub-scanning direction due to the variation in the currents I1'-I3' generated by the drive circuits 30-1-30-3 is also narrow. As a result, the visibility of the unevenness in the recorded image due to the phosphorescence unevenness is reduced. The alphabets a-f shown in FIG. 2(c) indicate the control signals a-f shown in FIG. 2(d) and indicate the connection combination between the load blocks 20-1-20-3 and the drive circuits 30-1-30-3.

[0023] In this embodiment, the connection circuit 10 sequentially switches the combination of connections between each of the multiple load blocks 20 and each of the multiple drive circuits 30. As a result, even if the characteristics of the transistors 31 of the drive circuits 30 vary and the drive amounts (amounts of current) for the load elements 23 driven by the drive circuits 30 vary, the variations can be dispersed by increasing the spatial frequency in the sub-scanning direction. For example, the visual sensitivity of unevenness caused by the variations in the transistors 31 of the drive circuits 30 can be reduced according to the visual spatial frequency characteristic (Visual Transfer Function: VTF).

[0024] Next, specific configuration and operation examples of the connection circuit 10 will be described with reference to Figures 3(a) to 3(c). Figure 3(a) is a circuit diagram showing a configuration example of the connection circuit 10. Figure 3(b) is a diagram showing a combination of connections within the connection circuit 10. Figure 3(c) is a timing chart showing the operation of the connection circuit 10.

[0025] 3(a) shows a connection circuit 10 in which there are three load blocks 20 and three drive circuits 30, as shown in FIG 2(a). Therefore, the connection circuit 10 is provided with three switches sw1 to sw3, each having three connection taps tap1 to tap3 for one load block 20.

[0026] There are n! number of combination patterns of connections between the load blocks 20 and the drive circuits 30, which is factorial of the number (n) of load blocks 20. When there are three load blocks 20, there are six combination patterns of connections between the load blocks 20 and the drive circuits 30, which are controlled by control signals af shown in Fig. 2(d). In this case, the taps connected in the switches sw1 to sw3 arranged in the connection circuit 10 according to the control signals a to f are as shown in Fig. 3(b).

[0027] FIG. 3(c) shows the timing of the operation of the connection circuit 10. At time t1, the control signal b goes High, and at time t2, it goes Low. During the period when the control signal b is High, the switch sw1 is connected to the tap tap1, the switch sw2 is connected to the tap tap3, and the switch sw3 is connected to the tap tap2. Therefore, during this period, the load block 20-1 is connected to the drive circuit 30-1, and the current I1 flowing through the load block 20-1 becomes the current I1' generated by the drive circuit 30-1. Similarly, during this period, the load block 20-2 is connected to the drive circuit 30-3, and the current I2 flowing through the load block 20-1 becomes the current I3' generated by the drive circuit 30-3. Moreover, the load block 20-3 is connected to the drive circuit 30-2, and the current I3 flowing through the load block 20-3 becomes the current I2' generated by the drive circuit 30-2.

[0028] Thereafter, logical operations according to the control signals a to f are performed in conjunction with the time when the photoconductor drum moves a predetermined distance in the sub-scanning direction. As a result, the currents I1 to I3 flowing through the load blocks 20-1 to 20-3 are switched between the currents I1' to I3' generated by the drive circuits 30-1 to 30-3 as shown in Fig. 2(d). This makes it possible to obtain the above-mentioned effect as shown in Fig. 2(c).

[0029] Also, as shown in FIG. 3(c), when the control signal b goes Low at time t2 and is switched to the control signal f, the control signal f may be supplied from time t2' before time t2 when the control signal b goes Low. An overlap period Tovlap during which the control signal b and the control signal f are supplied simultaneously is provided. This makes it possible to prevent a momentary interruption in the current path formed by the load block 20 and the drive circuit 30 when switching the tap in each switch sw. For example, attention is paid to the load block 20-1 that was driven by the drive circuit 30-1 until time t2. The connection circuit 10 switches the load block 20-1 that was driven by the drive circuit 30-1 to be driven by the drive circuit 30-3. At this time, the connection circuit 10 switches the combination of connections so that the drive by the drive circuit 30-3 starts (time t2') before the drive by the drive circuit 30-1 ends (time t2). By further utilizing the effect of the overlap period Tovlap, it becomes possible to smoothly change the current flowing through the current path when the combination of the load block 20 and the drive circuit 30 is switched.

[0030] In this manner, the driving device 80 of the present embodiment is used. This makes it possible to suppress the occurrence of unevenness in the recorded image due to the variation in the amount of light emitted by the load elements 23 caused by the variation in the characteristics of the transistors 31 of the driving circuit 30, which causes the variation in the amount of drive of the load elements 23, when driving the load elements 23 to record an image. More specifically, the control of switching the combination of the connection between the load blocks 20 of the connection circuit 10 and the driving circuit 30 is performed in conjunction with the movement of the photosensitive drum in the sub-scanning direction. This makes it possible to reduce the visual sensitivity of unevenness caused by the variation in the transistors 31 of the driving circuit 30. In addition, as shown in FIG. 3(a), the connection circuit 10 can be realized with a simple circuit configuration. As a result, the driving device 80 of the present embodiment can improve the quality of the recorded image. Here, the recorded image includes not only so-called pictures but also graphs, figures, characters, and the like.

[0031] In the above, an example has been shown in which the load blocks 20 are arranged one-dimensionally and the photosensitive drum is moved in a direction different from the direction in which the load blocks 20 are arranged. However, the present disclosure is not limited to this. For example, the load blocks 20 (load elements 23) may be arranged two-dimensionally in a matrix. In a lighting device used in a display device or backlight, it is possible to perform display or the like with a constant amount of light. In this case, the above-mentioned connection circuit 10 is used to switch the combination of connections between the load blocks 20 and the drive circuit 30. This allows the two-dimensionally arranged load blocks 20 (load elements 23) to emit light with a uniform amount of light averaged over a two-dimensional surface.

[0032] FIG. 4 is a diagram showing a modified example of the driving device 80 shown in FIG. 1. In the driving device 80 shown in FIG. 4, a transistor 41 is further arranged between the load block 20 and the driving circuit 30 in each current path formed by the load block 20 and the driving circuit 30 connected to each other, compared to the configuration shown in FIG. 1. At this time, the transistor 31 of the driving circuit 30 and the transistor 41 form a cascode circuit. In addition, in the configuration shown in FIG. 4, a connection circuit 10 is arranged between the transistor 31 and the transistor 41 in each current path formed by the load block 20 and the driving circuit 30 connected to each other. The other configurations may be the same as those of the driving device 80 shown in FIG. 1 described above. In addition, the operation of the connection circuit 10 may be the same as those of FIGS. 3(a) to 3(c) described above.

[0033] Next, the effect of providing the transistor 41 will be described. In each current path, a common voltage signal Vb2 is input to the gate terminal of the transistor 41, which is a common base transistor of the cascode circuit. Therefore, the potentials V1 to Vn on the source side of the transistor 41 are approximately equal to each other. Therefore, the potentials V1' to Vn' of the drains of the transistors 31 via the connection circuit 10 are also approximately equal to each other.

[0034] In this way, the potentials V1 to Vn and the potentials V1' to Vn' are almost the same value. Therefore, when the connection combination of the load block 20 and the drive circuit 30 is switched, the potential fluctuation of the terminal connected to the transistor 31 side of the connection circuit 10 and the terminal connected to the transistor 41 is small. Since the potential fluctuation of each external connection terminal of the connection circuit 10 is small when the connection combination is switched, it is possible to suppress the generation of excess charge / discharge current with the parasitic capacitance existing at each connection point connecting the load block 20 and the drive circuit 30 as a load. As a result, the fluctuation of the current I' generated by the drive circuit 30 is suppressed when switching the combination of the load block 20 and the drive circuit 30. Since the fluctuation of the current I' generated by the drive circuit 30 is small, even if the connection circuit 10 performs an operation of switching the combination of the load block 20 and the drive circuit 30 at a higher speed, the fluctuation of the light emission amount of the load element 23 at the time of switching is small, and the influence on the image quality is small.

[0035] When the number of load blocks 20 increases, the number of logic circuits and wiring patterns may increase and become complicated in the configuration shown in Fig. 3(a). Figs. 5(a) to 5(d) are examples of the configuration and operation of the connection circuit 10 that are different from the examples shown in Figs. 3(a) to 3(c) above. Figs. 5(a) to 5(d) are examples of the configuration and operation when the combination of the drive circuit 30 with the load blocks 20 is switched cyclically.

[0036] FIG. 5(a) is a circuit diagram showing a configuration example of the connection circuit 10 in the case where the combination of the load blocks 20 and the drive circuits 30 is cyclically switched. In the configuration shown in FIG. 5(a), 20 load blocks 20, 20-1 to 20-20, are arranged. In this case, 20 drive circuits 30 may be arranged in the drive device 80. 21 or more drive circuits 30 may be arranged in the drive circuit 30. FIG. 5(b) is a diagram showing a combination of connections in the connection circuit 10. FIGS. 5(c) and 5(d) are timing diagrams showing the operation of the connection circuit 10. FIG. 5(c) shows the operation of the switch sw1 among the switches sw1 to sw20 arranged in the connection circuit 10. FIG. 5(d) shows the operation of the switch sw2 among the switches sw1 to sw20 arranged in the connection circuit 10.

[0037] 5(a) to 5(d), similarly to the embodiment described above, for example, the control signal time changes to control signals time1, time2, ..., time20, time1, and time2 in conjunction with the movement of the photosensitive drum in the sub-scanning direction. In response to the change in the control signal time, the taps tap1 to tap20 connected to each of the switches sw1 to sw20 of the connection circuit 10 are cyclically switched to the adjacent tap in order.

[0038] The circuit for switching the connection of the taps of each switch sw can be configured, for example, by a simple shift register circuit. In this case, the control signal time may be a clock signal supplied to the driving device 80. Each time a clock signal is input, the control signal time changes cyclically to time1, time2, ...

[0039] 5(a) can simplify the circuit configuration by suppressing an increase in logic circuits and wiring patterns even when the number of load blocks 20 is increased. As a result, the chip size of the connection circuit 10 is reduced, and restrictions on the chip size of the connection circuit 10 can be alleviated.

[0040] 5(a)-(d), by using the driving device 80 of this embodiment, when the load elements 23 are driven to record an image or the like, it is possible to suppress unevenness in the recorded image caused by variations in the characteristics of the transistors 31 in the driving circuit 30, such as the amount of light emitted by the load elements 23. In other words, the driving device 80 including the connection circuit 10 having the configuration and operation shown in FIG. 5(a)-(d) can achieve the same effect as described above with a simpler circuit configuration, even when the number of load blocks 20 to be driven is increased.

[0041] Next, a recording device equipped with the driving device 80 will be described as an application example of the driving device 80 of this embodiment. Fig. 6 shows an example of the overall configuration of an electrophotographic image forming apparatus AP. The image forming apparatus AP is an example of a recording apparatus. The image forming apparatus AP includes a scanner unit 100, an image creating unit 103, a fixing unit 104, a paper feed / transport unit 105, and a printer control unit (not shown) that controls these units.

[0042] The scanner unit 100 illuminates the document placed on the document glass, optically reads the document image, and converts the image into an electrical signal to generate image data. The image creating unit 103 rotates the photosensitive drum 102, and charges the photosensitive drum 102 with a charger 107.

[0043] The exposure head 106 emits light according to image data, and the light emitted from the chip surfaces of the arranged light-emitting element group is collected on the photosensitive drum 102 by a rod lens array to form an electrostatic latent image. Exposure heads 106a, 106b, 106c, and 106d shown in FIG. 6 show an arrangement of four exposure heads for four-color full-color printing. The above-mentioned driving device 80 may be disposed in the exposure head 106. Furthermore, the exposure head 106 is equipped with light-emitting elements as load elements 23 driven by a driving circuit 30 disposed in the driving device 80.

[0044] The developing unit 108 develops the electrostatic latent image formed on the photosensitive drum 102 with toner. The developed toner image is transferred onto a sheet of paper conveyed onto a transfer belt 111.

[0045] The imaging unit 103 has four imaging units that perform a series of electrophotographic processes (charging, exposing, developing, and transferring), and forms a full-color image by arranging them in the order of cyan (C), magenta (M), yellow (Y), and black (K). After a predetermined time has elapsed since the start of imaging at the cyan station, the four imaging units sequentially perform imaging operations for magenta, yellow, and black.

[0046] In the paper feed / transport section 105, paper is fed from a paper feed unit designated in advance among the main body paper feed units 109a and 109b, the external paper feed unit 109c, and the manual paper feed unit 109d, and the fed paper is transported to the registration rollers 110. The registration rollers 110 transport the paper onto the transfer belt 111 at the timing when the toner image formed in the image forming section 103 is transferred onto the paper. An optical sensor 113 is disposed at a position facing the transfer belt 111, and detects the position of a test chart printed on the transfer belt 111 in order to derive the amount of color misregistration between each station. The amount of color misregistration derived here is notified to an image controller (not shown), and the image position of each color is corrected. This control allows a full-color toner image without color misregistration to be transferred onto the paper. The fixing unit 104 is composed of a combination of rollers and has a built-in heat source such as a halogen heater. It melts and fixes the toner on the paper onto which the toner image has been transferred from the transfer belt 111 using heat and pressure, and then discharges the paper outside the image forming apparatus using paper discharge rollers 112.

[0047] The printer control unit communicates with an MFP control unit (not shown) that controls the entire multifunction device (MFP) and executes control according to its instructions, while also managing the status of the aforementioned scanner, imaging, fixing, and paper feeding / transport units, and issuing instructions to ensure that the entire unit operates smoothly and in harmony.

[0048] 7(a) and 7(b) respectively show the arrangement of the exposure head 106 with respect to the photoconductor drum 102, and how the light emitted from the light emitting element group 201 is condensed on the photoconductor drum 102 by the rod lens array 203. The exposure head 106 and the photoconductor drum 102 are each attached to the image forming apparatus AP by an attachment member (not shown). The exposure head 106 is configured to include the light emitting element group 201, a printed circuit board 202 on which the light emitting element group 201 is mounted, a rod lens array 203, and a housing 204 to which the rod lens array 203 and the printed circuit board 202 are attached. In the assembly factory, assembly and adjustment work is performed on the exposure head 106 alone, and focus adjustment and light amount adjustment are performed to adjust the spot at the condensed position to a predetermined size. Here, the distance between the photoconductor drum 102 and the rod lens array 203, and the distance between the rod lens array 203 and the light emitting element group 201 are arranged to be a predetermined interval, so that the light emitted from the light emitting element group 201 is imaged on the photoconductor drum 102. For this reason, when adjusting the focus, the attachment position of the rod lens array 203 is adjusted so that the distance between the rod lens array 203 and the light emitting element group 201 is a desired value. When adjusting the amount of light, each light emitting element is made to emit light individually and in sequence, and the drive current of each light emitting element is adjusted so that the light condensed through the rod lens array 203 has a predetermined light amount.

[0049] 8(a) and 8(b) show a group of light emitting elements 201 and a printed circuit board 202 on which connectors 305 are arranged.

[0050] Fig. 8(a) shows the surface opposite to the surface on which the light emitting element group 201 is mounted (hereinafter referred to as the light emitting element non-mounted surface), and Fig. 8(b) shows the surface on which the light emitting element group 201 is mounted (hereinafter referred to as the light emitting element mounting surface). The light emitting element group 201 is configured with 20 light emitting element array chips 400-1 to 400-20 arranged in a staggered pattern. In each light emitting element array chip, light emitting elements corresponding to the above-mentioned load elements 23 are arranged at a predetermined pitch in the longitudinal and lateral directions of the chip.

[0051] In this example, several hundred light emitting elements are arranged in the chip longitudinal direction at a pitch of 1200 dpi resolution (approximately 21.16 um), and these light emitting element rows are arranged in multiple rows in the chip transverse direction. In other words, the distance from one end of the several hundred light emitting points to the other end in the longitudinal direction within the chip is approximately 10 to 20 mm. The light emitting element group 201 is formed by arranging several chips in the longitudinal direction. The light emitting element array chips 400-1 to 400-20 are arranged in two rows in a staggered pattern, and each row is arranged along the longitudinal direction of the printed circuit board 202.

[0052] The disclosure of this specification includes the following drive device and recording device.

[0053] (Item 1) A drive device comprising: a plurality of load blocks each including a load element; a plurality of drive circuits for driving the plurality of load blocks; and a connection circuit for connecting the plurality of load blocks to the plurality of drive circuits, The drive device, wherein the connection circuit switches a combination of connections between each of the plurality of load blocks and each of the plurality of drive circuits.

[0054] (Item 2) 2. The drive device according to item 1, wherein the number of the plurality of load blocks is the same as the number of the plurality of drive circuits.

[0055] (Item 3) each of the plurality of drive circuits includes a transistor that passes a current in response to a voltage signal; 3. The drive device according to item 1 or 2, wherein a common voltage signal is input to the gate terminals of the transistors.

[0056] (Item 4) The transistor is a first transistor, a second transistor is further disposed between a load block and a drive circuit in a current path formed by the load block and the drive circuit that are connected to each other among the plurality of load blocks and the plurality of drive circuits; 4. The driving device according to item 3, wherein the first transistor and the second transistor form a cascode circuit.

[0057] (Item 5) 5. The drive device according to item 4, wherein the connection circuit is disposed in the current path between the first transistor and the second transistor.

[0058] (Item 6) the plurality of drive circuits include a first drive circuit and a second drive circuit; The drive device according to any one of items 1 to 5, characterized in that when switching a load block among the plurality of load blocks that has been driven by the first drive circuit to be driven by the second drive circuit, the connection circuit switches a combination of connections so that driving by the second drive circuit begins before driving by the first drive circuit ends.

[0059] (Item 7) 7. The drive device according to any one of items 1 to 6, wherein a plurality of the load elements are arranged on each of the plurality of load blocks.

[0060] (Item 8) 8. The driving device according to any one of items 1 to 7, wherein the load element is a current-driven element.

[0061] (Item 9) 9. The drive device according to any one of items 1 to 8, wherein each of the load elements arranged in the plurality of load blocks is arranged along one direction.

[0062] (Item 10) 10. The driving device according to any one of items 1 to 9, wherein the load element is a light-emitting element.

[0063] (Item 11) An exposure head including a driving device according to any one of items 1 to 10; a light-emitting element mounted on the exposure head as the load element; A photoconductor drum that receives light from the light emitting element; A recording device comprising:

[0064] (Item 12) An exposure head including the drive device according to item 9; a light-emitting element mounted on the exposure head as the load element; A photoconductor drum that receives light from the light emitting element; Including, A recording device, wherein a surface of the photosensitive drum that receives light from the light-emitting element moves in a direction intersecting the one direction.

[0065] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0066] 10: connection circuit, 20: load block, 23: load element, 30: drive circuit, 80: drive device

Claims

1. A driving device comprising: a plurality of load blocks each including a load element; a plurality of driving circuits for driving the plurality of load blocks; and a connection circuit for connecting the plurality of load blocks to the plurality of driving circuits respectively, wherein the connection circuit switches a combination of connections between each of the plurality of load blocks and each of the plurality of driving circuits.

2. The driving device according to claim 1, wherein the connection circuit switches a combination of connections between each of the plurality of load blocks and each of the plurality of driving circuits such that each of the plurality of load blocks is connected to one of the plurality of driving circuits.

3. The driving device according to claim 1, wherein the number of the plurality of load blocks is the same as the number of the plurality of driving circuits.

4. Each of the plurality of driving circuits includes a transistor that conducts a current according to a voltage signal, and a common voltage signal is input to a gate terminal of the transistor.

5. Taking the transistor as a first transistor, in a current path formed by a load block and a driving circuit that are connected to each other among the plurality of load blocks and the plurality of driving circuits, a second transistor is further disposed between the load block and the driving circuit, and the first transistor and the second transistor constitute a cascode circuit.

6. The driving device according to claim 5, wherein the connection circuit is disposed between the first transistor and the second transistor in the current path.

7. The plurality of driving circuits include a first driving circuit and a second driving circuit, and when the connection circuit switches a load block driven by the first driving circuit among the plurality of load blocks to be driven by the second driving circuit, the connection circuit switches the combination of connections such that driving by the second driving circuit is started before driving by the first driving circuit ends.

8. The driving device according to claim 1, wherein a plurality of the load elements are arranged in each of the plurality of load blocks.

9. The driving device according to claim 1, wherein the load element is a current-driven element.

10. The drive device according to claim 1, characterized in that each of the load elements arranged in the plurality of load blocks is arranged along one direction.

11. The drive device according to claim 1, characterized in that the load element is a light-emitting element.

12. An exposure head including the drive device according to any one of claims 1 to 11, As the load element, a light-emitting element mounted on the exposure head, A photosensitive drum that receives the light of the light-emitting element, A recording device characterized by including the above.

13. An exposure head including the drive device according to claim 10, As the load element, a light-emitting element mounted on the exposure head, A photosensitive drum that receives the light of the light-emitting element, Including, A recording device characterized in that the surface of the photosensitive drum that receives the light of the light-emitting element moves in a direction intersecting the one direction.

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